CMake/Modules/CMakePushCheckState.cmake
2018-12-01 17:56:23 +01:00

92 lines
3.9 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
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_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:
.. code-block:: cmake
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()
#]=======================================================================]
macro(CMAKE_RESET_CHECK_STATE)
set(CMAKE_EXTRA_INCLUDE_FILES)
set(CMAKE_REQUIRED_INCLUDES)
set(CMAKE_REQUIRED_DEFINITIONS)
set(CMAKE_REQUIRED_LINK_OPTIONS)
set(CMAKE_REQUIRED_LIBRARIES)
set(CMAKE_REQUIRED_FLAGS)
set(CMAKE_REQUIRED_QUIET)
endmacro()
macro(CMAKE_PUSH_CHECK_STATE)
if(NOT DEFINED _CMAKE_PUSH_CHECK_STATE_COUNTER)
set(_CMAKE_PUSH_CHECK_STATE_COUNTER 0)
endif()
math(EXPR _CMAKE_PUSH_CHECK_STATE_COUNTER "${_CMAKE_PUSH_CHECK_STATE_COUNTER}+1")
set(_CMAKE_EXTRA_INCLUDE_FILES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER} ${CMAKE_EXTRA_INCLUDE_FILES})
set(_CMAKE_REQUIRED_INCLUDES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER} ${CMAKE_REQUIRED_INCLUDES})
set(_CMAKE_REQUIRED_DEFINITIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER} ${CMAKE_REQUIRED_DEFINITIONS})
set(_CMAKE_REQUIRED_LINK_OPTIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER} ${CMAKE_REQUIRED_LINK_OPTIONS})
set(_CMAKE_REQUIRED_LIBRARIES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER} ${CMAKE_REQUIRED_LIBRARIES})
set(_CMAKE_REQUIRED_FLAGS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER} ${CMAKE_REQUIRED_FLAGS})
set(_CMAKE_REQUIRED_QUIET_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER} ${CMAKE_REQUIRED_QUIET})
if (${ARGC} GREATER 0 AND "${ARGV0}" STREQUAL "RESET")
cmake_reset_check_state()
endif()
endmacro()
macro(CMAKE_POP_CHECK_STATE)
# don't pop more than we pushed
if("${_CMAKE_PUSH_CHECK_STATE_COUNTER}" GREATER "0")
set(CMAKE_EXTRA_INCLUDE_FILES ${_CMAKE_EXTRA_INCLUDE_FILES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
set(CMAKE_REQUIRED_INCLUDES ${_CMAKE_REQUIRED_INCLUDES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
set(CMAKE_REQUIRED_DEFINITIONS ${_CMAKE_REQUIRED_DEFINITIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
set(CMAKE_REQUIRED_LINK_OPTIONS ${_CMAKE_REQUIRED_LINK_OPTIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
set(CMAKE_REQUIRED_LIBRARIES ${_CMAKE_REQUIRED_LIBRARIES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
set(CMAKE_REQUIRED_FLAGS ${_CMAKE_REQUIRED_FLAGS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
set(CMAKE_REQUIRED_QUIET ${_CMAKE_REQUIRED_QUIET_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
math(EXPR _CMAKE_PUSH_CHECK_STATE_COUNTER "${_CMAKE_PUSH_CHECK_STATE_COUNTER}-1")
endif()
endmacro()