RetainCountChecker.cpp revision 7a87e520e42c1e58c358e3a9a436ef17f551fd13
1//==-- RetainCountChecker.cpp - Checks for leaks and other issues -*- 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 file defines the methods for RetainCountChecker, which implements 11// a reference count checker for Core Foundation and Cocoa on (Mac OS X). 12// 13//===----------------------------------------------------------------------===// 14 15#include "ClangSACheckers.h" 16#include "clang/AST/Attr.h" 17#include "clang/AST/DeclCXX.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/ParentMap.h" 20#include "clang/Analysis/DomainSpecific/CocoaConventions.h" 21#include "clang/Basic/LangOptions.h" 22#include "clang/Basic/SourceManager.h" 23#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 24#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" 25#include "clang/StaticAnalyzer/Core/Checker.h" 26#include "clang/StaticAnalyzer/Core/CheckerManager.h" 27#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 28#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 29#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 30#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h" 31#include "llvm/ADT/DenseMap.h" 32#include "llvm/ADT/FoldingSet.h" 33#include "llvm/ADT/ImmutableList.h" 34#include "llvm/ADT/ImmutableMap.h" 35#include "llvm/ADT/STLExtras.h" 36#include "llvm/ADT/SmallString.h" 37#include "llvm/ADT/StringExtras.h" 38#include <cstdarg> 39 40using namespace clang; 41using namespace ento; 42using llvm::StrInStrNoCase; 43 44//===----------------------------------------------------------------------===// 45// Primitives used for constructing summaries for function/method calls. 46//===----------------------------------------------------------------------===// 47 48/// ArgEffect is used to summarize a function/method call's effect on a 49/// particular argument. 50enum ArgEffect { DoNothing, Autorelease, Dealloc, DecRef, DecRefMsg, 51 DecRefBridgedTransfered, 52 IncRefMsg, IncRef, MakeCollectable, MayEscape, 53 54 // Stop tracking the argument - the effect of the call is 55 // unknown. 56 StopTracking, 57 58 // In some cases, we obtain a better summary for this checker 59 // by looking at the call site than by inlining the function. 60 // Signifies that we should stop tracking the symbol even if 61 // the function is inlined. 62 StopTrackingHard, 63 64 // The function decrements the reference count and the checker 65 // should stop tracking the argument. 66 DecRefAndStopTrackingHard, DecRefMsgAndStopTrackingHard 67 }; 68 69namespace llvm { 70template <> struct FoldingSetTrait<ArgEffect> { 71static inline void Profile(const ArgEffect X, FoldingSetNodeID& ID) { 72 ID.AddInteger((unsigned) X); 73} 74}; 75} // end llvm namespace 76 77/// ArgEffects summarizes the effects of a function/method call on all of 78/// its arguments. 79typedef llvm::ImmutableMap<unsigned,ArgEffect> ArgEffects; 80 81namespace { 82 83/// RetEffect is used to summarize a function/method call's behavior with 84/// respect to its return value. 85class RetEffect { 86public: 87 enum Kind { NoRet, OwnedSymbol, OwnedAllocatedSymbol, 88 NotOwnedSymbol, GCNotOwnedSymbol, ARCNotOwnedSymbol, 89 OwnedWhenTrackedReceiver, 90 // Treat this function as returning a non-tracked symbol even if 91 // the function has been inlined. This is used where the call 92 // site summary is more presise than the summary indirectly produced 93 // by inlining the function 94 NoRetHard 95 }; 96 97 enum ObjKind { CF, ObjC, AnyObj }; 98 99private: 100 Kind K; 101 ObjKind O; 102 103 RetEffect(Kind k, ObjKind o = AnyObj) : K(k), O(o) {} 104 105public: 106 Kind getKind() const { return K; } 107 108 ObjKind getObjKind() const { return O; } 109 110 bool isOwned() const { 111 return K == OwnedSymbol || K == OwnedAllocatedSymbol || 112 K == OwnedWhenTrackedReceiver; 113 } 114 115 bool operator==(const RetEffect &Other) const { 116 return K == Other.K && O == Other.O; 117 } 118 119 static RetEffect MakeOwnedWhenTrackedReceiver() { 120 return RetEffect(OwnedWhenTrackedReceiver, ObjC); 121 } 122 123 static RetEffect MakeOwned(ObjKind o, bool isAllocated = false) { 124 return RetEffect(isAllocated ? OwnedAllocatedSymbol : OwnedSymbol, o); 125 } 126 static RetEffect MakeNotOwned(ObjKind o) { 127 return RetEffect(NotOwnedSymbol, o); 128 } 129 static RetEffect MakeGCNotOwned() { 130 return RetEffect(GCNotOwnedSymbol, ObjC); 131 } 132 static RetEffect MakeARCNotOwned() { 133 return RetEffect(ARCNotOwnedSymbol, ObjC); 134 } 135 static RetEffect MakeNoRet() { 136 return RetEffect(NoRet); 137 } 138 static RetEffect MakeNoRetHard() { 139 return RetEffect(NoRetHard); 140 } 141 142 void Profile(llvm::FoldingSetNodeID& ID) const { 143 ID.AddInteger((unsigned) K); 144 ID.AddInteger((unsigned) O); 145 } 146}; 147 148//===----------------------------------------------------------------------===// 149// Reference-counting logic (typestate + counts). 150//===----------------------------------------------------------------------===// 151 152class RefVal { 153public: 154 enum Kind { 155 Owned = 0, // Owning reference. 156 NotOwned, // Reference is not owned by still valid (not freed). 157 Released, // Object has been released. 158 ReturnedOwned, // Returned object passes ownership to caller. 159 ReturnedNotOwned, // Return object does not pass ownership to caller. 160 ERROR_START, 161 ErrorDeallocNotOwned, // -dealloc called on non-owned object. 162 ErrorDeallocGC, // Calling -dealloc with GC enabled. 163 ErrorUseAfterRelease, // Object used after released. 164 ErrorReleaseNotOwned, // Release of an object that was not owned. 165 ERROR_LEAK_START, 166 ErrorLeak, // A memory leak due to excessive reference counts. 167 ErrorLeakReturned, // A memory leak due to the returning method not having 168 // the correct naming conventions. 169 ErrorGCLeakReturned, 170 ErrorOverAutorelease, 171 ErrorReturnedNotOwned 172 }; 173 174private: 175 Kind kind; 176 RetEffect::ObjKind okind; 177 unsigned Cnt; 178 unsigned ACnt; 179 QualType T; 180 181 RefVal(Kind k, RetEffect::ObjKind o, unsigned cnt, unsigned acnt, QualType t) 182 : kind(k), okind(o), Cnt(cnt), ACnt(acnt), T(t) {} 183 184public: 185 Kind getKind() const { return kind; } 186 187 RetEffect::ObjKind getObjKind() const { return okind; } 188 189 unsigned getCount() const { return Cnt; } 190 unsigned getAutoreleaseCount() const { return ACnt; } 191 unsigned getCombinedCounts() const { return Cnt + ACnt; } 192 void clearCounts() { Cnt = 0; ACnt = 0; } 193 void setCount(unsigned i) { Cnt = i; } 194 void setAutoreleaseCount(unsigned i) { ACnt = i; } 195 196 QualType getType() const { return T; } 197 198 bool isOwned() const { 199 return getKind() == Owned; 200 } 201 202 bool isNotOwned() const { 203 return getKind() == NotOwned; 204 } 205 206 bool isReturnedOwned() const { 207 return getKind() == ReturnedOwned; 208 } 209 210 bool isReturnedNotOwned() const { 211 return getKind() == ReturnedNotOwned; 212 } 213 214 static RefVal makeOwned(RetEffect::ObjKind o, QualType t, 215 unsigned Count = 1) { 216 return RefVal(Owned, o, Count, 0, t); 217 } 218 219 static RefVal makeNotOwned(RetEffect::ObjKind o, QualType t, 220 unsigned Count = 0) { 221 return RefVal(NotOwned, o, Count, 0, t); 222 } 223 224 // Comparison, profiling, and pretty-printing. 225 226 bool operator==(const RefVal& X) const { 227 return kind == X.kind && Cnt == X.Cnt && T == X.T && ACnt == X.ACnt; 228 } 229 230 RefVal operator-(size_t i) const { 231 return RefVal(getKind(), getObjKind(), getCount() - i, 232 getAutoreleaseCount(), getType()); 233 } 234 235 RefVal operator+(size_t i) const { 236 return RefVal(getKind(), getObjKind(), getCount() + i, 237 getAutoreleaseCount(), getType()); 238 } 239 240 RefVal operator^(Kind k) const { 241 return RefVal(k, getObjKind(), getCount(), getAutoreleaseCount(), 242 getType()); 243 } 244 245 RefVal autorelease() const { 246 return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount()+1, 247 getType()); 248 } 249 250 void Profile(llvm::FoldingSetNodeID& ID) const { 251 ID.AddInteger((unsigned) kind); 252 ID.AddInteger(Cnt); 253 ID.AddInteger(ACnt); 254 ID.Add(T); 255 } 256 257 void print(raw_ostream &Out) const; 258}; 259 260void RefVal::print(raw_ostream &Out) const { 261 if (!T.isNull()) 262 Out << "Tracked " << T.getAsString() << '/'; 263 264 switch (getKind()) { 265 default: llvm_unreachable("Invalid RefVal kind"); 266 case Owned: { 267 Out << "Owned"; 268 unsigned cnt = getCount(); 269 if (cnt) Out << " (+ " << cnt << ")"; 270 break; 271 } 272 273 case NotOwned: { 274 Out << "NotOwned"; 275 unsigned cnt = getCount(); 276 if (cnt) Out << " (+ " << cnt << ")"; 277 break; 278 } 279 280 case ReturnedOwned: { 281 Out << "ReturnedOwned"; 282 unsigned cnt = getCount(); 283 if (cnt) Out << " (+ " << cnt << ")"; 284 break; 285 } 286 287 case ReturnedNotOwned: { 288 Out << "ReturnedNotOwned"; 289 unsigned cnt = getCount(); 290 if (cnt) Out << " (+ " << cnt << ")"; 291 break; 292 } 293 294 case Released: 295 Out << "Released"; 296 break; 297 298 case ErrorDeallocGC: 299 Out << "-dealloc (GC)"; 300 break; 301 302 case ErrorDeallocNotOwned: 303 Out << "-dealloc (not-owned)"; 304 break; 305 306 case ErrorLeak: 307 Out << "Leaked"; 308 break; 309 310 case ErrorLeakReturned: 311 Out << "Leaked (Bad naming)"; 312 break; 313 314 case ErrorGCLeakReturned: 315 Out << "Leaked (GC-ed at return)"; 316 break; 317 318 case ErrorUseAfterRelease: 319 Out << "Use-After-Release [ERROR]"; 320 break; 321 322 case ErrorReleaseNotOwned: 323 Out << "Release of Not-Owned [ERROR]"; 324 break; 325 326 case RefVal::ErrorOverAutorelease: 327 Out << "Over autoreleased"; 328 break; 329 330 case RefVal::ErrorReturnedNotOwned: 331 Out << "Non-owned object returned instead of owned"; 332 break; 333 } 334 335 if (ACnt) { 336 Out << " [ARC +" << ACnt << ']'; 337 } 338} 339} //end anonymous namespace 340 341//===----------------------------------------------------------------------===// 342// RefBindings - State used to track object reference counts. 343//===----------------------------------------------------------------------===// 344 345REGISTER_MAP_WITH_PROGRAMSTATE(RefBindings, SymbolRef, RefVal) 346 347static inline const RefVal *getRefBinding(ProgramStateRef State, 348 SymbolRef Sym) { 349 return State->get<RefBindings>(Sym); 350} 351 352static inline ProgramStateRef setRefBinding(ProgramStateRef State, 353 SymbolRef Sym, RefVal Val) { 354 return State->set<RefBindings>(Sym, Val); 355} 356 357static ProgramStateRef removeRefBinding(ProgramStateRef State, SymbolRef Sym) { 358 return State->remove<RefBindings>(Sym); 359} 360 361//===----------------------------------------------------------------------===// 362// Function/Method behavior summaries. 363//===----------------------------------------------------------------------===// 364 365namespace { 366class RetainSummary { 367 /// Args - a map of (index, ArgEffect) pairs, where index 368 /// specifies the argument (starting from 0). This can be sparsely 369 /// populated; arguments with no entry in Args use 'DefaultArgEffect'. 370 ArgEffects Args; 371 372 /// DefaultArgEffect - The default ArgEffect to apply to arguments that 373 /// do not have an entry in Args. 374 ArgEffect DefaultArgEffect; 375 376 /// Receiver - If this summary applies to an Objective-C message expression, 377 /// this is the effect applied to the state of the receiver. 378 ArgEffect Receiver; 379 380 /// Ret - The effect on the return value. Used to indicate if the 381 /// function/method call returns a new tracked symbol. 382 RetEffect Ret; 383 384public: 385 RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff, 386 ArgEffect ReceiverEff) 387 : Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {} 388 389 /// getArg - Return the argument effect on the argument specified by 390 /// idx (starting from 0). 391 ArgEffect getArg(unsigned idx) const { 392 if (const ArgEffect *AE = Args.lookup(idx)) 393 return *AE; 394 395 return DefaultArgEffect; 396 } 397 398 void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) { 399 Args = af.add(Args, idx, e); 400 } 401 402 /// setDefaultArgEffect - Set the default argument effect. 403 void setDefaultArgEffect(ArgEffect E) { 404 DefaultArgEffect = E; 405 } 406 407 /// getRetEffect - Returns the effect on the return value of the call. 408 RetEffect getRetEffect() const { return Ret; } 409 410 /// setRetEffect - Set the effect of the return value of the call. 411 void setRetEffect(RetEffect E) { Ret = E; } 412 413 414 /// Sets the effect on the receiver of the message. 415 void setReceiverEffect(ArgEffect e) { Receiver = e; } 416 417 /// getReceiverEffect - Returns the effect on the receiver of the call. 418 /// This is only meaningful if the summary applies to an ObjCMessageExpr*. 419 ArgEffect getReceiverEffect() const { return Receiver; } 420 421 /// Test if two retain summaries are identical. Note that merely equivalent 422 /// summaries are not necessarily identical (for example, if an explicit 423 /// argument effect matches the default effect). 424 bool operator==(const RetainSummary &Other) const { 425 return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect && 426 Receiver == Other.Receiver && Ret == Other.Ret; 427 } 428 429 /// Profile this summary for inclusion in a FoldingSet. 430 void Profile(llvm::FoldingSetNodeID& ID) const { 431 ID.Add(Args); 432 ID.Add(DefaultArgEffect); 433 ID.Add(Receiver); 434 ID.Add(Ret); 435 } 436 437 /// A retain summary is simple if it has no ArgEffects other than the default. 438 bool isSimple() const { 439 return Args.isEmpty(); 440 } 441 442private: 443 ArgEffects getArgEffects() const { return Args; } 444 ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; } 445 446 friend class RetainSummaryManager; 447}; 448} // end anonymous namespace 449 450//===----------------------------------------------------------------------===// 451// Data structures for constructing summaries. 452//===----------------------------------------------------------------------===// 453 454namespace { 455class ObjCSummaryKey { 456 IdentifierInfo* II; 457 Selector S; 458public: 459 ObjCSummaryKey(IdentifierInfo* ii, Selector s) 460 : II(ii), S(s) {} 461 462 ObjCSummaryKey(const ObjCInterfaceDecl *d, Selector s) 463 : II(d ? d->getIdentifier() : 0), S(s) {} 464 465 ObjCSummaryKey(Selector s) 466 : II(0), S(s) {} 467 468 IdentifierInfo *getIdentifier() const { return II; } 469 Selector getSelector() const { return S; } 470}; 471} 472 473namespace llvm { 474template <> struct DenseMapInfo<ObjCSummaryKey> { 475 static inline ObjCSummaryKey getEmptyKey() { 476 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getEmptyKey(), 477 DenseMapInfo<Selector>::getEmptyKey()); 478 } 479 480 static inline ObjCSummaryKey getTombstoneKey() { 481 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getTombstoneKey(), 482 DenseMapInfo<Selector>::getTombstoneKey()); 483 } 484 485 static unsigned getHashValue(const ObjCSummaryKey &V) { 486 typedef std::pair<IdentifierInfo*, Selector> PairTy; 487 return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(), 488 V.getSelector())); 489 } 490 491 static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) { 492 return LHS.getIdentifier() == RHS.getIdentifier() && 493 LHS.getSelector() == RHS.getSelector(); 494 } 495 496}; 497template <> 498struct isPodLike<ObjCSummaryKey> { static const bool value = true; }; 499} // end llvm namespace 500 501namespace { 502class ObjCSummaryCache { 503 typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy; 504 MapTy M; 505public: 506 ObjCSummaryCache() {} 507 508 const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) { 509 // Do a lookup with the (D,S) pair. If we find a match return 510 // the iterator. 