build: add central file to check for cmake requirements

CMake allows to define variables (e.g. -D) even if they are not defined as options.
If a build feature requires a cmake version > 2.6 build might fail
therefore a check is required.

Check for WITH_MONOLITHIC_BUILD requirements added (prevents issue #724)

CMakeLists.txt

@@ -34,6 +34,7 @@ set(CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/)
 
 include(AutoVersioning)
 include(ConfigOptions)
+include(BuildFeatureCheck)
 include(FindOptionalPackage)
 include(CheckCCompilerFlag)
 include(GNUInstallDirsWrapper)

cmake/BuildFeatureCheck.cmake

@@ -0,0 +1,24 @@
+# Central location to check for cmake (version) requirements
+#
+#=============================================================================
+# Copyright 2012 Bernhard Miklautz <bmiklautz@thinstuff.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#=============================================================================
+
+# If WITH_MONOLITHIC_BUILD is used with cmake < 2.8.8 build fails
+if (WITH_MONOLITHIC_BUILD)
+	if(${CMAKE_VERSION} VERSION_LESS 2.8.8)
+		message(FATAL_ERROR "CMAKE version >= 2.8.8 required for WITH_MONOLITHIC_BUILD")
+	endif()
+endif(WITH_MONOLITHIC_BUILD)