QML: Port QV4::CompiledData::Alias to new special integer bitfield

Task-number: QTBUG-99545
Change-Id: I554f9f903a39a83eaf601fd4fd932f685bf343d0
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Sami Shalayel <sami.shalayel@qt.io>
(cherry picked from commit 8d03b13a59a5e3866c982eb14ca2dc57b687d218)

7 files changed, 127 insertions, 51 deletions

diff --git a/src/qml/common/qv4compileddata_p.h b/src/qml/common/qv4compileddata_p.h
index fb4c13c81d..97b4d8466d 100644
--- a/src/qml/common/qv4compileddata_p.h
+++ b/src/qml/common/qv4compileddata_p.h
@@ -767,20 +767,31 @@ struct RequiredPropertyExtraData {
 static_assert (sizeof(RequiredPropertyExtraData) == 4, "RequiredPropertyExtraData structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Alias {
-    enum Flags : unsigned int {
+private:
+    using NameIndexField = quint32_le_bitfield_member<0, 29>;
+    using FlagsField = quint32_le_bitfield_member<29, 3>;
+
+    // object id index (in QQmlContextData::idValues)
+    using TargetObjectIdField = quint32_le_bitfield_member<0, 31>;
+    using AliasToLocalAliasField = quint32_le_bitfield_member<31, 1>;
+
+public:
+
+    enum Flag : unsigned int {
         IsReadOnly = 0x1,
         Resolved = 0x2,
         AliasPointsToPointerObject = 0x4
     };
-    union {
-        quint32_le_bitfield<0, 29> nameIndex;
-        quint32_le_bitfield<29, 3> flags;
-    };
+    Q_DECLARE_FLAGS(Flags, Flag)
+
+    quint32_le_bitfield_union<NameIndexField, FlagsField> nameIndexAndFlags;
+
     union {
         quint32_le idIndex; // string index
-        quint32_le_bitfield<0, 31> targetObjectId; // object id index (in QQmlContextData::idValues)
-        quint32_le_bitfield<31, 1> aliasToLocalAlias;
+        quint32_le_bitfield_union<TargetObjectIdField, AliasToLocalAliasField>
+                targetObjectIdAndAliasToLocalAlias;
     };
+
     union {
         quint32_le propertyNameIndex; // string index
         qint32_le encodedMetaPropertyIndex;
@@ -789,10 +800,56 @@ struct Alias {
     Location location;
     Location referenceLocation;
 
-    bool isObjectAlias() const {
-        Q_ASSERT(flags & Resolved);
+    bool hasFlag(Flag flag) const
+    {
+        return nameIndexAndFlags.get<FlagsField>() & flag;
+    }
+
+    void setFlag(Flag flag)
+    {
+        nameIndexAndFlags.set<FlagsField>(nameIndexAndFlags.get<FlagsField>() | flag);
+    }
+
+    void clearFlags()
+    {
+        nameIndexAndFlags.set<FlagsField>(0);
+    }
+
+    quint32 nameIndex() const
+    {
+        return nameIndexAndFlags.get<NameIndexField>();
+    }
+
+    void setNameIndex(quint32 nameIndex)
+    {
+        nameIndexAndFlags.set<NameIndexField>(nameIndex);
+    }
+
+    bool isObjectAlias() const
+    {
+        Q_ASSERT(hasFlag(Resolved));
         return encodedMetaPropertyIndex == -1;
     }
+
+    bool isAliasToLocalAlias() const
+    {
+        return targetObjectIdAndAliasToLocalAlias.get<AliasToLocalAliasField>();
+    }
+
+    void setIsAliasToLocalAlias(bool isAliasToLocalAlias)
+    {
+        targetObjectIdAndAliasToLocalAlias.set<AliasToLocalAliasField>(isAliasToLocalAlias);
+    }
+
+    quint32 targetObjectId() const
+    {
+        return targetObjectIdAndAliasToLocalAlias.get<TargetObjectIdField>();
+    }
+
+    void setTargetObjectId(quint32 targetObjectId)
+    {
+        targetObjectIdAndAliasToLocalAlias.set<TargetObjectIdField>(targetObjectId);
+    }
 };
 static_assert(sizeof(Alias) == 20, "Alias structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 20c6b9d290..ed5f3032d5 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -257,7 +257,7 @@ QString Object::appendProperty(Property *prop, const QString &propertyName, bool
             return tr("Duplicate property name");
 
