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, 16 insertions, 8 deletions

diff --git a/src/qml/jsruntime/qv4lookup.cpp b/src/qml/jsruntime/qv4lookup.cpp
index 46e47307ef..42e561bc7c 100644
--- a/src/qml/jsruntime/qv4lookup.cpp
+++ b/src/qml/jsruntime/qv4lookup.cpp
@@ -451,7 +451,8 @@ ReturnedValue Lookup::getterAccessor0(Lookup *l, ExecutionEngine *engine, const
 
             ScopedCallData callData(scope, 0);
             callData->thisObject = object;
-            return getter->call(callData);
+            getter->call(scope, callData);
+            return scope.result.asReturnedValue();
         }
     }
     l->getter = getterFallback;
@@ -473,7 +474,8 @@ ReturnedValue Lookup::getterAccessor1(Lookup *l, ExecutionEngine *engine, const
 
             ScopedCallData callData(scope, 0);
             callData->thisObject = object;
-            return getter->call(callData);
+            getter->call(scope, callData);
+            return scope.result.asReturnedValue();
         }
     }
     l->getter = getterFallback;
@@ -498,7 +500,8 @@ ReturnedValue Lookup::getterAccessor2(Lookup *l, ExecutionEngine *engine, const
 
                     ScopedCallData callData(scope, 0);
                     callData->thisObject = object;
-                    return getter->call(callData);
+                    getter->call(scope, callData);
+                    return scope.result.asReturnedValue();
                 }
             }
         }
@@ -542,7 +545,8 @@ ReturnedValue Lookup::primitiveGetterAccessor0(Lookup *l, ExecutionEngine *engin
 
             ScopedCallData callData(scope, 0);
             callData->thisObject = object;
-            return getter->call(callData);
+            getter->call(scope, callData);
+            return scope.result.asReturnedValue();
         }
     }
     l->getter = getterGeneric;
@@ -562,7 +566,8 @@ ReturnedValue Lookup::primitiveGetterAccessor1(Lookup *l, ExecutionEngine *engin
 
             ScopedCallData callData(scope, 0);
             callData->thisObject = object;
-            return getter->call(callData);
+            getter->call(scope, callData);
+            return scope.result.asReturnedValue();
         }
     }
     l->getter = getterGeneric;
@@ -665,7 +670,8 @@ ReturnedValue Lookup::globalGetterAccessor0(Lookup *l, ExecutionEngine *engine)
 
         ScopedCallData callData(scope, 0);
         callData->thisObject = Primitive::undefinedValue();
-        return getter->call(callData);
+        getter->call(scope, callData);
+        return scope.result.asReturnedValue();
     }
     l->globalGetter = globalGetterGeneric;
     return globalGetterGeneric(l, engine);
@@ -683,7 +689,8 @@ ReturnedValue Lookup::globalGetterAccessor1(Lookup *l, ExecutionEngine *engine)
 
         ScopedCallData callData(scope, 0);
         callData->thisObject = Primitive::undefinedValue();
-        return getter->call(callData);
+        getter->call(scope, callData);
+        return scope.result.asReturnedValue();
     }
     l->globalGetter = globalGetterGeneric;
     return globalGetterGeneric(l, engine);
@@ -704,7 +711,8 @@ ReturnedValue Lookup::globalGetterAccessor2(Lookup *l, ExecutionEngine *engine)
 
                 ScopedCallData callData(scope, 0);
                 callData->thisObject = Primitive::undefinedValue();
-                return getter->call(callData);
+                getter->call(scope, callData);
+                return scope.result.asReturnedValue();
             }
         }
     }