1 //== BasicObjCFoundationChecks.cpp - Simple Apple-Foundation checks -*- C++ -*-- 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines BasicObjCFoundationChecks, a class that encapsulates 10 // a set of simple checks to run on Objective-C code using Apple's Foundation 11 // classes. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" 16 #include "clang/AST/ASTContext.h" 17 #include "clang/AST/DeclObjC.h" 18 #include "clang/AST/Expr.h" 19 #include "clang/AST/ExprObjC.h" 20 #include "clang/AST/StmtObjC.h" 21 #include "clang/Analysis/DomainSpecific/CocoaConventions.h" 22 #include "clang/Analysis/SelectorExtras.h" 23 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 24 #include "clang/StaticAnalyzer/Core/Checker.h" 25 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 26 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 27 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 28 #include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h" 29 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 30 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" 31 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 32 #include "llvm/ADT/SmallString.h" 33 #include "llvm/ADT/StringMap.h" 34 #include "llvm/Support/raw_ostream.h" 35 36 using namespace clang; 37 using namespace ento; 38 using namespace llvm; 39 40 namespace { 41 class APIMisuse : public BugType { 42 public: 43 APIMisuse(const CheckerBase *checker, const char *name) 44 : BugType(checker, name, "API Misuse (Apple)") {} 45 }; 46 } // end anonymous namespace 47 48 //===----------------------------------------------------------------------===// 49 // Utility functions. 50 //===----------------------------------------------------------------------===// 51 52 static StringRef GetReceiverInterfaceName(const ObjCMethodCall &msg) { 53 if (const ObjCInterfaceDecl *ID = msg.getReceiverInterface()) 54 return ID->getIdentifier()->getName(); 55 return StringRef(); 56 } 57 58 enum FoundationClass { 59 FC_None, 60 FC_NSArray, 61 FC_NSDictionary, 62 FC_NSEnumerator, 63 FC_NSNull, 64 FC_NSOrderedSet, 65 FC_NSSet, 66 FC_NSString 67 }; 68 69 static FoundationClass findKnownClass(const ObjCInterfaceDecl *ID, 70 bool IncludeSuperclasses = true) { 71 static llvm::StringMap<FoundationClass> Classes; 72 if (Classes.empty()) { 73 Classes["NSArray"] = FC_NSArray; 74 Classes["NSDictionary"] = FC_NSDictionary; 75 Classes["NSEnumerator"] = FC_NSEnumerator; 76 Classes["NSNull"] = FC_NSNull; 77 Classes["NSOrderedSet"] = FC_NSOrderedSet; 78 Classes["NSSet"] = FC_NSSet; 79 Classes["NSString"] = FC_NSString; 80 } 81 82 // FIXME: Should we cache this at all? 83 FoundationClass result = Classes.lookup(ID->getIdentifier()->getName()); 84 if (result == FC_None && IncludeSuperclasses) 85 if (const ObjCInterfaceDecl *Super = ID->getSuperClass()) 86 return findKnownClass(Super); 87 88 return result; 89 } 90 91 //===----------------------------------------------------------------------===// 92 // NilArgChecker - Check for prohibited nil arguments to ObjC method calls. 93 //===----------------------------------------------------------------------===// 94 95 namespace { 96 class NilArgChecker : public Checker<check::PreObjCMessage, 97 check::PostStmt<ObjCDictionaryLiteral>, 98 check::PostStmt<ObjCArrayLiteral> > { 99 mutable std::unique_ptr<APIMisuse> BT; 100 101 mutable llvm::SmallDenseMap<Selector, unsigned, 16> StringSelectors; 102 mutable Selector ArrayWithObjectSel; 103 mutable Selector AddObjectSel; 104 mutable Selector InsertObjectAtIndexSel; 105 mutable Selector ReplaceObjectAtIndexWithObjectSel; 106 mutable Selector SetObjectAtIndexedSubscriptSel; 107 mutable Selector ArrayByAddingObjectSel; 108 mutable Selector DictionaryWithObjectForKeySel; 109 mutable Selector SetObjectForKeySel; 110 mutable Selector SetObjectForKeyedSubscriptSel; 111 mutable Selector RemoveObjectForKeySel; 112 113 void warnIfNilExpr(const Expr *E, 114 const char *Msg, 115 CheckerContext &C) const; 116 117 void warnIfNilArg(CheckerContext &C, 118 const ObjCMethodCall &msg, unsigned Arg, 119 FoundationClass Class, 120 bool CanBeSubscript = false) const; 121 122 void generateBugReport(ExplodedNode *N, 123 StringRef Msg, 124 SourceRange Range, 125 const Expr *Expr, 126 CheckerContext &C) const; 127 128 public: 129 void checkPreObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const; 130 void checkPostStmt(const ObjCDictionaryLiteral *DL, 131 CheckerContext &C) const; 132 void checkPostStmt(const ObjCArrayLiteral *AL, 133 CheckerContext &C) const; 134 }; 135 } // end anonymous namespace 136 137 void NilArgChecker::warnIfNilExpr(const Expr *E, 138 const char *Msg, 139 CheckerContext &C) const { 140 ProgramStateRef State = C.getState(); 141 if (State->isNull(C.getSVal(E)).isConstrainedTrue()) { 142 143 if (ExplodedNode *N = C.generateErrorNode()) { 144 generateBugReport(N, Msg, E->getSourceRange(), E, C); 145 } 146 } 147 } 148 149 void NilArgChecker::warnIfNilArg(CheckerContext &C, 150 const ObjCMethodCall &msg, 151 unsigned int Arg, 152 FoundationClass Class, 153 bool CanBeSubscript) const { 154 // Check if the argument is nil. 155 ProgramStateRef State = C.getState(); 156 if (!State->isNull(msg.getArgSVal(Arg)).isConstrainedTrue()) 157 return; 158 159 // NOTE: We cannot throw non-fatal errors from warnIfNilExpr, 160 // because it's called multiple times from some callers, so it'd cause 161 // an unwanted state split if two or more non-fatal errors are thrown 162 // within the same