> -----Original Message-----
> From: Joseph Myers <josmy...@redhat.com>
> Sent: 03 January 2025 22:22
> To: Prathamesh Kulkarni <prathame...@nvidia.com>
> Cc: Tobias Burnus <tbur...@baylibre.com>; Xi Ruoyao
> <xry...@xry111.site>; Matthew Malcomson <mmalcom...@nvidia.com>; gcc-
> patc...@gcc.gnu.org
> Subject: RE: [RFC] PR81358: Enable automatic linking of libatomic
>
> External email: Use caution opening links or attachments
>
>
> On Fri, 20 Dec 2024, Prathamesh Kulkarni wrote:
>
> > Hi,
> > The previous patch (now reverted) had two different issues both
> stemming from the rule added in libatomic/Makefile.am:
> > (1) As mentioned above, it broke multilib builds because it
> > incorrectly copies libatomic.a in $(gcc_objdir). The attached patch
> > fixes it by instead copying libatomic.a over to
> $(gcc_objdir)$(MULTISUBDIR)/, and can confirm that 64-bit libatomic.a
> is copied to $build/gcc/ and 32-bit libatomic.a is copied to
> $build/gcc/32/.
> >
> > (2) libatomic_convenience.la was not getting generated for some
> reason, which resulted in build failure while building libdruntime.
> > The patch adds libatomic_convenience.la as a dependency, and I can
> see it now getting generated, which seems to fix the build issue with
> libdruntime.
> >
> > Patch passes bootstrap+test with multilib enabled for --enable-
> languages=all on x86_64-linux-gnu, and for --enable-
> languages=c,c++,fortran on aarch64-linux-gnu.
> > Does this version look OK ?
>
> This is OK.
Hi Joseph,
Thanks for the approval!
I requested for wider testing on PR, and there was following comment
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81358#c29):
"I've now bootstrapped the patch on i386-pc-solaris2.11 (and
x86_64-pc-linux-gnu for comparison's sake, still running). The good
news is that this version no longer breaks Solaris bootstrap. However,
it has one fundamental problem: on anything but Linux, -flink-libatomic
is a no-op: LINK_LIBATOMIC_SPEC is only used in gcc/config/gnu-user.h
while the docs suggest this is a generic option. I don't think this is
acceptable."
The attached patch makes formatting changes, and modifies the doc for
flink-libatomic to:
"Enable linking of libatomic if it's supported by target. Enabled by default,
and currently supported on targets using glibc."
Does that look OK ?
I am not sure if the patch may need reworking for automatically linking
libatomic for non glibc based systems, and can look into it as follow-up.
Thanks,
Prathamesh
>
> To answer Jakub's question about passing -fno-link-libatomic when
> building target libraries, I think it's reasonable for target
> libraries to use atomic interfaces that may, on some targets, need
> libatomic.
>
> (I'm not asserting that this patch by itself will make target
> libraries using atomic interfaces work in cases that are currently
> broken.
> Empirically, some such cases are broken already in ways that this
> patch wouldn't fix. Bug 118280 reports libstdc++ for microblaze using
> __atomic_test_and_set, which is not defined in libatomic - libatomic
> for microblaze-linux-gnu has an undefined reference to that symbol
> itself, only defining __atomic_test_and_set_{1,2,4,8,16}. And I'm not
> sure there's currently a bug open for it, but for m68k-linux-gnu built
> for ColdFire, libstdc++ has undefined references to hidden __sync_*
> symbols defined in libgcc.a, which also prevents linking with
> libstdc++, but I expect the fix for that would be to use t-slibgcc-
> libgcc in libgcc/config.host for those targets, nothing to do with
> libatomic since the symbols aren't in libatomic. In both cases, we
> could also take the breakage as evidence that those targets are no
> longer being used outside of bots building many different targets and
> so might be ripe for
> obsolescence.)
