vala/vala-c99.patch

codegen: Emit GCC diagnostics pragmata for GCC 14 compatibility

GCC 14 refuses to compile C sources with certain type errors, to
provide prompt feedback to programmers about mistakes.  Vala does not
generate valid C in some cases (see issues #358, #1005, #1408, and
perhaps others).  As a stop-gap measure, this commit introduces
pragmata to turn the relevant GCC diagnostics into warnings.  For
experimentation, this can be avoided at C compilation time by defining
the VALA_STRICT_C macro.

Submitted upstream: <https://gitlab.gnome.org/GNOME/vala/-/merge_requests/369>

diff --git a/ccode/valaccodefile.vala b/ccode/valaccodefile.vala
index f61da07dfa103986..c627743ee112fe62 100644
--- a/ccode/valaccodefile.vala
+++ b/ccode/valaccodefile.vala
@@ -161,6 +161,7 @@ public class Vala.CCodeFile {
 			writer.line_directives = line_directives;
 
 			comments.write (writer);
+			write_compiler_compatibility (writer);
 			writer.write_newline ();
 			feature_test_macros.write (writer);
 			writer.write_newline ();
@@ -218,6 +219,23 @@ public class Vala.CCodeFile {
 
 		return true;
 	}
+
+	static void write_compiler_compatibility (CCodeWriter writer) {
+		writer.write_string ("#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14");
+		writer.write_newline ();
+		write_compiler_compatibility_pragma_warning (writer, "-Wimplicit-function-declaration");
+		write_compiler_compatibility_pragma_warning (writer, "-Wreturn-mismatch");
+		write_compiler_compatibility_pragma_warning (writer, "-Wincompatible-pointer-types");
+		writer.write_string ("#endif");
+		writer.write_newline ();
+	}
+
+	static void write_compiler_compatibility_pragma_warning (CCodeWriter writer, string warning) {
+		writer.write_string ("#pragma GCC diagnostic warning \"");
+		writer.write_string (warning);
+		writer.write_string ("\"");
+		writer.write_newline ();
+	}
 }
 
 [Flags]
diff --git a/tests/annotations/deprecated-delegate-minimal.c-expected b/tests/annotations/deprecated-delegate-minimal.c-expected
index 5f70e82fde933006..962224ada50b9965 100644
--- a/tests/annotations/deprecated-delegate-minimal.c-expected
+++ b/tests/annotations/deprecated-delegate-minimal.c-expected
@@ -1,6 +1,12 @@
 /* annotations_deprecated_delegate_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_delegate_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 typedef void (*Foo) (void) G_GNUC_DEPRECATED ;
diff --git a/tests/annotations/deprecated-enum-minimal.c-expected b/tests/annotations/deprecated-enum-minimal.c-expected
index c809a7aef5b2bb19..86bf50f8caf06f96 100644
--- a/tests/annotations/deprecated-enum-minimal.c-expected
+++ b/tests/annotations/deprecated-enum-minimal.c-expected
@@ -1,6 +1,12 @@
 /* annotations_deprecated_enum_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_enum_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 typedef enum  {
diff --git a/tests/annotations/deprecated-method-minimal.c-expected b/tests/annotations/deprecated-method-minimal.c-expected
index 02168bc6ca3be60c..db8e66e26036df13 100644
--- a/tests/annotations/deprecated-method-minimal.c-expected
+++ b/tests/annotations/deprecated-method-minimal.c-expected
@@ -1,6 +1,12 @@
 /* annotations_deprecated_method_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_method_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/annotations/deprecated-property-minimal.c-expected b/tests/annotations/deprecated-property-minimal.c-expected
index cebd8f46d6a2bca9..ad084ff79b154695 100644
--- a/tests/annotations/deprecated-property-minimal.c-expected
+++ b/tests/annotations/deprecated-property-minimal.c-expected
@@ -1,6 +1,12 @@
 /* annotations_deprecated_property_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_property_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/annotations/deprecated-struct-minimal.c-expected b/tests/annotations/deprecated-struct-minimal.c-expected
index cbc9b5d9de97e8f5..d094ce14a2083198 100644
--- a/tests/annotations/deprecated-struct-minimal.c-expected
+++ b/tests/annotations/deprecated-struct-minimal.c-expected
@@ -1,6 +1,12 @@
 /* annotations_deprecated_struct_minimal.c generated by valac, the Vala compiler
  * generated from annotations_deprecated_struct_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 typedef struct _Foo Foo;
diff --git a/tests/annotations/deprecated.c-expected b/tests/annotations/deprecated.c-expected
index c867d18f83f60f65..819291c63222375e 100644
--- a/tests/annotations/deprecated.c-expected
+++ b/tests/annotations/deprecated.c-expected
@@ -1,6 +1,12 @@
 /* annotations_deprecated.c generated by valac, the Vala compiler
  * generated from annotations_deprecated.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <string.h>
diff --git a/tests/annotations/description.c-expected b/tests/annotations/description.c-expected
index d6527b7e8b9f8fc6..98f96f9f53db97d5 100644
--- a/tests/annotations/description.c-expected
+++ b/tests/annotations/description.c-expected
@@ -1,6 +1,12 @@
 /* annotations_description.c generated by valac, the Vala compiler
  * generated from annotations_description.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/arrays/cast-struct-boxed-element-access.c-expected b/tests/arrays/cast-struct-boxed-element-access.c-expected
index 82e734768a99efe7..edfbf86fc68d67fd 100644
--- a/tests/arrays/cast-struct-boxed-element-access.c-expected
+++ b/tests/arrays/cast-struct-boxed-element-access.c-expected
@@ -1,6 +1,12 @@
 /* arrays_cast_struct_boxed_element_access.c generated by valac, the Vala compiler
  * generated from arrays_cast_struct_boxed_element_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/arrays/class-field-fixed-length-initializer.c-expected b/tests/arrays/class-field-fixed-length-initializer.c-expected
index 4b402f912d089142..557f0a15fca4b7fb 100644
--- a/tests/arrays/class-field-fixed-length-initializer.c-expected
+++ b/tests/arrays/class-field-fixed-length-initializer.c-expected
@@ -1,6 +1,12 @@
 /* arrays_class_field_fixed_length_initializer.c generated by valac, the Vala compiler
  * generated from arrays_class_field_fixed_length_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/class-field-initializer.c-expected b/tests/arrays/class-field-initializer.c-expected
index 5faddf3db1842b11..c41b13cc467e8790 100644
--- a/tests/arrays/class-field-initializer.c-expected
+++ b/tests/arrays/class-field-initializer.c-expected
@@ -1,6 +1,12 @@
 /* arrays_class_field_initializer.c generated by valac, the Vala compiler
  * generated from arrays_class_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/class-field-length-cname.c-expected b/tests/arrays/class-field-length-cname.c-expected
index 389a0d79a299d829..8b1b3c0e7e72a5f9 100644
--- a/tests/arrays/class-field-length-cname.c-expected
+++ b/tests/arrays/class-field-length-cname.c-expected
@@ -1,6 +1,12 @@
 /* arrays_class_field_length_cname.c generated by valac, the Vala compiler
  * generated from arrays_class_field_length_cname.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/arrays/constant-element-access.c-expected b/tests/arrays/constant-element-access.c-expected
index 7fd70f27b197652b..a8d370f3bef59981 100644
--- a/tests/arrays/constant-element-access.c-expected
+++ b/tests/arrays/constant-element-access.c-expected
@@ -1,6 +1,12 @@
 /* arrays_constant_element_access.c generated by valac, the Vala compiler
  * generated from arrays_constant_element_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/element-class-assignment.c-expected b/tests/arrays/element-class-assignment.c-expected
index 646d0ac077cd8fab..f512dda8d6d94a06 100644
--- a/tests/arrays/element-class-assignment.c-expected
+++ b/tests/arrays/element-class-assignment.c-expected
@@ -1,6 +1,12 @@
 /* arrays_element_class_assignment.c generated by valac, the Vala compiler
  * generated from arrays_element_class_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/arrays/element-nullable-assignment.c-expected b/tests/arrays/element-nullable-assignment.c-expected
index ffba74e24aecdc12..bf5a2437152425f6 100644
--- a/tests/arrays/element-nullable-assignment.c-expected
+++ b/tests/arrays/element-nullable-assignment.c-expected
@@ -1,6 +1,12 @@
 /* arrays_element_nullable_assignment.c generated by valac, the Vala compiler
  * generated from arrays_element_nullable_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/empty-length-0.c-expected b/tests/arrays/empty-length-0.c-expected
index c4d7cbf68257824a..42d913cdbf91af24 100644
--- a/tests/arrays/empty-length-0.c-expected
+++ b/tests/arrays/empty-length-0.c-expected
@@ -1,6 +1,12 @@
 /* arrays_empty_length_0.c generated by valac, the Vala compiler
  * generated from arrays_empty_length_0.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/field-global-length-cname.c-expected b/tests/arrays/field-global-length-cname.c-expected
index 33e3ef1ae9d51e50..b28d76c5873aa229 100644
--- a/tests/arrays/field-global-length-cname.c-expected
+++ b/tests/arrays/field-global-length-cname.c-expected
@@ -1,6 +1,12 @@
 /* arrays_field_global_length_cname.c generated by valac, the Vala compiler
  * generated from arrays_field_global_length_cname.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/arrays/fixed-length-enum-value.c-expected b/tests/arrays/fixed-length-enum-value.c-expected
index 372dcf4ae3ce19be..21ab606d22599da5 100644
--- a/tests/arrays/fixed-length-enum-value.c-expected
+++ b/tests/arrays/fixed-length-enum-value.c-expected
@@ -1,6 +1,12 @@
 /* arrays_fixed_length_enum_value.c generated by valac, the Vala compiler
  * generated from arrays_fixed_length_enum_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/arrays/fixed-length-init0-not-allowed.c-expected b/tests/arrays/fixed-length-init0-not-allowed.c-expected
index 4bf72a2f72ff3515..642dbed968517513 100644
--- a/tests/arrays/fixed-length-init0-not-allowed.c-expected
+++ b/tests/arrays/fixed-length-init0-not-allowed.c-expected
@@ -1,6 +1,12 @@
 /* arrays_fixed_length_init0_not_allowed.c generated by valac, the Vala compiler
  * generated from arrays_fixed_length_init0_not_allowed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/in-operator-with-boxed-needle.c-expected b/tests/arrays/in-operator-with-boxed-needle.c-expected
index e5c5864b2a4e356e..5919c0f94a0c4c85 100644
--- a/tests/arrays/in-operator-with-boxed-needle.c-expected
+++ b/tests/arrays/in-operator-with-boxed-needle.c-expected
@@ -1,6 +1,12 @@
 /* arrays_in_operator_with_boxed_needle.c generated by valac, the Vala compiler
  * generated from arrays_in_operator_with_boxed_needle.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/inline-namespace-field.c-expected b/tests/arrays/inline-namespace-field.c-expected
index 8a73504cb6cc2746..364914cc41dcc134 100644
--- a/tests/arrays/inline-namespace-field.c-expected
+++ b/tests/arrays/inline-namespace-field.c-expected
@@ -1,6 +1,12 @@
 /* arrays_inline_namespace_field.c generated by valac, the Vala compiler
  * generated from arrays_inline_namespace_field.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/inline-struct.c-expected b/tests/arrays/inline-struct.c-expected
index 7d0e0aa50c23fc24..62fb4391fab696ff 100644
--- a/tests/arrays/inline-struct.c-expected
+++ b/tests/arrays/inline-struct.c-expected
@@ -1,6 +1,12 @@
 /* arrays_inline_struct.c generated by valac, the Vala compiler
  * generated from arrays_inline_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/length-inline-assignment.c-expected b/tests/arrays/length-inline-assignment.c-expected
index 0255ae4ce741970f..dfc8a0682dc616d1 100644
--- a/tests/arrays/length-inline-assignment.c-expected
+++ b/tests/arrays/length-inline-assignment.c-expected
@@ -1,6 +1,12 @@
 /* arrays_length_inline_assignment.c generated by valac, the Vala compiler
  * generated from arrays_length_inline_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/arrays/length-type-include.c-expected b/tests/arrays/length-type-include.c-expected
index a282eecfa2fa4967..5178ef85be3cf425 100644
--- a/tests/arrays/length-type-include.c-expected
+++ b/tests/arrays/length-type-include.c-expected
@@ -1,6 +1,12 @@
 /* arrays_length_type_include.c generated by valac, the Vala compiler
  * generated from arrays_length_type_include.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/arrays/length-type.c-expected b/tests/arrays/length-type.c-expected
index 01bb8f7b91868768..7197a0f146371be0 100644
--- a/tests/arrays/length-type.c-expected
+++ b/tests/arrays/length-type.c-expected
@@ -1,6 +1,12 @@
 /* arrays_length_type.c generated by valac, the Vala compiler
  * generated from arrays_length_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/arrays/resize-local-size-captured.c-expected b/tests/arrays/resize-local-size-captured.c-expected
index 190b450014a13ed3..ba11e14bf12512af 100644
--- a/tests/arrays/resize-local-size-captured.c-expected
+++ b/tests/arrays/resize-local-size-captured.c-expected
@@ -1,6 +1,12 @@
 /* arrays_resize_local_size_captured.c generated by valac, the Vala compiler
  * generated from arrays_resize_local_size_captured.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/resize-local-size.c-expected b/tests/arrays/resize-local-size.c-expected
index f3c0464c151c725b..02e112cdfe7edeeb 100644
--- a/tests/arrays/resize-local-size.c-expected
+++ b/tests/arrays/resize-local-size.c-expected
@@ -1,6 +1,12 @@
 /* arrays_resize_local_size.c generated by valac, the Vala compiler
  * generated from arrays_resize_local_size.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/arrays/resize.c-expected b/tests/arrays/resize.c-expected
index 086493fa4494a601..133d02fae093e319 100644
--- a/tests/arrays/resize.c-expected
+++ b/tests/arrays/resize.c-expected
@@ -1,6 +1,12 @@
 /* arrays_resize.c generated by valac, the Vala compiler
  * generated from arrays_resize.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/slice-fixed-length.c-expected b/tests/arrays/slice-fixed-length.c-expected
index 0a6d311260c018a8..8556291b4d6a188d 100644
--- a/tests/arrays/slice-fixed-length.c-expected
+++ b/tests/arrays/slice-fixed-length.c-expected
@@ -1,6 +1,12 @@
 /* arrays_slice_fixed_length.c generated by valac, the Vala compiler
  * generated from arrays_slice_fixed_length.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/struct-field-initializer.c-expected b/tests/arrays/struct-field-initializer.c-expected
index 5bf92c2cff7af4f5..05eb9c745b8ab5c7 100644
--- a/tests/arrays/struct-field-initializer.c-expected
+++ b/tests/arrays/struct-field-initializer.c-expected
@@ -1,6 +1,12 @@
 /* arrays_struct_field_initializer.c generated by valac, the Vala compiler
  * generated from arrays_struct_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/arrays/struct-field-length-cname.c-expected b/tests/arrays/struct-field-length-cname.c-expected
index 3df783b34cdc108e..fdbb94c621192d0d 100644
--- a/tests/arrays/struct-field-length-cname.c-expected
+++ b/tests/arrays/struct-field-length-cname.c-expected
@@ -1,6 +1,12 @@
 /* arrays_struct_field_length_cname.c generated by valac, the Vala compiler
  * generated from arrays_struct_field_length_cname.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/arrays/struct-initializer-null.c-expected b/tests/arrays/struct-initializer-null.c-expected
index 4de284d9eb026f33..2e7b422c3b48b685 100644
--- a/tests/arrays/struct-initializer-null.c-expected
+++ b/tests/arrays/struct-initializer-null.c-expected
@@ -1,6 +1,12 @@
 /* arrays_struct_initializer_null.c generated by valac, the Vala compiler
  * generated from arrays_struct_initializer_null.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/arrays/struct-namespaced-initializer.c-expected b/tests/arrays/struct-namespaced-initializer.c-expected
index 17512a6abe16b4bb..dbf8777cb8c31dc6 100644
--- a/tests/arrays/struct-namespaced-initializer.c-expected
+++ b/tests/arrays/struct-namespaced-initializer.c-expected
@@ -1,6 +1,12 @@
 /* arrays_struct_namespaced_initializer.c generated by valac, the Vala compiler
  * generated from arrays_struct_namespaced_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug595735.c-expected b/tests/asynchronous/bug595735.c-expected
index 3775738475bbec6c..2357259631625247 100644
--- a/tests/asynchronous/bug595735.c-expected
+++ b/tests/asynchronous/bug595735.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug595735.c generated by valac, the Vala compiler
  * generated from asynchronous_bug595735.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug595755.c-expected b/tests/asynchronous/bug595755.c-expected
index 4a3b786c22fd7d6d..0534d0cbbe40484e 100644
--- a/tests/asynchronous/bug595755.c-expected
+++ b/tests/asynchronous/bug595755.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug595755.c generated by valac, the Vala compiler
  * generated from asynchronous_bug595755.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug596177.c-expected b/tests/asynchronous/bug596177.c-expected
index f80ac45e771506d9..68062134fe4768db 100644
--- a/tests/asynchronous/bug596177.c-expected
+++ b/tests/asynchronous/bug596177.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug596177.c generated by valac, the Vala compiler
  * generated from asynchronous_bug596177.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug596861.c-expected b/tests/asynchronous/bug596861.c-expected
index 8139574a9ac64a28..7dcb2bc0961430f9 100644
--- a/tests/asynchronous/bug596861.c-expected
+++ b/tests/asynchronous/bug596861.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug596861.c generated by valac, the Vala compiler
  * generated from asynchronous_bug596861.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 
diff --git a/tests/asynchronous/bug597294.c-expected b/tests/asynchronous/bug597294.c-expected
index ee890d6fb86fdf88..f9c35f13f9cb417b 100644
--- a/tests/asynchronous/bug597294.c-expected
+++ b/tests/asynchronous/bug597294.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug597294.c generated by valac, the Vala compiler
  * generated from asynchronous_bug597294.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug598677.c-expected b/tests/asynchronous/bug598677.c-expected
index 9724f6fcf5bcb93b..fd5e5682b91eae6f 100644
--- a/tests/asynchronous/bug598677.c-expected
+++ b/tests/asynchronous/bug598677.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug598677.c generated by valac, the Vala compiler
  * generated from asynchronous_bug598677.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug598697.c-expected b/tests/asynchronous/bug598697.c-expected
index 028b443c10d30da3..70d29a3c2bac6044 100644
--- a/tests/asynchronous/bug598697.c-expected
+++ b/tests/asynchronous/bug598697.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug598697.c generated by valac, the Vala compiler
  * generated from asynchronous_bug598697.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug598698.c-expected b/tests/asynchronous/bug598698.c-expected
index 1fb02af007116994..f0f811bb7e3c50a8 100644
--- a/tests/asynchronous/bug598698.c-expected
+++ b/tests/asynchronous/bug598698.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug598698.c generated by valac, the Vala compiler
  * generated from asynchronous_bug598698.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug599568.c-expected b/tests/asynchronous/bug599568.c-expected
index 8ae3247b5a48bd59..5e313516d6166f73 100644
--- a/tests/asynchronous/bug599568.c-expected
+++ b/tests/asynchronous/bug599568.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug599568.c generated by valac, the Vala compiler
  * generated from asynchronous_bug599568.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/bug600827.c-expected b/tests/asynchronous/bug600827.c-expected
index 3e94f402b4691706..8126d9e0a8de9f4c 100644
--- a/tests/asynchronous/bug600827.c-expected
+++ b/tests/asynchronous/bug600827.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug600827.c generated by valac, the Vala compiler
  * generated from asynchronous_bug600827.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug601558.c-expected b/tests/asynchronous/bug601558.c-expected
index 081693d164c35c03..dde454dd89fbc254 100644
--- a/tests/asynchronous/bug601558.c-expected
+++ b/tests/asynchronous/bug601558.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug601558.c generated by valac, the Vala compiler
  * generated from asynchronous_bug601558.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug602594.c-expected b/tests/asynchronous/bug602594.c-expected
index 0aabc315be93d4dd..d56f9618f53b4e9e 100644
--- a/tests/asynchronous/bug602594.c-expected
+++ b/tests/asynchronous/bug602594.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug602594.c generated by valac, the Vala compiler
  * generated from asynchronous_bug602594.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug612641.c-expected b/tests/asynchronous/bug612641.c-expected
index 78565ef37a23e3c5..4375dceaca0370d2 100644
--- a/tests/asynchronous/bug612641.c-expected
+++ b/tests/asynchronous/bug612641.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug612641.c generated by valac, the Vala compiler
  * generated from asynchronous_bug612641.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug613484.c-expected b/tests/asynchronous/bug613484.c-expected
index 4ddf9a96272cf02b..4fd302726291433c 100644
--- a/tests/asynchronous/bug613484.c-expected
+++ b/tests/asynchronous/bug613484.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug613484.c generated by valac, the Vala compiler
  * generated from asynchronous_bug613484.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug614294.c-expected b/tests/asynchronous/bug614294.c-expected
index d92b9a8fe6638004..549dc8f2cd8e3d85 100644
--- a/tests/asynchronous/bug614294.c-expected
+++ b/tests/asynchronous/bug614294.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug614294.c generated by valac, the Vala compiler
  * generated from asynchronous_bug614294.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug620740.c-expected b/tests/asynchronous/bug620740.c-expected
index e6a23ef23db74d95..12ec869faadf290f 100644
--- a/tests/asynchronous/bug620740.c-expected
+++ b/tests/asynchronous/bug620740.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug620740.c generated by valac, the Vala compiler
  * generated from asynchronous_bug620740.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/bug626053.c-expected b/tests/asynchronous/bug626053.c-expected
index 6fa949ac1fc02e97..f31247e61111b433 100644
--- a/tests/asynchronous/bug626053.c-expected
+++ b/tests/asynchronous/bug626053.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug626053.c generated by valac, the Vala compiler
  * generated from asynchronous_bug626053.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug639591.c-expected b/tests/asynchronous/bug639591.c-expected
index ecc5ec2979d5afd8..c26f48ac0192c638 100644
--- a/tests/asynchronous/bug639591.c-expected
+++ b/tests/asynchronous/bug639591.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug639591.c generated by valac, the Vala compiler
  * generated from asynchronous_bug639591.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug640721.c-expected b/tests/asynchronous/bug640721.c-expected
index 3a0427f2879a6471..e567167cb517749d 100644
--- a/tests/asynchronous/bug640721.c-expected
+++ b/tests/asynchronous/bug640721.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug640721.c generated by valac, the Vala compiler
  * generated from asynchronous_bug640721.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/bug641182.c-expected b/tests/asynchronous/bug641182.c-expected
index da0975cc4c5a1261..8459d0d63f011554 100644
--- a/tests/asynchronous/bug641182.c-expected
+++ b/tests/asynchronous/bug641182.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug641182.c generated by valac, the Vala compiler
  * generated from asynchronous_bug641182.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/bug646945.c-expected b/tests/asynchronous/bug646945.c-expected
index baab03038385e2a6..5d076c753ae8fe66 100644
--- a/tests/asynchronous/bug646945.c-expected
+++ b/tests/asynchronous/bug646945.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug646945.c generated by valac, the Vala compiler
  * generated from asynchronous_bug646945.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug652252.c-expected b/tests/asynchronous/bug652252.c-expected
index a4337dce18cd1a61..ad1ee97a8faf48dd 100644
--- a/tests/asynchronous/bug652252.c-expected
+++ b/tests/asynchronous/bug652252.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug652252.c generated by valac, the Vala compiler
  * generated from asynchronous_bug652252.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug653861.c-expected b/tests/asynchronous/bug653861.c-expected
index 380dfacdfedca947..109ab19af9b65108 100644
--- a/tests/asynchronous/bug653861.c-expected
+++ b/tests/asynchronous/bug653861.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug653861.c generated by valac, the Vala compiler
  * generated from asynchronous_bug653861.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug654336.c-expected b/tests/asynchronous/bug654336.c-expected
index 71a1e1a4761b34bb..64959fbcd5ee7532 100644
--- a/tests/asynchronous/bug654336.c-expected
+++ b/tests/asynchronous/bug654336.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug654336.c generated by valac, the Vala compiler
  * generated from asynchronous_bug654336.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug654337.c-expected b/tests/asynchronous/bug654337.c-expected
index 3237071f269723d9..9a4771731c33c9c6 100644
--- a/tests/asynchronous/bug654337.c-expected
+++ b/tests/asynchronous/bug654337.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug654337.c generated by valac, the Vala compiler
  * generated from asynchronous_bug654337.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug659886.c-expected b/tests/asynchronous/bug659886.c-expected
index 75de1ed66853c1b4..f1838d896855565e 100644
--- a/tests/asynchronous/bug659886.c-expected
+++ b/tests/asynchronous/bug659886.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug659886.c generated by valac, the Vala compiler
  * generated from asynchronous_bug659886.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 
diff --git a/tests/asynchronous/bug661961.c-expected b/tests/asynchronous/bug661961.c-expected
index c6f8da66481c847a..2c919d3081a5272d 100644
--- a/tests/asynchronous/bug661961.c-expected
+++ b/tests/asynchronous/bug661961.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug661961.c generated by valac, the Vala compiler
  * generated from asynchronous_bug661961.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug710103.c-expected b/tests/asynchronous/bug710103.c-expected
index 0913a72b6b526c45..d8d4cec01cbf1485 100644
--- a/tests/asynchronous/bug710103.c-expected
+++ b/tests/asynchronous/bug710103.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug710103.c generated by valac, the Vala compiler
  * generated from asynchronous_bug710103.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/bug741929.c-expected b/tests/asynchronous/bug741929.c-expected
index 57ed28780d36f1b4..c1240cef79007d7d 100644
--- a/tests/asynchronous/bug741929.c-expected
+++ b/tests/asynchronous/bug741929.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug741929.c generated by valac, the Vala compiler
  * generated from asynchronous_bug741929.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug742621.c-expected b/tests/asynchronous/bug742621.c-expected
index 093e6c43d80b91ae..eaf16b94fb3358df 100644
--- a/tests/asynchronous/bug742621.c-expected
+++ b/tests/asynchronous/bug742621.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug742621.c generated by valac, the Vala compiler
  * generated from asynchronous_bug742621.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/bug762819.c-expected b/tests/asynchronous/bug762819.c-expected
index ffb97eca08f4547e..730b0e0f8817f3b3 100644
--- a/tests/asynchronous/bug762819.c-expected
+++ b/tests/asynchronous/bug762819.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug762819.c generated by valac, the Vala compiler
  * generated from asynchronous_bug762819.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/bug777242.c-expected b/tests/asynchronous/bug777242.c-expected
index 1bfa9d03181b26ee..576919a111ee5b9e 100644
--- a/tests/asynchronous/bug777242.c-expected
+++ b/tests/asynchronous/bug777242.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug777242.c generated by valac, the Vala compiler
  * generated from asynchronous_bug777242.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/bug783543.c-expected b/tests/asynchronous/bug783543.c-expected
index 9d3542f6329d292c..b57aebbc0078a7a2 100644
--- a/tests/asynchronous/bug783543.c-expected
+++ b/tests/asynchronous/bug783543.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug783543.c generated by valac, the Vala compiler
  * generated from asynchronous_bug783543.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug792660.c-expected b/tests/asynchronous/bug792660.c-expected
index 20c76608d449cc88..04c64cb05413b7ab 100644
--- a/tests/asynchronous/bug792660.c-expected
+++ b/tests/asynchronous/bug792660.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug792660.c generated by valac, the Vala compiler
  * generated from asynchronous_bug792660.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/bug792942.c-expected b/tests/asynchronous/bug792942.c-expected
index 841d2cf0bda65e4a..e212aaaf3eef008e 100644
--- a/tests/asynchronous/bug792942.c-expected
+++ b/tests/asynchronous/bug792942.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug792942.c generated by valac, the Vala compiler
  * generated from asynchronous_bug792942.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/bug793158.c-expected b/tests/asynchronous/bug793158.c-expected
index 242de48dccf6123c..12d577bcf9102004 100644
--- a/tests/asynchronous/bug793158.c-expected
+++ b/tests/asynchronous/bug793158.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_bug793158.c generated by valac, the Vala compiler
  * generated from asynchronous_bug793158.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/captured-fixed-array.c-expected b/tests/asynchronous/captured-fixed-array.c-expected
index 9d6faa29903a43f3..cfbbd19227e893f5 100644
--- a/tests/asynchronous/captured-fixed-array.c-expected
+++ b/tests/asynchronous/captured-fixed-array.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_captured_fixed_array.c generated by valac, the Vala compiler
  * generated from asynchronous_captured_fixed_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/asynchronous/catch-error-scope.c-expected b/tests/asynchronous/catch-error-scope.c-expected
index c4d055f0c484c891..204fb462d850a353 100644
--- a/tests/asynchronous/catch-error-scope.c-expected
+++ b/tests/asynchronous/catch-error-scope.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_catch_error_scope.c generated by valac, the Vala compiler
  * generated from asynchronous_catch_error_scope.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/catch-in-finally.c-expected b/tests/asynchronous/catch-in-finally.c-expected
index 996c154ae605e2db..00a7151940aa9967 100644
--- a/tests/asynchronous/catch-in-finally.c-expected
+++ b/tests/asynchronous/catch-in-finally.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_catch_in_finally.c generated by valac, the Vala compiler
  * generated from asynchronous_catch_in_finally.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/closures.c-expected b/tests/asynchronous/closures.c-expected
index 9c2d0f92c09ede53..38b97118bfd1e41b 100644
--- a/tests/asynchronous/closures.c-expected
+++ b/tests/asynchronous/closures.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_closures.c generated by valac, the Vala compiler
  * generated from asynchronous_closures.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/constructor-argument-check.c-expected b/tests/asynchronous/constructor-argument-check.c-expected
index 76d364bb0669b58a..1321de8a1d782c62 100644
--- a/tests/asynchronous/constructor-argument-check.c-expected
+++ b/tests/asynchronous/constructor-argument-check.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_constructor_argument_check.c generated by valac, the Vala compiler
  * generated from asynchronous_constructor_argument_check.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/finish-name.c-expected b/tests/asynchronous/finish-name.c-expected
index e12dcc9b91d284e3..0cbd8f2361d75bc4 100644
--- a/tests/asynchronous/finish-name.c-expected
+++ b/tests/asynchronous/finish-name.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_finish_name.c generated by valac, the Vala compiler
  * generated from asynchronous_finish_name.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/asynchronous/generator.c-expected b/tests/asynchronous/generator.c-expected
index 56db316e605327f2..0d4bb0136a897436 100644
--- a/tests/asynchronous/generator.c-expected
+++ b/tests/asynchronous/generator.c-expected
@@ -4,6 +4,11 @@
 /* This is based on Luca Bruno's Generator. It illustrates using async methods*/
 /* to emulate a generator style of iterator coding. Note that this runs fine*/
 /* without a main loop.*/
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
 
