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 = std::make_unique<PathSensitiveBugReport>(*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 = std::make_unique<PathSensitiveBugReport>(*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 = std::make_unique<PathSensitiveBugReport>(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 = std::make_unique<PathSensitiveBugReport>(*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 = std::make_unique<PathSensitiveBugReport>(*BT, os.str(), 792 errorNode.getValue()); 793 R->addRange(msg.getArgSourceRange(I)); 794 C.emitReport(std::move(R)); 795 } 796 } 797 798 //===----------------------------------------------------------------------===// 799 // Improves the modeling of loops over Cocoa collections. 800 //===----------------------------------------------------------------------===// 801 802 // The map from container symbol to the container count symbol. 803 // We currently will remember the last container count symbol encountered. 804 REGISTER_MAP_WITH_PROGRAMSTATE(ContainerCountMap, SymbolRef, SymbolRef) 805 REGISTER_MAP_WITH_PROGRAMSTATE(ContainerNonEmptyMap, SymbolRef, bool) 806 807 namespace { 808 class ObjCLoopChecker 809 : public Checker<check::PostStmt<ObjCForCollectionStmt>, 810 check::PostObjCMessage, 811 check::DeadSymbols, 812 check::PointerEscape > { 813 mutable IdentifierInfo *CountSelectorII; 814 815 bool isCollectionCountMethod(const ObjCMethodCall &M, 816 CheckerContext &C) const; 817 818 public: 819 ObjCLoopChecker() : CountSelectorII(nullptr) {} 820 void checkPostStmt(const ObjCForCollectionStmt *FCS, CheckerContext &C) const; 821 void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const; 822 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 823 ProgramStateRef checkPointerEscape(ProgramStateRef State, 824 const InvalidatedSymbols &Escaped, 825 const CallEvent *Call, 826 PointerEscapeKind Kind) const; 827 }; 828 } // end anonymous namespace 829 830 static bool isKnownNonNilCollectionType(QualType T) { 831 const ObjCObjectPointerType *PT = T->getAs<ObjCObjectPointerType>(); 832 if (!PT) 833 return false; 834 835 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 836 if (!ID) 837 return false; 838 839 switch (findKnownClass(ID)) { 840 case FC_NSArray: 841 case FC_NSDictionary: 842 case FC_NSEnumerator: 843 case FC_NSOrderedSet: 844 case FC_NSSet: 845 return true; 846 default: 847 return false; 848 } 849 } 850 851 /// Assumes that the collection is non-nil. 852 /// 853 /// If the collection is known to be nil, returns NULL to indicate an infeasible 854 /// path. 855 static ProgramStateRef checkCollectionNonNil(CheckerContext &C, 856 ProgramStateRef State, 857 const ObjCForCollectionStmt *FCS) { 858 if (!State) 859 return nullptr; 860 861 SVal CollectionVal = C.getSVal(FCS->getCollection()); 862 Optional<DefinedSVal> KnownCollection = CollectionVal.getAs<DefinedSVal>(); 863 if (!KnownCollection) 864 return State; 865 866 ProgramStateRef StNonNil, StNil; 867 std::tie(StNonNil, StNil) = State->assume(*KnownCollection); 868 if (StNil && !StNonNil) { 869 // The collection is nil. This path is infeasible. 870 return nullptr; 871 } 872 873 return StNonNil; 874 } 875 876 /// Assumes that the collection elements are non-nil. 877 /// 878 /// This only applies if the collection is one of those known not to contain 879 /// nil values. 