From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1698) id E54453858D39; Sun, 21 Apr 2024 13:04:13 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E54453858D39 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1713704653; bh=eDa/A9TQnneCZ7UhtDDujZA8Z9WKWe2Ijjf5z2W/bwo=; h=From:To:Subject:Date:From; b=WxY0TUKoDNWAe06dTf9VXwMs50FrcFsrh3r/xZcjble45SPH+KlU7z0jvszIt+33R GPvhOO+slc5pWS+Jjk9/sXHPimaIVouDh3gBb+t4EfQhyizmuT+05Aw/bm4wmoEH30 xw6ygwbd+iYJ2Db+iykfmB2b7mvRmUY3Zf9QdNBM= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Iain D Sandoe To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r12-10376] libstdc++, Darwin: Handle a linker warning [PR112397]. X-Act-Checkin: gcc X-Git-Author: Iain Sandoe X-Git-Refname: refs/heads/releases/gcc-12 X-Git-Oldrev: 4c8d37badaa42e85218eb9b89aef3e4f6cf4486e X-Git-Newrev: 77f17e405a0669db9a6c8af69bde6eb1170f48bd Message-Id: <20240421130413.E54453858D39@sourceware.org> Date: Sun, 21 Apr 2024 13:04:13 +0000 (GMT) List-Id: https://gcc.gnu.org/g:77f17e405a0669db9a6c8af69bde6eb1170f48bd commit r12-10376-g77f17e405a0669db9a6c8af69bde6eb1170f48bd Author: Iain Sandoe Date: Thu Feb 8 17:54:31 2024 +0000 libstdc++, Darwin: Handle a linker warning [PR112397]. Darwin's linker warns when we make a direct branch to code that is in a weak definition (citing that if a different implementation of the weak function is chosen by the dynamic linker this would be an error). As the analysis in the PR shows, this can happen when we have hot/ cold partitioning and there is an error path that is primarily cold but makes use of epilogue code in the hot section. In this simple case, we can easily deduce that the code is in fact safe; however that is not something we can realistically implement in the linker. Since the user-replaceable allocators are implemented using weak definitions, this is a warning that is frequently flagged up in both the testsuite and end-user code. The chosen solution here is to suppress the hot/cold partitioning for these cases (it is unlikely to impact performance much c.f. the actual allocation). PR target/112397 libstdc++-v3/ChangeLog: * configure: Regenerate. * configure.ac: Detect if we are building for Darwin. * libsupc++/Makefile.am: If we are building for Darwin, then suppress hot/cold partitioning for the array allocators. * libsupc++/Makefile.in: Regenerated. Signed-off-by: Iain Sandoe Co-authored-by: Jonathan Wakely (cherry picked from commit 1609fdff16f17ead37666f6d0e801800ee3d04d2) Diff: --- libstdc++-v3/configure | 36 ++++++++++++++++++++++++++++-------- libstdc++-v3/configure.ac | 7 +++++++ libstdc++-v3/libsupc++/Makefile.am | 8 ++++++++ libstdc++-v3/libsupc++/Makefile.in | 6 ++++++ 4 files changed, 49 insertions(+), 8 deletions(-) diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure index bc92ce1303c..ccc23f1b352 100755 --- a/libstdc++-v3/configure +++ b/libstdc++-v3/configure @@ -786,6 +786,8 @@ GLIBCXX_HOSTED_TRUE glibcxx_compiler_shared_flag glibcxx_compiler_pic_flag glibcxx_lt_pic_flag +OS_IS_DARWIN_FALSE +OS_IS_DARWIN_TRUE enable_static enable_shared lt_host_flags @@ -12191,7 +12193,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 12194 "configure" +#line 12196 "configure" #include "confdefs.h" #if HAVE_DLFCN_H @@ -12297,7 +12299,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 12300 "configure" +#line 12302 "configure" #include "confdefs.h" #if HAVE_DLFCN_H @@ -15579,6 +15581,20 @@ esac +os_is_darwin=no +case ${host_os} in + darwin*) os_is_darwin=yes ;; + *) ;; +esac + if test x${os_is_darwin} = xyes; then + OS_IS_DARWIN_TRUE= + OS_IS_DARWIN_FALSE='#' +else + OS_IS_DARWIN_TRUE='#' + OS_IS_DARWIN_FALSE= +fi + + if test "$enable_vtable_verify" = yes; then predep_objects_CXX="${predep_objects_CXX} ${glibcxx_builddir}/../libgcc/vtv_start.o" postdep_objects_CXX="${postdep_objects_CXX} ${glibcxx_builddir}/../libgcc/vtv_end.o" @@ -15981,7 +15997,7 @@ $as_echo "$glibcxx_cv_atomic_long_long" >&6; } # Fake what AC_TRY_COMPILE does. cat > conftest.