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/main-block-async-call.c-expected b/tests/asynchronous/main-block-async-call.c-expected
index 4eae9bfdc5f27ef7..7899e872b9edeb97 100644
--- a/tests/asynchronous/main-block-async-call.c-expected
+++ b/tests/asynchronous/main-block-async-call.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_main_block_async_call.c generated by valac, the Vala compiler
  * generated from asynchronous_main_block_async_call.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/main-block-async-creation.c-expected b/tests/asynchronous/main-block-async-creation.c-expected
index f84673cd4bd7c907..f4670ca0b21cff46 100644
--- a/tests/asynchronous/main-block-async-creation.c-expected
+++ b/tests/asynchronous/main-block-async-creation.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_main_block_async_creation.c generated by valac, the Vala compiler
  * generated from asynchronous_main_block_async_creation.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/asynchronous/main-block-async-yield.c-expected b/tests/asynchronous/main-block-async-yield.c-expected
index 99419124399fe233..152947c139604f34 100644
--- a/tests/asynchronous/main-block-async-yield.c-expected
+++ b/tests/asynchronous/main-block-async-yield.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_main_block_async_yield.c generated by valac, the Vala compiler
  * generated from asynchronous_main_block_async_yield.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 
diff --git a/tests/asynchronous/method-main-async-void.c-expected b/tests/asynchronous/method-main-async-void.c-expected
index c0733f84eaf58721..8273dd5a27cd61dc 100644
--- a/tests/asynchronous/method-main-async-void.c-expected
+++ b/tests/asynchronous/method-main-async-void.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_method_main_async_void.c generated by valac, the Vala compiler
  * generated from asynchronous_method_main_async_void.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/method-main-async.c-expected b/tests/asynchronous/method-main-async.c-expected
index e8148c4dcd18e96a..c7d84ce3b6f43686 100644
--- a/tests/asynchronous/method-main-async.c-expected
+++ b/tests/asynchronous/method-main-async.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_method_main_async.c generated by valac, the Vala compiler
  * generated from asynchronous_method_main_async.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/asynchronous/nowrapper.c-expected b/tests/asynchronous/nowrapper.c-expected
index 2424afda6bc52c6e..74e9f83c1be407fc 100644
--- a/tests/asynchronous/nowrapper.c-expected
+++ b/tests/asynchronous/nowrapper.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_nowrapper.c generated by valac, the Vala compiler
  * generated from asynchronous_nowrapper.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/asynchronous/out-parameter-free-on-error.c-expected b/tests/asynchronous/out-parameter-free-on-error.c-expected
index de41c609ee59efb8..a485c0ed59c1faf9 100644
--- a/tests/asynchronous/out-parameter-free-on-error.c-expected
+++ b/tests/asynchronous/out-parameter-free-on-error.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_out_parameter_free_on_error.c generated by valac, the Vala compiler
  * generated from asynchronous_out_parameter_free_on_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/asynchronous/result-pos.c-expected b/tests/asynchronous/result-pos.c-expected
index 0875b0cd8cc5bf91..e61b002acafc5924 100644
--- a/tests/asynchronous/result-pos.c-expected
+++ b/tests/asynchronous/result-pos.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_result_pos.c generated by valac, the Vala compiler
  * generated from asynchronous_result_pos.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/asynchronous/yield.c-expected b/tests/asynchronous/yield.c-expected
index 993fdbc33a43387a..80069ff7b70d358e 100644
--- a/tests/asynchronous/yield.c-expected
+++ b/tests/asynchronous/yield.c-expected
@@ -1,6 +1,12 @@
 /* asynchronous_yield.c generated by valac, the Vala compiler
  * generated from asynchronous_yield.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/basic-types/array-uint8-uchar-compat.c-expected b/tests/basic-types/array-uint8-uchar-compat.c-expected
index 17cf9aed704e5fb6..e16322c651dbf75f 100644
--- a/tests/basic-types/array-uint8-uchar-compat.c-expected
+++ b/tests/basic-types/array-uint8-uchar-compat.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_array_uint8_uchar_compat.c generated by valac, the Vala compiler
  * generated from basic_types_array_uint8_uchar_compat.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/arrays-fixed-assignment.c-expected b/tests/basic-types/arrays-fixed-assignment.c-expected
index fac6d616f8847ff4..0cdb409fb2890fe4 100644
--- a/tests/basic-types/arrays-fixed-assignment.c-expected
+++ b/tests/basic-types/arrays-fixed-assignment.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_arrays_fixed_assignment.c generated by valac, the Vala compiler
  * generated from basic_types_arrays_fixed_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/arrays-generics.c-expected b/tests/basic-types/arrays-generics.c-expected
index 01da8c6d53972922..c4e0414a3efbfdc1 100644
--- a/tests/basic-types/arrays-generics.c-expected
+++ b/tests/basic-types/arrays-generics.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_arrays_generics.c generated by valac, the Vala compiler
  * generated from basic_types_arrays_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/arrays.c-expected b/tests/basic-types/arrays.c-expected
index 5c4a167092470270..1a9f27dc57e329d4 100644
--- a/tests/basic-types/arrays.c-expected
+++ b/tests/basic-types/arrays.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_arrays.c generated by valac, the Vala compiler
  * generated from basic_types_arrays.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/tests/basic-types/boolean-literal.c-expected b/tests/basic-types/boolean-literal.c-expected
index 89441a6c1c12934d..e4c4cd590a680bbd 100644
--- a/tests/basic-types/boolean-literal.c-expected
+++ b/tests/basic-types/boolean-literal.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_boolean_literal.c generated by valac, the Vala compiler
  * generated from basic_types_boolean_literal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/boolean.c-expected b/tests/basic-types/boolean.c-expected
index 75de4a5bd295eb2c..e2110f39235c941a 100644
--- a/tests/basic-types/boolean.c-expected
+++ b/tests/basic-types/boolean.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_boolean.c generated by valac, the Vala compiler
  * generated from basic_types_boolean.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdbool.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/bug571486.c-expected b/tests/basic-types/bug571486.c-expected
index 9949111772bef60a..d5430fec3951e9b1 100644
--- a/tests/basic-types/bug571486.c-expected
+++ b/tests/basic-types/bug571486.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug571486.c generated by valac, the Vala compiler
  * generated from basic_types_bug571486.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug591552.c-expected b/tests/basic-types/bug591552.c-expected
index a61a51c7ac2fa429..679c3af829b72d47 100644
--- a/tests/basic-types/bug591552.c-expected
+++ b/tests/basic-types/bug591552.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug591552.c generated by valac, the Vala compiler
  * generated from basic_types_bug591552.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug595751.c-expected b/tests/basic-types/bug595751.c-expected
index 7f02e18714c4b256..6e326e37acaff65f 100644
--- a/tests/basic-types/bug595751.c-expected
+++ b/tests/basic-types/bug595751.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug595751.c generated by valac, the Vala compiler
  * generated from basic_types_bug595751.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/bug596637.c-expected b/tests/basic-types/bug596637.c-expected
index 2bdb6d02c56d6c88..5b660c1c163678f9 100644
--- a/tests/basic-types/bug596637.c-expected
+++ b/tests/basic-types/bug596637.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug596637.c generated by valac, the Vala compiler
  * generated from basic_types_bug596637.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug596785.c-expected b/tests/basic-types/bug596785.c-expected
index f950f5325805270d..bd314810ad63f98f 100644
--- a/tests/basic-types/bug596785.c-expected
+++ b/tests/basic-types/bug596785.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug596785.c generated by valac, the Vala compiler
  * generated from basic_types_bug596785.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug604371.c-expected b/tests/basic-types/bug604371.c-expected
index 3f1ee88b5a6ec9ac..b7abb13178f54325 100644
--- a/tests/basic-types/bug604371.c-expected
+++ b/tests/basic-types/bug604371.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug604371.c generated by valac, the Vala compiler
  * generated from basic_types_bug604371.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/bug610660.c-expected b/tests/basic-types/bug610660.c-expected
index 164232e75a6f6ef2..98c9d961bf1fd842 100644
--- a/tests/basic-types/bug610660.c-expected
+++ b/tests/basic-types/bug610660.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug610660.c generated by valac, the Vala compiler
  * generated from basic_types_bug610660.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/bug622178.c-expected b/tests/basic-types/bug622178.c-expected
index a8b9cefedc120286..4a0c44189b8eb0e2 100644
--- a/tests/basic-types/bug622178.c-expected
+++ b/tests/basic-types/bug622178.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug622178.c generated by valac, the Vala compiler
  * generated from basic_types_bug622178.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/basic-types/bug632322.c-expected b/tests/basic-types/bug632322.c-expected
index 5fba8e5db1506d3a..3d57779411299e27 100644
--- a/tests/basic-types/bug632322.c-expected
+++ b/tests/basic-types/bug632322.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug632322.c generated by valac, the Vala compiler
  * generated from basic_types_bug632322.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug643612.c-expected b/tests/basic-types/bug643612.c-expected
index e6312a702a0f1088..b5f5fdf225583986 100644
--- a/tests/basic-types/bug643612.c-expected
+++ b/tests/basic-types/bug643612.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug643612.c generated by valac, the Vala compiler
  * generated from basic_types_bug643612.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug644046.c-expected b/tests/basic-types/bug644046.c-expected
index 21672aab2e324c6b..0999646053b2120d 100644
--- a/tests/basic-types/bug644046.c-expected
+++ b/tests/basic-types/bug644046.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug644046.c generated by valac, the Vala compiler
  * generated from basic_types_bug644046.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug647222.c-expected b/tests/basic-types/bug647222.c-expected
index ac7a23a329178cf8..770ca60ada547a49 100644
--- a/tests/basic-types/bug647222.c-expected
+++ b/tests/basic-types/bug647222.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug647222.c generated by valac, the Vala compiler
  * generated from basic_types_bug647222.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/bug648364.c-expected b/tests/basic-types/bug648364.c-expected
index 69d7e181f75ce1d9..570e9a8412d4ba88 100644
--- a/tests/basic-types/bug648364.c-expected
+++ b/tests/basic-types/bug648364.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug648364.c generated by valac, the Vala compiler
  * generated from basic_types_bug648364.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug650993.c-expected b/tests/basic-types/bug650993.c-expected
index 52b5df15f8c8ac61..606abba862cccef4 100644
--- a/tests/basic-types/bug650993.c-expected
+++ b/tests/basic-types/bug650993.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug650993.c generated by valac, the Vala compiler
  * generated from basic_types_bug650993.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/basic-types/bug652380.c-expected b/tests/basic-types/bug652380.c-expected
index 00e5740f61e9c7d0..7b86d0794b1f6d05 100644
--- a/tests/basic-types/bug652380.c-expected
+++ b/tests/basic-types/bug652380.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug652380.c generated by valac, the Vala compiler
  * generated from basic_types_bug652380.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug655908.c-expected b/tests/basic-types/bug655908.c-expected
index cc8d61546dbe5708..d984d3d2f6a029fa 100644
--- a/tests/basic-types/bug655908.c-expected
+++ b/tests/basic-types/bug655908.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug655908.c generated by valac, the Vala compiler
  * generated from basic_types_bug655908.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug659975.c-expected b/tests/basic-types/bug659975.c-expected
index 27c3250ec375a094..0c95ba32562227f7 100644
--- a/tests/basic-types/bug659975.c-expected
+++ b/tests/basic-types/bug659975.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug659975.c generated by valac, the Vala compiler
  * generated from basic_types_bug659975.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug678791.c-expected b/tests/basic-types/bug678791.c-expected
index 9826ce745e2f7e55..10112f3de0432f13 100644
--- a/tests/basic-types/bug678791.c-expected
+++ b/tests/basic-types/bug678791.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug678791.c generated by valac, the Vala compiler
  * generated from basic_types_bug678791.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/bug686336.c-expected b/tests/basic-types/bug686336.c-expected
index f485d7871b3ddeea..b9a004a7f333bc20 100644
--- a/tests/basic-types/bug686336.c-expected
+++ b/tests/basic-types/bug686336.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug686336.c generated by valac, the Vala compiler
  * generated from basic_types_bug686336.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/basic-types/bug729907.c-expected b/tests/basic-types/bug729907.c-expected
index efe52397a878da3d..c5cc0ce86ffd59a7 100644
--- a/tests/basic-types/bug729907.c-expected
+++ b/tests/basic-types/bug729907.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug729907.c generated by valac, the Vala compiler
  * generated from basic_types_bug729907.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/bug731017.c-expected b/tests/basic-types/bug731017.c-expected
index 5de4afa6feed980e..889add82e92af4b8 100644
--- a/tests/basic-types/bug731017.c-expected
+++ b/tests/basic-types/bug731017.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug731017.c generated by valac, the Vala compiler
  * generated from basic_types_bug731017.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug756376.c-expected b/tests/basic-types/bug756376.c-expected
index 773d6921ce50f4f3..548d46c46aa89884 100644
--- a/tests/basic-types/bug756376.c-expected
+++ b/tests/basic-types/bug756376.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug756376.c generated by valac, the Vala compiler
  * generated from basic_types_bug756376.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define FOO_BAR 5
diff --git a/tests/basic-types/bug761307.c-expected b/tests/basic-types/bug761307.c-expected
index 8fe2e99626de3a75..5af211cc6c7af31d 100644
--- a/tests/basic-types/bug761307.c-expected
+++ b/tests/basic-types/bug761307.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug761307.c generated by valac, the Vala compiler
  * generated from basic_types_bug761307.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug761736.c-expected b/tests/basic-types/bug761736.c-expected
index 1a2ecb8b4e99daf4..aea1d287e3dc8963 100644
--- a/tests/basic-types/bug761736.c-expected
+++ b/tests/basic-types/bug761736.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug761736.c generated by valac, the Vala compiler
  * generated from basic_types_bug761736.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/bug772426.c-expected b/tests/basic-types/bug772426.c-expected
index 07c92c0d1dfe89e2..82b5618d327eeb47 100644
--- a/tests/basic-types/bug772426.c-expected
+++ b/tests/basic-types/bug772426.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug772426.c generated by valac, the Vala compiler
  * generated from basic_types_bug772426.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug787152.c-expected b/tests/basic-types/bug787152.c-expected
index f06e3ddbbae26118..535e2baa0f12d856 100644
--- a/tests/basic-types/bug787152.c-expected
+++ b/tests/basic-types/bug787152.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug787152.c generated by valac, the Vala compiler
  * generated from basic_types_bug787152.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/bug788775.c-expected b/tests/basic-types/bug788775.c-expected
index f0f5c33b6bdbfb08..71addc19166aa47b 100644
--- a/tests/basic-types/bug788775.c-expected
+++ b/tests/basic-types/bug788775.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_bug788775.c generated by valac, the Vala compiler
  * generated from basic_types_bug788775.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/custom-types.c-expected b/tests/basic-types/custom-types.c-expected
index 2e053ab4ea002711..1280a58c313b4b58 100644
--- a/tests/basic-types/custom-types.c-expected
+++ b/tests/basic-types/custom-types.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_custom_types.c generated by valac, the Vala compiler
  * generated from basic_types_custom_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdint.h>
 #include <stdbool.h>
 #include <glib.h>
diff --git a/tests/basic-types/default-gtype.c-expected b/tests/basic-types/default-gtype.c-expected
index 2d99e950ad2e5cdd..9ff0d82936157004 100644
--- a/tests/basic-types/default-gtype.c-expected
+++ b/tests/basic-types/default-gtype.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_default_gtype.c generated by valac, the Vala compiler
  * generated from basic_types_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/basic-types/escape-chars.c-expected b/tests/basic-types/escape-chars.c-expected
index 2bb8e148d89bf286..e7530064fd4f5f2e 100644
--- a/tests/basic-types/escape-chars.c-expected
+++ b/tests/basic-types/escape-chars.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_escape_chars.c generated by valac, the Vala compiler
  * generated from basic_types_escape_chars.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/float-literals.c-expected b/tests/basic-types/float-literals.c-expected
index 2447e3e680f66840..3a813fbe8cc75564 100644
--- a/tests/basic-types/float-literals.c-expected
+++ b/tests/basic-types/float-literals.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_float_literals.c generated by valac, the Vala compiler
  * generated from basic_types_float_literals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/floats-boxed-cast.c-expected b/tests/basic-types/floats-boxed-cast.c-expected
index b5d331fd05812ebd..36e101a4008cc11c 100644
--- a/tests/basic-types/floats-boxed-cast.c-expected
+++ b/tests/basic-types/floats-boxed-cast.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_floats_boxed_cast.c generated by valac, the Vala compiler
  * generated from basic_types_floats_boxed_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/floats.c-expected b/tests/basic-types/floats.c-expected
index 5d66d89398da46cb..a4c8604f9e410bf4 100644
--- a/tests/basic-types/floats.c-expected
+++ b/tests/basic-types/floats.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_floats.c generated by valac, the Vala compiler
  * generated from basic_types_floats.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/garray.c-expected b/tests/basic-types/garray.c-expected
index 6365624182f204c5..c65c586a5d287aa6 100644
--- a/tests/basic-types/garray.c-expected
+++ b/tests/basic-types/garray.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_garray.c generated by valac, the Vala compiler
  * generated from basic_types_garray.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/gassert.c-expected b/tests/basic-types/gassert.c-expected
index f73315a56b63e6bc..fdab648c5c1153fd 100644
--- a/tests/basic-types/gassert.c-expected
+++ b/tests/basic-types/gassert.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_gassert.c generated by valac, the Vala compiler
  * generated from basic_types_gassert.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/basic-types/glists.c-expected b/tests/basic-types/glists.c-expected
index 4f3763c60d366cd7..03fdf757c1b27938 100644
--- a/tests/basic-types/glists.c-expected
+++ b/tests/basic-types/glists.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_glists.c generated by valac, the Vala compiler
  * generated from basic_types_glists.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/glists_remove.c-expected b/tests/basic-types/glists_remove.c-expected
index f8407854bbcf64e9..e4771889d3592453 100644
--- a/tests/basic-types/glists_remove.c-expected
+++ b/tests/basic-types/glists_remove.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_glists_remove.c generated by valac, the Vala compiler
  * generated from basic_types_glists_remove.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/basic-types/gptrarray.c-expected b/tests/basic-types/gptrarray.c-expected
index 73dd27e3b6bcf0eb..366cbbb8887ce941 100644
--- a/tests/basic-types/gptrarray.c-expected
+++ b/tests/basic-types/gptrarray.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_gptrarray.c generated by valac, the Vala compiler
  * generated from basic_types_gptrarray.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/basic-types/gvariants-unboxing-safe.c-expected b/tests/basic-types/gvariants-unboxing-safe.c-expected
index 2c8c4e8a4dd4a2b6..dcba351f8ad6d18a 100644
--- a/tests/basic-types/gvariants-unboxing-safe.c-expected
+++ b/tests/basic-types/gvariants-unboxing-safe.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_gvariants_unboxing_safe.c generated by valac, the Vala compiler
  * generated from basic_types_gvariants_unboxing_safe.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/gvariants.c-expected b/tests/basic-types/gvariants.c-expected
index 8d4cfdd799daef04..657b06bf77b9cdba 100644
--- a/tests/basic-types/gvariants.c-expected
+++ b/tests/basic-types/gvariants.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_gvariants.c generated by valac, the Vala compiler
  * generated from basic_types_gvariants.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/integer-literals.c-expected b/tests/basic-types/integer-literals.c-expected
index c534fbe7f03b1934..f6c4dadd97838ea6 100644
--- a/tests/basic-types/integer-literals.c-expected
+++ b/tests/basic-types/integer-literals.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_integer_literals.c generated by valac, the Vala compiler
  * generated from basic_types_integer_literals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/integers-boxed-cast.c-expected b/tests/basic-types/integers-boxed-cast.c-expected
index e13d9a94d0bfb741..d53b3174e2a8fa50 100644
--- a/tests/basic-types/integers-boxed-cast.c-expected
+++ b/tests/basic-types/integers-boxed-cast.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_integers_boxed_cast.c generated by valac, the Vala compiler
  * generated from basic_types_integers_boxed_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/basic-types/integers.c-expected b/tests/basic-types/integers.c-expected
index cdad296a0a7b0bb7..7697e6df4496973c 100644
--- a/tests/basic-types/integers.c-expected
+++ b/tests/basic-types/integers.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_integers.c generated by valac, the Vala compiler
  * generated from basic_types_integers.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/null.c-expected b/tests/basic-types/null.c-expected
index 8aaf78b18e1cee04..173a00d07066867a 100644
--- a/tests/basic-types/null.c-expected
+++ b/tests/basic-types/null.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_null.c generated by valac, the Vala compiler
  * generated from basic_types_null.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/basic-types/pointers-arithmetic.c-expected b/tests/basic-types/pointers-arithmetic.c-expected
index 848f092a438196bf..0c15d8112c501177 100644
--- a/tests/basic-types/pointers-arithmetic.c-expected
+++ b/tests/basic-types/pointers-arithmetic.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_pointers_arithmetic.c generated by valac, the Vala compiler
  * generated from basic_types_pointers_arithmetic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/basic-types/pointers.c-expected b/tests/basic-types/pointers.c-expected
index ed1a1aa5d69c020d..c3a8b1e79e553b01 100644
--- a/tests/basic-types/pointers.c-expected
+++ b/tests/basic-types/pointers.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_pointers.c generated by valac, the Vala compiler
  * generated from basic_types_pointers.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/basic-types/sizeof.c-expected b/tests/basic-types/sizeof.c-expected
index 1beba725b050d03c..0a08f9b628f5462e 100644
--- a/tests/basic-types/sizeof.c-expected
+++ b/tests/basic-types/sizeof.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_sizeof.c generated by valac, the Vala compiler
  * generated from basic_types_sizeof.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define simple_size ((gsize) sizeof (gint))
diff --git a/tests/basic-types/string-array-append.c-expected b/tests/basic-types/string-array-append.c-expected
index 222f34faa55d8c91..f7dc4c010def1633 100644
--- a/tests/basic-types/string-array-append.c-expected
+++ b/tests/basic-types/string-array-append.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_string_array_append.c generated by valac, the Vala compiler
  * generated from basic_types_string_array_append.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/basic-types/string-relation.c-expected b/tests/basic-types/string-relation.c-expected
index 8fcb00f5dfc2402a..29f104c0502f95c8 100644
--- a/tests/basic-types/string-relation.c-expected
+++ b/tests/basic-types/string-relation.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_string_relation.c generated by valac, the Vala compiler
  * generated from basic_types_string_relation.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/basic-types/strings.c-expected b/tests/basic-types/strings.c-expected
index d48d7b2805c5e87e..8d2a8b189594434e 100644
--- a/tests/basic-types/strings.c-expected
+++ b/tests/basic-types/strings.c-expected
@@ -1,6 +1,12 @@
 /* basic_types_strings.c generated by valac, the Vala compiler
  * generated from basic_types_strings.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/chainup/bug791785.c-expected b/tests/chainup/bug791785.c-expected
index bfc93915145a9ece..11f8e389c4287429 100644
--- a/tests/chainup/bug791785.c-expected
+++ b/tests/chainup/bug791785.c-expected
@@ -1,6 +1,12 @@
 /* chainup_bug791785.c generated by valac, the Vala compiler
  * generated from chainup_bug791785.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/class-base-foo.c-expected b/tests/chainup/class-base-foo.c-expected
index 54766f06d7e04e35..ae227e6adc708cb1 100644
--- a/tests/chainup/class-base-foo.c-expected
+++ b/tests/chainup/class-base-foo.c-expected
@@ -1,6 +1,12 @@
 /* chainup_class_base_foo.c generated by valac, the Vala compiler
  * generated from chainup_class_base_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/class-base.c-expected b/tests/chainup/class-base.c-expected
index 9752d6f66aa56716..0c0d8d64fb532e59 100644
--- a/tests/chainup/class-base.c-expected
+++ b/tests/chainup/class-base.c-expected
@@ -1,6 +1,12 @@
 /* chainup_class_base.c generated by valac, the Vala compiler
  * generated from chainup_class_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/class-compact-base.c-expected b/tests/chainup/class-compact-base.c-expected
index 519b2e6b6f929e08..1568658bf1942382 100644
--- a/tests/chainup/class-compact-base.c-expected
+++ b/tests/chainup/class-compact-base.c-expected
@@ -1,6 +1,12 @@
 /* chainup_class_compact_base.c generated by valac, the Vala compiler
  * generated from chainup_class_compact_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/chainup/class-compact-this.c-expected b/tests/chainup/class-compact-this.c-expected
index aaeb7299e4e2feaa..53b584bfa10b8e77 100644
--- a/tests/chainup/class-compact-this.c-expected
+++ b/tests/chainup/class-compact-this.c-expected
@@ -1,6 +1,12 @@
 /* chainup_class_compact_this.c generated by valac, the Vala compiler
  * generated from chainup_class_compact_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/chainup/class-object.c-expected b/tests/chainup/class-object.c-expected
index 9d95ec4c618b5fe6..4080d20bcf42d656 100644
--- a/tests/chainup/class-object.c-expected
+++ b/tests/chainup/class-object.c-expected
@@ -1,6 +1,12 @@
 /* chainup_class_object.c generated by valac, the Vala compiler
  * generated from chainup_class_object.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/chainup/class-this-foo.c-expected b/tests/chainup/class-this-foo.c-expected
index 3e2de9849c703429..54c89a6a4e801852 100644
--- a/tests/chainup/class-this-foo.c-expected
+++ b/tests/chainup/class-this-foo.c-expected
@@ -1,6 +1,12 @@
 /* chainup_class_this_foo.c generated by valac, the Vala compiler
  * generated from chainup_class_this_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/class-this.c-expected b/tests/chainup/class-this.c-expected
index 1fe914c03447d027..a9bc419a97c22bbe 100644
--- a/tests/chainup/class-this.c-expected
+++ b/tests/chainup/class-this.c-expected
@@ -1,6 +1,12 @@
 /* chainup_class_this.c generated by valac, the Vala compiler
  * generated from chainup_class_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/method-lambda-base.c-expected b/tests/chainup/method-lambda-base.c-expected
index cfc1a553f1d4bfd1..4550d8f383bbca6e 100644
--- a/tests/chainup/method-lambda-base.c-expected
+++ b/tests/chainup/method-lambda-base.c-expected
@@ -1,6 +1,12 @@
 /* chainup_method_lambda_base.c generated by valac, the Vala compiler
  * generated from chainup_method_lambda_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/no-chainup.c-expected b/tests/chainup/no-chainup.c-expected
index 1791f50843333f9e..bb289e4eeabfbeb2 100644
--- a/tests/chainup/no-chainup.c-expected
+++ b/tests/chainup/no-chainup.c-expected
@@ -1,6 +1,12 @@
 /* chainup_no_chainup.c generated by valac, the Vala compiler
  * generated from chainup_no_chainup.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/chainup/signal-default-handler.c-expected b/tests/chainup/signal-default-handler.c-expected
index a4b6f5a7539beecf..ee38220ec4b298b7 100644
--- a/tests/chainup/signal-default-handler.c-expected
+++ b/tests/chainup/signal-default-handler.c-expected
@@ -1,6 +1,12 @@
 /* chainup_signal_default_handler.c generated by valac, the Vala compiler
  * generated from chainup_signal_default_handler.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/chainup/struct-base-foo.c-expected b/tests/chainup/struct-base-foo.c-expected
index 47c39e8d6eac9dfa..f6bd0a01927de00f 100644
--- a/tests/chainup/struct-base-foo.c-expected
+++ b/tests/chainup/struct-base-foo.c-expected
@@ -1,6 +1,12 @@
 /* chainup_struct_base_foo.c generated by valac, the Vala compiler
  * generated from chainup_struct_base_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/struct-base.c-expected b/tests/chainup/struct-base.c-expected
index c9c2fa049e6563b2..c33638d38cd31ba4 100644
--- a/tests/chainup/struct-base.c-expected
+++ b/tests/chainup/struct-base.c-expected
@@ -1,6 +1,12 @@
 /* chainup_struct_base.c generated by valac, the Vala compiler
  * generated from chainup_struct_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/struct-no-gtype-base.c-expected b/tests/chainup/struct-no-gtype-base.c-expected
index 1926db7806874732..5876b931a7599684 100644
--- a/tests/chainup/struct-no-gtype-base.c-expected
+++ b/tests/chainup/struct-no-gtype-base.c-expected
@@ -1,6 +1,12 @@
 /* chainup_struct_no_gtype_base.c generated by valac, the Vala compiler
  * generated from chainup_struct_no_gtype_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/chainup/struct-simple-no-gtype-base.c-expected b/tests/chainup/struct-simple-no-gtype-base.c-expected
index 8ade7ae6e02818ad..5a1cfaa0bcf94fc4 100644
--- a/tests/chainup/struct-simple-no-gtype-base.c-expected
+++ b/tests/chainup/struct-simple-no-gtype-base.c-expected
@@ -1,6 +1,12 @@
 /* chainup_struct_simple_no_gtype_base.c generated by valac, the Vala compiler
  * generated from chainup_struct_simple_no_gtype_base.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdint.h>
 #include <glib.h>
 
