Required properties: Allow retroactive require specification

It is now possible to mark a property of a parent class as required in
the child by writing required <propertyName>

Change-Id: I9e9d58c7b5c00577b056e905b39744b2fa359ea0
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

21 files changed, 237 insertions, 21 deletions

diff --git a/src/qml/common/qv4compileddata_p.h b/src/qml/common/qv4compileddata_p.h
index 42c476763e..a5a1cf8969 100644
--- a/src/qml/common/qv4compileddata_p.h
+++ b/src/qml/common/qv4compileddata_p.h
@@ -75,7 +75,7 @@ QT_BEGIN_NAMESPACE
 // Also change the comment behind the number to describe the latest change. This has the added
 // benefit that if another patch changes the version too, it will result in a merge conflict, and
 // not get removed silently.
-#define QV4_DATA_STRUCTURE_VERSION 0x28// support inline components
+#define QV4_DATA_STRUCTURE_VERSION 0x29// support additional required property features
 
 class QIODevice;
 class QQmlTypeNameCache;
@@ -695,6 +695,12 @@ struct Property
 };
 static_assert(sizeof(Property) == 12, "Property structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
+struct RequiredPropertyExtraData {
+    quint32_le nameIndex;
+};
+
+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 {
         IsReadOnly = 0x1,
@@ -765,13 +771,16 @@ struct Object
     Location locationOfIdProperty;
     quint32_le offsetToInlineComponents;
     quint16_le nInlineComponents;
+    quint32_le offsetToRequiredPropertyExtraData;
+    quint16_le nRequiredPropertyExtraData;
 //    Function[]
 //    Property[]
 //    Signal[]
 //    Binding[]
 //    InlineComponent[]
+//    RequiredPropertyExtraData[]
 
-    static int calculateSizeExcludingSignalsAndEnums(int nFunctions, int nProperties, int nAliases, int nEnums, int nSignals, int nBindings, int nNamedObjectsInComponent, int nInlineComponents)
+    static int calculateSizeExcludingSignalsAndEnums(int nFunctions, int nProperties, int nAliases, int nEnums, int nSignals, int nBindings, int nNamedObjectsInComponent, int nInlineComponents, int nRequiredPropertyExtraData)
     {
         return ( sizeof(Object)
                  + nFunctions * sizeof(quint32)
@@ -782,6 +791,7 @@ struct Object
                  + nBindings * sizeof(Binding)
                  + nNamedObjectsInComponent * sizeof(int)
                  + nInlineComponents * sizeof(InlineComponent)
+                 + nRequiredPropertyExtraData * sizeof(RequiredPropertyExtraData)
                  + 0x7
                ) & ~0x7;
     }
@@ -835,6 +845,16 @@ struct Object
         return reinterpret_cast<const InlineComponent*>(reinterpret_cast<const char *>(this) + offsetToInlineComponents);
     }
 
+    const RequiredPropertyExtraData *requiredPropertyExtraDataAt(int idx) const
+    {
+        return requiredPropertyExtraDataTable() + idx;
+    }
+
+    const RequiredPropertyExtraData *requiredPropertyExtraDataTable() const
+    {
+        return reinterpret_cast<const RequiredPropertyExtraData*>(reinterpret_cast<const char *>(this) + offsetToRequiredPropertyExtraData);
+    }
+
     // --- QQmlPropertyCacheCreator interface
     int propertyCount() const { return nProperties; }
     int aliasCount() const { return nAliases; }
@@ -863,10 +883,14 @@ struct Object
     InlineComponentIterator inlineComponentsBegin() const {return InlineComponentIterator(this, 0);}
     InlineComponentIterator inlineComponentsEnd() const {return InlineComponentIterator(this, nInlineComponents);}
 