checker callback. For now we don't want to, but 163 // it'll need to be fixed if we ever want to. 164 if (ExplodedNode *N = C.generateErrorNode()) { 165 SmallString<128> sbuf; 166 llvm::raw_svector_ostream os(sbuf); 167 168 if (CanBeSubscript && msg.getMessageKind() == OCM_Subscript) { 169 170 if (Class == FC_NSArray) { 171 os << "Array element cannot be nil"; 172 } else if (Class == FC_NSDictionary) { 173 if (Arg == 0) { 174 os << "Value stored into '"; 175 os << GetReceiverInterfaceName(msg) << "' cannot be nil"; 176 } else { 177 assert(Arg == 1); 178 os << "'"<< GetReceiverInterfaceName(msg) << "' key cannot be nil"; 179 } 180 } else 181 llvm_unreachable("Missing foundation class for the subscript expr"); 182 183 } else { 184 if (Class == FC_NSDictionary) { 185 if (Arg == 0) 186 os << "Value argument "; 187 else { 188 assert(Arg == 1); 189 os << "Key argument "; 190 } 191 os << "to '"; 192 msg.getSelector().print(os); 193 os << "' cannot be nil"; 194 } else { 195 os << "Argument to '" << GetReceiverInterfaceName(msg) << "' method '"; 196 msg.getSelector().print(os); 197 os << "' cannot be nil"; 198 } 199 } 200 201 generateBugReport(N, os.str(), msg.getArgSourceRange(Arg), 202 msg.getArgExpr(Arg), C); 203 } 204 } 205 206 void NilArgChecker::generateBugReport(ExplodedNode *N, 207 StringRef Msg, 208 SourceRange Range, 209 const Expr *E, 210 CheckerContext &C) const { 211 if (!BT) 212 BT.reset(new APIMisuse(this, "nil argument")); 213 214 auto R = llvm::make_unique<BugReport>(*BT, Msg, N); 215 R->addRange(Range); 216 bugreporter::trackExpressionValue(N, E, *R); 217 C.emitReport(std::move(R)); 218 } 219 220 void NilArgChecker::checkPreObjCMessage(const ObjCMethodCall &msg, 221 CheckerContext &C) const { 222 const ObjCInterfaceDecl *ID = msg.getReceiverInterface(); 223 if (!ID) 224 return; 225 226 FoundationClass Class = findKnownClass(ID); 227 228 static const unsigned InvalidArgIndex = UINT_MAX; 229 unsigned Arg = InvalidArgIndex; 230 bool CanBeSubscript = false; 231 232 if (Class == FC_NSString) { 233 Selector S = msg.getSelector(); 234 235 if (S.isUnarySelector()) 236 return; 237 238 if (StringSelectors.empty()) { 239 ASTContext &Ctx = C.getASTContext(); 240 Selector Sels[] = { 241 getKeywordSelector(Ctx, "caseInsensitiveCompare"), 242 getKeywordSelector(Ctx, "compare"), 243 getKeywordSelector(Ctx, "compare", "options"), 244 getKeywordSelector(Ctx, "compare", "options", "range"), 245 getKeywordSelector(Ctx, "compare", "options", "range", "locale"), 246 getKeywordSelector(Ctx, "componentsSeparatedByCharactersInSet"), 247 getKeywordSelector(Ctx, "initWithFormat"), 248 getKeywordSelector(Ctx, "localizedCaseInsensitiveCompare"), 249 getKeywordSelector(Ctx, "localizedCompare"), 250 getKeywordSelector(Ctx, "localizedStandardCompare"), 251 }; 252 for (Selector KnownSel : Sels) 253 StringSelectors[KnownSel] = 0; 254 } 255 auto I = StringSelectors.find(S); 256 if (I == StringSelectors.end()) 257 return; 258 Arg = I->second; 259 } else if (Class == FC_NSArray) { 260 Selector S = msg.getSelector(); 261 262 if (S.isUnarySelector()) 263 return; 264 265 if (ArrayWithObjectSel.isNull()) { 266 ASTContext &Ctx = C.getASTContext(); 267 ArrayWithObjectSel = getKeywordSelector(Ctx, "arrayWithObject"); 268 AddObjectSel = getKeywordSelector(Ctx, "addObject"); 269 InsertObjectAtIndexSel = 270 getKeywordSelector(Ctx, "insertObject", "atIndex"); 271 ReplaceObjectAtIndexWithObjectSel = 272 getKeywordSelector(Ctx, "replaceObjectAtIndex", "withObject"); 273 SetObjectAtIndexedSubscriptSel = 274 getKeywordSelector(Ctx, "setObject", "atIndexedSubscript"); 275 ArrayByAddingObjectSel = getKeywordSelector(Ctx, "arrayByAddingObject"); 276 } 277 278 if (S == ArrayWithObjectSel || S == AddObjectSel || 279 S == InsertObjectAtIndexSel || S == ArrayByAddingObjectSel) { 280 Arg = 0; 281 } else if (S == SetObjectAtIndexedSubscriptSel) { 282 Arg = 0; 283 CanBeSubscript = true; 284 } else if (S == ReplaceObjectAtIndexWithObjectSel) { 285 Arg = 1; 286 } 287 } else if (Class == FC_NSDictionary) { 288 Selector S = msg.getSelector(); 289 290 if (S.isUnarySelector()) 291 return; 292 293 if (DictionaryWithObjectForKeySel.isNull()) { 294 ASTContext &Ctx = C.getASTContext(); 295 DictionaryWithObjectForKeySel = 296 getKeywordSelector(Ctx, "dictionaryWithObject", "forKey"); 297 SetObjectForKeySel = getKeywordSelector(Ctx, "setObject", "forKey"); 298 SetObjectForKeyedSubscriptSel = 299 getKeywordSelector(Ctx, "setObject", "forKeyedSubscript"); 300 RemoveObjectForKeySel = getKeywordSelector(Ctx, "removeObjectForKey"); 301 } 302 303 if (S == DictionaryWithObjectForKeySel || S == SetObjectForKeySel) { 304 Arg = 0; 305 warnIfNilArg(C, msg, /* Arg */1, Class); 306 } else if (S == SetObjectForKeyedSubscriptSel) { 307 CanBeSubscript = true; 308 Arg = 1; 309 } else if (S == RemoveObjectForKeySel) { 310 Arg = 0; 311 } 312 } 313 314 // If argument is '0', report a warning. 315 if ((Arg != InvalidArgIndex)) 316 warnIfNilArg(C, msg, Arg, Class, CanBeSubscript); 317 } 318 319 void NilArgChecker::checkPostStmt(const ObjCArrayLiteral *AL, 320 CheckerContext &C) const { 321 unsigned NumOfElements = AL->getNumElements(); 322 for (unsigned i = 0; i < NumOfElements; ++i) { 323 warnIfNilExpr(AL->getElement(i), "Array element cannot be nil", C); 324 } 325 } 326 327 void NilArgChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 328 CheckerContext &C) const { 329 unsigned NumOfElements = DL->getNumElements(); 330 for (unsigned i = 0; i < NumOfElements; ++i) { 331 ObjCDictionaryElement Element = DL->getKeyValueElement(i); 332 warnIfNilExpr(Element.Key, "Dictionary key cannot be nil", C); 333 warnIfNilExpr(Element.Value, "Dictionary value cannot be nil", C); 334 } 335 } 336 337 //===----------------------------------------------------------------------===// 338 // Checking for mismatched types passed to CFNumberCreate/CFNumberGetValue. 