diff --git a/tests/chainup/struct-this-foo.c-expected b/tests/chainup/struct-this-foo.c-expected
index cee0a3e9a75a1146..5f1435ff99984024 100644
--- a/tests/chainup/struct-this-foo.c-expected
+++ b/tests/chainup/struct-this-foo.c-expected
@@ -1,6 +1,12 @@
 /* chainup_struct_this_foo.c generated by valac, the Vala compiler
  * generated from chainup_struct_this_foo.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/chainup/struct-this.c-expected b/tests/chainup/struct-this.c-expected
index 4c8ee333600ea995..9108252b3f376dd6 100644
--- a/tests/chainup/struct-this.c-expected
+++ b/tests/chainup/struct-this.c-expected
@@ -1,6 +1,12 @@
 /* chainup_struct_this.c generated by valac, the Vala compiler
  * generated from chainup_struct_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/constants/delegate-type.c-expected b/tests/constants/delegate-type.c-expected
index 126728767baffcf2..f9e213273f65bc6e 100644
--- a/tests/constants/delegate-type.c-expected
+++ b/tests/constants/delegate-type.c-expected
@@ -1,6 +1,12 @@
 /* constants_delegate_type.c generated by valac, the Vala compiler
  * generated from constants_delegate_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/constants/glog.c-expected b/tests/constants/glog.c-expected
index 02322fbd14752cfc..1fc6a943d5991ebc 100644
--- a/tests/constants/glog.c-expected
+++ b/tests/constants/glog.c-expected
@@ -1,6 +1,12 @@
 /* constants_glog.c generated by valac, the Vala compiler
  * generated from constants_glog.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/constants/member-access-enum.c-expected b/tests/constants/member-access-enum.c-expected
index 9cea27ce87456cc9..225588ddb2ba81e7 100644
--- a/tests/constants/member-access-enum.c-expected
+++ b/tests/constants/member-access-enum.c-expected
@@ -1,6 +1,12 @@
 /* constants_member_access_enum.c generated by valac, the Vala compiler
  * generated from constants_member_access_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/constants/member-access.c-expected b/tests/constants/member-access.c-expected
index c120ffd5be4ff0b7..b936174c96a95c29 100644
--- a/tests/constants/member-access.c-expected
+++ b/tests/constants/member-access.c-expected
@@ -1,6 +1,12 @@
 /* constants_member_access.c generated by valac, the Vala compiler
  * generated from constants_member_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/constants/strings.c-expected b/tests/constants/strings.c-expected
index f0bb50459c90c303..727190badb3f8a36 100644
--- a/tests/constants/strings.c-expected
+++ b/tests/constants/strings.c-expected
@@ -1,6 +1,12 @@
 /* constants_strings.c generated by valac, the Vala compiler
  * generated from constants_strings.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/assigned-local-variable.c-expected b/tests/control-flow/assigned-local-variable.c-expected
index ad1119fae4536550..e5a690d464e72307 100644
--- a/tests/control-flow/assigned-local-variable.c-expected
+++ b/tests/control-flow/assigned-local-variable.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_assigned_local_variable.c generated by valac, the Vala compiler
  * generated from control_flow_assigned_local_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/break.c-expected b/tests/control-flow/break.c-expected
index a806409b320523f3..c87085021a153b54 100644
--- a/tests/control-flow/break.c-expected
+++ b/tests/control-flow/break.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_break.c generated by valac, the Vala compiler
  * generated from control_flow_break.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/control-flow/bug628336.c-expected b/tests/control-flow/bug628336.c-expected
index 1e5fb82ce2cf7a56..a189102b05b89196 100644
--- a/tests/control-flow/bug628336.c-expected
+++ b/tests/control-flow/bug628336.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug628336.c generated by valac, the Vala compiler
  * generated from control_flow_bug628336.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug639482.c-expected b/tests/control-flow/bug639482.c-expected
index d98351ebc5d4a9d0..5c2b0846106e12ac 100644
--- a/tests/control-flow/bug639482.c-expected
+++ b/tests/control-flow/bug639482.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug639482.c generated by valac, the Vala compiler
  * generated from control_flow_bug639482.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug652549.c-expected b/tests/control-flow/bug652549.c-expected
index 6e0999e7c9fbda24..a84895838ec600be 100644
--- a/tests/control-flow/bug652549.c-expected
+++ b/tests/control-flow/bug652549.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug652549.c generated by valac, the Vala compiler
  * generated from control_flow_bug652549.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/control-flow/bug661985.c-expected b/tests/control-flow/bug661985.c-expected
index 6e81e5156327f95e..28948469e047be9c 100644
--- a/tests/control-flow/bug661985.c-expected
+++ b/tests/control-flow/bug661985.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug661985.c generated by valac, the Vala compiler
  * generated from control_flow_bug661985.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug665904.c-expected b/tests/control-flow/bug665904.c-expected
index a66522b72d8cff39..c6aa71ca19800ba3 100644
--- a/tests/control-flow/bug665904.c-expected
+++ b/tests/control-flow/bug665904.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug665904.c generated by valac, the Vala compiler
  * generated from control_flow_bug665904.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/control-flow/bug691514.c-expected b/tests/control-flow/bug691514.c-expected
index a9d9a29b1c2d4214..6320986b94763646 100644
--- a/tests/control-flow/bug691514.c-expected
+++ b/tests/control-flow/bug691514.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug691514.c generated by valac, the Vala compiler
  * generated from control_flow_bug691514.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/bug736774-1.c-expected b/tests/control-flow/bug736774-1.c-expected
index f687209d92a8f988..9ee7cf58e9350e4e 100644
--- a/tests/control-flow/bug736774-1.c-expected
+++ b/tests/control-flow/bug736774-1.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug736774_1.c generated by valac, the Vala compiler
  * generated from control_flow_bug736774_1.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/control-flow/bug736774-2.c-expected b/tests/control-flow/bug736774-2.c-expected
index b9567e16dc27e928..9278531182c3a5dc 100644
--- a/tests/control-flow/bug736774-2.c-expected
+++ b/tests/control-flow/bug736774-2.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug736774_2.c generated by valac, the Vala compiler
  * generated from control_flow_bug736774_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/control-flow/bug761267-1.c-expected b/tests/control-flow/bug761267-1.c-expected
index fdf7617e906303b4..c86e1c49bc0d85d6 100644
--- a/tests/control-flow/bug761267-1.c-expected
+++ b/tests/control-flow/bug761267-1.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug761267_1.c generated by valac, the Vala compiler
  * generated from control_flow_bug761267_1.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/bug761267-2.c-expected b/tests/control-flow/bug761267-2.c-expected
index 14476bde57f8a5ab..daf3c493c60e25cb 100644
--- a/tests/control-flow/bug761267-2.c-expected
+++ b/tests/control-flow/bug761267-2.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug761267_2.c generated by valac, the Vala compiler
  * generated from control_flow_bug761267_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/bug764440.c-expected b/tests/control-flow/bug764440.c-expected
index 1b5cf751c092d36d..6ffca8dabb13d705 100644
--- a/tests/control-flow/bug764440.c-expected
+++ b/tests/control-flow/bug764440.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_bug764440.c generated by valac, the Vala compiler
  * generated from control_flow_bug764440.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/control-flow/coalesce-as-argument.c-expected b/tests/control-flow/coalesce-as-argument.c-expected
index 2ca2a881fba49ed3..fe990053091fe4a1 100644
--- a/tests/control-flow/coalesce-as-argument.c-expected
+++ b/tests/control-flow/coalesce-as-argument.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_coalesce_as_argument.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_as_argument.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/coalesce-execution-order.c-expected b/tests/control-flow/coalesce-execution-order.c-expected
index efaf3e11ed364cb8..7f5414a4f5d78048 100644
--- a/tests/control-flow/coalesce-execution-order.c-expected
+++ b/tests/control-flow/coalesce-execution-order.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_coalesce_execution_order.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_execution_order.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/coalesce-reference-transfer.c-expected b/tests/control-flow/coalesce-reference-transfer.c-expected
index 9a27fcba1a21ac72..0003af012dc51f09 100644
--- a/tests/control-flow/coalesce-reference-transfer.c-expected
+++ b/tests/control-flow/coalesce-reference-transfer.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_coalesce_reference_transfer.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_reference_transfer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/coalesce-right-value.c-expected b/tests/control-flow/coalesce-right-value.c-expected
index 85fb39c40dbc0a15..4a244300199bf728 100644
--- a/tests/control-flow/coalesce-right-value.c-expected
+++ b/tests/control-flow/coalesce-right-value.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_coalesce_right_value.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_right_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/control-flow/coalesce-short-circuit.c-expected b/tests/control-flow/coalesce-short-circuit.c-expected
index 461a854a03d977e2..289d1be04f67d802 100644
--- a/tests/control-flow/coalesce-short-circuit.c-expected
+++ b/tests/control-flow/coalesce-short-circuit.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_coalesce_short_circuit.c generated by valac, the Vala compiler
  * generated from control_flow_coalesce_short_circuit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/conditional-as-argument.c-expected b/tests/control-flow/conditional-as-argument.c-expected
index 880af4204bc25db3..e45bbda2f654f9ee 100644
--- a/tests/control-flow/conditional-as-argument.c-expected
+++ b/tests/control-flow/conditional-as-argument.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_conditional_as_argument.c generated by valac, the Vala compiler
  * generated from control_flow_conditional_as_argument.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/expressions-conditional.c-expected b/tests/control-flow/expressions-conditional.c-expected
index 0e026d8648fc7049..2e375661adc1d31d 100644
--- a/tests/control-flow/expressions-conditional.c-expected
+++ b/tests/control-flow/expressions-conditional.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_expressions_conditional.c generated by valac, the Vala compiler
  * generated from control_flow_expressions_conditional.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/control-flow/finally-no-return.c-expected b/tests/control-flow/finally-no-return.c-expected
index bdbb991c1a92e9dd..3182ac7cf25ecf67 100644
--- a/tests/control-flow/finally-no-return.c-expected
+++ b/tests/control-flow/finally-no-return.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_finally_no_return.c generated by valac, the Vala compiler
  * generated from control_flow_finally_no_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/for-switch-continue.c-expected b/tests/control-flow/for-switch-continue.c-expected
index b6a5eeafed934faa..2bc0823da10a1d97 100644
--- a/tests/control-flow/for-switch-continue.c-expected
+++ b/tests/control-flow/for-switch-continue.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_for_switch_continue.c generated by valac, the Vala compiler
  * generated from control_flow_for_switch_continue.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/control-flow/for.c-expected b/tests/control-flow/for.c-expected
index f873866c40233abb..2b6ffcee394eb974 100644
--- a/tests/control-flow/for.c-expected
+++ b/tests/control-flow/for.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_for.c generated by valac, the Vala compiler
  * generated from control_flow_for.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/foreach.c-expected b/tests/control-flow/foreach.c-expected
index 0f9bd45f9d318341..59d120c0c54575ca 100644
--- a/tests/control-flow/foreach.c-expected
+++ b/tests/control-flow/foreach.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_foreach.c generated by valac, the Vala compiler
  * generated from control_flow_foreach.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/control-flow/local-clash-with-implicit-this.c-expected b/tests/control-flow/local-clash-with-implicit-this.c-expected
index ea99a1cc2fd3d28f..a7a8520522f34456 100644
--- a/tests/control-flow/local-clash-with-implicit-this.c-expected
+++ b/tests/control-flow/local-clash-with-implicit-this.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_local_clash_with_implicit_this.c generated by valac, the Vala compiler
  * generated from control_flow_local_clash_with_implicit_this.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/lock-if-throw.c-expected b/tests/control-flow/lock-if-throw.c-expected
index 7eedf1239e55c12e..c09b8ad89086fbd6 100644
--- a/tests/control-flow/lock-if-throw.c-expected
+++ b/tests/control-flow/lock-if-throw.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_lock_if_throw.c generated by valac, the Vala compiler
  * generated from control_flow_lock_if_throw.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/nested-conditional.c-expected b/tests/control-flow/nested-conditional.c-expected
index 75f1eba35a79172e..4b361f4a824eb4eb 100644
--- a/tests/control-flow/nested-conditional.c-expected
+++ b/tests/control-flow/nested-conditional.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_nested_conditional.c generated by valac, the Vala compiler
  * generated from control_flow_nested_conditional.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/null-conditional-bool.c-expected b/tests/control-flow/null-conditional-bool.c-expected
index 4ab15553a8a382c6..9a728e2c9869db6e 100644
--- a/tests/control-flow/null-conditional-bool.c-expected
+++ b/tests/control-flow/null-conditional-bool.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_null_conditional_bool.c generated by valac, the Vala compiler
  * generated from control_flow_null_conditional_bool.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/pre-post-increment-array-index.c-expected b/tests/control-flow/pre-post-increment-array-index.c-expected
index f10350740a66c31d..8613700a5ac1f5c6 100644
--- a/tests/control-flow/pre-post-increment-array-index.c-expected
+++ b/tests/control-flow/pre-post-increment-array-index.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_pre_post_increment_array_index.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_array_index.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/control-flow/pre-post-increment-field.c-expected b/tests/control-flow/pre-post-increment-field.c-expected
index d8d16ceb56717989..e063942140bcfec9 100644
--- a/tests/control-flow/pre-post-increment-field.c-expected
+++ b/tests/control-flow/pre-post-increment-field.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_pre_post_increment_field.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_field.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/pre-post-increment-local.c-expected b/tests/control-flow/pre-post-increment-local.c-expected
index fe58a03cb71ffce3..a4ddec0814d44501 100644
--- a/tests/control-flow/pre-post-increment-local.c-expected
+++ b/tests/control-flow/pre-post-increment-local.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_pre_post_increment_local.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_local.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/control-flow/pre-post-increment-parameter.c-expected b/tests/control-flow/pre-post-increment-parameter.c-expected
index 2e328efdc29b8aae..c2799f392dd21101 100644
--- a/tests/control-flow/pre-post-increment-parameter.c-expected
+++ b/tests/control-flow/pre-post-increment-parameter.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_pre_post_increment_parameter.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_parameter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/control-flow/pre-post-increment-property.c-expected b/tests/control-flow/pre-post-increment-property.c-expected
index 96949d2242a2300c..036012f88993e4d6 100644
--- a/tests/control-flow/pre-post-increment-property.c-expected
+++ b/tests/control-flow/pre-post-increment-property.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_pre_post_increment_property.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment_property.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/control-flow/pre-post-increment.c-expected b/tests/control-flow/pre-post-increment.c-expected
index 186e9f88fe5b27c8..fe9020e908fe10f0 100644
--- a/tests/control-flow/pre-post-increment.c-expected
+++ b/tests/control-flow/pre-post-increment.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_pre_post_increment.c generated by valac, the Vala compiler
  * generated from control_flow_pre_post_increment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/control-flow/sideeffects.c-expected b/tests/control-flow/sideeffects.c-expected
index 81c928fd6bd6db8c..2324c4d6096ad0ce 100644
--- a/tests/control-flow/sideeffects.c-expected
+++ b/tests/control-flow/sideeffects.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_sideeffects.c generated by valac, the Vala compiler
  * generated from control_flow_sideeffects.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/control-flow/switch-enum.c-expected b/tests/control-flow/switch-enum.c-expected
index fc8507bc435ddeec..5e3e5bb59276d9de 100644
--- a/tests/control-flow/switch-enum.c-expected
+++ b/tests/control-flow/switch-enum.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_switch_enum.c generated by valac, the Vala compiler
  * generated from control_flow_switch_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/control-flow/switch-string.c-expected b/tests/control-flow/switch-string.c-expected
index c8d66e6fff45bdfc..90473dcb3e9a08dc 100644
--- a/tests/control-flow/switch-string.c-expected
+++ b/tests/control-flow/switch-string.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_switch_string.c generated by valac, the Vala compiler
  * generated from control_flow_switch_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/control-flow/switch.c-expected b/tests/control-flow/switch.c-expected
index 6e7834d96c77faeb..bf4ff3cae0bdf5d4 100644
--- a/tests/control-flow/switch.c-expected
+++ b/tests/control-flow/switch.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_switch.c generated by valac, the Vala compiler
  * generated from control_flow_switch.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/control-flow/while-false.c-expected b/tests/control-flow/while-false.c-expected
index 63525993d6642cd3..5efdebd365829678 100644
--- a/tests/control-flow/while-false.c-expected
+++ b/tests/control-flow/while-false.c-expected
@@ -1,6 +1,12 @@
 /* control_flow_while_false.c generated by valac, the Vala compiler
  * generated from control_flow_while_false.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/dbus/arrays_client.c-expected b/tests/dbus/arrays_client.c-expected
index b46f5548d3812088..e5ac230927e75f7c 100644
--- a/tests/dbus/arrays_client.c-expected
+++ b/tests/dbus/arrays_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_arrays_client.c generated by valac, the Vala compiler
  * generated from dbus_arrays_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/arrays_server.c-expected b/tests/dbus/arrays_server.c-expected
index e382242ddc6d3f9a..87d7a55dd6747326 100644
--- a/tests/dbus/arrays_server.c-expected
+++ b/tests/dbus/arrays_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_arrays_server.c generated by valac, the Vala compiler
  * generated from dbus_arrays_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/async-bus_client.c-expected b/tests/dbus/async-bus_client.c-expected
index dfac708c26aa1f3e..6a7ce6ef15294c08 100644
--- a/tests/dbus/async-bus_client.c-expected
+++ b/tests/dbus/async-bus_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_bus_client.c generated by valac, the Vala compiler
  * generated from dbus_async_bus_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-bus_server.c-expected b/tests/dbus/async-bus_server.c-expected
index f26a333500a226eb..be54b7405ffc27b9 100644
--- a/tests/dbus/async-bus_server.c-expected
+++ b/tests/dbus/async-bus_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_bus_server.c generated by valac, the Vala compiler
  * generated from dbus_async_bus_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-connection_client.c-expected b/tests/dbus/async-connection_client.c-expected
index c76d0834d484f19f..a5c6b241855a3465 100644
--- a/tests/dbus/async-connection_client.c-expected
+++ b/tests/dbus/async-connection_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_connection_client.c generated by valac, the Vala compiler
  * generated from dbus_async_connection_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-connection_server.c-expected b/tests/dbus/async-connection_server.c-expected
index ba068319983a7f80..8b899d2eac376e60 100644
--- a/tests/dbus/async-connection_server.c-expected
+++ b/tests/dbus/async-connection_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_connection_server.c generated by valac, the Vala compiler
  * generated from dbus_async_connection_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-errors_client.c-expected b/tests/dbus/async-errors_client.c-expected
index 5733445517275ad3..5d4590c81022cd74 100644
--- a/tests/dbus/async-errors_client.c-expected
+++ b/tests/dbus/async-errors_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_errors_client.c generated by valac, the Vala compiler
  * generated from dbus_async_errors_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-errors_server.c-expected b/tests/dbus/async-errors_server.c-expected
index aaae816ebc227c3e..85d0a41447a0c5e9 100644
--- a/tests/dbus/async-errors_server.c-expected
+++ b/tests/dbus/async-errors_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_errors_server.c generated by valac, the Vala compiler
  * generated from dbus_async_errors_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async-no-reply_client.c-expected b/tests/dbus/async-no-reply_client.c-expected
index 995bc1dc3da177ac..824b384472bb4435 100644
--- a/tests/dbus/async-no-reply_client.c-expected
+++ b/tests/dbus/async-no-reply_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_no_reply_client.c generated by valac, the Vala compiler
  * generated from dbus_async_no_reply_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/async-no-reply_server.c-expected b/tests/dbus/async-no-reply_server.c-expected
index e2e894c6054d5cba..7e9644464b2ea6b6 100644
--- a/tests/dbus/async-no-reply_server.c-expected
+++ b/tests/dbus/async-no-reply_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_no_reply_server.c generated by valac, the Vala compiler
  * generated from dbus_async_no_reply_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/async_client.c-expected b/tests/dbus/async_client.c-expected
index c108a12b8bcd1628..96cb3d02062501f8 100644
--- a/tests/dbus/async_client.c-expected
+++ b/tests/dbus/async_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_client.c generated by valac, the Vala compiler
  * generated from dbus_async_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/async_server.c-expected b/tests/dbus/async_server.c-expected
index 81a1ee80b8f524c9..8010c97627e347df 100644
--- a/tests/dbus/async_server.c-expected
+++ b/tests/dbus/async_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_async_server.c generated by valac, the Vala compiler
  * generated from dbus_async_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/basic-types_client.c-expected b/tests/dbus/basic-types_client.c-expected
index 71da10ef26f023e7..6b2b33bbafdc041d 100644
--- a/tests/dbus/basic-types_client.c-expected
+++ b/tests/dbus/basic-types_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_basic_types_client.c generated by valac, the Vala compiler
  * generated from dbus_basic_types_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/basic-types_server.c-expected b/tests/dbus/basic-types_server.c-expected
index dd8f53d52e652118..d6e36649839edf02 100644
--- a/tests/dbus/basic-types_server.c-expected
+++ b/tests/dbus/basic-types_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_basic_types_server.c generated by valac, the Vala compiler
  * generated from dbus_basic_types_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/bug596862.c-expected b/tests/dbus/bug596862.c-expected
index 0d0f8156914913e8..c6439c268211e38b 100644
--- a/tests/dbus/bug596862.c-expected
+++ b/tests/dbus/bug596862.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug596862.c generated by valac, the Vala compiler
  * generated from dbus_bug596862.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug602003_client.c-expected b/tests/dbus/bug602003_client.c-expected
index ec06c433ffe8df95..5e8df239b0e31bcd 100644
--- a/tests/dbus/bug602003_client.c-expected
+++ b/tests/dbus/bug602003_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug602003_client.c generated by valac, the Vala compiler
  * generated from dbus_bug602003_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug602003_server.c-expected b/tests/dbus/bug602003_server.c-expected
index 7fe965ed631cef92..69c8cd0467468c71 100644
--- a/tests/dbus/bug602003_server.c-expected
+++ b/tests/dbus/bug602003_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug602003_server.c generated by valac, the Vala compiler
  * generated from dbus_bug602003_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug735437_client.c-expected b/tests/dbus/bug735437_client.c-expected
index dc44533a53ea92a9..dae3396742fc80aa 100644
--- a/tests/dbus/bug735437_client.c-expected
+++ b/tests/dbus/bug735437_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug735437_client.c generated by valac, the Vala compiler
  * generated from dbus_bug735437_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug735437_server.c-expected b/tests/dbus/bug735437_server.c-expected
index 82e199e41bf1f1f2..57fe38f9e67b5be5 100644
--- a/tests/dbus/bug735437_server.c-expected
+++ b/tests/dbus/bug735437_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug735437_server.c generated by valac, the Vala compiler
  * generated from dbus_bug735437_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug782719_client.c-expected b/tests/dbus/bug782719_client.c-expected
index 22512e652c8040c1..d6b8712b29897b27 100644
--- a/tests/dbus/bug782719_client.c-expected
+++ b/tests/dbus/bug782719_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug782719_client.c generated by valac, the Vala compiler
  * generated from dbus_bug782719_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug782719_server.c-expected b/tests/dbus/bug782719_server.c-expected
index 970ddcf5d9f3b473..1042d27196ce55ef 100644
--- a/tests/dbus/bug782719_server.c-expected
+++ b/tests/dbus/bug782719_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug782719_server.c generated by valac, the Vala compiler
  * generated from dbus_bug782719_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/bug783002_client.c-expected b/tests/dbus/bug783002_client.c-expected
index 270f433d4316622d..65bf92231085cc3b 100644
--- a/tests/dbus/bug783002_client.c-expected
+++ b/tests/dbus/bug783002_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug783002_client.c generated by valac, the Vala compiler
  * generated from dbus_bug783002_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/bug783002_server.c-expected b/tests/dbus/bug783002_server.c-expected
index 679154f0fa86737d..13aedaf05ab49439 100644
--- a/tests/dbus/bug783002_server.c-expected
+++ b/tests/dbus/bug783002_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug783002_server.c generated by valac, the Vala compiler
  * generated from dbus_bug783002_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/bug792277.c-expected b/tests/dbus/bug792277.c-expected
index a9aca9d154500f17..8191f676fdbe9b7f 100644
--- a/tests/dbus/bug792277.c-expected
+++ b/tests/dbus/bug792277.c-expected
@@ -1,6 +1,12 @@
 /* dbus_bug792277.c generated by valac, the Vala compiler
  * generated from dbus_bug792277.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/connection_client.c-expected b/tests/dbus/connection_client.c-expected
index ad172cced4f59a59..62ba6e6a825952ef 100644
--- a/tests/dbus/connection_client.c-expected
+++ b/tests/dbus/connection_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_connection_client.c generated by valac, the Vala compiler
  * generated from dbus_connection_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/connection_server.c-expected b/tests/dbus/connection_server.c-expected
index 561a66db63c3f4f0..16d2f1f7d9e33147 100644
--- a/tests/dbus/connection_server.c-expected
+++ b/tests/dbus/connection_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_connection_server.c generated by valac, the Vala compiler
  * generated from dbus_connection_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/dicts_client.c-expected b/tests/dbus/dicts_client.c-expected
index ad7130d8fa2805f6..712982cfd285f645 100644
--- a/tests/dbus/dicts_client.c-expected
+++ b/tests/dbus/dicts_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_dicts_client.c generated by valac, the Vala compiler
  * generated from dbus_dicts_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/dicts_server.c-expected b/tests/dbus/dicts_server.c-expected
index 1e22e2c83d65aef0..768f4c9984dde5dc 100644
--- a/tests/dbus/dicts_server.c-expected
+++ b/tests/dbus/dicts_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_dicts_server.c generated by valac, the Vala compiler
  * generated from dbus_dicts_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/dynamic-method_client.c-expected b/tests/dbus/dynamic-method_client.c-expected
index d06bec69df7cbdbf..d22d2a4a72982e45 100644
--- a/tests/dbus/dynamic-method_client.c-expected
+++ b/tests/dbus/dynamic-method_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_dynamic_method_client.c generated by valac, the Vala compiler
  * generated from dbus_dynamic_method_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/dbus/dynamic-method_server.c-expected b/tests/dbus/dynamic-method_server.c-expected
index 926a5b25d4253b90..b6a88ab11d99ba38 100644
--- a/tests/dbus/dynamic-method_server.c-expected
+++ b/tests/dbus/dynamic-method_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_dynamic_method_server.c generated by valac, the Vala compiler
  * generated from dbus_dynamic_method_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/enum-string-marshalling.c-expected b/tests/dbus/enum-string-marshalling.c-expected
index 2694775d2e605413..aeebe82b12456a67 100644
--- a/tests/dbus/enum-string-marshalling.c-expected
+++ b/tests/dbus/enum-string-marshalling.c-expected
@@ -1,6 +1,12 @@
 /* dbus_enum_string_marshalling.c generated by valac, the Vala compiler
  * generated from dbus_enum_string_marshalling.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <string.h>
 #include <gio/gio.h>
diff --git a/tests/dbus/errors_client.c-expected b/tests/dbus/errors_client.c-expected
index a7c9fdd65391167c..877a1e10bf7f211a 100644
--- a/tests/dbus/errors_client.c-expected
+++ b/tests/dbus/errors_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_errors_client.c generated by valac, the Vala compiler
  * generated from dbus_errors_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/dbus/errors_server.c-expected b/tests/dbus/errors_server.c-expected
index 26e66c8e1610170b..3793364e6e11d8cb 100644
--- a/tests/dbus/errors_server.c-expected
+++ b/tests/dbus/errors_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_errors_server.c generated by valac, the Vala compiler
  * generated from dbus_errors_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/dbus/filedescriptor-async_client.c-expected b/tests/dbus/filedescriptor-async_client.c-expected
index b458ecf0236eff1f..1ea926aec10e38d1 100644
--- a/tests/dbus/filedescriptor-async_client.c-expected
+++ b/tests/dbus/filedescriptor-async_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_filedescriptor_async_client.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_async_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/filedescriptor-async_server.c-expected b/tests/dbus/filedescriptor-async_server.c-expected
index 5c9aa9720580f798..1e60dcb9f0e1a583 100644
--- a/tests/dbus/filedescriptor-async_server.c-expected
+++ b/tests/dbus/filedescriptor-async_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_filedescriptor_async_server.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_async_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/filedescriptor-errors_client.c-expected b/tests/dbus/filedescriptor-errors_client.c-expected
index 13e5b50bcc33731a..aff0f2ec2b4df091 100644
--- a/tests/dbus/filedescriptor-errors_client.c-expected
+++ b/tests/dbus/filedescriptor-errors_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_filedescriptor_errors_client.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_errors_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixoutputstream.h>
diff --git a/tests/dbus/filedescriptor-errors_server.c-expected b/tests/dbus/filedescriptor-errors_server.c-expected
index 23c14621b96289fc..12f322f896557c1c 100644
--- a/tests/dbus/filedescriptor-errors_server.c-expected
+++ b/tests/dbus/filedescriptor-errors_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_filedescriptor_errors_server.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_errors_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixoutputstream.h>
diff --git a/tests/dbus/filedescriptor_client.c-expected b/tests/dbus/filedescriptor_client.c-expected
index 1a3a8473af911e4f..999aecbad49f2667 100644
--- a/tests/dbus/filedescriptor_client.c-expected
+++ b/tests/dbus/filedescriptor_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_filedescriptor_client.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/filedescriptor_server.c-expected b/tests/dbus/filedescriptor_server.c-expected
index 4ff455497db9f800..b03b2042a363dcd2 100644
--- a/tests/dbus/filedescriptor_server.c-expected
+++ b/tests/dbus/filedescriptor_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_filedescriptor_server.c generated by valac, the Vala compiler
  * generated from dbus_filedescriptor_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gio/gunixinputstream.h>
diff --git a/tests/dbus/generics_client.c-expected b/tests/dbus/generics_client.c-expected
index 358753685b1a7dab..c614bd30494b79d7 100644
--- a/tests/dbus/generics_client.c-expected
+++ b/tests/dbus/generics_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_generics_client.c generated by valac, the Vala compiler
  * generated from dbus_generics_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/generics_server.c-expected b/tests/dbus/generics_server.c-expected
index e7b173f862445d09..66cc934631414b8f 100644
--- a/tests/dbus/generics_server.c-expected
+++ b/tests/dbus/generics_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_generics_server.c generated by valac, the Vala compiler
  * generated from dbus_generics_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/interface-info_client.c-expected b/tests/dbus/interface-info_client.c-expected
index 3822e2dc3db23a52..95197a65a67eca4a 100644
--- a/tests/dbus/interface-info_client.c-expected
+++ b/tests/dbus/interface-info_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_interface_info_client.c generated by valac, the Vala compiler
  * generated from dbus_interface_info_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/interface-info_server.c-expected b/tests/dbus/interface-info_server.c-expected
index a23553fda0a8b212..ea07f746d89e3080 100644
--- a/tests/dbus/interface-info_server.c-expected
+++ b/tests/dbus/interface-info_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_interface_info_server.c generated by valac, the Vala compiler
  * generated from dbus_interface_info_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/no-reply_client.c-expected b/tests/dbus/no-reply_client.c-expected
index 354f61cbb5a4abfd..d572b24c7eee08a9 100644
--- a/tests/dbus/no-reply_client.c-expected
+++ b/tests/dbus/no-reply_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_no_reply_client.c generated by valac, the Vala compiler
  * generated from dbus_no_reply_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/no-reply_server.c-expected b/tests/dbus/no-reply_server.c-expected
index c1f2584a7ac08fad..2bbde458ac7d3350 100644
--- a/tests/dbus/no-reply_server.c-expected
+++ b/tests/dbus/no-reply_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_no_reply_server.c generated by valac, the Vala compiler
  * generated from dbus_no_reply_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/rawvariants_client.c-expected b/tests/dbus/rawvariants_client.c-expected
index 801109028e7ff8c9..9980cd700b585563 100644
--- a/tests/dbus/rawvariants_client.c-expected
+++ b/tests/dbus/rawvariants_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_rawvariants_client.c generated by valac, the Vala compiler
  * generated from dbus_rawvariants_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/rawvariants_server.c-expected b/tests/dbus/rawvariants_server.c-expected
index ec24125dec74f462..c7b63a83177a7ee3 100644
--- a/tests/dbus/rawvariants_server.c-expected
+++ b/tests/dbus/rawvariants_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_rawvariants_server.c generated by valac, the Vala compiler
  * generated from dbus_rawvariants_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/dbus/signals_client.c-expected b/tests/dbus/signals_client.c-expected
index 9442943e9f199bc6..1c4823e8e1451780 100644
--- a/tests/dbus/signals_client.c-expected
+++ b/tests/dbus/signals_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_signals_client.c generated by valac, the Vala compiler
  * generated from dbus_signals_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/signals_server.c-expected b/tests/dbus/signals_server.c-expected
index 9f9c78102a118dfb..18b9ca64c452aba4 100644
--- a/tests/dbus/signals_server.c-expected
+++ b/tests/dbus/signals_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_signals_server.c generated by valac, the Vala compiler
  * generated from dbus_signals_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/dbus/structs_client.c-expected b/tests/dbus/structs_client.c-expected
index 00223fea23f074cb..947499a798f8e26f 100644
--- a/tests/dbus/structs_client.c-expected
+++ b/tests/dbus/structs_client.c-expected
@@ -1,6 +1,12 @@
 /* dbus_structs_client.c generated by valac, the Vala compiler
  * generated from dbus_structs_client.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/dbus/structs_server.c-expected b/tests/dbus/structs_server.c-expected
index 83250e523481f0dd..cffc53470942610f 100644
--- a/tests/dbus/structs_server.c-expected
+++ b/tests/dbus/structs_server.c-expected
@@ -1,6 +1,12 @@
 /* dbus_structs_server.c generated by valac, the Vala compiler
  * generated from dbus_structs_server.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/delegates/bug539166.c-expected b/tests/delegates/bug539166.c-expected
index c335a36fe367d0f3..d4b887c70edcf130 100644
--- a/tests/delegates/bug539166.c-expected
+++ b/tests/delegates/bug539166.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug539166.c generated by valac, the Vala compiler
  * generated from delegates_bug539166.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/bug595610.c-expected b/tests/delegates/bug595610.c-expected
index 898b76b6554f8da3..0393ce01e8992864 100644
--- a/tests/delegates/bug595610.c-expected
+++ b/tests/delegates/bug595610.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug595610.c generated by valac, the Vala compiler
  * generated from delegates_bug595610.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/delegates/bug595639.c-expected b/tests/delegates/bug595639.c-expected
index c39528bf71099ad8..da4ba363e2326d46 100644
--- a/tests/delegates/bug595639.c-expected
+++ b/tests/delegates/bug595639.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug595639.c generated by valac, the Vala compiler
  * generated from delegates_bug595639.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/bug638415.c-expected b/tests/delegates/bug638415.c-expected
index 367a2cc95866c1a1..87fb6470098db9a8 100644
--- a/tests/delegates/bug638415.c-expected
+++ b/tests/delegates/bug638415.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug638415.c generated by valac, the Vala compiler
  * generated from delegates_bug638415.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/bug639751.c-expected b/tests/delegates/bug639751.c-expected
index b0586a6fd8b692da..d6e936c2391cbaf2 100644
--- a/tests/delegates/bug639751.c-expected
+++ b/tests/delegates/bug639751.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug639751.c generated by valac, the Vala compiler
  * generated from delegates_bug639751.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/delegates/bug659778.c-expected b/tests/delegates/bug659778.c-expected
index 135d5f436788990a..3c5bf1adbecbf554 100644
--- a/tests/delegates/bug659778.c-expected
+++ b/tests/delegates/bug659778.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug659778.c generated by valac, the Vala compiler
  * generated from delegates_bug659778.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/delegates/bug683925.c-expected b/tests/delegates/bug683925.c-expected
index cc747164a02b82ce..91410040bf2a59ae 100644
--- a/tests/delegates/bug683925.c-expected
+++ b/tests/delegates/bug683925.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug683925.c generated by valac, the Vala compiler
  * generated from delegates_bug683925.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/bug703804.c-expected b/tests/delegates/bug703804.c-expected
index b26578a3b75a54c3..745d8a130366e976 100644
--- a/tests/delegates/bug703804.c-expected
+++ b/tests/delegates/bug703804.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug703804.c generated by valac, the Vala compiler
  * generated from delegates_bug703804.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/bug761360.c-expected b/tests/delegates/bug761360.c-expected
index f180a86d7dc31ad8..659e581881b20940 100644
--- a/tests/delegates/bug761360.c-expected
+++ b/tests/delegates/bug761360.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug761360.c generated by valac, the Vala compiler
  * generated from delegates_bug761360.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 typedef gint* (*ArrayReturnFunc) (gint* result_length1, gpointer user_data);
diff --git a/tests/delegates/bug792077.c-expected b/tests/delegates/bug792077.c-expected
index 5abd863a4855d215..7e56c5d26c8ff0cf 100644
--- a/tests/delegates/bug792077.c-expected
+++ b/tests/delegates/bug792077.c-expected
@@ -1,6 +1,12 @@
 /* delegates_bug792077.c generated by valac, the Vala compiler
  * generated from delegates_bug792077.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/casting.c-expected b/tests/delegates/casting.c-expected
index fe15b7acfe2323a6..ea0679b630b701a1 100644
--- a/tests/delegates/casting.c-expected
+++ b/tests/delegates/casting.c-expected
@@ -1,6 +1,12 @@
 /* delegates_casting.c generated by valac, the Vala compiler
  * generated from delegates_casting.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/class-field-initializer.c-expected b/tests/delegates/class-field-initializer.c-expected
index c2113884885af971..034cef9b699cc430 100644
--- a/tests/delegates/class-field-initializer.c-expected
+++ b/tests/delegates/class-field-initializer.c-expected
@@ -1,6 +1,12 @@
 /* delegates_class_field_initializer.c generated by valac, the Vala compiler
  * generated from delegates_class_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/compatible.c-expected b/tests/delegates/compatible.c-expected
index 3eaecad79c84c616..c4af48275a6248d6 100644
--- a/tests/delegates/compatible.c-expected
+++ b/tests/delegates/compatible.c-expected
@@ -1,6 +1,12 @@
 /* delegates_compatible.c generated by valac, the Vala compiler
  * generated from delegates_compatible.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/delegate-recusive.c-expected b/tests/delegates/delegate-recusive.c-expected
index fcafb34a5dab1898..163094aea9e2d30e 100644
--- a/tests/delegates/delegate-recusive.c-expected
+++ b/tests/delegates/delegate-recusive.c-expected
@@ -1,6 +1,12 @@
 /* delegates_delegate_recusive.c generated by valac, the Vala compiler
  * generated from delegates_delegate_recusive.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/delegates/delegate_only.c-expected b/tests/delegates/delegate_only.c-expected
index dfcf7a5d2df10fa0..20efb32b52fce493 100644
--- a/tests/delegates/delegate_only.c-expected
+++ b/tests/delegates/delegate_only.c-expected
@@ -1,6 +1,12 @@
 /* delegates_delegate_only.c generated by valac, the Vala compiler
  * generated from delegates_delegate_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 typedef void (*FooFunc) (gpointer user_data);
diff --git a/tests/delegates/delegates.c-expected b/tests/delegates/delegates.c-expected
index 06d31b398b22f6b2..ae82b1a6d2a5753b 100644
--- a/tests/delegates/delegates.c-expected
+++ b/tests/delegates/delegates.c-expected
@@ -1,6 +1,12 @@
 /* delegates_delegates.c generated by valac, the Vala compiler
  * generated from delegates_delegates.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/delegates/error-pos.c-expected b/tests/delegates/error-pos.c-expected
index 9a4a338f754ae637..5eed68bf265882aa 100644
--- a/tests/delegates/error-pos.c-expected
+++ b/tests/delegates/error-pos.c-expected
@@ -1,6 +1,12 @@
 /* delegates_error_pos.c generated by valac, the Vala compiler
  * generated from delegates_error_pos.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/delegates/fields-no-target.c-expected b/tests/delegates/fields-no-target.c-expected
index d065ea232c78868c..5c4b8a61cb96d215 100644
--- a/tests/delegates/fields-no-target.c-expected
+++ b/tests/delegates/fields-no-target.c-expected
@@ -1,6 +1,12 @@
 /* delegates_fields_no_target.c generated by valac, the Vala compiler
  * generated from delegates_fields_no_target.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <string.h>
diff --git a/tests/delegates/fields.c-expected b/tests/delegates/fields.c-expected
index 3b4ae26fc8bb8ccd..826066c773d223c4 100644
--- a/tests/delegates/fields.c-expected
+++ b/tests/delegates/fields.c-expected
@@ -1,6 +1,12 @@
 /* delegates_fields.c generated by valac, the Vala compiler
  * generated from delegates_fields.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/gclosure-conversion.c-expected b/tests/delegates/gclosure-conversion.c-expected
index 916299d7c6d64772..6e1785f99c60350b 100644
--- a/tests/delegates/gclosure-conversion.c-expected
+++ b/tests/delegates/gclosure-conversion.c-expected
@@ -1,6 +1,12 @@
 /* delegates_gclosure_conversion.c generated by valac, the Vala compiler
  * generated from delegates_gclosure_conversion.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/delegates/implicit-local-variable.c-expected b/tests/delegates/implicit-local-variable.c-expected
index 48922109698f1f3f..38ab0b668eddaa48 100644
--- a/tests/delegates/implicit-local-variable.c-expected
+++ b/tests/delegates/implicit-local-variable.c-expected
@@ -1,6 +1,12 @@
 /* delegates_implicit_local_variable.c generated by valac, the Vala compiler
  * generated from delegates_implicit_local_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 typedef gboolean (*GSourceDispatchFunc) (GSource* source, GSourceFunc _callback, gpointer _callback_target);
diff --git a/tests/delegates/lambda-mixed-instance-static.c-expected b/tests/delegates/lambda-mixed-instance-static.c-expected
index 1beb45a964aeef21..9cddc6fcb210056c 100644
--- a/tests/delegates/lambda-mixed-instance-static.c-expected
+++ b/tests/delegates/lambda-mixed-instance-static.c-expected
@@ -1,6 +1,12 @@
 /* delegates_lambda_mixed_instance_static.c generated by valac, the Vala compiler
  * generated from delegates_lambda_mixed_instance_static.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/delegates/lambda-shared-closure.c-expected b/tests/delegates/lambda-shared-closure.c-expected
index 7d99502c3d6bebbf..3144bcf15d43c1c5 100644
--- a/tests/delegates/lambda-shared-closure.c-expected
+++ b/tests/delegates/lambda-shared-closure.c-expected
@@ -1,6 +1,12 @@
 /* delegates_lambda_shared_closure.c generated by valac, the Vala compiler
  * generated from delegates_lambda_shared_closure.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/delegates/member-target-destroy-2.c-expected b/tests/delegates/member-target-destroy-2.c-expected
index 17b11e2237fd0247..ae4556711d08a858 100644
--- a/tests/delegates/member-target-destroy-2.c-expected
+++ b/tests/delegates/member-target-destroy-2.c-expected
@@ -1,6 +1,12 @@
 /* delegates_member_target_destroy_2.c generated by valac, the Vala compiler
  * generated from delegates_member_target_destroy_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/delegates/member-target-destroy.c-expected b/tests/delegates/member-target-destroy.c-expected
index 0fd0ff7146d6eb56..8c0f4c09dc927e38 100644
--- a/tests/delegates/member-target-destroy.c-expected
+++ b/tests/delegates/member-target-destroy.c-expected
@@ -1,6 +1,12 @@
 /* delegates_member_target_destroy.c generated by valac, the Vala compiler
  * generated from delegates_member_target_destroy.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/params-array-with-throws.c-expected b/tests/delegates/params-array-with-throws.c-expected
index 024eed82b7d03c78..00ae9aa1cf19994e 100644
--- a/tests/delegates/params-array-with-throws.c-expected
+++ b/tests/delegates/params-array-with-throws.c-expected
@@ -1,6 +1,12 @@
 /* delegates_params_array_with_throws.c generated by valac, the Vala compiler
  * generated from delegates_params_array_with_throws.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/delegates/params-array.c-expected b/tests/delegates/params-array.c-expected
index 701827b18ef5bd44..de5ac49ccf4d9d3e 100644
--- a/tests/delegates/params-array.c-expected
+++ b/tests/delegates/params-array.c-expected
@@ -1,6 +1,12 @@
 /* delegates_params_array.c generated by valac, the Vala compiler
  * generated from delegates_params_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/reference_transfer.c-expected b/tests/delegates/reference_transfer.c-expected
index 9a8d00e42de53097..4c4b81d4f8c38ee0 100644
--- a/tests/delegates/reference_transfer.c-expected
+++ b/tests/delegates/reference_transfer.c-expected
@@ -1,6 +1,12 @@
 /* delegates_reference_transfer.c generated by valac, the Vala compiler
  * generated from delegates_reference_transfer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/delegates/return-array-null-terminated.c-expected b/tests/delegates/return-array-null-terminated.c-expected
index 4a89bb8f973914d7..e79b0620fe36ea18 100644
--- a/tests/delegates/return-array-null-terminated.c-expected
+++ b/tests/delegates/return-array-null-terminated.c-expected
@@ -1,6 +1,12 @@
 /* delegates_return_array_null_terminated.c generated by valac, the Vala compiler
  * generated from delegates_return_array_null_terminated.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/variadic.c-expected b/tests/delegates/variadic.c-expected
index e390cc4567cc8c98..43e1e2a520cd7582 100644
--- a/tests/delegates/variadic.c-expected
+++ b/tests/delegates/variadic.c-expected
@@ -1,6 +1,12 @@
 /* delegates_variadic.c generated by valac, the Vala compiler
  * generated from delegates_variadic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/delegates/wrapper.c-expected b/tests/delegates/wrapper.c-expected
index 361445eccbd10e99..686a22df86977012 100644
--- a/tests/delegates/wrapper.c-expected
+++ b/tests/delegates/wrapper.c-expected
@@ -1,6 +1,12 @@
 /* delegates_wrapper.c generated by valac, the Vala compiler
  * generated from delegates_wrapper.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/enums/bug614424.c-expected b/tests/enums/bug614424.c-expected
index 70268aa83cae8768..1fe79ae50fc2aa69 100644
--- a/tests/enums/bug614424.c-expected
+++ b/tests/enums/bug614424.c-expected
@@ -1,6 +1,12 @@
 /* enums_bug614424.c generated by valac, the Vala compiler
  * generated from enums_bug614424.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/enums/bug666035.c-expected b/tests/enums/bug666035.c-expected
index cbc78c93b3634896..aaef3f32a9e37f82 100644
--- a/tests/enums/bug666035.c-expected
+++ b/tests/enums/bug666035.c-expected
@@ -1,6 +1,12 @@
 /* enums_bug666035.c generated by valac, the Vala compiler
  * generated from enums_bug666035.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/enums/bug673879.c-expected b/tests/enums/bug673879.c-expected
index 98853ff129eb8d04..5ef94b5e91020d54 100644
--- a/tests/enums/bug673879.c-expected
+++ b/tests/enums/bug673879.c-expected
@@ -1,6 +1,12 @@
 /* enums_bug673879.c generated by valac, the Vala compiler
  * generated from enums_bug673879.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/enums/bug763831.c-expected b/tests/enums/bug763831.c-expected
index 94bdf4ed5f7676a2..b17592a19126520a 100644
--- a/tests/enums/bug763831.c-expected
+++ b/tests/enums/bug763831.c-expected
@@ -1,6 +1,12 @@
 /* enums_bug763831.c generated by valac, the Vala compiler
  * generated from enums_bug763831.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/bug780050.c-expected b/tests/enums/bug780050.c-expected
index a9f1f51e61cca1e1..8f12e24b4db9bcaf 100644
--- a/tests/enums/bug780050.c-expected
+++ b/tests/enums/bug780050.c-expected
@@ -1,6 +1,12 @@
 /* enums_bug780050.c generated by valac, the Vala compiler
  * generated from enums_bug780050.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/default-gtype.c-expected b/tests/enums/default-gtype.c-expected
index 41b4b2970913c337..a357fd4ae123080f 100644
--- a/tests/enums/default-gtype.c-expected
+++ b/tests/enums/default-gtype.c-expected
@@ -1,6 +1,12 @@
 /* enums_default_gtype.c generated by valac, the Vala compiler
  * generated from enums_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/enums/enum-boxed.c-expected b/tests/enums/enum-boxed.c-expected
index 56ed9339ce382205..6de8802c27952296 100644
--- a/tests/enums/enum-boxed.c-expected
+++ b/tests/enums/enum-boxed.c-expected
@@ -1,6 +1,12 @@
 /* enums_enum_boxed.c generated by valac, the Vala compiler
  * generated from enums_enum_boxed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/enums/enum-no-gtype.c-expected b/tests/enums/enum-no-gtype.c-expected
index c2a05e86dc3fe5ab..da39fcc9304f92b9 100644
--- a/tests/enums/enum-no-gtype.c-expected
+++ b/tests/enums/enum-no-gtype.c-expected
@@ -1,6 +1,12 @@
 /* enums_enum_no_gtype.c generated by valac, the Vala compiler
  * generated from enums_enum_no_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 typedef enum  {
 	FOO_BAR,
 	FOO_BAZ
diff --git a/tests/enums/enum_only.c-expected b/tests/enums/enum_only.c-expected
index 9162eace41e48f56..75dedf8663517afb 100644
--- a/tests/enums/enum_only.c-expected
+++ b/tests/enums/enum_only.c-expected
@@ -1,6 +1,12 @@
 /* enums_enum_only.c generated by valac, the Vala compiler
  * generated from enums_enum_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/enums.c-expected b/tests/enums/enums.c-expected
index a6594015bb5723ed..a1a7632a29bf9455 100644
--- a/tests/enums/enums.c-expected
+++ b/tests/enums/enums.c-expected
@@ -1,6 +1,12 @@
