RetainCountChecker.cpp revision 785950e59424dca7ce0081bebf13c0acd2c4fff6
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/DeclObjC.h" 17#include "clang/AST/DeclCXX.h" 18#include "clang/Basic/LangOptions.h" 19#include "clang/Basic/SourceManager.h" 20#include "clang/Analysis/DomainSpecific/CocoaConventions.h" 21#include "clang/AST/ParentMap.h" 22#include "clang/StaticAnalyzer/Core/Checker.h" 23#include "clang/StaticAnalyzer/Core/CheckerManager.h" 24#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 25#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" 26#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 27#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 28#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 29#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h" 30#include "llvm/ADT/DenseMap.h" 31#include "llvm/ADT/FoldingSet.h" 32#include "llvm/ADT/ImmutableList.h" 33#include "llvm/ADT/ImmutableMap.h" 34#include "llvm/ADT/SmallString.h" 35#include "llvm/ADT/STLExtras.h" 36#include "llvm/ADT/StringExtras.h" 37#include <cstdarg> 38 39using namespace clang; 40using namespace ento; 41using llvm::StrInStrNoCase; 42 43//===----------------------------------------------------------------------===// 44// Primitives used for constructing summaries for function/method calls. 45//===----------------------------------------------------------------------===// 46 47/// ArgEffect is used to summarize a function/method call's effect on a 48/// particular argument. 49enum ArgEffect { DoNothing, Autorelease, Dealloc, DecRef, DecRefMsg, 50 DecRefBridgedTransfered, 51 IncRefMsg, IncRef, MakeCollectable, MayEscape, 52 NewAutoreleasePool, 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 345typedef llvm::ImmutableMap<SymbolRef, RefVal> RefBindings; 346 347namespace clang { 348namespace ento { 349template<> 350struct ProgramStateTrait<RefBindings> 351 : public ProgramStatePartialTrait<RefBindings> { 352 static void *GDMIndex() { 353 static int RefBIndex = 0; 354 return &RefBIndex; 355 } 356}; 357} 358} 359 360static inline const RefVal *getRefBinding(ProgramStateRef State, 361 SymbolRef Sym) { 362 return State->get<RefBindings>(Sym); 363} 364 365static inline ProgramStateRef setRefBinding(ProgramStateRef State, 366 SymbolRef Sym, RefVal Val) { 367 return State->set<RefBindings>(Sym, Val); 368} 369 370static ProgramStateRef removeRefBinding(ProgramStateRef State, SymbolRef Sym) { 371 return State->remove<RefBindings>(Sym); 372} 373 374//===----------------------------------------------------------------------===// 375// Function/Method behavior summaries. 376//===----------------------------------------------------------------------===// 377 378namespace { 379class RetainSummary { 380 /// Args - a map of (index, ArgEffect) pairs, where index 381 /// specifies the argument (starting from 0). This can be sparsely 382 /// populated; arguments with no entry in Args use 'DefaultArgEffect'. 383 ArgEffects Args; 384 385 /// DefaultArgEffect - The default ArgEffect to apply to arguments that 386 /// do not have an entry in Args. 387 ArgEffect DefaultArgEffect; 388 389 /// Receiver - If this summary applies to an Objective-C message expression, 390 /// this is the effect applied to the state of the receiver. 391 ArgEffect Receiver; 392 393 /// Ret - The effect on the return value. Used to indicate if the 394 /// function/method call returns a new tracked symbol. 395 RetEffect Ret; 396 397public: 398 RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff, 399 ArgEffect ReceiverEff) 400 : Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {} 401 402 /// getArg - Return the argument effect on the argument specified by 403 /// idx (starting from 0). 404 ArgEffect getArg(unsigned idx) const { 405 if (const ArgEffect *AE = Args.lookup(idx)) 406 return *AE; 407 408 return DefaultArgEffect; 409 } 410 411 void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) { 412 Args = af.add(Args, idx, e); 413 } 414 415 /// setDefaultArgEffect - Set the default argument effect. 416 void setDefaultArgEffect(ArgEffect E) { 417 DefaultArgEffect = E; 418 } 419 420 /// getRetEffect - Returns the effect on the return value of the call. 421 RetEffect getRetEffect() const { return Ret; } 422 423 /// setRetEffect - Set the effect of the return value of the call. 424 void setRetEffect(RetEffect E) { Ret = E; } 425 426 427 /// Sets the effect on the receiver of the message. 428 void setReceiverEffect(ArgEffect e) { Receiver = e; } 429 430 /// getReceiverEffect - Returns the effect on the receiver of the call. 431 /// This is only meaningful if the summary applies to an ObjCMessageExpr*. 432 ArgEffect getReceiverEffect() const { return Receiver; } 433 434 /// Test if two retain summaries are identical. Note that merely equivalent 435 /// summaries are not necessarily identical (for example, if an explicit 436 /// argument effect matches the default effect). 437 bool operator==(const RetainSummary &Other) const { 438 return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect && 439 Receiver == Other.Receiver && Ret == Other.Ret; 440 } 441 442 /// Profile this summary for inclusion in a FoldingSet. 