339 //===----------------------------------------------------------------------===// 340 341 namespace { 342 class CFNumberChecker : public Checker< check::PreStmt<CallExpr> > { 343 mutable std::unique_ptr<APIMisuse> BT; 344 mutable IdentifierInfo *ICreate, *IGetValue; 345 public: 346 CFNumberChecker() : ICreate(nullptr), IGetValue(nullptr) {} 347 348 void checkPreStmt(const CallExpr *CE, CheckerContext &C) const; 349 350 private: 351 void EmitError(const TypedRegion* R, const Expr *Ex, 352 uint64_t SourceSize, uint64_t TargetSize, uint64_t NumberKind); 353 }; 354 } // end anonymous namespace 355 356 enum CFNumberType { 357 kCFNumberSInt8Type = 1, 358 kCFNumberSInt16Type = 2, 359 kCFNumberSInt32Type = 3, 360 kCFNumberSInt64Type = 4, 361 kCFNumberFloat32Type = 5, 362 kCFNumberFloat64Type = 6, 363 kCFNumberCharType = 7, 364 kCFNumberShortType = 8, 365 kCFNumberIntType = 9, 366 kCFNumberLongType = 10, 367 kCFNumberLongLongType = 11, 368 kCFNumberFloatType = 12, 369 kCFNumberDoubleType = 13, 370 kCFNumberCFIndexType = 14, 371 kCFNumberNSIntegerType = 15, 372 kCFNumberCGFloatType = 16 373 }; 374 375 static Optional<uint64_t> GetCFNumberSize(ASTContext &Ctx, uint64_t i) { 376 static const unsigned char FixedSize[] = { 8, 16, 32, 64, 32, 64 }; 377 378 if (i < kCFNumberCharType) 379 return FixedSize[i-1]; 380 381 QualType T; 382 383 switch (i) { 384 case kCFNumberCharType: T = Ctx.CharTy; break; 385 case kCFNumberShortType: T = Ctx.ShortTy; break; 386 case kCFNumberIntType: T = Ctx.IntTy; break; 387 case kCFNumberLongType: T = Ctx.LongTy; break; 388 case kCFNumberLongLongType: T = Ctx.LongLongTy; break; 389 case kCFNumberFloatType: T = Ctx.FloatTy; break; 390 case kCFNumberDoubleType: T = Ctx.DoubleTy; break; 391 case kCFNumberCFIndexType: 392 case kCFNumberNSIntegerType: 393 case kCFNumberCGFloatType: 394 // FIXME: We need a way to map from names to Type*. 395 default: 396 return None; 397 } 398 399 return Ctx.getTypeSize(T); 400 } 401 402 #if 0 403 static const char* GetCFNumberTypeStr(uint64_t i) { 404 static const char* Names[] = { 405 "kCFNumberSInt8Type", 406 "kCFNumberSInt16Type", 407 "kCFNumberSInt32Type", 408 "kCFNumberSInt64Type", 409 "kCFNumberFloat32Type", 410 "kCFNumberFloat64Type", 411 "kCFNumberCharType", 412 "kCFNumberShortType", 413 "kCFNumberIntType", 414 "kCFNumberLongType", 415 "kCFNumberLongLongType", 416 "kCFNumberFloatType", 417 "kCFNumberDoubleType", 418 "kCFNumberCFIndexType", 419 "kCFNumberNSIntegerType", 420 "kCFNumberCGFloatType" 421 }; 422 423 return i <= kCFNumberCGFloatType ? Names[i-1] : "Invalid CFNumberType"; 424 } 425 #endif 426 427 void CFNumberChecker::checkPreStmt(const CallExpr *CE, 428 CheckerContext &C) const { 429 ProgramStateRef state = C.getState(); 430 const FunctionDecl *FD = C.getCalleeDecl(CE); 431 if (!FD) 432 return; 433 434 ASTContext &Ctx = C.getASTContext(); 435 if (!ICreate) { 436 ICreate = &Ctx.Idents.get("CFNumberCreate"); 437 IGetValue = &Ctx.Idents.get("CFNumberGetValue"); 438 } 439 if (!(FD->getIdentifier() == ICreate || FD->getIdentifier() == IGetValue) || 440 CE->getNumArgs() != 3) 441 return; 442 443 // Get the value of the "theType" argument. 444 SVal TheTypeVal = C.getSVal(CE->getArg(1)); 445 446 // FIXME: We really should allow ranges of valid theType values, and 447 // bifurcate the state appropriately. 448 Optional<nonloc::ConcreteInt> V = TheTypeVal.getAs<nonloc::ConcreteInt>(); 449 if (!V) 450 return; 451 452 uint64_t NumberKind = V->getValue().getLimitedValue(); 453 Optional<uint64_t> OptCFNumberSize = GetCFNumberSize(Ctx, NumberKind); 454 455 // FIXME: In some cases we can emit an error. 456 if (!OptCFNumberSize) 457 return; 458 459 uint64_t CFNumberSize = *OptCFNumberSize; 460 461 // Look at the value of the integer being passed by reference. Essentially 462 // we want to catch cases where the value passed in is not equal to the 463 // size of the type being created. 464 SVal TheValueExpr = C.getSVal(CE->getArg(2)); 465 466 // FIXME: Eventually we should handle arbitrary locations. We can do this 467 // by having an enhanced memory model that does low-level typing. 468 Optional<loc::MemRegionVal> LV = TheValueExpr.getAs<loc::MemRegionVal>(); 469 if (!LV) 470 return; 471 472 const TypedValueRegion* R = dyn_cast<TypedValueRegion>(LV->stripCasts()); 473 if (!R) 474 return; 475 476 QualType T = Ctx.getCanonicalType(R->getValueType()); 477 478 // FIXME: If the pointee isn't an integer type, should we flag a warning? 479 // People can do weird stuff with pointers. 480 481 if (!T->isIntegralOrEnumerationType()) 482 return; 483 484 uint64_t PrimitiveTypeSize = Ctx.getTypeSize(T); 485 486 if (PrimitiveTypeSize == CFNumberSize) 487 return; 488 489 // FIXME: We can actually create an abstract "CFNumber" object that has 490 // the bits initialized to the provided values. 