gas: Default to -mrelax-relocations=no on Solaris/x86 [PR19520]

I recently noticed a complex case statement in gas/configure.ac controlling
the setting of ac_default_x86_relax_relocations on Solaris/x86.  Since it
included all versions of Solaris, it could be massively simplified.

Looking closer however, I found that it was introduced in

commit 0cb4071ef9
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Feb 3 08:25:15 2016 -0800

    Add -mrelax-relocations= to x86 assembler

based on PR gas/19520.  This PR reported that the new R_386_GOT32X
etc. relocations weren't supported on older versions of Solaris,
breaking gcc bootstrap.  In response, they were disabled on all Solaris
versions except Solaris 12, where they had been implemented in the
native toolchain based on my findings.

However, Solaris 12 has been rechristened to 11.4 before release,
effectively disabling DEFAULT_GENERATE_X86_RELAX_RELOCATIONS on all
versions of Solaris/x86.

Since Solaris 11.4 cannot be distinguished from earlier versions in
cross configurations, this patch fixes this by removing
--enable-x86-relax-relocations completely, instead disabling
DEFAULT_GENERATE_X86_RELAX_RELOCATIONS in tc-i386.c on Solaris.  It also
adds testcases to verify the -mrelax-relocations default.

Tested on {i386,amd64}-pc-solaris2.11 and {i686,x86_64}-pc-linux-gnu.

2025-10-16  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gas:
	PR gas/19520
	* configure.ac (ac_default_x86_relax_relocations): Remove.
	<i386-*-solaris2* | x86_64-*-solaris2>: Likewise.
	* configure: Regenerate.
	* config.in: Regenerate.
	* config/tc-i386.c (DEFAULT_GENERATE_X86_RELAX_RELOCATIONS): Define.
	* doc/c-i386.texi (i386-Options, -mrelax-relocations): Remove
	--enable-x86-relax-relocations reference.
	* testsuite/gas/i386/gotx.s: New source.
	* testsuite/gas/i386/gotx-default.d: New test.
	* testsuite/gas/i386/no-gotx-default.d: Likewise.
	* testsuite/gas/i386/i386.exp: Run them.
This commit is contained in:
Rainer Orth
2025-11-06 17:18:16 +01:00
parent 51b48a997d
commit 70abf8984b
9 changed files with 42 additions and 70 deletions

View File

@@ -42,9 +42,6 @@
type by default. */
#undef DEFAULT_GENERATE_ELF_STT_COMMON
/* Define to 1 if you want to generate x86 relax relocations by default. */
#undef DEFAULT_GENERATE_X86_RELAX_RELOCATIONS
/* Define to 1 if you want to fix Loongson3 LLSC Errata by default. */
#undef DEFAULT_MIPS_FIX_LOONGSON3_LLSC

View File

@@ -750,6 +750,15 @@ lfence_before_ret;
/* 1 if the assembler should generate relax relocations. */
#ifdef TE_SOLARIS
/* PR gas/19520: The Solaris/x86 linker cannot handle relax relocations
before Solaris 11.4 which cannot easily be detected in cross
configurations. */
#define DEFAULT_GENERATE_X86_RELAX_RELOCATIONS 0
#else
#define DEFAULT_GENERATE_X86_RELAX_RELOCATIONS 1
#endif
static int generate_relax_relocations
= DEFAULT_GENERATE_X86_RELAX_RELOCATIONS;

38
gas/configure vendored
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@@ -818,7 +818,6 @@ enable_targets
enable_checking
enable_compressed_debug_sections
enable_default_compressed_debug_sections_algorithm
enable_x86_relax_relocations
enable_x86_tls_check
enable_elf_stt_common
enable_default_sframe
@@ -1494,8 +1493,6 @@ Optional Features:
--enable-default-compressed-debug-sections-algorithm={zlib,zstd}
Default compression algorithm for
--enable-compressed-debug-sections.
--enable-x86-relax-relocations
generate x86 relax relocations by default
--enable-x86-tls-check check x86 TLS relocation by default
--enable-elf-stt-common generate ELF common symbols with STT_COMMON type by
default
@@ -11153,7 +11150,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
#line 11156 "configure"
#line 11153 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -11259,7 +11256,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
#line 11262 "configure"
#line 11259 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -11942,17 +11939,6 @@ if test "${enable_default_compressed_debug_sections_algorithm+set}" = set; then
esac
fi
# PR gas/19520
# Decide if x86 assembler should generate relax relocations.
ac_default_x86_relax_relocations=unset
# Provide a configure time option to override our default.
# Check whether --enable-x86_relax_relocations was given.
if test "${enable_x86_relax_relocations+set}" = set; then :
enableval=$enable_x86_relax_relocations; case "${enableval}" in
no) ac_default_x86_relax_relocations=0 ;;
esac
fi
# PR gas/32022
# Decide if x86 assembler should check TLS relocation.
ac_default_x86_tls_check=unset
@@ -12540,17 +12526,6 @@ $as_echo "#define STRICTCOFF 1" >>confdefs.h
fi
;;
i386-*-solaris2 \
| x86_64-*-solaris2 \
| i386-*-solaris2.[0-9] \
| i386-*-solaris2.1[01] \
| x86_64-*-solaris2.1[01])
if test ${this_target} = $target \
&& test ${ac_default_x86_relax_relocations} = unset; then
ac_default_x86_relax_relocations=0
fi
;;
microblaze*)
;;
@@ -13071,15 +13046,6 @@ $as_echo "$with_priv_spec" >&6; }
done
if test ${ac_default_x86_relax_relocations} = unset; then
ac_default_x86_relax_relocations=1
fi
cat >>confdefs.h <<_ACEOF
#define DEFAULT_GENERATE_X86_RELAX_RELOCATIONS $ac_default_x86_relax_relocations
_ACEOF
if test ${ac_default_x86_tls_check} = unset; then
ac_default_x86_tls_check=1
fi

