cmake support: first cut from David Vaz work.i

cmake/MacroOptionalAddSubdirectory.cmake

@@ -0,0 +1,41 @@
+# - MACRO_OPTIONAL_ADD_SUBDIRECTORY() combines ADD_SUBDIRECTORY() with an OPTION()
+# MACRO_OPTIONAL_ADD_SUBDIRECTORY( <dir> )
+# If you use MACRO_OPTIONAL_ADD_SUBDIRECTORY() instead of ADD_SUBDIRECTORY(),
+# this will have two effects
+# 1 - CMake will not complain if the directory doesn't exist
+#     This makes sense if you want to distribute just one of the subdirs
+#     in a source package, e.g. just one of the subdirs in kdeextragear.
+# 2 - If the directory exists, it will offer an option to skip the 
+#     subdirectory.
+#     This is useful if you want to compile only a subset of all
+#     directories.
+#
+# If the CMake variable DISABLE_ALL_OPTIONAL_SUBDIRECTORIES is set to TRUE
+# for the first CMake run on the project, all optional subdirectories will be disabled
+# by default (but can of course be enabled via the respective options).
+# E.g. the following will disable all optional subdirectories except the one named "kcalc":
+#   $ cmake -DDISABLE_ALL_OPTIONAL_SUBDIRECTORIES=TRUE -DBUILD_kcalc=TRUE <srcdir>
+
+# Copyright (c) 2007, Alexander Neundorf, <neundorf@kde.org>
+#
+# Redistribution and use is allowed according to the terms of the BSD license.
+# For details see the accompanying COPYING-CMAKE-SCRIPTS file.
+
+
+MACRO (MACRO_OPTIONAL_ADD_SUBDIRECTORY _dir )
+   GET_FILENAME_COMPONENT(_fullPath ${_dir} ABSOLUTE)
+   IF(EXISTS ${_fullPath}/CMakeLists.txt)
+      IF(DISABLE_ALL_OPTIONAL_SUBDIRECTORIES)
+         SET(_DEFAULT_OPTION_VALUE FALSE)
+      ELSE(DISABLE_ALL_OPTIONAL_SUBDIRECTORIES)
+         SET(_DEFAULT_OPTION_VALUE TRUE)
+      ENDIF(DISABLE_ALL_OPTIONAL_SUBDIRECTORIES)
+      IF(DISABLE_ALL_OPTIONAL_SUBDIRS  AND NOT DEFINED  BUILD_${_dir})
+         SET(_DEFAULT_OPTION_VALUE FALSE)
+      ENDIF(DISABLE_ALL_OPTIONAL_SUBDIRS  AND NOT DEFINED  BUILD_${_dir})
+      OPTION(BUILD_${_dir} "Build directory ${_dir}" ${_DEFAULT_OPTION_VALUE})
+      IF(BUILD_${_dir})
+         ADD_SUBDIRECTORY(${_dir})
+      ENDIF(BUILD_${_dir})
+   ENDIF(EXISTS ${_fullPath}/CMakeLists.txt)
+ENDMACRO (MACRO_OPTIONAL_ADD_SUBDIRECTORY)