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,
  36                         FlowContext flowContext, FlowInfo flowInfo, Assignment assignment,
  37                         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()
  47                                         .fieldsOrThisBeforeConstructorInvocation(this);
  48                         return false;
  49                 }
  50
  51                 // static may not refer to this/super
  52                 if (methodScope.isStatic) {
  53                         methodScope.problemReporter().errorThisSuperInStatic(this);
  54                         return false;
  55                 }
  56                 return true;
  57         }
  58
  59         /*
  60          * @see Reference#generateAssignment(...)
  61          */
  62         // public void generateAssignment(BlockScope currentScope, CodeStream
  63         // codeStream, Assignment assignment, boolean valueRequired) {
  64         //
  65         // // this cannot be assigned
  66         // }
  67         //
  68         // public void generateCode(BlockScope currentScope, CodeStream codeStream,
  69         // boolean valueRequired) {
  70         //
  71         // int pc = codeStream.position;
  72         // if (valueRequired)
  73         // codeStream.aload_0();
  74         // if ((this.bits & IsImplicitThisMask) == 0)
  75         // codeStream.recordPositionsFrom(pc, this.sourceStart);
  76         // }
  77         //
  78         // /*
  79         // * @see Reference#generateCompoundAssignment(...)
  80         // */
  81         // public void generateCompoundAssignment(BlockScope currentScope,
  82         // CodeStream codeStream, Expression expression, int operator, int
  83         // assignmentImplicitConversion, boolean valueRequired) {
  84         //
  85         // // this cannot be assigned
  86         // }
  87         //
  88         // /*
  89         // * @see
  90         // net.sourceforge.phpdt.internal.compiler.ast.Reference#generatePostIncrement()
  91         // */
  92         // public void generatePostIncrement(BlockScope currentScope, CodeStream
  93         // codeStream, CompoundAssignment postIncrement, boolean
  94         // valueRequired) {
  95         //
  96         // // this cannot be assigned
  97         // }
  98         public boolean isImplicitThis() {
  99
 100                 return (this.bits & IsImplicitThisMask) != 0;
 101         }
 102
 103         public boolean isThis() {
 104
 105                 return true;
 106         }
 107
 108         public TypeBinding resolveType(BlockScope scope) {
 109
 110                 constant = NotAConstant;
 111                 if (!this.isImplicitThis() && !checkAccess(scope.methodScope()))
 112                         return null;
 113                 return this.resolvedType = scope.enclosingSourceType();
 114         }
 115
 116         public StringBuffer printExpression(int indent, StringBuffer output) {
 117
 118                 if (this.isImplicitThis())
 119                         return output;
 120                 return output.append("this"); //$NON-NLS-1$
 121         }
 122
 123         public String toStringExpression() {
 124
 125                 if (this.isImplicitThis())
 126                         return ""; //$NON-NLS-1$
 127                 return "this"; //$NON-NLS-1$
 128         }
 129
 130         public void traverse(IAbstractSyntaxTreeVisitor visitor,
 131                         BlockScope blockScope) {
 132
 133                 visitor.visit(this, blockScope);
 134                 visitor.endVisit(this, blockScope);
 135         }
 136 }