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diff --git a/src/lib/corelib/loader/modulepropertymerger.h b/src/lib/corelib/loader/modulepropertymerger.h
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+/****************************************************************************
+**
+** Copyright (C) 2023 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qbs.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#pragma once
+
+#include <QtGlobal>
+
+QT_BEGIN_NAMESPACE
+class QString;
+QT_END_NAMESPACE
+
+namespace qbs::Internal {
+class Item;
+class LoaderState;
+class ProductContext;
+
+// This module comprises functions for collecting values attached to module properties
+// in different contexts.
+// For example, in the Qt.core module you will find a property binding such as this:
+//   cpp.defines: "QT_CORE_LIB"
+// while in the Qt.widgets module, it will look like this:
+//   cpp.defines: "QT_WIDGETS_LIB"
+// A product with a dependency on both these modules will end up with a value of
+// ["QT_WIDGETS_LIB", "QT_CORE_LIB"], plus potentially other defines set elsewhere.
+// Each of these values is assigned a priority that roughly corresponds to the "level" at which
+// the module containing the property binding resides in the dependency hierarchy.
+// For list properties, the priorities determine the order of the respecive values in the
+// final array, for scalar values they determine which one survives. Different scalar values
+// with the same priority trigger a warning message.
+// Since the right-hand side of a binding can refer to properties of the surrounding context,
+// each such value gets its own scope.
+
+// This function is called when a module is loaded via a Depends item.
+// loadingItem is the product or module containing the Depends item.
+// loadingName is the name of that module. It is used as a tie-breaker for list property values
+//             with equal priority.
+// localInstance is the module instance placeholder in the ItemValue of a property binding,
+//               i.e. the "cpp" in "cpp.defines".
+// globalInstance is the actual module into which the properties from localInstance get merged.
+void mergeFromLocalInstance(ProductContext &product, Item *loadingItem,
+                            const QString &loadingName, const Item *localInstance,
+                            Item *globalInstance, LoaderState &loaderState);
+
+// This function is called after all dependencies have been resolved. It uses its global
+// knowledge of module priorities to potentially adjust the order of list values or
+// favor different scalar values. It can also remove previously merged-in values again;
+// this can happen if a module fails to load after it already merged some values, or
+// if it fails validation in the end.
+void doFinalMerge(ProductContext &product, LoaderState &loaderState);
+
+} // namespace qbs::Internal