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
  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(); // for supporting nested labels:   a:b:c: someStatement (see 21912)
  74                 return statement;
  75         }
  76
  77         /**
  78          * Code generation for labeled statement
  79          *
  80          * may not need actual source positions recording
  81          *
  82          * @param currentScope net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
  83          * @param codeStream net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
  84          */
  85 //      public void generateCode(BlockScope currentScope, CodeStream codeStream) {
  86 //
  87 //              int pc = codeStream.position;
  88 //              if (targetLabel != null) {
  89 //                      targetLabel.codeStream = codeStream;
  90 //                      if (statement != null) {
  91 //                              statement.generateCode(currentScope, codeStream);
  92 //                      }
  93 //                      targetLabel.place();
  94 //              }
  95 //              // May loose some local variable initializations : affecting the local variable attributes
  96 //              if (mergedInitStateIndex != -1) {
  97 //                      codeStream.removeNotDefinitelyAssignedVariables(
  98 //                              currentScope,
  99 //                              mergedInitStateIndex);
 100 //              }
 101 //              codeStream.recordPositionsFrom(pc, this.sourceStart);
 102 //      }
 103         public StringBuffer printStatement(int tab, StringBuffer output) {
 104
 105                 printIndent(tab, output).append(label).append(": "); //$NON-NLS-1$
 106                 if (this.statement == null)
 107                         output.append(';');
 108                 else
 109                         this.statement.printStatement(0, output);
 110                 return output;
 111         }
 112         public void resolve(BlockScope scope) {
 113
 114                 statement.resolve(scope);
 115         }
 116
 117         public String toString(int tab) {
 118
 119                 String s = tabString(tab);
 120                 s += new String(label) + ": " + statement.toString(0); //$NON-NLS-1$
 121                 return s;
 122         }
 123
 124         public void traverse(
 125             ASTVisitor visitor,
 126                 BlockScope blockScope) {
 127
 128                 if (visitor.visit(this, blockScope)) {
 129                         statement.traverse(visitor, blockScope);
 130                 }
 131                 visitor.endVisit(this, blockScope);
 132         }
 133
 134         public void resetStateForCodeGeneration() {
 135                 if (this.targetLabel != null) {
 136                         this.targetLabel.resetStateForCodeGeneration();
 137                 }
 138         }
 139 }