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