repo/org.ibex.tool/src/org/eclipse/jdt/internal/compiler/ast/BreakStatement.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 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 org.eclipse.jdt.internal.compiler.ast;
  12
  13 import org.eclipse.jdt.internal.compiler.ASTVisitor;
  14 import org.eclipse.jdt.internal.compiler.flow.*;
  15 import org.eclipse.jdt.internal.compiler.lookup.*;
  16
  17 public class BreakStatement extends BranchStatement {
  18
  19         public BreakStatement(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 = (label == null)
  33                         ? flowContext.getTargetContextForDefaultBreak()
  34                         : flowContext.getTargetContextForBreakLabel(label);
  35
  36                 if (targetContext == null) {
  37                         if (label == null) {
  38                                 currentScope.problemReporter().invalidBreak(this);
  39                         } else {
  40                                 currentScope.problemReporter().undefinedLabel(this);
  41                         }
  42                         return flowInfo; // pretend it did not break since no actual target
  43                 }
  44
  45                 targetLabel = targetContext.breakLabel();
  46                 FlowContext traversedContext = flowContext;
  47                 int subIndex = 0, maxSub = 5;
  48                 subroutines = new SubRoutineStatement[maxSub];
  49
  50                 do {
  51                         SubRoutineStatement sub;
  52                         if ((sub = traversedContext.subRoutine()) != null) {
  53                                 if (subIndex == maxSub) {
  54                                         System.arraycopy(subroutines, 0, (subroutines = new SubRoutineStatement[maxSub*=2]), 0, subIndex); // grow
  55                                 }
  56                                 subroutines[subIndex++] = sub;
  57                                 if (sub.isSubRoutineEscaping()) {
  58                                         break;
  59                                 }
  60                         }
  61                         traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
  62
  63                         ASTNode node;
  64                         if ((node = traversedContext.associatedNode) instanceof TryStatement) {
  65                                 TryStatement tryStatement = (TryStatement) node;
  66                                 flowInfo.addInitializationsFrom(tryStatement.subRoutineInits); // collect inits
  67                         } else if (traversedContext == targetContext) {
  68                                 // only record break info once accumulated through subroutines, and only against target context
  69                                 targetContext.recordBreakFrom(flowInfo);
  70                                 break;
  71                         }
  72                 } while ((traversedContext = traversedContext.parent) != null);
  73
  74                 // resize subroutines
  75                 if (subIndex != maxSub) {
  76                         System.arraycopy(subroutines, 0, (subroutines = new SubRoutineStatement[subIndex]), 0, subIndex);
  77                 }
  78                 return FlowInfo.DEAD_END;
  79         }
  80
  81         public StringBuffer printStatement(int tab, StringBuffer output) {
  82
  83                 printIndent(tab, output).append("break "); //$NON-NLS-1$
  84                 if (label != null) output.append(label);
  85                 return output.append(';');
  86         }
  87
  88         public void traverse(
  89                 ASTVisitor visitor,
  90                 BlockScope blockscope) {
  91
  92                 visitor.visit(this, blockscope);
  93                 visitor.endVisit(this, blockscope);
  94         }
  95 }