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
4#include "qqmlpropertycache_p.h"
5
6#include <private/qqmlengine_p.h>
7#include <private/qqmlbinding_p.h>
8#include <private/qqmlvmemetaobject_p.h>
9
10#include <private/qmetaobject_p.h>
11#include <private/qmetaobjectbuilder_p.h>
12#include <private/qqmlpropertycachemethodarguments_p.h>
13#include <private/qqmlsignalnames_p.h>
14
15#include <private/qv4value_p.h>
16
17#include <QtCore/qdebug.h>
18#include <QtCore/QCryptographicHash>
19#include <QtCore/private/qtools_p.h>
20
21#include <limits.h>
22#include <algorithm>
23
24#ifdef Q_CC_MSVC
25// nonstandard extension used : zero-sized array in struct/union.
26# pragma warning( disable : 4200 )
27#endif
28
29QT_BEGIN_NAMESPACE
30
31#define Q_INT16_MAX 32767
32
33static int metaObjectSignalCount(const QMetaObject *metaObject)
34{
35 int signalCount = 0;
36 for (const QMetaObject *obj = metaObject; obj; obj = obj->superClass())
37 signalCount += QMetaObjectPrivate::get(metaobject: obj)->signalCount;
38 return signalCount;
39}
40
41QQmlPropertyData::Flags
42QQmlPropertyData::flagsForProperty(const QMetaProperty &p)
43{
44 QQmlPropertyData::Flags flags;
45
46 flags.setIsConstant(p.isConstant());
47 flags.setIsWritable(p.isWritable());
48 flags.setIsResettable(p.isResettable());
49 flags.setIsFinal(p.isFinal());
50 flags.setIsRequired(p.isRequired());
51 flags.setIsBindable(p.isBindable());
52
53
54 const QMetaType metaType = p.metaType();
55 int propType = metaType.id();
56 if (p.isEnumType()) {
57 flags.setType(QQmlPropertyData::Flags::EnumType);
58 } else if (metaType.flags() & QMetaType::PointerToQObject) {
59 flags.setType(QQmlPropertyData::Flags::QObjectDerivedType);
60 } else if (propType == QMetaType::QVariant) {
61 flags.setType(QQmlPropertyData::Flags::QVariantType);
62 } else if (metaType.flags() & QMetaType::IsQmlList) {
63 flags.setType(QQmlPropertyData::Flags::QListType);
64 }
65
66 return flags;
67}
68
69void QQmlPropertyData::load(const QMetaProperty &p)
70{
71 Q_ASSERT(p.revision() <= std::numeric_limits<quint16>::max());
72 setCoreIndex(p.propertyIndex());
73 setNotifyIndex(QMetaObjectPrivate::signalIndex(m: p.notifySignal()));
74 setFlags(flagsForProperty(p));
75 setRevision(QTypeRevision::fromEncodedVersion(value: p.revision()));
76 QMetaType type = p.metaType();
77 setPropType(type);
78}
79
80void QQmlPropertyData::load(const QMetaMethod &m)
81{
82 setCoreIndex(m.methodIndex());
83 m_flags.setType(Flags::FunctionType);
84
85 // We need to set the constructor, signal, constant, arguments, V4Function, cloned flags.
86 // These are specific to methods and change with each method.
87 // The same QQmlPropertyData may be loaded with multiple methods in sequence.
88
89 switch (m.methodType()) {
90 case QMetaMethod::Signal:
91 m_flags.setIsSignal(true);
92 m_flags.setIsConstructor(false);
93 setPropType(m.returnMetaType());
94 break;
95 case QMetaMethod::Constructor:
96 m_flags.setIsSignal(false);
97 m_flags.setIsConstructor(true);
98 break;
99 default:
100 m_flags.setIsSignal(false);
101 m_flags.setIsConstructor(false);
102 setPropType(m.returnMetaType());
103 break;
104 }
105
106 m_flags.setIsConstant(m.isConst());
107
108 const int paramCount = m.parameterCount();
109 if (paramCount) {
110 m_flags.setHasArguments(true);
111 m_flags.setIsV4Function(
112 paramCount == 1 &&
113 m.parameterMetaType(index: 0) == QMetaType::fromType<QQmlV4FunctionPtr>());
114 } else {
115 m_flags.setHasArguments(false);
116 m_flags.setIsV4Function(false);
117 }
118
119 m_flags.setIsCloned(m.attributes() & QMetaMethod::Cloned);
120
121 Q_ASSERT(m.revision() <= std::numeric_limits<quint16>::max());
122 setRevision(QTypeRevision::fromEncodedVersion(value: m.revision()));
123}
124
125/*!
126 Creates a standalone QQmlPropertyCache of \a metaObject. It is separate from the usual
127 QQmlPropertyCache hierarchy. It's parent is not equal to any other QQmlPropertyCache
128 created from QObject::staticMetaObject, for example.
129*/
130QQmlPropertyCache::Ptr QQmlPropertyCache::createStandalone(
131 const QMetaObject *metaObject, QTypeRevision metaObjectRevision)
132{
133 Q_ASSERT(metaObject);
134
135 Ptr result;
136 if (const QMetaObject *super = metaObject->superClass()) {
137 result = createStandalone(
138 metaObject: super, metaObjectRevision)->copyAndAppend(metaObject, typeVersion: metaObjectRevision);
139 } else {
140 result.adopt(other: new QQmlPropertyCache(metaObject));
141 result->update(metaObject);
142 }
143
144 if (metaObjectRevision.isValid() && metaObjectRevision != QTypeRevision::zero()) {
145 // Set the revision of the meta object that this cache describes to be
146 // 'metaObjectRevision'. This is useful when constructing a property cache
147 // from a type that was created directly in C++, and not through QML. For such
148 // types, the revision for each recorded QMetaObject would normally be zero, which
149 // would exclude any revisioned properties.
