Simplify JSCallData construction

Change-Id: Ic53532edae9a209aa7125af6f00a9d993d74f1a3
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

30 files changed, 80 insertions, 103 deletions

diff --git a/src/imports/localstorage/plugin.cpp b/src/imports/localstorage/plugin.cpp
index 4de4a9520f..9d78773fe1 100644
--- a/src/imports/localstorage/plugin.cpp
+++ b/src/imports/localstorage/plugin.cpp
@@ -414,12 +414,12 @@ static ReturnedValue qmlsqldatabase_changeVersion(const QV4::BuiltinFunction *b,
         ok = false;
         db.transaction();
 
-        JSCallData jsCall(scope, callback, 1);
-        jsCall->thisObject = scope.engine->globalObject;
+        JSCallData jsCall(scope, 1);
+        *jsCall->thisObject = scope.engine->globalObject;
         jsCall->args[0] = w;
 
         TransactionRollback rollbackOnException(&db, &w->d()->inTransaction);
-        jsCall.call();
+        callback->call(jsCall);
         rollbackOnException.clear();
         if (!db.commit()) {
             db.rollback();
@@ -464,11 +464,11 @@ static ReturnedValue qmlsqldatabase_transaction_shared(const QV4::BuiltinFunctio
 
     db.transaction();
     if (callback) {
-        JSCallData jsCall(scope, callback, 1);
-        jsCall->thisObject = scope.engine->globalObject;
+        JSCallData jsCall(scope, 1);
+        *jsCall->thisObject = scope.engine->globalObject;
         jsCall->args[0] = w;
         TransactionRollback rollbackOnException(&db, &w->d()->inTransaction);
-        jsCall.call();
+        callback->call(jsCall);
         rollbackOnException.clear();
 
         if (!db.commit())
@@ -763,10 +763,10 @@ void QQuickLocalStorage::openDatabaseSync(QQmlV4Function *args)
     *db->d()->version = version;
 
     if (created && dbcreationCallback) {
-        JSCallData jsCall(scope, dbcreationCallback, 1);
-        jsCall->thisObject = scope.engine->globalObject;
+        JSCallData jsCall(scope, 1);
+        *jsCall->thisObject = scope.engine->globalObject;
         jsCall->args[0] = db;
-        jsCall.call();
+        dbcreationCallback->call(jsCall);
     }
 
     args->setReturnValue(db.asReturnedValue());
diff --git a/src/qml/jsapi/qjsvalue.cpp b/src/qml/jsapi/qjsvalue.cpp
index 77bf587509..654a497950 100644
--- a/src/qml/jsapi/qjsvalue.cpp
+++ b/src/qml/jsapi/qjsvalue.cpp
@@ -657,7 +657,7 @@ QJSValue QJSValue::call(const QJSValueList &args)
     Q_ASSERT(engine);
 
     Scope scope(engine);
-    JSCallData jsCallData(scope, f, args.length());
+    JSCallData jsCallData(scope, args.length());
     jsCallData->thisObject = engine->globalObject;
     for (int i = 0; i < args.size(); ++i) {
         if (!QJSValuePrivate::checkEngine(engine, args.at(i))) {
@@ -713,7 +713,7 @@ QJSValue QJSValue::callWithInstance(const QJSValue &instance, const QJSValueList
         return QJSValue();
     }
 
-    JSCallData jsCallData(scope, f, args.size());
+    JSCallData jsCallData(scope, args.size());
     jsCallData->thisObject = QJSValuePrivate::convertedToValue(engine, instance);
     for (int i = 0; i < args.size(); ++i) {
         if (!QJSValuePrivate::checkEngine(engine, args.at(i))) {
@@ -762,7 +762,7 @@ QJSValue QJSValue::callAsConstructor(const QJSValueList &args)
     Q_ASSERT(engine);
 
     Scope scope(engine);
-    JSCallData jsCallData(scope, f, args.size());
+    JSCallData jsCallData(scope, args.size());
     for (int i = 0; i < args.size(); ++i) {
         if (!QJSValuePrivate::checkEngine(engine, args.at(i))) {
             qWarning("QJSValue::callAsConstructor() failed: cannot construct function with argument created in a different engine");
diff --git a/src/qml/jsruntime/qv4argumentsobject.cpp b/src/qml/jsruntime/qv4argumentsobject.cpp
index 298c674504..db0a7db068 100644
--- a/src/qml/jsruntime/qv4argumentsobject.cpp
+++ b/src/qml/jsruntime/qv4argumentsobject.cpp
@@ -139,7 +139,7 @@ bool ArgumentsObject::defineOwnProperty(ExecutionEngine *engine, uint index, con
     if (isMapped && attrs.isData()) {
         Q_ASSERT(arrayData());
         ScopedFunctionObject setter(scope, map->setter());
-        JSCallData jsCallData(scope, setter, 1);
+        JSCallData jsCallData(scope, 1);
         jsCallData->thisObject = this->asReturnedValue();
         jsCallData->args[0] = desc->value;
         setter->call(jsCallData);
diff --git a/src/qml/jsruntime/qv4arraybuffer.cpp b/src/qml/jsruntime/qv4arraybuffer.cpp
index 3bbec7957a..dd29411b46 100644
--- a/src/qml/jsruntime/qv4arraybuffer.cpp
+++ b/src/qml/jsruntime/qv4arraybuffer.cpp
@@ -187,7 +187,7 @@ ReturnedValue ArrayBufferPrototype::method_slice(const BuiltinFunction *b, CallD
     if (!constructor)
         return v4->throwTypeError();
 
