1include(CMakePushCheckState) 2include(CheckCCompilerFlag) 3include(CheckCXXCompilerFlag) 4include(CheckLibraryExists) 5include(LLVMCheckCompilerLinkerFlag) 6include(CheckSymbolExists) 7include(CheckCSourceCompiles) 8 9# The compiler driver may be implicitly trying to link against libunwind, which 10# might not work if libunwind doesn't exist yet. Try to check if 11# --unwindlib=none is supported, and use that if possible. 12llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG) 13 14check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB) 15 16if (NOT LIBUNWIND_USE_COMPILER_RT) 17 if (ANDROID) 18 check_library_exists(gcc __gcc_personality_v0 "" LIBUNWIND_HAS_GCC_LIB) 19 else () 20 check_library_exists(gcc_s __gcc_personality_v0 "" LIBUNWIND_HAS_GCC_S_LIB) 21 check_library_exists(gcc __absvdi2 "" LIBUNWIND_HAS_GCC_LIB) 22 endif () 23endif() 24 25# libunwind is using -nostdlib++ at the link step when available, 26# otherwise -nodefaultlibs is used. We want all our checks to also 27# use one of these options, otherwise we may end up with an inconsistency between 28# the flags we think we require during configuration (if the checks are 29# performed without one of those options) and the flags that are actually 30# required during compilation (which has the -nostdlib++ or -nodefaultlibs). libc is 31# required for the link to go through. We remove sanitizers from the 32# configuration checks to avoid spurious link errors. 33 34llvm_check_compiler_linker_flag(CXX "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG) 35if (CXX_SUPPORTS_NOSTDLIBXX_FLAG) 36 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++") 37else() 38 llvm_check_compiler_linker_flag(C "-nodefaultlibs" C_SUPPORTS_NODEFAULTLIBS_FLAG) 39 if (C_SUPPORTS_NODEFAULTLIBS_FLAG) 40 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs") 41 endif() 42endif() 43 44if (CXX_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG) 45 if (LIBUNWIND_HAS_C_LIB) 46 list(APPEND CMAKE_REQUIRED_LIBRARIES c) 47 endif () 48 if (LIBUNWIND_USE_COMPILER_RT) 49 include(HandleCompilerRT) 50 find_compiler_rt_library(builtins LIBUNWIND_BUILTINS_LIBRARY 51 FLAGS ${LIBUNWIND_COMPILE_FLAGS}) 52 list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBUNWIND_BUILTINS_LIBRARY}") 53 else () 54 if (LIBUNWIND_HAS_GCC_S_LIB) 55 list(APPEND CMAKE_REQUIRED_LIBRARIES gcc_s) 56 endif () 57 if (LIBUNWIND_HAS_GCC_LIB) 58 list(APPEND CMAKE_REQUIRED_LIBRARIES gcc) 59 endif () 60 endif () 61 if (MINGW) 62 # Mingw64 requires quite a few "C" runtime libraries in order for basic 63 # programs to link successfully with -nodefaultlibs. 64 if (LIBUNWIND_USE_COMPILER_RT) 65 set(MINGW_RUNTIME ${LIBUNWIND_BUILTINS_LIBRARY}) 66 else () 67 set(MINGW_RUNTIME gcc_s gcc) 68 endif() 69 set(MINGW_LIBRARIES mingw32 ${MINGW_RUNTIME} moldname mingwex msvcrt advapi32 70 shell32 user32 kernel32 mingw32 ${MINGW_RUNTIME} 71 moldname mingwex msvcrt) 72 list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES}) 73 endif() 74 if (CMAKE_C_FLAGS MATCHES -fsanitize OR CMAKE_CXX_FLAGS MATCHES -fsanitize) 75 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize=all") 76 endif () 77 if (CMAKE_C_FLAGS MATCHES -fsanitize-coverage OR CMAKE_CXX_FLAGS MATCHES -fsanitize-coverage) 78 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fsanitize-coverage=0") 79 endif () 80endif () 81 82# Check compiler pragmas 83if(CMAKE_CXX_COMPILER_ID MATCHES "Clang") 84 cmake_push_check_state() 85 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=unknown-pragmas") 86 check_c_source_compiles(" 87#pragma comment(lib, \"c\") 88int main(void) { return 0; } 89" C_SUPPORTS_COMMENT_LIB_PRAGMA) 90 cmake_pop_check_state() 91endif() 92 93# Check compiler flags 94check_cxx_compiler_flag(-nostdinc++ CXX_SUPPORTS_NOSTDINCXX_FLAG) 95 96# Check symbols 97check_symbol_exists(__arm__ "" LIBUNWIND_TARGET_ARM) 98check_symbol_exists(__USING_SJLJ_EXCEPTIONS__ "" LIBUNWIND_USES_SJLJ_EXCEPTIONS) 99check_symbol_exists(__ARM_DWARF_EH__ "" LIBUNWIND_USES_DWARF_EH) 100 101if(LIBUNWIND_TARGET_ARM AND NOT LIBUNWIND_USES_SJLJ_EXCEPTIONS AND NOT LIBUNWIND_USES_DWARF_EH) 102 # This condition is copied from __libunwind_config.h 103 set(LIBUNWIND_USES_ARM_EHABI ON) 104endif() 105 106# Check libraries 107if(FUCHSIA) 108 set(LIBUNWIND_HAS_DL_LIB NO) 109 set(LIBUNWIND_HAS_PTHREAD_LIB NO) 110else() 111 check_library_exists(dl dladdr "" LIBUNWIND_HAS_DL_LIB) 112 check_library_exists(pthread pthread_once "" LIBUNWIND_HAS_PTHREAD_LIB) 113endif() 114