net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/FieldReference.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.impl.*;
  15 import net.sourceforge.phpdt.internal.compiler.codegen.*;
  16 import net.sourceforge.phpdt.internal.compiler.flow.*;
  17 import net.sourceforge.phpdt.internal.compiler.lookup.*;
  18
  19 public class FieldReference extends Reference implements InvocationSite {
  20
  21         public Expression receiver;
  22         public char[] token;
  23         public FieldBinding binding, codegenBinding;
  24         public long nameSourcePosition; //(start<<32)+end
  25         MethodBinding syntheticReadAccessor, syntheticWriteAccessor;
  26         public TypeBinding receiverType;
  27
  28         public FieldReference(char[] source, long pos) {
  29
  30                 token = source;
  31                 nameSourcePosition = pos;
  32                 //by default the position are the one of the field (not true for super access)
  33                 sourceStart = (int) (pos >>> 32);
  34                 sourceEnd = (int) (pos & 0x00000000FFFFFFFFL);
  35                 bits |= BindingIds.FIELD;
  36
  37         }
  38
  39         public FlowInfo analyseAssignment(
  40                 BlockScope currentScope,
  41                 FlowContext flowContext,
  42                 FlowInfo flowInfo,
  43                 Assignment assignment,
  44                 boolean isCompound) {
  45
  46                 // compound assignment extra work
  47                 if (isCompound) { // check the variable part is initialized if blank final
  48                         if (binding.isFinal()
  49                                 && receiver.isThis()
  50                                 && currentScope.allowBlankFinalFieldAssignment(binding)
  51                                 && (!flowInfo.isDefinitelyAssigned(binding))) {
  52                                 currentScope.problemReporter().uninitializedBlankFinalField(binding, this);
  53                                 // we could improve error msg here telling "cannot use compound assignment on final blank field"
  54                         }
  55                         manageSyntheticReadAccessIfNecessary(currentScope);
  56                 }
  57                 if (assignment.expression != null) {
  58                         flowInfo =
  59                                 assignment
  60                                         .expression
  61                                         .analyseCode(currentScope, flowContext, flowInfo)
  62                                         .unconditionalInits();
  63                 }
  64                 flowInfo =
  65                         receiver
  66                                 .analyseCode(currentScope, flowContext, flowInfo, !binding.isStatic())
  67                                 .unconditionalInits();
  68                 manageSyntheticWriteAccessIfNecessary(currentScope);
  69
  70                 // check if assigning a final field
  71                 if (binding.isFinal()) {
  72                         // in a context where it can be assigned?
  73                         if (receiver.isThis()
  74                                 && !(receiver instanceof QualifiedThisReference)
  75                                 && currentScope.allowBlankFinalFieldAssignment(binding)) {
  76                                 if (flowInfo.isPotentiallyAssigned(binding)) {
  77                                         currentScope.problemReporter().duplicateInitializationOfBlankFinalField(
  78                                                 binding,
  79                                                 this);
  80                                 }
  81                                 flowInfo.markAsDefinitelyAssigned(binding);
  82                                 flowContext.recordSettingFinal(binding, this);
  83                         } else {
  84                                 // assigning a final field outside an initializer or constructor
  85                                 currentScope.problemReporter().cannotAssignToFinalField(binding, this);
  86                         }
  87                 }
  88                 return flowInfo;
  89         }
  90
  91         public FlowInfo analyseCode(
  92                 BlockScope currentScope,
  93                 FlowContext flowContext,
  94                 FlowInfo flowInfo) {
  95
  96                 return analyseCode(currentScope, flowContext, flowInfo, true);
  97         }
  98
  99         public FlowInfo analyseCode(
 100                 BlockScope currentScope,
 101                 FlowContext flowContext,
 102                 FlowInfo flowInfo,
 103                 boolean valueRequired) {
 104
 105                 receiver.analyseCode(currentScope, flowContext, flowInfo, !binding.isStatic());
 106                 if (valueRequired) {
 107                         manageSyntheticReadAccessIfNecessary(currentScope);
 108                 }
 109                 return flowInfo;
 110         }
 111
 112         public FieldBinding fieldBinding() {
 113
 114                 return binding;
 115         }
 116
 117         public void generateAssignment(
 118                 BlockScope currentScope,
 119                 CodeStream codeStream,
 120                 Assignment assignment,
 121                 boolean valueRequired) {
 122
 123                 receiver.generateCode(
 124                         currentScope,
 125                         codeStream,
 126                         !this.codegenBinding.isStatic());
 127                 assignment.expression.generateCode(currentScope, codeStream, true);
 128                 fieldStore(
 129                         codeStream,
 130                         this.codegenBinding,
 131                         syntheticWriteAccessor,
 132                         valueRequired);
 133                 if (valueRequired) {
 134                         codeStream.generateImplicitConversion(assignment.implicitConversion);
 135                 }
 136         }
 137
 138         /**
 139          * Field reference code generation
 140          *
 141          * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
