Hi Vasileios, This patch doesn't quite work correctly. I've committed a follow up fix to it as r260524.
Let me know if you have any issues. /Eric On Thu, Feb 11, 2016 at 5:43 AM, Vasileios Kalintiris via cfe-commits < cfe-commits@lists.llvm.org> wrote: > Author: vkalintiris > Date: Thu Feb 11 06:43:04 2016 > New Revision: 260515 > > URL: http://llvm.org/viewvc/llvm-project?rev=260515&view=rev > Log: > Re-commit "Introduce a cmake module to figure out whether we need to link > with libatomic." > > This re-applies commit r260235. However, this time we add -gcc-toolchain > to the compiler's flags when the user has specified the > LIBCXX_GCC_TOOLCHAIN > variable. > > Added: > libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake > Modified: > libcxx/trunk/cmake/config-ix.cmake > libcxx/trunk/lib/CMakeLists.txt > libcxx/trunk/test/CMakeLists.txt > libcxx/trunk/test/libcxx/test/target_info.py > libcxx/trunk/test/lit.site.cfg.in > > Added: libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake > URL: > http://llvm.org/viewvc/llvm-project/libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake?rev=260515&view=auto > > ============================================================================== > --- libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake (added) > +++ libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake Thu Feb 11 06:43:04 > 2016 > @@ -0,0 +1,41 @@ > +INCLUDE(CheckCXXSourceCompiles) > + > +# Sometimes linking against libatomic is required for atomic ops, if > +# the platform doesn't support lock-free atomics. > +# > +# We could modify LLVM's CheckAtomic module and have it check for 64-bit > +# atomics instead. However, we would like to avoid careless uses of 64-bit > +# atomics inside LLVM over time on 32-bit platforms. > + > +function(check_cxx_atomics varname) > + set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS}) > + set(CMAKE_REQUIRED_FLAGS "-std=c++11") > + if (${LIBCXX_GCC_TOOLCHAIN}) > + set(CMAKE_REQUIRED_FLAGS "-std=c++11 > --gcc-toolchain=${LIBCXX_GCC_TOOLCHAIN}") > + endif() > + check_cxx_source_compiles(" > +#include <cstdint> > +#include <atomic> > +std::atomic<uintptr_t> x; > +std::atomic<uintmax_t> y; > +int main() { > + return x + y; > +} > +" ${varname}) > + set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS}) > +endfunction(check_cxx_atomics) > + > +check_cxx_atomics(LIBCXX_HAVE_CXX_ATOMICS_WITH_LIB) > +# If not, check if the library exists, and atomics work with it. > +if(NOT LIBCXX_HAVE_CXX_ATOMICS_WITH_LIB) > + check_library_exists(atomic __atomic_fetch_add_8 "" HAVE_LIBATOMIC) > + if(HAVE_LIBATOMIC) > + list(APPEND CMAKE_REQUIRED_LIBRARIES "atomic") > + check_cxx_atomics(HAVE_CXX_ATOMICS_WITH_LIB) > + if (NOT HAVE_CXX_ATOMICS_WITH_LIB) > + message(FATAL_ERROR "Host compiler must support std::atomic!") > + endif() > + else() > + message(FATAL_ERROR "Host compiler appears to require libatomic, but > cannot find it.") > + endif() > +endif() > > Modified: libcxx/trunk/cmake/config-ix.cmake > URL: > http://llvm.org/viewvc/llvm-project/libcxx/trunk/cmake/config-ix.cmake?rev=260515&r1=260514&r2=260515&view=diff > > ============================================================================== > --- libcxx/trunk/cmake/config-ix.cmake (original) > +++ libcxx/trunk/cmake/config-ix.cmake Thu Feb 11 06:43:04 2016 > @@ -1,5 +1,6 @@ > include(CheckLibraryExists) > include(CheckCXXCompilerFlag) > +include(CheckLibcxxAtomic) > > # Check