 /* enums_enums.c generated by valac, the Vala compiler
  * generated from enums_enums.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/enums/flags.c-expected b/tests/enums/flags.c-expected
index d44b84f8989d0c7e..cd6d2265b0ceb4d1 100644
--- a/tests/enums/flags.c-expected
+++ b/tests/enums/flags.c-expected
@@ -1,6 +1,12 @@
 /* enums_flags.c generated by valac, the Vala compiler
  * generated from enums_flags.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/enums/from-0-literal.c-expected b/tests/enums/from-0-literal.c-expected
index e06f40799839cf7c..0b4dc5730269f33b 100644
--- a/tests/enums/from-0-literal.c-expected
+++ b/tests/enums/from-0-literal.c-expected
@@ -1,6 +1,12 @@
 /* enums_from_0_literal.c generated by valac, the Vala compiler
  * generated from enums_from_0_literal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/enums/in-inference.c-expected b/tests/enums/in-inference.c-expected
index c859a06765afde86..1c92a907afd8843b 100644
--- a/tests/enums/in-inference.c-expected
+++ b/tests/enums/in-inference.c-expected
@@ -1,6 +1,12 @@
 /* enums_in_inference.c generated by valac, the Vala compiler
  * generated from enums_in_inference.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/enums/no_gtype_to_string.c-expected b/tests/enums/no_gtype_to_string.c-expected
index 89201fa8b705cb48..b405241079236ee5 100644
--- a/tests/enums/no_gtype_to_string.c-expected
+++ b/tests/enums/no_gtype_to_string.c-expected
@@ -1,6 +1,12 @@
 /* enums_no_gtype_to_string.c generated by valac, the Vala compiler
  * generated from enums_no_gtype_to_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/enums/switch.c-expected b/tests/enums/switch.c-expected
index 91c674d3b4530112..932c73fc55cb672c 100644
--- a/tests/enums/switch.c-expected
+++ b/tests/enums/switch.c-expected
@@ -1,6 +1,12 @@
 /* enums_switch.c generated by valac, the Vala compiler
  * generated from enums_switch.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/enums/unsafe-assignment.c-expected b/tests/enums/unsafe-assignment.c-expected
index ba8ac7084bb1fc47..7677bd425085f032 100644
--- a/tests/enums/unsafe-assignment.c-expected
+++ b/tests/enums/unsafe-assignment.c-expected
@@ -1,6 +1,12 @@
 /* enums_unsafe_assignment.c generated by valac, the Vala compiler
  * generated from enums_unsafe_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/errors/bug567181.c-expected b/tests/errors/bug567181.c-expected
index b2af28b59344a39a..8f035939a081129e 100644
--- a/tests/errors/bug567181.c-expected
+++ b/tests/errors/bug567181.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug567181.c generated by valac, the Vala compiler
  * generated from errors_bug567181.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/bug579101.c-expected b/tests/errors/bug579101.c-expected
index ea1a7f7773ee35ff..b67d3366252904b5 100644
--- a/tests/errors/bug579101.c-expected
+++ b/tests/errors/bug579101.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug579101.c generated by valac, the Vala compiler
  * generated from errors_bug579101.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/bug596228.c-expected b/tests/errors/bug596228.c-expected
index 11172b49d9fb4532..6afc32e984752f9e 100644
--- a/tests/errors/bug596228.c-expected
+++ b/tests/errors/bug596228.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug596228.c generated by valac, the Vala compiler
  * generated from errors_bug596228.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/errors/bug623049.c-expected b/tests/errors/bug623049.c-expected
index f7a79c44ae780dce..0acf4be1cdd76d60 100644
--- a/tests/errors/bug623049.c-expected
+++ b/tests/errors/bug623049.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug623049.c generated by valac, the Vala compiler
  * generated from errors_bug623049.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/bug627090.c-expected b/tests/errors/bug627090.c-expected
index 6ad044d7ecb2848b..3b7245cc4ee7ce1c 100644
--- a/tests/errors/bug627090.c-expected
+++ b/tests/errors/bug627090.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug627090.c generated by valac, the Vala compiler
  * generated from errors_bug627090.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/errors/bug639589.c-expected b/tests/errors/bug639589.c-expected
index f3e3c8212971f222..6260b4fbe8e9e752 100644
--- a/tests/errors/bug639589.c-expected
+++ b/tests/errors/bug639589.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug639589.c generated by valac, the Vala compiler
  * generated from errors_bug639589.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/bug651145.c-expected b/tests/errors/bug651145.c-expected
index 484bf6432d247dbb..ebd7ad361ed4e85c 100644
--- a/tests/errors/bug651145.c-expected
+++ b/tests/errors/bug651145.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug651145.c generated by valac, the Vala compiler
  * generated from errors_bug651145.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/errors/bug762377.c-expected b/tests/errors/bug762377.c-expected
index dfb878ef77879476..555fa093d1ebf2d5 100644
--- a/tests/errors/bug762377.c-expected
+++ b/tests/errors/bug762377.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug762377.c generated by valac, the Vala compiler
  * generated from errors_bug762377.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/errors/bug778224.c-expected b/tests/errors/bug778224.c-expected
index 8f0e3c06d3134e24..b79c21e87f2e4b63 100644
--- a/tests/errors/bug778224.c-expected
+++ b/tests/errors/bug778224.c-expected
@@ -1,6 +1,12 @@
 /* errors_bug778224.c generated by valac, the Vala compiler
  * generated from errors_bug778224.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/catch-error-code.c-expected b/tests/errors/catch-error-code.c-expected
index 7e8c9a55f5e6d027..d494a5abeac8df31 100644
--- a/tests/errors/catch-error-code.c-expected
+++ b/tests/errors/catch-error-code.c-expected
@@ -1,6 +1,12 @@
 /* errors_catch_error_code.c generated by valac, the Vala compiler
  * generated from errors_catch_error_code.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/catch-in-finally.c-expected b/tests/errors/catch-in-finally.c-expected
index 299b83db10c9dc4e..163a3f2917be9b5a 100644
--- a/tests/errors/catch-in-finally.c-expected
+++ b/tests/errors/catch-in-finally.c-expected
@@ -1,6 +1,12 @@
 /* errors_catch_in_finally.c generated by valac, the Vala compiler
  * generated from errors_catch_in_finally.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/default-gtype.c-expected b/tests/errors/default-gtype.c-expected
index eba50fda8633b707..3afb99ecb6f8b762 100644
--- a/tests/errors/default-gtype.c-expected
+++ b/tests/errors/default-gtype.c-expected
@@ -1,6 +1,12 @@
 /* errors_default_gtype.c generated by valac, the Vala compiler
  * generated from errors_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/delegate-throws-error-code.c-expected b/tests/errors/delegate-throws-error-code.c-expected
index 9848b053513e030e..8e9e293e0945a787 100644
--- a/tests/errors/delegate-throws-error-code.c-expected
+++ b/tests/errors/delegate-throws-error-code.c-expected
@@ -1,6 +1,12 @@
 /* errors_delegate_throws_error_code.c generated by valac, the Vala compiler
  * generated from errors_delegate_throws_error_code.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/errorcode.c-expected b/tests/errors/errorcode.c-expected
index 785b8565a977f55b..a68cddac2679003a 100644
--- a/tests/errors/errorcode.c-expected
+++ b/tests/errors/errorcode.c-expected
@@ -1,6 +1,12 @@
 /* errors_errorcode.c generated by valac, the Vala compiler
  * generated from errors_errorcode.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gio/gio.h>
diff --git a/tests/errors/errordomain-static-method.c-expected b/tests/errors/errordomain-static-method.c-expected
index e18a5f395fb32243..8cb3f61e31c43a91 100644
--- a/tests/errors/errordomain-static-method.c-expected
+++ b/tests/errors/errordomain-static-method.c-expected
@@ -1,6 +1,12 @@
 /* errors_errordomain_static_method.c generated by valac, the Vala compiler
  * generated from errors_errordomain_static_method.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/errordomain.c-expected b/tests/errors/errordomain.c-expected
index 1f18ffcdd21427a9..1259eb7b37d253da 100644
--- a/tests/errors/errordomain.c-expected
+++ b/tests/errors/errordomain.c-expected
@@ -1,6 +1,12 @@
 /* errors_errordomain.c generated by valac, the Vala compiler
  * generated from errors_errordomain.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/errors.c-expected b/tests/errors/errors.c-expected
index d7574a03d1a49d87..84201f4bbd1f463b 100644
--- a/tests/errors/errors.c-expected
+++ b/tests/errors/errors.c-expected
@@ -1,6 +1,12 @@
 /* errors_errors.c generated by valac, the Vala compiler
  * generated from errors_errors.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdio.h>
diff --git a/tests/errors/loops.c-expected b/tests/errors/loops.c-expected
index 605ac4389d232e8a..5ca5c854d3d9ce43 100644
--- a/tests/errors/loops.c-expected
+++ b/tests/errors/loops.c-expected
@@ -1,6 +1,12 @@
 /* errors_loops.c generated by valac, the Vala compiler
  * generated from errors_loops.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/errors/method-throws-error-code.c-expected b/tests/errors/method-throws-error-code.c-expected
index 90ab3eb95194f691..2bc86715ffffeff3 100644
--- a/tests/errors/method-throws-error-code.c-expected
+++ b/tests/errors/method-throws-error-code.c-expected
@@ -1,6 +1,12 @@
 /* errors_method_throws_error_code.c generated by valac, the Vala compiler
  * generated from errors_method_throws_error_code.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/errors/method-throws.c-expected b/tests/errors/method-throws.c-expected
index 146c6bceb97f6db3..c4cad08ac525ea69 100644
--- a/tests/errors/method-throws.c-expected
+++ b/tests/errors/method-throws.c-expected
@@ -1,6 +1,12 @@
 /* errors_method_throws.c generated by valac, the Vala compiler
  * generated from errors_method_throws.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/errors/unhandled.c-expected b/tests/errors/unhandled.c-expected
index c5e670413d54b9af..47631b00d307c7db 100644
--- a/tests/errors/unhandled.c-expected
+++ b/tests/errors/unhandled.c-expected
@@ -1,6 +1,12 @@
 /* errors_unhandled.c generated by valac, the Vala compiler
  * generated from errors_unhandled.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/generics/arrays.c-expected b/tests/generics/arrays.c-expected
index 157f22f429c455d7..2da2ffe1627c7fd6 100644
--- a/tests/generics/arrays.c-expected
+++ b/tests/generics/arrays.c-expected
@@ -1,6 +1,12 @@
 /* generics_arrays.c generated by valac, the Vala compiler
  * generated from generics_arrays.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/bug640330.c-expected b/tests/generics/bug640330.c-expected
index 1c29f40cf49a596c..1a31cd733c9d9240 100644
--- a/tests/generics/bug640330.c-expected
+++ b/tests/generics/bug640330.c-expected
@@ -1,6 +1,12 @@
 /* generics_bug640330.c generated by valac, the Vala compiler
  * generated from generics_bug640330.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/bug694765-1.c-expected b/tests/generics/bug694765-1.c-expected
index 221bd42fce3f3045..292a90d12f88c843 100644
--- a/tests/generics/bug694765-1.c-expected
+++ b/tests/generics/bug694765-1.c-expected
@@ -1,6 +1,12 @@
 /* generics_bug694765_1.c generated by valac, the Vala compiler
  * generated from generics_bug694765_1.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/bug694765-2.c-expected b/tests/generics/bug694765-2.c-expected
index 1cf5dba069cb9b07..d65814bbbd464df4 100644
--- a/tests/generics/bug694765-2.c-expected
+++ b/tests/generics/bug694765-2.c-expected
@@ -1,6 +1,12 @@
 /* generics_bug694765_2.c generated by valac, the Vala compiler
  * generated from generics_bug694765_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/generics/bug694765-3.c-expected b/tests/generics/bug694765-3.c-expected
index 5dfd97d33cf5954f..adb2525d208b0ef3 100644
--- a/tests/generics/bug694765-3.c-expected
+++ b/tests/generics/bug694765-3.c-expected
@@ -1,6 +1,12 @@
 /* generics_bug694765_3.c generated by valac, the Vala compiler
  * generated from generics_bug694765_3.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/class-property-override.c-expected b/tests/generics/class-property-override.c-expected
index 02e626ac627166f4..0e91b2fce29ddb82 100644
--- a/tests/generics/class-property-override.c-expected
+++ b/tests/generics/class-property-override.c-expected
@@ -1,6 +1,12 @@
 /* generics_class_property_override.c generated by valac, the Vala compiler
  * generated from generics_class_property_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/constructor-chain-up.c-expected b/tests/generics/constructor-chain-up.c-expected
index 32a0cef0294ecd5f..b627d80044fcfb3e 100644
--- a/tests/generics/constructor-chain-up.c-expected
+++ b/tests/generics/constructor-chain-up.c-expected
@@ -1,6 +1,12 @@
 /* generics_constructor_chain_up.c generated by valac, the Vala compiler
  * generated from generics_constructor_chain_up.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/floating-type-cast.c-expected b/tests/generics/floating-type-cast.c-expected
index 405a376d9896f400..350acc9107807559 100644
--- a/tests/generics/floating-type-cast.c-expected
+++ b/tests/generics/floating-type-cast.c-expected
@@ -1,6 +1,12 @@
 /* generics_floating_type_cast.c generated by valac, the Vala compiler
  * generated from generics_floating_type_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <float.h>
diff --git a/tests/generics/inference-argument-may-fail.c-expected b/tests/generics/inference-argument-may-fail.c-expected
index f4d91abd68f681d1..58ab1817e1b6d384 100644
--- a/tests/generics/inference-argument-may-fail.c-expected
+++ b/tests/generics/inference-argument-may-fail.c-expected
@@ -1,6 +1,12 @@
 /* generics_inference_argument_may_fail.c generated by valac, the Vala compiler
  * generated from generics_inference_argument_may_fail.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/inference-static-function.c-expected b/tests/generics/inference-static-function.c-expected
index 25ac2348e13579dc..3062771c4fd30add 100644
--- a/tests/generics/inference-static-function.c-expected
+++ b/tests/generics/inference-static-function.c-expected
@@ -1,6 +1,12 @@
 /* generics_inference_static_function.c generated by valac, the Vala compiler
  * generated from generics_inference_static_function.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/integer-member-access.c-expected b/tests/generics/integer-member-access.c-expected
index 19e803fa45be5934..9d9a8eb92a6e4a1d 100644
--- a/tests/generics/integer-member-access.c-expected
+++ b/tests/generics/integer-member-access.c-expected
@@ -1,6 +1,12 @@
 /* generics_integer_member_access.c generated by valac, the Vala compiler
  * generated from generics_integer_member_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/generics/integer-type-cast-return.c-expected b/tests/generics/integer-type-cast-return.c-expected
index 47e1ae95cdd5771a..8efeaefd6f05c9d2 100644
--- a/tests/generics/integer-type-cast-return.c-expected
+++ b/tests/generics/integer-type-cast-return.c-expected
@@ -1,6 +1,12 @@
 /* generics_integer_type_cast_return.c generated by valac, the Vala compiler
  * generated from generics_integer_type_cast_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/generics/integer-type-cast.c-expected b/tests/generics/integer-type-cast.c-expected
index 35f7fb6bccfd8552..a48225c62c6a9ee9 100644
--- a/tests/generics/integer-type-cast.c-expected
+++ b/tests/generics/integer-type-cast.c-expected
@@ -1,6 +1,12 @@
 /* generics_integer_type_cast.c generated by valac, the Vala compiler
  * generated from generics_integer_type_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/generics/interface-property-impl.c-expected b/tests/generics/interface-property-impl.c-expected
index a845e088571af11f..4b4b5d60027f0521 100644
--- a/tests/generics/interface-property-impl.c-expected
+++ b/tests/generics/interface-property-impl.c-expected
@@ -1,6 +1,12 @@
 /* generics_interface_property_impl.c generated by valac, the Vala compiler
  * generated from generics_interface_property_impl.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/member-dup-destroy.c-expected b/tests/generics/member-dup-destroy.c-expected
index aba13ad020a5c542..a017ad0cec271a05 100644
--- a/tests/generics/member-dup-destroy.c-expected
+++ b/tests/generics/member-dup-destroy.c-expected
@@ -1,6 +1,12 @@
 /* generics_member_dup_destroy.c generated by valac, the Vala compiler
  * generated from generics_member_dup_destroy.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/generics/method-return-cast.c-expected b/tests/generics/method-return-cast.c-expected
index 5d1553c74dfc5282..688adeaaa4b40846 100644
--- a/tests/generics/method-return-cast.c-expected
+++ b/tests/generics/method-return-cast.c-expected
@@ -1,6 +1,12 @@
 /* generics_method_return_cast.c generated by valac, the Vala compiler
  * generated from generics_method_return_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/generics/null-type.c-expected b/tests/generics/null-type.c-expected
index 3988e36094a76df0..aa7672e98cab7d7e 100644
--- a/tests/generics/null-type.c-expected
+++ b/tests/generics/null-type.c-expected
@@ -1,6 +1,12 @@
 /* generics_null_type.c generated by valac, the Vala compiler
  * generated from generics_null_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/generics/parameter-in-cast.c-expected b/tests/generics/parameter-in-cast.c-expected
index f5ea0718c72ba268..c8590cc7b134a713 100644
--- a/tests/generics/parameter-in-cast.c-expected
+++ b/tests/generics/parameter-in-cast.c-expected
@@ -1,6 +1,12 @@
 /* generics_parameter_in_cast.c generated by valac, the Vala compiler
  * generated from generics_parameter_in_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-out-cast.c-expected b/tests/generics/parameter-out-cast.c-expected
index d43b977b5c339766..416e700629c3167b 100644
--- a/tests/generics/parameter-out-cast.c-expected
+++ b/tests/generics/parameter-out-cast.c-expected
@@ -1,6 +1,12 @@
 /* generics_parameter_out_cast.c generated by valac, the Vala compiler
  * generated from generics_parameter_out_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-sizeof-initializer-2.c-expected b/tests/generics/parameter-sizeof-initializer-2.c-expected
index d8de851525de5c27..aa4e5529eda86fc4 100644
--- a/tests/generics/parameter-sizeof-initializer-2.c-expected
+++ b/tests/generics/parameter-sizeof-initializer-2.c-expected
@@ -1,6 +1,12 @@
 /* generics_parameter_sizeof_initializer_2.c generated by valac, the Vala compiler
  * generated from generics_parameter_sizeof_initializer_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-sizeof-initializer.c-expected b/tests/generics/parameter-sizeof-initializer.c-expected
index cd21eb8d0b64cd12..295715c52de8ba4e 100644
--- a/tests/generics/parameter-sizeof-initializer.c-expected
+++ b/tests/generics/parameter-sizeof-initializer.c-expected
@@ -1,6 +1,12 @@
 /* generics_parameter_sizeof_initializer.c generated by valac, the Vala compiler
  * generated from generics_parameter_sizeof_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/generics/parameter-typeof-initializer.c-expected b/tests/generics/parameter-typeof-initializer.c-expected
index 05beefc2f8128f86..5bf2e3419b9944a7 100644
--- a/tests/generics/parameter-typeof-initializer.c-expected
+++ b/tests/generics/parameter-typeof-initializer.c-expected
@@ -1,6 +1,12 @@
 /* generics_parameter_typeof_initializer.c generated by valac, the Vala compiler
  * generated from generics_parameter_typeof_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/parameter-typeof.c-expected b/tests/generics/parameter-typeof.c-expected
index e13b2b71a4868c93..9dbf6fad043e1d9d 100644
--- a/tests/generics/parameter-typeof.c-expected
+++ b/tests/generics/parameter-typeof.c-expected
@@ -1,6 +1,12 @@
 /* generics_parameter_typeof.c generated by valac, the Vala compiler
  * generated from generics_parameter_typeof.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/property-gobject-set.c-expected b/tests/generics/property-gobject-set.c-expected
index 8308f85a8d17d65b..4121c0f7793da893 100644
--- a/tests/generics/property-gobject-set.c-expected
+++ b/tests/generics/property-gobject-set.c-expected
@@ -1,6 +1,12 @@
 /* generics_property_gobject_set.c generated by valac, the Vala compiler
  * generated from generics_property_gobject_set.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/property-int-cast.c-expected b/tests/generics/property-int-cast.c-expected
index b2708305aa0b320d..7c726ec23b472b03 100644
--- a/tests/generics/property-int-cast.c-expected
+++ b/tests/generics/property-int-cast.c-expected
@@ -1,6 +1,12 @@
 /* generics_property_int_cast.c generated by valac, the Vala compiler
  * generated from generics_property_int_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/reference-transfer.c-expected b/tests/generics/reference-transfer.c-expected
index e3818a195168a103..29dcf15106c5b7cc 100644
--- a/tests/generics/reference-transfer.c-expected
+++ b/tests/generics/reference-transfer.c-expected
@@ -1,6 +1,12 @@
 /* generics_reference_transfer.c generated by valac, the Vala compiler
  * generated from generics_reference_transfer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/string-literal-comparison.c-expected b/tests/generics/string-literal-comparison.c-expected
index 4a4222f22b8ceed1..6ca35c2edc2ec666 100644
--- a/tests/generics/string-literal-comparison.c-expected
+++ b/tests/generics/string-literal-comparison.c-expected
@@ -1,6 +1,12 @@
 /* generics_string_literal_comparison.c generated by valac, the Vala compiler
  * generated from generics_string_literal_comparison.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/generics/type-parameter-properties.c-expected b/tests/generics/type-parameter-properties.c-expected
index 263c957a385f6480..327f1dbfb609c36b 100644
--- a/tests/generics/type-parameter-properties.c-expected
+++ b/tests/generics/type-parameter-properties.c-expected
@@ -1,6 +1,12 @@
 /* generics_type_parameter_properties.c generated by valac, the Vala compiler
  * generated from generics_type_parameter_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/generics/type-parameter-property-clash.c-expected b/tests/generics/type-parameter-property-clash.c-expected
index 1f849dfdba464d2c..ddae2efe4c8e0499 100644
--- a/tests/generics/type-parameter-property-clash.c-expected
+++ b/tests/generics/type-parameter-property-clash.c-expected
@@ -1,6 +1,12 @@
 /* generics_type_parameter_property_clash.c generated by valac, the Vala compiler
  * generated from generics_type_parameter_property_clash.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/generics/value-pointer-type-access.c-expected b/tests/generics/value-pointer-type-access.c-expected
index e98d7fa45c09b574..f6f33977031bafd5 100644
--- a/tests/generics/value-pointer-type-access.c-expected
+++ b/tests/generics/value-pointer-type-access.c-expected
@@ -1,6 +1,12 @@
 /* generics_value_pointer_type_access.c generated by valac, the Vala compiler
  * generated from generics_value_pointer_type_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/genie/case.c-expected b/tests/genie/case.c-expected
index 5bca8f57c56dcfbe..3cead0626645a337 100644
--- a/tests/genie/case.c-expected
+++ b/tests/genie/case.c-expected
@@ -1,6 +1,12 @@
 /* genie_case.c generated by valac, the Vala compiler
  * generated from genie_case.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-abstract.c-expected b/tests/genie/class-abstract.c-expected
index 68b860a53fe1337e..fdc841e9b67a4a10 100644
--- a/tests/genie/class-abstract.c-expected
+++ b/tests/genie/class-abstract.c-expected
@@ -1,6 +1,12 @@
 /* genie_class_abstract.c generated by valac, the Vala compiler
  * generated from genie_class_abstract.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-field.c-expected b/tests/genie/class-field.c-expected
index 18dbc12b52e7b798..86c82bf1c0d72ce7 100644
--- a/tests/genie/class-field.c-expected
+++ b/tests/genie/class-field.c-expected
@@ -1,6 +1,12 @@
 /* genie_class_field.c generated by valac, the Vala compiler
  * generated from genie_class_field.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-init.c-expected b/tests/genie/class-init.c-expected
index b0cf044bb4bbb572..d556de33a9e1a95e 100644
--- a/tests/genie/class-init.c-expected
+++ b/tests/genie/class-init.c-expected
@@ -1,6 +1,12 @@
 /* genie_class_init.c generated by valac, the Vala compiler
  * generated from genie_class_init.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-property.c-expected b/tests/genie/class-property.c-expected
index f936f2f7d5149bd7..5702b74a72bcac12 100644
--- a/tests/genie/class-property.c-expected
+++ b/tests/genie/class-property.c-expected
@@ -1,6 +1,12 @@
 /* genie_class_property.c generated by valac, the Vala compiler
  * generated from genie_class_property.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class-signal.c-expected b/tests/genie/class-signal.c-expected
index 281b12fdf4d190e3..a0bc432a2d953c8b 100644
--- a/tests/genie/class-signal.c-expected
+++ b/tests/genie/class-signal.c-expected
@@ -1,6 +1,12 @@
 /* genie_class_signal.c generated by valac, the Vala compiler
  * generated from genie_class_signal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/class.c-expected b/tests/genie/class.c-expected
index f202bc5de4287222..413bc92dff7ca377 100644
--- a/tests/genie/class.c-expected
+++ b/tests/genie/class.c-expected
@@ -1,6 +1,12 @@
 /* genie_class.c generated by valac, the Vala compiler
  * generated from genie_class.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/constant.c-expected b/tests/genie/constant.c-expected
index 24099c0fc4011f9c..1263efe17587214f 100644
--- a/tests/genie/constant.c-expected
+++ b/tests/genie/constant.c-expected
@@ -1,6 +1,12 @@
 /* genie_constant.c generated by valac, the Vala compiler
  * generated from genie_constant.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-do.c-expected b/tests/genie/control-flow-if-do.c-expected
index e12b668654b64db2..7dcd6f1a58dc7f58 100644
--- a/tests/genie/control-flow-if-do.c-expected
+++ b/tests/genie/control-flow-if-do.c-expected
@@ -1,6 +1,12 @@
 /* genie_control_flow_if_do.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_do.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-else-if.c-expected b/tests/genie/control-flow-if-else-if.c-expected
index 41ed9beb40f4cb38..83edd3a539d7592f 100644
--- a/tests/genie/control-flow-if-else-if.c-expected
+++ b/tests/genie/control-flow-if-else-if.c-expected
@@ -1,6 +1,12 @@
 /* genie_control_flow_if_else_if.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_else_if.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-else.c-expected b/tests/genie/control-flow-if-else.c-expected
index 2662e5d1cd2613b6..751720deae058ebe 100644
--- a/tests/genie/control-flow-if-else.c-expected
+++ b/tests/genie/control-flow-if-else.c-expected
@@ -1,6 +1,12 @@
 /* genie_control_flow_if_else.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_else.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-greater-than.c-expected b/tests/genie/control-flow-if-greater-than.c-expected
index d9c9a21462497f47..e373b0bc8eafbd37 100644
--- a/tests/genie/control-flow-if-greater-than.c-expected
+++ b/tests/genie/control-flow-if-greater-than.c-expected
@@ -1,6 +1,12 @@
 /* genie_control_flow_if_greater_than.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_greater_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-identity.c-expected b/tests/genie/control-flow-if-identity.c-expected
index a8f2b2bc4562c692..8ee6ea42fb09a78e 100644
--- a/tests/genie/control-flow-if-identity.c-expected
+++ b/tests/genie/control-flow-if-identity.c-expected
@@ -1,6 +1,12 @@
 /* genie_control_flow_if_identity.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_identity.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if-less-than.c-expected b/tests/genie/control-flow-if-less-than.c-expected
index ad03ce963b00a399..315f8f2501a4b73e 100644
--- a/tests/genie/control-flow-if-less-than.c-expected
+++ b/tests/genie/control-flow-if-less-than.c-expected
@@ -1,6 +1,12 @@
 /* genie_control_flow_if_less_than.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if_less_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/control-flow-if.c-expected b/tests/genie/control-flow-if.c-expected
index 749c45ce78f1e59f..5b0f8dbd4c655677 100644
--- a/tests/genie/control-flow-if.c-expected
+++ b/tests/genie/control-flow-if.c-expected
@@ -1,6 +1,12 @@
 /* genie_control_flow_if.c generated by valac, the Vala compiler
  * generated from genie_control_flow_if.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/do-while.c-expected b/tests/genie/do-while.c-expected
index d5f3c5fd85236a6f..423d6069843eb635 100644
--- a/tests/genie/do-while.c-expected
+++ b/tests/genie/do-while.c-expected
@@ -1,6 +1,12 @@
 /* genie_do_while.c generated by valac, the Vala compiler
  * generated from genie_do_while.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/enum-with-keyword-values.c-expected b/tests/genie/enum-with-keyword-values.c-expected
index 73251008d32d3eee..b0aae2d1ad24f35e 100644
--- a/tests/genie/enum-with-keyword-values.c-expected
+++ b/tests/genie/enum-with-keyword-values.c-expected
@@ -1,6 +1,12 @@
 /* genie_enum_with_keyword_values.c generated by valac, the Vala compiler
  * generated from genie_enum_with_keyword_values.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/enum.c-expected b/tests/genie/enum.c-expected
index 4e82a099d976af79..f8231731133c5781 100644
--- a/tests/genie/enum.c-expected
+++ b/tests/genie/enum.c-expected
@@ -1,6 +1,12 @@
 /* genie_enum.c generated by valac, the Vala compiler
  * generated from genie_enum.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/exception.c-expected b/tests/genie/exception.c-expected
index 269d7925e6a96710..dfa500c7b54a0e2c 100644
--- a/tests/genie/exception.c-expected
+++ b/tests/genie/exception.c-expected
@@ -1,6 +1,12 @@
 /* genie_exception.c generated by valac, the Vala compiler
  * generated from genie_exception.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/for-downto.c-expected b/tests/genie/for-downto.c-expected
index e286dbadae510236..7a1df1ec6a016965 100644
--- a/tests/genie/for-downto.c-expected
+++ b/tests/genie/for-downto.c-expected
@@ -1,6 +1,12 @@
 /* genie_for_downto.c generated by valac, the Vala compiler
  * generated from genie_for_downto.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/for-in.c-expected b/tests/genie/for-in.c-expected
index 461ae185e10a005d..a4e1fb91a38ccefe 100644
--- a/tests/genie/for-in.c-expected
+++ b/tests/genie/for-in.c-expected
@@ -1,6 +1,12 @@
 /* genie_for_in.c generated by valac, the Vala compiler
  * generated from genie_for_in.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/for-to.c-expected b/tests/genie/for-to.c-expected
index 5b3cf80f3f088e10..cc3a56a65d2399c2 100644
--- a/tests/genie/for-to.c-expected
+++ b/tests/genie/for-to.c-expected
@@ -1,6 +1,12 @@
 /* genie_for_to.c generated by valac, the Vala compiler
  * generated from genie_for_to.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/function-returns-closure.c-expected b/tests/genie/function-returns-closure.c-expected
index d3e148330dfa7acc..9c5352efd1b8c16c 100644
--- a/tests/genie/function-returns-closure.c-expected
+++ b/tests/genie/function-returns-closure.c-expected
@@ -1,6 +1,12 @@
 /* genie_function_returns_closure.c generated by valac, the Vala compiler
  * generated from genie_function_returns_closure.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/genie/function-with-argument.c-expected b/tests/genie/function-with-argument.c-expected
index fc6293b798894faf..369c17ea4a88d569 100644
--- a/tests/genie/function-with-argument.c-expected
+++ b/tests/genie/function-with-argument.c-expected
@@ -1,6 +1,12 @@
 /* genie_function_with_argument.c generated by valac, the Vala compiler
  * generated from genie_function_with_argument.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/function-with-return-value.c-expected b/tests/genie/function-with-return-value.c-expected
index 15b6a81091892083..939d68dfc9b3daa7 100644
--- a/tests/genie/function-with-return-value.c-expected
+++ b/tests/genie/function-with-return-value.c-expected
@@ -1,6 +1,12 @@
 /* genie_function_with_return_value.c generated by valac, the Vala compiler
  * generated from genie_function_with_return_value.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/function.c-expected b/tests/genie/function.c-expected
index f3955085dcc4b891..951e21f1326e5f6d 100644
--- a/tests/genie/function.c-expected
+++ b/tests/genie/function.c-expected
@@ -1,6 +1,12 @@
 /* genie_function.c generated by valac, the Vala compiler
  * generated from genie_function.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/genie/indentation-with-spaces.c-expected b/tests/genie/indentation-with-spaces.c-expected
index a157ee9930e73898..eb2a4e4ce442a523 100644
--- a/tests/genie/indentation-with-spaces.c-expected
+++ b/tests/genie/indentation-with-spaces.c-expected
@@ -1,6 +1,12 @@
 /* genie_indentation_with_spaces.c generated by valac, the Vala compiler
  * generated from genie_indentation_with_spaces.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/init-int.c-expected b/tests/genie/init-int.c-expected
index 745372794a5b8fa0..f94743986aede907 100644
--- a/tests/genie/init-int.c-expected
+++ b/tests/genie/init-int.c-expected
@@ -1,6 +1,12 @@
 /* genie_init_int.c generated by valac, the Vala compiler
  * generated from genie_init_int.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/init.c-expected b/tests/genie/init.c-expected
index e97f519df931050b..5d5a9dbdc52f5eb3 100644
--- a/tests/genie/init.c-expected
+++ b/tests/genie/init.c-expected
@@ -1,6 +1,12 @@
 /* genie_init.c generated by valac, the Vala compiler
  * generated from genie_init.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/initializer-list.c-expected b/tests/genie/initializer-list.c-expected
index 9bc4e7bafeee2fdf..81bdf4fee889756c 100644
--- a/tests/genie/initializer-list.c-expected
+++ b/tests/genie/initializer-list.c-expected
@@ -1,6 +1,12 @@
 /* genie_initializer_list.c generated by valac, the Vala compiler
  * generated from genie_initializer_list.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/interface.c-expected b/tests/genie/interface.c-expected
index 3a8087f1aa5ea443..55d4bbad523e2aa8 100644
--- a/tests/genie/interface.c-expected
+++ b/tests/genie/interface.c-expected
@@ -1,6 +1,12 @@
 /* genie_interface.c generated by valac, the Vala compiler
  * generated from genie_interface.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-boolean-assignment.c-expected b/tests/genie/literal-boolean-assignment.c-expected
index 77b90dc18af308c1..3451cafa5c209f3c 100644
--- a/tests/genie/literal-boolean-assignment.c-expected
+++ b/tests/genie/literal-boolean-assignment.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_boolean_assignment.c generated by valac, the Vala compiler
  * generated from genie_literal_boolean_assignment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-boolean.c-expected b/tests/genie/literal-boolean.c-expected
index 4d04b24e85ab4052..6cf9bd59f67b8a47 100644
--- a/tests/genie/literal-boolean.c-expected
+++ b/tests/genie/literal-boolean.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_boolean.c generated by valac, the Vala compiler
  * generated from genie_literal_boolean.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-character.c-expected b/tests/genie/literal-character.c-expected
index 3a8e35e6f3cdb5f5..f92b4e9c8df253be 100644
--- a/tests/genie/literal-character.c-expected
+++ b/tests/genie/literal-character.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_character.c generated by valac, the Vala compiler
  * generated from genie_literal_character.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-hexadecimal.c-expected b/tests/genie/literal-hexadecimal.c-expected
index f7098075db368d64..40ea7c34fc478715 100644
--- a/tests/genie/literal-hexadecimal.c-expected
+++ b/tests/genie/literal-hexadecimal.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_hexadecimal.c generated by valac, the Vala compiler
  * generated from genie_literal_hexadecimal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-integer-long-long-suffix.c-expected b/tests/genie/literal-integer-long-long-suffix.c-expected
index ad71e61dce4b5a71..093491a2b3c53864 100644
--- a/tests/genie/literal-integer-long-long-suffix.c-expected
+++ b/tests/genie/literal-integer-long-long-suffix.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_integer_long_long_suffix.c generated by valac, the Vala compiler
  * generated from genie_literal_integer_long_long_suffix.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-integer.c-expected b/tests/genie/literal-integer.c-expected
index 1f94181037ab13d6..d558907741f80653 100644
--- a/tests/genie/literal-integer.c-expected
+++ b/tests/genie/literal-integer.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_integer.c generated by valac, the Vala compiler
  * generated from genie_literal_integer.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-null.c-expected b/tests/genie/literal-null.c-expected
index 822f14b263b00a23..0b1b573c19603f9a 100644
--- a/tests/genie/literal-null.c-expected
+++ b/tests/genie/literal-null.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_null.c generated by valac, the Vala compiler
  * generated from genie_literal_null.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-octal.c-expected b/tests/genie/literal-octal.c-expected
index 8feeb804ce397ebe..9fc868c528d1cb1a 100644
--- a/tests/genie/literal-octal.c-expected
+++ b/tests/genie/literal-octal.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_octal.c generated by valac, the Vala compiler
  * generated from genie_literal_octal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-real.c-expected b/tests/genie/literal-real.c-expected
index 2d6a8c7d64130e08..2c521e52873dc044 100644
--- a/tests/genie/literal-real.c-expected
+++ b/tests/genie/literal-real.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_real.c generated by valac, the Vala compiler
  * generated from genie_literal_real.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-regex.c-expected b/tests/genie/literal-regex.c-expected
index 2c3496e4aaf46786..484f4e88baed7b1e 100644
--- a/tests/genie/literal-regex.c-expected
+++ b/tests/genie/literal-regex.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_regex.c generated by valac, the Vala compiler
  * generated from genie_literal_regex.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-template-string.c-expected b/tests/genie/literal-template-string.c-expected
index 9dad5e4320003503..cf5642659c94f75a 100644
--- a/tests/genie/literal-template-string.c-expected
+++ b/tests/genie/literal-template-string.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_template_string.c generated by valac, the Vala compiler
  * generated from genie_literal_template_string.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/literal-verbatim-string.c-expected b/tests/genie/literal-verbatim-string.c-expected
index d10367a7a74e3d16..4c72d04931743188 100644
--- a/tests/genie/literal-verbatim-string.c-expected
+++ b/tests/genie/literal-verbatim-string.c-expected
@@ -1,6 +1,12 @@
 /* genie_literal_verbatim_string.c generated by valac, the Vala compiler
  * generated from genie_literal_verbatim_string.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-addition.c-expected b/tests/genie/operator-addition.c-expected
index 867d27f058b12dc5..2a7b871707901c56 100644
--- a/tests/genie/operator-addition.c-expected
+++ b/tests/genie/operator-addition.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_addition.c generated by valac, the Vala compiler
  * generated from genie_operator_addition.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-assignment-combined.c-expected b/tests/genie/operator-assignment-combined.c-expected
index f92f2010b2a254f2..a57a2169ea2a8ad7 100644
--- a/tests/genie/operator-assignment-combined.c-expected
+++ b/tests/genie/operator-assignment-combined.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_assignment_combined.c generated by valac, the Vala compiler
  * generated from genie_operator_assignment_combined.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-assignment.c-expected b/tests/genie/operator-assignment.c-expected
index 39020a6c4e01e69a..764278df6ab01a38 100644
--- a/tests/genie/operator-assignment.c-expected
+++ b/tests/genie/operator-assignment.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_assignment.c generated by valac, the Vala compiler
  * generated from genie_operator_assignment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-and.c-expected b/tests/genie/operator-bitwise-and.c-expected
index cb7dc1850a616c9a..97ce97edc12fcdb4 100644
--- a/tests/genie/operator-bitwise-and.c-expected
+++ b/tests/genie/operator-bitwise-and.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_bitwise_and.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_and.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-left-shift.c-expected b/tests/genie/operator-bitwise-left-shift.c-expected
index 79aa349c9b1ef20a..150b18e56dc3c25a 100644
--- a/tests/genie/operator-bitwise-left-shift.c-expected
+++ b/tests/genie/operator-bitwise-left-shift.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_bitwise_left_shift.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_left_shift.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-not.c-expected b/tests/genie/operator-bitwise-not.c-expected
index 526bc2dd6d319743..6766f97a863f985f 100644
--- a/tests/genie/operator-bitwise-not.c-expected
+++ b/tests/genie/operator-bitwise-not.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_bitwise_not.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_not.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-or.c-expected b/tests/genie/operator-bitwise-or.c-expected
index d14ba9f53cd7416f..c6a8b011c9926c81 100644
--- a/tests/genie/operator-bitwise-or.c-expected
+++ b/tests/genie/operator-bitwise-or.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_bitwise_or.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_or.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-right-shift.c-expected b/tests/genie/operator-bitwise-right-shift.c-expected
index c0700350eb6b90c8..fa1ee7c0ff3f9c08 100644
--- a/tests/genie/operator-bitwise-right-shift.c-expected
+++ b/tests/genie/operator-bitwise-right-shift.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_bitwise_right_shift.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_right_shift.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-bitwise-xor.c-expected b/tests/genie/operator-bitwise-xor.c-expected
index 6a8db99dc92e874b..7c9f49c51a814470 100644
--- a/tests/genie/operator-bitwise-xor.c-expected
+++ b/tests/genie/operator-bitwise-xor.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_bitwise_xor.c generated by valac, the Vala compiler
  * generated from genie_operator_bitwise_xor.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-division.c-expected b/tests/genie/operator-division.c-expected
index edcf3054105159f4..a950b0608b32c3b1 100644
--- a/tests/genie/operator-division.c-expected
+++ b/tests/genie/operator-division.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_division.c generated by valac, the Vala compiler
  * generated from genie_operator_division.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-equal.c-expected b/tests/genie/operator-equal.c-expected
index c481f40cf7474faf..cc23eb09c4e5698d 100644
--- a/tests/genie/operator-equal.c-expected
+++ b/tests/genie/operator-equal.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-greater-than-equal.c-expected b/tests/genie/operator-greater-than-equal.c-expected
index 20c23ce144c0d6dc..8f1bea8cdc311956 100644
--- a/tests/genie/operator-greater-than-equal.c-expected
+++ b/tests/genie/operator-greater-than-equal.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_greater_than_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_greater_than_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-less-than-equal.c-expected b/tests/genie/operator-less-than-equal.c-expected
index 8d742948c47c48c8..422bc11d2c1f7dc0 100644
--- a/tests/genie/operator-less-than-equal.c-expected
+++ b/tests/genie/operator-less-than-equal.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_less_than_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_less_than_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-less-than.c-expected b/tests/genie/operator-less-than.c-expected
index 7996517c21db0c68..d4b8ec0ae0f31a46 100644
--- a/tests/genie/operator-less-than.c-expected
+++ b/tests/genie/operator-less-than.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_less_than.c generated by valac, the Vala compiler
  * generated from genie_operator_less_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-logical-and.c-expected b/tests/genie/operator-logical-and.c-expected
index ee0de64b62e891a5..f9a4adbcb4dbcf7c 100644
--- a/tests/genie/operator-logical-and.c-expected
+++ b/tests/genie/operator-logical-and.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_logical_and.c generated by valac, the Vala compiler
  * generated from genie_operator_logical_and.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-logical-not.c-expected b/tests/genie/operator-logical-not.c-expected
index 0113033030f1f534..bb93fb1f23910ad2 100644
--- a/tests/genie/operator-logical-not.c-expected
+++ b/tests/genie/operator-logical-not.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_logical_not.c generated by valac, the Vala compiler
  * generated from genie_operator_logical_not.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-logical-or.c-expected b/tests/genie/operator-logical-or.c-expected
index d90e3dfad6b343a3..acafe67422ab1a27 100644
--- a/tests/genie/operator-logical-or.c-expected
+++ b/tests/genie/operator-logical-or.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_logical_or.c generated by valac, the Vala compiler
  * generated from genie_operator_logical_or.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-modulo.c-expected b/tests/genie/operator-modulo.c-expected
index 23560bdb6b164763..3e0aeaa0dabb67cc 100644
--- a/tests/genie/operator-modulo.c-expected
+++ b/tests/genie/operator-modulo.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_modulo.c generated by valac, the Vala compiler
  * generated from genie_operator_modulo.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-multiply.c-expected b/tests/genie/operator-multiply.c-expected
index ec60325786861e7c..51c2a99ae76a3656 100644
--- a/tests/genie/operator-multiply.c-expected
+++ b/tests/genie/operator-multiply.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_multiply.c generated by valac, the Vala compiler
  * generated from genie_operator_multiply.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-not-equal.c-expected b/tests/genie/operator-not-equal.c-expected
index 35b3326c5a295467..3d3d5cac26e950a2 100644
--- a/tests/genie/operator-not-equal.c-expected
+++ b/tests/genie/operator-not-equal.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_not_equal.c generated by valac, the Vala compiler
  * generated from genie_operator_not_equal.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-post-decrement.c-expected b/tests/genie/operator-post-decrement.c-expected
index 855e924018c08b2e..03932c2e4affe7c5 100644
--- a/tests/genie/operator-post-decrement.c-expected
+++ b/tests/genie/operator-post-decrement.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_post_decrement.c generated by valac, the Vala compiler
  * generated from genie_operator_post_decrement.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-post-increment.c-expected b/tests/genie/operator-post-increment.c-expected
index 3ff86cfb794ee14e..35612e50ec115afd 100644
--- a/tests/genie/operator-post-increment.c-expected
+++ b/tests/genie/operator-post-increment.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_post_increment.c generated by valac, the Vala compiler
  * generated from genie_operator_post_increment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-pre-decrement.c-expected b/tests/genie/operator-pre-decrement.c-expected
index 3841761c627c68a3..a281ddd3614b489f 100644
--- a/tests/genie/operator-pre-decrement.c-expected
+++ b/tests/genie/operator-pre-decrement.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_pre_decrement.c generated by valac, the Vala compiler
  * generated from genie_operator_pre_decrement.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-pre-increment.c-expected b/tests/genie/operator-pre-increment.c-expected
index d02e3b06bb9d5a79..3dbdf8bd5884b8b0 100644
--- a/tests/genie/operator-pre-increment.c-expected
+++ b/tests/genie/operator-pre-increment.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_pre_increment.c generated by valac, the Vala compiler
  * generated from genie_operator_pre_increment.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-subtraction.c-expected b/tests/genie/operator-subtraction.c-expected
index b5cbf4fe63307165..a845124f4638f691 100644
--- a/tests/genie/operator-subtraction.c-expected
+++ b/tests/genie/operator-subtraction.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_subtraction.c generated by valac, the Vala compiler
  * generated from genie_operator_subtraction.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operator-ternary.c-expected b/tests/genie/operator-ternary.c-expected
index e22d41c8d0da5b01..7059db06c9097717 100644
--- a/tests/genie/operator-ternary.c-expected
+++ b/tests/genie/operator-ternary.c-expected
@@ -1,6 +1,12 @@
 /* genie_operator_ternary.c generated by valac, the Vala compiler
  * generated from genie_operator_ternary.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/operators-greater-than.c-expected b/tests/genie/operators-greater-than.c-expected
index 85d707767486efe0..7853239af0825a02 100644
--- a/tests/genie/operators-greater-than.c-expected
+++ b/tests/genie/operators-greater-than.c-expected
@@ -1,6 +1,12 @@
 /* genie_operators_greater_than.c generated by valac, the Vala compiler
  * generated from genie_operators_greater_than.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-and-expression.c-expected b/tests/genie/preparser-and-expression.c-expected
index b1c2e293b2fca0a8..bafb0b90c471622f 100644
--- a/tests/genie/preparser-and-expression.c-expected
+++ b/tests/genie/preparser-and-expression.c-expected
@@ -1,6 +1,12 @@
 /* genie_preparser_and_expression.c generated by valac, the Vala compiler
  * generated from genie_preparser_and_expression.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-elif.c-expected b/tests/genie/preparser-elif.c-expected
index 785a90927f0691a8..a0af42f939030079 100644
--- a/tests/genie/preparser-elif.c-expected
+++ b/tests/genie/preparser-elif.c-expected
@@ -1,6 +1,12 @@
 /* genie_preparser_elif.c generated by valac, the Vala compiler
  * generated from genie_preparser_elif.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-equality-expression.c-expected b/tests/genie/preparser-equality-expression.c-expected
index fced1071e9f895a2..632bd682427527bd 100644
--- a/tests/genie/preparser-equality-expression.c-expected
+++ b/tests/genie/preparser-equality-expression.c-expected
@@ -1,6 +1,12 @@
 /* genie_preparser_equality_expression.c generated by valac, the Vala compiler
  * generated from genie_preparser_equality_expression.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-not.c-expected b/tests/genie/preparser-not.c-expected
index ddc0b1e91848f25d..5db98460835203ec 100644
--- a/tests/genie/preparser-not.c-expected
+++ b/tests/genie/preparser-not.c-expected
@@ -1,6 +1,12 @@
 /* genie_preparser_not.c generated by valac, the Vala compiler
  * generated from genie_preparser_not.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser-or-expression.c-expected b/tests/genie/preparser-or-expression.c-expected
index 0967bc9b715d62f9..9b3c87c68850b6ce 100644
--- a/tests/genie/preparser-or-expression.c-expected
+++ b/tests/genie/preparser-or-expression.c-expected
@@ -1,6 +1,12 @@
 /* genie_preparser_or_expression.c generated by valac, the Vala compiler
  * generated from genie_preparser_or_expression.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/preparser.c-expected b/tests/genie/preparser.c-expected
index a472a63b0cfbc430..6a34ce9b4bf0f106 100644
--- a/tests/genie/preparser.c-expected
+++ b/tests/genie/preparser.c-expected
@@ -1,6 +1,12 @@
 /* genie_preparser.c generated by valac, the Vala compiler
  * generated from genie_preparser.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/print.c-expected b/tests/genie/print.c-expected
index d74c80c1ee495595..6d8baa95bb2b30af 100644
--- a/tests/genie/print.c-expected
+++ b/tests/genie/print.c-expected
@@ -1,6 +1,12 @@
 /* genie_print.c generated by valac, the Vala compiler
  * generated from genie_print.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/sizeof.c-expected b/tests/genie/sizeof.c-expected
index 18c1deaac9883d0d..4deba62da0a144bf 100644
--- a/tests/genie/sizeof.c-expected
+++ b/tests/genie/sizeof.c-expected
@@ -1,6 +1,12 @@
 /* genie_sizeof.c generated by valac, the Vala compiler
  * generated from genie_sizeof.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/struct-after-class.c-expected b/tests/genie/struct-after-class.c-expected
index 7047db9ad38b5654..ca14d007e72b97de 100644
--- a/tests/genie/struct-after-class.c-expected
+++ b/tests/genie/struct-after-class.c-expected
@@ -1,6 +1,12 @@
 /* genie_struct_after_class.c generated by valac, the Vala compiler
  * generated from genie_struct_after_class.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/struct.c-expected b/tests/genie/struct.c-expected
index 9d4e4cb504d527b0..8d0bc121282e82d9 100644
--- a/tests/genie/struct.c-expected
+++ b/tests/genie/struct.c-expected
@@ -1,6 +1,12 @@
 /* genie_struct.c generated by valac, the Vala compiler
  * generated from genie_struct.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/try-except-finally.c-expected b/tests/genie/try-except-finally.c-expected
index 4c945480dbb6d65c..88be91e8ad1afd1c 100644
--- a/tests/genie/try-except-finally.c-expected
+++ b/tests/genie/try-except-finally.c-expected
@@ -1,6 +1,12 @@
 /* genie_try_except_finally.c generated by valac, the Vala compiler
  * generated from genie_try_except_finally.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/genie/typeof.c-expected b/tests/genie/typeof.c-expected
index 0428b636baed7835..f2dbe6555da84e4f 100644
--- a/tests/genie/typeof.c-expected
+++ b/tests/genie/typeof.c-expected
@@ -1,6 +1,12 @@
 /* genie_typeof.c generated by valac, the Vala compiler
  * generated from genie_typeof.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/genie/while.c-expected b/tests/genie/while.c-expected
index 42a2f172f074da3c..41c653aed48ccb9a 100644
--- a/tests/genie/while.c-expected
+++ b/tests/genie/while.c-expected
@@ -1,6 +1,12 @@
 /* genie_while.c generated by valac, the Vala compiler
  * generated from genie_while.gs, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/headers/sealed-class.c-expected b/tests/headers/sealed-class.c-expected
index 579a68cdfff47d2d..7b7cdadc65129640 100644
--- a/tests/headers/sealed-class.c-expected
+++ b/tests/headers/sealed-class.c-expected
@@ -1,6 +1,12 @@
 /* headers_sealed_class.c generated by valac, the Vala compiler
  * generated from headers_sealed_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include "test.h"
 #include <glib.h>
 #include <glib-object.h>
diff --git a/tests/linux/bug793444.c-expected b/tests/linux/bug793444.c-expected
index 0d4973b08113248a..c0f4e39a6e8ce76d 100644
--- a/tests/linux/bug793444.c-expected
+++ b/tests/linux/bug793444.c-expected
@@ -1,6 +1,12 @@
 /* linux_bug793444.c generated by valac, the Vala compiler
  * generated from linux_bug793444.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #define _GNU_SOURCE
 
