IvarInvalidationChecker.cpp revision 249423
1//=- IvarInvalidationChecker.cpp - -*- C++ -------------------------------*-==// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This checker implements annotation driven invalidation checking. If a class 11// contains a method annotated with 'objc_instance_variable_invalidator', 12// - (void) foo 13// __attribute__((annotate("objc_instance_variable_invalidator"))); 14// all the "ivalidatable" instance variables of this class should be 15// invalidated. We call an instance variable ivalidatable if it is an object of 16// a class which contains an invalidation method. There could be multiple 17// methods annotated with such annotations per class, either one can be used 18// to invalidate the ivar. An ivar or property are considered to be 19// invalidated if they are being assigned 'nil' or an invalidation method has 20// been called on them. An invalidation method should either invalidate all 21// the ivars or call another invalidation method (on self). 22// 23// Partial invalidor annotation allows to addess cases when ivars are 24// invalidated by other methods, which might or might not be called from 25// the invalidation method. The checker checks that each invalidation 26// method and all the partial methods cumulatively invalidate all ivars. 27// __attribute__((annotate("objc_instance_variable_invalidator_partial"))); 28// 29//===----------------------------------------------------------------------===// 30 31#include "ClangSACheckers.h" 32#include "clang/AST/Attr.h" 33#include "clang/AST/DeclObjC.h" 34#include "clang/AST/StmtVisitor.h" 35#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 36#include "clang/StaticAnalyzer/Core/Checker.h" 37#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" 38#include "llvm/ADT/DenseMap.h" 39#include "llvm/ADT/SetVector.h" 40#include "llvm/ADT/SmallString.h" 41 42using namespace clang; 43using namespace ento; 44 45namespace { 46 47struct ChecksFilter { 48 /// Check for missing invalidation method declarations. 49 DefaultBool check_MissingInvalidationMethod; 50 /// Check that all ivars are invalidated. 51 DefaultBool check_InstanceVariableInvalidation; 52}; 53 54class IvarInvalidationCheckerImpl { 55 56 typedef llvm::SmallSetVector<const ObjCMethodDecl*, 2> MethodSet; 57 typedef llvm::DenseMap<const ObjCMethodDecl*, 58 const ObjCIvarDecl*> MethToIvarMapTy; 59 typedef llvm::DenseMap<const ObjCPropertyDecl*, 60 const ObjCIvarDecl*> PropToIvarMapTy; 61 typedef llvm::DenseMap<const ObjCIvarDecl*, 62 const ObjCPropertyDecl*> IvarToPropMapTy; 63 64 65 struct InvalidationInfo { 66 /// Has the ivar been invalidated? 67 bool IsInvalidated; 68 69 /// The methods which can be used to invalidate the ivar. 70 MethodSet InvalidationMethods; 71 72 InvalidationInfo() : IsInvalidated(false) {} 73 void addInvalidationMethod(const ObjCMethodDecl *MD) { 74 InvalidationMethods.insert(MD); 75 } 76 77 bool needsInvalidation() const { 78 return !InvalidationMethods.empty(); 79 } 80 81 bool hasMethod(const ObjCMethodDecl *MD) { 82 if (IsInvalidated) 83 return true; 84 for (MethodSet::iterator I = InvalidationMethods.begin(), 85 E = InvalidationMethods.end(); I != E; ++I) { 86 if (*I == MD) { 87 IsInvalidated = true; 88 return true; 89 } 90 } 91 return false; 92 } 93 }; 94 95 typedef llvm::DenseMap<const ObjCIvarDecl*, InvalidationInfo> IvarSet; 96 97 /// Statement visitor, which walks the method body and flags the ivars 98 /// referenced in it (either directly or via property). 