|  | 
 | include(CheckCCompilerFlag) | 
 | include(CheckCXXCompilerFlag) | 
 | include(CheckLibraryExists) | 
 |  | 
 | check_library_exists(c fopen "" LIBUNWIND_HAS_C_LIB) | 
 |  | 
 | if (NOT LIBUNWIND_USE_COMPILER_RT) | 
 |   check_library_exists(gcc_s __gcc_personality_v0 "" LIBUNWIND_HAS_GCC_S_LIB) | 
 | endif() | 
 |  | 
 | # libunwind is built with -nodefaultlibs, so we want all our checks to also | 
 | # use this option, otherwise we may end up with an inconsistency between | 
 | # the flags we think we require during configuration (if the checks are | 
 | # performed without -nodefaultlibs) and the flags that are actually | 
 | # required during compilation (which has the -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(-nodefaultlibs LIBUNWIND_HAS_NODEFAULTLIBS_FLAG) | 
 | if (LIBUNWIND_HAS_NODEFAULTLIBS_FLAG) | 
 |   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs") | 
 |   if (LIBUNWIND_HAS_C_LIB) | 
 |     list(APPEND CMAKE_REQUIRED_LIBRARIES c) | 
 |   endif () | 
 |   if (LIBUNWIND_USE_COMPILER_RT) | 
 |     list(APPEND CMAKE_REQUIRED_FLAGS -rtlib=compiler-rt) | 
 |     find_compiler_rt_library(builtins LIBUNWIND_BUILTINS_LIBRARY) | 
 |     list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBUNWIND_BUILTINS_LIBRARY}") | 
 |   elseif (LIBUNWIND_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 (LIBUNWIND_USE_COMPILER_RT) | 
 |       set(MINGW_RUNTIME ${LIBUNWIND_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 flags | 
 | check_c_compiler_flag(-funwind-tables         LIBUNWIND_HAS_FUNWIND_TABLES) | 
 | check_cxx_compiler_flag(-fno-exceptions       LIBUNWIND_HAS_NO_EXCEPTIONS_FLAG) | 
 | check_cxx_compiler_flag(-fno-rtti             LIBUNWIND_HAS_NO_RTTI_FLAG) | 
 | check_cxx_compiler_flag(-fstrict-aliasing     LIBUNWIND_HAS_FSTRICT_ALIASING_FLAG) | 
 | check_cxx_compiler_flag(-nostdinc++           LIBUNWIND_HAS_NOSTDINCXX_FLAG) | 
 | check_cxx_compiler_flag(-Wall                 LIBUNWIND_HAS_WALL_FLAG) | 
 | check_cxx_compiler_flag(-W                    LIBUNWIND_HAS_W_FLAG) | 
 | check_cxx_compiler_flag(-Wno-unused-function  LIBUNWIND_HAS_WNO_UNUSED_FUNCTION_FLAG) | 
 | check_cxx_compiler_flag(-Wunused-variable     LIBUNWIND_HAS_WUNUSED_VARIABLE_FLAG) | 
 | check_cxx_compiler_flag(-Wunused-parameter    LIBUNWIND_HAS_WUNUSED_PARAMETER_FLAG) | 
 | check_cxx_compiler_flag(-Wstrict-aliasing     LIBUNWIND_HAS_WSTRICT_ALIASING_FLAG) | 
 | check_cxx_compiler_flag(-Wstrict-overflow     LIBUNWIND_HAS_WSTRICT_OVERFLOW_FLAG) | 
 | check_cxx_compiler_flag(-Wwrite-strings       LIBUNWIND_HAS_WWRITE_STRINGS_FLAG) | 
 | check_cxx_compiler_flag(-Wchar-subscripts     LIBUNWIND_HAS_WCHAR_SUBSCRIPTS_FLAG) | 
 | check_cxx_compiler_flag(-Wmismatched-tags     LIBUNWIND_HAS_WMISMATCHED_TAGS_FLAG) | 
 | check_cxx_compiler_flag(-Wmissing-braces      LIBUNWIND_HAS_WMISSING_BRACES_FLAG) | 
 | check_cxx_compiler_flag(-Wshorten-64-to-32    LIBUNWIND_HAS_WSHORTEN_64_TO_32_FLAG) | 
 | check_cxx_compiler_flag(-Wsign-conversion     LIBUNWIND_HAS_WSIGN_CONVERSION_FLAG) | 
 | check_cxx_compiler_flag(-Wsign-compare        LIBUNWIND_HAS_WSIGN_COMPARE_FLAG) | 
 | check_cxx_compiler_flag(-Wshadow              LIBUNWIND_HAS_WSHADOW_FLAG) | 
 | check_cxx_compiler_flag(-Wconversion          LIBUNWIND_HAS_WCONVERSION_FLAG) | 
 | check_cxx_compiler_flag(-Wnewline-eof         LIBUNWIND_HAS_WNEWLINE_EOF_FLAG) | 
 | check_cxx_compiler_flag(-Wundef               LIBUNWIND_HAS_WUNDEF_FLAG) | 
 | check_cxx_compiler_flag(-pedantic             LIBUNWIND_HAS_PEDANTIC_FLAG) | 
 | check_cxx_compiler_flag(-Werror               LIBUNWIND_HAS_WERROR_FLAG) | 
 | check_cxx_compiler_flag(-Wno-error            LIBUNWIND_HAS_WNO_ERROR_FLAG) | 
 | check_cxx_compiler_flag(/WX                   LIBUNWIND_HAS_WX_FLAG) | 
 | check_cxx_compiler_flag(/WX-                  LIBUNWIND_HAS_NO_WX_FLAG) | 
 | check_cxx_compiler_flag(/EHsc                 LIBUNWIND_HAS_EHSC_FLAG) | 
 | check_cxx_compiler_flag(/EHs-                 LIBUNWIND_HAS_NO_EHS_FLAG) | 
 | check_cxx_compiler_flag(/EHa-                 LIBUNWIND_HAS_NO_EHA_FLAG) | 
 | check_cxx_compiler_flag(/GR-                  LIBUNWIND_HAS_NO_GR_FLAG) | 
 | check_cxx_compiler_flag(-std=c++11            LIBUNWIND_HAS_STD_CXX11) | 
 |  | 
 | if(LIBUNWIND_HAS_STD_CXX11) | 
 |   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11") | 
 | endif() | 
 |  | 
 | check_library_exists(dl dladdr "" LIBUNWIND_HAS_DL_LIB) | 
 | check_library_exists(pthread pthread_once "" LIBUNWIND_HAS_PTHREAD_LIB) | 
 |  |