ceph/cmake/modules/FindStdFilesystem.cmake
Kefu Chai e6c7e0f521 cmake: extract std::filesystem linkage checking into module
see
https://libcxx.llvm.org/docs/UsingLibcxx.html#using-libc-experimental-and-experimental,

> Note that as of libc++ 7.0 using the <experimental/filesystem>
> requires linking libc++fs instead of libc++experimental.

do not build ceph_test_admin_socket_output if we are not able to find
the library for std::experimental::filesystem . it is a workaround of
https://reviews.freebsd.org/D10840 where FreeBSD 11.2 does not ship
libc++experimental.a .

Signed-off-by: Kefu Chai <kchai@redhat.com>
2018-07-29 20:25:32 +08:00

38 lines
1.1 KiB
CMake

set(_std_filesystem_test_src
${CMAKE_CURRENT_LIST_DIR}/FindStdFilesystem_test.cc)
macro(try_std_filesystem_library _library _result)
try_compile(_std_filesystem_compiles
${CMAKE_CURRENT_BINARY_DIR}
SOURCES ${_std_filesystem_test_src}
CMAKE_FLAGS -DCMAKE_CXX_FLAGS="-std=c++17"
LINK_LIBRARIES ${_library})
if(_std_filesystem_compiles)
set(${_result} ${_library})
endif()
endmacro()
if(NOT StdFilesystem_LIBRARY)
try_std_filesystem_library("stdc++fs" StdFilesystem_LIBRARY)
endif()
if(NOT StdFilesystem_LIBRARY)
try_std_filesystem_library("c++experimental" StdFilesystem_LIBRARY)
endif()
if(NOT StdFilesystem_LIBRARY)
try_std_filesystem_library("c++fs" StdFilesystem_LIBRARY)
endif()
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(StdFilesystem
FOUND_VAR StdFilesystem_FOUND
REQUIRED_VARS StdFilesystem_LIBRARY)
mark_as_advanced(StdFilesystem_LIBRARY)
if(StdFilesystem_FOUND AND NOT (TARGET StdFilesystem::filesystem))
add_library(StdFilesystem::filesystem INTERFACE IMPORTED)
set_target_properties(StdFilesystem::filesystem PROPERTIES
INTERFACE_LINK_LIBRARIES ${StdFilesystem_LIBRARY})
endif()