1include(CMakePushCheckState) 2include(CheckLibraryExists) 3include(CheckCCompilerFlag) 4include(CheckCXXCompilerFlag) 5include(CheckCSourceCompiles) 6 7check_library_exists(c fopen "" LIBCXXABI_HAS_C_LIB) 8if (NOT LIBCXXABI_USE_COMPILER_RT) 9 if (ANDROID) 10 check_library_exists(gcc __gcc_personality_v0 "" LIBCXXABI_HAS_GCC_LIB) 11 else () 12 check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXXABI_HAS_GCC_S_LIB) 13 check_library_exists(gcc __aeabi_uldivmod "" LIBCXXABI_HAS_GCC_LIB) 14 endif () 15endif () 16 17# libc++abi is using -nostdlib++ at the link step when available, 18# otherwise -nodefaultlibs is used. We want all our checks to also 19# use one of these options, otherwise we may end up with an inconsistency between 20# the flags we think we require during configuration (if the checks are 21# performed without -nodefaultlibs) and the flags that are actually 22# required during compilation (which has the -nodefaultlibs). libc is 23# required for the link to go through. We remove sanitizers from the 24# configuration checks to avoid spurious link errors. 25 26check_cxx_compiler_flag(-nostdlib++ CXX_SUPPORTS_NOSTDLIBXX_FLAG) 27if (CXX_SUPPORTS_NOSTDLIBXX_FLAG) 28 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++") 29else() 30 check_c_compiler_flag(-nodefaultlibs C_SUPPORTS_NODEFAULTLIBS_FLAG) 31 if (C_SUPPORTS_NODEFAULTLIBS_FLAG) 32 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs") 33 endif() 34endif() 35 36if (CXX_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG) 37 if (LIBCXXABI_HAS_C_LIB) 38 list(APPEND CMAKE_REQUIRED_LIBRARIES c) 39 endif () 40 if (LIBCXXABI_USE_COMPILER_RT) 41 include(HandleCompilerRT) 42 find_compiler_rt_library(builtins LIBCXXABI_BUILTINS_LIBRARY 43 FLAGS "${LIBCXXABI_COMPILE_FLAGS}") 44 if (LIBCXXABI_BUILTINS_LIBRARY) 45 list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBCXXABI_BUILTINS_LIBRARY}") 46 else() 47 message(WARNING "Could not find builtins library from libc++abi") 48 endif() 49 else () 50 if (LIBCXXABI_HAS_GCC_S_LIB) 51 list(APPEND CMAKE_REQUIRED_LIBRARIES gcc_s) 52 endif () 53 if (LIBCXXABI_HAS_GCC_LIB) 54 list(APPEND CMAKE_REQUIRED_LIBRARIES gcc) 55 endif () 56 endif () 57 if (MINGW) 58 # Mingw64 requires quite a few "C" runtime libraries in order for basic 59 # programs to link successfully with -nodefaultlibs. 60 if (LIBCXXABI_USE_COMPILER_RT) 61 set(MINGW_RUNTIME ${LIBCXXABI_BUILTINS_LIBRARY}) 62 else () 63 set(MINGW_RUNTIME gcc_s gcc) 64 endif() 65 set(MINGW_LIBRARIES mingw32 ${MINGW_RUNTIME} moldname mingwex msvcrt advapi32 66 shell32 user32 kernel32 mingw32 ${MINGW_RUNTIME} 67 moldname mingwex msvcrt) 68 list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES}) 69 endif() 70 if (CMAKE_C_FLAGS MATCHES -fsanitize OR CMAKE_CXX_FLAGS MATCHES -fsanitize) 71 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize=all") 72 endif () 73 if (CMAKE_C_FLAGS MATCHES -fsanitize-coverage OR CMAKE_CXX_FLAGS MATCHES -fsanitize-coverage) 74 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fsanitize-coverage=0") 75 endif () 76endif () 77 78# Check compiler pragmas 79if(CMAKE_CXX_COMPILER_ID MATCHES "Clang") 80 cmake_push_check_state() 81 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=unknown-pragmas") 82 check_c_source_compiles(" 83#pragma comment(lib, \"c\") 84int main(void) { return 0; } 85" C_SUPPORTS_COMMENT_LIB_PRAGMA) 86 cmake_pop_check_state() 87endif() 88 89# Check compiler flags 90check_cxx_compiler_flag(-nostdinc++ CXX_SUPPORTS_NOSTDINCXX_FLAG) 91 92# Check libraries 93if(FUCHSIA) 94 set(LIBCXXABI_HAS_DL_LIB NO) 95 set(LIBCXXABI_HAS_PTHREAD_LIB NO) 96 check_library_exists(c __cxa_thread_atexit_impl "" 97 LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL) 98 set(LIBCXXABI_HAS_SYSTEM_LIB NO) 99else() 100 check_library_exists(dl dladdr "" LIBCXXABI_HAS_DL_LIB) 101 check_library_exists(pthread pthread_once "" LIBCXXABI_HAS_PTHREAD_LIB) 102 check_library_exists(c __cxa_thread_atexit_impl "" 103 LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL) 104 check_library_exists(System write "" LIBCXXABI_HAS_SYSTEM_LIB) 105endif() 106