CMake/Modules/CheckIncludeFile.cmake
Brad King 81d58b0de6 Help: Revise CheckIncludeFile* documentation
Improve formatting.  Link from each module to the other two.  Explain
the command signatures in more detail.
2015-06-25 09:41:02 -04:00

100 lines
3.6 KiB
CMake

#.rst:
# CheckIncludeFile
# ----------------
#
# Provides a macro to check if a header file can be included in ``C``.
#
# .. command:: CHECK_INCLUDE_FILE
#
# ::
#
# CHECK_INCLUDE_FILE(<include> <variable> [<flags>])
#
# Check if the given ``<include>`` file may be included in a ``C``
# 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``
# list of macros to define (-DFOO=bar)
# ``CMAKE_REQUIRED_INCLUDES``
# list of include directories
# ``CMAKE_REQUIRED_QUIET``
# execute quietly without messages
#
# See the :module:`CheckIncludeFiles` module to check for multiple headers
# at once. See the :module:`CheckIncludeFileCXX` module to check for headers
# using the ``CXX`` language.
#=============================================================================
# Copyright 2002-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
macro(CHECK_INCLUDE_FILE INCLUDE VARIABLE)
if(NOT DEFINED "${VARIABLE}")
if(CMAKE_REQUIRED_INCLUDES)
set(CHECK_INCLUDE_FILE_C_INCLUDE_DIRS "-DINCLUDE_DIRECTORIES=${CMAKE_REQUIRED_INCLUDES}")
else()
set(CHECK_INCLUDE_FILE_C_INCLUDE_DIRS)
endif()
set(MACRO_CHECK_INCLUDE_FILE_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(CHECK_INCLUDE_FILE_VAR ${INCLUDE})
configure_file(${CMAKE_ROOT}/Modules/CheckIncludeFile.c.in
${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckIncludeFile.c)
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${INCLUDE}")
endif()
if(${ARGC} EQUAL 3)
set(CMAKE_C_FLAGS_SAVE ${CMAKE_C_FLAGS})
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${ARGV2}")
endif()
try_compile(${VARIABLE}
${CMAKE_BINARY_DIR}
${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckIncludeFile.c
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
CMAKE_FLAGS
-DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_INCLUDE_FILE_FLAGS}
"${CHECK_INCLUDE_FILE_C_INCLUDE_DIRS}"
OUTPUT_VARIABLE OUTPUT)
if(${ARGC} EQUAL 3)
set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS_SAVE})
endif()
if(${VARIABLE})
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${INCLUDE} - found")
endif()
set(${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 ${INCLUDE} - not found")
endif()
set(${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()