Use qmltc compiler prototype as a fallback implementation

Task-number: QTBUG-91927
Task-number: QTBUG-96041
Task-number: QTBUG-84368
Change-Id: I47320b5f3ed8efff6fb234778df5fae5be5b64f2
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit e7ce5abf24f04d1b071343f07ca28b6a5d9ad4b9)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 373 insertions, 0 deletions

diff --git a/src/qml/qmltc/supportlibrary/qqmlcppbinding.cpp b/src/qml/qmltc/supportlibrary/qqmlcppbinding.cpp
new file mode 100644
index 0000000000..142f9be024
--- /dev/null
+++ b/src/qml/qmltc/supportlibrary/qqmlcppbinding.cpp
@@ -0,0 +1,147 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlcppbinding_p.h"
+
+#include <QtQml/qqmlengine.h>
+#include <QtQml/qqmlcontext.h>
+#include <QtCore/qmetaobject.h>
+
+#include <private/qqmltypedata_p.h>
+#include <private/qqmlpropertybinding_p.h>
+#include <private/qqmlbinding_p.h>
+#include <private/qv4qmlcontext_p.h>
+#include <private/qqmlproperty_p.h>
+#include <private/qqmlbinding_p.h>
+
+QT_BEGIN_NAMESPACE
+
+template<typename CreateBinding>
+inline decltype(auto) createBindingInScope(QObject *thisObject, CreateBinding create)
+{
+    QQmlEngine *qmlengine = qmlEngine(thisObject);
+    Q_ASSERT(qmlengine);
+    QV4::ExecutionEngine *v4 = qmlengine->handle();
+    Q_ASSERT(v4);
+
+    QQmlData *ddata = QQmlData::get(thisObject);
+    Q_ASSERT(ddata && ddata->outerContext);
+    QQmlRefPointer<QQmlContextData> ctxtdata = QQmlRefPointer<QQmlContextData>(ddata->outerContext);
+
+    QV4::Scope scope(v4);
+    QV4::ExecutionContext *executionCtx = v4->scriptContext();
+    QV4::Scoped<QV4::QmlContext> qmlContext(
+            scope, QV4::QmlContext::create(executionCtx, ctxtdata, thisObject));
+
+    return create(ctxtdata, qmlContext);
+}
+
+QUntypedPropertyBinding
+QQmlCppBinding::createBindingForBindable(const QV4::ExecutableCompilationUnit *unit,
+                                         QObject *thisObject, qsizetype functionIndex,
+                                         QObject *bindingTarget, int metaPropertyIndex,
+                                         int valueTypePropertyIndex, const QString &propertyName)
+{
+    Q_UNUSED(propertyName);
+
+    QV4::Function *v4Function = unit->runtimeFunctions.value(functionIndex, nullptr);
+    if (!v4Function) {
+        // TODO: align with existing logging of such
+        qCritical() << "invalid JavaScript function index (internal error)";
+        return QUntypedPropertyBinding();
+    }
+    if (metaPropertyIndex < 0) {
+        // TODO: align with existing logging of such
+        qCritical() << "invalid meta property index (internal error)";
+        return QUntypedPropertyBinding();
+    }
+
+    const QMetaObject *mo = bindingTarget->metaObject();
+    Q_ASSERT(mo);
+    QMetaProperty property = mo->property(metaPropertyIndex);
+    Q_ASSERT(valueTypePropertyIndex == -1 || QString::fromUtf8(property.name()) == propertyName);
+
+    return createBindingInScope(
+            thisObject,
+            [&](const QQmlRefPointer<QQmlContextData> &ctxt, QV4::ExecutionContext *scope) {
+                auto index = QQmlPropertyIndex(property.propertyIndex(), valueTypePropertyIndex);
+                return QQmlPropertyBinding::create(property.metaType(), v4Function, thisObject,
+                                                   ctxt, scope, bindingTarget, index);
+            });
+}
+
+void QQmlCppBinding::createBindingForNonBindable(const QV4::ExecutableCompilationUnit *unit,
+                                                 QObject *thisObject, qsizetype functionIndex,
+                                                 QObject *bindingTarget, int metaPropertyIndex,
+                                                 int valueTypePropertyIndex,
+                                                 const QString &propertyName)
+{
+    Q_UNUSED(propertyName);
+
+    QV4::Function *v4Function = unit->runtimeFunctions.value(functionIndex, nullptr);
+    if (!v4Function) {
+        // TODO: align with existing logging of such
+        qCritical() << "invalid JavaScript function index (internal error)";
+        return;
+    }
+    if (metaPropertyIndex < 0) {
+        // TODO: align with existing logging of such
+        qCritical() << "invalid meta property index (internal error)";
+        return;
+    }
+
+    const QMetaObject *mo = bindingTarget->metaObject();
+    Q_ASSERT(mo);
+    QMetaProperty property = mo->property(metaPropertyIndex);
+    Q_ASSERT(valueTypePropertyIndex != -1 || QString::fromUtf8(property.name()) == propertyName);
+
+    createBindingInScope(
+            thisObject,
+            [&](const QQmlRefPointer<QQmlContextData> &ctxt, QV4::ExecutionContext *scope) -> void {
