add CMakePushCheckState.cmake for older cmake versions

http://cmake.org/gitweb?p=cmake.git;a=blob;f=Modules/CMakePushCheckState.cmake
with licence copied from:
http://cmake.org/gitweb?p=cmake.git;a=blob;f=Copyright.txt

1 files changed, 103 insertions, 0 deletions

diff --git a/cmake/CMakePushCheckState.cmake b/cmake/CMakePushCheckState.cmake
new file mode 100644
index 0000000..038319b
--- /dev/null
+++ b/cmake/CMakePushCheckState.cmake
@@ -0,0 +1,103 @@
+# This module defines two macros:
+# CMAKE_PUSH_CHECK_STATE()
+# and
+# CMAKE_POP_CHECK_STATE()
+# These two macros can be used to save and restore the state of the variables
+# CMAKE_REQUIRED_FLAGS, CMAKE_REQUIRED_DEFINITIONS, CMAKE_REQUIRED_LIBRARIES
+# and CMAKE_REQUIRED_INCLUDES 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.
+#
+# Usage:
+#   cmake_push_check_state()
+#   set(CMAKE_REQUIRED_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} -DSOME_MORE_DEF)
+#   check_function_exists(...)
+#   cmake_pop_check_state()
+
+#=============================================================================
+# Copyright 2006-2011 Alexander Neundorf, <neundorf@kde.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 
+# * Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+# 
+# * Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+# 
+# * Neither the names of Kitware, Inc., the Insight Software Consortium,
+#   nor the names of their contributors may be used to endorse or promote
+#   products derived from this software without specific prior written
+#   permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# 
+# ------------------------------------------------------------------------------
+# 
+# The above copyright and license notice applies to distributions of
+# CMake in source and binary form.  Some source files contain additional
+# notices of original copyright by their contributors; see each source
+# for details.  Third-party software packages supplied with CMake under
+# compatible licenses provide their own copyright notices documented in
+# corresponding subdirectories.
+# 
+# ------------------------------------------------------------------------------
+# 
+# CMake was initially developed by Kitware with the following sponsorship:
+# 
+#  * National Library of Medicine at the National Institutes of Health
+#    as part of the Insight Segmentation and Registration Toolkit (ITK).
+# 
+#  * US National Labs (Los Alamos, Livermore, Sandia) ASC Parallel
+#    Visualization Initiative.
+# 
+#  * National Alliance for Medical Image Computing (NAMIC) is funded by the
+#    National Institutes of Health through the NIH Roadmap for Medical Research,
+#    Grant U54 EB005149.
+# 
+#  * Kitware, Inc.
+
+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_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}       ${CMAKE_REQUIRED_FLAGS})
+endmacro()
+
+macro(CMAKE_POP_CHECK_STATE)
+
+# don't pop more than we pushed
+   if("${_CMAKE_PUSH_CHECK_STATE_COUNTER}" GREATER "0")
+
+      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}})
+
+      math(EXPR _CMAKE_PUSH_CHECK_STATE_COUNTER "${_CMAKE_PUSH_CHECK_STATE_COUNTER}-1")
+   endif()
+
+endmacro()