QmlCompiler: Allow for multiple extensions per object

Previously, the assumption was that each object could only have a single
extension object. As proven by the new qqmllanguage test this is not the
case. Each registered object in the type hierarchy can have its own
extension. Therefore, adjust the algorithms that generate qmltypes and
iterate the extension objects when analyzing them.

This leads us to the realization that anonymous types can in fact
meaningfully carry extensions and implement interfaces. Adapt
qmltyperegistrar accordingly.

For the test to compile, however, we need to realize that the class
declaring interfaces needs to befriend all potential subclass's
QmlInterface structs. Fix that, too. The rabbit hole went deep.

Change-Id: Ia451897e927e03b95c3062e829edf1dfcd216613
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

8 files changed, 189 insertions, 0 deletions

diff --git a/tests/auto/qml/qmllint/data/StaticTest/multi.qmltypes b/tests/auto/qml/qmllint/data/StaticTest/multi.qmltypes
new file mode 100644
index 0000000000..9a2ed24482
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/StaticTest/multi.qmltypes
@@ -0,0 +1,41 @@
+import QtQuick.tooling 1.2
+
+// This file describes the plugin-supplied types contained in the library.
+// It is used for QML tooling purposes only.
+//
+// This file was auto-generated by qmltyperegistrar.
+
+Module {
+    Component {
+        file: "testtypes.h"
+        name: "ExtensionA"
+        accessSemantics: "reference"
+        prototype: "QObject"
+        Property { name: "a"; type: "int"; isReadonly: true; read: "a" }
+    }
+    Component {
+        file: "testtypes.h"
+        name: "ExtensionB"
+        accessSemantics: "reference"
+        prototype: "QObject"
+        Property { name: "b"; type: "int"; isReadonly: true; read: "b" }
+    }
+    Component {
+        file: "testtypes.h"
+        name: "MultiExtension"
+        accessSemantics: "reference"
+        prototype: "MultiExtensionParent"
+        exports: ["StaticTest/MultiExtension 1.0"]
+        exportMetaObjectRevisions: [256]
+        extension: "ExtensionB"
+        Property { name: "e"; type: "int"; isReadonly: true; read: "e" }
+    }
+    Component {
+        file: "testtypes.h"
+        name: "MultiExtensionParent"
+        accessSemantics: "reference"
+        prototype: "QObject"
+        extension: "ExtensionA"
+        Property { name: "p"; type: "int"; isReadonly: true; read: "p" }
+    }
+}
diff --git a/tests/auto/qml/qmllint/data/StaticTest/qmldir b/tests/auto/qml/qmllint/data/StaticTest/qmldir
new file mode 100644
index 0000000000..4702175b79
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/StaticTest/qmldir
@@ -0,0 +1,2 @@
+module StaticTest
+typeinfo multi.qmltypes
diff --git a/tests/auto/qml/qmllint/data/multiExtension.qml b/tests/auto/qml/qmllint/data/multiExtension.qml
new file mode 100644
index 0000000000..12b36dbb4f
--- /dev/null
+++ b/tests/auto/qml/qmllint/data/multiExtension.qml
@@ -0,0 +1,6 @@
+import StaticTest
+
+MultiExtension {
+    property int t: a + b + e + p
+}
+
diff --git a/tests/auto/qml/qmllint/tst_qmllint.cpp b/tests/auto/qml/qmllint/tst_qmllint.cpp
index 895953c2f7..b874d3cc6f 100644
--- a/tests/auto/qml/qmllint/tst_qmllint.cpp
+++ b/tests/auto/qml/qmllint/tst_qmllint.cpp
@@ -337,6 +337,7 @@ void TestQmllint::cleanQmlCode_data()
     QTest::newRow("goodAliasObject") << QStringLiteral("goodAliasObject.qml");
     QTest::newRow("jsmoduleimport") << QStringLiteral("jsmoduleimport.qml");
     QTest::newRow("overridescript") << QStringLiteral("overridescript.qml");
+    QTest::newRow("multiExtension") << QStringLiteral("multiExtension.qml");
 }
 
 void TestQmllint::cleanQmlCode()
diff --git a/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.cpp b/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.cpp
index f7a29948a0..b752c4d6c1 100644
--- a/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.cpp
+++ b/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.cpp
@@ -161,4 +161,14 @@ void tst_qmltyperegistrar::metaTypesRegistered()
     verifyMetaType("Ccc*", "Ccc");
 }
 
