/*
*
*  ConfParser.java
*
*  mic1 microarchitecture simulator 
*  Copyright (C) 1999, Prentice-Hall, 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 2 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: 
* 
*    Free Software Foundation, Inc. 
*    59 Temple Place - Suite 330 
*    Boston, MA 02111-1307, USA. 
* 
*  A copy of the GPL is available online the GNU web site: 
* 
*    http://www.gnu.org/copyleft/gpl.html
* 
*/ 

import java.io.*;
import java.util.*;

/**
* Parses a macrolanguage description file
*
* @author 
*   Dan Stone (<a href="mailto:dans@ontko.com"><i>dans@ontko.com</i></a>),
*   Ray Ontko & Co,
*   Richmond, Indiana, US
*/
public class ConfParser {

  private static final int radix = 16;
  private static final int exit_code = 1;
  private BufferedInputStream in = null;
  private int lineno;
  private String filename = null;
  private Vector instruction_set = null;

  public ConfParser(InputStream instream) {
    in = new BufferedInputStream(instream);
    parse();
  }

  public ConfParser(String filename) {
    this.filename = filename;
    try {
      in = new BufferedInputStream(new FileInputStream(filename));
      parse();
    }
    catch (FileNotFoundException e) {
      System.out.println("File not found: " + filename);
      System.exit(exit_code);
    }
  }

  public Vector getInstructionSet() {
    return instruction_set;
  }

  private void parse() {
    instruction_set = new Vector();
    lineno = 0;
    String s = readLine();
    while (s.length() > 0) {
      StringTokenizer st = new StringTokenizer(s);
      int opcode;
      String mnemonic = null;
      try {
	if (st.hasMoreTokens()) {
	  String str = st.nextToken();
	  opcode = decode(str).intValue();
	  if (st.hasMoreTokens()) { 
	    mnemonic = st.nextToken();
	    int type = Instruction.NOPARAM;
	    if (st.hasMoreTokens()) {
	      String param = st.nextToken();
	      if (param.equalsIgnoreCase("varnum")) {
		if (st.hasMoreTokens() && st.nextToken().equalsIgnoreCase("const"))
		  type = Instruction.VARNUM_CONST;
		else type = Instruction.VARNUM;
	      }
	      else if (param.equalsIgnoreCase("index"))
		type = Instruction.INDEX;
	      else if (param.equalsIgnoreCase("label"))
		type = Instruction.LABEL;
	      else if (param.equalsIgnoreCase("byte"))
		type = Instruction.BYTE;
	      else if (param.equalsIgnoreCase("const"))
		type = Instruction.CONST;
	      else if (param.equalsIgnoreCase("offset"))
		type = Instruction.OFFSET;
	      else System.out.println("Parameter type " + param + " not supported");
	    }
	    instruction_set.addElement(new Instruction(opcode, mnemonic, type));
	  }
	}
      }
      catch (NumberFormatException nfe) {
	System.out.println(" " + filename + " " + lineno + ": invalid number format for opcode");
      }
      s = readLine();
    }
  }

  /**
     decode() parses a String and creates an Integer object with the appropriate value.  
     This method performs the same function as the java.lang.Integer.decode() method. It is
     included to ensure compatability with Java 1.0 compilers.
  */
  private Integer decode(String str) throws NumberFormatException {
    if (str.startsWith("0x") || str.startsWith("0X")) {
      return Integer.valueOf(str.substring(2), 16);
    }
    if (str.startsWith("#")) {
      return Integer.valueOf(str.substring(1), 16);
    }
    if (str.startsWith("0") && str.length() > 1) {
      return Integer.valueOf(str.substring(1), 8);
    }
    return Integer.valueOf(str);
  }    

  private String readLine() {
    String s = new String();
    try {
      int ch = 0;
      while (((char)ch) != '\n' && ch > -1) {
	ch = in.read();
	if (ch == '/' && in.read() == '/') {
	  ch = in.read();
	  while (((char)ch) != '\n' && ch > -1)
	    ch = in.read();
	  lineno++;
	  return s.toLowerCase() + " ";
	}
	if (ch != '\n' && ch > -1)
	  s += (char)ch;
      }
      lineno++;
      return s.toLowerCase();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
    return s.toLowerCase();
  }
}