1// Copyright (C) 2016 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#ifndef QV4LOOKUP_H
4#define QV4LOOKUP_H
5
6//
7// W A R N I N G
8// -------------
9//
10// This file is not part of the Qt API. It exists purely as an
11// implementation detail. This header file may change from version to
12// version without notice, or even be removed.
13//
14// We mean it.
15//
16
17#include "qv4engine_p.h"
18#include "qv4object_p.h"
19#include "qv4internalclass_p.h"
20#include "qv4qmlcontext_p.h"
21#include <private/qqmltypewrapper_p.h>
22#include <private/qv4mm_p.h>
23
24QT_BEGIN_NAMESPACE
25
26namespace QV4 {
27
28namespace Heap {
29 struct QObjectMethod;
30}
31
32template <typename T, int PhantomTag>
33using HeapObjectWrapper = WriteBarrier::HeapObjectWrapper<T, PhantomTag>;
34
35// Note: We cannot hide the copy ctor and assignment operator of this class because it needs to
36// be trivially copyable. But you should never ever copy it. There are refcounted members
37// in there.
38struct Q_QML_EXPORT Lookup {
39 union {
40 ReturnedValue (*getter)(Lookup *l, ExecutionEngine *engine, const Value &object);
41 ReturnedValue (*globalGetter)(Lookup *l, ExecutionEngine *engine);
42 ReturnedValue (*qmlContextPropertyGetter)(Lookup *l, ExecutionEngine *engine, Value *thisObject);
43 bool (*setter)(Lookup *l, ExecutionEngine *engine, Value &object, const Value &v);
44 };
45 // NOTE: gc assumes the first two entries in the struct are pointers to heap objects or null
46 // or that the least significant bit is 1 (see the Lookup::markObjects function)
47 union {
48 struct {
49 Heap::Base *h1;
50 Heap::Base *h2;
51 quintptr unused;
52 quintptr unused2;
53 } markDef;
54 struct {
55 HeapObjectWrapper<Heap::InternalClass, 0> ic;
56 quintptr unused;
57 uint index;
58 uint offset;
59 } objectLookup;
60 struct {
61 quintptr protoId;
62 quintptr _unused;
63 const Value *data;
64 } protoLookup;
65 struct {
66 HeapObjectWrapper<Heap::InternalClass, 1> ic;
67 HeapObjectWrapper<Heap::InternalClass, 2> ic2;
68 uint offset;
69 uint offset2;
70 } objectLookupTwoClasses;
71 struct {
72 quintptr protoId;
73 quintptr protoId2;
74 const Value *data;
75 const Value *data2;
76 } protoLookupTwoClasses;
77 struct {
78 // Make sure the next two values are in sync with protoLookup
79 quintptr protoId;
80 HeapObjectWrapper<Heap::Object, 3> proto;
81 const Value *data;
82 quintptr type;
83 } primitiveLookup;
84 struct {
85 HeapObjectWrapper<Heap::InternalClass, 4> newClass;
86 quintptr protoId;
87 uint offset;
88 uint unused;
89 } insertionLookup;
90 struct {
91 quintptr _unused;
92 quintptr _unused2;
93 uint index;
94 uint unused;
95 } indexedLookup;
96 struct {
97 HeapObjectWrapper<Heap::InternalClass, 5> ic;
98 HeapObjectWrapper<Heap::InternalClass, 6> qmlTypeIc; // only used when lookup goes through QQmlTypeWrapper
99 const QQmlPropertyCache *propertyCache;
100 const QQmlPropertyData *propertyData;
101 } qobjectLookup;
102 struct {
103 HeapObjectWrapper<Heap::InternalClass, 7> ic;
104 HeapObjectWrapper<Heap::QObjectMethod, 8> method;
105 const QQmlPropertyCache *propertyCache;
106 const QQmlPropertyData *propertyData;
107 } qobjectMethodLookup;
108 struct {
109 quintptr isConstant; // This is a bool, encoded as 0 or 1. Both values are ignored by gc
110 quintptr metaObject; // a (const QMetaObject* & 1) or nullptr
111 int coreIndex;
112 int notifyIndex;
113 } qobjectFallbackLookup;
114 struct {
115 HeapObjectWrapper<Heap::InternalClass, 9> ic;
116 quintptr metaObject; // a (const QMetaObject* & 1) or nullptr
117 const QtPrivate::QMetaTypeInterface *metaType; // cannot use QMetaType; class must be trivial
118 quint16 coreIndex;
119 bool isFunction;
120 bool isEnum;
121 } qgadgetLookup;
122 struct {
123 quintptr unused1;
124 quintptr unused2;
125 int scriptIndex;
126 } qmlContextScriptLookup;
127 struct {
128 HeapObjectWrapper<Heap::Base, 10> singletonObject;
129 quintptr unused2;
130 QV4::ReturnedValue singletonValue;
131 } qmlContextSingletonLookup;
132 struct {
133 quintptr unused1;
134 quintptr unused2;
135 int objectId;
136 } qmlContextIdObjectLookup;
137 struct {
