[new compiler] Initial support for group properties

This implements support for "font.pixelSize: 24" for example. The representation
in the compile data structure is so that font.pixelSize is short-hand for

font {
    pixelSize: 24
}

which means that inside the braces is a complete object initializer. For that
initializer we create a dedicated CompiledData::Object, which however has its
type name empty. When populating the outer instance then, the "font" property
is read as QQmlValueType (a QObject) and instead of creating a new QObject we
use that value type as instance to run the rest of the QML object initializer
(everything in braces).

Change-Id: Ic0a37ac77ab88f582546b9c09a3d06a07726420b
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

3 files changed, 78 insertions, 7 deletions

diff --git a/src/qml/compiler/qqmlcodegenerator.cpp b/src/qml/compiler/qqmlcodegenerator.cpp
index 6ca7078e69..b875067620 100644
--- a/src/qml/compiler/qqmlcodegenerator.cpp
+++ b/src/qml/compiler/qqmlcodegenerator.cpp
@@ -152,21 +152,38 @@ bool QQmlCodeGenerator::visit(AST::UiProgram *)
 
 bool QQmlCodeGenerator::visit(AST::UiObjectDefinition *node)
 {
-    int idx = defineQMLObject(node);
-    appendBinding(AST::SourceLocation(), registerString(QString()), idx);
+    // The grammar can't distinguish between two different definitions here:
+    //     Item { ... }
+    // versus
+    //     font { ... }
+    // The former is a new binding with no property name and "Item" as type name,
+    // and the latter is a binding to the font property with no type name but
+    // only initializer.
+
+    AST::UiQualifiedId *lastId = node->qualifiedTypeNameId;
+    while (lastId->next)
+        lastId = lastId->next;
+    bool isType = lastId->name.unicode()->isUpper();
+    if (isType) {
+        int idx = defineQMLObject(node);
+        appendBinding(AST::SourceLocation(), registerString(QString()), idx);
+    } else {
+        int idx = defineQMLObject(/*qualfied type name id*/0, node->initializer);
+        appendBinding(node->qualifiedTypeNameId, idx);
+    }
     return false;
 }
 
 bool QQmlCodeGenerator::visit(AST::UiObjectBinding *node)
 {
     int idx = defineQMLObject(node->qualifiedTypeNameId, node->initializer);
-    appendBinding(node->qualifiedId->identifierToken, registerString(asString(node->qualifiedId)), idx);
+    appendBinding(node->qualifiedId, idx);
     return false;
 }
 
 bool QQmlCodeGenerator::visit(AST::UiScriptBinding *node)
 {
-    appendBinding(node->qualifiedId->identifierToken, registerString(asString(node->qualifiedId)), node->statement);
+    appendBinding(node->qualifiedId, node->statement);
     return false;
 }
 
@@ -237,7 +254,9 @@ int QQmlCodeGenerator::defineQMLObject(AST::UiQualifiedId *qualifiedTypeNameId,
 
     _object->inheritedTypeNameIndex = registerString(asString(qualifiedTypeNameId));
 
-    AST::SourceLocation loc = qualifiedTypeNameId->firstSourceLocation();
+    AST::SourceLocation loc;
+    if (qualifiedTypeNameId)
+        loc = qualifiedTypeNameId->firstSourceLocation();
     _object->location.line = loc.startLine;
     _object->location.column = loc.startColumn;
 
@@ -664,6 +683,24 @@ void QQmlCodeGenerator::setBindingValue(QV4::CompiledData::Binding *binding, AST
     }
 }
 
+void QQmlCodeGenerator::appendBinding(AST::UiQualifiedId *name, AST::Statement *value)
+{
+    QmlObject *object = 0;
+    name = resolveQualifiedId(name, &object);
+    qSwap(_object, object);
+    appendBinding(name->identifierToken, registerString(name->name.toString()), value);
+    qSwap(_object, object);
+}
+
+void QQmlCodeGenerator::appendBinding(AST::UiQualifiedId *name, int objectIndex)
+{
+    QmlObject *object = 0;
+    name = resolveQualifiedId(name, &object);
+    qSwap(_object, object);
+    appendBinding(name->identifierToken, registerString(name->name.toString()), objectIndex);
+    qSwap(_object, object);
+}
+
 void QQmlCodeGenerator::appendBinding(const AST::SourceLocation &nameLocation, int propertyNameIndex, AST::Statement *value)
 {
     if (!sanityCheckPropertyName(nameLocation, propertyNameIndex))
@@ -685,9 +722,31 @@ void QQmlCodeGenerator::appendBinding(const AST::SourceLocation &nameLocation, i
     _object->bindings->append(binding);
 }
 