511 ObjCSummaryKey K(D, S); 512 MapTy::iterator I = M.find(K); 513 514 if (I != M.end()) 515 return I->second; 516 if (!D) 517 return NULL; 518 519 // Walk the super chain. If we find a hit with a parent, we'll end 520 // up returning that summary. We actually allow that key (null,S), as 521 // we cache summaries for the null ObjCInterfaceDecl* to allow us to 522 // generate initial summaries without having to worry about NSObject 523 // being declared. 524 // FIXME: We may change this at some point. 525 for (ObjCInterfaceDecl *C=D->getSuperClass() ;; C=C->getSuperClass()) { 526 if ((I = M.find(ObjCSummaryKey(C, S))) != M.end()) 527 break; 528 529 if (!C) 530 return NULL; 531 } 532 533 // Cache the summary with original key to make the next lookup faster 534 // and return the iterator. 535 const RetainSummary *Summ = I->second; 536 M[K] = Summ; 537 return Summ; 538 } 539 540 const RetainSummary *find(IdentifierInfo* II, Selector S) { 541 // FIXME: Class method lookup. Right now we dont' have a good way 542 // of going between IdentifierInfo* and the class hierarchy. 543 MapTy::iterator I = M.find(ObjCSummaryKey(II, S)); 544 545 if (I == M.end()) 546 I = M.find(ObjCSummaryKey(S)); 547 548 return I == M.end() ? NULL : I->second; 549 } 550 551 const RetainSummary *& operator[](ObjCSummaryKey K) { 552 return M[K]; 553 } 554 555 const RetainSummary *& operator[](Selector S) { 556 return M[ ObjCSummaryKey(S) ]; 557 } 558}; 559} // end anonymous namespace 560 561//===----------------------------------------------------------------------===// 562// Data structures for managing collections of summaries. 563//===----------------------------------------------------------------------===// 564 565namespace { 566class RetainSummaryManager { 567 568 //==-----------------------------------------------------------------==// 569 // Typedefs. 570 //==-----------------------------------------------------------------==// 571 572 typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *> 573 FuncSummariesTy; 574 575 typedef ObjCSummaryCache ObjCMethodSummariesTy; 576 577 typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode; 578 579 //==-----------------------------------------------------------------==// 580 // Data. 581 //==-----------------------------------------------------------------==// 582 583 /// Ctx - The ASTContext object for the analyzed ASTs. 584 ASTContext &Ctx; 585 586 /// GCEnabled - Records whether or not the analyzed code runs in GC mode. 587 const bool GCEnabled; 588 589 /// Records whether or not the analyzed code runs in ARC mode. 590 const bool ARCEnabled; 591 592 /// FuncSummaries - A map from FunctionDecls to summaries. 593 FuncSummariesTy FuncSummaries; 594 595 /// ObjCClassMethodSummaries - A map from selectors (for instance methods) 596 /// to summaries. 597 ObjCMethodSummariesTy ObjCClassMethodSummaries; 598 599 /// ObjCMethodSummaries - A map from selectors to summaries. 600 ObjCMethodSummariesTy ObjCMethodSummaries; 601 602 /// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects, 603 /// and all other data used by the checker. 604 llvm::BumpPtrAllocator BPAlloc; 605 606 /// AF - A factory for ArgEffects objects. 607 ArgEffects::Factory AF; 608 609 /// ScratchArgs - A holding buffer for construct ArgEffects. 610 ArgEffects ScratchArgs; 611 612 /// ObjCAllocRetE - Default return effect for methods returning Objective-C 613 /// objects. 614 RetEffect ObjCAllocRetE; 615 616 /// ObjCInitRetE - Default return effect for init methods returning 617 /// Objective-C objects. 618 RetEffect ObjCInitRetE; 619 620 /// SimpleSummaries - Used for uniquing summaries that don't have special 621 /// effects. 622 llvm::FoldingSet<CachedSummaryNode> SimpleSummaries; 623 624 //==-----------------------------------------------------------------==// 625 // Methods. 626 //==-----------------------------------------------------------------==// 627 628 /// getArgEffects - Returns a persistent ArgEffects object based on the 629 /// data in ScratchArgs. 630 ArgEffects getArgEffects(); 631 632 enum UnaryFuncKind { cfretain, cfrelease, cfmakecollectable }; 633 634 const RetainSummary *getUnarySummary(const FunctionType* FT, 635 UnaryFuncKind func); 636 637 const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD); 638 const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD); 639 const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD); 640 641 const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm); 642 643 const RetainSummary *getPersistentSummary(RetEffect RetEff, 644 ArgEffect ReceiverEff = DoNothing, 645 ArgEffect DefaultEff = MayEscape) { 646 RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff); 647 return getPersistentSummary(Summ); 648 } 649 650 const RetainSummary *getDoNothingSummary() { 651 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 652 } 653 654 const RetainSummary *getDefaultSummary() { 655 return getPersistentSummary(RetEffect::MakeNoRet(), 656 DoNothing, MayEscape); 657 } 658 659 const RetainSummary *getPersistentStopSummary() { 660 return getPersistentSummary(RetEffect::MakeNoRet(), 661 StopTracking, StopTracking); 662 } 663 664 void InitializeClassMethodSummaries(); 665 void InitializeMethodSummaries(); 666private: 667 void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) { 668 ObjCClassMethodSummaries[S] = Summ; 669 } 670 671 void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) { 672 ObjCMethodSummaries[S] = Summ; 673 } 674 675 void addClassMethSummary(const char* Cls, const char* name, 676 const RetainSummary *Summ, bool isNullary = true) { 677 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 678 Selector S = isNullary ? GetNullarySelector(name, Ctx) 679 : GetUnarySelector(name, Ctx); 680 ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 681 } 682 683 void addInstMethSummary(const char* Cls, const char* nullaryName, 684 const RetainSummary *Summ) { 685 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 686 Selector S = GetNullarySelector(nullaryName, Ctx); 687 ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 688 } 689 690 Selector generateSelector(va_list argp) { 691 SmallVector<IdentifierInfo*, 10> II; 692 693 while (const char* s = va_arg(argp, const char*)) 694 II.push_back(&Ctx.Idents.get(s)); 695 696 return Ctx.Selectors.getSelector(II.size(), &II[0]); 697 } 698 699 void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy& Summaries, 700 const RetainSummary * Summ, va_list argp) { 701 Selector S = generateSelector(argp); 702 Summaries[ObjCSummaryKey(ClsII, S)] = Summ; 703 } 704 705 void addInstMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 706 va_list argp; 707 va_start(argp, Summ); 708 addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp); 709 va_end(argp); 710 } 711 712 void addClsMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 713 va_list argp; 714 va_start(argp, Summ); 715 addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp); 716 va_end(argp); 717 } 718 719 void addClsMethSummary(IdentifierInfo *II, const RetainSummary * Summ, ...) { 720 va_list argp; 721 va_start(argp, Summ); 722 addMethodSummary(II, ObjCClassMethodSummaries, Summ, argp); 723 va_end(argp); 724 } 725 726public: 727 728 RetainSummaryManager(ASTContext &ctx, bool gcenabled, bool usesARC) 729 : Ctx(ctx), 730 GCEnabled(gcenabled), 731 ARCEnabled(usesARC), 732 AF(BPAlloc), ScratchArgs(AF.getEmptyMap()), 733 ObjCAllocRetE(gcenabled 734 ? RetEffect::MakeGCNotOwned() 735 : (usesARC ? RetEffect::MakeARCNotOwned() 736 : RetEffect::MakeOwned(RetEffect::ObjC, true))), 737 ObjCInitRetE(gcenabled 738 ? RetEffect::MakeGCNotOwned() 739 : (usesARC ? RetEffect::MakeARCNotOwned() 740 : RetEffect::MakeOwnedWhenTrackedReceiver())) { 741 InitializeClassMethodSummaries(); 742 InitializeMethodSummaries(); 743 } 744 745 const RetainSummary *getSummary(const CallEvent &Call, 746 ProgramStateRef State = 0); 747 748 const RetainSummary *getFunctionSummary(const FunctionDecl *FD); 749 750 const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 751 const ObjCMethodDecl *MD, 752 QualType RetTy, 753 ObjCMethodSummariesTy &CachedSummaries); 754 755 const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M, 756 ProgramStateRef State); 757 758 const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) { 759 assert(!M.isInstanceMessage()); 760 const ObjCInterfaceDecl *Class = M.getReceiverInterface(); 761 762 return getMethodSummary(M.getSelector(), Class, M.getDecl(), 763 M.getResultType(), ObjCClassMethodSummaries); 764 } 765 766 /// getMethodSummary - This version of getMethodSummary is used to query 767 /// the summary for the current method being analyzed. 768 const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) { 769 const ObjCInterfaceDecl *ID = MD->getClassInterface(); 770 Selector S = MD->getSelector(); 771 QualType ResultTy = MD->getResultType(); 772 773 ObjCMethodSummariesTy *CachedSummaries; 774 if (MD->isInstanceMethod()) 775 CachedSummaries = &ObjCMethodSummaries; 776 else 777 CachedSummaries = &ObjCClassMethodSummaries; 778 779 return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries); 780 } 781 782 const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD, 783 Selector S, QualType RetTy); 784 785 /// Determine if there is a special return effect for this function or method. 786 Optional<RetEffect> getRetEffectFromAnnotations(QualType RetTy, 787 const Decl *D); 788 789 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 790 const ObjCMethodDecl *MD); 791 792 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 793 const FunctionDecl *FD); 794 795 void updateSummaryForCall(const RetainSummary *&Summ, 796 const CallEvent &Call); 797 798 bool isGCEnabled() const { return GCEnabled; } 799 800 bool isARCEnabled() const { return ARCEnabled; } 801 802 bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; } 803 804 RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; } 805 806 friend class RetainSummaryTemplate; 807}; 808 809// Used to avoid allocating long-term (BPAlloc'd) memory for default retain 810// summaries. If a function or method looks like it has a default summary, but 811// it has annotations, the annotations are added to the stack-based template 812// and then copied into managed memory. 813class RetainSummaryTemplate { 814 RetainSummaryManager &Manager; 815 const RetainSummary *&RealSummary; 816 RetainSummary ScratchSummary; 817 bool Accessed; 818public: 819 RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr) 820 : Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {} 821 822 ~RetainSummaryTemplate() { 823 if (Accessed) 824 RealSummary = Manager.getPersistentSummary(ScratchSummary); 825 } 826 827 RetainSummary &operator*() { 828 Accessed = true; 829 return ScratchSummary; 830 } 831 832 RetainSummary *operator->() { 833 Accessed = true; 834 return &ScratchSummary; 835 } 836}; 837 838} // end anonymous namespace 839 840//===----------------------------------------------------------------------===// 841// Implementation of checker data structures. 842//===----------------------------------------------------------------------===// 843 844ArgEffects RetainSummaryManager::getArgEffects() { 845 ArgEffects AE = ScratchArgs; 846 ScratchArgs = AF.getEmptyMap(); 847 return AE; 848} 849 850const RetainSummary * 851RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) { 852 // Unique "simple" summaries -- those without ArgEffects. 853 if (OldSumm.isSimple()) { 854 llvm::FoldingSetNodeID ID; 855 OldSumm.Profile(ID); 856 857 void *Pos; 858 CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos); 859 860 if (!N) { 861 N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>(); 862 new (N) CachedSummaryNode(OldSumm); 863 SimpleSummaries.InsertNode(N, Pos); 864 } 865 866 return &N->getValue(); 867 } 868 869 RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>(); 870 new (Summ) RetainSummary(OldSumm); 871 return Summ; 872} 873 874//===----------------------------------------------------------------------===// 875// Summary creation for functions (largely uses of Core Foundation). 876//===----------------------------------------------------------------------===// 877 878static bool isRetain(const FunctionDecl *FD, StringRef FName) { 879 return FName.endswith("Retain"); 880} 881 882static bool isRelease(const FunctionDecl *FD, StringRef FName) { 883 return FName.endswith("Release"); 884} 885 886static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) { 887 // FIXME: Remove FunctionDecl parameter. 888 // FIXME: Is it really okay if MakeCollectable isn't a suffix? 889 return FName.find("MakeCollectable") != StringRef::npos; 890} 891 892static ArgEffect getStopTrackingHardEquivalent(ArgEffect E) { 893 switch (E) { 894 case DoNothing: 895 case Autorelease: 896 case DecRefBridgedTransfered: 897 case IncRef: 898 case IncRefMsg: 899 case MakeCollectable: 900 case MayEscape: 901 case StopTracking: 902 case StopTrackingHard: 903 return StopTrackingHard; 904 case DecRef: 905 case DecRefAndStopTrackingHard: 906 return DecRefAndStopTrackingHard; 907 case DecRefMsg: 908 case DecRefMsgAndStopTrackingHard: 909 return DecRefMsgAndStopTrackingHard; 910 case Dealloc: 911 return Dealloc; 912 } 913 914 llvm_unreachable("Unknown ArgEffect kind"); 915} 916 917void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S, 918 const CallEvent &Call) { 919 if (Call.hasNonZeroCallbackArg()) { 920 ArgEffect RecEffect = 921 getStopTrackingHardEquivalent(S->getReceiverEffect()); 922 ArgEffect DefEffect = 923 getStopTrackingHardEquivalent(S->getDefaultArgEffect()); 924 925 ArgEffects CustomArgEffects = S->getArgEffects(); 926 for (ArgEffects::iterator I = CustomArgEffects.begin(), 927 E = CustomArgEffects.end(); 928 I != E; ++I) { 929 ArgEffect Translated = getStopTrackingHardEquivalent(I->second); 930 if (Translated != DefEffect) 931 ScratchArgs = AF.add(ScratchArgs, I->first, Translated); 932 } 933 934 RetEffect RE = RetEffect::MakeNoRetHard(); 935 936 // Special cases where the callback argument CANNOT free the return value. 937 // This can generally only happen if we know that the callback will only be 938 // called when the return value is already being deallocated. 939 if (const FunctionCall *FC = dyn_cast<FunctionCall>(&Call)) { 940 if (IdentifierInfo *Name = FC->getDecl()->getIdentifier()) { 941 // When the CGBitmapContext is deallocated, the callback here will free 942 // the associated data buffer. 943 if (Name->isStr("CGBitmapContextCreateWithData")) 944 RE = S->getRetEffect(); 945 } 946 } 947 948 S = getPersistentSummary(RE, RecEffect, DefEffect); 949 } 950 951 // Special case '[super init];' and '[self init];' 952 // 953 // Even though calling '[super init]' without assigning the result to self 954 // and checking if the parent returns 'nil' is a bad pattern, it is common. 955 // Additionally, our Self Init checker already warns about it. To avoid 956 // overwhelming the user with messages from both checkers, we model the case 957 // of '[super init]' in cases when it is not consumed by another expression 958 // as if the call preserves the value of 'self'; essentially, assuming it can 959 // never fail and return 'nil'. 960 // Note, we don't want to just stop tracking the value since we want the 961 // RetainCount checker to report leaks and use-after-free if SelfInit checker 962 // is turned off. 963 if (const ObjCMethodCall *MC = dyn_cast<ObjCMethodCall>(&Call)) { 964 if (MC->getMethodFamily() == OMF_init && MC->isReceiverSelfOrSuper()) { 965 966 // Check if the message is not consumed, we know it will not be used in 967 // an assignment, ex: "self = [super init]". 968 const Expr *ME = MC->getOriginExpr(); 969 const LocationContext *LCtx = MC->getLocationContext(); 970 ParentMap &PM = LCtx->getAnalysisDeclContext()->getParentMap(); 971 if (!PM.isConsumedExpr(ME)) { 972 RetainSummaryTemplate ModifiableSummaryTemplate(S, *this); 973 ModifiableSummaryTemplate->setReceiverEffect(DoNothing); 974 ModifiableSummaryTemplate->setRetEffect(RetEffect::MakeNoRet()); 975 } 976 } 977 978 } 979} 980 981const RetainSummary * 982RetainSummaryManager::getSummary(const CallEvent &Call, 983 ProgramStateRef State) { 984 const RetainSummary *Summ; 985 switch (Call.getKind()) { 986 case CE_Function: 987 Summ = getFunctionSummary(cast<FunctionCall>(Call).getDecl()); 988 break; 989 case CE_CXXMember: 990 case CE_CXXMemberOperator: 991 case CE_Block: 992 case CE_CXXConstructor: 993 case CE_CXXDestructor: 994 case CE_CXXAllocator: 995 // FIXME: These calls are currently unsupported. 996 return getPersistentStopSummary(); 997 case CE_ObjCMessage: { 998 const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call); 999 if (Msg.isInstanceMessage()) 1000 Summ = getInstanceMethodSummary(Msg, State); 1001 else 1002 Summ = getClassMethodSummary(Msg); 1003 break; 1004 } 1005 } 1006 1007 updateSummaryForCall(Summ, Call); 1008 1009 assert(Summ && "Unknown call type?"); 1010 return Summ; 1011} 1012 1013const RetainSummary * 1014RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) { 1015 // If we don't know what function we're calling, use our default summary. 1016 if (!FD) 1017 return getDefaultSummary(); 1018 1019 // Look up a summary in our cache of FunctionDecls -> Summaries. 1020 FuncSummariesTy::iterator I = FuncSummaries.find(FD); 1021 if (I != FuncSummaries.end()) 1022 return I->second; 1023 1024 // No summary? Generate one. 1025 const RetainSummary *S = 0; 1026 bool AllowAnnotations = true; 1027 1028 do { 1029 // We generate "stop" summaries for implicitly defined functions. 1030 if (FD->isImplicit()) { 1031 S = getPersistentStopSummary(); 1032 break; 1033 } 1034 1035 // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the 1036 // function's type. 1037 const FunctionType* FT = FD->getType()->getAs<FunctionType>(); 1038 const IdentifierInfo *II = FD->getIdentifier(); 1039 if (!II) 1040 break; 1041 1042 StringRef FName = II->getName(); 1043 1044 // Strip away preceding '_'. Doing this here will effect all the checks 1045 // down below. 1046 FName = FName.substr(FName.find_first_not_of('_')); 1047 1048 // Inspect the result type. 1049 QualType RetTy = FT->getResultType(); 1050 1051 // FIXME: This should all be refactored into a chain of "summary lookup" 1052 // filters. 1053 assert(ScratchArgs.isEmpty()); 1054 1055 if (FName == "pthread_create" || FName == "pthread_setspecific") { 1056 // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>. 1057 // This will be addressed better with IPA. 1058 S = getPersistentStopSummary(); 1059 } else if (FName == "NSMakeCollectable") { 1060 // Handle: id NSMakeCollectable(CFTypeRef) 1061 S = (RetTy->isObjCIdType()) 1062 ? getUnarySummary(FT, cfmakecollectable) 1063 : getPersistentStopSummary(); 1064 // The headers on OS X 10.8 use cf_consumed/ns_returns_retained, 1065 // but we can fully model NSMakeCollectable ourselves. 1066 AllowAnnotations = false; 1067 } else if (FName == "CFPlugInInstanceCreate") { 1068 S = getPersistentSummary(RetEffect::MakeNoRet()); 1069 } else if (FName == "IOBSDNameMatching" || 1070 FName == "IOServiceMatching" || 1071 FName == "IOServiceNameMatching" || 1072 FName == "IORegistryEntrySearchCFProperty" || 1073 FName == "IORegistryEntryIDMatching" || 1074 FName == "IOOpenFirmwarePathMatching") { 1075 // Part of <rdar://problem/6961230>. (IOKit) 1076 // This should be addressed using a API table. 1077 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1078 DoNothing, DoNothing); 1079 } else if (FName == "IOServiceGetMatchingService" || 1080 FName == "IOServiceGetMatchingServices") { 1081 // FIXES: <rdar://problem/6326900> 1082 // This should be addressed using a API table. This strcmp is also 1083 // a little gross, but there is no need to super optimize here. 1084 ScratchArgs = AF.add(ScratchArgs, 1, DecRef); 1085 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1086 } else if (FName == "IOServiceAddNotification" || 1087 FName == "IOServiceAddMatchingNotification") { 1088 // Part of <rdar://problem/6961230>. (IOKit) 1089 // This should be addressed using a API table. 1090 ScratchArgs = AF.add(ScratchArgs, 2, DecRef); 1091 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1092 } else if (FName == "CVPixelBufferCreateWithBytes") { 1093 // FIXES: <rdar://problem/7283567> 1094 // Eventually this can be improved by recognizing that the pixel 1095 // buffer passed to CVPixelBufferCreateWithBytes is released via 1096 // a callback and doing full IPA to make sure this is done correctly. 1097 // FIXME: This function has an out parameter that returns an 1098 // allocated object. 1099 ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); 1100 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1101 } else if (FName == "CGBitmapContextCreateWithData") { 1102 // FIXES: <rdar://problem/7358899> 1103 // Eventually this can be improved by recognizing that 'releaseInfo' 1104 // passed to CGBitmapContextCreateWithData is released via 1105 // a callback and doing full IPA to make sure this is done correctly. 1106 ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); 1107 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1108 DoNothing, DoNothing); 1109 } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { 1110 // FIXES: <rdar://problem/7283567> 1111 // Eventually this can be improved by recognizing that the pixel 1112 // buffer passed to CVPixelBufferCreateWithPlanarBytes is released 1113 // via a callback and doing full IPA to make sure this is done 1114 // correctly. 1115 ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); 1116 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1117 } else if (FName == "dispatch_set_context") { 1118 // <rdar://problem/11059275> - The analyzer currently doesn't have 1119 // a good way to reason about the finalizer function for libdispatch. 1120 // If we pass a context object that is memory managed, stop tracking it. 1121 // FIXME: this hack should possibly go away once we can handle 1122 // libdispatch finalizers. 1123 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1124 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1125 } else if (FName.startswith("NSLog")) { 1126 S = getDoNothingSummary(); 1127 } else if (FName.startswith("NS") && 1128 (FName.find("Insert") != StringRef::npos)) { 1129 // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 1130 // be deallocated by NSMapRemove. (radar://11152419) 1131 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1132 ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); 1133 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1134 } 1135 1136 // Did we get a summary? 1137 if (S) 1138 break; 1139 1140 if (RetTy->isPointerType()) { 1141 // For CoreFoundation ('CF') types. 1142 if (cocoa::isRefType(RetTy, "CF", FName)) { 1143 if (isRetain(FD, FName)) 1144 S = getUnarySummary(FT, cfretain); 1145 else if (isMakeCollectable(FD, FName)) 1146 S = getUnarySummary(FT, cfmakecollectable); 1147 else 1148 S = getCFCreateGetRuleSummary(FD); 1149 1150 break; 1151 } 1152 1153 // For CoreGraphics ('CG') types. 1154 if (cocoa::isRefType(RetTy, "CG", FName)) { 1155 if (isRetain(FD, FName)) 1156 S = getUnarySummary(FT, cfretain); 1157 else 1158 S = getCFCreateGetRuleSummary(FD); 1159 1160 break; 1161 } 1162 1163 // For the Disk Arbitration API (DiskArbitration/DADisk.h) 1164 if (cocoa::isRefType(RetTy, "DADisk") || 1165 cocoa::isRefType(RetTy, "DADissenter") || 1166 cocoa::isRefType(RetTy, "DASessionRef")) { 1167 S = getCFCreateGetRuleSummary(FD); 1168 break; 1169 } 1170 1171 if (FD->getAttr<CFAuditedTransferAttr>()) { 1172 S = getCFCreateGetRuleSummary(FD); 1173 break; 1174 } 1175 1176 break; 1177 } 1178 1179 // Check for release functions, the only kind of functions that we care 1180 // about that don't return a pointer type. 1181 if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { 1182 // Test for 'CGCF'. 1183 FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); 1184 1185 if (isRelease(FD, FName)) 1186 S = getUnarySummary(FT, cfrelease); 1187 else { 1188 assert (ScratchArgs.isEmpty()); 1189 // Remaining CoreFoundation and CoreGraphics functions. 1190 // We use to assume that they all strictly followed the ownership idiom 1191 // and that ownership cannot be transferred. While this is technically 1192 // correct, many methods allow a tracked object to escape. For example: 1193 // 1194 // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); 1195 // CFDictionaryAddValue(y, key, x); 1196 // CFRelease(x); 1197 // ... it is okay to use 'x' since 'y' has a reference to it 1198 // 1199 // We handle this and similar cases with the follow heuristic. If the 1200 // function name contains "InsertValue", "SetValue", "AddValue", 1201 // "AppendValue", or "SetAttribute", then we assume that arguments may 1202 // "escape." This means that something else holds on to the object, 1203 // allowing it be used even after its local retain count drops to 0. 1204 ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| 1205 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 1206 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 1207 StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| 1208 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) 1209 ? MayEscape : DoNothing; 1210 1211 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); 1212 } 1213 } 1214 } 1215 while (0); 1216 1217 // If we got all the way here without any luck, use a default summary. 1218 if (!S) 1219 S = getDefaultSummary(); 1220 1221 // Annotations override defaults. 1222 if (AllowAnnotations) 1223 updateSummaryFromAnnotations(S, FD); 1224 1225 FuncSummaries[FD] = S; 1226 return S; 1227} 1228 1229const RetainSummary * 1230RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { 1231 if (coreFoundation::followsCreateRule(FD)) 1232 return getCFSummaryCreateRule(FD); 1233 1234 return getCFSummaryGetRule(FD); 1235} 1236 1237const RetainSummary * 1238RetainSummaryManager::getUnarySummary(const FunctionType* FT, 1239 UnaryFuncKind func) { 1240 1241 // Sanity check that this is *really* a unary function. This can 1242 // happen if people do weird things. 1243 const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); 1244 if (!FTP || FTP->getNumArgs() != 1) 1245 return getPersistentStopSummary(); 1246 1247 assert (ScratchArgs.isEmpty()); 1248 1249 ArgEffect Effect; 1250 switch (func) { 1251 case cfretain: Effect = IncRef; break; 1252 case cfrelease: Effect = DecRef; break; 1253 case cfmakecollectable: Effect = MakeCollectable; break; 1254 } 1255 1256 ScratchArgs = AF.add(ScratchArgs, 0, Effect); 1257 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1258} 1259 1260const RetainSummary * 1261RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { 1262 assert (ScratchArgs.isEmpty()); 1263 1264 return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1265} 1266 1267const RetainSummary * 1268RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { 1269 assert (ScratchArgs.isEmpty()); 1270 return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), 1271 DoNothing, DoNothing); 1272} 1273 1274//===----------------------------------------------------------------------===// 1275// Summary creation for Selectors. 1276//===----------------------------------------------------------------------===// 1277 1278Optional<RetEffect> 1279RetainSummaryManager::getRetEffectFromAnnotations(QualType RetTy, 1280 const Decl *D) { 1281 if (cocoa::isCocoaObjectRef(RetTy)) { 1282 if (D->getAttr<NSReturnsRetainedAttr>()) 1283 return ObjCAllocRetE; 1284 1285 if (D->getAttr<NSReturnsNotRetainedAttr>() || 1286 D->getAttr<NSReturnsAutoreleasedAttr>()) 1287 return RetEffect::MakeNotOwned(RetEffect::ObjC); 1288 1289 } else if (!RetTy->isPointerType()) { 1290 return None; 1291 } 1292 1293 if (D->getAttr<CFReturnsRetainedAttr>()) 1294 return RetEffect::MakeOwned(RetEffect::CF, true); 1295 1296 if (D->getAttr<CFReturnsNotRetainedAttr>()) 1297 return RetEffect::MakeNotOwned(RetEffect::CF); 1298 1299 return None; 1300} 1301 1302void 1303RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1304 const FunctionDecl *FD) { 1305 if (!FD) 1306 return; 1307 1308 assert(Summ && "Must have a summary to add annotations to."); 1309 RetainSummaryTemplate Template(Summ, *this); 1310 1311 // Effects on the parameters. 1312 unsigned parm_idx = 0; 1313 for (FunctionDecl::param_const_iterator pi = FD->param_begin(), 1314 pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { 1315 const ParmVarDecl *pd = *pi; 1316 if (pd->getAttr<NSConsumedAttr>()) 1317 Template->addArg(AF, parm_idx, DecRefMsg); 1318 else if (pd->getAttr<CFConsumedAttr>()) 1319 Template->addArg(AF, parm_idx, DecRef); 1320 } 1321 1322 QualType RetTy = FD->getResultType(); 1323 if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, FD)) 1324 Template->setRetEffect(*RetE); 1325} 1326 1327void 1328RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1329 const ObjCMethodDecl *MD) { 1330 if (!MD) 1331 return; 1332 1333 assert(Summ && "Must have a valid summary to add annotations to"); 1334 RetainSummaryTemplate Template(Summ, *this); 1335 1336 // Effects on the receiver. 1337 if (MD->getAttr<NSConsumesSelfAttr>()) 1338 Template->setReceiverEffect(DecRefMsg); 1339 1340 // Effects on the parameters. 1341 unsigned parm_idx = 0; 1342 for (ObjCMethodDecl::param_const_iterator 1343 pi=MD->param_begin(), pe=MD->param_end(); 1344 pi != pe; ++pi, ++parm_idx) { 1345 const ParmVarDecl *pd = *pi; 1346 if (pd->getAttr<NSConsumedAttr>()) 1347 Template->addArg(AF, parm_idx, DecRefMsg); 1348 else if (pd->getAttr<CFConsumedAttr>()) { 1349 Template->addArg(AF, parm_idx, DecRef); 1350 } 1351 } 1352 1353 QualType RetTy = MD->getResultType(); 1354 if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, MD)) 1355 Template->setRetEffect(*RetE); 1356} 1357 1358const RetainSummary * 1359RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, 1360 Selector S, QualType RetTy) { 1361 // Any special effects? 1362 ArgEffect ReceiverEff = DoNothing; 1363 RetEffect ResultEff = RetEffect::MakeNoRet(); 1364 1365 // Check the method family, and apply any default annotations. 1366 switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { 1367 case OMF_None: 1368 case OMF_performSelector: 1369 // Assume all Objective-C methods follow Cocoa Memory Management rules. 1370 // FIXME: Does the non-threaded performSelector family really belong here? 1371 // The selector could be, say, @selector(copy). 1372 if (cocoa::isCocoaObjectRef(RetTy)) 1373 ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); 1374 else if (coreFoundation::isCFObjectRef(RetTy)) { 1375 // ObjCMethodDecl currently doesn't consider CF objects as valid return 1376 // values for alloc, new, copy, or mutableCopy, so we have to 1377 // double-check with the selector. This is ugly, but there aren't that 1378 // many Objective-C methods that return CF objects, right? 1379 if (MD) { 1380 switch (S.getMethodFamily()) { 1381 case OMF_alloc: 1382 case OMF_new: 1383 case OMF_copy: 1384 case OMF_mutableCopy: 1385 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1386 break; 1387 default: 1388 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1389 break; 1390 } 1391 } else { 1392 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1393 } 1394 } 1395 break; 1396 case OMF_init: 1397 ResultEff = ObjCInitRetE; 1398 ReceiverEff = DecRefMsg; 1399 break; 1400 case OMF_alloc: 1401 case OMF_new: 1402 case OMF_copy: 1403 case OMF_mutableCopy: 1404 if (cocoa::isCocoaObjectRef(RetTy)) 1405 ResultEff = ObjCAllocRetE; 1406 else if (coreFoundation::isCFObjectRef(RetTy)) 1407 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1408 break; 1409 case OMF_autorelease: 1410 ReceiverEff = Autorelease; 1411 break; 1412 case OMF_retain: 1413 ReceiverEff = IncRefMsg; 1414 break; 1415 case OMF_release: 1416 ReceiverEff = DecRefMsg; 1417 break; 1418 case OMF_dealloc: 1419 ReceiverEff = Dealloc; 1420 break; 1421 case OMF_self: 1422 // -self is handled specially by the ExprEngine to propagate the receiver. 