99 class MethodCrawler : public ConstStmtVisitor<MethodCrawler> { 100 /// The set of Ivars which need to be invalidated. 101 IvarSet &IVars; 102 103 /// Flag is set as the result of a message send to another 104 /// invalidation method. 105 bool &CalledAnotherInvalidationMethod; 106 107 /// Property setter to ivar mapping. 108 const MethToIvarMapTy &PropertySetterToIvarMap; 109 110 /// Property getter to ivar mapping. 111 const MethToIvarMapTy &PropertyGetterToIvarMap; 112 113 /// Property to ivar mapping. 114 const PropToIvarMapTy &PropertyToIvarMap; 115 116 /// The invalidation method being currently processed. 117 const ObjCMethodDecl *InvalidationMethod; 118 119 ASTContext &Ctx; 120 121 /// Peel off parens, casts, OpaqueValueExpr, and PseudoObjectExpr. 122 const Expr *peel(const Expr *E) const; 123 124 /// Does this expression represent zero: '0'? 125 bool isZero(const Expr *E) const; 126 127 /// Mark the given ivar as invalidated. 128 void markInvalidated(const ObjCIvarDecl *Iv); 129 130 /// Checks if IvarRef refers to the tracked IVar, if yes, marks it as 131 /// invalidated. 132 void checkObjCIvarRefExpr(const ObjCIvarRefExpr *IvarRef); 133 134 /// Checks if ObjCPropertyRefExpr refers to the tracked IVar, if yes, marks 135 /// it as invalidated. 136 void checkObjCPropertyRefExpr(const ObjCPropertyRefExpr *PA); 137 138 /// Checks if ObjCMessageExpr refers to (is a getter for) the tracked IVar, 139 /// if yes, marks it as invalidated. 140 void checkObjCMessageExpr(const ObjCMessageExpr *ME); 141 142 /// Checks if the Expr refers to an ivar, if yes, marks it as invalidated. 143 void check(const Expr *E); 144 145 public: 146 MethodCrawler(IvarSet &InIVars, 147 bool &InCalledAnotherInvalidationMethod, 148 const MethToIvarMapTy &InPropertySetterToIvarMap, 149 const MethToIvarMapTy &InPropertyGetterToIvarMap, 150 const PropToIvarMapTy &InPropertyToIvarMap, 151 ASTContext &InCtx) 152 : IVars(InIVars), 153 CalledAnotherInvalidationMethod(InCalledAnotherInvalidationMethod), 154 PropertySetterToIvarMap(InPropertySetterToIvarMap), 155 PropertyGetterToIvarMap(InPropertyGetterToIvarMap), 156 PropertyToIvarMap(InPropertyToIvarMap), 157 InvalidationMethod(0), 158 Ctx(InCtx) {} 159 160 void VisitStmt(const Stmt *S) { VisitChildren(S); } 161 162 void VisitBinaryOperator(const BinaryOperator *BO); 163 164 void VisitObjCMessageExpr(const ObjCMessageExpr *ME); 165 166 void VisitChildren(const Stmt *S) { 167 for (Stmt::const_child_range I = S->children(); I; ++I) { 168 if (*I) 169 this->Visit(*I); 170 if (CalledAnotherInvalidationMethod) 171 return; 172 } 173 } 174 }; 175 176 /// Check if the any of the methods inside the interface are annotated with 177 /// the invalidation annotation, update the IvarInfo accordingly. 178 /// \param LookForPartial is set when we are searching for partial 179 /// invalidators. 