Merge "Merge remote-tracking branch 'origin/5.15' into dev"

93 files changed, 1286 insertions, 941 deletions

diff --git a/examples/qml/referenceexamples/adding/main.cpp b/examples/qml/referenceexamples/adding/main.cpp
index e312149da1..87a7b75764 100644
--- a/examples/qml/referenceexamples/adding/main.cpp
+++ b/examples/qml/referenceexamples/adding/main.cpp
@@ -70,5 +70,5 @@ int main(int argc, char ** argv)
         qWarning() << component.errors();
     }
 
-    return 0;
+    return EXIT_SUCCESS;
 }
diff --git a/examples/qml/referenceexamples/attached/main.cpp b/examples/qml/referenceexamples/attached/main.cpp
index 581b033dfc..eb70625bea 100644
--- a/examples/qml/referenceexamples/attached/main.cpp
+++ b/examples/qml/referenceexamples/attached/main.cpp
@@ -58,10 +58,10 @@ int main(int argc, char ** argv)
 {
     QCoreApplication app(argc, argv);
 
-    qmlRegisterType<BirthdayPartyAttached>();
+    qmlRegisterAnonymousType<BirthdayPartyAttached>("People", 1);
     qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");
-    qmlRegisterType<ShoeDescription>();
-    qmlRegisterType<Person>();
+    qmlRegisterAnonymousType<ShoeDescription>("People", 1);
+    qmlRegisterAnonymousType<Person>("People", 1);
     qmlRegisterType<Boy>("People", 1,0, "Boy");
     qmlRegisterType<Girl>("People", 1,0, "Girl");
 
@@ -93,9 +93,9 @@ int main(int argc, char ** argv)
                 qWarning() << "   " << guest->name() << "RSVP date:" << qPrintable(rsvpDate.toString());
         }
 
-    } else {
-        qWarning() << component.errors();
+        return EXIT_SUCCESS;
     }
 
-    return 0;
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/binding/main.cpp b/examples/qml/referenceexamples/binding/main.cpp
index 99187eba3e..eca524dfe2 100644
--- a/examples/qml/referenceexamples/binding/main.cpp
+++ b/examples/qml/referenceexamples/binding/main.cpp
@@ -58,11 +58,11 @@
 int main(int argc, char ** argv)
 {
     QCoreApplication app(argc, argv);
-    qmlRegisterType<BirthdayPartyAttached>();
+    qmlRegisterAnonymousType<BirthdayPartyAttached>("People", 1);
     qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");
     qmlRegisterType<HappyBirthdaySong>("People", 1,0, "HappyBirthdaySong");
-    qmlRegisterType<ShoeDescription>();
-    qmlRegisterType<Person>();
+    qmlRegisterAnonymousType<ShoeDescription>("People", 1);
+    qmlRegisterAnonymousType<Person>("People", 1);
     qmlRegisterType<Boy>("People", 1,0, "Boy");
     qmlRegisterType<Girl>("People", 1,0, "Girl");
 
@@ -94,9 +94,9 @@ int main(int argc, char ** argv)
         }
 
         party->startParty();
-    } else {
-        qWarning() << component.errors();
+        return QCoreApplication::exec();
     }
 
-    return app.exec();
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/coercion/main.cpp b/examples/qml/referenceexamples/coercion/main.cpp
index 262cdf6320..39064f8b89 100644
--- a/examples/qml/referenceexamples/coercion/main.cpp
+++ b/examples/qml/referenceexamples/coercion/main.cpp
@@ -60,7 +60,7 @@ int main(int argc, char ** argv)
 
     qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");
     //![0]
-    qmlRegisterType<Person>();
+    qmlRegisterAnonymousType<Person>("People", 1);
     //![0]
 
     //![register boy girl]
@@ -82,9 +82,10 @@ int main(int argc, char ** argv)
 
         for (int ii = 0; ii < party->guestCount(); ++ii)
             qWarning() << "   " << party->guest(ii)->name();
-    } else {
-        qWarning() << component.errors();
+
+        return EXIT_SUCCESS;
     }
 
-    return 0;
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/default/main.cpp b/examples/qml/referenceexamples/default/main.cpp
index 017d6495cd..f6ca77e82d 100644
--- a/examples/qml/referenceexamples/default/main.cpp
+++ b/examples/qml/referenceexamples/default/main.cpp
@@ -59,7 +59,7 @@ int main(int argc, char ** argv)
     QCoreApplication app(argc, argv);
 
     qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");
-    qmlRegisterType<Person>();
+    qmlRegisterAnonymousType<Person>("People", 1);
     qmlRegisterType<Boy>("People", 1,0, "Boy");
     qmlRegisterType<Girl>("People", 1,0, "Girl");
 
@@ -77,9 +77,10 @@ int main(int argc, char ** argv)
 
         for (int ii = 0; ii < party->guestCount(); ++ii)
             qWarning() << "   " << party->guest(ii)->name();
-    } else {
-        qWarning() << component.errors();
+
+        return EXIT_SUCCESS;
     }
 
-    return 0;
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/extended/main.cpp b/examples/qml/referenceexamples/extended/main.cpp
index f91cec76b1..5f8582d08f 100644
--- a/examples/qml/referenceexamples/extended/main.cpp
+++ b/examples/qml/referenceexamples/extended/main.cpp
@@ -70,9 +70,9 @@ int main(int argc, char ** argv)
 
     if (edit) {
         edit->show();
-        return app.exec();
-    } else {
-        qWarning() << component.errors();
-        return 0;
+        return QApplication::exec();
     }
+
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/grouped/main.cpp b/examples/qml/referenceexamples/grouped/main.cpp
index 14cd64fe68..4f4b828cef 100644
--- a/examples/qml/referenceexamples/grouped/main.cpp
+++ b/examples/qml/referenceexamples/grouped/main.cpp
@@ -59,8 +59,8 @@ int main(int argc, char ** argv)
     QCoreApplication app(argc, argv);
 
     qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");
-    qmlRegisterType<ShoeDescription>();
-    qmlRegisterType<Person>();
+    qmlRegisterAnonymousType<ShoeDescription>("People", 1);
+    qmlRegisterAnonymousType<Person>("People", 1);
     qmlRegisterType<Boy>("People", 1,0, "Boy");
     qmlRegisterType<Girl>("People", 1,0, "Girl");
 
@@ -87,9 +87,9 @@ int main(int argc, char ** argv)
         if (bestShoe)
             qWarning() << bestShoe->name() << "is wearing the best shoes!";
 
-    } else {
-        qWarning() << component.errors();
+        return EXIT_SUCCESS;
     }
 
-    return 0;
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/methods/main.cpp b/examples/qml/referenceexamples/methods/main.cpp
index 89404ec822..e2a1a28c8b 100644
--- a/examples/qml/referenceexamples/methods/main.cpp
+++ b/examples/qml/referenceexamples/methods/main.cpp
@@ -70,9 +70,9 @@ int main(int argc, char ** argv)
         qWarning() << "They are inviting:";
         for (int ii = 0; ii < party->guestCount(); ++ii)
             qWarning() << "   " << party->guest(ii)->name();
-    } else {
-        qWarning() << component.errors();
+        return EXIT_SUCCESS;
     }
 
-    return 0;
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/properties/main.cpp b/examples/qml/referenceexamples/properties/main.cpp
index a0a2335034..60b56bd247 100644
--- a/examples/qml/referenceexamples/properties/main.cpp
+++ b/examples/qml/referenceexamples/properties/main.cpp
@@ -72,9 +72,9 @@ int main(int argc, char ** argv)
         qWarning() << "They are inviting:";
         for (int ii = 0; ii < party->guestCount(); ++ii)
             qWarning() << "   " << party->guest(ii)->name();
-    } else {
-        qWarning() << component.errors();
+        return EXIT_SUCCESS;
     }
 
-    return 0;
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/signal/main.cpp b/examples/qml/referenceexamples/signal/main.cpp
index bb75e02bc2..f55b4cb419 100644
--- a/examples/qml/referenceexamples/signal/main.cpp
+++ b/examples/qml/referenceexamples/signal/main.cpp
@@ -58,10 +58,10 @@ int main(int argc, char ** argv)
 {
     QCoreApplication app(argc, argv);
 
-    qmlRegisterType<BirthdayPartyAttached>();
+    qmlRegisterAnonymousType<BirthdayPartyAttached>("People", 1);
     qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");
-    qmlRegisterType<ShoeDescription>();
-    qmlRegisterType<Person>();
+    qmlRegisterAnonymousType<ShoeDescription>("People", 1);
+    qmlRegisterAnonymousType<Person>("People", 1);
     qmlRegisterType<Boy>("People", 1,0, "Boy");
     qmlRegisterType<Girl>("People", 1,0, "Girl");
 
@@ -93,9 +93,9 @@ int main(int argc, char ** argv)
         }
 
         party->startParty();
-    } else {
-        qWarning() << component.errors();
+        return EXIT_SUCCESS;
     }
 
-    return 0;
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/examples/qml/referenceexamples/valuesource/main.cpp b/examples/qml/referenceexamples/valuesource/main.cpp
index 4bef695fe2..ab50f00696 100644
--- a/examples/qml/referenceexamples/valuesource/main.cpp
+++ b/examples/qml/referenceexamples/valuesource/main.cpp
@@ -59,11 +59,11 @@ int main(int argc, char ** argv)
 {
     QCoreApplication app(argc, argv);
 
-    qmlRegisterType<BirthdayPartyAttached>();
+    qmlRegisterAnonymousType<BirthdayPartyAttached>("People", 1);
     qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");
     qmlRegisterType<HappyBirthdaySong>("People", 1,0, "HappyBirthdaySong");
-    qmlRegisterType<ShoeDescription>();
-    qmlRegisterType<Person>();
+    qmlRegisterAnonymousType<ShoeDescription>("People", 1);
+    qmlRegisterAnonymousType<Person>("People", 1);
     qmlRegisterType<Boy>("People", 1,0, "Boy");
     qmlRegisterType<Girl>("People", 1,0, "Girl");
 
@@ -95,9 +95,9 @@ int main(int argc, char ** argv)
         }
 
         party->startParty();
-    } else {
-        qWarning() << component.errors();
+        return QCoreApplication::exec();
     }
 
-    return app.exec();
+    qWarning() << component.errors();
+    return EXIT_FAILURE;
 }
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp b/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
index d0f9833c2e..be83f63bfc 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qqmlenginedebugservice.cpp
@@ -191,22 +191,18 @@ QQmlEngineDebugServiceImpl::propertyData(QObject *obj, int propIdx)
     if (binding)
         rv.binding = binding->expression();
 
-    if (QQmlValueTypeFactory::isValueType(prop.userType())) {
-        rv.type = QQmlObjectProperty::Basic;
-    } else if (QQmlMetaType::isQObject(prop.userType()))  {
+    rv.value = valueContents(prop.read(obj));
+
+    if (QQmlMetaType::isQObject(prop.userType()))  {
         rv.type = QQmlObjectProperty::Object;
     } else if (QQmlMetaType::isList(prop.userType())) {
         rv.type = QQmlObjectProperty::List;
     } else if (prop.userType() == QMetaType::QVariant) {
         rv.type = QQmlObjectProperty::Variant;
+    } else if (rv.value.isValid()) {
+        rv.type = QQmlObjectProperty::Basic;
     }
 
-    QVariant value;
-    if (rv.type != QQmlObjectProperty::Unknown && prop.userType() != 0) {
-        value = prop.read(obj);
-    }
-    rv.value = valueContents(value);
-
     return rv;
 }
 
@@ -269,10 +265,10 @@ QVariant QQmlEngineDebugServiceImpl::valueContents(QVariant value) const
                         return s;
                 }
             }
-
-            if (isSaveable(value))
-                return value;
         }
+
+        if (isSaveable(value))
+            return value;
     }
 
     if (QQmlMetaType::isQObject(userType)) {
diff --git a/src/plugins/qmltooling/qmldbg_debugger/qqmlwatcher.cpp b/src/plugins/qmltooling/qmldbg_debugger/qqmlwatcher.cpp
index 86571e6cbe..8caa5ac23e 100644
--- a/src/plugins/qmltooling/qmldbg_debugger/qqmlwatcher.cpp
+++ b/src/plugins/qmltooling/qmldbg_debugger/qqmlwatcher.cpp
@@ -109,12 +109,7 @@ QQmlWatchProxy::QQmlWatchProxy(int id,
 
 void QQmlWatchProxy::notifyValueChanged()
 {
-    QVariant v;
-    if (m_expr)
-        v = m_expr->evaluate();
-    else if (QQmlValueTypeFactory::isValueType(m_property.userType()))
-        v = m_property.read(m_object);
-
+    const QVariant v = m_expr ? m_expr->evaluate() : m_property.read(m_object);
     emit m_watch->propertyChanged(m_id, m_debugId, m_property, v);
 }
 
diff --git a/src/qml/common/qv4compileddata_p.h b/src/qml/common/qv4compileddata_p.h
index c3ddce5884..11de506a53 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 0x24 // Collect function parameter types
+#define QV4_DATA_STRUCTURE_VERSION 0x26// support required properties
 
 class QIODevice;
 class QQmlTypeNameCache;
@@ -656,7 +656,8 @@ struct Property
 {
     quint32_le nameIndex;
     union {
-        quint32_le_bitfield<0, 29> builtinTypeOrTypeNameIndex;
+        quint32_le_bitfield<0, 28> builtinTypeOrTypeNameIndex;
+        quint32_le_bitfield<28, 1> isRequired;
         quint32_le_bitfield<29, 1> isBuiltinType;
         quint32_le_bitfield<30, 1> isList;
         quint32_le_bitfield<31, 1> isReadOnly;
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 171dc641d3..fbb6a07b1b 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -792,7 +792,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiPublicMember *node)
 {
     if (node->type == QQmlJS::AST::UiPublicMember::Signal) {
         Signal *signal = New<Signal>();
-        QString signalName = node->name.toString();
+        const QString signalName = node->name.toString();
         signal->nameIndex = registerString(signalName);
 
         QQmlJS::AST::SourceLocation loc = node->typeToken;
@@ -821,8 +821,14 @@ bool IRBuilder::visit(QQmlJS::AST::UiPublicMember *node)
             p = p->next;
         }
 
-        if (signalName.at(0).isUpper())
-            COMPILE_EXCEPTION(node->identifierToken, tr("Signal names cannot begin with an upper case letter"));
+        for (const QChar &ch : signalName) {
+            if (ch.isLower())
+                break;
+            if (ch.isUpper()) {
+                COMPILE_EXCEPTION(node->identifierToken,
+                                  tr("Signal names cannot begin with an upper case letter"));
+            }
+        }
 
         if (illegalNames.contains(signalName))
             COMPILE_EXCEPTION(node->identifierToken, tr("Illegal signal name"));
@@ -841,6 +847,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiPublicMember *node)
 
             Property *property = New<Property>();
             property->isReadOnly = node->isReadonlyMember;
+            property->isRequired = node->isRequired;
 
             QV4::CompiledData::BuiltinType builtinPropertyType = Parameter::stringToBuiltinType(memberType);
             bool typeFound = builtinPropertyType != QV4::CompiledData::BuiltinType::InvalidBuiltin;
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index c36da3815d..2b5e8bd2b9 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -2077,7 +2077,7 @@ ReturnedValue QObjectMethod::callInternal(const Value *thisObject, const Value *
         if (!d()->valueTypeWrapper)
             return Encode::undefined();
 
-        object = QQmlObjectOrGadget(d()->propertyCache(), d()->valueTypeWrapper->gadgetPtr);
+        object = QQmlObjectOrGadget(d()->propertyCache(), d()->valueTypeWrapper->gadgetPtr());
     }
 
     QQmlPropertyData method;
diff --git a/src/qml/parser/qqmljs.g b/src/qml/parser/qqmljs.g
index 8ac7633ae0..cc560c5912 100644
--- a/src/qml/parser/qqmljs.g
+++ b/src/qml/parser/qqmljs.g
@@ -49,6 +49,7 @@
 %token T_DIVIDE_EQ "/="         T_DO "do"                   T_DOT "."
 %token T_ELSE "else"            T_EQ "="                    T_EQ_EQ "=="
 %token T_EQ_EQ_EQ "==="         T_FINALLY "finally"         T_FOR "for"
+%token T_FUNCTION_STAR "function *"
 %token T_FUNCTION "function"    T_GE ">="                   T_GT ">"
 %token T_GT_GT ">>"             T_GT_GT_EQ ">>="            T_GT_GT_GT ">>>"
 %token T_GT_GT_GT_EQ ">>>="     T_IDENTIFIER "identifier"   T_IF "if"
@@ -88,6 +89,7 @@
 %token T_STATIC "static"
 %token T_EXPORT "export"
 %token T_FROM "from"
+%token T_REQUIRED "required"
 
 --- template strings
 %token T_NO_SUBSTITUTION_TEMPLATE"(no subst template)"
@@ -120,8 +122,9 @@
 %token T_FOR_LOOKAHEAD_OK "(for lookahead ok)"
 
 --%left T_PLUS T_MINUS
-%nonassoc T_IDENTIFIER T_COLON T_SIGNAL T_PROPERTY T_READONLY T_ON T_SET T_GET T_OF T_STATIC T_FROM T_AS
+%nonassoc T_IDENTIFIER T_COLON T_SIGNAL T_PROPERTY T_READONLY T_ON T_SET T_GET T_OF T_STATIC T_FROM T_AS T_REQUIRED
 %nonassoc REDUCE_HERE
+%right T_THEN T_ELSE
 
 %start TopLevel
 
@@ -1175,7 +1178,7 @@ UiObjectMember: T_SIGNAL T_IDENTIFIER Semicolon;
     } break;
 ./
 
-UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier Semicolon;
+UiObjectMemberListPropertyNoInitialiser: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier Semicolon;
 /.
     case $rule_number: {
         AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
@@ -1189,23 +1192,19 @@ UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier S
     } break;
 ./
 
-UiObjectMember: T_READONLY T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier Semicolon;
+UiObjectMember: UiObjectMemberListPropertyNoInitialiser;
+
+UiObjectMember: T_READONLY UiObjectMemberListPropertyNoInitialiser;
 /.
     case $rule_number: {
-        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(5).UiQualifiedId->finish(), stringRef(7));
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
         node->isReadonlyMember = true;
         node->readonlyToken = loc(1);
-        node->typeModifier = stringRef(3);
-        node->propertyToken = loc(2);
-        node->typeModifierToken = loc(3);
-        node->typeToken = loc(5);
-        node->identifierToken = loc(7);
-        node->semicolonToken = loc(8);
         sym(1).Node = node;
     } break;
 ./
 
-UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier Semicolon;
+UiObjectMemberPropertyNoInitialiser: T_PROPERTY UiPropertyType QmlIdentifier Semicolon;
 /.
     case $rule_number: {
         AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
@@ -1217,42 +1216,47 @@ UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier Semicolon;
     } break;
 ./
 
-UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType QmlIdentifier Semicolon;
+
+UiObjectMember: UiObjectMemberPropertyNoInitialiser;
+
+UiObjectMember: T_DEFAULT UiObjectMemberPropertyNoInitialiser;
 /.
     case $rule_number: {
-        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
         node->isDefaultMember = true;
         node->defaultToken = loc(1);
-        node->propertyToken = loc(2);
-        node->typeToken = loc(3);
-        node->identifierToken = loc(4);
-        node->semicolonToken = loc(5);
         sym(1).Node = node;
     } break;
 ./
 
-UiObjectMember: T_DEFAULT T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier Semicolon;
+UiObjectMember: T_DEFAULT UiObjectMemberListPropertyNoInitialiser;
 /.
     case $rule_number: {
-        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(5).UiQualifiedId->finish(), stringRef(7));
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
         node->isDefaultMember = true;
         node->defaultToken = loc(1);
-        node->typeModifier = stringRef(3);
-        node->propertyToken = loc(2);
-        node->typeModifierToken = loc(2);
-        node->typeToken = loc(4);
-        node->identifierToken = loc(7);
-        node->semicolonToken = loc(8);
         sym(1).Node = node;
     } break;
 ./
+
 OptionalSemicolon: | Semicolon;
 /.
 /* we need OptionalSemicolon because UiScriptStatement might already parse the last semicolon
   and then we would miss a semicolon (see tests/auto/quick/qquickvisualdatamodel/data/objectlist.qml)*/
  ./
 
-UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement OptionalSemicolon;
+UiObjectMember: T_REQUIRED UiObjectMemberPropertyNoInitialiser;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
+        node->requiredToken = loc(1);
+        node->isRequired = true;
+        sym(1).Node = node;
+    } break;
+./
+
+
+UiObjectMemberWithScriptStatement: T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement OptionalSemicolon;
 /.
     case $rule_number: {
         AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3), sym(5).Statement);
@@ -1264,35 +1268,29 @@ UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatemen
     } break;
 ./
 
-UiObjectMember: T_READONLY T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement OptionalSemicolon;
+UiObjectMember: UiObjectMemberWithScriptStatement;
+
+UiObjectMember: T_READONLY UiObjectMemberWithScriptStatement;
 /.
     case $rule_number: {
-        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4), sym(6).Statement);
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
         node->isReadonlyMember = true;
         node->readonlyToken = loc(1);
-        node->propertyToken = loc(2);
-        node->typeToken = loc(3);
-        node->identifierToken = loc(4);
-        node->colonToken = loc(5);
         sym(1).Node = node;
     } break;
 ./
 
-UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement OptionalSemicolon;
+UiObjectMember: T_DEFAULT UiObjectMemberWithScriptStatement;
 /.
     case $rule_number: {
-        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4), sym(6).Statement);
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
         node->isDefaultMember = true;
         node->defaultToken = loc(1);
-        node->propertyToken = loc(2);
-        node->typeToken = loc(3);
-        node->identifierToken = loc(4);
-        node->colonToken = loc(5);
         sym(1).Node = node;
     } break;
 ./
 
-UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_COLON T_LBRACKET UiArrayMemberList T_RBRACKET Semicolon;
+UiObjectMemberWithArray: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_COLON T_LBRACKET UiArrayMemberList T_RBRACKET Semicolon;
 /.
     case $rule_number: {
         AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
@@ -1318,35 +1316,19 @@ UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T
     } break;
 ./
 
