[PATCH] i386, debug: Default to -gdwarf-4 on Windows targets with broken ld.bfd [PR98860]
Jakub Jelinek
jakub@redhat.com
Wed Mar 24 13:56:54 GMT 2021
Hi!
As mentioned in the PR, before the
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba6eb62ff0ea9843a018cfd7cd06777bd66ae0a0
fix from March 1st, PECOFF ld.bfd didn't know about .debug_loclists,
.debug_rnglists and other debug sections new in DWARF 5. Unfortunately,
unlike for ELF linkers, that means the sections were placed in wrong
ordering with wrong VMA/LMA, so the resulting executables are apparently
unusable.
As that is pretty new change, newer than 2.35.2 or 2.36 binutils releases,
the following patch adds a workaround that turns -gdwarf-4 by default
instead of -gdwarf-5 if a broken linker is found at configure time.
Users can still explicitly play with -gdwarf-5 and either use a non-broken
linker or use custom linker scripts for the broken one, but at least
by default it should work.
Bootstrapped/regtested on x86_64-linux and i686-linux and Jonathan said
he has tested it on Windows in the PR. Ok for trunk?
2021-03-24 Jakub Jelinek <jakub@redhat.com>
PR bootstrap/98860
* configure.ac (HAVE_LD_BROKEN_PE_DWARF5): New AC_DEFINE if PECOFF
linker doesn't support DWARF sections new in DWARF5.
* config/i386/i386-options.c (ix86_option_override_internal): Default
to dwarf_version 4 if HAVE_LD_BROKEN_PE_DWARF5 for TARGET_PECOFF
targets.
* config.in: Regenerated.
* configure: Regenerated.
--- gcc/configure.ac.jj 2021-01-25 14:20:01.818334183 +0100
+++ gcc/configure.ac 2021-03-23 16:59:47.199192635 +0100
@@ -6190,6 +6190,31 @@ if test x"$ld64_flag" = x"yes"; then
[Define to 1 if ld64 supports '-export_dynamic'.])
fi
+case $target_os in
+ win32 | pe | cygwin* | mingw32*)
+ AC_MSG_CHECKING(broken PE linker dwarf5 support)
+ gcc_cv_ld_broken_pe_dwarf5=yes
+ if test $in_tree_ld = yes ; then
+ if grep -q '\.debug_loclists.*BLOCK.*__section_alignment__.*NOLOAD.*:' \
+ $gcc_cv_ld_gld_srcdir/scripttempl/pe*.sc \
+ && grep -q '\.debug_rnglists.*BLOCK.*__section_alignment__.*NOLOAD.*:' \
+ $gcc_cv_ld_gld_srcdir/scripttempl/pe*.sc; then
+ gcc_cv_ld_broken_pe_dwarf5=no
+ fi
+ else
+ if $gcc_cv_ld --verbose 2>&1 | grep -q '\.debug_loclists.*BLOCK.*__section_alignment__.*NOLOAD.*:' \
+ && $gcc_cv_ld --verbose 2>&1 | grep -q '\.debug_rnglists.*BLOCK.*__section_alignment__.*NOLOAD.*:'; then
+ gcc_cv_ld_broken_pe_dwarf5=no
+ fi
+ fi
+ if test x$gcc_cv_ld_broken_pe_dwarf5 = xyes; then
+ AC_DEFINE(HAVE_LD_BROKEN_PE_DWARF5, 1,
+ [Define if the PE linker has broken DWARF 5 support.])