1423 break; 1424 case OMF_retainCount: 1425 case OMF_finalize: 1426 // These methods don't return objects. 1427 break; 1428 } 1429 1430 // If one of the arguments in the selector has the keyword 'delegate' we 1431 // should stop tracking the reference count for the receiver. This is 1432 // because the reference count is quite possibly handled by a delegate 1433 // method. 1434 if (S.isKeywordSelector()) { 1435 for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { 1436 StringRef Slot = S.getNameForSlot(i); 1437 if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { 1438 if (ResultEff == ObjCInitRetE) 1439 ResultEff = RetEffect::MakeNoRetHard(); 1440 else 1441 ReceiverEff = StopTrackingHard; 1442 } 1443 } 1444 } 1445 1446 if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && 1447 ResultEff.getKind() == RetEffect::NoRet) 1448 return getDefaultSummary(); 1449 1450 return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); 1451} 1452 1453const RetainSummary * 1454RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, 1455 ProgramStateRef State) { 1456 const ObjCInterfaceDecl *ReceiverClass = 0; 1457 1458 // We do better tracking of the type of the object than the core ExprEngine. 1459 // See if we have its type in our private state. 1460 // FIXME: Eventually replace the use of state->get<RefBindings> with 1461 // a generic API for reasoning about the Objective-C types of symbolic 1462 // objects. 1463 SVal ReceiverV = Msg.getReceiverSVal(); 1464 if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) 1465 if (const RefVal *T = getRefBinding(State, Sym)) 1466 if (const ObjCObjectPointerType *PT = 1467 T->getType()->getAs<ObjCObjectPointerType>()) 1468 ReceiverClass = PT->getInterfaceDecl(); 1469 1470 // If we don't know what kind of object this is, fall back to its static type. 1471 if (!ReceiverClass) 1472 ReceiverClass = Msg.getReceiverInterface(); 1473 1474 // FIXME: The receiver could be a reference to a class, meaning that 1475 // we should use the class method. 1476 // id x = [NSObject class]; 1477 // [x performSelector:... withObject:... afterDelay:...]; 1478 Selector S = Msg.getSelector(); 1479 const ObjCMethodDecl *Method = Msg.getDecl(); 1480 if (!Method && ReceiverClass) 1481 Method = ReceiverClass->getInstanceMethod(S); 1482 1483 return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), 1484 ObjCMethodSummaries); 1485} 1486 1487const RetainSummary * 1488RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 1489 const ObjCMethodDecl *MD, QualType RetTy, 1490 ObjCMethodSummariesTy &CachedSummaries) { 1491 1492 // Look up a summary in our summary cache. 1493 const RetainSummary *Summ = CachedSummaries.find(ID, S); 1494 1495 if (!Summ) { 1496 Summ = getStandardMethodSummary(MD, S, RetTy); 1497 1498 // Annotations override defaults. 1499 updateSummaryFromAnnotations(Summ, MD); 1500 1501 // Memoize the summary. 1502 CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; 1503 } 1504 1505 return Summ; 1506} 1507 1508void RetainSummaryManager::InitializeClassMethodSummaries() { 1509 assert(ScratchArgs.isEmpty()); 1510 // Create the [NSAssertionHandler currentHander] summary. 1511 addClassMethSummary("NSAssertionHandler", "currentHandler", 1512 getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); 1513 1514 // Create the [NSAutoreleasePool addObject:] summary. 1515 ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); 1516 addClassMethSummary("NSAutoreleasePool", "addObject", 1517 getPersistentSummary(RetEffect::MakeNoRet(), 1518 DoNothing, Autorelease)); 1519} 1520 1521void RetainSummaryManager::InitializeMethodSummaries() { 1522 1523 assert (ScratchArgs.isEmpty()); 1524 1525 // Create the "init" selector. It just acts as a pass-through for the 1526 // receiver. 1527 const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); 1528 addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); 1529 1530 // awakeAfterUsingCoder: behaves basically like an 'init' method. It 1531 // claims the receiver and returns a retained object. 1532 addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), 1533 InitSumm); 1534 1535 // The next methods are allocators. 1536 const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); 1537 const RetainSummary *CFAllocSumm = 1538 getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1539 1540 // Create the "retain" selector. 1541 RetEffect NoRet = RetEffect::MakeNoRet(); 1542 const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); 1543 addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); 1544 1545 // Create the "release" selector. 1546 Summ = getPersistentSummary(NoRet, DecRefMsg); 1547 addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); 1548 1549 // Create the -dealloc summary. 1550 Summ = getPersistentSummary(NoRet, Dealloc); 1551 addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); 1552 1553 // Create the "autorelease" selector. 1554 Summ = getPersistentSummary(NoRet, Autorelease); 1555 addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); 1556 1557 // For NSWindow, allocated objects are (initially) self-owned. 1558 // FIXME: For now we opt for false negatives with NSWindow, as these objects 1559 // self-own themselves. However, they only do this once they are displayed. 1560 // Thus, we need to track an NSWindow's display status. 1561 // This is tracked in <rdar://problem/6062711>. 1562 // See also http://llvm.org/bugs/show_bug.cgi?id=3714. 1563 const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), 1564 StopTracking, 1565 StopTracking); 1566 1567 addClassMethSummary("NSWindow", "alloc", NoTrackYet); 1568 1569 // For NSPanel (which subclasses NSWindow), allocated objects are not 1570 // self-owned. 1571 // FIXME: For now we don't track NSPanels. object for the same reason 1572 // as for NSWindow objects. 1573 addClassMethSummary("NSPanel", "alloc", NoTrackYet); 1574 1575 // Don't track allocated autorelease pools, as it is okay to prematurely 1576 // exit a method. 1577 addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); 1578 addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); 1579 addClassMethSummary("NSAutoreleasePool", "new", NoTrackYet); 1580 1581 // Create summaries QCRenderer/QCView -createSnapShotImageOfType: 1582 addInstMethSummary("QCRenderer", AllocSumm, 1583 "createSnapshotImageOfType", NULL); 1584 addInstMethSummary("QCView", AllocSumm, 1585 "createSnapshotImageOfType", NULL); 1586 1587 // Create summaries for CIContext, 'createCGImage' and 1588 // 'createCGLayerWithSize'. These objects are CF objects, and are not 1589 // automatically garbage collected. 1590 addInstMethSummary("CIContext", CFAllocSumm, 1591 "createCGImage", "fromRect", NULL); 1592 addInstMethSummary("CIContext", CFAllocSumm, 1593 "createCGImage", "fromRect", "format", "colorSpace", NULL); 1594 addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", 1595 "info", NULL); 1596} 1597 1598//===----------------------------------------------------------------------===// 1599// Error reporting. 1600//===----------------------------------------------------------------------===// 1601namespace { 1602 typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> 1603 SummaryLogTy; 1604 1605 //===-------------===// 1606 // Bug Descriptions. // 1607 //===-------------===// 1608 1609 class CFRefBug : public BugType { 1610 protected: 1611 CFRefBug(StringRef name) 1612 : BugType(name, categories::MemoryCoreFoundationObjectiveC) {} 1613 public: 1614 1615 // FIXME: Eventually remove. 1616 virtual const char *getDescription() const = 0; 1617 1618 virtual bool isLeak() const { return false; } 1619 }; 1620 1621 class UseAfterRelease : public CFRefBug { 1622 public: 1623 UseAfterRelease() : CFRefBug("Use-after-release") {} 1624 1625 const char *getDescription() const { 1626 return "Reference-counted object is used after it is released"; 1627 } 1628 }; 1629 1630 class BadRelease : public CFRefBug { 1631 public: 1632 BadRelease() : CFRefBug("Bad release") {} 1633 1634 const char *getDescription() const { 1635 return "Incorrect decrement of the reference count of an object that is " 1636 "not owned at this point by the caller"; 1637 } 1638 }; 1639 1640 class DeallocGC : public CFRefBug { 1641 public: 1642 DeallocGC() 1643 : CFRefBug("-dealloc called while using garbage collection") {} 1644 1645 const char *getDescription() const { 1646 return "-dealloc called while using garbage collection"; 1647 } 1648 }; 1649 1650 class DeallocNotOwned : public CFRefBug { 1651 public: 1652 DeallocNotOwned() 1653 : CFRefBug("-dealloc sent to non-exclusively owned object") {} 1654 1655 const char *getDescription() const { 1656 return "-dealloc sent to object that may be referenced elsewhere"; 1657 } 1658 }; 1659 1660 class OverAutorelease : public CFRefBug { 1661 public: 1662 OverAutorelease() 1663 : CFRefBug("Object sent -autorelease too many times") {} 1664 1665 const char *getDescription() const { 1666 return "Object sent -autorelease too many times"; 1667 } 1668 }; 1669 1670 class ReturnedNotOwnedForOwned : public CFRefBug { 1671 public: 1672 ReturnedNotOwnedForOwned() 1673 : CFRefBug("Method should return an owned object") {} 1674 1675 const char *getDescription() const { 1676 return "Object with a +0 retain count returned to caller where a +1 " 1677 "(owning) retain count is expected"; 1678 } 1679 }; 1680 1681 class Leak : public CFRefBug { 1682 public: 1683 Leak(StringRef name) 1684 : CFRefBug(name) { 1685 // Leaks should not be reported if they are post-dominated by a sink. 1686 setSuppressOnSink(true); 1687 } 1688 1689 const char *getDescription() const { return ""; } 1690 1691 bool isLeak() const { return true; } 1692 }; 1693 1694 //===---------===// 1695 // Bug Reports. // 1696 //===---------===// 1697 1698 class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> { 1699 protected: 1700 SymbolRef Sym; 1701 const SummaryLogTy &SummaryLog; 1702 bool GCEnabled; 1703 1704 public: 1705 CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) 1706 : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} 1707 1708 virtual void Profile(llvm::FoldingSetNodeID &ID) const { 1709 static int x = 0; 1710 ID.AddPointer(&x); 1711 ID.AddPointer(Sym); 1712 } 1713 1714 virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N, 1715 const ExplodedNode *PrevN, 1716 BugReporterContext &BRC, 1717 BugReport &BR); 1718 1719 virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1720 const ExplodedNode *N, 1721 BugReport &BR); 1722 }; 1723 1724 class CFRefLeakReportVisitor : public CFRefReportVisitor { 1725 public: 1726 CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, 1727 const SummaryLogTy &log) 1728 : CFRefReportVisitor(sym, GCEnabled, log) {} 1729 1730 PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1731 const ExplodedNode *N, 1732 BugReport &BR); 1733 1734 virtual BugReporterVisitor *clone() const { 1735 // The curiously-recurring template pattern only works for one level of 1736 // subclassing. Rather than make a new template base for 1737 // CFRefReportVisitor, we simply override clone() to do the right thing. 1738 // This could be trouble someday if BugReporterVisitorImpl is ever 1739 // used for something else besides a convenient implementation of clone(). 1740 return new CFRefLeakReportVisitor(*this); 1741 } 1742 }; 1743 1744 class CFRefReport : public BugReport { 1745 void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); 1746 1747 public: 1748 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1749 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1750 bool registerVisitor = true) 1751 : BugReport(D, D.getDescription(), n) { 1752 if (registerVisitor) 1753 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1754 addGCModeDescription(LOpts, GCEnabled); 1755 } 1756 1757 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1758 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1759 StringRef endText) 1760 : BugReport(D, D.getDescription(), endText, n) { 1761 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1762 addGCModeDescription(LOpts, GCEnabled); 1763 } 1764 1765 virtual std::pair<ranges_iterator, ranges_iterator> getRanges() { 1766 const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); 1767 if (!BugTy.isLeak()) 1768 return BugReport::getRanges(); 1769 else 1770 return std::make_pair(ranges_iterator(), ranges_iterator()); 1771 } 1772 }; 1773 1774 class CFRefLeakReport : public CFRefReport { 1775 const MemRegion* AllocBinding; 1776 1777 public: 1778 CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1779 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1780 CheckerContext &Ctx); 1781 1782 PathDiagnosticLocation getLocation(const SourceManager &SM) const { 1783 assert(Location.isValid()); 1784 return Location; 1785 } 1786 }; 1787} // end anonymous namespace 1788 1789void CFRefReport::addGCModeDescription(const LangOptions &LOpts, 1790 bool GCEnabled) { 1791 const char *GCModeDescription = 0; 1792 1793 switch (LOpts.getGC()) { 1794 case LangOptions::GCOnly: 1795 assert(GCEnabled); 1796 GCModeDescription = "Code is compiled to only use garbage collection"; 1797 break; 1798 1799 case LangOptions::NonGC: 1800 assert(!GCEnabled); 1801 GCModeDescription = "Code is compiled to use reference counts"; 1802 break; 1803 1804 case LangOptions::HybridGC: 1805 if (GCEnabled) { 1806 GCModeDescription = "Code is compiled to use either garbage collection " 1807 "(GC) or reference counts (non-GC). The bug occurs " 1808 "with GC enabled"; 1809 break; 1810 } else { 1811 GCModeDescription = "Code is compiled to use either garbage collection " 1812 "(GC) or reference counts (non-GC). The bug occurs " 1813 "in non-GC mode"; 1814 break; 1815 } 1816 } 1817 1818 assert(GCModeDescription && "invalid/unknown GC mode"); 1819 addExtraText(GCModeDescription); 1820} 1821 1822// FIXME: This should be a method on SmallVector. 1823static inline bool contains(const SmallVectorImpl<ArgEffect>& V, 1824 ArgEffect X) { 1825 for (SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end(); 1826 I!=E; ++I) 1827 if (*I == X) return true; 1828 1829 return false; 1830} 1831 1832static bool isNumericLiteralExpression(const Expr *E) { 1833 // FIXME: This set of cases was copied from SemaExprObjC. 1834 return isa<IntegerLiteral>(E) || 1835 isa<CharacterLiteral>(E) || 1836 isa<FloatingLiteral>(E) || 1837 isa<ObjCBoolLiteralExpr>(E) || 1838 isa<CXXBoolLiteralExpr>(E); 1839} 1840 1841PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N, 1842 const ExplodedNode *PrevN, 1843 BugReporterContext &BRC, 1844 BugReport &BR) { 1845 // FIXME: We will eventually need to handle non-statement-based events 1846 // (__attribute__((cleanup))). 1847 if (!N->getLocation().getAs<StmtPoint>()) 1848 return NULL; 1849 1850 // Check if the type state has changed. 1851 ProgramStateRef PrevSt = PrevN->getState(); 1852 ProgramStateRef CurrSt = N->getState(); 1853 const LocationContext *LCtx = N->getLocationContext(); 1854 1855 const RefVal* CurrT = getRefBinding(CurrSt, Sym); 1856 if (!CurrT) return NULL; 1857 1858 const RefVal &CurrV = *CurrT; 1859 const RefVal *PrevT = getRefBinding(PrevSt, Sym); 1860 1861 // Create a string buffer to constain all the useful things we want 1862 // to tell the user. 1863 std::string sbuf; 1864 llvm::raw_string_ostream os(sbuf); 1865 1866 // This is the allocation site since the previous node had no bindings 1867 // for this symbol. 