-UiObjectMember: T_READONLY T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_COLON T_LBRACKET UiArrayMemberList T_RBRACKET Semicolon;
+UiObjectMember: UiObjectMemberWithArray;
+
+UiObjectMember: T_READONLY UiObjectMemberWithArray;
 /.
     case $rule_number: {
-        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(5).UiQualifiedId->finish(), stringRef(7));
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
         node->isReadonlyMember = true;
         node->readonlyToken = loc(1);
-        node->typeModifier = stringRef(3);
-        node->propertyToken = loc(2);
-        node->typeModifierToken = loc(3);
-        node->typeToken = loc(5);
-        node->identifierToken = loc(7);
-        node->semicolonToken = loc(8); // insert a fake ';' before ':'
-
-        AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(7));
-        propertyName->identifierToken = loc(7);
-        propertyName->next = 0;
-
-        AST::UiArrayBinding *binding = new (pool) AST::UiArrayBinding(propertyName, sym(10).UiArrayMemberList->finish());
-        binding->colonToken = loc(8);
-        binding->lbracketToken = loc(9);
-        binding->rbracketToken = loc(11);
-
-        node->binding = binding;
-
         sym(1).Node = node;
     } break;
 ./
 
-UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_COLON ExpressionStatementLookahead UiQualifiedId UiObjectInitializer Semicolon;
+UiObjectMemberExpressionStatementLookahead: T_PROPERTY UiPropertyType QmlIdentifier T_COLON ExpressionStatementLookahead UiQualifiedId UiObjectInitializer Semicolon;
 /.
     case $rule_number: {
         AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
@@ -1369,43 +1351,30 @@ UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_COLON ExpressionStatem
     } break;
 ./
 
-UiObjectMember: T_READONLY T_PROPERTY UiPropertyType QmlIdentifier T_COLON ExpressionStatementLookahead UiQualifiedId UiObjectInitializer Semicolon;
+UiObjectMember: UiObjectMemberExpressionStatementLookahead;
+
+UiObjectMember: T_READONLY UiObjectMemberExpressionStatementLookahead;
 /.
     case $rule_number: {
-        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
+        AST::UiPublicMember *node = sym(2).UiPublicMember;
         node->isReadonlyMember = true;
         node->readonlyToken = loc(1);
-        node->propertyToken = loc(2);
-        node->typeToken = loc(3);
-        node->identifierToken = loc(4);
-        node->semicolonToken = loc(5); // insert a fake ';' before ':'
-
-        AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(4));
-        propertyName->identifierToken = loc(4);
-        propertyName->next = 0;
-
-        AST::UiObjectBinding *binding = new (pool) AST::UiObjectBinding(
-          propertyName, sym(7).UiQualifiedId, sym(8).UiObjectInitializer);
-        binding->colonToken = loc(5);
-
-        node->binding = binding;
-
         sym(1).Node = node;
     } break;
 ./
 
-UiObjectMember: FunctionDeclarationWithTypes;
+UiObjectMember: GeneratorDeclaration;
 /.
     case $rule_number: {
-        sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
+        auto node = new (pool) AST::UiSourceElement(sym(1).Node);
+        sym(1).Node = node;
     } break;
 ./
 
-UiObjectMember: GeneratorExpression;
+UiObjectMember: FunctionDeclarationWithTypes;
 /.
     case $rule_number: {
-        auto node = new (pool) AST::UiSourceElement(sym(1).Node);
-        sym(1).Node = node;
+        sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
     } break;
 ./
 
@@ -1501,6 +1470,7 @@ QmlIdentifier: T_GET;
 QmlIdentifier: T_SET;
 QmlIdentifier: T_FROM;
 QmlIdentifier: T_OF;
+QmlIdentifier: T_REQUIRED;
 
 JsIdentifier: T_IDENTIFIER;
 JsIdentifier: T_PROPERTY;
@@ -1513,6 +1483,7 @@ JsIdentifier: T_FROM;
 JsIdentifier: T_STATIC;
 JsIdentifier: T_OF;
 JsIdentifier: T_AS;
+JsIdentifier: T_REQUIRED;
 
 IdentifierReference: JsIdentifier;
 BindingIdentifier: IdentifierReference;
@@ -3232,7 +3203,7 @@ ExpressionStatementLookahead: ;
         int token = lookaheadToken(lexer);
         if (token == T_LBRACE)
             pushToken(T_FORCE_BLOCK);
-        else if (token == T_FUNCTION || token == T_CLASS || token == T_LET || token == T_CONST)
+        else if (token == T_FUNCTION || token == T_FUNCTION_STAR || token == T_CLASS || token == T_LET || token == T_CONST)
             pushToken(T_FORCE_DECLARATION);
     } break;
 ./
@@ -3980,27 +3951,14 @@ GeneratorRBrace: T_RBRACE;
     } break;
 ./
 
-GeneratorDeclaration: Function T_STAR BindingIdentifier GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
-/.
-    case $rule_number: {
-        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(stringRef(3), sym(5).FormalParameterList, sym(8).StatementList);
-        node->functionToken = loc(1);
-        node->identifierToken = loc(3);
-        node->lparenToken = loc(4);
-        node->rparenToken = loc(6);
-        node->lbraceToken = loc(7);
-        node->rbraceToken = loc(9);
-        node->isGenerator = true;
-        sym(1).Node = node;
-    } break;
-./
+FunctionStar: T_FUNCTION_STAR %prec REDUCE_HERE;
 
-GeneratorDeclaration_Default: GeneratorDeclaration;
-GeneratorDeclaration_Default: Function T_STAR GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
+GeneratorDeclaration: FunctionStar BindingIdentifier GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
 /.
     case $rule_number: {
-        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(QStringRef(), sym(4).FormalParameterList, sym(7).StatementList);
+        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(stringRef(2), sym(4).FormalParameterList, sym(7).StatementList);
         node->functionToken = loc(1);
+        node->identifierToken = loc(2);
         node->lparenToken = loc(3);
         node->rparenToken = loc(5);
         node->lbraceToken = loc(6);
@@ -4010,27 +3968,28 @@ GeneratorDeclaration_Default: Function T_STAR GeneratorLParen FormalParameters T
     } break;
 ./
 
-GeneratorExpression: T_FUNCTION T_STAR BindingIdentifier GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
+GeneratorDeclaration_Default: GeneratorDeclaration;
+GeneratorDeclaration_Default: FunctionStar GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
 /.
     case $rule_number: {
-        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(stringRef(3), sym(5).FormalParameterList, sym(8).StatementList);
+        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(QStringRef(), sym(3).FormalParameterList, sym(6).StatementList);
         node->functionToken = loc(1);
-        if (!stringRef(3).isNull())
-          node->identifierToken = loc(3);
-        node->lparenToken = loc(4);
-        node->rparenToken = loc(6);
-        node->lbraceToken = loc(7);
-        node->rbraceToken = loc(9);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        node->lbraceToken = loc(5);
+        node->rbraceToken = loc(7);
         node->isGenerator = true;
         sym(1).Node = node;
     } break;
 ./
 
-GeneratorExpression: T_FUNCTION T_STAR GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
+GeneratorExpression: T_FUNCTION_STAR BindingIdentifier GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
 /.
     case $rule_number: {
-        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(QStringRef(), sym(4).FormalParameterList, sym(7).StatementList);
+        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(stringRef(2), sym(4).FormalParameterList, sym(7).StatementList);
         node->functionToken = loc(1);
+        if (!stringRef(2).isNull())
+          node->identifierToken = loc(2);
         node->lparenToken = loc(3);
         node->rparenToken = loc(5);
         node->lbraceToken = loc(6);
@@ -4040,6 +3999,20 @@ GeneratorExpression: T_FUNCTION T_STAR GeneratorLParen FormalParameters T_RPAREN
     } break;
 ./
 
+GeneratorExpression: T_FUNCTION_STAR GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
+/.
+    case $rule_number: {
+        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(QStringRef(), sym(3).FormalParameterList, sym(6).StatementList);
+        node->functionToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        node->lbraceToken = loc(5);
+        node->rbraceToken = loc(7);
+        node->isGenerator = true;
+        sym(1).Node = node;
+    } break;
+./
+
 GeneratorBody: FunctionBody;
 
 YieldExpression: T_YIELD;
@@ -4419,7 +4392,7 @@ ExportDeclarationLookahead: ;
 /.
     case $rule_number: {
         int token = lookaheadToken(lexer);
-        if (token == T_FUNCTION || token == T_CLASS)
+        if (token == T_FUNCTION || token == T_FUNCTION_STAR || token == T_CLASS)
             pushToken(T_FORCE_DECLARATION);
     } break;
 ./
diff --git a/src/qml/parser/qqmljsast_p.h b/src/qml/parser/qqmljsast_p.h
index 39194068bf..4247785905 100644
--- a/src/qml/parser/qqmljsast_p.h
+++ b/src/qml/parser/qqmljsast_p.h
@@ -307,6 +307,14 @@ public:
     int kind = Kind_Undefined;
 };
 
+template<typename T>
+T lastListElement(T head)
+{
+    auto current = head;
+    while (current->next)
+        current = current->next;
+    return current;
+}
 
 class QML_PARSER_EXPORT UiQualifiedId: public Node
 {
@@ -338,7 +346,7 @@ public:
     { return identifierToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : identifierToken; }
+    { return lastListElement(this)->identifierToken; }
 
 // attributes
     UiQualifiedId *next;
@@ -397,7 +405,7 @@ public:
     { return typeId->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : typeId->lastSourceLocation(); }
+    { return lastListElement(this)->typeId->lastSourceLocation(); }
 
     inline TypeArgumentList *finish()
     {
@@ -678,7 +686,10 @@ public:
     { return literalToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : (expression ? expression->lastSourceLocation() : literalToken); }
+    {
+        auto last = lastListElement(this);
+        return (last->expression ? last->expression->lastSourceLocation() : last->literalToken);
+    }
 
     void accept0(Visitor *visitor) override;
 
@@ -800,7 +811,7 @@ public:
     { return commaToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : commaToken; }
+    { return lastListElement(this)->commaToken; }
 
     inline Elision *finish ()
     {
@@ -961,7 +972,10 @@ public:
     { return elision ? elision->firstSourceLocation() : element->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : (element ? element->lastSourceLocation() : elision->lastSourceLocation()); }
+    {
+        auto last = lastListElement(this);
+        return last->element ? last->element->lastSourceLocation() : last->elision->lastSourceLocation();
+    }
 
     Elision *elision = nullptr;
     PatternElement *element = nullptr;
@@ -1036,7 +1050,7 @@ public:
     { return property->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : property->lastSourceLocation(); }
+    { return lastListElement(this)->property->lastSourceLocation(); }
 
     PatternProperty *property;
     PatternPropertyList *next;
@@ -1645,7 +1659,9 @@ public:
     { return statement->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : statement->lastSourceLocation(); }
+    {
+        return lastListElement(this)->statement->lastSourceLocation();
+    }
 
     inline StatementList *finish ()
     {
@@ -2138,7 +2154,9 @@ public:
     { return clause->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : clause->lastSourceLocation(); }
+    {
+        return lastListElement(this)->clause->lastSourceLocation();
+    }
 
     inline CaseClauses *finish ()
     {
@@ -2429,7 +2447,9 @@ public:
     { return element->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : element->lastSourceLocation(); }
+    {
+        return lastListElement(this)->element->lastSourceLocation();
+    }
 
     FormalParameterList *finish(MemoryPool *pool);
 
@@ -2606,7 +2626,9 @@ public:
     { return importSpecifierToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : importSpecifierToken; }
+    {
+        return lastListElement(this)->importSpecifierToken;
+    }
 
 // attributes
     SourceLocation importSpecifierToken;
@@ -2843,7 +2865,7 @@ public:
     SourceLocation firstSourceLocation() const override
     { return exportSpecifier->firstSourceLocation(); }
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : exportSpecifier->lastSourceLocation(); }
+    { return lastListElement(this)->exportSpecifier->lastSourceLocation(); }
 
 // attributes
     ExportSpecifier *exportSpecifier;
@@ -3036,7 +3058,7 @@ public:
     { return member->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : member->lastSourceLocation(); }
+    { return lastListElement(this)->member->lastSourceLocation(); }
 
     UiObjectMemberList *finish()
     {
@@ -3115,7 +3137,7 @@ public:
     { return headerItem->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : headerItem->lastSourceLocation(); }
+    { return lastListElement(this)->headerItem->lastSourceLocation(); }
 
 // attributes
     Node *headerItem;
@@ -3179,7 +3201,7 @@ public:
     { return member->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : member->lastSourceLocation(); }
+    { return lastListElement(this)->member->lastSourceLocation(); }
 
     UiArrayMemberList *finish()
     {
@@ -3240,7 +3262,10 @@ public:
     { return colonToken.isValid() ? identifierToken : propertyTypeToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : (colonToken.isValid() ? propertyTypeToken : identifierToken); }
+    {
+        auto last = lastListElement(this);
+        return (last->colonToken.isValid() ? last->propertyTypeToken : last->identifierToken);
+    }
 
     inline UiParameterList *finish ()
     {
@@ -3283,6 +3308,8 @@ public:
         return defaultToken;
       else if (readonlyToken.isValid())
           return readonlyToken;
+      else if (requiredToken.isValid())
+          return requiredToken;
 
       return propertyToken;
     }
@@ -3306,10 +3333,13 @@ public:
     UiObjectMember *binding; // initialized with a QML object or array.
     bool isDefaultMember;
     bool isReadonlyMember;
+    bool isRequired = false;
     UiParameterList *parameters;
+    // TODO: merge source locations
     SourceLocation defaultToken;
     SourceLocation readonlyToken;
     SourceLocation propertyToken;
+    SourceLocation requiredToken;
     SourceLocation typeModifierToken;
     SourceLocation typeToken;
     SourceLocation identifierToken;
@@ -3493,8 +3523,10 @@ public:
     { return memberToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() :
-                    valueToken.isValid() ? valueToken : memberToken; }
+    {
+        auto last = lastListElement(this);
+        return last->valueToken.isValid() ? last->valueToken : last->memberToken;
+    }
 
     void accept0(Visitor *visitor) override;
 
diff --git a/src/qml/parser/qqmljskeywords_p.h b/src/qml/parser/qqmljskeywords_p.h
index 96b3709162..3eb054341f 100644
--- a/src/qml/parser/qqmljskeywords_p.h
+++ b/src/qml/parser/qqmljskeywords_p.h
@@ -743,6 +743,18 @@ static inline int classify8(const QChar *s, int parseModeFlags) {
             }
           }
         }
+      } else if (s[2].unicode() == 'q') {
+        if (s[3].unicode() == 'u') {
+          if (s[4].unicode() == 'i') {
+            if (s[5].unicode() == 'r') {
+              if (s[6].unicode() == 'e') {
+                if (s[7].unicode() == 'd') {
+                  return Lexer::T_REQUIRED;
+                }
+              }
+            }
+          }
+        }
       }
     }
   }
diff --git a/src/qml/parser/qqmljslexer.cpp b/src/qml/parser/qqmljslexer.cpp
index 1e0ac72bd1..443e1a7476 100644
--- a/src/qml/parser/qqmljslexer.cpp
+++ b/src/qml/parser/qqmljslexer.cpp
@@ -492,6 +492,42 @@ int Lexer::scanToken()
 again:
     _validTokenText = false;
 
+    // handle comment can be called after a '/' has been read
+    // and returns true if it actually encountered a comment
+    auto handleComment = [this](){
+        if (_char == QLatin1Char('*')) {
+            scanChar();
+            while (_codePtr <= _endPtr) {
+                if (_char == QLatin1Char('*')) {
+                    scanChar();
+                    if (_char == QLatin1Char('/')) {
+                        scanChar();
+
+                        if (_engine) {
+                            _engine->addComment(tokenOffset() + 2, _codePtr - _tokenStartPtr - 1 - 4,
+                                                tokenStartLine(), tokenStartColumn() + 2);
+                        }
+
+                        return true;
+                    }
+                } else {
+                    scanChar();
+                }
+            }
+        } else if (_char == QLatin1Char('/')) {
+            while (_codePtr <= _endPtr && !isLineTerminator()) {
+                scanChar();
+            }
+            if (_engine) {
+                _engine->addComment(tokenOffset() + 2, _codePtr - _tokenStartPtr - 1 - 2,
+                                    tokenStartLine(), tokenStartColumn() + 2);
+            }
+            return true;
+        }
+        return false;
+    };
+
+
     while (_char.isSpace()) {
         if (isLineTerminator()) {
             if (_restrictedKeyword) {
@@ -599,35 +635,9 @@ again:
     case ':': return T_COLON;
 
     case '/':
-        if (_char == QLatin1Char('*')) {
-            scanChar();
-            while (_codePtr <= _endPtr) {
-                if (_char == QLatin1Char('*')) {
-                    scanChar();
-                    if (_char == QLatin1Char('/')) {
-                        scanChar();
-
-                        if (_engine) {
-                            _engine->addComment(tokenOffset() + 2, _codePtr - _tokenStartPtr - 1 - 4,
-                                                tokenStartLine(), tokenStartColumn() + 2);
-                        }
-
-                        goto again;
-                    }
-                } else {
-                    scanChar();
-                }
-            }
-        } else if (_char == QLatin1Char('/')) {
-            while (_codePtr <= _endPtr && !isLineTerminator()) {
-                scanChar();
-            }
-            if (_engine) {
-                _engine->addComment(tokenOffset() + 2, _codePtr - _tokenStartPtr - 1 - 2,
-                                    tokenStartLine(), tokenStartColumn() + 2);
-            }
+        if (handleComment())
             goto again;
-        } if (_char == QLatin1Char('=')) {
+        else if (_char == QLatin1Char('=')) {
             scanChar();
             return T_DIVIDE_EQ;
         }
@@ -829,6 +839,21 @@ again:
             if (!identifierWithEscapeChars)
                 kind = classify(_tokenStartPtr, _tokenLength, parseModeFlags());
 
+            if (kind == T_FUNCTION) {
+                continue_skipping:
+                while (_codePtr < _endPtr && _char.isSpace())
+                    scanChar();
+                if (_char == QLatin1Char('*')) {
+                    _tokenLength = _codePtr - _tokenStartPtr - 1;
+                    kind = T_FUNCTION_STAR;
+                    scanChar();
+                } else if (_char == QLatin1Char('/')) {
+                    scanChar();
+                    if (handleComment())
+                        goto continue_skipping;
+                }
+            }
+
             if (_engine) {
                 if (kind == T_IDENTIFIER && identifierWithEscapeChars)
                     _tokenSpell = _engine->newStringRef(_tokenText);
@@ -1407,6 +1432,7 @@ static const int uriTokens[] = {
     QQmlJSGrammar::T_FINALLY,
     QQmlJSGrammar::T_FOR,
     QQmlJSGrammar::T_FUNCTION,
+    QQmlJSGrammar::T_FUNCTION_STAR,
     QQmlJSGrammar::T_IF,
     QQmlJSGrammar::T_IN,
     QQmlJSGrammar::T_OF,
diff --git a/src/qml/qml/qqmlbinding.cpp b/src/qml/qml/qqmlbinding.cpp
index 3a437eab8d..2f6aabf61e 100644
--- a/src/qml/qml/qqmlbinding.cpp
+++ b/src/qml/qml/qqmlbinding.cpp
@@ -315,7 +315,7 @@ protected:
                 break;
             default:
                 if (const QV4::QQmlValueTypeWrapper *vtw = result.as<const QV4::QQmlValueTypeWrapper>()) {
-                    if (vtw->d()->valueType->metaType.id() == pd->propType()) {
+                    if (vtw->d()->valueType()->metaType.id() == pd->propType()) {
                         return vtw->write(m_target.data(), pd->coreIndex());
                     }
                 }
diff --git a/src/qml/qml/qqmlcomponent.cpp b/src/qml/qml/qqmlcomponent.cpp
index ed8c41a582..b72c745490 100644
--- a/src/qml/qml/qqmlcomponent.cpp
+++ b/src/qml/qml/qqmlcomponent.cpp
@@ -340,6 +340,11 @@ void QQmlComponentPrivate::fromTypeData(const QQmlRefPointer<QQmlTypeData> &data
     }
 }
 
+RequiredProperties &QQmlComponentPrivate::requiredProperties()
+{
+    return state.creator->requiredProperties();
+}
+
 void QQmlComponentPrivate::clear()
 {
     if (typeData) {
@@ -364,8 +369,8 @@ QObject *QQmlComponentPrivate::doBeginCreate(QQmlComponent *q, QQmlContext *cont
 
 bool QQmlComponentPrivate::setInitialProperty(QObject *component, const QString& name, const QVariant &value)
 {
-    QQmlProperty prop(component, name);
-    auto privProp = QQmlPropertyPrivate::get(prop);
+    QQmlProperty prop = QQmlComponentPrivate::removePropertyFromRequired(component, name, requiredProperties());
+    QQmlPropertyPrivate *privProp = QQmlPropertyPrivate::get(prop);
     if (!prop.isValid() || !privProp->writeValueProperty(value, nullptr)) {
         QQmlError error{};
         error.setUrl(url);
@@ -809,6 +814,10 @@ QObject *QQmlComponent::create(QQmlContext *context)
     QObject *rv = d->doBeginCreate(this, context);
     if (rv)
         completeCreate();
+    if (rv && !d->requiredProperties().empty()) {
+        delete  rv;
+        return nullptr;
+    }
     return rv;
 }
 
@@ -828,6 +837,10 @@ QObject *QQmlComponent::createWithInitialProperties(const QVariantMap& initialPr
         setInitialProperties(rv, initialProperties);
         completeCreate();
     }
+    if (!d->requiredProperties().empty()) {
+        d->requiredProperties().clear();
+        return nullptr;
+    }
     return rv;
 }
 
@@ -980,6 +993,57 @@ void QQmlComponentPrivate::complete(QQmlEnginePrivate *enginePriv, ConstructionS
 }
 
