moc: handle attributes in class declarations

We already had code to handle attributes on funtcions, but we didn't
handle them correctly for classes so far.
Fix this by simply skipping over the attribute.

Fixes: QTBUG-105310
Pick-to: 5.15 6.2 6.3 6.4
Change-Id: Ic4149f940e74820de4f2fa9540d9dc5b4e626a3a
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/tools/moc/moc.cpp

@@ -40,6 +40,9 @@ bool Moc::parseClassHead(ClassDef *def)
             return false;
     } while (token);
 
+    // support attributes like "class [[deprecated]]] name"
+    skipCxxAttributes();
+
     if (!test(IDENTIFIER)) // typedef struct { ... }
         return false;
     QByteArray name = lexem();

tests/auto/tools/moc/cxx-attributes.h

@@ -10,7 +10,7 @@ QT_WARNING_PUSH
 QT_WARNING_DISABLE_CLANG("-Wunknown-attributes")
 QT_WARNING_DISABLE_GCC("-Wattributes")
 
-class CppAttribute : public QObject
+class [[deprecated]] CppAttribute : public QObject
 {
     Q_OBJECT
 signals: