Compiler: Handle method list return types from qmltypes file

When parsing methods details from qmltypes files, the `isList` value
was ignored. It indicates that the return type of the method is a list
of the type specified in the `type` value.

Add the isList flag to QQmlJSMetaParameter and make the return value a
QQmlJSMetaParameter, too, so that we can pass the flag to the type
resolution.

Fixes: QTBUG-122106
Change-Id: I6ea07c02fbeb6cb07d9fe9184205ff7f3274fd73
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit e303d12827)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 411f6cce09)
(cherry picked from commit 7d3204ff06)
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Olivier De Cannière <olivier.decanniere@qt.io>

src/qmlcompiler/qqmljsmetatypes_p.h

@@ -120,7 +120,7 @@ public:
         Const,
     };
 
-    QQmlJSMetaParameter(const QString &name, const QString &typeName,
+    QQmlJSMetaParameter(const QString &name = QString(), const QString &typeName = QString(),
                         Constness typeQualifier = NonConst,
                         QWeakPointer<const QQmlJSScope> type = {})
         : m_name(name), m_typeName(typeName), m_type(type), m_typeQualifier(typeQualifier)
@@ -135,9 +135,13 @@ public:
     void setType(QWeakPointer<const QQmlJSScope> type) { m_type = type; }
     Constness typeQualifier() const { return m_typeQualifier; }
     void setTypeQualifier(Constness typeQualifier) { m_typeQualifier = typeQualifier; }
+
     bool isPointer() const { return m_isPointer; }
     void setIsPointer(bool isPointer) { m_isPointer = isPointer; }
 
+    bool isList() const { return m_isList; }
+    void setIsList(bool isList) { m_isList = isList; }
+
     friend bool operator==(const QQmlJSMetaParameter &a, const QQmlJSMetaParameter &b)
     {
         return a.m_name == b.m_name && a.m_typeName == b.m_typeName
@@ -162,8 +166,11 @@ private:
     QWeakPointer<const QQmlJSScope> m_type;
     Constness m_typeQualifier = NonConst;
     bool m_isPointer = false;
+    bool m_isList = false;
 };
 
+using QQmlJSMetaReturnType = QQmlJSMetaParameter;
+
 class QQmlJSMetaMethod
 {
 public:
@@ -191,20 +198,18 @@ public:
     QQmlJSMetaMethod() = default;
     explicit QQmlJSMetaMethod(QString name, QString returnType = QString())
         : m_name(std::move(name))
-        , m_returnTypeName(std::move(returnType))
+        , m_returnType(QString(), std::move(returnType))
         , m_methodType(Method)
     {}
 
     QString methodName() const { return m_name; }
     void setMethodName(const QString &name) { m_name = name; }
 
-    QString returnTypeName() const { return m_returnTypeName; }
-    QSharedPointer<const QQmlJSScope> returnType() const { return m_returnType.toStrongRef(); }
-    void setReturnTypeName(const QString &type) { m_returnTypeName = type; }
-    void setReturnType(const QSharedPointer<const QQmlJSScope> &type)
-    {
-        m_returnType = type;
-    }
+    QQmlJSMetaReturnType returnValue() const { return m_returnType; }
+    void setReturnValue(const QQmlJSMetaReturnType returnValue) { m_returnType = returnValue; }
+    QString returnTypeName() const { return m_returnType.typeName(); }
+    QSharedPointer<const QQmlJSScope> returnType() const { return m_returnType.type(); }
+    void setReturnTypeName(const QString &type) { m_returnType.setTypeName(type); }
 
     QList<QQmlJSMetaParameter> parameters() const { return m_parameters; }
 
@@ -257,7 +262,7 @@ public:
 
     friend bool operator==(const QQmlJSMetaMethod &a, const QQmlJSMetaMethod &b)
     {
-        return a.m_name == b.m_name && a.m_returnTypeName == b.m_returnTypeName
+        return a.m_name == b.m_name && a.m_returnType == b.m_returnType
                 && a.m_returnType == b.m_returnType && a.m_parameters == b.m_parameters
                 && a.m_annotations == b.m_annotations && a.m_methodType == b.m_methodType
                 && a.m_methodAccess == b.m_methodAccess && a.m_revision == b.m_revision
@@ -274,8 +279,7 @@ public:
         QtPrivate::QHashCombine combine;
 
         seed = combine(seed, method.m_name);
-        seed = combine(seed, method.m_returnTypeName);
-        seed = combine(seed, method.m_returnType.toStrongRef().data());
+        seed = combine(seed, method.m_returnType);
         seed = combine(seed, method.m_annotations);
         seed = combine(seed, method.m_methodType);
         seed = combine(seed, method.m_methodAccess);
@@ -291,8 +295,8 @@ public:
 
 private:
     QString m_name;
-    QString m_returnTypeName;
-    QWeakPointer<const QQmlJSScope> m_returnType;
+
+    QQmlJSMetaReturnType m_returnType;
 
