[libcxx] r260323 - Revert "Introduce a cmake module to figure out whether we need to link with libatomic."
Vasileios Kalintiris via cfe-commits
cfe-commits at lists.llvm.org
Tue Feb 9 15:38:29 PST 2016
Author: vkalintiris
Date: Tue Feb 9 17:38:28 2016
New Revision: 260323
URL: http://llvm.org/viewvc/llvm-project?rev=260323&view=rev
Log:
Revert "Introduce a cmake module to figure out whether we need to link with libatomic."
This reverts commit r260235. It breaks LLVM's bootstrap when building
with a -gcc-toolchain and the system's gcc installation does not provide
the libatomic library and its headers. We should check whether
LIBCXX_GCC_TOOLCHAIN is set and adjust the flags accordingly.
Removed:
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
Removed: libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake?rev=260322&view=auto
==============================================================================
--- libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake (original)
+++ libcxx/trunk/cmake/Modules/CheckLibcxxAtomic.cmake (removed)
@@ -1,38 +0,0 @@
-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")
- 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(HAVE_CXX_ATOMICS_WITHOUT_LIB)
-# If not, check if the library exists, and atomics work with it.
-if(NOT HAVE_CXX_ATOMICS_WITHOUT_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=260323&r1=260322&r2=260323&view=diff
==============================================================================
--- libcxx/trunk/cmake/config-ix.cmake (original)
+++ libcxx/trunk/cmake/config-ix.cmake Tue Feb 9 17:38:28 2016
@@ -1,6 +1,5 @@
include(CheckLibraryExists)
include(CheckCXXCompilerFlag)
-include(CheckLibcxxAtomic)
# Check compiler flags
@@ -18,7 +17,3 @@ 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=260323&r1=260322&r2=260323&view=diff
==============================================================================
--- libcxx/trunk/lib/CMakeLists.txt (original)
+++ libcxx/trunk/lib/CMakeLists.txt Tue Feb 9 17:38:28 2016
@@ -79,7 +79,6 @@ 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=260323&r1=260322&r2=260323&view=diff
==============================================================================
--- libcxx/trunk/test/CMakeLists.txt (original)
+++ libcxx/trunk/test/CMakeLists.txt Tue Feb 9 17:38:28 2016
@@ -15,7 +15,6 @@ 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=260323&r1=260322&r2=260323&view=diff
==============================================================================
--- libcxx/trunk/test/libcxx/test/target_info.py (original)
+++ libcxx/trunk/test/libcxx/test/target_info.py Tue Feb 9 17:38:28 2016
@@ -172,9 +172,6 @@ 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=260323&r1=260322&r2=260323&view=diff
==============================================================================
--- libcxx/trunk/test/lit.site.cfg.in (original)
+++ libcxx/trunk/test/lit.site.cfg.in Tue Feb 9 17:38:28 2016
@@ -20,7 +20,6 @@ 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")
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