180 static void containsInvalidationMethod(const ObjCContainerDecl *D, 181 InvalidationInfo &Out, 182 bool LookForPartial); 183 184 /// Check if ivar should be tracked and add to TrackedIvars if positive. 185 /// Returns true if ivar should be tracked. 186 static bool trackIvar(const ObjCIvarDecl *Iv, IvarSet &TrackedIvars, 187 const ObjCIvarDecl **FirstIvarDecl); 188 189 /// Given the property declaration, and the list of tracked ivars, finds 190 /// the ivar backing the property when possible. Returns '0' when no such 191 /// ivar could be found. 192 static const ObjCIvarDecl *findPropertyBackingIvar( 193 const ObjCPropertyDecl *Prop, 194 const ObjCInterfaceDecl *InterfaceD, 195 IvarSet &TrackedIvars, 196 const ObjCIvarDecl **FirstIvarDecl); 197 198 /// Print ivar name or the property if the given ivar backs a property. 199 static void printIvar(llvm::raw_svector_ostream &os, 200 const ObjCIvarDecl *IvarDecl, 201 const IvarToPropMapTy &IvarToPopertyMap); 202 203 void reportNoInvalidationMethod(const ObjCIvarDecl *FirstIvarDecl, 204 const IvarToPropMapTy &IvarToPopertyMap, 205 const ObjCInterfaceDecl *InterfaceD, 206 bool MissingDeclaration) const; 207 void reportIvarNeedsInvalidation(const ObjCIvarDecl *IvarD, 208 const IvarToPropMapTy &IvarToPopertyMap, 209 const ObjCMethodDecl *MethodD) const; 210 211 AnalysisManager& Mgr; 212 BugReporter &BR; 213 /// Filter on the checks performed. 214 const ChecksFilter &Filter; 215 216public: 217 IvarInvalidationCheckerImpl(AnalysisManager& InMgr, 218 BugReporter &InBR, 219 const ChecksFilter &InFilter) : 220 Mgr (InMgr), BR(InBR), Filter(InFilter) {} 221 222 void visit(const ObjCImplementationDecl *D) const; 223}; 224 225static bool isInvalidationMethod(const ObjCMethodDecl *M, bool LookForPartial) { 226 for (specific_attr_iterator<AnnotateAttr> 227 AI = M->specific_attr_begin<AnnotateAttr>(), 228 AE = M->specific_attr_end<AnnotateAttr>(); AI != AE; ++AI) { 229 const AnnotateAttr *Ann = *AI; 230 if (!LookForPartial && 231 Ann->getAnnotation() == "objc_instance_variable_invalidator") 232 return true; 233 if (LookForPartial && 234 Ann->getAnnotation() == "objc_instance_variable_invalidator_partial") 235 return true; 236 } 237 return false; 238} 239 240void IvarInvalidationCheckerImpl::containsInvalidationMethod( 241 const ObjCContainerDecl *D, InvalidationInfo &OutInfo, bool Partial) { 242 243 if (!D) 244 return; 245 246 assert(!isa<ObjCImplementationDecl>(D)); 247 // TODO: Cache the results. 248 249 // Check all methods. 250 for (ObjCContainerDecl::method_iterator 251 I = D->meth_begin(), 252 E = D->meth_end(); I != E; ++I) { 253 const ObjCMethodDecl *MDI = *I; 254 if (isInvalidationMethod(MDI, Partial)) 255 OutInfo.addInvalidationMethod( 256 cast<ObjCMethodDecl>(MDI->getCanonicalDecl())); 257 } 258 259 // If interface, check all parent protocols and super. 260 if (const ObjCInterfaceDecl *InterfD = dyn_cast<ObjCInterfaceDecl>(D)) { 261 262 // Visit all protocols. 263 for (ObjCInterfaceDecl::protocol_iterator 264 I = InterfD->protocol_begin(), 265 E = InterfD->protocol_end(); I != E; ++I) { 266 containsInvalidationMethod((*I)->getDefinition(), OutInfo, Partial); 267 } 268 269 // Visit all categories in case the invalidation method is declared in 270 // a category. 