150 for (int metaObjectOffset = 0; metaObjectOffset < result->allowedRevisionCache.size();
151 ++metaObjectOffset) {
152 result->allowedRevisionCache[metaObjectOffset] = metaObjectRevision;
153 }
154 }
155
156 return result;
157}
158
159QQmlPropertyCache::~QQmlPropertyCache()
160{
161 QQmlPropertyCacheMethodArguments *args = argumentsCache;
162 while (args) {
163 QQmlPropertyCacheMethodArguments *next = args->next;
164 delete args->names;
165 free(ptr: args);
166 args = next;
167 }
168
169 // We must clear this prior to releasing the parent incase it is a
170 // linked hash
171 stringCache.clear();
172}
173
174QQmlPropertyCache::Ptr QQmlPropertyCache::copy(const QQmlMetaObjectPointer &mo, int reserve) const
175{
176 QQmlPropertyCache::Ptr cache = QQmlPropertyCache::Ptr(
177 new QQmlPropertyCache(mo), QQmlPropertyCache::Ptr::Adopt);
178 cache->_parent.reset(t: this);
179 cache->propertyIndexCacheStart = propertyIndexCache.size() + propertyIndexCacheStart;
180 cache->methodIndexCacheStart = methodIndexCache.size() + methodIndexCacheStart;
181 cache->signalHandlerIndexCacheStart = signalHandlerIndexCache.size() + signalHandlerIndexCacheStart;
182 cache->stringCache.linkAndReserve(other: stringCache, additionalReserve: reserve);
183 cache->allowedRevisionCache = allowedRevisionCache;
184 cache->_defaultPropertyName = _defaultPropertyName;
185 cache->_listPropertyAssignBehavior = _listPropertyAssignBehavior;
186
187 return cache;
188}
189
190QQmlPropertyCache::Ptr QQmlPropertyCache::copy() const
191{
192 return copy(mo: _metaObject, reserve: 0);
193}
194
195QQmlPropertyCache::Ptr QQmlPropertyCache::copyAndReserve(
196 int propertyCount, int methodCount, int signalCount, int enumCount) const
197{
198 QQmlPropertyCache::Ptr rv = copy(
199 mo: QQmlMetaObjectPointer(), reserve: propertyCount + methodCount + signalCount);
200 rv->propertyIndexCache.reserve(asize: propertyCount);
201 rv->methodIndexCache.reserve(asize: methodCount);
202 rv->signalHandlerIndexCache.reserve(asize: signalCount);
203 rv->enumCache.reserve(asize: enumCount);
204 return rv;
205}
206
207/*! \internal
208
209 \a notifyIndex MUST be in the signal index range (see QObjectPrivate::signalIndex()).
210 This is different from QMetaMethod::methodIndex().
211*/
212void QQmlPropertyCache::appendProperty(const QString &name, QQmlPropertyData::Flags flags,
213 int coreIndex, QMetaType propType, QTypeRevision version,
214 int notifyIndex)
215{
216 QQmlPropertyData data;
217 data.setPropType(propType);
218 data.setCoreIndex(coreIndex);
219 data.setNotifyIndex(notifyIndex);
220 data.setFlags(flags);
221 data.setTypeVersion(version);
222
223 const OverrideResult overrideResult = handleOverride(name, data: &data);
224 if (overrideResult == InvalidOverride)
225 return;
226
227 int index = propertyIndexCache.size();
228 propertyIndexCache.append(t: data);
229
230 setNamedProperty(key: name, index: index + propertyOffset(), data: propertyIndexCache.data() + index);
231}
232
233void QQmlPropertyCache::appendSignal(const QString &name, QQmlPropertyData::Flags flags,
234 int coreIndex, const QMetaType *types,
235 const QList<QByteArray> &names)
236{
237 QQmlPropertyData data;
238 data.setPropType(QMetaType());
239 data.setCoreIndex(coreIndex);
240 data.setFlags(flags);
241 data.setArguments(nullptr);
242
243 QQmlPropertyData handler = data;
244 handler.m_flags.setIsSignalHandler(true);
245
246 if (types) {
247 const auto argumentCount = names.size();
248 QQmlPropertyCacheMethodArguments *args = createArgumentsObject(count: argumentCount, names);
249 new (args->types) QMetaType; // Invalid return type
250 ::memcpy(dest: args->types + 1, src: types, n: argumentCount * sizeof(QMetaType));
251 data.setArguments(args);
252 }
253
254 const OverrideResult overrideResult = handleOverride(name, data: &data);
255 if (overrideResult == InvalidOverride)
256 return;
257
258 int methodIndex = methodIndexCache.size();
259 methodIndexCache.append(t: data);
260
261 int signalHandlerIndex = signalHandlerIndexCache.size();
262 signalHandlerIndexCache.append(t: handler);
263
264 const QString handlerName = QQmlSignalNames::signalNameToHandlerName(signal: name);
265
266 setNamedProperty(key: name, index: methodIndex + methodOffset(), data: methodIndexCache.data() + methodIndex);
267 setNamedProperty(key: handlerName, index: signalHandlerIndex + signalOffset(),
268 data: signalHandlerIndexCache.data() + signalHandlerIndex);
269}
270
271void QQmlPropertyCache::appendMethod(const QString &name, QQmlPropertyData::Flags flags,
272 int coreIndex, QMetaType returnType,
273 const QList<QByteArray> &names,
274 const QVector<QMetaType> &parameterTypes)
275{
276 int argumentCount = names.size();
277
278 QQmlPropertyData data;
279 data.setPropType(returnType);
280 data.setCoreIndex(coreIndex);
281 data.setFlags(flags);
282 const OverrideResult overrideResult = handleOverride(name, data: &data);
283 if (overrideResult == InvalidOverride)
284 return;
285
286 QQmlPropertyCacheMethodArguments *args = createArgumentsObject(count: argumentCount, names);
287 new (args->types) QMetaType(returnType);
288 for (int ii = 0; ii < argumentCount; ++ii)
289 new (args->types + ii + 1) QMetaType(parameterTypes.at(i: ii));
290 data.setArguments(args);
291
292 int methodIndex = methodIndexCache.size();
293 methodIndexCache.append(t: data);
294
295 setNamedProperty(key: name, index: methodIndex + methodOffset(), data: methodIndexCache.data() + methodIndex);
296}
297
298void QQmlPropertyCache::appendEnum(const QString &name, const QVector<QQmlEnumValue> &values)
299{
300 QQmlEnumData data;
301 data.name = name;
302 data.values = values;
303 enumCache.append(t: data);
304}
305
306// Returns this property cache's metaObject, creating it if necessary.