     for (Alias *a = target->aliases->first; a; a = a->next)
-        if (a->nameIndex == prop->nameIndex)
+        if (a->nameIndex() == prop->nameIndex)
             return tr("Property duplicates alias name");
 
     if (propertyName.constData()->isUpper())
@@ -281,13 +281,13 @@ QString Object::appendAlias(Alias *alias, const QString &aliasName, bool isDefau
         target = this;
 
     const auto aliasWithSameName = std::find_if(target->aliases->begin(), target->aliases->end(), [&alias](const Alias &targetAlias){
-        return targetAlias.nameIndex == alias->nameIndex;
+        return targetAlias.nameIndex() == alias->nameIndex();
     });
     if (aliasWithSameName != target->aliases->end())
         return tr("Duplicate alias name");
 
     const auto aliasSameAsProperty = std::find_if(target->properties->begin(), target->properties->end(), [&alias](const Property &targetProp){
-        return targetProp.nameIndex == alias->nameIndex;
+        return targetProp.nameIndex == alias->nameIndex();
     });
 
     if (aliasSameAsProperty != target->properties->end())
@@ -1308,12 +1308,12 @@ void IRBuilder::appendBinding(const QQmlJS::SourceLocation &qualifiedNameLocatio
 bool IRBuilder::appendAlias(QQmlJS::AST::UiPublicMember *node)
 {
     Alias *alias = New<Alias>();
-    alias->flags = 0;
+    alias->clearFlags();
     if (node->isReadonly())
-        alias->flags |= QV4::CompiledData::Alias::IsReadOnly;
+        alias->setFlag(QV4::CompiledData::Alias::IsReadOnly);
 
     const QString propName = node->name.toString();
-    alias->nameIndex = registerString(propName);
+    alias->setNameIndex(registerString(propName));
 
     QQmlJS::SourceLocation loc = node->firstSourceLocation();
     alias->location.line = loc.startLine;
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index a4140e8a57..cb7c15c678 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -1668,12 +1668,12 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
     for (int aliasIndex = 0; aliasIndex != _compiledObject->aliasCount(); ++aliasIndex) {
         const QV4::CompiledData::Alias* alias = _compiledObject->aliasesBegin() + aliasIndex;
         const auto originalAlias = alias;
-        while (alias->aliasToLocalAlias)
+        while (alias->isAliasToLocalAlias())
             alias = _compiledObject->aliasesBegin() + alias->localAliasIndex;
-        Q_ASSERT(alias->flags & QV4::CompiledData::Alias::Resolved);
+        Q_ASSERT(alias->hasFlag(QV4::CompiledData::Alias::Resolved));
         if (!context->isIdValueSet(0)) // TODO: Do we really want 0 here?
             continue;
-        QObject *target = context->idValue(alias->targetObjectId);
+        QObject *target = context->idValue(alias->targetObjectId());
         if (!target)
             continue;
         QQmlData *targetDData = QQmlData::get(target, /*create*/false);
@@ -1685,7 +1685,11 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
             continue;
         auto it = sharedState->requiredProperties.find(targetProperty);
         if (it != sharedState->requiredProperties.end())
-            it->aliasesToRequired.push_back(AliasToRequiredInfo {compilationUnit->stringAt(originalAlias->nameIndex), compilationUnit->finalUrl()});
+            it->aliasesToRequired.push_back(
+                    AliasToRequiredInfo {
+                            compilationUnit->stringAt(originalAlias->nameIndex()),
+                            compilationUnit->finalUrl()
+                    });
     }
 
     qSwap(_vmeMetaObject, vmeMetaObject);
diff --git a/src/qml/qml/qqmlpropertycachecreator_p.h b/src/qml/qml/qqmlpropertycachecreator_p.h
index f6d85f9214..044c01f203 100644
--- a/src/qml/qml/qqmlpropertycachecreator_p.h
+++ b/src/qml/qml/qqmlpropertycachecreator_p.h
@@ -496,7 +496,7 @@ inline QQmlError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObject(int
     auto aend = obj->aliasesEnd();
     for ( ; a != aend; ++a) {
         bool notInRevision = false;
-        QQmlPropertyData *d = resolver.property(stringAt(a->nameIndex), &notInRevision);
+        QQmlPropertyData *d = resolver.property(stringAt(a->nameIndex()), &notInRevision);
         if (d && d->isFinal())
             return qQmlCompileError(a->location, QQmlPropertyCacheCreatorBase::tr("Cannot override FINAL property"));
     }
@@ -544,7 +544,7 @@ inline QQmlError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObject(int
     for ( ; a != aend; ++a) {
         auto flags = QQmlPropertyData::defaultSignalFlags();
 