+    typedef TableIterator<RequiredPropertyExtraData, Object, &Object::requiredPropertyExtraDataAt> RequiredPropertyExtraDataIterator;
+    RequiredPropertyExtraDataIterator requiredPropertyExtraDataBegin() const {return RequiredPropertyExtraDataIterator(this, 0); };
+    RequiredPropertyExtraDataIterator requiredPropertyExtraDataEnd() const {return RequiredPropertyExtraDataIterator(this, nRequiredPropertyExtraData); };
+
     int namedObjectsInComponentCount() const { return nNamedObjectsInComponent; }
     // ---
 };
-static_assert(sizeof(Object) == 76, "Object structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+static_assert(sizeof(Object) == 84, "Object structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Import
 {
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 811f88cb73..a3ee431e90 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -64,6 +64,33 @@ using namespace QQmlJS;
         return false; \
     }
 
+void Object::simplifyRequiredProperties() {
+    // if a property of the current object was marked as required
+    // do not store that information in the ExtraData
+    // but rather mark the property as required
+    QSet<int> required;
+    for (auto it = this->requiredPropertyExtraDataBegin(); it != this->requiredPropertyExtraDataEnd(); ++it)
+        required.insert(it->nameIndex);
+    if (required.isEmpty())
+        return;
+    for (auto it = this->propertiesBegin(); it != this->propertiesEnd(); ++it) {
+        auto requiredIt = required.find(it->nameIndex);
+        if (requiredIt != required.end()) {
+            it->isRequired = true;
+            required.erase(requiredIt);
+        }
+    }
+    QmlIR::RequiredPropertyExtraData *prev = nullptr;
+    auto current = this->requiredPropertyExtraDatas->first;
+    while (current) {
+        if (required.contains(current->nameIndex))
+            prev = current;
+        else
+            requiredPropertyExtraDatas->unlink(prev, current);
+        current = current->next;
+    }
+}
+
 bool Parameter::init(QV4::Compiler::JSUnitGenerator *stringGenerator, const QString &parameterName,
                      const QString &typeName)
 {
@@ -162,6 +189,7 @@ void Object::init(QQmlJS::MemoryPool *pool, int typeNameIndex, int idIndex, cons
     functions = pool->New<PoolList<Function> >();
     functionsAndExpressions = pool->New<PoolList<CompiledFunctionOrExpression> >();
     inlineComponents = pool->New<PoolList<InlineComponent>>();
+    requiredPropertyExtraDatas = pool->New<PoolList<RequiredPropertyExtraData>>();
     declarationsOverride = nullptr;
 }
 
@@ -287,6 +315,11 @@ void Object::appendInlineComponent(InlineComponent *ic)
     inlineComponents->append(ic);
 }
 
+void Object::appendRequiredPropertyExtraData(RequiredPropertyExtraData *extraData)
+{
+    requiredPropertyExtraDatas->append(extraData);
+}
+
 QString Object::appendBinding(Binding *b, bool isListBinding)
 {
     const bool bindingToDefaultProperty = (b->propertyNameIndex == quint32(0));
@@ -452,6 +485,10 @@ bool IRBuilder::generateFromQml(const QString &code, const QString &url, Documen
     qSwap(_imports, output->imports);
     qSwap(_pragmas, output->pragmas);
     qSwap(_objects, output->objects);
+
+    for (auto object: output->objects)
+        object->simplifyRequiredProperties();
+
     return errors.isEmpty();
 }
 
@@ -988,6 +1025,14 @@ bool IRBuilder::visit(QQmlJS::AST::UiSourceElement *node)
     return false;
 }
 
+bool IRBuilder::visit(AST::UiRequired *ast)
+{
+    auto extraData = New<RequiredPropertyExtraData>();
+    extraData->nameIndex = registerString(ast->name.toString());
+    _object->appendRequiredPropertyExtraData(extraData);
+    return false;
+}
+
 QString IRBuilder::asString(QQmlJS::AST::UiQualifiedId *node)
 {
     QString s;
@@ -1590,7 +1635,7 @@ void QmlUnitGenerator::generate(Document &output, const QV4::CompiledData::Depen
     uint nextOffset = objectOffset + objectOffsetTableSize;
     for (Object *o : qAsConst(output.objects)) {
         objectOffsets.insert(o, nextOffset);
-        nextOffset += QV4::CompiledData::Object::calculateSizeExcludingSignalsAndEnums(o->functionCount(), o->propertyCount(), o->aliasCount(), o->enumCount(), o->signalCount(), o->bindingCount(), o->namedObjectsInComponent.size(), o->inlineComponentCount());
+        nextOffset += QV4::CompiledData::Object::calculateSizeExcludingSignalsAndEnums(o->functionCount(), o->propertyCount(), o->aliasCount(), o->enumCount(), o->signalCount(), o->bindingCount(), o->namedObjectsInComponent.size(), o->inlineComponentCount(), o->requiredPropertyExtraDataCount());
 
