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   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v0.5
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v05.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  ******************************************************************************/
  11 package net.sourceforge.phpdt.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
  14 import net.sourceforge.phpdt.internal.compiler.codegen.*;
  15 import net.sourceforge.phpdt.internal.compiler.flow.*;
  16 import net.sourceforge.phpdt.internal.compiler.lookup.*;
  17
  18 public class QualifiedThisReference extends ThisReference {
  19
  20         public TypeReference qualification;
  21         ReferenceBinding currentCompatibleType;
  22
  23         public QualifiedThisReference(TypeReference name, int pos, int sourceEnd) {
  24
  25                 qualification = name;
  26                 this.sourceEnd = sourceEnd;
  27                 this.sourceStart = name.sourceStart;
  28         }
  29
  30         public FlowInfo analyseCode(
  31                 BlockScope currentScope,
  32                 FlowContext flowContext,
  33                 FlowInfo flowInfo) {
  34
  35                 manageEnclosingInstanceAccessIfNecessary(currentScope);
  36                 return flowInfo;
  37         }
  38
  39         public FlowInfo analyseCode(
  40                 BlockScope currentScope,
  41                 FlowContext flowContext,
  42                 FlowInfo flowInfo,
  43                 boolean valueRequired) {
  44
  45                 if (valueRequired) {
  46                         manageEnclosingInstanceAccessIfNecessary(currentScope);
  47                 }
  48                 return flowInfo;
  49         }
  50
  51         protected boolean checkAccess(
  52                 MethodScope methodScope,
  53                 TypeBinding targetType) {
  54
  55                 // this/super cannot be used in constructor call
  56                 if (methodScope.isConstructorCall) {
  57                         methodScope.problemReporter().fieldsOrThisBeforeConstructorInvocation(this);
  58                         return false;
  59                 }
  60
  61                 // static may not refer to this/super
  62                 if (methodScope.isStatic) {
  63                         methodScope.problemReporter().incorrectEnclosingInstanceReference(
  64                                 this,
  65                                 targetType);
  66                         return false;
  67                 }
  68                 return true;
  69         }
  70
  71         /**
  72          * Code generation for QualifiedThisReference
  73          *
  74          * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
  75          * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  76          * @param valueRequired boolean
  77          */
  78         public void generateCode(
  79                 BlockScope currentScope,
  80                 CodeStream codeStream,
  81                 boolean valueRequired) {
  82
  83                 int pc = codeStream.position;
  84                 if (valueRequired) {
  85                         if ((bits & DepthMASK) != 0) {
  86                                 Object[] emulationPath =
  87                                         currentScope.getExactEmulationPath(currentCompatibleType);
  88                                 if (emulationPath == null) {
  89                                         // internal error, per construction we should have found it
  90                                         currentScope.problemReporter().needImplementation();
  91                                 } else {
  92                                         codeStream.generateOuterAccess(emulationPath, this, currentScope);
  93                                 }
  94                         } else {
  95                                 // nothing particular after all
  96                                 codeStream.aload_0();
  97                         }
  98                 }
  99                 codeStream.recordPositionsFrom(pc, this.sourceStart);
 100         }
 101
 102         void manageEnclosingInstanceAccessIfNecessary(BlockScope currentScope) {
 103
 104                 currentScope.emulateOuterAccess(
 105                         (SourceTypeBinding) currentCompatibleType,
 106                         false);
 107                 // request cascade of accesses
 108         }
 109
 110         public TypeBinding resolveType(BlockScope scope) {
 111
 112                 constant = NotAConstant;
 113                 TypeBinding qualificationTb = qualification.resolveType(scope);
 114                 if (qualificationTb == null)
 115                         return null;
 116
 117                 // the qualification MUST exactly match some enclosing type name
 118                 // Its possible to qualify 'this' by the name of the current class
 119                 int depth = 0;
 120                 currentCompatibleType = scope.referenceType().binding;
 121                 while (currentCompatibleType != null
 122                         && currentCompatibleType != qualificationTb) {
 123                         depth++;
 124                         currentCompatibleType =
 125                                 currentCompatibleType.isStatic() ? null : currentCompatibleType.enclosingType();
 126                 }
 127                 bits &= ~DepthMASK; // flush previous depth if any
 128                 bits |= (depth & 0xFF) << DepthSHIFT; // encoded depth into 8 bits
 129
 130                 if (currentCompatibleType == null) {
 131                         scope.problemReporter().incorrectEnclosingInstanceReference(
 132                                 this,
 133                                 qualificationTb);
 134                         return null;
 135                 }
 136
 137                 // Ensure one cannot write code like: B() { super(B.this); }
 138                 if (depth == 0) {
 139                         if (!checkAccess(scope.methodScope(), qualificationTb))
 140                                 return null;
 141                 } else {
 142                         // Could also be targeting an enclosing instance inside a super constructor invocation
 143                         //      class X {
 144                         //              public X(int i) {
 145                         //                      this(new Object() { Object obj = X.this; });
 146                         //              }
 147                         //      }
 148
 149                         MethodScope methodScope = scope.methodScope();
 150                         while (methodScope != null) {
 151                                 if (methodScope.enclosingSourceType() == currentCompatibleType) {
 152                                         if (!this.checkAccess(methodScope, qualificationTb))
 153                                                 return null;
 154                                         break;
 155                                 }
 156                                 methodScope = methodScope.parent.methodScope();
 157                         }
 158                 }
 159                 return qualificationTb;
 160         }
 161
 162         public String toStringExpression() {
 163
 164                 return qualification.toString(0) + ".this"; //$NON-NLS-1$
 165         }
 166
 167         public void traverse(
 168                 IAbstractSyntaxTreeVisitor visitor,
 169                 BlockScope blockScope) {
 170
 171                 if (visitor.visit(this, blockScope)) {
 172                         qualification.traverse(visitor, blockScope);
 173                 }
 174                 visitor.endVisit(this, blockScope);
 175         }
 176 }