Clean up manual reference of QQmlTypeData and QQmlPropertyCache

We have a few places in the type loader where we do adventurous manual
reference counting, where getType() returns a raw pointer that has been
addref()'ed and then sometimes somehow we call release() later. Commit
0b394e30bba4f6bb7e6f7dbe5585a2e15aa0f21d is an example of where this can
easily go wrong. As a consequence and also in preparation for future
work on the type loader, this patch starts replacing the manual
reference counting there.

Changing the return type from QQmlTypeData *getType() to a
QQmlRefPointer<> itself is not sufficient though, as the implicit
operator T*() will still allow the caller to store the result as a raw
pointer. Therefore this patch removes the "unsafe" implicit extraction
operator.

As a result of that change, other types that are sometimes stored in
QQmlRefPointer are also affected and their usage needs to be adapted
to QQmlRefPointer usage or manual raw pointer extraction with .data().

Change-Id: I18fd40634047f13196a237f4e6766cbef3bfbea2
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 3 insertions, 4 deletions

diff --git a/src/qml/qml/qqmltypewrapper.cpp b/src/qml/qml/qqmltypewrapper.cpp
index de077b6d38..8ddfa860d1 100644
--- a/src/qml/qml/qqmltypewrapper.cpp
+++ b/src/qml/qml/qqmltypewrapper.cpp
@@ -120,7 +120,7 @@ ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o,
 
 // Returns a type wrapper for importNamespace (of t) on o.  This allows nested resolution of a type in a
 // namespace.
-ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o, QQmlTypeNameCache *t, const QQmlImportRef *importNamespace,
+ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o, const QQmlRefPointer<QQmlTypeNameCache> &t, const QQmlImportRef *importNamespace,
                                      Heap::QQmlTypeWrapper::TypeNameMode mode)
 {
     Q_ASSERT(t);
@@ -128,7 +128,7 @@ ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o,
     Scope scope(engine);
 
     Scoped<QQmlTypeWrapper> w(scope, engine->memoryManager->allocate<QQmlTypeWrapper>());
-    w->d()->mode = mode; w->d()->object = o; w->d()->typeNamespace = t; w->d()->importNamespace = importNamespace;
+    w->d()->mode = mode; w->d()->object = o; w->d()->typeNamespace = t.data(); w->d()->importNamespace = importNamespace;
     t->addref();
     return w.asReturnedValue();
 }
@@ -385,10 +385,9 @@ ReturnedValue QQmlTypeWrapper::instanceOf(const Object *typeObject, const Value
         if (!theirDData->compilationUnit)
             return Encode(false);
 
-        QQmlTypeData *td = qenginepriv->typeLoader.getType(typeWrapper->d()->type().sourceUrl());
+        QQmlRefPointer<QQmlTypeData> td = qenginepriv->typeLoader.getType(typeWrapper->d()->type().sourceUrl());
         CompiledData::CompilationUnit *cu = td->compilationUnit();
         myQmlType = qenginepriv->metaObjectForType(cu->metaTypeId);
-        td->release();
     } else {
         myQmlType = qenginepriv->metaObjectForType(myTypeId);
     }