880 static ProgramStateRef checkElementNonNil(CheckerContext &C, 881 ProgramStateRef State, 882 const ObjCForCollectionStmt *FCS) { 883 if (!State) 884 return nullptr; 885 886 // See if the collection is one where we /know/ the elements are non-nil. 887 if (!isKnownNonNilCollectionType(FCS->getCollection()->getType())) 888 return State; 889 890 const LocationContext *LCtx = C.getLocationContext(); 891 const Stmt *Element = FCS->getElement(); 892 893 // FIXME: Copied from ExprEngineObjC. 894 Optional<Loc> ElementLoc; 895 if (const DeclStmt *DS = dyn_cast<DeclStmt>(Element)) { 896 const VarDecl *ElemDecl = cast<VarDecl>(DS->getSingleDecl()); 897 assert(ElemDecl->getInit() == nullptr); 898 ElementLoc = State->getLValue(ElemDecl, LCtx); 899 } else { 900 ElementLoc = State->getSVal(Element, LCtx).getAs<Loc>(); 901 } 902 903 if (!ElementLoc) 904 return State; 905 906 // Go ahead and assume the value is non-nil. 907 SVal Val = State->getSVal(*ElementLoc); 908 return State->assume(Val.castAs<DefinedOrUnknownSVal>(), true); 909 } 910 911 /// Returns NULL state if the collection is known to contain elements 912 /// (or is known not to contain elements if the Assumption parameter is false.) 913 static ProgramStateRef 914 assumeCollectionNonEmpty(CheckerContext &C, ProgramStateRef State, 915 SymbolRef CollectionS, bool Assumption) { 916 if (!State || !CollectionS) 917 return State; 918 919 const SymbolRef *CountS = State->get<ContainerCountMap>(CollectionS); 920 if (!CountS) { 921 const bool *KnownNonEmpty = State->get<ContainerNonEmptyMap>(CollectionS); 922 if (!KnownNonEmpty) 923 return State->set<ContainerNonEmptyMap>(CollectionS, Assumption); 924 return (Assumption == *KnownNonEmpty) ? State : nullptr; 925 } 926 927 SValBuilder &SvalBuilder = C.getSValBuilder(); 928 SVal CountGreaterThanZeroVal = 929 SvalBuilder.evalBinOp(State, BO_GT, 930 nonloc::SymbolVal(*CountS), 931 SvalBuilder.makeIntVal(0, (*CountS)->getType()), 932 SvalBuilder.getConditionType()); 933 Optional<DefinedSVal> CountGreaterThanZero = 934 CountGreaterThanZeroVal.getAs<DefinedSVal>(); 935 if (!CountGreaterThanZero) { 936 // The SValBuilder cannot construct a valid SVal for this condition. 937 // This means we cannot properly reason about it. 938 return State; 939 } 940 941 return State->assume(*CountGreaterThanZero, Assumption); 942 } 943 944 static ProgramStateRef 945 assumeCollectionNonEmpty(CheckerContext &C, ProgramStateRef State, 946 const ObjCForCollectionStmt *FCS, 947 bool Assumption) { 948 if (!State) 949 return nullptr; 950 951 SymbolRef CollectionS = C.getSVal(FCS->getCollection()).getAsSymbol(); 952 return assumeCollectionNonEmpty(C, State, CollectionS, Assumption); 953 } 954 955 /// If the fist block edge is a back edge, we are reentering the loop. 956 static bool alreadyExecutedAtLeastOneLoopIteration(const ExplodedNode *N, 957 const ObjCForCollectionStmt *FCS) { 958 if (!N) 959 return false; 960 961 ProgramPoint P = N->getLocation(); 962 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 963 return BE->getSrc()->getLoopTarget() == FCS; 964 } 965 966 // Keep looking for a block edge. 967 for (ExplodedNode::const_pred_iterator I = N->pred_begin(), 968 E = N->pred_end(); I != E; ++I) { 969 if (alreadyExecutedAtLeastOneLoopIteration(*I, FCS)) 970 return true; 971 } 972 973 return false; 974 } 975 976 void ObjCLoopChecker::checkPostStmt(const ObjCForCollectionStmt *FCS, 977 CheckerContext &C) const { 978 ProgramStateRef State = C.getState(); 979 980 // Check if this is the branch for the end of the loop. 981 SVal CollectionSentinel = C.getSVal(FCS); 982 if (CollectionSentinel.isZeroConstant()) { 983 if (!alreadyExecutedAtLeastOneLoopIteration(C.getPredecessor(), FCS)) 984 State = assumeCollectionNonEmpty(C, State, FCS, /*Assumption*/false); 