Fix un undefined behavior in Perl_custom_op_get_field()

perl-5.33.3-Perl_custom_op_get_field-remove-undef-behaviour.patch

@@ -0,0 +1,76 @@
+From e050064b67c501e9fdc7bc3f513ba2b8b9e795f8 Mon Sep 17 00:00:00 2001
+From: David Mitchell <davem@iabyn.com>
+Date: Fri, 30 Oct 2020 20:50:58 +0000
+Subject: [PATCH] Perl_custom_op_get_field(): remove undef behaviour
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Thus function has a couple a switches with
+
+               default:
+                   NOT_REACHED; /* NOTREACHED */
+
+but clang is complaining that the value returned by the function is
+undefined if those default branches are taken, since the 'any' variable
+doesn't get set in that path.
+
+Replace the NOTREACHED with a croak("panic: ..."). It's possible (albeit
+not intended) for Perl_custom_op_get_field() to be called with a 'field'
+arg which triggers the default case. So if this ever happens, make it
+clear that something has gone wrong, rather than just silently
+continuing on non-debugging builds.
+
+In any case, this shuts up clang.
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ op.c | 14 ++++++--------
+ 1 file changed, 6 insertions(+), 8 deletions(-)
+
+diff --git a/op.c b/op.c
+index c30c6b7c8f..2933e2ed7d 100644
+--- a/op.c
++++ b/op.c
+@@ -18100,6 +18100,7 @@ Perl_custom_op_get_field(pTHX_ const OP *o, const xop_flags_enum field)
+ 	else
+ 	    xop = INT2PTR(XOP *, SvIV(HeVAL(he)));
+     }
++
+     {
+ 	XOPRETANY any;
+ 	if(field == XOPe_xop_ptr) {
+@@ -18121,7 +18122,10 @@ Perl_custom_op_get_field(pTHX_ const OP *o, const xop_flags_enum field)
+ 		    any.xop_peep = xop->xop_peep;
+ 		    break;
+ 		default:
+-		    NOT_REACHED; /* NOTREACHED */
++                  field_panic:
++                    Perl_croak(aTHX_
++                        "panic: custom_op_get_field(): invalid field %d\n",
++                        (int)field);
+ 		    break;
+ 		}
+ 	    } else {
+@@ -18139,17 +18143,11 @@ Perl_custom_op_get_field(pTHX_ const OP *o, const xop_flags_enum field)
+ 		    any.xop_peep = XOPd_xop_peep;
+ 		    break;
+ 		default:
+-		    NOT_REACHED; /* NOTREACHED */
++                    goto field_panic;
+ 		    break;
+ 		}
+ 	    }
+ 	}
+-        /* On some platforms (HP-UX, IA64) gcc emits a warning for this function:
+-         * op.c: In function 'Perl_custom_op_get_field':
+-         * op.c:...: warning: 'any.xop_name' may be used uninitialized in this function [-Wmaybe-uninitialized]
+-         * This is because on those platforms (with -DEBUGGING) NOT_REACHED
+-         * expands to assert(0), which expands to ((0) ? (void)0 :
+-         * __assert(...)), and gcc doesn't know that __assert can never return. */
+ 	return any;
+     }
+ }
+-- 
+2.25.4
+

perl.spec

@@ -100,7 +100,7 @@ License:        GPL+ or Artistic
 Epoch:          %{perl_epoch}
 Version:        %{perl_version}
 # release number must be even higher, because dual-lived modules will be broken otherwise
-Release:        465%{?dist}
+Release:        466%{?dist}
 Summary:        Practical Extraction and Report Language
 Url:            https://www.perl.org/
 Source0:        https://www.cpan.org/src/5.0/perl-%{perl_version}.tar.xz
@@ -255,6 +255,10 @@ Patch39:        perl-5.33.2-mro.xs-Fix-compiler-warning.patch
 # Fix a code flow in Perl_sv_inc_nomg(), in upstream after 5.33.2
 Patch40:        perl-5.33.2-sv.c-Added-missing-braces-in-Perl_sv_inc_nomg.patch
 
+# Fix un undefined behavior in Perl_custom_op_get_field(),
+# in upstream after 5.33.3
+Patch41:        perl-5.33.3-Perl_custom_op_get_field-remove-undef-behaviour.patch
+
 # Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048
 Patch200:       perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
 
@@ -4297,6 +4301,7 @@ you're not running VMS, this module does nothing.
 %patch38 -p1
 %patch39 -p1
 %patch40 -p1
+%patch41 -p1
 %patch200 -p1
 %patch201 -p1
 
@@ -4344,6 +4349,7 @@ perl -x patchlevel.h \
     'Fedora Patch38: Fix sv_collxfrm macro to respect locale' \
     'Fedora Patch39: Fix an iterator signedness in handling a mro exception (GH#18155)' \
     'Fedora Patch40: Fix a code flow in Perl_sv_inc_nomg()' \
+    'Fedora Patch41: Fix un undefined behavior in Perl_custom_op_get_field()' \
     'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \
     'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
     %{nil}
@@ -7062,6 +7068,9 @@ popd
 
 # Old changelog entries are preserved in CVS.
 %changelog
+* Thu Nov 12 2020 Petr Pisar <ppisar@redhat.com> - 4:5.32.0-466
+- Fix un undefined behavior in Perl_custom_op_get_field()
+
 * Wed Oct 14 2020 Petr Pisar <ppisar@redhat.com> - 4:5.32.0-465
 - Fix sv_collxfrm macro to respect locale
 - Fix an iterator signedness in handling a mro exception (GH#18155)