-    JSCallData jsCallData(scope, constructor, 1);
+    JSCallData jsCallData(scope, 1);
     double newLen = qMax(final - first, 0.);
     jsCallData->args[0] = QV4::Encode(newLen);
     QV4::Scoped<ArrayBuffer> newBuffer(scope, constructor->callAsConstructor(jsCallData));
diff --git a/src/qml/jsruntime/qv4arraydata.cpp b/src/qml/jsruntime/qv4arraydata.cpp
index 8d048ca1d6..b77fab3305 100644
--- a/src/qml/jsruntime/qv4arraydata.cpp
+++ b/src/qml/jsruntime/qv4arraydata.cpp
@@ -677,7 +677,7 @@ bool ArrayElementLessThan::operator()(Value v1, Value v2) const
     if (o) {
         Scope scope(o->engine());
         ScopedValue result(scope);
-        JSCallData jsCallData(scope, o, 2);
+        JSCallData jsCallData(scope, 2);
         jsCallData->args[0] = v1;
         jsCallData->args[1] = v2;
         result = o->call(jsCallData);
diff --git a/src/qml/jsruntime/qv4arrayobject.cpp b/src/qml/jsruntime/qv4arrayobject.cpp
index 83bfe8e84c..eef9ac0820 100644
--- a/src/qml/jsruntime/qv4arrayobject.cpp
+++ b/src/qml/jsruntime/qv4arrayobject.cpp
@@ -198,7 +198,7 @@ ReturnedValue ArrayPrototype::method_find(const BuiltinFunction *b, CallData *ca
     if (!callback)
         THROW_TYPE_ERROR();
 
-    JSCallData jsCallData(scope, callback, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->thisObject = callData->argument(1);
 
     ScopedValue v(scope);
@@ -234,7 +234,7 @@ ReturnedValue ArrayPrototype::method_findIndex(const BuiltinFunction *b, CallDat
     if (!callback)
         THROW_TYPE_ERROR();
 
-    JSCallData jsCallData(scope, callback, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->thisObject = callData->argument(1);
 
     ScopedValue v(scope);
@@ -793,7 +793,7 @@ ReturnedValue ArrayPrototype::method_every(const BuiltinFunction *b, CallData *c
 
     ScopedValue r(scope);
     ScopedValue v(scope);
-    JSCallData jsCallData(scope, callback, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->thisObject = callData->argument(1);
 
     bool ok = true;
@@ -827,7 +827,7 @@ ReturnedValue ArrayPrototype::method_some(const BuiltinFunction *b, CallData *ca
 
     ScopedValue v(scope);
     ScopedValue result(scope);
-    JSCallData jsCallData(scope, callback, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->thisObject = callData->argument(1);
 
     for (uint k = 0; k < len; ++k) {
@@ -860,7 +860,7 @@ ReturnedValue ArrayPrototype::method_forEach(const BuiltinFunction *b, CallData
         THROW_TYPE_ERROR();
 
     ScopedValue v(scope);
-    JSCallData jsCallData(scope, callback, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->thisObject = callData->argument(1);
 
     for (uint k = 0; k < len; ++k) {
@@ -896,7 +896,7 @@ ReturnedValue ArrayPrototype::method_map(const BuiltinFunction *b, CallData *cal
 
     ScopedValue v(scope);
     ScopedValue mapped(scope);
-    JSCallData jsCallData(scope, callback, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->thisObject = callData->argument(1);
 
     for (uint k = 0; k < len; ++k) {
@@ -932,7 +932,7 @@ ReturnedValue ArrayPrototype::method_filter(const BuiltinFunction *b, CallData *
 
     ScopedValue selected(scope);
     ScopedValue v(scope);
-    JSCallData jsCallData(scope, callback, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->thisObject = callData->argument(1);
 
     uint to = 0;
@@ -985,7 +985,7 @@ ReturnedValue ArrayPrototype::method_reduce(const BuiltinFunction *b, CallData *
             THROW_TYPE_ERROR();
     }
 
-    JSCallData jsCallData(scope, callback, 4);
+    JSCallData jsCallData(scope, 4);
 
     while (k < len) {
         bool kPresent;
@@ -1038,7 +1038,7 @@ ReturnedValue ArrayPrototype::method_reduceRight(const BuiltinFunction *b, CallD
             THROW_TYPE_ERROR();
     }
 