View File

@@ -84,17 +84,6 @@ AC_ARG_ENABLE(default_compressed_debug_sections_algorithm,
zstd) ac_default_compressed_debug_sections_algorithm=COMPRESS_DEBUG_ZSTD ;;
esac])dnl
# PR gas/19520
# Decide if x86 assembler should generate relax relocations.
ac_default_x86_relax_relocations=unset
# Provide a configure time option to override our default.
AC_ARG_ENABLE(x86_relax_relocations,
AS_HELP_STRING([--enable-x86-relax-relocations],
[generate x86 relax relocations by default]),
[case "${enableval}" in
no) ac_default_x86_relax_relocations=0 ;;
esac])dnl
# PR gas/32022
# Decide if x86 assembler should check TLS relocation.
ac_default_x86_tls_check=unset
@@ -276,17 +265,6 @@ for this_target in $target $canon_targets ; do
fi
;;
i386-*-solaris2 \
| x86_64-*-solaris2 \
| i386-*-solaris2.[[0-9]] \
| i386-*-solaris2.1[[01]] \
| x86_64-*-solaris2.1[[01]])
if test ${this_target} = $target \
&& test ${ac_default_x86_relax_relocations} = unset; then
ac_default_x86_relax_relocations=0
fi
;;
microblaze*)
;;
@@ -735,13 +713,6 @@ changequote([,])dnl
done
if test ${ac_default_x86_relax_relocations} = unset; then
ac_default_x86_relax_relocations=1
fi
AC_DEFINE_UNQUOTED(DEFAULT_GENERATE_X86_RELAX_RELOCATIONS,
$ac_default_x86_relax_relocations,
[Define to 1 if you want to generate x86 relax relocations by default.])
if test ${ac_default_x86_tls_check} = unset; then
ac_default_x86_tls_check=1
fi

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@@ -478,8 +478,7 @@ relocations, R_386_GOT32X, in 32-bit mode, or R_X86_64_GOTPCRELX and
R_X86_64_REX_GOTPCRELX, in 64-bit mode.
@option{-mrelax-relocations=@var{yes}} will generate relax relocations.
@option{-mrelax-relocations=@var{no}} will not generate relax
relocations. The default can be controlled by a configure option
@option{--enable-x86-relax-relocations}.
relocations.
@cindex @samp{-mtls-check=} option, i386
@cindex @samp{-mtls-check=} option, x86-64

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@@ -0,0 +1,11 @@
#source: gotx.s
#objdump: -dwr
#xfail: *-*-solaris*
.*: +file format .*
Disassembly of section .text:
0+ <_start>:
[ ]*[a-f0-9]+: ff a3 00 00 00 00 jmp \*0x0\(%ebx\) 2: R_386_GOT32X _start

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@@ -0,0 +1,4 @@
.text
.global _start
_start:
jmp *_start@GOT(%ebx)

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@@ -777,6 +777,9 @@ if [gas_32_check] then {
run_dump_test "no-got"
run_dump_test "gotx-default"
run_dump_test "no-gotx-default"
run_dump_test "addend"
run_dump_test "nop-3"
run_dump_test "nop-4"

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@@ -0,0 +1,12 @@
#source: gotx.s
#objdump: -dwr
#xfail: *-*-*
#noxfail: *-*-solaris*
.*: +file format .*
Disassembly of section .text:
0+ <_start>:
[ ]*[a-f0-9]+: ff a3 00 00 00 00 jmp \*0x0\(%ebx\) 2: R_386_GOT32 _start