groundwork for making "configure -nomake tools" sane

the idea is that "tools" actually means "graphical applications". that
means that all bootstrapped/build tools are consistently built,
regardless of their location in the source tree.
non-bootstrapped non-graphical tools are a bit of a grey area. it's
going to be decided on a case-by-case basis.

Change-Id: I28b959b7e659d8aa86cf6769ab6d2689c855ec6b
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

mkspecs/features/qt_build_config.prf

@@ -50,3 +50,19 @@ CONFIG += \
     # Qt modules get compiled without exceptions enabled by default.
     # However, testcases should be still built with exceptions.
     exceptions_off testcase_exceptions
+
+
+defineTest(qtBuildPart) {
+    bp = $$eval($$upper($$section(_QMAKE_CONF_, /, -2, -2))_BUILD_PARTS)
+    isEmpty(bp): bp = $$QT_BUILD_PARTS
+    contains(bp, $$1): return(true)
+    return(false)
+}
+
+defineTest(qtNomakeTools) {
+    qtBuildPart(tools): return()
+    for (d, 1) {
+        $${d}.CONFIG += no_default_target no_default_install
+        export($${d}.CONFIG)
+    }
+}

mkspecs/features/qt_parts.prf

@@ -27,7 +27,7 @@ exists($$_PRO_FILE_PWD_/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
+    # conditional treatment happens on a case-by-case basis
     SUBDIRS += sub_tools
 }