On 10/2/20 12:55 AM, Joseph Myers wrote:
As discussed in bug 81358, I think --as-needed -latomic --no-as-needed
should be used by the driver by default (when the compiler is configured
with libatomic supported).
I make a thinko initially by believing that the '-latomic' has to
be specified by the user-invoked compiler via -foffload=-latomic'
and that had to be put into the .spec file, causing all kind
of problems.
However, this flag can be added into the offload-target's libgomp.spec,
which avoids all kind of issues. That's what this patch now does.
I tested it with x86_64-gnu-linux w/o + w/ nvptx-none. Result:
* x86_64-gnu-linux's libgomp.spec:
"*link_gomp: -lgomp %{static: -ldl } --as-needed -latomic --no-as-needed"
* nvptx-none's libgomp.spec:
"*link_gomp: -lgomp -latomic"
On x86-64, a simple test program did not use and also did not link libatomic.
OK?
Tobias
-----------------
Mentor Graphics (Deutschland) GmbH, Arnulfstraße 201, 80634 München / Germany
Registergericht München HRB 106955, Geschäftsführer: Thomas Heurung, Alexander
Walter
libgomp: Add, if existing, -latomic to libgomp.spec --as-needed
libgomp/ChangeLog:
* acinclude.m4 (LIBGOMP_CHECK_LIBATOMIC): New; set
@LIBATOMICSPEC@ is the target libatomic is built.
* configure.ac: Call LIBGOMP_CHECK_LIBATOMIC.
* libgomp.spec.in: Add @LIBATOMICSPEC@.
* Makefile.in: Regenerate.
* configure: Regenerate.
* testsuite/Makefile.in: Regenerate.
libgomp/Makefile.in | 1 +
libgomp/acinclude.m4 | 63 ++++++++++++++++++++++++++
libgomp/configure | 100 +++++++++++++++++++++++++++++++++++++++++-
libgomp/configure.ac | 2 +
libgomp/libgomp.spec.in | 2 +-
libgomp/testsuite/Makefile.in | 1 +
6 files changed, 166 insertions(+), 3 deletions(-)
diff --git a/libgomp/Makefile.in b/libgomp/Makefile.in
index 00d5e2919ee..a8ec69f1822 100644
--- a/libgomp/Makefile.in
+++ b/libgomp/Makefile.in
@@ -395,6 +395,7 @@ INSTALL_STRIP_PROGRAM = @INSTALL_STRIP_PROGRAM@
INTPTR_T_KIND = @INTPTR_T_KIND@
LD = @LD@
LDFLAGS = @LDFLAGS@
+LIBATOMICSPEC = @LIBATOMICSPEC@
LIBOBJS = @LIBOBJS@
LIBS = @LIBS@
LIBTOOL = @LIBTOOL@
diff --git a/libgomp/acinclude.m4 b/libgomp/acinclude.m4
index dbf54d06db9..3d7e5e08c3a 100644
--- a/libgomp/acinclude.m4
+++ b/libgomp/acinclude.m4
@@ -365,3 +365,66 @@ if test $enable_symvers != no ; then
esac
fi
])
+
+dnl Check whether libatomic exists
+AC_DEFUN([LIBGOMP_CHECK_LIBATOMIC], [
+ LIBATOMICSPEC=
+ libgomp_libatomic=no
+
+ if echo " ${TARGET_CONFIGDIRS} " | grep " libatomic " > /dev/null 2>&1 ; then
+ libgomp_libatomic=yes;
+ fi
+
+ AC_MSG_CHECKING([for target-libatomic support])
+ AC_MSG_RESULT([$libgomp_libatomic])
+
+ if test "x$libgomp_libatomic" = xyes; then
+ dnl Check whether -Wl,--as-needed resp. -Wl,-zignore is supported
+ dnl
+ dnl Turn warnings into error to avoid testsuite breakage. So enable
+ dnl AC_LANG_WERROR, but there's currently (autoconf 2.64) no way to turn
+ dnl it off again. As a workaround, save and restore werror flag like
+ dnl AC_PATH_XTRA.