 142          * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
 143          * @param valueRequired boolean
 144          */
 145         public void generateCode(
 146                 BlockScope currentScope,
 147                 CodeStream codeStream,
 148                 boolean valueRequired) {
 149
 150                 int pc = codeStream.position;
 151                 if (constant != NotAConstant) {
 152                         if (valueRequired) {
 153                                 codeStream.generateConstant(constant, implicitConversion);
 154                         }
 155                 } else {
 156                         boolean isStatic = this.codegenBinding.isStatic();
 157                         receiver.generateCode(
 158                                 currentScope,
 159                                 codeStream,
 160                                 valueRequired && (!isStatic) && (this.codegenBinding.constant == NotAConstant));
 161                         if (valueRequired) {
 162                                 if (this.codegenBinding.constant == NotAConstant) {
 163                                         if (this.codegenBinding.declaringClass == null) { // array length
 164                                                 codeStream.arraylength();
 165                                         } else {
 166                                                 if (syntheticReadAccessor == null) {
 167                                                         if (isStatic) {
 168                                                                 codeStream.getstatic(this.codegenBinding);
 169                                                         } else {
 170                                                                 codeStream.getfield(this.codegenBinding);
 171                                                         }
 172                                                 } else {
 173                                                         codeStream.invokestatic(syntheticReadAccessor);
 174                                                 }
 175                                         }
 176                                         codeStream.generateImplicitConversion(implicitConversion);
 177                                 } else {
 178                                         codeStream.generateConstant(this.codegenBinding.constant, implicitConversion);
 179                                 }
 180                         }
 181                 }
 182                 codeStream.recordPositionsFrom(pc, this.sourceStart);
 183         }
 184
 185         public void generateCompoundAssignment(
 186                 BlockScope currentScope,
 187                 CodeStream codeStream,
 188                 Expression expression,
 189                 int operator,
 190                 int assignmentImplicitConversion,
 191                 boolean valueRequired) {
 192
 193                 boolean isStatic;
 194                 receiver.generateCode(
 195                         currentScope,
 196                         codeStream,
 197                         !(isStatic = this.codegenBinding.isStatic()));
 198                 if (isStatic) {
 199                         if (syntheticReadAccessor == null) {
 200                                 codeStream.getstatic(this.codegenBinding);
 201                         } else {
 202                                 codeStream.invokestatic(syntheticReadAccessor);
 203                         }
 204                 } else {
 205                         codeStream.dup();
 206                         if (syntheticReadAccessor == null) {
 207                                 codeStream.getfield(this.codegenBinding);
 208                         } else {
 209                                 codeStream.invokestatic(syntheticReadAccessor);
 210                         }
 211                 }
 212                 int operationTypeID;
 213                 if ((operationTypeID = implicitConversion >> 4) == T_String) {
 214                         codeStream.generateStringAppend(currentScope, null, expression);
 215                 } else {
 216                         // promote the array reference to the suitable operation type
 217                         codeStream.generateImplicitConversion(implicitConversion);
 218                         // generate the increment value (will by itself  be promoted to the operation value)
 219                         if (expression == IntLiteral.One) { // prefix operation
 220                                 codeStream.generateConstant(expression.constant, implicitConversion);
 221                         } else {
 222                                 expression.generateCode(currentScope, codeStream, true);
 223                         }
 224                         // perform the operation
 225                         codeStream.sendOperator(operator, operationTypeID);
 226                         // cast the value back to the array reference type
 227                         codeStream.generateImplicitConversion(assignmentImplicitConversion);
 228                 }
 229                 fieldStore(
 230                         codeStream,
 231                         this.codegenBinding,
 232                         syntheticWriteAccessor,
 233                         valueRequired);
 234         }
 235
 236         public void generatePostIncrement(
 237                 BlockScope currentScope,
 238                 CodeStream codeStream,
 239                 CompoundAssignment postIncrement,
 240                 boolean valueRequired) {
 241
 242                 boolean isStatic;
 243                 receiver.generateCode(
 244                         currentScope,
 245                         codeStream,
 246                         !(isStatic = this.codegenBinding.isStatic()));
 247                 if (isStatic) {
 248                         if (syntheticReadAccessor == null) {
 249                                 codeStream.getstatic(this.codegenBinding);
 250                         } else {
 251                                 codeStream.invokestatic(syntheticReadAccessor);
 252                         }
 253                 } else {