+void tst_qmltyperegistrar::multiExtensions()
+{
+    QVERIFY(qmltypesData.contains("name: \"MultiExtension\""));
+    QVERIFY(qmltypesData.contains("prototype: \"MultiExtensionParent\""));
+    QVERIFY(qmltypesData.contains("name: \"MultiExtensionParent\""));
+    QVERIFY(qmltypesData.contains("extension: \"ExtensionA\""));
+    QVERIFY(qmltypesData.contains("extension: \"ExtensionB\""));
+    QVERIFY(qmltypesData.contains("interfaces: [\"Interface3\"]"));
+}
+
 QTEST_MAIN(tst_qmltyperegistrar)
diff --git a/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.h b/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.h
index 6267868375..40569879ec 100644
--- a/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.h
+++ b/tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.h
@@ -37,10 +37,12 @@
 
 class Interface {};
 class Interface2 {};
+class Interface3 {};
 
 QT_BEGIN_NAMESPACE
 Q_DECLARE_INTERFACE(Interface, "io.qt.bugreports.Interface");
 Q_DECLARE_INTERFACE(Interface2, "io.qt.bugreports.Interface2");
+Q_DECLARE_INTERFACE(Interface3, "io.qt.bugreports.Interface3");
 QT_END_NAMESPACE
 
 
@@ -150,6 +152,49 @@ public:
     DerivedFromForeign(QObject *parent) : QTimeLine(1000, parent) {}
 };
 
+class ExtensionA : public QObject
+{
+    Q_OBJECT
+    QML_ANONYMOUS
+    Q_PROPERTY(int a READ a CONSTANT)
+public:
+    ExtensionA(QObject *parent = nullptr) : QObject(parent) {}
+    int a() const { return 'a'; }
+};
+
+class ExtensionB : public QObject
+{
+    Q_OBJECT
+    QML_ANONYMOUS
+    Q_PROPERTY(int b READ b CONSTANT)
+public:
+    ExtensionB(QObject *parent = nullptr) : QObject(parent) {}
+    int b() const { return 'b'; }
+};
+
+class MultiExtensionParent : public QObject, public Interface3
+{
+    Q_OBJECT
+    QML_ANONYMOUS
+    QML_EXTENDED(ExtensionA)
+    QML_IMPLEMENTS_INTERFACES(Interface3)
+    Q_PROPERTY(int p READ p CONSTANT)
+public:
+    MultiExtensionParent(QObject *parent = nullptr) : QObject(parent) {}
+    int p() const { return 'p'; }
+};
+
+class MultiExtension : public MultiExtensionParent
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_EXTENDED(ExtensionB)
+    Q_PROPERTY(int e READ e CONSTANT)
+public:
+    MultiExtension(QObject *parent = nullptr) : MultiExtensionParent(parent) {}
+    int e() const { return 'e'; }
+};
+
 class tst_qmltyperegistrar : public QObject
 {
     Q_OBJECT
@@ -170,6 +215,7 @@ private slots:
     void namespacedElement();
     void derivedFromForeign();
     void metaTypesRegistered();
+    void multiExtensions();
 
 private:
     QByteArray qmltypesData;
diff --git a/tests/auto/qml/qqmllanguage/testtypes.h b/tests/auto/qml/qqmllanguage/testtypes.h
index 758b9e2f62..77f09a232c 100644
--- a/tests/auto/qml/qqmllanguage/testtypes.h
+++ b/tests/auto/qml/qqmllanguage/testtypes.h
@@ -1638,6 +1638,68 @@ private:
     WrapperSingleton() = default;
 };
 
