V4: Pass scope around as parameters inside the runtime.

The implementation of many (or all) runtime functions consist of first
creating a QV4::Scope, which saves and restores the JS stack pointer.
It also prevents tail-calls because of that restoring behavior. In many
cases it suffices to do that at the entry-point of the runtime.

The return value of a JS function call is now also stored in the scope.
Previously, all return values were stored in a ScopedValue, got loaded
on return, and immediately stored in another ScopedValue in the caller.
This resulted in a lot of stores, where now there is only one store
needed, and no extra ScopedValue for every function.

Change-Id: I13d80fc0ce72c5702ef1536d41d12f710c5914fa
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 6 insertions, 6 deletions

diff --git a/src/qml/types/qquickworkerscript.cpp b/src/qml/types/qquickworkerscript.cpp
index bc15b2fd9b..10666476fe 100644
--- a/src/qml/types/qquickworkerscript.cpp
+++ b/src/qml/types/qquickworkerscript.cpp
@@ -251,7 +251,8 @@ void QQuickWorkerScriptEnginePrivate::WorkerEngine::init()
     QV4::ScopedCallData callData(scope, 1);
     callData->args[0] = function;
     callData->thisObject = global();
-    createsend.set(scope.engine, createsendconstructor->call(callData));
+    createsendconstructor->call(scope, callData);
+    createsend.set(scope.engine, scope.result.asReturnedValue());
 }
 
 // Requires handle and context scope
@@ -264,14 +265,13 @@ QV4::ReturnedValue QQuickWorkerScriptEnginePrivate::WorkerEngine::sendFunction(i
     QV4::Scope scope(v4);
     QV4::ScopedFunctionObject f(scope, createsend.value());
 
-    QV4::ScopedValue v(scope);
     QV4::ScopedCallData callData(scope, 1);
     callData->args[0] = QV4::Primitive::fromInt32(id);
     callData->thisObject = global();
-    v = f->call(callData);
+    f->call(scope, callData);
     if (scope.hasException())
-        v = scope.engine->catchException();
-    return v->asReturnedValue();
+        scope.result = scope.engine->catchException();
+    return scope.result.asReturnedValue();
 }
 
 #ifndef QT_NO_NETWORK
@@ -380,7 +380,7 @@ void QQuickWorkerScriptEnginePrivate::processMessage(int id, const QByteArray &d
     callData->thisObject = workerEngine->global();
     callData->args[0] = qmlContext->d()->qml; // ###
     callData->args[1] = value;
-    f->call(callData);
+    f->call(scope, callData);
     if (scope.hasException()) {
         QQmlError error = scope.engine->catchExceptionAsQmlError();
         reportScriptException(script, error);