271 for (ObjCInterfaceDecl::visible_extensions_iterator 272 Ext = InterfD->visible_extensions_begin(), 273 ExtEnd = InterfD->visible_extensions_end(); 274 Ext != ExtEnd; ++Ext) { 275 containsInvalidationMethod(*Ext, OutInfo, Partial); 276 } 277 278 containsInvalidationMethod(InterfD->getSuperClass(), OutInfo, Partial); 279 return; 280 } 281 282 // If protocol, check all parent protocols. 283 if (const ObjCProtocolDecl *ProtD = dyn_cast<ObjCProtocolDecl>(D)) { 284 for (ObjCInterfaceDecl::protocol_iterator 285 I = ProtD->protocol_begin(), 286 E = ProtD->protocol_end(); I != E; ++I) { 287 containsInvalidationMethod((*I)->getDefinition(), OutInfo, Partial); 288 } 289 return; 290 } 291 292 return; 293} 294 295bool IvarInvalidationCheckerImpl::trackIvar(const ObjCIvarDecl *Iv, 296 IvarSet &TrackedIvars, 297 const ObjCIvarDecl **FirstIvarDecl) { 298 QualType IvQTy = Iv->getType(); 299 const ObjCObjectPointerType *IvTy = IvQTy->getAs<ObjCObjectPointerType>(); 300 if (!IvTy) 301 return false; 302 const ObjCInterfaceDecl *IvInterf = IvTy->getInterfaceDecl(); 303 304 InvalidationInfo Info; 305 containsInvalidationMethod(IvInterf, Info, /*LookForPartial*/ false); 306 if (Info.needsInvalidation()) { 307 const ObjCIvarDecl *I = cast<ObjCIvarDecl>(Iv->getCanonicalDecl()); 308 TrackedIvars[I] = Info; 309 if (!*FirstIvarDecl) 310 *FirstIvarDecl = I; 311 return true; 312 } 313 return false; 314} 315 316const ObjCIvarDecl *IvarInvalidationCheckerImpl::findPropertyBackingIvar( 317 const ObjCPropertyDecl *Prop, 318 const ObjCInterfaceDecl *InterfaceD, 319 IvarSet &TrackedIvars, 320 const ObjCIvarDecl **FirstIvarDecl) { 321 const ObjCIvarDecl *IvarD = 0; 322 323 // Lookup for the synthesized case. 324 IvarD = Prop->getPropertyIvarDecl(); 325 // We only track the ivars/properties that are defined in the current 326 // class (not the parent). 327 if (IvarD && IvarD->getContainingInterface() == InterfaceD) { 328 if (TrackedIvars.count(IvarD)) { 329 return IvarD; 330 } 331 // If the ivar is synthesized we still want to track it. 332 if (trackIvar(IvarD, TrackedIvars, FirstIvarDecl)) 333 return IvarD; 334 } 335 336 // Lookup IVars named "_PropName"or "PropName" among the tracked Ivars. 337 StringRef PropName = Prop->getIdentifier()->getName(); 338 for (IvarSet::const_iterator I = TrackedIvars.begin(), 339 E = TrackedIvars.end(); I != E; ++I) { 340 const ObjCIvarDecl *Iv = I->first; 341 StringRef IvarName = Iv->getName(); 342 343 if (IvarName == PropName) 344 return Iv; 345 346 SmallString<128> PropNameWithUnderscore; 347 { 348 llvm::raw_svector_ostream os(PropNameWithUnderscore); 349 os << '_' << PropName; 350 } 351 if (IvarName == PropNameWithUnderscore.str()) 352 return Iv; 353 } 354 355 // Note, this is a possible source of false positives. We could look at the 356 // getter implementation to find the ivar when its name is not derived from 357 // the property name. 358 return 0; 359} 360 361void IvarInvalidationCheckerImpl::printIvar(llvm::raw_svector_ostream &os, 362 const ObjCIvarDecl *IvarDecl, 363 const IvarToPropMapTy &IvarToPopertyMap) { 364 if (IvarDecl->getSynthesize()) { 365 const ObjCPropertyDecl *PD = IvarToPopertyMap.lookup(IvarDecl); 366 assert(PD &&"Do we synthesize ivars for something other than properties?"); 367 os << "Property "<< PD->getName() << " "; 368 } else { 369 os << "Instance variable "<< IvarDecl->getName() << " "; 370 } 371} 372 373// Check that the invalidatable interfaces with ivars/properties implement the 374// invalidation methods. 