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