491 ExplodedNode *N = C.generateNonFatalErrorNode(); 492 if (N) { 493 SmallString<128> sbuf; 494 llvm::raw_svector_ostream os(sbuf); 495 bool isCreate = (FD->getIdentifier() == ICreate); 496 497 if (isCreate) { 498 os << (PrimitiveTypeSize == 8 ? "An " : "A ") 499 << PrimitiveTypeSize << "-bit integer is used to initialize a " 500 << "CFNumber object that represents " 501 << (CFNumberSize == 8 ? "an " : "a ") 502 << CFNumberSize << "-bit integer; "; 503 } else { 504 os << "A CFNumber object that represents " 505 << (CFNumberSize == 8 ? "an " : "a ") 506 << CFNumberSize << "-bit integer is used to initialize " 507 << (PrimitiveTypeSize == 8 ? "an " : "a ") 508 << PrimitiveTypeSize << "-bit integer; "; 509 } 510 511 if (PrimitiveTypeSize < CFNumberSize) 512 os << (CFNumberSize - PrimitiveTypeSize) 513 << " bits of the CFNumber value will " 514 << (isCreate ? "be garbage." : "overwrite adjacent storage."); 515 else 516 os << (PrimitiveTypeSize - CFNumberSize) 517 << " bits of the integer value will be " 518 << (isCreate ? "lost." : "garbage."); 519 520 if (!BT) 521 BT.reset(new APIMisuse(this, "Bad use of CFNumber APIs")); 522 523 auto report = llvm::make_unique<BugReport>(*BT, os.str(), N); 524 report->addRange(CE->getArg(2)->getSourceRange()); 525 C.emitReport(std::move(report)); 526 } 527 } 528 529 //===----------------------------------------------------------------------===// 530 // CFRetain/CFRelease/CFMakeCollectable/CFAutorelease checking for null arguments. 531 //===----------------------------------------------------------------------===// 532 533 namespace { 534 class CFRetainReleaseChecker : public Checker<check::PreCall> { 535 mutable APIMisuse BT{this, "null passed to CF memory management function"}; 536 CallDescription CFRetain{"CFRetain", 1}, 537 CFRelease{"CFRelease", 1}, 538 CFMakeCollectable{"CFMakeCollectable", 1}, 539 CFAutorelease{"CFAutorelease", 1}; 540 541 public: 542 void checkPreCall(const CallEvent &Call, CheckerContext &C) const; 543 }; 544 } // end anonymous namespace 545 546 void CFRetainReleaseChecker::checkPreCall(const CallEvent &Call, 547 CheckerContext &C) const { 548 // TODO: Make this check part of CallDescription. 549 if (!Call.isGlobalCFunction()) 550 return; 551 552 // Check if we called CFRetain/CFRelease/CFMakeCollectable/CFAutorelease. 553 if (!(Call.isCalled(CFRetain) || Call.isCalled(CFRelease) || 554 Call.isCalled(CFMakeCollectable) || Call.isCalled(CFAutorelease))) 555 return; 556 557 // Get the argument's value. 558 SVal ArgVal = Call.getArgSVal(0); 559 Optional<DefinedSVal> DefArgVal = ArgVal.getAs<DefinedSVal>(); 560 if (!DefArgVal) 561 return; 562 563 // Is it null? 564 ProgramStateRef state = C.getState(); 565 ProgramStateRef stateNonNull, stateNull; 566 std::tie(stateNonNull, stateNull) = state->assume(*DefArgVal); 567 568 if (!stateNonNull) { 569 ExplodedNode *N = C.generateErrorNode(stateNull); 570 if (!N) 571 return; 572 573 SmallString<64> Str; 574 raw_svector_ostream OS(Str); 575 OS << "Null pointer argument in call to " 576 << cast<FunctionDecl>(Call.getDecl())->getName(); 577 578 auto report = llvm::make_unique<BugReport>(BT, OS.str(), N); 579 report->addRange(Call.getArgSourceRange(0)); 580 bugreporter::trackExpressionValue(N, Call.getArgExpr(0), *report); 581 C.emitReport(std::move(report)); 582 return; 583 } 584 585 // From here on, we know the argument is non-null. 586 C.addTransition(stateNonNull); 587 } 588 589 //===----------------------------------------------------------------------===// 590 // Check for sending 'retain', 'release', or 'autorelease' directly to a Class. 591 //===----------------------------------------------------------------------===// 592 593 namespace { 594 class ClassReleaseChecker : public Checker<check::PreObjCMessage> { 595 mutable Selector releaseS; 596 mutable Selector retainS; 597 mutable Selector autoreleaseS; 598 mutable Selector drainS; 599 mutable std::unique_ptr<BugType> BT; 600 601 public: 602 void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const; 603 }; 604 } // end anonymous namespace 605 606 void ClassReleaseChecker::checkPreObjCMessage(const ObjCMethodCall &msg, 607 CheckerContext &C) const { 608 if (!BT) { 609 BT.reset(new APIMisuse( 610 this, "message incorrectly sent to class instead of class instance")); 611 612 ASTContext &Ctx = C.getASTContext(); 613 releaseS = GetNullarySelector("release", Ctx); 614 retainS = GetNullarySelector("retain", Ctx); 615 autoreleaseS = GetNullarySelector("autorelease", Ctx); 616 drainS = GetNullarySelector("drain", Ctx); 617 } 618 619 if (msg.isInstanceMessage()) 620 return; 621 const ObjCInterfaceDecl *Class = msg.getReceiverInterface(); 622 assert(Class); 623 624 Selector S = msg.getSelector(); 625 if (!(S == releaseS || S == retainS || S == autoreleaseS || S == drainS)) 626 return; 627 628 if (ExplodedNode *N = C.generateNonFatalErrorNode()) { 629 SmallString<200> buf; 630 llvm::raw_svector_ostream os(buf); 631 632 os << "The '"; 633 S.print(os); 634 os << "' message should be sent to instances " 635 "of class '" << Class->getName() 636 << "' and not the class directly"; 637 638 auto report = llvm::make_unique<BugReport>(*BT, os.str(), N); 639 report->addRange(msg.getSourceRange()); 640 C.emitReport(std::move(report)); 641 } 642 } 643 644 //===----------------------------------------------------------------------===// 645 // Check for passing non-Objective-C types to variadic methods that expect 646 // only Objective-C types. 