         int signalTableSize = 0;
         for (const Signal *s = o->firstSignal(); s; s = s->next)
@@ -1673,6 +1718,10 @@ void QmlUnitGenerator::generate(Document &output, const QV4::CompiledData::Depen
         objectToWrite->offsetToInlineComponents = nextOffset;
         nextOffset += objectToWrite->nInlineComponents * sizeof (QV4::CompiledData::InlineComponent);
 
+        objectToWrite->nRequiredPropertyExtraData = o->requiredPropertyExtraDataCount();
+        objectToWrite->offsetToRequiredPropertyExtraData = nextOffset;
+        nextOffset += objectToWrite->nRequiredPropertyExtraData * sizeof(QV4::CompiledData::RequiredPropertyExtraData);
+
         quint32_le *functionsTable = reinterpret_cast<quint32_le *>(objectPtr + objectToWrite->offsetToFunctions);
         for (const Function *f = o->firstFunction(); f; f = f->next)
             *functionsTable++ = o->runtimeFunctionIndices.at(f->index);
@@ -1752,6 +1801,14 @@ void QmlUnitGenerator::generate(Document &output, const QV4::CompiledData::Depen
             *icToWrite = *ic;
             inlineComponentPtr += sizeof(QV4::CompiledData::InlineComponent);
         }
+
+        char *requiredPropertyExtraDataPtr = objectPtr + objectToWrite->offsetToRequiredPropertyExtraData;
+        for (auto it = o->requiredPropertyExtraDataBegin(); it != o->requiredPropertyExtraDataEnd(); ++it) {
+            const RequiredPropertyExtraData *extraData = it.ptr;
+            QV4::CompiledData::RequiredPropertyExtraData *extraDataToWrite = reinterpret_cast<QV4::CompiledData::RequiredPropertyExtraData*>(requiredPropertyExtraDataPtr);
+            *extraDataToWrite = *extraData;
+            requiredPropertyExtraDataPtr += sizeof(QV4::CompiledData::RequiredPropertyExtraData);
+        }
     }
 
     if (!output.javaScriptCompilationUnit.data) {
diff --git a/src/qml/compiler/qqmlirbuilder_p.h b/src/qml/compiler/qqmlirbuilder_p.h
index d4f2eb8dd4..32921638af 100644
--- a/src/qml/compiler/qqmlirbuilder_p.h
+++ b/src/qml/compiler/qqmlirbuilder_p.h
@@ -285,6 +285,11 @@ struct Alias : public QV4::CompiledData::Alias
     Alias *next;
 };
 
+struct RequiredPropertyExtraData : public QV4::CompiledData::RequiredPropertyExtraData
+{
+    RequiredPropertyExtraData *next;
+};
+
 struct Function
 {
     QV4::CompiledData::Location location;
@@ -341,6 +346,9 @@ public:
     int functionCount() const { return functions->count; }
     const InlineComponent *inlineComponent() const { return inlineComponents->first; }
     int inlineComponentCount() const { return inlineComponents->count; }
+    const RequiredPropertyExtraData *requiredPropertyExtraData() const {return requiredPropertyExtraDatas->first; }
+    int requiredPropertyExtraDataCount() const { return requiredPropertyExtraDatas->count; }
+    void simplifyRequiredProperties();
 
