Correctly set this object when calling scope/context functions

When a function is called that is in a QML scope or a QML context, set
the 'this' object to the QML scope. This is done by introducing two new
interpreter instructions, which get the context passed in.

Note: this patch is 5.11 specific. 5.9 had a similair issue, but the
implementation is quite different, so that was fixed separately.

Task-number: QTBUG-66432
Change-Id: Ie43150cdd26360025895df28d31264985abf1c15
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

10 files changed, 133 insertions, 1 deletions

diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index b2808784a0..f236683506 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -1263,6 +1263,8 @@ bool Codegen::visit(CallExpression *ast)
     switch (base.type) {
     case Reference::Member:
     case Reference::Subscript:
+    case Reference::QmlScopeObject:
+    case Reference::QmlContextObject:
         base = base.asLValue();
         break;
     case Reference::Name:
@@ -1277,7 +1279,21 @@ bool Codegen::visit(CallExpression *ast)
         return false;
 
     //### Do we really need all these call instructions? can's we load the callee in a temp?
-    if (base.type == Reference::Member) {
+    if (base.type == Reference::QmlScopeObject) {
+        Instruction::CallScopeObjectProperty call;
+        call.base = base.qmlBase.stackSlot();
+        call.name = base.qmlCoreIndex;
+        call.argc = calldata.argc;
+        call.argv = calldata.argv;
+        bytecodeGenerator->addInstruction(call);
+    } else if (base.type == Reference::QmlContextObject) {
+        Instruction::CallContextObjectProperty call;
+        call.base = base.qmlBase.stackSlot();
+        call.name = base.qmlCoreIndex;
+        call.argc = calldata.argc;
+        call.argv = calldata.argv;
+        bytecodeGenerator->addInstruction(call);
+    } else if (base.type == Reference::Member) {
         if (useFastLookups) {
             Instruction::CallPropertyLookup call;
             call.base = base.propertyBase.stackSlot();
diff --git a/src/qml/compiler/qv4instr_moth.cpp b/src/qml/compiler/qv4instr_moth.cpp
index 3a81aca7f6..34953d52ce 100644
--- a/src/qml/compiler/qv4instr_moth.cpp
+++ b/src/qml/compiler/qv4instr_moth.cpp
@@ -369,6 +369,14 @@ void dumpBytecode(const char *code, int len, int nLocals, int nFormals, int /*st
             d << index << dumpArguments(argc, argv, nFormals);
         MOTH_END_INSTR(CallGlobalLookup)
 
+        MOTH_BEGIN_INSTR(CallScopeObjectProperty)
+            d << dumpRegister(base, nFormals) << "." << name << dumpArguments(argc, argv, nFormals);
+        MOTH_END_INSTR(CallScopeObjectProperty)
+
+        MOTH_BEGIN_INSTR(CallContextObjectProperty)
+            d << dumpRegister(base, nFormals) << "." << name << dumpArguments(argc, argv, nFormals);
+        MOTH_END_INSTR(CallContextObjectProperty)
+
         MOTH_BEGIN_INSTR(SetExceptionHandler)
             if (offset)
                 d << ABSOLUTE_OFFSET();
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index 4eeeed1fbc..2d1428bd19 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -105,6 +105,8 @@ QT_BEGIN_NAMESPACE
 #define INSTR_CallName(op) INSTRUCTION(op, CallName, 3, name, argc, argv)
 #define INSTR_CallPossiblyDirectEval(op) INSTRUCTION(op, CallPossiblyDirectEval, 2, argc, argv)
 #define INSTR_CallGlobalLookup(op) INSTRUCTION(op, CallGlobalLookup, 3, index, argc, argv)
+#define INSTR_CallScopeObjectProperty(op) INSTRUCTION(op, CallScopeObjectProperty, 4, name, base, argc, argv)
+#define INSTR_CallContextObjectProperty(op) INSTRUCTION(op, CallContextObjectProperty, 4, name, base, argc, argv)
 #define INSTR_SetExceptionHandler(op) INSTRUCTION(op, SetExceptionHandler, 1, offset)
 #define INSTR_ThrowException(op) INSTRUCTION(op, ThrowException, 0)
 #define INSTR_GetException(op) INSTRUCTION(op, GetException, 0)
@@ -221,6 +223,8 @@ QT_BEGIN_NAMESPACE
     F(CallName) \
     F(CallPossiblyDirectEval) \
     F(CallGlobalLookup) \
+    F(CallScopeObjectProperty) \
+    F(CallContextObjectProperty) \
     F(SetExceptionHandler) \
     F(ThrowException) \
     F(GetException) \
diff --git a/src/qml/jit/qv4jit.cpp b/src/qml/jit/qv4jit.cpp
index 1ef6cc4add..5dc98a591a 100644
--- a/src/qml/jit/qv4jit.cpp
+++ b/src/qml/jit/qv4jit.cpp
@@ -548,6 +548,32 @@ void BaselineJIT::generate_CallGlobalLookup(int index, int argc, int argv)
     as->checkException();
 }
 