307const QMetaObject *QQmlPropertyCache::createMetaObject() const
308{
309 if (_metaObject.isNull()) {
310 QMetaObjectBuilder builder;
311 toMetaObjectBuilder(builder);
312 builder.setSuperClass(_parent->createMetaObject());
313 _metaObject.setSharedOnce(builder.toMetaObject());
314 }
315
316 return _metaObject.metaObject();
317}
318
319const QQmlPropertyData *QQmlPropertyCache::maybeUnresolvedProperty(int index) const
320{
321 if (index < 0 || index >= propertyCount())
322 return nullptr;
323
324 const QQmlPropertyData *rv = nullptr;
325 if (index < propertyIndexCacheStart)
326 return _parent->maybeUnresolvedProperty(index);
327 else
328 rv = const_cast<const QQmlPropertyData *>(&propertyIndexCache.at(i: index - propertyIndexCacheStart));
329 return rv;
330}
331
332const QQmlPropertyData *QQmlPropertyCache::defaultProperty() const
333{
334 return property(key: defaultPropertyName(), object: nullptr, context: nullptr);
335}
336
337void QQmlPropertyCache::setParent(QQmlPropertyCache::ConstPtr newParent)
338{
339 if (_parent != newParent)
340 _parent = std::move(newParent);
341}
342
343QQmlPropertyCache::Ptr
344QQmlPropertyCache::copyAndAppend(const QMetaObject *metaObject,
345 QTypeRevision typeVersion,
346 QQmlPropertyData::Flags propertyFlags,
347 QQmlPropertyData::Flags methodFlags,
348 QQmlPropertyData::Flags signalFlags) const
349{
350 Q_ASSERT(QMetaObjectPrivate::get(metaObject)->revision >= 4);
351
352 // Reserve enough space in the name hash for all the methods (including signals), all the
353 // signal handlers and all the properties. This assumes no name clashes, but this is the
354 // common case.
355 QQmlPropertyCache::Ptr rv = copy(
356 mo: metaObject,
357 reserve: QMetaObjectPrivate::get(metaobject: metaObject)->methodCount
358 + QMetaObjectPrivate::get(metaobject: metaObject)->signalCount
359 + QMetaObjectPrivate::get(metaobject: metaObject)->propertyCount);
360
361 rv->append(metaObject, typeVersion, propertyFlags, methodFlags, signalFlags);
362
363 return rv;
364}
365
366static QHashedString signalNameToHandlerName(const QHashedString &methodName)
367{
368 return QQmlSignalNames::signalNameToHandlerName(signal: methodName);
369}
370
371static QHashedString signalNameToHandlerName(const QHashedCStringRef &methodName)
372{
373 return QQmlSignalNames::signalNameToHandlerName(
374 signal: QLatin1StringView{ methodName.constData(), methodName.length() });
375}
376
377
378void QQmlPropertyCache::append(const QMetaObject *metaObject,
379 QTypeRevision typeVersion,
380 QQmlPropertyData::Flags propertyFlags,
381 QQmlPropertyData::Flags methodFlags,
382 QQmlPropertyData::Flags signalFlags)
383{
384 allowedRevisionCache.append(t: QTypeRevision::zero());
385
386 int methodCount = metaObject->methodCount();
387 Q_ASSERT(QMetaObjectPrivate::get(metaObject)->revision >= 4);
388 int signalCount = metaObjectSignalCount(metaObject);
389 int classInfoCount = QMetaObjectPrivate::get(metaobject: metaObject)->classInfoCount;
390
391 if (classInfoCount) {
392 int classInfoOffset = metaObject->classInfoOffset();
393 for (int ii = 0; ii < classInfoCount; ++ii) {
394 int idx = ii + classInfoOffset;
395 QMetaClassInfo mci = metaObject->classInfo(index: idx);
396 const char *name = mci.name();
397 if (0 == qstrcmp(str1: name, str2: "DefaultProperty")) {
398 _defaultPropertyName = QString::fromUtf8(utf8: mci.value());
399 } else if (0 == qstrcmp(str1: name, str2: "qt_QmlJSWrapperFactoryMethod")) {
400 const char * const factoryMethod = mci.value();
401 _jsFactoryMethodIndex = metaObject->indexOfSlot(slot: factoryMethod);
402 if (_jsFactoryMethodIndex != -1)
403 _jsFactoryMethodIndex -= metaObject->methodOffset();
404 } else if (0 == qstrcmp(str1: name, str2: "QML.ListPropertyAssignBehavior")) {
405 _listPropertyAssignBehavior = mci.value();
406 }
407 }
408 }
409
410 //Used to block access to QObject::destroyed() and QObject::deleteLater() from QML
411 static const int destroyedIdx1 = QObject::staticMetaObject.indexOfSignal(signal: "destroyed(QObject*)");
412 static const int destroyedIdx2 = QObject::staticMetaObject.indexOfSignal(signal: "destroyed()");
413 static const int deleteLaterIdx = QObject::staticMetaObject.indexOfSlot(slot: "deleteLater()");
414 // These indices don't apply to gadgets, so don't block them.
415 // It is enough to check for QObject::staticMetaObject here because the loop below excludes
416 // methods of parent classes: It starts at metaObject->methodOffset()
417 const bool preventDestruction = (metaObject == &QObject::staticMetaObject);
418
419 int methodOffset = metaObject->methodOffset();
420 int signalOffset = signalCount - QMetaObjectPrivate::get(metaobject: metaObject)->signalCount;
421
422 // update() should have reserved enough space in the vector that this doesn't cause a realloc
423 // and invalidate the stringCache.
424 methodIndexCache.resize(size: methodCount - methodIndexCacheStart);
425 signalHandlerIndexCache.resize(size: signalCount - signalHandlerIndexCacheStart);
426 int signalHandlerIndex = signalOffset;
427 for (int ii = methodOffset; ii < methodCount; ++ii) {
428 if (preventDestruction && (ii == destroyedIdx1 || ii == destroyedIdx2 || ii == deleteLaterIdx))
429 continue;
430 QMetaMethod m = metaObject->method(index: ii);
431 if (m.access() == QMetaMethod::Private)
432 continue;
433
434 // Extract method name
435 // It's safe to keep the raw name pointer
436 Q_ASSERT(QMetaObjectPrivate::get(metaObject)->revision >= 7);
437 const char *rawName = m.name().constData();
438 const char *cptr = rawName;
439 char utf8 = 0;
440 while (*cptr) {
441 utf8 |= *cptr & 0x80;
442 ++cptr;
443 }
444
445 QQmlPropertyData *data = &methodIndexCache[ii - methodIndexCacheStart];
446 QQmlPropertyData *sigdata = nullptr;
447
448 if (m.methodType() == QMetaMethod::Signal)
449 data->setFlags(signalFlags);
450 else
451 data->setFlags(methodFlags);
452
453 data->load(m);
454
455 Q_ASSERT((allowedRevisionCache.size() - 1) < Q_INT16_MAX);
456 data->setMetaObjectOffset(allowedRevisionCache.size() - 1);
457
458 if (data->isSignal()) {
459 sigdata = &signalHandlerIndexCache[signalHandlerIndex - signalHandlerIndexCacheStart];
460 *sigdata = *data;
461 sigdata->m_flags.setIsSignalHandler(true);
462 }
463
464 QQmlPropertyData *old = nullptr;
465
466 const auto doSetNamedProperty = [&](const auto &methodName) {
467 if (StringCache::mapped_type *it = stringCache.value(methodName)) {
468 if (handleOverride(methodName, data, (old = it->second)) == InvalidOverride)
469 return;
470 }
471
472 setNamedProperty(methodName, ii, data);
473
474 if (data->isSignal()) {
475
476 // TODO: Remove this once we can. Signals should not be overridable.