compiler flags > > @@ -17,3 +18,7 @@ check_library_exists(c fopen "" LIBCXX_H > check_library_exists(m ccos "" LIBCXX_HAS_M_LIB) > check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB) > check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXX_HAS_GCC_S_LIB) > + > +if (NOT HAVE_CXX_ATOMICS_WITHOUT_LIB) > + set(LIBCXX_HAS_ATOMIC_LIB True) > +endif() > > Modified: libcxx/trunk/lib/CMakeLists.txt > URL: > http://llvm.org/viewvc/llvm-project/libcxx/trunk/lib/CMakeLists.txt?rev=260515&r1=260514&r2=260515&view=diff > > ============================================================================== > --- libcxx/trunk/lib/CMakeLists.txt (original) > +++ libcxx/trunk/lib/CMakeLists.txt Thu Feb 11 06:43:04 2016 > @@ -79,6 +79,7 @@ add_library_flags_if(LIBCXX_HAS_C_LIB c) > add_library_flags_if(LIBCXX_HAS_M_LIB m) > add_library_flags_if(LIBCXX_HAS_RT_LIB rt) > add_library_flags_if(LIBCXX_HAS_GCC_S_LIB gcc_s) > +add_library_flags_if(LIBCXX_HAS_ATOMIC_LIB atomic) > > # Setup flags. > add_flags_if_supported(-fPIC) > > Modified: libcxx/trunk/test/CMakeLists.txt > URL: > http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/CMakeLists.txt?rev=260515&r1=260514&r2=260515&view=diff > > ============================================================================== > --- libcxx/trunk/test/CMakeLists.txt (original) > +++ libcxx/trunk/test/CMakeLists.txt Thu Feb 11 06:43:04 2016 > @@ -15,6 +15,7 @@ pythonize_bool(LIBCXX_ENABLE_SHARED) > pythonize_bool(LIBCXX_BUILD_32_BITS) > pythonize_bool(LIBCXX_GENERATE_COVERAGE) > pythonize_bool(LIBCXXABI_USE_LLVM_UNWINDER) > +pythonize_bool(LIBCXX_HAS_ATOMIC_LIB) > > # The tests shouldn't link to any ABI library when it has been linked into > # libc++ statically or via a linker script. > > Modified: libcxx/trunk/test/libcxx/test/target_info.py > URL: > http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx/test/target_info.py?rev=260515&r1=260514&r2=260515&view=diff > > ============================================================================== > --- libcxx/trunk/test/libcxx/test/target_info.py (original) > +++ libcxx/trunk/test/libcxx/test/target_info.py Thu Feb 11 06:43:04 2016 > @@ -172,6 +172,9 @@ class LinuxLocalTI(DefaultTargetInfo): > flags += ['-lunwind', '-ldl'] > else: > flags += ['-lgcc_s', '-lgcc'] > + use_libatomic = self.full_config.get_lit_bool('use_libatomic', > False) > + if use_libatomic: > + flags += ['-latomic'] > san = self.full_config.get_lit_conf('use_sanitizer', '').strip() > if san: > # The libraries and their order are taken from the > > Modified: libcxx/trunk/test/lit.site.cfg.in > URL: > http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/lit.site.cfg.in?rev=260515&r1=260514&r2=260515&view=diff > > ============================================================================== > --- libcxx/trunk/test/lit.site.cfg.in (original) > +++ libcxx/trunk/test/lit.site.cfg.in Thu Feb 11 06:43:04 2016 > @@ -20,6 +20,7 @@ config.generate_coverage = "@LIBC > config.target_info = "@LIBCXX_TARGET_INFO@" > config.executor = "@LIBCXX_EXECUTOR@" > config.llvm_unwinder = "@LIBCXXABI_USE_LLVM_UNWINDER@" > +config.use_libatomic = "@LIBCXX_HAS_ATOMIC_LIB@" > > # Let the main config do the real work. > lit_config.load_config(config, "@LIBCXX_SOURCE_DIR@/test/lit.cfg") > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >
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