repo/org.ibex.tool/src/org/eclipse/jdt/internal/compiler/ast/FieldReference.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.impl.*;
  15 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
  16 import org.eclipse.jdt.internal.compiler.codegen.*;
  17 import org.eclipse.jdt.internal.compiler.flow.*;
  18 import org.eclipse.jdt.internal.compiler.lookup.*;
  19
  20 public class FieldReference extends Reference implements InvocationSite {
  21
  22         public Expression receiver;
  23         public char[] token;
  24         public FieldBinding binding, codegenBinding;
  25         public long nameSourcePosition; //(start<<32)+end
  26         MethodBinding syntheticReadAccessor, syntheticWriteAccessor;
  27         public TypeBinding receiverType;
  28
  29         public FieldReference(char[] source, long pos) {
  30
  31                 token = source;
  32                 nameSourcePosition = pos;
  33                 //by default the position are the one of the field (not true for super access)
  34                 sourceStart = (int) (pos >>> 32);
  35                 sourceEnd = (int) (pos & 0x00000000FFFFFFFFL);
  36                 bits |= BindingIds.FIELD;
  37
  38         }
  39
  40         public FlowInfo analyseAssignment(
  41                 BlockScope currentScope,
  42                 FlowContext flowContext,
  43                 FlowInfo flowInfo,
  44                 Assignment assignment,
  45                 boolean isCompound) {
  46
  47                 // compound assignment extra work
  48                 if (isCompound) { // check the variable part is initialized if blank final
  49                         if (binding.isBlankFinal()
  50                                 && receiver.isThis()
  51                                 && currentScope.allowBlankFinalFieldAssignment(binding)
  52                                 && (!flowInfo.isDefinitelyAssigned(binding))) {
  53                                 currentScope.problemReporter().uninitializedBlankFinalField(binding, this);
  54                                 // we could improve error msg here telling "cannot use compound assignment on final blank field"
  55                         }
  56                         manageSyntheticReadAccessIfNecessary(currentScope, flowInfo);
  57                 }
  58                 flowInfo =
  59                         receiver
  60                                 .analyseCode(currentScope, flowContext, flowInfo, !binding.isStatic())
  61                                 .unconditionalInits();
  62                 if (assignment.expression != null) {
  63                         flowInfo =
  64                                 assignment
  65                                         .expression
  66                                         .analyseCode(currentScope, flowContext, flowInfo)
  67                                         .unconditionalInits();
  68                 }
  69                 manageSyntheticWriteAccessIfNecessary(currentScope, flowInfo);
  70
  71                 // check if assigning a final field
  72                 if (binding.isFinal()) {
  73                         // in a context where it can be assigned?
  74                         if (binding.isBlankFinal()
  75                                 && !isCompound
  76                                 && receiver.isThis()
  77                                 && !(receiver instanceof QualifiedThisReference)
  78                                 && ((receiver.bits & ParenthesizedMASK) == 0) // (this).x is forbidden
  79                                 && currentScope.allowBlankFinalFieldAssignment(binding)) {
  80                                 if (flowInfo.isPotentiallyAssigned(binding)) {
  81                                         currentScope.problemReporter().duplicateInitializationOfBlankFinalField(
  82                                                 binding,
  83                                                 this);
  84                                 } else {
  85                                         flowContext.recordSettingFinal(binding, this, flowInfo);
  86                                 }
  87                                 flowInfo.markAsDefinitelyAssigned(binding);
  88                         } else {
  89                                 // assigning a final field outside an initializer or constructor or wrong reference
  90                                 currentScope.problemReporter().cannotAssignToFinalField(binding, this);
  91                         }
  92                 }
  93                 return flowInfo;
  94         }
  95
  96         public FlowInfo analyseCode(
  97                 BlockScope currentScope,
  98                 FlowContext flowContext,
  99                 FlowInfo flowInfo) {
 100
 101                 return analyseCode(currentScope, flowContext, flowInfo, true);
 102         }
 103
 104         public FlowInfo analyseCode(
 105                 BlockScope currentScope,
 106                 FlowContext flowContext,
 107                 FlowInfo flowInfo,
 108                 boolean valueRequired) {
 109
 110                 receiver.analyseCode(currentScope, flowContext, flowInfo, !binding.isStatic());
 111                 if (valueRequired) {
 112                         manageSyntheticReadAccessIfNecessary(currentScope, flowInfo);
 113                 }
 114                 return flowInfo;
 115         }
 116
 117         public FieldBinding fieldBinding() {
 118
 119                 return binding;
 120         }
 121
 122         public void generateAssignment(
 123                 BlockScope currentScope,
 124                 CodeStream codeStream,
 125                 Assignment assignment,
