| include(CMakePushCheckState) |
| include(CheckLibraryExists) |
| include(CheckCCompilerFlag) |
| include(CheckCXXCompilerFlag) |
| include(CheckCSourceCompiles) |
| |
| if(WIN32 AND NOT MINGW) |
| # NOTE(compnerd) this is technically a lie, there is msvcrt, but for now, lets |
| # let the default linking take care of that. |
| set(LIBCXX_HAS_C_LIB NO) |
| else() |
| check_library_exists(c fopen "" LIBCXX_HAS_C_LIB) |
| endif() |
| |
| if (NOT LIBCXX_USE_COMPILER_RT) |
| if(WIN32 AND NOT MINGW) |
| set(LIBCXX_HAS_GCC_S_LIB NO) |
| else() |
| if(ANDROID) |
| check_library_exists(gcc __gcc_personality_v0 "" LIBCXX_HAS_GCC_LIB) |
| else() |
| check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXX_HAS_GCC_S_LIB) |
| endif() |
| endif() |
| endif() |
| |
| # libc++ is using -nostdlib++ at the link step when available, |
| # otherwise -nodefaultlibs is used. We want all our checks to also |
| # use one of these options, otherwise we may end up with an inconsistency between |
| # the flags we think we require during configuration (if the checks are |
| # performed without one of those options) and the flags that are actually |
| # required during compilation (which has the -nostdlib++ or -nodefaultlibs). libc is |
| # required for the link to go through. We remove sanitizers from the |
| # configuration checks to avoid spurious link errors. |
| |
| check_c_compiler_flag(-nostdlib++ LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG) |
| if (LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG) |
| set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++") |
| else() |
| check_c_compiler_flag(-nodefaultlibs LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG) |
| if (LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG) |
| set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs") |
| endif() |
| endif() |
| |
| if (LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG OR LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG) |
| if (LIBCXX_HAS_C_LIB) |
| list(APPEND CMAKE_REQUIRED_LIBRARIES c) |
| endif () |
| if (LIBCXX_USE_COMPILER_RT) |
| list(APPEND CMAKE_REQUIRED_FLAGS -rtlib=compiler-rt) |
| find_compiler_rt_library(builtins LIBCXX_BUILTINS_LIBRARY) |
| list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBCXX_BUILTINS_LIBRARY}") |
| elseif (LIBCXX_HAS_GCC_LIB) |
| list(APPEND CMAKE_REQUIRED_LIBRARIES gcc) |
| elseif (LIBCXX_HAS_GCC_S_LIB) |
| list(APPEND CMAKE_REQUIRED_LIBRARIES gcc_s) |
| endif () |
| if (MINGW) |
| # Mingw64 requires quite a few "C" runtime libraries in order for basic |
| # programs to link successfully with -nodefaultlibs. |
| if (LIBCXX_USE_COMPILER_RT) |
| set(MINGW_RUNTIME ${LIBCXX_BUILTINS_LIBRARY}) |
| else () |
| set(MINGW_RUNTIME gcc_s gcc) |
| endif() |
| set(MINGW_LIBRARIES mingw32 ${MINGW_RUNTIME} moldname mingwex msvcrt advapi32 |
| shell32 user32 kernel32 mingw32 ${MINGW_RUNTIME} |
| moldname mingwex msvcrt) |
| list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES}) |
| endif() |
| if (CMAKE_C_FLAGS MATCHES -fsanitize OR CMAKE_CXX_FLAGS MATCHES -fsanitize) |
| set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize=all") |
| endif () |
| if (CMAKE_C_FLAGS MATCHES -fsanitize-coverage OR CMAKE_CXX_FLAGS MATCHES -fsanitize-coverage) |
| set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize-coverage=edge,trace-cmp,indirect-calls,8bit-counters") |
| endif () |
| endif () |
| |
| # Check compiler pragmas |
| if(CMAKE_CXX_COMPILER_ID MATCHES "Clang") |
| cmake_push_check_state() |
| set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=unknown-pragmas") |
| check_c_source_compiles(" |
| #pragma comment(lib, \"c\") |
| int main() { return 0; } |
| " LIBCXX_HAS_COMMENT_LIB_PRAGMA) |
| cmake_pop_check_state() |
| endif() |
| |
| # Check libraries |
| if(WIN32 AND NOT MINGW) |
| # TODO(compnerd) do we want to support an emulation layer that allows for the |
| # use of pthread-win32 or similar libraries to emulate pthreads on Windows? |
| set(LIBCXX_HAS_PTHREAD_LIB NO) |
| set(LIBCXX_HAS_M_LIB NO) |
| set(LIBCXX_HAS_RT_LIB NO) |
| set(LIBCXX_HAS_SYSTEM_LIB NO) |
| set(LIBCXX_HAS_ATOMIC_LIB NO) |
| elseif(APPLE) |
| check_library_exists(System write "" LIBCXX_HAS_SYSTEM_LIB) |
| set(LIBCXX_HAS_PTHREAD_LIB NO) |
| set(LIBCXX_HAS_M_LIB NO) |
| set(LIBCXX_HAS_RT_LIB NO) |
| set(LIBCXX_HAS_ATOMIC_LIB NO) |
| elseif(FUCHSIA) |
| set(LIBCXX_HAS_M_LIB NO) |
| set(LIBCXX_HAS_PTHREAD_LIB NO) |
| set(LIBCXX_HAS_RT_LIB NO) |
| set(LIBCXX_HAS_SYSTEM_LIB NO) |
| check_library_exists(atomic __atomic_fetch_add_8 "" LIBCXX_HAS_ATOMIC_LIB) |
| else() |
| check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB) |
| check_library_exists(m ccos "" LIBCXX_HAS_M_LIB) |
| check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB) |
| set(LIBCXX_HAS_SYSTEM_LIB NO) |
| check_library_exists(atomic __atomic_fetch_add_8 "" LIBCXX_HAS_ATOMIC_LIB) |
| endif() |