>
> --
> Joseph S. Myers
> josmy...@redhat.com
PR81358: Enable automatic linking of libatomic.
ChangeLog:
PR driver/81358
* Makefile.def: Add dependencies so libatomic is built before target
libraries are configured.
* Makefile.tpl: Export TARGET_CONFIGDIRS.
* configure.ac: Add libatomic to bootstrap_target_libs.
* Makefile.in: Regenerate.
* configure: Regenerate.
gcc/ChangeLog:
PR driver/81358
* common.opt: New option -flink-libatomic.
* gcc.cc (LINK_LIBATOMIC_SPEC): New macro.
* config/gnu-user.h (GNU_USER_TARGET_LINK_GCC_C_SEQUENCE_SPEC): Use
LINK_LIBATOMIC_SPEC.
* doc/invoke.texi: Document -flink-libatomic.
* configure.ac: Define TARGET_PROVIDES_LIBATOMIC.
* configure: Regenerate.
* config.in: Regenerate.
libatomic/ChangeLog:
PR driver/81358
* Makefile.am: Pass -fno-link-libatomic.
New rule all.
* configure.ac: Assert that CFLAGS is set and pass -fno-link-libatomic.
* Makefile.in: Regenerate.
* configure: Regenerate.
Signed-off-by: Prathamesh Kulkarni <prathame...@nvidia.com>
Co-authored-by: Matthew Malcolmson <mmalcolm...@nvidia.com>
diff --git a/Makefile.def b/Makefile.def
index 19954e7d731..90899fa28cf 100644
--- a/Makefile.def
+++ b/Makefile.def
@@ -656,6 +656,26 @@ lang_env_dependencies = { module=libgcc; no_gcc=true;
no_c=true; };
// a dependency on libgcc for native targets to configure.
lang_env_dependencies = { module=libiberty; no_c=true; };
+dependencies = { module=configure-target-libbacktrace;
on=all-target-libatomic; };
+dependencies = { module=configure-target-libgloss; on=all-target-libatomic; };
+dependencies = { module=configure-target-newlib; on=all-target-libatomic; };
+dependencies = { module=configure-target-libgomp; on=all-target-libatomic; };
+dependencies = { module=configure-target-libitm; on=all-target-libatomic; };
+dependencies = { module=configure-target-libstdc++v3; on=all-target-libatomic;
};
+dependencies = { module=configure-target-libsanitizer;
on=all-target-libatomic; };
+dependencies = { module=configure-target-libvtv; on=all-target-libatomic; };
+dependencies = { module=configure-target-libssp; on=all-target-libatomic; };
+dependencies = { module=configure-target-libquadmath; on=all-target-libatomic;
};
+dependencies = { module=configure-target-libgfortran; on=all-target-libatomic;
};
+dependencies = { module=configure-target-libffi; on=all-target-libatomic; };
+dependencies = { module=configure-target-libobjc; on=all-target-libatomic; };
+dependencies = { module=configure-target-libada; on=all-target-libatomic; };
+dependencies = { module=configure-target-libgm2; on=all-target-libatomic; };
+dependencies = { module=configure-target-libgo; on=all-target-libatomic; };
+dependencies = { module=configure-target-libgrust; on=all-target-libatomic; };
+dependencies = { module=configure-target-libphobos; on=all-target-libatomic; };
+dependencies = { module=configure-target-zlib; on=all-target-libatomic; };
+
dependencies = { module=configure-target-fastjar; on=configure-target-zlib; };
dependencies = { module=all-target-fastjar; on=all-target-zlib; };
dependencies = { module=configure-target-libgo; on=configure-target-libffi; };
diff --git a/Makefile.in b/Makefile.in
index 966d6045496..4a85f11d7e6 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -242,6 +242,7 @@ HOST_EXPORTS = \
