QML: When available, use QQmlAccessors to read properties.

When a property is read from a QObject or the QML scope object, and we
can statically resolve the type to qreal/QObject/int/bool/QString, and
the property has an accessor declared for it, then use that accessor to
do the read.

This collapses the path of e.g.:
  Runtime::getQmlScopeObjectProperty
    -> QObjectWrapper::getProperty
      -> QObjectWrapper::getProperty
        -> LoadProperty
          -> QQmlAccessor::read
(all of which do various checks for all the stuff mentioned above) to:
  Runtime::accessQmlScopeObjectQRealProperty
    -> QQmlAccessor::read
which is a simple 4-line function, and doesn't need to do any check.

According to valgrind, this saves 170 instructions on x86 for the
simple binding:

Item {
    width: height
}

Change-Id: I0761d01e8f1a3c13ecbffe2d8e0317ce9c0a4db0
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlpropertycache_p.h b/src/qml/qml/qqmlpropertycache_p.h
index bb39a5e371..4fb84198d9 100644
--- a/src/qml/qml/qqmlpropertycache_p.h
+++ b/src/qml/qml/qqmlpropertycache_p.h
@@ -162,6 +162,8 @@ public:
                                       overrideIndex >= 0; }
     bool hasRevision() const { return !(flags & HasAccessors) && revision != 0; }
 
+    bool isFullyResolved() const { return !(flags & NotFullyResolved); }
+
     // Returns -1 if not a value type virtual property
     inline int getValueTypeCoreIndex() const;