 #include <glib.h>
diff --git a/tests/linux/file-commandpipe.c-expected b/tests/linux/file-commandpipe.c-expected
index be210e2a6d91479e..2ba33449ab7b64a9 100644
--- a/tests/linux/file-commandpipe.c-expected
+++ b/tests/linux/file-commandpipe.c-expected
@@ -1,6 +1,12 @@
 /* linux_file_commandpipe.c generated by valac, the Vala compiler
  * generated from linux_file_commandpipe.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdio.h>
 #include <glib.h>
 
diff --git a/tests/methods/argument-array-initilizer.c-expected b/tests/methods/argument-array-initilizer.c-expected
index 9fb7a9ab0e12713a..3dde688655f74a1c 100644
--- a/tests/methods/argument-array-initilizer.c-expected
+++ b/tests/methods/argument-array-initilizer.c-expected
@@ -1,6 +1,12 @@
 /* methods_argument_array_initilizer.c generated by valac, the Vala compiler
  * generated from methods_argument_array_initilizer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/argument-named.c-expected b/tests/methods/argument-named.c-expected
index ae239b7f1145381f..7bdeb54595e53c5b 100644
--- a/tests/methods/argument-named.c-expected
+++ b/tests/methods/argument-named.c-expected
@@ -1,6 +1,12 @@
 /* methods_argument_named.c generated by valac, the Vala compiler
  * generated from methods_argument_named.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdarg.h>
diff --git a/tests/methods/array-length-type.c-expected b/tests/methods/array-length-type.c-expected
index 89d97931b2627576..217a76d51ef58cc9 100644
--- a/tests/methods/array-length-type.c-expected
+++ b/tests/methods/array-length-type.c-expected
@@ -1,6 +1,12 @@
 /* methods_array_length_type.c generated by valac, the Vala compiler
  * generated from methods_array_length_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug540483.c-expected b/tests/methods/bug540483.c-expected
index 5dc573fbe093f724..d37a04ebb042eab9 100644
--- a/tests/methods/bug540483.c-expected
+++ b/tests/methods/bug540483.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug540483.c generated by valac, the Vala compiler
  * generated from methods_bug540483.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug595538.c-expected b/tests/methods/bug595538.c-expected
index 4cca222a129baaef..18708fb976eb96ee 100644
--- a/tests/methods/bug595538.c-expected
+++ b/tests/methods/bug595538.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug595538.c generated by valac, the Vala compiler
  * generated from methods_bug595538.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/bug596726.c-expected b/tests/methods/bug596726.c-expected
index 6fa956d62ebb2613..e4242937c5978751 100644
--- a/tests/methods/bug596726.c-expected
+++ b/tests/methods/bug596726.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug596726.c generated by valac, the Vala compiler
  * generated from methods_bug596726.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/bug597426.c-expected b/tests/methods/bug597426.c-expected
index f13a810576e28a44..6d8a5c285a8de4c0 100644
--- a/tests/methods/bug597426.c-expected
+++ b/tests/methods/bug597426.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug597426.c generated by valac, the Vala compiler
  * generated from methods_bug597426.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/bug598738.c-expected b/tests/methods/bug598738.c-expected
index 8eb818bcc4d9ec16..caf50d946d26a7cf 100644
--- a/tests/methods/bug598738.c-expected
+++ b/tests/methods/bug598738.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug598738.c generated by valac, the Vala compiler
  * generated from methods_bug598738.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 typedef void (*Func) (gpointer user_data);
diff --git a/tests/methods/bug599892.c-expected b/tests/methods/bug599892.c-expected
index ea79e50fad555848..8f3799cd2ea527e2 100644
--- a/tests/methods/bug599892.c-expected
+++ b/tests/methods/bug599892.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug599892.c generated by valac, the Vala compiler
  * generated from methods_bug599892.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug613483.c-expected b/tests/methods/bug613483.c-expected
index 77c03269e274922c..fee085723e5d4fda 100644
--- a/tests/methods/bug613483.c-expected
+++ b/tests/methods/bug613483.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug613483.c generated by valac, the Vala compiler
  * generated from methods_bug613483.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug620673.c-expected b/tests/methods/bug620673.c-expected
index 248cfcef02188938..d318ddec777278c4 100644
--- a/tests/methods/bug620673.c-expected
+++ b/tests/methods/bug620673.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug620673.c generated by valac, the Vala compiler
  * generated from methods_bug620673.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 #include <float.h>
diff --git a/tests/methods/bug622570.c-expected b/tests/methods/bug622570.c-expected
index 0787494f2f6d7c13..cfc2f35ea0cc0ba8 100644
--- a/tests/methods/bug622570.c-expected
+++ b/tests/methods/bug622570.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug622570.c generated by valac, the Vala compiler
  * generated from methods_bug622570.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/bug626783.c-expected b/tests/methods/bug626783.c-expected
index 4038dc962be18334..9a0bc42fe20a37b7 100644
--- a/tests/methods/bug626783.c-expected
+++ b/tests/methods/bug626783.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug626783.c generated by valac, the Vala compiler
  * generated from methods_bug626783.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/methods/bug634753.c-expected b/tests/methods/bug634753.c-expected
index e6398fe2efa5f207..c2d0a0862e996aa6 100644
--- a/tests/methods/bug634753.c-expected
+++ b/tests/methods/bug634753.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug634753.c generated by valac, the Vala compiler
  * generated from methods_bug634753.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/bug639054.c-expected b/tests/methods/bug639054.c-expected
index 4429c8ebb6612433..d3fd34a5d4b19eeb 100644
--- a/tests/methods/bug639054.c-expected
+++ b/tests/methods/bug639054.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug639054.c generated by valac, the Vala compiler
  * generated from methods_bug639054.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 #include <stdlib.h>
diff --git a/tests/methods/bug642350.c-expected b/tests/methods/bug642350.c-expected
index 1048cb4b23ce12c4..e31263f7e4d8277c 100644
--- a/tests/methods/bug642350.c-expected
+++ b/tests/methods/bug642350.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug642350.c generated by valac, the Vala compiler
  * generated from methods_bug642350.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug642885.c-expected b/tests/methods/bug642885.c-expected
index 6b093eb1d5c84641..420f6fec7927ef75 100644
--- a/tests/methods/bug642885.c-expected
+++ b/tests/methods/bug642885.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug642885.c generated by valac, the Vala compiler
  * generated from methods_bug642885.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <gio/gio.h>
 #include <glib-object.h>
 #include <glib.h>
diff --git a/tests/methods/bug642899.c-expected b/tests/methods/bug642899.c-expected
index e95bb0f14ab2300c..dad574c5b1a6ea21 100644
--- a/tests/methods/bug642899.c-expected
+++ b/tests/methods/bug642899.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug642899.c generated by valac, the Vala compiler
  * generated from methods_bug642899.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug646345.c-expected b/tests/methods/bug646345.c-expected
index 4591c3e1278ceb4e..f1a962e4afe7a2ad 100644
--- a/tests/methods/bug646345.c-expected
+++ b/tests/methods/bug646345.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug646345.c generated by valac, the Vala compiler
  * generated from methods_bug646345.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug648320.c-expected b/tests/methods/bug648320.c-expected
index 4026eba9dd6b23e5..9b47df2c699e07b2 100644
--- a/tests/methods/bug648320.c-expected
+++ b/tests/methods/bug648320.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug648320.c generated by valac, the Vala compiler
  * generated from methods_bug648320.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/bug649562.c-expected b/tests/methods/bug649562.c-expected
index ec1d60c13ca9036e..e53650d7e6ec63c1 100644
--- a/tests/methods/bug649562.c-expected
+++ b/tests/methods/bug649562.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug649562.c generated by valac, the Vala compiler
  * generated from methods_bug649562.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/methods/bug652098.c-expected b/tests/methods/bug652098.c-expected
index 871617da4c2ab288..7698aea3a384b366 100644
--- a/tests/methods/bug652098.c-expected
+++ b/tests/methods/bug652098.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug652098.c generated by valac, the Vala compiler
  * generated from methods_bug652098.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/bug653391.c-expected b/tests/methods/bug653391.c-expected
index 1f9c89ea603c5346..7688511e6be2359f 100644
--- a/tests/methods/bug653391.c-expected
+++ b/tests/methods/bug653391.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug653391.c generated by valac, the Vala compiler
  * generated from methods_bug653391.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug653908.c-expected b/tests/methods/bug653908.c-expected
index 891aacdc34088fb2..7667ad28df99fa47 100644
--- a/tests/methods/bug653908.c-expected
+++ b/tests/methods/bug653908.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug653908.c generated by valac, the Vala compiler
  * generated from methods_bug653908.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/methods/bug663210.c-expected b/tests/methods/bug663210.c-expected
index d248a449f2d0c227..84a83275fad2d67e 100644
--- a/tests/methods/bug663210.c-expected
+++ b/tests/methods/bug663210.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug663210.c generated by valac, the Vala compiler
  * generated from methods_bug663210.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/bug699956.c-expected b/tests/methods/bug699956.c-expected
index b8b789c115ea32d9..ff2ae0fb77be7d1c 100644
--- a/tests/methods/bug699956.c-expected
+++ b/tests/methods/bug699956.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug699956.c generated by valac, the Vala compiler
  * generated from methods_bug699956.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/methods/bug710862.c-expected b/tests/methods/bug710862.c-expected
index a5a54036b5f5adfb..9ed20d43d79145db 100644
--- a/tests/methods/bug710862.c-expected
+++ b/tests/methods/bug710862.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug710862.c generated by valac, the Vala compiler
  * generated from methods_bug710862.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug723009.c-expected b/tests/methods/bug723009.c-expected
index f7376c656ea93bed..4d1ce0f7f0c75606 100644
--- a/tests/methods/bug723009.c-expected
+++ b/tests/methods/bug723009.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug723009.c generated by valac, the Vala compiler
  * generated from methods_bug723009.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug723195.c-expected b/tests/methods/bug723195.c-expected
index 1178b69b7ec85df6..e45a0e6c7ca97c38 100644
--- a/tests/methods/bug723195.c-expected
+++ b/tests/methods/bug723195.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug723195.c generated by valac, the Vala compiler
  * generated from methods_bug723195.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug726347.c-expected b/tests/methods/bug726347.c-expected
index 84681feb5569c05a..1ec695c66a4fa688 100644
--- a/tests/methods/bug726347.c-expected
+++ b/tests/methods/bug726347.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug726347.c generated by valac, the Vala compiler
  * generated from methods_bug726347.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdarg.h>
diff --git a/tests/methods/bug736235.c-expected b/tests/methods/bug736235.c-expected
index 5f65d8936a40ffd3..d4d2396db956738a 100644
--- a/tests/methods/bug736235.c-expected
+++ b/tests/methods/bug736235.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug736235.c generated by valac, the Vala compiler
  * generated from methods_bug736235.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug737222.c-expected b/tests/methods/bug737222.c-expected
index c79c0cd513098fc7..8f00bd1c39dc7c6b 100644
--- a/tests/methods/bug737222.c-expected
+++ b/tests/methods/bug737222.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug737222.c generated by valac, the Vala compiler
  * generated from methods_bug737222.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug743877.c-expected b/tests/methods/bug743877.c-expected
index b5e893902fcf78c6..521da58eb91b898b 100644
--- a/tests/methods/bug743877.c-expected
+++ b/tests/methods/bug743877.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug743877.c generated by valac, the Vala compiler
  * generated from methods_bug743877.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <locale.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug771964.c-expected b/tests/methods/bug771964.c-expected
index 74f16bb9afa55609..5c3eddc172e18747 100644
--- a/tests/methods/bug771964.c-expected
+++ b/tests/methods/bug771964.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug771964.c generated by valac, the Vala compiler
  * generated from methods_bug771964.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/methods/bug774060.c-expected b/tests/methods/bug774060.c-expected
index 367b76b790afdde1..66bac77b2e9ca633 100644
--- a/tests/methods/bug774060.c-expected
+++ b/tests/methods/bug774060.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug774060.c generated by valac, the Vala compiler
  * generated from methods_bug774060.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/bug781061.c-expected b/tests/methods/bug781061.c-expected
index 477b8e67fe33ed90..4d0a934ce27ae978 100644
--- a/tests/methods/bug781061.c-expected
+++ b/tests/methods/bug781061.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug781061.c generated by valac, the Vala compiler
  * generated from methods_bug781061.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/methods/bug784691.c-expected b/tests/methods/bug784691.c-expected
index 7c7ccccecf517217..bbb4796b21c40553 100644
--- a/tests/methods/bug784691.c-expected
+++ b/tests/methods/bug784691.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug784691.c generated by valac, the Vala compiler
  * generated from methods_bug784691.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/bug791215.c-expected b/tests/methods/bug791215.c-expected
index 69066096a03d94b0..fee1b8057255c02a 100644
--- a/tests/methods/bug791215.c-expected
+++ b/tests/methods/bug791215.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug791215.c generated by valac, the Vala compiler
  * generated from methods_bug791215.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/bug791283.c-expected b/tests/methods/bug791283.c-expected
index 30d862fdf37b90bc..a6c75cef3ed164b4 100644
--- a/tests/methods/bug791283.c-expected
+++ b/tests/methods/bug791283.c-expected
@@ -1,6 +1,12 @@
 /* methods_bug791283.c generated by valac, the Vala compiler
  * generated from methods_bug791283.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/closures.c-expected b/tests/methods/closures.c-expected
index baafa40d99bbe743..abac8b700ac9c69b 100644
--- a/tests/methods/closures.c-expected
+++ b/tests/methods/closures.c-expected
@@ -1,6 +1,12 @@
 /* methods_closures.c generated by valac, the Vala compiler
  * generated from methods_closures.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/contains.c-expected b/tests/methods/contains.c-expected
index 38ce0855dcb643e5..d96dcd46d7f6efaa 100644
--- a/tests/methods/contains.c-expected
+++ b/tests/methods/contains.c-expected
@@ -1,6 +1,12 @@
 /* methods_contains.c generated by valac, the Vala compiler
  * generated from methods_contains.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/delegate-target.c-expected b/tests/methods/delegate-target.c-expected
index f1c6add6cdd52e5b..a5610848f061673d 100644
--- a/tests/methods/delegate-target.c-expected
+++ b/tests/methods/delegate-target.c-expected
@@ -1,6 +1,12 @@
 /* methods_delegate_target.c generated by valac, the Vala compiler
  * generated from methods_delegate_target.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/extern.c-expected b/tests/methods/extern.c-expected
index e8877a601b18317a..232a4c94dc41973f 100644
--- a/tests/methods/extern.c-expected
+++ b/tests/methods/extern.c-expected
@@ -1,6 +1,12 @@
 /* methods_extern.c generated by valac, the Vala compiler
  * generated from methods_extern.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/generics.c-expected b/tests/methods/generics.c-expected
index 8cc76765bd0d7988..1f440ac86a1778b1 100644
--- a/tests/methods/generics.c-expected
+++ b/tests/methods/generics.c-expected
@@ -1,6 +1,12 @@
 /* methods_generics.c generated by valac, the Vala compiler
  * generated from methods_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/iterator.c-expected b/tests/methods/iterator.c-expected
index 9f20bc38acb484d4..e49822b50bfd1bd3 100644
--- a/tests/methods/iterator.c-expected
+++ b/tests/methods/iterator.c-expected
@@ -1,6 +1,12 @@
 /* methods_iterator.c generated by valac, the Vala compiler
  * generated from methods_iterator.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/methods/lambda.c-expected b/tests/methods/lambda.c-expected
index 2eaa626423a26504..69f3782fb07d1473 100644
--- a/tests/methods/lambda.c-expected
+++ b/tests/methods/lambda.c-expected
@@ -1,6 +1,12 @@
 /* methods_lambda.c generated by valac, the Vala compiler
  * generated from methods_lambda.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/local-functions.c-expected b/tests/methods/local-functions.c-expected
index 92ac20ce4b1bdb2f..45a878d041f970e0 100644
--- a/tests/methods/local-functions.c-expected
+++ b/tests/methods/local-functions.c-expected
@@ -1,6 +1,12 @@
 /* methods_local_functions.c generated by valac, the Vala compiler
  * generated from methods_local_functions.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/nowrapper-interface.c-expected b/tests/methods/nowrapper-interface.c-expected
index 92cf1c1e7b12beac..bc4248b735aeaa66 100644
--- a/tests/methods/nowrapper-interface.c-expected
+++ b/tests/methods/nowrapper-interface.c-expected
@@ -1,6 +1,12 @@
 /* methods_nowrapper_interface.c generated by valac, the Vala compiler
  * generated from methods_nowrapper_interface.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/methods/parameter-ccode-type.c-expected b/tests/methods/parameter-ccode-type.c-expected
index 1718ba5dcb423bf4..8d6f1239937d701b 100644
--- a/tests/methods/parameter-ccode-type.c-expected
+++ b/tests/methods/parameter-ccode-type.c-expected
@@ -1,6 +1,12 @@
 /* methods_parameter_ccode_type.c generated by valac, the Vala compiler
  * generated from methods_parameter_ccode_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/parameter-fixed-array-initializer.c-expected b/tests/methods/parameter-fixed-array-initializer.c-expected
index b940fab63abadb53..fca6df6ffe5e864a 100644
--- a/tests/methods/parameter-fixed-array-initializer.c-expected
+++ b/tests/methods/parameter-fixed-array-initializer.c-expected
@@ -1,6 +1,12 @@
 /* methods_parameter_fixed_array_initializer.c generated by valac, the Vala compiler
  * generated from methods_parameter_fixed_array_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <float.h>
diff --git a/tests/methods/parameter-out-free-on-error.c-expected b/tests/methods/parameter-out-free-on-error.c-expected
index 1cd0a5cbe62d8c8a..7bb3722927b938a6 100644
--- a/tests/methods/parameter-out-free-on-error.c-expected
+++ b/tests/methods/parameter-out-free-on-error.c-expected
@@ -1,6 +1,12 @@
 /* methods_parameter_out_free_on_error.c generated by valac, the Vala compiler
  * generated from methods_parameter_out_free_on_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/methods/parameter-ref-array-resize-captured.c-expected b/tests/methods/parameter-ref-array-resize-captured.c-expected
index 2b06a3a23e6dc287..d996796a500a59dd 100644
--- a/tests/methods/parameter-ref-array-resize-captured.c-expected
+++ b/tests/methods/parameter-ref-array-resize-captured.c-expected
@@ -1,6 +1,12 @@
 /* methods_parameter_ref_array_resize_captured.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_array_resize_captured.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/parameter-ref-array-resize.c-expected b/tests/methods/parameter-ref-array-resize.c-expected
index ece83e9884d207d7..be2724bcdf3a6bed 100644
--- a/tests/methods/parameter-ref-array-resize.c-expected
+++ b/tests/methods/parameter-ref-array-resize.c-expected
@@ -1,6 +1,12 @@
 /* methods_parameter_ref_array_resize.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_array_resize.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/parameter-ref-delegate.c-expected b/tests/methods/parameter-ref-delegate.c-expected
index dafddddf65956a96..5cbbf445320445a4 100644
--- a/tests/methods/parameter-ref-delegate.c-expected
+++ b/tests/methods/parameter-ref-delegate.c-expected
@@ -1,6 +1,12 @@
 /* methods_parameter_ref_delegate.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/parameter-ref-element-access.c-expected b/tests/methods/parameter-ref-element-access.c-expected
index e87761df92ac8f7e..4c9994de8a1331f2 100644
--- a/tests/methods/parameter-ref-element-access.c-expected
+++ b/tests/methods/parameter-ref-element-access.c-expected
@@ -1,6 +1,12 @@
 /* methods_parameter_ref_element_access.c generated by valac, the Vala compiler
  * generated from methods_parameter_ref_element_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/params-array-with-throws.c-expected b/tests/methods/params-array-with-throws.c-expected
index 43e3f55d65a59df1..d884fd895f81b16d 100644
--- a/tests/methods/params-array-with-throws.c-expected
+++ b/tests/methods/params-array-with-throws.c-expected
@@ -1,6 +1,12 @@
 /* methods_params_array_with_throws.c generated by valac, the Vala compiler
  * generated from methods_params_array_with_throws.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/methods/params-array.c-expected b/tests/methods/params-array.c-expected
index 00cd25a25166d635..902ea09a50439400 100644
--- a/tests/methods/params-array.c-expected
+++ b/tests/methods/params-array.c-expected
@@ -1,6 +1,12 @@
 /* methods_params_array.c generated by valac, the Vala compiler
  * generated from methods_params_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/postconditions-temp-variables.c-expected b/tests/methods/postconditions-temp-variables.c-expected
index fbc76445f7de4100..07b5df64f1eb2535 100644
--- a/tests/methods/postconditions-temp-variables.c-expected
+++ b/tests/methods/postconditions-temp-variables.c-expected
@@ -1,6 +1,12 @@
 /* methods_postconditions_temp_variables.c generated by valac, the Vala compiler
  * generated from methods_postconditions_temp_variables.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/postconditions.c-expected b/tests/methods/postconditions.c-expected
index f577e535d07cbfbc..2dbf1f4f05f9fdce 100644
--- a/tests/methods/postconditions.c-expected
+++ b/tests/methods/postconditions.c-expected
@@ -1,6 +1,12 @@
 /* methods_postconditions.c generated by valac, the Vala compiler
  * generated from methods_postconditions.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/preconditions-temp-variables.c-expected b/tests/methods/preconditions-temp-variables.c-expected
index 25d4267b344b435c..d2d844670be643f2 100644
--- a/tests/methods/preconditions-temp-variables.c-expected
+++ b/tests/methods/preconditions-temp-variables.c-expected
@@ -1,6 +1,12 @@
 /* methods_preconditions_temp_variables.c generated by valac, the Vala compiler
  * generated from methods_preconditions_temp_variables.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/prepostconditions-captured.c-expected b/tests/methods/prepostconditions-captured.c-expected
index 7d8484f552ce8aa6..def85beb6cc80904 100644
--- a/tests/methods/prepostconditions-captured.c-expected
+++ b/tests/methods/prepostconditions-captured.c-expected
@@ -1,6 +1,12 @@
 /* methods_prepostconditions_captured.c generated by valac, the Vala compiler
  * generated from methods_prepostconditions_captured.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/methods/prepostconditions-contains.c-expected b/tests/methods/prepostconditions-contains.c-expected
index 5409cd2186b16d19..c3f5e9747334c534 100644
--- a/tests/methods/prepostconditions-contains.c-expected
+++ b/tests/methods/prepostconditions-contains.c-expected
@@ -1,6 +1,12 @@
 /* methods_prepostconditions_contains.c generated by valac, the Vala compiler
  * generated from methods_prepostconditions_contains.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/prepostconditions.c-expected b/tests/methods/prepostconditions.c-expected
index b9917451637d450c..08658a37e9643169 100644
--- a/tests/methods/prepostconditions.c-expected
+++ b/tests/methods/prepostconditions.c-expected
@@ -1,6 +1,12 @@
 /* methods_prepostconditions.c generated by valac, the Vala compiler
  * generated from methods_prepostconditions.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/methods/print-attribute.c-expected b/tests/methods/print-attribute.c-expected
index 744d84bb9c8f0b33..e64d927dc66f0d99 100644
--- a/tests/methods/print-attribute.c-expected
+++ b/tests/methods/print-attribute.c-expected
@@ -1,6 +1,12 @@
 /* methods_print_attribute.c generated by valac, the Vala compiler
  * generated from methods_print_attribute.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/methods/printf-constructor.c-expected b/tests/methods/printf-constructor.c-expected
index 6f465f49568efdcc..ac0e59a4a05dd447 100644
--- a/tests/methods/printf-constructor.c-expected
+++ b/tests/methods/printf-constructor.c-expected
@@ -1,6 +1,12 @@
 /* methods_printf_constructor.c generated by valac, the Vala compiler
  * generated from methods_printf_constructor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _g_error_free0(var) ((var == NULL) ? NULL : (var = (g_error_free (var), NULL)))
diff --git a/tests/methods/profile.c-expected b/tests/methods/profile.c-expected
index 9a0bba52beccb78e..7c0b594a6330a2c8 100644
--- a/tests/methods/profile.c-expected
+++ b/tests/methods/profile.c-expected
@@ -1,6 +1,12 @@
 /* methods_profile.c generated by valac, the Vala compiler
  * generated from methods_profile.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdio.h>
 #include <glib.h>
 