 254                         codeStream.dup();
 255                         if (syntheticReadAccessor == null) {
 256                                 codeStream.getfield(this.codegenBinding);
 257                         } else {
 258                                 codeStream.invokestatic(syntheticReadAccessor);
 259                         }
 260                 }
 261                 if (valueRequired) {
 262                         if (isStatic) {
 263                                 if ((this.codegenBinding.type == LongBinding)
 264                                         || (this.codegenBinding.type == DoubleBinding)) {
 265                                         codeStream.dup2();
 266                                 } else {
 267                                         codeStream.dup();
 268                                 }
 269                         } else { // Stack:  [owner][old field value]  ---> [old field value][owner][old field value]
 270                                 if ((this.codegenBinding.type == LongBinding)
 271                                         || (this.codegenBinding.type == DoubleBinding)) {
 272                                         codeStream.dup2_x1();
 273                                 } else {
 274                                         codeStream.dup_x1();
 275                                 }
 276                         }
 277                 }
 278                 codeStream.generateConstant(
 279                         postIncrement.expression.constant,
 280                         implicitConversion);
 281                 codeStream.sendOperator(postIncrement.operator, this.codegenBinding.type.id);
 282                 codeStream.generateImplicitConversion(
 283                         postIncrement.assignmentImplicitConversion);
 284                 fieldStore(codeStream, this.codegenBinding, syntheticWriteAccessor, false);
 285         }
 286
 287         public static final Constant getConstantFor(
 288                 FieldBinding binding,
 289                 boolean implicitReceiver,
 290                 Reference reference,
 291                 Scope referenceScope,
 292                 int indexInQualification) {
 293
 294                 //propagation of the constant.
 295
 296                 //ref can be a FieldReference, a SingleNameReference or a QualifiedNameReference
 297                 //indexInQualification may have a value greater than zero only for QualifiednameReference
 298                 //if ref==null then indexInQualification==0 AND implicitReceiver == false. This case is a
 299                 //degenerated case where a fake reference field (null)
 300                 //is associted to a real FieldBinding in order
 301                 //to allow its constant computation using the regular path (i.e. find the fieldDeclaration
 302                 //and proceed to its type resolution). As implicitReceiver is false, no error reporting
 303                 //against ref will be used ==> no nullPointerException risk ....
 304
 305                 //special treatment for langage-built-in  field (their declaring class is null)
 306                 if (binding.declaringClass == null) {
 307                         //currently only one field "length" : the constant computation is never done
 308                         return NotAConstant;
 309                 }
 310                 if (!binding.isFinal()) {
 311                         return binding.constant = NotAConstant;
 312                 }
 313                 if (binding.constant != null) {
 314                         if (indexInQualification == 0) {
 315                                 return binding.constant;
 316                         }
 317                         //see previous comment for the (sould-always-be) valid cast
 318                         QualifiedNameReference qualifiedReference = (QualifiedNameReference) reference;
 319                         if (indexInQualification == (qualifiedReference.indexOfFirstFieldBinding - 1)) {
 320                                 return binding.constant;
 321                         }
 322                         return NotAConstant;
 323                 }
 324
 325                 //The field has not been yet type checked.
 326                 //It also means that the field is not coming from a class that
 327                 //has already been compiled. It can only be from a class within
 328                 //compilation units to process. Thus the field is NOT from a BinaryTypeBinbing
 329
 330                 SourceTypeBinding typeBinding = (SourceTypeBinding) binding.declaringClass;
 331                 TypeDeclaration typeDecl = typeBinding.scope.referenceContext;
 332                 FieldDeclaration fieldDecl = typeDecl.declarationOf(binding);
 333
 334                 //what scope to use (depend on the staticness of the field binding)
 335                 MethodScope fieldScope =
 336                         binding.isStatic()
 337                                 ? typeDecl.staticInitializerScope
 338                                 : typeDecl.initializerScope;
 339
 340                 if (implicitReceiver) { //Determine if the ref is legal in the current class of the field
 341                         //i.e. not a forward reference .... (they are allowed when the receiver is explicit ! ... Please don't ask me why !...yet another java mystery...)
 342                         if (fieldScope.fieldDeclarationIndex == MethodScope.NotInFieldDecl) {
 343                                 // no field is currently being analysed in typeDecl
 344                                 fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 345                                 return binding.constant;
 346                         }
 347                         //We are re-entering the same class fields analysing
 348                         if ((reference != null)
 349                                 && (binding.declaringClass == referenceScope.enclosingSourceType()) // only complain for access inside same type
 350                                 && (binding.id > fieldScope.fieldDeclarationIndex)) {
 351                                 //forward reference. The declaration remains unresolved.
