Introduce QMetaType::UnknownType.

QMetaType::Void was ambiguous, it was pointing to a valid type (void)
and in the same time it was signaling errors in QMetaType. There was
no clean way to check if returned type was valid void or some
unregistered type.

This feature will be used by new QMetaObject revision which will
store type ids instead of type names. So it will be easy to
distinguish between:
 void mySlot();
 MyUnregisteredType mySlot();

Change-Id: I73ff097f75585a95e12df74d50c6f3141153e771
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

4 files changed, 8 insertions, 12 deletions

diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp
index f86365025f..8d46ee4801 100644
--- a/src/dbus/qdbusintegrator.cpp
+++ b/src/dbus/qdbusintegrator.cpp
@@ -686,7 +686,7 @@ static int findSlot(const QMetaObject *mo, const QByteArray &name, int flags,
             ++i;
 
         // make sure that the output parameters have signatures too
-        if (returnType != 0 && QDBusMetaType::typeToSignature(returnType) == 0)
+        if (returnType != QMetaType::UnknownType && returnType != QMetaType::Void && QDBusMetaType::typeToSignature(returnType) == 0)
             continue;
 
         bool ok = true;
@@ -919,7 +919,7 @@ void QDBusConnectionPrivate::deliverCall(QObject *object, int /*flags*/, const Q
     // output arguments
     QVariantList outputArgs;
     void *null = 0;
-    if (metaTypes[0] != QMetaType::Void) {
+    if (metaTypes[0] != QMetaType::Void && metaTypes[0] != QMetaType::UnknownType) {
         QVariant arg(metaTypes[0], null);
         outputArgs.append( arg );
         params[0] = const_cast<void*>(outputArgs.at( outputArgs.count() - 1 ).constData());
diff --git a/src/dbus/qdbusmetaobject.cpp b/src/dbus/qdbusmetaobject.cpp
index 7b8a67f343..ce8146f639 100644
--- a/src/dbus/qdbusmetaobject.cpp
+++ b/src/dbus/qdbusmetaobject.cpp
@@ -71,7 +71,6 @@ public:
 private:
     struct Method {
         QList<QByteArray> parameterNames;
-        QByteArray typeName;
         QByteArray tag;
         QByteArray name;
         QVarLengthArray<int, 4> inputTypes;
@@ -266,10 +265,7 @@ void QDBusMetaObjectGenerator::parseMethods()
 
             mm.outputTypes.append(type.id);
 
-            if (i == 0) {
-                // return value
-                mm.typeName = type.name;
-            } else {
+            if (i != 0) {
                 // non-const ref parameter
                 mm.parameterNames.append(arg.name.toLatin1());
 
@@ -477,7 +473,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
                     typeName = QMetaType::typeName(type);
                     typeName.append('&');
                 }
-                Q_ASSERT(type || (i < 0));
+                Q_ASSERT(type != QMetaType::UnknownType);
                 int typeInfo;
                 if (!typeName.isEmpty())
                     typeInfo = IsUnresolvedType | strings.enter(typeName);
@@ -516,7 +512,7 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
 
         // form is name, typeinfo, flags
         idata[offset++] = strings.enter(it.key()); // name
-        Q_ASSERT(mp.type != 0);
+        Q_ASSERT(mp.type != QMetaType::UnknownType);
         idata[offset++] = mp.type;
         idata[offset++] = mp.flags;
 
diff --git a/src/dbus/qdbusmetatype.cpp b/src/dbus/qdbusmetatype.cpp
index b0d640608a..7c8d8cf679 100644
--- a/src/dbus/qdbusmetatype.cpp
+++ b/src/dbus/qdbusmetatype.cpp
@@ -311,7 +311,7 @@ bool QDBusMetaType::demarshall(const QDBusArgument &arg, int id, void *data)
 int QDBusMetaType::signatureToType(const char *signature)
 {
     if (!signature)
-        return QVariant::Invalid;
+        return QMetaType::UnknownType;
 
     QDBusMetaTypeId::init();
     switch (signature[0])
@@ -378,7 +378,7 @@ int QDBusMetaType::signatureToType(const char *signature)
         }
         // fall through
     default:
-        return QVariant::Invalid;
+        return QMetaType::UnknownType;
     }
 }
 
diff --git a/src/dbus/qdbusmisc.cpp b/src/dbus/qdbusmisc.cpp
index 0a5da604f2..88bab88a13 100644
--- a/src/dbus/qdbusmisc.cpp
+++ b/src/dbus/qdbusmisc.cpp
@@ -170,7 +170,7 @@ int qDBusParametersForMethod(const QMetaMethod &mm, QList<int>& metaTypes)
         }
 
         int id = QMetaType::type(type);
-        if (id == 0) {
+        if (id == QMetaType::UnknownType) {
             //qWarning("Could not parse the method '%s'", mm.methodSignature().constData());
             // invalid type in method parameter list
             return -1;