 /*!
+ * \internal
+ * Finds the matching toplevel property with name \a name of the component \a createdComponent.
+ * If it was a required property or an alias to a required property contained in \a
+ * requiredProperties, it is removed from it.
+ *
+ * If wasInRequiredProperties is non-null, the referenced boolean is set to true iff the property
+ * was found in requiredProperties.
+ *
+ * Returns the QQmlProperty with name \a name (which might be invalid if there is no such property),
+ * for further processing (for instance, actually setting the property value).
+ *
+ * Note: This method is used in QQmlComponent and QQmlIncubator to manage required properties. Most
+ * classes which create components should not need it and should only need to call
+ * setInitialProperties.
+ */
+QQmlProperty QQmlComponentPrivate::removePropertyFromRequired(QObject *createdComponent, const QString &name, RequiredProperties &requiredProperties, bool* wasInRequiredProperties)
+{
+    QQmlProperty prop(createdComponent, name);
+    auto privProp = QQmlPropertyPrivate::get(prop);
+    if (prop.isValid()) {
+        // resolve outstanding required properties
+        auto targetProp = &privProp->core;
+        if (targetProp->isAlias()) {
+            auto target = createdComponent;
+            QQmlPropertyIndex originalIndex(targetProp->coreIndex());
+            QQmlPropertyIndex propIndex;
+            QQmlPropertyPrivate::findAliasTarget(target, originalIndex, &target, &propIndex);
+            QQmlData *data = QQmlData::get(target);
+            Q_ASSERT(data && data->propertyCache);
+            targetProp = data->propertyCache->property(propIndex.coreIndex());
+        } else {
+            // we need to get the pointer from the property cache instead of directly using
+            // targetProp else the lookup will fail
+            QQmlData *data = QQmlData::get(createdComponent);
+            Q_ASSERT(data && data->propertyCache);
+            targetProp = data->propertyCache->property(targetProp->coreIndex());
+        }
+        auto it = requiredProperties.find(targetProp);
+        if (it != requiredProperties.end()) {
+            if (wasInRequiredProperties)
+                *wasInRequiredProperties = true;
+            requiredProperties.erase(it);
+        } else {
+            if (wasInRequiredProperties)
+                *wasInRequiredProperties = false;
+        }
+    }
+    return prop;
+}
+
+/*!
     This method provides advanced control over component instance creation.
     In general, programmers should use QQmlComponent::create() to create a
     component.
@@ -998,6 +1062,11 @@ void QQmlComponent::completeCreate()
 
 void QQmlComponentPrivate::completeCreate()
 {
+    const RequiredProperties& unsetRequiredProperties = requiredProperties();
+    for (const auto& unsetRequiredProperty: unsetRequiredProperties) {
+        QQmlError error = unsetRequiredPropertyToQQmlError(unsetRequiredProperty);
+        state.errors.push_back(error);
+    }
     if (state.completePending) {
         ++creationDepth.localData();
         QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
@@ -1185,7 +1254,7 @@ struct QmlIncubatorObject : public QV4::Object
     static ReturnedValue method_forceCompletion(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
     void statusChanged(QQmlIncubator::Status);
-    void setInitialState(QObject *);
+    void setInitialState(QObject *, RequiredProperties &requiredProperties);
 };
 
 }
@@ -1210,7 +1279,8 @@ public:
     void setInitialState(QObject *o) override {
         QV4::Scope scope(incubatorObject.engine());
         QV4::Scoped<QV4::QmlIncubatorObject> i(scope, incubatorObject.as<QV4::QmlIncubatorObject>());
-        i->setInitialState(o);
+        auto d = QQmlIncubatorPrivate::get(this);
+        i->setInitialState(o, d->requiredProperties());
     }
 
     QV4::PersistentValue incubatorObject; // keep a strong internal reference while incubating
@@ -1282,7 +1352,7 @@ static void QQmlComponent_setQmlParent(QObject *me, QObject *parent)
 */
 
 
-void QQmlComponentPrivate::setInitialProperties(QV4::ExecutionEngine *engine, QV4::QmlContext *qmlContext, const QV4::Value &o, const QV4::Value &v)
+void QQmlComponentPrivate::setInitialProperties(QV4::ExecutionEngine *engine, QV4::QmlContext *qmlContext, const QV4::Value &o, const QV4::Value &v, RequiredProperties &requiredProperties, QObject *createdComponent)
 {
     QV4::Scope scope(engine);
     QV4::ScopedObject object(scope);
@@ -1301,6 +1371,7 @@ void QQmlComponentPrivate::setInitialProperties(QV4::ExecutionEngine *engine, QV
             break;
         object = o;
         const QStringList properties = name->toQString().split(QLatin1Char('.'));
+        bool isTopLevelProperty = properties.size() == 1;
         for (int i = 0; i < properties.length() - 1; ++i) {
             name = engine->newString(properties.at(i));
             object = object->get(name);
@@ -1317,12 +1388,40 @@ void QQmlComponentPrivate::setInitialProperties(QV4::ExecutionEngine *engine, QV
         if (engine->hasException) {
             engine->hasException = false;
             continue;
+        } else if (isTopLevelProperty) {
+            auto prop = removePropertyFromRequired(createdComponent, name->toQString(), requiredProperties);
         }
     }
 
     engine->hasException = false;
 }
 
+QQmlError QQmlComponentPrivate::unsetRequiredPropertyToQQmlError(const RequiredPropertyInfo &unsetRequiredProperty)
+{
+    QQmlError error;
+    QString description = QLatin1String("Required property %1 was not initialized").arg(unsetRequiredProperty.propertyName);
+    switch (unsetRequiredProperty.aliasesToRequired.size()) {
+    case 0:
+        break;
+    case 1: {
+        const auto info = unsetRequiredProperty.aliasesToRequired.first();
+        description += QLatin1String("\nIt can be set via the alias property %1 from %2\n").arg(info.propertyName, info.fileUrl.toString());
+        break;
+    }
+    default:
+        description += QLatin1String("\nIt can be set via one of the following alias properties:");
+        for (auto aliasInfo: unsetRequiredProperty.aliasesToRequired) {
+            description += QLatin1String("\n- %1 (%2)").arg(aliasInfo.propertyName, aliasInfo.fileUrl.toString());
+        }
+        description += QLatin1Char('\n');
+    }
+    error.setDescription(description);
+    error.setUrl(unsetRequiredProperty.fileUrl);
+    error.setLine(unsetRequiredProperty.location.line);
+    error.setColumn(unsetRequiredProperty.location.column);
+    return  error;
+}
+
 /*!
     \internal
 */
@@ -1370,7 +1469,17 @@ void QQmlComponent::createObject(QQmlV4Function *args)
 
     if (!valuemap->isUndefined()) {
         QV4::Scoped<QV4::QmlContext> qmlContext(scope, v4->qmlContext());
-        QQmlComponentPrivate::setInitialProperties(v4, qmlContext, object, valuemap);
+        QQmlComponentPrivate::setInitialProperties(v4, qmlContext, object, valuemap, d->requiredProperties(), rv);
+    }
+    if (!d->requiredProperties().empty()) {
+        QList<QQmlError> errors;
+        for (const auto &requiredProperty: d->requiredProperties()) {
+            errors.push_back(QQmlComponentPrivate::unsetRequiredPropertyToQQmlError(requiredProperty));
+        }
+        qmlWarning(rv, errors);
+        args->setReturnValue(QV4::Encode::null());
+        delete rv;
+        return;
     }
 
     d->completeCreate();
@@ -1502,7 +1611,7 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
 }
 
 // XXX used by QSGLoader
-void QQmlComponentPrivate::initializeObjectWithInitialProperties(QV4::QmlContext *qmlContext, const QV4::Value &valuemap, QObject *toCreate)
+void QQmlComponentPrivate::initializeObjectWithInitialProperties(QV4::QmlContext *qmlContext, const QV4::Value &valuemap, QObject *toCreate, RequiredProperties &requiredProperties)
 {
     QV4::ExecutionEngine *v4engine = engine->handle();
     QV4::Scope scope(v4engine);
@@ -1511,7 +1620,7 @@ void QQmlComponentPrivate::initializeObjectWithInitialProperties(QV4::QmlContext
     Q_ASSERT(object->as<QV4::Object>());
 
     if (!valuemap.isUndefined())
-        setInitialProperties(v4engine, qmlContext, object, valuemap);
+        setInitialProperties(v4engine, qmlContext, object, valuemap, requiredProperties, toCreate);
 }
 
 QQmlComponentExtension::QQmlComponentExtension(QV4::ExecutionEngine *v4)
@@ -1601,7 +1710,7 @@ void QV4::Heap::QmlIncubatorObject::destroy() {
     Object::destroy();
 }
 
-void QV4::QmlIncubatorObject::setInitialState(QObject *o)
+void QV4::QmlIncubatorObject::setInitialState(QObject *o, RequiredProperties &requiredProperties)
 {
     QQmlComponent_setQmlParent(o, d()->parent);
 
@@ -1610,7 +1719,7 @@ void QV4::QmlIncubatorObject::setInitialState(QObject *o)
         QV4::Scope scope(v4);
         QV4::ScopedObject obj(scope, QV4::QObjectWrapper::wrap(v4, o));
         QV4::Scoped<QV4::QmlContext> qmlCtxt(scope, d()->qmlContext);
-        QQmlComponentPrivate::setInitialProperties(v4, qmlCtxt, obj, d()->valuemap);
+        QQmlComponentPrivate::setInitialProperties(v4, qmlCtxt, obj, d()->valuemap, requiredProperties, o);
     }
 }
 
diff --git a/src/qml/qml/qqmlcomponent_p.h b/src/qml/qml/qqmlcomponent_p.h
index 2170646b89..8ae7672c19 100644
--- a/src/qml/qml/qqmlcomponent_p.h
+++ b/src/qml/qml/qqmlcomponent_p.h
@@ -86,8 +86,9 @@ public:
 
     QObject *beginCreate(QQmlContextData *);
     void completeCreate();
-    void initializeObjectWithInitialProperties(QV4::QmlContext *qmlContext, const QV4::Value &valuemap, QObject *toCreate);
-    static void setInitialProperties(QV4::ExecutionEngine *engine, QV4::QmlContext *qmlContext, const QV4::Value &o, const QV4::Value &v);
+    void initializeObjectWithInitialProperties(QV4::QmlContext *qmlContext, const QV4::Value &valuemap, QObject *toCreate, RequiredProperties &requiredProperties);
+    static void setInitialProperties(QV4::ExecutionEngine *engine, QV4::QmlContext *qmlContext, const QV4::Value &o, const QV4::Value &v, RequiredProperties &requiredProperties, QObject *createdComponent);
+    static QQmlError unsetRequiredPropertyToQQmlError(const RequiredPropertyInfo &unsetRequiredProperty);
 
     virtual void incubateObject(
             QQmlIncubator *incubationTask,
@@ -106,6 +107,7 @@ public:
     qreal progress;
 
     int start;
+    RequiredProperties& requiredProperties();
     QQmlRefPointer<QV4::ExecutableCompilationUnit> compilationUnit;
 
     struct ConstructionState {
@@ -134,6 +136,7 @@ public:
     static void completeDeferred(QQmlEnginePrivate *enginePriv, DeferredState *deferredState);
 
     static void complete(QQmlEnginePrivate *enginePriv, ConstructionState *state);
+    static QQmlProperty removePropertyFromRequired(QObject *createdComponent, const QString &name, RequiredProperties& requiredProperties, bool *wasInRequiredProperties = nullptr);
 
     QQmlEngine *engine;
     QQmlGuardedContextData creationContext;
diff --git a/src/qml/qml/qqmlincubator.cpp b/src/qml/qml/qqmlincubator.cpp
index bc06226cbf..7b3ae31c08 100644
--- a/src/qml/qml/qqmlincubator.cpp
+++ b/src/qml/qml/qqmlincubator.cpp
@@ -43,6 +43,7 @@
 
 #include "qqmlexpression_p.h"
 #include "qqmlobjectcreator_p.h"
+#include <private/qqmlcomponent_p.h>
 
 void QQmlEnginePrivate::incubate(QQmlIncubator &i, QQmlContextData *forContext)
 {
@@ -296,6 +297,20 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
         tresult = creator->create(subComponentToCreate, /*parent*/nullptr, &i);
         if (!tresult)
             errors = creator->errors;
+        else {
+           RequiredProperties& requiredProperties = creator->requiredProperties();
+           for (auto it = initialProperties.cbegin(); it != initialProperties.cend(); ++it) {
+               auto component = tresult;
+               auto name = it.key();
+               QQmlProperty prop = QQmlComponentPrivate::removePropertyFromRequired(component, name, requiredProperties);
+               if (!prop.isValid() || !prop.write(it.value())) {
+                   QQmlError error{};
+                   error.setUrl(compilationUnit->url());
+                   error.setDescription(QLatin1String("Could not set property %1").arg(name));
+                   errors.push_back(error);
+               }
+           }
+        }
         enginePriv->dereferenceScarceResources();
 
         if (watcher.hasRecursed())
@@ -312,8 +327,14 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
             ddata->indestructible = true;
             ddata->explicitIndestructibleSet = true;
             ddata->rootObjectInCreation = false;
-            if (q)
+            if (q) {
                 q->setInitialState(result);
+                if (!creator->requiredProperties().empty()) {
+                    const auto& unsetRequiredProperties = creator->requiredProperties();
+                    for (const auto& unsetRequiredProperty: unsetRequiredProperties)
+                        errors << QQmlComponentPrivate::unsetRequiredPropertyToQQmlError(unsetRequiredProperty);
+                }
+            }
         }
 
         if (watcher.hasRecursed())
@@ -657,6 +678,31 @@ QObject *QQmlIncubator::object() const
 }
 
 /*!
+Return a list of properties which are required but haven't been set yet.
+This list can be modified, so that subclasses which implement special logic
+setInitialProperties can mark properties set there as no longer required.
+
+\sa QQmlIncubator::setInitialProperties
+\since 5.15
+*/
+RequiredProperties &QQmlIncubatorPrivate::requiredProperties()
+{
+    return creator->requiredProperties();
+}
+
+/*!
+Stores a mapping from property names to initial values with which the incubated
+component will be initialized
+
+\sa QQmlComponent::setInitialProperties
+\since 5.15
+*/
+void QQmlIncubator::setInitialProperties(const QVariantMap &initialProperties)
+{
+    d->initialProperties = initialProperties;
+}
+
+/*!
 Called when the status of the incubator changes.  \a status is the new status.
 
 The default implementation does nothing.
diff --git a/src/qml/qml/qqmlincubator.h b/src/qml/qml/qqmlincubator.h
index e68f6e3c45..f075407e73 100644
--- a/src/qml/qml/qqmlincubator.h
+++ b/src/qml/qml/qqmlincubator.h
@@ -47,6 +47,9 @@ QT_BEGIN_NAMESPACE
 
 
 class QQmlEngine;
+class QQmlPropertyData;
+class QVariant;
+using QVariantMap = QMap<QString, QVariant>;
 
 class QQmlIncubatorPrivate;
 class Q_QML_EXPORT QQmlIncubator
@@ -84,6 +87,8 @@ public:
 
     QObject *object() const;
 
+    void setInitialProperties(const QVariantMap &initialProperties);
+
 protected:
     virtual void statusChanged(Status);
     virtual void setInitialState(QObject *);
diff --git a/src/qml/qml/qqmlincubator_p.h b/src/qml/qml/qqmlincubator_p.h
index 57ec8249cb..731db7aad3 100644
--- a/src/qml/qml/qqmlincubator_p.h
+++ b/src/qml/qml/qqmlincubator_p.h
@@ -61,8 +61,12 @@
 
 QT_BEGIN_NAMESPACE
 
+class QQmlPropertyData;
+struct RequiredPropertyInfo;
+using RequiredProperties = QHash<QQmlPropertyData*, RequiredPropertyInfo>;
+
 class QQmlIncubator;
-class QQmlIncubatorPrivate : public QQmlEnginePrivate::Incubator
+class Q_QML_PRIVATE_EXPORT QQmlIncubatorPrivate : public QQmlEnginePrivate::Incubator
 {
 public:
     QQmlIncubatorPrivate(QQmlIncubator *q, QQmlIncubator::IncubationMode m);
@@ -97,11 +101,13 @@ public:
     QIntrusiveList<QIPBase, &QIPBase::nextWaitingFor> waitingFor;
 
     QRecursionNode recursion;
+    QVariantMap initialProperties;
 
     void clear();
 
     void forceCompletion(QQmlInstantiationInterrupt &i);
     void incubate(QQmlInstantiationInterrupt &i);
+    RequiredProperties &requiredProperties();
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index f89608cd5d..b723ddb381 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -783,6 +783,23 @@ void QQmlObjectCreator::setupBindings(bool applyDeferredBindings)
 
     const QV4::CompiledData::Binding *binding = _compiledObject->bindingTable();
     for (quint32 i = 0; i < _compiledObject->nBindings; ++i, ++binding) {
+        QQmlPropertyData *const property = propertyData.at(i);
+        if (property) {
+            QQmlPropertyData* targetProperty = property;
+            if (targetProperty->isAlias()) {
+                // follow alias
+                auto target = _bindingTarget;
+                QQmlPropertyIndex originalIndex(targetProperty->coreIndex(), _valueTypeProperty ? _valueTypeProperty->coreIndex() : -1);
+                QQmlPropertyIndex propIndex;
+                QQmlPropertyPrivate::findAliasTarget(target, originalIndex, &target, &propIndex);
+                QQmlData *data = QQmlData::get(target);
+                Q_ASSERT(data && data->propertyCache);
+                targetProperty = data->propertyCache->property(propIndex.coreIndex());
+            }
+            sharedState->requiredProperties.remove(targetProperty);
+        }
+
+
         if (binding->flags & QV4::CompiledData::Binding::IsCustomParserBinding)
             continue;
 
@@ -794,8 +811,6 @@ void QQmlObjectCreator::setupBindings(bool applyDeferredBindings)
                 continue;
         }
 
-        const QQmlPropertyData *property = propertyData.at(i);
-
         if (property && property->isQList()) {
             if (property->coreIndex() != currentListPropertyIndex) {
                 void *argv[1] = { (void*)&_currentList };
@@ -1504,10 +1519,42 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
     if (_compiledObject->flags & QV4::CompiledData::Object::HasDeferredBindings)
         _ddata->deferData(_compiledObjectIndex, compilationUnit, context);
 
+    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->requiredProperties.insert(propertyData,
+                                                   RequiredPropertyInfo {compilationUnit->stringAt(property->nameIndex), compilationUnit->finalUrl(), property->location, {}});
+        }
+    }
+
     if (_compiledObject->nFunctions > 0)
         setupFunctions();
     setupBindings();
 
+    for (int aliasIndex = 0; aliasIndex != _compiledObject->aliasCount(); ++aliasIndex) {
+        const QV4::CompiledData::Alias* alias = _compiledObject->aliasesBegin() + aliasIndex;
+        const auto originalAlias = alias;
+        while (alias->aliasToLocalAlias)
+            alias = _compiledObject->aliasesBegin() + alias->localAliasIndex;
+        Q_ASSERT(alias->flags & QV4::CompiledData::Alias::Resolved);
+        if (!context->idValues->wasSet())
+            continue;
+        QObject *target = context->idValues[alias->targetObjectId].data();
+        if (!target)
+            continue;
+        QQmlData *targetDData = QQmlData::get(target, /*create*/false);
+        if (!targetDData)
+            continue;
+        int coreIndex = QQmlPropertyIndex::fromEncoded(alias->encodedMetaPropertyIndex).coreIndex();
+        QQmlPropertyData *const targetProperty = targetDData->propertyCache->property(coreIndex);
+        if (!targetProperty)
+            continue;
+        auto it = sharedState->requiredProperties.find(targetProperty);
+        if (it != sharedState->requiredProperties.end())
+            it->aliasesToRequired.push_back(AliasToRequiredInfo {compilationUnit->stringAt(originalAlias->nameIndex), compilationUnit->finalUrl()});
+    }
+
     qSwap(_vmeMetaObject, vmeMetaObject);
     qSwap(_bindingTarget, bindingTarget);
     qSwap(_ddata, declarativeData);
diff --git a/src/qml/qml/qqmlobjectcreator_p.h b/src/qml/qml/qqmlobjectcreator_p.h
index ecdbcc56dd..ee1d82d4e3 100644
--- a/src/qml/qml/qqmlobjectcreator_p.h
+++ b/src/qml/qml/qqmlobjectcreator_p.h
@@ -66,6 +66,28 @@ class QQmlAbstractBinding;
 class QQmlInstantiationInterrupt;
 class QQmlIncubatorPrivate;
 
+struct AliasToRequiredInfo {
+    QString propertyName;
+    QUrl fileUrl;
+};
+
+/*!
+\internal
+This struct contains information solely used for displaying error messages
+\variable aliasesToRequired allows us to give the user a way to know which (aliasing) properties
+can be set to set the required property
+\sa QQmlComponentPrivate::unsetRequiredPropertyToQQmlError
+*/
+struct RequiredPropertyInfo
+{
+    QString propertyName;
+    QUrl fileUrl;
+    QV4::CompiledData::Location location;
+    QVector<AliasToRequiredInfo> aliasesToRequired;
+};
+
+using RequiredProperties = QHash<QQmlPropertyData*, RequiredPropertyInfo>;
+
 struct QQmlObjectCreatorSharedState : public QSharedData
 {
     QQmlContextData *rootContext;
@@ -78,6 +100,7 @@ struct QQmlObjectCreatorSharedState : public QSharedData
     QList<QQmlEnginePrivate::FinalizeCallback> finalizeCallbacks;
     QQmlVmeProfiler profiler;
     QRecursionNode recursionNode;
+    RequiredProperties requiredProperties;
 };
 
 class Q_QML_PRIVATE_EXPORT QQmlObjectCreator
@@ -102,6 +125,8 @@ public:
     QQmlContextData *parentContextData() const { return parentContext.contextData(); }
     QFiniteStack<QPointer<QObject> > &allCreatedObjects() { return sharedState->allCreatedObjects; }
 
