code: /**
   * Copyright (c) 2005, Regents of the University of California
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * Neither the name of the University of California, Los Angeles nor the
   * names of its contributors may be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * Created Oct 25, 2005
   */
  package jintgen.gen;
  
  import jintgen.isdl.GlobalDecl;
  import jintgen.isdl.parser.Token;
  import jintgen.jigir.*;
  import jintgen.types.Type;
  import java.util.HashMap;
  
  /**
   * @author Ben L. Titzer
   */
  public class VarRenamer {
  
      protected final HashMap<String, String> varMap;
      int tmpcount;
  
      VarRenamer() {
          varMap = new HashMap<String, String>();
      }
  
      public VarExpr getVarExpr(VarExpr e) {
          Decl decl = e.getDecl();
          if ( decl == null || !(decl instanceof GlobalDecl) ) {
              String orig = e.variable.image;
              String nn = varMap.get(orig);
              if ( nn != null && !orig.equals(nn) ) {
                  VarExpr ne = new VarExpr(nn);
                  ne.setDecl(decl);
                  ne.setType(e.getType());
                  return ne;
              }
          }
          return e;
      }
  
      public ReadExpr getReadExpr(ReadExpr e) {
          String orig = e.operand.image;
          String nn = varMap.get(orig);
          if ( nn != null && !orig.equals(nn) ) {
              Token tok = new Token();
              tok.image = nn;
              ReadExpr ne = new ReadExpr(e.method, e.typeRef, tok);
              ne.setType(e.getType());
              ne.setAccessor(e.getAccessor());
              return ne;
          }
          return e;
      }
  
      public VarExpr visit(String v) {
          String nn = varMap.get(v);
          if ( !v.equals(nn) ) v = nn;
          return new VarExpr(v);
      }
  
      public void addVariable(String v, String nv) {
          varMap.put(v, nv);
      }
  
      public DeclStmt getDecl(DeclStmt s) {
          // default: do nothing
          return s;
      }
  
      public WriteStmt getWrite(WriteStmt s) {
          String orig = s.operand.image;
          String nn = varMap.get(orig);
          if ( nn != null && !orig.equals(nn) ) {
              Token tok = new Token();
              tok.image = nn;
              WriteStmt writeStmt = new WriteStmt(s.method, s.typeRef, tok, s.expr);
              writeStmt.setAccessor(s.getAccessor());
              return writeStmt;
          }
          return s;
      }
  
      public VarExpr newTemp(Type t) {
          Token tok = new Token();
          tok.image = "$tmp_" + (tmpcount++);
          VarExpr varExpr = new VarExpr(tok);
          varExpr.setType(t);
          return varExpr;
      }
  }
  