$ac_ext << EOF -#line 15984 "configure" +#line 16000 "configure" int main() { typedef bool atomic_type; @@ -16016,7 +16032,7 @@ $as_echo "$glibcxx_cv_atomic_bool" >&6; } rm -f conftest* cat > conftest.$ac_ext << EOF -#line 16019 "configure" +#line 16035 "configure" int main() { typedef short atomic_type; @@ -16051,7 +16067,7 @@ $as_echo "$glibcxx_cv_atomic_short" >&6; } rm -f conftest* cat > conftest.$ac_ext << EOF -#line 16054 "configure" +#line 16070 "configure" int main() { // NB: _Atomic_word not necessarily int. @@ -16087,7 +16103,7 @@ $as_echo "$glibcxx_cv_atomic_int" >&6; } rm -f conftest* cat > conftest.$ac_ext << EOF -#line 16090 "configure" +#line 16106 "configure" int main() { typedef long long atomic_type; @@ -16243,7 +16259,7 @@ $as_echo "mutex" >&6; } # unnecessary for this test. cat > conftest.$ac_ext << EOF -#line 16246 "configure" +#line 16262 "configure" int main() { _Decimal32 d1; @@ -16285,7 +16301,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu # unnecessary for this test. cat > conftest.$ac_ext << EOF -#line 16288 "configure" +#line 16304 "configure" template struct same { typedef T2 type; }; @@ -79293,6 +79309,10 @@ if test -z "${MAINTAINER_MODE_TRUE}" && test -z "${MAINTAINER_MODE_FALSE}"; then as_fn_error $? "conditional \"MAINTAINER_MODE\" was never defined. Usually this means the macro was only invoked conditionally." "$LINENO" 5 fi +if test -z "${OS_IS_DARWIN_TRUE}" && test -z "${OS_IS_DARWIN_FALSE}"; then + as_fn_error $? "conditional \"OS_IS_DARWIN\" was never defined. +Usually this means the macro was only invoked conditionally." "$LINENO" 5 +fi if test -z "${GLIBCXX_HOSTED_TRUE}" && test -z "${GLIBCXX_HOSTED_FALSE}"; then as_fn_error $? "conditional \"GLIBCXX_HOSTED\" was never defined. Usually this means the macro was only invoked conditionally." "$LINENO" 5 diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac index e59bcdb2944..dc0c61973d1 100644 --- a/libstdc++-v3/configure.ac +++ b/libstdc++-v3/configure.ac @@ -100,6 +100,13 @@ ACX_LT_HOST_FLAGS AC_SUBST(enable_shared) AC_SUBST(enable_static) +os_is_darwin=no +case ${host_os} in + darwin*) os_is_darwin=yes ;; + *) ;; +esac +AM_CONDITIONAL([OS_IS_DARWIN], [test x${os_is_darwin} = xyes]) + if test "$enable_vtable_verify" = yes; then predep_objects_CXX="${predep_objects_CXX} ${glibcxx_builddir}/../libgcc/vtv_start.o" postdep_objects_CXX="${postdep_objects_CXX} ${glibcxx_builddir}/../libgcc/vtv_end.o" diff --git a/libstdc++-v3/libsupc++/Makefile.am b/libstdc++-v3/libsupc++/Makefile.am index 65b5c1a87fd..4e63ad04a58 100644 --- a/libstdc++-v3/libsupc++/Makefile.am +++ b/libstdc++-v3/libsupc++/Makefile.am @@ -132,6 +132,14 @@ atomicity_file = ${glibcxx_srcdir}/$(ATOMICITY_SRCDIR)/atomicity.h atomicity.cc: ${atomicity_file} $(LN_S) ${atomicity_file} ./atomicity.cc || true +if OS_IS_DARWIN +# See PR 112397 +new_opvnt.lo: new_opvnt.cc + $(LTCXXCOMPILE) -fno-reorder-blocks-and-partition -I. -c $< +new_opvnt.o: new_opvnt.cc + $(CXXCOMPILE) -fno-reorder-blocks-and-partition -I. -c $< +endif + # AM_CXXFLAGS needs to be in each subdirectory so that it can be # modified in a per-library or per-sub-library way. Need to manually # set this option because CONFIG_CXXFLAGS has to be after diff --git a/libstdc++-v3/libsupc++/Makefile.in b/libstdc++-v3/libsupc++/Makefile.in index a4402009b85..22c9680f979 100644 --- a/libstdc++-v3/libsupc++/Makefile.in +++ b/libstdc++-v3/libsupc++/Makefile.in @@ -973,6 +973,12 @@ cp-demangle.o: cp-demangle.c atomicity.cc: ${atomicity_file} $(LN_S) ${atomicity_file} ./atomicity.cc || true +# See PR 112397 +@OS_IS_DARWIN_TRUE@new_opvnt.lo: new_opvnt.cc +@OS_IS_DARWIN_TRUE@ $(LTCXXCOMPILE) -fno-reorder-blocks-and-partition -I. -c $< +@OS_IS_DARWIN_TRUE@new_opvnt.o: new_opvnt.cc +@OS_IS_DARWIN_TRUE@ $(CXXCOMPILE) -fno-reorder-blocks-and-partition -I. -c $< + install-stdHEADERS: $(std_HEADERS) @$(NORMAL_INSTALL) $(mkinstalldirs) $(DESTDIR)$(stddir)