477 if (!utf8)
478 data->m_flags.setIsOverridableSignal(true);
479
480 setNamedProperty(signalNameToHandlerName(methodName), ii, sigdata);
481 ++signalHandlerIndex;
482 }
483 };
484
485 if (utf8)
486 doSetNamedProperty(QHashedString(QString::fromUtf8(utf8: rawName, size: cptr - rawName)));
487 else
488 doSetNamedProperty(QHashedCStringRef(rawName, cptr - rawName));
489 }
490
491 int propCount = metaObject->propertyCount();
492 int propOffset = metaObject->propertyOffset();
493
494 // update() should have reserved enough space in the vector that this doesn't cause a realloc
495 // and invalidate the stringCache.
496 propertyIndexCache.resize(size: propCount - propertyIndexCacheStart);
497 for (int ii = propOffset; ii < propCount; ++ii) {
498 QMetaProperty p = metaObject->property(index: ii);
499 if (!p.isScriptable())
500 continue;
501
502 const char *str = p.name();
503 char utf8 = 0;
504 const char *cptr = str;
505 while (*cptr != 0) {
506 utf8 |= *cptr & 0x80;
507 ++cptr;
508 }
509
510 QQmlPropertyData *data = &propertyIndexCache[ii - propertyIndexCacheStart];
511
512 data->setFlags(propertyFlags);
513 data->load(p);
514 data->setTypeVersion(typeVersion);
515
516 Q_ASSERT((allowedRevisionCache.size() - 1) < Q_INT16_MAX);
517 data->setMetaObjectOffset(allowedRevisionCache.size() - 1);
518
519 QQmlPropertyData *old = nullptr;
520
521 if (utf8) {
522 QHashedString propName(QString::fromUtf8(utf8: str, size: cptr - str));
523 if (StringCache::mapped_type *it = stringCache.value(key: propName)) {
524 if (handleOverride(name: propName, data, old: (old = it->second)) == InvalidOverride)
525 continue;
526 }
527 setNamedProperty(key: propName, index: ii, data);
528 } else {
529 QHashedCStringRef propName(str, cptr - str);
530 if (StringCache::mapped_type *it = stringCache.value(key: propName)) {
531 if (handleOverride(name: propName, data, old: (old = it->second)) == InvalidOverride)
532 continue;
533 }
534 setNamedProperty(key: propName, index: ii, data);
535 }
536
537 bool isGadget = true;
538 for (const QMetaObject *it = metaObject; it != nullptr; it = it->superClass()) {
539 if (it == &QObject::staticMetaObject)
540 isGadget = false;
541 }
542
543 // otherwise always dispatch over a 'normal' meta-call so the QQmlValueType can intercept
544 if (!isGadget)
545 data->trySetStaticMetaCallFunction(f: metaObject->d.static_metacall, relativePropertyIndex: ii - propOffset);
546 }
547}
548
549void QQmlPropertyCache::update(const QMetaObject *metaObject)
550{
551 Q_ASSERT(metaObject);
552 stringCache.clear();
553
554 // Preallocate enough space in the index caches for all the properties/methods/signals that
555 // are not cached in a parent cache so that the caches never need to be reallocated as this
556 // would invalidate pointers stored in the stringCache.
557 int pc = metaObject->propertyCount();
558 int mc = metaObject->methodCount();
559 int sc = metaObjectSignalCount(metaObject);
560 propertyIndexCache.reserve(asize: pc - propertyIndexCacheStart);
561 methodIndexCache.reserve(asize: mc - methodIndexCacheStart);
562 signalHandlerIndexCache.reserve(asize: sc - signalHandlerIndexCacheStart);
563
564 // Reserve enough space in the stringCache for all properties/methods/signals including those
565 // cached in a parent cache.
566 stringCache.reserve(n: pc + mc + sc);
567
568 if (metaObject)
569 append(metaObject, typeVersion: QTypeRevision());
570}
571
572/*! \internal
573 invalidates and updates the PropertyCache if the QMetaObject has changed.