 352                                 referenceScope.problemReporter().forwardReference(reference, indexInQualification, typeBinding);
 353                                 return NotAConstant;
 354                         }
 355                         fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 356                         return binding.constant;
 357                 }
 358                 //the field reference is explicity. It has to be a "simple" like field reference to get the
 359                 //constant propagation. For example in Packahe.Type.field1.field2 , field1 may have its
 360                 //constant having a propagation where field2 is always not propagating its
 361                 if (indexInQualification == 0) {
 362                         fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 363                         return binding.constant;
 364                 }
 365                 // Side-effect on the field binding may not be propagated out for the qualified reference
 366                 // unless it occurs in first place of the name sequence
 367                 fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 368                 //see previous comment for the cast that should always be valid
 369                 QualifiedNameReference qualifiedReference = (QualifiedNameReference) reference;
 370                 if (indexInQualification == (qualifiedReference.indexOfFirstFieldBinding - 1)) {
 371                         return binding.constant;
 372                 } else {
 373                         return NotAConstant;
 374                 }
 375         }
 376
 377         public boolean isSuperAccess() {
 378
 379                 return receiver.isSuper();
 380         }
 381
 382         public boolean isTypeAccess() {
 383
 384                 return receiver != null && receiver.isTypeReference();
 385         }
 386
 387         /*
 388          * No need to emulate access to protected fields since not implicitly accessed
 389          */
 390         public void manageSyntheticReadAccessIfNecessary(BlockScope currentScope) {
 391
 392                 if (binding.isPrivate()) {
 393                         if ((currentScope.enclosingSourceType() != binding.declaringClass)
 394                                 && (binding.constant == NotAConstant)) {
 395                                 syntheticReadAccessor =
 396                                         ((SourceTypeBinding) binding.declaringClass).addSyntheticMethod(binding, true);
 397                                 currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 398                                 return;
 399                         }
 400
 401                 } else if (receiver instanceof QualifiedSuperReference) { // qualified super
 402
 403                         // qualified super need emulation always
 404                         SourceTypeBinding destinationType =
 405                                 (SourceTypeBinding) (((QualifiedSuperReference) receiver)
 406                                         .currentCompatibleType);
 407                         syntheticReadAccessor = destinationType.addSyntheticMethod(binding, true);
 408                         currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 409                         return;
 410
 411                 } else if (binding.isProtected()) {
 412
 413                         SourceTypeBinding enclosingSourceType;
 414                         if (((bits & DepthMASK) != 0)
 415                                 && binding.declaringClass.getPackage()
 416                                         != (enclosingSourceType = currentScope.enclosingSourceType()).getPackage()) {
 417
 418                                 SourceTypeBinding currentCompatibleType =
 419                                         (SourceTypeBinding) enclosingSourceType.enclosingTypeAt(
 420                                                 (bits & DepthMASK) >> DepthSHIFT);
 421                                 syntheticReadAccessor = currentCompatibleType.addSyntheticMethod(binding, true);
 422                                 currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 423                                 return;
 424                         }
 425                 }
 426                 // if the binding declaring class is not visible, need special action
 427                 // for runtime compatibility on 1.2 VMs : change the declaring class of the binding
 428                 // NOTE: from 1.4 on, field's declaring class is touched if any different from receiver type
 429                 if (binding.declaringClass != this.receiverType
 430                         && !this.receiverType.isArrayType()
 431                         && binding.declaringClass != null // array.length
 432                         && binding.constant == NotAConstant
 433                         && ((currentScope.environment().options.complianceLevel >= CompilerOptions.JDK1_4
 434                                 && binding.declaringClass.id != T_Object)
 435                         //no change for Object fields (in case there was)
 436                                 || !binding.declaringClass.canBeSeenBy(currentScope))) {
 437                         this.codegenBinding =
 438                                 currentScope.enclosingSourceType().getUpdatedFieldBinding(
 439                                         binding,
 440                                         (ReferenceBinding) this.receiverType);
 441                 }
 442         }
 443
 444         /*
 445          * No need to emulate access to protected fields since not implicitly accessed
 446          */
 447         public void manageSyntheticWriteAccessIfNecessary(BlockScope currentScope) {
 448
 449                 if (binding.isPrivate()) {
 450                         if (currentScope.enclosingSourceType() != binding.declaringClass) {
 451                                 syntheticWriteAccessor =