-    JSCallData jsCallData(scope, callback, 4);
+    JSCallData jsCallData(scope, 4);
     jsCallData->thisObject = Primitive::undefinedValue();
 
     while (k > 0) {
diff --git a/src/qml/jsruntime/qv4dateobject.cpp b/src/qml/jsruntime/qv4dateobject.cpp
index 436950bf28..3397e5418b 100644
--- a/src/qml/jsruntime/qv4dateobject.cpp
+++ b/src/qml/jsruntime/qv4dateobject.cpp
@@ -1451,7 +1451,7 @@ ReturnedValue DatePrototype::method_toJSON(const BuiltinFunction *b, CallData *c
     if (!toIso)
         return v4->throwTypeError();
 
-    JSCallData jsCallData(scope, toIso);
+    JSCallData jsCallData(scope);
     jsCallData->thisObject = callData->thisObject;
     return toIso->call(jsCallData);
 }
diff --git a/src/qml/jsruntime/qv4functionobject.cpp b/src/qml/jsruntime/qv4functionobject.cpp
index 208af838a7..21aacb68d6 100644
--- a/src/qml/jsruntime/qv4functionobject.cpp
+++ b/src/qml/jsruntime/qv4functionobject.cpp
@@ -73,13 +73,13 @@ Q_STATIC_ASSERT((Heap::FunctionObject::markTable & Heap::Object::markTable) == H
 static ReturnedValue jsCallWrapper(const QV4::FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
 {
     Scope scope(f->engine());
-    JSCallData callData(scope, f->asReturnedValue(), argv, argc, thisObject);
+    JSCallData callData(scope, argc, argv, thisObject);
     return f->vtable()->call(f, callData.callData(f));
 }
 ReturnedValue jsConstructWrapper(const QV4::FunctionObject *f, const Value *argv, int argc)
 {
     Scope scope(f->engine());
-    JSCallData callData(scope, f->asReturnedValue(), argv, argc);
+    JSCallData callData(scope, argc, argv);
     return f->vtable()->construct(f, callData.callData(f));
 }
 
diff --git a/src/qml/jsruntime/qv4globalobject.cpp b/src/qml/jsruntime/qv4globalobject.cpp
index 3c91417b0e..4e96b01185 100644
--- a/src/qml/jsruntime/qv4globalobject.cpp
+++ b/src/qml/jsruntime/qv4globalobject.cpp
@@ -374,7 +374,7 @@ ReturnedValue EvalFunction::evalCall(CallData *callData, bool directCall) const
 
     if (function->isStrict() || (ctx->d()->v4Function->isStrict())) {
         ScopedFunctionObject e(scope, FunctionObject::createScriptFunction(ctx, function));
-        JSCallData jsCallData(scope, e, 0);
+        JSCallData jsCallData(scope, 0);
         if (directCall)
             jsCallData->thisObject = scope.engine->currentStackFrame->thisObject();
         else
@@ -387,7 +387,7 @@ ReturnedValue EvalFunction::evalCall(CallData *callData, bool directCall) const
     // set the correct v4 function for the context
     ctx->d()->v4Function = function;
 
-    JSCallData jsCall(scope, nullptr);
+    JSCallData jsCall(scope);
     jsCall->thisObject = scope.engine->currentStackFrame->thisObject();
     jsCall->context = *ctx;
     return function->call(jsCall.callData());
diff --git a/src/qml/jsruntime/qv4include.cpp b/src/qml/jsruntime/qv4include.cpp
index 7feea14a05..df20b2802d 100644
--- a/src/qml/jsruntime/qv4include.cpp
+++ b/src/qml/jsruntime/qv4include.cpp
@@ -119,7 +119,7 @@ void QV4Include::callback(const QV4::Value &callback, const QV4::Value &status)
     if (!f)
         return;
 
-    QV4::JSCallData jsCallData(scope, f, 1);
+    QV4::JSCallData jsCallData(scope, 1);
     jsCallData->thisObject = v4->globalObject->asReturnedValue();
     jsCallData->args[0] = status;
     f->call(jsCallData);
diff --git a/src/qml/jsruntime/qv4jscall_p.h b/src/qml/jsruntime/qv4jscall_p.h
index 0bb2d840da..0f22aa1aa7 100644
--- a/src/qml/jsruntime/qv4jscall_p.h
+++ b/src/qml/jsruntime/qv4jscall_p.h
@@ -61,20 +61,7 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 
 struct JSCallData {
-    JSCallData(const Scope &scope, std::nullptr_t, int argc = 0)
-    {
-        int size = int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)) + argc;
-        ptr = reinterpret_cast<CallData *>(scope.alloc(size));
-        ptr->setArgc(argc);
-    }
-    JSCallData(const Scope &scope, const FunctionObject *function, int argc = 0)
-    {
-        int size = int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)) + argc;
-        ptr = reinterpret_cast<CallData *>(scope.alloc(size));
-        ptr->setArgc(argc);
-        ptr->function = *function;
-    }
-    JSCallData(const Scope &scope, Value *argv, int argc, Value *thisObject = 0)
+    JSCallData(const Scope &scope, int argc = 0, const Value *argv = 0, const Value *thisObject = 0)
     {
         int size = int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)) + argc;
         ptr = reinterpret_cast<CallData *>(scope.engine->jsStackTop);
@@ -84,19 +71,8 @@ struct JSCallData {
         ptr->accumulator = Encode::undefined();
         ptr->thisObject = thisObject ? thisObject->asReturnedValue() : Encode::undefined();
         ptr->setArgc(argc);
-        memcpy(ptr->args, argv, argc*sizeof(Value));
-    }
-    JSCallData(const Scope &scope, ReturnedValue function, const Value *argv, int argc, const Value *thisObject = 0)
-    {
-        int size = int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)) + argc;
-        ptr = reinterpret_cast<CallData *>(scope.engine->jsStackTop);
-        scope.engine->jsStackTop += size;
-        ptr->function = function;
-        ptr->context = Encode::undefined();
-        ptr->accumulator = Encode::undefined();
-        ptr->thisObject = thisObject ? thisObject->asReturnedValue() : Encode::undefined();
-        ptr->setArgc(argc);
-        memcpy(ptr->args, argv, argc*sizeof(Value));
+        if (argv)
+            memcpy(ptr->args, argv, argc*sizeof(Value));
     }
 
