OpCode.cs :  » 2.6.4-mono-.net-core » System.Reflection » System » Reflection » Emit » C# / CSharp Open Source

//
// System.Reflection.Emit.OpCode
//
// Author:
//   Duncan Mak (duncan@ximian.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;

namespace System.Reflection.Emit{

  [ComVisible (true)]
  public struct OpCode {

    internal byte op1, op2;
    byte push, pop, size, type, args, flow;

    //
    // The order is:
    //   Op1, Op2, StackBehaviourPush, StackBehaviourPop
    //   Size, OpCodeType, OperandType, FlowControl
    //
    internal OpCode (int p, int q)
    {

      op1  = (byte) ((p >> 0)  & 0xFF);
      op2  = (byte) ((p >> 8)  & 0xFF);
      push = (byte) ((p >> 16) & 0xFF);
      pop  = (byte) ((p >> 24) & 0xFF);

      size = (byte) ((q >> 0)  & 0xFF);
      type = (byte) ((q >> 8)  & 0xFF);
      args = (byte) ((q >> 16) & 0xFF);
      flow = (byte) ((q >> 24) & 0xFF);
    }


    public override int GetHashCode ()
    {
      return Name.GetHashCode ();
    }

    public override bool Equals (Object obj)
    {
      if (obj == null || !(obj is OpCode))
        return false;

      OpCode v = (OpCode) obj;

      return v.op1 == op1 && v.op2 == op2;
    }

    public bool Equals (OpCode obj)
    {
      return obj.op1 == op1 && obj.op2 == op2;
    }

    public override string ToString ()
    {
      return Name;
    }

    public string Name {
      get {
        if (op1 == 0xFF)
          return OpCodeNames.names [op2];

        return OpCodeNames.names [256 + op2];
      }
    }

    public int Size {
      get {
        return (int) size;
      }
    }

    public OpCodeType OpCodeType {
      get {
        return (OpCodeType) type;
      }
    }

    public OperandType OperandType {
      get {
        return (OperandType) args;
      }
    }

    public FlowControl FlowControl {
      get {
        return (FlowControl) flow;
      }
    }

    public StackBehaviour StackBehaviourPop {
      get {
        return (StackBehaviour) pop;
      }
    }

    public StackBehaviour StackBehaviourPush {
      get {
        return (StackBehaviour) push;
      }
    }

    public short Value {
      get {
        if (size == 1) {
          return op2;
        } else {
          // two byte instruction - combine
          // Some old MS betas returned (op1 << 2) | op2 here...
          return (short) ((op1 << 8) | op2);
        }
      }
    }

    public static bool operator == (OpCode a, OpCode b)
    {
      return a.op1 == b.op1 && a.op2 == b.op2;
    }

    public static bool operator != (OpCode a, OpCode b)
    {
      return a.op1 != b.op1 || a.op2 != b.op2;
    }
  }
}