GMPINC="$(HOST_GMPINC)"; export GMPINC; \
ISLLIBS="$(HOST_ISLLIBS)"; export ISLLIBS; \
ISLINC="$(HOST_ISLINC)"; export ISLINC; \
+ TARGET_CONFIGDIRS="$(TARGET_CONFIGDIRS)"; export TARGET_CONFIGDIRS; \
XGCC_FLAGS_FOR_TARGET="$(XGCC_FLAGS_FOR_TARGET)"; export
XGCC_FLAGS_FOR_TARGET; \
@if gcc-bootstrap
$(RPATH_ENVVAR)=`echo "$(TARGET_LIB_PATH)$$$(RPATH_ENVVAR)" | sed
's,::*,:,g;s,^:*,,;s,:*$$,,'`; export $(RPATH_ENVVAR); \
@@ -68551,6 +68552,66 @@ all-flex: maybe-all-build-bison
all-flex: maybe-all-m4
all-flex: maybe-all-build-texinfo
all-m4: maybe-all-build-texinfo
+configure-target-libbacktrace: maybe-all-target-libatomic
+configure-stage1-target-libbacktrace: maybe-all-stage1-target-libatomic
+configure-stage2-target-libbacktrace: maybe-all-stage2-target-libatomic
+configure-stage3-target-libbacktrace: maybe-all-stage3-target-libatomic
+configure-stage4-target-libbacktrace: maybe-all-stage4-target-libatomic
+configure-stageprofile-target-libbacktrace:
maybe-all-stageprofile-target-libatomic
+configure-stagetrain-target-libbacktrace: maybe-all-stagetrain-target-libatomic
+configure-stagefeedback-target-libbacktrace:
maybe-all-stagefeedback-target-libatomic
+configure-stageautoprofile-target-libbacktrace:
maybe-all-stageautoprofile-target-libatomic
+configure-stageautofeedback-target-libbacktrace:
maybe-all-stageautofeedback-target-libatomic
+configure-target-libgomp: maybe-all-target-libatomic
+configure-stage1-target-libgomp: maybe-all-stage1-target-libatomic
+configure-stage2-target-libgomp: maybe-all-stage2-target-libatomic
+configure-stage3-target-libgomp: maybe-all-stage3-target-libatomic
+configure-stage4-target-libgomp: maybe-all-stage4-target-libatomic
+configure-stageprofile-target-libgomp: maybe-all-stageprofile-target-libatomic
+configure-stagetrain-target-libgomp: maybe-all-stagetrain-target-libatomic
+configure-stagefeedback-target-libgomp:
maybe-all-stagefeedback-target-libatomic
+configure-stageautoprofile-target-libgomp:
maybe-all-stageautoprofile-target-libatomic
+configure-stageautofeedback-target-libgomp:
maybe-all-stageautofeedback-target-libatomic
+configure-target-libsanitizer: maybe-all-target-libatomic
+configure-stage1-target-libsanitizer: maybe-all-stage1-target-libatomic
+configure-stage2-target-libsanitizer: maybe-all-stage2-target-libatomic
+configure-stage3-target-libsanitizer: maybe-all-stage3-target-libatomic
+configure-stage4-target-libsanitizer: maybe-all-stage4-target-libatomic
+configure-stageprofile-target-libsanitizer:
maybe-all-stageprofile-target-libatomic
+configure-stagetrain-target-libsanitizer: maybe-all-stagetrain-target-libatomic
+configure-stagefeedback-target-libsanitizer:
maybe-all-stagefeedback-target-libatomic
+configure-stageautoprofile-target-libsanitizer:
maybe-all-stageautoprofile-target-libatomic
+configure-stageautofeedback-target-libsanitizer:
maybe-all-stageautofeedback-target-libatomic
+configure-target-libvtv: maybe-all-target-libatomic
+configure-stage1-target-libvtv: maybe-all-stage1-target-libatomic
+configure-stage2-target-libvtv: maybe-all-stage2-target-libatomic
+configure-stage3-target-libvtv: maybe-all-stage3-target-libatomic
+configure-stage4-target-libvtv: maybe-all-stage4-target-libatomic
+configure-stageprofile-target-libvtv: maybe-all-stageprofile-target-libatomic
