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

   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.CodeStream;
  15 import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
  16 import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
  17 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  18 import net.sourceforge.phpdt.internal.compiler.lookup.MethodScope;
  19 import net.sourceforge.phpdt.internal.compiler.lookup.ReferenceBinding;
  20 import net.sourceforge.phpdt.internal.compiler.lookup.SourceTypeBinding;
  21 import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
  22
  23 public class QualifiedThisReference extends ThisReference {
  24
  25         public TypeReference qualification;
  26         ReferenceBinding currentCompatibleType;
  27
  28         public QualifiedThisReference(TypeReference name, int pos, int sourceEnd) {
  29
  30                 qualification = name;
  31                 this.sourceEnd = sourceEnd;
  32                 this.sourceStart = name.sourceStart;
  33         }
  34
  35         public FlowInfo analyseCode(
  36                 BlockScope currentScope,
  37                 FlowContext flowContext,
  38                 FlowInfo flowInfo) {
  39
  40                 manageEnclosingInstanceAccessIfNecessary(currentScope);
  41                 return flowInfo;
  42         }
  43
  44         public FlowInfo analyseCode(
  45                 BlockScope currentScope,
  46                 FlowContext flowContext,
  47                 FlowInfo flowInfo,
  48                 boolean valueRequired) {
  49
  50                 if (valueRequired) {
  51                         manageEnclosingInstanceAccessIfNecessary(currentScope);
  52                 }
  53                 return flowInfo;
  54         }
  55
  56         protected boolean checkAccess(
  57                 MethodScope methodScope,
  58                 TypeBinding targetType) {
  59
  60                 // this/super cannot be used in constructor call
  61                 if (methodScope.isConstructorCall) {
  62                         methodScope.problemReporter().fieldsOrThisBeforeConstructorInvocation(this);
  63                         return false;
  64                 }
  65
  66                 // static may not refer to this/super
  67                 if (methodScope.isStatic) {
  68                         methodScope.problemReporter().incorrectEnclosingInstanceReference(
  69                                 this,
  70                                 targetType);
  71                         return false;
  72                 }
  73                 return true;
  74         }
  75
  76         /**
  77          * Code generation for QualifiedThisReference
  78          *
  79          * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
  80          * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  81          * @param valueRequired boolean
  82          */
  83         public void generateCode(
  84                 BlockScope currentScope,
  85                 CodeStream codeStream,
  86                 boolean valueRequired) {
  87
  88                 int pc = codeStream.position;
  89                 if (valueRequired) {
  90                         if ((bits & DepthMASK) != 0) {
  91                                 Object[] emulationPath =
  92                                         currentScope.getExactEmulationPath(currentCompatibleType);
  93                                 if (emulationPath == null) {
  94                                         // internal error, per construction we should have found it
  95                                         currentScope.problemReporter().needImplementation();
  96                                 } else {
  97                                         codeStream.generateOuterAccess(emulationPath, this, currentScope);
  98                                 }
  99                         } else {
 100                                 // nothing particular after all
 101                                 codeStream.aload_0();
 102                         }
 103                 }
 104                 codeStream.recordPositionsFrom(pc, this.sourceStart);
 105         }
 106
 107         void manageEnclosingInstanceAccessIfNecessary(BlockScope currentScope) {
 108
 109                 currentScope.emulateOuterAccess(
 110                         (SourceTypeBinding) currentCompatibleType,
 111                         false);
 112                 // request cascade of accesses
 113         }
 114
 115         public TypeBinding resolveType(BlockScope scope) {
 116
 117                 constant = NotAConstant;
 118                 TypeBinding qualificationTb = qualification.resolveType(scope);
 119                 if (qualificationTb == null)
 120                         return null;
 121
 122                 // the qualification MUST exactly match some enclosing type name
 123                 // Its possible to qualify 'this' by the name of the current class
 124                 int depth = 0;
 125                 currentCompatibleType = scope.referenceType().binding;
 126                 while (currentCompatibleType != null
 127                         && currentCompatibleType != qualificationTb) {
 128                         depth++;
 129                         currentCompatibleType =
 130                                 currentCompatibleType.isStatic() ? null : currentCompatibleType.enclosingType();
 131                 }
 132                 bits &= ~DepthMASK; // flush previous depth if any
 133                 bits |= (depth & 0xFF) << DepthSHIFT; // encoded depth into 8 bits
 134
 135                 if (currentCompatibleType == null) {
 136                         scope.problemReporter().incorrectEnclosingInstanceReference(
 137                                 this,
 138                                 qualificationTb);
 139                         return null;
 140                 }
 141
 142                 // Ensure one cannot write code like: B() { super(B.this); }
 143                 if (depth == 0) {
 144                         if (!checkAccess(scope.methodScope(), qualificationTb))
 145                                 return null;
 146                 } else {
 147                         // Could also be targeting an enclosing instance inside a super constructor invocation
 148                         //      class X {
 149                         //              public X(int i) {
 150                         //                      this(new Object() { Object obj = X.this; });
 151                         //              }
 152                         //      }
 153
 154                         MethodScope methodScope = scope.methodScope();
 155                         while (methodScope != null) {
 156                                 if (methodScope.enclosingSourceType() == currentCompatibleType) {
 157                                         if (!this.checkAccess(methodScope, qualificationTb))
 158                                                 return null;
 159                                         break;
 160                                 }
 161                                 methodScope = methodScope.parent.methodScope();
 162                         }
 163                 }
 164                 return qualificationTb;
 165         }
 166
 167         public String toStringExpression() {
 168
 169                 return qualification.toString(0) + ".this"; //$NON-NLS-1$
 170         }
 171
 172         public void traverse(
 173                 IAbstractSyntaxTreeVisitor visitor,
 174                 BlockScope blockScope) {
 175
 176                 if (visitor.visit(this, blockScope)) {
 177                         qualification.traverse(visitor, blockScope);
 178                 }
 179                 visitor.endVisit(this, blockScope);
 180         }
 181 }