574 This function is used in the tooling to update dynamic properties.
575*/
576void QQmlPropertyCache::invalidate(const QMetaObject *metaObject)
577{
578 propertyIndexCache.clear();
579 methodIndexCache.clear();
580 signalHandlerIndexCache.clear();
581
582 argumentsCache = nullptr;
583
584 int pc = metaObject->propertyCount();
585 int mc = metaObject->methodCount();
586 int sc = metaObjectSignalCount(metaObject);
587 int reserve = pc + mc + sc;
588
589 if (parent()) {
590 propertyIndexCacheStart = parent()->propertyIndexCache.size() + parent()->propertyIndexCacheStart;
591 methodIndexCacheStart = parent()->methodIndexCache.size() + parent()->methodIndexCacheStart;
592 signalHandlerIndexCacheStart = parent()->signalHandlerIndexCache.size() + parent()->signalHandlerIndexCacheStart;
593 stringCache.linkAndReserve(other: parent()->stringCache, additionalReserve: reserve);
594 append(metaObject, typeVersion: QTypeRevision());
595 } else {
596 propertyIndexCacheStart = 0;
597 methodIndexCacheStart = 0;
598 signalHandlerIndexCacheStart = 0;
599 update(metaObject);
600 }
601}
602
603const QQmlPropertyData *QQmlPropertyCache::findProperty(
604 StringCache::ConstIterator it, QObject *object,
605 const QQmlRefPointer<QQmlContextData> &context) const
606{
607 QQmlData *data = (object ? QQmlData::get(object) : nullptr);
608 const QQmlVMEMetaObject *vmemo = nullptr;
609 if (data && data->hasVMEMetaObject) {
610 QObjectPrivate *op = QObjectPrivate::get(o: object);
611 vmemo = static_cast<const QQmlVMEMetaObject *>(op->metaObject);
612 }
613 return findProperty(it, vmemo, context);
614}
615
616namespace {
617
618inline bool contextHasNoExtensions(const QQmlRefPointer<QQmlContextData> &context)
619{
620 // This context has no extension if its parent is the engine's rootContext,
621 // which has children but no imports
622 const QQmlRefPointer<QQmlContextData> parent = context->parent();
623 return (!parent || !parent->imports());
624}
625
626inline int maximumIndexForProperty(const QQmlPropertyData *prop, const int methodCount, const int signalCount, const int propertyCount)
627{
628 return prop->isFunction() ? methodCount
629 : prop->isSignalHandler() ? signalCount
630 : propertyCount;
631}
632
633}
634
635const QQmlPropertyData *QQmlPropertyCache::findProperty(
636 StringCache::ConstIterator it, const QQmlVMEMetaObject *vmemo,
637 const QQmlRefPointer<QQmlContextData> &context) const
638{
639 StringCache::ConstIterator end = stringCache.end();
640
641 if (it != end) {
642 const QQmlPropertyData *result = it.value().second;
643
644 // If there exists a typed property (not a function or signal handler), of the
645 // right name available to the specified context, we need to return that
646 // property rather than any subsequent override
647
648 if (vmemo && context && !contextHasNoExtensions(context)) {
649 // Find the meta-object that corresponds to the supplied context
650 do {
651 if (vmemo->ctxt.contextData().data() == context.data())
652 break;
653
654 vmemo = vmemo->parentVMEMetaObject();
655 } while (vmemo);
656 }
657
658 if (vmemo) {
659 const int methodCount = vmemo->cache->methodCount();
660 const int signalCount = vmemo->cache->signalCount();
661 const int propertyCount = vmemo->cache->propertyCount();
662
663 // Ensure that the property we resolve to is accessible from this meta-object
664 do {
665 const StringCache::mapped_type &property(it.value());
666
667 if (property.first < maximumIndexForProperty(prop: property.second, methodCount, signalCount, propertyCount)) {
668 // This property is available in the specified context
669 if (property.second->isFunction() || property.second->isSignalHandler()) {
670 // Prefer the earlier resolution
671 } else {
672 // Prefer the typed property to any previous property found
673 result = property.second;
674 }
675 break;
676 }
677
678 // See if there is a better candidate
679 it = stringCache.findNext(iter: it);
680 } while (it != end);
681 }
682
683 return result;
684 }
685
686 return nullptr;
687}
688
689
690
691
692
693bool QQmlPropertyData::markAsOverrideOf(QQmlPropertyData *predecessor)
694{
695 Q_ASSERT(predecessor != this);
696 if (predecessor->isFinal())
697 return false;
698
699 setOverrideIndexIsProperty(!predecessor->isFunction());
700 setOverrideIndex(predecessor->coreIndex());
701 predecessor->m_flags.setIsOverridden(true);
702 Q_ASSERT(predecessor->isOverridden());
703 return true;
704}
705
706QQmlPropertyCacheMethodArguments *QQmlPropertyCache::createArgumentsObject(
707 int argc, const QList<QByteArray> &names)
708{
709 typedef QQmlPropertyCacheMethodArguments A;
710 A *args = static_cast<A *>(malloc(size: sizeof(A) + argc * sizeof(QMetaType)));
711 args->names = argc ? new QList<QByteArray>(names) : nullptr;
712 args->next = argumentsCache;
713 argumentsCache = args;
714 return args;
715}
716
717QString QQmlPropertyCache::signalParameterStringForJS(QV4::ExecutionEngine *engine, const QList<QByteArray> &parameterNameList, QString *errorString)
718{
719 bool unnamedParameter = false;
720 const QSet<QString> &illegalNames = engine->illegalNames();
721 QString parameters;
722
723 const qsizetype count = parameterNameList.size();
724 if (count > std::numeric_limits<quint16>::max())
725 *errorString = QCoreApplication::translate(context: "QQmlRewrite", key: "Signal has an excessive number of parameters: %1").arg(a: count);
726
727 for (qsizetype i = 0; i < count; ++i) {
728 if (i > 0)
729 parameters += QLatin1Char(',');
730 const QByteArray &param = parameterNameList.at(i);
731 if (param.isEmpty()) {
732 unnamedParameter = true;
733 } else if (unnamedParameter) {
734 if (errorString)
735 *errorString = QCoreApplication::translate(context: "QQmlRewrite", key: "Signal uses unnamed parameter followed by named parameter.");
736 return QString();
737 } else if (illegalNames.contains(value: QString::fromUtf8(ba: param))) {
738 if (errorString)
739 *errorString = QCoreApplication::translate(context: "QQmlRewrite", key: "Signal parameter \"%1\" hides global variable.").arg(a: QString::fromUtf8(ba: param));
740 return QString();
741 }
742 parameters += QString::fromUtf8(ba: param);
743 }
744
745 return parameters;
746}
747
748int QQmlPropertyCache::originalClone(int index) const
749{
750 while (signal(index)->isCloned())
751 --index;
752 return index;
753}
754
755int QQmlPropertyCache::originalClone(const QObject *object, int index)
756{
757 QQmlData *data = QQmlData::get(object);
758 if (data && data->propertyCache) {
759 const QQmlPropertyCache *cache = data->propertyCache.data();
760 const QQmlPropertyData *sig = cache->signal(index);
761 while (sig && sig->isCloned()) {
762 --index;
763 sig = cache->signal(index);
764 }
765 } else {
766 while (QMetaObjectPrivate::signal(m: object->metaObject(), signal_index: index).attributes() & QMetaMethod::Cloned)
767 --index;
768 }
769 return index;
770}
771
772template<typename T>
773static QQmlPropertyData qQmlPropertyCacheCreate(const QMetaObject *metaObject, const T& propertyName)
774{
775 Q_ASSERT(metaObject);
776
777 QQmlPropertyData rv;
778
779 /* It's important to check the method list before checking for properties;
780 * otherwise, if the meta object is dynamic, a property will be created even
781 * if not found and it might obscure a method having the same name. */
782
783 //Used to block access to QObject::destroyed() and QObject::deleteLater() from QML
784 static const int destroyedIdx1 = QObject::staticMetaObject.indexOfSignal(signal: "destroyed(QObject*)");
785 static const int destroyedIdx2 = QObject::staticMetaObject.indexOfSignal(signal: "destroyed()");
786 static const int deleteLaterIdx = QObject::staticMetaObject.indexOfSlot(slot: "deleteLater()");
787 // These indices don't apply to gadgets, so don't block them.
