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.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.impl.CompilerOptions;
  18 import net.sourceforge.phpdt.internal.compiler.impl.Constant;
  19 import net.sourceforge.phpdt.internal.compiler.lookup.BindingIds;
  20 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  21 import net.sourceforge.phpdt.internal.compiler.lookup.FieldBinding;
  22 import net.sourceforge.phpdt.internal.compiler.lookup.InvocationSite;
  23 import net.sourceforge.phpdt.internal.compiler.lookup.MethodBinding;
  24 import net.sourceforge.phpdt.internal.compiler.lookup.MethodScope;
  25 import net.sourceforge.phpdt.internal.compiler.lookup.ReferenceBinding;
  26 import net.sourceforge.phpdt.internal.compiler.lookup.Scope;
  27 import net.sourceforge.phpdt.internal.compiler.lookup.SourceTypeBinding;
  28 import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
  29
  30 public class FieldReference extends Reference implements InvocationSite {
  31
  32         public Expression receiver;
  33         public char[] token;
  34         public FieldBinding binding, codegenBinding;
  35         public long nameSourcePosition; //(start<<32)+end
  36         MethodBinding syntheticReadAccessor, syntheticWriteAccessor;
  37         public TypeBinding receiverType;
  38
  39         public FieldReference(char[] source, long pos) {
  40
  41                 token = source;
  42                 nameSourcePosition = pos;
  43                 //by default the position are the one of the field (not true for super access)
  44                 sourceStart = (int) (pos >>> 32);
  45                 sourceEnd = (int) (pos & 0x00000000FFFFFFFFL);
  46                 bits |= BindingIds.FIELD;
  47
  48         }
  49
  50         public FlowInfo analyseAssignment(
  51                 BlockScope currentScope,
  52                 FlowContext flowContext,
  53                 FlowInfo flowInfo,
  54                 Assignment assignment,
  55                 boolean isCompound) {
  56
  57                 // compound assignment extra work
  58                 if (isCompound) { // check the variable part is initialized if blank final
  59                         if (binding.isFinal()
  60                                 && receiver.isThis()
  61                                 && currentScope.allowBlankFinalFieldAssignment(binding)
  62                                 && (!flowInfo.isDefinitelyAssigned(binding))) {
  63                                 currentScope.problemReporter().uninitializedBlankFinalField(binding, this);
  64                                 // we could improve error msg here telling "cannot use compound assignment on final blank field"
  65                         }
  66                         manageSyntheticReadAccessIfNecessary(currentScope);
  67                 }
  68                 if (assignment.expression != null) {
  69                         flowInfo =
  70                                 assignment
  71                                         .expression
  72                                         .analyseCode(currentScope, flowContext, flowInfo)
  73                                         .unconditionalInits();
  74                 }
  75                 flowInfo =
  76                         receiver
  77                                 .analyseCode(currentScope, flowContext, flowInfo, !binding.isStatic())
  78                                 .unconditionalInits();
  79                 manageSyntheticWriteAccessIfNecessary(currentScope);
  80
  81                 // check if assigning a final field
  82                 if (binding.isFinal()) {
  83                         // in a context where it can be assigned?