     PoolList<Binding>::Iterator bindingsBegin() const { return bindings->begin(); }
     PoolList<Binding>::Iterator bindingsEnd() const { return bindings->end(); }
@@ -356,6 +364,8 @@ public:
     PoolList<Function>::Iterator functionsEnd() const { return functions->end(); }
     PoolList<InlineComponent>::Iterator inlineComponentsBegin() const { return inlineComponents->begin(); }
     PoolList<InlineComponent>::Iterator inlineComponentsEnd() const { return inlineComponents->end(); }
+    PoolList<RequiredPropertyExtraData>::Iterator requiredPropertyExtraDataBegin() const {return requiredPropertyExtraDatas->begin(); }
+    PoolList<RequiredPropertyExtraData>::Iterator requiredPropertyExtraDataEnd() const {return requiredPropertyExtraDatas->end(); }
 
     // If set, then declarations for this object (and init bindings for these) should go into the
     // specified object. Used for declarations inside group properties.
@@ -369,6 +379,7 @@ public:
     QString appendAlias(Alias *prop, const QString &aliasName, bool isDefaultProperty, const QQmlJS::AST::SourceLocation &defaultToken, QQmlJS::AST::SourceLocation *errorLocation);
     void appendFunction(QmlIR::Function *f);
     void appendInlineComponent(InlineComponent *ic);
+    void appendRequiredPropertyExtraData(RequiredPropertyExtraData *extraData);
 
     QString appendBinding(Binding *b, bool isListBinding);
     Binding *findBinding(quint32 nameIndex) const;
@@ -393,6 +404,7 @@ private:
     PoolList<Binding> *bindings;
     PoolList<Function> *functions;
     PoolList<InlineComponent> *inlineComponents;
+    PoolList<RequiredPropertyExtraData> *requiredPropertyExtraDatas;
 };
 
 struct Q_QMLCOMPILER_PRIVATE_EXPORT Pragma
@@ -469,6 +481,7 @@ public:
     bool visit(QQmlJS::AST::UiPublicMember *ast) override;
     bool visit(QQmlJS::AST::UiScriptBinding *ast) override;
     bool visit(QQmlJS::AST::UiSourceElement *ast) override;
+    bool visit(QQmlJS::AST::UiRequired *ast) override;
 
     void throwRecursionDepthError() override
     {
diff --git a/src/qml/parser/qqmljs.g b/src/qml/parser/qqmljs.g
index b0f0f6a809..879de92e5f 100644
--- a/src/qml/parser/qqmljs.g
+++ b/src/qml/parser/qqmljs.g
@@ -1350,6 +1350,18 @@ OptionalSemicolon: | Semicolon;
   and then we would miss a semicolon (see tests/auto/quick/qquickvisualdatamodel/data/objectlist.qml)*/
  ./
 
+UiRequired: T_REQUIRED QmlIdentifier Semicolon;
+/.
+    case $rule_number: {
+        AST::UiRequired *node = new (pool) AST::UiRequired(stringRef(2));
+        node->requiredToken = loc(1);
+        node->semicolonToken = loc(3);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: UiRequired;
+
 UiObjectMember: T_REQUIRED UiObjectMemberPropertyNoInitialiser;
 /.
     case $rule_number: {
@@ -1360,7 +1372,6 @@ UiObjectMember: T_REQUIRED UiObjectMemberPropertyNoInitialiser;
     } break;
 ./
 
-
 UiObjectMemberWithScriptStatement: T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement OptionalSemicolon;
 /.
     case $rule_number: {
diff --git a/src/qml/parser/qqmljsast.cpp b/src/qml/parser/qqmljsast.cpp
index aa3e8ab5e3..416916c547 100644
--- a/src/qml/parser/qqmljsast.cpp
+++ b/src/qml/parser/qqmljsast.cpp
@@ -1554,6 +1554,14 @@ void UiInlineComponent::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
+void UiRequired::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+    }
+
+    visitor->endVisit(this);
+}
+
 } } // namespace QQmlJS::AST
 
 QT_END_NAMESPACE
diff --git a/src/qml/parser/qqmljsast_p.h b/src/qml/parser/qqmljsast_p.h
index 48a994cd33..f3369676e9 100644
--- a/src/qml/parser/qqmljsast_p.h
+++ b/src/qml/parser/qqmljsast_p.h
@@ -258,7 +258,8 @@ public:
         Kind_UiHeaderItemList,
         Kind_UiEnumDeclaration,
         Kind_UiEnumMemberList,
-        Kind_UiVersionSpecifier
+        Kind_UiVersionSpecifier,
+        Kind_UiRequired
     };
 
     inline Node() {}
@@ -3103,6 +3104,28 @@ public:
     SourceLocation semicolonToken;
 };
 