+    RequiredProperties &requiredProperties() {return sharedState->requiredProperties;}
+
 private:
     QQmlObjectCreator(QQmlContextData *contextData, const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit, QQmlObjectCreatorSharedState *inheritedSharedState);
 
diff --git a/src/qml/qml/qqmlproperty.cpp b/src/qml/qml/qqmlproperty.cpp
index 5f57e0eca1..eff3e94fbd 100644
--- a/src/qml/qml/qqmlproperty.cpp
+++ b/src/qml/qml/qqmlproperty.cpp
@@ -885,7 +885,7 @@ void QQmlPropertyPrivate::setBinding(QQmlAbstractBinding *binding, BindingFlags
     QQmlData *data = QQmlData::get(object, true);
     if (data->propertyCache) {
         QQmlPropertyData *propertyData = data->propertyCache->property(coreIndex);
-        Q_ASSERT(propertyData && !propertyData->isAlias());
+        Q_ASSERT(propertyData);
     }
 #endif
 
diff --git a/src/qml/qml/qqmlpropertyvalidator.cpp b/src/qml/qml/qqmlpropertyvalidator.cpp
index 7dbcbe986b..6959b05105 100644
--- a/src/qml/qml/qqmlpropertyvalidator.cpp
+++ b/src/qml/qml/qqmlpropertyvalidator.cpp
@@ -49,6 +49,19 @@
 
 QT_BEGIN_NAMESPACE
 
+static bool isPrimitiveType(int typeId)
+{
+    switch (typeId) {
+#define HANDLE_PRIMITIVE(Type, id, T) \
+    case QMetaType::Type:
+QT_FOR_EACH_STATIC_PRIMITIVE_TYPE(HANDLE_PRIMITIVE);
+#undef HANDLE_PRIMITIVE
+        return true;
+    default:
+        return false;
+    }
+}
+
 QQmlPropertyValidator::QQmlPropertyValidator(QQmlEnginePrivate *enginePrivate, const QQmlImports &imports, const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit)
     : enginePrivate(enginePrivate)
     , compilationUnit(compilationUnit)
@@ -281,11 +294,21 @@ QVector<QQmlJS::DiagnosticMessage> QQmlPropertyValidator::validateObject(
                         return recordError(binding->location, tr("Invalid grouped property access"));
                     }
                 } else {
-                    if (!enginePrivate->propertyCacheForType(pd->propType())) {
+                    const int typeId = pd->propType();
+                    if (isPrimitiveType(typeId)) {
+                        return recordError(
+                                    binding->location,
+                                    tr("Invalid grouped property access: Property \"%1\" with primitive type \"%2\".")
+                                        .arg(name)
+                                        .arg(QString::fromLatin1(QMetaType::typeName(typeId)))
+                                    );
+                    }
+
+                    if (!enginePrivate->propertyCacheForType(typeId)) {
                         return recordError(binding->location,
                                            tr("Invalid grouped property access: Property \"%1\" with type \"%2\", which is not a value type")
                                            .arg(name)
-                                           .arg(QString::fromLatin1(QMetaType::typeName(pd->propType())))
+                                           .arg(QString::fromLatin1(QMetaType::typeName(typeId)))
                                           );
                     }
                 }
@@ -679,15 +702,21 @@ QQmlJS::DiagnosticMessage QQmlPropertyValidator::validateObjectBinding(QQmlPrope
         return noError;
     }
 
-    if (QQmlMetaType::isInterface(property->propType())) {
+    const int propType = property->propType();
+    const auto rhsType = [&]() {
+        return stringAt(compilationUnit->objectAt(binding->value.objectIndex)
+                        ->inheritedTypeNameIndex);
+    };
+
+    if (QQmlMetaType::isInterface(propType)) {
         // Can only check at instantiation time if the created sub-object successfully casts to the
         // target interface.
         return noError;
-    } else if (property->propType() == QMetaType::QVariant || property->propType() == qMetaTypeId<QJSValue>()) {
+    } else if (propType == QMetaType::QVariant || propType == qMetaTypeId<QJSValue>()) {
         // We can convert everything to QVariant :)
         return noError;
     } else if (property->isQList()) {
-        const int listType = enginePrivate->listType(property->propType());
+        const int listType = enginePrivate->listType(propType);
         if (!QQmlMetaType::isInterface(listType)) {
             QQmlPropertyCache *source = propertyCaches.at(binding->value.objectIndex);
             if (!canCoerce(listType, source)) {
@@ -697,19 +726,23 @@ QQmlJS::DiagnosticMessage QQmlPropertyValidator::validateObjectBinding(QQmlPrope
         return noError;
     } else if (binding->flags & QV4::CompiledData::Binding::IsSignalHandlerObject && property->isFunction()) {
         return noError;
-    } else if (QQmlValueTypeFactory::isValueType(property->propType())) {
-        auto typeName = QMetaType::typeName(property->propType());
+    } else if (isPrimitiveType(propType)) {
+        auto typeName = QMetaType::typeName(propType);
+        return qQmlCompileError(binding->location, tr("Can not assign value of type \"%1\" to property \"%2\", expecting \"%3\"")
+                                                      .arg(rhsType())
+                                                      .arg(propertyName)
+                                                      .arg(typeName));
+    } else if (QQmlValueTypeFactory::isValueType(propType)) {
         return qQmlCompileError(binding->location, tr("Can not assign value of type \"%1\" to property \"%2\", expecting an object")
-                                                      .arg(typeName ? QString::fromLatin1(typeName) : QString::fromLatin1("<unknown type>"))
-                                                      .arg(propertyName));
-    } else if (property->propType() == qMetaTypeId<QQmlScriptString>()) {
+                                                      .arg(rhsType()).arg(propertyName));
+    } else if (propType == qMetaTypeId<QQmlScriptString>()) {
         return qQmlCompileError(binding->valueLocation, tr("Invalid property assignment: script expected"));
     } else {
         // We want to use the raw metaObject here as the raw metaobject is the
         // actual property type before we applied any extensions that might
         // effect the properties on the type, but don't effect assignability
         // Using -1 for the minor version ensures that we get the raw metaObject.
-        QQmlPropertyCache *propertyMetaObject = enginePrivate->rawPropertyCacheForType(property->propType(), -1);
+        QQmlPropertyCache *propertyMetaObject = enginePrivate->rawPropertyCacheForType(propType, -1);
 
         if (propertyMetaObject) {
             // Will be true if the assigned type inherits propertyMetaObject
@@ -723,11 +756,11 @@ QQmlJS::DiagnosticMessage QQmlPropertyValidator::validateObjectBinding(QQmlPrope
 
             if (!isAssignable) {
                 return qQmlCompileError(binding->valueLocation, tr("Cannot assign object of type \"%1\" to property of type \"%2\" as the former is neither the same as the latter nor a sub-class of it.")
-                        .arg(stringAt(compilationUnit->objectAt(binding->value.objectIndex)->inheritedTypeNameIndex)).arg(QLatin1String(QMetaType::typeName(property->propType()))));
+                        .arg(rhsType()).arg(QLatin1String(QMetaType::typeName(propType))));
             }
         } else {
             return qQmlCompileError(binding->valueLocation, tr("Cannot assign to property of unknown type \"%1\".")
-                        .arg(QLatin1String(QMetaType::typeName(property->propType()))));
+                        .arg(QLatin1String(QMetaType::typeName(propType))));
         }
 
     }
diff --git a/src/qml/qml/qqmltype.cpp b/src/qml/qml/qqmltype.cpp
index 2a6831d898..252ff26a64 100644
--- a/src/qml/qml/qqmltype.cpp
+++ b/src/qml/qml/qqmltype.cpp
@@ -154,23 +154,6 @@ bool QQmlType::availableInVersion(const QHashedStringRef &module, int vmajor, in
     return module == d->module && vmajor == d->version_maj && vminor >= d->version_min;
 }
 
-// returns the nearest _registered_ super class
-QQmlType QQmlType::superType() const
-{
-    if (!d)
-        return QQmlType();
-    if (!d->haveSuperType && d->baseMetaObject) {
-        const QMetaObject *mo = d->baseMetaObject->superClass();
-        while (mo && !d->superType.isValid()) {
-            d->superType = QQmlMetaType::qmlType(mo, d->module, d->version_maj, d->version_min);
-            mo = mo->superClass();
-        }
-        d->haveSuperType = true;
-    }
-
-    return d->superType;
-}
-
 QQmlType QQmlType::resolveCompositeBaseType(QQmlEnginePrivate *engine) const
 {
     Q_ASSERT(isComposite());
diff --git a/src/qml/qml/qqmltype_p.h b/src/qml/qml/qqmltype_p.h
index 158fefad2c..4dec20600b 100644
--- a/src/qml/qml/qqmltype_p.h
+++ b/src/qml/qml/qqmltype_p.h
@@ -182,7 +182,6 @@ public:
     };
 
 private:
-    QQmlType superType() const;
     QQmlType resolveCompositeBaseType(QQmlEnginePrivate *engine) const;
     int resolveCompositeEnumValue(QQmlEnginePrivate *engine, const QString &name, bool *ok) const;
     QQmlPropertyCache *compositePropertyCache(QQmlEnginePrivate *engine) const;
diff --git a/src/qml/qml/qqmlvaluetype.cpp b/src/qml/qml/qqmlvaluetype.cpp
index 2225191a9d..d83fc4bb48 100644
--- a/src/qml/qml/qqmlvaluetype.cpp
+++ b/src/qml/qml/qqmlvaluetype.cpp
@@ -65,11 +65,13 @@ struct QQmlValueTypeFactoryImpl
     QQmlValueType *valueTypes[QVariant::UserType];
     QHash<int, QQmlValueType *> userTypes;
     QMutex mutex;
+
+    QQmlValueType invalidValueType;
 };
 
 QQmlValueTypeFactoryImpl::QQmlValueTypeFactoryImpl()
 {
-    std::fill_n(valueTypes, int(QVariant::UserType), nullptr);
+    std::fill_n(valueTypes, int(QVariant::UserType), &invalidValueType);
 
 #if QT_CONFIG(qml_itemmodel)
     // See types wrapped in qqmlmodelindexvaluetype_p.h
@@ -79,20 +81,18 @@ QQmlValueTypeFactoryImpl::QQmlValueTypeFactoryImpl()
 
 QQmlValueTypeFactoryImpl::~QQmlValueTypeFactoryImpl()
 {
-    qDeleteAll(valueTypes, valueTypes + QVariant::UserType);
+    for (QQmlValueType *type : valueTypes) {
+        if (type != &invalidValueType)
+            delete type;
+    }
     qDeleteAll(userTypes);
 }
 
-bool QQmlValueTypeFactoryImpl::isValueType(int idx)
+bool isInternalType(int idx)
 {
-    if (idx >= QMetaType::User)
-        return valueType(idx) != nullptr;
-
-    if (idx < 0)
-        return false;
-
     // Qt internal types
     switch (idx) {
+    case QMetaType::UnknownType:
     case QMetaType::QStringList:
     case QMetaType::QObjectStar:
     case QMetaType::VoidStar:
@@ -101,12 +101,20 @@ bool QQmlValueTypeFactoryImpl::isValueType(int idx)
     case QMetaType::QLocale:
     case QMetaType::QImage:  // scarce type, keep as QVariant
     case QMetaType::QPixmap: // scarce type, keep as QVariant
-        return false;
-    default:
         return true;
+    default:
+        return false;
     }
 }
 
+bool QQmlValueTypeFactoryImpl::isValueType(int idx)
+{
+    if (idx < 0 || isInternalType(idx))
+        return false;
+
+    return valueType(idx) != nullptr;
+}
+
 const QMetaObject *QQmlValueTypeFactoryImpl::metaObjectForMetaType(int t)
 {
     switch (t) {
@@ -168,15 +176,17 @@ QQmlValueType *QQmlValueTypeFactoryImpl::valueType(int idx)
     }
 
     QQmlValueType *rv = valueTypes[idx];
-    if (!rv) {
+    if (rv == &invalidValueType) {
         // No need for mutex protection - the most we can lose is a valueType instance
 
         // TODO: Investigate the performance/memory characteristics of
         // removing the preallocated array
-        if (const QMetaObject *mo = metaObjectForMetaType(idx)) {
-            rv = new QQmlValueType(idx, mo);
-            valueTypes[idx] = rv;
-        }
+        if (isInternalType(idx))
+            rv = valueTypes[idx] = nullptr;
+        else if (const QMetaObject *mo = metaObjectForMetaType(idx))
+            rv = valueTypes[idx] = new QQmlValueType(idx, mo);
+        else
+            rv = valueTypes[idx] = nullptr;
     }
 
     return rv;
@@ -208,6 +218,13 @@ void QQmlValueTypeFactory::registerValueTypes(const char *uri, int versionMajor,
 #endif
 }
 
+QQmlValueType::QQmlValueType() :
+    _metaObject(nullptr),
+    gadgetPtr(nullptr),
+    metaType(QMetaType::UnknownType)
+{
+}
+
 QQmlValueType::QQmlValueType(int typeId, const QMetaObject *gadgetMetaObject)
     : gadgetPtr(QMetaType::create(typeId))
     , metaType(typeId)
@@ -225,7 +242,7 @@ QQmlValueType::QQmlValueType(int typeId, const QMetaObject *gadgetMetaObject)
 QQmlValueType::~QQmlValueType()
 {
     QObjectPrivate *op = QObjectPrivate::get(this);
-    Q_ASSERT(op->metaObject == this);
+    Q_ASSERT(op->metaObject == nullptr || op->metaObject == this);
     op->metaObject = nullptr;
     ::free(const_cast<QMetaObject *>(_metaObject));
     metaType.destroy(gadgetPtr);
diff --git a/src/qml/qml/qqmlvaluetype_p.h b/src/qml/qml/qqmlvaluetype_p.h
index 75150b3f32..95ad81d045 100644
--- a/src/qml/qml/qqmlvaluetype_p.h
+++ b/src/qml/qml/qqmlvaluetype_p.h
@@ -68,6 +68,7 @@ QT_BEGIN_NAMESPACE
 class Q_QML_PRIVATE_EXPORT QQmlValueType : public QObject, public QAbstractDynamicMetaObject
 {
 public:
+    QQmlValueType();
     QQmlValueType(int userType, const QMetaObject *metaObject);
     ~QQmlValueType() override;
     void read(QObject *, int);
@@ -92,7 +93,7 @@ public:
 class Q_QML_PRIVATE_EXPORT QQmlValueTypeFactory
 {
 public:
-    static bool isValueType(int);
+    static bool isValueType(int idx);
     static QQmlValueType *valueType(int idx);
     static const QMetaObject *metaObjectForMetaType(int type);
 
diff --git a/src/qml/qml/qqmlvaluetypewrapper.cpp b/src/qml/qml/qqmlvaluetypewrapper.cpp
index cf6553d129..f23921497c 100644
--- a/src/qml/qml/qqmlvaluetypewrapper.cpp
+++ b/src/qml/qml/qqmlvaluetypewrapper.cpp
@@ -96,29 +96,29 @@ using namespace QV4;
 
 void Heap::QQmlValueTypeWrapper::destroy()
 {
-    if (gadgetPtr) {
-        valueType->metaType.destruct(gadgetPtr);
-        ::operator delete(gadgetPtr);
+    if (m_gadgetPtr) {
+        m_valueType->metaType.destruct(m_gadgetPtr);
+        ::operator delete(m_gadgetPtr);
     }
-    if (_propertyCache)
-        _propertyCache->release();
+    if (m_propertyCache)
+        m_propertyCache->release();
     Object::destroy();
 }
 
 void Heap::QQmlValueTypeWrapper::setValue(const QVariant &value) const
 {
-    Q_ASSERT(valueType->metaType.id() == value.userType());
-    if (gadgetPtr)
-        valueType->metaType.destruct(gadgetPtr);
-    if (!gadgetPtr)
-        gadgetPtr = ::operator new(valueType->metaType.sizeOf());
-    valueType->metaType.construct(gadgetPtr, value.constData());
+    Q_ASSERT(valueType()->metaType.id() == value.userType());
+    if (auto *gadget = gadgetPtr())
+        valueType()->metaType.destruct(gadget);
+    if (!gadgetPtr())
+        setGadgetPtr(::operator new(valueType()->metaType.sizeOf()));
+    valueType()->metaType.construct(gadgetPtr(), value.constData());
 }
 
 QVariant Heap::QQmlValueTypeWrapper::toVariant() const
 {
-    Q_ASSERT(gadgetPtr);
-    return QVariant(valueType->metaType.id(), gadgetPtr);
+    Q_ASSERT(gadgetPtr());
+    return QVariant(valueType()->metaType.id(), gadgetPtr());
 }
 
 
@@ -146,13 +146,13 @@ bool QQmlValueTypeReference::readReferenceValue() const
                 QQmlPropertyCache *cache = nullptr;
                 if (const QMetaObject *mo = QQmlValueTypeFactory::metaObjectForMetaType(variantReferenceType))
                     cache = QJSEnginePrivate::get(engine())->cache(mo);
-                if (d()->gadgetPtr) {
-                    d()->valueType->metaType.destruct(d()->gadgetPtr);
-                    ::operator delete(d()->gadgetPtr);
+                if (d()->gadgetPtr()) {
+                    d()->valueType()->metaType.destruct(d()->gadgetPtr());
+                    ::operator delete(d()->gadgetPtr());
                 }
-                d()->gadgetPtr =nullptr;
+                d()->setGadgetPtr(nullptr);
                 d()->setPropertyCache(cache);
-                d()->valueType = QQmlValueTypeFactory::valueType(variantReferenceType);
+                d()->setValueType(QQmlValueTypeFactory::valueType(variantReferenceType));
                 if (!cache)
                     return false;
             } else {
@@ -161,12 +161,12 @@ bool QQmlValueTypeReference::readReferenceValue() const
         }
         d()->setValue(variantReferenceValue);
     } else {
-        if (!d()->gadgetPtr) {
-            d()->gadgetPtr = ::operator new(d()->valueType->metaType.sizeOf());
-            d()->valueType->metaType.construct(d()->gadgetPtr, nullptr);
+        if (!d()->gadgetPtr()) {
+            d()->setGadgetPtr(::operator new(d()->valueType()->metaType.sizeOf()));
+            d()->valueType()->metaType.construct(d()->gadgetPtr(), nullptr);
         }
         // value-type reference
-        void *args[] = { d()->gadgetPtr, nullptr };
+        void *args[] = { d()->gadgetPtr(), nullptr };
         QMetaObject::metacall(d()->object, QMetaObject::ReadProperty, d()->property, args);
     }
     return true;
@@ -192,8 +192,8 @@ ReturnedValue QQmlValueTypeWrapper::create(ExecutionEngine *engine, QObject *obj
     r->d()->object = object;
     r->d()->property = property;
     r->d()->setPropertyCache(QJSEnginePrivate::get(engine)->cache(metaObject));
-    r->d()->valueType = QQmlValueTypeFactory::valueType(typeId);
-    r->d()->gadgetPtr = nullptr;
+    r->d()->setValueType(QQmlValueTypeFactory::valueType(typeId));
+    r->d()->setGadgetPtr(nullptr);
     return r->asReturnedValue();
 }
 
@@ -204,8 +204,8 @@ ReturnedValue QQmlValueTypeWrapper::create(ExecutionEngine *engine, const QVaria
 
     Scoped<QQmlValueTypeWrapper> r(scope, engine->memoryManager->allocate<QQmlValueTypeWrapper>());
     r->d()->setPropertyCache(QJSEnginePrivate::get(engine)->cache(metaObject));
-    r->d()->valueType = QQmlValueTypeFactory::valueType(typeId);
-    r->d()->gadgetPtr = nullptr;
+    r->d()->setValueType(QQmlValueTypeFactory::valueType(typeId));
+    r->d()->setGadgetPtr(nullptr);
     r->d()->setValue(value);
     return r->asReturnedValue();
 }
@@ -223,9 +223,9 @@ bool QQmlValueTypeWrapper::toGadget(void *data) const
     if (const QQmlValueTypeReference *ref = as<const QQmlValueTypeReference>())
         if (!ref->readReferenceValue())
             return false;
-    const int typeId = d()->valueType->metaType.id();
+    const int typeId = d()->valueType()->metaType.id();
     QMetaType::destruct(typeId, data);
-    QMetaType::construct(typeId, data, d()->gadgetPtr);
+    QMetaType::construct(typeId, data, d()->gadgetPtr());
     return true;
 }
 