  84                         if (receiver.isThis()
  85                                 && !(receiver instanceof QualifiedThisReference)
  86                                 && currentScope.allowBlankFinalFieldAssignment(binding)) {
  87                                 if (flowInfo.isPotentiallyAssigned(binding)) {
  88                                         currentScope.problemReporter().duplicateInitializationOfBlankFinalField(
  89                                                 binding,
  90                                                 this);
  91                                 }
  92                                 flowInfo.markAsDefinitelyAssigned(binding);
  93                                 flowContext.recordSettingFinal(binding, this);
  94                         } else {
  95                                 // assigning a final field outside an initializer or constructor
  96                                 currentScope.problemReporter().cannotAssignToFinalField(binding, this);
  97                         }
  98                 }
  99                 return flowInfo;
 100         }
 101
 102         public FlowInfo analyseCode(
 103                 BlockScope currentScope,
 104                 FlowContext flowContext,
 105                 FlowInfo flowInfo) {
 106
 107                 return analyseCode(currentScope, flowContext, flowInfo, true);
 108         }
 109
 110         public FlowInfo analyseCode(
 111                 BlockScope currentScope,
 112                 FlowContext flowContext,
 113                 FlowInfo flowInfo,
 114                 boolean valueRequired) {
 115
 116                 receiver.analyseCode(currentScope, flowContext, flowInfo, !binding.isStatic());
 117                 if (valueRequired) {
 118                         manageSyntheticReadAccessIfNecessary(currentScope);
 119                 }
 120                 return flowInfo;
 121         }
 122
 123         public FieldBinding fieldBinding() {
 124
 125                 return binding;
 126         }
 127
 128         public void generateAssignment(
 129                 BlockScope currentScope,
 130                 CodeStream codeStream,
 131                 Assignment assignment,
 132                 boolean valueRequired) {
 133
 134                 receiver.generateCode(
 135                         currentScope,
 136                         codeStream,
 137                         !this.codegenBinding.isStatic());
 138                 assignment.expression.generateCode(currentScope, codeStream, true);
 139                 fieldStore(
 140                         codeStream,
 141                         this.codegenBinding,
 142                         syntheticWriteAccessor,
 143                         valueRequired);
 144                 if (valueRequired) {
 145                         codeStream.generateImplicitConversion(assignment.implicitConversion);
 146                 }
 147         }
 148
 149         /**
 150          * Field reference code generation
 151          *
 152          * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
 153          * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
 154          * @param valueRequired boolean
 155          */
 156         public void generateCode(
 157                 BlockScope currentScope,
 158                 CodeStream codeStream,
 159                 boolean valueRequired) {
 160
 161                 int pc = codeStream.position;
 162                 if (constant != NotAConstant) {
 163                         if (valueRequired) {
 164                                 codeStream.generateConstant(constant, implicitConversion);
 165                         }
 166                 } else {
 167                         boolean isStatic = this.codegenBinding.isStatic();
 168                         receiver.generateCode(
 169                                 currentScope,
 170                                 codeStream,
 171                                 valueRequired && (!isStatic) && (this.codegenBinding.constant == NotAConstant));
 172                         if (valueRequired) {
 173                                 if (this.codegenBinding.constant == NotAConstant) {
 174                                         if (this.codegenBinding.declaringClass == null) { // array length
 175                                                 codeStream.arraylength();
 176                                         } else {
 177                                                 if (syntheticReadAccessor == null) {
 178                                                         if (isStatic) {
 179                                                                 codeStream.getstatic(this.codegenBinding);
 180                                                         } else {
 181                                                                 codeStream.getfield(this.codegenBinding);
 182                                                         }
 183                                                 } else {
 184                                                         codeStream.invokestatic(syntheticReadAccessor);
 185                                                 }
 186                                         }
 187                                         codeStream.generateImplicitConversion(implicitConversion);
 188                                 } else {
 189                                         codeStream.generateConstant(this.codegenBinding.constant, implicitConversion);
 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                 boolean implicitReceiver,
 301                 Reference reference,
 302                 Scope referenceScope,
 303                 int indexInQualification) {
 304
 305                 //propagation of the constant.
 306
 307                 //ref can be a FieldReference, a SingleNameReference or a QualifiedNameReference
 308                 //indexInQualification may have a value greater than zero only for QualifiednameReference
 309                 //if ref==null then indexInQualification==0 AND implicitReceiver == false. This case is a
 310                 //degenerated case where a fake reference field (null)
 311                 //is associted to a real FieldBinding in order
 312                 //to allow its constant computation using the regular path (i.e. find the fieldDeclaration
 313                 //and proceed to its type resolution). As implicitReceiver is false, no error reporting
 314                 //against ref will be used ==> no nullPointerException risk ....