     CallData *operator->() const {
diff --git a/src/qml/jsruntime/qv4jsonobject.cpp b/src/qml/jsruntime/qv4jsonobject.cpp
index 7a4ae595ae..16018722cb 100644
--- a/src/qml/jsruntime/qv4jsonobject.cpp
+++ b/src/qml/jsruntime/qv4jsonobject.cpp
@@ -697,7 +697,7 @@ QString Stringify::Str(const QString &key, const Value &v)
         ScopedString s(scope, v4->newString(QStringLiteral("toJSON")));
         ScopedFunctionObject toJSON(scope, o->get(s));
         if (!!toJSON) {
-            JSCallData jsCallData(scope, toJSON, 1);
+            JSCallData jsCallData(scope, 1);
             jsCallData->thisObject = value;
             jsCallData->args[0] = v4->newString(key);
             value = toJSON->call(jsCallData);
@@ -707,7 +707,7 @@ QString Stringify::Str(const QString &key, const Value &v)
     if (replacerFunction) {
         ScopedObject holder(scope, v4->newObject());
         holder->put(scope.engine->id_empty(), value);
-        JSCallData jsCallData(scope, replacerFunction, 2);
+        JSCallData jsCallData(scope, 2);
         jsCallData->args[0] = v4->newString(key);
         jsCallData->args[1] = value;
         jsCallData->thisObject = holder;
diff --git a/src/qml/jsruntime/qv4lookup.cpp b/src/qml/jsruntime/qv4lookup.cpp
index 17667cbae6..87c396be73 100644
--- a/src/qml/jsruntime/qv4lookup.cpp
+++ b/src/qml/jsruntime/qv4lookup.cpp
@@ -400,7 +400,7 @@ ReturnedValue Lookup::getterAccessor0(Lookup *l, ExecutionEngine *engine, const
             if (!getter)
                 return Encode::undefined();
 
-            JSCallData jsCallData(scope, getter, 0);
+            JSCallData jsCallData(scope);
             jsCallData->thisObject = object;
             return getter->call(jsCallData);
         }
@@ -422,7 +422,7 @@ ReturnedValue Lookup::getterAccessor1(Lookup *l, ExecutionEngine *engine, const
             if (!getter)
                 return Encode::undefined();
 
-            JSCallData jsCallData(scope, getter, 0);
+            JSCallData jsCallData(scope);
             jsCallData->thisObject = object;
             return getter->call(jsCallData);
         }
@@ -447,7 +447,7 @@ ReturnedValue Lookup::getterAccessor2(Lookup *l, ExecutionEngine *engine, const
                     if (!getter)
                         return Encode::undefined();
 
-                    JSCallData jsCallData(scope, getter, 0);
+                    JSCallData jsCallData(scope);
                     jsCallData->thisObject = object;
                     return getter->call(jsCallData);
                 }
@@ -502,7 +502,7 @@ ReturnedValue Lookup::primitiveGetterAccessor0(Lookup *l, ExecutionEngine *engin
             if (!getter)
                 return Encode::undefined();
 
-            JSCallData jsCallData(scope, getter, 0);
+            JSCallData jsCallData(scope);
             jsCallData->thisObject = object;
             return getter->call(jsCallData);
         }
@@ -522,7 +522,7 @@ ReturnedValue Lookup::primitiveGetterAccessor1(Lookup *l, ExecutionEngine *engin
             if (!getter)
                 return Encode::undefined();
 
-            JSCallData jsCallData(scope, getter, 0);
+            JSCallData jsCallData(scope);
             jsCallData->thisObject = object;
             return getter->call(jsCallData);
         }
@@ -641,7 +641,7 @@ ReturnedValue Lookup::globalGetterAccessor0(Lookup *l, ExecutionEngine *engine)
         if (!getter)
             return Encode::undefined();
 
-        JSCallData jsCallData(scope, getter, 0);
+        JSCallData jsCallData(scope);
         return getter->call(jsCallData);
     }
     l->globalGetter = globalGetterGeneric;
@@ -658,7 +658,7 @@ ReturnedValue Lookup::globalGetterAccessor1(Lookup *l, ExecutionEngine *engine)
         if (!getter)
             return Encode::undefined();
 