-        QString changedSigName = stringAt(a->nameIndex) + QLatin1String("Changed");
+        QString changedSigName = stringAt(a->nameIndex()) + QLatin1String("Changed");
         seenSignals.insert(changedSigName);
 
         cache->appendSignal(changedSigName, flags, effectiveMethodIndex++);
@@ -828,12 +828,12 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasPropertie
         auto alias = object.aliasesBegin();
         auto end = object.aliasesEnd();
         for ( ; alias != end; ++alias) {
-            Q_ASSERT(alias->flags & QV4::CompiledData::Alias::Resolved);
+            Q_ASSERT(alias->hasFlag(QV4::CompiledData::Alias::Resolved));
 
-            const int targetObjectIndex = objectForId(component, alias->targetObjectId);
+            const int targetObjectIndex = objectForId(component, alias->targetObjectId());
             Q_ASSERT(targetObjectIndex >= 0);
 
-            if (alias->aliasToLocalAlias)
+            if (alias->isAliasToLocalAlias())
                 continue;
 
             if (alias->encodedMetaPropertyIndex == -1)
@@ -906,12 +906,12 @@ inline QQmlError QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataFor
 
     propertyFlags->setIsAlias(true);
 
-    if (alias.aliasToLocalAlias) {
+    if (alias.isAliasToLocalAlias()) {
         const QV4::CompiledData::Alias *lastAlias = &alias;
         QVarLengthArray<const QV4::CompiledData::Alias *, 4> seenAliases({lastAlias});
 
         do {
-            const int targetObjectIndex = objectForId(component, lastAlias->targetObjectId);
+            const int targetObjectIndex = objectForId(component, lastAlias->targetObjectId());
             Q_ASSERT(targetObjectIndex >= 0);
             const CompiledObject *targetObject = objectContainer->objectAt(targetObjectIndex);
             Q_ASSERT(targetObject);
@@ -928,17 +928,17 @@ inline QQmlError QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataFor
 
             seenAliases.append(targetAlias);
             lastAlias = targetAlias;
-        } while (lastAlias->aliasToLocalAlias);
+        } while (lastAlias->isAliasToLocalAlias());
 
         return propertyDataForAlias(component, *lastAlias, type, version, propertyFlags, enginePriv);
     }
 
-    const int targetObjectIndex = objectForId(component, alias.targetObjectId);
+    const int targetObjectIndex = objectForId(component, alias.targetObjectId());
     Q_ASSERT(targetObjectIndex >= 0);
     const CompiledObject &targetObject = *objectContainer->objectAt(targetObjectIndex);
 
     if (alias.encodedMetaPropertyIndex == -1) {
-        Q_ASSERT(alias.flags & QV4::CompiledData::Alias::AliasPointsToPointerObject);
+        Q_ASSERT(alias.hasFlag(QV4::CompiledData::Alias::AliasPointsToPointerObject));
         auto *typeRef = objectContainer->resolvedType(targetObject.inheritedTypeNameIndex);
         if (!typeRef) {
             // Can be caused by the alias target not being a valid id or property. E.g.:
@@ -1012,7 +1012,8 @@ inline QQmlError QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataFor
         }
     }
 
-    propertyFlags->setIsWritable(!(alias.flags & QV4::CompiledData::Alias::IsReadOnly) && writable);
+    propertyFlags->setIsWritable(!(alias.hasFlag(QV4::CompiledData::Alias::IsReadOnly))
+                                 && writable);
     propertyFlags->setIsResettable(resettable);
     propertyFlags->setIsBindable(bindable);
     return QQmlError();
@@ -1036,7 +1037,7 @@ inline QQmlError QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasesTo
     auto alias = object.aliasesBegin();
     auto end = object.aliasesEnd();
     for ( ; alias != end; ++alias, ++aliasIndex) {
-        Q_ASSERT(alias->flags & QV4::CompiledData::Alias::Resolved);
+        Q_ASSERT(alias->hasFlag(QV4::CompiledData::Alias::Resolved));
 