138 // Same as protoLookup, as used for global lookups
139 quintptr reserved1;
140 quintptr reserved2;
141 quintptr reserved3;
142 ReturnedValue (*getterTrampoline)(Lookup *l, ExecutionEngine *engine);
143 } qmlContextGlobalLookup;
144 struct {
145 HeapObjectWrapper<Heap::Base, 11> qmlTypeWrapper;
146 quintptr unused2;
147 } qmlTypeLookup;
148 struct {
149 HeapObjectWrapper<Heap::InternalClass, 12> ic;
150 quintptr unused;
151 ReturnedValue encodedEnumValue;
152 const QtPrivate::QMetaTypeInterface *metaType;
153 } qmlEnumValueLookup;
154 struct {
155 HeapObjectWrapper<Heap::InternalClass, 13> ic;
156 HeapObjectWrapper<Heap::Object, 14> qmlScopedEnumWrapper;
157 } qmlScopedEnumWrapperLookup;
158 };
159
160 uint nameIndex: 28; // Same number of bits we store in the compilation unit for name indices
161 uint forCall: 1; // Whether we are looking up a value in order to call it right away
162 uint reserved: 3;
163
164 ReturnedValue resolveGetter(ExecutionEngine *engine, const Object *object);
165 ReturnedValue resolvePrimitiveGetter(ExecutionEngine *engine, const Value &object);
166 ReturnedValue resolveGlobalGetter(ExecutionEngine *engine);
167 void resolveProtoGetter(PropertyKey name, const Heap::Object *proto);
168
169 static ReturnedValue getterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object);
170 static ReturnedValue getterTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
171 static ReturnedValue getterFallback(Lookup *l, ExecutionEngine *engine, const Value &object);
172 static ReturnedValue getterFallbackAsVariant(Lookup *l, ExecutionEngine *engine, const Value &object);
173
174 static ReturnedValue getter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
175 static ReturnedValue getter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object);
176 static ReturnedValue getterProto(Lookup *l, ExecutionEngine *engine, const Value &object);
177 static ReturnedValue getter0Inlinegetter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object);
178 static ReturnedValue getter0Inlinegetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
179 static ReturnedValue getter0MemberDatagetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
180 static ReturnedValue getterProtoTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
181 static ReturnedValue getterAccessor(Lookup *l, ExecutionEngine *engine, const Value &object);
182 static ReturnedValue getterProtoAccessor(Lookup *l, ExecutionEngine *engine, const Value &object);
183 static ReturnedValue getterProtoAccessorTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
184 static ReturnedValue getterIndexed(Lookup *l, ExecutionEngine *engine, const Value &object);
185 static ReturnedValue getterQObject(Lookup *l, ExecutionEngine *engine, const Value &object);
186 static ReturnedValue getterQObjectAsVariant(Lookup *l, ExecutionEngine *engine, const Value &object);
187 static ReturnedValue getterQObjectMethod(Lookup *l, ExecutionEngine *engine, const Value &object);
188
189 static ReturnedValue primitiveGetterProto(Lookup *l, ExecutionEngine *engine, const Value &object);
190 static ReturnedValue primitiveGetterAccessor(Lookup *l, ExecutionEngine *engine, const Value &object);
191 static ReturnedValue stringLengthGetter(Lookup *l, ExecutionEngine *engine, const Value &object);
192
193 static ReturnedValue globalGetterGeneric(Lookup *l, ExecutionEngine *engine);
194 static ReturnedValue globalGetterProto(Lookup *l, ExecutionEngine *engine);
195 static ReturnedValue globalGetterProtoAccessor(Lookup *l, ExecutionEngine *engine);
196
197 bool resolveSetter(ExecutionEngine *engine, Object *object, const Value &value);
198 static bool setterGeneric(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
199 Q_NEVER_INLINE static bool setterTwoClasses(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
200 static bool setterFallback(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
201 static bool setterFallbackAsVariant(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
202 static bool setter0MemberData(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