-        JSCallData jsCallData(scope, getter, 0);
+        JSCallData jsCallData(scope);
         return getter->call(jsCallData);
     }
     l->globalGetter = globalGetterGeneric;
@@ -678,7 +678,7 @@ ReturnedValue Lookup::globalGetterAccessor2(Lookup *l, ExecutionEngine *engine)
                 if (!getter)
                     return Encode::undefined();
 
-                JSCallData jsCallData(scope, getter, 0);
+                JSCallData jsCallData(scope);
                 return getter->call(jsCallData);
             }
         }
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index c52cad69d1..18a831a4ba 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -107,7 +107,7 @@ ReturnedValue Object::getValue(const Value &thisObject, const Value &v, Property
         return Encode::undefined();
 
     Scope scope(f->engine());
-    JSCallData jsCallData(scope, f);
+    JSCallData jsCallData(scope);
     jsCallData->thisObject = thisObject;
     return f->call(jsCallData);
 }
@@ -125,7 +125,7 @@ bool Object::putValue(uint memberIndex, const Value &value)
         if (set) {
             Scope scope(ic->engine);
             ScopedFunctionObject setter(scope, set);
-            JSCallData jsCallData(scope, setter, 1);
+            JSCallData jsCallData(scope, 1);
             jsCallData->args[0] = value;
             jsCallData->thisObject = this;
             setter->call(jsCallData);
@@ -764,7 +764,7 @@ bool Object::internalPut(String *name, const Value &value)
 
         Scope scope(engine);
         ScopedFunctionObject setter(scope, *memberIndex);
-        JSCallData jsCallData(scope, setter, 1);
+        JSCallData jsCallData(scope, 1);
         jsCallData->args[0] = value;
         jsCallData->thisObject = this;
         setter->call(jsCallData);
@@ -829,7 +829,7 @@ bool Object::internalPutIndexed(uint index, const Value &value)
 
         Scope scope(engine);
         ScopedFunctionObject setter(scope, *arrayIndex);
-        JSCallData jsCallData(scope, setter, 1);
+        JSCallData jsCallData(scope, 1);
         jsCallData->args[0] = value;
         jsCallData->thisObject = this;
         setter->call(jsCallData);
diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index 198d7d285e..c174cb4dcd 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -479,7 +479,7 @@ ReturnedValue ObjectPrototype::method_toLocaleString(const BuiltinFunction *b, C
     ScopedFunctionObject f(scope, o->get(scope.engine->id_toString()));
     if (!f)
         THROW_TYPE_ERROR();
-    JSCallData jsCallData(scope, f);
+    JSCallData jsCallData(scope);
     jsCallData->thisObject = o;
     return f->call(jsCallData);
 }
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index a6c0218c2b..febcc22fa3 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -816,7 +816,7 @@ struct QObjectSlotDispatcher : public QtPrivate::QSlotObjectBase
             QV4::Scope scope(v4);
             QV4::ScopedFunctionObject f(scope, This->function.value());
 
-            QV4::JSCallData jsCallData(scope, f, argCount);
+            QV4::JSCallData jsCallData(scope, argCount);
             jsCallData->thisObject = This->thisObject.isUndefined() ? v4->globalObject->asReturnedValue() : This->thisObject.value();
             for (int ii = 0; ii < argCount; ++ii) {
                 int type = argsTypes[ii + 1];
diff --git a/src/qml/jsruntime/qv4regexpobject.cpp b/src/qml/jsruntime/qv4regexpobject.cpp
index 556a2a5339..1d1a786e61 100644
--- a/src/qml/jsruntime/qv4regexpobject.cpp
+++ b/src/qml/jsruntime/qv4regexpobject.cpp
@@ -436,7 +436,7 @@ ReturnedValue RegExpPrototype::method_compile(const BuiltinFunction *b, CallData
     if (!r)
         return scope.engine->throwTypeError();
 
-    JSCallData jsCallData(scope, scope.engine->regExpCtor(), callData->argc());
+    JSCallData jsCallData(scope, callData->argc());
     memcpy(jsCallData->args, callData->args, callData->argc()*sizeof(Value));
 
     Scoped<RegExpObject> re(scope, scope.engine->regExpCtor()->callAsConstructor(jsCallData));
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index aecff0f629..00882d699c 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -429,7 +429,7 @@ ReturnedValue RuntimeHelpers::objectDefaultValue(const Object *object, int typeH
     ScopedValue result(scope);
     ScopedValue conv(scope, object->get(meth1));
 
-    JSCallData jsCallData(scope, nullptr, 0);
+    JSCallData jsCallData(scope, 0);
     jsCallData->thisObject = *object;
 
     if (FunctionObject *o = conv->as<FunctionObject>()) {
@@ -982,7 +982,7 @@ ReturnedValue Runtime::method_callGlobalLookup(ExecutionEngine *engine, uint ind
 ReturnedValue Runtime::method_callPossiblyDirectEval(ExecutionEngine *engine, Value *argv, int argc)
 {
     Scope scope(engine);
-    JSCallData callData(scope, argv, argc);
+    JSCallData callData(scope, argc, argv);
     Q_ASSERT(callData->args + callData->argc() == engine->jsStackTop);
 