         QMetaType type;
         QTypeRevision version = QTypeRevision::zero();
@@ -1046,7 +1047,7 @@ inline QQmlError QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasesTo
         if (error.isValid())
             return error;
 
-        const QString propertyName = objectContainer->stringAt(alias->nameIndex);
+        const QString propertyName = objectContainer->stringAt(alias->nameIndex());
 
         if (object.hasAliasAsDefaultProperty() && aliasIndex == object.indexOfDefaultPropertyOrAlias)
             propertyCache->_defaultPropertyName = propertyName;
diff --git a/src/qml/qml/qqmltypecompiler.cpp b/src/qml/qml/qqmltypecompiler.cpp
index 34ea7db029..b633f2fb6f 100644
--- a/src/qml/qml/qqmltypecompiler.cpp
+++ b/src/qml/qml/qqmltypecompiler.cpp
@@ -1075,7 +1075,7 @@ bool QQmlComponentAndAliasResolver::resolveAliases(int componentIndex)
     if (!atLeastOneAliasResolved && !_objectsWithAliases.isEmpty()) {
         const QmlIR::Object *obj = qmlObjects->at(_objectsWithAliases.first());
         for (auto alias = obj->aliasesBegin(), end = obj->aliasesEnd(); alias != end; ++alias) {
-            if (!(alias->flags & QV4::CompiledData::Alias::Resolved)) {
+            if (!alias->hasFlag(QV4::CompiledData::Alias::Resolved)) {
                 recordError(alias->location, tr("Circular alias reference detected"));
                 return false;
             }
@@ -1097,7 +1097,7 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
     bool seenUnresolvedAlias = false;
 
     for (QmlIR::Alias *alias = obj->firstAlias(); alias; alias = alias->next) {
-        if (alias->flags & QV4::CompiledData::Alias::Resolved)
+        if (alias->hasFlag(QV4::CompiledData::Alias::Resolved))
             continue;
 
         seenUnresolvedAlias = true;
@@ -1113,8 +1113,8 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
 
         const QmlIR::Object *targetObject = qmlObjects->at(targetObjectIndex);
         Q_ASSERT(targetObject->id >= 0);
-        alias->targetObjectId = targetObject->id;
-        alias->aliasToLocalAlias = false;
+        alias->setTargetObjectId(targetObject->id);
+        alias->setIsAliasToLocalAlias(false);
 
         const QString aliasPropertyValue = stringAt(alias->propertyNameIndex);
 
@@ -1131,7 +1131,7 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
         QQmlPropertyIndex propIdx;
 
         if (property.isEmpty()) {
-            alias->flags |= QV4::CompiledData::Alias::AliasPointsToPointerObject;
+            alias->setFlag(QV4::CompiledData::Alias::AliasPointsToPointerObject);
         } else {
             QQmlPropertyCache *targetCache = propertyCaches.at(targetObjectIndex);
             if (!targetCache) {
@@ -1150,7 +1150,7 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
                 bool aliasPointsToOtherAlias = false;
                 int localAliasIndex = 0;
                 for (auto targetAlias = targetObject->aliasesBegin(), end = targetObject->aliasesEnd(); targetAlias != end; ++targetAlias, ++localAliasIndex) {
-                    if (stringAt(targetAlias->nameIndex) == property) {
+                    if (stringAt(targetAlias->nameIndex()) == property) {
                         aliasPointsToOtherAlias = true;
                         break;
                     }
@@ -1158,8 +1158,8 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
                 if (aliasPointsToOtherAlias) {
                     if (targetObjectIndex == objectIndex) {
                         alias->localAliasIndex = localAliasIndex;
-                        alias->aliasToLocalAlias = true;
-                        alias->flags |= QV4::CompiledData::Alias::Resolved;
+                        alias->setIsAliasToLocalAlias(true);
+                        alias->setFlag(QV4::CompiledData::Alias::Resolved);
                         ++numResolvedAliases;
                         continue;
                     }
@@ -1221,12 +1221,12 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
                 }
             } else {
                 if (targetProperty->isQObject())
-                    alias->flags |= QV4::CompiledData::Alias::AliasPointsToPointerObject;
+                    alias->setFlag(QV4::CompiledData::Alias::AliasPointsToPointerObject);
             }
         }
 