+class ExtensionA : public QObject
+{
+    Q_OBJECT
+    QML_ANONYMOUS
+    Q_PROPERTY(int a READ a CONSTANT)
+    Q_PROPERTY(int c READ c CONSTANT)
+    Q_PROPERTY(int d READ d CONSTANT)
+    Q_PROPERTY(int f READ f CONSTANT)
+    Q_PROPERTY(int g READ g CONSTANT)
+public:
+    ExtensionA(QObject *parent = nullptr) : QObject(parent) {}
+    int a() const { return 'a'; }
+    int c() const { return 11; }
+    int d() const { return 21; }
+    int f() const { return 31; }
+    int g() const { return 41; }
+};
+
+class ExtensionB : public QObject
+{
+    Q_OBJECT
+    QML_ANONYMOUS
+    Q_PROPERTY(int b READ b CONSTANT)
+    Q_PROPERTY(int c READ c CONSTANT)
+    Q_PROPERTY(int d READ d CONSTANT)
+public:
+    ExtensionB(QObject *parent = nullptr) : QObject(parent) {}
+    int b() const { return 'b'; }
+    int c() const { return 12; }
+    int d() const { return 22; }
+};
+
+class MultiExtensionParent : public QObject
+{
+    Q_OBJECT
+    QML_ANONYMOUS
+    QML_EXTENDED(ExtensionA)
+    Q_PROPERTY(int p READ p CONSTANT)
+    Q_PROPERTY(int c READ c CONSTANT)
+    Q_PROPERTY(int f READ f CONSTANT)
+public:
+    MultiExtensionParent(QObject *parent = nullptr) : QObject(parent) {}
+    int p() const { return 'p'; }
+    int c() const { return 13; }
+    int f() const { return 33; }
+};
+
+class MultiExtension : public MultiExtensionParent
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_EXTENDED(ExtensionB)
+    Q_PROPERTY(int e READ e CONSTANT)
+    Q_PROPERTY(int c READ c CONSTANT)
+    Q_PROPERTY(int g READ g CONSTANT)
+public:
+    MultiExtension(QObject *parent = nullptr) : MultiExtensionParent(parent) {}
+    int e() const { return 'e'; }
+    int c() const { return 14; }
+    int g() const { return 44; }
+};
+
 void registerTypes();
 
 #endif // TESTTYPES_H
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 454ae59ad3..5e40387ceb 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -347,6 +347,8 @@ private slots:
     void extendedSingleton();
     void qtbug_85932();
 
+    void multiExtension();
+
 private:
     QQmlEngine engine;
     QStringList defaultImportPathList;
@@ -6128,6 +6130,25 @@ void tst_qqmllanguage::qtbug_85932()
     QCOMPARE(allWarnings.at(1).toString(), warning2);
 }
 
+void tst_qqmllanguage::multiExtension()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine);
+    c.setData("import StaticTest\nMultiExtension {}", QUrl());
+    QVERIFY2(c.isReady(), qPrintable(c.errorString()));
+    QScopedPointer<QObject> o(c.create());
+    QCOMPARE(o->property("a").toInt(), int('a'));
+    QCOMPARE(o->property("b").toInt(), int('b'));
+    QCOMPARE(o->property("p").toInt(), int('p'));
+    QCOMPARE(o->property("e").toInt(), int('e'));
+
+    // Extension properties override base object properties
+    QCOMPARE(o->property("c").toInt(), 12);
+    QCOMPARE(o->property("d").toInt(), 22);
+    QCOMPARE(o->property("f").toInt(), 31);
+    QCOMPARE(o->property("g").toInt(), 44);
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"