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