diff --git a/tests/methods/return-unowned-delegate.c-expected b/tests/methods/return-unowned-delegate.c-expected
index 96904ba1e560467e..b2db5bf47d311151 100644
--- a/tests/methods/return-unowned-delegate.c-expected
+++ b/tests/methods/return-unowned-delegate.c-expected
@@ -1,6 +1,12 @@
 /* methods_return_unowned_delegate.c generated by valac, the Vala compiler
  * generated from methods_return_unowned_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/methods/same-name.c-expected b/tests/methods/same-name.c-expected
index e68b4f3d21f70646..fa8860d8b0dd5793 100644
--- a/tests/methods/same-name.c-expected
+++ b/tests/methods/same-name.c-expected
@@ -1,6 +1,12 @@
 /* methods_same_name.c generated by valac, the Vala compiler
  * generated from methods_same_name.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/methods/symbolresolution.c-expected b/tests/methods/symbolresolution.c-expected
index 301a18c58c5f4d8f..ce974972a61340ce 100644
--- a/tests/methods/symbolresolution.c-expected
+++ b/tests/methods/symbolresolution.c-expected
@@ -1,6 +1,12 @@
 /* methods_symbolresolution.c generated by valac, the Vala compiler
  * generated from methods_symbolresolution.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/methods/varargs-delegate-without-target.c-expected b/tests/methods/varargs-delegate-without-target.c-expected
index 5b8caa4811a3c1ae..1b8d2768e2f9cfbd 100644
--- a/tests/methods/varargs-delegate-without-target.c-expected
+++ b/tests/methods/varargs-delegate-without-target.c-expected
@@ -1,6 +1,12 @@
 /* methods_varargs_delegate_without_target.c generated by valac, the Vala compiler
  * generated from methods_varargs_delegate_without_target.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/varargs-delegate.c-expected b/tests/methods/varargs-delegate.c-expected
index 2a20d4e156a00f1e..66e556ed4df72655 100644
--- a/tests/methods/varargs-delegate.c-expected
+++ b/tests/methods/varargs-delegate.c-expected
@@ -1,6 +1,12 @@
 /* methods_varargs_delegate.c generated by valac, the Vala compiler
  * generated from methods_varargs_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/varargs-gvalue.c-expected b/tests/methods/varargs-gvalue.c-expected
index 5c5d26a69220be5c..4662b0d519bebe22 100644
--- a/tests/methods/varargs-gvalue.c-expected
+++ b/tests/methods/varargs-gvalue.c-expected
@@ -1,6 +1,12 @@
 /* methods_varargs_gvalue.c generated by valac, the Vala compiler
  * generated from methods_varargs_gvalue.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 #include <glib-object.h>
diff --git a/tests/methods/varargs-out.c-expected b/tests/methods/varargs-out.c-expected
index 35e5ef5eb6d09fca..f12aed3ae2c3937d 100644
--- a/tests/methods/varargs-out.c-expected
+++ b/tests/methods/varargs-out.c-expected
@@ -1,6 +1,12 @@
 /* methods_varargs_out.c generated by valac, the Vala compiler
  * generated from methods_varargs_out.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/methods/varargs-ref.c-expected b/tests/methods/varargs-ref.c-expected
index cc68f4ab71d7a5b2..f94e5da6b38fcc56 100644
--- a/tests/methods/varargs-ref.c-expected
+++ b/tests/methods/varargs-ref.c-expected
@@ -1,6 +1,12 @@
 /* methods_varargs_ref.c generated by valac, the Vala compiler
  * generated from methods_varargs_ref.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/methods/varargs-struct.c-expected b/tests/methods/varargs-struct.c-expected
index 5b6e85af94a524f7..ba12f2045309fbf5 100644
--- a/tests/methods/varargs-struct.c-expected
+++ b/tests/methods/varargs-struct.c-expected
@@ -1,6 +1,12 @@
 /* methods_varargs_struct.c generated by valac, the Vala compiler
  * generated from methods_varargs_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 #include <stdarg.h>
diff --git a/tests/namespace/unique.c-expected b/tests/namespace/unique.c-expected
index 102796fd020fa91a..8be25de7417f213a 100644
--- a/tests/namespace/unique.c-expected
+++ b/tests/namespace/unique.c-expected
@@ -1,6 +1,12 @@
 /* namespace_unique.c generated by valac, the Vala compiler
  * generated from namespace_unique.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/nullability/array-element-class.c-expected b/tests/nullability/array-element-class.c-expected
index db59e2382770ec29..05a0f4c24d553704 100644
--- a/tests/nullability/array-element-class.c-expected
+++ b/tests/nullability/array-element-class.c-expected
@@ -1,6 +1,12 @@
 /* nullability_array_element_class.c generated by valac, the Vala compiler
  * generated from nullability_array_element_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/nullability/array-element-string.c-expected b/tests/nullability/array-element-string.c-expected
index 4ce699022505d869..5489188623612990 100644
--- a/tests/nullability/array-element-string.c-expected
+++ b/tests/nullability/array-element-string.c-expected
@@ -1,6 +1,12 @@
 /* nullability_array_element_string.c generated by valac, the Vala compiler
  * generated from nullability_array_element_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/nullability/bug611223.c-expected b/tests/nullability/bug611223.c-expected
index e79eb96908bfc4bf..2c71a864eac16b2b 100644
--- a/tests/nullability/bug611223.c-expected
+++ b/tests/nullability/bug611223.c-expected
@@ -1,6 +1,12 @@
 /* nullability_bug611223.c generated by valac, the Vala compiler
  * generated from nullability_bug611223.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/nullability/member-access-narrowed-instance.c-expected b/tests/nullability/member-access-narrowed-instance.c-expected
index 4f4051bc1f366e69..48169a8ba9bb637b 100644
--- a/tests/nullability/member-access-narrowed-instance.c-expected
+++ b/tests/nullability/member-access-narrowed-instance.c-expected
@@ -1,6 +1,12 @@
 /* nullability_member_access_narrowed_instance.c generated by valac, the Vala compiler
  * generated from nullability_member_access_narrowed_instance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/nullability/var-type.c-expected b/tests/nullability/var-type.c-expected
index 10be13b515f09979..64d1de6649788864 100644
--- a/tests/nullability/var-type.c-expected
+++ b/tests/nullability/var-type.c-expected
@@ -1,6 +1,12 @@
 /* nullability_var_type.c generated by valac, the Vala compiler
  * generated from nullability_var_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/bug566909.c-expected b/tests/objects/bug566909.c-expected
index 05ada381fd9eee19..47563b67a2c7b400 100644
--- a/tests/objects/bug566909.c-expected
+++ b/tests/objects/bug566909.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug566909.c generated by valac, the Vala compiler
  * generated from objects_bug566909.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug588203.c-expected b/tests/objects/bug588203.c-expected
index 762390cd123c9f0d..8619710dda239b78 100644
--- a/tests/objects/bug588203.c-expected
+++ b/tests/objects/bug588203.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug588203.c generated by valac, the Vala compiler
  * generated from objects_bug588203.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug589928.c-expected b/tests/objects/bug589928.c-expected
index 9dcde3e70851b919..7883a82737b9d8fd 100644
--- a/tests/objects/bug589928.c-expected
+++ b/tests/objects/bug589928.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug589928.c generated by valac, the Vala compiler
  * generated from objects_bug589928.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug593137.c-expected b/tests/objects/bug593137.c-expected
index 287bc43fa899232f..c47f5de1945644e5 100644
--- a/tests/objects/bug593137.c-expected
+++ b/tests/objects/bug593137.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug593137.c generated by valac, the Vala compiler
  * generated from objects_bug593137.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug593260.c-expected b/tests/objects/bug593260.c-expected
index a0b3fb9c8b5d49be..6d7da75a4f1c205a 100644
--- a/tests/objects/bug593260.c-expected
+++ b/tests/objects/bug593260.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug593260.c generated by valac, the Vala compiler
  * generated from objects_bug593260.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug596621.c-expected b/tests/objects/bug596621.c-expected
index 1beebed6c67d1b40..0aa49d09f22549f4 100644
--- a/tests/objects/bug596621.c-expected
+++ b/tests/objects/bug596621.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug596621.c generated by valac, the Vala compiler
  * generated from objects_bug596621.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/bug597155.c-expected b/tests/objects/bug597155.c-expected
index e1336728c9141e46..75115fc106306367 100644
--- a/tests/objects/bug597155.c-expected
+++ b/tests/objects/bug597155.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug597155.c generated by valac, the Vala compiler
  * generated from objects_bug597155.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug597161.c-expected b/tests/objects/bug597161.c-expected
index 958cbda3e73cab35..a9e25b5d9fc1c6cb 100644
--- a/tests/objects/bug597161.c-expected
+++ b/tests/objects/bug597161.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug597161.c generated by valac, the Vala compiler
  * generated from objects_bug597161.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug613486.c-expected b/tests/objects/bug613486.c-expected
index ce02c4d4a18526d2..900b8999161a6065 100644
--- a/tests/objects/bug613486.c-expected
+++ b/tests/objects/bug613486.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug613486.c generated by valac, the Vala compiler
  * generated from objects_bug613486.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug613840.c-expected b/tests/objects/bug613840.c-expected
index 3acd5e764c1735a7..136243be611e8e7c 100644
--- a/tests/objects/bug613840.c-expected
+++ b/tests/objects/bug613840.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug613840.c generated by valac, the Vala compiler
  * generated from objects_bug613840.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug620675.c-expected b/tests/objects/bug620675.c-expected
index 46dd1a3a0db1a346..2a946a4c00b12652 100644
--- a/tests/objects/bug620675.c-expected
+++ b/tests/objects/bug620675.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug620675.c generated by valac, the Vala compiler
  * generated from objects_bug620675.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug620706.c-expected b/tests/objects/bug620706.c-expected
index 7165a7b62cbd69ba..40650811391938d7 100644
--- a/tests/objects/bug620706.c-expected
+++ b/tests/objects/bug620706.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug620706.c generated by valac, the Vala compiler
  * generated from objects_bug620706.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug624594.c-expected b/tests/objects/bug624594.c-expected
index ee199a553cff417e..abdb837eec70b1d9 100644
--- a/tests/objects/bug624594.c-expected
+++ b/tests/objects/bug624594.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug624594.c generated by valac, the Vala compiler
  * generated from objects_bug624594.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug626038-2.c-expected b/tests/objects/bug626038-2.c-expected
index 9c4f767bf23f0165..a9fc461c53d7dcbb 100644
--- a/tests/objects/bug626038-2.c-expected
+++ b/tests/objects/bug626038-2.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug626038_2.c generated by valac, the Vala compiler
  * generated from objects_bug626038_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/bug626038.c-expected b/tests/objects/bug626038.c-expected
index 994cb86ac6577ded..cbf68e29faa71942 100644
--- a/tests/objects/bug626038.c-expected
+++ b/tests/objects/bug626038.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug626038.c generated by valac, the Vala compiler
  * generated from objects_bug626038.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/objects/bug628639.c-expected b/tests/objects/bug628639.c-expected
index 71864fa2e047b1ac..b54340cd82d7e3e9 100644
--- a/tests/objects/bug628639.c-expected
+++ b/tests/objects/bug628639.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug628639.c generated by valac, the Vala compiler
  * generated from objects_bug628639.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug629593.c-expected b/tests/objects/bug629593.c-expected
index 4f4814f0190849cd..3cb860e5de36f2e8 100644
--- a/tests/objects/bug629593.c-expected
+++ b/tests/objects/bug629593.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug629593.c generated by valac, the Vala compiler
  * generated from objects_bug629593.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug631267.c-expected b/tests/objects/bug631267.c-expected
index 7f39c30d055fb512..5e5e17f97ff0553c 100644
--- a/tests/objects/bug631267.c-expected
+++ b/tests/objects/bug631267.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug631267.c generated by valac, the Vala compiler
  * generated from objects_bug631267.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug634782.c-expected b/tests/objects/bug634782.c-expected
index 9aaf333e7d2413d4..50dcf11e1beebaf2 100644
--- a/tests/objects/bug634782.c-expected
+++ b/tests/objects/bug634782.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug634782.c generated by valac, the Vala compiler
  * generated from objects_bug634782.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug641828.c-expected b/tests/objects/bug641828.c-expected
index 9ce869b9c19228fb..7ff08f6d6b9b8709 100644
--- a/tests/objects/bug641828.c-expected
+++ b/tests/objects/bug641828.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug641828.c generated by valac, the Vala compiler
  * generated from objects_bug641828.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug642809.c-expected b/tests/objects/bug642809.c-expected
index 01a87924443a3a6d..d8f0e8b0b5224a5e 100644
--- a/tests/objects/bug642809.c-expected
+++ b/tests/objects/bug642809.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug642809.c generated by valac, the Vala compiler
  * generated from objects_bug642809.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/bug643711.c-expected b/tests/objects/bug643711.c-expected
index c6f609155f69ffab..a59665386552863e 100644
--- a/tests/objects/bug643711.c-expected
+++ b/tests/objects/bug643711.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug643711.c generated by valac, the Vala compiler
  * generated from objects_bug643711.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug644938.c-expected b/tests/objects/bug644938.c-expected
index cc264a45b2ebf866..2e00da9c762e05f4 100644
--- a/tests/objects/bug644938.c-expected
+++ b/tests/objects/bug644938.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug644938.c generated by valac, the Vala compiler
  * generated from objects_bug644938.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug646362.c-expected b/tests/objects/bug646362.c-expected
index ebe50de6b9e27c3b..aa46addc1abf52f2 100644
--- a/tests/objects/bug646362.c-expected
+++ b/tests/objects/bug646362.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug646362.c generated by valac, the Vala compiler
  * generated from objects_bug646362.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug646792.c-expected b/tests/objects/bug646792.c-expected
index a2d9bfcec9e941b0..27800fc6796d9697 100644
--- a/tests/objects/bug646792.c-expected
+++ b/tests/objects/bug646792.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug646792.c generated by valac, the Vala compiler
  * generated from objects_bug646792.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <stdlib.h>
diff --git a/tests/objects/bug647018.c-expected b/tests/objects/bug647018.c-expected
index 5ddb3f2167f8510d..565d9f28bbafb515 100644
--- a/tests/objects/bug647018.c-expected
+++ b/tests/objects/bug647018.c-expected
@@ -2,6 +2,11 @@
  * generated from objects_bug647018.vala, do not modify */
 
 /* allow fields starting with a digit if the cname is valid*/
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
 
 #include <glib.h>
 
diff --git a/tests/objects/bug653138.c-expected b/tests/objects/bug653138.c-expected
index eaef9d195c42e825..c926a5a71bafd7e0 100644
--- a/tests/objects/bug653138.c-expected
+++ b/tests/objects/bug653138.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug653138.c generated by valac, the Vala compiler
  * generated from objects_bug653138.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug654702.c-expected b/tests/objects/bug654702.c-expected
index 0d0b8a4302118cfe..8c5d102cbc1a5b21 100644
--- a/tests/objects/bug654702.c-expected
+++ b/tests/objects/bug654702.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug654702.c generated by valac, the Vala compiler
  * generated from objects_bug654702.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug663134.c-expected b/tests/objects/bug663134.c-expected
index 945de99f5ee7ab82..ae991c672feddb8b 100644
--- a/tests/objects/bug663134.c-expected
+++ b/tests/objects/bug663134.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug663134.c generated by valac, the Vala compiler
  * generated from objects_bug663134.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/bug664529.c-expected b/tests/objects/bug664529.c-expected
index 42398dc81d79b6d7..369369e4b26658f5 100644
--- a/tests/objects/bug664529.c-expected
+++ b/tests/objects/bug664529.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug664529.c generated by valac, the Vala compiler
  * generated from objects_bug664529.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug681356.c-expected b/tests/objects/bug681356.c-expected
index 82fff780e4f4971a..23042a76953f8881 100644
--- a/tests/objects/bug681356.c-expected
+++ b/tests/objects/bug681356.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug681356.c generated by valac, the Vala compiler
  * generated from objects_bug681356.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug683646.c-expected b/tests/objects/bug683646.c-expected
index 97f2b21a25127a31..03ec9c39207535a3 100644
--- a/tests/objects/bug683646.c-expected
+++ b/tests/objects/bug683646.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug683646.c generated by valac, the Vala compiler
  * generated from objects_bug683646.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/bug695671.c-expected b/tests/objects/bug695671.c-expected
index bd8cf12956cf19a9..76cd4480dc58b4b2 100644
--- a/tests/objects/bug695671.c-expected
+++ b/tests/objects/bug695671.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug695671.c generated by valac, the Vala compiler
  * generated from objects_bug695671.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug702736.c-expected b/tests/objects/bug702736.c-expected
index 49621ee3c3889112..4cf4664ec3ed836f 100644
--- a/tests/objects/bug702736.c-expected
+++ b/tests/objects/bug702736.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug702736.c generated by valac, the Vala compiler
  * generated from objects_bug702736.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug702846.c-expected b/tests/objects/bug702846.c-expected
index 452e33ef12febe22..682922b88612c33a 100644
--- a/tests/objects/bug702846.c-expected
+++ b/tests/objects/bug702846.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug702846.c generated by valac, the Vala compiler
  * generated from objects_bug702846.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug731547.c-expected b/tests/objects/bug731547.c-expected
index 51d6391aa4ef705c..994fdb75d175a7ff 100644
--- a/tests/objects/bug731547.c-expected
+++ b/tests/objects/bug731547.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug731547.c generated by valac, the Vala compiler
  * generated from objects_bug731547.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug741465.c-expected b/tests/objects/bug741465.c-expected
index d52a7a5604d22128..1e0e84704820011e 100644
--- a/tests/objects/bug741465.c-expected
+++ b/tests/objects/bug741465.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug741465.c generated by valac, the Vala compiler
  * generated from objects_bug741465.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/bug751338.c-expected b/tests/objects/bug751338.c-expected
index b03bc708b608e36e..44d6428ecec582c0 100644
--- a/tests/objects/bug751338.c-expected
+++ b/tests/objects/bug751338.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug751338.c generated by valac, the Vala compiler
  * generated from objects_bug751338.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug758816.c-expected b/tests/objects/bug758816.c-expected
index c22e446368351091..ad028395c5656a4d 100644
--- a/tests/objects/bug758816.c-expected
+++ b/tests/objects/bug758816.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug758816.c generated by valac, the Vala compiler
  * generated from objects_bug758816.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug764481.c-expected b/tests/objects/bug764481.c-expected
index b9404cec098ec7d0..e9ba1c51cfe655ea 100644
--- a/tests/objects/bug764481.c-expected
+++ b/tests/objects/bug764481.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug764481.c generated by valac, the Vala compiler
  * generated from objects_bug764481.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug766739.c-expected b/tests/objects/bug766739.c-expected
index 17f4adb529afc5eb..ba7c5bd0632f8035 100644
--- a/tests/objects/bug766739.c-expected
+++ b/tests/objects/bug766739.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug766739.c generated by valac, the Vala compiler
  * generated from objects_bug766739.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug778632.c-expected b/tests/objects/bug778632.c-expected
index ef8387d12cbf8b8a..cb7c1a4dc1af909e 100644
--- a/tests/objects/bug778632.c-expected
+++ b/tests/objects/bug778632.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug778632.c generated by valac, the Vala compiler
  * generated from objects_bug778632.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug779219.c-expected b/tests/objects/bug779219.c-expected
index d2eb9960943abc62..42b298334418dc25 100644
--- a/tests/objects/bug779219.c-expected
+++ b/tests/objects/bug779219.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug779219.c generated by valac, the Vala compiler
  * generated from objects_bug779219.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug779955.c-expected b/tests/objects/bug779955.c-expected
index 43451cbc91a5b3af..78dc7d0757244bb2 100644
--- a/tests/objects/bug779955.c-expected
+++ b/tests/objects/bug779955.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug779955.c generated by valac, the Vala compiler
  * generated from objects_bug779955.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/bug783897.c-expected b/tests/objects/bug783897.c-expected
index 389f3a547d282dc4..ecb32ae9c6b77401 100644
--- a/tests/objects/bug783897.c-expected
+++ b/tests/objects/bug783897.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug783897.c generated by valac, the Vala compiler
  * generated from objects_bug783897.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/bug788964.c-expected b/tests/objects/bug788964.c-expected
index 2f2cca4bab5b43d6..8b30ccc534d88103 100644
--- a/tests/objects/bug788964.c-expected
+++ b/tests/objects/bug788964.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug788964.c generated by valac, the Vala compiler
  * generated from objects_bug788964.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/bug795521.c-expected b/tests/objects/bug795521.c-expected
index 07a62749482115c5..e74e73e63d0e1fe0 100644
--- a/tests/objects/bug795521.c-expected
+++ b/tests/objects/bug795521.c-expected
@@ -1,6 +1,12 @@
 /* objects_bug795521.c generated by valac, the Vala compiler
  * generated from objects_bug795521.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/chainup.c-expected b/tests/objects/chainup.c-expected
index a3d35c3efa974ab2..ecff40e8b1e0b332 100644
--- a/tests/objects/chainup.c-expected
+++ b/tests/objects/chainup.c-expected
@@ -1,6 +1,12 @@
 /* objects_chainup.c generated by valac, the Vala compiler
  * generated from objects_chainup.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdarg.h>
diff --git a/tests/objects/class-ccode-cprefix.c-expected b/tests/objects/class-ccode-cprefix.c-expected
index e2dbcc440559d143..4373958897c8e0b0 100644
--- a/tests/objects/class-ccode-cprefix.c-expected
+++ b/tests/objects/class-ccode-cprefix.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_ccode_cprefix.c generated by valac, the Vala compiler
  * generated from objects_class_ccode_cprefix.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/objects/class-destroysinstance.c-expected b/tests/objects/class-destroysinstance.c-expected
index 4f52cd7f71064631..ded013e7d187a9ae 100644
--- a/tests/objects/class-destroysinstance.c-expected
+++ b/tests/objects/class-destroysinstance.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_destroysinstance.c generated by valac, the Vala compiler
  * generated from objects_class_destroysinstance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/class-inner-types.c-expected b/tests/objects/class-inner-types.c-expected
index 110ad6abb8c87479..b68d5a8083f78685 100644
--- a/tests/objects/class-inner-types.c-expected
+++ b/tests/objects/class-inner-types.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_inner_types.c generated by valac, the Vala compiler
  * generated from objects_class_inner_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/class-new-no-override.c-expected b/tests/objects/class-new-no-override.c-expected
index 6d9dec170eaa5dec..96626dc8f6a85557 100644
--- a/tests/objects/class-new-no-override.c-expected
+++ b/tests/objects/class-new-no-override.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_new_no_override.c generated by valac, the Vala compiler
  * generated from objects_class_new_no_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/class-partial-nested.c-expected b/tests/objects/class-partial-nested.c-expected
index c0ddeafd9d3a3612..e3d8a4fef2f5470f 100644
--- a/tests/objects/class-partial-nested.c-expected
+++ b/tests/objects/class-partial-nested.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_partial_nested.c generated by valac, the Vala compiler
  * generated from objects_class_partial_nested.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/class-partial.c-expected b/tests/objects/class-partial.c-expected
index 0b9f77d2f8551aa5..cb632f003d823af2 100644
--- a/tests/objects/class-partial.c-expected
+++ b/tests/objects/class-partial.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_partial.c generated by valac, the Vala compiler
  * generated from objects_class_partial.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/class-ref-void.c-expected b/tests/objects/class-ref-void.c-expected
index d0038ab464dc4310..3b86adcb86ba9cc5 100644
--- a/tests/objects/class-ref-void.c-expected
+++ b/tests/objects/class-ref-void.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_ref_void.c generated by valac, the Vala compiler
  * generated from objects_class_ref_void.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/class-vfunc-base-access.c-expected b/tests/objects/class-vfunc-base-access.c-expected
index 2ad5c9cdf383b852..ac39d81dd4c05354 100644
--- a/tests/objects/class-vfunc-base-access.c-expected
+++ b/tests/objects/class-vfunc-base-access.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_vfunc_base_access.c generated by valac, the Vala compiler
  * generated from objects_class_vfunc_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/class_only.c-expected b/tests/objects/class_only.c-expected
index b4e6d87cc2762c4a..f2398840f5fa0eda 100644
--- a/tests/objects/class_only.c-expected
+++ b/tests/objects/class_only.c-expected
@@ -1,6 +1,12 @@
 /* objects_class_only.c generated by valac, the Vala compiler
  * generated from objects_class_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/objects/classes-implicit-implementation.c-expected b/tests/objects/classes-implicit-implementation.c-expected
index 3008fbc0107c7963..7d7e97ba06bfd40c 100644
--- a/tests/objects/classes-implicit-implementation.c-expected
+++ b/tests/objects/classes-implicit-implementation.c-expected
@@ -1,6 +1,12 @@
 /* objects_classes_implicit_implementation.c generated by valac, the Vala compiler
  * generated from objects_classes_implicit_implementation.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/classes-interfaces-virtuals.c-expected b/tests/objects/classes-interfaces-virtuals.c-expected
index a770c2b32deb9a50..02a0f36a4bd986d5 100644
--- a/tests/objects/classes-interfaces-virtuals.c-expected
+++ b/tests/objects/classes-interfaces-virtuals.c-expected
@@ -1,6 +1,12 @@
 /* objects_classes_interfaces_virtuals.c generated by valac, the Vala compiler
  * generated from objects_classes_interfaces_virtuals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/classes-interfaces.c-expected b/tests/objects/classes-interfaces.c-expected
index fce71f4e7ace44ef..c327a206f4727543 100644
--- a/tests/objects/classes-interfaces.c-expected
+++ b/tests/objects/classes-interfaces.c-expected
@@ -1,6 +1,12 @@
 /* objects_classes_interfaces.c generated by valac, the Vala compiler
  * generated from objects_classes_interfaces.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/classes.c-expected b/tests/objects/classes.c-expected
index afe167367a783d70..66f9b5fa3f9661ba 100644
--- a/tests/objects/classes.c-expected
+++ b/tests/objects/classes.c-expected
@@ -1,6 +1,12 @@
 /* objects_classes.c generated by valac, the Vala compiler
  * generated from objects_classes.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdio.h>
 #include <glib-object.h>
diff --git a/tests/objects/compact-class-custom-ref.c-expected b/tests/objects/compact-class-custom-ref.c-expected
index 7d15c46c78b179cd..5be7b4a5291b64e3 100644
--- a/tests/objects/compact-class-custom-ref.c-expected
+++ b/tests/objects/compact-class-custom-ref.c-expected
@@ -1,6 +1,12 @@
 /* objects_compact_class_custom_ref.c generated by valac, the Vala compiler
  * generated from objects_compact_class_custom_ref.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/compact-class-destructor.c-expected b/tests/objects/compact-class-destructor.c-expected
index 7214f19d81ed7a69..88fa4073fb2d09d6 100644
--- a/tests/objects/compact-class-destructor.c-expected
+++ b/tests/objects/compact-class-destructor.c-expected
@@ -1,6 +1,12 @@
 /* objects_compact_class_destructor.c generated by valac, the Vala compiler
  * generated from objects_compact_class_destructor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/compact-class-refcount.c-expected b/tests/objects/compact-class-refcount.c-expected
index 1d0cf67ee00ed543..c1856df22a2e5743 100644
--- a/tests/objects/compact-class-refcount.c-expected
+++ b/tests/objects/compact-class-refcount.c-expected
@@ -1,6 +1,12 @@
 /* objects_compact_class_refcount.c generated by valac, the Vala compiler
  * generated from objects_compact_class_refcount.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/compact-class.c-expected b/tests/objects/compact-class.c-expected
index 4a2ab95f9696c992..253f7326871e5a44 100644
--- a/tests/objects/compact-class.c-expected
+++ b/tests/objects/compact-class.c-expected
@@ -1,6 +1,12 @@
 /* objects_compact_class.c generated by valac, the Vala compiler
  * generated from objects_compact_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/constructor-inner-error.c-expected b/tests/objects/constructor-inner-error.c-expected
index 702c79511b755047..5e0c78461ea14668 100644
--- a/tests/objects/constructor-inner-error.c-expected
+++ b/tests/objects/constructor-inner-error.c-expected
@@ -1,6 +1,12 @@
 /* objects_constructor_inner_error.c generated by valac, the Vala compiler
  * generated from objects_constructor_inner_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/constructor-variadic.c-expected b/tests/objects/constructor-variadic.c-expected
index 522fb8325d86e993..1ffc204772052f06 100644
--- a/tests/objects/constructor-variadic.c-expected
+++ b/tests/objects/constructor-variadic.c-expected
@@ -1,6 +1,12 @@
 /* objects_constructor_variadic.c generated by valac, the Vala compiler
  * generated from objects_constructor_variadic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/constructors.c-expected b/tests/objects/constructors.c-expected
index a928d36fafc8e8cb..d934961c3f9742ea 100644
--- a/tests/objects/constructors.c-expected
+++ b/tests/objects/constructors.c-expected
@@ -1,6 +1,12 @@
 /* objects_constructors.c generated by valac, the Vala compiler
  * generated from objects_constructors.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/destructors.c-expected b/tests/objects/destructors.c-expected
index a3e969bef7382682..534d20e118daedf2 100644
--- a/tests/objects/destructors.c-expected
+++ b/tests/objects/destructors.c-expected
@@ -1,6 +1,12 @@
 /* objects_destructors.c generated by valac, the Vala compiler
  * generated from objects_destructors.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/dynamic.c-expected b/tests/objects/dynamic.c-expected
index c1a3aed501b65e5d..6b5ebf2cc088d9a6 100644
--- a/tests/objects/dynamic.c-expected
+++ b/tests/objects/dynamic.c-expected
@@ -1,6 +1,12 @@
 /* objects_dynamic.c generated by valac, the Vala compiler
  * generated from objects_dynamic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/fields.c-expected b/tests/objects/fields.c-expected
index c0fdf2f7cb268e5a..43d6b26c14d37762 100644
--- a/tests/objects/fields.c-expected
+++ b/tests/objects/fields.c-expected
@@ -1,6 +1,12 @@
 /* objects_fields.c generated by valac, the Vala compiler
  * generated from objects_fields.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/generics.c-expected b/tests/objects/generics.c-expected
index 09b90174acfd7fe1..3e0f470ee2afe45c 100644
--- a/tests/objects/generics.c-expected
+++ b/tests/objects/generics.c-expected
@@ -1,6 +1,12 @@
 /* objects_generics.c generated by valac, the Vala compiler
  * generated from objects_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/gobject-class-lifetime.c-expected b/tests/objects/gobject-class-lifetime.c-expected
index d2c971e12fd0c476..97b96b8236a178e4 100644
--- a/tests/objects/gobject-class-lifetime.c-expected
+++ b/tests/objects/gobject-class-lifetime.c-expected
@@ -1,6 +1,12 @@
 /* objects_gobject_class_lifetime.c generated by valac, the Vala compiler
  * generated from objects_gobject_class_lifetime.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/gsource.c-expected b/tests/objects/gsource.c-expected
index 3413e072676600b9..61870b3e507f1bc9 100644
--- a/tests/objects/gsource.c-expected
+++ b/tests/objects/gsource.c-expected
@@ -1,6 +1,12 @@
 /* objects_gsource.c generated by valac, the Vala compiler
  * generated from objects_gsource.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/gtype-class-lifetime.c-expected b/tests/objects/gtype-class-lifetime.c-expected
index ce13f2e2014aac59..90dd5e5cae15220a 100644
--- a/tests/objects/gtype-class-lifetime.c-expected
+++ b/tests/objects/gtype-class-lifetime.c-expected
@@ -1,6 +1,12 @@
 /* objects_gtype_class_lifetime.c generated by valac, the Vala compiler
  * generated from objects_gtype_class_lifetime.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/initially-unowned.c-expected b/tests/objects/initially-unowned.c-expected
index 3cc673fc005c0d65..dad6cbd660bd28bb 100644
--- a/tests/objects/initially-unowned.c-expected
+++ b/tests/objects/initially-unowned.c-expected
@@ -1,6 +1,12 @@
 /* objects_initially_unowned.c generated by valac, the Vala compiler
  * generated from objects_initially_unowned.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/instance-comparison.c-expected b/tests/objects/instance-comparison.c-expected
index 8119180765bd9bf2..af864617f012bd9d 100644
--- a/tests/objects/instance-comparison.c-expected
+++ b/tests/objects/instance-comparison.c-expected
@@ -1,6 +1,12 @@
 /* objects_instance_comparison.c generated by valac, the Vala compiler
  * generated from objects_instance_comparison.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/interface-abstract-async-override.c-expected b/tests/objects/interface-abstract-async-override.c-expected
index 494585889f4afe82..66d38800cd52333d 100644
--- a/tests/objects/interface-abstract-async-override.c-expected
+++ b/tests/objects/interface-abstract-async-override.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_abstract_async_override.c generated by valac, the Vala compiler
  * generated from objects_interface_abstract_async_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/objects/interface-async-base-access.c-expected b/tests/objects/interface-async-base-access.c-expected
index a84c03a393bd0f9d..7023173bba489dad 100644
--- a/tests/objects/interface-async-base-access.c-expected
+++ b/tests/objects/interface-async-base-access.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_async_base_access.c generated by valac, the Vala compiler
  * generated from objects_interface_async_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/objects/interface-async-captured-generic.c-expected b/tests/objects/interface-async-captured-generic.c-expected
index 6c709b0bac795a9a..0e2ec03f244a3dfb 100644
--- a/tests/objects/interface-async-captured-generic.c-expected
+++ b/tests/objects/interface-async-captured-generic.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_async_captured_generic.c generated by valac, the Vala compiler
  * generated from objects_interface_async_captured_generic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <glib.h>
diff --git a/tests/objects/interface-base-access.c-expected b/tests/objects/interface-base-access.c-expected
index 185c70f2db18d71d..2fe6b85748789434 100644
--- a/tests/objects/interface-base-access.c-expected
+++ b/tests/objects/interface-base-access.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_base_access.c generated by valac, the Vala compiler
  * generated from objects_interface_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-generics.c-expected b/tests/objects/interface-generics.c-expected
index d6cd58a21ea399ec..303e85dacb83d2d3 100644
--- a/tests/objects/interface-generics.c-expected
+++ b/tests/objects/interface-generics.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_generics.c generated by valac, the Vala compiler
  * generated from objects_interface_generics.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/interface-inner-types.c-expected b/tests/objects/interface-inner-types.c-expected
index cb7386ab2afd8ba7..ce4285db4822fb85 100644
--- a/tests/objects/interface-inner-types.c-expected
+++ b/tests/objects/interface-inner-types.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_inner_types.c generated by valac, the Vala compiler
  * generated from objects_interface_inner_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/interface-parameter-nowrapper.c-expected b/tests/objects/interface-parameter-nowrapper.c-expected
index 289a961564c25d3f..2cfc144428450dbf 100644
--- a/tests/objects/interface-parameter-nowrapper.c-expected
+++ b/tests/objects/interface-parameter-nowrapper.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_parameter_nowrapper.c generated by valac, the Vala compiler
  * generated from objects_interface_parameter_nowrapper.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-property-base-access.c-expected b/tests/objects/interface-property-base-access.c-expected
index 5a71890760c8796a..d9d7731d5e3353ce 100644
--- a/tests/objects/interface-property-base-access.c-expected
+++ b/tests/objects/interface-property-base-access.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_property_base_access.c generated by valac, the Vala compiler
  * generated from objects_interface_property_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/interface-property-base-impl.c-expected b/tests/objects/interface-property-base-impl.c-expected
index 021cce6471e33e17..10b78d6ebfc9c399 100644
--- a/tests/objects/interface-property-base-impl.c-expected
+++ b/tests/objects/interface-property-base-impl.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_property_base_impl.c generated by valac, the Vala compiler
  * generated from objects_interface_property_base_impl.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/interface-property-delegate.c-expected b/tests/objects/interface-property-delegate.c-expected
index 919b29c944719995..899dd87e0d82f545 100644
--- a/tests/objects/interface-property-delegate.c-expected
+++ b/tests/objects/interface-property-delegate.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_property_delegate.c generated by valac, the Vala compiler
  * generated from objects_interface_property_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-property-override.c-expected b/tests/objects/interface-property-override.c-expected
index 8e10b48d8073abb8..1562e0bcf35583f7 100644
--- a/tests/objects/interface-property-override.c-expected
+++ b/tests/objects/interface-property-override.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_property_override.c generated by valac, the Vala compiler
  * generated from objects_interface_property_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/interface-virtual-override.c-expected b/tests/objects/interface-virtual-override.c-expected
index 5181438c15d6b46a..27c39af276ade559 100644
--- a/tests/objects/interface-virtual-override.c-expected
+++ b/tests/objects/interface-virtual-override.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_virtual_override.c generated by valac, the Vala compiler
  * generated from objects_interface_virtual_override.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gio/gio.h>
diff --git a/tests/objects/interface_only.c-expected b/tests/objects/interface_only.c-expected
index ee32d2c568e1aabe..8e6a01e388f19490 100644
--- a/tests/objects/interface_only.c-expected
+++ b/tests/objects/interface_only.c-expected
@@ -1,6 +1,12 @@
 /* objects_interface_only.c generated by valac, the Vala compiler
  * generated from objects_interface_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/objects/interfaces.c-expected b/tests/objects/interfaces.c-expected
index f5762fce1f25dc25..1de1773b7378b96c 100644
--- a/tests/objects/interfaces.c-expected
+++ b/tests/objects/interfaces.c-expected
@@ -1,6 +1,12 @@
 /* objects_interfaces.c generated by valac, the Vala compiler
  * generated from objects_interfaces.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/member-initializer-base-properties.c-expected b/tests/objects/member-initializer-base-properties.c-expected
index f5b763e4c06813ad..9c8e4c766e0fb396 100644
--- a/tests/objects/member-initializer-base-properties.c-expected
+++ b/tests/objects/member-initializer-base-properties.c-expected
@@ -1,6 +1,12 @@
 /* objects_member_initializer_base_properties.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_base_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/member-initializer-chained-2.c-expected b/tests/objects/member-initializer-chained-2.c-expected
index 6ea0aad0ce32169f..2c952d2cb8037dab 100644
--- a/tests/objects/member-initializer-chained-2.c-expected
+++ b/tests/objects/member-initializer-chained-2.c-expected
@@ -1,6 +1,12 @@
 /* objects_member_initializer_chained_2.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_chained_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/member-initializer-chained.c-expected b/tests/objects/member-initializer-chained.c-expected
index 1ea6a71a5789ad0f..d15d55219acb3aa1 100644
--- a/tests/objects/member-initializer-chained.c-expected
+++ b/tests/objects/member-initializer-chained.c-expected
@@ -1,6 +1,12 @@
 /* objects_member_initializer_chained.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_chained.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/member-initializer-private.c-expected b/tests/objects/member-initializer-private.c-expected
index 9027b52e5a5d46e7..e7c37cb7e15f28d9 100644
--- a/tests/objects/member-initializer-private.c-expected
+++ b/tests/objects/member-initializer-private.c-expected
@@ -1,6 +1,12 @@
 /* objects_member_initializer_private.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_private.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/member-initializer-property-owned-setter.c-expected b/tests/objects/member-initializer-property-owned-setter.c-expected
index 94e126c4b0ac5e61..e55e42db12c1923c 100644
--- a/tests/objects/member-initializer-property-owned-setter.c-expected
+++ b/tests/objects/member-initializer-property-owned-setter.c-expected
@@ -1,6 +1,12 @@
 /* objects_member_initializer_property_owned_setter.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_property_owned_setter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/member-initializer-property.c-expected b/tests/objects/member-initializer-property.c-expected
index 8cdaf3e4e23b9f65..96a66c543a91b800 100644
--- a/tests/objects/member-initializer-property.c-expected
+++ b/tests/objects/member-initializer-property.c-expected
@@ -1,6 +1,12 @@
 /* objects_member_initializer_property.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_property.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/member-initializer-protected.c-expected b/tests/objects/member-initializer-protected.c-expected
index 951bb1b0fc809d01..cc863a38c0da0c56 100644
--- a/tests/objects/member-initializer-protected.c-expected
+++ b/tests/objects/member-initializer-protected.c-expected
@@ -1,6 +1,12 @@
 /* objects_member_initializer_protected.c generated by valac, the Vala compiler
  * generated from objects_member_initializer_protected.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/methods.c-expected b/tests/objects/methods.c-expected
index 38321f5cb875ba68..154f47f6d67d53af 100644
--- a/tests/objects/methods.c-expected
+++ b/tests/objects/methods.c-expected
@@ -1,6 +1,12 @@
 /* objects_methods.c generated by valac, the Vala compiler
  * generated from objects_methods.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/paramspec.c-expected b/tests/objects/paramspec.c-expected
index da4999822c8e4022..2798dba025baa4b9 100644
--- a/tests/objects/paramspec.c-expected
+++ b/tests/objects/paramspec.c-expected
@@ -1,6 +1,12 @@
 /* objects_paramspec.c generated by valac, the Vala compiler
  * generated from objects_paramspec.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/plugin-module-init.c-expected b/tests/objects/plugin-module-init.c-expected
index aeffdff2f1da340f..d6aab1e46429df4a 100644
--- a/tests/objects/plugin-module-init.c-expected
+++ b/tests/objects/plugin-module-init.c-expected
@@ -1,6 +1,12 @@
 /* objects_plugin_module_init.c generated by valac, the Vala compiler
  * generated from objects_plugin_module_init.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/properties.c-expected b/tests/objects/properties.c-expected
index 22ed9869b4500cd2..94efbde3df68f883 100644
--- a/tests/objects/properties.c-expected
+++ b/tests/objects/properties.c-expected
@@ -1,6 +1,12 @@
 /* objects_properties.c generated by valac, the Vala compiler
  * generated from objects_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-array-length.c-expected b/tests/objects/property-array-length.c-expected
index e41c57e995d39232..8899ae0dd66f8952 100644
--- a/tests/objects/property-array-length.c-expected
+++ b/tests/objects/property-array-length.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_array_length.c generated by valac, the Vala compiler
  * generated from objects_property_array_length.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <gio/gio.h>
 