1868 if (!PrevT) { 1869 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 1870 1871 if (isa<ObjCArrayLiteral>(S)) { 1872 os << "NSArray literal is an object with a +0 retain count"; 1873 } 1874 else if (isa<ObjCDictionaryLiteral>(S)) { 1875 os << "NSDictionary literal is an object with a +0 retain count"; 1876 } 1877 else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { 1878 if (isNumericLiteralExpression(BL->getSubExpr())) 1879 os << "NSNumber literal is an object with a +0 retain count"; 1880 else { 1881 const ObjCInterfaceDecl *BoxClass = 0; 1882 if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) 1883 BoxClass = Method->getClassInterface(); 1884 1885 // We should always be able to find the boxing class interface, 1886 // but consider this future-proofing. 1887 if (BoxClass) 1888 os << *BoxClass << " b"; 1889 else 1890 os << "B"; 1891 1892 os << "oxed expression produces an object with a +0 retain count"; 1893 } 1894 } 1895 else { 1896 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1897 // Get the name of the callee (if it is available). 1898 SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); 1899 if (const FunctionDecl *FD = X.getAsFunctionDecl()) 1900 os << "Call to function '" << *FD << '\''; 1901 else 1902 os << "function call"; 1903 } 1904 else { 1905 assert(isa<ObjCMessageExpr>(S)); 1906 CallEventManager &Mgr = CurrSt->getStateManager().getCallEventManager(); 1907 CallEventRef<ObjCMethodCall> Call 1908 = Mgr.getObjCMethodCall(cast<ObjCMessageExpr>(S), CurrSt, LCtx); 1909 1910 switch (Call->getMessageKind()) { 1911 case OCM_Message: 1912 os << "Method"; 1913 break; 1914 case OCM_PropertyAccess: 1915 os << "Property"; 1916 break; 1917 case OCM_Subscript: 1918 os << "Subscript"; 1919 break; 1920 } 1921 } 1922 1923 if (CurrV.getObjKind() == RetEffect::CF) { 1924 os << " returns a Core Foundation object with a "; 1925 } 1926 else { 1927 assert (CurrV.getObjKind() == RetEffect::ObjC); 1928 os << " returns an Objective-C object with a "; 1929 } 1930 1931 if (CurrV.isOwned()) { 1932 os << "+1 retain count"; 1933 1934 if (GCEnabled) { 1935 assert(CurrV.getObjKind() == RetEffect::CF); 1936 os << ". " 1937 "Core Foundation objects are not automatically garbage collected."; 1938 } 1939 } 1940 else { 1941 assert (CurrV.isNotOwned()); 1942 os << "+0 retain count"; 1943 } 1944 } 1945 1946 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 1947 N->getLocationContext()); 1948 return new PathDiagnosticEventPiece(Pos, os.str()); 1949 } 1950 1951 // Gather up the effects that were performed on the object at this 1952 // program point 1953 SmallVector<ArgEffect, 2> AEffects; 1954 1955 const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); 1956 if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { 1957 // We only have summaries attached to nodes after evaluating CallExpr and 1958 // ObjCMessageExprs. 1959 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 1960 1961 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1962 // Iterate through the parameter expressions and see if the symbol 1963 // was ever passed as an argument. 1964 unsigned i = 0; 1965 1966 for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); 1967 AI!=AE; ++AI, ++i) { 1968 1969 // Retrieve the value of the argument. Is it the symbol 1970 // we are interested in? 1971 if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) 1972 continue; 1973 1974 // We have an argument. Get the effect! 1975 AEffects.push_back(Summ->getArg(i)); 1976 } 1977 } 1978 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { 1979 if (const Expr *receiver = ME->getInstanceReceiver()) 1980 if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) 1981 .getAsLocSymbol() == Sym) { 1982 // The symbol we are tracking is the receiver. 1983 AEffects.push_back(Summ->getReceiverEffect()); 1984 } 1985 } 1986 } 1987 1988 do { 1989 // Get the previous type state. 1990 RefVal PrevV = *PrevT; 1991 1992 // Specially handle -dealloc. 1993 if (!GCEnabled && contains(AEffects, Dealloc)) { 1994 // Determine if the object's reference count was pushed to zero. 1995 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 1996 // We may not have transitioned to 'release' if we hit an error. 1997 // This case is handled elsewhere. 1998 if (CurrV.getKind() == RefVal::Released) { 1999 assert(CurrV.getCombinedCounts() == 0); 2000 os << "Object released by directly sending the '-dealloc' message"; 2001 break; 2002 } 2003 } 2004 2005 // Specially handle CFMakeCollectable and friends. 2006 if (contains(AEffects, MakeCollectable)) { 2007 // Get the name of the function. 2008 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 2009 SVal X = 2010 CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); 2011 const FunctionDecl *FD = X.getAsFunctionDecl(); 2012 2013 if (GCEnabled) { 2014 // Determine if the object's reference count was pushed to zero. 2015 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2016 2017 os << "In GC mode a call to '" << *FD 2018 << "' decrements an object's retain count and registers the " 2019 "object with the garbage collector. "; 2020 2021 if (CurrV.getKind() == RefVal::Released) { 2022 assert(CurrV.getCount() == 0); 2023 os << "Since it now has a 0 retain count the object can be " 2024 "automatically collected by the garbage collector."; 2025 } 2026 else 2027 os << "An object must have a 0 retain count to be garbage collected. " 2028 "After this call its retain count is +" << CurrV.getCount() 2029 << '.'; 2030 } 2031 else 2032 os << "When GC is not enabled a call to '" << *FD 2033 << "' has no effect on its argument."; 2034 2035 // Nothing more to say. 2036 break; 2037 } 2038 2039 // Determine if the typestate has changed. 2040 if (!(PrevV == CurrV)) 2041 switch (CurrV.getKind()) { 2042 case RefVal::Owned: 2043 case RefVal::NotOwned: 2044 2045 if (PrevV.getCount() == CurrV.getCount()) { 2046 // Did an autorelease message get sent? 2047 if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) 2048 return 0; 2049 2050 assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); 2051 os << "Object sent -autorelease message"; 2052 break; 2053 } 2054 2055 if (PrevV.getCount() > CurrV.getCount()) 2056 os << "Reference count decremented."; 2057 else 2058 os << "Reference count incremented."; 2059 2060 if (unsigned Count = CurrV.getCount()) 2061 os << " The object now has a +" << Count << " retain count."; 2062 2063 if (PrevV.getKind() == RefVal::Released) { 2064 assert(GCEnabled && CurrV.getCount() > 0); 2065 os << " The object is not eligible for garbage collection until " 2066 "the retain count reaches 0 again."; 2067 } 2068 2069 break; 2070 2071 case RefVal::Released: 2072 os << "Object released."; 2073 break; 2074 2075 case RefVal::ReturnedOwned: 2076 // Autoreleases can be applied after marking a node ReturnedOwned. 2077 if (CurrV.getAutoreleaseCount()) 2078 return NULL; 2079 2080 os << "Object returned to caller as an owning reference (single " 2081 "retain count transferred to caller)"; 2082 break; 2083 2084 case RefVal::ReturnedNotOwned: 2085 os << "Object returned to caller with a +0 retain count"; 2086 break; 2087 2088 default: 2089 return NULL; 2090 } 2091 2092 // Emit any remaining diagnostics for the argument effects (if any). 2093 for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), 2094 E=AEffects.end(); I != E; ++I) { 2095 2096 // A bunch of things have alternate behavior under GC. 2097 if (GCEnabled) 2098 switch (*I) { 2099 default: break; 2100 case Autorelease: 2101 os << "In GC mode an 'autorelease' has no effect."; 2102 continue; 2103 case IncRefMsg: 2104 os << "In GC mode the 'retain' message has no effect."; 2105 continue; 2106 case DecRefMsg: 2107 os << "In GC mode the 'release' message has no effect."; 2108 continue; 2109 } 2110 } 2111 } while (0); 2112 2113 if (os.str().empty()) 2114 return 0; // We have nothing to say! 2115 2116 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 2117 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2118 N->getLocationContext()); 2119 PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str()); 2120 2121 // Add the range by scanning the children of the statement for any bindings 2122 // to Sym. 2123 for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); 2124 I!=E; ++I) 2125 if (const Expr *Exp = dyn_cast_or_null<Expr>(*I)) 2126 if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { 2127 P->addRange(Exp->getSourceRange()); 2128 break; 2129 } 2130 2131 return P; 2132} 2133 2134// Find the first node in the current function context that referred to the 2135// tracked symbol and the memory location that value was stored to. Note, the 2136// value is only reported if the allocation occurred in the same function as 2137// the leak. The function can also return a location context, which should be 2138// treated as interesting. 2139struct AllocationInfo { 2140 const ExplodedNode* N; 2141 const MemRegion* R; 2142 const LocationContext *InterestingMethodContext; 2143 AllocationInfo(const ExplodedNode* InN, 2144 const MemRegion* InR, 2145 const LocationContext *InInterestingMethodContext) : 2146 N(InN), R(InR), InterestingMethodContext(InInterestingMethodContext) {} 2147}; 2148 2149static AllocationInfo 2150GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, 2151 SymbolRef Sym) { 2152 const ExplodedNode *AllocationNode = N; 2153 const ExplodedNode *AllocationNodeInCurrentContext = N; 2154 const MemRegion* FirstBinding = 0; 2155 const LocationContext *LeakContext = N->getLocationContext(); 2156 2157 // The location context of the init method called on the leaked object, if 2158 // available. 2159 const LocationContext *InitMethodContext = 0; 2160 2161 while (N) { 2162 ProgramStateRef St = N->getState(); 2163 const LocationContext *NContext = N->getLocationContext(); 2164 2165 if (!getRefBinding(St, Sym)) 2166 break; 2167 2168 StoreManager::FindUniqueBinding FB(Sym); 2169 StateMgr.iterBindings(St, FB); 2170 2171 if (FB) { 2172 const MemRegion *R = FB.getRegion(); 2173 const VarRegion *VR = R->getAs<VarRegion>(); 2174 // Do not show local variables belonging to a function other than 2175 // where the error is reported. 2176 if (!VR || VR->getStackFrame() == LeakContext->getCurrentStackFrame()) 2177 FirstBinding = R; 2178 } 2179 2180 // AllocationNode is the last node in which the symbol was tracked. 2181 AllocationNode = N; 2182 2183 // AllocationNodeInCurrentContext, is the last node in the current context 2184 // in which the symbol was tracked. 2185 if (NContext == LeakContext) 2186 AllocationNodeInCurrentContext = N; 2187 2188 // If init was called on the given symbol, store the init method's location 2189 // context. 2190 if (Optional<CallEnter> CEP = N->getLocation().getAs<CallEnter>()) { 2191 const Stmt *CE = CEP->getCallExpr(); 2192 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(CE)) { 2193 SVal RecVal = St->getSVal(ME->getInstanceReceiver(), NContext); 2194 if (RecVal.getAsSymbol() == Sym && ME->getMethodFamily() == OMF_init) 2195 InitMethodContext = CEP->getCalleeContext(); 2196 } 2197 } 2198 2199 N = N->pred_empty() ? NULL : *(N->pred_begin()); 2200 } 2201 2202 // If we are reporting a leak of the object that was allocated with alloc, 2203 // mark it's init method as interesting. 2204 const LocationContext *InterestingMethodContext = 0; 2205 if (InitMethodContext) { 2206 const ProgramPoint AllocPP = AllocationNode->getLocation(); 2207 if (Optional<StmtPoint> SP = AllocPP.getAs<StmtPoint>()) 2208 if (const ObjCMessageExpr *ME = SP->getStmtAs<ObjCMessageExpr>()) 2209 if (ME->getMethodFamily() == OMF_alloc) 2210 InterestingMethodContext = InitMethodContext; 2211 } 2212 2213 // If allocation happened in a function different from the leak node context, 2214 // do not report the binding. 2215 assert(N && "Could not find allocation node"); 2216 if (N->getLocationContext() != LeakContext) { 2217 FirstBinding = 0; 2218 } 2219 2220 return AllocationInfo(AllocationNodeInCurrentContext, 2221 FirstBinding, 2222 InterestingMethodContext); 2223} 2224 2225PathDiagnosticPiece* 2226CFRefReportVisitor::getEndPath(BugReporterContext &BRC, 2227 const ExplodedNode *EndN, 2228 BugReport &BR) { 2229 BR.markInteresting(Sym); 2230 return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); 2231} 2232 2233PathDiagnosticPiece* 2234CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, 2235 const ExplodedNode *EndN, 2236 BugReport &BR) { 2237 2238 // Tell the BugReporterContext to report cases when the tracked symbol is 2239 // assigned to different variables, etc. 2240 BR.markInteresting(Sym); 2241 2242 // We are reporting a leak. Walk up the graph to get to the first node where 2243 // the symbol appeared, and also get the first VarDecl that tracked object 2244 // is stored to. 2245 AllocationInfo AllocI = 2246 GetAllocationSite(BRC.getStateManager(), EndN, Sym); 2247 2248 const MemRegion* FirstBinding = AllocI.R; 2249 BR.markInteresting(AllocI.InterestingMethodContext); 2250 2251 SourceManager& SM = BRC.getSourceManager(); 2252 2253 // Compute an actual location for the leak. Sometimes a leak doesn't 2254 // occur at an actual statement (e.g., transition between blocks; end 2255 // of function) so we need to walk the graph and compute a real location. 2256 const ExplodedNode *LeakN = EndN; 2257 PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); 2258 2259 std::string sbuf; 2260 llvm::raw_string_ostream os(sbuf); 2261 2262 os << "Object leaked: "; 2263 2264 if (FirstBinding) { 2265 os << "object allocated and stored into '" 2266 << FirstBinding->getString() << '\''; 2267 } 2268 else 2269 os << "allocated object"; 2270 2271 // Get the retain count. 2272 const RefVal* RV = getRefBinding(EndN->getState(), Sym); 2273 assert(RV); 2274 2275 if (RV->getKind() == RefVal::ErrorLeakReturned) { 2276 // FIXME: Per comments in rdar://6320065, "create" only applies to CF 2277 // objects. Only "copy", "alloc", "retain" and "new" transfer ownership 2278 // to the caller for NS objects. 2279 const Decl *D = &EndN->getCodeDecl(); 2280 2281 os << (isa<ObjCMethodDecl>(D) ? " is returned from a method " 2282 : " is returned from a function "); 2283 2284 if (D->getAttr<CFReturnsNotRetainedAttr>()) 2285 os << "that is annotated as CF_RETURNS_NOT_RETAINED"; 2286 else if (D->getAttr<NSReturnsNotRetainedAttr>()) 2287 os << "that is annotated as NS_RETURNS_NOT_RETAINED"; 2288 else { 2289 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 2290 os << "whose name ('" << MD->getSelector().getAsString() 2291 << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'." 2292 " This violates the naming convention rules" 2293 " given in the Memory Management Guide for Cocoa"; 2294 } 2295 else { 2296 const FunctionDecl *FD = cast<FunctionDecl>(D); 2297 os << "whose name ('" << *FD 2298 << "') does not contain 'Copy' or 'Create'. This violates the naming" 2299 " convention rules given in the Memory Management Guide for Core" 2300 " Foundation"; 2301 } 2302 } 2303 } 2304 else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { 2305 const ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); 2306 os << " and returned from method '" << MD.getSelector().getAsString() 2307 << "' is potentially leaked when using garbage collection. Callers " 2308 "of this method do not expect a returned object with a +1 retain " 2309 "count since they expect the object to be managed by the garbage " 2310 "collector"; 2311 } 2312 else 2313 os << " is not referenced later in this execution path and has a retain " 2314 "count of +" << RV->getCount(); 2315 2316 return new PathDiagnosticEventPiece(L, os.str()); 2317} 2318 2319CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, 2320 bool GCEnabled, const SummaryLogTy &Log, 2321 ExplodedNode *n, SymbolRef sym, 2322 CheckerContext &Ctx) 2323: CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { 2324 2325 // Most bug reports are cached at the location where they occurred. 