net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/LabeledStatement.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.phpdt.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
  14 import net.sourceforge.phpdt.internal.compiler.codegen.Label;
  15 import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
  16 import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
  17 import net.sourceforge.phpdt.internal.compiler.flow.LabelFlowContext;
  18 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  19
  20 public class LabeledStatement extends Statement {
  21
  22         public Statement statement;
  23
  24         public char[] label;
  25
  26         public Label targetLabel;
  27
  28         // for local variables table attributes
  29         int mergedInitStateIndex = -1;
  30
  31         /**
  32          * LabeledStatement constructor comment.
  33          */
  34         public LabeledStatement(char[] l, Statement st, int s, int e) {
  35
  36                 this.statement = st;
  37                 this.label = l;
  38                 this.sourceStart = s;
  39                 this.sourceEnd = e;
  40         }
  41
  42         public FlowInfo analyseCode(BlockScope currentScope,
  43                         FlowContext flowContext, FlowInfo flowInfo) {
  44
  45                 // need to stack a context to store explicit label, answer inits in case
  46                 // of normal completion merged
  47                 // with those relative to the exit path from break statement occurring
  48                 // inside the labeled statement.
  49                 if (statement == null) {
  50                         return flowInfo;
  51                 } else {
  52                         LabelFlowContext labelContext;
  53                         FlowInfo mergedInfo = statement.analyseCode(
  54                                         currentScope,
  55                                         (labelContext = new LabelFlowContext(flowContext, this,
  56                                                         label, (targetLabel = new Label()), currentScope)),
  57                                         flowInfo).mergedWith(labelContext.initsOnBreak);
  58                         mergedInitStateIndex = currentScope.methodScope()
  59                                         .recordInitializationStates(mergedInfo);
  60                         return mergedInfo;
  61                 }
  62         }
  63
  64         public ASTNode concreteStatement() {
  65
  66                 // return statement.concreteStatement(); // for supporting nested
  67                 // labels: a:b:c: someStatement (see 21912)
  68                 return statement;
  69         }
  70
  71         /**
  72          * Code generation for labeled statement
  73          *
  74          * may not need actual source positions recording
  75          *
  76          * @param currentScope
  77          *            net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
  78          * @param codeStream
  79          *            net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
  80          */
  81         // public void generateCode(BlockScope currentScope, CodeStream codeStream)
  82         // {
  83         //
  84         // int pc = codeStream.position;
  85         // if (targetLabel != null) {
  86         // targetLabel.codeStream = codeStream;
  87         // if (statement != null) {
  88         // statement.generateCode(currentScope, codeStream);
  89         // }
  90         // targetLabel.place();
  91         // }
  92         // // May loose some local variable initializations : affecting the local
  93         // variable attributes
  94         // if (mergedInitStateIndex != -1) {
  95         // codeStream.removeNotDefinitelyAssignedVariables(
  96         // currentScope,
  97         // mergedInitStateIndex);
  98         // }
  99         // codeStream.recordPositionsFrom(pc, this.sourceStart);
 100         // }
 101         public StringBuffer printStatement(int tab, StringBuffer output) {
 102
 103                 printIndent(tab, output).append(label).append(": "); //$NON-NLS-1$
 104                 if (this.statement == null)
 105                         output.append(';');
 106                 else
 107                         this.statement.printStatement(0, output);
 108                 return output;
 109         }
 110
 111         public void resolve(BlockScope scope) {
 112
 113                 statement.resolve(scope);
 114         }
 115
 116         public String toString(int tab) {
 117
 118                 String s = tabString(tab);
 119                 s += new String(label) + ": " + statement.toString(0); //$NON-NLS-1$
 120                 return s;
 121         }
 122
 123         public void traverse(ASTVisitor visitor, BlockScope blockScope) {
 124
 125                 if (visitor.visit(this, blockScope)) {
 126                         statement.traverse(visitor, blockScope);
 127                 }
 128                 visitor.endVisit(this, blockScope);
 129         }
 130
 131         public void resetStateForCodeGeneration() {
 132                 if (this.targetLabel != null) {
 133                         this.targetLabel.resetStateForCodeGeneration();
 134                 }
 135         }
 136 }