centralize handling of QT_BUILD_PARTS

Change-Id: I33b8c3958a102d87461ad887fa5749bd9a6dc037
Reviewed-by: Sergio Ahumada <sergio.ahumada@nokia.com>
Reviewed-by: Marius Storm-Olsen <marius.storm-olsen@nokia.com>

mkspecs/features/qt_parts.prf

+load(qt_build_config)
+
+TEMPLATE = subdirs
+
+sub_src.subdir = src
+sub_src.target = sub-src
+SUBDIRS = sub_src
+
+exists(tools/tools.pro) {
+    sub_tools.subdir = tools
+    sub_tools.target = sub-tools
+    sub_tools.depends = sub_src
+    !contains(QT_BUILD_PARTS, tools): sub_tools.CONFIG = no_default_target no_default_install
+    SUBDIRS += sub_tools
+}
+
+exists(examples/examples.pro) {
+    sub_examples.subdir = examples
+    sub_examples.target = sub-examples
+    sub_examples.depends = sub_src
+    !contains(QT_BUILD_PARTS, examples): sub_examples.CONFIG = no_default_target no_default_install
+    SUBDIRS += sub_examples
+}
+
+# Some modules still have these
+exists(demos/demos.pro) {
+    sub_demos.subdir = examples
+    sub_demos.target = sub-examples
+    sub_demos.depends = sub_src
+    !contains(QT_BUILD_PARTS, examples): sub_demos.CONFIG = no_default_target no_default_install
+    SUBDIRS += sub_demos
+}
+
+exists(tests/tests.pro) {
+    sub_tests.subdir = tests
+    sub_tests.target = sub-tests
+    sub_tests.depends = sub_src   # The tests may have a run-time only dependency on tools
+    sub_tests.CONFIG = no_default_install
+    !contains(QT_BUILD_PARTS, tests): sub_tests.CONFIG += no_default_target
+    SUBDIRS += sub_tests
+}
+
+QT_BUILD_PARTS -= libs tools examples tests
+!isEmpty(QT_BUILD_PARTS): warning("Unknown build part(s): $$QT_BUILD_PARTS")

qtbase.pro

@@ -2,39 +2,10 @@
 # Main projectfile
 #####################################################################
 
-CONFIG += ordered
-TEMPLATE = subdirs
+load(qt_parts)
 
 cross_compile: CONFIG += nostrip
 
-module_qtbase_tests.subdir = tests
-module_qtbase_tests.target = module-qtbase-tests
-module_qtbase_tests.depends = module_qtbase_src
-module_qtbase_tests.CONFIG = no_default_install
-
-#process the projects
-PROJECTS=$$eval($$list($$lower($$unique(QT_BUILD_PARTS))))
-# note that the order matters for these blocks!
-contains(PROJECTS, qmake) {
-    PROJECTS -= qmake
-    # nothing to be done
-}
-contains(PROJECTS, libs) {
-    PROJECTS -= libs
-    SUBDIRS += src
-}
-contains(PROJECTS, examples) {
-    PROJECTS -= examples
-    SUBDIRS += examples
-}
-contains(PROJECTS, tests) {
-    PROJECTS -= tests
-    SUBDIRS += module_qtbase_tests
-}
-!isEmpty(PROJECTS) {
-    message(Unknown PROJECTS: $$PROJECTS)
-}
-
 confclean.depends += clean
 confclean.commands =
 unix {