+configure-stagetrain-target-libvtv: maybe-all-stagetrain-target-libatomic
+configure-stagefeedback-target-libvtv: maybe-all-stagefeedback-target-libatomic
+configure-stageautoprofile-target-libvtv:
maybe-all-stageautoprofile-target-libatomic
+configure-stageautofeedback-target-libvtv:
maybe-all-stageautofeedback-target-libatomic
+configure-target-libphobos: maybe-all-target-libatomic
+configure-stage1-target-libphobos: maybe-all-stage1-target-libatomic
+configure-stage2-target-libphobos: maybe-all-stage2-target-libatomic
+configure-stage3-target-libphobos: maybe-all-stage3-target-libatomic
+configure-stage4-target-libphobos: maybe-all-stage4-target-libatomic
+configure-stageprofile-target-libphobos:
maybe-all-stageprofile-target-libatomic
+configure-stagetrain-target-libphobos: maybe-all-stagetrain-target-libatomic
+configure-stagefeedback-target-libphobos:
maybe-all-stagefeedback-target-libatomic
+configure-stageautoprofile-target-libphobos:
maybe-all-stageautoprofile-target-libatomic
+configure-stageautofeedback-target-libphobos:
maybe-all-stageautofeedback-target-libatomic
+configure-target-zlib: maybe-all-target-libatomic
+configure-stage1-target-zlib: maybe-all-stage1-target-libatomic
+configure-stage2-target-zlib: maybe-all-stage2-target-libatomic
+configure-stage3-target-zlib: maybe-all-stage3-target-libatomic
+configure-stage4-target-zlib: maybe-all-stage4-target-libatomic
+configure-stageprofile-target-zlib: maybe-all-stageprofile-target-libatomic
+configure-stagetrain-target-zlib: maybe-all-stagetrain-target-libatomic
+configure-stagefeedback-target-zlib: maybe-all-stagefeedback-target-libatomic
+configure-stageautoprofile-target-zlib:
maybe-all-stageautoprofile-target-libatomic
+configure-stageautofeedback-target-zlib:
maybe-all-stageautofeedback-target-libatomic
configure-target-libgo: maybe-configure-target-libffi
all-target-libgo: maybe-all-target-libffi
configure-target-libphobos: maybe-configure-target-libbacktrace
@@ -68678,6 +68739,45 @@ configure-m4: stage_last
@endif gcc-bootstrap
@if gcc-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libgloss: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-newlib: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libitm: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libstdc++v3: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libssp: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libquadmath: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libgfortran: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libffi: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libobjc: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libada: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libgm2: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libgo: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
+@unless target-libatomic-bootstrap
+configure-target-libgrust: maybe-all-target-libatomic
+@endunless target-libatomic-bootstrap
@unless target-zlib-bootstrap
configure-target-fastjar: maybe-configure-target-zlib
@endunless target-zlib-bootstrap
@@ -68755,6 +68855,19 @@ all-fastjar: maybe-all-libiberty
all-bison: maybe-all-gettext
all-flex: maybe-all-gettext
all-m4: maybe-all-gettext
