// $Id: BasicBlockExprIterator.java,v 1.5 2000/05/01 02:42:52 msato Exp $
// $RWC_Release: Omni-1.6 $
// $RWC_Copyright:
//  Omni Compiler Software Version 1.5-1.6
//  Copyright (C) 2002 PC Cluster Consortium
//  
//  This software is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License version
//  2.1 published by the Free Software Foundation.
//  
//  Omni Compiler Software Version 1.0-1.4
//  Copyright (C) 1999, 2000, 2001.
//   Tsukuba Research Center, Real World Computing Partnership, Japan.
//  
//  Please check the Copyright and License information in the files named
//  COPYRIGHT and LICENSE under the top  directory of the Omni Compiler
//  Software release kit.
//  
//  
//  $
package exc.block;
import exc.object.*;
import exc.block.*;

public class BasicBlockExprIterator {
  BasicBlockIterator i;
  protected StatementIterator is;
  protected Statement current_statement;
  protected BasicBlock current_bblock;

  // constructor
  public BasicBlockExprIterator(Block b){
    init(b);
  }

  public BasicBlockExprIterator(BlockList body){
    init(body);
  }

  public BasicBlockExprIterator(){  }
  
  public void init(Block b){
    i = new BasicBlockIterator(b);
    initialize();
  }

  public void init(BlockList body){
    i = new BasicBlockIterator(body);
    initialize();
  }
  
  public void init(){
    i.init();
    initialize();
  }
  
  // initialize internal iterators
  void initialize(){
    current_bblock = i.getBasicBlock();
    if(current_bblock == null) return;
    is = current_bblock.statements();
    next();
  }

  public void next(){
    current_statement = null;	// unset current_statment
    do {
      if(is != null){	// if statement iterator is active,
	if(is.hasMoreStatement()){
	  current_statement = is.nextStatement();
	  return;
	} else {
	  is = null;  // inactive
	  if(current_bblock.getExpr() != null)
	    return;
	}
      }
      // move to the next basic block.
      nextBasicBlock();
      if(current_bblock == null) return;
      is = current_bblock.statements();
    } while(true);
  }
  
  public void nextBasicBlock(){
    i.next();
    if(i.end()) current_bblock = null;
    else current_bblock = i.getBasicBlock();
  }

  public boolean end(){ return current_bblock == null; }

  public Statement getStatement(){ return current_statement; }
  public BasicBlock getBasicBlock() { return current_bblock; }

  public Xobject getExpr(){
    if(current_statement != null) return current_statement.getExpr();
    else return current_bblock.getExpr();
  }

  public void setExpr(Xobject x){
    if(current_statement != null) current_statement.setExpr(x);
    else current_bblock.setExpr(x);
  }
  
  public void insertStatement(Xobject s){
    if(current_statement != null) current_statement.insert(s);
    else current_bblock.add(s);
  }

  public void addStatement(Xobject s){
    if(current_statement != null) current_statement.add(s);
    else current_bblock.add(s);
  }

  public LineNo getLineNo(){
    if(current_statement != null) return current_statement.getLineNo();
    else return current_bblock.getParent().getLineNo();
  }
}