diff --git a/tests/objects/property-array.c-expected b/tests/objects/property-array.c-expected
index 8f9a7bf85b00d496..ff0ba03d77ca5cf3 100644
--- a/tests/objects/property-array.c-expected
+++ b/tests/objects/property-array.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_array.c generated by valac, the Vala compiler
  * generated from objects_property_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-base-access.c-expected b/tests/objects/property-base-access.c-expected
index f36956810b0bb256..a5750d0ab27ed486 100644
--- a/tests/objects/property-base-access.c-expected
+++ b/tests/objects/property-base-access.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_base_access.c generated by valac, the Vala compiler
  * generated from objects_property_base_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-construct-only.c-expected b/tests/objects/property-construct-only.c-expected
index a38d8885ac43b5f4..32cff33a3cd96051 100644
--- a/tests/objects/property-construct-only.c-expected
+++ b/tests/objects/property-construct-only.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_construct_only.c generated by valac, the Vala compiler
  * generated from objects_property_construct_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-delegate-owned.c-expected b/tests/objects/property-delegate-owned.c-expected
index 7334eb6969eb08a2..d30b36065f2bd67a 100644
--- a/tests/objects/property-delegate-owned.c-expected
+++ b/tests/objects/property-delegate-owned.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_delegate_owned.c generated by valac, the Vala compiler
  * generated from objects_property_delegate_owned.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-delegate.c-expected b/tests/objects/property-delegate.c-expected
index c8be81390b4f9d63..d33d685aaefe83f6 100644
--- a/tests/objects/property-delegate.c-expected
+++ b/tests/objects/property-delegate.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_delegate.c generated by valac, the Vala compiler
  * generated from objects_property_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/property-dynamic-type-inference.c-expected b/tests/objects/property-dynamic-type-inference.c-expected
index c8e9cd5db9187731..ee2420e26610f80d 100644
--- a/tests/objects/property-dynamic-type-inference.c-expected
+++ b/tests/objects/property-dynamic-type-inference.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_dynamic_type_inference.c generated by valac, the Vala compiler
  * generated from objects_property_dynamic_type_inference.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/property-enum-nullable.c-expected b/tests/objects/property-enum-nullable.c-expected
index 38b6bf2d82215a7c..bfc30312add34d97 100644
--- a/tests/objects/property-enum-nullable.c-expected
+++ b/tests/objects/property-enum-nullable.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_enum_nullable.c generated by valac, the Vala compiler
  * generated from objects_property_enum_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-enum.c-expected b/tests/objects/property-enum.c-expected
index b46b26cb46499cff..d8685b8621b1107d 100644
--- a/tests/objects/property-enum.c-expected
+++ b/tests/objects/property-enum.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_enum.c generated by valac, the Vala compiler
  * generated from objects_property_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-error.c-expected b/tests/objects/property-error.c-expected
index feffb48902fe864f..b53f29cc6f661c75 100644
--- a/tests/objects/property-error.c-expected
+++ b/tests/objects/property-error.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_error.c generated by valac, the Vala compiler
  * generated from objects_property_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-gboxed-nullable.c-expected b/tests/objects/property-gboxed-nullable.c-expected
index 1438750ac3c410f4..0e852d279b70de46 100644
--- a/tests/objects/property-gboxed-nullable.c-expected
+++ b/tests/objects/property-gboxed-nullable.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_gboxed_nullable.c generated by valac, the Vala compiler
  * generated from objects_property_gboxed_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-notify-owned-getter.c-expected b/tests/objects/property-notify-owned-getter.c-expected
index b287aad858c5f319..ee98265baeb30fc9 100644
--- a/tests/objects/property-notify-owned-getter.c-expected
+++ b/tests/objects/property-notify-owned-getter.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_notify_owned_getter.c generated by valac, the Vala compiler
  * generated from objects_property_notify_owned_getter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-notify.c-expected b/tests/objects/property-notify.c-expected
index 093715144dcbb8a6..4483af2fb38b4ac2 100644
--- a/tests/objects/property-notify.c-expected
+++ b/tests/objects/property-notify.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_notify.c generated by valac, the Vala compiler
  * generated from objects_property_notify.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-ownership.c-expected b/tests/objects/property-ownership.c-expected
index 8b353c1f52e5ea36..9626ce6a13e1aaa7 100644
--- a/tests/objects/property-ownership.c-expected
+++ b/tests/objects/property-ownership.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_ownership.c generated by valac, the Vala compiler
  * generated from objects_property_ownership.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-read-only-auto.c-expected b/tests/objects/property-read-only-auto.c-expected
index ad5ba37e7536cecc..33fec518e70b1178 100644
--- a/tests/objects/property-read-only-auto.c-expected
+++ b/tests/objects/property-read-only-auto.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_read_only_auto.c generated by valac, the Vala compiler
  * generated from objects_property_read_only_auto.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-real-struct-assignment.c-expected b/tests/objects/property-real-struct-assignment.c-expected
index 7f4b4e7889ad1094..0df4a56ba9e8976f 100644
--- a/tests/objects/property-real-struct-assignment.c-expected
+++ b/tests/objects/property-real-struct-assignment.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_real_struct_assignment.c generated by valac, the Vala compiler
  * generated from objects_property_real_struct_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-simple-type-struct-nullable.c-expected b/tests/objects/property-simple-type-struct-nullable.c-expected
index ebed89e1890c30d4..d1fd645f72fc49c6 100644
--- a/tests/objects/property-simple-type-struct-nullable.c-expected
+++ b/tests/objects/property-simple-type-struct-nullable.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_simple_type_struct_nullable.c generated by valac, the Vala compiler
  * generated from objects_property_simple_type_struct_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/objects/property-static.c-expected b/tests/objects/property-static.c-expected
index 1d57142f60b7cefc..ee0f9bddb8ee2751 100644
--- a/tests/objects/property-static.c-expected
+++ b/tests/objects/property-static.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_static.c generated by valac, the Vala compiler
  * generated from objects_property_static.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/property-struct-no-gtype.c-expected b/tests/objects/property-struct-no-gtype.c-expected
index c6a88a7bf25e7fc0..9f3cb87f87278694 100644
--- a/tests/objects/property-struct-no-gtype.c-expected
+++ b/tests/objects/property-struct-no-gtype.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_struct_no_gtype.c generated by valac, the Vala compiler
  * generated from objects_property_struct_no_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/property-struct.c-expected b/tests/objects/property-struct.c-expected
index 42da46c8f0c9f243..8832487226b7c0ea 100644
--- a/tests/objects/property-struct.c-expected
+++ b/tests/objects/property-struct.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_struct.c generated by valac, the Vala compiler
  * generated from objects_property_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/property-strv-noaccessor.c-expected b/tests/objects/property-strv-noaccessor.c-expected
index 7443e002e570f2ca..9da9f63f7206674c 100644
--- a/tests/objects/property-strv-noaccessor.c-expected
+++ b/tests/objects/property-strv-noaccessor.c-expected
@@ -1,6 +1,12 @@
 /* objects_property_strv_noaccessor.c generated by valac, the Vala compiler
  * generated from objects_property_strv_noaccessor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/regex.c-expected b/tests/objects/regex.c-expected
index 3c05606fdb419860..5a556d4c21c8e2f4 100644
--- a/tests/objects/regex.c-expected
+++ b/tests/objects/regex.c-expected
@@ -1,6 +1,12 @@
 /* objects_regex.c generated by valac, the Vala compiler
  * generated from objects_regex.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdlib.h>
diff --git a/tests/objects/signals-default-class-handler.c-expected b/tests/objects/signals-default-class-handler.c-expected
index 55ee90c32da56199..f060b9d896f13398 100644
--- a/tests/objects/signals-default-class-handler.c-expected
+++ b/tests/objects/signals-default-class-handler.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_default_class_handler.c generated by valac, the Vala compiler
  * generated from objects_signals_default_class_handler.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/signals-delegate-parameter.c-expected b/tests/objects/signals-delegate-parameter.c-expected
index a2dbe9af00b3749d..b20920d77be2a772 100644
--- a/tests/objects/signals-delegate-parameter.c-expected
+++ b/tests/objects/signals-delegate-parameter.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_delegate_parameter.c generated by valac, the Vala compiler
  * generated from objects_signals_delegate_parameter.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/objects/signals-delegate.c-expected b/tests/objects/signals-delegate.c-expected
index ee1bc862a8c5ce36..6fdbcb36ca0d901c 100644
--- a/tests/objects/signals-delegate.c-expected
+++ b/tests/objects/signals-delegate.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_delegate.c generated by valac, the Vala compiler
  * generated from objects_signals_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/signals-dynamic-emit.c-expected b/tests/objects/signals-dynamic-emit.c-expected
index 7c71e3b42f047be1..6bd111bf2480160e 100644
--- a/tests/objects/signals-dynamic-emit.c-expected
+++ b/tests/objects/signals-dynamic-emit.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_dynamic_emit.c generated by valac, the Vala compiler
  * generated from objects_signals_dynamic_emit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-emit.c-expected b/tests/objects/signals-emit.c-expected
index 3836abc87ac13c0c..071b9570788ba8fe 100644
--- a/tests/objects/signals-emit.c-expected
+++ b/tests/objects/signals-emit.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_emit.c generated by valac, the Vala compiler
  * generated from objects_signals_emit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/signals-enum-marshal.c-expected b/tests/objects/signals-enum-marshal.c-expected
index 4158246a5306873c..46b91bfd778ef818 100644
--- a/tests/objects/signals-enum-marshal.c-expected
+++ b/tests/objects/signals-enum-marshal.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_enum_marshal.c generated by valac, the Vala compiler
  * generated from objects_signals_enum_marshal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-error-marshal.c-expected b/tests/objects/signals-error-marshal.c-expected
index 87270af12eeeb988..52f597ac96db747d 100644
--- a/tests/objects/signals-error-marshal.c-expected
+++ b/tests/objects/signals-error-marshal.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_error_marshal.c generated by valac, the Vala compiler
  * generated from objects_signals_error_marshal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <string.h>
diff --git a/tests/objects/signals-fundamental-return.c-expected b/tests/objects/signals-fundamental-return.c-expected
index 0fee3f75fde6eee0..d4651287c6d486cb 100644
--- a/tests/objects/signals-fundamental-return.c-expected
+++ b/tests/objects/signals-fundamental-return.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_fundamental_return.c generated by valac, the Vala compiler
  * generated from objects_signals_fundamental_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/objects/signals-generic-return.c-expected b/tests/objects/signals-generic-return.c-expected
index 0f156d2940e8667c..4300ee0662feb68f 100644
--- a/tests/objects/signals-generic-return.c-expected
+++ b/tests/objects/signals-generic-return.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_generic_return.c generated by valac, the Vala compiler
  * generated from objects_signals_generic_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/signals-gobject-return.c-expected b/tests/objects/signals-gobject-return.c-expected
index a8cbb9597fe65c28..9fd1bd2cc9d84894 100644
--- a/tests/objects/signals-gobject-return.c-expected
+++ b/tests/objects/signals-gobject-return.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_gobject_return.c generated by valac, the Vala compiler
  * generated from objects_signals_gobject_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/signals-lambda-delegate-2.c-expected b/tests/objects/signals-lambda-delegate-2.c-expected
index 1ed3b85110f89992..ac64752a5015a67f 100644
--- a/tests/objects/signals-lambda-delegate-2.c-expected
+++ b/tests/objects/signals-lambda-delegate-2.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_lambda_delegate_2.c generated by valac, the Vala compiler
  * generated from objects_signals_lambda_delegate_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/objects/signals-lambda-delegate.c-expected b/tests/objects/signals-lambda-delegate.c-expected
index 0e6ba11c2ca6b9f5..8256fcdb8a6d566e 100644
--- a/tests/objects/signals-lambda-delegate.c-expected
+++ b/tests/objects/signals-lambda-delegate.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_lambda_delegate.c generated by valac, the Vala compiler
  * generated from objects_signals_lambda_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-prototype-access.c-expected b/tests/objects/signals-prototype-access.c-expected
index 8c46ef8dd76cc473..f32a4bfc5fbe0297 100644
--- a/tests/objects/signals-prototype-access.c-expected
+++ b/tests/objects/signals-prototype-access.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_prototype_access.c generated by valac, the Vala compiler
  * generated from objects_signals_prototype_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/signals-struct-return.c-expected b/tests/objects/signals-struct-return.c-expected
index d1c7ca1665021cd9..18c8b235f94177af 100644
--- a/tests/objects/signals-struct-return.c-expected
+++ b/tests/objects/signals-struct-return.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_struct_return.c generated by valac, the Vala compiler
  * generated from objects_signals_struct_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals-struct.c-expected b/tests/objects/signals-struct.c-expected
index efa6609b2ba2da91..726f58d23b5e72c8 100644
--- a/tests/objects/signals-struct.c-expected
+++ b/tests/objects/signals-struct.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals_struct.c generated by valac, the Vala compiler
  * generated from objects_signals_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/signals.c-expected b/tests/objects/signals.c-expected
index 2bf57024e0632b63..9f72ff47e85ef1bb 100644
--- a/tests/objects/signals.c-expected
+++ b/tests/objects/signals.c-expected
@@ -1,6 +1,12 @@
 /* objects_signals.c generated by valac, the Vala compiler
  * generated from objects_signals.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <stdio.h>
diff --git a/tests/objects/simple-generics-chainup.c-expected b/tests/objects/simple-generics-chainup.c-expected
index a4831fc3332a71c2..e83a6bb5c4be7ab5 100644
--- a/tests/objects/simple-generics-chainup.c-expected
+++ b/tests/objects/simple-generics-chainup.c-expected
@@ -1,6 +1,12 @@
 /* objects_simple_generics_chainup.c generated by valac, the Vala compiler
  * generated from objects_simple_generics_chainup.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/objects/singleton.c-expected b/tests/objects/singleton.c-expected
index 5bb18fba630cb023..cf799e4c06d88bb4 100644
--- a/tests/objects/singleton.c-expected
+++ b/tests/objects/singleton.c-expected
@@ -1,6 +1,12 @@
 /* objects_singleton.c generated by valac, the Vala compiler
  * generated from objects_singleton.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/test-025.c-expected b/tests/objects/test-025.c-expected
index b251c1c053c49745..1d2c7f9751f9ecec 100644
--- a/tests/objects/test-025.c-expected
+++ b/tests/objects/test-025.c-expected
@@ -1,6 +1,12 @@
 /* objects_test_025.c generated by valac, the Vala compiler
  * generated from objects_test_025.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdio.h>
 #include <glib.h>
diff --git a/tests/objects/test-026.c-expected b/tests/objects/test-026.c-expected
index 29be53b9b9fcde17..2c721c1c1929e771 100644
--- a/tests/objects/test-026.c-expected
+++ b/tests/objects/test-026.c-expected
@@ -1,6 +1,12 @@
 /* objects_test_026.c generated by valac, the Vala compiler
  * generated from objects_test_026.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/test-029.c-expected b/tests/objects/test-029.c-expected
index d2942c7c30dbfea9..e2e9807b68053fe1 100644
--- a/tests/objects/test-029.c-expected
+++ b/tests/objects/test-029.c-expected
@@ -1,6 +1,12 @@
 /* objects_test_029.c generated by valac, the Vala compiler
  * generated from objects_test_029.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/test-034.c-expected b/tests/objects/test-034.c-expected
index 8dffb9553e4b93a1..6cb360bdd12da617 100644
--- a/tests/objects/test-034.c-expected
+++ b/tests/objects/test-034.c-expected
@@ -1,6 +1,12 @@
 /* objects_test_034.c generated by valac, the Vala compiler
  * generated from objects_test_034.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdio.h>
diff --git a/tests/objects/type-narrowing-by-precondition.c-expected b/tests/objects/type-narrowing-by-precondition.c-expected
index 672d70d728731cb7..20f0bcd7966104c9 100644
--- a/tests/objects/type-narrowing-by-precondition.c-expected
+++ b/tests/objects/type-narrowing-by-precondition.c-expected
@@ -1,6 +1,12 @@
 /* objects_type_narrowing_by_precondition.c generated by valac, the Vala compiler
  * generated from objects_type_narrowing_by_precondition.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/type-narrowing-fallback.c-expected b/tests/objects/type-narrowing-fallback.c-expected
index ce85370f1aa39dab..25722ee79e0e3bcc 100644
--- a/tests/objects/type-narrowing-fallback.c-expected
+++ b/tests/objects/type-narrowing-fallback.c-expected
@@ -1,6 +1,12 @@
 /* objects_type_narrowing_fallback.c generated by valac, the Vala compiler
  * generated from objects_type_narrowing_fallback.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/objects/type-narrowing.c-expected b/tests/objects/type-narrowing.c-expected
index 78d8f78ff5546975..917dbe5526400bc2 100644
--- a/tests/objects/type-narrowing.c-expected
+++ b/tests/objects/type-narrowing.c-expected
@@ -1,6 +1,12 @@
 /* objects_type_narrowing.c generated by valac, the Vala compiler
  * generated from objects_type_narrowing.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/with-expression.c-expected b/tests/objects/with-expression.c-expected
index 7d8bdb913b3c0554..8abc4e811fc71f4f 100644
--- a/tests/objects/with-expression.c-expected
+++ b/tests/objects/with-expression.c-expected
@@ -1,6 +1,12 @@
 /* objects_with_expression.c generated by valac, the Vala compiler
  * generated from objects_with_expression.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-instance.c-expected b/tests/objects/with-instance.c-expected
index 8efaf2072a2b4cab..453756e84ac4bf5e 100644
--- a/tests/objects/with-instance.c-expected
+++ b/tests/objects/with-instance.c-expected
@@ -1,6 +1,12 @@
 /* objects_with_instance.c generated by valac, the Vala compiler
  * generated from objects_with_instance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/objects/with-nested-in-lambda.c-expected b/tests/objects/with-nested-in-lambda.c-expected
index 58969da425c9b1ba..b7c1f203a96a8cb1 100644
--- a/tests/objects/with-nested-in-lambda.c-expected
+++ b/tests/objects/with-nested-in-lambda.c-expected
@@ -1,6 +1,12 @@
 /* objects_with_nested_in_lambda.c generated by valac, the Vala compiler
  * generated from objects_with_nested_in_lambda.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested-method.c-expected b/tests/objects/with-nested-method.c-expected
index cfb09338fd876b22..ff650b0c910e17c2 100644
--- a/tests/objects/with-nested-method.c-expected
+++ b/tests/objects/with-nested-method.c-expected
@@ -1,6 +1,12 @@
 /* objects_with_nested_method.c generated by valac, the Vala compiler
  * generated from objects_with_nested_method.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested-signal.c-expected b/tests/objects/with-nested-signal.c-expected
index 3d55f4e68a655395..75975e16ff78c098 100644
--- a/tests/objects/with-nested-signal.c-expected
+++ b/tests/objects/with-nested-signal.c-expected
@@ -1,6 +1,12 @@
 /* objects_with_nested_signal.c generated by valac, the Vala compiler
  * generated from objects_with_nested_signal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested-unambigous-signal.c-expected b/tests/objects/with-nested-unambigous-signal.c-expected
index f4f1f04c732191ee..c392682ab52cbf7c 100644
--- a/tests/objects/with-nested-unambigous-signal.c-expected
+++ b/tests/objects/with-nested-unambigous-signal.c-expected
@@ -1,6 +1,12 @@
 /* objects_with_nested_unambigous_signal.c generated by valac, the Vala compiler
  * generated from objects_with_nested_unambigous_signal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/objects/with-nested.c-expected b/tests/objects/with-nested.c-expected
index 29a34825876231ca..66834fb9af1b7689 100644
--- a/tests/objects/with-nested.c-expected
+++ b/tests/objects/with-nested.c-expected
@@ -1,6 +1,12 @@
 /* objects_with_nested.c generated by valac, the Vala compiler
  * generated from objects_with_nested.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/ordering/constant-class.c-expected b/tests/ordering/constant-class.c-expected
index c6ce5c2340de8c9d..5da53fa9ccddedad 100644
--- a/tests/ordering/constant-class.c-expected
+++ b/tests/ordering/constant-class.c-expected
@@ -1,6 +1,12 @@
 /* ordering_constant_class.c generated by valac, the Vala compiler
  * generated from ordering_constant_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/ordering/constant-constant.c-expected b/tests/ordering/constant-constant.c-expected
index e42751a152cc26ab..a56d44754eb80cdf 100644
--- a/tests/ordering/constant-constant.c-expected
+++ b/tests/ordering/constant-constant.c-expected
@@ -1,6 +1,12 @@
 /* ordering_constant_constant.c generated by valac, the Vala compiler
  * generated from ordering_constant_constant.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define FOO 42
diff --git a/tests/ordering/constant-enum.c-expected b/tests/ordering/constant-enum.c-expected
index d21a63354d1fcc92..0d4c7acbb59bc86e 100644
--- a/tests/ordering/constant-enum.c-expected
+++ b/tests/ordering/constant-enum.c-expected
@@ -1,6 +1,12 @@
 /* ordering_constant_enum.c generated by valac, the Vala compiler
  * generated from ordering_constant_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/ordering/constant-field.c-expected b/tests/ordering/constant-field.c-expected
index ffc093b52768cebc..06a9c330be5b8e53 100644
--- a/tests/ordering/constant-field.c-expected
+++ b/tests/ordering/constant-field.c-expected
@@ -1,6 +1,12 @@
 /* ordering_constant_field.c generated by valac, the Vala compiler
  * generated from ordering_constant_field.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define FOO 42
diff --git a/tests/ordering/constant-struct.c-expected b/tests/ordering/constant-struct.c-expected
index 79d558cfc8740c3c..494f02fd01c23a30 100644
--- a/tests/ordering/constant-struct.c-expected
+++ b/tests/ordering/constant-struct.c-expected
@@ -1,6 +1,12 @@
 /* ordering_constant_struct.c generated by valac, the Vala compiler
  * generated from ordering_constant_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/ordering/delegate-class.c-expected b/tests/ordering/delegate-class.c-expected
index d128ee437d70936a..04b42696d1c4a6f5 100644
--- a/tests/ordering/delegate-class.c-expected
+++ b/tests/ordering/delegate-class.c-expected
@@ -1,6 +1,12 @@
 /* ordering_delegate_class.c generated by valac, the Vala compiler
  * generated from ordering_delegate_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/ordering/delegate-enum.c-expected b/tests/ordering/delegate-enum.c-expected
index 08c0cadf761b2f85..1363fac7bfe33df3 100644
--- a/tests/ordering/delegate-enum.c-expected
+++ b/tests/ordering/delegate-enum.c-expected
@@ -1,6 +1,12 @@
 /* ordering_delegate_enum.c generated by valac, the Vala compiler
  * generated from ordering_delegate_enum.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/ordering/delegate-interface.c-expected b/tests/ordering/delegate-interface.c-expected
index eb971637c8b2cdf9..7063461f5c37d7a4 100644
--- a/tests/ordering/delegate-interface.c-expected
+++ b/tests/ordering/delegate-interface.c-expected
@@ -1,6 +1,12 @@
 /* ordering_delegate_interface.c generated by valac, the Vala compiler
  * generated from ordering_delegate_interface.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/ordering/delegate-struct.c-expected b/tests/ordering/delegate-struct.c-expected
index b4630c7de4817028..79996eed22eda0c1 100644
--- a/tests/ordering/delegate-struct.c-expected
+++ b/tests/ordering/delegate-struct.c-expected
@@ -1,6 +1,12 @@
 /* ordering_delegate_struct.c generated by valac, the Vala compiler
  * generated from ordering_delegate_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/ordering/struct-delegate.c-expected b/tests/ordering/struct-delegate.c-expected
index c2a0932e87ab1b23..2efb82ed19d218fd 100644
--- a/tests/ordering/struct-delegate.c-expected
+++ b/tests/ordering/struct-delegate.c-expected
@@ -1,6 +1,12 @@
 /* ordering_struct_delegate.c generated by valac, the Vala compiler
  * generated from ordering_struct_delegate.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/parser-keep-going/member-initializer.c-expected b/tests/parser-keep-going/member-initializer.c-expected
index 912b045c91777d58..7896d048bcd994ae 100644
--- a/tests/parser-keep-going/member-initializer.c-expected
+++ b/tests/parser-keep-going/member-initializer.c-expected
@@ -1,6 +1,12 @@
 /* parser_keep_going_member_initializer.c generated by valac, the Vala compiler
  * generated from parser_keep_going_member_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/parser/array-length.c-expected b/tests/parser/array-length.c-expected
index 9ef0f8f97e061b27..ce1bb9ef543e2c2e 100644
--- a/tests/parser/array-length.c-expected
+++ b/tests/parser/array-length.c-expected
@@ -1,6 +1,12 @@
 /* parser_array_length.c generated by valac, the Vala compiler
  * generated from parser_array_length.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/parser/assignment.c-expected b/tests/parser/assignment.c-expected
index 64aa5c6c6b225729..74ee016be339ca46 100644
--- a/tests/parser/assignment.c-expected
+++ b/tests/parser/assignment.c-expected
@@ -1,6 +1,12 @@
 /* parser_assignment.c generated by valac, the Vala compiler
  * generated from parser_assignment.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/parser/bug728574.c-expected b/tests/parser/bug728574.c-expected
index bbbc957670c2cc9a..6db1b2a33df34132 100644
--- a/tests/parser/bug728574.c-expected
+++ b/tests/parser/bug728574.c-expected
@@ -1,6 +1,12 @@
 /* parser_bug728574.c generated by valac, the Vala compiler
  * generated from parser_bug728574.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _g_regex_unref0(var) ((var == NULL) ? NULL : (var = (g_regex_unref (var), NULL)))
diff --git a/tests/parser/bug749576.c-expected b/tests/parser/bug749576.c-expected
index b483b0fc87c5f5d6..0fcffb0e8ec17fe1 100644
--- a/tests/parser/bug749576.c-expected
+++ b/tests/parser/bug749576.c-expected
@@ -1,6 +1,12 @@
 /* parser_bug749576.c generated by valac, the Vala compiler
  * generated from parser_bug749576.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/chained-equality.c-expected b/tests/parser/chained-equality.c-expected
index 3e59b5d34668d132..fb590e2a7b8fabd6 100644
--- a/tests/parser/chained-equality.c-expected
+++ b/tests/parser/chained-equality.c-expected
@@ -1,6 +1,12 @@
 /* parser_chained_equality.c generated by valac, the Vala compiler
  * generated from parser_chained_equality.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/parser/continue-statement.c-expected b/tests/parser/continue-statement.c-expected
index 0c2386d3f6ad5816..d714ba17a372db99 100644
--- a/tests/parser/continue-statement.c-expected
+++ b/tests/parser/continue-statement.c-expected
@@ -1,6 +1,12 @@
 /* parser_continue_statement.c generated by valac, the Vala compiler
  * generated from parser_continue_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/do-statement.c-expected b/tests/parser/do-statement.c-expected
index 57682cbb7dab1b89..59dc08b0e5a7a851 100644
--- a/tests/parser/do-statement.c-expected
+++ b/tests/parser/do-statement.c-expected
@@ -1,6 +1,12 @@
 /* parser_do_statement.c generated by valac, the Vala compiler
  * generated from parser_do_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/foreach.c-expected b/tests/parser/foreach.c-expected
index 5d013475a51da034..820e0755e95454bf 100644
--- a/tests/parser/foreach.c-expected
+++ b/tests/parser/foreach.c-expected
@@ -1,6 +1,12 @@
 /* parser_foreach.c generated by valac, the Vala compiler
  * generated from parser_foreach.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/local-variable-multi-one-line.c-expected b/tests/parser/local-variable-multi-one-line.c-expected
index 943cf79a88236fac..fa0a4d3dcfa4b379 100644
--- a/tests/parser/local-variable-multi-one-line.c-expected
+++ b/tests/parser/local-variable-multi-one-line.c-expected
@@ -1,6 +1,12 @@
 /* parser_local_variable_multi_one_line.c generated by valac, the Vala compiler
  * generated from parser_local_variable_multi_one_line.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/parser/local-variable.c-expected b/tests/parser/local-variable.c-expected
index 1f8612827fc8f804..bc4aa2c0ac1f8381 100644
--- a/tests/parser/local-variable.c-expected
+++ b/tests/parser/local-variable.c-expected
@@ -1,6 +1,12 @@
 /* parser_local_variable.c generated by valac, the Vala compiler
  * generated from parser_local_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/lock-statement.c-expected b/tests/parser/lock-statement.c-expected
index 6deb21ef321b74ea..742e6618616d17a8 100644
--- a/tests/parser/lock-statement.c-expected
+++ b/tests/parser/lock-statement.c-expected
@@ -1,6 +1,12 @@
 /* parser_lock_statement.c generated by valac, the Vala compiler
  * generated from parser_lock_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/main-block-minimal.c-expected b/tests/parser/main-block-minimal.c-expected
index a8b8a94dcc15a168..e7d629b15541d891 100644
--- a/tests/parser/main-block-minimal.c-expected
+++ b/tests/parser/main-block-minimal.c-expected
@@ -1,6 +1,12 @@
 /* parser_main_block_minimal.c generated by valac, the Vala compiler
  * generated from parser_main_block_minimal.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/parser/main-block.c-expected b/tests/parser/main-block.c-expected
index fcb0e57486c6005c..35ac5d0e258f8387 100644
--- a/tests/parser/main-block.c-expected
+++ b/tests/parser/main-block.c-expected
@@ -1,6 +1,12 @@
 /* parser_main_block.c generated by valac, the Vala compiler
  * generated from parser_main_block.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/member-access-pointer.c-expected b/tests/parser/member-access-pointer.c-expected
index af66c6effe14fbf1..ebb27cb7416e928f 100644
--- a/tests/parser/member-access-pointer.c-expected
+++ b/tests/parser/member-access-pointer.c-expected
@@ -1,6 +1,12 @@
 /* parser_member_access_pointer.c generated by valac, the Vala compiler
  * generated from parser_member_access_pointer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/parser/member-initializer-empty.c-expected b/tests/parser/member-initializer-empty.c-expected
index 6e82e37fdd5409e5..9ce59fdba31eaaf0 100644
--- a/tests/parser/member-initializer-empty.c-expected
+++ b/tests/parser/member-initializer-empty.c-expected
@@ -1,6 +1,12 @@
 /* parser_member_initializer_empty.c generated by valac, the Vala compiler
  * generated from parser_member_initializer_empty.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/member-initializer-trailing-comma.c-expected b/tests/parser/member-initializer-trailing-comma.c-expected
index 70c745aecd1d03f9..80d84871990e2bcf 100644
--- a/tests/parser/member-initializer-trailing-comma.c-expected
+++ b/tests/parser/member-initializer-trailing-comma.c-expected
@@ -1,6 +1,12 @@
 /* parser_member_initializer_trailing_comma.c generated by valac, the Vala compiler
  * generated from parser_member_initializer_trailing_comma.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/member-initializer.c-expected b/tests/parser/member-initializer.c-expected
index 2b018ebf6009c323..c922b26f40a7c1bf 100644
--- a/tests/parser/member-initializer.c-expected
+++ b/tests/parser/member-initializer.c-expected
@@ -1,6 +1,12 @@
 /* parser_member_initializer.c generated by valac, the Vala compiler
  * generated from parser_member_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/namespaces.c-expected b/tests/parser/namespaces.c-expected
index 36cfb4b90024d904..3c8e99b38df74082 100644
--- a/tests/parser/namespaces.c-expected
+++ b/tests/parser/namespaces.c-expected
@@ -1,6 +1,12 @@
 /* parser_namespaces.c generated by valac, the Vala compiler
  * generated from parser_namespaces.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <stdio.h>
diff --git a/tests/parser/preprocessor-glib.c-expected b/tests/parser/preprocessor-glib.c-expected
index 9300c6d8d8211414..ff7651bd8232d43a 100644
--- a/tests/parser/preprocessor-glib.c-expected
+++ b/tests/parser/preprocessor-glib.c-expected
@@ -1,6 +1,12 @@
 /* parser_preprocessor_glib.c generated by valac, the Vala compiler
  * generated from parser_preprocessor_glib.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/preprocessor-vala.c-expected b/tests/parser/preprocessor-vala.c-expected
index 7de470816a67ce49..666792bf9b5a83a0 100644
--- a/tests/parser/preprocessor-vala.c-expected
+++ b/tests/parser/preprocessor-vala.c-expected
@@ -1,6 +1,12 @@
 /* parser_preprocessor_vala.c generated by valac, the Vala compiler
  * generated from parser_preprocessor_vala.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/preprocessor.c-expected b/tests/parser/preprocessor.c-expected
index 0d9cce314dd7dc99..c523d361c6db4cfd 100644
--- a/tests/parser/preprocessor.c-expected
+++ b/tests/parser/preprocessor.c-expected
@@ -1,6 +1,12 @@
 /* parser_preprocessor.c generated by valac, the Vala compiler
  * generated from parser_preprocessor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/qualified-member-access.c-expected b/tests/parser/qualified-member-access.c-expected
index c18b53b062d905d3..67fec9be90326001 100644
--- a/tests/parser/qualified-member-access.c-expected
+++ b/tests/parser/qualified-member-access.c-expected
@@ -1,6 +1,12 @@
 /* parser_qualified_member_access.c generated by valac, the Vala compiler
  * generated from parser_qualified_member_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/parser/qualified-symbol-access.c-expected b/tests/parser/qualified-symbol-access.c-expected
index 824787809bddcbf5..8d39ab61d73faaa1 100644
--- a/tests/parser/qualified-symbol-access.c-expected
+++ b/tests/parser/qualified-symbol-access.c-expected
@@ -1,6 +1,12 @@
 /* parser_qualified_symbol_access.c generated by valac, the Vala compiler
  * generated from parser_qualified_symbol_access.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/parser/sealed-class.c-expected b/tests/parser/sealed-class.c-expected
index c8b4dca917cea64c..f3a69be8241cc4a9 100644
--- a/tests/parser/sealed-class.c-expected
+++ b/tests/parser/sealed-class.c-expected
@@ -1,6 +1,12 @@
 /* parser_sealed_class.c generated by valac, the Vala compiler
  * generated from parser_sealed_class.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/parser/statement-keyword-as-identifier.c-expected b/tests/parser/statement-keyword-as-identifier.c-expected
index 58860adbbc0962f3..c0aed882988cb0c0 100644
--- a/tests/parser/statement-keyword-as-identifier.c-expected
+++ b/tests/parser/statement-keyword-as-identifier.c-expected
@@ -1,6 +1,12 @@
 /* parser_statement_keyword_as_identifier.c generated by valac, the Vala compiler
  * generated from parser_statement_keyword_as_identifier.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
diff --git a/tests/parser/switch-statement.c-expected b/tests/parser/switch-statement.c-expected
index b1715aab276967f8..10d9290bb927756b 100644
--- a/tests/parser/switch-statement.c-expected
+++ b/tests/parser/switch-statement.c-expected
@@ -1,6 +1,12 @@
 /* parser_switch_statement.c generated by valac, the Vala compiler
  * generated from parser_switch_statement.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/parser/template.c-expected b/tests/parser/template.c-expected
index 933aa14f54cbd1ab..5e3fa8777dec25cf 100644
--- a/tests/parser/template.c-expected
+++ b/tests/parser/template.c-expected
@@ -1,6 +1,12 @@
 /* parser_template.c generated by valac, the Vala compiler
  * generated from parser_template.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/tuple.c-expected b/tests/parser/tuple.c-expected
index 6271f3b19b7c2b5d..f0eb35e02c66952a 100644
--- a/tests/parser/tuple.c-expected
+++ b/tests/parser/tuple.c-expected
@@ -1,6 +1,12 @@
 /* parser_tuple.c generated by valac, the Vala compiler
  * generated from parser_tuple.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/using-directive.c-expected b/tests/parser/using-directive.c-expected
index 1f10b8863b652c06..ea9ac9da06e6fffe 100644
--- a/tests/parser/using-directive.c-expected
+++ b/tests/parser/using-directive.c-expected
@@ -1,6 +1,12 @@
 /* parser_using_directive.c generated by valac, the Vala compiler
  * generated from parser_using_directive.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #if !defined(VALA_EXTERN)
 #if defined(_MSC_VER)
 #define VALA_EXTERN __declspec(dllexport) extern
diff --git a/tests/parser/var-type-dynamic.c-expected b/tests/parser/var-type-dynamic.c-expected
index 75eaaae572180e2e..3309a98f2a46dd91 100644
--- a/tests/parser/var-type-dynamic.c-expected
+++ b/tests/parser/var-type-dynamic.c-expected
@@ -1,6 +1,12 @@
 /* parser_var_type_dynamic.c generated by valac, the Vala compiler
  * generated from parser_var_type_dynamic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/parser/var-type-nullable.c-expected b/tests/parser/var-type-nullable.c-expected
index 84096141ec23bee7..d3041ca943be4344 100644
--- a/tests/parser/var-type-nullable.c-expected
+++ b/tests/parser/var-type-nullable.c-expected
@@ -1,6 +1,12 @@
 /* parser_var_type_nullable.c generated by valac, the Vala compiler
  * generated from parser_var_type_nullable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/parser/with-embedded.c-expected b/tests/parser/with-embedded.c-expected
index 29935c99e6b593a4..005f9dd89ae32862 100644
--- a/tests/parser/with-embedded.c-expected
+++ b/tests/parser/with-embedded.c-expected
@@ -1,6 +1,12 @@
 /* parser_with_embedded.c generated by valac, the Vala compiler
  * generated from parser_with_embedded.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/parser/with-empty.c-expected b/tests/parser/with-empty.c-expected
index 63149d164dd85718..089435a7fdf192c8 100644
--- a/tests/parser/with-empty.c-expected
+++ b/tests/parser/with-empty.c-expected
@@ -1,6 +1,12 @@
 /* parser_with_empty.c generated by valac, the Vala compiler
  * generated from parser_with_empty.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 static void _vala_main (void);
diff --git a/tests/parser/yield-return.c-expected b/tests/parser/yield-return.c-expected
index 11a23c41ee9fbaa6..00f915f770c1e052 100644
--- a/tests/parser/yield-return.c-expected
+++ b/tests/parser/yield-return.c-expected
@@ -1,6 +1,12 @@
 /* parser_yield_return.c generated by valac, the Vala compiler
  * generated from parser_yield_return.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gio/gio.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/pointers/bug590641.c-expected b/tests/pointers/bug590641.c-expected
index ec0d96a3cf1255ce..f87d2a592ae0b9c6 100644
--- a/tests/pointers/bug590641.c-expected
+++ b/tests/pointers/bug590641.c-expected
@@ -1,6 +1,12 @@
 /* pointers_bug590641.c generated by valac, the Vala compiler
  * generated from pointers_bug590641.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/pointers/delete.c-expected b/tests/pointers/delete.c-expected
index f0652e5619d4b691..c529f02b6e3e90ad 100644
--- a/tests/pointers/delete.c-expected
+++ b/tests/pointers/delete.c-expected
@@ -1,6 +1,12 @@
 /* pointers_delete.c generated by valac, the Vala compiler
  * generated from pointers_delete.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/posix/arrays.c-expected b/tests/posix/arrays.c-expected
index b59712f6b07af91a..fa782affe675b0d5 100644
--- a/tests/posix/arrays.c-expected
+++ b/tests/posix/arrays.c-expected
@@ -1,6 +1,12 @@
 /* posix_arrays.c generated by valac, the Vala compiler
  * generated from posix_arrays.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <assert.h>
 #include <stddef.h>
diff --git a/tests/posix/delegate_only.c-expected b/tests/posix/delegate_only.c-expected
index e9df8bb8cd49af40..fba7317f6ef75b3c 100644
--- a/tests/posix/delegate_only.c-expected
+++ b/tests/posix/delegate_only.c-expected
@@ -1,6 +1,12 @@
 /* posix_delegate_only.c generated by valac, the Vala compiler
  * generated from posix_delegate_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 typedef void (*FooFunc) (void* user_data);
 