+configure-target-libgloss: maybe-all-target-libatomic
+configure-target-newlib: maybe-all-target-libatomic
+configure-target-libitm: maybe-all-target-libatomic
+configure-target-libstdc++v3: maybe-all-target-libatomic
+configure-target-libssp: maybe-all-target-libatomic
+configure-target-libquadmath: maybe-all-target-libatomic
+configure-target-libgfortran: maybe-all-target-libatomic
+configure-target-libffi: maybe-all-target-libatomic
+configure-target-libobjc: maybe-all-target-libatomic
+configure-target-libada: maybe-all-target-libatomic
+configure-target-libgm2: maybe-all-target-libatomic
+configure-target-libgo: maybe-all-target-libatomic
+configure-target-libgrust: maybe-all-target-libatomic
configure-target-fastjar: maybe-configure-target-zlib
all-target-fastjar: maybe-all-target-zlib
configure-target-libgo: maybe-all-target-libstdc++-v3
diff --git a/Makefile.tpl b/Makefile.tpl
index da38dca697a..c6b2f7504ad 100644
--- a/Makefile.tpl
+++ b/Makefile.tpl
@@ -245,6 +245,7 @@ HOST_EXPORTS = \
GMPINC="$(HOST_GMPINC)"; export GMPINC; \
ISLLIBS="$(HOST_ISLLIBS)"; export ISLLIBS; \
ISLINC="$(HOST_ISLINC)"; export ISLINC; \
+ TARGET_CONFIGDIRS="$(TARGET_CONFIGDIRS)"; export TARGET_CONFIGDIRS; \
XGCC_FLAGS_FOR_TARGET="$(XGCC_FLAGS_FOR_TARGET)"; export
XGCC_FLAGS_FOR_TARGET; \
@if gcc-bootstrap
$(RPATH_ENVVAR)=`echo "$(TARGET_LIB_PATH)$$$(RPATH_ENVVAR)" | sed
's,::*,:,g;s,^:*,,;s,:*$$,,'`; export $(RPATH_ENVVAR); \
diff --git a/configure b/configure
index 4ae8e1242af..532e4527719 100755
--- a/configure
+++ b/configure
@@ -10924,6 +10924,11 @@ if echo " ${target_configdirs} " | grep " libgomp " >
/dev/null 2>&1 ; then
bootstrap_target_libs=${bootstrap_target_libs}target-libgomp,
fi
+# If we are building libatomic, bootstrap it.
+if echo " ${target_configdirs} " | grep " libatomic " > /dev/null 2>&1 ; then
+ bootstrap_target_libs=${bootstrap_target_libs}target-libatomic,
+fi
+
# If we are building libsanitizer and $BUILD_CONFIG contains bootstrap-asan
# or bootstrap-ubsan, bootstrap it.
if echo " ${target_configdirs} " | grep " libsanitizer " > /dev/null 2>&1; then
diff --git a/configure.ac b/configure.ac
index 9a72b2311bd..c44d84f32ce 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3151,6 +3151,11 @@ if echo " ${target_configdirs} " | grep " libgomp " >
/dev/null 2>&1 ; then
bootstrap_target_libs=${bootstrap_target_libs}target-libgomp,
fi
+# If we are building libatomic, bootstrap it.
+if echo " ${target_configdirs} " | grep " libatomic " > /dev/null 2>&1 ; then
+ bootstrap_target_libs=${bootstrap_target_libs}target-libatomic,
+fi
+
# If we are building libsanitizer and $BUILD_CONFIG contains bootstrap-asan
# or bootstrap-ubsan, bootstrap it.
if echo " ${target_configdirs} " | grep " libsanitizer " > /dev/null 2>&1; then
diff --git a/gcc/common.opt b/gcc/common.opt
index a42537c5f1e..6eb6515157a 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -3350,6 +3350,9 @@ Use the Modern linker (MOLD) linker instead of the
default linker.
fuse-linker-plugin
Common Undocumented Var(flag_use_linker_plugin)
+flink-libatomic
+Common Driver Var(flag_link_libatomic) Init(1)
+
; Positive if we should track variables, negative if we should run
; the var-tracking pass only to discard debug annotations, zero if
; we're not to run it.
