/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt Build Suite.
**
** 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 Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
****************************************************************************/
#ifndef QBS_CYCLEDETECTOR_H
#define QBS_CYCLEDETECTOR_H

#include "buildgraphvisitor.h"
#include <language/forward_decls.h>
#include <logging/logger.h>

#include <QSet>

namespace qbs {
namespace Internal {

class BuildGraphNode;

class CycleDetector : private BuildGraphVisitor
{
public:
    CycleDetector(const Logger &logger);

    void visitProject(const TopLevelProjectConstPtr &project);
    void visitProduct(const ResolvedProductConstPtr &product);

private:
    bool visit(Artifact *artifact);
    bool visit(RuleNode *ruleNode);

    bool visitNode(BuildGraphNode *node);

    QList<BuildGraphNode *> cycle(BuildGraphNode *doubleEntry);

    QSet<BuildGraphNode *> m_allNodes;
    QSet<BuildGraphNode *> m_nodesInCurrentPath;
    BuildGraphNode *m_parent;
    Logger m_logger;
};

} // namespace Internal
} // namespace qbs

#endif // QBS_CYCLEDETECTOR_H