@@ -307,7 +307,7 @@ bool QQmlValueTypeWrapper::isEqual(const QVariant& value) const
 
 int QQmlValueTypeWrapper::typeId() const
 {
-    return d()->valueType->metaType.id();
+    return d()->valueType()->metaType.id();
 }
 
 bool QQmlValueTypeWrapper::write(QObject *target, int propertyIndex) const
@@ -315,10 +315,10 @@ bool QQmlValueTypeWrapper::write(QObject *target, int propertyIndex) const
     bool destructGadgetOnExit = false;
     Q_ALLOCA_DECLARE(void, gadget);
     if (const QQmlValueTypeReference *ref = as<const QQmlValueTypeReference>()) {
-        if (!d()->gadgetPtr) {
-            Q_ALLOCA_ASSIGN(void, gadget, d()->valueType->metaType.sizeOf());
-            d()->gadgetPtr = gadget;
-            d()->valueType->metaType.construct(d()->gadgetPtr, nullptr);
+        if (!d()->gadgetPtr()) {
+            Q_ALLOCA_ASSIGN(void, gadget, d()->valueType()->metaType.sizeOf());
+            d()->setGadgetPtr(gadget);
+            d()->valueType()->metaType.construct(d()->gadgetPtr(), nullptr);
             destructGadgetOnExit = true;
         }
         if (!ref->readReferenceValue())
@@ -327,12 +327,12 @@ bool QQmlValueTypeWrapper::write(QObject *target, int propertyIndex) const
 
     int flags = 0;
     int status = -1;
-    void *a[] = { d()->gadgetPtr, nullptr, &status, &flags };
+    void *a[] = { d()->gadgetPtr(), nullptr, &status, &flags };
     QMetaObject::metacall(target, QMetaObject::WriteProperty, propertyIndex, a);
 
     if (destructGadgetOnExit) {
-        d()->valueType->metaType.destruct(d()->gadgetPtr);
-        d()->gadgetPtr = nullptr;
+        d()->valueType()->metaType.destruct(d()->gadgetPtr());
+        d()->setGadgetPtr(nullptr);
     }
     return true;
 }
@@ -354,16 +354,16 @@ ReturnedValue QQmlValueTypeWrapper::method_toString(const FunctionObject *b, con
     // Prepare a buffer to pass to QMetaType::convert()
     QString convertResult;
     convertResult.~QString();
-    if (QMetaType::convert(w->d()->gadgetPtr, w->d()->valueType->metaType.id(), &convertResult, QMetaType::QString)) {
+    if (QMetaType::convert(w->d()->gadgetPtr(), w->d()->valueType()->metaType.id(), &convertResult, QMetaType::QString)) {
         result = convertResult;
     } else {
-        result += QString::fromUtf8(QMetaType::typeName(w->d()->valueType->metaType.id()))
+        result += QString::fromUtf8(QMetaType::typeName(w->d()->valueType()->metaType.id()))
                 + QLatin1Char('(');
         const QMetaObject *mo = w->d()->propertyCache()->metaObject();
         const int propCount = mo->propertyCount();
         for (int i = 0; i < propCount; ++i) {
             if (mo->property(i).isDesignable()) {
-                QVariant value = mo->property(i).readOnGadget(w->d()->gadgetPtr);
+                QVariant value = mo->property(i).readOnGadget(w->d()->gadgetPtr());
                 if (i > 0)
                     result += QLatin1String(", ");
                 result += value.toString();
@@ -387,7 +387,7 @@ Q_ALWAYS_INLINE static ReturnedValue getGadgetProperty(ExecutionEngine *engine,
     if (property->propType() == metatype) { \
         cpptype v; \
         void *args[] = { &v, nullptr }; \
-        metaObject->d.static_metacall(reinterpret_cast<QObject*>(valueTypeWrapper->gadgetPtr), \
+        metaObject->d.static_metacall(reinterpret_cast<QObject*>(valueTypeWrapper->gadgetPtr()), \
                                       QMetaObject::ReadProperty, index, args); \
         return QV4::Encode(constructor(v)); \
     }
@@ -412,7 +412,7 @@ Q_ALWAYS_INLINE static ReturnedValue getGadgetProperty(ExecutionEngine *engine,
         v = QVariant(property->propType(), static_cast<void *>(nullptr));
         args[0] = v.data();
     }
-    metaObject->d.static_metacall(reinterpret_cast<QObject*>(valueTypeWrapper->gadgetPtr), QMetaObject::ReadProperty,
+    metaObject->d.static_metacall(reinterpret_cast<QObject*>(valueTypeWrapper->gadgetPtr()), QMetaObject::ReadProperty,
                                   index, args);
     return engine->fromVariant(v);
 #undef VALUE_TYPE_LOAD
@@ -604,7 +604,7 @@ bool QQmlValueTypeWrapper::virtualPut(Managed *m, PropertyKey id, const Value &v
     if (property.isEnumType() && (QMetaType::Type)v.type() == QMetaType::Double)
         v = v.toInt();
 
-    void *gadget = r->d()->gadgetPtr;
+    void *gadget = r->d()->gadgetPtr();
     property.writeOnGadget(gadget, v);
 
 
@@ -620,7 +620,7 @@ bool QQmlValueTypeWrapper::virtualPut(Managed *m, PropertyKey id, const Value &v
         } else {
             int flags = 0;
             int status = -1;
-            void *a[] = { r->d()->gadgetPtr, nullptr, &status, &flags };
+            void *a[] = { r->d()->gadgetPtr(), nullptr, &status, &flags };
             QMetaObject::metacall(reference->d()->object, QMetaObject::WriteProperty, reference->d()->property, a);
         }
     }
diff --git a/src/qml/qml/qqmlvaluetypewrapper_p.h b/src/qml/qml/qqmlvaluetypewrapper_p.h
index baac129afa..60079aa623 100644
--- a/src/qml/qml/qqmlvaluetypewrapper_p.h
+++ b/src/qml/qml/qqmlvaluetypewrapper_p.h
@@ -69,22 +69,45 @@ namespace Heap {
 struct QQmlValueTypeWrapper : Object {
     void init() { Object::init(); }
     void destroy();
-    QQmlPropertyCache *propertyCache() const { return _propertyCache; }
+
+    QQmlPropertyCache *propertyCache() const { return m_propertyCache; }
     void setPropertyCache(QQmlPropertyCache *c) {
         if (c)
             c->addref();
-        if (_propertyCache)
-            _propertyCache->release();
-        _propertyCache = c;
+        if (m_propertyCache)
+            m_propertyCache->release();
+        m_propertyCache = c;
+    }
+
+    void setValueType(QQmlValueType *valueType)
+    {
+        Q_ASSERT(valueType != nullptr);
+        m_valueType = valueType;
+    }
+
+    QQmlValueType *valueType() const
+    {
+        Q_ASSERT(m_valueType != nullptr);
+        return m_valueType;
+    }
+
+    void setGadgetPtr(void *gadgetPtr) const
+    {
+        m_gadgetPtr = gadgetPtr;
+    }
+
+    void *gadgetPtr() const
+    {
+        return m_gadgetPtr;
     }
-    mutable void *gadgetPtr;
-    QQmlValueType *valueType;
 
     void setValue(const QVariant &value) const;
     QVariant toVariant() const;
 
 private:
-    QQmlPropertyCache *_propertyCache;
+    mutable void *m_gadgetPtr;
+    QQmlValueType *m_valueType;
+    QQmlPropertyCache *m_propertyCache;
 };
 
 }
diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index b9d8fed243..a67ac7384d 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -1180,6 +1180,8 @@ 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)
+        aliasData = &compiledObject->aliasTable()[aliasData->localAliasIndex];
     *target = ctxt->idValues[aliasData->targetObjectId].data();
     if (!*target)
         return false;
diff --git a/src/quick/items/qquickloader.cpp b/src/quick/items/qquickloader.cpp
index d0e29c204e..819a3a73e3 100644
--- a/src/quick/items/qquickloader.cpp
+++ b/src/quick/items/qquickloader.cpp
@@ -45,6 +45,7 @@
 #include <private/qqmlglobal_p.h>
 
 #include <private/qqmlcomponent_p.h>
+#include <private/qqmlincubator_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -664,7 +665,8 @@ void QQuickLoaderPrivate::setInitialState(QObject *obj)
     QV4::Scope scope(v4);
     QV4::ScopedValue ipv(scope, initialPropertyValues.value());
     QV4::Scoped<QV4::QmlContext> qmlContext(scope, qmlCallingContext.value());
-    d->initializeObjectWithInitialProperties(qmlContext, ipv, obj);
+    auto incubatorPriv = QQmlIncubatorPrivate::get(incubator);
+    d->initializeObjectWithInitialProperties(qmlContext, ipv, obj, incubatorPriv->requiredProperties());
 }
 
 void QQuickLoaderIncubator::statusChanged(Status status)
diff --git a/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp b/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
index 102acf73d6..04f45bb902 100644
--- a/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
+++ b/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
@@ -360,7 +360,7 @@ static QQmlPrivate::CachedQmlUnit *temporaryModifiedCachedUnit = nullptr;
 void tst_qmlcachegen::versionChecksForAheadOfTimeUnits()
 {
     QVERIFY(QFile::exists(":/data/versionchecks.qml"));
-    QCOMPARE(QFileInfo(":/data/versionchecks.qml").size(), 0);
+    QVERIFY(QFileInfo(":/data/versionchecks.qml").size() > 0);
 
     Q_ASSERT(!temporaryModifiedCachedUnit);
     QQmlMetaType::CachedUnitLookupError error = QQmlMetaType::CachedUnitLookupError::NoError;
@@ -387,12 +387,8 @@ void tst_qmlcachegen::versionChecksForAheadOfTimeUnits()
 
     {
         QQmlEngine engine;
-        QQmlComponent component(&engine, QUrl("qrc:/data/versionchecks.qml"));
-        QCOMPARE(component.status(), QQmlComponent::Error);
-        QCOMPARE(component.errorString(),
-                 QString("qrc:/data/versionchecks.qml:-1 File was compiled ahead of time with an "
-                         "incompatible version of Qt and the original file cannot be found. Please "
-                         "recompile\n"));
+        CleanlyLoadingComponent component(&engine, QUrl("qrc:/data/versionchecks.qml"));
+        QCOMPARE(component.status(), QQmlComponent::Ready);
     }
 
     Q_ASSERT(temporaryModifiedCachedUnit);
@@ -414,7 +410,7 @@ void tst_qmlcachegen::workerScripts()
 {
     QVERIFY(QFile::exists(":/workerscripts/data/worker.js"));
     QVERIFY(QFile::exists(":/workerscripts/data/worker.qml"));
-    QCOMPARE(QFileInfo(":/workerscripts/data/worker.js").size(), 0);
+    QVERIFY(QFileInfo(":/workerscripts/data/worker.js").size() > 0);
 
     QQmlEngine engine;
     CleanlyLoadingComponent component(&engine, QUrl("qrc:///workerscripts/data/worker.qml"));
@@ -503,7 +499,7 @@ void tst_qmlcachegen::trickyPaths()
 {
     QFETCH(QString, filePath);
     QVERIFY2(QFile::exists(filePath), qPrintable(filePath));
-    QCOMPARE(QFileInfo(filePath).size(), 0);
+    QVERIFY(QFileInfo(filePath).size() > 0);
     QQmlEngine engine;
     QQmlComponent component(&engine, QUrl("qrc" + filePath));
     QScopedPointer<QObject> obj(component.create());
@@ -584,7 +580,7 @@ void tst_qmlcachegen::moduleScriptImport()
     QTRY_VERIFY(obj->property("ok").toBool());
 
     QVERIFY(QFile::exists(":/data/script.mjs"));
-    QCOMPARE(QFileInfo(":/data/script.mjs").size(), 0);
+    QVERIFY(QFileInfo(":/data/script.mjs").size() > 0);
 
     {
         auto componentPrivate = QQmlComponentPrivate::get(&component);
@@ -617,7 +613,7 @@ void tst_qmlcachegen::enums()
 void tst_qmlcachegen::sourceFileIndices()
 {
     QVERIFY(QFile::exists(":/data/versionchecks.qml"));
-    QCOMPARE(QFileInfo(":/data/versionchecks.qml").size(), 0);
+    QVERIFY(QFileInfo(":/data/versionchecks.qml").size() > 0);
 
     QQmlMetaType::CachedUnitLookupError error = QQmlMetaType::CachedUnitLookupError::NoError;
     const QV4::CompiledData::Unit *unitFromResources = QQmlMetaType::findCachedCompilationUnit(
diff --git a/tests/auto/qml/qmllint/data/Form.ui.qml b/tests/auto/qml/qmllint/data/Form.ui.qml
new file mode 100644
index 0000000000..459c82afbb
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/Form.ui.qml
@@ -0,0 +1,4 @@
+import QtQuick 2.0
+
+Item {
+}
diff --git a/tests/auto/qml/qmllint/data/FormUser.qml b/tests/auto/qml/qmllint/data/FormUser.qml
new file mode 100644
index 0000000000..ea3621586f
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/FormUser.qml
@@ -0,0 +1,7 @@
+import QtQuick 2.0
+
+Form {
+    x: 12
+    y: 13
+    objectName: "horst"
+}
diff --git a/tests/auto/qml/qmllint/data/ImportWithPrefix.qml b/tests/auto/qml/qmllint/data/ImportWithPrefix.qml
new file mode 100644
index 0000000000..6d070da21a
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/ImportWithPrefix.qml
@@ -0,0 +1,5 @@
+import "." as MyStuff
+
+MyStuff.Simple {
+    property bool something: contains(Qt.point(12, 34))
+}
diff --git a/tests/auto/qml/qmllint/data/MethodInItem.qml b/tests/auto/qml/qmllint/data/MethodInItem.qml
new file mode 100644
index 0000000000..dbdaf8bcc1
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/MethodInItem.qml
@@ -0,0 +1,5 @@
+import QtQml 2.0
+
+QtObject {
+    function doThings() { console.log("things") }
+}
diff --git a/tests/auto/qml/qmllint/data/MethodInScope.qml b/tests/auto/qml/qmllint/data/MethodInScope.qml
new file mode 100644
index 0000000000..7ba0829f61
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/MethodInScope.qml
@@ -0,0 +1,5 @@
+import QtQml 2.0
+
+MethodInItem {
+    Component.onCompleted: doThings()
+}
diff --git a/tests/auto/qml/qmllint/data/UnmatchedSignalHandler.qml b/tests/auto/qml/qmllint/data/UnmatchedSignalHandler.qml
new file mode 100644
index 0000000000..064444e182
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/UnmatchedSignalHandler.qml
@@ -0,0 +1,15 @@
+import QtQuick 2.12
+
+Item {
+    width: 640
+    height: 480
+
+    MouseArea {
+        anchors.fill: parent
+        onClicked: console.log("okok")
+
+        Connections {
+            onClicked: console.log(mouse.x)
+        }
+    }
+}
diff --git a/tests/auto/qml/qmllint/tst_qmllint.cpp b/tests/auto/qml/qmllint/tst_qmllint.cpp
index 582f146dca..2d225aebd3 100644
--- a/tests/auto/qml/qmllint/tst_qmllint.cpp
+++ b/tests/auto/qml/qmllint/tst_qmllint.cpp
@@ -44,7 +44,14 @@ private Q_SLOTS:
     void testUnqualified_data();
     void testUnqualifiedNoSpuriousParentWarning();
     void catchIdentifierNoFalsePositive();
+    void testUnmatchedSignalHandler();
+    void uiQml();
+    void methodInScope();
+    void importWithPrefix();
+
 private:
+    QString runQmllint(const QString &fileToLint, bool shouldSucceed);
+
     QString m_qmllintPath;
 };
 
@@ -83,15 +90,8 @@ void TestQmllint::testUnqualified()
     QFETCH(QString, warningMessage);
     QFETCH(int, warningLine);
     QFETCH(int, warningColumn);
-    QStringList args;
-    args << QStringLiteral("-U") << testFile(filename) << QStringLiteral("-I") << qmlImportDir;
 
-    QProcess process;
-    process.start(m_qmllintPath, args);
-    QVERIFY(process.waitForFinished());
-    QVERIFY(process.exitStatus() == QProcess::NormalExit);
-    QVERIFY(process.exitCode());
-    QString output = process.readAllStandardError();
+    const QString output = runQmllint(filename, false);
     QVERIFY(output.contains(QString::asprintf("Warning: unqualified access at %d:%d", warningLine, warningColumn)));
     QVERIFY(output.contains(warningMessage));
 }
@@ -122,41 +122,39 @@ void TestQmllint::testUnqualified_data()
 
 void TestQmllint::testUnqualifiedNoSpuriousParentWarning()
 {
-    auto qmlImportDir = QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath);
-    {
-        QString filename = testFile("spuriousParentWarning.qml");
-        QStringList args;
-        args << QStringLiteral("-U") << filename << QStringLiteral("-I") << qmlImportDir;
-        QProcess process;
-        process.start(m_qmllintPath, args);
-        QVERIFY(process.waitForFinished());
-        QVERIFY(process.exitStatus() == QProcess::NormalExit);
-        QVERIFY(process.exitCode() == 0);
-    }
-    {
-        QString filename = testFile("nonSpuriousParentWarning.qml");
-        QStringList args;
-        args << QStringLiteral("-U") << filename << QStringLiteral("-I") << qmlImportDir;
-        QProcess process;
-        process.start(m_qmllintPath, args);
-        QVERIFY(process.waitForFinished());
-        QVERIFY(process.exitStatus() == QProcess::NormalExit);
-        QVERIFY(process.exitCode());
-    }
+    runQmllint("spuriousParentWarning.qml", true);
+    runQmllint("nonSpuriousParentWarning.qml", false);
 }
 
 void TestQmllint::catchIdentifierNoFalsePositive()
 {
-    auto qmlImportDir = QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath);
-    QString filename = QLatin1String("catchIdentifierNoWarning.qml");
-    filename.prepend(QStringLiteral("data/"));
-    QStringList args;
-    args << QStringLiteral("-U") << filename << QStringLiteral("-I") << qmlImportDir;
-    QProcess process;
-    process.start(m_qmllintPath, args);
-    QVERIFY(process.waitForFinished());
-    QVERIFY(process.exitStatus() == QProcess::NormalExit);
-    QVERIFY(process.exitCode() == 0);
+    runQmllint("catchIdentifierNoWarning.qml", true);
+}
+
+void TestQmllint::testUnmatchedSignalHandler()
+{
+    const QString output = runQmllint("UnmatchedSignalHandler.qml", false);
+    QVERIFY(output.contains(QString::asprintf(
+            "Warning: no matching signal found for handler \"onClicked\" at %d:%d", 12, 13)));
+    QVERIFY(!output.contains(QStringLiteral("onMouseXChanged")));
+}
+
+void TestQmllint::uiQml()
+{
+    const QString output = runQmllint("FormUser.qml", true);
+    QVERIFY(output.isEmpty());
+}
+
+void TestQmllint::methodInScope()
+{
+    const QString output = runQmllint("MethodInScope.qml", true);
+    QVERIFY(output.isEmpty());
+}
+
+void TestQmllint::importWithPrefix()
+{
+    const QString output = runQmllint("ImportWithPrefix.qml", true);
+    QVERIFY(output.isEmpty());
 }
 
 void TestQmllint::test()
@@ -170,5 +168,24 @@ void TestQmllint::test()
     QCOMPARE(success, isValid);
 }
 
+QString TestQmllint::runQmllint(const QString &fileToLint, bool shouldSucceed)
+{
+    auto qmlImportDir = QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath);
+    QStringList args;
+    args << QStringLiteral("-U") << testFile(fileToLint)
+         << QStringLiteral("-I") << qmlImportDir;
+    QProcess process;
+    process.start(m_qmllintPath, args);
+    [&]() {
+        QVERIFY(process.waitForFinished());
+        QCOMPARE(process.exitStatus(), QProcess::NormalExit);
+        if (shouldSucceed)
+            QCOMPARE(process.exitCode(), 0);
+        else
+            QVERIFY(process.exitCode() != 0);
+    }();
+    return process.readAllStandardError();
+}
+
 QTEST_MAIN(TestQmllint)
 #include "tst_qmllint.moc"
diff --git a/tests/auto/qml/qmlmin/tst_qmlmin.cpp b/tests/auto/qml/qmlmin/tst_qmlmin.cpp
index cae833cd60..79a73299a4 100644
--- a/tests/auto/qml/qmlmin/tst_qmlmin.cpp
+++ b/tests/auto/qml/qmlmin/tst_qmlmin.cpp
@@ -130,6 +130,8 @@ void tst_qmlmin::initTestCase()
     invalidFiles << "tests/auto/qml/qjsengine/script/com/trolltech/syntaxerror/__init__.js";
     invalidFiles << "tests/auto/qml/debugger/qqmlpreview/data/broken.qml";
     invalidFiles << "tests/auto/qml/qqmllanguage/data/fuzzed.2.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/qqmlcomponent/data/AliasToSubcomponentRequiredBase.qml b/tests/auto/qml/qqmlcomponent/data/AliasToSubcomponentRequiredBase.qml
new file mode 100644
index 0000000000..f693cb4c2e
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/AliasToSubcomponentRequiredBase.qml
@@ -0,0 +1,10 @@
+import QtQuick 2.13
+
+Item {
+    property alias i_alias: sub.i
+
+    Item {
+        id: sub
+        required property int i
+    }
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/BaseWithRequired.qml b/tests/auto/qml/qqmlcomponent/data/BaseWithRequired.qml
new file mode 100644
index 0000000000..0ce61c8d9d
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/BaseWithRequired.qml
@@ -0,0 +1,6 @@
+import QtQuick 2.14
+
+Item {
+    id: base
+    required property int i
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/aliasToSubcomponentNotSet.qml b/tests/auto/qml/qqmlcomponent/data/aliasToSubcomponentNotSet.qml
new file mode 100644
index 0000000000..527eb417e5
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/aliasToSubcomponentNotSet.qml
@@ -0,0 +1,4 @@
+import QtQuick 2.13
+
+AliasToSubcomponentRequiredBase {
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/createdFromQml.qml b/tests/auto/qml/qqmlcomponent/data/createdFromQml.qml
new file mode 100644
index 0000000000..60a2077606
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/createdFromQml.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.14
+
+Item {
+    id: root
+    property Item it
+    Component.onCompleted: function() {
+        let component = Qt.createComponent("requiredNotSet.qml", Component.PreferSynchronous, root)
+        console.assert(component.status == Component.Ready)
+        it = component.createObject(component, {i: 42})
+    }
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/createdFromQmlFail.qml b/tests/auto/qml/qqmlcomponent/data/createdFromQmlFail.qml
new file mode 100644
index 0000000000..e09ddcccc1
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/createdFromQmlFail.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.14
+
+Item {
+    id: root
+    property Item it
+    Component.onCompleted: function() {
+        let component = Qt.createComponent("requiredNotSet.qml", Component.PreferSynchronous, root)
+        console.assert(component.status == Component.Ready)
+        root.it = component.createObject(component)
+    }
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/requiredNotSet.qml b/tests/auto/qml/qqmlcomponent/data/requiredNotSet.qml
new file mode 100644
index 0000000000..c0b5d695f1
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/requiredNotSet.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.14
+
+Item {
+    required property int i
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/requiredSetInSameFile.qml b/tests/auto/qml/qqmlcomponent/data/requiredSetInSameFile.qml
new file mode 100644
index 0000000000..76dfcd87e5
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/requiredSetInSameFile.qml
@@ -0,0 +1,6 @@
+import QtQuick 2.14
+
+Item {
+    required property int i
+    i: 42
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/requiredSetLater.qml b/tests/auto/qml/qqmlcomponent/data/requiredSetLater.qml
new file mode 100644
index 0000000000..3b7811e453
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/requiredSetLater.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.14
+
+BaseWithRequired {
+    i: 13
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasAfterSameFile.qml b/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasAfterSameFile.qml
new file mode 100644
index 0000000000..163616bc8a
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasAfterSameFile.qml
@@ -0,0 +1,8 @@
+import QtQuick 2.14
+
+Item {
+    id: withAlias
+    j: 42
+    required property int i
+    property alias j: withAlias.i
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasBeforeSameFile.qml b/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasBeforeSameFile.qml
new file mode 100644
index 0000000000..e59bccf379
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasBeforeSameFile.qml
@@ -0,0 +1,8 @@
+import QtQuick 2.14
+
+Item {
+    id: withAlias
+    required property int i
+    j: 42
+    property alias j: withAlias.i
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasParentFile.qml b/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasParentFile.qml
new file mode 100644
index 0000000000..0bc2f8a7df
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/requiredSetViaAliasParentFile.qml
@@ -0,0 +1,7 @@
+import QtQuick 2.14
+
+BaseWithRequired {
+    id: withAlias
+    property alias j: withAlias.i
+    j: 42
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/requiredSetViaChainedAlias.qml b/tests/auto/qml/qqmlcomponent/data/requiredSetViaChainedAlias.qml
new file mode 100644
index 0000000000..45cf02d3d8
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/requiredSetViaChainedAlias.qml
@@ -0,0 +1,9 @@
+import QtQml 2.12
+
+QtObject {
+    id: stuff
+    required property int x;
+    property alias y: stuff.x
+    property alias z: stuff.y
+    z: 5
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/setViaAliasToSubcomponent.qml b/tests/auto/qml/qqmlcomponent/data/setViaAliasToSubcomponent.qml
new file mode 100644
index 0000000000..2dc182ea82
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/setViaAliasToSubcomponent.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.13
+
+AliasToSubcomponentRequiredBase {
+    i_alias: 42
+}
diff --git a/tests/auto/qml/qqmlcomponent/data/shadowing.qml b/tests/auto/qml/qqmlcomponent/data/shadowing.qml
new file mode 100644
index 0000000000..4d119d8884
--- /dev/null
+++ b/tests/auto/qml/qqmlcomponent/data/shadowing.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.14
+
+BaseWithRequired {
+    property int i: 13
+}
diff --git a/tests/auto/qml/qqmlcomponent/tst_qqmlcomponent.cpp b/tests/auto/qml/qqmlcomponent/tst_qqmlcomponent.cpp
index 79ec507388..b6cc7fd866 100644
--- a/tests/auto/qml/qqmlcomponent/tst_qqmlcomponent.cpp
+++ b/tests/auto/qml/qqmlcomponent/tst_qqmlcomponent.cpp
@@ -121,6 +121,9 @@ private slots:
     void relativeUrl_data();
     void relativeUrl();
     void setDataNoEngineNoSegfault();
+    void testRequiredProperties_data();
+    void testRequiredProperties();
+    void testRequiredPropertiesFromQml();
     void testSetInitialProperties();
 
 private:
@@ -668,35 +671,80 @@ void tst_qqmlcomponent::setDataNoEngineNoSegfault()
     QVERIFY(!c);
 }
 