788 const bool preventDestruction = metaObject->superClass() || metaObject == &QObject::staticMetaObject;
789
790 int methodCount = metaObject->methodCount();
791 for (int ii = methodCount - 1; ii >= 0; --ii) {
792 if (preventDestruction && (ii == destroyedIdx1 || ii == destroyedIdx2 || ii == deleteLaterIdx))
793 continue;
794 QMetaMethod m = metaObject->method(index: ii);
795 if (m.access() == QMetaMethod::Private)
796 continue;
797
798 if (m.name() == propertyName) {
799 rv.load(m);
800 return rv;
801 }
802 }
803
804 {
805 const QMetaObject *cmo = metaObject;
806 while (cmo) {
807 int idx = cmo->indexOfProperty(name: propertyName);
808 if (idx != -1) {
809 QMetaProperty p = cmo->property(index: idx);
810 if (p.isScriptable()) {
811 rv.load(p);
812 return rv;
813 } else {
814 bool changed = false;
815 while (cmo && cmo->propertyOffset() >= idx) {
816 cmo = cmo->superClass();
817 changed = true;
818 }
819 /* If the "cmo" variable didn't change, set it to 0 to
820 * avoid running into an infinite loop */
821 if (!changed) cmo = nullptr;
822 }
823 } else {
824 cmo = nullptr;
825 }
826 }
827 }
828 return rv;
829}
830
831static inline const char *qQmlPropertyCacheToString(QLatin1String string)
832{
833 return string.data();
834}
835
836static inline QByteArray qQmlPropertyCacheToString(QStringView string)
837{
838 return string.toUtf8();
839}
840
841static inline QByteArray qQmlPropertyCacheToString(const QV4::String *string)
842{
843 return string->toQString().toUtf8();
844}
845
846template<typename T>
847const QQmlPropertyData *
848qQmlPropertyCacheProperty(QObject *obj, T name, const QQmlRefPointer<QQmlContextData> &context,
849 QQmlPropertyData *local)
850{
851 const QQmlPropertyCache *cache = nullptr;
852
853 QQmlData *ddata = QQmlData::get(object: obj, create: false);
854
855 if (ddata && ddata->propertyCache) {
856 cache = ddata->propertyCache.data();
857 } else if (auto newCache = QQmlMetaType::propertyCache(object: obj)) {
858 cache = newCache.data();
859 ddata = QQmlData::get(object: obj, create: true);
860 ddata->propertyCache = std::move(newCache);
861 }
862
863 const QQmlPropertyData *rv = nullptr;
864
865 if (cache) {
866 rv = cache->property(name, obj, context);
867 } else if (local) {
868 *local = qQmlPropertyCacheCreate(obj->metaObject(), qQmlPropertyCacheToString(name));
869 if (local->isValid())
870 rv = local;
871 }
872
873 return rv;
874}
875
876const QQmlPropertyData *QQmlPropertyCache::property(
877 QObject *obj, const QV4::String *name, const QQmlRefPointer<QQmlContextData> &context,
878 QQmlPropertyData *local)
879{
880 return qQmlPropertyCacheProperty<const QV4::String *>(obj, name, context, local);
881}
882
883const QQmlPropertyData *QQmlPropertyCache::property(
884 QObject *obj, QStringView name, const QQmlRefPointer<QQmlContextData> &context,
885 QQmlPropertyData *local)
886{
887 return qQmlPropertyCacheProperty<const QStringView &>(obj, name, context, local);
888}
889
890const QQmlPropertyData *QQmlPropertyCache::property(
891 QObject *obj, const QLatin1String &name, const QQmlRefPointer<QQmlContextData> &context,
892 QQmlPropertyData *local)
893{
894 return qQmlPropertyCacheProperty<const QLatin1String &>(obj, name, context, local);
895}
896
897// this function is copied from qmetaobject.cpp
898static inline const QByteArray stringData(const QMetaObject *mo, int index)
899{
900 uint offset = mo->d.stringdata[2*index];
901 uint length = mo->d.stringdata[2*index + 1];
902 const char *string = reinterpret_cast<const char *>(mo->d.stringdata) + offset;
903 return QByteArray::fromRawData(data: string, size: length);
904}
905
906const char *QQmlPropertyCache::className() const
907{
908 if (const QMetaObject *mo = _metaObject.metaObject())
909 return mo->className();
910 else
911 return _dynamicClassName.constData();
912}
913
914void QQmlPropertyCache::toMetaObjectBuilder(QMetaObjectBuilder &builder) const
915{
916 struct Sort { static bool lt(const QPair<QString, const QQmlPropertyData *> &lhs,
917 const QPair<QString, const QQmlPropertyData *> &rhs) {
918 return lhs.second->coreIndex() < rhs.second->coreIndex();
919 } };
920
921 struct Insert { static void in(const QQmlPropertyCache *This,
922 QList<QPair<QString, const QQmlPropertyData *> > &properties,
923 QList<QPair<QString, const QQmlPropertyData *> > &methods,
924 StringCache::ConstIterator iter, const QQmlPropertyData *data) {
925 if (data->isSignalHandler())
926 return;
927
928 if (data->isFunction()) {
929 if (data->coreIndex() < This->methodIndexCacheStart)
930 return;
931
932 QPair<QString, const QQmlPropertyData *> entry = qMakePair(value1: (QString)iter.key(), value2&: data);
933 // Overrides can cause the entry to already exist
934 if (!methods.contains(t: entry)) methods.append(t: entry);
935
936 data = This->overrideData(data);
937 if (data && !data->isFunction()) Insert::in(This, properties, methods, iter, data);
938 } else {
939 if (data->coreIndex() < This->propertyIndexCacheStart)
940 return;
941
942 QPair<QString, const QQmlPropertyData *> entry = qMakePair(value1: (QString)iter.key(), value2&: data);
943 // Overrides can cause the entry to already exist
944 if (!properties.contains(t: entry)) properties.append(t: entry);
945
946 data = This->overrideData(data);
947 if (data) Insert::in(This, properties, methods, iter, data);
948 }
949
950 } };
951
952 builder.setClassName(_dynamicClassName);
953
954 QList<QPair<QString, const QQmlPropertyData *> > properties;
955 QList<QPair<QString, const QQmlPropertyData *> > methods;
956
957 for (StringCache::ConstIterator iter = stringCache.begin(), cend = stringCache.end(); iter != cend; ++iter)
958 Insert::in(This: this, properties, methods, iter, data: iter.value().second);
959
960 Q_ASSERT(properties.size() == propertyIndexCache.size());
961 Q_ASSERT(methods.size() == methodIndexCache.size());
962
963 std::sort(first: properties.begin(), last: properties.end(), comp: Sort::lt);
964 std::sort(first: methods.begin(), last: methods.end(), comp: Sort::lt);
965
966 for (int ii = 0; ii < properties.size(); ++ii) {
967 const QQmlPropertyData *data = properties.at(i: ii).second;
968
969 int notifierId = -1;
970 if (data->notifyIndex() != -1)
971 notifierId = data->notifyIndex() - signalHandlerIndexCacheStart;
972
973 QMetaPropertyBuilder property = builder.addProperty(name: properties.at(i: ii).first.toUtf8(),
974 type: data->propType().name(),
975 metaType: data->propType(),
976 notifierId);
977
978 property.setReadable(true);
979 property.setWritable(data->isWritable());
980 property.setResettable(data->isResettable());
981 property.setBindable(data->isBindable());
982 property.setAlias(data->isAlias());
983 }
984
985 for (int ii = 0; ii < methods.size(); ++ii) {
986 const QQmlPropertyData *data = methods.at(i: ii).second;
987
988 QByteArray returnType;
989 if (data->propType().isValid())
990 returnType = data->propType().name();
991
992 QByteArray signature;
993 // '+=' reserves extra capacity. Follow-up appending will be probably free.