+class QML_PARSER_EXPORT UiRequired: public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(UiRequired)
+
+    UiRequired(QStringRef name)
+        :name(name)
+    { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return requiredToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return semicolonToken; }
+
+    QStringRef name;
+    SourceLocation requiredToken;
+    SourceLocation semicolonToken;
+};
+
 class QML_PARSER_EXPORT UiHeaderItemList: public Node
 {
 public:
diff --git a/src/qml/parser/qqmljsastfwd_p.h b/src/qml/parser/qqmljsastfwd_p.h
index 8a8ee2dfae..fe260e2bb5 100644
--- a/src/qml/parser/qqmljsastfwd_p.h
+++ b/src/qml/parser/qqmljsastfwd_p.h
@@ -183,6 +183,7 @@ class UiHeaderItemList;
 class UiEnumDeclaration;
 class UiEnumMemberList;
 class UiVersionSpecifier;
+class UiRequired;
 
 } // namespace AST
 } // namespace QQmlJS
diff --git a/src/qml/parser/qqmljsastvisitor_p.h b/src/qml/parser/qqmljsastvisitor_p.h
index d6b92990ad..fcc48da1d3 100644
--- a/src/qml/parser/qqmljsastvisitor_p.h
+++ b/src/qml/parser/qqmljsastvisitor_p.h
@@ -414,6 +414,9 @@ public:
     virtual bool visit(TypeAnnotation *) { return true; }
     virtual void endVisit(TypeAnnotation *) {}
 
+    virtual bool visit(UiRequired *) { return true; }
+    virtual void endVisit(UiRequired *) {}
+
     virtual void throwRecursionDepthError() = 0;
 
     quint16 recursionDepth() const { return m_recursionDepth; }
diff --git a/src/qml/qml/qqmlincubator_p.h b/src/qml/qml/qqmlincubator_p.h
index aadb147bd5..a674ff274f 100644
--- a/src/qml/qml/qqmlincubator_p.h
+++ b/src/qml/qml/qqmlincubator_p.h
@@ -61,9 +61,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QQmlPropertyData;
-struct RequiredPropertyInfo;
-using RequiredProperties = QHash<QQmlPropertyData*, RequiredPropertyInfo>;
+class RequiredProperties;
 
 class QQmlIncubator;
 class Q_QML_PRIVATE_EXPORT QQmlIncubatorPrivate : public QQmlEnginePrivate::Incubator
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index a26cdba53a..e990376fbc 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -1505,23 +1505,45 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
     if (_compiledObject->flags & QV4::CompiledData::Object::HasDeferredBindings)
         _ddata->deferData(_compiledObjectIndex, compilationUnit, context);
 
+    QSet<QString> postHocRequired;
+    for (auto it = _compiledObject->requiredPropertyExtraDataBegin(); it != _compiledObject->requiredPropertyExtraDataEnd(); ++it)
+        postHocRequired.insert(stringAt(it->nameIndex));
+    bool hadInheritedRequiredProperties = !postHocRequired.empty();
+
     for (int propertyIndex = 0; propertyIndex != _compiledObject->propertyCount(); ++propertyIndex) {
         const QV4::CompiledData::Property* property = _compiledObject->propertiesBegin() + propertyIndex;
         QQmlPropertyData *propertyData = _propertyCache->property(_propertyCache->propertyOffset() + propertyIndex);
-        if (property->isRequired) {
-            sharedState->hadRequiredProperties = true;
-            sharedState->requiredProperties.insert(propertyData,
-                                                   RequiredPropertyInfo {compilationUnit->stringAt(property->nameIndex), compilationUnit->finalUrl(), property->location, {}});
-        }
+        // only compute stringAt if there's a chance for the lookup to succeed
+        auto postHocIt = postHocRequired.isEmpty() ? postHocRequired.end() : postHocRequired.find(stringAt(property->nameIndex));
+        if (!property->isRequired && postHocRequired.end() == postHocIt)
+            continue;
+        if (postHocIt != postHocRequired.end())
+            postHocRequired.erase(postHocIt);
+        sharedState->hadRequiredProperties = true;
+        sharedState->requiredProperties.insert(propertyData,
+                                               RequiredPropertyInfo {compilationUnit->stringAt(property->nameIndex), compilationUnit->finalUrl(), property->location, {}});
+
     }
 
