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Diffstat (limited to 'share/cmake-3.22/Modules/CheckSymbolExists.cmake')
| -rw-r--r-- | share/cmake-3.22/Modules/CheckSymbolExists.cmake | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/share/cmake-3.22/Modules/CheckSymbolExists.cmake b/share/cmake-3.22/Modules/CheckSymbolExists.cmake new file mode 100644 index 0000000..48ee3c4 --- /dev/null +++ b/share/cmake-3.22/Modules/CheckSymbolExists.cmake @@ -0,0 +1,168 @@ +# Distributed under the OSI-approved BSD 3-Clause License. See accompanying +# file Copyright.txt or https://cmake.org/licensing for details. + +#[=======================================================================[.rst: +CheckSymbolExists +----------------- + +Provides a macro to check if a symbol exists as a function, variable, +or macro in ``C``. + +.. command:: check_symbol_exists + + .. code-block:: cmake + + 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 (so intrinsics may not be detected). +If the symbol is a type, enum value, or intrinsic it will not be recognized +(consider using :module:`CheckTypeSize` or :module:`CheckSourceCompiles`). +If the check needs to be done in C++, consider using +:module:`CheckCXXSymbolExists` instead. + +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`` + .. versionadded:: 3.14 + 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`` + .. versionadded:: 3.1 + execute quietly without messages. + +For example: + +.. code-block:: cmake + + include(CheckSymbolExists) + + # Check for macro SEEK_SET + check_symbol_exists(SEEK_SET "stdio.h" HAVE_SEEK_SET) + # Check for function fopen + check_symbol_exists(fopen "stdio.h" HAVE_FOPEN) +#]=======================================================================] + +include_guard(GLOBAL) + +cmake_policy(PUSH) +cmake_policy(SET CMP0054 NEW) # if() quoted variables not dereferenced + +macro(CHECK_SYMBOL_EXISTS SYMBOL FILES VARIABLE) + if(CMAKE_C_COMPILER_LOADED) + __CHECK_SYMBOL_EXISTS_IMPL("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.c" "${SYMBOL}" "${FILES}" "${VARIABLE}" ) + elseif(CMAKE_CXX_COMPILER_LOADED) + __CHECK_SYMBOL_EXISTS_IMPL("${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_IMPL 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_LINK_OPTIONS) + set(CHECK_SYMBOL_EXISTS_LINK_OPTIONS + LINK_OPTIONS ${CMAKE_REQUIRED_LINK_OPTIONS}) + else() + set(CHECK_SYMBOL_EXISTS_LINK_OPTIONS) + endif() + 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 " +int main(int argc, char** argv) +{ + (void)argv;") + set(_CSE_CHECK_NON_MACRO "return ((int*)(&${SYMBOL}))[argc];") + if("${SYMBOL}" MATCHES "^[a-zA-Z_][a-zA-Z0-9_]*$") + # The SYMBOL has a legal macro name. Test whether it exists as a macro. + string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT " +#ifndef ${SYMBOL} + ${_CSE_CHECK_NON_MACRO} +#else + (void)argc; + return 0; +#endif") + else() + # The SYMBOL cannot be a macro (e.g., a template function). + string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT " + ${_CSE_CHECK_NON_MACRO}") + endif() + string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT " +}") + unset(_CSE_CHECK_NON_MACRO) + + configure_file("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in" + "${SOURCEFILE}" @ONLY) + + if(NOT CMAKE_REQUIRED_QUIET) + message(CHECK_START "Looking for ${SYMBOL}") + endif() + try_compile(${VARIABLE} + ${CMAKE_BINARY_DIR} + "${SOURCEFILE}" + COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} + ${CHECK_SYMBOL_EXISTS_LINK_OPTIONS} + ${CHECK_SYMBOL_EXISTS_LIBS} + CMAKE_FLAGS + -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_SYMBOL_EXISTS_FLAGS} + "${CMAKE_SYMBOL_EXISTS_INCLUDES}" + OUTPUT_VARIABLE OUTPUT) + if(${VARIABLE}) + if(NOT CMAKE_REQUIRED_QUIET) + message(CHECK_PASS "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(CHECK_FAIL "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() + unset(CMAKE_CONFIGURABLE_FILE_CONTENT) + endif() +endmacro() + +cmake_policy(POP) |