Refactor context handling

Fix the push/pop context instructions to not modify the JS
stack anymore, as that can cause conflicts with the VME
(and was an ugly hack in any case). Instead, these instructions
not return the old context, that is then stored in a temporary.

Get rid of Engine::current and Engine::currentContext. The
StackFrame structures do now contain the only and authoritive
data. This finally gives us a nice setup where we create and
destroy frames on the stack when entering/leaving functions.

Change-Id: If161e3e941f59865c47ecfe1e094faf62b52bfa0
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 12 insertions, 19 deletions

diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index ddb5dc4ea5..c9565468ad 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -232,18 +232,16 @@ bool ExecutionContext::deleteProperty(String *name)
 // Do a standard call with this execution context as the outer scope
 ReturnedValue ExecutionContext::call(ExecutionEngine *engine, CallData *callData, Function *function, const FunctionObject *f)
 {
-    Scope scope(engine);
-    ExecutionContextSaver ctxSaver(engine);
-
-    Scoped<CallContext> ctx(scope, newCallContext(function, callData));
+    Heap::CallContext *ctx = newCallContext(function, callData);
     if (f)
-        ctx->d()->function.set(engine, f->d());
-    engine->pushContext(ctx);
+        ctx->function.set(engine, f->d());
 
-    ReturnedValue res = Q_V4_PROFILE(engine, function, f);
+    ReturnedValue res = Q_V4_PROFILE(engine, ctx, function, f);
 
-    if (function->hasQmlDependencies)
-        QQmlPropertyCapture::registerQmlDependencies(engine, function->compiledFunction);
+    if (function->hasQmlDependencies) {
+        Q_ASSERT(d()->type == Heap::ExecutionContext::Type_QmlContext);
+        QQmlPropertyCapture::registerQmlDependencies(static_cast<QmlContext *>(this), engine, function->compiledFunction);
+    }
 
     return res;
 }
@@ -258,17 +256,12 @@ ReturnedValue QV4::ExecutionContext::simpleCall(ExecutionEngine *engine, CallDat
     for (int i = callData->argc; i < (int)function->nFormals; ++i)
         callData->args[i] = Encode::undefined();
 
-    ExecutionContext *old = engine->currentContext;
-    engine->currentContext = this;
-    engine->current = d();
-
-    ReturnedValue res = Q_V4_PROFILE(engine, function, 0);
+    ReturnedValue res = Q_V4_PROFILE(engine, d(), function, 0);
 
-    if (function->hasQmlDependencies)
-        QQmlPropertyCapture::registerQmlDependencies(engine, function->compiledFunction);
-
-    engine->currentContext = old;
-    engine->current = old->d();
+    if (function->hasQmlDependencies) {
+        Q_ASSERT(d()->type == Heap::ExecutionContext::Type_QmlContext);
+        QQmlPropertyCapture::registerQmlDependencies(static_cast<QmlContext *>(this), engine, function->compiledFunction);
+    }
 
     engine->jsStackTop = jsStackTop;