surround loading of spec with loading spec_pre.prf and spec_post.prf

follow suit with qmake ...

once we move currently builtin functionality to these feature files,
things would break with qt4 (which does not have them). consequently,
we provide our own fallback versions of them.

Change-Id: Ie318f3419d78214472835c41ec1388977f2e9269
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

src/shared/proparser/proparser.pri

@@ -27,3 +27,4 @@ SOURCES += \
         ioutils.cpp
 
 RESOURCES += proparser.qrc
+DEFINES += QMAKE_BUILTIN_PRFS

src/shared/proparser/proparser.qrc

@@ -9,4 +9,8 @@
         <file>images/remove.png</file>
         <file>proiteminfo.xml</file>
     </qresource>
+    <qresource prefix="/qmake/features" >
+        <file>spec_pre.prf</file>
+        <file>spec_post.prf</file>
+    </qresource>
 </RCC>

src/shared/proparser/qmakeevaluator.cpp

@@ -885,6 +885,8 @@ bool QMakeEvaluator::loadSpec()
   cool:
     m_option->qmakespec = QDir::cleanPath(qmakespec);
 
+    if (!evaluateFeatureFile(QLatin1String("spec_pre.prf")))
+        return false;
     QString spec = m_option->qmakespec + QLatin1String("/qmake.conf");
     if (!evaluateFileDirect(spec, QMakeHandler::EvalConfigFile, LoadProOnly)) {
         m_handler->configError(
@@ -901,6 +903,8 @@ bool QMakeEvaluator::loadSpec()
     QString real_spec = orig_spec.isEmpty() ? m_option->qmakespec : orig_spec.toQString();
 #endif
     m_option->qmakespec_name = IoUtils::fileName(real_spec).toString();
+    if (!evaluateFeatureFile(QLatin1String("spec_post.prf")))
+        return false;
     if (!m_option->cachefile.isEmpty()
         && !evaluateFileDirect(m_option->cachefile, QMakeHandler::EvalConfigFile, LoadProOnly)) {
         return false;
@@ -1900,6 +1904,11 @@ bool QMakeEvaluator::evaluateFeatureFile(const QString &fileName)
                 goto cool;
             }
         }
+#ifdef QMAKE_BUILTIN_PRFS
+        fn.prepend(QLatin1String(":/qmake/features/"));
+        if (QFileInfo(fn).exists())
+            goto cool;
+#endif
         return false;
 
       cool:

tests/manual/proparser/testreader.pro

@@ -18,6 +18,9 @@ build_all:!build_pass {
 SOURCES = main.cpp qmakeglobals.cpp qmakeparser.cpp qmakeevaluator.cpp profileevaluator.cpp qmakebuiltins.cpp proitems.cpp ioutils.cpp
 HEADERS = qmakeglobals.h qmakeparser.h profileevaluator.h qmakeevaluator.h qmakeevaluator_p.h proitems.h ioutils.h
 
+RESOURCES += proparser.qrc
+DEFINES += QMAKE_BUILTIN_PRFS
+
 DEFINES += QT_NO_CAST_TO_ASCII QT_NO_CAST_FROM_ASCII
 DEFINES += QT_USE_FAST_OPERATOR_PLUS QT_USE_FAST_CONCATENATION
 DEFINES += PROEVALUATOR_CUMULATIVE PROEVALUATOR_INIT_PROPS