+ dnl Cf. http://gcc.gnu.org/ml/gcc-patches/2010-05/msg01889.html
+ ac_xsave_[]_AC_LANG_ABBREV[]_werror_flag=$ac_[]_AC_LANG_ABBREV[]_werror_flag
+ AC_CACHE_CHECK([whether --as-needed/-z ignore works],
+ [libgomp_cv_have_as_needed],
+ [
+ # Test for native Solaris options first.
+ # No whitespace after -z to pass it through -Wl.
+ libgomp_cv_as_needed_option="-zignore"
+ libgomp_cv_no_as_needed_option="-zrecord"
+ save_LDFLAGS="$LDFLAGS"
+ LDFLAGS="$LDFLAGS -Wl,$libgomp_cv_as_needed_option -lm -Wl,$libompr_cv_no_as_needed_option"
+ libgomp_cv_have_as_needed=no
+ AC_LANG_WERROR
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([])],
+ [libgomp_cv_have_as_needed=yes],
+ [libgomp_cv_have_as_needed=no])
+ LDFLAGS="$save_LDFLAGS"
+ if test "x$libgomp_cv_have_as_needed" = xno; then
+ libgomp_cv_as_needed_option="--as-needed"
+ libgomp_cv_no_as_needed_option="--no-as-needed"
+ save_LDFLAGS="$LDFLAGS"
+ LDFLAGS="$LDFLAGS -Wl,$libgomp_cv_as_needed_option -lm -Wl,$libgomp_cv_no_as_needed_option"
+ libgomp_cv_have_as_needed=no
+ AC_LANG_WERROR
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([])],
+ [libgomp_cv_have_as_needed=yes],
+ [libgomp_cv_have_as_needed=no])
+ LDFLAGS="$save_LDFLAGS"
+ fi
+ ac_[]_AC_LANG_ABBREV[]_werror_flag=$ac_xsave_[]_AC_LANG_ABBREV[]_werror_flag
+ ])
+
+ dnl For static libgfortran linkage, depend on libquadmath only if needed.
+ if test "x$libgomp_cv_have_as_needed" = xyes; then
+ LIBATOMICSPEC="$libgomp_cv_as_needed_option -latomic $libgomp_cv_no_as_needed_option"
+ else
+ LIBATOMICSPEC="-latomic"
+ fi
+ fi
+
+ dnl For the spec file
+ AC_SUBST(LIBATOMICSPEC)
+])
diff --git a/libgomp/configure b/libgomp/configure
index e48371d5093..a4d93974084 100755
--- a/libgomp/configure
+++ b/libgomp/configure
@@ -630,6 +630,8 @@ ac_includes_default="\
ac_header_list=
ac_func_list=
+ac_c_werror_flag=
+ac_c_werror_flag=
ac_subst_vars='am__EXEEXT_FALSE
am__EXEEXT_TRUE
LTLIBOBJS
@@ -653,6 +655,7 @@ USE_FORTRAN_FALSE
USE_FORTRAN_TRUE
link_gomp
tmake_file
+LIBATOMICSPEC
XLDFLAGS
XCFLAGS
config_path
@@ -11429,7 +11432,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11432 "configure"
+#line 11435 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -11535,7 +11538,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11538 "configure"
+#line 11541 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -16756,6 +16759,99 @@ FCFLAGS="$FCFLAGS $CET_FLAGS"
+
+ LIBATOMICSPEC=
+ libgomp_libatomic=no
+
+ if echo " ${TARGET_CONFIGDIRS} " | grep " libatomic " > /dev/null 2>&1 ; then
+ libgomp_libatomic=yes;
+ fi
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for target-libatomic support" >&5
+$as_echo_n "checking for target-libatomic support... " >&6; }
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $libgomp_libatomic" >&5
+$as_echo "$libgomp_libatomic" >&6; }
+
+ if test "x$libgomp_libatomic" = xyes; then
+ ac_xsave_c_werror_flag=$ac_c_werror_flag
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether --as-needed/-z ignore works" >&5
+$as_echo_n "checking whether --as-needed/-z ignore works... " >&6; }
+if ${libgomp_cv_have_as_needed+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+
+ # Test for native Solaris options first.
