gcc: use --enable-autolink-libatomic for platforms that often need atomics.

As explained in #35992, gcc often generates code that needs libatomic
on these platforms, so link to libatomic by default (as-needed).

Patches taken from Alpine.
This commit is contained in:
Leah Neukirchen 2022-03-05 18:03:37 +01:00 committed by John Zimmermann
parent cda2fad4cc
commit effe9a6d2b
4 changed files with 373 additions and 7 deletions

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@ -0,0 +1,41 @@
From 548720bca6bff21ebc9aba22249d9ce45bbd90c7 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <iant@golang.org>
Date: Wed, 29 Jun 2022 15:32:04 -0700
Subject: [PATCH] libgo: handle stat st_atim32 field and SYS_SECCOMP
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Patches for musl support, from Sören Tempel.
Fixes https://gcc.gnu.org/PR105225
Change-Id: If396877d4a4c7d27962226d7a6e3bb91b1344413
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/415294
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
---
libgo/mksysinfo.sh | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/libgo/mksysinfo.sh b/libgo/mksysinfo.sh
index 5aa30915..ea1fa17d 100755
--- a/libgo/mksysinfo.sh
+++ b/libgo/mksysinfo.sh
@@ -127,6 +127,7 @@ fi
# The syscall numbers. We force the names to upper case.
grep '^const _SYS_' gen-sysinfo.go | \
+ grep -v '^const _SYS_SECCOMP = ' | \
sed -e 's/const _\(SYS_[^= ]*\).*$/\1/' | \
while read sys; do
sup=`echo $sys | tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ`
@@ -506,7 +507,7 @@ fi
# For historical reasons Go uses the suffix "timespec" instead of "tim" for
# stat_t's time fields on NetBSD.
-st_times='-e s/st_atim/Atim/ -e s/st_mtim/Mtim/ -e s/st_ctim/Ctim/'
+st_times='-e s/st_atim/Atim/g -e s/st_mtim/Mtim/g -e s/st_ctim/Ctim/g'
if test "${GOOS}" = "netbsd"; then
st_times='-e s/st_atim/Atimespec/ -e s/st_mtim/Mtimespec/ -e s/st_ctim/Ctimespec/'
fi