+AST::UiQualifiedId *QQmlCodeGenerator::resolveQualifiedId(AST::UiQualifiedId *name, QmlObject **object)
+{
+    *object = _object;
+    while (name->next) {
+        Binding *binding = New<Binding>();
+        binding->propertyNameIndex = registerString(name->name.toString());
+        binding->value.type = QV4::CompiledData::Value::Type_Object;
+
+        int objIndex = defineQMLObject(0, 0);
+        binding->value.objectIndex = objIndex;
+
+        (*object)->bindings->append(binding);
+        *object = _objects[objIndex];
+
+        name = name->next;
+    }
+    return name;
+}
+
 bool QQmlCodeGenerator::sanityCheckPropertyName(const AST::SourceLocation &nameLocation, int nameIndex)
 {
-    QString name = jsGenerator->strings.at(nameIndex);
+    const QString &name = jsGenerator->strings.at(nameIndex);
+    if (name.isEmpty())
+        return true;
+
     if (_propertyNames.contains(name))
         COMPILE_EXCEPTION(nameLocation, tr("Duplicate property name"));
 
@@ -720,7 +779,8 @@ void QQmlCodeGenerator::recordError(const AST::SourceLocation &location, const Q
 void QQmlCodeGenerator::collectTypeReferences()
 {
     foreach (QmlObject *obj, _objects) {
-        _typeReferences.add(obj->inheritedTypeNameIndex, obj->location);
+        if (!stringAt(obj->inheritedTypeNameIndex).isEmpty())
+            _typeReferences.add(obj->inheritedTypeNameIndex, obj->location);
 
         for (QmlProperty *prop = obj->properties->first; prop; prop = prop->next) {
             if (prop->type >= QV4::CompiledData::Property::Custom)
diff --git a/src/qml/compiler/qqmlcodegenerator_p.h b/src/qml/compiler/qqmlcodegenerator_p.h
index 97ba3ef075..5344dc1535 100644
--- a/src/qml/compiler/qqmlcodegenerator_p.h
+++ b/src/qml/compiler/qqmlcodegenerator_p.h
@@ -215,9 +215,15 @@ public:
 
     void setBindingValue(QV4::CompiledData::Binding *binding, AST::Statement *statement);
 
+    void appendBinding(AST::UiQualifiedId *name, AST::Statement *value);
+    void appendBinding(AST::UiQualifiedId *name, int objectIndex);
     void appendBinding(const AST::SourceLocation &nameLocation, int propertyNameIndex, AST::Statement *value);
     void appendBinding(const AST::SourceLocation &nameLocation, int propertyNameIndex, int objectIndex);
 
+    // resolves qualified name (font.pixelSize for example) and returns the last name along
+    // with the object any right-hand-side of a binding should apply to.
+    AST::UiQualifiedId *resolveQualifiedId(AST::UiQualifiedId *name, QmlObject **object);
+
     bool sanityCheckPropertyName(const AST::SourceLocation &nameLocation, int nameIndex);
 
     void recordError(const AST::SourceLocation &location, const QString &description);
@@ -229,6 +235,8 @@ public:
     int registerString(const QString &str) const { return jsGenerator->registerString(str); }
     template <typename _Tp> _Tp *New() { return new (pool->allocate(sizeof(_Tp))) _Tp(); }
 
+    QString stringAt(int index) const { return jsGenerator->strings.at(index); }
+
     QList<QQmlError> errors;
 
     QList<QV4::CompiledData::Import*> _imports;
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index c98d53a1fa..9f8bd80f4d 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -315,6 +315,9 @@ struct Property
 
 struct Object
 {
+    // An empty inherited type name suggests that this object doesn't require to be instantiated
+    // by itself but is merely used for grouped properties. It can therefore only have bindings,
+    // so nProperties, nFunctions and nSignals must be zero.
     quint32 inheritedTypeNameIndex;
     quint32 idIndex;
     quint32 indexOfDefaultProperty;