src/org/eclipse/jdt/internal/compiler/lookup/LocalVariableBinding.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.lookup;
  12
  13 import org.eclipse.jdt.internal.compiler.ast.LocalDeclaration;
  14 import org.eclipse.jdt.internal.compiler.impl.Constant;
  15
  16 public class LocalVariableBinding extends VariableBinding {
  17
  18         public boolean isArgument;
  19         public int resolvedPosition; // for code generation (position in method context)
  20
  21         public static final int UNUSED = 0;
  22         public static final int USED = 1;
  23         public static final int FAKE_USED = 2;
  24         public int useFlag; // for flow analysis (default is UNUSED)
  25
  26         public BlockScope declaringScope; // back-pointer to its declaring scope
  27         public LocalDeclaration declaration; // for source-positions
  28
  29         public int[] initializationPCs;
  30         public int initializationCount = 0;
  31
  32         // for synthetic local variables
  33         public LocalVariableBinding(char[] name, TypeBinding type, int modifiers, boolean isArgument) {
  34
  35                 this.name = name;
  36                 this.type = type;
  37                 this.modifiers = modifiers;
  38                 this.isArgument = isArgument;
  39                 if (isArgument)
  40                         this.constant = Constant.NotAConstant;
  41         }
  42
  43         // regular local variable or argument
  44         public LocalVariableBinding(LocalDeclaration declaration, TypeBinding type, int modifiers, boolean isArgument) {
  45
  46                 this(declaration.name, type, modifiers, isArgument);
  47                 this.declaration = declaration;
  48         }
  49
  50         /* API
  51         * Answer the receiver's binding type from Binding.BindingID.
  52         */
  53         public final int bindingType() {
  54
  55                 return LOCAL;
  56         }
  57
  58         // Answer whether the variable binding is a secret variable added for code gen purposes
  59         public boolean isSecret() {
  60
  61                 return declaration == null && !isArgument;
  62         }
  63
  64         public void recordInitializationEndPC(int pc) {
  65
  66                 if (initializationPCs[((initializationCount - 1) << 1) + 1] == -1)
  67                         initializationPCs[((initializationCount - 1) << 1) + 1] = pc;
  68         }
  69
  70         public void recordInitializationStartPC(int pc) {
  71
  72                 if (initializationPCs == null)  return;
  73                 // optimize cases where reopening a contiguous interval
  74                 if ((initializationCount > 0) && (initializationPCs[ ((initializationCount - 1) << 1) + 1] == pc)) {
  75                         initializationPCs[ ((initializationCount - 1) << 1) + 1] = -1; // reuse previous interval (its range will be augmented)
  76                 } else {
  77                         int index = initializationCount << 1;
  78                         if (index == initializationPCs.length) {
  79                                 System.arraycopy(initializationPCs, 0, (initializationPCs = new int[initializationCount << 2]), 0, index);
  80                         }
  81                         initializationPCs[index] = pc;
  82                         initializationPCs[index + 1] = -1;
  83                         initializationCount++;
  84                 }
  85         }
  86
  87         public String toString() {
  88
  89                 String s = super.toString();
  90                 switch (useFlag){
  91                         case USED:
  92                                 s += "[pos: " + String.valueOf(resolvedPosition) + "]"; //$NON-NLS-2$ //$NON-NLS-1$
  93                                 break;
  94                         case UNUSED:
  95                                 s += "[pos: unused]"; //$NON-NLS-1$
  96                                 break;
  97                         case FAKE_USED:
  98                                 s += "[pos: fake_used]"; //$NON-NLS-1$
  99                                 break;
 100                 }
 101                 s += "[id:" + String.valueOf(id) + "]"; //$NON-NLS-2$ //$NON-NLS-1$
 102                 if (initializationCount > 0) {
 103                         s += "[pc: "; //$NON-NLS-1$
 104                         for (int i = 0; i < initializationCount; i++) {
 105                                 if (i > 0)
 106                                         s += ", "; //$NON-NLS-1$
 107                                 s += String.valueOf(initializationPCs[i << 1]) + "-" + ((initializationPCs[(i << 1) + 1] == -1) ? "?" : String.valueOf(initializationPCs[(i<< 1) + 1])); //$NON-NLS-2$ //$NON-NLS-1$
 108                         }
 109                         s += "]"; //$NON-NLS-1$
 110                 }
 111                 return s;
 112         }
 113 }