375void IvarInvalidationCheckerImpl:: 376visit(const ObjCImplementationDecl *ImplD) const { 377 // Collect all ivars that need cleanup. 378 IvarSet Ivars; 379 // Record the first Ivar needing invalidation; used in reporting when only 380 // one ivar is sufficient. Cannot grab the first on the Ivars set to ensure 381 // deterministic output. 382 const ObjCIvarDecl *FirstIvarDecl = 0; 383 const ObjCInterfaceDecl *InterfaceD = ImplD->getClassInterface(); 384 385 // Collect ivars declared in this class, its extensions and its implementation 386 ObjCInterfaceDecl *IDecl = const_cast<ObjCInterfaceDecl *>(InterfaceD); 387 for (const ObjCIvarDecl *Iv = IDecl->all_declared_ivar_begin(); Iv; 388 Iv= Iv->getNextIvar()) 389 trackIvar(Iv, Ivars, &FirstIvarDecl); 390 391 // Construct Property/Property Accessor to Ivar maps to assist checking if an 392 // ivar which is backing a property has been reset. 393 MethToIvarMapTy PropSetterToIvarMap; 394 MethToIvarMapTy PropGetterToIvarMap; 395 PropToIvarMapTy PropertyToIvarMap; 396 IvarToPropMapTy IvarToPopertyMap; 397 398 ObjCInterfaceDecl::PropertyMap PropMap; 399 ObjCInterfaceDecl::PropertyDeclOrder PropOrder; 400 InterfaceD->collectPropertiesToImplement(PropMap, PropOrder); 401 402 for (ObjCInterfaceDecl::PropertyMap::iterator 403 I = PropMap.begin(), E = PropMap.end(); I != E; ++I) { 404 const ObjCPropertyDecl *PD = I->second; 405 406 const ObjCIvarDecl *ID = findPropertyBackingIvar(PD, InterfaceD, Ivars, 407 &FirstIvarDecl); 408 if (!ID) 409 continue; 410 411 // Store the mappings. 412 PD = cast<ObjCPropertyDecl>(PD->getCanonicalDecl()); 413 PropertyToIvarMap[PD] = ID; 414 IvarToPopertyMap[ID] = PD; 415 416 // Find the setter and the getter. 417 const ObjCMethodDecl *SetterD = PD->getSetterMethodDecl(); 418 if (SetterD) { 419 SetterD = cast<ObjCMethodDecl>(SetterD->getCanonicalDecl()); 420 PropSetterToIvarMap[SetterD] = ID; 421 } 422 423 const ObjCMethodDecl *GetterD = PD->getGetterMethodDecl(); 424 if (GetterD) { 425 GetterD = cast<ObjCMethodDecl>(GetterD->getCanonicalDecl()); 426 PropGetterToIvarMap[GetterD] = ID; 427 } 428 } 429 430 // If no ivars need invalidation, there is nothing to check here. 431 if (Ivars.empty()) 432 return; 433 434 // Find all partial invalidation methods. 435 InvalidationInfo PartialInfo; 436 containsInvalidationMethod(InterfaceD, PartialInfo, /*LookForPartial*/ true); 437 438 // Remove ivars invalidated by the partial invalidation methods. They do not 439 // need to be invalidated in the regular invalidation methods. 440 for (MethodSet::iterator 441 I = PartialInfo.InvalidationMethods.begin(), 442 E = PartialInfo.InvalidationMethods.end(); I != E; ++I) { 443 const ObjCMethodDecl *InterfD = *I; 444 445 // Get the corresponding method in the @implementation. 446 const ObjCMethodDecl *D = ImplD->getMethod(InterfD->getSelector(), 447 InterfD->isInstanceMethod()); 448 if (D && D->hasBody()) { 449 bool CalledAnotherInvalidationMethod = false; 450 // The MethodCrowler is going to remove the invalidated ivars. 