repo/org.ibex.tool/src/org/eclipse/jdt/internal/compiler/ast/ThisReference.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.ast;
  12
  13 import org.eclipse.jdt.internal.compiler.ASTVisitor;
  14 import org.eclipse.jdt.internal.compiler.codegen.*;
  15 import org.eclipse.jdt.internal.compiler.flow.FlowContext;
  16 import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
  17 import org.eclipse.jdt.internal.compiler.lookup.*;
  18
  19 public class ThisReference extends Reference {
  20
  21         public static ThisReference implicitThis(){
  22
  23                 ThisReference implicitThis = new ThisReference(0, 0);
  24                 implicitThis.bits |= IsImplicitThisMask;
  25                 return implicitThis;
  26         }
  27
  28         public ThisReference(int sourceStart, int sourceEnd) {
  29
  30                 this.sourceStart = sourceStart;
  31                 this.sourceEnd = sourceEnd;
  32         }
  33
  34         /*
  35          * @see Reference#analyseAssignment(...)
  36          */
  37         public FlowInfo analyseAssignment(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo, Assignment assignment, boolean isCompound) {
  38
  39                 return flowInfo; // this cannot be assigned
  40         }
  41
  42         public boolean checkAccess(MethodScope methodScope) {
  43
  44                 // this/super cannot be used in constructor call
  45                 if (methodScope.isConstructorCall) {
  46                         methodScope.problemReporter().fieldsOrThisBeforeConstructorInvocation(this);
  47                         return false;
  48                 }
  49
  50                 // static may not refer to this/super
  51                 if (methodScope.isStatic) {
  52                         methodScope.problemReporter().errorThisSuperInStatic(this);
  53                         return false;
  54                 }
  55                 return true;
  56         }
  57
  58         /*
  59          * @see Reference#generateAssignment(...)
  60          */
  61         public void generateAssignment(BlockScope currentScope, CodeStream codeStream, Assignment assignment, boolean valueRequired) {
  62
  63                  // this cannot be assigned
  64         }
  65
  66         public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
  67
  68                 int pc = codeStream.position;
  69                 if (valueRequired)
  70                         codeStream.aload_0();
  71                 if ((this.bits & IsImplicitThisMask) == 0) codeStream.recordPositionsFrom(pc, this.sourceStart);
  72         }
  73
  74         /*
  75          * @see Reference#generateCompoundAssignment(...)
  76          */
  77         public void generateCompoundAssignment(BlockScope currentScope, CodeStream codeStream, Expression expression, int operator, int assignmentImplicitConversion,  boolean valueRequired) {
  78
  79                  // this cannot be assigned
  80         }
  81
  82         /*
  83          * @see org.eclipse.jdt.internal.compiler.ast.Reference#generatePostIncrement()
  84          */
  85         public void generatePostIncrement(BlockScope currentScope, CodeStream codeStream, CompoundAssignment postIncrement, boolean valueRequired) {
  86
  87                  // this cannot be assigned
  88         }
  89
  90         public boolean isImplicitThis() {
  91
  92                 return (this.bits & IsImplicitThisMask) != 0;
  93         }
  94
  95         public boolean isThis() {
  96
  97                 return true ;
  98         }
  99
 100         public StringBuffer printExpression(int indent, StringBuffer output){
 101
 102                 if (this.isImplicitThis()) return output;
 103                 return output.append("this"); //$NON-NLS-1$
 104         }
 105
 106         public TypeBinding resolveType(BlockScope scope) {
 107
 108                 constant = NotAConstant;
 109                 if (!this.isImplicitThis() &&!checkAccess(scope.methodScope())) {
 110                         return null;
 111                 }
 112                 return this.resolvedType = scope.enclosingSourceType();
 113         }
 114
 115         public void traverse(ASTVisitor visitor, BlockScope blockScope) {
 116
 117                 visitor.visit(this, blockScope);
 118                 visitor.endVisit(this, blockScope);
 119         }
 120 }