+ fi
+ AC_MSG_RESULT($gcc_cv_ld_broken_pe_dwarf5)
+ ;;
+esac
+
# --------
# UNSORTED
# --------
--- gcc/config/i386/i386-options.c.jj 2021-03-19 18:36:23.018588431 +0100
+++ gcc/config/i386/i386-options.c 2021-03-23 16:58:52.536791866 +0100
@@ -1861,6 +1861,13 @@ ix86_option_override_internal (bool main
SUBSUBTARGET_OVERRIDE_OPTIONS;
#endif
+#ifdef HAVE_LD_BROKEN_PE_DWARF5
+ /* If the PE linker has broken DWARF 5 support, make
+ DWARF 4 the default. */
+ if (TARGET_PECOFF)
+ SET_OPTION_IF_UNSET (opts, opts_set, dwarf_version, 4);
+#endif
+
/* -fPIC is the default for x86_64. */
if (TARGET_MACHO && TARGET_64BIT_P (opts->x_ix86_isa_flags))
opts->x_flag_pic = 2;
--- gcc/config.in.jj 2020-12-28 12:27:32.302754870 +0100
+++ gcc/config.in 2021-03-23 16:59:11.450584412 +0100
@@ -1580,6 +1580,12 @@
#endif
+/* Define if the PE linker has broken DWARF 5 support. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_LD_BROKEN_PE_DWARF5
+#endif
+
+
/* Define if your linker supports --build-id. */
#ifndef USED_FOR_TARGET
#undef HAVE_LD_BUILDID
--- gcc/configure.jj 2021-01-25 14:20:01.821334150 +0100
+++ gcc/configure 2021-03-23 16:59:53.375124921 +0100
@@ -19392,7 +19392,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 19405 "configure"
+#line 19395 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -19498,7 +19498,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 19511 "configure"
+#line 19501 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -22237,16 +22237,6 @@ freebsd* | dragonfly*)
esac
;;
-gnu*)
- version_type=linux
- need_lib_prefix=no
- need_version=no
- library_names_spec='${libname}${release}${shared_ext}$versuffix ${libname}${release}${shared_ext}${major} ${libname}${shared_ext}'
- soname_spec='${libname}${release}${shared_ext}$major'
- shlibpath_var=LD_LIBRARY_PATH
- hardcode_into_libs=yes
- ;;
-
haiku*)
version_type=linux
need_lib_prefix=no
@@ -22368,7 +22358,7 @@ linux*oldld* | linux*aout* | linux*coff*
# project, but have not yet been accepted: they are GCC-local changes
# for the time being. (See
# https://lists.gnu.org/archive/html/libtool-patches/2018-05/msg00000.html)
-linux* | k*bsd*-gnu | kopensolaris*-gnu | uclinuxfdpiceabi)
+linux* | k*bsd*-gnu | kopensolaris*-gnu | gnu* | uclinuxfdpiceabi)
version_type=linux
need_lib_prefix=no
need_version=no
@@ -30223,6 +30213,34 @@ _ACEOF
fi
+case $target_os in
+ win32 | pe | cygwin* | mingw32*)
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking broken PE linker dwarf5 support" >&5
+$as_echo_n "checking broken PE linker dwarf5 support... " >&6; }
+ gcc_cv_ld_broken_pe_dwarf5=yes
+ if test $in_tree_ld = yes ; then
+ if grep -q '\.debug_loclists.*BLOCK.*__section_alignment__.*NOLOAD.*:' \
+ $gcc_cv_ld_gld_srcdir/scripttempl/pe*.sc \
+ && grep -q '\.debug_rnglists.*BLOCK.*__section_alignment__.*NOLOAD.*:' \
+ $gcc_cv_ld_gld_srcdir/scripttempl/pe*.sc; then
+ gcc_cv_ld_broken_pe_dwarf5=no
+ fi
+ else
+ if $gcc_cv_ld --verbose 2>&1 | grep -q '\.debug_loclists.*BLOCK.*__section_alignment__.*NOLOAD.*:' \
+ && $gcc_cv_ld --verbose 2>&1 | grep -q '\.debug_rnglists.*BLOCK.*__section_alignment__.*NOLOAD.*:'; then
+ gcc_cv_ld_broken_pe_dwarf5=no
+ fi
+ fi
+ if test x$gcc_cv_ld_broken_pe_dwarf5 = xyes; then
+
+$as_echo "#define HAVE_LD_BROKEN_PE_DWARF5 1" >>confdefs.h
+
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_ld_broken_pe_dwarf5" >&5
+$as_echo "$gcc_cv_ld_broken_pe_dwarf5" >&6; }
+ ;;
+esac
+
# --------
# UNSORTED
# --------
Jakub
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