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@ -0,0 +1,267 @@
Add --enable-autolink-libatomic, to make gcc link -latomic by default.
Taken from Alpine: https://git.alpinelinux.org/aports/tree/main/gcc/0035-configure-Add-enable-autolink-libatomic-use-in-LINK_.patch
From 573a66e4146c9a65d895af9081a4d3d49cfc9e7a Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Wed, 9 Dec 2020 16:07:26 +0000
Subject: [PATCH] configure: Add --enable-autolink-libatomic, use in
LINK_GCC_C_SEQUENCE_SPEC [PR81358]
This fixes issues with RISC-V.
---
Makefile.in | 1 +
gcc/config.in | 6 ++++++
gcc/config/gnu-user.h | 12 +++++++++++-
gcc/configure | 32 ++++++++++++++++++++++++++++++--
gcc/configure.ac | 22 +++++++++++++++++++++-
gcc/doc/install.texi | 8 ++++++++
gcc/doc/tm.texi | 8 +++++++-
gcc/doc/tm.texi.in | 8 +++++++-
gcc/gcc.cc | 12 +++++++++++-
9 files changed, 102 insertions(+), 7 deletions(-)
diff --git a/Makefile.in b/Makefile.in
index b564ddbf792..a95c7407d16 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -232,6 +232,7 @@ HOST_EXPORTS = \
RANLIB_FOR_TARGET="$(RANLIB_FOR_TARGET)"; export RANLIB_FOR_TARGET; \
READELF_FOR_TARGET="$(READELF_FOR_TARGET)"; export READELF_FOR_TARGET; \
TOPLEVEL_CONFIGURE_ARGUMENTS="$(TOPLEVEL_CONFIGURE_ARGUMENTS)"; export TOPLEVEL_CONFIGURE_ARGUMENTS; \
+ TARGET_CONFIGDIRS="$(TARGET_CONFIGDIRS)"; export TARGET_CONFIGDIRS; \
HOST_LIBS="$(STAGE1_LIBS)"; export HOST_LIBS; \
GMPLIBS="$(HOST_GMPLIBS)"; export GMPLIBS; \
GMPINC="$(HOST_GMPINC)"; export GMPINC; \
diff --git a/gcc/config.in b/gcc/config.in
index f0fbf123aa8..af84efc4f9e 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -118,6 +118,12 @@
#endif
+/* Define if libatomic should always be linked. */
+#ifndef USED_FOR_TARGET
+#undef ENABLE_AUTOLINK_LIBATOMIC
+#endif
+
+
/* Define to 1 to specify that we are using the BID decimal floating point
format instead of DPD */
#ifndef USED_FOR_TARGET
diff --git a/gcc/config/gnu-user.h b/gcc/config/gnu-user.h
index 8433e56c3e1..0347f10da8b 100644
--- a/gcc/config/gnu-user.h
+++ b/gcc/config/gnu-user.h
@@ -109,8 +109,18 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
#define LINK_EH_SPEC "%{!static|static-pie:--eh-frame-hdr} "
#endif
+#if !defined(LINK_LIBATOMIC_SPEC) && defined(ENABLE_AUTOLINK_LIBATOMIC)
+# ifdef LD_AS_NEEDED_OPTION
+# define LINK_LIBATOMIC_SPEC LD_AS_NEEDED_OPTION " -latomic " LD_NO_AS_NEEDED_OPTION
+# else
+# define LINK_LIBATOMIC_SPEC "-latomic"
+# endif
+#elif !defined(LINK_LIBATOMIC_SPEC)
+# define LINK_LIBATOMIC_SPEC ""
+#endif
+
#define GNU_USER_TARGET_LINK_GCC_C_SEQUENCE_SPEC \
- "%{static|static-pie:--start-group} %G %{!nolibc:%L} \
+ "%{static|static-pie:--start-group} %G %{!nolibc:" LINK_LIBATOMIC_SPEC " %L} \
%{static|static-pie:--end-group}%{!static:%{!static-pie:%G}}"
#undef LINK_GCC_C_SEQUENCE_SPEC
diff --git a/gcc/configure b/gcc/configure
index 2f6b3265a6c..6dc65bf4ccb 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -981,6 +981,7 @@ with_changes_root_url
enable_languages
with_multilib_list
with_multilib_generator
+enable_autolink_libatomic
with_zstd
with_zstd_include
with_zstd_lib
@@ -1710,6 +1711,9 @@ Optional Features:
--disable-shared don't provide a shared libgcc
--disable-gcov don't provide libgcov and related host tools
--enable-languages=LIST specify which front-ends to build
+ --enable-autolink-libatomic
+ enable automatic linking of libatomic (ignored if
+ not built)
--disable-rpath do not hardcode runtime library paths
--enable-sjlj-exceptions
arrange to use setjmp/longjmp exception handling
@@ -8324,7 +8328,6 @@ else
fi
-
# Check whether --with-multilib-generator was given.
if test "${with_multilib_generator+set}" = set; then :
withval=$with_multilib_generator; :
@@ -8332,6 +8335,32 @@ else
with_multilib_generator=default
fi
+# If libatomic is available, whether it should be linked automatically
+# Check whether --enable-autolink-libatomic was given.
+if test "${enable_autolink_libatomic+set}" = set; then :
+ enableval=$enable_autolink_libatomic;
+ case $enable_autolink_libatomic in
+ yes | no) ;;
+ *) as_fn_error $? "'$enable_autolink_libatomic' is an invalid value for
+--enable-autolink-libatomic. Valid choices are 'yes' and 'no'." "$LINENO" 5 ;;
+ esac
+
+else
+ enable_autolink_libatomic=''
+fi
+
+
+if test x$enable_autolink_libatomic = xyes; then
+ if echo " ${TARGET_CONFIGDIRS} " | grep " libatomic " > /dev/null 2>&1 ; then
+
+$as_echo "#define ENABLE_AUTOLINK_LIBATOMIC 1" >>confdefs.h
+
+ else
+ { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: libatomic is not build for this target, --enable-autolink-libatomic ignored" >&5
+$as_echo "$as_me: WARNING: libatomic is not build for this target, --enable-autolink-libatomic ignored" >&2;}
+ fi
+fi
+
# -------------------------
# Checks for other programs
@@ -34296,4 +34325,3 @@ if test -n "$ac_unrecognized_opts" && test "$enable_option_checking" != no; then
$as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
fi
-
diff --git a/gcc/configure.ac b/gcc/configure.ac
index e683d3a7a5f..07c81c78336 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -1205,6 +1205,27 @@ AC_ARG_WITH(multilib-generator,
:,
with_multilib_generator=default)
+# If libatomic is available, whether it should be linked automatically
+AC_ARG_ENABLE(autolink-libatomic,
+[AS_HELP_STRING([--enable-autolink-libatomic],
+ [enable automatic linking of libatomic (ignored if not built)])],
+[
+ case $enable_autolink_libatomic in
+ yes | no) ;;
+ *) AC_MSG_ERROR(['$enable_autolink_libatomic' is an invalid value for
+--enable-autolink-libatomic. Valid choices are 'yes' and 'no'.]) ;;
+ esac
+], [enable_autolink_libatomic=''])
+
+if test x$enable_autolink_libatomic = xyes; then
+ if echo " ${TARGET_CONFIGDIRS} " | grep " libatomic " > /dev/null 2>&1 ; then
+ AC_DEFINE(ENABLE_AUTOLINK_LIBATOMIC, 1,
+ [Define if libatomic should always be linked.])
+ else
+ AC_MSG_WARN([libatomic is not build for this target, --enable-autolink-libatomic ignored])
+ fi
+fi
+
# -------------------------
# Checks for other programs
# -------------------------
@@ -7839,4 +7860,3 @@ done
],
[subdirs='$subdirs'])
AC_OUTPUT
-
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 48408d842db..c90be0ee750 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -2295,6 +2295,14 @@ files, but these changed header paths may conflict with some compilation
environments. Enabled by default, and may be disabled using
@option{--disable-canonical-system-headers}.
+@item --enable-autolink-libatomic
+@itemx --disable-autolink-libatomic
+Tell GCC that it should automatically link libatomic; if supported by
+the linker, the file is only linked as needed. This flag is ignored
+when libatomic is not built. Note that this conigure flag is in particular
+useful when building an offloading-target compiler; as for those, a
+user had to specify @code{-foffload=target=-latomic} otherwise.
+
@item --with-glibc-version=@var{major}.@var{minor}
Tell GCC that when the GNU C Library (glibc) is used on the target it
will be version @var{major}.@var{minor} or later. Normally this can
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index c5006afc00d..56b62c69ae8 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -381,7 +381,13 @@ the argument @option{-lgcc} to tell the linker to do the search.
@defmac LINK_GCC_C_SEQUENCE_SPEC
The sequence in which libgcc and libc are specified to the linker.
-By default this is @code{%G %L %G}.
+By default this is @code{%G LINK_LIBATOMIC_SPEC %L %G}.
+@end defmac
+
+@defmac LINK_LIBATOMIC_SPEC
+This macro is used in the default @code{LINK_GCC_C_SEQUENCE_SPEC} to link
+libatomic. By default, it is unset unless @code{ENABLE_AUTOLINK_LIBATOMIC}
+is set.
@end defmac
@defmac POST_LINK_SPEC
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index f869ddd5e5b..57c93f24ac3 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -381,7 +381,13 @@ the argument @option{-lgcc} to tell the linker to do the search.
@defmac LINK_GCC_C_SEQUENCE_SPEC
The sequence in which libgcc and libc are specified to the linker.
-By default this is @code{%G %L %G}.
+By default this is @code{%G LINK_LIBATOMIC_SPEC %L %G}.
+@end defmac
+
+@defmac LINK_LIBATOMIC_SPEC
+This macro is used in the default @code{LINK_GCC_C_SEQUENCE_SPEC} to link
+libatomic. By default, it is unset unless @code{ENABLE_AUTOLINK_LIBATOMIC}
+is set.
@end defmac
@defmac POST_LINK_SPEC
diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index 735b2b1bba1..f10f3c91aa7 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -987,13 +987,23 @@ proper position among the other output files. */
# define ASM_DEBUG_OPTION_SPEC ""
#endif
+#if !defined(LINK_LIBATOMIC_SPEC) && defined(ENABLE_AUTOLINK_LIBATOMIC)
+# ifdef LD_AS_NEEDED_OPTION
+# define LINK_LIBATOMIC_SPEC LD_AS_NEEDED_OPTION " -latomic " LD_NO_AS_NEEDED_OPTION
+# else
+# define LINK_LIBATOMIC_SPEC "-latomic"
+# endif
+#elif !defined(LINK_LIBATOMIC_SPEC)
+# define LINK_LIBATOMIC_SPEC ""
+#endif
+
/* Here is the spec for running the linker, after compiling all files. */
/* This is overridable by the target in case they need to specify the
-lgcc and -lc order specially, yet not require them to override all
of LINK_COMMAND_SPEC. */
#ifndef LINK_GCC_C_SEQUENCE_SPEC
-#define LINK_GCC_C_SEQUENCE_SPEC "%G %{!nolibc:%L %G}"
+#define LINK_GCC_C_SEQUENCE_SPEC "%G %{!nolibc:" LINK_LIBATOMIC_SPEC " %L %G}"
#endif
#ifdef ENABLE_DEFAULT_SSP

