net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/codegen/CaseLabel.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v0.5
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v05.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  ******************************************************************************/
  11 package net.sourceforge.phpdt.internal.compiler.codegen;
  12
  13 public class CaseLabel extends Label {
  14         public int instructionPosition = POS_NOT_SET;
  15         public int backwardsBranch = POS_NOT_SET;
  16 /**
  17  * CaseLabel constructor comment.
  18  * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  19  */
  20 public CaseLabel(CodeStream codeStream) {
  21         super(codeStream);
  22 }
  23 /*
  24 * Put down  a refernece to the array at the location in the codestream.
  25 */
  26 void branch() {
  27         if (position == POS_NOT_SET) {
  28                 addForwardReference(codeStream.position);
  29                 // Leave 4 bytes free to generate the jump offset afterwards
  30                 codeStream.position += 4;
  31                 codeStream.classFileOffset += 4;
  32         } else { //Position is set. Write it!
  33                 codeStream.writeSignedWord(position - codeStream.position + 1);
  34         }
  35 }
  36 /*
  37 * Put down  a refernece to the array at the location in the codestream.
  38 */
  39 void branchWide() {
  40         if (position == POS_NOT_SET) {
  41                 addForwardReference(codeStream.position);
  42                 // Leave 4 bytes free to generate the jump offset afterwards
  43                 codeStream.position += 4;
  44         } else { //Position is set. Write it!
  45                 codeStream.writeSignedWord(position - codeStream.position + 1);
  46         }
  47 }
  48 public boolean isStandardLabel(){
  49         return false;
  50 }
  51 /*
  52 * Put down  a reference to the array at the location in the codestream.
  53 */
  54 public void place() {
  55         position = codeStream.position;
  56         if (instructionPosition == POS_NOT_SET)
  57                 backwardsBranch = position;
  58         else {
  59                 int offset = position - instructionPosition;
  60                 for (int i = 0; i < forwardReferenceCount; i++) {
  61                         codeStream.writeSignedWord(forwardReferences[i], offset);
  62                 }
  63                 // add the label int the codeStream labels collection
  64                 codeStream.addLabel(this);
  65         }
  66 }
  67 /*
  68 * Put down  a refernece to the array at the location in the codestream.
  69 */
  70 void placeInstruction() {
  71         if (instructionPosition == POS_NOT_SET) {
  72                 instructionPosition = codeStream.position;
  73                 if (backwardsBranch != POS_NOT_SET) {
  74                         int offset = backwardsBranch - instructionPosition;
  75                         for (int i = 0; i < forwardReferenceCount; i++)
  76                                 codeStream.writeSignedWord(forwardReferences[i], offset);
  77                         backwardsBranch = POS_NOT_SET;
  78                 }
  79         }
  80 }
  81 }