     for (int i = 0; i <= _propertyCache->propertyOffset(); ++i) {
         QQmlPropertyData *propertyData = _propertyCache->property(i);
-        if (propertyData && propertyData->isRequired()) {
-            sharedState->hadRequiredProperties = true;
-            sharedState->requiredProperties.insert(propertyData, RequiredPropertyInfo {propertyData->name(_qobject),  compilationUnit->finalUrl(), _compiledObject->location, {}});
-        }
+        if (!propertyData)
+            continue;
+        if (!propertyData->isRequired() && postHocRequired.isEmpty())
+            continue;
+        QString name = propertyData->name(_qobject);
+        auto postHocIt = postHocRequired.find(name);
+        if (!propertyData->isRequired() && postHocRequired.end() == postHocIt )
+            continue;
+
+        if (postHocIt != postHocRequired.end())
+            postHocRequired.erase(postHocIt);
+
+        sharedState->hadRequiredProperties = true;
+        sharedState->requiredProperties.insert(propertyData, RequiredPropertyInfo {name,  compilationUnit->finalUrl(), _compiledObject->location, {}});
     }
+    if (!postHocRequired.isEmpty() && hadInheritedRequiredProperties)
+        recordError({}, QLatin1String("Property %1 was marked as required but does not exist").arg(*postHocRequired.begin()));
 
     if (_compiledObject->nFunctions > 0)
         setupFunctions();
diff --git a/src/qml/qml/qqmlobjectcreator_p.h b/src/qml/qml/qqmlobjectcreator_p.h
index f8ad90be15..bca450addb 100644
--- a/src/qml/qml/qqmlobjectcreator_p.h
+++ b/src/qml/qml/qqmlobjectcreator_p.h
@@ -86,7 +86,7 @@ struct RequiredPropertyInfo
     QVector<AliasToRequiredInfo> aliasesToRequired;
 };
 
-using RequiredProperties = QHash<QQmlPropertyData*, RequiredPropertyInfo>;
+class RequiredProperties : public QHash<QQmlPropertyData*, RequiredPropertyInfo> {};
 