 static void _vala_main (void);
diff --git a/tests/posix/empty-length-0.c-expected b/tests/posix/empty-length-0.c-expected
index b11d450f34fccbfb..d097473e6ddef0df 100644
--- a/tests/posix/empty-length-0.c-expected
+++ b/tests/posix/empty-length-0.c-expected
@@ -1,6 +1,12 @@
 /* posix_empty_length_0.c generated by valac, the Vala compiler
  * generated from posix_empty_length_0.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <stddef.h>
diff --git a/tests/posix/enum-to-string.c-expected b/tests/posix/enum-to-string.c-expected
index ca84c862acbec90f..78727f0b14a7cf66 100644
--- a/tests/posix/enum-to-string.c-expected
+++ b/tests/posix/enum-to-string.c-expected
@@ -1,6 +1,12 @@
 /* posix_enum_to_string.c generated by valac, the Vala compiler
  * generated from posix_enum_to_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/posix/enum_only.c-expected b/tests/posix/enum_only.c-expected
index 7582787072435039..650d298fd3029cd6 100644
--- a/tests/posix/enum_only.c-expected
+++ b/tests/posix/enum_only.c-expected
@@ -1,6 +1,12 @@
 /* posix_enum_only.c generated by valac, the Vala compiler
  * generated from posix_enum_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 typedef enum  {
 	FOO_BAR,
 	FOO_BAZ
diff --git a/tests/posix/string-concat.c-expected b/tests/posix/string-concat.c-expected
index 5c9e3b301184094a..ec8c5bc5bdcb0882 100644
--- a/tests/posix/string-concat.c-expected
+++ b/tests/posix/string-concat.c-expected
@@ -1,6 +1,12 @@
 /* posix_string_concat.c generated by valac, the Vala compiler
  * generated from posix_string_concat.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <stddef.h>
diff --git a/tests/posix/string-printf.c-expected b/tests/posix/string-printf.c-expected
index c63c6e0fe37c2c69..988c60c962269cbb 100644
--- a/tests/posix/string-printf.c-expected
+++ b/tests/posix/string-printf.c-expected
@@ -1,6 +1,12 @@
 /* posix_string_printf.c generated by valac, the Vala compiler
  * generated from posix_string_printf.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
diff --git a/tests/posix/struct_only.c-expected b/tests/posix/struct_only.c-expected
index da17479a4df002aa..4e6c7d40b9791ea0 100644
--- a/tests/posix/struct_only.c-expected
+++ b/tests/posix/struct_only.c-expected
@@ -1,6 +1,12 @@
 /* posix_struct_only.c generated by valac, the Vala compiler
  * generated from posix_struct_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/tests/resolver/peek-inner-types.c-expected b/tests/resolver/peek-inner-types.c-expected
index 11a862f44bab882c..1bffa3362bf98fa3 100644
--- a/tests/resolver/peek-inner-types.c-expected
+++ b/tests/resolver/peek-inner-types.c-expected
@@ -1,6 +1,12 @@
 /* resolver_peek_inner_types.c generated by valac, the Vala compiler
  * generated from resolver_peek_inner_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/scanner/regex-escape-x.c-expected b/tests/scanner/regex-escape-x.c-expected
index e330cc0250e486f4..6c20441c6c35b1c2 100644
--- a/tests/scanner/regex-escape-x.c-expected
+++ b/tests/scanner/regex-escape-x.c-expected
@@ -1,6 +1,12 @@
 /* scanner_regex_escape_x.c generated by valac, the Vala compiler
  * generated from scanner_regex_escape_x.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #define _g_regex_unref0(var) ((var == NULL) ? NULL : (var = (g_regex_unref (var), NULL)))
diff --git a/tests/scanner/string-escape-x.c-expected b/tests/scanner/string-escape-x.c-expected
index 06567f0b3c24f6c0..0768c3fdefda4356 100644
--- a/tests/scanner/string-escape-x.c-expected
+++ b/tests/scanner/string-escape-x.c-expected
@@ -1,6 +1,12 @@
 /* scanner_string_escape_x.c generated by valac, the Vala compiler
  * generated from scanner_string_escape_x.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/semantic/assignment-same-variable.c-expected b/tests/semantic/assignment-same-variable.c-expected
index 8fa29a4b4cec4c7d..da4b380bfe899d43 100644
--- a/tests/semantic/assignment-same-variable.c-expected
+++ b/tests/semantic/assignment-same-variable.c-expected
@@ -1,6 +1,12 @@
 /* semantic_assignment_same_variable.c generated by valac, the Vala compiler
  * generated from semantic_assignment_same_variable.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/cast-void-not-allowed.c-expected b/tests/semantic/cast-void-not-allowed.c-expected
index 93f91458f2886875..8d5c4b5a937a1270 100644
--- a/tests/semantic/cast-void-not-allowed.c-expected
+++ b/tests/semantic/cast-void-not-allowed.c-expected
@@ -1,6 +1,12 @@
 /* semantic_cast_void_not_allowed.c generated by valac, the Vala compiler
  * generated from semantic_cast_void_not_allowed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/class-opaque-automatic-property.c-expected b/tests/semantic/class-opaque-automatic-property.c-expected
index fbb7cb85c6310b8e..cf05007efb76bb08 100644
--- a/tests/semantic/class-opaque-automatic-property.c-expected
+++ b/tests/semantic/class-opaque-automatic-property.c-expected
@@ -1,6 +1,12 @@
 /* semantic_class_opaque_automatic_property.c generated by valac, the Vala compiler
  * generated from semantic_class_opaque_automatic_property.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/class-opaque.c-expected b/tests/semantic/class-opaque.c-expected
index 0a1252961eabbb82..ae26fee9aa4e395e 100644
--- a/tests/semantic/class-opaque.c-expected
+++ b/tests/semantic/class-opaque.c-expected
@@ -1,6 +1,12 @@
 /* semantic_class_opaque.c generated by valac, the Vala compiler
  * generated from semantic_class_opaque.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/compare-type-check.c-expected b/tests/semantic/compare-type-check.c-expected
index 61bb0da0bad2250a..8df4071df59d2e8e 100644
--- a/tests/semantic/compare-type-check.c-expected
+++ b/tests/semantic/compare-type-check.c-expected
@@ -1,6 +1,12 @@
 /* semantic_compare_type_check.c generated by valac, the Vala compiler
  * generated from semantic_compare_type_check.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 #include <glib.h>
diff --git a/tests/semantic/field-constant.c-expected b/tests/semantic/field-constant.c-expected
index 84d863ea1e543fe9..844608f110e7a80b 100644
--- a/tests/semantic/field-constant.c-expected
+++ b/tests/semantic/field-constant.c-expected
@@ -1,6 +1,12 @@
 /* semantic_field_constant.c generated by valac, the Vala compiler
  * generated from semantic_field_constant.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/semantic/floating-reference-base-method.c-expected b/tests/semantic/floating-reference-base-method.c-expected
index 77d97147b0815169..d0bbd9774713261e 100644
--- a/tests/semantic/floating-reference-base-method.c-expected
+++ b/tests/semantic/floating-reference-base-method.c-expected
@@ -1,6 +1,12 @@
 /* semantic_floating_reference_base_method.c generated by valac, the Vala compiler
  * generated from semantic_floating_reference_base_method.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/floating-reference-error.c-expected b/tests/semantic/floating-reference-error.c-expected
index 5e582f5db91a74c5..45c46358629cbec8 100644
--- a/tests/semantic/floating-reference-error.c-expected
+++ b/tests/semantic/floating-reference-error.c-expected
@@ -1,6 +1,12 @@
 /* semantic_floating_reference_error.c generated by valac, the Vala compiler
  * generated from semantic_floating_reference_error.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 
diff --git a/tests/semantic/floating-reference.c-expected b/tests/semantic/floating-reference.c-expected
index 685f20108a7e6d30..108f0c74c9457072 100644
--- a/tests/semantic/floating-reference.c-expected
+++ b/tests/semantic/floating-reference.c-expected
@@ -1,6 +1,12 @@
 /* semantic_floating_reference.c generated by valac, the Vala compiler
  * generated from semantic_floating_reference.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/semantic/localvariable-var-pointer-initializer.c-expected b/tests/semantic/localvariable-var-pointer-initializer.c-expected
index 4b9b4c009be6f819..c7df9ffda20f928a 100644
--- a/tests/semantic/localvariable-var-pointer-initializer.c-expected
+++ b/tests/semantic/localvariable-var-pointer-initializer.c-expected
@@ -1,6 +1,12 @@
 /* semantic_localvariable_var_pointer_initializer.c generated by valac, the Vala compiler
  * generated from semantic_localvariable_var_pointer_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/semantic/member-access-static-transformed-qualified.c-expected b/tests/semantic/member-access-static-transformed-qualified.c-expected
index d81553866f7e3130..0beede48ac6cf4e8 100644
--- a/tests/semantic/member-access-static-transformed-qualified.c-expected
+++ b/tests/semantic/member-access-static-transformed-qualified.c-expected
@@ -1,6 +1,12 @@
 /* semantic_member_access_static_transformed_qualified.c generated by valac, the Vala compiler
  * generated from semantic_member_access_static_transformed_qualified.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/semantic/member-access-static-with-instance.c-expected b/tests/semantic/member-access-static-with-instance.c-expected
index fc27197c9f12f755..5b0ec7569215c92d 100644
--- a/tests/semantic/member-access-static-with-instance.c-expected
+++ b/tests/semantic/member-access-static-with-instance.c-expected
@@ -1,6 +1,12 @@
 /* semantic_member_access_static_with_instance.c generated by valac, the Vala compiler
  * generated from semantic_member_access_static_with_instance.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/semantic/member-access-transformed-qualified.c-expected b/tests/semantic/member-access-transformed-qualified.c-expected
index 5b26dfc66e1ca9ab..5eae8fd68814238b 100644
--- a/tests/semantic/member-access-transformed-qualified.c-expected
+++ b/tests/semantic/member-access-transformed-qualified.c-expected
@@ -1,6 +1,12 @@
 /* semantic_member_access_transformed_qualified.c generated by valac, the Vala compiler
  * generated from semantic_member_access_transformed_qualified.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/unary-ref-in-initializer-list.c-expected b/tests/semantic/unary-ref-in-initializer-list.c-expected
index d4e004eee73a030d..46643c56a6929998 100644
--- a/tests/semantic/unary-ref-in-initializer-list.c-expected
+++ b/tests/semantic/unary-ref-in-initializer-list.c-expected
@@ -1,6 +1,12 @@
 /* semantic_unary_ref_in_initializer_list.c generated by valac, the Vala compiler
  * generated from semantic_unary_ref_in_initializer_list.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/semantic/unary-ref-in-member-initializer.c-expected b/tests/semantic/unary-ref-in-member-initializer.c-expected
index 5799be9a040c7b42..69d5770c6c8e0b5f 100644
--- a/tests/semantic/unary-ref-in-member-initializer.c-expected
+++ b/tests/semantic/unary-ref-in-member-initializer.c-expected
@@ -1,6 +1,12 @@
 /* semantic_unary_ref_in_member_initializer.c generated by valac, the Vala compiler
  * generated from semantic_unary_ref_in_member_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/semantic/with-buildin.c-expected b/tests/semantic/with-buildin.c-expected
index a0a15512d5e49e7f..f92a2b945d7ded4b 100644
--- a/tests/semantic/with-buildin.c-expected
+++ b/tests/semantic/with-buildin.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_buildin.c generated by valac, the Vala compiler
  * generated from semantic_with_buildin.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdio.h>
 #include <glib.h>
 
diff --git a/tests/semantic/with-compact.c-expected b/tests/semantic/with-compact.c-expected
index aa892e2392d79853..42f5b99735f5538a 100644
--- a/tests/semantic/with-compact.c-expected
+++ b/tests/semantic/with-compact.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_compact.c generated by valac, the Vala compiler
  * generated from semantic_with_compact.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/with-declaration-cast-type.c-expected b/tests/semantic/with-declaration-cast-type.c-expected
index 497e40268843b69f..8a375b697958c324 100644
--- a/tests/semantic/with-declaration-cast-type.c-expected
+++ b/tests/semantic/with-declaration-cast-type.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_declaration_cast_type.c generated by valac, the Vala compiler
  * generated from semantic_with_declaration_cast_type.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <gobject/gvaluecollector.h>
 
diff --git a/tests/semantic/with-declaration.c-expected b/tests/semantic/with-declaration.c-expected
index 3f0957f0545b5795..ac6f34e2ed0e9414 100644
--- a/tests/semantic/with-declaration.c-expected
+++ b/tests/semantic/with-declaration.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_declaration.c generated by valac, the Vala compiler
  * generated from semantic_with_declaration.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/with-dereferenced-pointer.c-expected b/tests/semantic/with-dereferenced-pointer.c-expected
index 1faf737e2b483c2a..7b5c90ea30fa26a3 100644
--- a/tests/semantic/with-dereferenced-pointer.c-expected
+++ b/tests/semantic/with-dereferenced-pointer.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_dereferenced_pointer.c generated by valac, the Vala compiler
  * generated from semantic_with_dereferenced_pointer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/with-enum-member.c-expected b/tests/semantic/with-enum-member.c-expected
index d7347f70b3c61220..aa9ed3ba96849df1 100644
--- a/tests/semantic/with-enum-member.c-expected
+++ b/tests/semantic/with-enum-member.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_enum_member.c generated by valac, the Vala compiler
  * generated from semantic_with_enum_member.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/semantic/with-null.c-expected b/tests/semantic/with-null.c-expected
index 0d5488110fb4aa53..3449937b6f32771b 100644
--- a/tests/semantic/with-null.c-expected
+++ b/tests/semantic/with-null.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_null.c generated by valac, the Vala compiler
  * generated from semantic_with_null.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <gobject/gvaluecollector.h>
diff --git a/tests/semantic/with-string.c-expected b/tests/semantic/with-string.c-expected
index 7d80c4782967e2df..ef022ff1698f57c8 100644
--- a/tests/semantic/with-string.c-expected
+++ b/tests/semantic/with-string.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_string.c generated by valac, the Vala compiler
  * generated from semantic_with_string.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/semantic/with-value.c-expected b/tests/semantic/with-value.c-expected
index 1f09b30727c1c4b7..2001436f84019520 100644
--- a/tests/semantic/with-value.c-expected
+++ b/tests/semantic/with-value.c-expected
@@ -1,6 +1,12 @@
 /* semantic_with_value.c generated by valac, the Vala compiler
  * generated from semantic_with_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug530605.c-expected b/tests/structs/bug530605.c-expected
index ad65d7af3a54d564..b60412bc14b52857 100644
--- a/tests/structs/bug530605.c-expected
+++ b/tests/structs/bug530605.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug530605.c generated by valac, the Vala compiler
  * generated from structs_bug530605.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/bug572091.c-expected b/tests/structs/bug572091.c-expected
index 8046ad9b74cbcd42..cf3c13515c1bc98d 100644
--- a/tests/structs/bug572091.c-expected
+++ b/tests/structs/bug572091.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug572091.c generated by valac, the Vala compiler
  * generated from structs_bug572091.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug583603.c-expected b/tests/structs/bug583603.c-expected
index 8bbabae5954963e0..4b7dc9df0637e79e 100644
--- a/tests/structs/bug583603.c-expected
+++ b/tests/structs/bug583603.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug583603.c generated by valac, the Vala compiler
  * generated from structs_bug583603.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug595587.c-expected b/tests/structs/bug595587.c-expected
index 3d5f56781fc5f068..6b61c1f53eca15b6 100644
--- a/tests/structs/bug595587.c-expected
+++ b/tests/structs/bug595587.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug595587.c generated by valac, the Vala compiler
  * generated from structs_bug595587.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug596144.c-expected b/tests/structs/bug596144.c-expected
index deb8529465c09b3c..e6a584d048e92172 100644
--- a/tests/structs/bug596144.c-expected
+++ b/tests/structs/bug596144.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug596144.c generated by valac, the Vala compiler
  * generated from structs_bug596144.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug603056.c-expected b/tests/structs/bug603056.c-expected
index 7530689b91fadb06..a463c2121146814c 100644
--- a/tests/structs/bug603056.c-expected
+++ b/tests/structs/bug603056.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug603056.c generated by valac, the Vala compiler
  * generated from structs_bug603056.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug606202.c-expected b/tests/structs/bug606202.c-expected
index 9bfe67888eefc64f..eac1feda860792cf 100644
--- a/tests/structs/bug606202.c-expected
+++ b/tests/structs/bug606202.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug606202.c generated by valac, the Vala compiler
  * generated from structs_bug606202.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug609642.c-expected b/tests/structs/bug609642.c-expected
index 9f5e0a43a53b19fe..8d654de098b921bc 100644
--- a/tests/structs/bug609642.c-expected
+++ b/tests/structs/bug609642.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug609642.c generated by valac, the Vala compiler
  * generated from structs_bug609642.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug613513.c-expected b/tests/structs/bug613513.c-expected
index f0af93b3896ea957..d52e3d0806e4281d 100644
--- a/tests/structs/bug613513.c-expected
+++ b/tests/structs/bug613513.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug613513.c generated by valac, the Vala compiler
  * generated from structs_bug613513.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/bug613825.c-expected b/tests/structs/bug613825.c-expected
index fd6775b9d417036e..3dcb3a527bb5dfc7 100644
--- a/tests/structs/bug613825.c-expected
+++ b/tests/structs/bug613825.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug613825.c generated by valac, the Vala compiler
  * generated from structs_bug613825.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug621176.c-expected b/tests/structs/bug621176.c-expected
index 77cae89372772545..44e0c053b1592625 100644
--- a/tests/structs/bug621176.c-expected
+++ b/tests/structs/bug621176.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug621176.c generated by valac, the Vala compiler
  * generated from structs_bug621176.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug622422.c-expected b/tests/structs/bug622422.c-expected
index 561b64dd1c633a9e..eed8d0eaac4910a3 100644
--- a/tests/structs/bug622422.c-expected
+++ b/tests/structs/bug622422.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug622422.c generated by valac, the Vala compiler
  * generated from structs_bug622422.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug623092.c-expected b/tests/structs/bug623092.c-expected
index 003620863f304f91..010da6df8249c906 100644
--- a/tests/structs/bug623092.c-expected
+++ b/tests/structs/bug623092.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug623092.c generated by valac, the Vala compiler
  * generated from structs_bug623092.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug651441.c-expected b/tests/structs/bug651441.c-expected
index 05d39686026da9d2..b302e1f903dfb897 100644
--- a/tests/structs/bug651441.c-expected
+++ b/tests/structs/bug651441.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug651441.c generated by valac, the Vala compiler
  * generated from structs_bug651441.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug654646.c-expected b/tests/structs/bug654646.c-expected
index ac2e178a4e95793b..f2fad32dc62fd9ec 100644
--- a/tests/structs/bug654646.c-expected
+++ b/tests/structs/bug654646.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug654646.c generated by valac, the Vala compiler
  * generated from structs_bug654646.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdarg.h>
 
diff --git a/tests/structs/bug654753.c-expected b/tests/structs/bug654753.c-expected
index 4c60a22acd3f19fc..68ec75e71be3009f 100644
--- a/tests/structs/bug654753.c-expected
+++ b/tests/structs/bug654753.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug654753.c generated by valac, the Vala compiler
  * generated from structs_bug654753.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug656693.c-expected b/tests/structs/bug656693.c-expected
index 392fe9d3b91860a5..1cae92866cdfffbb 100644
--- a/tests/structs/bug656693.c-expected
+++ b/tests/structs/bug656693.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug656693.c generated by valac, the Vala compiler
  * generated from structs_bug656693.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug657378.c-expected b/tests/structs/bug657378.c-expected
index 2ab07075a3733eb8..64e49e1681b7bc9a 100644
--- a/tests/structs/bug657378.c-expected
+++ b/tests/structs/bug657378.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug657378.c generated by valac, the Vala compiler
  * generated from structs_bug657378.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/structs/bug658048.c-expected b/tests/structs/bug658048.c-expected
index ad1b358558860d2d..3f675da73893cbd2 100644
--- a/tests/structs/bug658048.c-expected
+++ b/tests/structs/bug658048.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug658048.c generated by valac, the Vala compiler
  * generated from structs_bug658048.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/structs/bug660426.c-expected b/tests/structs/bug660426.c-expected
index 79459ede52f4ccee..3d7f1b8d598fc14e 100644
--- a/tests/structs/bug660426.c-expected
+++ b/tests/structs/bug660426.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug660426.c generated by valac, the Vala compiler
  * generated from structs_bug660426.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug661945.c-expected b/tests/structs/bug661945.c-expected
index 5d699a61214ab978..6057456a47cfae08 100644
--- a/tests/structs/bug661945.c-expected
+++ b/tests/structs/bug661945.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug661945.c generated by valac, the Vala compiler
  * generated from structs_bug661945.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug667890.c-expected b/tests/structs/bug667890.c-expected
index 958f3df9eedd4313..101249e249ce69d2 100644
--- a/tests/structs/bug667890.c-expected
+++ b/tests/structs/bug667890.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug667890.c generated by valac, the Vala compiler
  * generated from structs_bug667890.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/structs/bug669580.c-expected b/tests/structs/bug669580.c-expected
index 1b00223a98c22a64..47b84ce724825806 100644
--- a/tests/structs/bug669580.c-expected
+++ b/tests/structs/bug669580.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug669580.c generated by valac, the Vala compiler
  * generated from structs_bug669580.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug685177.c-expected b/tests/structs/bug685177.c-expected
index 501cf7c0ae213863..18c2bf70d5dce4e6 100644
--- a/tests/structs/bug685177.c-expected
+++ b/tests/structs/bug685177.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug685177.c generated by valac, the Vala compiler
  * generated from structs_bug685177.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/structs/bug686190.c-expected b/tests/structs/bug686190.c-expected
index 67b25b0c9bda0316..a25548025107a54b 100644
--- a/tests/structs/bug686190.c-expected
+++ b/tests/structs/bug686190.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug686190.c generated by valac, the Vala compiler
  * generated from structs_bug686190.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug688732.c-expected b/tests/structs/bug688732.c-expected
index 74232f52e2a78534..0187b6f6c71ed6da 100644
--- a/tests/structs/bug688732.c-expected
+++ b/tests/structs/bug688732.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug688732.c generated by valac, the Vala compiler
  * generated from structs_bug688732.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 
diff --git a/tests/structs/bug690380.c-expected b/tests/structs/bug690380.c-expected
index aa4c9f7cef607675..2e692ab24060050f 100644
--- a/tests/structs/bug690380.c-expected
+++ b/tests/structs/bug690380.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug690380.c generated by valac, the Vala compiler
  * generated from structs_bug690380.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug694140.c-expected b/tests/structs/bug694140.c-expected
index e00332124239ed8b..5b9b620a23f0f23b 100644
--- a/tests/structs/bug694140.c-expected
+++ b/tests/structs/bug694140.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug694140.c generated by valac, the Vala compiler
  * generated from structs_bug694140.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <glib.h>
diff --git a/tests/structs/bug749952.c-expected b/tests/structs/bug749952.c-expected
index b10c074e01ec0289..d78b72a8b3907e0e 100644
--- a/tests/structs/bug749952.c-expected
+++ b/tests/structs/bug749952.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug749952.c generated by valac, the Vala compiler
  * generated from structs_bug749952.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/bug775761.c-expected b/tests/structs/bug775761.c-expected
index 811f8626587fc3b1..fbcf91ca27975ee5 100644
--- a/tests/structs/bug775761.c-expected
+++ b/tests/structs/bug775761.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug775761.c generated by valac, the Vala compiler
  * generated from structs_bug775761.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/bug777194-2.c-expected b/tests/structs/bug777194-2.c-expected
index 101c5d55a1268a1c..c2667dfba3ddda35 100644
--- a/tests/structs/bug777194-2.c-expected
+++ b/tests/structs/bug777194-2.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug777194_2.c generated by valac, the Vala compiler
  * generated from structs_bug777194_2.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/structs/bug777194.c-expected b/tests/structs/bug777194.c-expected
index 055c37c70074d9d7..05dde111fad9722a 100644
--- a/tests/structs/bug777194.c-expected
+++ b/tests/structs/bug777194.c-expected
@@ -1,6 +1,12 @@
 /* structs_bug777194.c generated by valac, the Vala compiler
  * generated from structs_bug777194.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/cast-struct-boxed.c-expected b/tests/structs/cast-struct-boxed.c-expected
index 23472fd1afc3bfa1..002492463f44e542 100644
--- a/tests/structs/cast-struct-boxed.c-expected
+++ b/tests/structs/cast-struct-boxed.c-expected
@@ -1,6 +1,12 @@
 /* structs_cast_struct_boxed.c generated by valac, the Vala compiler
  * generated from structs_cast_struct_boxed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/constructor-params-array.c-expected b/tests/structs/constructor-params-array.c-expected
index d60648f81ff0c74a..45d59f9f2715990f 100644
--- a/tests/structs/constructor-params-array.c-expected
+++ b/tests/structs/constructor-params-array.c-expected
@@ -1,6 +1,12 @@
 /* structs_constructor_params_array.c generated by valac, the Vala compiler
  * generated from structs_constructor_params_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/constructor-variadic.c-expected b/tests/structs/constructor-variadic.c-expected
index 696f35bba604f697..645183ebf4cf3297 100644
--- a/tests/structs/constructor-variadic.c-expected
+++ b/tests/structs/constructor-variadic.c-expected
@@ -1,6 +1,12 @@
 /* structs_constructor_variadic.c generated by valac, the Vala compiler
  * generated from structs_constructor_variadic.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/default-gtype.c-expected b/tests/structs/default-gtype.c-expected
index 93efcd45afd99b66..430ed9d70fc101c8 100644
--- a/tests/structs/default-gtype.c-expected
+++ b/tests/structs/default-gtype.c-expected
@@ -1,6 +1,12 @@
 /* structs_default_gtype.c generated by valac, the Vala compiler
  * generated from structs_default_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/gmutex.c-expected b/tests/structs/gmutex.c-expected
index 740fc21683aa375a..643b271bbaba10de 100644
--- a/tests/structs/gmutex.c-expected
+++ b/tests/structs/gmutex.c-expected
@@ -1,6 +1,12 @@
 /* structs_gmutex.c generated by valac, the Vala compiler
  * generated from structs_gmutex.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/structs/gtype-base-struct.c-expected b/tests/structs/gtype-base-struct.c-expected
index e5966d7ed7f3c9c4..31e24419ff4f60aa 100644
--- a/tests/structs/gtype-base-struct.c-expected
+++ b/tests/structs/gtype-base-struct.c-expected
@@ -1,6 +1,12 @@
 /* structs_gtype_base_struct.c generated by valac, the Vala compiler
  * generated from structs_gtype_base_struct.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <float.h>
 #include <math.h>
diff --git a/tests/structs/gvalue-implicit-comparison.c-expected b/tests/structs/gvalue-implicit-comparison.c-expected
index 21d2e91bbf3e7252..0ed8f991ee887415 100644
--- a/tests/structs/gvalue-implicit-comparison.c-expected
+++ b/tests/structs/gvalue-implicit-comparison.c-expected
@@ -1,6 +1,12 @@
 /* structs_gvalue_implicit_comparison.c generated by valac, the Vala compiler
  * generated from structs_gvalue_implicit_comparison.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/gvalue.c-expected b/tests/structs/gvalue.c-expected
index 695fcc1806598ffb..5a16adbd3b506290 100644
--- a/tests/structs/gvalue.c-expected
+++ b/tests/structs/gvalue.c-expected
@@ -1,6 +1,12 @@
 /* structs_gvalue.c generated by valac, the Vala compiler
  * generated from structs_gvalue.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/namespace-field-nested-initializer.c-expected b/tests/structs/namespace-field-nested-initializer.c-expected
index 8151ab7f6e812e8c..70e9849f0dc2dee0 100644
--- a/tests/structs/namespace-field-nested-initializer.c-expected
+++ b/tests/structs/namespace-field-nested-initializer.c-expected
@@ -1,6 +1,12 @@
 /* structs_namespace_field_nested_initializer.c generated by valac, the Vala compiler
  * generated from structs_namespace_field_nested_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/properties.c-expected b/tests/structs/properties.c-expected
index 16cc2b65417d918a..02743762d0c275cb 100644
--- a/tests/structs/properties.c-expected
+++ b/tests/structs/properties.c-expected
@@ -1,6 +1,12 @@
 /* structs_properties.c generated by valac, the Vala compiler
  * generated from structs_properties.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/simple-type-boxed.c-expected b/tests/structs/simple-type-boxed.c-expected
index 45da6945b29ec231..12c966e0c81ac0c3 100644
--- a/tests/structs/simple-type-boxed.c-expected
+++ b/tests/structs/simple-type-boxed.c-expected
@@ -1,6 +1,12 @@
 /* structs_simple_type_boxed.c generated by valac, the Vala compiler
  * generated from structs_simple_type_boxed.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/structs/simple-type-constructor.c-expected b/tests/structs/simple-type-constructor.c-expected
index 00a17265ca76ea7a..2186674b8ef30d31 100644
--- a/tests/structs/simple-type-constructor.c-expected
+++ b/tests/structs/simple-type-constructor.c-expected
@@ -1,6 +1,12 @@
 /* structs_simple_type_constructor.c generated by valac, the Vala compiler
  * generated from structs_simple_type_constructor.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/structs/simple-type-default-value.c-expected b/tests/structs/simple-type-default-value.c-expected
index c7bc26b224c211cc..f86072bff9800c13 100644
--- a/tests/structs/simple-type-default-value.c-expected
+++ b/tests/structs/simple-type-default-value.c-expected
@@ -1,6 +1,12 @@
 /* structs_simple_type_default_value.c generated by valac, the Vala compiler
  * generated from structs_simple_type_default_value.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <glib-object.h>
 
diff --git a/tests/structs/struct-base-types.c-expected b/tests/structs/struct-base-types.c-expected
index 7bbaaf579a657d5e..0ff419df371f9433 100644
--- a/tests/structs/struct-base-types.c-expected
+++ b/tests/structs/struct-base-types.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_base_types.c generated by valac, the Vala compiler
  * generated from structs_struct_base_types.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/struct-boxed-cast.c-expected b/tests/structs/struct-boxed-cast.c-expected
index 6b351221aaa3b7f5..4b4ae944a66a78f7 100644
--- a/tests/structs/struct-boxed-cast.c-expected
+++ b/tests/structs/struct-boxed-cast.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_boxed_cast.c generated by valac, the Vala compiler
  * generated from structs_struct_boxed_cast.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/struct-initializer-list-in-array.c-expected b/tests/structs/struct-initializer-list-in-array.c-expected
index 5158e3d764906117..e4cf9aa3e46ebf0c 100644
--- a/tests/structs/struct-initializer-list-in-array.c-expected
+++ b/tests/structs/struct-initializer-list-in-array.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_initializer_list_in_array.c generated by valac, the Vala compiler
  * generated from structs_struct_initializer_list_in_array.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/structs/struct-initializer-list-nested.c-expected b/tests/structs/struct-initializer-list-nested.c-expected
index 441dd9ab16212eec..62197a2984725471 100644
--- a/tests/structs/struct-initializer-list-nested.c-expected
+++ b/tests/structs/struct-initializer-list-nested.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_initializer_list_nested.c generated by valac, the Vala compiler
  * generated from structs_struct_initializer_list_nested.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/struct-no-gtype-inherit.c-expected b/tests/structs/struct-no-gtype-inherit.c-expected
index 99211b9f3a928c97..819a3772366f49b8 100644
--- a/tests/structs/struct-no-gtype-inherit.c-expected
+++ b/tests/structs/struct-no-gtype-inherit.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_no_gtype_inherit.c generated by valac, the Vala compiler
  * generated from structs_struct_no_gtype_inherit.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <stdint.h>
 
 typedef int32_t foo_t;
diff --git a/tests/structs/struct-no-gtype.c-expected b/tests/structs/struct-no-gtype.c-expected
index b12fb74fcd881929..a6a1848305dd6903 100644
--- a/tests/structs/struct-no-gtype.c-expected
+++ b/tests/structs/struct-no-gtype.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_no_gtype.c generated by valac, the Vala compiler
  * generated from structs_struct_no_gtype.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <string.h>
 
diff --git a/tests/structs/struct-static-field-initializer-3.c-expected b/tests/structs/struct-static-field-initializer-3.c-expected
index e0241e830fa98b2b..0111f17220795577 100644
--- a/tests/structs/struct-static-field-initializer-3.c-expected
+++ b/tests/structs/struct-static-field-initializer-3.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_static_field_initializer_3.c generated by valac, the Vala compiler
  * generated from structs_struct_static_field_initializer_3.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 
 #if !defined(VALA_EXTERN)
diff --git a/tests/structs/struct-static-field-initializer.c-expected b/tests/structs/struct-static-field-initializer.c-expected
index 6c6c164705b765f5..173b8ff874de42b5 100644
--- a/tests/structs/struct-static-field-initializer.c-expected
+++ b/tests/structs/struct-static-field-initializer.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_static_field_initializer.c generated by valac, the Vala compiler
  * generated from structs_struct_static_field_initializer.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <stdlib.h>
diff --git a/tests/structs/struct_only.c-expected b/tests/structs/struct_only.c-expected
index fe1b35e0b0817a59..3ff129daabd5d9ad 100644
--- a/tests/structs/struct_only.c-expected
+++ b/tests/structs/struct_only.c-expected
@@ -1,6 +1,12 @@
 /* structs_struct_only.c generated by valac, the Vala compiler
  * generated from structs_struct_only.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/structs/structs.c-expected b/tests/structs/structs.c-expected
index 4fba50587fa8e821..fc9b4eb73ec57042 100644
--- a/tests/structs/structs.c-expected
+++ b/tests/structs/structs.c-expected
@@ -1,6 +1,12 @@
 /* structs_structs.c generated by valac, the Vala compiler
  * generated from structs_structs.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib-object.h>
 #include <glib.h>
 #include <string.h>
diff --git a/tests/threads/threadpool.c-expected b/tests/threads/threadpool.c-expected
index 0ff74363f9e6f083..1a6e73f2b5e5d84f 100644
--- a/tests/threads/threadpool.c-expected
+++ b/tests/threads/threadpool.c-expected
@@ -1,6 +1,12 @@
 /* threads_threadpool.c generated by valac, the Vala compiler
  * generated from threads_threadpool.vala, do not modify */
 
+#if !defined VALA_STRICT_C && defined __GNUC__ && __GNUC__ >= 14
+#pragma GCC diagnostic warning "-Wimplicit-function-declaration"
+#pragma GCC diagnostic warning "-Wreturn-mismatch"
+#pragma GCC diagnostic warning "-Wincompatible-pointer-types"
+#endif
+
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>