Recursively write back value types and sequences

Both types have functionality to write themselves back to the properties
they were loaded from on change, but so far we could not nest those
writes.

[ChangeLog][QtQml] You can now assign to properties of nested value
types and to elements of containers from QML functions. You cannot,
however, take references of such values and elements. This is in
contrast to non-nested value types and the containers themselves.
However, passing references of value types and containers around
generally leads to very confusing effects. Don't do this.

Fixes: QTBUG-99766
Change-Id: I74cb89e5c3d733b0b61e42969d617b2ecc1562f4
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/qml/jsruntime/qv4vtable_p.h b/src/qml/jsruntime/qv4vtable_p.h
index 6bcbd7e20c..7db1e71704 100644
--- a/src/qml/jsruntime/qv4vtable_p.h
+++ b/src/qml/jsruntime/qv4vtable_p.h
@@ -15,6 +15,7 @@
 //
 
 #include "qv4global_p.h"
+#include <QtCore/qmetaobject.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -55,6 +56,8 @@ struct VTable
     typedef ReturnedValue (*ResolveLookupGetter)(const Object *, ExecutionEngine *, Lookup *);
     typedef bool (*ResolveLookupSetter)(Object *, ExecutionEngine *, Lookup *, const Value &);
 
+    typedef int (*Metacall)(Object *, QMetaObject::Call, int, void **);
+
     const VTable * const parent;
     quint16 inlinePropertyOffset;
     quint16 nInlineProperties;
@@ -93,6 +96,8 @@ struct VTable
 
     ResolveLookupGetter resolveLookupGetter;
     ResolveLookupSetter resolveLookupSetter;
+
+    Metacall metacall;
 };
 
 template<VTable::CallWithMetaTypes call>
@@ -173,6 +178,8 @@ protected:
     static constexpr VTable::ResolveLookupGetter virtualResolveLookupGetter = nullptr;
     static constexpr VTable::ResolveLookupSetter virtualResolveLookupSetter = nullptr;
 
+    static constexpr VTable::Metacall virtualMetacall = nullptr;
+
     template<class Class>
     friend constexpr VTable::CallWithMetaTypes vtableMetaTypesCallEntry();
 
@@ -220,7 +227,8 @@ protected:
     QV4::vtableMetaTypesCallEntry<classname>(), \
     \
     classname::virtualResolveLookupGetter,  \
-    classname::virtualResolveLookupSetter   \
+    classname::virtualResolveLookupSetter,  \
+    classname::virtualMetacall              \
 }
 
 #define DEFINE_MANAGED_VTABLE(classname) \