compat-sap-cplusplus-15/gcc15-pr123667.patch
Patrick Palka 4293cf5a65 Initial version.
Resolves: RHEL-152992
2026-05-07 11:37:29 -04:00

95 lines
2.9 KiB
Diff

2026-01-21 Jakub Jelinek <jakub@redhat.com>
PR c++/123667
* semantics.cc (finish_decltype_type): Allow a structured binding
for ptds.saved to have DECL_HAS_VALUE_EXPR_P cleared, if it is
not within current_function_decl, but in that case assert that
lookup_decomp_type succeeded.
* g++.dg/cpp1z/decomp66.C: New test.
* g++.dg/cpp1z/decomp67.C: New test.
--- gcc/cp/semantics.cc.jj 2026-01-15 16:33:46.000000000 +0100
+++ gcc/cp/semantics.cc 2026-01-21 17:55:14.272577246 +0100
@@ -13062,12 +13062,16 @@ finish_decltype_type (tree expr, bool id
{
if (ptds.saved)
{
- gcc_checking_assert (DECL_HAS_VALUE_EXPR_P (expr));
+ gcc_checking_assert (DECL_HAS_VALUE_EXPR_P (expr)
+ || (DECL_CONTEXT (expr)
+ != current_function_decl));
/* DECL_HAS_VALUE_EXPR_P is always set if
- processing_template_decl. If lookup_decomp_type
+ processing_template_decl at least for structured bindings
+ within the template. If lookup_decomp_type
returns non-NULL, it is the tuple case. */
if (tree ret = lookup_decomp_type (expr))
return ret;
+ gcc_checking_assert (DECL_HAS_VALUE_EXPR_P (expr));
}
if (DECL_HAS_VALUE_EXPR_P (expr))
/* Expr is an array or struct subobject proxy, handle
--- gcc/testsuite/g++.dg/cpp1z/decomp66.C.jj 2026-01-21 17:59:28.122275457 +0100
+++ gcc/testsuite/g++.dg/cpp1z/decomp66.C 2026-01-21 17:58:30.737247916 +0100
@@ -0,0 +1,23 @@
+// PR c++/123667
+// { dg-do compile { target c++14 } }
+// { dg-options "" }
+
+namespace std {
+ template <typename T> struct tuple_size;
+ template <int, typename> struct tuple_element;
+}
+
+struct A {
+ int i;
+ template <int I> int &get () { return i; }
+};
+
+template <> struct std::tuple_size <A> { static const int value = 2; };
+template <int I> struct std::tuple_element <I,A> { using type = int; };
+
+int
+main ()
+{
+ auto [ x, y ] = A { 0 }; // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ [] (auto t) { using z = decltype (x); } (1);
+}
--- gcc/testsuite/g++.dg/cpp1z/decomp67.C.jj 2026-01-21 17:59:31.139224331 +0100
+++ gcc/testsuite/g++.dg/cpp1z/decomp67.C 2026-01-21 17:59:07.235629406 +0100
@@ -0,0 +1,33 @@
+// PR c++/123667
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+namespace std {
+ template <typename T> struct tuple_size;
+ template <int, typename> struct tuple_element;
+}
+
+struct A {
+ int i;
+ template <int I> int &get () { return i; }
+};
+
+template <> struct std::tuple_size <A> { static const int value = 2; };
+template <int I> struct std::tuple_element <I,A> { using type = int; };
+
+auto [ x, y ] = A { 0 }; // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+
+template <int N>
+void
+foo ()
+{
+ using a = decltype (x);
+ auto [ x, y ] = A { 0 }; // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ using b = decltype (x);
+}
+
+void
+bar ()
+{
+ foo <42> ();
+}