451 MethodCrawler(Ivars, 452 CalledAnotherInvalidationMethod, 453 PropSetterToIvarMap, 454 PropGetterToIvarMap, 455 PropertyToIvarMap, 456 BR.getContext()).VisitStmt(D->getBody()); 457 // If another invalidation method was called, trust that full invalidation 458 // has occurred. 459 if (CalledAnotherInvalidationMethod) 460 Ivars.clear(); 461 } 462 } 463 464 // If all ivars have been invalidated by partial invalidators, there is 465 // nothing to check here. 466 if (Ivars.empty()) 467 return; 468 469 // Find all invalidation methods in this @interface declaration and parents. 470 InvalidationInfo Info; 471 containsInvalidationMethod(InterfaceD, Info, /*LookForPartial*/ false); 472 473 // Report an error in case none of the invalidation methods are declared. 474 if (!Info.needsInvalidation()) { 475 if (Filter.check_MissingInvalidationMethod) 476 reportNoInvalidationMethod(FirstIvarDecl, IvarToPopertyMap, InterfaceD, 477 /*MissingDeclaration*/ true); 478 // If there are no invalidation methods, there is no ivar validation work 479 // to be done. 480 return; 481 } 482 483 // Only check if Ivars are invalidated when InstanceVariableInvalidation 484 // has been requested. 485 if (!Filter.check_InstanceVariableInvalidation) 486 return; 487 488 // Check that all ivars are invalidated by the invalidation methods. 489 bool AtImplementationContainsAtLeastOneInvalidationMethod = false; 490 for (MethodSet::iterator I = Info.InvalidationMethods.begin(), 491 E = Info.InvalidationMethods.end(); I != E; ++I) { 492 const ObjCMethodDecl *InterfD = *I; 493 494 // Get the corresponding method in the @implementation. 495 const ObjCMethodDecl *D = ImplD->getMethod(InterfD->getSelector(), 496 InterfD->isInstanceMethod()); 497 if (D && D->hasBody()) { 498 AtImplementationContainsAtLeastOneInvalidationMethod = true; 499 500 // Get a copy of ivars needing invalidation. 501 IvarSet IvarsI = Ivars; 502 503 bool CalledAnotherInvalidationMethod = false; 504 MethodCrawler(IvarsI, 505 CalledAnotherInvalidationMethod, 506 PropSetterToIvarMap, 507 PropGetterToIvarMap, 508 PropertyToIvarMap, 509 BR.getContext()).VisitStmt(D->getBody()); 510 // If another invalidation method was called, trust that full invalidation 511 // has occurred. 512 if (CalledAnotherInvalidationMethod) 513 continue; 514 515 // Warn on the ivars that were not invalidated by the method. 516 for (IvarSet::const_iterator 517 I = IvarsI.begin(), E = IvarsI.end(); I != E; ++I) 518 reportIvarNeedsInvalidation(I->first, IvarToPopertyMap, D); 519 } 520 } 521 522 // Report an error in case none of the invalidation methods are implemented. 523 if (!AtImplementationContainsAtLeastOneInvalidationMethod) 524 reportNoInvalidationMethod(FirstIvarDecl, IvarToPopertyMap, InterfaceD, 525 /*MissingDeclaration*/ false); 526} 527 528void IvarInvalidationCheckerImpl:: 529reportNoInvalidationMethod(const ObjCIvarDecl *FirstIvarDecl, 530 const IvarToPropMapTy &IvarToPopertyMap, 531 const ObjCInterfaceDecl *InterfaceD, 532 bool MissingDeclaration) const { 533 SmallString<128> sbuf; 534 llvm::raw_svector_ostream os(sbuf); 535 assert(FirstIvarDecl); 536 printIvar(os, FirstIvarDecl, IvarToPopertyMap); 537 os << "needs to be invalidated; "; 