 struct QQmlObjectCreatorSharedState : public QSharedData
 {
diff --git a/tests/auto/qml/qmlformat/tst_qmlformat.cpp b/tests/auto/qml/qmlformat/tst_qmlformat.cpp
index 3201fa5ace..b10eaf26f1 100644
--- a/tests/auto/qml/qmlformat/tst_qmlformat.cpp
+++ b/tests/auto/qml/qmlformat/tst_qmlformat.cpp
@@ -113,7 +113,6 @@ void TestQmlformat::initTestCase()
     m_invalidFiles << "tests/auto/qml/qqmllanguage/data/fuzzed.2.qml";
     m_invalidFiles << "tests/auto/qml/qqmllanguage/data/fuzzed.3.qml";
     m_invalidFiles << "tests/auto/qml/qqmllanguage/data/requiredProperties.2.qml";
-    m_invalidFiles << "tests/auto/qml/qqmllanguage/data/requiredProperties.3.qml";
     m_invalidFiles << "tests/auto/qml/qqmllanguage/data/nullishCoalescing_LHS_And.qml";
     m_invalidFiles << "tests/auto/qml/qqmllanguage/data/nullishCoalescing_LHS_And.qml";
     m_invalidFiles << "tests/auto/qml/qqmllanguage/data/nullishCoalescing_LHS_Or.qml";
diff --git a/tests/auto/qml/qmlmin/tst_qmlmin.cpp b/tests/auto/qml/qmlmin/tst_qmlmin.cpp
index e7498a8583..0501a8112a 100644
--- a/tests/auto/qml/qmlmin/tst_qmlmin.cpp
+++ b/tests/auto/qml/qmlmin/tst_qmlmin.cpp
@@ -132,7 +132,6 @@ void tst_qmlmin::initTestCase()
     invalidFiles << "tests/auto/qml/qqmllanguage/data/fuzzed.2.qml";
     invalidFiles << "tests/auto/qml/qqmllanguage/data/fuzzed.3.qml";
     invalidFiles << "tests/auto/qml/qqmllanguage/data/requiredProperties.2.qml";
-    invalidFiles << "tests/auto/qml/qqmllanguage/data/requiredProperties.3.qml";
     // generatorFunction.qml is not invalid per se, but the minifier cannot handle yield statements
     invalidFiles << "tests/auto/qml/qqmlecmascript/data/generatorFunction.qml";
 #endif
diff --git a/tests/auto/qml/qqmllanguage/data/NonRequiredBase.qml b/tests/auto/qml/qqmllanguage/data/NonRequiredBase.qml
new file mode 100644
index 0000000000..60d45c2b1e
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/NonRequiredBase.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.15
+
+Item {
+    property int i
+}
diff --git a/tests/auto/qml/qqmllanguage/data/RequiredBase.qml b/tests/auto/qml/qqmllanguage/data/RequiredBase.qml
new file mode 100644
index 0000000000..4effdbf1c7
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/RequiredBase.qml
@@ -0,0 +1,3 @@
+NonRequiredBase {
+    required i
+}
diff --git a/tests/auto/qml/qqmllanguage/data/requiredProperties.3.qml b/tests/auto/qml/qqmllanguage/data/requiredProperties.3.qml
new file mode 100644
index 0000000000..2585cf361e
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.3.qml
@@ -0,0 +1,6 @@
+import QtQuick 2.15
+
+Item {
+    property int i;
+    required i;
+}
diff --git a/tests/auto/qml/qqmllanguage/data/requiredProperties.4.qml b/tests/auto/qml/qqmllanguage/data/requiredProperties.4.qml
new file mode 100644
index 0000000000..1126f845c9
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.4.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.15
+
+Item {
+    required objectName
+}
diff --git a/tests/auto/qml/qqmllanguage/data/requiredProperties.5.qml b/tests/auto/qml/qqmllanguage/data/requiredProperties.5.qml
new file mode 100644
index 0000000000..c2d155b123
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.5.qml
@@ -0,0 +1 @@
+RequiredBase {}
diff --git a/tests/auto/qml/qqmllanguage/data/requiredProperties.6.qml b/tests/auto/qml/qqmllanguage/data/requiredProperties.6.qml
new file mode 100644
index 0000000000..e8802aef20
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.6.qml
@@ -0,0 +1,3 @@
+RequiredBase {
+    i: 42
+}
diff --git a/tests/auto/qml/qqmllanguage/data/requiredProperties.7.qml b/tests/auto/qml/qqmllanguage/data/requiredProperties.7.qml
new file mode 100644
index 0000000000..40987f5c56
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.7.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.15
+
+Item {
+    required blub
+}
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 5027c0825f..b4ad9bd7b3 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -1675,6 +1675,36 @@ void tst_qqmllanguage::requiredProperty()
         QQmlComponent component(&engine, testFileUrl("requiredProperties.2.qml"));
         QVERIFY(!component.errors().empty());
     }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.4.qml"));
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(!component.errors().empty());
+        QVERIFY(component.errorString().contains("Required property objectName was not initialized"));
+    }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.3.qml"));
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(!component.errors().empty());
+        QVERIFY(component.errorString().contains("Required property i was not initialized"));
+    }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.5.qml"));
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(!component.errors().empty());
+        QVERIFY(component.errorString().contains("Required property i was not initialized"));
+    }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.6.qml"));
+        VERIFY_ERRORS(0);
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(object);
+    }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.7.qml"));
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(!component.errors().empty());
+        QVERIFY(component.errorString().contains("Property blub was marked as required but does not exist"));
+    }
 }
 
 class MyClassWithRequiredProperty : public QObject