CMake/Modules/CMakePushCheckState.cmake
Brad King 86578eccf2 Simplify CMake per-source license notices
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool.  Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience.  Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.

Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices.  It also references version control
history for more precise information.  Therefore we no longer need to spell
out the list of Contributors in each source file notice.

Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing".  The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.

Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically.  Manually fix up shebang lines and trailing
newlines in a few files.  Manually update the notices in a few files that the
script does not handle.
2016-09-27 15:14:44 -04:00

87 lines
3.4 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_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:
#
# ::
#
# 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_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} ${CMAKE_REQUIRED_DEFINITIONS})
set(_CMAKE_REQUIRED_LIBRARIES_SAVE_${_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_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()