203 static bool setter0Inline(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
204 static bool setter0setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
205 static bool setterInsert(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
206 static bool setterQObject(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
207 static bool setterQObjectAsVariant(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
208 static bool arrayLengthSetter(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
209
210 void markObjects(MarkStack *stack) {
211 if (markDef.h1 && !(reinterpret_cast<quintptr>(markDef.h1) & 1))
212 markDef.h1->mark(markStack: stack);
213 if (markDef.h2 && !(reinterpret_cast<quintptr>(markDef.h2) & 1))
214 markDef.h2->mark(markStack: stack);
215 }
216
217 void releasePropertyCache()
218 {
219 if (getter == getterQObject
220 || getter == QQmlTypeWrapper::lookupSingletonProperty
221 || setter == setterQObject
222 || qmlContextPropertyGetter == QQmlContextWrapper::lookupScopeObjectProperty
223 || qmlContextPropertyGetter == QQmlContextWrapper::lookupContextObjectProperty
224 || getter == getterQObjectAsVariant
225 || setter == setterQObjectAsVariant) {
226 if (const QQmlPropertyCache *pc = qobjectLookup.propertyCache)
227 pc->release();
228 } else if (getter == getterQObjectMethod
229 || getter == QQmlTypeWrapper::lookupSingletonMethod
230 || qmlContextPropertyGetter == QQmlContextWrapper::lookupScopeObjectMethod
231 || qmlContextPropertyGetter == QQmlContextWrapper::lookupContextObjectMethod) {
232 if (const QQmlPropertyCache *pc = qobjectMethodLookup.propertyCache)
233 pc->release();
234 }
235 }
236};
237
238Q_STATIC_ASSERT(std::is_standard_layout<Lookup>::value);
239// Ensure that these offsets are always at this point to keep generated code compatible
240// across 32-bit and 64-bit (matters when cross-compiling).
241Q_STATIC_ASSERT(offsetof(Lookup, getter) == 0);
242
243inline void setupQObjectLookup(
244 Lookup *lookup, const QQmlData *ddata, const QQmlPropertyData *propertyData)
245{
246 lookup->releasePropertyCache();
247 Q_ASSERT(!ddata->propertyCache.isNull());
248 lookup->qobjectLookup.propertyCache = ddata->propertyCache.data();
249 lookup->qobjectLookup.propertyCache->addref();
250 lookup->qobjectLookup.propertyData = propertyData;
251}
252
253inline void setupQObjectLookup(
254 Lookup *lookup, const QQmlData *ddata, const QQmlPropertyData *propertyData,
255 const Object *self)
256{
257 setupQObjectLookup(lookup, ddata, propertyData);
258 lookup->qobjectLookup.ic.set(engine: self->engine(), heapObject: self->internalClass());
259}
260
261
262inline void setupQObjectLookup(
263 Lookup *lookup, const QQmlData *ddata, const QQmlPropertyData *propertyData,
264 const Object *self, const Object *qmlType)
265{
266 setupQObjectLookup(lookup, ddata, propertyData, self);
267 lookup->qobjectLookup.qmlTypeIc.set(engine: self->engine(), heapObject: qmlType->internalClass());
268}
269
270// template parameter is an ugly trick to avoid pulling in the QObjectMethod header here
271template<typename QObjectMethod = Heap::QObjectMethod>
272inline void setupQObjectMethodLookup(
273 Lookup *lookup, const QQmlData *ddata, const QQmlPropertyData *propertyData,
274 const Object *self, QObjectMethod *method)
275{
276 lookup->releasePropertyCache();
277 Q_ASSERT(!ddata->propertyCache.isNull());
278 auto engine = self->engine();
279 lookup->qobjectMethodLookup.method.set(engine, method);
280 lookup->qobjectMethodLookup.ic.set(engine, heapObject: self->internalClass());
281 lookup->qobjectMethodLookup.propertyCache = ddata->propertyCache.data();
282 lookup->qobjectMethodLookup.propertyCache->addref();
283 lookup->qobjectMethodLookup.propertyData = propertyData;
284}
285
286inline bool qualifiesForMethodLookup(const QQmlPropertyData *propertyData)
287{
288 return propertyData->isFunction()
289 && !propertyData->isSignalHandler() // TODO: Optimize SignalHandler, too
290 && !propertyData->isVMEFunction() // Handled by QObjectLookup
291 && !propertyData->isVarProperty();
292}
293
294}
295
296QT_END_NAMESPACE
297
298#endif
299

source code of qtdeclarative/src/qml/jsruntime/qv4lookup_p.h