diff --git a/gcc/config.in b/gcc/config.in
index d8145a1453b..8dabc938849 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -2558,6 +2558,12 @@
#endif
+/* Define if libatomic is built for the target. */
+#ifndef USED_FOR_TARGET
+#undef TARGET_PROVIDES_LIBATOMIC
+#endif
+
+
/* Define to 1 if you can safely include both <sys/time.h> and <time.h>. */
#ifndef USED_FOR_TARGET
#undef TIME_WITH_SYS_TIME
diff --git a/gcc/config/gnu-user.h b/gcc/config/gnu-user.h
index f7eefdafe8b..27d0ef07e1e 100644
--- a/gcc/config/gnu-user.h
+++ b/gcc/config/gnu-user.h
@@ -109,8 +109,9 @@ see the files COPYING3 and COPYING.RUNTIME respectively.
If not, see
#define LINK_EH_SPEC "%{!static|static-pie:--eh-frame-hdr} "
#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 e7f85b78ad9..a8f1bb3139d 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -33404,6 +33404,12 @@ $as_echo "#define ENABLE_DEFAULT_SSP 1" >>confdefs.h
fi
+if echo " ${TARGET_CONFIGDIRS} " | grep " libatomic " > /dev/null 2>&1 ; then
+
+$as_echo "#define TARGET_PROVIDES_LIBATOMIC 1" >>confdefs.h
+
+fi
+
# Test for <sys/sdt.h> on the target.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking sys/sdt.h in the target C
library" >&5
diff --git a/gcc/configure.ac b/gcc/configure.ac
index e9bddc6db21..a86236425ff 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -6995,6 +6995,11 @@ if test x$enable_default_ssp = xyes ; then
fi
AC_SUBST([enable_default_ssp])
+if echo " ${TARGET_CONFIGDIRS} " | grep " libatomic " > /dev/null 2>&1 ; then
+ AC_DEFINE(TARGET_PROVIDES_LIBATOMIC, 1,
+ [Define if libatomic is built for the target.])
+fi
+
# Test for <sys/sdt.h> on the target.
GCC_TARGET_TEMPLATE([HAVE_SYS_SDT_H])
AC_CACHE_CHECK([sys/sdt.h in the target C library], [gcc_cv_sys_sdt_h], [
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index e3c2adc2507..5f6e587835b 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -208,7 +208,7 @@ in the following sections.
-fpermitted-flt-eval-methods=@var{standard}
-fplan9-extensions -fsigned-bitfields -funsigned-bitfields
-fsigned-char -funsigned-char -fstrict-flex-arrays[=@var{n}]
--fsso-struct=@var{endianness}}
+-flink-libatomic -fsso-struct=@var{endianness}}
@item C++ Language Options
@xref{C++ Dialect Options,,Options Controlling C++ Dialect}.
@@ -2999,6 +2999,11 @@ The @option{-fstrict_flex_arrays} option interacts with
the
@option{-Wstrict-flex-arrays} option. @xref{Warning Options}, for more
information.
+@opindex flink-libatomic
+@item -flink-libatomic
+Enable linking of libatomic if it's supported by target. Enabled by default,
+and currently supported on targets using glibc.
+
@opindex fsso-struct
@item -fsso-struct=@var{endianness}
Set the default scalar storage order of structures and unions to the
diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index 92c92996401..43d4c8763cb 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -980,6 +980,13 @@ proper position among the other output files. */
/* Here is the spec for running the linker, after compiling all files. */
+#if defined(TARGET_PROVIDES_LIBATOMIC) && defined(USE_LD_AS_NEEDED)
+#define LINK_LIBATOMIC_SPEC "%{!fno-link-libatomic:" LD_AS_NEEDED_OPTION \
+ " -latomic " LD_NO_AS_NEEDED_OPTION "} "
+#else
+#define LINK_LIBATOMIC_SPEC ""
+#endif
+
/* 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. */
diff --git a/libatomic/Makefile.am b/libatomic/Makefile.am
index efadd9dcd48..80bb6fbf477 100644
--- a/libatomic/Makefile.am
+++ b/libatomic/Makefile.am
@@ -69,7 +69,7 @@ libatomic_darwin_rpath += -Wl,-rpath,@loader_path
endif
libatomic_la_LDFLAGS = $(libatomic_version_info) $(libatomic_version_script) \
- $(lt_host_flags) $(libatomic_darwin_rpath)
+ -Wc,-fno-link-libatomic $(lt_host_flags) $(libatomic_darwin_rpath)
libatomic_la_SOURCES = gload.c gstore.c gcas.c gexch.c glfree.c lock.c init.c \
fenv.c fence.c flag.c
@@ -162,6 +162,11 @@ libatomic_convenience_la_LIBADD = $(libatomic_la_LIBADD)