538 if (MissingDeclaration) 539 os << "no invalidation method is declared for "; 540 else 541 os << "no invalidation method is defined in the @implementation for "; 542 os << InterfaceD->getName(); 543 544 PathDiagnosticLocation IvarDecLocation = 545 PathDiagnosticLocation::createBegin(FirstIvarDecl, BR.getSourceManager()); 546 547 BR.EmitBasicReport(FirstIvarDecl, "Incomplete invalidation", 548 categories::CoreFoundationObjectiveC, os.str(), 549 IvarDecLocation); 550} 551 552void IvarInvalidationCheckerImpl:: 553reportIvarNeedsInvalidation(const ObjCIvarDecl *IvarD, 554 const IvarToPropMapTy &IvarToPopertyMap, 555 const ObjCMethodDecl *MethodD) const { 556 SmallString<128> sbuf; 557 llvm::raw_svector_ostream os(sbuf); 558 printIvar(os, IvarD, IvarToPopertyMap); 559 os << "needs to be invalidated or set to nil"; 560 PathDiagnosticLocation MethodDecLocation = 561 PathDiagnosticLocation::createEnd(MethodD->getBody(), 562 BR.getSourceManager(), 563 Mgr.getAnalysisDeclContext(MethodD)); 564 BR.EmitBasicReport(MethodD, "Incomplete invalidation", 565 categories::CoreFoundationObjectiveC, os.str(), 566 MethodDecLocation); 567} 568 569void IvarInvalidationCheckerImpl::MethodCrawler::markInvalidated( 570 const ObjCIvarDecl *Iv) { 571 IvarSet::iterator I = IVars.find(Iv); 572 if (I != IVars.end()) { 573 // If InvalidationMethod is present, we are processing the message send and 574 // should ensure we are invalidating with the appropriate method, 575 // otherwise, we are processing setting to 'nil'. 576 if (!InvalidationMethod || 577 (InvalidationMethod && I->second.hasMethod(InvalidationMethod))) 578 IVars.erase(I); 579 } 580} 581 582const Expr *IvarInvalidationCheckerImpl::MethodCrawler::peel(const Expr *E) const { 583 E = E->IgnoreParenCasts(); 584 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) 585 E = POE->getSyntacticForm()->IgnoreParenCasts(); 586 if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) 587 E = OVE->getSourceExpr()->IgnoreParenCasts(); 588 return E; 589} 590 591void IvarInvalidationCheckerImpl::MethodCrawler::checkObjCIvarRefExpr( 592 const ObjCIvarRefExpr *IvarRef) { 593 if (const Decl *D = IvarRef->getDecl()) 594 markInvalidated(cast<ObjCIvarDecl>(D->getCanonicalDecl())); 595} 596 597void IvarInvalidationCheckerImpl::MethodCrawler::checkObjCMessageExpr( 598 const ObjCMessageExpr *ME) { 599 const ObjCMethodDecl *MD = ME->getMethodDecl(); 600 if (MD) { 601 MD = cast<ObjCMethodDecl>(MD->getCanonicalDecl()); 602 MethToIvarMapTy::const_iterator IvI = PropertyGetterToIvarMap.find(MD); 603 if (IvI != PropertyGetterToIvarMap.end()) 604 markInvalidated(IvI->second); 605 } 606} 607 608void IvarInvalidationCheckerImpl::MethodCrawler::checkObjCPropertyRefExpr( 609 const ObjCPropertyRefExpr *PA) { 610 611 if (PA->isExplicitProperty()) { 612 const ObjCPropertyDecl *PD = PA->getExplicitProperty(); 613 if (PD) { 614 PD = cast<ObjCPropertyDecl>(PD->getCanonicalDecl()); 615 PropToIvarMapTy::const_iterator IvI = PropertyToIvarMap.find(PD); 616 if (IvI != PropertyToIvarMap.end()) 617 markInvalidated(IvI->second); 618 return; 619 } 620 } 621 622 if (PA->isImplicitProperty()) { 623 const ObjCMethodDecl *MD = PA->getImplicitPropertySetter(); 624 if (MD) { 625 