extends test case to fail if macro is undefined durcing preprocessing

test cases/frameworks/4 qt/manualinclude.cpp

@@ -10,9 +10,14 @@ class MocClass : public QObject {
     Q_OBJECT
 };
 
+void testSlot() {
+	;
+}
+
 int main(int argc, char **argv) {
     ManualInclude mi;
     MocClass mc;
+    QObject::connect(&mi, &ManualInclude::mysignal, &testSlot);
     return 0;
 }
 

test cases/frameworks/4 qt/manualinclude.h

@@ -9,7 +9,9 @@ class ManualInclude : public QObject {
 public:
     ManualInclude();
 
+#if defined(MOC_EXTRA_FLAG)
 signals:
+#endif
     int mysignal();
 };
 

test cases/frameworks/4 qt/meson.build

@@ -61,6 +61,7 @@ foreach qt : ['qt4', 'qt5']
     # headers but the user must manually include moc
     # files from sources.
     manpreprocessed = qtmodule.preprocess(
+      moc_extra_arguments : ['-DMOC_EXTRA_FLAG'], # This is just a random macro to test `moc_extra_arguments`
       moc_sources : 'manualinclude.cpp',
       moc_headers : 'manualinclude.h',
       method : get_option('method'))