 126                 boolean valueRequired) {
 127
 128                 receiver.generateCode(
 129                         currentScope,
 130                         codeStream,
 131                         !this.codegenBinding.isStatic());
 132                 assignment.expression.generateCode(currentScope, codeStream, true);
 133                 fieldStore(
 134                         codeStream,
 135                         this.codegenBinding,
 136                         syntheticWriteAccessor,
 137                         valueRequired);
 138                 if (valueRequired) {
 139                         codeStream.generateImplicitConversion(assignment.implicitConversion);
 140                 }
 141         }
 142
 143         /**
 144          * Field reference code generation
 145          *
 146          * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
 147          * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
 148          * @param valueRequired boolean
 149          */
 150         public void generateCode(
 151                 BlockScope currentScope,
 152                 CodeStream codeStream,
 153                 boolean valueRequired) {
 154
 155                 int pc = codeStream.position;
 156                 if (constant != NotAConstant) {
 157                         if (valueRequired) {
 158                                 codeStream.generateConstant(constant, implicitConversion);
 159                         }
 160                 } else {
 161                         boolean isStatic = this.codegenBinding.isStatic();
 162                         receiver.generateCode(currentScope, codeStream, !isStatic);
 163                         if (valueRequired) {
 164                                 if (this.codegenBinding.constant == NotAConstant) {
 165                                         if (this.codegenBinding.declaringClass == null) { // array length
 166                                                 codeStream.arraylength();
 167                                         } else {
 168                                                 if (syntheticReadAccessor == null) {
 169                                                         if (isStatic) {
 170                                                                 codeStream.getstatic(this.codegenBinding);
 171                                                         } else {
 172                                                                 codeStream.getfield(this.codegenBinding);
 173                                                         }
 174                                                 } else {
 175                                                         codeStream.invokestatic(syntheticReadAccessor);
 176                                                 }
 177                                         }
 178                                         codeStream.generateImplicitConversion(implicitConversion);
 179                                 } else {
 180                                         if (!isStatic) {
 181                                                 codeStream.invokeObjectGetClass(); // perform null check
 182                                                 codeStream.pop();
 183                                         }
 184                                         codeStream.generateConstant(this.codegenBinding.constant, implicitConversion);
 185                                 }
 186                         } else {
 187                                 if (!isStatic){
 188                                         codeStream.invokeObjectGetClass(); // perform null check
 189                                         codeStream.pop();
 190                                 }
 191                         }
 192                 }
 193                 codeStream.recordPositionsFrom(pc, this.sourceStart);
 194         }
 195
 196         public void generateCompoundAssignment(
 197                 BlockScope currentScope,
 198                 CodeStream codeStream,
 199                 Expression expression,
 200                 int operator,
 201                 int assignmentImplicitConversion,
 202                 boolean valueRequired) {
 203
 204                 boolean isStatic;
 205                 receiver.generateCode(
 206                         currentScope,
 207                         codeStream,
 208                         !(isStatic = this.codegenBinding.isStatic()));
 209                 if (isStatic) {
 210                         if (syntheticReadAccessor == null) {
 211                                 codeStream.getstatic(this.codegenBinding);
 212                         } else {
 213                                 codeStream.invokestatic(syntheticReadAccessor);
 214                         }
 215                 } else {
 216                         codeStream.dup();
 217                         if (syntheticReadAccessor == null) {
 218                                 codeStream.getfield(this.codegenBinding);
 219                         } else {
 220                                 codeStream.invokestatic(syntheticReadAccessor);
 221                         }
 222                 }
 223                 int operationTypeID;
 224                 if ((operationTypeID = implicitConversion >> 4) == T_String) {
 225                         codeStream.generateStringAppend(currentScope, null, expression);
 226                 } else {
 227                         // promote the array reference to the suitable operation type
 228                         codeStream.generateImplicitConversion(implicitConversion);
 229                         // generate the increment value (will by itself  be promoted to the operation value)
