net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/ThisReference.java

   1 /***********************************************************************************************************************************
   2  * Copyright (c) 2000, 2003 IBM Corporation and others. All rights reserved. This program and the accompanying materials are made
   3  * available under the terms of the Common Public License v1.0 which accompanies this distribution, and is available at
   4  * http://www.eclipse.org/legal/cpl-v10.html
   5  *
   6  * Contributors: IBM Corporation - initial API and implementation
   7  **********************************************************************************************************************************/
   8 package net.sourceforge.phpdt.internal.compiler.ast;
   9
  10 import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
  11 import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
  12 import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
  13 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  14 import net.sourceforge.phpdt.internal.compiler.lookup.MethodScope;
  15 import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
  16
  17 public class ThisReference extends Reference {
  18
  19   public static ThisReference implicitThis() {
  20
  21     ThisReference implicitThis = new ThisReference(0, 0);
  22     implicitThis.bits |= IsImplicitThisMask;
  23     return implicitThis;
  24   }
  25
  26   public ThisReference(int sourceStart, int sourceEnd) {
  27
  28     this.sourceStart = sourceStart;
  29     this.sourceEnd = sourceEnd;
  30   }
  31
  32   /*
  33    * @see Reference#analyseAssignment(...)
  34    */
  35   public FlowInfo analyseAssignment(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo, Assignment assignment,
  36       boolean isCompound) {
  37
  38     return flowInfo; // this cannot be assigned
  39   }
  40
  41   public boolean checkAccess(MethodScope methodScope) {
  42
  43     // this/super cannot be used in constructor call
  44     if (methodScope.isConstructorCall) {
  45       methodScope.problemReporter().fieldsOrThisBeforeConstructorInvocation(this);
  46       return false;
  47     }
  48
  49     // static may not refer to this/super
  50     if (methodScope.isStatic) {
  51       methodScope.problemReporter().errorThisSuperInStatic(this);
  52       return false;
  53     }
  54     return true;
  55   }
  56
  57   /*
  58    * @see Reference#generateAssignment(...)
  59    */
  60   //    public void generateAssignment(BlockScope currentScope, CodeStream codeStream, Assignment assignment, boolean valueRequired) {
  61   //
  62   //             // this cannot be assigned
  63   //    }
  64   //
  65   //    public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
  66   //
  67   //            int pc = codeStream.position;
  68   //            if (valueRequired)
  69   //                    codeStream.aload_0();
  70   //            if ((this.bits & IsImplicitThisMask) == 0) codeStream.recordPositionsFrom(pc, this.sourceStart);
  71   //    }
  72   //
  73   //    /*
  74   //     * @see Reference#generateCompoundAssignment(...)
  75   //     */
  76   //    public void generateCompoundAssignment(BlockScope currentScope, CodeStream codeStream, Expression expression, int operator, int
  77   // assignmentImplicitConversion, boolean valueRequired) {
  78   //
  79   //             // this cannot be assigned
  80   //    }
  81   //
  82   //    /*
  83   //     * @see net.sourceforge.phpdt.internal.compiler.ast.Reference#generatePostIncrement()
  84   //     */
  85   //    public void generatePostIncrement(BlockScope currentScope, CodeStream codeStream, CompoundAssignment postIncrement, boolean
  86   // valueRequired) {
  87   //
  88   //             // this cannot be assigned
  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 TypeBinding resolveType(BlockScope scope) {
 101
 102     constant = NotAConstant;
 103     if (!this.isImplicitThis() && !checkAccess(scope.methodScope()))
 104       return null;
 105     return this.resolvedType = scope.enclosingSourceType();
 106   }
 107
 108   public StringBuffer printExpression(int indent, StringBuffer output) {
 109
 110     if (this.isImplicitThis())
 111       return output;
 112     return output.append("this"); //$NON-NLS-1$
 113   }
 114
 115   public String toStringExpression() {
 116
 117     if (this.isImplicitThis())
 118       return ""; //$NON-NLS-1$
 119     return "this"; //$NON-NLS-1$
 120   }
 121
 122   public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope blockScope) {
 123
 124     visitor.visit(this, blockScope);
 125     visitor.endVisit(this, blockScope);
 126   }
 127 }