994 signature += methods.at(i: ii).first.toUtf8() + '(';
995
996 QQmlPropertyCacheMethodArguments *arguments = nullptr;
997 if (data->hasArguments()) {
998 arguments = data->arguments();
999 for (int ii = 0, end = arguments->names ? arguments->names->size() : 0;
1000 ii < end; ++ii) {
1001 if (ii != 0)
1002 signature.append(c: ',');
1003 signature.append(s: arguments->types[1 + ii].name());
1004 }
1005 }
1006
1007 signature.append(c: ')');
1008
1009 QMetaMethodBuilder method;
1010 if (data->isSignal()) {
1011 method = builder.addSignal(signature);
1012 } else {
1013 method = builder.addSlot(signature);
1014 }
1015 method.setAccess(QMetaMethod::Public);
1016
1017 if (arguments && arguments->names)
1018 method.setParameterNames(*arguments->names);
1019
1020 if (!returnType.isEmpty())
1021 method.setReturnType(returnType);
1022 }
1023
1024 for (int ii = 0; ii < enumCache.size(); ++ii) {
1025 const QQmlEnumData &enumData = enumCache.at(i: ii);
1026 QMetaEnumBuilder enumeration = builder.addEnumerator(name: enumData.name.toUtf8());
1027 enumeration.setIsScoped(true);
1028 for (int jj = 0; jj < enumData.values.size(); ++jj) {
1029 const QQmlEnumValue &value = enumData.values.at(i: jj);
1030 enumeration.addKey(name: value.namedValue.toUtf8(), value: value.value);
1031 }
1032 }
1033
1034 if (!_defaultPropertyName.isEmpty()) {
1035 const QQmlPropertyData *dp = property(key: _defaultPropertyName, object: nullptr, context: nullptr);
1036 if (dp && dp->coreIndex() >= propertyIndexCacheStart) {
1037 Q_ASSERT(!dp->isFunction());
1038 builder.addClassInfo(name: "DefaultProperty", value: _defaultPropertyName.toUtf8());
1039 }
1040 }
1041
1042 if (!_listPropertyAssignBehavior.isEmpty())
1043 builder.addClassInfo(name: "QML.ListPropertyAssignBehavior", value: _listPropertyAssignBehavior);
1044}
1045
1046namespace {
1047template <typename StringVisitor, typename TypeInfoVisitor>
1048int visitMethods(const QMetaObject &mo, int methodOffset, int methodCount,
1049 StringVisitor visitString, TypeInfoVisitor visitTypeInfo)
1050{
1051 int fieldsForParameterData = 0;
1052
1053 bool hasRevisionedMethods = false;
1054
1055 for (int i = 0; i < methodCount; ++i) {
1056 const int handle = methodOffset + i * QMetaObjectPrivate::IntsPerMethod;
1057
1058 const uint flags = mo.d.data[handle + 4];
1059 if (flags & MethodRevisioned)
1060 hasRevisionedMethods = true;
1061
1062 visitString(mo.d.data[handle + 0]); // name
1063 visitString(mo.d.data[handle + 3]); // tag
1064
1065 const int argc = mo.d.data[handle + 1];
1066 const int paramIndex = mo.d.data[handle + 2];
1067
1068 fieldsForParameterData += argc * 2; // type and name
1069 fieldsForParameterData += 1; // + return type
1070
1071 // return type + args
1072 for (int i = 0; i < 1 + argc; ++i) {
1073 // type name (maybe)
1074 visitTypeInfo(mo.d.data[paramIndex + i]);
1075
1076 // parameter name
1077 if (i > 0)
1078 visitString(mo.d.data[paramIndex + argc + i]);
1079 }
1080 }
1081
1082 int fieldsForRevisions = 0;
1083 if (hasRevisionedMethods)
1084 fieldsForRevisions = methodCount;
1085
1086 return methodCount * QMetaObjectPrivate::IntsPerMethod
1087 + fieldsForRevisions + fieldsForParameterData;
1088}
1089
1090template <typename StringVisitor, typename TypeInfoVisitor>
1091int visitProperties(const QMetaObject &mo, StringVisitor visitString, TypeInfoVisitor visitTypeInfo)
1092{
1093 const QMetaObjectPrivate *const priv = reinterpret_cast<const QMetaObjectPrivate*>(mo.d.data);
1094
1095 for (int i = 0; i < priv->propertyCount; ++i) {
1096 const int handle = priv->propertyData + i * QMetaObjectPrivate::IntsPerProperty;
1097
1098 visitString(mo.d.data[handle]); // name
1099 visitTypeInfo(mo.d.data[handle + 1]);
1100 }
1101
1102 return priv->propertyCount * QMetaObjectPrivate::IntsPerProperty;
1103}
1104
1105template <typename StringVisitor>
1106int visitClassInfo(const QMetaObject &mo, StringVisitor visitString)
1107{
1108 const QMetaObjectPrivate *const priv = reinterpret_cast<const QMetaObjectPrivate*>(mo.d.data);
1109 const int intsPerClassInfo = 2;
1110
1111 for (int i = 0; i < priv->classInfoCount; ++i) {
1112 const int handle = priv->classInfoData + i * intsPerClassInfo;
1113
1114 visitString(mo.d.data[handle]); // key
1115 visitString(mo.d.data[handle + 1]); // value
1116 }
1117
1118 return priv->classInfoCount * intsPerClassInfo;
1119}
1120
1121template <typename StringVisitor>
1122int visitEnumerations(const QMetaObject &mo, StringVisitor visitString)
1123{
1124 const QMetaObjectPrivate *const priv = reinterpret_cast<const QMetaObjectPrivate*>(mo.d.data);
1125
