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