// Copyright (C) 2022 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0 #ifndef QMLTCCOMPILERPIECES_H #define QMLTCCOMPILERPIECES_H #include #include #include #include #include "qmltcoutputir.h" #include "qmltcvisitor.h" QT_BEGIN_NAMESPACE /*! \internal Helper class that generates code for the output IR. Takes care of complicated, repetitive, nasty logic which is better kept in a single confined place. */ struct QmltcCodeGenerator { static const QString privateEngineName; static const QString typeCountName; QString documentUrl; QmltcVisitor *visitor = nullptr; [[nodiscard]] inline decltype(auto) generate_initCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const; inline void generate_initCodeForTopLevelComponent(QmltcType ¤t, const QQmlJSScope::ConstPtr &type); inline void generate_qmltcInstructionCallCode(QmltcMethod *function, const QQmlJSScope::ConstPtr &type, const QString &baseInstructionArgs, const QString &childInstructionArgs) const; inline void generate_endInitCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const; inline void generate_setComplexBindingsCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const; inline void generate_interfaceCallCode(QmltcMethod *function, const QQmlJSScope::ConstPtr &type, const QString &interfaceName, const QString &interfaceCall) const; inline void generate_beginClassCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const; inline void generate_completeComponentCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const; inline void generate_finalizeComponentCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const; inline void generate_handleOnCompletedCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const; static void generate_assignToProperty(QStringList *block, const QQmlJSScope::ConstPtr &type, const QQmlJSMetaProperty &p, const QString &value, const QString &accessor, bool constructFromQObject = false); static void generate_setIdValue(QStringList *block, const QString &context, qsizetype index, const QString &accessor, const QString &idString); inline QString generate_typeCount() const { return generate_typeCount([](const QQmlJSScope::ConstPtr &) { return false; }); } template inline QString generate_typeCount(Predicate p) const; static void generate_callExecuteRuntimeFunction(QStringList *block, const QString &url, QQmlJSMetaMethod::AbsoluteFunctionIndex index, const QString &accessor, const QString &returnType, const QList ¶meters = {}); static void generate_createBindingOnProperty(QStringList *block, const QString &unitVarName, const QString &scope, qsizetype functionIndex, const QString &target, int propertyIndex, const QQmlJSMetaProperty &p, int valueTypeIndex, const QString &subTarget); static inline void generate_getCompilationUnitFromUrl(); struct PreparedValue { QStringList prologue; QString value; QStringList epilogue; }; static PreparedValue wrap_mismatchingTypeConversion(const QQmlJSMetaProperty &p, QString value); static PreparedValue wrap_extensionType(const QQmlJSScope::ConstPtr &type, const QQmlJSMetaProperty &p, const QString &accessor); static QString wrap_privateClass(const QString &accessor, const QQmlJSMetaProperty &p); static QString wrap_qOverload(const QList ¶meters, const QString &overloaded); static QString wrap_addressof(const QString &addressed); QString urlMethodName() const { using namespace Qt::StringLiterals; QFileInfo fi(documentUrl); return u"q_qmltc_docUrl_" + fi.fileName().replace(u".qml"_s, u""_s).replace(u'.', u'_'); } }; /*! \internal Generates \a{current.init}'s code. The init method sets up a QQmlContext for the object and (in case \a type is a document root) calls other object creation methods in a well-defined order: 1. current.beginClass 2. current.endInit 3. current.completeComponent 4. current.finalizeComponent 5. current.handleOnCompleted This function returns a QScopeGuard with the final instructions that have to be generated at a later point, once everything else is compiled. \sa generate_initCodeForTopLevelComponent */ inline decltype(auto) QmltcCodeGenerator::generate_initCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const { using namespace Qt::StringLiterals; // qmltc_init()'s parameters: // * QQmltcObjectCreationHelper* creator // * QQmlEngine* engine // * const QQmlRefPointer& parentContext // * bool canFinalize [optional, when document root] const bool isDocumentRoot = type == visitor->result(); current.init.body << u"Q_UNUSED(creator);"_s; // can happen