llvm-project/libcxx/cmake/config-ix.cmake

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

133 lines
5.1 KiB
CMake
Raw Normal View History

include(CMakePushCheckState)
include(CheckLibraryExists)
include(CheckLinkerFlag)
include(CheckCCompilerFlag)
include(CheckCXXCompilerFlag)
include(CheckCSourceCompiles)
# The compiler driver may be implicitly trying to link against libunwind.
# This is normally ok (libcxx relies on an unwinder), but if libunwind is
# built in the same cmake invocation as libcxx and we've got
# LIBCXXABI_USE_LLVM_UNWINDER set, we'd be linking against the just-built
# libunwind (and the compiler implicit -lunwind wouldn't succeed as the newly
# built libunwind isn't installed yet). For those cases, it'd be good to
# link with --uwnindlib=none. Check if that option works.
llvm_check_linker_flag("--unwindlib=none" LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
if (LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} --unwindlib=none")
endif()
if(WIN32 AND NOT MINGW)
# NOTE(compnerd) this is technically a lie, there is msvcrt, but for now, lets
# let the default linking take care of that.
set(LIBCXX_HAS_C_LIB NO)
else()
check_library_exists(c fopen "" LIBCXX_HAS_C_LIB)
endif()
if (NOT LIBCXX_USE_COMPILER_RT)
if(WIN32 AND NOT MINGW)
set(LIBCXX_HAS_GCC_S_LIB NO)
else()
if(ANDROID)
check_library_exists(gcc __gcc_personality_v0 "" LIBCXX_HAS_GCC_LIB)
else()
check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXX_HAS_GCC_S_LIB)
endif()
endif()
endif()
# libc++ is using -nostdlib++ at the link step when available,
# otherwise -nodefaultlibs is used. We want all our checks to also
# use one of these options, otherwise we may end up with an inconsistency between
# the flags we think we require during configuration (if the checks are
# performed without one of those options) and the flags that are actually
# required during compilation (which has the -nostdlib++ or -nodefaultlibs). libc is
# required for the link to go through. We remove sanitizers from the
# configuration checks to avoid spurious link errors.
check_c_compiler_flag(-nostdlib++ LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG)
if (LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG)
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
else()
check_c_compiler_flag(-nodefaultlibs LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG)
if (LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG)
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs")
endif()
endif()
if (LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG OR LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG)
if (LIBCXX_HAS_C_LIB)
list(APPEND CMAKE_REQUIRED_LIBRARIES c)
endif ()
if (LIBCXX_USE_COMPILER_RT)
include(HandleCompilerRT)
find_compiler_rt_library(builtins LIBCXX_BUILTINS_LIBRARY
FLAGS ${LIBCXX_COMPILE_FLAGS})
list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBCXX_BUILTINS_LIBRARY}")
elseif (LIBCXX_HAS_GCC_LIB)
list(APPEND CMAKE_REQUIRED_LIBRARIES gcc)
elseif (LIBCXX_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 (LIBCXX_USE_COMPILER_RT)
set(MINGW_RUNTIME ${LIBCXX_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)
[libc++] Disable coverage with sanitize-coverage=0 When building libcxx, libcxxabi, and libunwind the build environment may specify any number of sanitizers. For some build feature tests these sanitizers must be disabled to prevent spurious linking errors. With -fsanitize= this is straight forward with -fno-sanitize=all. With -fsanitize-coverage= there is no -fno-sanitize-coverage=all, but there is the equivalent undocumented but tested -fsanitize-coverage=0. The current build rules fail to disable 'trace-pc-guard'. By disabling all sanitize-coverage flags, including 'trace-pc-guard', possible spurious linker errors are prevented. In particular, this allows libcxx, libcxxabi, and libunwind to be built with HonggFuzz. CMAKE_REQUIRED_FLAGS is extra compile flags when running CMake build configuration steps (like check_cxx_compiler_flag). It does not affect the compile flags for the actual build of the project (unless of course these flags change whether or not a given source compiles and links or not). So libcxx, libcxxabi, and libunwind will still be built with any specified sanitize-coverage as before. The build configuration steps (which are mostly checking to see if certain compiler flags are available) will not try to compile and link "int main() { return 0;}" (or other specified source) with sanitize-coverage (which can fail to link at this stage in building, since the final compile flags required are yet to be determined). The change to LIBFUZZER_CFLAGS was done to keep it consistent with the obvious intention of disabling all sanitize-coverage. This appears to be intentional, preventing the fuzzer driver itself from showing up in any coverage calculations. Reviewed By: #libunwind, #libc, #libc_abi, ldionne, phosek Differential Revision: https://reviews.llvm.org/D116050
2022-01-08 09:34:05 +08:00
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -fsanitize-coverage=0")
endif ()
endif ()
# Check compiler pragmas
if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
cmake_push_check_state()
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=unknown-pragmas")
check_c_source_compiles("
#pragma comment(lib, \"c\")
int main() { return 0; }
" LIBCXX_HAS_COMMENT_LIB_PRAGMA)
cmake_pop_check_state()
endif()
# Check libraries
if(WIN32 AND NOT MINGW)
# TODO(compnerd) do we want to support an emulation layer that allows for the
# use of pthread-win32 or similar libraries to emulate pthreads on Windows?
set(LIBCXX_HAS_PTHREAD_LIB NO)
set(LIBCXX_HAS_M_LIB NO)
set(LIBCXX_HAS_RT_LIB NO)
set(LIBCXX_HAS_SYSTEM_LIB NO)
set(LIBCXX_HAS_ATOMIC_LIB NO)
elseif(APPLE)
check_library_exists(System write "" LIBCXX_HAS_SYSTEM_LIB)
set(LIBCXX_HAS_PTHREAD_LIB NO)
set(LIBCXX_HAS_M_LIB NO)
set(LIBCXX_HAS_RT_LIB NO)
set(LIBCXX_HAS_ATOMIC_LIB NO)
elseif(FUCHSIA)
set(LIBCXX_HAS_M_LIB NO)
set(LIBCXX_HAS_PTHREAD_LIB NO)
set(LIBCXX_HAS_RT_LIB NO)
set(LIBCXX_HAS_SYSTEM_LIB NO)
check_library_exists(atomic __atomic_fetch_add_8 "" LIBCXX_HAS_ATOMIC_LIB)
else()
check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)
check_library_exists(m ccos "" LIBCXX_HAS_M_LIB)
check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB)
set(LIBCXX_HAS_SYSTEM_LIB NO)
check_library_exists(atomic __atomic_fetch_add_8 "" LIBCXX_HAS_ATOMIC_LIB)
endif()