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

169 lines
6.4 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
CheckIncludeFiles
-----------------
Provides a macro to check if a list of one or more header files can
be included together.
.. command:: CHECK_INCLUDE_FILES
.. code-block:: cmake
CHECK_INCLUDE_FILES("<includes>" <variable> [LANGUAGE <language>])
Check if the given ``<includes>`` list may be included together
in a source file and store the result in an internal cache
entry named ``<variable>``. Specify the ``<includes>`` argument
as a :ref:`;-list <CMake Language Lists>` of header file names.
If ``LANGUAGE`` is set, the specified compiler will be used to perform the
check. Acceptable values are ``C`` and ``CXX``. If not set, the C compiler
will be used if enabled. If the C compiler is not enabled, the C++
compiler will be used if enabled.
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:`CheckIncludeFileCXX`
to check for a single header file in ``C`` or ``CXX`` languages.
#]=======================================================================]
include_guard(GLOBAL)
macro(CHECK_INCLUDE_FILES INCLUDE VARIABLE)
if(NOT DEFINED "${VARIABLE}")
set(CMAKE_CONFIGURABLE_FILE_CONTENT "/* */\n")
if("x${ARGN}" STREQUAL "x")
if(CMAKE_C_COMPILER_LOADED)
set(_lang C)
elseif(CMAKE_CXX_COMPILER_LOADED)
set(_lang CXX)
else()
message(FATAL_ERROR "CHECK_INCLUDE_FILES needs either C or CXX language enabled.\n")
endif()
elseif("x${ARGN}" MATCHES "^xLANGUAGE;([a-zA-Z]+)$")
set(_lang "${CMAKE_MATCH_1}")
elseif("x${ARGN}" MATCHES "^xLANGUAGE$")
message(FATAL_ERROR "No languages listed for LANGUAGE option.\nSupported languages: C, CXX.\n")
else()
message(FATAL_ERROR "Unknown arguments:\n ${ARGN}\n")
endif()
if(_lang STREQUAL "C")
set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckIncludeFiles/${VARIABLE}.c)
elseif(_lang STREQUAL "CXX")
set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckIncludeFiles/${VARIABLE}.cpp)
else()
message(FATAL_ERROR "Unknown language:\n ${_lang}\nSupported languages: C, CXX.\n")
endif()
if(CMAKE_REQUIRED_INCLUDES)
set(CHECK_INCLUDE_FILES_INCLUDE_DIRS "-DINCLUDE_DIRECTORIES=${CMAKE_REQUIRED_INCLUDES}")
else()
set(CHECK_INCLUDE_FILES_INCLUDE_DIRS)
endif()
set(CHECK_INCLUDE_FILES_CONTENT "/* */\n")
set(MACRO_CHECK_INCLUDE_FILES_FLAGS ${CMAKE_REQUIRED_FLAGS})
foreach(FILE ${INCLUDE})
string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT
"#include <${FILE}>\n")
endforeach()
string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT
"\n\nint main(void){return 0;}\n")
configure_file("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in"
"${src}" @ONLY)
set(_INCLUDE ${INCLUDE}) # remove empty elements
if("${_INCLUDE}" MATCHES "^([^;]+);.+;([^;]+)$")
list(LENGTH _INCLUDE _INCLUDE_LEN)
set(_description "${_INCLUDE_LEN} include files ${CMAKE_MATCH_1}, ..., ${CMAKE_MATCH_2}")
elseif("${_INCLUDE}" MATCHES "^([^;]+);([^;]+)$")
set(_description "include files ${CMAKE_MATCH_1}, ${CMAKE_MATCH_2}")
else()
set(_description "include file ${_INCLUDE}")
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()
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${_description}")
endif()
try_compile(${VARIABLE}
${CMAKE_BINARY_DIR}
${src}
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
${_CIF_LINK_OPTIONS}
${_CIF_LINK_LIBRARIES}
CMAKE_FLAGS
-DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_INCLUDE_FILES_FLAGS}
"${CHECK_INCLUDE_FILES_INCLUDE_DIRS}"
OUTPUT_VARIABLE OUTPUT)
unset(_CIF_LINK_OPTIONS)
unset(_CIF_LINK_LIBRARIES)
if(${VARIABLE})
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${_description} - found")
endif()
set(${VARIABLE} 1 CACHE INTERNAL "Have include ${INCLUDE}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"Determining if files ${INCLUDE} "
"exist passed with the following output:\n"
"${OUTPUT}\n\n")
else()
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${_description} - not found")
endif()
set(${VARIABLE} "" CACHE INTERNAL "Have includes ${INCLUDE}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Determining if files ${INCLUDE} "
"exist failed with the following output:\n"
"${OUTPUT}\nSource:\n${CMAKE_CONFIGURABLE_FILE_CONTENT}\n")
endif()
endif()
endmacro()