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