-void tst_qqmlcomponent::testSetInitialProperties()
+void tst_qqmlcomponent::testRequiredProperties_data()
+{
+    QTest::addColumn<QUrl>("testFile");
+    QTest::addColumn<bool>("shouldSucceed");
+    QTest::addColumn<QString>("errorMsg");
+
+    QTest::addRow("requiredSetViaChainedAlias") << testFileUrl("requiredSetViaChainedAlias.qml") << true << "";
+    QTest::addRow("requiredNotSet") << testFileUrl("requiredNotSet.qml") << false << "Required property i was not initialized";
+    QTest::addRow("requiredSetInSameFile") << testFileUrl("requiredSetInSameFile.qml") << true << "";
+    QTest::addRow("requiredSetViaAlias1") << testFileUrl("requiredSetViaAliasBeforeSameFile.qml") << true << "";
+    QTest::addRow("requiredSetViaAlias2") << testFileUrl("requiredSetViaAliasAfterSameFile.qml") << true << "";
+    QTest::addRow("requiredSetViaAlias3") << testFileUrl("requiredSetViaAliasParentFile.qml") << true << "";
+    QTest::addRow("shadowing") << testFileUrl("shadowing.qml") << false <<  "Required property i was not initialized";
+    QTest::addRow("setLater") << testFileUrl("requiredSetLater.qml") << true << "";
+    QTest::addRow("setViaAliasToSubcomponent") << testFileUrl("setViaAliasToSubcomponent.qml") << true << "";
+    QTest::addRow("aliasToSubcomponentNotSet") << testFileUrl("aliasToSubcomponentNotSet.qml") << false << "It can be set via the alias property i_alias";
+}
+
+
+void tst_qqmlcomponent::testRequiredProperties()
+{
+    QQmlEngine eng;
+    using QScopedObjPointer = QScopedPointer<QObject>;
+    QFETCH(QUrl, testFile);
+    QFETCH(bool, shouldSucceed);
+    QQmlComponent comp(&eng);
+    comp.loadUrl(testFile);
+    QScopedObjPointer obj {comp.create()};
+    if (shouldSucceed)
+        QVERIFY(obj);
+    else {
+        QVERIFY(!obj);
+        QFETCH(QString, errorMsg);
+        QVERIFY(comp.errorString().contains(errorMsg));
+    }
+}
+
+void tst_qqmlcomponent::testRequiredPropertiesFromQml()
 {
     QQmlEngine eng;
     {
-        // JSON based initialization
         QQmlComponent comp(&eng);
-        comp.loadUrl(testFileUrl("allJSONTypes.qml"));
-        QScopedPointer<QObject> obj { comp.beginCreate(eng.rootContext()) };
+        comp.loadUrl(testFileUrl("createdFromQml.qml"));
+        QScopedPointer<QObject> obj { comp.create() };
         QVERIFY(obj);
-        comp.setInitialProperties(obj.get(), QVariantMap {
-                {QLatin1String("i"), 42},
-                {QLatin1String("b"), true},
-                {QLatin1String("d"), 3.1416},
-                {QLatin1String("s"), QLatin1String("hello world")},
-                {QLatin1String("nothing"), QVariant::fromValue(nullptr)}
-        });
-        comp.completeCreate();
-        if (!comp.errors().empty())
-            qDebug() << comp.errorString() << comp.errors();
-        QVERIFY(comp.errors().empty());
-        QCOMPARE(obj->property("i"), 42);
-        QCOMPARE(obj->property("b"), true);
-        QCOMPARE(obj->property("d"), 3.1416);
-        QCOMPARE(obj->property("s"), QLatin1String("hello world"));
-        QCOMPARE(obj->property("nothing"), QVariant::fromValue(nullptr));
+        auto root = qvariant_cast<QQuickItem*>(obj->property("it"));
+        QVERIFY(root);
+        QCOMPARE(root->property("i").toInt(), 42);
     }
     {
-        //  QVariant
+        QTest::ignoreMessage(QtMsgType::QtWarningMsg, QRegularExpression(".*requiredNotSet.qml:4:5: Required property i was not initialized"));
         QQmlComponent comp(&eng);
+        comp.loadUrl(testFileUrl("createdFromQmlFail.qml"));
+        QScopedPointer<QObject> obj { comp.create() };
+        QVERIFY(obj);
+        QCOMPARE(qvariant_cast<QQuickItem *>(obj->property("it")), nullptr);
+    }
+}
+
+struct ComponentWithPublicSetInitial : QQmlComponent
+{
+    using QQmlComponent::QQmlComponent;
+    void setInitialProperties(QObject *o, QVariantMap map)
+    {
+        QQmlComponent::setInitialProperties(o, map);
+    }
+};
+
+void tst_qqmlcomponent::testSetInitialProperties()
+{
+    QQmlEngine eng;
+    {
+        //  QVariant
+        ComponentWithPublicSetInitial comp(&eng);
         comp.loadUrl(testFileUrl("variantBasedInitialization.qml"));
         QScopedPointer<QObject> obj { comp.beginCreate(eng.rootContext()) };
         QVERIFY(obj);
@@ -728,8 +776,6 @@ void tst_qqmlcomponent::testSetInitialProperties()
                                              });
 #undef ASJSON
         comp.completeCreate();
-        if (!comp.errors().empty())
-            qDebug() << comp.errorString() << comp.errors();
         QVERIFY(comp.errors().empty());
         QCOMPARE(obj->property("i"), 42);
         QCOMPARE(obj->property("b"), true);
@@ -751,13 +797,20 @@ void tst_qqmlcomponent::testSetInitialProperties()
 
     }
     {
+        // createWithInitialProperties convenience function
+        QQmlComponent comp(&eng);
+        comp.loadUrl(testFileUrl("requiredNotSet.qml"));
+        QScopedPointer<QObject> obj {comp.createWithInitialProperties( QVariantMap { {QLatin1String("i"), QJsonValue{42}}  })};
+        QVERIFY(obj);
+        QCOMPARE(obj->property("i"), 42);
+    }
+    {
         // createWithInitialProperties: setting a nonexistent property
         QQmlComponent comp(&eng);
         comp.loadUrl(testFileUrl("allJSONTypes.qml"));
         QScopedPointer<QObject> obj {
             comp.createWithInitialProperties(QVariantMap { {"notThePropertiesYoureLookingFor", 42} })
         };
-        qDebug() << comp.errorString();
         QVERIFY(obj);
         QVERIFY(comp.errorString().contains("Could not set property notThePropertiesYoureLookingFor"));
     }
diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 269d90c891..cfdb15304d 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -6357,6 +6357,8 @@ void tst_qqmlecmascript::topLevelGeneratorFunction()
     QQmlComponent component(&engine, testFileUrl("generatorFunction.qml"));
 
     QScopedPointer<QObject> o {component.create()};
+    if (!o)
+        qDebug() << component.errorString();
     QVERIFY(o != nullptr);
 
     // check that generator works correctly in QML
diff --git a/tests/auto/qml/qqmlincubator/data/requiredProperty.qml b/tests/auto/qml/qqmlincubator/data/requiredProperty.qml
new file mode 100644
index 0000000000..9e355dce72
--- /dev/null
+++ b/tests/auto/qml/qqmlincubator/data/requiredProperty.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.12
+
+Item {
+    required property int requiredProperty
+}
diff --git a/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp b/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
index 8e25079703..756b3b1d7c 100644
--- a/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
+++ b/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
@@ -70,6 +70,7 @@ private slots:
     void selfDelete();
     void contextDelete();
     void garbageCollection();
+    void requiredProperties();
 
 private:
     QQmlIncubationController controller;
@@ -1174,6 +1175,44 @@ void tst_qqmlincubator::garbageCollection()
     QVERIFY(weakIncubatorRef.isNullOrUndefined());
 }
 
+void tst_qqmlincubator::requiredProperties()
+{
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperty.qml"));
+        QVERIFY(component.isReady());
+        // forceCompletion immediately after creating an asynchronous object completes it
+        QQmlIncubator incubator;
+        incubator.setInitialProperties({{"requiredProperty", 42}});
+        QVERIFY(incubator.isNull());
+        component.create(incubator);
+        QVERIFY(incubator.isLoading());
+
+        incubator.forceCompletion();
+
+        QVERIFY(incubator.isReady());
+        QVERIFY(incubator.object() != nullptr);
+        QCOMPARE(incubator.object()->property("requiredProperty").toInt(), 42);
+
+        delete incubator.object();
+    }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperty.qml"));
+        QVERIFY(component.isReady());
+        // forceCompletion immediately after creating an asynchronous object completes it
+        QQmlIncubator incubator;
+        QVERIFY(incubator.isNull());
+        component.create(incubator);
+        QVERIFY(incubator.isLoading());
+
+        incubator.forceCompletion();
+
+        QVERIFY(incubator.isError());
+        auto error = incubator.errors().first();
+        QVERIFY(error.description().contains(QLatin1String("Required property requiredProperty was not initialized")));
+        QVERIFY(incubator.object() == nullptr);
+    }
+}
+
 QTEST_MAIN(tst_qqmlincubator)
 
 #include "tst_qqmlincubator.moc"
diff --git a/tests/auto/qml/qqmllanguage/data/fakeDotProperty.errors.txt b/tests/auto/qml/qqmllanguage/data/fakeDotProperty.errors.txt
index 30748234bc..5a144f2db5 100644
--- a/tests/auto/qml/qqmllanguage/data/fakeDotProperty.errors.txt
+++ b/tests/auto/qml/qqmllanguage/data/fakeDotProperty.errors.txt
@@ -1 +1 @@
-3:5:Invalid grouped property access
+3:5:Invalid grouped property access: Property "value" with primitive type "int".
diff --git a/tests/auto/qml/qqmllanguage/data/invalidGroupedProperty.2.errors.txt b/tests/auto/qml/qqmllanguage/data/invalidGroupedProperty.2.errors.txt
index 810fd31b41..5deec4ccf9 100644
--- a/tests/auto/qml/qqmllanguage/data/invalidGroupedProperty.2.errors.txt
+++ b/tests/auto/qml/qqmllanguage/data/invalidGroupedProperty.2.errors.txt
@@ -1 +1 @@
-5:5:Invalid grouped property access
+5:5:Invalid grouped property access: Property "o" with primitive type "int".
diff --git a/tests/auto/qml/qqmllanguage/data/objectValueTypeProperty.errors.txt b/tests/auto/qml/qqmllanguage/data/objectValueTypeProperty.errors.txt
index 945dacf8ab..043f714636 100644
--- a/tests/auto/qml/qqmllanguage/data/objectValueTypeProperty.errors.txt
+++ b/tests/auto/qml/qqmllanguage/data/objectValueTypeProperty.errors.txt
@@ -1 +1 @@
-4:18:Can not assign value of type "int" to property "x", expecting an object
+4:18:Can not assign value of type "MyTypeObject" to property "x", expecting "int"
diff --git a/tests/auto/qml/qqmllanguage/data/requiredProperties.1.qml b/tests/auto/qml/qqmllanguage/data/requiredProperties.1.qml
new file mode 100644
index 0000000000..dac43c6d88
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.1.qml
@@ -0,0 +1,8 @@
+import QtQuick 2.13
+Item {
+     property var required: 32  // required is still allowed as an identifier for properties
+     function f(required) { // for javascript
+         required = required + required;
+         console.log(required);
+    }
+}
diff --git a/tests/auto/qml/qqmllanguage/data/requiredProperties.2.qml b/tests/auto/qml/qqmllanguage/data/requiredProperties.2.qml
new file mode 100644
index 0000000000..4c12c7b602
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.2.qml
@@ -0,0 +1,4 @@
+import QtQuick 2.13
+Item {
+     required property int test: 42 // cannot specify value for required property
+}
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..534322215f
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/requiredProperties.3.qml
@@ -0,0 +1,4 @@
+import QtQuick 2.13
+Item {
+    default required property int test // cannot have required default property
+}
diff --git a/tests/auto/qml/qqmllanguage/testtypes.cpp b/tests/auto/qml/qqmllanguage/testtypes.cpp
index 6956533196..226a78b960 100644
--- a/tests/auto/qml/qqmllanguage/testtypes.cpp
+++ b/tests/auto/qml/qqmllanguage/testtypes.cpp
@@ -57,7 +57,7 @@ void registerTypes()
     qmlRegisterType<MyNamespace::MySecondNamespacedType>("Test",1,0,"MySecondNamespacedType");
     qmlRegisterUncreatableMetaObject(MyNamespace::staticMetaObject, "Test", 1, 0, "MyNamespace", "Access to enums & flags only");
     qmlRegisterType<MyParserStatus>("Test",1,0,"MyParserStatus");
-    qmlRegisterType<MyGroupedObject>();
+    qmlRegisterAnonymousType<MyGroupedObject>("Test", 1);
     qmlRegisterType<MyRevisionedClass>("Test",1,0,"MyRevisionedClass");
     qmlRegisterType<MyRevisionedClass,1>("Test",1,1,"MyRevisionedClass");
     qmlRegisterType<MyRevisionedIllegalOverload>("Test",1,0,"MyRevisionedIllegalOverload");
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 8adacd8829..674da19afc 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -132,6 +132,7 @@ private slots:
     void autoComponentCreation();
     void autoComponentCreationInGroupProperty();
     void propertyValueSource();
+    void requiredProperty();
     void attachedProperties();
     void dynamicObjects();
     void customVariantTypes();
@@ -1634,6 +1635,25 @@ void tst_qqmllanguage::propertyValueSource()
     }
 }
 
+void tst_qqmllanguage::requiredProperty()
+{
+    QQmlEngine engine;
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.1.qml"));
+        VERIFY_ERRORS(0);
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(object);
+    }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.2.qml"));
+        QVERIFY(!component.errors().empty());
+    }
+    {
+        QQmlComponent component(&engine, testFileUrl("requiredProperties.3.qml"));
+        QVERIFY(!component.errors().empty());
+    }
+}
+
 void tst_qqmllanguage::attachedProperties()
 {
     QQmlComponent component(&engine, testFileUrl("attachedProperties.qml"));
diff --git a/tests/auto/qml/qqmllistreference/tst_qqmllistreference.cpp b/tests/auto/qml/qqmllistreference/tst_qqmllistreference.cpp
index 199f7bc7e4..8efaedf5b5 100644
--- a/tests/auto/qml/qqmllistreference/tst_qqmllistreference.cpp
+++ b/tests/auto/qml/qqmllistreference/tst_qqmllistreference.cpp
@@ -87,7 +87,7 @@ public:
 void tst_qqmllistreference::initTestCase()
 {
     QQmlDataTest::initTestCase();
-    qmlRegisterType<TestType>();
+    qmlRegisterAnonymousType<TestType>("Test", 1);
 }
 
 void tst_qqmllistreference::qmllistreference()
diff --git a/tests/auto/qml/qqmlproperty/data/aliasToBinding.qml b/tests/auto/qml/qqmlproperty/data/aliasToBinding.qml
new file mode 100644
index 0000000000..54f9e3f944
--- /dev/null
+++ b/tests/auto/qml/qqmlproperty/data/aliasToBinding.qml
@@ -0,0 +1,23 @@
+import QtQuick 2.7
+
+Item {
+    id: _window
+    property bool userFontStrikeout: true
+
+    Component.onCompleted: {
+            _box.font.strikeout = Qt.binding(function() { return _window.userFontStrikeout; });
+    }
+
+    Rectangle {
+        id: _box
+        width: 100
+        height: 100
+        property alias font: _text.font
+
+        Text {
+            id: _text
+            anchors.fill: parent
+            text: "Text"
+        }
+    }
+}
diff --git a/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp b/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
index 67da768f73..ad901c4eba 100644
--- a/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
+++ b/tests/auto/qml/qqmlproperty/tst_qqmlproperty.cpp
@@ -150,6 +150,8 @@ private slots:
     void floatToStringPrecision();
 
     void copy();
+
+    void bindingToAlias();
 private:
     QQmlEngine engine;
 };
@@ -2123,6 +2125,15 @@ void tst_qqmlproperty::initTestCase()
     qmlRegisterType<MyContainer>("Test",1,0,"MyContainer");
 }
 
+// QTBUG-60908
+void tst_qqmlproperty::bindingToAlias()
+{
+    QQmlEngine engine;
+    QQmlComponent component(&engine, testFileUrl("aliasToBinding.qml"));
+    QScopedPointer<QObject> o(component.create());
+    QVERIFY(!o.isNull());
+}
+
 QTEST_MAIN(tst_qqmlproperty)
 
 #include "tst_qqmlproperty.moc"
diff --git a/tests/auto/qml/qqmlvaluetypes/tst_qqmlvaluetypes.cpp b/tests/auto/qml/qqmlvaluetypes/tst_qqmlvaluetypes.cpp
index 8a602a0356..a55da25a91 100644
--- a/tests/auto/qml/qqmlvaluetypes/tst_qqmlvaluetypes.cpp
+++ b/tests/auto/qml/qqmlvaluetypes/tst_qqmlvaluetypes.cpp
@@ -97,6 +97,7 @@ private slots:
     void enumerableProperties();
     void enumProperties();
     void scarceTypes();
+    void nonValueTypes();
 
 private:
     QQmlEngine engine;
@@ -1844,6 +1845,16 @@ void tst_qqmlvaluetypes::scarceTypes()
     QCOMPARE(QByteArray(pixmapValue->vtable()->className), QByteArray("VariantObject"));
 }
 
+#define CHECK_TYPE_IS_NOT_VALUETYPE(Type, typeId, cppType) \
+    QVERIFY(!QQmlValueTypeFactory::isValueType(QMetaType::Type));
+
+void tst_qqmlvaluetypes::nonValueTypes()
+{
+    CHECK_TYPE_IS_NOT_VALUETYPE(UnknownType, 0, void)
+    QT_FOR_EACH_STATIC_PRIMITIVE_TYPE(CHECK_TYPE_IS_NOT_VALUETYPE);
+}
+
+#undef CHECK_TYPE_IS_NOT_VALUETYPE
 
 QTEST_MAIN(tst_qqmlvaluetypes)
 
