Avoid side effects when en exception has been thrown.

We don't want to check for exceptions after every single
line on our runtime methods. A better way to handle this
is to add the check in all methods that have direct side
effects (as e.g. writing to a property of the JS stack).

We also need to return whereever we throw an exception.
To simplify the code, ExecutionContext::throwXxx methods now
return a ReturnedValue (always undefined) for convenience.

Change-Id: Ide6c804f819c731a3f14c6c43121d08029c9fb90
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/src/qml/jsruntime/qv4managed.cpp b/src/qml/jsruntime/qv4managed.cpp
index 31bb8f2b94..4d40b72bab 100644
--- a/src/qml/jsruntime/qv4managed.cpp
+++ b/src/qml/jsruntime/qv4managed.cpp
@@ -174,23 +174,22 @@ QString Managed::className() const
 
 bool Managed::hasInstance(Managed *m, const ValueRef)
 {
-    m->engine()->current->throwTypeError();
+    return m->engine()->current->throwTypeError();
 }
 
 ReturnedValue Managed::construct(Managed *m, CallData *)
 {
-    m->engine()->current->throwTypeError();
+    return m->engine()->current->throwTypeError();
 }
 
 ReturnedValue Managed::call(Managed *m, CallData *)
 {
-    m->engine()->current->throwTypeError();
+    return m->engine()->current->throwTypeError();
 }
 
 ReturnedValue Managed::getLookup(Managed *m, Lookup *)
 {
-    m->engine()->current->throwTypeError();
-    return 0;
+    return m->engine()->current->throwTypeError();
 }
 
 void Managed::setLookup(Managed *m, Lookup *, const ValueRef)