2326 // With leaks, we want to unique them by the location where they were 2327 // allocated, and only report a single path. To do this, we need to find 2328 // the allocation site of a piece of tracked memory, which we do via a 2329 // call to GetAllocationSite. This will walk the ExplodedGraph backwards. 2330 // Note that this is *not* the trimmed graph; we are guaranteed, however, 2331 // that all ancestor nodes that represent the allocation site have the 2332 // same SourceLocation. 2333 const ExplodedNode *AllocNode = 0; 2334 2335 const SourceManager& SMgr = Ctx.getSourceManager(); 2336 2337 AllocationInfo AllocI = 2338 GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); 2339 2340 AllocNode = AllocI.N; 2341 AllocBinding = AllocI.R; 2342 markInteresting(AllocI.InterestingMethodContext); 2343 2344 // Get the SourceLocation for the allocation site. 2345 // FIXME: This will crash the analyzer if an allocation comes from an 2346 // implicit call. (Currently there are no such allocations in Cocoa, though.) 2347 const Stmt *AllocStmt; 2348 ProgramPoint P = AllocNode->getLocation(); 2349 if (Optional<CallExitEnd> Exit = P.getAs<CallExitEnd>()) 2350 AllocStmt = Exit->getCalleeContext()->getCallSite(); 2351 else 2352 AllocStmt = P.castAs<PostStmt>().getStmt(); 2353 assert(AllocStmt && "All allocations must come from explicit calls"); 2354 Location = PathDiagnosticLocation::createBegin(AllocStmt, SMgr, 2355 n->getLocationContext()); 2356 // Fill in the description of the bug. 2357 Description.clear(); 2358 llvm::raw_string_ostream os(Description); 2359 os << "Potential leak "; 2360 if (GCEnabled) 2361 os << "(when using garbage collection) "; 2362 os << "of an object"; 2363 2364 // FIXME: AllocBinding doesn't get populated for RegionStore yet. 2365 if (AllocBinding) 2366 os << " stored into '" << AllocBinding->getString() << '\''; 2367 2368 addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log)); 2369} 2370 2371//===----------------------------------------------------------------------===// 2372// Main checker logic. 2373//===----------------------------------------------------------------------===// 2374 2375namespace { 2376class RetainCountChecker 2377 : public Checker< check::Bind, 2378 check::DeadSymbols, 2379 check::EndAnalysis, 2380 check::EndFunction, 2381 check::PostStmt<BlockExpr>, 2382 check::PostStmt<CastExpr>, 2383 check::PostStmt<ObjCArrayLiteral>, 2384 check::PostStmt<ObjCDictionaryLiteral>, 2385 check::PostStmt<ObjCBoxedExpr>, 2386 check::PostCall, 2387 check::PreStmt<ReturnStmt>, 2388 check::RegionChanges, 2389 eval::Assume, 2390 eval::Call > { 2391 mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned; 2392 mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned; 2393 mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned; 2394 mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn; 2395 mutable OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; 2396 2397 typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap; 2398 2399 // This map is only used to ensure proper deletion of any allocated tags. 2400 mutable SymbolTagMap DeadSymbolTags; 2401 2402 mutable OwningPtr<RetainSummaryManager> Summaries; 2403 mutable OwningPtr<RetainSummaryManager> SummariesGC; 2404 mutable SummaryLogTy SummaryLog; 2405 mutable bool ShouldResetSummaryLog; 2406 2407public: 2408 RetainCountChecker() : ShouldResetSummaryLog(false) {} 2409 2410 virtual ~RetainCountChecker() { 2411 DeleteContainerSeconds(DeadSymbolTags); 2412 } 2413 2414 void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, 2415 ExprEngine &Eng) const { 2416 // FIXME: This is a hack to make sure the summary log gets cleared between 2417 // analyses of different code bodies. 2418 // 2419 // Why is this necessary? Because a checker's lifetime is tied to a 2420 // translation unit, but an ExplodedGraph's lifetime is just a code body. 2421 // Once in a blue moon, a new ExplodedNode will have the same address as an 2422 // old one with an associated summary, and the bug report visitor gets very 2423 // confused. (To make things worse, the summary lifetime is currently also 2424 // tied to a code body, so we get a crash instead of incorrect results.) 2425 // 2426 // Why is this a bad solution? Because if the lifetime of the ExplodedGraph 2427 // changes, things will start going wrong again. Really the lifetime of this 2428 // log needs to be tied to either the specific nodes in it or the entire 2429 // ExplodedGraph, not to a specific part of the code being analyzed. 2430 // 2431 // (Also, having stateful local data means that the same checker can't be 2432 // used from multiple threads, but a lot of checkers have incorrect 2433 // assumptions about that anyway. So that wasn't a priority at the time of 2434 // this fix.) 2435 // 2436 // This happens at the end of analysis, but bug reports are emitted /after/ 2437 // this point. So we can't just clear the summary log now. Instead, we mark 2438 // that the next time we access the summary log, it should be cleared. 2439 2440 // If we never reset the summary log during /this/ code body analysis, 2441 // there were no new summaries. There might still have been summaries from 2442 // the /last/ analysis, so clear them out to make sure the bug report 2443 // visitors don't get confused. 2444 if (ShouldResetSummaryLog) 2445 SummaryLog.clear(); 2446 2447 ShouldResetSummaryLog = !SummaryLog.empty(); 2448 } 2449 2450 CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, 2451 bool GCEnabled) const { 2452 if (GCEnabled) { 2453 if (!leakWithinFunctionGC) 2454 leakWithinFunctionGC.reset(new Leak("Leak of object when using " 2455 "garbage collection")); 2456 return leakWithinFunctionGC.get(); 2457 } else { 2458 if (!leakWithinFunction) { 2459 if (LOpts.getGC() == LangOptions::HybridGC) { 2460 leakWithinFunction.reset(new Leak("Leak of object when not using " 2461 "garbage collection (GC) in " 2462 "dual GC/non-GC code")); 2463 } else { 2464 leakWithinFunction.reset(new Leak("Leak")); 2465 } 2466 } 2467 return leakWithinFunction.get(); 2468 } 2469 } 2470 2471 CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { 2472 if (GCEnabled) { 2473 if (!leakAtReturnGC) 2474 leakAtReturnGC.reset(new Leak("Leak of returned object when using " 2475 "garbage collection")); 2476 return leakAtReturnGC.get(); 2477 } else { 2478 if (!leakAtReturn) { 2479 if (LOpts.getGC() == LangOptions::HybridGC) { 2480 leakAtReturn.reset(new Leak("Leak of returned object when not using " 2481 "garbage collection (GC) in dual " 2482 "GC/non-GC code")); 2483 } else { 2484 leakAtReturn.reset(new Leak("Leak of returned object")); 2485 } 2486 } 2487 return leakAtReturn.get(); 2488 } 2489 } 2490 2491 RetainSummaryManager &getSummaryManager(ASTContext &Ctx, 2492 bool GCEnabled) const { 2493 // FIXME: We don't support ARC being turned on and off during one analysis. 2494 // (nor, for that matter, do we support changing ASTContexts) 2495 bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; 2496 if (GCEnabled) { 2497 if (!SummariesGC) 2498 SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); 2499 else 2500 assert(SummariesGC->isARCEnabled() == ARCEnabled); 2501 return *SummariesGC; 2502 } else { 2503 if (!Summaries) 2504 Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); 2505 else 2506 assert(Summaries->isARCEnabled() == ARCEnabled); 2507 return *Summaries; 2508 } 2509 } 2510 2511 RetainSummaryManager &getSummaryManager(CheckerContext &C) const { 2512 return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); 2513 } 2514 2515 void printState(raw_ostream &Out, ProgramStateRef State, 2516 const char *NL, const char *Sep) const; 2517 2518 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; 2519 void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; 2520 void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; 2521 2522 void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; 2523 void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; 2524 void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; 2525 2526 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 2527 2528 void checkSummary(const RetainSummary &Summ, const CallEvent &Call, 2529 CheckerContext &C) const; 2530 2531 void processSummaryOfInlined(const RetainSummary &Summ, 2532 const CallEvent &Call, 2533 CheckerContext &C) const; 2534 2535 bool evalCall(const CallExpr *CE, CheckerContext &C) const; 2536 2537 ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, 2538 bool Assumption) const; 2539 2540 ProgramStateRef 2541 checkRegionChanges(ProgramStateRef state, 2542 const InvalidatedSymbols *invalidated, 2543 ArrayRef<const MemRegion *> ExplicitRegions, 2544 ArrayRef<const MemRegion *> Regions, 2545 const CallEvent *Call) const; 2546 2547 bool wantsRegionChangeUpdate(ProgramStateRef state) const { 2548 return true; 2549 } 2550 2551 void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; 2552 void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, 2553 ExplodedNode *Pred, RetEffect RE, RefVal X, 2554 SymbolRef Sym, ProgramStateRef state) const; 2555 2556 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 2557 void checkEndFunction(CheckerContext &C) const; 2558 2559 ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, 2560 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2561 CheckerContext &C) const; 2562 2563 void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, 2564 RefVal::Kind ErrorKind, SymbolRef Sym, 2565 CheckerContext &C) const; 2566 2567 void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; 2568 2569 const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; 2570 2571 ProgramStateRef handleSymbolDeath(ProgramStateRef state, 2572 SymbolRef sid, RefVal V, 2573 SmallVectorImpl<SymbolRef> &Leaked) const; 2574 2575 ProgramStateRef 2576 handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred, 2577 const ProgramPointTag *Tag, CheckerContext &Ctx, 2578 SymbolRef Sym, RefVal V) const; 2579 2580 ExplodedNode *processLeaks(ProgramStateRef state, 2581 SmallVectorImpl<SymbolRef> &Leaked, 2582 CheckerContext &Ctx, 2583 ExplodedNode *Pred = 0) const; 2584}; 2585} // end anonymous namespace 2586 2587namespace { 2588class StopTrackingCallback : public SymbolVisitor { 2589 ProgramStateRef state; 2590public: 2591 StopTrackingCallback(ProgramStateRef st) : state(st) {} 2592 ProgramStateRef getState() const { return state; } 2593 2594 bool VisitSymbol(SymbolRef sym) { 2595 state = state->remove<RefBindings>(sym); 2596 return true; 2597 } 2598}; 2599} // end anonymous namespace 2600 2601//===----------------------------------------------------------------------===// 2602// Handle statements that may have an effect on refcounts. 2603//===----------------------------------------------------------------------===// 2604 2605void RetainCountChecker::checkPostStmt(const BlockExpr *BE, 2606 CheckerContext &C) const { 2607 2608 // Scan the BlockDecRefExprs for any object the retain count checker 2609 // may be tracking. 2610 if (!BE->getBlockDecl()->hasCaptures()) 2611 return; 2612 2613 ProgramStateRef state = C.getState(); 2614 const BlockDataRegion *R = 2615 cast<BlockDataRegion>(state->getSVal(BE, 2616 C.getLocationContext()).getAsRegion()); 2617 2618 BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), 2619 E = R->referenced_vars_end(); 2620 2621 if (I == E) 2622 return; 2623 2624 // FIXME: For now we invalidate the tracking of all symbols passed to blocks 2625 // via captured variables, even though captured variables result in a copy 2626 // and in implicit increment/decrement of a retain count. 2627 SmallVector<const MemRegion*, 10> Regions; 2628 const LocationContext *LC = C.getLocationContext(); 2629 MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); 2630 2631 for ( ; I != E; ++I) { 2632 const VarRegion *VR = I.getCapturedRegion(); 2633 if (VR->getSuperRegion() == R) { 2634 VR = MemMgr.getVarRegion(VR->getDecl(), LC); 2635 } 2636 Regions.push_back(VR); 2637 } 2638 2639 state = 2640 state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), 2641 Regions.data() + Regions.size()).getState(); 2642 C.addTransition(state); 2643} 2644 2645void RetainCountChecker::checkPostStmt(const CastExpr *CE, 2646 CheckerContext &C) const { 2647 const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); 2648 if (!BE) 2649 return; 2650 2651 ArgEffect AE = IncRef; 2652 2653 switch (BE->getBridgeKind()) { 2654 case clang::OBC_Bridge: 2655 // Do nothing. 2656 return; 2657 case clang::OBC_BridgeRetained: 2658 AE = IncRef; 2659 break; 2660 case clang::OBC_BridgeTransfer: 2661 AE = DecRefBridgedTransfered; 2662 break; 2663 } 2664 2665 ProgramStateRef state = C.getState(); 2666 SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol(); 2667 if (!Sym) 2668 return; 2669 const RefVal* T = getRefBinding(state, Sym); 2670 if (!T) 2671 return; 2672 2673 RefVal::Kind hasErr = (RefVal::Kind) 0; 2674 state = updateSymbol(state, Sym, *T, AE, hasErr, C); 2675 2676 if (hasErr) { 2677 // FIXME: If we get an error during a bridge cast, should we report it? 2678 // Should we assert that there is no error? 2679 return; 2680 } 2681 2682 C.addTransition(state); 2683} 2684 2685void RetainCountChecker::processObjCLiterals(CheckerContext &C, 2686 const Expr *Ex) const { 2687 ProgramStateRef state = C.getState(); 2688 const ExplodedNode *pred = C.getPredecessor(); 2689 for (Stmt::const_child_iterator it = Ex->child_begin(), et = Ex->child_end() ; 2690 it != et ; ++it) { 2691 const Stmt *child = *it; 2692 SVal V = state->getSVal(child, pred->getLocationContext()); 2693 if (SymbolRef sym = V.getAsSymbol()) 2694 if (const RefVal* T = getRefBinding(state, sym)) { 2695 RefVal::Kind hasErr = (RefVal::Kind) 0; 2696 state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); 2697 if (hasErr) { 2698 processNonLeakError(state, child->getSourceRange(), hasErr, sym, C); 2699 return; 2700 } 2701 } 2702 } 2703 2704 // Return the object as autoreleased. 2705 // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); 2706 if (SymbolRef sym = 2707 state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { 2708 QualType ResultTy = Ex->getType(); 2709 state = setRefBinding(state, sym, 2710 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2711 } 2712 2713 C.addTransition(state); 2714} 2715 2716void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, 2717 CheckerContext &C) const { 2718 // Apply the 'MayEscape' to all values. 2719 processObjCLiterals(C, AL); 2720} 2721 2722void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 2723 CheckerContext &C) const { 2724 // Apply the 'MayEscape' to all keys and values. 2725 processObjCLiterals(C, DL); 2726} 2727 2728void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, 2729 CheckerContext &C) const { 2730 const ExplodedNode *Pred = C.getPredecessor(); 2731 const LocationContext *LCtx = Pred->getLocationContext(); 2732 ProgramStateRef State = Pred->getState(); 2733 2734 if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) { 2735 QualType ResultTy = Ex->getType(); 2736 State = setRefBinding(State, Sym, 2737 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2738 } 2739 2740 C.addTransition(State); 2741} 2742 2743void RetainCountChecker::checkPostCall(const CallEvent &Call, 2744 CheckerContext &C) const { 2745 RetainSummaryManager &Summaries = getSummaryManager(C); 2746 const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); 2747 2748 if (C.wasInlined) { 2749 processSummaryOfInlined(*Summ, Call, C); 2750 return; 2751 } 2752 checkSummary(*Summ, Call, C); 2753} 2754 2755/// GetReturnType - Used to get the return type of a message expression or 2756/// function call with the intention of affixing that type to a tracked symbol. 