net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/lookup/LocalVariableBinding.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.lookup;
  12
  13 import net.sourceforge.phpdt.internal.compiler.ast.LocalDeclaration;
  14 import net.sourceforge.phpdt.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                 if (this.isArgument = isArgument)
  39                         this.constant = Constant.NotAConstant;
  40         }
  41
  42         // regular local variable or argument
  43         public LocalVariableBinding(LocalDeclaration declaration, TypeBinding type, int modifiers, boolean isArgument) {
  44
  45                 this(declaration.name, type, modifiers, isArgument);
  46                 this.declaration = declaration;
  47         }
  48
  49         /* API
  50         * Answer the receiver's binding type from Binding.BindingID.
  51         */
  52         public final int bindingType() {
  53
  54                 return LOCAL;
  55         }
  56
  57         // Answer whether the variable binding is a secret variable added for code gen purposes
  58         public boolean isSecret() {
  59
  60                 return declaration == null && !isArgument;
  61         }
  62
  63         public void recordInitializationEndPC(int pc) {
  64
  65                 if (initializationPCs[((initializationCount - 1) << 1) + 1] == -1)
  66                         initializationPCs[((initializationCount - 1) << 1) + 1] = pc;
  67         }
  68
  69         public void recordInitializationStartPC(int pc) {
  70
  71                 if (initializationPCs == null)  return;
  72                 // optimize cases where reopening a contiguous interval
  73                 if ((initializationCount > 0) && (initializationPCs[ ((initializationCount - 1) << 1) + 1] == pc)) {
  74                         initializationPCs[ ((initializationCount - 1) << 1) + 1] = -1; // reuse previous interval (its range will be augmented)
  75                 } else {
  76                         int index = initializationCount << 1;
  77                         if (index == initializationPCs.length) {
  78                                 System.arraycopy(initializationPCs, 0, (initializationPCs = new int[initializationCount << 2]), 0, index);
  79                         }
  80                         initializationPCs[index] = pc;
  81                         initializationPCs[index + 1] = -1;
  82                         initializationCount++;
  83                 }
  84         }
  85
  86         public String toString() {
  87
  88                 String s = super.toString();
  89                 switch (useFlag){
  90                         case USED:
  91                                 s += "[pos: " + String.valueOf(resolvedPosition) + "]"; //$NON-NLS-2$ //$NON-NLS-1$
  92                                 break;
  93                         case UNUSED:
  94                                 s += "[pos: unused]"; //$NON-NLS-1$
  95                                 break;
  96                         case FAKE_USED:
  97                                 s += "[pos: fake_used]"; //$NON-NLS-1$
  98                                 break;
  99                 }
 100                 s += "[id:" + String.valueOf(id) + "]"; //$NON-NLS-2$ //$NON-NLS-1$
 101                 if (initializationCount > 0) {
 102                         s += "[pc: "; //$NON-NLS-1$
 103                         for (int i = 0; i < initializationCount; i++) {
 104                                 if (i > 0)
 105                                         s += ", "; //$NON-NLS-1$
 106                                 s += String.valueOf(initializationPCs[i << 1]) + "-" + ((initializationPCs[(i << 1) + 1] == -1) ? "?" : String.valueOf(initializationPCs[(i<< 1) + 1])); //$NON-NLS-2$ //$NON-NLS-1$
 107                         }
 108                         s += "]"; //$NON-NLS-1$
 109                 }
 110                 return s;
 111         }
 112 }