647 //===----------------------------------------------------------------------===// 648 649 namespace { 650 class VariadicMethodTypeChecker : public Checker<check::PreObjCMessage> { 651 mutable Selector arrayWithObjectsS; 652 mutable Selector dictionaryWithObjectsAndKeysS; 653 mutable Selector setWithObjectsS; 654 mutable Selector orderedSetWithObjectsS; 655 mutable Selector initWithObjectsS; 656 mutable Selector initWithObjectsAndKeysS; 657 mutable std::unique_ptr<BugType> BT; 658 659 bool isVariadicMessage(const ObjCMethodCall &msg) const; 660 661 public: 662 void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const; 663 }; 664 } // end anonymous namespace 665 666 /// isVariadicMessage - Returns whether the given message is a variadic message, 667 /// where all arguments must be Objective-C types. 668 bool 669 VariadicMethodTypeChecker::isVariadicMessage(const ObjCMethodCall &msg) const { 670 const ObjCMethodDecl *MD = msg.getDecl(); 671 672 if (!MD || !MD->isVariadic() || isa<ObjCProtocolDecl>(MD->getDeclContext())) 673 return false; 674 675 Selector S = msg.getSelector(); 676 677 if (msg.isInstanceMessage()) { 678 // FIXME: Ideally we'd look at the receiver interface here, but that's not 679 // useful for init, because alloc returns 'id'. In theory, this could lead 680 // to false positives, for example if there existed a class that had an 681 // initWithObjects: implementation that does accept non-Objective-C pointer 682 // types, but the chance of that happening is pretty small compared to the 683 // gains that this analysis gives. 684 const ObjCInterfaceDecl *Class = MD->getClassInterface(); 685 686 switch (findKnownClass(Class)) { 687 case FC_NSArray: 688 case FC_NSOrderedSet: 689 case FC_NSSet: 690 return S == initWithObjectsS; 691 case FC_NSDictionary: 692 return S == initWithObjectsAndKeysS; 693 default: 694 return false; 695 } 696 } else { 697 const ObjCInterfaceDecl *Class = msg.getReceiverInterface(); 698 699 switch (findKnownClass(Class)) { 700 case FC_NSArray: 701 return S == arrayWithObjectsS; 702 case FC_NSOrderedSet: 703 return S == orderedSetWithObjectsS; 704 case FC_NSSet: 705 return S == setWithObjectsS; 706 case FC_NSDictionary: 707 return S == dictionaryWithObjectsAndKeysS; 708 default: 709 return false; 710 } 711 } 712 } 713 714 void VariadicMethodTypeChecker::checkPreObjCMessage(const ObjCMethodCall &msg, 715 CheckerContext &C) const { 716 if (!BT) { 717 BT.reset(new APIMisuse(this, 718 "Arguments passed to variadic method aren't all " 719 "Objective-C pointer types")); 720 721 ASTContext &Ctx = C.getASTContext(); 722 arrayWithObjectsS = GetUnarySelector("arrayWithObjects", Ctx); 723 dictionaryWithObjectsAndKeysS = 724 GetUnarySelector("dictionaryWithObjectsAndKeys", Ctx); 725 setWithObjectsS = GetUnarySelector("setWithObjects", Ctx); 726 orderedSetWithObjectsS = GetUnarySelector("orderedSetWithObjects", Ctx); 727 728 initWithObjectsS = GetUnarySelector("initWithObjects", Ctx); 729 initWithObjectsAndKeysS = GetUnarySelector("initWithObjectsAndKeys", Ctx); 730 } 731 732 if (!isVariadicMessage(msg)) 733 return; 734 735 // We are not interested in the selector arguments since they have 736 // well-defined types, so the compiler will issue a warning for them. 737 unsigned variadicArgsBegin = msg.getSelector().getNumArgs(); 738 739 // We're not interested in the last argument since it has to be nil or the 740 // compiler would have issued a warning for it elsewhere. 741 unsigned variadicArgsEnd = msg.getNumArgs() - 1; 742 743 if (variadicArgsEnd <= variadicArgsBegin) 744 return; 745 746 // Verify that all arguments have Objective-C types. 747 Optional<ExplodedNode*> errorNode; 748 749 for (unsigned I = variadicArgsBegin; I != variadicArgsEnd; ++I) { 750 QualType ArgTy = msg.getArgExpr(I)->getType(); 751 if (ArgTy->isObjCObjectPointerType()) 752 continue; 753 754 // Block pointers are treaded as Objective-C pointers. 755 if (ArgTy->isBlockPointerType()) 756 continue; 757 758 // Ignore pointer constants. 759 if (msg.getArgSVal(I).getAs<loc::ConcreteInt>()) 760 continue; 761 762 // Ignore pointer types annotated with 'NSObject' attribute. 763 if (C.getASTContext().isObjCNSObjectType(ArgTy)) 764 continue; 765 766 // Ignore CF references, which can be toll-free bridged. 767 if (coreFoundation::isCFObjectRef(ArgTy)) 768 continue; 769 770 // Generate only one error node to use for all bug reports. 771 if (!errorNode.hasValue()) 772 errorNode = C.generateNonFatalErrorNode(); 773 774 if (!errorNode.getValue()) 775 continue; 776 777 SmallString<128> sbuf; 778 llvm::raw_svector_ostream os(sbuf); 779 780 StringRef TypeName = GetReceiverInterfaceName(msg); 781 if (!TypeName.empty()) 782 os << "Argument to '" << TypeName << "' method '"; 783 else 784 os << "Argument to method '"; 785 786 msg.getSelector().print(os); 787 os << "' should be an Objective-C pointer type, not '"; 788 ArgTy.print(os, C.getLangOpts()); 789 os << "'"; 790 791 auto R = llvm::make_unique<BugReport>(*BT, os.str(), errorNode.getValue()); 792 R->addRange(msg.getArgSourceRange(I)); 793 C.emitReport(std::move(R)); 794 } 795 } 796 797 //===----------------------------------------------------------------------===// 798 // Improves the modeling of loops over Cocoa collections. 799 //===----------------------------------------------------------------------===// 800 801 // The map from container symbol to the container count symbol. 802 // We currently will remember the last container count symbol encountered. 