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index 08149a1786..7c26c22217 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -389,7 +389,7 @@ void tst_QQuickListView::init()
         m_view = nullptr;
     }
 #endif
-    qmlRegisterType<QAbstractItemModel>();
+    qmlRegisterAnonymousType<QAbstractItemModel>("Proxy", 1);
     qmlRegisterType<ProxyTestInnerModel>("Proxy", 1, 0, "ProxyTestInnerModel");
     qmlRegisterType<QSortFilterProxyModel>("Proxy", 1, 0, "QSortFilterProxyModel");
 }
diff --git a/tests/auto/quick/qquickloader/data/RequiredPropertyValuesComponent.qml b/tests/auto/quick/qquickloader/data/RequiredPropertyValuesComponent.qml
new file mode 100644
index 0000000000..7bb21e8b93
--- /dev/null
+++ b/tests/auto/quick/qquickloader/data/RequiredPropertyValuesComponent.qml
@@ -0,0 +1,8 @@
+import QtQuick 2.0
+
+Item {
+    id: behaviorCounter
+    required property int i
+    required property string s
+
+}
diff --git a/tests/auto/quick/qquickloader/data/initialPropertyValues.10.qml b/tests/auto/quick/qquickloader/data/initialPropertyValues.10.qml
new file mode 100644
index 0000000000..4728346ca1
--- /dev/null
+++ b/tests/auto/quick/qquickloader/data/initialPropertyValues.10.qml
@@ -0,0 +1,20 @@
+import QtQuick 2.0
+
+Item {
+    id: root
+    property int i: 0
+    property string s: ""
+
+    Loader {
+        id: loader
+        objectName: "loader"
+        onLoaded: {
+            root.i = loader.item.i;         // should be 42
+            root.s = loader.item.s; // should be 11
+        }
+    }
+
+    Component.onCompleted: {
+        loader.setSource("RequiredPropertyValuesComponent.qml", {"i": 42});
+    }
+}
diff --git a/tests/auto/quick/qquickloader/data/initialPropertyValues.9.qml b/tests/auto/quick/qquickloader/data/initialPropertyValues.9.qml
new file mode 100644
index 0000000000..5d6e3171a0
--- /dev/null
+++ b/tests/auto/quick/qquickloader/data/initialPropertyValues.9.qml
@@ -0,0 +1,20 @@
+import QtQuick 2.0
+
+Item {
+    id: root
+    property int i: 0
+    property string s: ""
+
+    Loader {
+        id: loader
+        objectName: "loader"
+        onLoaded: {
+            root.i = loader.item.i;         // should be 42
+            root.s = loader.item.s; // should be 11
+        }
+    }
+
+    Component.onCompleted: {
+        loader.setSource("RequiredPropertyValuesComponent.qml", {"i": 42, "s": "hello world"});
+    }
+}
diff --git a/tests/auto/quick/qquickloader/tst_qquickloader.cpp b/tests/auto/quick/qquickloader/tst_qquickloader.cpp
index fbdd87905b..da923d4d41 100644
--- a/tests/auto/quick/qquickloader/tst_qquickloader.cpp
+++ b/tests/auto/quick/qquickloader/tst_qquickloader.cpp
@@ -681,6 +681,16 @@ void tst_QQuickLoader::initialPropertyValues_data()
             << QStringList()
             << (QStringList() << "initialValue")
             << (QVariantList() << 6);
+
+    QTest::newRow("ensure required properties are set correctly") << testFileUrl("initialPropertyValues.9.qml")
+            << QStringList()
+            << (QStringList() << "i" << "s")
+            << (QVariantList() << 42 << QLatin1String("hello world"));
+
+    QTest::newRow("required properties only partially set =") << testFileUrl("initialPropertyValues.10.qml")
+            << (QStringList() << QString(testFileUrl("RequiredPropertyValuesComponent.qml").toString() +  QLatin1String(":6:5: Required property s was not initialized")))
+            << (QStringList() << "i" << "s")
+            << (QVariantList() << 0 << QLatin1String(""));
 }
 
 void tst_QQuickLoader::initialPropertyValues()
diff --git a/tools/qmlcachegen/Qt5QuickCompilerConfig.cmake.in b/tools/qmlcachegen/Qt5QuickCompilerConfig.cmake.in
index 75fbb0fcf3..baa437a947 100644
--- a/tools/qmlcachegen/Qt5QuickCompilerConfig.cmake.in
+++ b/tools/qmlcachegen/Qt5QuickCompilerConfig.cmake.in
@@ -50,13 +50,9 @@ but not all the files it references.
 
         get_filename_component(input_resource ${_resource} ABSOLUTE)
 
-        execute_process(COMMAND ${compiler_path} -filter-resource-file ${input_resource} -o ${new_resource_file} OUTPUT_VARIABLE remaining_files)
-        if(remaining_files)
-            list(APPEND filtered_rcc_files ${new_resource_file})
-            list(APPEND loader_flags \"--resource-file-mapping=${_resource}=${new_resource_file}\")
-        else()
-            list(APPEND loader_flags \"--resource-file-mapping=${_resource}\")
-        endif()
+        configure_file(${input_resource} ${new_resource_file} COPYONLY)
+        list(APPEND filtered_rcc_files ${new_resource_file})
+        list(APPEND loader_flags \"--resource-file-mapping=${_resource}=${new_resource_file}\")
 
         set(rcc_file_with_compilation_units)
 
diff --git a/tools/qmlcachegen/generateloader.cpp b/tools/qmlcachegen/generateloader.cpp
index 1c8a5a016a..71286137eb 100644
--- a/tools/qmlcachegen/generateloader.cpp
+++ b/tools/qmlcachegen/generateloader.cpp
@@ -100,228 +100,6 @@ QString symbolNamespaceForPath(const QString &relativePath)
     return mangledIdentifier(symbol);
 }
 
-struct VirtualDirectoryEntry
-{
-    QString name;
-    QVector<VirtualDirectoryEntry*> dirEntries;
-    int firstChildIndex = -1; // node index inside generated data
-    bool isDirectory = true;
-
-    VirtualDirectoryEntry()
-    {}
-
-    ~VirtualDirectoryEntry()
-    {
-        qDeleteAll(dirEntries);
-    }
-
-    VirtualDirectoryEntry *append(const QString &name)
-    {
-        for (QVector<VirtualDirectoryEntry*>::Iterator it = dirEntries.begin(), end = dirEntries.end();
-             it != end; ++it) {
-            if ((*it)->name == name)
-                return *it;
-        }
-
-        VirtualDirectoryEntry *subEntry = new VirtualDirectoryEntry;
-        subEntry->name = name;
-        dirEntries.append(subEntry);
-        return subEntry;
-    }
-
-    void appendEmptyFile(const QString &name)
-    {
-        VirtualDirectoryEntry *subEntry = new VirtualDirectoryEntry;
-        subEntry->name = name;
-        subEntry->isDirectory = false;
-        dirEntries.append(subEntry);
-    }
-
-    bool isEmpty() const { return dirEntries.isEmpty(); }
-};
-
-struct DataStream
-{
-    DataStream(QVector<unsigned char > *data = nullptr)
-        : data(data)
-    {}
-
-    qint64 currentOffset() const { return data->size(); }
-
-    DataStream &operator<<(quint16 value)
-    {
-        unsigned char d[2];
-        qToBigEndian(value, d);
-        data->append(d[0]);
-        data->append(d[1]);
-        return *this;
-    }
-    DataStream &operator<<(quint32 value)
-    {
-        unsigned char d[4];
-        qToBigEndian(value, d);
-        data->append(d[0]);
-        data->append(d[1]);
-        data->append(d[2]);
-        data->append(d[3]);
-        return *this;
-    }
-private:
-    QVector<unsigned char> *data;
-};
-
-static bool resource_sort_order(const VirtualDirectoryEntry *lhs, const VirtualDirectoryEntry *rhs)
-{
-    return qt_hash(lhs->name) < qt_hash(rhs->name);
-}
-
-struct ResourceTree
-{
-    ResourceTree()
-    {}
-
-    void serialize(VirtualDirectoryEntry &root, QVector<unsigned char> *treeData, QVector<unsigned char> *stringData)
-    {
-        treeStream = DataStream(treeData);
-        stringStream = DataStream(stringData);
-
-        QStack<VirtualDirectoryEntry *> directories;
-
-        {
-            directories.push(&root);
-            while (!directories.isEmpty()) {
-                VirtualDirectoryEntry *entry = directories.pop();
-                registerString(entry->name);
-                if (entry->isDirectory)
-                    directories << entry->dirEntries;
-            }
-        }
-
-        {
-            quint32 currentDirectoryIndex = 1;
-            directories.push(&root);
-            while (!directories.isEmpty()) {
-                VirtualDirectoryEntry *entry = directories.pop();
-                entry->firstChildIndex = currentDirectoryIndex;
-                currentDirectoryIndex += entry->dirEntries.count();
-                std::sort(entry->dirEntries.begin(), entry->dirEntries.end(), resource_sort_order);
-
-                for (QVector<VirtualDirectoryEntry*>::ConstIterator child = entry->dirEntries.constBegin(), end = entry->dirEntries.constEnd();
-                     child != end; ++child) {
-                    if ((*child)->isDirectory)
-                        directories << *child;
-                }
-            }
-        }
-
-        {
-            writeTreeEntry(&root);
-            directories.push(&root);
-            while (!directories.isEmpty()) {
-                VirtualDirectoryEntry *entry = directories.pop();
-
-                for (QVector<VirtualDirectoryEntry*>::ConstIterator child = entry->dirEntries.constBegin(), end = entry->dirEntries.constEnd();
-                     child != end; ++child) {
-                    writeTreeEntry(*child);
-                    if ((*child)->isDirectory)
-                        directories << (*child);
-                }
-            }
-        }
-    }
-
-private:
-    DataStream treeStream;
-    DataStream stringStream;
-    QHash<QString, qint64> stringOffsets;
-
-    void registerString(const QString &name)
-    {
-        if (stringOffsets.contains(name))
-            return;
-        const qint64 offset = stringStream.currentOffset();
-        stringOffsets.insert(name, offset);
-
-        stringStream << quint16(name.length())
-                     << quint32(qt_hash(name));
-        for (int i = 0; i < name.length(); ++i)
-            stringStream << quint16(name.at(i).unicode());
-    }
-
-    void writeTreeEntry(VirtualDirectoryEntry *entry)
-    {
-        treeStream << quint32(stringOffsets.value(entry->name))
-                   << quint16(entry->isDirectory ? 0x2 : 0x0); // Flags: File or Directory
-
-        if (entry->isDirectory) {
-            treeStream << quint32(entry->dirEntries.count())
-                       << quint32(entry->firstChildIndex);
-        } else {
-            treeStream << quint16(QLocale::AnyCountry) << quint16(QLocale::C)
-                       << quint32(0x0);
-        }
-    }
-};
-
-static QByteArray generateResourceDirectoryTree(QTextStream &code, const QStringList &qrcFiles,
-                                                const QStringList &sortedRetainedFiles)
-{
-    QByteArray call;
-    if (qrcFiles.isEmpty())
-        return call;
-
-    VirtualDirectoryEntry resourceDirs;
-    resourceDirs.name = QStringLiteral("/");
-
-    for (const QString &entry : qrcFiles) {
-        const QStringList segments = entry.split(QLatin1Char('/'), QString::SkipEmptyParts);
-
-        VirtualDirectoryEntry *dirEntry = &resourceDirs;
-
-        for (int i = 0; i < segments.count() - 1; ++i)
-            dirEntry = dirEntry->append(segments.at(i));
-        if (!std::binary_search(sortedRetainedFiles.begin(), sortedRetainedFiles.end(), entry))
-            dirEntry->appendEmptyFile(segments.last());
-    }
-
-    if (resourceDirs.isEmpty())
-        return call;
-
-    QVector<unsigned char> names;
-    QVector<unsigned char> tree;
-    ResourceTree().serialize(resourceDirs, &tree, &names);
-
-    code << "static const unsigned char qt_resource_tree[] = {\n";
-    for (int i = 0; i < tree.count(); ++i) {
-        code << uint(tree.at(i));
-        if (i < tree.count() - 1)
-            code << ',';
-        if (i % 16 == 0)
-            code << '\n';
-    }
-    code << "};\n";
-
-    code << "static const unsigned char qt_resource_names[] = {\n";
-    for (int i = 0; i < names.count(); ++i) {
-        code << uint(names.at(i));
-        if (i < names.count() - 1)
-            code << ',';
-        if (i % 16 == 0)
-            code << '\n';
-    }
-    code << "};\n";
-
-    code << "static const unsigned char qt_resource_empty_payout[] = { 0, 0, 0, 0, 0 };\n";
-
-    code << "QT_BEGIN_NAMESPACE\n";
-    code << "extern Q_CORE_EXPORT bool qRegisterResourceData(int, const unsigned char *, const unsigned char *, const unsigned char *);\n";
-    code << "QT_END_NAMESPACE\n";
-
-    call = "QT_PREPEND_NAMESPACE(qRegisterResourceData)(/*version*/0x01, qt_resource_tree, qt_resource_names, qt_resource_empty_payout);\n";
-
-    return call;
-}
-
 static QString qtResourceNameForFile(const QString &fileName)
 {
     QFileInfo fi(fileName);
@@ -332,9 +110,8 @@ static QString qtResourceNameForFile(const QString &fileName)
     return name;
 }
 
-bool generateLoader(const QStringList &compiledFiles, const QStringList &sortedRetainedFiles,
-                    const QString &outputFileName, const QStringList &resourceFileMappings,
-                    QString *errorString)
+bool generateLoader(const QStringList &compiledFiles, const QString &outputFileName,
+                    const QStringList &resourceFileMappings, QString *errorString)
 {
     QByteArray generatedLoaderCode;
 
@@ -345,9 +122,6 @@ bool generateLoader(const QStringList &compiledFiles, const QStringList &sortedR
         stream << "#include <QtCore/qurl.h>\n";
         stream << "\n";
 
-        QByteArray resourceRegisterCall = generateResourceDirectoryTree(stream, compiledFiles,
-                                                                        sortedRetainedFiles);
-
         stream << "namespace QmlCacheGeneratedCode {\n";
         for (int i = 0; i < compiledFiles.count(); ++i) {
             const QString compiledFile = compiledFiles.at(i);
@@ -385,9 +159,6 @@ bool generateLoader(const QStringList &compiledFiles, const QStringList &sortedR
         stream << "    registration.lookupCachedQmlUnit = &lookupCachedUnit;\n";
         stream << "    QQmlPrivate::qmlregister(QQmlPrivate::QmlUnitCacheHookRegistration, &registration);\n";
 
-        if (!resourceRegisterCall.isEmpty())
-            stream << resourceRegisterCall;
-
         stream << "}\n\n";
         stream << "Registry::~Registry() {\n";
         stream << "    QQmlPrivate::qmlunregister(QQmlPrivate::QmlUnitCacheHookRegistration, quintptr(&lookupCachedUnit));\n";
diff --git a/tools/qmlcachegen/qmlcachegen.cpp b/tools/qmlcachegen/qmlcachegen.cpp
index ac9cf039d3..41171b3f07 100644
--- a/tools/qmlcachegen/qmlcachegen.cpp
+++ b/tools/qmlcachegen/qmlcachegen.cpp
@@ -47,10 +47,8 @@
 
 using namespace QQmlJS;
 
-int filterResourceFile(const QString &input, const QString &output);
-bool generateLoader(const QStringList &compiledFiles, const QStringList &retainedFiles,
-                    const QString &output, const QStringList &resourceFileMappings,
-                    QString *errorString);
+bool generateLoader(const QStringList &compiledFiles, const QString &output,
+                    const QStringList &resourceFileMappings, QString *errorString);
 QString symbolNamespaceForPath(const QString &relativePath);
 
 QSet<QString> illegalNames;
@@ -419,14 +417,10 @@ int main(int argc, char **argv)
     parser.addHelpOption();
     parser.addVersionOption();
 
-    QCommandLineOption filterResourceFileOption(QStringLiteral("filter-resource-file"), QCoreApplication::translate("main", "Filter out QML/JS files from a resource file that can be cached ahead of time instead"));
-    parser.addOption(filterResourceFileOption);
     QCommandLineOption resourceFileMappingOption(QStringLiteral("resource-file-mapping"), QCoreApplication::translate("main", "Path from original resource file to new one"), QCoreApplication::translate("main", "old-name:new-name"));
     parser.addOption(resourceFileMappingOption);
     QCommandLineOption resourceOption(QStringLiteral("resource"), QCoreApplication::translate("main", "Qt resource file that might later contain one of the compiled files"), QCoreApplication::translate("main", "resource-file-name"));
     parser.addOption(resourceOption);
-    QCommandLineOption retainOption(QStringLiteral("retain"), QCoreApplication::translate("main", "Qt resource file the contents of which should not be replaced by empty stubs"), QCoreApplication::translate("main", "resource-file-name"));
-    parser.addOption(retainOption);
     QCommandLineOption resourcePathOption(QStringLiteral("resource-path"), QCoreApplication::translate("main", "Qt resource file path corresponding to the file being compiled"), QCoreApplication::translate("main", "resource-path"));
     parser.addOption(resourcePathOption);
 
@@ -468,18 +462,11 @@ int main(int argc, char **argv)
     if (outputFileName.isEmpty())
         outputFileName = inputFile + QLatin1Char('c');
 
-    if (parser.isSet(filterResourceFileOption)) {
-        return filterResourceFile(inputFile, outputFileName);
-    }
-
     if (target == GenerateLoader) {
         ResourceFileMapper mapper(sources);
-        ResourceFileMapper retain(parser.values(retainOption));
 
         Error error;
-        QStringList retainedFiles = retain.qmlCompilerFiles();
-        std::sort(retainedFiles.begin(), retainedFiles.end());
-        if (!generateLoader(mapper.qmlCompilerFiles(), retainedFiles, outputFileName,
+        if (!generateLoader(mapper.qmlCompilerFiles(), outputFileName,
                             parser.values(resourceFileMappingOption), &error.message)) {
             error.augment(QLatin1String("Error generating loader stub: ")).print();
             return EXIT_FAILURE;
diff --git a/tools/qmlcachegen/qmlcachegen.pro b/tools/qmlcachegen/qmlcachegen.pro
index bee0b9a37e..910cb657d7 100644
--- a/tools/qmlcachegen/qmlcachegen.pro
+++ b/tools/qmlcachegen/qmlcachegen.pro
@@ -4,7 +4,6 @@ QT = qmldevtools-private
 DEFINES += QT_NO_CAST_TO_ASCII QT_NO_CAST_FROM_ASCII
 
 SOURCES = qmlcachegen.cpp \
-    resourcefilter.cpp \
     generateloader.cpp \
     resourcefilemapper.cpp
 TARGET = qmlcachegen
diff --git a/tools/qmlcachegen/qtquickcompiler.prf b/tools/qmlcachegen/qtquickcompiler.prf
index 2f98aadefe..0129122157 100644
--- a/tools/qmlcachegen/qtquickcompiler.prf
+++ b/tools/qmlcachegen/qtquickcompiler.prf
@@ -16,20 +16,6 @@ defineReplace(qmlCacheResourceFileOutputName) {
     return($${name})
 }
 
-defineTest(qtQuickRetainSources) {
-    for(retainedRes, QTQUICK_COMPILER_RETAINED_RESOURCES) {
-        equals(1, $$retainedRes): return(true)
-    }
-    return(false)
-}
-
-defineTest(qtQuickSkippedResourceFile) {
-    for(skippedRes, QTQUICK_COMPILER_SKIPPED_RESOURCES) {
-        equals(1, $$skippedRes): return(true)
-    }
-    return(false)
-}
-
 # Flatten RESOURCES that may contain individual files or objects
 load(resources)
 
@@ -37,29 +23,14 @@ NEWRESOURCES =
 QMLCACHE_RESOURCE_FILES =
 
 for(res, RESOURCES) {
-    qtQuickSkippedResourceFile($$res) {
-        NEWRESOURCES += $$res
-        next()
-    }
-
     absRes = $$absolute_path($$res, $$_PRO_FILE_PWD_)
     rccContents = $$system($$QMAKE_RCC_DEP -list $$system_quote($$absRes),lines)
     contains(rccContents,.*\\.js$)|contains(rccContents,.*\\.qml$)|contains(rccContents,.*\\.mjs$) {
         new_resource = $$qmlCacheResourceFileOutputName($$res)
         mkpath($$dirname(new_resource))
-        qtQuickRetainSources($$res) {
-            NEWRESOURCES += $$res
-            QMLCACHE_LOADER_FLAGS += --retain=$$shell_quote($$absRes)
-        } else {
-            remaining_files = $$system($$QML_CACHEGEN_FILTER -filter-resource-file \
-                    -o $$system_quote($$new_resource) $$system_quote($$absRes),lines)
-            !isEmpty(remaining_files) {
-                NEWRESOURCES += $$new_resource
-                QMLCACHE_LOADER_FLAGS += --resource-file-mapping=$$shell_quote($$absRes=$$new_resource)
-            } else {
-                QMLCACHE_LOADER_FLAGS += --resource-file-mapping=$$shell_quote($$absRes)
-            }
-        }
+        system($$QMAKE_QMAKE -install qinstall $$system_quote($$absRes) $$system_quote($$new_resource))
+        NEWRESOURCES += $$new_resource
+        QMLCACHE_LOADER_FLAGS += --resource-file-mapping=$$shell_quote($$absRes=$$new_resource)
 
