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, 2 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4script_p.h b/src/qml/jsruntime/qv4script_p.h
index d7b82218e7..e13388393b 100644
--- a/src/qml/jsruntime/qv4script_p.h
+++ b/src/qml/jsruntime/qv4script_p.h
@@ -74,7 +74,7 @@ struct ContextStateSaver {
     CompiledData::CompilationUnit *compilationUnit;
     int lineNumber;
 
-    ContextStateSaver(Scope &scope, ExecutionContext *context)
+    ContextStateSaver(const Scope &scope, ExecutionContext *context)
         : savedContext(scope.alloc(1))
         , strictMode(context->d()->strictMode)
         , lookups(context->d()->lookups)
@@ -83,7 +83,7 @@ struct ContextStateSaver {
     {
         savedContext->setM(context->d());
     }
-    ContextStateSaver(Scope &scope, Heap::ExecutionContext *context)
+    ContextStateSaver(const Scope &scope, Heap::ExecutionContext *context)
         : savedContext(scope.alloc(1))
         , strictMode(context->strictMode)
         , lookups(context->lookups)