803 REGISTER_MAP_WITH_PROGRAMSTATE(ContainerCountMap, SymbolRef, SymbolRef) 804 REGISTER_MAP_WITH_PROGRAMSTATE(ContainerNonEmptyMap, SymbolRef, bool) 805 806 namespace { 807 class ObjCLoopChecker 808 : public Checker<check::PostStmt<ObjCForCollectionStmt>, 809 check::PostObjCMessage, 810 check::DeadSymbols, 811 check::PointerEscape > { 812 mutable IdentifierInfo *CountSelectorII; 813 814 bool isCollectionCountMethod(const ObjCMethodCall &M, 815 CheckerContext &C) const; 816 817 public: 818 ObjCLoopChecker() : CountSelectorII(nullptr) {} 819 void checkPostStmt(const ObjCForCollectionStmt *FCS, CheckerContext &C) const; 820 void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const; 821 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 822 ProgramStateRef checkPointerEscape(ProgramStateRef State, 823 const InvalidatedSymbols &Escaped, 824 const CallEvent *Call, 825 PointerEscapeKind Kind) const; 826 }; 827 } // end anonymous namespace 828 829 static bool isKnownNonNilCollectionType(QualType T) { 830 const ObjCObjectPointerType *PT = T->getAs<ObjCObjectPointerType>(); 831 if (!PT) 832 return false; 833 834 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 835 if (!ID) 836 return false; 837 838 switch (findKnownClass(ID)) { 839 case FC_NSArray: 840 case FC_NSDictionary: 841 case FC_NSEnumerator: 842 case FC_NSOrderedSet: 843 case FC_NSSet: 844 return true; 845 default: 846 return false; 847 } 848 } 849 850 /// Assumes that the collection is non-nil. 851 /// 852 /// If the collection is known to be nil, returns NULL to indicate an infeasible 853 /// path. 854 static ProgramStateRef checkCollectionNonNil(CheckerContext &C, 855 ProgramStateRef State, 856 const ObjCForCollectionStmt *FCS) { 857 if (!State) 858 return nullptr; 859 860 SVal CollectionVal = C.getSVal(FCS->getCollection()); 861 Optional<DefinedSVal> KnownCollection = CollectionVal.getAs<DefinedSVal>(); 862 if (!KnownCollection) 863 return State; 864 865 ProgramStateRef StNonNil, StNil; 866 std::tie(StNonNil, StNil) = State->assume(*KnownCollection); 867 if (StNil && !StNonNil) { 868 // The collection is nil. This path is infeasible. 869 return nullptr; 870 } 871 872 return StNonNil; 873 } 874 875 /// Assumes that the collection elements are non-nil. 876 /// 877 /// This only applies if the collection is one of those known not to contain 878 /// nil values. 879 static ProgramStateRef checkElementNonNil(CheckerContext &C, 880 ProgramStateRef State, 881 const ObjCForCollectionStmt *FCS) { 882 if (!State) 883 return nullptr; 884 885 // See if the collection is one where we /know/ the elements are non-nil. 886 if (!isKnownNonNilCollectionType(FCS->getCollection()->getType())) 887 return State; 888 889 const LocationContext *LCtx = C.getLocationContext(); 890 const Stmt *Element = FCS->getElement(); 891 892 // FIXME: Copied from ExprEngineObjC. 893 Optional<Loc> ElementLoc; 894 if (const DeclStmt *DS = dyn_cast<DeclStmt>(Element)) { 895 const VarDecl *ElemDecl = cast<VarDecl>(DS->getSingleDecl()); 896 assert(ElemDecl->getInit() == nullptr); 897 ElementLoc = State->getLValue(ElemDecl, LCtx); 898 } else { 899 ElementLoc = State->getSVal(Element, LCtx).getAs<Loc>(); 900 } 901 902 if (!ElementLoc) 903 return State; 904 905 // Go ahead and assume the value is non-nil. 906 SVal Val = State->getSVal(*ElementLoc); 907 return State->assume(Val.castAs<DefinedOrUnknownSVal>(), true); 908 } 909 910 /// Returns NULL state if the collection is known to contain elements 911 /// (or is known not to contain elements if the Assumption parameter is false.) 912 static ProgramStateRef 913 assumeCollectionNonEmpty(CheckerContext &C, ProgramStateRef State, 914 SymbolRef CollectionS, bool Assumption) { 915 if (!State || !CollectionS) 916 return State; 917 918 const SymbolRef *CountS = State->get<ContainerCountMap>(CollectionS); 919 if (!CountS) { 920 const bool *KnownNonEmpty = State->get<ContainerNonEmptyMap>(CollectionS); 921 if (!KnownNonEmpty) 922 return State->set<ContainerNonEmptyMap>(CollectionS, Assumption); 923 return (Assumption == *KnownNonEmpty) ? State : nullptr; 924 } 925 926 SValBuilder &SvalBuilder = C.getSValBuilder(); 927 SVal CountGreaterThanZeroVal = 928 SvalBuilder.evalBinOp(State, BO_GT, 929 nonloc::SymbolVal(*CountS), 930 SvalBuilder.makeIntVal(0, (*CountS)->getType()), 931 SvalBuilder.getConditionType()); 932 Optional<DefinedSVal> CountGreaterThanZero = 933 CountGreaterThanZeroVal.getAs<DefinedSVal>(); 934 if (!CountGreaterThanZero) { 935 // The SValBuilder cannot construct a valid SVal for this condition. 936 // This means we cannot properly reason about it. 937 return State; 938 } 939 940 return State->assume(*CountGreaterThanZero, Assumption); 941 } 942 943 static ProgramStateRef 944 assumeCollectionNonEmpty(CheckerContext &C, ProgramStateRef State, 945 const ObjCForCollectionStmt *FCS, 946 bool Assumption) { 947 if (!State) 948 return nullptr; 949 950 SymbolRef CollectionS = C.getSVal(FCS->getCollection()).getAsSymbol(); 951 return assumeCollectionNonEmpty(C, State, CollectionS, Assumption); 952 } 953 954 /// If the fist block edge is a back edge, we are reentering the loop. 955 static bool alreadyExecutedAtLeastOneLoopIteration(const ExplodedNode *N, 956 const ObjCForCollectionStmt *FCS) { 957 if (!N) 958 return false; 959 960 ProgramPoint P = N->getLocation(); 961 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 962 return BE->getSrc()->getLoopTarget() == FCS; 963 } 964 965 // Keep looking for a block edge. 966 for (ExplodedNode::const_pred_iterator I = N->pred_begin(), 967 E = N->pred_end(); I != E; ++I) { 968 if (alreadyExecutedAtLeastOneLoopIteration(*I, FCS)) 969 return true; 970 } 971 972 return false; 973 } 974 975 void ObjCLoopChecker::checkPostStmt(const ObjCForCollectionStmt *FCS, 976 CheckerContext &C) const { 977 ProgramStateRef State = C.getState(); 978 979 // Check if this is the branch for the end of the loop. 980 SVal CollectionSentinel = C.getSVal(FCS); 981 if (CollectionSentinel.isZeroConstant()) { 982 if (!alreadyExecutedAtLeastOneLoopIteration(C.getPredecessor(), FCS)) 983 State = assumeCollectionNonEmpty(C, State, FCS, /*Assumption*/false); 984 985 // Otherwise, this is a branch that goes through the loop body. 986 } else { 987 State = checkCollectionNonNil(C, State, FCS); 988 State = checkElementNonNil(C, State, FCS); 989 State = assumeCollectionNonEmpty(C, State, FCS, /*Assumption*/true); 990 } 991 992 if (!State) 993 C.generateSink(C.getState(), C.getPredecessor()); 994 else if (State != C.getState()) 995 C.addTransition(State); 996 } 997 998 bool ObjCLoopChecker::isCollectionCountMethod(const ObjCMethodCall &M, 999 CheckerContext &C) const { 1000 Selector S = M.getSelector(); 1001 // Initialize the identifiers on first use. 1002 if (!CountSelectorII) 1003 CountSelectorII = &C.getASTContext().Idents.get("count"); 1004 1005 // If the method returns collection count, record the value. 1006 return S.isUnarySelector() && 1007 (S.getIdentifierInfoForSlot(0) == CountSelectorII); 1008 } 1009 1010 void ObjCLoopChecker::checkPostObjCMessage(const ObjCMethodCall &M, 1011 CheckerContext &C) const { 1012 if (!M.isInstanceMessage()) 1013 return; 1014 1015 const ObjCInterfaceDecl *ClassID = M.getReceiverInterface(); 1016 if (!ClassID) 1017 return; 1018 1019 FoundationClass Class = findKnownClass(ClassID); 1020 if (Class != FC_NSDictionary && 1021 Class != FC_NSArray && 1022 Class != FC_NSSet && 1023 Class != FC_NSOrderedSet) 1024 return; 1025 1026 SymbolRef ContainerS = M.getReceiverSVal().getAsSymbol(); 1027 if (!ContainerS) 1028 return; 1029 1030 // If we are processing a call to "count", get the symbolic value returned by 1031 // a call to "count" and add it to the map. 1032 if (!isCollectionCountMethod(M, C)) 1033 return; 1034 1035 const Expr *MsgExpr = M.getOriginExpr(); 1036 SymbolRef CountS = C.getSVal(MsgExpr).getAsSymbol(); 1037 if (CountS) { 1038 ProgramStateRef State = C.getState(); 1039 1040 C.getSymbolManager().addSymbolDependency(ContainerS, CountS); 1041 State = State->set<ContainerCountMap>(ContainerS, CountS); 1042 1043 if (const bool *NonEmpty = State->get<ContainerNonEmptyMap>(ContainerS)) { 1044 State = State->remove<ContainerNonEmptyMap>(ContainerS); 1045 State = assumeCollectionNonEmpty(C, State, ContainerS, *NonEmpty); 1046 } 1047 1048 C.addTransition(State); 1049 } 1050 } 1051 1052 static SymbolRef getMethodReceiverIfKnownImmutable(const CallEvent *Call) { 1053 const ObjCMethodCall *Message = dyn_cast_or_null<ObjCMethodCall>(Call); 1054 if (!Message) 1055 return nullptr; 1056 1057 const ObjCMethodDecl *MD = Message->getDecl(); 1058 if (!MD) 1059 return nullptr; 1060 1061 const ObjCInterfaceDecl *StaticClass; 1062 if (isa<ObjCProtocolDecl>(MD->getDeclContext())) { 1063 // We can't find out where the method was declared without doing more work. 1064 // Instead, see if the receiver is statically typed as a known immutable 1065 // collection. 1066 StaticClass = Message->getOriginExpr()->getReceiverInterface(); 1067 } else { 1068 StaticClass = MD->getClassInterface(); 1069 } 1070 1071 if (!StaticClass) 1072 return nullptr; 1073 1074 switch (findKnownClass(StaticClass, /*IncludeSuper=*/false)) { 1075 case FC_None: 1076 return nullptr; 1077 case FC_NSArray: 1078 case FC_NSDictionary: 1079 case FC_NSEnumerator: 1080 case FC_NSNull: 1081 case FC_NSOrderedSet: 1082 case FC_NSSet: 1083 case FC_NSString: 1084 break; 1085 } 1086 1087 return Message->getReceiverSVal().getAsSymbol(); 1088 } 1089 1090 ProgramStateRef 1091 ObjCLoopChecker::checkPointerEscape(ProgramStateRef State, 1092 const InvalidatedSymbols &Escaped, 1093 const CallEvent *Call, 1094 PointerEscapeKind Kind) const { 1095 SymbolRef ImmutableReceiver = getMethodReceiverIfKnownImmutable(Call); 1096 1097 // Remove the invalidated symbols form the collection count map. 1098 for (InvalidatedSymbols::const_iterator I = Escaped.begin(), 1099 E = Escaped.end(); 1100 I != E; ++I) { 1101 SymbolRef Sym = *I; 1102 1103 // Don't invalidate this symbol's count if we know the method being called 1104 // is declared on an immutable class. This isn't completely correct if the 1105 // receiver is also passed as an argument, but in most uses of NSArray, 1106 // NSDictionary, etc. this isn't likely to happen in a dangerous way. 1107 if (Sym == ImmutableReceiver) 1108 continue; 1109 1110 // The symbol escaped. Pessimistically, assume that the count could have 1111 // changed. 1112 State = State->remove<ContainerCountMap>(Sym); 1113 State = State->remove<ContainerNonEmptyMap>(Sym); 1114 } 1115 return State; 1116 } 1117 1118 void ObjCLoopChecker::checkDeadSymbols(SymbolReaper &SymReaper, 1119 CheckerContext &C) const { 1120 ProgramStateRef State = C.getState(); 1121 1122 // Remove the dead symbols from the collection count map. 1123 ContainerCountMapTy Tracked = State->get<ContainerCountMap>(); 1124 for (ContainerCountMapTy::iterator I = Tracked.begin(), 1125 E = Tracked.end(); I != E; ++I) { 1126 SymbolRef Sym = I->first; 1127 if (SymReaper.isDead(Sym)) { 1128 State = State->remove<ContainerCountMap>(Sym); 1129 State = State->remove<ContainerNonEmptyMap>(Sym); 1130 } 1131 } 1132 1133 C.addTransition(State); 1134 } 1135 1136 namespace { 1137 /// \class ObjCNonNilReturnValueChecker 1138 /// The checker restricts the return values of APIs known to 1139 /// never (or almost never) return 'nil'. 