sometimes current.init.body << u"auto context = parentContext;"_s; // if parent scope has a QML base type and is not a (current) document root, // the parentContext we passed as input to this object is a context of // another document. we need to fix it by using parentContext->parent() const auto realQmlScope = [](const QQmlJSScope::ConstPtr &scope) { if (scope->isArrayScope()) return scope->parentScope(); return scope; }; if (auto parentScope = realQmlScope(type->parentScope()); parentScope != visitor->result() && QQmlJSUtils::hasCompositeBase(parentScope)) { current.init.body << u"// NB: context->parent() is the context of this document"_s; current.init.body << u"context = context->parent();"_s; } // any object with QML base class has to call base's init method if (auto base = type->baseType(); base->isComposite()) { QString lhs; // init creates new context. for document root, it's going to be a real // parent context, so store it temporarily in `context` variable if (isDocumentRoot) lhs = u"context = "_s; current.init.body << u"// 0. call base's init method"_s; Q_ASSERT(!isDocumentRoot || visitor->qmlTypesWithQmlBases()[0] == visitor->result()); const auto isCurrentType = [&](const QQmlJSScope::ConstPtr &qmlType) { return qmlType == type; }; const QString creationOffset = generate_typeCount(isCurrentType); current.init.body << u"{"_s; current.init.body << u"QQmltcObjectCreationHelper subCreator(creator, %1);"_s.arg( creationOffset); current.init.body << QStringLiteral("%1%2::%3(&subCreator, engine, context, /* finalize */ false);") .arg(lhs, base->internalName(), current.init.name); current.init.body << u"}"_s; } current.init.body << QStringLiteral("auto %1 = QQmlEnginePrivate::get(engine);").arg(privateEngineName); current.init.body << QStringLiteral("Q_UNUSED(%1);").arg(privateEngineName); // precaution // when generating root, we need to create a new (document-level) context. // otherwise, just use existing context as is if (isDocumentRoot) { current.init.body << u"// 1. create new QML context for this document"_s; // TODO: the last 2 parameters are {0, true} because we deal with // document root only here. in reality, there are inline components // which need { index, true } instead current.init.body << QStringLiteral( "context = %1->createInternalContext(%1->compilationUnitFromUrl(%2()), " "context, 0, true);") .arg(privateEngineName, urlMethodName()); } else { current.init.body << u"// 1. use current context as this object's context"_s; current.init.body << u"// context = context;"_s; } if (!type->baseType()->isComposite() || isDocumentRoot) { current.init.body << u"// 2. set context for this object"_s; current.init.body << QStringLiteral( "%1->setInternalContext(this, context, QQmlContextData::%2);") .arg(privateEngineName, (isDocumentRoot ? u"DocumentRoot"_s : u"OrdinaryObject"_s)); if (isDocumentRoot) current.init.body << u"context->setContextObject(this);"_s; } // context is this document's context. we must remember it in each type current.variables.emplaceBack(u"QQmlRefPointer"_s, u"q_qmltc_thisContext"_s, u"nullptr"_s); current.init.body << u"%1::q_qmltc_thisContext = context;"_s.arg(type->internalName()); if (int id = visitor->runtimeId(type); id >= 0) { current.init.body << u"// 3. set id since it is provided"_s; QString idString = visitor->addressableScopes().id(type); if (idString.isEmpty()) idString = u""_s; QmltcCodeGenerator::generate_setIdValue(¤t.init.body, u"context"_s, id, u"this"_s, idString); } // if type has an extension, create a dynamic meta object for it bool hasExtension = false; for (auto cppBase = QQmlJSScope::nonCompositeBaseType(type); cppBase; cppBase = cppBase->baseType()) { // QObject is special: we have a pseudo-extension on it due to builtins if (cppBase->internalName() == u"QObject"_s) break; if (cppBase->extensionType().extensionSpecifier != QQmlJSScope::NotExtension) { hasExtension = true; break; } } if (hasExtension) { current.init.body << u"{"_s; current.init.body << u"auto cppData = QmltcTypeData(this);"_s; current.init.body << u"qmltcCreateDynamicMetaObject(this, cppData);"_s; current.init.body << u"}"_s; } const auto generateFinalLines = [¤t, isDocumentRoot]() { if (isDocumentRoot) { current.init.body << u"// 4. finish the document root creation"_s; current.init.body << u"if (canFinalize) {"_s; current.init.body << QStringLiteral(" %1(creator, /* finalize */ true);") .arg(current.beginClass.name); current.init.body << QStringLiteral(" %1(creator, engine);") .arg(current.endInit.name); current.init.body << QStringLiteral(" %1(creator, engine);") .arg(current.setComplexBindings.name); current.init.body << QStringLiteral(" %1(creator, /* finalize */ true);") .arg(current.completeComponent.name); current.init.body << QStringLiteral(" %1(creator, /* finalize */ true);") .arg(current.finalizeComponent.name); current.init.body << QStringLiteral(" %1(creator);") .arg(current.handleOnCompleted.name); current.init.body << u"}"_s; } current.init.body << u"return context;"_s; }; return QScopeGuard(generateFinalLines); } /*! \internal Generates \a{current.init}'s code in case when \a type is a top-level Component type. The init method in this case mimics QQmlObjectCreator::createComponent() logic. \sa generate_initCode */ inline void QmltcCodeGenerator::generate_initCodeForTopLevelComponent(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) { Q_UNUSED(type); using namespace Qt::StringLiterals; // since we create a document root as QQmlComponent, we only need to fake // QQmlComponent construction in init: current.init.body << u"// init QQmlComponent: see QQmlObjectCreator::createComponent()"_s; current.init.body << u"{"_s; // we already called QQmlComponent(parent) constructor. now we need: // 1. QQmlComponent(engine, parent) logic: current.init.body << u"// QQmlComponent(engine, parent):"_s; current.init.body << u"auto d = QQmlComponentPrivate::get(this);"_s; current.init.body << u"Q_ASSERT(d);"_s; current.init.body << u"d->engine = engine;"_s; current.init.body << u"QObject::connect(engine, &QObject::destroyed, this, [d]() {"_s; current.init.body << u" d->state.creator.reset();"_s; current.init.body << u" d->engine = nullptr;"_s; current.init.body << u"});"_s; // 2. QQmlComponent(engine, compilationUnit, start, parent) logic: current.init.body << u"// QQmlComponent(engine, compilationUnit, start, parent):"_s; current.init.body << u"auto compilationUnit = QQmlEnginePrivate::get(engine)->compilationUnitFromUrl(" + QmltcCodeGenerator::urlMethodName() + u"());"; current.init.body << u"d->compilationUnit = compilationUnit;"_s; current.init.body << u"d->start = 0;"_s; current.init.body << u"d->url = compilationUnit->finalUrl();"_s; current.init.body << u"d->progress = 1.0;"_s; // 3. QQmlObjectCreator::createComponent() logic which is left: current.init.body << u"// QQmlObjectCreator::createComponent():"_s; current.init.body << u"d->creationContext = context;"_s; current.init.body << u"Q_ASSERT(QQmlData::get(this, /*create*/ false));"_s; current.init.body << u"}"_s; } /*! \internal A generic helper function that generates special qmltc instruction code boilerplate, adding it to a passed \a function. This is a building block used to generate e.g. QML_endInit code. */ inline void QmltcCodeGenerator::generate_qmltcInstructionCallCode( QmltcMethod *function, const QQmlJSScope::ConstPtr &type, const QString &baseInstructionArgs, const QString &childInstructionArgs) const { using namespace Qt::StringLiterals; const bool isDocumentRoot = type == visitor->result(); if (auto base = type->baseType(); base->isComposite()) { function->body << u"// call base's method"_s; Q_ASSERT(!isDocumentRoot || visitor->qmlTypesWithQmlBases()[0] == visitor->result()); const auto isCurrentType = [&](const QQmlJSScope::ConstPtr &qmlType) { return qmlType == type; }; const QString creationOffset = generate_typeCount(isCurrentType); function->body << u"{"_s; function->body << u"QQmltcObjectCreationHelper subCreator(creator, %1);"_s.arg( creationOffset); if (!baseInstructionArgs.isEmpty()) { function->body << u"%1::%2(&subCreator, %3);"_s.arg( base->internalName(), function->name, baseInstructionArgs); } else { function->body << u"%1::%2(&subCreator);"_s.arg(base->internalName(), function->name); } function->body << u"}"_s; } if (!isDocumentRoot) // document root does all the work here return; const auto types = visitor->pureQmlTypes(); function->body << u"// call children's methods"_s; for (qsizetype i = 1; i < types.size(); ++i) { const auto &type = types[i]; Q_ASSERT(!type->isComponentRootElement()); function->body << u"creator->get<%1>(%2)->%3(%4);"_s.arg( type->internalName(), QString::number(i), function->name, childInstructionArgs); } function->body << u"// call own method code"_s; } /*! \internal Generates \a{current.endInit}'s code. The endInit method creates bindings, connects signals with slots and generally performs other within-object initialization. Additionally, the