CMake/Modules/CheckSymbolExists.cmake

71 lines
3.0 KiB
CMake

# - Check if the symbol exists in include files
# CHECK_SYMBOL_EXISTS(SYMBOL FILES VARIABLE)
#
# SYMBOL - symbol
# FILES - include files to check
# VARIABLE - variable to return result
#
# 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_LIBRARIES = list of libraries to link
MACRO(CHECK_SYMBOL_EXISTS SYMBOL FILES VARIABLE)
IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
SET(CHECK_SYMBOL_EXISTS_CONTENT "/* */\n")
SET(MACRO_CHECK_SYMBOL_EXISTS_FLAGS ${CMAKE_REQUIRED_FLAGS})
IF(CMAKE_REQUIRED_LIBRARIES)
SET(CHECK_SYMBOL_EXISTS_LIBS
"-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
ELSE(CMAKE_REQUIRED_LIBRARIES)
SET(CHECK_SYMBOL_EXISTS_LIBS)
ENDIF(CMAKE_REQUIRED_LIBRARIES)
IF(CMAKE_REQUIRED_INCLUDES)
SET(CMAKE_SYMBOL_EXISTS_INCLUDES
"-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
ELSE(CMAKE_REQUIRED_INCLUDES)
SET(CMAKE_SYMBOL_EXISTS_INCLUDES)
ENDIF(CMAKE_REQUIRED_INCLUDES)
FOREACH(FILE ${FILES})
SET(CHECK_SYMBOL_EXISTS_CONTENT
"${CHECK_SYMBOL_EXISTS_CONTENT}#include <${FILE}>\n")
ENDFOREACH(FILE)
SET(CHECK_SYMBOL_EXISTS_CONTENT
"${CHECK_SYMBOL_EXISTS_CONTENT}\nvoid cmakeRequireSymbol(int dummy,...){(void)dummy;}\nint main()\n{\n#ifndef ${SYMBOL}\n cmakeRequireSymbol(0,&${SYMBOL});\n#endif\n return 0;\n}\n")
FILE(WRITE ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeTmp/CheckSymbolExists.c
"${CHECK_SYMBOL_EXISTS_CONTENT}")
MESSAGE(STATUS "Looking for ${SYMBOL}")
TRY_COMPILE(${VARIABLE}
${CMAKE_BINARY_DIR}
${CMAKE_BINARY_DIR}/CMakeFiles/CMakeTmp/CheckSymbolExists.c
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
CMAKE_FLAGS
-DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_SYMBOL_EXISTS_FLAGS}
"${CHECK_SYMBOL_EXISTS_LIBS}"
"${CMAKE_SYMBOL_EXISTS_INCLUDES}"
OUTPUT_VARIABLE OUTPUT)
IF(${VARIABLE})
MESSAGE(STATUS "Looking for ${SYMBOL} - found")
SET(${VARIABLE} 1 CACHE INTERNAL "Have symbol ${SYMBOL}")
FILE(APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeOutput.log
"Determining if the ${SYMBOL} "
"exist passed with the following output:\n"
"${OUTPUT}\nFile ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeTmp/CheckSymbolExists.c:\n"
"${CHECK_SYMBOL_EXISTS_CONTENT}\n")
ELSE(${VARIABLE})
MESSAGE(STATUS "Looking for ${SYMBOL} - not found.")
SET(${VARIABLE} "" CACHE INTERNAL "Have symbol ${SYMBOL}")
FILE(APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeError.log
"Determining if the ${SYMBOL} "
"exist failed with the following output:\n"
"${OUTPUT}\nFile ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeTmp/CheckSymbolExists.c:\n"
"${CHECK_SYMBOL_EXISTS_CONTENT}\n")
ENDIF(${VARIABLE})
ENDIF("${VARIABLE}" MATCHES "^${VARIABLE}$")
ENDMACRO(CHECK_SYMBOL_EXISTS)