 230                         if (expression == IntLiteral.One) { // prefix operation
 231                                 codeStream.generateConstant(expression.constant, implicitConversion);
 232                         } else {
 233                                 expression.generateCode(currentScope, codeStream, true);
 234                         }
 235                         // perform the operation
 236                         codeStream.sendOperator(operator, operationTypeID);
 237                         // cast the value back to the array reference type
 238                         codeStream.generateImplicitConversion(assignmentImplicitConversion);
 239                 }
 240                 fieldStore(
 241                         codeStream,
 242                         this.codegenBinding,
 243                         syntheticWriteAccessor,
 244                         valueRequired);
 245         }
 246
 247         public void generatePostIncrement(
 248                 BlockScope currentScope,
 249                 CodeStream codeStream,
 250                 CompoundAssignment postIncrement,
 251                 boolean valueRequired) {
 252
 253                 boolean isStatic;
 254                 receiver.generateCode(
 255                         currentScope,
 256                         codeStream,
 257                         !(isStatic = this.codegenBinding.isStatic()));
 258                 if (isStatic) {
 259                         if (syntheticReadAccessor == null) {
 260                                 codeStream.getstatic(this.codegenBinding);
 261                         } else {
 262                                 codeStream.invokestatic(syntheticReadAccessor);
 263                         }
 264                 } else {
 265                         codeStream.dup();
 266                         if (syntheticReadAccessor == null) {
 267                                 codeStream.getfield(this.codegenBinding);
 268                         } else {
 269                                 codeStream.invokestatic(syntheticReadAccessor);
 270                         }
 271                 }
 272                 if (valueRequired) {
 273                         if (isStatic) {
 274                                 if ((this.codegenBinding.type == LongBinding)
 275                                         || (this.codegenBinding.type == DoubleBinding)) {
 276                                         codeStream.dup2();
 277                                 } else {
 278                                         codeStream.dup();
 279                                 }
 280                         } else { // Stack:  [owner][old field value]  ---> [old field value][owner][old field value]
 281                                 if ((this.codegenBinding.type == LongBinding)
 282                                         || (this.codegenBinding.type == DoubleBinding)) {
 283                                         codeStream.dup2_x1();
 284                                 } else {
 285                                         codeStream.dup_x1();
 286                                 }
 287                         }
 288                 }
 289                 codeStream.generateConstant(
 290                         postIncrement.expression.constant,
 291                         implicitConversion);
 292                 codeStream.sendOperator(postIncrement.operator, this.codegenBinding.type.id);
 293                 codeStream.generateImplicitConversion(
 294                         postIncrement.assignmentImplicitConversion);
 295                 fieldStore(codeStream, this.codegenBinding, syntheticWriteAccessor, false);
 296         }
 297
 298         public static final Constant getConstantFor(
 299                 FieldBinding binding,
 300                 Reference reference,
 301                 boolean isImplicit,
 302                 Scope referenceScope) {
 303
 304                 //propagation of the constant.
 305
 306                 //ref can be a FieldReference, a SingleNameReference or a QualifiedNameReference
 307                 //indexInQualification may have a value greater than zero only for QualifiednameReference
 308                 //if ref==null then indexInQualification==0 AND implicitReceiver == false. This case is a
 309                 //degenerated case where a fake reference field (null)
 310                 //is associted to a real FieldBinding in order
 311                 //to allow its constant computation using the regular path (in other words, find the fieldDeclaration
 312                 //and proceed to its type resolution). As implicitReceiver is false, no error reporting
 313                 //against ref will be used ==> no nullPointerException risk ....
 314
 315                 //special treatment for langage-built-in  field (their declaring class is null)
 316                 if (binding.declaringClass == null) {
 317                         //currently only one field "length" : the constant computation is never done
 318                         return NotAConstant;
 319                 }
 320                 if (!binding.isFinal()) {
 321                         return binding.constant = NotAConstant;
 322                 }
 323                 if (binding.constant != null) {
 324                         if (isImplicit || (reference instanceof QualifiedNameReference
 325                                         && binding == ((QualifiedNameReference)reference).binding)) {
 326                                 return binding.constant;
 327                         }
 328                         return NotAConstant;
 329                 }
 330
 331                 //The field has not been yet type checked.