1140 class ObjCNonNilReturnValueChecker 1141 : public Checker<check::PostObjCMessage, 1142 check::PostStmt<ObjCArrayLiteral>, 1143 check::PostStmt<ObjCDictionaryLiteral>, 1144 check::PostStmt<ObjCBoxedExpr> > { 1145 mutable bool Initialized; 1146 mutable Selector ObjectAtIndex; 1147 mutable Selector ObjectAtIndexedSubscript; 1148 mutable Selector NullSelector; 1149 1150 public: 1151 ObjCNonNilReturnValueChecker() : Initialized(false) {} 1152 1153 ProgramStateRef assumeExprIsNonNull(const Expr *NonNullExpr, 1154 ProgramStateRef State, 1155 CheckerContext &C) const; 1156 void assumeExprIsNonNull(const Expr *E, CheckerContext &C) const { 1157 C.addTransition(assumeExprIsNonNull(E, C.getState(), C)); 1158 } 1159 1160 void checkPostStmt(const ObjCArrayLiteral *E, CheckerContext &C) const { 1161 assumeExprIsNonNull(E, C); 1162 } 1163 void checkPostStmt(const ObjCDictionaryLiteral *E, CheckerContext &C) const { 1164 assumeExprIsNonNull(E, C); 1165 } 1166 void checkPostStmt(const ObjCBoxedExpr *E, CheckerContext &C) const { 1167 assumeExprIsNonNull(E, C); 1168 } 1169 1170 void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const; 1171 }; 1172 } // end anonymous namespace 1173 1174 ProgramStateRef 1175 ObjCNonNilReturnValueChecker::assumeExprIsNonNull(const Expr *NonNullExpr, 1176 ProgramStateRef State, 1177 CheckerContext &C) const { 1178 SVal Val = C.getSVal(NonNullExpr); 1179 if (Optional<DefinedOrUnknownSVal> DV = Val.getAs<DefinedOrUnknownSVal>()) 1180 return State->assume(*DV, true); 1181 return State; 1182 } 1183 1184 void ObjCNonNilReturnValueChecker::checkPostObjCMessage(const ObjCMethodCall &M, 1185 CheckerContext &C) 1186 const { 1187 ProgramStateRef State = C.getState(); 1188 1189 if (!Initialized) { 1190 ASTContext &Ctx = C.getASTContext(); 1191 ObjectAtIndex = GetUnarySelector("objectAtIndex", Ctx); 1192 ObjectAtIndexedSubscript = GetUnarySelector("objectAtIndexedSubscript", Ctx); 1193 NullSelector = GetNullarySelector("null", Ctx); 1194 } 1195 1196 // Check the receiver type. 1197 if (const ObjCInterfaceDecl *Interface = M.getReceiverInterface()) { 1198 1199 // Assume that object returned from '[self init]' or '[super init]' is not 1200 // 'nil' if we are processing an inlined function/method. 1201 // 1202 // A defensive callee will (and should) check if the object returned by 1203 // '[super init]' is 'nil' before doing it's own initialization. However, 1204 // since 'nil' is rarely returned in practice, we should not warn when the 1205 // caller to the defensive constructor uses the object in contexts where 1206 // 'nil' is not accepted. 1207 if (!C.inTopFrame() && M.getDecl() && 1208 M.getDecl()->getMethodFamily() == OMF_init && 1209 M.isReceiverSelfOrSuper()) { 1210 State = assumeExprIsNonNull(M.getOriginExpr(), State, C); 1211 } 1212 1213 FoundationClass Cl = findKnownClass(Interface); 1214 1215 // Objects returned from 1216 // [NSArray|NSOrderedSet]::[ObjectAtIndex|ObjectAtIndexedSubscript] 1217 // are never 'nil'. 1218 if (Cl == FC_NSArray || Cl == FC_NSOrderedSet) { 1219 Selector Sel = M.getSelector(); 1220 if (Sel == ObjectAtIndex || Sel == ObjectAtIndexedSubscript) { 1221 // Go ahead and assume the value is non-nil. 1222 State = assumeExprIsNonNull(M.getOriginExpr(), State, C); 1223 } 1224 } 1225 1226 // Objects returned from [NSNull null] are not nil. 1227 if (Cl == FC_NSNull) { 1228 if (M.getSelector() == NullSelector) { 1229 // Go ahead and assume the value is non-nil. 1230 State = assumeExprIsNonNull(M.getOriginExpr(), State, C); 1231 } 1232 } 1233 } 1234 C.addTransition(State); 1235 } 1236 1237 //===----------------------------------------------------------------------===// 1238 // Check registration. 1239 //===----------------------------------------------------------------------===// 1240 1241 void ento::registerNilArgChecker(CheckerManager &mgr) { 1242 mgr.registerChecker<NilArgChecker>(); 1243 } 1244 1245 bool ento::shouldRegisterNilArgChecker(const LangOptions &LO) { 1246 return true; 1247 } 1248 1249 void ento::registerCFNumberChecker(CheckerManager &mgr) { 1250 mgr.registerChecker<CFNumberChecker>(); 1251 } 1252 1253 bool ento::shouldRegisterCFNumberChecker(const LangOptions &LO) { 1254 return true; 1255 } 1256 1257 void ento::registerCFRetainReleaseChecker(CheckerManager &mgr) { 1258 mgr.registerChecker<CFRetainReleaseChecker>(); 1259 } 1260 1261 bool ento::shouldRegisterCFRetainReleaseChecker(const LangOptions &LO) { 1262 return true; 1263 } 1264 1265 void ento::registerClassReleaseChecker(CheckerManager &mgr) { 1266 mgr.registerChecker<ClassReleaseChecker>(); 1267 } 1268 1269 bool ento::shouldRegisterClassReleaseChecker(const LangOptions &LO) { 1270 return true; 1271 } 1272 1273 void ento::registerVariadicMethodTypeChecker(CheckerManager &mgr) { 1274 mgr.registerChecker<VariadicMethodTypeChecker>(); 1275 } 1276 1277 bool ento::shouldRegisterVariadicMethodTypeChecker(const LangOptions &LO) { 1278 return true; 1279 } 1280 1281 void ento::registerObjCLoopChecker(CheckerManager &mgr) { 1282 mgr.registerChecker<ObjCLoopChecker>(); 1283 } 1284 1285 bool ento::shouldRegisterObjCLoopChecker(const LangOptions &LO) { 1286 return true; 1287 } 1288 1289 void ento::registerObjCNonNilReturnValueChecker(CheckerManager &mgr) { 1290 mgr.registerChecker<ObjCNonNilReturnValueChecker>(); 1291 } 1292 1293 bool ento::shouldRegisterObjCNonNilReturnValueChecker(const LangOptions &LO) { 1294 return true; 1295 } 1296