| # Distributed under the OSI-approved BSD 3-Clause License. See accompanying |
| # file Copyright.txt or https://cmake.org/licensing for details. |
| |
| #.rst: |
| # CheckSymbolExists |
| # ----------------- |
| # |
| # Check if a symbol exists as a function, variable, or macro |
| # |
| # CHECK_SYMBOL_EXISTS(<symbol> <files> <variable>) |
| # |
| # Check that the <symbol> is available after including given header |
| # <files> and store the result in a <variable>. Specify the list of |
| # files in one argument as a semicolon-separated list. |
| # <variable> will be created as an internal cache variable. |
| # |
| # If the header files define the symbol as a macro it is considered |
| # available and assumed to work. If the header files declare the symbol |
| # as a function or variable then the symbol must also be available for |
| # linking. If the symbol is a type or enum value it will not be |
| # recognized (consider using CheckTypeSize or CheckCSourceCompiles). If |
| # the check needs to be done in C++, consider using |
| # CHECK_CXX_SYMBOL_EXISTS(), which does the same as |
| # CHECK_SYMBOL_EXISTS(), but in C++. |
| # |
| # 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 |
| # CMAKE_REQUIRED_QUIET = execute quietly without messages |
| |
| macro(CHECK_SYMBOL_EXISTS SYMBOL FILES VARIABLE) |
| if(CMAKE_C_COMPILER_LOADED) |
| _CHECK_SYMBOL_EXISTS("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.c" "${SYMBOL}" "${FILES}" "${VARIABLE}" ) |
| elseif(CMAKE_CXX_COMPILER_LOADED) |
| _CHECK_SYMBOL_EXISTS("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.cxx" "${SYMBOL}" "${FILES}" "${VARIABLE}" ) |
| else() |
| message(FATAL_ERROR "CHECK_SYMBOL_EXISTS needs either C or CXX language enabled") |
| endif() |
| endmacro() |
| |
| macro(_CHECK_SYMBOL_EXISTS SOURCEFILE SYMBOL FILES VARIABLE) |
| if(NOT DEFINED "${VARIABLE}" OR "x${${VARIABLE}}" STREQUAL "x${VARIABLE}") |
| set(CMAKE_CONFIGURABLE_FILE_CONTENT "/* */\n") |
| set(MACRO_CHECK_SYMBOL_EXISTS_FLAGS ${CMAKE_REQUIRED_FLAGS}) |
| if(CMAKE_REQUIRED_LIBRARIES) |
| set(CHECK_SYMBOL_EXISTS_LIBS |
| LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES}) |
| else() |
| set(CHECK_SYMBOL_EXISTS_LIBS) |
| endif() |
| if(CMAKE_REQUIRED_INCLUDES) |
| set(CMAKE_SYMBOL_EXISTS_INCLUDES |
| "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}") |
| else() |
| set(CMAKE_SYMBOL_EXISTS_INCLUDES) |
| endif() |
| foreach(FILE ${FILES}) |
| string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT |
| "#include <${FILE}>\n") |
| endforeach() |
| string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT |
| "\nint main(int argc, char** argv)\n{\n (void)argv;\n#ifndef ${SYMBOL}\n return ((int*)(&${SYMBOL}))[argc];\n#else\n (void)argc;\n return 0;\n#endif\n}\n") |
| |
| configure_file("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in" |
| "${SOURCEFILE}" @ONLY) |
| |
| if(NOT CMAKE_REQUIRED_QUIET) |
| message(STATUS "Looking for ${SYMBOL}") |
| endif() |
| try_compile(${VARIABLE} |
| ${CMAKE_BINARY_DIR} |
| "${SOURCEFILE}" |
| COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} |
| ${CHECK_SYMBOL_EXISTS_LIBS} |
| CMAKE_FLAGS |
| -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_SYMBOL_EXISTS_FLAGS} |
| "${CMAKE_SYMBOL_EXISTS_INCLUDES}" |
| OUTPUT_VARIABLE OUTPUT) |
| if(${VARIABLE}) |
| if(NOT CMAKE_REQUIRED_QUIET) |
| message(STATUS "Looking for ${SYMBOL} - found") |
| endif() |
| set(${VARIABLE} 1 CACHE INTERNAL "Have symbol ${SYMBOL}") |
| file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log |
| "Determining if the ${SYMBOL} " |
| "exist passed with the following output:\n" |
| "${OUTPUT}\nFile ${SOURCEFILE}:\n" |
| "${CMAKE_CONFIGURABLE_FILE_CONTENT}\n") |
| else() |
| if(NOT CMAKE_REQUIRED_QUIET) |
| message(STATUS "Looking for ${SYMBOL} - not found") |
| endif() |
| set(${VARIABLE} "" CACHE INTERNAL "Have symbol ${SYMBOL}") |
| file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log |
| "Determining if the ${SYMBOL} " |
| "exist failed with the following output:\n" |
| "${OUTPUT}\nFile ${SOURCEFILE}:\n" |
| "${CMAKE_CONFIGURABLE_FILE_CONTENT}\n") |
| endif() |
| endif() |
| endmacro() |