/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
 *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
 *  Copyright (C) 2003, 2006, 2007 Apple Inc.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public License
 *  along with this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 */

#ifndef Parser_h
#define Parser_h

#include <wtf/Forward.h>
#include <wtf/Noncopyable.h>
#include <wtf/RefPtr.h>
#include <wtf/Vector.h>

namespace KJS
{

class Node;
class FunctionBodyNode;
class ProgramNode;
class UString;

struct UChar;

/**
 * @internal
 *
 * Parses ECMAScript source code and converts into ProgramNode objects, which
 * represent the root of a parse tree. The tree is then semantically
 * checked with a semantic analyzer. This class provides a convenient
 * workaround for the problem of the bison parser working in a static context.
 */
class Parser : Noncopyable
{
public:
    PassRefPtr<ProgramNode> parseProgram(const UString &sourceURL, int startingLineNumber,
                                         const UChar *code, unsigned length,
                                         int *sourceId = nullptr, int *errLine = nullptr, UString *errMsg = nullptr);

    PassRefPtr<FunctionBodyNode> parseFunctionBody(const UString &sourceURL, int startingLineNumber,
            const UChar *code, unsigned length,
            int *sourceId = nullptr, int *errLine = nullptr, UString *errMsg = nullptr);

    int sourceId()
    {
        return m_sourceId;
    }

    void didFinishParsing(PassRefPtr<ProgramNode>);

    static void noteNodeCycle(Node *);
    static void removeNodeCycle(Node *);

    // We keep track of various flags about the function body we're
    // tracking on a stack; the FunctionBody ctor pops them off
    // when we're done parsing and are making the body node.
    void pushFunctionContext(unsigned initialFlags);
    void setFunctionFlags(unsigned newFlags);
    unsigned popFunctionContext();

private:
    friend Parser &parser();

    Parser(); // Use parser() instead.
    void parse(const UString &sourceURL, int startingLineNumber,
               const UChar *code, unsigned length,
               int *sourceId = nullptr, int *errLine = nullptr, UString *errMsg = nullptr);

    int m_sourceId;
    RefPtr<ProgramNode> m_progNode;
    WTF::Vector<unsigned, 8> m_functionFlags;
};

Parser &parser(); // Returns the singleton JavaScript parser.

inline void Parser::pushFunctionContext(unsigned initialFlags)
{
    m_functionFlags.append(initialFlags);
}

inline void Parser::setFunctionFlags(unsigned newFlags)
{
    m_functionFlags.last() |= newFlags;
}

inline unsigned Parser::popFunctionContext()
{
    unsigned flags = m_functionFlags.last();
    m_functionFlags.removeLast();
    return flags;
}

} // namespace KJS

#endif // Parser_h