985 986 // Otherwise, this is a branch that goes through the loop body. 987 } else { 988 State = checkCollectionNonNil(C, State, FCS); 989 State = checkElementNonNil(C, State, FCS); 990 State = assumeCollectionNonEmpty(C, State, FCS, /*Assumption*/true); 991 } 992 993 if (!State) 994 C.generateSink(C.getState(), C.getPredecessor()); 995 else if (State != C.getState()) 996 C.addTransition(State); 997 } 998 999 bool ObjCLoopChecker::isCollectionCountMethod(const ObjCMethodCall &M, 1000 CheckerContext &C) const { 1001 Selector S = M.getSelector(); 1002 // Initialize the identifiers on first use. 1003 if (!CountSelectorII) 1004 CountSelectorII = &C.getASTContext().Idents.get("count"); 1005 1006 // If the method returns collection count, record the value. 1007 return S.isUnarySelector() && 1008 (S.getIdentifierInfoForSlot(0) == CountSelectorII); 1009 } 1010 1011 void ObjCLoopChecker::checkPostObjCMessage(const ObjCMethodCall &M, 1012 CheckerContext &C) const { 1013 if (!M.isInstanceMessage()) 1014 return; 1015 1016 const ObjCInterfaceDecl *ClassID = M.getReceiverInterface(); 1017 if (!ClassID) 1018 return; 1019 1020 FoundationClass Class = findKnownClass(ClassID); 1021 if (Class != FC_NSDictionary && 1022 Class != FC_NSArray && 1023 Class != FC_NSSet && 1024 Class != FC_NSOrderedSet) 1025 return; 1026 1027 SymbolRef ContainerS = M.getReceiverSVal().getAsSymbol(); 1028 if (!ContainerS) 1029 return; 1030 1031 // If we are processing a call to "count", get the symbolic value returned by 1032 // a call to "count" and add it to the map. 1033 if (!isCollectionCountMethod(M, C)) 1034 return; 1035 1036 const Expr *MsgExpr = M.getOriginExpr(); 1037 SymbolRef CountS = C.getSVal(MsgExpr).getAsSymbol(); 1038 if (CountS) { 1039 ProgramStateRef State = C.getState(); 1040 1041 C.getSymbolManager().addSymbolDependency(ContainerS, CountS); 1042 State = State->set<ContainerCountMap>(ContainerS, CountS); 1043 1044 if (const bool *NonEmpty = State->get<ContainerNonEmptyMap>(ContainerS)) { 1045 State = State->remove<ContainerNonEmptyMap>(ContainerS); 1046 State = assumeCollectionNonEmpty(C, State, ContainerS, *NonEmpty); 1047 } 1048 1049 C.addTransition(State); 1050 } 1051 } 1052 1053 static SymbolRef getMethodReceiverIfKnownImmutable(const CallEvent *Call) { 1054 const ObjCMethodCall *Message = dyn_cast_or_null<ObjCMethodCall>(Call); 1055 if (!Message) 1056 return nullptr; 1057 1058 const ObjCMethodDecl *MD = Message->getDecl(); 1059 if (!MD) 1060 return nullptr; 1061 1062 const ObjCInterfaceDecl *StaticClass; 1063 if (isa<ObjCProtocolDecl>(MD->getDeclContext())) { 1064 // We can't find out where the method was declared without doing more work. 1065 // Instead, see if the receiver is statically typed as a known immutable 1066 // collection. 1067 StaticClass = Message->getOriginExpr()->getReceiverInterface(); 1068 } else { 1069 StaticClass = MD->getClassInterface(); 1070 } 1071 1072 if (!StaticClass) 1073 return nullptr; 1074 1075 switch (findKnownClass(StaticClass, /*IncludeSuper=*/false)) { 1076 case FC_None: 1077 return nullptr; 1078 case FC_NSArray: 1079 case FC_NSDictionary: 1080 case FC_NSEnumerator: 1081 case FC_NSNull: 1082 case FC_NSOrderedSet: 1083 case FC_NSSet: 1084 case FC_NSString: 1085 break; 1086 } 1087 1088 return Message->getReceiverSVal().getAsSymbol(); 1089 } 1090 1091 ProgramStateRef 1092 ObjCLoopChecker::checkPointerEscape(ProgramStateRef State, 1093 const InvalidatedSymbols &Escaped, 1094 const CallEvent *Call, 1095 PointerEscapeKind Kind) const { 1096 SymbolRef