+void BaselineJIT::generate_CallScopeObjectProperty(int propIdx, int base, int argc, int argv)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passRegAsArg(argv, 3);
+    as->passInt32AsArg(propIdx, 2);
+    as->passRegAsArg(base, 1);
+    as->passEngineAsArg(0);
+    JIT_GENERATE_RUNTIME_CALL(Runtime::method_callQmlScopeObjectProperty, Assembler::ResultInAccumulator);
+    as->checkException();
+}
+
+void BaselineJIT::generate_CallContextObjectProperty(int propIdx, int base, int argc, int argv)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passRegAsArg(argv, 3);
+    as->passInt32AsArg(propIdx, 2);
+    as->passRegAsArg(base, 1);
+    as->passEngineAsArg(0);
+    JIT_GENERATE_RUNTIME_CALL(Runtime::method_callQmlContextObjectProperty, Assembler::ResultInAccumulator);
+    as->checkException();
+}
+
 void BaselineJIT::generate_SetExceptionHandler(int offset)
 {
     if (offset)
@@ -1087,6 +1113,12 @@ void BaselineJIT::collectLabelsInBytecode()
         MOTH_BEGIN_INSTR(CallGlobalLookup)
         MOTH_END_INSTR(CallGlobalLookup)
 
+        MOTH_BEGIN_INSTR(CallScopeObjectProperty)
+        MOTH_END_INSTR(CallScopeObjectProperty)
+
+        MOTH_BEGIN_INSTR(CallContextObjectProperty)
+        MOTH_END_INSTR(CallContextObjectProperty)
+
         MOTH_BEGIN_INSTR(SetExceptionHandler)
             addLabel(code - start + offset);
         MOTH_END_INSTR(SetExceptionHandler)
diff --git a/src/qml/jit/qv4jit_p.h b/src/qml/jit/qv4jit_p.h
index c7ec1700c3..077c2e2177 100644
--- a/src/qml/jit/qv4jit_p.h
+++ b/src/qml/jit/qv4jit_p.h
@@ -168,6 +168,8 @@ public:
     void generate_CallName(int name, int argc, int argv) Q_DECL_OVERRIDE;
     void generate_CallPossiblyDirectEval(int argc, int argv) Q_DECL_OVERRIDE;
     void generate_CallGlobalLookup(int index, int argc, int argv) Q_DECL_OVERRIDE;
+    void generate_CallScopeObjectProperty(int propIdx, int base, int argc, int argv) Q_DECL_OVERRIDE;
+    void generate_CallContextObjectProperty(int propIdx, int base, int argc, int argv) Q_DECL_OVERRIDE;
     void generate_SetExceptionHandler(int offset) Q_DECL_OVERRIDE;
     void generate_ThrowException() Q_DECL_OVERRIDE;
     void generate_GetException() Q_DECL_OVERRIDE;
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index e7a104af66..eb4f6a21fc 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -1098,6 +1098,37 @@ ReturnedValue Runtime::method_callValue(ExecutionEngine *engine, const Value &fu
     return static_cast<const FunctionObject &>(func).call(nullptr, argv, argc);
 }
 
+ReturnedValue Runtime::method_callQmlScopeObjectProperty(ExecutionEngine *engine, Value *base,
+                                                         int propertyIndex, Value *argv, int argc)
+{
+    Scope scope(engine);
+    ScopedFunctionObject fo(scope, method_loadQmlScopeObjectProperty(engine, *base, propertyIndex,
+                                                                     /*captureRequired*/true));
+    if (!fo) {
+        QString error = QStringLiteral("Property '%1' of scope object is not a function").arg(propertyIndex);
+        return engine->throwTypeError(error);
+    }
+
+    QObject *qmlScopeObj = static_cast<QmlContext *>(base)->d()->qml()->scopeObject;
+    ScopedValue qmlScopeValue(scope, QObjectWrapper::wrap(engine, qmlScopeObj));
+    return fo->call(qmlScopeValue, argv, argc);
+}
+
+ReturnedValue Runtime::method_callQmlContextObjectProperty(ExecutionEngine *engine, Value *base,
+                                                           int propertyIndex, Value *argv, int argc)
+{
+    Scope scope(engine);
+    ScopedFunctionObject fo(scope, method_loadQmlContextObjectProperty(engine, *base, propertyIndex,
+                                                                       /*captureRequired*/true));
+    if (!fo) {
+        QString error = QStringLiteral("Property '%1' of context object is not a function").arg(propertyIndex);
+        return engine->throwTypeError(error);
+    }
+
+    QObject *qmlContextObj = static_cast<QmlContext *>(base)->d()->qml()->context->contextData()->contextObject;
+    ScopedValue qmlContextValue(scope, QObjectWrapper::wrap(engine, qmlContextObj));
+    return fo->call(qmlContextValue, argv, argc);
+}
 