     QList<QQmlJSMetaParameter> m_parameters;
     QList<QQmlJSAnnotation> m_annotations;

src/qmlcompiler/qqmljsscope.cpp

@@ -502,24 +502,26 @@ QTypeRevision QQmlJSScope::resolveType(
         }
     }
 
-    for (auto it = self->m_methods.begin(), end = self->m_methods.end(); it != end; ++it) {
-        const QString returnTypeName = it->returnTypeName();
-        if (!it->returnType() && !returnTypeName.isEmpty()) {
-            const auto returnType = findType(returnTypeName, context, usedTypes);
-            it->setReturnType(returnType.scope);
+    const auto resolveParameter = [&](QQmlJSMetaParameter &parameter) {
+        if (const QString typeName = parameter.typeName();
+            !parameter.type() && !typeName.isEmpty()) {
+            const auto type = findType(typeName, context, usedTypes);
+            if (type.scope && type.scope->isReferenceType())
+                parameter.setIsPointer(true);
+            parameter.setType({ (type.scope && parameter.isList())
+                                        ? type.scope->listType()
+                                        : type.scope });
         }
+    };
+
+    for (auto it = self->m_methods.begin(), end = self->m_methods.end(); it != end; ++it) {
+        auto returnValue = it->returnValue();
+        resolveParameter(returnValue);
+        it->setReturnValue(returnValue);
 
         auto parameters = it->parameters();
-        for (int i = 0, length = parameters.size(); i < length; ++i) {
-            auto &parameter = parameters[i];
-            if (const QString typeName = parameter.typeName();
-                !parameter.type() && !typeName.isEmpty()) {
-                const auto type = findType(typeName, context, usedTypes);
-                if (type.scope && type.scope->isReferenceType())
-                    parameter.setIsPointer(true);
-                parameter.setType({ type.scope });
-            }
-        }
+        for (int i = 0, length = parameters.size(); i < length; ++i)
+            resolveParameter(parameters[i]);
 
         it->setParameters(parameters);
     }

src/qmlcompiler/qqmljstypedescriptionreader.cpp

@@ -299,7 +299,9 @@ void QQmlJSTypeDescriptionReader::readSignalOrMethod(UiObjectDefinition *ast, bo
             } else if (name == QLatin1String("isJavaScriptFunction")) {
                 metaMethod.setIsJavaScriptFunction(true);
             } else if (name == QLatin1String("isList")) {
-                // TODO: Theoretically this can happen. QQmlJSMetaMethod should store it.
+                auto metaReturnType = metaMethod.returnValue();
+                metaReturnType.setIsList(true);
+                metaMethod.setReturnValue(metaReturnType);
             } else if (name == QLatin1String("isPointer")) {
                 // TODO: We don't need this information. We can probably drop all isPointer members
                 //       once we make sure that the type information is always complete. The
@@ -429,6 +431,7 @@ void QQmlJSTypeDescriptionReader::readParameter(UiObjectDefinition *ast, QQmlJSM
     QString type;
     bool isConstant = false;
     bool isPointer = false;
+    bool isList = false;
 
     for (UiObjectMemberList *it = ast->initializer->members; it; it = it->next) {
         UiObjectMember *member = it->member;
@@ -450,7 +453,7 @@ void QQmlJSTypeDescriptionReader::readParameter(UiObjectDefinition *ast, QQmlJSM
         } else if (id == QLatin1String("isReadonly")) {
             // ### unhandled
         } else if (id == QLatin1String("isList")) {
-            // ### unhandled
+            isList = readBoolBinding(script);
         } else {
             addWarning(script->firstSourceLocation(),
                        tr("Expected only name and type script bindings."));
@@ -460,6 +463,7 @@ void QQmlJSTypeDescriptionReader::readParameter(UiObjectDefinition *ast, QQmlJSM
     QQmlJSMetaParameter p(name, type);
     p.setTypeQualifier(isConstant ? QQmlJSMetaParameter::Const : QQmlJSMetaParameter::NonConst);
     p.setIsPointer(isPointer);
+    p.setIsList(isList);
     metaMethod->addParameter(std::move(p));
 }
 

tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt

@@ -12,6 +12,7 @@ set(cpp_sources
     enumProperty.h
     gadgetwithenum.h
     invisible.h
+    listprovider.h
     multiforeign.h
     objectwithmethod.h
     person.cpp person.h
@@ -37,6 +38,7 @@ set(qml_files
     Cycle1.qml
     Cycle2.qml
     Cycle3.qml
+    CppMethodListReturnType.qml
     CxxTypeFromDir.qml
     CxxTypeFromImplicit.qml
     Dummy.qml

tests/auto/qml/qmlcppcodegen/data/CppMethodListReturnType.qml

@@ -0,0 +1,12 @@
+pragma Strict
+
+import QtQuick
+import TestTypes
+
+Item {
+    ListProvider {
+        id: listProvider
+    }
+
+    property var list: listProvider.intList()
+}

tests/auto/qml/qmlcppcodegen/data/listprovider.h

@@ -0,0 +1,24 @@
+#ifndef QLISTPROVIDER_H
+#define QLISTPROVIDER_H
+
+#include <QObject>
+#include <QQmlEngine>
+
+class QListProvider : public QObject
+{
+    Q_OBJECT
+    QML_NAMED_ELEMENT(ListProvider)
+
+public:
+    explicit QListProvider(QObject *parent = nullptr) : QObject(parent) { }
+
+    Q_INVOKABLE QList<int> intList() const
+    {
+        QList<int> list;
+        for (int i = 0; i < 3; ++i)
+            list.append(i);
+        return list;
+    }
+};
+
+#endif // QLISTPROVIDER_H

tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp

@@ -29,6 +29,7 @@ private slots:
     void initTestCase();
 
     void simpleBinding();
+    void cppMethodListReturnType();
     void cppValueTypeList();
     void anchorsFill();
     void signalHandler();
@@ -221,6 +222,17 @@ void tst_QmlCppCodegen::simpleBinding()
     }
 }
 
+void tst_QmlCppCodegen::cppMethodListReturnType()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, QUrl(u"qrc:/qt/qml/TestTypes/CppMethodListReturnType.qml"_s));
+    QVERIFY2(c.isReady(), qPrintable(c.errorString()));
+    QScopedPointer<QObject> o(c.create());
+    QVERIFY(!o.isNull());
+
+    QCOMPARE(o->property("list").toList()[2].toInt(), 2);
+}
+
 void tst_QmlCppCodegen::cppValueTypeList()
 {
     QQmlEngine engine;