src/org/eclipse/jdt/internal/compiler/ast/ContinueStatement.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.jdt.internal.compiler.ast;
  12
  13 import org.eclipse.jdt.internal.compiler.ASTVisitor;
  14 import org.eclipse.jdt.internal.compiler.flow.*;
  15 import org.eclipse.jdt.internal.compiler.lookup.*;
  16
  17 public class ContinueStatement extends BranchStatement {
  18
  19         public ContinueStatement(char[] l, int s, int e) {
  20
  21                 super(l, s, e);
  22         }
  23
  24         public FlowInfo analyseCode(
  25                 BlockScope currentScope,
  26                 FlowContext flowContext,
  27                 FlowInfo flowInfo) {
  28
  29                 // here requires to generate a sequence of finally blocks invocations depending corresponding
  30                 // to each of the traversed try statements, so that execution will terminate properly.
  31
  32                 // lookup the label, this should answer the returnContext
  33                 FlowContext targetContext = (label == null)
  34                                 ? flowContext.getTargetContextForDefaultContinue()
  35                                 : flowContext.getTargetContextForContinueLabel(label);
  36
  37                 if (targetContext == null) {
  38                         if (label == null) {
  39                                 currentScope.problemReporter().invalidContinue(this);
  40                         } else {
  41                                 currentScope.problemReporter().undefinedLabel(this);
  42                         }
  43                         return flowInfo; // pretend it did not continue since no actual target
  44                 }
  45
  46                 if (targetContext == FlowContext.NotContinuableContext) {
  47                         currentScope.problemReporter().invalidContinue(this);
  48                         return flowInfo; // pretend it did not continue since no actual target
  49                 }
  50                 targetLabel = targetContext.continueLabel();
  51                 FlowContext traversedContext = flowContext;
  52                 int subIndex = 0, maxSub = 5;
  53                 subroutines = new SubRoutineStatement[maxSub];
  54
  55                 do {
  56                         SubRoutineStatement sub;
  57                         if ((sub = traversedContext.subRoutine()) != null) {
  58                                 if (subIndex == maxSub) {
  59                                         System.arraycopy(subroutines, 0, (subroutines = new SubRoutineStatement[maxSub*=2]), 0, subIndex); // grow
  60                                 }
  61                                 subroutines[subIndex++] = sub;
  62                                 if (sub.isSubRoutineEscaping()) {
  63                                         break;
  64                                 }
  65                         }
  66                         traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
  67
  68                         ASTNode node;
  69                         if ((node = traversedContext.associatedNode) instanceof TryStatement) {
  70                                 TryStatement tryStatement = (TryStatement) node;
  71                                 flowInfo.addInitializationsFrom(tryStatement.subRoutineInits); // collect inits
  72                         } else if (traversedContext == targetContext) {
  73                                 // only record continue info once accumulated through subroutines, and only against target context
  74                                 targetContext.recordContinueFrom(flowInfo);
  75                                 break;
  76                         }
  77                 } while ((traversedContext = traversedContext.parent) != null);
  78
  79                 // resize subroutines
  80                 if (subIndex != maxSub) {
  81                         System.arraycopy(subroutines, 0, (subroutines = new SubRoutineStatement[subIndex]), 0, subIndex);
  82                 }
  83                 return FlowInfo.DEAD_END;
  84         }
  85
  86         public StringBuffer printStatement(int tab, StringBuffer output) {
  87
  88                 printIndent(tab, output).append("continue "); //$NON-NLS-1$
  89                 if (label != null) output.append(label);
  90                 return output.append(';');
  91         }
  92
  93         public void traverse(
  94                 ASTVisitor visitor,
  95                 BlockScope blockScope) {
  96
  97                 visitor.visit(this, blockScope);
  98                 visitor.endVisit(this, blockScope);
  99         }
 100 }