     ExecutionContext &ctx = static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context);
@@ -1009,7 +1009,7 @@ ReturnedValue Runtime::method_callPossiblyDirectEval(ExecutionEngine *engine, Va
 ReturnedValue Runtime::method_callName(ExecutionEngine *engine, int nameIndex, Value *argv, int argc)
 {
     Scope scope(engine);
-    JSCallData callData(scope, argv, argc);
+    JSCallData callData(scope, argc, argv);
     Q_ASSERT(callData->args + callData->argc() == engine->jsStackTop);
 
     callData->function = engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex];
@@ -1036,7 +1036,7 @@ ReturnedValue Runtime::method_callName(ExecutionEngine *engine, int nameIndex, V
 ReturnedValue Runtime::method_callProperty(ExecutionEngine *engine, Value *base, int nameIndex, Value *argv, int argc)
 {
     Scope scope(engine);
-    JSCallData callData(scope, argv, argc, base);
+    JSCallData callData(scope, argc, argv, base);
     Q_ASSERT(callData->args + callData->argc() == engine->jsStackTop);
 
     if (!callData->thisObject.isObject()) {
@@ -1070,7 +1070,7 @@ ReturnedValue Runtime::method_callProperty(ExecutionEngine *engine, Value *base,
 ReturnedValue Runtime::method_callPropertyLookup(ExecutionEngine *engine, Value *base, uint index, Value *argv, int argc)
 {
     Scope scope(engine);
-    JSCallData callData(scope, argv, argc, base);
+    JSCallData callData(scope, argc, argv, base);
     Q_ASSERT(callData->args + callData->argc() == engine->jsStackTop);
 
     Q_ASSERT(engine->jsStackTop >= callData->args + callData->argc());
@@ -1087,7 +1087,7 @@ ReturnedValue Runtime::method_callPropertyLookup(ExecutionEngine *engine, Value
 ReturnedValue Runtime::method_callElement(ExecutionEngine *engine, Value *base, const Value &index, Value *argv, int argc)
 {
     Scope scope(engine);
-    JSCallData callData(scope, argv, argc, base);
+    JSCallData callData(scope, argc, argv, base);
     Q_ASSERT(callData->args + callData->argc() == engine->jsStackTop);
 
     callData->thisObject = callData->thisObject.toObject(engine);
@@ -1108,10 +1108,10 @@ ReturnedValue Runtime::method_callValue(ExecutionEngine *engine, const Value &fu
         return engine->throwTypeError(QStringLiteral("%1 is not a function").arg(func.toQStringNoThrow()));
 
     Scope scope(engine);
-    JSCallData callData(scope, func.asReturnedValue(), argv, argc);
+    JSCallData callData(scope, argc, argv);
     Q_ASSERT(callData->args + callData->argc() == engine->jsStackTop);
 
-    return static_cast<FunctionObject &>(callData->function).call(&callData->thisObject, callData->args, callData->argc());
+    return static_cast<const FunctionObject &>(func).call(&callData->thisObject, callData->args, callData->argc());
 }
 
 
diff --git a/src/qml/jsruntime/qv4script.cpp b/src/qml/jsruntime/qv4script.cpp
index c0a00032dd..8ca4985b32 100644
--- a/src/qml/jsruntime/qv4script.cpp
+++ b/src/qml/jsruntime/qv4script.cpp
@@ -152,13 +152,13 @@ ReturnedValue Script::run()
         ContextStateSaver stateSaver(valueScope, context);
         context->d()->v4Function = vmFunction;
 
-        QV4::JSCallData jsCall(valueScope, nullptr);
+        QV4::JSCallData jsCall(valueScope);
         jsCall->thisObject = engine->globalObject;
         jsCall->context = *context;
         return vmFunction->call(jsCall.callData());
     } else {
         Scoped<QmlContext> qml(valueScope, qmlContext.value());
-        JSCallData jsCall(valueScope, nullptr);
+        JSCallData jsCall(valueScope);
         jsCall->thisObject = Primitive::undefinedValue();
         jsCall->context = *qml;
         return vmFunction->call(jsCall.callData());
diff --git a/src/qml/jsruntime/qv4sequenceobject.cpp b/src/qml/jsruntime/qv4sequenceobject.cpp
index 818711fc99..4dd71fe582 100644
--- a/src/qml/jsruntime/qv4sequenceobject.cpp
+++ b/src/qml/jsruntime/qv4sequenceobject.cpp
@@ -420,7 +420,7 @@ public:
             ScopedFunctionObject compare(scope, m_compareFn);
             if (!compare)
                 return m_v4->throwTypeError();
-            JSCallData jsCallData(scope, compare, 2);
+            JSCallData jsCallData(scope, 2);
             jsCallData->args[0] = convertElementToValue(m_v4, lhs);
             jsCallData->args[1] = convertElementToValue(m_v4, rhs);
             jsCallData->thisObject = m_v4->globalObject;
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index 11fdcae6f8..d8bd51ac39 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -583,7 +583,7 @@ ReturnedValue StringPrototype::method_replace(const BuiltinFunction *b, CallData
     if (!!searchCallback) {
         result.reserve(string.length() + 10*numStringMatches);
         ScopedValue entry(scope);
-        JSCallData jsCallData(scope, searchCallback, numCaptures + 2);
+        JSCallData jsCallData(scope, numCaptures + 2);
         jsCallData->thisObject = Primitive::undefinedValue();
         int lastEnd = 0;
         for (int i = 0; i < numStringMatches; ++i) {
@@ -644,9 +644,9 @@ ReturnedValue StringPrototype::method_search(const BuiltinFunction *b, CallData
 