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@ -0,0 +1,58 @@
Fix gcc check to build libatomic properly with --enable-autolink-libatomic.
Taken from Alpine: https://git.alpinelinux.org/aports/tree/main/gcc/0036-configure-fix-detection-of-atomic-builtins-in-libato.patch
From 4baaeb9661fa4015d9701e3616ce1ad4e8a07fd8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6ren=20Tempel?= <soeren+git@soeren-tempel.net>
Date: Sun, 29 Aug 2021 09:45:27 +0200
Subject: [PATCH] configure: fix detection of atomic builtins in libatomic
configure script
Alpine's --enable-autolink-libatomic (which is enabled for riscv64 by
default) causes the libatomic configure script to incorrectly detect
which builtins are available on riscv64. This then causes incorrect code
generation for libatomic since it assumes compiler builtins to be
available which are not actually available on riscv64.
This commit fixes this issue by disabling linking of libatomic configure
test code entirely, thereby preventing linking against libatomic.
See:
* https://gitlab.alpinelinux.org/alpine/aports/-/issues/12948
* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101996#c6
---
libatomic/configure.tgt | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/libatomic/configure.tgt b/libatomic/configure.tgt
index 33f8c91ce77..3999db2cf8a 100644
--- a/libatomic/configure.tgt
+++ b/libatomic/configure.tgt
@@ -30,6 +30,26 @@
# on ${target_cpu}. For example to allow proper use of multilibs.
configure_tgt_pre_target_cpu_XCFLAGS="${XCFLAGS}"
+# The libatomic configure script performs several checks to determine
+# whether builtins for atomic operations are available. When compiling
+# with --enable-autolink-libatomic the test code compiled by the
+# configure script is also linked against libatomic. This causes it
+# to think that builtins are available, even if there are not, since
+# the tested symbols are provided by libatomic.
+#
+# This is a hack to ensure that we don't link against libatomic by not
+# linking any configure test code at all when --enable-autolink-libatomic
+# is given.
+#
+# See:
+#
+# * https://gitlab.alpinelinux.org/alpine/aports/-/issues/12817
+# * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101996#c4
+#
+if test x$enable_autolink_libatomic = xyes; then
+ gcc_no_link=yes
+fi
+
case "${target_cpu}" in
alpha*)
# fenv.c needs this option to generate inexact exceptions.