         alias->encodedMetaPropertyIndex = propIdx.toEncoded();
-        alias->flags |= QV4::CompiledData::Alias::Resolved;
+        alias->setFlag(QV4::CompiledData::Alias::Resolved);
         numResolvedAliases++;
     }
 
diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index 056ada9a8d..9988294f29 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -237,7 +237,7 @@ void QQmlVMEMetaObjectEndpoint::tryConnect()
         const QV4::CompiledData::Alias *aliasData = &metaObject->compiledObject->aliasTable()[aliasId];
         if (!aliasData->isObjectAlias()) {
             QQmlRefPointer<QQmlContextData> ctxt = metaObject->ctxt;
-            QObject *target = ctxt->idValue(aliasData->targetObjectId);
+            QObject *target = ctxt->idValue(aliasData->targetObjectId());
             if (!target)
                 return;
 
@@ -888,16 +888,18 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
             if (id < aliasCount) {
                 const QV4::CompiledData::Alias *aliasData = &compiledObject->aliasTable()[id];
 
-                if ((aliasData->flags & QV4::CompiledData::Alias::AliasPointsToPointerObject) && c == QMetaObject::ReadProperty)
-                        *reinterpret_cast<void **>(a[0]) = nullptr;
+                if (aliasData->hasFlag(QV4::CompiledData::Alias::AliasPointsToPointerObject)
+                        && c == QMetaObject::ReadProperty){
+                    *reinterpret_cast<void **>(a[0]) = nullptr;
+                }
 
                 if (ctxt.isNull())
                     return -1;
 
-                while (aliasData->aliasToLocalAlias)
+                while (aliasData->isAliasToLocalAlias())
                     aliasData = &compiledObject->aliasTable()[aliasData->localAliasIndex];
 
-                QObject *target = ctxt->idValue(aliasData->targetObjectId);
+                QObject *target = ctxt->idValue(aliasData->targetObjectId());
                 if (!target)
                     return -1;
 
@@ -1244,9 +1246,9 @@ bool QQmlVMEMetaObject::aliasTarget(int index, QObject **target, int *coreIndex,
 
     const int aliasId = index - propOffset() - compiledObject->nProperties;
     const QV4::CompiledData::Alias *aliasData = &compiledObject->aliasTable()[aliasId];
-    while (aliasData->aliasToLocalAlias)
+    while (aliasData->isAliasToLocalAlias())
         aliasData = &compiledObject->aliasTable()[aliasData->localAliasIndex];
-    *target = ctxt->idValue(aliasData->targetObjectId);
+    *target = ctxt->idValue(aliasData->targetObjectId());
     if (!*target)
         return false;
 
@@ -1274,7 +1276,7 @@ void QQmlVMEMetaObject::connectAlias(int aliasId)
     }
 
     endpoint->metaObject = this;
-    endpoint->connect(ctxt->idValueBindings(aliasData->targetObjectId));
+    endpoint->connect(ctxt->idValueBindings(aliasData->targetObjectId()));
     endpoint->tryConnect();
 }
 
diff --git a/tools/qmltc/prototype/qml2cppdefaultpasses.cpp b/tools/qmltc/prototype/qml2cppdefaultpasses.cpp
index 8eda649441..f037402295 100644
--- a/tools/qmltc/prototype/qml2cppdefaultpasses.cpp
+++ b/tools/qmltc/prototype/qml2cppdefaultpasses.cpp
@@ -143,12 +143,24 @@ static bool isReservedWord(QStringView word)
     return std::binary_search(std::begin(cppKeywords), std::end(cppKeywords), word);
 }
 
+template<typename IRElement>
+quint32 irNameIndex(const IRElement &irElement)
+{
+    return irElement.nameIndex;
+}
+
+template<>
+quint32 irNameIndex<QmlIR::Alias>(const QmlIR::Alias &alias)
+{
+    return alias.nameIndex();
+}
+
 template<typename InputIterator>
 static decltype(auto) findIrElement(const QmlIR::Document *doc, InputIterator first,
                                     InputIterator last, QStringView name)
 {
     auto it = std::find_if(first, last, [&](const auto &candidate) {
-        return name == doc->stringAt(candidate.nameIndex);
+        return name == doc->stringAt(irNameIndex(candidate));
     });
     Q_ASSERT(it != last); // must be satisfied by the caller
     return *it;