> -----Original Message-----
> From: Prathamesh Kulkarni <prathame...@nvidia.com>
> Sent: 18 December 2024 21:09
> To: Tobias Burnus <tbur...@baylibre.com>; Joseph Myers
> <josmy...@redhat.com>
> Cc: Xi Ruoyao <xry...@xry111.site>; Matthew Malcomson
> <mmalcom...@nvidia.com>; gcc-patches@gcc.gnu.org
> Subject: RE: [RFC] PR81358: Enable automatic linking of libatomic
> 
> External email: Use caution opening links or attachments
> 
> 
> > -----Original Message-----
> > From: Tobias Burnus <tbur...@baylibre.com>
> > Sent: 18 December 2024 17:46
> > To: Prathamesh Kulkarni <prathame...@nvidia.com>; Joseph Myers
> > <josmy...@redhat.com>
> > Cc: Xi Ruoyao <xry...@xry111.site>; Matthew Malcomson
> > <mmalcom...@nvidia.com>; gcc-patches@gcc.gnu.org
> > Subject: Re: [RFC] PR81358: Enable automatic linking of libatomic
> >
> > External email: Use caution opening links or attachments
> >
> >
> > A x86_64-gnu-linux bootstrap which also builds -m32 now fails.
> >
> > While I have local patches, they should not affect this, hence, I
> fear
> > that it has been caused by this patch.
> >
> > Namely, if I do a bootstrap into an empty directory with:
> >
> >    $ ..../configure --prefix=...
> > --enable-languages=c,c++,fortran,lto,objc
> > --enable-offload-targets=nvptx-none,amdgcn-amdhsa
> >
> > I get during stage1 bootstrap:
> >
> > checking whether -lc should be explicitly linked in... no checking
> > dynamic linker characteristics... configure: error: Link tests are
> not
> > allowed after GCC_NO_EXECUTABLES.
> > make[2]: *** [Makefile:17281: configure-stage1-target-libstdc++-v3]
> > Error 1
> >
> > And while ./x86_64-pc-linux-gnu/libstdc++-v3/config.log is okay,
> > ./x86_64-pc-linux-gnu/32/libstdc++-v3/config.log fails with:
> >
> > configure:10962: $? = 0
> > configure:10976: result: no
> > configure:11141: checking dynamic linker characteristics
> > configure:11577: error: Link tests are not allowed after
> > GCC_NO_EXECUTABLES.
> >
> > Can you check?
> Hi Tobias,
> Sorry for the breakage. IIUC, the issue seems to be happening with
> libatomic/Makefile.am all: rule added in the patch, that incorrectly
> copies libatomic.a in $(gcc_objdir).
> I have a local patch that instead copies it over to
> $(gcc_objdir)$(MULTISUBDIR)/, which seems to fix the issue with stage-
> 1 multilib build (with -m32) on x86_64-linux-gnu.
> I will post it after running it thru bootstrap+test.
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 ?

Signed-off-by: Prathamesh Kulkarni <prathame...@nvidia.com>

Thanks,
Prathamesh
> 
> Thanks,
> Prathamesh
> >
> > Tobias
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 1b72826d44b..30530cc8b71 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -3361,6 +3361,9 @@ 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..b5060d2c0c8 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 a8b531d8fae..6793d97820d 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -33420,6 +33420,12 @@ $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 77fab885a42..a6dd5786bd9 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -7011,6 +7011,11 @@ 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 8ed5536365f..edf6c9f8684 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -206,7 +206,7 @@ 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}.
@@ -2899,6 +2899,10 @@ 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.
+
 @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..0a340276ca6 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..23a9695be36 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)

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