 315
 316                 //special treatment for langage-built-in  field (their declaring class is null)
 317                 if (binding.declaringClass == null) {
 318                         //currently only one field "length" : the constant computation is never done
 319                         return NotAConstant;
 320                 }
 321                 if (!binding.isFinal()) {
 322                         return binding.constant = NotAConstant;
 323                 }
 324                 if (binding.constant != null) {
 325                         if (indexInQualification == 0) {
 326                                 return binding.constant;
 327                         }
 328                         //see previous comment for the (sould-always-be) valid cast
 329                         QualifiedNameReference qualifiedReference = (QualifiedNameReference) reference;
 330                         if (indexInQualification == (qualifiedReference.indexOfFirstFieldBinding - 1)) {
 331                                 return binding.constant;
 332                         }
 333                         return NotAConstant;
 334                 }
 335
 336                 //The field has not been yet type checked.
 337                 //It also means that the field is not coming from a class that
 338                 //has already been compiled. It can only be from a class within
 339                 //compilation units to process. Thus the field is NOT from a BinaryTypeBinbing
 340
 341                 SourceTypeBinding typeBinding = (SourceTypeBinding) binding.declaringClass;
 342                 TypeDeclaration typeDecl = typeBinding.scope.referenceContext;
 343                 FieldDeclaration fieldDecl = typeDecl.declarationOf(binding);
 344
 345                 //what scope to use (depend on the staticness of the field binding)
 346                 MethodScope fieldScope =
 347                         binding.isStatic()
 348                                 ? typeDecl.staticInitializerScope
 349                                 : typeDecl.initializerScope;
 350
 351                 if (implicitReceiver) { //Determine if the ref is legal in the current class of the field
 352                         //i.e. not a forward reference .... (they are allowed when the receiver is explicit ! ... Please don't ask me why !...yet another java mystery...)
 353                         if (fieldScope.fieldDeclarationIndex == MethodScope.NotInFieldDecl) {
 354                                 // no field is currently being analysed in typeDecl
 355                                 fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 356                                 return binding.constant;
 357                         }
 358                         //We are re-entering the same class fields analysing
 359                         if ((reference != null)
 360                                 && (binding.declaringClass == referenceScope.enclosingSourceType()) // only complain for access inside same type
 361                                 && (binding.id > fieldScope.fieldDeclarationIndex)) {
 362                                 //forward reference. The declaration remains unresolved.
 363                                 referenceScope.problemReporter().forwardReference(reference, indexInQualification, typeBinding);
 364                                 return NotAConstant;
 365                         }
 366                         fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 367                         return binding.constant;
 368                 }
 369                 //the field reference is explicity. It has to be a "simple" like field reference to get the
 370                 //constant propagation. For example in Packahe.Type.field1.field2 , field1 may have its
 371                 //constant having a propagation where field2 is always not propagating its
 372                 if (indexInQualification == 0) {
 373                         fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 374                         return binding.constant;
 375                 }
 376                 // Side-effect on the field binding may not be propagated out for the qualified reference
 377                 // unless it occurs in first place of the name sequence
 378                 fieldDecl.resolve(fieldScope); //side effect on binding :-) ...
