CMakePushCheckState

This module defines three macros: CMAKE_PUSH_CHECK_STATE() CMAKE_POP_CHECK_STATE() and CMAKE_RESET_CHECK_STATE() These macros can be used to save, restore and reset (i.e., clear contents) the state of the variables CMAKE_REQUIRED_FLAGS, CMAKE_REQUIRED_DEFINITIONS, CMAKE_REQUIRED_LINK_OPTIONS, CMAKE_REQUIRED_LIBRARIES, CMAKE_REQUIRED_LINK_DIRECTORIES, CMAKE_REQUIRED_INCLUDES and CMAKE_EXTRA_INCLUDE_FILES used by the various Check-files coming with CMake, like e.g. check_function_exists() etc. The variable contents are pushed on a stack, pushing multiple times is supported. This is useful e.g. when executing such tests in a Find-module, where they have to be set, but after the Find-module has been executed they should have the same value as they had before.

CMAKE_PUSH_CHECK_STATE() macro receives optional argument RESET. Whether it's specified, CMAKE_PUSH_CHECK_STATE() will set all CMAKE_REQUIRED_* variables to empty values, same as CMAKE_RESET_CHECK_STATE() call will do.

Usage:

cmake_push_check_state(RESET)
set(CMAKE_REQUIRED_DEFINITIONS -DSOME_MORE_DEF)
check_function_exists(...)
cmake_reset_check_state()
set(CMAKE_REQUIRED_DEFINITIONS -DANOTHER_DEF)
check_function_exists(...)
cmake_pop_check_state()