MD = cast<ObjCMethodDecl>(MD->getCanonicalDecl()); 626 MethToIvarMapTy::const_iterator IvI =PropertyGetterToIvarMap.find(MD); 627 if (IvI != PropertyGetterToIvarMap.end()) 628 markInvalidated(IvI->second); 629 return; 630 } 631 } 632} 633 634bool IvarInvalidationCheckerImpl::MethodCrawler::isZero(const Expr *E) const { 635 E = peel(E); 636 637 return (E->isNullPointerConstant(Ctx, Expr::NPC_ValueDependentIsNotNull) 638 != Expr::NPCK_NotNull); 639} 640 641void IvarInvalidationCheckerImpl::MethodCrawler::check(const Expr *E) { 642 E = peel(E); 643 644 if (const ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(E)) { 645 checkObjCIvarRefExpr(IvarRef); 646 return; 647 } 648 649 if (const ObjCPropertyRefExpr *PropRef = dyn_cast<ObjCPropertyRefExpr>(E)) { 650 checkObjCPropertyRefExpr(PropRef); 651 return; 652 } 653 654 if (const ObjCMessageExpr *MsgExpr = dyn_cast<ObjCMessageExpr>(E)) { 655 checkObjCMessageExpr(MsgExpr); 656 return; 657 } 658} 659 660void IvarInvalidationCheckerImpl::MethodCrawler::VisitBinaryOperator( 661 const BinaryOperator *BO) { 662 VisitStmt(BO); 663 664 // Do we assign/compare against zero? If yes, check the variable we are 665 // assigning to. 666 BinaryOperatorKind Opcode = BO->getOpcode(); 667 if (Opcode != BO_Assign && 668 Opcode != BO_EQ && 669 Opcode != BO_NE) 670 return; 671 672 if (isZero(BO->getRHS())) { 673 check(BO->getLHS()); 674 return; 675 } 676 677 if (Opcode != BO_Assign && isZero(BO->getLHS())) { 678 check(BO->getRHS()); 679 return; 680 } 681} 682 683void IvarInvalidationCheckerImpl::MethodCrawler::VisitObjCMessageExpr( 684 const ObjCMessageExpr *ME) { 685 const ObjCMethodDecl *MD = ME->getMethodDecl(); 686 const Expr *Receiver = ME->getInstanceReceiver(); 687 688 // Stop if we are calling '[self invalidate]'. 689 if (Receiver && isInvalidationMethod(MD, /*LookForPartial*/ false)) 690 if (Receiver->isObjCSelfExpr()) { 691 CalledAnotherInvalidationMethod = true; 692 return; 693 } 694 695 // Check if we call a setter and set the property to 'nil'. 696 if (MD && (ME->getNumArgs() == 1) && isZero(ME->getArg(0))) { 697 MD = cast<ObjCMethodDecl>(MD->getCanonicalDecl()); 698 MethToIvarMapTy::const_iterator IvI = PropertySetterToIvarMap.find(MD); 699 if (IvI != PropertySetterToIvarMap.end()) { 700 markInvalidated(IvI->second); 701 return; 702 } 703 } 704 705 // Check if we call the 'invalidation' routine on the ivar. 706 if (Receiver) { 707 InvalidationMethod = MD; 708 check(Receiver->IgnoreParenCasts()); 709 InvalidationMethod = 0; 710 } 711 712 VisitStmt(ME); 713} 714} 715 716// Register the checkers. 717namespace { 718 719class IvarInvalidationChecker : 720 public Checker<check::ASTDecl<ObjCImplementationDecl> > { 721public: 722 ChecksFilter Filter; 723public: 724 void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager& Mgr, 725 BugReporter &BR) const { 726 IvarInvalidationCheckerImpl Walker(Mgr, BR, Filter); 727 Walker.visit(D); 728 } 729}; 730} 731 732#define REGISTER_CHECKER(name) \ 733void ento::register##name(CheckerManager &mgr) {\ 734 mgr.registerChecker<IvarInvalidationChecker>()->Filter.check_##name = true;\ 735} 736 737REGISTER_CHECKER(InstanceVariableInvalidation) 738REGISTER_CHECKER(MissingInvalidationMethod) 739 740