net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/Continue.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.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
  14 import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
  15 import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
  16 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  17
  18 public class Continue extends BranchStatement {
  19
  20         public Continue(char[] l, int s, int e) {
  21
  22                 super(l, s, e);
  23         }
  24
  25         public FlowInfo analyseCode(
  26                 BlockScope currentScope,
  27                 FlowContext flowContext,
  28                 FlowInfo flowInfo) {
  29
  30                 // here requires to generate a sequence of finally blocks invocations depending corresponding
  31                 // to each of the traversed try statements, so that execution will terminate properly.
  32
  33                 // lookup the label, this should answer the returnContext
  34                 FlowContext targetContext;
  35                 if (label == null) {
  36                         targetContext = flowContext.getTargetContextForDefaultContinue();
  37                 } else {
  38                         targetContext = flowContext.getTargetContextForContinueLabel(label);
  39                 }
  40                 if (targetContext == null) {
  41                         if (label == null) {
  42                                 currentScope.problemReporter().invalidContinue(this);
  43                         } else {
  44                                 currentScope.problemReporter().undefinedLabel(this); // need to improve
  45                         }
  46                 } else {
  47                         if (targetContext == FlowContext.NotContinuableContext) {
  48                                 currentScope.problemReporter().invalidContinue(this);
  49                                 return FlowInfo.DeadEnd;
  50                         }
  51                         targetLabel = targetContext.continueLabel();
  52                         targetContext.recordContinueFrom(flowInfo);
  53                         FlowContext traversedContext = flowContext;
  54                         int subIndex = 0, maxSub = 5;
  55                         subroutines = new AstNode[maxSub];
  56                         while (true) {
  57                                 AstNode sub;
  58                                 if ((sub = traversedContext.subRoutine()) != null) {
  59                                         if (subIndex == maxSub) {
  60                                                 System.arraycopy(
  61                                                         subroutines,
  62                                                         0,
  63                                                         (subroutines = new AstNode[maxSub *= 2]),
  64                                                         0,
  65                                                         subIndex);
  66                                                 // grow
  67                                         }
  68                                         subroutines[subIndex++] = sub;
  69                                         if (sub.cannotReturn()) {
  70                                                 break;
  71                                         }
  72                                 }
  73                                 // remember the initialization at this
  74                                 // point for dealing with blank final variables.
  75                                 traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
  76
  77                                 if (traversedContext == targetContext) {
  78                                         break;
  79                                 } else {
  80                                         traversedContext = traversedContext.parent;
  81                                 }
  82                         }
  83                         // resize subroutines
  84                         if (subIndex != maxSub) {
  85                                 System.arraycopy(
  86                                         subroutines,
  87                                         0,
  88                                         (subroutines = new AstNode[subIndex]),
  89                                         0,
  90                                         subIndex);
  91                         }
  92                 }
  93                 return FlowInfo.DeadEnd;
  94         }
  95
  96         public String toString(int tab) {
  97
  98                 String s = tabString(tab);
  99                 s = s + "continue "; //$NON-NLS-1$
 100                 if (label != null)
 101                         s = s + new String(label);
 102                 return s;
 103         }
 104
 105         public void traverse(
 106                 IAbstractSyntaxTreeVisitor visitor,
 107                 BlockScope blockScope) {
 108
 109                 visitor.visit(this, blockScope);
 110                 visitor.endVisit(this, blockScope);
 111         }
 112 }