1126 int fieldCount = priv->enumeratorCount * QMetaObjectPrivate::IntsPerEnum;
1127
1128 for (int i = 0; i < priv->enumeratorCount; ++i) {
1129 const uint *enumeratorData = mo.d.data + priv->enumeratorData + i * QMetaObjectPrivate::IntsPerEnum;
1130
1131 const uint keyCount = enumeratorData[3];
1132 fieldCount += keyCount * 2;
1133
1134 visitString(enumeratorData[0]); // name
1135 visitString(enumeratorData[1]); // enum name
1136
1137 const uint keyOffset = enumeratorData[4];
1138
1139 for (uint j = 0; j < keyCount; ++j) {
1140 visitString(mo.d.data[keyOffset + 2 * j]);
1141 }
1142 }
1143
1144 return fieldCount;
1145}
1146
1147template <typename StringVisitor>
1148int countMetaObjectFields(const QMetaObject &mo, StringVisitor stringVisitor)
1149{
1150 const QMetaObjectPrivate *const priv = reinterpret_cast<const QMetaObjectPrivate*>(mo.d.data);
1151
1152 const auto typeInfoVisitor = [&stringVisitor](uint typeInfo) {
1153 if (typeInfo & IsUnresolvedType)
1154 stringVisitor(typeInfo & TypeNameIndexMask);
1155 };
1156
1157 int fieldCount = MetaObjectPrivateFieldCount;
1158
1159 fieldCount += visitMethods(mo, priv->methodData, priv->methodCount, stringVisitor,
1160 typeInfoVisitor);
1161 fieldCount += visitMethods(mo, priv->constructorData, priv->constructorCount, stringVisitor,
1162 typeInfoVisitor);
1163
1164 fieldCount += visitProperties(mo, stringVisitor, typeInfoVisitor);
1165 fieldCount += visitClassInfo(mo, stringVisitor);
1166 fieldCount += visitEnumerations(mo, stringVisitor);
1167
1168 return fieldCount;
1169}
1170
1171} // anonymous namespace
1172
1173static_assert(QMetaObjectPrivate::OutputRevision == 12, "Check and adjust determineMetaObjectSizes");
1174
1175bool QQmlPropertyCache::determineMetaObjectSizes(const QMetaObject &mo, int *fieldCount,
1176 int *stringCount)
1177{
1178 const QMetaObjectPrivate *priv = reinterpret_cast<const QMetaObjectPrivate*>(mo.d.data);
1179 if (priv->revision != QMetaObjectPrivate::OutputRevision)
1180 return false;
1181
1182 uint highestStringIndex = 0;
1183 const auto stringIndexVisitor = [&highestStringIndex](uint index) {
1184 highestStringIndex = qMax(a: highestStringIndex, b: index);
1185 };
1186
1187 *fieldCount = countMetaObjectFields(mo, stringVisitor: stringIndexVisitor);
1188 *stringCount = highestStringIndex + 1;
1189
1190 return true;
1191}
1192
1193bool QQmlPropertyCache::addToHash(QCryptographicHash &hash, const QMetaObject &mo)
1194{
1195 int fieldCount = 0;
1196 int stringCount = 0;
1197 if (!determineMetaObjectSizes(mo, fieldCount: &fieldCount, stringCount: &stringCount)) {
1198 return false;
1199 }
1200
1201 hash.addData(data: {reinterpret_cast<const char *>(mo.d.data), qsizetype(fieldCount * sizeof(uint))});
1202 for (int i = 0; i < stringCount; ++i) {
1203 hash.addData(data: stringData(mo: &mo, index: i));
1204 }
1205
1206 return true;
1207}
1208
1209QByteArray QQmlPropertyCache::checksum(QHash<quintptr, QByteArray> *checksums, bool *ok) const
1210{
1211 auto it = checksums->constFind(key: quintptr(this));
1212 if (it != checksums->constEnd()) {
1213 *ok = true;
1214 return *it;
1215 }
1216
1217 // Generate a checksum on the meta-object data only on C++ types.
1218 if (_metaObject.isShared()) {
1219 *ok = false;
1220 return QByteArray();
1221 }
1222
1223 QCryptographicHash hash(QCryptographicHash::Md5);
1224
1225 if (_parent) {
1226 hash.addData(data: _parent->checksum(checksums, ok));
1227 if (!*ok)
1228 return QByteArray();
1229 }
1230
1231 if (!addToHash(hash, mo: *_metaObject.metaObject())) {
1232 *ok = false;
1233 return QByteArray();
1234 }
1235
1236 const QByteArray result = hash.result();
1237 if (result.isEmpty()) {
1238 *ok = false;
1239 } else {
1240 *ok = true;
1241 checksums->insert(key: quintptr(this), value: result);
1242 }
1243 return result;
1244}
1245
1246/*! \internal
1247 \a index MUST be in the signal index range (see QObjectPrivate::signalIndex()).
1248 This is different from QMetaMethod::methodIndex().
1249*/
1250QList<QByteArray> QQmlPropertyCache::signalParameterNames(int index) const
1251{
1252 const QQmlPropertyData *signalData = signal(index);
1253 if (signalData && signalData->hasArguments()) {
1254 QQmlPropertyCacheMethodArguments *args = (QQmlPropertyCacheMethodArguments *)signalData->arguments();
1255 if (args && args->names)
1256 return *args->names;
1257 const QMetaMethod &method = QMetaObjectPrivate::signal(m: firstCppMetaObject(), signal_index: index);
1258 return method.parameterNames();
1259 }
1260 return QList<QByteArray>();
1261}
1262
1263QT_END_NAMESPACE
1264

source code of qtdeclarative/src/qml/qml/qqmlpropertycache.cpp