https://github.com/Kitware/CMake
Tip revision: c69d4b177fb3f6ebd22cddec919dbe1c30f43714 authored by Brad King on 11 March 2021, 14:23:18 UTC
CMake 3.20.0-rc4
CMake 3.20.0-rc4
Tip revision: c69d4b1
CheckLanguage.cmake
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
CheckLanguage
-------------
Check if a language can be enabled
Usage:
::
check_language(<lang>)
where ``<lang>`` is a language that may be passed to :command:`enable_language`
such as ``Fortran``. If :variable:`CMAKE_<LANG>_COMPILER` is already defined
the check does nothing. Otherwise it tries enabling the language in a
test project. The result is cached in :variable:`CMAKE_<LANG>_COMPILER`
as the compiler that was found, or ``NOTFOUND`` if the language cannot be
enabled. For CUDA which can have an explicit host compiler, the cache
:variable:`CMAKE_CUDA_HOST_COMPILER` variable will be set if it was required
for compilation (and cleared if it was not).
Example:
::
check_language(Fortran)
if(CMAKE_Fortran_COMPILER)
enable_language(Fortran)
else()
message(STATUS "No Fortran support")
endif()
#]=======================================================================]
include_guard(GLOBAL)
macro(check_language lang)
if(NOT DEFINED CMAKE_${lang}_COMPILER)
set(_desc "Looking for a ${lang} compiler")
message(CHECK_START "${_desc}")
file(REMOVE_RECURSE ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/Check${lang})
set(extra_compiler_variables)
if(${lang} STREQUAL CUDA)
set(extra_compiler_variables "set(CMAKE_CUDA_HOST_COMPILER \\\"\${CMAKE_CUDA_HOST_COMPILER}\\\")")
endif()
set(_cl_content
"cmake_minimum_required(VERSION ${CMAKE_VERSION})
project(Check${lang} ${lang})
file(WRITE \"\${CMAKE_CURRENT_BINARY_DIR}/result.cmake\"
\"set(CMAKE_${lang}_COMPILER \\\"\${CMAKE_${lang}_COMPILER}\\\")\\n\"
\"${extra_compiler_variables}\\n\"
)"
)
file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/Check${lang}/CMakeLists.txt"
"${_cl_content}")
if(CMAKE_GENERATOR_INSTANCE)
set(_D_CMAKE_GENERATOR_INSTANCE "-DCMAKE_GENERATOR_INSTANCE:INTERNAL=${CMAKE_GENERATOR_INSTANCE}")
else()
set(_D_CMAKE_GENERATOR_INSTANCE "")
endif()
if(CMAKE_GENERATOR MATCHES "^(Xcode$|Green Hills MULTI$|Visual Studio)")
set(_D_CMAKE_MAKE_PROGRAM "")
else()
set(_D_CMAKE_MAKE_PROGRAM "-DCMAKE_MAKE_PROGRAM:FILEPATH=${CMAKE_MAKE_PROGRAM}")
endif()
if(CMAKE_TOOLCHAIN_FILE)
set(_D_CMAKE_TOOLCHAIN_FILE "-DCMAKE_TOOLCHAIN_FILE:FILEPATH=${CMAKE_TOOLCHAIN_FILE}")
else()
set(_D_CMAKE_TOOLCHAIN_FILE "")
endif()
execute_process(
WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/Check${lang}
COMMAND ${CMAKE_COMMAND} . -G ${CMAKE_GENERATOR}
-A "${CMAKE_GENERATOR_PLATFORM}"
-T "${CMAKE_GENERATOR_TOOLSET}"
${_D_CMAKE_GENERATOR_INSTANCE}
${_D_CMAKE_MAKE_PROGRAM}
${_D_CMAKE_TOOLCHAIN_FILE}
OUTPUT_VARIABLE _cl_output
ERROR_VARIABLE _cl_output
RESULT_VARIABLE _cl_result
)
include(${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/Check${lang}/result.cmake OPTIONAL)
if(CMAKE_${lang}_COMPILER AND "${_cl_result}" STREQUAL "0")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"${_desc} passed with the following output:\n"
"${_cl_output}\n")
set(_CHECK_COMPILER_STATUS CHECK_PASS)
else()
set(CMAKE_${lang}_COMPILER NOTFOUND)
set(_CHECK_COMPILER_STATUS CHECK_FAIL)
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"${_desc} failed with the following output:\n"
"${_cl_output}\n")
endif()
message(${_CHECK_COMPILER_STATUS} "${CMAKE_${lang}_COMPILER}")
set(CMAKE_${lang}_COMPILER "${CMAKE_${lang}_COMPILER}" CACHE FILEPATH "${lang} compiler")
mark_as_advanced(CMAKE_${lang}_COMPILER)
if(CMAKE_${lang}_HOST_COMPILER)
message(STATUS "Looking for a ${lang} host compiler - ${CMAKE_${lang}_HOST_COMPILER}")
set(CMAKE_${lang}_HOST_COMPILER "${CMAKE_${lang}_HOST_COMPILER}" CACHE FILEPATH "${lang} host compiler")
mark_as_advanced(CMAKE_${lang}_HOST_COMPILER)
endif()
endif()
endmacro()