     RegExpObject *regExp = regExpObj->as<RegExpObject>();
     if (!regExp) {
-        JSCallData jsCallDataData(scope, scope.engine->regExpCtor(), 1);
-        jsCallDataData->args[0] = regExpObj;
-        regExpObj = scope.engine->regExpCtor()->callAsConstructor(jsCallDataData);
+        JSCallData jsCallData(scope, 1);
+        jsCallData->args[0] = regExpObj;
+        regExpObj = scope.engine->regExpCtor()->callAsConstructor(jsCallData);
         if (scope.engine->hasException)
             return QV4::Encode::undefined();
 
diff --git a/src/qml/jsruntime/qv4typedarray.cpp b/src/qml/jsruntime/qv4typedarray.cpp
index 8583d5da06..631fed426a 100644
--- a/src/qml/jsruntime/qv4typedarray.cpp
+++ b/src/qml/jsruntime/qv4typedarray.cpp
@@ -572,7 +572,7 @@ ReturnedValue TypedArrayPrototype::method_subarray(const BuiltinFunction *builti
     if (!constructor)
         return scope.engine->throwTypeError();
 
-    JSCallData jsCallData(scope, constructor, 3);
+    JSCallData jsCallData(scope, 3);
     jsCallData->args[0] = buffer;
     jsCallData->args[1] = Encode(a->d()->byteOffset + begin*a->d()->type->bytesPerElement);
     jsCallData->args[2] = Encode(newLen);
diff --git a/src/qml/qml/qqmlboundsignal.cpp b/src/qml/qml/qqmlboundsignal.cpp
index 65af68621a..1d7a37fc99 100644
--- a/src/qml/qml/qqmlboundsignal.cpp
+++ b/src/qml/qml/qqmlboundsignal.cpp
@@ -193,7 +193,7 @@ void QQmlBoundSignalExpression::evaluate(void **a)
     int *argsTypes = QQmlMetaObject(m_target).methodParameterTypes(methodIndex, &storage, 0);
     int argCount = argsTypes ? *argsTypes : 0;
 
-    QV4::JSCallData jsCall(scope, nullptr, argCount);
+    QV4::JSCallData jsCall(scope, argCount);
     for (int ii = 0; ii < argCount; ++ii) {
         int type = argsTypes[ii + 1];
         //### ideally we would use metaTypeToJS, however it currently gives different results
@@ -238,7 +238,7 @@ void QQmlBoundSignalExpression::evaluate(const QList<QVariant> &args)
 
     ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
 
-    QV4::JSCallData jsCall(scope, nullptr, args.count());
+    QV4::JSCallData jsCall(scope, args.count());
     for (int ii = 0; ii < args.count(); ++ii) {
         jsCall->args[ii] = scope.engine->fromVariant(args[ii]);
     }
diff --git a/src/qml/qml/qqmlcomponent.cpp b/src/qml/qml/qqmlcomponent.cpp
index e64d72a5ca..956083238b 100644
--- a/src/qml/qml/qqmlcomponent.cpp
+++ b/src/qml/qml/qqmlcomponent.cpp
@@ -1547,7 +1547,7 @@ void QV4::QmlIncubatorObject::statusChanged(QQmlIncubator::Status s)
 
     QV4::ScopedFunctionObject f(scope, d()->statusChanged);
     if (f) {
-        QV4::JSCallData jsCallData(scope, f, 1);
+        QV4::JSCallData jsCallData(scope, 1);
         jsCallData->thisObject = this;
         jsCallData->args[0] = QV4::Primitive::fromUInt32(s);
         f->call(jsCallData);
diff --git a/src/qml/qml/qqmldelayedcallqueue.cpp b/src/qml/qml/qqmldelayedcallqueue.cpp
index 9d570f18b0..8b01630628 100644
--- a/src/qml/qml/qqmldelayedcallqueue.cpp
+++ b/src/qml/qml/qqmldelayedcallqueue.cpp
@@ -67,7 +67,7 @@ void QQmlDelayedCallQueue::DelayedFunctionCall::execute(QV4::ExecutionEngine *en
         const QV4::FunctionObject *callback = m_function.as<QV4::FunctionObject>();
         Q_ASSERT(callback);
         const int argCount = array ? array->getLength() : 0;
-        QV4::JSCallData jsCallData(scope, callback, argCount);
+        QV4::JSCallData jsCallData(scope, argCount);
         jsCallData->thisObject = QV4::Encode::undefined();
 
