CMake/Source/Checks/cm_cxx14_cstdio.cmake
Brad King 3307e10fc4 Avoid using C++14 to build CMake if cstdio breaks
The GNU 4.8 standard library's cstdio header is not aware that C++14
honors C11's removal of "gets" from stdio.h and results in an error:

  /.../include/c++/4.8/cstdio:120:11: error: no member named 'gets' in the global namespace

Detect this problematic case and default to using C++11 instead of
C++14 for building CMake itself.
2015-05-08 11:04:21 -04:00

34 lines
1.3 KiB
CMake

set(CMake_CXX14_CSTDIO_BROKEN 0)
if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang" AND CMAKE_CXX14_STANDARD_COMPILE_OPTION)
if(NOT DEFINED CMake_CXX14_CSTDIO_WORKS)
message(STATUS "Checking if compiler supports C++14 cstdio")
try_compile(CMake_CXX14_CSTDIO_WORKS
${CMAKE_CURRENT_BINARY_DIR}
${CMAKE_CURRENT_LIST_DIR}/cm_cxx14_cstdio.cpp
CMAKE_FLAGS -DCMAKE_CXX_STANDARD=14
OUTPUT_VARIABLE OUTPUT
)
if(CMake_CXX14_CSTDIO_WORKS AND "${OUTPUT}" MATCHES "error: no member named.*gets.*in the global namespace")
set_property(CACHE CMake_CXX14_CSTDIO_WORKS PROPERTY VALUE 0)
endif()
if(CMake_CXX14_CSTDIO_WORKS)
message(STATUS "Checking if compiler supports C++14 cstdio - yes")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"Determining if compiler supports C++14 cstdio passed with the following output:\n"
"${OUTPUT}\n"
"\n"
)
else()
message(STATUS "Checking if compiler supports C++14 cstdio - no")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Determining if compiler supports C++14 cstdio failed with the following output:\n"
"${OUTPUT}\n"
"\n"
)
endif()
endif()
if(NOT CMake_CXX14_CSTDIO_WORKS)
set(CMake_CXX14_CSTDIO_BROKEN 1)
endif()
endif()