QML document root's endInit calls endInit methods of all the necessary QML types within the document. */ inline void QmltcCodeGenerator::generate_endInitCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const { using namespace Qt::StringLiterals; // QML_endInit()'s parameters: // * QQmltcObjectCreationHelper* creator // * QQmlEngine* engine current.endInit.body << u"Q_UNUSED(creator);"_s; current.endInit.body << u"Q_UNUSED(engine);"_s; generate_qmltcInstructionCallCode(¤t.endInit, type, u"engine"_s, u"creator, engine"_s); if (visitor->hasDeferredBindings(type)) { current.endInit.body << u"{ // defer bindings"_s; current.endInit.body << u"auto ddata = QQmlData::get(this);"_s; current.endInit.body << u"auto thisContext = ddata->outerContext;"_s; current.endInit.body << u"Q_ASSERT(thisContext);"_s; current.endInit.body << QStringLiteral("ddata->deferData(%1, " "QQmlEnginePrivate::get(engine)->" "compilationUnitFromUrl(%2()), thisContext);") .arg(QString::number(visitor->qmlIrObjectIndex(type)), QmltcCodeGenerator::urlMethodName()); current.endInit.body << u"}"_s; } } /*! \internal Generates \a{current.setComplexBindings}'s code. The setComplexBindings method creates complex bindings (such as script bindings). Additionally, the QML document root's setComplexBindings calls setComplexBindings methods of all the necessary QML types within the document. */ inline void QmltcCodeGenerator::generate_setComplexBindingsCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const { using namespace Qt::StringLiterals; // QML_setComplexBindings()'s parameters: // * QQmltcObjectCreationHelper* creator // * QQmlEngine* engine current.setComplexBindings.body << u"Q_UNUSED(creator);"_s; current.setComplexBindings.body << u"Q_UNUSED(engine);"_s; generate_qmltcInstructionCallCode(¤t.setComplexBindings, type, u"engine"_s, u"creator, engine"_s); } /*! \internal A generic helper function that generates interface code boilerplate, adding it to a passed \a function. This is a building block used to generate e.g. QQmlParserStatus API calls. */ inline void QmltcCodeGenerator::generate_interfaceCallCode(QmltcMethod *function, const QQmlJSScope::ConstPtr &type, const QString &interfaceName, const QString &interfaceCall) const { using namespace Qt::StringLiterals; // function's parameters: // * QQmltcObjectCreationHelper* creator // * bool canFinalize [optional, when document root] const bool isDocumentRoot = type == visitor->result(); function->body << u"Q_UNUSED(creator);"_s; if (isDocumentRoot) function->body << u"Q_UNUSED(canFinalize);"_s; if (auto base = type->baseType(); base->isComposite()) { function->body << u"// call base's method"_s; Q_ASSERT(!isDocumentRoot || visitor->qmlTypesWithQmlBases()[0] == visitor->result()); const auto isCurrentType = [&](const QQmlJSScope::ConstPtr &qmlType) { return qmlType == type; }; const QString creationOffset = generate_typeCount(isCurrentType); function->body << u"{"_s; function->body << u"QQmltcObjectCreationHelper subCreator(creator, %1);"_s.arg( creationOffset); function->body << u"%1::%2(&subCreator, /* finalize */ false);"_s.arg(base->internalName(), function->name); function->body << u"}"_s; } if (!isDocumentRoot) return; const auto types = visitor->pureQmlTypes(); function->body << u"// call children's methods"_s; for (qsizetype i = 1; i < types.size(); ++i) { const auto &type = types[i]; Q_ASSERT(!type->isComponentRootElement()); function->body << u"{"_s; function->body << u"auto child = creator->get<%1>(%2);"_s.arg(type->internalName(), QString::number(i)); function->body << u"child->%1(creator);"_s.arg(function->name); if (type->hasInterface(interfaceName)) { function->body << u"static_assert(std::is_base_of<%1, %2>::value);"_s.arg( interfaceName, type->internalName()); function->body << u"child->%1();"_s.arg(interfaceCall); } function->body << u"}"_s; } if (type->hasInterface(interfaceName)) { function->body << u"if (canFinalize) {"_s; function->body << u" // call own method"_s; function->body << u" static_assert(std::is_base_of<%1, %2>::value);"_s.arg( interfaceName, type->internalName()); function->body << u" this->%1();"_s.arg(interfaceCall); function->body << u"}"_s; } } /*! \internal Generates \a{current.beginClass}'s code. The beginClass method optionally calls QQmlParserStatus::classBegin() when \a type implements the corresponding interface. */ inline void QmltcCodeGenerator::generate_beginClassCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const { using