# when it is reloaded during the build of all-multi.
all-multi: $(libatomic_la_LIBADD)
+gcc_objdir = $(MULTIBUILDTOP)../../$(host_subdir)/gcc
+all: all-multi libatomic.la libatomic_convenience.la
+ $(INSTALL_DATA) .libs/libatomic.a $(gcc_objdir)$(MULTISUBDIR)/
+ chmod 644 $(gcc_objdir)$(MULTISUBDIR)/libatomic.a
+
# target overrides
-include $(tmake_file)
diff --git a/libatomic/Makefile.in b/libatomic/Makefile.in
index 9798e7c09e9..1d0494543d7 100644
--- a/libatomic/Makefile.in
+++ b/libatomic/Makefile.in
@@ -421,7 +421,7 @@ libatomic_version_info = -version-info $(libtool_VERSION)
@ENABLE_DARWIN_AT_RPATH_TRUE@ -Wc,-nodefaultrpaths \
@ENABLE_DARWIN_AT_RPATH_TRUE@ -Wl,-rpath,@loader_path
libatomic_la_LDFLAGS = $(libatomic_version_info) $(libatomic_version_script) \
- $(lt_host_flags) $(libatomic_darwin_rpath)
+ -Wc,-fno-link-libatomic $(lt_host_flags) $(libatomic_darwin_rpath)
libatomic_la_SOURCES = gload.c gstore.c gcas.c gexch.c glfree.c lock.c \
init.c fenv.c fence.c flag.c $(am__append_5)
@@ -458,6 +458,7 @@ libatomic_la_LIBADD = $(foreach s,$(SIZES),$(addsuffix \
@ARCH_X86_64_TRUE@@HAVE_IFUNC_TRUE@IFUNC_OPTIONS = -mcx16 -mcx16
libatomic_convenience_la_SOURCES = $(libatomic_la_SOURCES)
libatomic_convenience_la_LIBADD = $(libatomic_la_LIBADD)
+gcc_objdir = $(MULTIBUILDTOP)../../$(host_subdir)/gcc
MULTISRCTOP =
MULTIBUILDTOP =
MULTIDIRS =
@@ -901,6 +902,9 @@ vpath % $(strip $(search_path))
# makefile fragments to avoid broken *.Ppo getting included into the Makefile
# when it is reloaded during the build of all-multi.
all-multi: $(libatomic_la_LIBADD)
+all: all-multi libatomic.la libatomic_convenience.la
+ $(INSTALL_DATA) .libs/libatomic.a $(gcc_objdir)$(MULTISUBDIR)/
+ chmod 644 $(gcc_objdir)$(MULTISUBDIR)/libatomic.a
# target overrides
-include $(tmake_file)
diff --git a/libatomic/configure b/libatomic/configure
index d579bab96f8..90a5a3b479a 100755
--- a/libatomic/configure
+++ b/libatomic/configure
@@ -3415,6 +3415,26 @@ esac
# the wrong, non-multilib-adjusted value will be used in multilibs.
# As a side effect, we have to subst CFLAGS ourselves.
+# AC_PROG_CC sets CFLAGS to "-g -O2" by default (if unset), and
+# then compile conftests with default CFLAGS, leaving no place to temporarily
+# modify CFLAGS and restore them later. However we need to pass
+# -fno-link-libatomic in CFLAGS so conftests compiled in AC_PROG_CC don't fail.
