root/libcore/Function2.h

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// 
//   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010,
//   2011 Free Software Foundation, Inc
// 
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// 
// This program 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 General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

#ifndef GNASH_FUNCTION2_H
#define GNASH_FUNCTION2_H

#include <vector>
#include <cassert>
#include <string>

#include "Function.h"
#include "smart_ptr.h"

// Forward declarations
namespace gnash {
    class action_buffer;
    class as_object;
}

namespace gnash {

/// Function2 adds extra sauce to ordinary Functions.
//
/// The Function2 was introduced in version 6 of the player. Differences from
/// ordinary functions are:
/// 1. Up to 256 local registers.
/// 2. Ability to suppress super, this, arguments
/// 3. Ability to store super, this, arguments, _global, _root, and _parent
///    in registers.
class Function2 : public Function
{

public:

        enum DefineFunction2Flags
        {
                /// Bind one register to "this" 
                PRELOAD_THIS = 0x01,

                /// No "this" variable accessible by name 
                SUPPRESS_THIS = 0x02,

                /// Bind one register to "arguments" 
                PRELOAD_ARGUMENTS = 0x04,

                /// No "argument" variable accessible by name 
                SUPPRESS_ARGUMENTS = 0x08,

                /// Bind one register to "super" 
                PRELOAD_SUPER = 0x10,

                /// No "super" variable accessible by name 
                SUPPRESS_SUPER = 0x20,

                /// Bind one register to "_root" 
                PRELOAD_ROOT = 0x40, 

                /// Bind one register to "_parent" 
                PRELOAD_PARENT = 0x80,

                /// Bind one register to "_global" 
                PRELOAD_GLOBAL = 256
        };

    // Create a function defined in a DefineFunction2 opcode.
        Function2(const action_buffer& ab, as_environment& env, size_t start,
                const ScopeStack& with_stack);

        virtual ~Function2() {}

    /// Return the number of registers to allocate for this function.
    virtual boost::uint8_t registers() const {
        return _registerCount;
    }

        void setRegisterCount(boost::uint8_t ct) {
        _registerCount = ct;
    }

        void setFlags(boost::uint16_t flags) {
        _function2Flags = flags;
    }

        /// Dispatch.
        virtual as_value call(const fn_call& fn);

private:

    /// The number of registers required.
        boost::uint8_t _registerCount;

        /// Used to control implicit arg register assignments
        boost::uint16_t _function2Flags;

};


} // end of gnash namespace

#endif