Use QStringRef to optimize memory allocation

Replace substring functions that return QString with
corresponding functions that return QStringRef where
it's possible.

Create QString from QStringRef only where necessary.

While touching the code, also port loops to C++11 style.

Change-Id: I04c99b24ea6afd3715e3edf9ea00bfab838fd53c
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>
Reviewed-by: Frank Meerkoetter <frank.meerkoetter@basyskom.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@theqtcompany.com>
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>

2 files changed, 8 insertions, 6 deletions

diff --git a/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp b/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
index a9996da7f4..ff4e30835d 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
@@ -683,11 +683,13 @@ bool QQmlEngineDebugServiceImpl::resetBinding(int objectId, const QString &prope
     QQmlContext *context = qmlContext(object);
 
     if (object && context) {
-        QString parentProperty = propertyName;
-        if (propertyName.indexOf(QLatin1Char('.')) != -1)
-            parentProperty = propertyName.left(propertyName.indexOf(QLatin1Char('.')));
+        QStringRef parentPropertyRef(&propertyName);
+        const int idx = parentPropertyRef.indexOf(QLatin1Char('.'));
+        if (idx != -1)
+            parentPropertyRef = parentPropertyRef.left(idx);
 
-        if (object->property(parentProperty.toLatin1()).isValid()) {
+        const QByteArray parentProperty = parentPropertyRef.toLatin1();
+        if (object->property(parentProperty).isValid()) {
             QQmlProperty property(object, propertyName);
             QQmlPropertyPrivate::removeBinding(property);
             if (property.isResettable()) {
@@ -700,7 +702,7 @@ bool QQmlEngineDebugServiceImpl::resetBinding(int objectId, const QString &prope
                 // overwrite with default value
                 if (QQmlType *objType = QQmlMetaType::qmlType(object->metaObject())) {
                     if (QObject *emptyObject = objType->create()) {
-                        if (emptyObject->property(parentProperty.toLatin1()).isValid()) {
+                        if (emptyObject->property(parentProperty).isValid()) {
                             QVariant defaultValue = QQmlProperty(emptyObject, propertyName).read();
                             if (defaultValue.isValid()) {
                                 setBinding(objectId, propertyName, defaultValue, true);
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qqmlnativedebugservice.cpp b/src/plugins/qmltooling/qmldbg_debugger/qqmlnativedebugservice.cpp
index 877821e03f..a9b9587aa9 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qqmlnativedebugservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qqmlnativedebugservice.cpp
@@ -704,7 +704,7 @@ bool NativeDebugger::reallyHitTheBreakPoint(const QV4::Function *function, int l
         const BreakPoint &bp = m_service->m_breakHandler->m_breakPoints.at(i);
         if (bp.lineNumber == lineNumber) {
             const QString fileName = function->sourceFile();
-            const QString base = fileName.mid(fileName.lastIndexOf('/') + 1);
+            const QStringRef base = fileName.midRef(fileName.lastIndexOf('/') + 1);
             if (bp.fileName.endsWith(base)) {
                 if (bp.condition.isEmpty() || checkCondition(bp.condition)) {
                     BreakPoint &mbp = m_service->m_breakHandler->m_breakPoints[i];