QmlCompiler: Extend shadow-checking

Method return values as well as whatever we hide behind "unknown" can
contain shadowable properties. We need to check it.

Pick-to: 6.5 6.2
Task-number: QTBUG-117800
Change-Id: I518bc11fd0c9c69340bf621198eeaf4c95d17dae
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Olivier De Cannière <olivier.decanniere@qt.io>
(cherry picked from commit 048c8f226ae09b79264e5dfc51f5d8fe7a8332a9)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

6 files changed, 81 insertions, 2 deletions

diff --git a/src/qmlcompiler/qqmljsshadowcheck.cpp b/src/qmlcompiler/qqmljsshadowcheck.cpp
index 5b07140490..167396f614 100644
--- a/src/qmlcompiler/qqmljsshadowcheck.cpp
+++ b/src/qmlcompiler/qqmljsshadowcheck.cpp
@@ -114,10 +114,12 @@ void QQmlJSShadowCheck::checkShadowing(
         return;
 
     switch (baseType.variant()) {
-    case QQmlJSRegisterContent::ObjectProperty:
     case QQmlJSRegisterContent::ExtensionObjectProperty:
+    case QQmlJSRegisterContent::ExtensionScopeProperty:
+    case QQmlJSRegisterContent::MethodReturnValue:
+    case QQmlJSRegisterContent::ObjectProperty:
     case QQmlJSRegisterContent::ScopeProperty:
-    case QQmlJSRegisterContent::ExtensionScopeProperty: {
+    case QQmlJSRegisterContent::Unknown: {
         const QQmlJSRegisterContent member = m_typeResolver->memberType(baseType, memberName);
 
         // You can have something like parent.QtQuick.Screen.pixelDensity
diff --git a/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt b/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
index 37d953ec8e..539fb39068 100644
--- a/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
+++ b/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
@@ -53,6 +53,8 @@ set(qml_files
     ProgressBar/TimelineAnimation.qml
     RootWithoutId.qml
     SelectionRectangle.qml
+    ShadowedObjectName.qml
+    ShadowedObjectNameDerived.qml
     Test.qml
     TestCase.qml
     WindowDerived.qml
@@ -199,6 +201,7 @@ set(qml_files
     script.mjs
     sequenceToIterable.qml
     setLookupConversion.qml
+    shadowedAsCasts.qml
     shadowedMethod.qml
     shared/Slider.qml
     shifts.qml
diff --git a/tests/auto/qml/qmlcppcodegen/data/ShadowedObjectName.qml b/tests/auto/qml/qmlcppcodegen/data/ShadowedObjectName.qml
new file mode 100644
index 0000000000..f079f4a94e
--- /dev/null
+++ b/tests/auto/qml/qmlcppcodegen/data/ShadowedObjectName.qml
@@ -0,0 +1,6 @@
+pragma Strict
+import QtQml
+
+QtObject {
+    property int objectName: 12
+}
diff --git a/tests/auto/qml/qmlcppcodegen/data/ShadowedObjectNameDerived.qml b/tests/auto/qml/qmlcppcodegen/data/ShadowedObjectNameDerived.qml
new file mode 100644
index 0000000000..f988cd6bc9
--- /dev/null
+++ b/tests/auto/qml/qmlcppcodegen/data/ShadowedObjectNameDerived.qml
@@ -0,0 +1,6 @@
+pragma Strict
+import QtQml
+
+ShadowedObjectName {
+    property double objectName: 17.4
+}
diff --git a/tests/auto/qml/qmlcppcodegen/data/shadowedAsCasts.qml b/tests/auto/qml/qmlcppcodegen/data/shadowedAsCasts.qml
new file mode 100644
index 0000000000..ccb50f4934
--- /dev/null
+++ b/tests/auto/qml/qmlcppcodegen/data/shadowedAsCasts.qml
@@ -0,0 +1,31 @@
+pragma Strict
+import QtQml
+
+QtObject {
+    property ShadowedObjectName shadowed1: ShadowedObjectName {}
+    property ShadowedObjectName shadowed2: ShadowedObjectName {}
+    property QtObject shadowed3: ShadowedObjectNameDerived {}
+
+    function returnShadowed2() : QtObject { return shadowed2 }
+
+    function a(mark: int) {
+        // as-cast can be optimized out if we're clever.
+        (shadowed1 as QtObject).objectName = mark;
+    }
+
+    function b(mark: int) {
+        // method return values can contain shadowed properties!
+        returnShadowed2().objectName = mark;
+    }
+
+    function c(mark: int) {
+        // Has to do an actual as-cast, but results in ShadowedObjectNameDerived!
+        (shadowed3 as ShadowedObjectName).objectName = mark;
+    }
+
+    Component.onCompleted: {
+        a(43);
+        b(42);
+        c(41);
+    }
+}
diff --git a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
index b1e97b2560..a6a8f5db14 100644
--- a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
+++ b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
@@ -166,6 +166,7 @@ private slots:
     void scopeVsObject();
     void sequenceToIterable();
     void setLookupConversion();
+    void shadowedAsCasts();
     void shadowedMethod();
     void shifts();
     void signalHandler();
@@ -3478,6 +3479,36 @@ void tst_QmlCppCodegen::setLookupConversion()
     QCOMPARE(o->objectName(), u"a"_s);
 }
 
+void tst_QmlCppCodegen::shadowedAsCasts()
+{
+    QQmlEngine e;
+    QQmlComponent c(&e, QUrl(u"qrc:/qt/qml/TestTypes/shadowedAsCasts.qml"_s));
+    QVERIFY2(c.isReady(), qPrintable(c.errorString()));
+    QScopedPointer<QObject> obj(c.create());
+    QVERIFY(!obj.isNull());
+
+    QObject *shadowed1 = obj->property("shadowed1").value<QObject *>();
+    QVERIFY(shadowed1);
+    QVERIFY(shadowed1->objectName().isEmpty());
+    const QVariant name1 = shadowed1->property("objectName");
+    QCOMPARE(name1.metaType(), QMetaType::fromType<int>());
+    QCOMPARE(name1.toInt(), 43);
+
+    QObject *shadowed2 = obj->property("shadowed2").value<QObject *>();
+    QVERIFY(shadowed2);
+    QVERIFY(shadowed2->objectName().isEmpty());
+    const QVariant name2 = shadowed2->property("objectName");
+    QCOMPARE(name2.metaType(), QMetaType::fromType<int>());
+    QCOMPARE(name2.toInt(), 42);
+
+    QObject *shadowed3 = obj->property("shadowed3").value<QObject *>();
+    QVERIFY(shadowed3);
+    QVERIFY(shadowed3->objectName().isEmpty());
+    const QVariant name3 = shadowed3->property("objectName");
+    QCOMPARE(name3.metaType(), QMetaType::fromType<double>());
+    QCOMPARE(name3.toDouble(), 41.0);
+}
+
 void tst_QmlCppCodegen::shadowedMethod()
 {
     QQmlEngine e;