QML: Make Heap::Object and all subclasses trivial

GCC6 might dead-store-eliminate out our secret write to Base::mmdata,
because it expects all memory content to be "undefined" before
constructor calls. Clang might take the same approach if the constructor
of Heap::Object is removed.

By making these structs trivial, it also makes them memcpy-able.

Change-Id: I055b2ad28311b997fbe059849ebda4d5894eaa9b
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4dataview_p.h b/src/qml/jsruntime/qv4dataview_p.h
index f996a4c2f1..246124394a 100644
--- a/src/qml/jsruntime/qv4dataview_p.h
+++ b/src/qml/jsruntime/qv4dataview_p.h
@@ -60,11 +60,11 @@ namespace QV4 {
 namespace Heap {
 
 struct DataViewCtor : FunctionObject {
-    DataViewCtor(QV4::ExecutionContext *scope);
+    void init(QV4::ExecutionContext *scope);
 };
 
 struct DataView : Object {
-    DataView() {}
+    void init() { Object::init(); }
     Pointer<ArrayBuffer> buffer;
     uint byteLength;
     uint byteOffset;