net.sourceforge.phpeclipse/src/net/sourceforge/phpeclipse/internal/compiler/ast/Break.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 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 net.sourceforge.phpeclipse.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 = (label == null)
  34                         ? flowContext.getTargetContextForDefaultBreak()
  35                         : flowContext.getTargetContextForBreakLabel(label);
  36
  37                 if (targetContext == null) {
  38                         if (label == null) {
  39                                 currentScope.problemReporter().invalidBreak(this);
  40                         } else {
  41                                 currentScope.problemReporter().undefinedLabel(this);
  42                         }
  43                         return flowInfo; // pretend it did not break since no actual target
  44                 }
  45
  46                 targetLabel = targetContext.breakLabel();
  47                 FlowContext traversedContext = flowContext;
  48                 int subIndex = 0, maxSub = 5;
  49                 subroutines = new ASTNode[maxSub];
  50
  51                 do {
  52                         ASTNode sub;
  53                         if ((sub = traversedContext.subRoutine()) != null) {
  54                                 if (subIndex == maxSub) {
  55                                         System.arraycopy(subroutines, 0, (subroutines = new ASTNode[maxSub*=2]), 0, subIndex); // grow
  56                                 }
  57                                 subroutines[subIndex++] = sub;
  58                                 if (sub.cannotReturn()) {
  59                                         break;
  60                                 }
  61                         }
  62                         traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
  63
  64                         ASTNode node;
  65                         if ((node = traversedContext.associatedNode) instanceof TryStatement) {
  66                                 TryStatement tryStatement = (TryStatement) node;
  67                                 flowInfo.addInitializationsFrom(tryStatement.subRoutineInits); // collect inits
  68                         } else if (traversedContext == targetContext) {
  69                                 // only record break info once accumulated through subroutines, and only against target context
  70                                 targetContext.recordBreakFrom(flowInfo);
  71                                 break;
  72                         }
  73                 } while ((traversedContext = traversedContext.parent) != null);
  74
  75                 // resize subroutines
  76                 if (subIndex != maxSub) {
  77                         System.arraycopy(subroutines, 0, (subroutines = new ASTNode[subIndex]), 0, subIndex);
  78                 }
  79                 return FlowInfo.DEAD_END;
  80         }
  81
  82         public String toString(int tab) {
  83
  84                 String s = tabString(tab);
  85                 s += "break "; //$NON-NLS-1$
  86                 if (label != null)
  87                         s += new String(label);
  88                 return s;
  89         }
  90
  91         public void traverse(
  92                 IAbstractSyntaxTreeVisitor visitor,
  93                 BlockScope blockscope) {
  94
  95                 visitor.visit(this, blockscope);
  96                 visitor.endVisit(this, blockscope);
  97         }
  98 }