+                QQmlBinding *binding = QQmlBinding::create(property.metaType(), v4Function,
+                                                           thisObject, ctxt, scope);
+                // almost as in qv4objectwrapper.cpp:535
+                Q_ASSERT(!property.isAlias()); // we convert aliases to (almost) real properties
+                binding->setTarget(bindingTarget, property.propertyIndex(), false,
+                                   valueTypePropertyIndex);
+                QQmlPropertyPrivate::setBinding(binding);
+            });
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qmltc/supportlibrary/qqmlcppbinding_p.h b/src/qml/qmltc/supportlibrary/qqmlcppbinding_p.h
new file mode 100644
index 0000000000..5c4a10e39d
--- /dev/null
+++ b/src/qml/qmltc/supportlibrary/qqmlcppbinding_p.h
@@ -0,0 +1,88 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLCPPBINDING_P_H
+#define QQMLCPPBINDING_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qobject.h>
+#include <QtCore/qproperty.h>
+#include <QtCore/qurl.h>
+
+#include <QtQml/qqmlengine.h>
+#include <QtQml/qqmlcontext.h>
+#include <QtCore/qmetaobject.h>
+
+#include <private/qqmltypedata_p.h>
+#include <private/qqmlpropertybinding_p.h>
+#include <private/qqmlbinding_p.h>
+#include <private/qv4qmlcontext_p.h>
+#include <private/qqmlproperty_p.h>
+#include <private/qqmlbinding_p.h>
+
+QT_BEGIN_NAMESPACE
+
+struct Q_QML_PRIVATE_EXPORT QQmlCppBinding
+{
+    // TODO: this might instead be put into the QQmlEngine or QQmlAnyBinding?
+    static QUntypedPropertyBinding
+    createBindingForBindable(const QV4::ExecutableCompilationUnit *unit, QObject *thisObject,
+                             qsizetype functionIndex, QObject *bindingTarget, int metaPropertyIndex,
+                             int valueTypePropertyIndex, const QString &propertyName);
+
+    static void createBindingForNonBindable(const QV4::ExecutableCompilationUnit *unit,
+                                            QObject *thisObject, qsizetype functionIndex,
+                                            QObject *bindingTarget, int metaPropertyIndex,
+                                            int valueTypePropertyIndex,
+                                            const QString &propertyName);
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLCPPBINDING_P_H
diff --git a/src/qml/qmltc/supportlibrary/qqmlcpponassignment.cpp b/src/qml/qmltc/supportlibrary/qqmlcpponassignment.cpp
new file mode 100644
index 0000000000..a471ef2594
--- /dev/null
+++ b/src/qml/qmltc/supportlibrary/qqmlcpponassignment.cpp
@@ -0,0 +1,56 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlcpponassignment_p.h"
+
+QT_BEGIN_NAMESPACE
+
+void QQmlCppOnAssignmentHelper::set(QQmlPropertyValueInterceptor *interceptor,
+                                    const QQmlProperty &property)
+{
+    interceptor->setTarget(property);
+}
+
+void QQmlCppOnAssignmentHelper::set(QQmlPropertyValueSource *valueSource,
+                                    const QQmlProperty &property)
+{
+    valueSource->setTarget(property);
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qmltc/supportlibrary/qqmlcpponassignment_p.h b/src/qml/qmltc/supportlibrary/qqmlcpponassignment_p.h
new file mode 100644
index 0000000000..5fb35aab97
--- /dev/null
+++ b/src/qml/qmltc/supportlibrary/qqmlcpponassignment_p.h
@@ -0,0 +1,82 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLCPPONASSIGNMENT_P_H
+#define QQMLCPPONASSIGNMENT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmlpropertyvalueinterceptor_p.h>
+#include <QtQml/qqmlpropertyvaluesource.h>
+
+QT_BEGIN_NAMESPACE
+
+/*! \internal
+
+    Helper class that provides setTarget() functionality for both value
+    interceptors and value sources.
+
+    Property value sources could be problematic because QQuickAbstractAnimation
+    changes access specifier of QQmlPropertyValueSource::setTarget() to private
+    (unintentionally?). This API allows to avoid manual casts to base types as
+    the C++ compiler would implicitly cast derived classes in this case.
+*/
+struct Q_QML_PRIVATE_EXPORT QQmlCppOnAssignmentHelper
+{
+    // TODO: in theory, this API might just accept QObject * and int that would
+    // give the QMetaProperty. using the meta property, one could create
+    // QQmlProperty with a call to QQmlProperty::restore() (if there's an
+    // overload that takes QMetaProperty instead of QQmlPropertyData - which is
+    // also possible to add by using QQmlPropertyData::load())
+    static void set(QQmlPropertyValueInterceptor *interceptor, const QQmlProperty &property);
+    static void set(QQmlPropertyValueSource *valueSource, const QQmlProperty &property);
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLCPPONASSIGNMENT_P_H