1 files changed, 43 insertions, 7 deletions

diff --git a/src/qml/memory/qv4heap_p.h b/src/qml/memory/qv4heap_p.h
index d15d14e463..5a3797f397 100644
--- a/src/qml/memory/qv4heap_p.h
+++ b/src/qml/memory/qv4heap_p.h
@@ -58,6 +58,12 @@
 // parent's init all up the inheritance chain), define QML_CHECK_INIT_DESTROY_CALLS below.
 #undef QML_CHECK_INIT_DESTROY_CALLS
 
+#if defined(_MSC_VER) && (_MSC_VER < 1900) // broken compilers:
+#  define V4_ASSERT_IS_TRIVIAL(x)
+#else // working compilers:
+#  define V4_ASSERT_IS_TRIVIAL(x) Q_STATIC_ASSERT(std::is_trivial< x >::value);
+#endif
+
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
@@ -82,6 +88,8 @@ struct VTable
 namespace Heap {
 
 struct Q_QML_EXPORT Base {
+    void *operator new(size_t) = delete;
+
     quintptr mm_data; // vtable and markbit
 
     inline ReturnedValue asReturnedValue() const;
@@ -125,16 +133,44 @@ struct Q_QML_EXPORT Base {
     void *operator new(size_t, Heap::Base *m) { return m; }
     void operator delete(void *, Heap::Base *) {}
 
-    void init() { setInitialized(); }
+    void init() { _setInitialized(); }
+    void destroy() { _setDestroyed(); }
 #ifdef QML_CHECK_INIT_DESTROY_CALLS
-    bool _isInitialized;
-    void _checkIsInitialized() { Q_ASSERT(_isInitialized); }
-    void setInitialized() { Q_ASSERT(!_isInitialized); _isInitialized = true; }
+    enum { Uninitialized = 0, Initialized, Destroyed } _livenessStatus;
+    void _checkIsInitialized() {
+        if (_livenessStatus == Uninitialized)
+            fprintf(stderr, "ERROR: use of object '%s' before call to init() !!\n",
+                    vtable()->className);
+        else if (_livenessStatus == Destroyed)
+            fprintf(stderr, "ERROR: use of object '%s' after call to destroy() !!\n",
+                    vtable()->className);
+        Q_ASSERT(_livenessStatus = Initialized);
+    }
+    void _checkIsDestroyed() {
+        if (_livenessStatus == Initialized)
+            fprintf(stderr, "ERROR: object '%s' was never destroyed completely !!\n",
+                    vtable()->className);
+        Q_ASSERT(_livenessStatus == Destroyed);
+    }
+    void _setInitialized() { Q_ASSERT(_livenessStatus == Uninitialized); _livenessStatus = Initialized; }
+    void _setDestroyed() {
+        if (_livenessStatus == Uninitialized)
+            fprintf(stderr, "ERROR: attempting to destroy an uninitialized object '%s' !!\n",
+                    vtable()->className);
+        else if (_livenessStatus == Destroyed)
+            fprintf(stderr, "ERROR: attempting to destroy repeatedly object '%s' !!\n",
+                    vtable()->className);
+        Q_ASSERT(_livenessStatus == Initialized);
+        _livenessStatus = Destroyed;
+    }
 #else
     Q_ALWAYS_INLINE void _checkIsInitialized() {}
-    Q_ALWAYS_INLINE void setInitialized() {}
+    Q_ALWAYS_INLINE void _checkIsDestroyed() {}
+    Q_ALWAYS_INLINE void _setInitialized() {}
+    Q_ALWAYS_INLINE void _setDestroyed() {}
 #endif
 };
+V4_ASSERT_IS_TRIVIAL(Base)
 
 template <typename T>
 struct Pointer {
@@ -148,7 +184,7 @@ struct Pointer {
 
     T *ptr;
 };
-Q_STATIC_ASSERT(std::is_trivial<Pointer<void>>::value);
+V4_ASSERT_IS_TRIVIAL(Pointer<void>)
 
 }
 
@@ -204,7 +240,7 @@ private:
     QtSharedPointer::ExternalRefCountData *d;
     QObject *qObject;
 };
-Q_STATIC_ASSERT(std::is_trivial<QQmlQPointer<QObject>>::value);
+V4_ASSERT_IS_TRIVIAL(QQmlQPointer<QObject>)
 #endif
 
 }