+ # No whitespace after -z to pass it through -Wl.
+ libgomp_cv_as_needed_option="-zignore"
+ libgomp_cv_no_as_needed_option="-zrecord"
+ save_LDFLAGS="$LDFLAGS"
+ LDFLAGS="$LDFLAGS -Wl,$libgomp_cv_as_needed_option -lm -Wl,$libompr_cv_no_as_needed_option"
+ libgomp_cv_have_as_needed=no
+
+ac_c_werror_flag=yes
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+ libgomp_cv_have_as_needed=yes
+else
+ libgomp_cv_have_as_needed=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+ LDFLAGS="$save_LDFLAGS"
+ if test "x$libgomp_cv_have_as_needed" = xno; then
+ libgomp_cv_as_needed_option="--as-needed"
+ libgomp_cv_no_as_needed_option="--no-as-needed"
+ save_LDFLAGS="$LDFLAGS"
+ LDFLAGS="$LDFLAGS -Wl,$libgomp_cv_as_needed_option -lm -Wl,$libgomp_cv_no_as_needed_option"
+ libgomp_cv_have_as_needed=no
+
+ac_c_werror_flag=yes
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+ libgomp_cv_have_as_needed=yes
+else
+ libgomp_cv_have_as_needed=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+ LDFLAGS="$save_LDFLAGS"
+ fi
+ ac_c_werror_flag=$ac_xsave_c_werror_flag
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libgomp_cv_have_as_needed" >&5
+$as_echo "$libgomp_cv_have_as_needed" >&6; }
+
+ if test "x$libgomp_cv_have_as_needed" = xyes; then
+ LIBATOMICSPEC="$libgomp_cv_as_needed_option -latomic $libgomp_cv_no_as_needed_option"
+ else
+ LIBATOMICSPEC="-latomic"
+ fi
+ fi
+
+
+
+
# Conditionalize the makefile for this target machine.
tmake_file_=
for f in ${tmake_file}
diff --git a/libgomp/configure.ac b/libgomp/configure.ac
index e4f30cbb082..2ee2c1a16d8 100644
--- a/libgomp/configure.ac
+++ b/libgomp/configure.ac
@@ -348,6 +348,8 @@ AC_SUBST(config_path)
AC_SUBST(XCFLAGS)
AC_SUBST(XLDFLAGS)
+LIBGOMP_CHECK_LIBATOMIC
+
# Conditionalize the makefile for this target machine.
tmake_file_=
for f in ${tmake_file}
diff --git a/libgomp/libgomp.spec.in b/libgomp/libgomp.spec.in
index 5651603f487..c42d8b28848 100644
--- a/libgomp/libgomp.spec.in
+++ b/libgomp/libgomp.spec.in
@@ -1,3 +1,3 @@
# This spec file is read by gcc when linking. It is used to specify the
# standard libraries we need in order to link with libgomp.
-*link_gomp: @link_gomp@
+*link_gomp: @link_gomp@ @LIBATOMICSPEC@
diff --git a/libgomp/testsuite/Makefile.in b/libgomp/testsuite/Makefile.in
index e48c3f2f9b0..cf2ce55d126 100644
--- a/libgomp/testsuite/Makefile.in
+++ b/libgomp/testsuite/Makefile.in
@@ -173,6 +173,7 @@ INSTALL_STRIP_PROGRAM = @INSTALL_STRIP_PROGRAM@
INTPTR_T_KIND = @INTPTR_T_KIND@
LD = @LD@
LDFLAGS = @LDFLAGS@
+LIBATOMICSPEC = @LIBATOMICSPEC@
LIBOBJS = @LIBOBJS@
LIBS = @LIBS@
LIBTOOL = @LIBTOOL@