         QMLCACHE_RESOURCE_FILES += $$absRes
 
diff --git a/tools/qmlcachegen/resourcefilter.cpp b/tools/qmlcachegen/resourcefilter.cpp
deleted file mode 100644
index 3ad6e9ca0d..0000000000
--- a/tools/qmlcachegen/resourcefilter.cpp
+++ /dev/null
@@ -1,185 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:GPL-EXCEPT$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 3 as published by the Free Software
-** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#include <QString>
-#include <QXmlStreamReader>
-#include <QFile>
-#include <QDir>
-
-int filterResourceFile(const QString &input, const QString &output)
-{
-    enum State {
-        InitialState,
-        InRCC,
-        InResource,
-        InFile
-    };
-    State state = InitialState;
-
-    QString prefix;
-    QString currentFileName;
-    QXmlStreamAttributes fileAttributes;
-
-    QFile file(input);
-    if (!file.open(QIODevice::ReadOnly)) {
-        fprintf(stderr, "Cannot open %s for reading.\n", qPrintable(input));
-        return EXIT_FAILURE;
-    }
-
-    QDir inputDirectory = QFileInfo(file).absoluteDir();
-    QDir outputDirectory = QFileInfo(output).absoluteDir();
-
-    QString outputString;
-    QXmlStreamWriter writer(&outputString);
-    writer.setAutoFormatting(true);
-
-    QStringList remainingFiles;
-
-    QXmlStreamReader reader(&file);
-    while (!reader.atEnd()) {
-        switch (reader.readNext()) {
-        case QXmlStreamReader::StartDocument: {
-            QStringRef version = reader.documentVersion();
-            if (!version.isEmpty())
-                writer.writeStartDocument(version.toString());
-            else
-                writer.writeStartDocument();
-            break;
-        }
-        case QXmlStreamReader::EndDocument:
-            writer.writeEndDocument();
-            break;
-        case QXmlStreamReader::StartElement:
-            if (reader.name() == QStringLiteral("RCC")) {
-                if (state != InitialState) {
-                    fprintf(stderr, "Unexpected RCC tag in line %d\n", int(reader.lineNumber()));
-                    return EXIT_FAILURE;
-                }
-                state = InRCC;
-            } else if (reader.name() == QStringLiteral("qresource")) {
-                if (state != InRCC) {
-                    fprintf(stderr, "Unexpected qresource tag in line %d\n", int(reader.lineNumber()));
-                    return EXIT_FAILURE;
-                }
-                state = InResource;
-                QXmlStreamAttributes attributes = reader.attributes();
-                if (attributes.hasAttribute(QStringLiteral("prefix")))
-                    prefix = attributes.value(QStringLiteral("prefix")).toString();
-                if (!prefix.startsWith(QLatin1Char('/')))
-                    prefix.prepend(QLatin1Char('/'));
-                if (!prefix.endsWith(QLatin1Char('/')))
-                    prefix.append(QLatin1Char('/'));
-            } else if (reader.name() == QStringLiteral("file")) {
-                if (state != InResource) {
-                    fprintf(stderr, "Unexpected file tag in line %d\n", int(reader.lineNumber()));
-                    return EXIT_FAILURE;
-                }
-                state = InFile;
-                fileAttributes = reader.attributes();
-                continue;
-            }
-            writer.writeStartElement(reader.name().toString());
-            writer.writeAttributes(reader.attributes());
-            continue;
-
-        case QXmlStreamReader::EndElement:
-            if (reader.name() == QStringLiteral("file")) {
-                if (state != InFile) {
-                    fprintf(stderr, "Unexpected end of file tag in line %d\n", int(reader.lineNumber()));
-                    return EXIT_FAILURE;
-                }
-                state = InResource;
-                continue;
-            } else if (reader.name() == QStringLiteral("qresource")) {
-                if (state != InResource) {
-                    fprintf(stderr, "Unexpected end of qresource tag in line %d\n", int(reader.lineNumber()));
-                    return EXIT_FAILURE;
-                }
-                state = InRCC;
-            } else if (reader.name() == QStringLiteral("RCC")) {
-                if (state != InRCC) {
-                    fprintf(stderr, "Unexpected end of RCC tag in line %d\n", int(reader.lineNumber()));
-                    return EXIT_FAILURE;
-                }
-                state = InitialState;
-            }
-            writer.writeEndElement();
-            continue;
-
-        case QXmlStreamReader::Characters:
-            if (reader.isWhitespace())
-                break;
-            if (state != InFile)
-                return EXIT_FAILURE;
-            currentFileName = reader.text().toString();
-            if (currentFileName.isEmpty())
-                continue;
-
-            if (!currentFileName.endsWith(QStringLiteral(".qml"))
-                && !currentFileName.endsWith(QStringLiteral(".js"))
-                && !currentFileName.endsWith(QStringLiteral(".mjs"))) {
-                writer.writeStartElement(QStringLiteral("file"));
-
-                if (!fileAttributes.hasAttribute(QStringLiteral("alias")))
-                    fileAttributes.append(QStringLiteral("alias"), currentFileName);
-
-                currentFileName = inputDirectory.absoluteFilePath(currentFileName);
-                currentFileName = outputDirectory.relativeFilePath(currentFileName);
-
-                remainingFiles << currentFileName;
-
-                writer.writeAttributes(fileAttributes);
-                writer.writeCharacters(currentFileName);
-                writer.writeEndElement();
-            }
-            continue;
-
-        default: break;
-    }
-    }
-
-    if (!remainingFiles.isEmpty()) {
-        QFile outputFile(output);
-        if (!outputFile.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
-            fprintf(stderr, "Cannot open %s for writing.\n", qPrintable(output));
-            return EXIT_FAILURE;
-        }
-        const QByteArray outputStringUtf8 = outputString.toUtf8();
-        if (outputFile.write(outputStringUtf8) != outputStringUtf8.size())
-            return EXIT_FAILURE;
-
-        outputFile.close();
-        if (outputFile.error() != QFileDevice::NoError)
-            return EXIT_FAILURE;
-
-        // The build system expects this output if we wrote a qrc file and no output
-        // if no files remain.
-        fprintf(stdout, "New resource file written with %d files.\n", remainingFiles.count());
-    }
-
-    return EXIT_SUCCESS;
-}
diff --git a/tools/qmllint/findunqualified.cpp b/tools/qmllint/findunqualified.cpp
index 27939608d7..4404ddf49a 100644
--- a/tools/qmllint/findunqualified.cpp
+++ b/tools/qmllint/findunqualified.cpp
@@ -170,7 +170,8 @@ FindUnqualifiedIDVisitor::localQmlFile2FakeMetaObject(QString filePath)
 {
     using namespace QQmlJS::AST;
     auto fake = new LanguageUtils::FakeMetaObject;
-    fake->setClassName(QFileInfo { filePath }.baseName());
+    QString baseName = QFileInfo { filePath }.baseName();
+    fake->setClassName(baseName.endsWith(".ui") ? baseName.chopped(3) : baseName);
     QFile file(filePath);
     if (!file.open(QFile::ReadOnly)) {
         return fake;
@@ -273,6 +274,7 @@ FindUnqualifiedIDVisitor::localQmlFile2FakeMetaObject(QString filePath)
             auto sourceElement = static_cast<UiSourceElement *>(initMembers->member);
             if (FunctionExpression *fexpr = sourceElement->sourceElement->asFunctionDefinition()) {
                 LanguageUtils::FakeMetaMethod method;
+                method.setMethodName(fexpr->name.toString());
                 method.setMethodType(LanguageUtils::FakeMetaMethod::Method);
                 FormalParameterList *parameters = fexpr->formals;
                 while (parameters) {
@@ -304,6 +306,22 @@ FindUnqualifiedIDVisitor::localQmlFile2FakeMetaObject(QString filePath)
     return fake;
 }
 
+void FindUnqualifiedIDVisitor::importDirectory(const QString &directory, const QString &prefix)
+{
+    QString dirname = directory;
+    QFileInfo info { dirname };
+    if (info.isRelative())
+        dirname = QDir(QFileInfo { m_filePath }.path()).filePath(dirname);
+
+    QDirIterator it { dirname, QStringList() << QLatin1String("*.qml"), QDir::NoFilter };
+    while (it.hasNext()) {
+        LanguageUtils::FakeMetaObject *fake = localQmlFile2FakeMetaObject(it.next());
+        m_exportedName2MetaObject.insert(
+                prefix + fake->className(),
+                QSharedPointer<const LanguageUtils::FakeMetaObject>(fake));
+    }
+}
+
 void FindUnqualifiedIDVisitor::importExportedNames(QStringRef prefix, QString name)
 {
     for (;;) {
@@ -377,6 +395,8 @@ bool FindUnqualifiedIDVisitor::visit(QQmlJS::AST::UiProgram *)
     meta->addProperty(LanguageUtils::FakeMetaProperty {"ignoreUnknownSignals", "bool", false, false, false, 0});
     meta->addProperty(LanguageUtils::FakeMetaProperty {"target", "QObject", false, false, false, 0});
     m_exportedName2MetaObject["Connections"] = LanguageUtils::FakeMetaObject::ConstPtr { meta };
+
+    importDirectory(".", QString());
     return true;
 }
 
@@ -476,6 +496,23 @@ void FindUnqualifiedIDVisitor::endVisit(QQmlJS::AST::WithStatement *)
     leaveEnvironment();
 }
 
+static QString signalName(const QStringRef &handlerName)
+{
+    if (handlerName.startsWith("on") && handlerName.size() > 2) {
+        QString signal = handlerName.mid(2).toString();
+        for (int i = 0; i < signal.length(); ++i) {
+            QCharRef ch = signal[i];
+            if (ch.isLower())
+                return QString();
+            if (ch.isUpper()) {
+                ch = ch.toLower();
+                return signal;
+            }
+        }
+    }
+    return QString();
+}
+
 bool FindUnqualifiedIDVisitor::visit(QQmlJS::AST::UiScriptBinding *uisb)
 {
     using namespace QQmlJS::AST;
@@ -489,8 +526,17 @@ bool FindUnqualifiedIDVisitor::visit(QQmlJS::AST::UiScriptBinding *uisb)
         if (m_currentScope->isVisualRootScope()) {
             m_rootId = identexp->name.toString();
         }
-    } else if (name.startsWith("on") && name.size() > 2 && name.at(2).isUpper()) {
-        auto statement = uisb->statement;
+    } else {
+        const QString signal = signalName(name);
+        if (signal.isEmpty())
+            return true;
+
+        if (!m_currentScope->methods().contains(signal)) {
+            m_currentScope->addUnmatchedSignalHandler(name.toString(), uisb->firstSourceLocation());
+            return true;
+        }
+
+        const auto statement = uisb->statement;
         if (statement->kind == Node::Kind::Kind_ExpressionStatement) {
             if (static_cast<ExpressionStatement *>(statement)->expression->asFunctionDefinition()) {
                 // functions are already handled
@@ -499,17 +545,14 @@ bool FindUnqualifiedIDVisitor::visit(QQmlJS::AST::UiScriptBinding *uisb)
                 return true;
             }
         }
-        QString signal = name.mid(2).toString();
-        signal[0] = signal[0].toLower();
-        if (!m_currentScope->methods().contains(signal)) {
-            qDebug() << "Info file does not contain signal" << signal;
-        } else {
-            auto method = m_currentScope->methods()[signal];
-            for (auto const &param : method.parameterNames()) {
-                auto firstSourceLocation = uisb->statement->firstSourceLocation();
-                bool hasMultilineStatementBody = uisb->statement->lastSourceLocation().startLine > firstSourceLocation.startLine;
-                m_currentScope->insertSignalIdentifier(param, method, firstSourceLocation, hasMultilineStatementBody);
-            }
+
+        auto method = m_currentScope->methods()[signal];
+        for (auto const &param : method.parameterNames()) {
+            const auto firstSourceLocation = statement->firstSourceLocation();
+            bool hasMultilineStatementBody
+                    = statement->lastSourceLocation().startLine > firstSourceLocation.startLine;
+            m_currentScope->insertSignalIdentifier(param, method, firstSourceLocation,
+                                                   hasMultilineStatementBody);
         }
         return true;
     }
@@ -649,18 +692,9 @@ bool FindUnqualifiedIDVisitor::visit(QQmlJS::AST::UiImport *import)
         prefix += import->importId + QLatin1Char('.');
     }
     auto dirname = import->fileName.toString();
-    if (!dirname.isEmpty()) {
-        QFileInfo info { dirname };
-        if (info.isRelative()) {
-            dirname = QDir(QFileInfo { m_filePath }.path()).filePath(dirname);
-        }
-        QDirIterator it { dirname, QStringList() << QLatin1String("*.qml"), QDir::NoFilter };
-        while (it.hasNext()) {
-            LanguageUtils::FakeMetaObject *fake = localQmlFile2FakeMetaObject(it.next());
-            m_exportedName2MetaObject.insert(
-                    fake->className(), QSharedPointer<const LanguageUtils::FakeMetaObject>(fake));
-        }
-    }
+    if (!dirname.isEmpty())
+        importDirectory(dirname, prefix);
+
     QString path {};
     if (!import->importId.isEmpty()) {
         m_qmlid2meta.insert(import->importId.toString(), {}); // TODO: do not put imported ids into the same space as qml IDs
diff --git a/tools/qmllint/findunqualified.h b/tools/qmllint/findunqualified.h
index 181f42f265..f7d1aab1f4 100644
--- a/tools/qmllint/findunqualified.h
+++ b/tools/qmllint/findunqualified.h
@@ -70,7 +70,7 @@ private:
     void importHelper(QString id, QString prefix, int major, int minor);
     LanguageUtils::FakeMetaObject* localQmlFile2FakeMetaObject(QString filePath);
 
-
+    void importDirectory(const QString &directory, const QString &prefix);
     void importExportedNames(QStringRef prefix, QString name);
 
     void throwRecursionDepthError() override;
diff --git a/tools/qmllint/scopetree.cpp b/tools/qmllint/scopetree.cpp
index 2eff3fa319..1e873cca8f 100644
--- a/tools/qmllint/scopetree.cpp
+++ b/tools/qmllint/scopetree.cpp
@@ -81,6 +81,12 @@ void ScopeTree::insertPropertyIdentifier(QString id)
     this->addMethod(method);
 }
 
+void ScopeTree::addUnmatchedSignalHandler(const QString &handler,
+                                          const QQmlJS::AST::SourceLocation &location)
+{
+    m_unmatchedSignalHandlers.append(qMakePair(handler, location));
+}
+
 bool ScopeTree::isIdInCurrentScope(const QString &id) const
 {
     return isIdInCurrentQMlScopes(id) || isIdInCurrentJSScopes(id);
@@ -132,6 +138,15 @@ bool ScopeTree::recheckIdentifiers(const QString& code, const QHash<QString, Lan
     workQueue.enqueue(this);
     while (!workQueue.empty()) {
         const ScopeTree* currentScope = workQueue.dequeue();
+        for (const auto &handler : currentScope->m_unmatchedSignalHandlers) {
+            colorOut.write("Warning: ", Warning);
+            colorOut.write(QString::fromLatin1(
+                                   "no matching signal found for handler \"%1\" at %2:%3\n")
+                                   .arg(handler.first).arg(handler.second.startLine)
+                                   .arg(handler.second.startColumn), Normal);
+            printContext(colorOut, code, handler.second);
+        }
+
         for (auto idLocationPair : currentScope->m_accessedIdentifiers) {
             if (qmlIDs.contains(idLocationPair.first))
                 continue;
@@ -141,13 +156,11 @@ bool ScopeTree::recheckIdentifiers(const QString& code, const QHash<QString, Lan
             noUnqualifiedIdentifier = false;
             colorOut.write("Warning: ", Warning);
             auto location = idLocationPair.second;
-            colorOut.write(QString::asprintf("unqualified access at %d:%d\n", location.startLine, location.startColumn), Normal);
-            IssueLocationWithContext issueLocationWithContext {code, location};
-            colorOut.write(issueLocationWithContext.beforeText.toString(), Normal);
-            colorOut.write(issueLocationWithContext.issueText.toString(), Error);
-            colorOut.write(issueLocationWithContext.afterText.toString() + QLatin1Char('\n'), Normal);
-            int tabCount = issueLocationWithContext.beforeText.count(QLatin1Char('\t'));
-            colorOut.write(QString(" ").repeated(issueLocationWithContext.beforeText.length() - tabCount) + QString("\t").repeated(tabCount) + QString("^").repeated(location.length) + QLatin1Char('\n'), Normal);
+            colorOut.write(QString::asprintf("unqualified access at %d:%d\n", location.startLine,
+                                             location.startColumn), Normal);
+
+            printContext(colorOut, code, location);
+
             // root(JS) --> program(qml) --> (first element)
             if (root->m_childScopes[0]->m_childScopes[0]->m_currentScopeQMLIdentifiers.contains(idLocationPair.first)) {
                 ScopeTree *parentScope = currentScope->m_parentScope;
@@ -161,6 +174,7 @@ bool ScopeTree::recheckIdentifiers(const QString& code, const QHash<QString, Lan
                     colorOut.write("Note: ", Warning);
                     colorOut.write(("You first have to give the root element an id\n"));
                 }
+                IssueLocationWithContext issueLocationWithContext {code, location};
                 colorOut.write(issueLocationWithContext.beforeText.toString(), Normal);
                 colorOut.write(rootId + QLatin1Char('.'), Hint);
                 colorOut.write(issueLocationWithContext.issueText.toString(), Normal);
@@ -212,7 +226,7 @@ QMap<QString, LanguageUtils::FakeMetaMethod>const &ScopeTree::methods() const
 bool ScopeTree::isIdInCurrentQMlScopes(QString id) const
 {
     auto qmlScope = getCurrentQMLScope();
-    return qmlScope->m_currentScopeQMLIdentifiers.contains(id);
+    return qmlScope->m_currentScopeQMLIdentifiers.contains(id) || qmlScope->m_methods.contains(id);
 }
 
 bool ScopeTree::isIdInCurrentJSScopes(QString id) const
@@ -250,6 +264,20 @@ ScopeTree *ScopeTree::getCurrentQMLScope()
     return qmlScope;
 }
 
+void ScopeTree::printContext(ColorOutput &colorOut, const QString &code,
+                             const QQmlJS::AST::SourceLocation &location) const
+{
+    IssueLocationWithContext issueLocationWithContext {code, location};
+    colorOut.write(issueLocationWithContext.beforeText.toString(), Normal);
+    colorOut.write(issueLocationWithContext.issueText.toString(), Error);
+    colorOut.write(issueLocationWithContext.afterText.toString() + QLatin1Char('\n'), Normal);
+    int tabCount = issueLocationWithContext.beforeText.count(QLatin1Char('\t'));
+    colorOut.write(QString(" ").repeated(issueLocationWithContext.beforeText.length() - tabCount)
+                           + QString("\t").repeated(tabCount)
+                           + QString("^").repeated(location.length)
+                           + QLatin1Char('\n'), Normal);
+}
+
 ScopeType ScopeTree::scopeType() {return m_scopeType;}
 
 void ScopeTree::addMethod(LanguageUtils::FakeMetaMethod method)
diff --git a/tools/qmllint/scopetree.h b/tools/qmllint/scopetree.h
index 872a509123..52cdc45e96 100644
--- a/tools/qmllint/scopetree.h
+++ b/tools/qmllint/scopetree.h
@@ -73,6 +73,8 @@ public:
     void insertQMLIdentifier(QString id);
     void insertSignalIdentifier(QString id, LanguageUtils::FakeMetaMethod method, QQmlJS::AST::SourceLocation loc, bool hasMultilineHandlerBody);
     void insertPropertyIdentifier(QString id); // inserts property as qml identifier as well as the corresponding
+    void addUnmatchedSignalHandler(const QString &handler,
+                                   const QQmlJS::AST::SourceLocation &location);
 
     bool isIdInCurrentScope(QString const &id) const;
     void addIdToAccssedIfNotInParentScopes(QPair<QString, QQmlJS::AST::SourceLocation> const& id_loc_pair, const QSet<QString>& unknownImports);
@@ -96,11 +98,14 @@ private:
     ScopeTree *m_parentScope;
     QString m_name;
     ScopeType m_scopeType;
+    QVector<QPair<QString, QQmlJS::AST::SourceLocation>> m_unmatchedSignalHandlers;
 
     bool isIdInCurrentQMlScopes(QString id) const;
     bool isIdInCurrentJSScopes(QString id) const;
     bool isIdInjectedFromSignal(QString id) const;
     const ScopeTree* getCurrentQMLScope() const;
     ScopeTree* getCurrentQMLScope();
+    void printContext(ColorOutput& colorOut, const QString &code,
+                      const QQmlJS::AST::SourceLocation &location) const;
 };
 #endif // SCOPETREE_H
diff --git a/tools/qmlplugindump/qmlstreamwriter.cpp b/tools/qmlplugindump/qmlstreamwriter.cpp
index 3632cee60d..b0fbc4e443 100644
--- a/tools/qmlplugindump/qmlstreamwriter.cpp
+++ b/tools/qmlplugindump/qmlstreamwriter.cpp
@@ -50,9 +50,9 @@ void QmlStreamWriter::writeEndDocument()
 
 void QmlStreamWriter::writeLibraryImport(const QString &uri, int majorVersion, int minorVersion, const QString &as)
 {
-    m_stream->write(QString("import %1 %2.%3").arg(uri, QString::number(majorVersion), QString::number(minorVersion)).toUtf8());
+    m_stream->write(QString::fromLatin1("import %1 %2.%3").arg(uri, QString::number(majorVersion), QString::number(minorVersion)).toUtf8());
     if (!as.isEmpty())
-        m_stream->write(QString(" as %1").arg(as).toUtf8());
+        m_stream->write(QString::fromLatin1(" as %1").arg(as).toUtf8());
     m_stream->write("\n");
 }
 
@@ -60,7 +60,7 @@ void QmlStreamWriter::writeStartObject(const QString &component)
 {
     flushPotentialLinesWithNewlines();
     writeIndent();
-    m_stream->write(QString("%1 {").arg(component).toUtf8());
+    m_stream->write(QString::fromLatin1("%1 {").arg(component).toUtf8());
     ++m_indentDepth;
     m_maybeOneline = true;
 }
@@ -89,7 +89,7 @@ void QmlStreamWriter::writeEndObject()
 
 void QmlStreamWriter::writeScriptBinding(const QString &name, const QString &rhs)
 {
-    writePotentialLine(QString("%1: %2").arg(name, rhs).toUtf8());
+    writePotentialLine(QString::fromLatin1("%1: %2").arg(name, rhs).toUtf8());
 }
 
 void QmlStreamWriter::writeBooleanBinding(const QString &name, bool value)
@@ -104,7 +104,7 @@ void QmlStreamWriter::writeArrayBinding(const QString &name, const QStringList &
 
     // try to use a single line
     QString singleLine;
-    singleLine += QString("%1: [").arg(name);
+    singleLine += QString::fromLatin1("%1: [").arg(name);
     for (int i = 0; i < elements.size(); ++i) {
         singleLine += elements.at(i);
         if (i != elements.size() - 1)
@@ -117,7 +117,7 @@ void QmlStreamWriter::writeArrayBinding(const QString &name, const QStringList &
     }
 
     // write multi-line
-    m_stream->write(QString("%1: [\n").arg(name).toUtf8());
+    m_stream->write(QString::fromLatin1("%1: [\n").arg(name).toUtf8());
     ++m_indentDepth;
     for (int i = 0; i < elements.size(); ++i) {
         writeIndent();
@@ -143,13 +143,13 @@ void QmlStreamWriter::writeScriptObjectLiteralBinding(const QString &name, const
 {
     flushPotentialLinesWithNewlines();
     writeIndent();
-    m_stream->write(QString("%1: {\n").arg(name).toUtf8());
+    m_stream->write(QString::fromLatin1("%1: {\n").arg(name).toUtf8());
     ++m_indentDepth;
     for (int i = 0; i < keyValue.size(); ++i) {
         const QString key = keyValue.at(i).first;
         const QString value = keyValue.at(i).second;
         writeIndent();
-        m_stream->write(QString("%1: %2").arg(key, value).toUtf8());
+        m_stream->write(QString::fromLatin1("%1: %2").arg(key, value).toUtf8());
         if (i != keyValue.size() - 1) {
             m_stream->write(",\n");
         } else {