 ReturnedValue Runtime::method_construct(ExecutionEngine *engine, const Value &function, Value *argv, int argc)
 {
diff --git a/src/qml/jsruntime/qv4runtimeapi_p.h b/src/qml/jsruntime/qv4runtimeapi_p.h
index ea31dfd08b..2956a4a463 100644
--- a/src/qml/jsruntime/qv4runtimeapi_p.h
+++ b/src/qml/jsruntime/qv4runtimeapi_p.h
@@ -188,6 +188,8 @@ struct ExceptionCheck<void (*)(QV4::NoThrowEngine *, A, B, C)> {
     F(ReturnedValue, loadQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)) \
     F(ReturnedValue, loadQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)) \
     F(ReturnedValue, loadQmlIdObject, (ExecutionEngine *engine, const Value &context, uint index)) \
+    F(ReturnedValue, callQmlScopeObjectProperty, (ExecutionEngine *engine, Value *base, int propertyIndex, Value *argv, int argc)) \
+    F(ReturnedValue, callQmlContextObjectProperty, (ExecutionEngine *engine, Value *base, int propertyIndex, Value *argv, int argc)) \
     \
     F(void, storeQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)) \
     F(void, storeQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)) \
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index e248d590f7..d44c219d18 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -840,6 +840,18 @@ QV4::ReturnedValue VME::exec(const FunctionObject *fo, const Value *thisObject,
         CHECK_EXCEPTION;
     MOTH_END_INSTR(CallGlobalLookup)
 
+    MOTH_BEGIN_INSTR(CallScopeObjectProperty)
+        STORE_IP();
+        acc = Runtime::method_callQmlScopeObjectProperty(engine, stack + base, name, stack + argv, argc);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(CallScopeObjectProperty)
+
+    MOTH_BEGIN_INSTR(CallContextObjectProperty)
+        STORE_IP();
+        acc = Runtime::method_callQmlContextObjectProperty(engine, stack + base, name, stack + argv, argc);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(CallContextObjectProperty)
+
     MOTH_BEGIN_INSTR(SetExceptionHandler)
         exceptionHandler = offset ? code + offset : nullptr;
     MOTH_END_INSTR(SetExceptionHandler)
diff --git a/tests/auto/qml/qqmllanguage/data/thisInQmlScope.qml b/tests/auto/qml/qqmllanguage/data/thisInQmlScope.qml
new file mode 100644
index 0000000000..e3c99e70e1
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/thisInQmlScope.qml
@@ -0,0 +1,10 @@
+import QtQml 2.2
+QtObject {
+    property int x: 42
+    property int y: 0
+    function g(){
+        y = this.x;
+    }
+    property var f: g
+    Component.onCompleted: f()
+}
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 03d53b755d..195a9687a8 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -281,6 +281,8 @@ private slots:
 
     void lowercaseTypeNames();
 
+    void thisInQmlScope();
+
 private:
     QQmlEngine engine;
     QStringList defaultImportPathList;
@@ -4911,6 +4913,19 @@ void tst_qqmllanguage::lowercaseTypeNames()
     QCOMPARE(qmlRegisterSingletonType<QObject>("Test", 1, 0, "lowerCaseTypeName", nullptr), -1);
 }
 
+void tst_qqmllanguage::thisInQmlScope()
+{
+    QQmlEngine engine;
+
+    QQmlComponent component(&engine, testFileUrl("thisInQmlScope.qml"));
+    QTRY_VERIFY(component.isReady());
+    VERIFY_ERRORS(0);
+    QScopedPointer<QObject> o(component.create());
+    QVERIFY(!o.isNull());
+    QCOMPARE(o->property("x"), QVariant(42));
+    QCOMPARE(o->property("y"), QVariant(42));
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"