2757/// While the return type can be queried directly from RetEx, when 2758/// invoking class methods we augment to the return type to be that of 2759/// a pointer to the class (as opposed it just being id). 2760// FIXME: We may be able to do this with related result types instead. 2761// This function is probably overestimating. 2762static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { 2763 QualType RetTy = RetE->getType(); 2764 // If RetE is not a message expression just return its type. 2765 // If RetE is a message expression, return its types if it is something 2766 /// more specific than id. 2767 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) 2768 if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) 2769 if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || 2770 PT->isObjCClassType()) { 2771 // At this point we know the return type of the message expression is 2772 // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this 2773 // is a call to a class method whose type we can resolve. In such 2774 // cases, promote the return type to XXX* (where XXX is the class). 2775 const ObjCInterfaceDecl *D = ME->getReceiverInterface(); 2776 return !D ? RetTy : 2777 Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); 2778 } 2779 2780 return RetTy; 2781} 2782 2783// We don't always get the exact modeling of the function with regards to the 2784// retain count checker even when the function is inlined. For example, we need 2785// to stop tracking the symbols which were marked with StopTrackingHard. 2786void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ, 2787 const CallEvent &CallOrMsg, 2788 CheckerContext &C) const { 2789 ProgramStateRef state = C.getState(); 2790 2791 // Evaluate the effect of the arguments. 2792 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2793 if (Summ.getArg(idx) == StopTrackingHard) { 2794 SVal V = CallOrMsg.getArgSVal(idx); 2795 if (SymbolRef Sym = V.getAsLocSymbol()) { 2796 state = removeRefBinding(state, Sym); 2797 } 2798 } 2799 } 2800 2801 // Evaluate the effect on the message receiver. 2802 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2803 if (MsgInvocation) { 2804 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2805 if (Summ.getReceiverEffect() == StopTrackingHard) { 2806 state = removeRefBinding(state, Sym); 2807 } 2808 } 2809 } 2810 2811 // Consult the summary for the return value. 2812 RetEffect RE = Summ.getRetEffect(); 2813 if (RE.getKind() == RetEffect::NoRetHard) { 2814 SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); 2815 if (Sym) 2816 state = removeRefBinding(state, Sym); 2817 } 2818 2819 C.addTransition(state); 2820} 2821 2822void RetainCountChecker::checkSummary(const RetainSummary &Summ, 2823 const CallEvent &CallOrMsg, 2824 CheckerContext &C) const { 2825 ProgramStateRef state = C.getState(); 2826 2827 // Evaluate the effect of the arguments. 2828 RefVal::Kind hasErr = (RefVal::Kind) 0; 2829 SourceRange ErrorRange; 2830 SymbolRef ErrorSym = 0; 2831 2832 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2833 SVal V = CallOrMsg.getArgSVal(idx); 2834 2835 if (SymbolRef Sym = V.getAsLocSymbol()) { 2836 if (const RefVal *T = getRefBinding(state, Sym)) { 2837 state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C); 2838 if (hasErr) { 2839 ErrorRange = CallOrMsg.getArgSourceRange(idx); 2840 ErrorSym = Sym; 2841 break; 2842 } 2843 } 2844 } 2845 } 2846 2847 // Evaluate the effect on the message receiver. 2848 bool ReceiverIsTracked = false; 2849 if (!hasErr) { 2850 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2851 if (MsgInvocation) { 2852 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2853 if (const RefVal *T = getRefBinding(state, Sym)) { 2854 ReceiverIsTracked = true; 2855 state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), 2856 hasErr, C); 2857 if (hasErr) { 2858 ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange(); 2859 ErrorSym = Sym; 2860 } 2861 } 2862 } 2863 } 2864 } 2865 2866 // Process any errors. 2867 if (hasErr) { 2868 processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); 2869 return; 2870 } 2871 2872 // Consult the summary for the return value. 2873 RetEffect RE = Summ.getRetEffect(); 2874 2875 if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { 2876 if (ReceiverIsTracked) 2877 RE = getSummaryManager(C).getObjAllocRetEffect(); 2878 else 2879 RE = RetEffect::MakeNoRet(); 2880 } 2881 2882 switch (RE.getKind()) { 2883 default: 2884 llvm_unreachable("Unhandled RetEffect."); 2885 2886 case RetEffect::NoRet: 2887 case RetEffect::NoRetHard: 2888 // No work necessary. 2889 break; 2890 2891 case RetEffect::OwnedAllocatedSymbol: 2892 case RetEffect::OwnedSymbol: { 2893 SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); 2894 if (!Sym) 2895 break; 2896 2897 // Use the result type from the CallEvent as it automatically adjusts 2898 // for methods/functions that return references. 2899 QualType ResultTy = CallOrMsg.getResultType(); 2900 state = setRefBinding(state, Sym, RefVal::makeOwned(RE.getObjKind(), 2901 ResultTy)); 2902 2903 // FIXME: Add a flag to the checker where allocations are assumed to 2904 // *not* fail. 2905 break; 2906 } 2907 2908 case RetEffect::GCNotOwnedSymbol: 2909 case RetEffect::ARCNotOwnedSymbol: 2910 case RetEffect::NotOwnedSymbol: { 2911 const Expr *Ex = CallOrMsg.getOriginExpr(); 2912 SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); 2913 if (!Sym) 2914 break; 2915 assert(Ex); 2916 // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. 2917 QualType ResultTy = GetReturnType(Ex, C.getASTContext()); 2918 state = setRefBinding(state, Sym, RefVal::makeNotOwned(RE.getObjKind(), 2919 ResultTy)); 2920 break; 2921 } 2922 } 2923 2924 // This check is actually necessary; otherwise the statement builder thinks 2925 // we've hit a previously-found path. 2926 // Normally addTransition takes care of this, but we want the node pointer. 2927 ExplodedNode *NewNode; 2928 if (state == C.getState()) { 2929 NewNode = C.getPredecessor(); 2930 } else { 2931 NewNode = C.addTransition(state); 2932 } 2933 2934 // Annotate the node with summary we used. 2935 if (NewNode) { 2936 // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. 2937 if (ShouldResetSummaryLog) { 2938 SummaryLog.clear(); 2939 ShouldResetSummaryLog = false; 2940 } 2941 SummaryLog[NewNode] = &Summ; 2942 } 2943} 2944 2945 2946ProgramStateRef 2947RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, 2948 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2949 CheckerContext &C) const { 2950 // In GC mode [... release] and [... retain] do nothing. 2951 // In ARC mode they shouldn't exist at all, but we just ignore them. 2952 bool IgnoreRetainMsg = C.isObjCGCEnabled(); 2953 if (!IgnoreRetainMsg) 2954 IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; 2955 2956 switch (E) { 2957 default: 2958 break; 2959 case IncRefMsg: 2960 E = IgnoreRetainMsg ? DoNothing : IncRef; 2961 break; 2962 case DecRefMsg: 2963 E = IgnoreRetainMsg ? DoNothing : DecRef; 2964 break; 2965 case DecRefMsgAndStopTrackingHard: 2966 E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTrackingHard; 2967 break; 2968 case MakeCollectable: 2969 E = C.isObjCGCEnabled() ? DecRef : DoNothing; 2970 break; 2971 } 2972 2973 // Handle all use-after-releases. 2974 if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { 2975 V = V ^ RefVal::ErrorUseAfterRelease; 2976 hasErr = V.getKind(); 2977 return setRefBinding(state, sym, V); 2978 } 2979 2980 switch (E) { 2981 case DecRefMsg: 2982 case IncRefMsg: 2983 case MakeCollectable: 2984 case DecRefMsgAndStopTrackingHard: 2985 llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); 2986 2987 case Dealloc: 2988 // Any use of -dealloc in GC is *bad*. 2989 if (C.isObjCGCEnabled()) { 2990 V = V ^ RefVal::ErrorDeallocGC; 2991 hasErr = V.getKind(); 2992 break; 2993 } 2994 2995 switch (V.getKind()) { 2996 default: 2997 llvm_unreachable("Invalid RefVal state for an explicit dealloc."); 2998 case RefVal::Owned: 2999 // The object immediately transitions to the released state. 3000 V = V ^ RefVal::Released; 3001 V.clearCounts(); 3002 return setRefBinding(state, sym, V); 3003 case RefVal::NotOwned: 3004 V = V ^ RefVal::ErrorDeallocNotOwned; 3005 hasErr = V.getKind(); 3006 break; 3007 } 3008 break; 3009 3010 case MayEscape: 3011 if (V.getKind() == RefVal::Owned) { 3012 V = V ^ RefVal::NotOwned; 3013 break; 3014 } 3015 3016 // Fall-through. 3017 3018 case DoNothing: 3019 return state; 3020 3021 case Autorelease: 3022 if (C.isObjCGCEnabled()) 3023 return state; 3024 // Update the autorelease counts. 3025 V = V.autorelease(); 3026 break; 3027 3028 case StopTracking: 3029 case StopTrackingHard: 3030 return removeRefBinding(state, sym); 3031 3032 case IncRef: 3033 switch (V.getKind()) { 3034 default: 3035 llvm_unreachable("Invalid RefVal state for a retain."); 3036 case RefVal::Owned: 3037 case RefVal::NotOwned: 3038 V = V + 1; 3039 break; 3040 case RefVal::Released: 3041 // Non-GC cases are handled above. 3042 assert(C.isObjCGCEnabled()); 3043 V = (V ^ RefVal::Owned) + 1; 3044 break; 3045 } 3046 break; 3047 3048 case DecRef: 3049 case DecRefBridgedTransfered: 3050 case DecRefAndStopTrackingHard: 3051 switch (V.getKind()) { 3052 default: 3053 // case 'RefVal::Released' handled above. 3054 llvm_unreachable("Invalid RefVal state for a release."); 3055 3056 case RefVal::Owned: 3057 assert(V.getCount() > 0); 3058 if (V.getCount() == 1) 3059 V = V ^ (E == DecRefBridgedTransfered ? 3060 RefVal::NotOwned : RefVal::Released); 3061 else if (E == DecRefAndStopTrackingHard) 3062 return removeRefBinding(state, sym); 3063 3064 V = V - 1; 3065 break; 3066 3067 case RefVal::NotOwned: 3068 if (V.getCount() > 0) { 3069 if (E == DecRefAndStopTrackingHard) 3070 return removeRefBinding(state, sym); 3071 V = V - 1; 3072 } else { 3073 V = V ^ RefVal::ErrorReleaseNotOwned; 3074 hasErr = V.getKind(); 3075 } 3076 break; 3077 3078 case RefVal::Released: 3079 // Non-GC cases are handled above. 3080 assert(C.isObjCGCEnabled()); 3081 V = V ^ RefVal::ErrorUseAfterRelease; 3082 hasErr = V.getKind(); 3083 break; 3084 } 3085 break; 3086 } 3087 return setRefBinding(state, sym, V); 3088} 3089 3090void RetainCountChecker::processNonLeakError(ProgramStateRef St, 3091 SourceRange ErrorRange, 3092 RefVal::Kind ErrorKind, 3093 SymbolRef Sym, 3094 CheckerContext &C) const { 3095 ExplodedNode *N = C.generateSink(St); 3096 if (!N) 3097 return; 3098 3099 CFRefBug *BT; 3100 switch (ErrorKind) { 3101 default: 3102 llvm_unreachable("Unhandled error."); 3103 case RefVal::ErrorUseAfterRelease: 3104 if (!useAfterRelease) 3105 useAfterRelease.reset(new UseAfterRelease()); 3106 BT = &*useAfterRelease; 3107 break; 3108 case RefVal::ErrorReleaseNotOwned: 3109 if (!releaseNotOwned) 3110 releaseNotOwned.reset(new BadRelease()); 3111 BT = &*releaseNotOwned; 3112 break; 3113 case RefVal::ErrorDeallocGC: 3114 if (!deallocGC) 3115 deallocGC.reset(new DeallocGC()); 3116 BT = &*deallocGC; 3117 break; 3118 case RefVal::ErrorDeallocNotOwned: 3119 if (!deallocNotOwned) 3120 deallocNotOwned.reset(new DeallocNotOwned()); 3121 BT = &*deallocNotOwned; 3122 break; 3123 } 3124 3125 assert(BT); 3126 CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOpts(), 3127 C.isObjCGCEnabled(), SummaryLog, 3128 N, Sym); 3129 report->addRange(ErrorRange); 3130 C.emitReport(report); 3131} 3132 3133//===----------------------------------------------------------------------===// 3134// Handle the return values of retain-count-related functions. 3135//===----------------------------------------------------------------------===// 3136 3137bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { 3138 // Get the callee. We're only interested in simple C functions. 3139 ProgramStateRef state = C.getState(); 3140 const FunctionDecl *FD = C.getCalleeDecl(CE); 3141 if (!FD) 3142 return false; 3143 3144 IdentifierInfo *II = FD->getIdentifier(); 3145 if (!II) 3146 return false; 3147 3148 // For now, we're only handling the functions that return aliases of their 3149 // arguments: CFRetain and CFMakeCollectable (and their families). 3150 // Eventually we should add other functions we can model entirely, 3151 // such as CFRelease, which don't invalidate their arguments or globals. 3152 if (CE->getNumArgs() != 1) 3153 return false; 3154 3155 // Get the name of the function. 3156 StringRef FName = II->getName(); 3157 FName = FName.substr(FName.find_first_not_of('_')); 3158 3159 // See if it's one of the specific functions we know how to eval. 3160 bool canEval = false; 3161 3162 QualType ResultTy = CE->getCallReturnType(); 3163 if (ResultTy->isObjCIdType()) { 3164 // Handle: id NSMakeCollectable(CFTypeRef) 3165 canEval = II->isStr("NSMakeCollectable"); 3166 } else if (ResultTy->isPointerType()) { 3167 // Handle: (CF|CG)Retain 3168 // CFMakeCollectable 3169 // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). 3170 if (cocoa::isRefType(ResultTy, "CF", FName) || 3171 cocoa::isRefType(ResultTy, "CG", FName)) { 3172 canEval = isRetain(FD, FName) || isMakeCollectable(FD, FName); 3173 } 3174 } 3175 3176 if (!canEval) 3177 return false; 3178 3179 // Bind the return value. 3180 const LocationContext *LCtx = C.getLocationContext(); 3181 SVal RetVal = state->getSVal(CE->getArg(0), LCtx); 3182 if (RetVal.isUnknown()) { 3183 // If the receiver is unknown, conjure a return value. 3184 SValBuilder &SVB = C.getSValBuilder(); 3185 RetVal = SVB.conjureSymbolVal(0, CE, LCtx, ResultTy, C.blockCount()); 3186 } 3187 state = state->BindExpr(CE, LCtx, RetVal, false); 3188 3189 // FIXME: This should not be necessary, but otherwise the argument seems to be 3190 // considered alive during the next statement. 3191 if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { 3192 // Save the refcount status of the argument. 3193 SymbolRef Sym = RetVal.getAsLocSymbol(); 3194 const RefVal *Binding = 0; 3195 if (Sym) 3196 Binding = getRefBinding(state, Sym); 3197 3198 // Invalidate the argument region. 3199 state = state->invalidateRegions(ArgRegion, CE, C.blockCount(), LCtx, 3200 /*CausesPointerEscape*/ false); 3201 3202 // Restore the refcount status of the argument. 3203 if (Binding) 3204 state = setRefBinding(state, Sym, *Binding); 3205 } 3206 3207 C.addTransition(state); 3208 return true; 3209} 3210 3211//===----------------------------------------------------------------------===// 3212// Handle return statements. 3213//===----------------------------------------------------------------------===// 3214 3215void RetainCountChecker::checkPreStmt(const ReturnStmt *S, 3216 CheckerContext &C) const { 3217 3218 // Only adjust the reference count if this is the top-level call frame, 3219 // and not the result of inlining. In the future, we should do 3220 // better checking even for inlined calls, and see if they match 3221 // with their expected semantics (e.g., the method should return a retained 3222 // object, etc.). 3223 if (!C.inTopFrame()) 3224 return; 3225 3226 const Expr *RetE = S->getRetValue(); 3227 if (!RetE) 3228 return; 3229 3230 ProgramStateRef state = C.getState(); 3231 SymbolRef Sym = 3232 state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); 3233 if (!Sym) 3234 return; 3235 3236 // Get the reference count binding (if any). 3237 const RefVal *T = getRefBinding(state, Sym); 3238 if (!T) 3239 return; 3240 3241 // Change the reference count. 