From: Jeremie Courreges-Anglas <jca@wxcvbn.org>
Subject: lang/gcc 11 and 15: fix unwinding and C++ exceptions
To: ports@openbsd.org
Cc: pascal@openbsd.org, claudio@openbsd.org, tb@openbsd.org, kirill@openbsd.org
Date: Mon, 10 Nov 2025 15:27:31 +0100


During the previous months our attempts at using gcc/11 or gcc/15 on
sparc64 had faced a crash in devel/boost.  The crash was the
"gcc_assert (code == _URC_NO_REASON);" in libgcc's uw_init_context_1()
meaning the code wasn't able to find frame information.  This was
reproducible also on amd64 or arm64.

The culprit was this check added between gcc 8 and 11:

   #if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+      && defined(TARGET_DL_ITERATE_PHDR) \
       && (defined(__OpenBSD__) || defined(__NetBSD__))
   # define ElfW(type) Elf_##type
   # define USE_PT_GNU_EH_FRAME
   #endif

With this additional check we're not using PT_GNU_EH_FRAME any more.
TARGET_DL_ITERATE_PHDR in turn wasn't defined because the code in
gcc/configure is pretty much hardcoded and nobody noticed the function
was needed on OpenBSD just like on Solaris or FreeBSD etc.  The diff
below addresses that.

There is some similar code hardcoding a differently named #define in
libgcc/crtstuff.c but the code is apparently not built.

Keeping our less-than-optimal habits, this diff:
- bumps the revision for all subpackages even though installing just
  the new gcc-libs subpackage seems enough in my tests.  Better safe
  than sorry.
- doesn't add a comment in this already long and undocumented
  patch-gcc_configure, but I can add a blurb if someone insists.

Making progress here was a team effort with claudio and tb!

ok?


Index: 11/Makefile
===================================================================
RCS file: /cvs/ports/lang/gcc/11/Makefile,v
diff -u -p -r1.56 Makefile
--- 11/Makefile	3 Nov 2025 07:46:20 -0000	1.56
+++ 11/Makefile	10 Nov 2025 14:06:32 -0000
@@ -15,7 +15,7 @@ USE_NOEXECONLY = Yes
 V = 11.2.0
 FULL_VERSION = $V
 FULL_PKGVERSION = $V
-REVISION = 19
+REVISION = 20
 
 ADASTRAP-amd64 = adastrap-amd64-$V-5.tar.xz
 ADASTRAP-i386 = adastrap-i386-$V-4.tar.xz
Index: 11/patches/patch-gcc_configure
===================================================================
RCS file: /cvs/ports/lang/gcc/11/patches/patch-gcc_configure,v
diff -u -p -r1.2 patch-gcc_configure
--- 11/patches/patch-gcc_configure	11 Mar 2022 19:28:58 -0000	1.2
+++ 11/patches/patch-gcc_configure	10 Nov 2025 14:06:05 -0000
@@ -55,3 +55,13 @@ Index: gcc/configure
      *) enable_default_ssp=$enableval ;;
    esac
  else
+@@ -30981,6 +30987,9 @@ case "$target" in
+     else
+       gcc_cv_target_dl_iterate_phdr=no
+     fi
++    ;;
++  *-*-openbsd*)
++    gcc_cv_target_dl_iterate_phdr=yes
+     ;;
+   *-*-dragonfly* | *-*-freebsd*)
+     if grep dl_iterate_phdr $target_header_dir/sys/link_elf.h > /dev/null 2>&1; then
Index: 15/Makefile
===================================================================
RCS file: /cvs/ports/lang/gcc/15/Makefile,v
diff -u -p -r1.10 Makefile
--- 15/Makefile	3 Nov 2025 07:46:20 -0000	1.10
+++ 15/Makefile	10 Nov 2025 14:06:41 -0000
@@ -14,7 +14,7 @@ V = 15.2.0
 FULL_VERSION = $V
 FULL_PKGVERSION = $V
 
-REVISION = 0
+REVISION = 1
 
 ADASTRAP-amd64 = adastrap-amd64-11.2.0-5.tar.xz
 ADASTRAP-arm = adastrap-arm-4.9.4-0.tar.xz
Index: 15/patches/patch-gcc_configure
===================================================================
RCS file: /cvs/ports/lang/gcc/15/patches/patch-gcc_configure,v
diff -u -p -r1.1.1.1 patch-gcc_configure
--- 15/patches/patch-gcc_configure	18 Aug 2025 19:49:24 -0000	1.1.1.1
+++ 15/patches/patch-gcc_configure	10 Nov 2025 14:06:05 -0000
@@ -55,3 +55,13 @@ Index: gcc/configure
      *) enable_default_ssp=$enableval ;;
    esac
  else
+@@ -33636,6 +33642,9 @@ $as_echo_n "checking dl_iterate_phdr in target C libra
+ gcc_cv_target_dl_iterate_phdr=unknown
+ case "$target" in
+   *-*-solaris2*)
++    gcc_cv_target_dl_iterate_phdr=yes
++    ;;
++  *-*-openbsd*)
+     gcc_cv_target_dl_iterate_phdr=yes
+     ;;
+   *-*-dragonfly* | *-*-freebsd*)

-- 
jca