1 | // Copyright (C) 2022 The Qt Company Ltd. |
2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
3 | |
4 | #ifndef QV4REFERENCEOBJECT_P_H |
5 | #define QV4REFERENCEOBJECT_P_H |
6 | |
7 | // |
8 | // W A R N I N G |
9 | // ------------- |
10 | // |
11 | // This file is not part of the Qt API. It exists purely as an |
12 | // implementation detail. This header file may change from version to |
13 | // version without notice, or even be removed. |
14 | // |
15 | // We mean it. |
16 | // |
17 | |
18 | #include <private/qv4object_p.h> |
19 | #include <private/qv4stackframe_p.h> |
20 | |
21 | QT_BEGIN_NAMESPACE |
22 | |
23 | namespace QV4 { |
24 | namespace Heap { |
25 | |
26 | |
27 | #define ReferenceObjectMembers(class, Member) \ |
28 | Member(class, Pointer, Object *, m_object) |
29 | |
30 | DECLARE_HEAP_OBJECT(ReferenceObject, Object) { |
31 | DECLARE_MARKOBJECTS(ReferenceObject); |
32 | |
33 | enum Flag : quint8 { |
34 | NoFlag = 0, |
35 | CanWriteBack = 1 << 0, |
36 | IsVariant = 1 << 1, |
37 | EnforcesLocation = 1 << 2, |
38 | }; |
39 | Q_DECLARE_FLAGS(Flags, Flag); |
40 | |
41 | void init(Object *object, int property, Flags flags) |
42 | { |
43 | setObject(object); |
44 | m_property = property; |
45 | m_flags = flags; |
46 | Object::init(); |
47 | } |
48 | |
49 | Flags flags() const { return Flags(m_flags); } |
50 | |
51 | Object *object() const { return m_object.get(); } |
52 | void setObject(Object *object) { m_object.set(e: internalClass->engine, newVal: object); } |
53 | |
54 | int property() const { return m_property; } |
55 | |
56 | bool canWriteBack() const { return hasFlag(flag: CanWriteBack); } |
57 | bool isVariant() const { return hasFlag(flag: IsVariant); } |
58 | bool enforcesLocation() const { return hasFlag(flag: EnforcesLocation); } |
59 | |
60 | void setLocation(const Function *function, quint16 statement) |
61 | { |
62 | m_function = function; |
63 | m_statementIndex = statement; |
64 | } |
65 | |
66 | const Function *function() const { return m_function; } |
67 | quint16 statementIndex() const { return m_statementIndex; } |
68 | |
69 | bool isAttachedToProperty() const |
70 | { |
71 | if (enforcesLocation()) { |
72 | if (CppStackFrame *frame = internalClass->engine->currentStackFrame) { |
73 | if (frame->v4Function != function() || frame->statementNumber() != statementIndex()) |
74 | return false; |
75 | } else { |
76 | return false; |
77 | } |
78 | } |
79 | |
80 | return true; |
81 | } |
82 | |
83 | bool isReference() const { return m_object; } |
84 | |
85 | private: |
86 | |
87 | bool hasFlag(Flag flag) const |
88 | { |
89 | return m_flags & quint8(flag); |
90 | } |
91 | |
92 | void setFlag(Flag flag, bool set) |
93 | { |
94 | m_flags = set ? (m_flags | quint8(flag)) : (m_flags & ~quint8(flag)); |
95 | } |
96 | |
97 | const Function *m_function; |
98 | int m_property; |
99 | quint16 m_statementIndex; |
100 | quint8 m_flags; |
101 | }; |
102 | |
103 | Q_DECLARE_OPERATORS_FOR_FLAGS(ReferenceObject::Flags) |
104 | |
105 | } // namespace Heap |
106 | |
107 | |
108 | struct ReferenceObject : public Object |
109 | { |
110 | V4_OBJECT2(ReferenceObject, Object) |
111 | V4_NEEDS_DESTROY |
112 | |
113 | public: |
114 | static constexpr const int AllProperties = -1; |
115 | |
116 | template<typename HeapObject> |
117 | static bool readReference(HeapObject *ref) |
118 | { |
119 | if (!ref->object()) |
120 | return false; |
121 | |
122 | QV4::Scope scope(ref->internalClass->engine); |
123 | QV4::ScopedObject object(scope, ref->object()); |
124 | |
125 | if (ref->isVariant()) { |
126 | QVariant variant; |
127 | void *a[] = { &variant }; |
128 | return object->metacall(call: QMetaObject::ReadProperty, index: ref->property(), a) |
129 | && ref->setVariant(variant); |
130 | } |
131 | |
132 | void *a[] = { ref->storagePointer() }; |
133 | return object->metacall(call: QMetaObject::ReadProperty, index: ref->property(), a); |
134 | } |
135 | |
136 | template<typename HeapObject> |
137 | static bool writeBack(HeapObject *ref, int internalIndex = AllProperties) |
138 | { |
139 | if (!ref->object() || !ref->canWriteBack()) |
140 | return false; |
141 | |
142 | QV4::Scope scope(ref->internalClass->engine); |
143 | QV4::ScopedObject object(scope, ref->object()); |
144 | |
145 | int flags = QQmlPropertyData::HasInternalIndex; |
146 | int status = -1; |
147 | if (ref->isVariant()) { |
148 | QVariant variant = ref->toVariant(); |
149 | void *a[] = { &variant, nullptr, &status, &flags, &internalIndex }; |
150 | return object->metacall(call: QMetaObject::WriteProperty, index: ref->property(), a); |
151 | } |
152 | |
153 | void *a[] = { ref->storagePointer(), nullptr, &status, &flags, &internalIndex }; |
154 | return object->metacall(call: QMetaObject::WriteProperty, index: ref->property(), a); |
155 | } |
156 | |
157 | template<typename HeapObject> |
158 | static HeapObject *detached(HeapObject *ref) |
159 | { |
160 | if (ref->object() && !ref->enforcesLocation() && !readReference(ref)) |
161 | return ref; // It's dead. No point in detaching it anymore |
162 | |
163 | return ref->detached(); |
164 | } |
165 | }; |
166 | |
167 | } // namespace QV4 |
168 | |
169 | QT_END_NAMESPACE |
170 | |
171 | #endif // QV4REFERENCEOBJECT_P_H |
172 | |