 332                 //It also means that the field is not coming from a class that
 333                 //has already been compiled. It can only be from a class within
 334                 //compilation units to process. Thus the field is NOT from a BinaryTypeBinbing
 335
 336                 SourceTypeBinding typeBinding = (SourceTypeBinding) binding.declaringClass;
 337                 TypeDeclaration typeDecl = typeBinding.scope.referenceContext;
 338                 FieldDeclaration fieldDecl = typeDecl.declarationOf(binding);
 339
 340                 fieldDecl.resolve(binding.isStatic() //side effect on binding
 341                                 ? typeDecl.staticInitializerScope
 342                                 : typeDecl.initializerScope);
 343
 344                 if (isImplicit || (reference instanceof QualifiedNameReference
 345                                 && binding == ((QualifiedNameReference)reference).binding)) {
 346                         return binding.constant;
 347                 }
 348                 return NotAConstant;
 349         }
 350
 351         public boolean isSuperAccess() {
 352
 353                 return receiver.isSuper();
 354         }
 355
 356         public boolean isTypeAccess() {
 357
 358                 return receiver != null && receiver.isTypeReference();
 359         }
 360
 361         /*
 362          * No need to emulate access to protected fields since not implicitly accessed
 363          */
 364         public void manageSyntheticReadAccessIfNecessary(BlockScope currentScope, FlowInfo flowInfo) {
 365
 366                 if (!flowInfo.isReachable()) return;
 367                 if (binding.isPrivate()) {
 368                         if ((currentScope.enclosingSourceType() != binding.declaringClass)
 369                                 && (binding.constant == NotAConstant)) {
 370                                 syntheticReadAccessor =
 371                                         ((SourceTypeBinding) binding.declaringClass).addSyntheticMethod(binding, true);
 372                                 currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 373                                 return;
 374                         }
 375
 376                 } else if (receiver instanceof QualifiedSuperReference) { // qualified super
 377
 378                         // qualified super need emulation always
 379                         SourceTypeBinding destinationType =
 380                                 (SourceTypeBinding) (((QualifiedSuperReference) receiver)
 381                                         .currentCompatibleType);
 382                         syntheticReadAccessor = destinationType.addSyntheticMethod(binding, true);
 383                         currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 384                         return;
 385
 386                 } else if (binding.isProtected()) {
 387
 388                         SourceTypeBinding enclosingSourceType;
 389                         if (((bits & DepthMASK) != 0)
 390                                 && binding.declaringClass.getPackage()
 391                                         != (enclosingSourceType = currentScope.enclosingSourceType()).getPackage()) {
 392
 393                                 SourceTypeBinding currentCompatibleType =
 394                                         (SourceTypeBinding) enclosingSourceType.enclosingTypeAt(
 395                                                 (bits & DepthMASK) >> DepthSHIFT);
 396                                 syntheticReadAccessor = currentCompatibleType.addSyntheticMethod(binding, true);
 397                                 currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 398                                 return;
 399                         }
 400                 }
 401                 // if the binding declaring class is not visible, need special action
 402                 // for runtime compatibility on 1.2 VMs : change the declaring class of the binding
 403                 // NOTE: from target 1.2 on, field's declaring class is touched if any different from receiver type
 404                 if (binding.declaringClass != this.receiverType
 405                         && !this.receiverType.isArrayType()
 406                         && binding.declaringClass != null // array.length
 407                         && binding.constant == NotAConstant
 408                         && ((currentScope.environment().options.targetJDK >= ClassFileConstants.JDK1_2
 409                                 && binding.declaringClass.id != T_Object)
 410                         //no change for Object fields (in case there was)
 411                                 || !binding.declaringClass.canBeSeenBy(currentScope))) {
 412                         this.codegenBinding =
 413                                 currentScope.enclosingSourceType().getUpdatedFieldBinding(
 414                                         binding,
 415                                         (ReferenceBinding) this.receiverType);
 416                 }
 417         }
 418
 419         /*
 420          * No need to emulate access to protected fields since not implicitly accessed
 421          */
 422         public void manageSyntheticWriteAccessIfNecessary(BlockScope currentScope, FlowInfo flowInfo) {
 423
 424                 if (!flowInfo.isReachable()) return;
 425                 if (binding.isPrivate()) {
 426                         if (currentScope.enclosingSourceType() != binding.declaringClass) {
 427                                 syntheticWriteAccessor =
 428                                         ((SourceTypeBinding) binding.declaringClass).addSyntheticMethod(binding, false);
 429                                 currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 430                                 return;
 431                         }
 432
 433                 } else if (receiver instanceof QualifiedSuperReference) { // qualified super
 434
 435                         // qualified super need emulation always
 436                         SourceTypeBinding destinationType =
 437                                 (SourceTypeBinding) (((QualifiedSuperReference) receiver)
 438                                         .currentCompatibleType);
 439                         syntheticWriteAccessor = destinationType.addSyntheticMethod(binding, false);
 440                         currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 441                         return;
 442
 443                 } else if (binding.isProtected()) {
 444
 445                         SourceTypeBinding enclosingSourceType;
 446                         if (((bits & DepthMASK) != 0)
 447                                 && binding.declaringClass.getPackage()
 448                                         != (enclosingSourceType = currentScope.enclosingSourceType()).getPackage()) {
 449
 450                                 SourceTypeBinding currentCompatibleType =
 451                                         (SourceTypeBinding) enclosingSourceType.enclosingTypeAt(
 452                                                 (bits & DepthMASK) >> DepthSHIFT);
 453                                 syntheticWriteAccessor =
 454                                         currentCompatibleType.addSyntheticMethod(binding, false);
 455                                 currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 456                                 return;
 457                         }
 458                 }
 459                 // if the binding declaring class is not visible, need special action
 460                 // for runtime compatibility on 1.2 VMs : change the declaring class of the binding
 461                 // NOTE: from target 1.2 on, field's declaring class is touched if any different from receiver type
 462                 if (binding.declaringClass != this.receiverType
 463                         && !this.receiverType.isArrayType()
 464                         && binding.declaringClass != null // array.length
 465                         && binding.constant == NotAConstant
 466                         && ((currentScope.environment().options.targetJDK >= ClassFileConstants.JDK1_2
 467                                 && binding.declaringClass.id != T_Object)
 468                         //no change for Object fields (in case there was)
 469                                 || !binding.declaringClass.canBeSeenBy(currentScope))) {
 470                         this.codegenBinding =
 471                                 currentScope.enclosingSourceType().getUpdatedFieldBinding(
 472                                         binding,
 473                                         (ReferenceBinding) this.receiverType);
 474                 }
 475         }
 476
 477         public StringBuffer printExpression(int indent, StringBuffer output) {
 478
 479                 return receiver.printExpression(0, output).append('.').append(token);
 480         }
 481
 482         public TypeBinding resolveType(BlockScope scope) {
 483
 484                 // Answer the signature type of the field.