ImmutableReceiver = getMethodReceiverIfKnownImmutable(Call); 1097 1098 // Remove the invalidated symbols form the collection count map. 1099 for (InvalidatedSymbols::const_iterator I = Escaped.begin(), 1100 E = Escaped.end(); 1101 I != E; ++I) { 1102 SymbolRef Sym = *I; 1103 1104 // Don't invalidate this symbol's count if we know the method being called 1105 // is declared on an immutable class. This isn't completely correct if the 1106 // receiver is also passed as an argument, but in most uses of NSArray, 1107 // NSDictionary, etc. this isn't likely to happen in a dangerous way. 1108 if (Sym == ImmutableReceiver) 1109 continue; 1110 1111 // The symbol escaped. Pessimistically, assume that the count could have 1112 // changed. 1113 State = State->remove<ContainerCountMap>(Sym); 1114 State = State->remove<ContainerNonEmptyMap>(Sym); 1115 } 1116 return State; 1117 } 1118 1119 void ObjCLoopChecker::checkDeadSymbols(SymbolReaper &SymReaper, 1120 CheckerContext &C) const { 1121 ProgramStateRef State = C.getState(); 1122 1123 // Remove the dead symbols from the collection count map. 1124 ContainerCountMapTy Tracked = State->get<ContainerCountMap>(); 1125 for (ContainerCountMapTy::iterator I = Tracked.begin(), 1126 E = Tracked.end(); I != E; ++I) { 1127 SymbolRef Sym = I->first; 1128 if (SymReaper.isDead(Sym)) { 1129 State = State->remove<ContainerCountMap>(Sym); 1130 State = State->remove<ContainerNonEmptyMap>(Sym); 1131 } 1132 } 1133 1134 C.addTransition(State); 1135 } 1136 1137 namespace { 1138 /// \class ObjCNonNilReturnValueChecker 1139 /// The checker restricts the return values of APIs known to 1140 /// never (or almost never) return 'nil'. 1141 class ObjCNonNilReturnValueChecker 1142 : public Checker<check::PostObjCMessage, 1143 check::PostStmt<ObjCArrayLiteral>, 1144 check::PostStmt<ObjCDictionaryLiteral>, 1145 check::PostStmt<ObjCBoxedExpr> > { 1146 mutable bool Initialized; 1147 mutable Selector ObjectAtIndex; 1148 mutable Selector ObjectAtIndexedSubscript; 1149 mutable Selector NullSelector; 1150 1151 public: 1152 ObjCNonNilReturnValueChecker() : Initialized(false) {} 1153 1154 ProgramStateRef assumeExprIsNonNull(const Expr *NonNullExpr, 1155 ProgramStateRef State, 1156 CheckerContext &C) const; 1157 void assumeExprIsNonNull(const Expr *E, CheckerContext &C) const { 1158 C.addTransition(assumeExprIsNonNull(E, C.getState(), C)); 1159 } 1160 1161 void checkPostStmt(const ObjCArrayLiteral *E, CheckerContext &C) const { 1162 assumeExprIsNonNull(E, C); 1163 } 1164 void checkPostStmt(const ObjCDictionaryLiteral *E, CheckerContext &C) const { 1165 assumeExprIsNonNull(E, C); 1166 } 1167 void checkPostStmt(const ObjCBoxedExpr *E, CheckerContext &C) const { 1168 assumeExprIsNonNull(E, C); 1169 } 1170 1171 void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const; 1172 }; 1173 } // end anonymous namespace 1174 1175 ProgramStateRef 1176 ObjCNonNilReturnValueChecker::assumeExprIsNonNull(const Expr *NonNullExpr, 1177 ProgramStateRef State, 1178 CheckerContext &C) const { 1179 SVal Val = C.getSVal(NonNullExpr); 1180 if (Optional<DefinedOrUnknownSVal> DV = Val.getAs<DefinedOrUnknownSVal>()) 1181 return State->assume(*DV, true); 1182 return State; 1183 } 1184 1185 void ObjCNonNilReturnValueChecker::checkPostObjCMessage(const ObjCMethodCall &M, 1186 CheckerContext &C) 1187 const { 1188 ProgramStateRef State = C.getState(); 1189 1190 if (!Initialized) { 1191 ASTContext &Ctx = C.getASTContext(); 1192 ObjectAtIndex = GetUnarySelector("objectAtIndex", Ctx); 1193 ObjectAtIndexedSubscript = GetUnarySelector("objectAtIndexedSubscript", Ctx); 1194 NullSelector = GetNullarySelector("null", Ctx); 1195 } 1196 1197 // Check the receiver type. 1198 if (const ObjCInterfaceDecl *Interface = M.getReceiverInterface()) { 1199 1200 // Assume that object returned from '[self init]' or '[super init]' is not 1201 // 'nil' if we are processing an inlined function/method. 