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.*;
  15 import net.sourceforge.phpdt.internal.compiler.lookup.*;
  16
  17 public class Continue extends BranchStatement {
  18
  19         public Continue(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;
  34                 if (label == null) {
  35                         targetContext = flowContext.getTargetContextForDefaultContinue();
  36                 } else {
  37                         targetContext = flowContext.getTargetContextForContinueLabel(label);
  38                 }
  39                 if (targetContext == null) {
  40                         if (label == null) {
  41                                 currentScope.problemReporter().invalidContinue(this);
  42                         } else {
  43                                 currentScope.problemReporter().undefinedLabel(this); // need to improve
  44                         }
  45                 } else {
  46                         if (targetContext == FlowContext.NotContinuableContext) {
  47                                 currentScope.problemReporter().invalidContinue(this);
  48                                 return FlowInfo.DeadEnd;
  49                         }
  50                         targetLabel = targetContext.continueLabel();
  51                         targetContext.recordContinueFrom(flowInfo);
  52                         FlowContext traversedContext = flowContext;
  53                         int subIndex = 0, maxSub = 5;
  54                         subroutines = new AstNode[maxSub];
  55                         while (true) {
  56                                 AstNode sub;
  57                                 if ((sub = traversedContext.subRoutine()) != null) {
  58                                         if (subIndex == maxSub) {
  59                                                 System.arraycopy(
  60                                                         subroutines,
  61                                                         0,
  62                                                         (subroutines = new AstNode[maxSub *= 2]),
  63                                                         0,
  64                                                         subIndex);
  65                                                 // grow
  66                                         }
  67                                         subroutines[subIndex++] = sub;
  68                                         if (sub.cannotReturn()) {
  69                                                 break;
  70                                         }
  71                                 }
  72                                 // remember the initialization at this
  73                                 // point for dealing with blank final variables.
  74                                 traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
  75
  76                                 if (traversedContext == targetContext) {
  77                                         break;
  78                                 } else {
  79                                         traversedContext = traversedContext.parent;
  80                                 }
  81                         }
  82                         // resize subroutines
  83                         if (subIndex != maxSub) {
  84                                 System.arraycopy(
  85                                         subroutines,
  86                                         0,
  87                                         (subroutines = new AstNode[subIndex]),
  88                                         0,
  89                                         subIndex);
  90                         }
  91                 }
  92                 return FlowInfo.DeadEnd;
  93         }
  94
  95         public String toString(int tab) {
  96
  97                 String s = tabString(tab);
  98                 s = s + "continue "; //$NON-NLS-1$
  99                 if (label != null)
 100                         s = s + new String(label);
 101                 return s;
 102         }
 103
 104         public void traverse(
 105                 IAbstractSyntaxTreeVisitor visitor,
 106                 BlockScope blockScope) {
 107
 108                 visitor.visit(this, blockScope);
 109                 visitor.endVisit(this, blockScope);
 110         }
 111 }