 485                 // constants are propaged when the field is final
 486                 // and initialized with a (compile time) constant
 487
 488                 //always ignore receiver cast, since may affect constant pool reference
 489                 boolean receiverCast = false;
 490                 if (this.receiver instanceof CastExpression) {
 491                         this.receiver.bits |= IgnoreNeedForCastCheckMASK; // will check later on
 492                         receiverCast = true;
 493                 }
 494                 this.receiverType = receiver.resolveType(scope);
 495                 if (this.receiverType == null) {
 496                         constant = NotAConstant;
 497                         return null;
 498                 }
 499                 if (receiverCast) {
 500                          // due to change of declaring class with receiver type, only identity cast should be notified
 501                         if (((CastExpression)this.receiver).expression.resolvedType == this.receiverType) {
 502                                                 scope.problemReporter().unnecessaryCast((CastExpression)this.receiver);
 503                         }
 504                 }
 505                 // the case receiverType.isArrayType and token = 'length' is handled by the scope API
 506                 this.codegenBinding = this.binding = scope.getField(this.receiverType, token, this);
 507                 if (!binding.isValidBinding()) {
 508                         constant = NotAConstant;
 509                         scope.problemReporter().invalidField(this, this.receiverType);
 510                         return null;
 511                 }
 512
 513                 if (isFieldUseDeprecated(binding, scope, (this.bits & IsStrictlyAssignedMASK) !=0)) {
 514                         scope.problemReporter().deprecatedField(binding, this);
 515                 }
 516                 boolean isImplicitThisRcv = receiver.isImplicitThis();
 517                 constant = FieldReference.getConstantFor(binding, this, isImplicitThisRcv, scope);
 518                 if (!isImplicitThisRcv) {
 519                         constant = NotAConstant;
 520                 }
 521                 if (binding.isStatic()) {
 522                         // static field accessed through receiver? legal but unoptimal (optional warning)
 523                         if (!(isImplicitThisRcv
 524                                         || receiver.isSuper()
 525                                         || (receiver instanceof NameReference
 526                                                 && (((NameReference) receiver).bits & BindingIds.TYPE) != 0))) {
 527                                 scope.problemReporter().nonStaticAccessToStaticField(this, binding);
 528                         }
 529                         if (!isImplicitThisRcv && binding.declaringClass != receiverType) {
 530                                 scope.problemReporter().indirectAccessToStaticField(this, binding);
 531                         }
 532                 }
 533                 return this.resolvedType = binding.type;
 534         }
 535
 536         public void setActualReceiverType(ReferenceBinding receiverType) {
 537                 // ignored
 538         }
 539
 540         public void setDepth(int depth) {
 541
 542                 bits &= ~DepthMASK; // flush previous depth if any
 543                 if (depth > 0) {
 544                         bits |= (depth & 0xFF) << DepthSHIFT; // encoded on 8 bits
 545                 }
 546         }
 547
 548         public void setFieldIndex(int index) {
 549                 // ignored
 550         }
 551
 552         public void traverse(ASTVisitor visitor, BlockScope scope) {
 553
 554                 if (visitor.visit(this, scope)) {
 555                         receiver.traverse(visitor, scope);
 556                 }
 557                 visitor.endVisit(this, scope);
 558         }
 559 }