namespace Qt::StringLiterals; generate_interfaceCallCode(¤t.beginClass, type, u"QQmlParserStatus"_s, u"classBegin"_s); } /*! \internal Generates \a{current.completeComponent}'s code. The completeComponent method optionally calls QQmlParserStatus::componentComplete() when \a type implements the corresponding interface. */ inline void QmltcCodeGenerator::generate_completeComponentCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const { using namespace Qt::StringLiterals; generate_interfaceCallCode(¤t.completeComponent, type, u"QQmlParserStatus"_s, u"componentComplete"_s); } /*! \internal Generates \a{current.finalizeComponent}'s code. The finalizeComponent method optionally calls QQmlFinalizerHook::componentFinalized() when \a type implements the corresponding interface. */ inline void QmltcCodeGenerator::generate_finalizeComponentCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const { using namespace Qt::StringLiterals; generate_interfaceCallCode(¤t.finalizeComponent, type, u"QQmlFinalizerHook"_s, u"componentFinalized"_s); } /*! \internal Generates \a{current.handleOnCompleted}'s code. The handleOnCompleted method optionally calls a Component.onCompleted handler if that is present in \a type. */ inline void QmltcCodeGenerator::generate_handleOnCompletedCode(QmltcType ¤t, const QQmlJSScope::ConstPtr &type) const { using namespace Qt::StringLiterals; // QML_handleOnCompleted()'s parameters: // * QQmltcObjectCreationHelper* creator current.handleOnCompleted.body << u"Q_UNUSED(creator);"_s; generate_qmltcInstructionCallCode(¤t.handleOnCompleted, type, QString(), u"creator"_s); } /*! \internal Generates a constexpr function consisting of a sum of type counts for a current QML document. Predicate \a p acts as a stop condition to prematurely end the sum generation. The high-level idea: Each qmltc-compiled document root has a notion of type count. Type count is a number of types the current QML document contains (except for Component-wrapped types) plus the sum of all type counts of all the QML documents used in the current document: if current document has a type with QML base type, this type's type count is added to the type count of the current document. To be able to lookup created objects during the creation process, one needs to know an index of each object within the document + an offset of the document. Index comes from QmltcVisitor and is basically a serial number of a type in the document (index < type count of the document root type). The offset is more indirect. The current document always starts with an offset of 0, each type that has a QML base type also "has a sub-document". Each sub-document has a non-0 offset X, where X is calculated as a sum of the current document's type count and a cumulative type count of all the previous sub-documents that appear before the sub-document of interest: \code // A.qml Item { // offset: 0; number of types == 1 (document root) + 3 (children) QmlBase1 { } // offset: 4 (number of types in A.qml itself) QmlBase2 { } // offset: 4 + N, where N == typeCount(QmlBase1.qml) QmlBase3 { } // offset: (4 + N) + M, where M == typeCount(QmlBase2.qml) } // typeCount(A.qml) == 4 + N + M + O, where O == typeCount(QmlBase3.qml) \endcode As all objects are put into an array, schematically you can look at it in the following way: ``` count: 4 N M O objects: aaaa|xxxxxxxxxxxxx|yyyyyyy|zzz ^ ^ ^ ^ files: | QmlBase1.qml | QmlBase3.qml A.qml QmlBase2.qml ``` For the object lookup logic itself, see QQmltcObjectCreationHelper */ template inline QString QmltcCodeGenerator::generate_typeCount(Predicate p) const { using namespace Qt::StringLiterals; const QList typesWithBaseTypeCount = visitor->qmlTypesWithQmlBases(); QStringList components; components.reserve(1 + typesWithBaseTypeCount.size()); // add this document's type counts minus document root Q_ASSERT(visitor->pureQmlTypes().size() > 0); Q_ASSERT(visitor->typeCount() >= visitor->pureQmlTypes().size()); components << QString::number(visitor->typeCount() - 1); // traverse types with QML base classes for (const QQmlJSScope::ConstPtr &t : typesWithBaseTypeCount) { if (p(t)) break; QString typeCountTemplate = u"QQmltcObjectCreationHelper::typeCount<%1>()"_s; if (t == visitor->result()) { // t is this document's root components << typeCountTemplate.arg(t->baseTypeName()); } else { components << typeCountTemplate.arg(t->internalName()); } } return components.join(u" + "_s); } QT_END_NAMESPACE #endif // QMLTCCOMPILERPIECES_H