 379                 //see previous comment for the cast that should always be valid
 380                 QualifiedNameReference qualifiedReference = (QualifiedNameReference) reference;
 381                 if (indexInQualification == (qualifiedReference.indexOfFirstFieldBinding - 1)) {
 382                         return binding.constant;
 383                 } else {
 384                         return NotAConstant;
 385                 }
 386         }
 387
 388         public boolean isSuperAccess() {
 389
 390                 return receiver.isSuper();
 391         }
 392
 393         public boolean isTypeAccess() {
 394
 395                 return receiver != null && receiver.isTypeReference();
 396         }
 397
 398         /*
 399          * No need to emulate access to protected fields since not implicitly accessed
 400          */
 401         public void manageSyntheticReadAccessIfNecessary(BlockScope currentScope) {
 402
 403                 if (binding.isPrivate()) {
 404                         if ((currentScope.enclosingSourceType() != binding.declaringClass)
 405                                 && (binding.constant == NotAConstant)) {
 406                                 syntheticReadAccessor =
 407                                         ((SourceTypeBinding) binding.declaringClass).addSyntheticMethod(binding, true);
 408                                 currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 409                                 return;
 410                         }
 411
 412                 } else if (receiver instanceof QualifiedSuperReference) { // qualified super
 413
 414                         // qualified super need emulation always
 415                         SourceTypeBinding destinationType =
 416                                 (SourceTypeBinding) (((QualifiedSuperReference) receiver)
 417                                         .currentCompatibleType);
 418                         syntheticReadAccessor = destinationType.addSyntheticMethod(binding, true);
 419                         currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 420                         return;
 421
 422                 } else if (binding.isProtected()) {
 423
 424                         SourceTypeBinding enclosingSourceType;
 425                         if (((bits & DepthMASK) != 0)
 426                                 && binding.declaringClass.getPackage()
 427                                         != (enclosingSourceType = currentScope.enclosingSourceType()).getPackage()) {
 428
 429                                 SourceTypeBinding currentCompatibleType =
 430                                         (SourceTypeBinding) enclosingSourceType.enclosingTypeAt(
 431                                                 (bits & DepthMASK) >> DepthSHIFT);
 432                                 syntheticReadAccessor = currentCompatibleType.addSyntheticMethod(binding, true);
 433                                 currentScope.problemReporter().needToEmulateFieldReadAccess(binding, this);
 434                                 return;
 435                         }
 436                 }
 437                 // if the binding declaring class is not visible, need special action
 438                 // for runtime compatibility on 1.2 VMs : change the declaring class of the binding
 439                 // NOTE: from 1.4 on, field's declaring class is touched if any different from receiver type
 440                 if (binding.declaringClass != this.receiverType
 441                         && !this.receiverType.isArrayType()
 442                         && binding.declaringClass != null // array.length
 443                         && binding.constant == NotAConstant
 444                         && ((currentScope.environment().options.complianceLevel >= CompilerOptions.JDK1_4
 445                                 && binding.declaringClass.id != T_Object)
 446                         //no change for Object fields (in case there was)
 447                                 || !binding.declaringClass.canBeSeenBy(currentScope))) {
 448                         this.codegenBinding =
 449                                 currentScope.enclosingSourceType().getUpdatedFieldBinding(
 450                                         binding,
 451                                         (ReferenceBinding) this.receiverType);
 452                 }
 453         }
 454
 455         /*
 456          * No need to emulate access to protected fields since not implicitly accessed
 457          */
 458         public void manageSyntheticWriteAccessIfNecessary(BlockScope currentScope) {
 459
 460                 if (binding.isPrivate()) {
 461                         if (currentScope.enclosingSourceType() != binding.declaringClass) {
 462                                 syntheticWriteAccessor =
 463                                         ((SourceTypeBinding) binding.declaringClass).addSyntheticMethod(binding, false);
 464                                 currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 465                                 return;
 466                         }
 467
 468                 } else if (receiver instanceof QualifiedSuperReference) { // qualified super
 469
 470                         // qualified super need emulation always
 471                         SourceTypeBinding destinationType =
 472                                 (SourceTypeBinding) (((QualifiedSuperReference) receiver)