View file

@ -195,17 +195,17 @@ do_configure() {
_hash=gnu
case "$XBPS_TARGET_MACHINE" in
mipselhf-musl) _args+=" --with-arch=mips32r2 --with-float=hard"; _hash=sysv;;
mipsel-musl) _args+=" --with-arch=mips32r2 --with-float=soft"; _hash=sysv;;
mipshf-musl) _args+=" --with-arch=mips32r2 --with-float=hard";;
mips-musl) _args+=" --with-arch=mips32r2 --with-float=soft";;
armv5*) _args+=" --with-arch=armv5te --with-float=soft";;
armv6l*) _args+=" --with-arch=armv6 --with-fpu=vfp --with-float=hard";;
mipselhf-musl) _args+=" --with-arch=mips32r2 --with-float=hard --enable-autolink-libatomic"; _hash=sysv;;
mipsel-musl) _args+=" --with-arch=mips32r2 --with-float=soft --enable-autolink-libatomic"; _hash=sysv;;
mipshf-musl) _args+=" --with-arch=mips32r2 --with-float=hard --enable-autolink-libatomic";;
mips-musl) _args+=" --with-arch=mips32r2 --with-float=soft --enable-autolink-libatomic";;
armv5*) _args+=" --with-arch=armv5te --with-float=soft --enable-autolink-libatomic";;
armv6l*) _args+=" --with-arch=armv6 --with-fpu=vfp --with-float=hard --enable-autolink-libatomic";;
armv7l*) _args+=" --with-arch=armv7-a --with-fpu=vfpv3 --with-float=hard";;
aarch64*) _args+=" --with-arch=armv8-a";;
ppc64le*) _args+=" --with-abi=elfv2 --enable-secureplt --enable-targets=powerpcle-linux";;
ppc64*) _args+=" --with-abi=elfv2 --enable-secureplt --enable-targets=powerpc-linux";;
ppc*) _args+=" --enable-secureplt";;
ppc*) _args+=" --enable-secureplt --enable-autolink-libatomic";;
esac
# on ppc64le-musl and all big endian ppc64