1202 // 1203 // A defensive callee will (and should) check if the object returned by 1204 // '[super init]' is 'nil' before doing it's own initialization. However, 1205 // since 'nil' is rarely returned in practice, we should not warn when the 1206 // caller to the defensive constructor uses the object in contexts where 1207 // 'nil' is not accepted. 1208 if (!C.inTopFrame() && M.getDecl() && 1209 M.getDecl()->getMethodFamily() == OMF_init && 1210 M.isReceiverSelfOrSuper()) { 1211 State = assumeExprIsNonNull(M.getOriginExpr(), State, C); 1212 } 1213 1214 FoundationClass Cl = findKnownClass(Interface); 1215 1216 // Objects returned from 1217 // [NSArray|NSOrderedSet]::[ObjectAtIndex|ObjectAtIndexedSubscript] 1218 // are never 'nil'. 1219 if (Cl == FC_NSArray || Cl == FC_NSOrderedSet) { 1220 Selector Sel = M.getSelector(); 1221 if (Sel == ObjectAtIndex || Sel == ObjectAtIndexedSubscript) { 1222 // Go ahead and assume the value is non-nil. 1223 State = assumeExprIsNonNull(M.getOriginExpr(), State, C); 1224 } 1225 } 1226 1227 // Objects returned from [NSNull null] are not nil. 1228 if (Cl == FC_NSNull) { 1229 if (M.getSelector() == NullSelector) { 1230 // Go ahead and assume the value is non-nil. 1231 State = assumeExprIsNonNull(M.getOriginExpr(), State, C); 1232 } 1233 } 1234 } 1235 C.addTransition(State); 1236 } 1237 1238 //===----------------------------------------------------------------------===// 1239 // Check registration. 1240 //===----------------------------------------------------------------------===// 1241 1242 void ento::registerNilArgChecker(CheckerManager &mgr) { 1243 mgr.registerChecker<NilArgChecker>(); 1244 } 1245 1246 bool ento::shouldRegisterNilArgChecker(const CheckerManager &mgr) { 1247 return true; 1248 } 1249 1250 void ento::registerCFNumberChecker(CheckerManager &mgr) { 1251 mgr.registerChecker<CFNumberChecker>(); 1252 } 1253 1254 bool ento::shouldRegisterCFNumberChecker(const CheckerManager &mgr) { 1255 return true; 1256 } 1257 1258 void ento::registerCFRetainReleaseChecker(CheckerManager &mgr) { 1259 mgr.registerChecker<CFRetainReleaseChecker>(); 1260 } 1261 1262 bool ento::shouldRegisterCFRetainReleaseChecker(const CheckerManager &mgr) { 1263 return true; 1264 } 1265 1266 void ento::registerClassReleaseChecker(CheckerManager &mgr) { 1267 mgr.registerChecker<ClassReleaseChecker>(); 1268 } 1269 1270 bool ento::shouldRegisterClassReleaseChecker(const CheckerManager &mgr) { 1271 return true; 1272 } 1273 1274 void ento::registerVariadicMethodTypeChecker(CheckerManager &mgr) { 1275 mgr.registerChecker<VariadicMethodTypeChecker>(); 1276 } 1277 1278 bool ento::shouldRegisterVariadicMethodTypeChecker(const CheckerManager &mgr) { 1279 return true; 1280 } 1281 1282 void ento::registerObjCLoopChecker(CheckerManager &mgr) { 1283 mgr.registerChecker<ObjCLoopChecker>(); 1284 } 1285 1286 bool ento::shouldRegisterObjCLoopChecker(const CheckerManager &mgr) { 1287 return true; 1288 } 1289 1290 void ento::registerObjCNonNilReturnValueChecker(CheckerManager &mgr) { 1291 mgr.registerChecker<ObjCNonNilReturnValueChecker>(); 1292 } 1293 1294 bool ento::shouldRegisterObjCNonNilReturnValueChecker(const CheckerManager &mgr) { 1295 return true; 1296 } 1297