 473                                         .currentCompatibleType);
 474                         syntheticWriteAccessor = destinationType.addSyntheticMethod(binding, false);
 475                         currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 476                         return;
 477
 478                 } else if (binding.isProtected()) {
 479
 480                         SourceTypeBinding enclosingSourceType;
 481                         if (((bits & DepthMASK) != 0)
 482                                 && binding.declaringClass.getPackage()
 483                                         != (enclosingSourceType = currentScope.enclosingSourceType()).getPackage()) {
 484
 485                                 SourceTypeBinding currentCompatibleType =
 486                                         (SourceTypeBinding) enclosingSourceType.enclosingTypeAt(
 487                                                 (bits & DepthMASK) >> DepthSHIFT);
 488                                 syntheticWriteAccessor =
 489                                         currentCompatibleType.addSyntheticMethod(binding, false);
 490                                 currentScope.problemReporter().needToEmulateFieldWriteAccess(binding, this);
 491                                 return;
 492                         }
 493                 }
 494                 // if the binding declaring class is not visible, need special action
 495                 // for runtime compatibility on 1.2 VMs : change the declaring class of the binding
 496                 // NOTE: from 1.4 on, field's declaring class is touched if any different from receiver type
 497                 if (binding.declaringClass != this.receiverType
 498                         && !this.receiverType.isArrayType()
 499                         && binding.declaringClass != null // array.length
 500                         && binding.constant == NotAConstant
 501                         && ((currentScope.environment().options.complianceLevel >= CompilerOptions.JDK1_4
 502                                 && binding.declaringClass.id != T_Object)
 503                         //no change for Object fields (in case there was)
 504                                 || !binding.declaringClass.canBeSeenBy(currentScope))) {
 505                         this.codegenBinding =
 506                                 currentScope.enclosingSourceType().getUpdatedFieldBinding(
 507                                         binding,
 508                                         (ReferenceBinding) this.receiverType);
 509                 }
 510         }
 511
 512         public TypeBinding resolveType(BlockScope scope) {
 513
 514                 // Answer the signature type of the field.
 515                 // constants are propaged when the field is final
 516                 // and initialized with a (compile time) constant
 517
 518                 // regular receiver reference
 519                 this.receiverType = receiver.resolveType(scope);
 520                 if (this.receiverType == null) {
 521                         constant = NotAConstant;
 522                         return null;
 523                 }
 524                 // the case receiverType.isArrayType and token = 'length' is handled by the scope API
 525                 this.codegenBinding =
 526                         this.binding = scope.getField(this.receiverType, token, this);
 527                 if (!binding.isValidBinding()) {
 528                         constant = NotAConstant;
 529                         scope.problemReporter().invalidField(this, this.receiverType);
 530                         return null;
 531                 }
 532
 533                 if (isFieldUseDeprecated(binding, scope))
 534                         scope.problemReporter().deprecatedField(binding, this);
 535
 536                 // check for this.x in static is done in the resolution of the receiver
 537                 constant =
 538                         FieldReference.getConstantFor(
 539                                 binding,
 540                                 receiver == ThisReference.ThisImplicit,
 541                                 this,
 542                                 scope,
 543                                 0);
 544                 if (receiver != ThisReference.ThisImplicit)
 545                         constant = NotAConstant;
 546
 547                 return binding.type;
 548         }
 549
 550         public void setActualReceiverType(ReferenceBinding receiverType) {
 551                 // ignored
 552         }
 553
 554         public void setDepth(int depth) {
 555
 556                 if (depth > 0) {
 557                         bits &= ~DepthMASK; // flush previous depth if any
 558                         bits |= (depth & 0xFF) << DepthSHIFT; // encoded on 8 bits
 559                 }
 560         }
 561
 562         public void setFieldIndex(int index) {
 563                 // ignored
 564         }
 565
 566         public String toStringExpression() {
 567
 568                 return receiver.toString() + "." //$NON-NLS-1$
 569                 + new String(token);
 570         }
 571
 572         public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope scope) {
 573
 574                 if (visitor.visit(this, scope)) {
 575                         receiver.traverse(visitor, scope);
 576                 }
 577                 visitor.endVisit(this, scope);
 578         }
 579 }