+# Assert that CFLAGS is always set by user so the default setting of CFLAGS by
+# AC_PROG_CC won't be applicable anyway.
+if test -z "${CFLAGS}"; then
+ as_fn_error $? "CFLAGS must be set." "$LINENO" 5
+fi
+
+# In order to override CFLAGS_FOR_TARGET, all of our special flags go
+# in XCFLAGS. But we need them in CFLAGS during configury. So put them
+# in both places for now and restore CFLAGS at the end of config.
+save_CFLAGS="$CFLAGS"
+
+# Append -fno-link-libatomic to avoid automatically linking libatomic,
+# while building libatomic itself.
+XCFLAGS="$XCFLAGS -fno-link-libatomic"
+CFLAGS="$save_CFLAGS $XCFLAGS"
+
ac_ext=c
@@ -4593,11 +4613,6 @@ fi
-# In order to override CFLAGS_FOR_TARGET, all of our special flags go
-# in XCFLAGS. But we need them in CFLAGS during configury. So put them
-# in both places for now and restore CFLAGS at the end of config.
-save_CFLAGS="$CFLAGS"
-
# Find other programs we need.
if test -n "$ac_tool_prefix"; then
# Extract the first word of "${ac_tool_prefix}ar", so it can be a program
name with args.
@@ -11456,7 +11471,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11459 "configure"
+#line 11474 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -11562,7 +11577,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11565 "configure"
+#line 11580 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
diff --git a/libatomic/configure.ac b/libatomic/configure.ac
index 32a2cdb13ae..f78efd31a02 100644
--- a/libatomic/configure.ac
+++ b/libatomic/configure.ac
@@ -129,6 +129,26 @@ AC_SUBST(toolexeclibdir)
# the wrong, non-multilib-adjusted value will be used in multilibs.
# As a side effect, we have to subst CFLAGS ourselves.
+# AC_PROG_CC sets CFLAGS to "-g -O2" by default (if unset), and
+# then compile conftests with default CFLAGS, leaving no place to temporarily
+# modify CFLAGS and restore them later. However we need to pass
+# -fno-link-libatomic in CFLAGS so conftests compiled in AC_PROG_CC don't fail.
+# Assert that CFLAGS is always set by user so the default setting of CFLAGS by
+# AC_PROG_CC won't be applicable anyway.
+if test -z "${CFLAGS}"; then
+ AC_MSG_ERROR([CFLAGS must be set.])
+fi
+
+# In order to override CFLAGS_FOR_TARGET, all of our special flags go
+# in XCFLAGS. But we need them in CFLAGS during configury. So put them
+# in both places for now and restore CFLAGS at the end of config.
+save_CFLAGS="$CFLAGS"
+
+# Append -fno-link-libatomic to avoid automatically linking libatomic,
+# while building libatomic itself.
+XCFLAGS="$XCFLAGS -fno-link-libatomic"
+CFLAGS="$save_CFLAGS $XCFLAGS"
+
m4_rename([_AC_ARG_VAR_PRECIOUS],[real_PRECIOUS])
m4_define([_AC_ARG_VAR_PRECIOUS],[])
AC_PROG_CC
@@ -137,11 +157,6 @@ m4_rename_force([real_PRECIOUS],[_AC_ARG_VAR_PRECIOUS])
AC_SUBST(CFLAGS)
-# In order to override CFLAGS_FOR_TARGET, all of our special flags go
-# in XCFLAGS. But we need them in CFLAGS during configury. So put them
-# in both places for now and restore CFLAGS at the end of config.
-save_CFLAGS="$CFLAGS"
-
# Find other programs we need.
AC_CHECK_TOOL(AR, ar)
AC_CHECK_TOOL(NM, nm)
