CMake/Modules/CheckIncludeFileCXX.cmake
2018-12-01 17:56:23 +01:00

130 lines
4.9 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
CheckIncludeFileCXX
-------------------
Provides a macro to check if a header file can be included in ``CXX``.
.. command:: CHECK_INCLUDE_FILE_CXX
.. code-block:: cmake
CHECK_INCLUDE_FILE_CXX(<include> <variable> [<flags>])
Check if the given ``<include>`` file may be included in a ``CXX``
source file and store the result in an internal cache entry named
``<variable>``. The optional third argument may be used to add
compilation flags to the check (or use ``CMAKE_REQUIRED_FLAGS`` below).
The following variables may be set before calling this macro to modify
the way the check is run:
``CMAKE_REQUIRED_FLAGS``
string of compile command line flags.
``CMAKE_REQUIRED_DEFINITIONS``
a :ref:`;-list <CMake Language Lists>` of macros to define (-DFOO=bar).
``CMAKE_REQUIRED_INCLUDES``
a :ref:`;-list <CMake Language Lists>` of header search paths to pass to
the compiler.
``CMAKE_REQUIRED_LINK_OPTIONS``
a :ref:`;-list <CMake Language Lists>` of options to add to the link command.
``CMAKE_REQUIRED_LIBRARIES``
a :ref:`;-list <CMake Language Lists>` of libraries to add to the link
command. See policy :policy:`CMP0075`.
``CMAKE_REQUIRED_QUIET``
execute quietly without messages.
See modules :module:`CheckIncludeFile` and :module:`CheckIncludeFiles`
to check for one or more ``C`` headers.
#]=======================================================================]
include_guard(GLOBAL)
macro(CHECK_INCLUDE_FILE_CXX INCLUDE VARIABLE)
if(NOT DEFINED "${VARIABLE}" OR "x${${VARIABLE}}" STREQUAL "x${VARIABLE}")
if(CMAKE_REQUIRED_INCLUDES)
set(CHECK_INCLUDE_FILE_CXX_INCLUDE_DIRS "-DINCLUDE_DIRECTORIES=${CMAKE_REQUIRED_INCLUDES}")
else()
set(CHECK_INCLUDE_FILE_CXX_INCLUDE_DIRS)
endif()
set(MACRO_CHECK_INCLUDE_FILE_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(CHECK_INCLUDE_FILE_VAR ${INCLUDE})
configure_file(${CMAKE_ROOT}/Modules/CheckIncludeFile.cxx.in
${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckIncludeFile.cxx)
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for C++ include ${INCLUDE}")
endif()
if(${ARGC} EQUAL 3)
set(CMAKE_CXX_FLAGS_SAVE ${CMAKE_CXX_FLAGS})
string(APPEND CMAKE_CXX_FLAGS " ${ARGV2}")
endif()
set(_CIF_LINK_OPTIONS)
if(CMAKE_REQUIRED_LINK_OPTIONS)
set(_CIF_LINK_OPTIONS LINK_OPTIONS ${CMAKE_REQUIRED_LINK_OPTIONS})
endif()
set(_CIF_LINK_LIBRARIES "")
if(CMAKE_REQUIRED_LIBRARIES)
cmake_policy(GET CMP0075 _CIF_CMP0075
PARENT_SCOPE # undocumented, do not use outside of CMake
)
if("x${_CIF_CMP0075}x" STREQUAL "xNEWx")
set(_CIF_LINK_LIBRARIES LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
elseif("x${_CIF_CMP0075}x" STREQUAL "xOLDx")
elseif(NOT _CIF_CMP0075_WARNED)
set(_CIF_CMP0075_WARNED 1)
message(AUTHOR_WARNING
"Policy CMP0075 is not set: Include file check macros honor CMAKE_REQUIRED_LIBRARIES. "
"Run \"cmake --help-policy CMP0075\" for policy details. "
"Use the cmake_policy command to set the policy and suppress this warning."
"\n"
"CMAKE_REQUIRED_LIBRARIES is set to:\n"
" ${CMAKE_REQUIRED_LIBRARIES}\n"
"For compatibility with CMake 3.11 and below this check is ignoring it."
)
endif()
unset(_CIF_CMP0075)
endif()
try_compile(${VARIABLE}
${CMAKE_BINARY_DIR}
${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckIncludeFile.cxx
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
${_CIF_LINK_OPTIONS}
${_CIF_LINK_LIBRARIES}
CMAKE_FLAGS
-DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_INCLUDE_FILE_FLAGS}
"${CHECK_INCLUDE_FILE_CXX_INCLUDE_DIRS}"
OUTPUT_VARIABLE OUTPUT)
unset(_CIF_LINK_OPTIONS)
unset(_CIF_LINK_LIBRARIES)
if(${ARGC} EQUAL 3)
set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS_SAVE})
endif()
if(${VARIABLE})
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for C++ include ${INCLUDE} - found")
endif()
set(${VARIABLE} 1 CACHE INTERNAL "Have include ${INCLUDE}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"Determining if the include file ${INCLUDE} "
"exists passed with the following output:\n"
"${OUTPUT}\n\n")
else()
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for C++ include ${INCLUDE} - not found")
endif()
set(${VARIABLE} "" CACHE INTERNAL "Have include ${INCLUDE}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Determining if the include file ${INCLUDE} "
"exists failed with the following output:\n"
"${OUTPUT}\n\n")
endif()
endif()
endmacro()