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 <prathameshk@nvidia.com>
Co-authored-by: Matthew Malcolmson <mmalcolmson@nvidia.com>

4 files changed, 53 insertions, 14 deletions

diff --git a/libatomic/Makefile.am b/libatomic/Makefile.am
index efadd9d..723e0be 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
+	$(INSTALL_DATA) .libs/libatomic.a $(gcc_objdir)/
+	chmod 644 $(gcc_objdir)/libatomic.a
+
 # target overrides
 -include $(tmake_file)
 
diff --git a/libatomic/Makefile.in b/libatomic/Makefile.in
index 9798e7c..f19e0a3 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
+	$(INSTALL_DATA) .libs/libatomic.a $(gcc_objdir)/
+	chmod 644 $(gcc_objdir)/libatomic.a
 
 # target overrides
 -include $(tmake_file)
diff --git a/libatomic/configure b/libatomic/configure
index d579bab..0a34027 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 32a2cdb..23a9695 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)