 452                                         ((SourceTypeBinding) binding.declaringClass).addSyntheticMethod(binding, false);
 453                                 currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 454                                 return;
 455                         }
 456
 457                 } else if (receiver instanceof QualifiedSuperReference) { // qualified super
 458
 459                         // qualified super need emulation always
 460                         SourceTypeBinding destinationType =
 461                                 (SourceTypeBinding) (((QualifiedSuperReference) receiver)
 462                                         .currentCompatibleType);
 463                         syntheticWriteAccessor = destinationType.addSyntheticMethod(binding, false);
 464                         currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 465                         return;
 466
 467                 } else if (binding.isProtected()) {
 468
 469                         SourceTypeBinding enclosingSourceType;
 470                         if (((bits & DepthMASK) != 0)
 471                                 && binding.declaringClass.getPackage()
 472                                         != (enclosingSourceType = currentScope.enclosingSourceType()).getPackage()) {
 473
 474                                 SourceTypeBinding currentCompatibleType =
 475                                         (SourceTypeBinding) enclosingSourceType.enclosingTypeAt(
 476                                                 (bits & DepthMASK) >> DepthSHIFT);
 477                                 syntheticWriteAccessor =
 478                                         currentCompatibleType.addSyntheticMethod(binding, false);
 479                                 currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 480                                 return;
 481                         }
 482                 }
 483                 // if the binding declaring class is not visible, need special action
 484                 // for runtime compatibility on 1.2 VMs : change the declaring class of the binding
 485                 // NOTE: from 1.4 on, field's declaring class is touched if any different from receiver type
 486                 if (binding.declaringClass != this.receiverType
 487                         && !this.receiverType.isArrayType()
 488                         && binding.declaringClass != null // array.length
 489                         && binding.constant == NotAConstant
 490                         && ((currentScope.environment().options.complianceLevel >= CompilerOptions.JDK1_4
 491                                 && binding.declaringClass.id != T_Object)
 492                         //no change for Object fields (in case there was)
 493                                 || !binding.declaringClass.canBeSeenBy(currentScope))) {
 494                         this.codegenBinding =
 495                                 currentScope.enclosingSourceType().getUpdatedFieldBinding(
 496                                         binding,
 497                                         (ReferenceBinding) this.receiverType);
 498                 }
 499         }
 500
 501         public TypeBinding resolveType(BlockScope scope) {
 502
 503                 // Answer the signature type of the field.
 504                 // constants are propaged when the field is final
 505                 // and initialized with a (compile time) constant
 506
 507                 // regular receiver reference
 508                 this.receiverType = receiver.resolveType(scope);
 509                 if (this.receiverType == null) {
 510                         constant = NotAConstant;
 511                         return null;
 512                 }
 513                 // the case receiverType.isArrayType and token = 'length' is handled by the scope API
 514                 this.codegenBinding =
 515                         this.binding = scope.getField(this.receiverType, token, this);
 516                 if (!binding.isValidBinding()) {
 517                         constant = NotAConstant;
 518                         scope.problemReporter().invalidField(this, this.receiverType);
 519                         return null;
 520                 }
 521
 522                 if (isFieldUseDeprecated(binding, scope))
 523                         scope.problemReporter().deprecatedField(binding, this);
 524
 525                 // check for this.x in static is done in the resolution of the receiver
 526                 constant =
 527                         FieldReference.getConstantFor(
 528                                 binding,
 529                                 receiver == ThisReference.ThisImplicit,
 530                                 this,
 531                                 scope,
 532                                 0);
 533                 if (receiver != ThisReference.ThisImplicit)
 534                         constant = NotAConstant;
 535
 536                 return binding.type;
 537         }
 538
 539         public void setActualReceiverType(ReferenceBinding receiverType) {
 540                 // ignored
 541         }
 542
 543         public void setDepth(int depth) {
 544
 545                 if (depth > 0) {
 546                         bits &= ~DepthMASK; // flush previous depth if any
 547                         bits |= (depth & 0xFF) << DepthSHIFT; // encoded on 8 bits
 548                 }
 549         }
 550
 551         public void setFieldIndex(int index) {
 552                 // ignored
 553         }
 554
 555         public String toStringExpression() {
 556
 557                 return receiver.toString() + "." //$NON-NLS-1$
 558                 + new String(token);
 559         }
 560
 561         public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope scope) {
 562
 563                 if (visitor.visit(this, scope)) {
 564                         receiver.traverse(visitor, scope);
 565                 }
 566                 visitor.endVisit(this, scope);
 567         }
 568 }