commit
71ad51b81443681014662c61d486c510966c6510 (HEAD -> master)
Author: Stephan Bergmann <sbergman@redhat.com>
Date: Mon Sep 2 10:20:24 2019 +0200
Add -latomic to the end of Linux C++ linker command lines
b11763dbaa0c7f427ea47abe9b98995cb49a8595 "link with -latomic on mips(el),
armel, powerpc, m68k" had added -latomic to the linker command lines of just
some Linux platforms (which apparently happened to actually require it). But
there were three issues with that:
* The -latomic came too early on the command line, so that it wasn't used to
satisfy dependencies of .o files that came later. See the discussion at
<https://gerrit.libreoffice.org/#/c/78319/> "set -Wl,--no-as-needed for
-latomic".
* There is presumably no need to include -latomic on C linker command lines.
* <https://gcc.gnu.org/onlinedocs/gcc-7.3.0/libstdc++/manual/manual/using.html
#manual.intro.using.flags> (matching our Linux libstdc++ 7.3.0 baseline as
per README.md) states: "Linking to libatomic is required for some uses of
ISO C++11 <atomic>." So we should better include -latomic on every Linux C++
linker command line that uses libstdc++. (This patch assumes that we always
use libstdc++ on Linux.)
Ideally we could rely on -latomic always being available with our baseline
libstdc++ 7.3.0, but when using Red Hat Developer Toolset 7 that appears not to
be the case, as reported by a Jenkins build for an older version of this change
(see below), so use ATOMIC_LIB from the preceding commit
<https://gerrit.libreoffice.org/#/c/78336/> "add -latomic configure check...".
<https://ci.libreoffice.org/job/gerrit_linux_gcc_release/40298/console>:
> [build LNK] Executable/unoapploader
> /opt/rh/devtoolset-7/root/usr/libexec/gcc/x86_64-redhat-linux/7/ld: cannot find -latomic
> collect2: error: ld returned 1 exit status
> /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/solenv/gbuild/LinkTarget.mk:636: recipe for target '/home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/LinkTarget/Executable/idxdict' failed
This patch adds -latomic only on Linux. Similar changes can be made for other
platforms if need be.
Change-Id: I75df5410677f4c31c796d7ba85532bcdb47eb111
commit
7bdac5b1567089b9ccb239c5031f03fa0d918fca
Author: Rene Engelhard <rene@debian.org>
Date: Fri Aug 30 21:00:55 2019 +0200
add -latomic configure check...
...in preparation for <https://gerrit.libreoffice.org/#/c/78380/> "Add -latomic to the end of Linux C++ linker command lines"
(copied from https://github.com/zelcash/zelcash/blob/master/build-aux/m4/l_atomic.m4)
Change-Id: I8879a72d730cc08a72c2d8b132ff9f5d2efe7b9f
Gbp-Pq: Name latomic.diff
export ASSERT_ALWAYS_ABORT=@ASSERT_ALWAYS_ABORT@
export ATL_INCLUDE=@ATL_INCLUDE@
export ATL_LIB=@ATL_LIB@
+export ATOMIC_LIB=@ATOMIC_LIB@
export AVAHI_CFLAGS=$(gb_SPACE)@AVAHI_CFLAGS@
export AVAHI_LIBS=$(gb_SPACE)@AVAHI_LIBS@
export LIBATOMIC_OPS_CFLAGS=$(gb_SPACE)@LIBATOMIC_OPS_CFLAGS@
--- /dev/null
+# Some versions of gcc/libstdc++ require linking with -latomic if
+# using the C++ atomic library.