         for (int i = 0; i < argCount; i++) {
diff --git a/src/qml/qml/qqmljavascriptexpression.cpp b/src/qml/qml/qqmljavascriptexpression.cpp
index 015471a13d..0208db2d48 100644
--- a/src/qml/qml/qqmljavascriptexpression.cpp
+++ b/src/qml/qml/qqmljavascriptexpression.cpp
@@ -185,7 +185,7 @@ QV4::ReturnedValue QQmlJavaScriptExpression::evaluate(bool *isUndefined)
 {
     QV4::ExecutionEngine *v4 = QV8Engine::getV4(m_context->engine);
     QV4::Scope scope(v4);
-    QV4::JSCallData jsCall(scope, nullptr);
+    QV4::JSCallData jsCall(scope);
 
     return evaluate(jsCall.callData(), isUndefined);
 }
diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index efd67bc446..8b5db2f9f1 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -950,7 +950,7 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                 }
 
                 const unsigned int parameterCount = function->formalParameterCount();
-                QV4::JSCallData jsCallData(scope, function, parameterCount);
+                QV4::JSCallData jsCallData(scope, parameterCount);
                 jsCallData->thisObject = ep->v8engine()->global();
 
                 for (uint ii = 0; ii < parameterCount; ++ii)
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index 35c6d2f0b7..f9052d249f 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -1576,7 +1576,7 @@ void QQmlXMLHttpRequest::dispatchCallback(Object *thisObj, QQmlContextData *cont
         return;
     }
 
-    QV4::JSCallData jsCallData(scope, callback);
+    QV4::JSCallData jsCallData(scope);
     callback->call(jsCallData);
 
     if (scope.engine->hasException) {
diff --git a/src/qml/types/qquickworkerscript.cpp b/src/qml/types/qquickworkerscript.cpp
index 64949ef5ae..6db1372465 100644
--- a/src/qml/types/qquickworkerscript.cpp
+++ b/src/qml/types/qquickworkerscript.cpp
@@ -248,7 +248,7 @@ void QQuickWorkerScriptEnginePrivate::WorkerEngine::init()
     QV4::ScopedString name(scope, m_v4Engine->newString(QStringLiteral("sendMessage")));
     QV4::ScopedValue function(scope, QV4::BuiltinFunction::create(globalContext, name,
                                                                   QQuickWorkerScriptEnginePrivate::method_sendMessage));
-    QV4::JSCallData jsCallData(scope, createsendconstructor, 1);
+    QV4::JSCallData jsCallData(scope, 1);
     jsCallData->args[0] = function;
     jsCallData->thisObject = global();
     createsend.set(scope.engine, createsendconstructor->call(jsCallData));
@@ -265,7 +265,7 @@ QV4::ReturnedValue QQuickWorkerScriptEnginePrivate::WorkerEngine::sendFunction(i
     QV4::ScopedFunctionObject f(scope, createsend.value());
 
     QV4::ScopedValue v(scope);
-    QV4::JSCallData jsCallData(scope, f, 1);
+    QV4::JSCallData jsCallData(scope, 1);
     jsCallData->args[0] = QV4::Primitive::fromInt32(id);
     jsCallData->thisObject = global();
     v = f->call(jsCallData);
@@ -366,7 +366,7 @@ void QQuickWorkerScriptEnginePrivate::processMessage(int id, const QByteArray &d
     QV4::Scoped<QV4::QmlContext> qmlContext(scope, script->qmlContext.value());
     Q_ASSERT(!!qmlContext);
 
-    QV4::JSCallData jsCallData(scope, f, 2);
+    QV4::JSCallData jsCallData(scope, 2);
     jsCallData->thisObject = workerEngine->global();
     jsCallData->args[0] = qmlContext->d()->qml(); // ###
     jsCallData->args[1] = value;
diff --git a/src/quick/items/context2d/qquickcanvasitem.cpp b/src/quick/items/context2d/qquickcanvasitem.cpp
index 5d5d785f7d..f9b5a7af81 100644
--- a/src/quick/items/context2d/qquickcanvasitem.cpp
+++ b/src/quick/items/context2d/qquickcanvasitem.cpp
@@ -729,13 +729,14 @@ void QQuickCanvasItem::updatePolish()
 
         QV4::ExecutionEngine *v4 = QQmlEnginePrivate::getV4Engine(qmlEngine(this));
         QV4::Scope scope(v4);
-        QV4::JSCallData jsCall(scope, nullptr, 1);
+        QV4::ScopedFunctionObject function(scope);
+        QV4::JSCallData jsCall(scope, 1);
         jsCall->thisObject = QV4::QObjectWrapper::wrap(v4, this);
 
         for (auto it = animationCallbacks.cbegin(), end = animationCallbacks.cend(); it != end; ++it) {
-            jsCall->function = it.value().value();
+            function = it.value().value();
             jsCall->args[0] = QV4::Primitive::fromUInt32(QDateTime::currentMSecsSinceEpoch() / 1000);
-            jsCall.call();
+            function->call(jsCall);
         }
     }
     else {