3242 RefVal X = *T; 3243 3244 switch (X.getKind()) { 3245 case RefVal::Owned: { 3246 unsigned cnt = X.getCount(); 3247 assert(cnt > 0); 3248 X.setCount(cnt - 1); 3249 X = X ^ RefVal::ReturnedOwned; 3250 break; 3251 } 3252 3253 case RefVal::NotOwned: { 3254 unsigned cnt = X.getCount(); 3255 if (cnt) { 3256 X.setCount(cnt - 1); 3257 X = X ^ RefVal::ReturnedOwned; 3258 } 3259 else { 3260 X = X ^ RefVal::ReturnedNotOwned; 3261 } 3262 break; 3263 } 3264 3265 default: 3266 return; 3267 } 3268 3269 // Update the binding. 3270 state = setRefBinding(state, Sym, X); 3271 ExplodedNode *Pred = C.addTransition(state); 3272 3273 // At this point we have updated the state properly. 3274 // Everything after this is merely checking to see if the return value has 3275 // been over- or under-retained. 3276 3277 // Did we cache out? 3278 if (!Pred) 3279 return; 3280 3281 // Update the autorelease counts. 3282 static SimpleProgramPointTag 3283 AutoreleaseTag("RetainCountChecker : Autorelease"); 3284 state = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, C, Sym, X); 3285 3286 // Did we cache out? 3287 if (!state) 3288 return; 3289 3290 // Get the updated binding. 3291 T = getRefBinding(state, Sym); 3292 assert(T); 3293 X = *T; 3294 3295 // Consult the summary of the enclosing method. 3296 RetainSummaryManager &Summaries = getSummaryManager(C); 3297 const Decl *CD = &Pred->getCodeDecl(); 3298 RetEffect RE = RetEffect::MakeNoRet(); 3299 3300 // FIXME: What is the convention for blocks? Is there one? 3301 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) { 3302 const RetainSummary *Summ = Summaries.getMethodSummary(MD); 3303 RE = Summ->getRetEffect(); 3304 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) { 3305 if (!isa<CXXMethodDecl>(FD)) { 3306 const RetainSummary *Summ = Summaries.getFunctionSummary(FD); 3307 RE = Summ->getRetEffect(); 3308 } 3309 } 3310 3311 checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state); 3312} 3313 3314void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S, 3315 CheckerContext &C, 3316 ExplodedNode *Pred, 3317 RetEffect RE, RefVal X, 3318 SymbolRef Sym, 3319 ProgramStateRef state) const { 3320 // Any leaks or other errors? 3321 if (X.isReturnedOwned() && X.getCount() == 0) { 3322 if (RE.getKind() != RetEffect::NoRet) { 3323 bool hasError = false; 3324 if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) { 3325 // Things are more complicated with garbage collection. If the 3326 // returned object is suppose to be an Objective-C object, we have 3327 // a leak (as the caller expects a GC'ed object) because no 3328 // method should return ownership unless it returns a CF object. 3329 hasError = true; 3330 X = X ^ RefVal::ErrorGCLeakReturned; 3331 } 3332 else if (!RE.isOwned()) { 3333 // Either we are using GC and the returned object is a CF type 3334 // or we aren't using GC. In either case, we expect that the 3335 // enclosing method is expected to return ownership. 3336 hasError = true; 3337 X = X ^ RefVal::ErrorLeakReturned; 3338 } 3339 3340 if (hasError) { 3341 // Generate an error node. 3342 state = setRefBinding(state, Sym, X); 3343 3344 static SimpleProgramPointTag 3345 ReturnOwnLeakTag("RetainCountChecker : ReturnsOwnLeak"); 3346 ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag); 3347 if (N) { 3348 const LangOptions &LOpts = C.getASTContext().getLangOpts(); 3349 bool GCEnabled = C.isObjCGCEnabled(); 3350 CFRefReport *report = 3351 new CFRefLeakReport(*getLeakAtReturnBug(LOpts, GCEnabled), 3352 LOpts, GCEnabled, SummaryLog, 3353 N, Sym, C); 3354 C.emitReport(report); 3355 } 3356 } 3357 } 3358 } else if (X.isReturnedNotOwned()) { 3359 if (RE.isOwned()) { 3360 // Trying to return a not owned object to a caller expecting an 3361 // owned object. 3362 state = setRefBinding(state, Sym, X ^ RefVal::ErrorReturnedNotOwned); 3363 3364 static SimpleProgramPointTag 3365 ReturnNotOwnedTag("RetainCountChecker : ReturnNotOwnedForOwned"); 3366 ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag); 3367 if (N) { 3368 if (!returnNotOwnedForOwned) 3369 returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned()); 3370 3371 CFRefReport *report = 3372 new CFRefReport(*returnNotOwnedForOwned, 3373 C.getASTContext().getLangOpts(), 3374 C.isObjCGCEnabled(), SummaryLog, N, Sym); 3375 C.emitReport(report); 3376 } 3377 } 3378 } 3379} 3380 3381//===----------------------------------------------------------------------===// 3382// Check various ways a symbol can be invalidated. 3383//===----------------------------------------------------------------------===// 3384 3385void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S, 3386 CheckerContext &C) const { 3387 // Are we storing to something that causes the value to "escape"? 3388 bool escapes = true; 3389 3390 // A value escapes in three possible cases (this may change): 3391 // 3392 // (1) we are binding to something that is not a memory region. 3393 // (2) we are binding to a memregion that does not have stack storage 3394 // (3) we are binding to a memregion with stack storage that the store 3395 // does not understand. 3396 ProgramStateRef state = C.getState(); 3397 3398 if (Optional<loc::MemRegionVal> regionLoc = loc.getAs<loc::MemRegionVal>()) { 3399 escapes = !regionLoc->getRegion()->hasStackStorage(); 3400 3401 if (!escapes) { 3402 // To test (3), generate a new state with the binding added. If it is 3403 // the same state, then it escapes (since the store cannot represent 3404 // the binding). 3405 // Do this only if we know that the store is not supposed to generate the 3406 // same state. 3407 SVal StoredVal = state->getSVal(regionLoc->getRegion()); 3408 if (StoredVal != val) 3409 escapes = (state == (state->bindLoc(*regionLoc, val))); 3410 } 3411 if (!escapes) { 3412 // Case 4: We do not currently model what happens when a symbol is 3413 // assigned to a struct field, so be conservative here and let the symbol 3414 // go. TODO: This could definitely be improved upon. 3415 escapes = !isa<VarRegion>(regionLoc->getRegion()); 3416 } 3417 } 3418 3419 // If our store can represent the binding and we aren't storing to something 3420 // that doesn't have local storage then just return and have the simulation 3421 // state continue as is. 3422 if (!escapes) 3423 return; 3424 3425 // Otherwise, find all symbols referenced by 'val' that we are tracking 3426 // and stop tracking them. 3427 state = state->scanReachableSymbols<StopTrackingCallback>(val).getState(); 3428 C.addTransition(state); 3429} 3430 3431ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state, 3432 SVal Cond, 3433 bool Assumption) const { 3434 3435 // FIXME: We may add to the interface of evalAssume the list of symbols 3436 // whose assumptions have changed. For now we just iterate through the 3437 // bindings and check if any of the tracked symbols are NULL. This isn't 3438 // too bad since the number of symbols we will track in practice are 3439 // probably small and evalAssume is only called at branches and a few 3440 // other places. 3441 RefBindingsTy B = state->get<RefBindings>(); 3442 3443 if (B.isEmpty()) 3444 return state; 3445 3446 bool changed = false; 3447 RefBindingsTy::Factory &RefBFactory = state->get_context<RefBindings>(); 3448 3449 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3450 // Check if the symbol is null stop tracking the symbol. 3451 ConstraintManager &CMgr = state->getConstraintManager(); 3452 ConditionTruthVal AllocFailed = CMgr.isNull(state, I.getKey()); 3453 if (AllocFailed.isConstrainedTrue()) { 3454 changed = true; 3455 B = RefBFactory.remove(B, I.getKey()); 3456 } 3457 } 3458 3459 if (changed) 3460 state = state->set<RefBindings>(B); 3461 3462 return state; 3463} 3464 3465ProgramStateRef 3466RetainCountChecker::checkRegionChanges(ProgramStateRef state, 3467 const InvalidatedSymbols *invalidated, 3468 ArrayRef<const MemRegion *> ExplicitRegions, 3469 ArrayRef<const MemRegion *> Regions, 3470 const CallEvent *Call) const { 3471 if (!invalidated) 3472 return state; 3473 3474 llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols; 3475 for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(), 3476 E = ExplicitRegions.end(); I != E; ++I) { 3477 if (const SymbolicRegion *SR = (*I)->StripCasts()->getAs<SymbolicRegion>()) 3478 WhitelistedSymbols.insert(SR->getSymbol()); 3479 } 3480 3481 for (InvalidatedSymbols::const_iterator I=invalidated->begin(), 3482 E = invalidated->end(); I!=E; ++I) { 3483 SymbolRef sym = *I; 3484 if (WhitelistedSymbols.count(sym)) 3485 continue; 3486 // Remove any existing reference-count binding. 3487 state = removeRefBinding(state, sym); 3488 } 3489 return state; 3490} 3491 3492//===----------------------------------------------------------------------===// 3493// Handle dead symbols and end-of-path. 3494//===----------------------------------------------------------------------===// 3495 3496ProgramStateRef 3497RetainCountChecker::handleAutoreleaseCounts(ProgramStateRef state, 3498 ExplodedNode *Pred, 3499 const ProgramPointTag *Tag, 3500 CheckerContext &Ctx, 3501 SymbolRef Sym, RefVal V) const { 3502 unsigned ACnt = V.getAutoreleaseCount(); 3503 3504 // No autorelease counts? Nothing to be done. 3505 if (!ACnt) 3506 return state; 3507 3508 assert(!Ctx.isObjCGCEnabled() && "Autorelease counts in GC mode?"); 3509 unsigned Cnt = V.getCount(); 3510 3511 // FIXME: Handle sending 'autorelease' to already released object. 3512 3513 if (V.getKind() == RefVal::ReturnedOwned) 3514 ++Cnt; 3515 3516 if (ACnt <= Cnt) { 3517 if (ACnt == Cnt) { 3518 V.clearCounts(); 3519 if (V.getKind() == RefVal::ReturnedOwned) 3520 V = V ^ RefVal::ReturnedNotOwned; 3521 else 3522 V = V ^ RefVal::NotOwned; 3523 } else { 3524 V.setCount(V.getCount() - ACnt); 3525 V.setAutoreleaseCount(0); 3526 } 3527 return setRefBinding(state, Sym, V); 3528 } 3529 3530 // Woah! More autorelease counts then retain counts left. 3531 // Emit hard error. 3532 V = V ^ RefVal::ErrorOverAutorelease; 3533 state = setRefBinding(state, Sym, V); 3534 3535 ExplodedNode *N = Ctx.generateSink(state, Pred, Tag); 3536 if (N) { 3537 SmallString<128> sbuf; 3538 llvm::raw_svector_ostream os(sbuf); 3539 os << "Object over-autoreleased: object was sent -autorelease "; 3540 if (V.getAutoreleaseCount() > 1) 3541 os << V.getAutoreleaseCount() << " times "; 3542 os << "but the object has a +" << V.getCount() << " retain count"; 3543 3544 if (!overAutorelease) 3545 overAutorelease.reset(new OverAutorelease()); 3546 3547 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3548 CFRefReport *report = 3549 new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false, 3550 SummaryLog, N, Sym, os.str()); 3551 Ctx.emitReport(report); 3552 } 3553 3554 return 0; 3555} 3556 3557ProgramStateRef 3558RetainCountChecker::handleSymbolDeath(ProgramStateRef state, 3559 SymbolRef sid, RefVal V, 3560 SmallVectorImpl<SymbolRef> &Leaked) const { 3561 bool hasLeak = false; 3562 if (V.isOwned()) 3563 hasLeak = true; 3564 else if (V.isNotOwned() || V.isReturnedOwned()) 3565 hasLeak = (V.getCount() > 0); 3566 3567 if (!hasLeak) 3568 return removeRefBinding(state, sid); 3569 3570 Leaked.push_back(sid); 3571 return setRefBinding(state, sid, V ^ RefVal::ErrorLeak); 3572} 3573 3574ExplodedNode * 3575RetainCountChecker::processLeaks(ProgramStateRef state, 3576 SmallVectorImpl<SymbolRef> &Leaked, 3577 CheckerContext &Ctx, 3578 ExplodedNode *Pred) const { 3579 // Generate an intermediate node representing the leak point. 3580 ExplodedNode *N = Ctx.addTransition(state, Pred); 3581 3582 if (N) { 3583 for (SmallVectorImpl<SymbolRef>::iterator 3584 I = Leaked.begin(), E = Leaked.end(); I != E; ++I) { 3585 3586 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3587 bool GCEnabled = Ctx.isObjCGCEnabled(); 3588 CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled) 3589 : getLeakAtReturnBug(LOpts, GCEnabled); 3590 assert(BT && "BugType not initialized."); 3591 3592 CFRefLeakReport *report = new CFRefLeakReport(*BT, LOpts, GCEnabled, 3593 SummaryLog, N, *I, Ctx); 3594 Ctx.emitReport(report); 3595 } 3596 } 3597 3598 return N; 3599} 3600 3601void RetainCountChecker::checkEndFunction(CheckerContext &Ctx) const { 3602 ProgramStateRef state = Ctx.getState(); 3603 RefBindingsTy B = state->get<RefBindings>(); 3604 ExplodedNode *Pred = Ctx.getPredecessor(); 3605 3606 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3607 state = handleAutoreleaseCounts(state, Pred, /*Tag=*/0, Ctx, 3608 I->first, I->second); 3609 if (!state) 3610 return; 3611 } 3612 3613 // If the current LocationContext has a parent, don't check for leaks. 3614 // We will do that later. 3615 // FIXME: we should instead check for imbalances of the retain/releases, 3616 // and suggest annotations. 3617 if (Ctx.getLocationContext()->getParent()) 3618 return; 3619 3620 B = state->get<RefBindings>(); 3621 SmallVector<SymbolRef, 10> Leaked; 3622 3623 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) 3624 state = handleSymbolDeath(state, I->first, I->second, Leaked); 3625 3626 processLeaks(state, Leaked, Ctx, Pred); 3627} 3628 3629const ProgramPointTag * 3630RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const { 3631 const SimpleProgramPointTag *&tag = DeadSymbolTags[sym]; 3632 if (!tag) { 3633 SmallString<64> buf; 3634 llvm::raw_svector_ostream out(buf); 3635 out << "RetainCountChecker : Dead Symbol : "; 3636 sym->dumpToStream(out); 3637 tag = new SimpleProgramPointTag(out.str()); 3638 } 3639 return tag; 3640} 3641 3642void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper, 3643 CheckerContext &C) const { 3644 ExplodedNode *Pred = C.getPredecessor(); 3645 3646 ProgramStateRef state = C.getState(); 3647 RefBindingsTy B = state->get<RefBindings>(); 3648 SmallVector<SymbolRef, 10> Leaked; 3649 3650 // Update counts from autorelease pools 3651 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3652 E = SymReaper.dead_end(); I != E; ++I) { 3653 SymbolRef Sym = *I; 3654 if (const RefVal *T = B.lookup(Sym)){ 3655 // Use the symbol as the tag. 3656 // FIXME: This might not be as unique as we would like. 3657 const ProgramPointTag *Tag = getDeadSymbolTag(Sym); 3658 state = handleAutoreleaseCounts(state, Pred, Tag, C, Sym, *T); 3659 if (!state) 3660 return; 3661 3662 // Fetch the new reference count from the state, and use it to handle 3663 // this symbol. 3664 state = handleSymbolDeath(state, *I, *getRefBinding(state, Sym), Leaked); 3665 } 3666 } 3667 3668 if (Leaked.empty()) { 3669 C.addTransition(state); 3670 return; 3671 } 3672 3673 Pred = processLeaks(state, Leaked, C, Pred); 3674 3675 // Did we cache out? 3676 if (!Pred) 3677 return; 3678 3679 // Now generate a new node that nukes the old bindings. 3680 // The only bindings left at this point are the leaked symbols. 3681 RefBindingsTy::Factory &F = state->get_context<RefBindings>(); 3682 B = state->get<RefBindings>(); 3683 3684 for (SmallVectorImpl<SymbolRef>::iterator I = Leaked.begin(), 3685 E = Leaked.end(); 3686 I != E; ++I) 3687 B = F.remove(B, *I); 3688 3689 state = state->set<RefBindings>(B); 3690 C.addTransition(state, Pred); 3691} 3692 3693void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State, 3694 const char *NL, const char *Sep) const { 3695 3696 RefBindingsTy B = State->get<RefBindings>(); 3697 3698 if (B.isEmpty()) 3699 return; 3700 3701 Out << Sep << NL; 3702 3703 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3704 Out << I->first << " : "; 3705 I->second.print(Out); 3706 Out << NL; 3707 } 3708} 3709 3710//===----------------------------------------------------------------------===// 3711// Checker registration. 3712//===----------------------------------------------------------------------===// 3713 3714void ento::registerRetainCountChecker(CheckerManager &Mgr) { 3715 Mgr.registerChecker<RetainCountChecker>(); 3716} 3717 3718