+#
+# Sourced from http://bugs.debian.org/797228
+
+m4_define([_CHECK_L_ATOMIC_testbody], [[
+ #include <atomic>
+ #include <cstdint>
+
+ int main() {
+ std::atomic<int64_t> a{};
+
+ int64_t v = 5;
+ int64_t r = a.fetch_add(v);
+ return static_cast<int>(r);
+ }
+]])
+
+AC_DEFUN([CHECK_L_ATOMIC], [
+
+ AC_LANG_PUSH(C++)
+
+ AC_MSG_CHECKING([whether std::atomic can be used without link library])
+
+ AC_LINK_IFELSE([AC_LANG_SOURCE([_CHECK_L_ATOMIC_testbody])],[
+ AC_MSG_RESULT([yes])
+ ],[
+ AC_MSG_RESULT([no])
+ LIBS="$LIBS -latomic"
+ AC_MSG_CHECKING([whether std::atomic needs -latomic])
+ AC_LINK_IFELSE([AC_LANG_SOURCE([_CHECK_L_ATOMIC_testbody])],[
+ AC_MSG_RESULT([yes])
+ ATOMIC_LIB=-latomic
+ ],[
+ AC_MSG_RESULT([no])
+ AC_MSG_FAILURE([cannot figure our how to use std::atomic])
+ ])
+ ])
+
+ AC_LANG_POP
+])
$(call gb_LinkTarget_get_target,$(1)) : LINKED_LIBS :=
$(call gb_LinkTarget_get_target,$(1)) : LINKED_STATIC_LIBS :=
$(call gb_LinkTarget_get_target,$(1)) : T_LIBS :=
+$(call gb_LinkTarget_get_target,$(1)) : T_STDLIBS_CXX := $(gb_STDLIBS_CXX)
$(call gb_LinkTarget_get_target,$(1)) : TARGETTYPE :=
$(call gb_LinkTarget_get_target,$(1)) : LIBRARY_X64 :=
$(call gb_LinkTarget_get_target,$(1)) : PCH_NAME :=
# call gb_LinkTarget_disable_standard_system_libs,linktarget
define gb_LinkTarget_disable_standard_system_libs
$(call gb_LinkTarget_get_target,$(1)) : T_LIBS := $$(filter-out $$(gb_STDLIBS),$$(T_LIBS))
+$(call gb_LinkTarget_get_target,$(1)) : T_STDLIBS_CXX :=
endef
include $(GBUILDDIR)/platform/linux.mk
-gb_LinkTarget_LDFLAGS += -latomic
-
# vim: set noet sw=4:
include $(GBUILDDIR)/platform/linux.mk
-gb_LinkTarget_LDFLAGS += -latomic
-
# vim: set noet sw=4:
include $(GBUILDDIR)/platform/linux.mk
-gb_LinkTarget_LDFLAGS += -latomic
-
# vim: set noet sw=4:
include $(GBUILDDIR)/platform/linux.mk
-gb_LinkTarget_LDFLAGS += -latomic
-
# vim: set noet sw=4:
gb_STDLIBS := -ldl
endif
+ifneq ($(ATOMIC_LIB),)
+gb_STDLIBS_CXX := $(ATOMIC_LIB)
+endif
+
# vim: set noet sw=4 ts=4:
$(patsubst lib%.a,-l%,$(patsubst lib%.so,-l%,$(patsubst %.$(gb_Library_UDK_MAJORVER),%,$(foreach lib,$(LINKED_LIBS),$(call gb_Library_get_filename,$(lib)))))) \
$(foreach lib,$(LINKED_STATIC_LIBS),$(call gb_StaticLibrary_get_target,$(lib))) \
$(T_LIBS) \
+ $(if $(CXXOBJECTS)$(GENCXXOBJECTS)$(EXTRAOBJECTLISTS)$(filter-out XTRUE,X$(ENABLE_RUNTIME_OPTIMIZATIONS)),$(T_STDLIBS_CXX)) \
-Wl$(COMMA)--end-group \
, \
-Wl$(COMMA)--start-group \
$(foreach lib,$(LINKED_STATIC_LIBS),$(call gb_StaticLibrary_get_target,$(lib))) \
$(T_LIBS) \
+ $(if $(CXXOBJECTS)$(GENCXXOBJECTS)$(EXTRAOBJECTLISTS)$(filter-out XTRUE,X$(ENABLE_RUNTIME_OPTIMIZATIONS)),$(T_STDLIBS_CXX)) \
-Wl$(COMMA)--end-group \
-Wl$(COMMA)--no-as-needed \
$(patsubst lib%.a,-l%,$(patsubst lib%.so,-l%,$(patsubst %.$(gb_Library_UDK_MAJORVER),%,$(foreach lib,$(LINKED_LIBS),$(call gb_Library_get_filename,$(lib)))))) \
projects / libreoffice.git / commitdiff