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 14if (HAIKU) 15 check_library_exists(root fopen "" LIBUNWIND_HAS_ROOT_LIB) 16else() 17 check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB) 18endif() 19 20if (NOT LIBUNWIND_USE_COMPILER_RT) 21 if (ANDROID) 22 check_library_exists(gcc __gcc_personality_v0 "" LIBUNWIND_HAS_GCC_LIB) 23 else () 24 check_library_exists(gcc_s __gcc_personality_v0 "" LIBUNWIND_HAS_GCC_S_LIB) 25 check_library_exists(gcc __absvdi2 "" LIBUNWIND_HAS_GCC_LIB) 26 endif () 27endif() 28 29# libunwind is using -nostdlib++ at the link step when available, 30# otherwise -nodefaultlibs is used. We want all our checks to also 31# use one of these options, otherwise we may end up with an inconsistency between 32# the flags we think we require during configuration (if the checks are 33# performed without one of those options) and the flags that are actually 34# required during compilation (which has the -nostdlib++ or -nodefaultlibs). libc is 35# required for the link to go through. We remove sanitizers from the 36# configuration checks to avoid spurious link errors. 37 38llvm_check_compiler_linker_flag(CXX "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG) 39if (CXX_SUPPORTS_NOSTDLIBXX_FLAG) 40 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++") 41else() 42 llvm_check_compiler_linker_flag(C "-nodefaultlibs" C_SUPPORTS_NODEFAULTLIBS_FLAG) 43 if (C_SUPPORTS_NODEFAULTLIBS_FLAG) 44 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs") 45 endif() 46endif() 47 48# Only link against compiler-rt manually if we use -nodefaultlibs, since 49# otherwise the compiler will do the right thing on its own. 50if (NOT CXX_SUPPORTS_NOSTDLIBXX_FLAG AND C_SUPPORTS_NODEFAULTLIBS_FLAG) 51 if (LIBUNWIND_HAS_C_LIB) 52 list(APPEND CMAKE_REQUIRED_LIBRARIES c) 53 endif () 54 if (LIBUNWIND_HAS_ROOT_LIB) 55 list(APPEND CMAKE_REQUIRED_LIBRARIES root) 56 endif () 57 if (LIBUNWIND_USE_COMPILER_RT) 58 include(HandleCompilerRT) 59 find_compiler_rt_library(builtins LIBUNWIND_BUILTINS_LIBRARY 60 FLAGS ${LIBUNWIND_COMPILE_FLAGS}) 61 list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBUNWIND_BUILTINS_LIBRARY}") 62 else () 63 if (LIBUNWIND_HAS_GCC_S_LIB) 64 list(APPEND CMAKE_REQUIRED_LIBRARIES gcc_s) 65 endif () 66 if (LIBUNWIND_HAS_GCC_LIB) 67 list(APPEND CMAKE_REQUIRED_LIBRARIES gcc) 68 endif () 69 endif () 70 if (MINGW) 71 # Mingw64 requires quite a few "C" runtime libraries in order for basic 72 # programs to link successfully with -nodefaultlibs. 73 if (LIBUNWIND_USE_COMPILER_RT) 74 set(MINGW_RUNTIME ${LIBUNWIND_BUILTINS_LIBRARY}) 75 else () 76 set(MINGW_RUNTIME gcc_s gcc) 77 endif() 78 set(MINGW_LIBRARIES mingw32 ${MINGW_RUNTIME} moldname mingwex msvcrt advapi32 79 shell32 user32 kernel32 mingw32 ${MINGW_RUNTIME} 80 moldname mingwex msvcrt) 81 list(APPEND CMAKE_REQUIRED_LIBRARIES ${MINGW_LIBRARIES}) 82 endif() 83endif() 84 85if (CXX_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG) 86 if (CMAKE_C_FLAGS MATCHES -fsanitize OR CMAKE_CXX_FLAGS MATCHES -fsanitize) 87 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fno-sanitize=all") 88 endif () 89 if (CMAKE_C_FLAGS MATCHES -fsanitize-coverage OR CMAKE_CXX_FLAGS MATCHES -fsanitize-coverage) 90 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fsanitize-coverage=0") 91 endif () 92endif () 93 94# Check compiler pragmas 95if(CMAKE_CXX_COMPILER_ID MATCHES "Clang") 96 cmake_push_check_state() 97 set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=unknown-pragmas") 98 check_c_source_compiles(" 99#pragma comment(lib, \"c\") 100int main(void) { return 0; } 101" C_SUPPORTS_COMMENT_LIB_PRAGMA) 102 cmake_pop_check_state() 103endif() 104 105# Check compiler flags 106check_cxx_compiler_flag(-nostdinc++ CXX_SUPPORTS_NOSTDINCXX_FLAG) 107 108# Check symbols 109check_symbol_exists(__arm__ "" LIBUNWIND_TARGET_ARM) 110check_symbol_exists(__USING_SJLJ_EXCEPTIONS__ "" LIBUNWIND_USES_SJLJ_EXCEPTIONS) 111check_symbol_exists(__ARM_DWARF_EH__ "" LIBUNWIND_USES_DWARF_EH) 112 113if(LIBUNWIND_TARGET_ARM AND NOT LIBUNWIND_USES_SJLJ_EXCEPTIONS AND NOT LIBUNWIND_USES_DWARF_EH) 114 # This condition is copied from __libunwind_config.h 115 set(LIBUNWIND_USES_ARM_EHABI ON) 116endif() 117 118# Check libraries 119if(FUCHSIA) 120 set(LIBUNWIND_HAS_DL_LIB NO) 121 set(LIBUNWIND_HAS_PTHREAD_LIB NO) 122else() 123 check_library_exists(dl dladdr "" LIBUNWIND_HAS_DL_LIB) 124 check_library_exists(pthread pthread_once "" LIBUNWIND_HAS_PTHREAD_LIB) 125endif() 126 127if(HAIKU) 128 check_library_exists(bsd dl_iterate_phdr "" LIBUNWIND_HAS_BSD_LIB) 129endif() 130