443 void Profile(llvm::FoldingSetNodeID& ID) const { 444 ID.Add(Args); 445 ID.Add(DefaultArgEffect); 446 ID.Add(Receiver); 447 ID.Add(Ret); 448 } 449 450 /// A retain summary is simple if it has no ArgEffects other than the default. 451 bool isSimple() const { 452 return Args.isEmpty(); 453 } 454 455private: 456 ArgEffects getArgEffects() const { return Args; } 457 ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; } 458 459 friend class RetainSummaryManager; 460}; 461} // end anonymous namespace 462 463//===----------------------------------------------------------------------===// 464// Data structures for constructing summaries. 465//===----------------------------------------------------------------------===// 466 467namespace { 468class ObjCSummaryKey { 469 IdentifierInfo* II; 470 Selector S; 471public: 472 ObjCSummaryKey(IdentifierInfo* ii, Selector s) 473 : II(ii), S(s) {} 474 475 ObjCSummaryKey(const ObjCInterfaceDecl *d, Selector s) 476 : II(d ? d->getIdentifier() : 0), S(s) {} 477 478 ObjCSummaryKey(Selector s) 479 : II(0), S(s) {} 480 481 IdentifierInfo *getIdentifier() const { return II; } 482 Selector getSelector() const { return S; } 483}; 484} 485 486namespace llvm { 487template <> struct DenseMapInfo<ObjCSummaryKey> { 488 static inline ObjCSummaryKey getEmptyKey() { 489 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getEmptyKey(), 490 DenseMapInfo<Selector>::getEmptyKey()); 491 } 492 493 static inline ObjCSummaryKey getTombstoneKey() { 494 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getTombstoneKey(), 495 DenseMapInfo<Selector>::getTombstoneKey()); 496 } 497 498 static unsigned getHashValue(const ObjCSummaryKey &V) { 499 typedef std::pair<IdentifierInfo*, Selector> PairTy; 500 return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(), 501 V.getSelector())); 502 } 503 504 static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) { 505 return LHS.getIdentifier() == RHS.getIdentifier() && 506 LHS.getSelector() == RHS.getSelector(); 507 } 508 509}; 510template <> 511struct isPodLike<ObjCSummaryKey> { static const bool value = true; }; 512} // end llvm namespace 513 514namespace { 515class ObjCSummaryCache { 516 typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy; 517 MapTy M; 518public: 519 ObjCSummaryCache() {} 520 521 const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) { 522 // Do a lookup with the (D,S) pair. If we find a match return 523 // the iterator. 524 ObjCSummaryKey K(D, S); 525 MapTy::iterator I = M.find(K); 526 527 if (I != M.end()) 528 return I->second; 529 if (!D) 530 return NULL; 531 532 // Walk the super chain. If we find a hit with a parent, we'll end 533 // up returning that summary. We actually allow that key (null,S), as 534 // we cache summaries for the null ObjCInterfaceDecl* to allow us to 535 // generate initial summaries without having to worry about NSObject 536 // being declared. 537 // FIXME: We may change this at some point. 538 for (ObjCInterfaceDecl *C=D->getSuperClass() ;; C=C->getSuperClass()) { 539 if ((I = M.find(ObjCSummaryKey(C, S))) != M.end()) 540 break; 541 542 if (!C) 543 return NULL; 544 } 545 546 // Cache the summary with original key to make the next lookup faster 547 // and return the iterator. 548 const RetainSummary *Summ = I->second; 549 M[K] = Summ; 550 return Summ; 551 } 552 553 const RetainSummary *find(IdentifierInfo* II, Selector S) { 554 // FIXME: Class method lookup. Right now we dont' have a good way 555 // of going between IdentifierInfo* and the class hierarchy. 556 MapTy::iterator I = M.find(ObjCSummaryKey(II, S)); 557 558 if (I == M.end()) 559 I = M.find(ObjCSummaryKey(S)); 560 561 return I == M.end() ? NULL : I->second; 562 } 563 564 const RetainSummary *& operator[](ObjCSummaryKey K) { 565 return M[K]; 566 } 567 568 const RetainSummary *& operator[](Selector S) { 569 return M[ ObjCSummaryKey(S) ]; 570 } 571}; 572} // end anonymous namespace 573 574//===----------------------------------------------------------------------===// 575// Data structures for managing collections of summaries. 576//===----------------------------------------------------------------------===// 577 578namespace { 579class RetainSummaryManager { 580 581 //==-----------------------------------------------------------------==// 582 // Typedefs. 583 //==-----------------------------------------------------------------==// 584 585 typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *> 586 FuncSummariesTy; 587 588 typedef ObjCSummaryCache ObjCMethodSummariesTy; 589 590 typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode; 591 592 //==-----------------------------------------------------------------==// 593 // Data. 594 //==-----------------------------------------------------------------==// 595 596 /// Ctx - The ASTContext object for the analyzed ASTs. 597 ASTContext &Ctx; 598 599 /// GCEnabled - Records whether or not the analyzed code runs in GC mode. 600 const bool GCEnabled; 601 602 /// Records whether or not the analyzed code runs in ARC mode. 603 const bool ARCEnabled; 604 605 /// FuncSummaries - A map from FunctionDecls to summaries. 606 FuncSummariesTy FuncSummaries; 607 608 /// ObjCClassMethodSummaries - A map from selectors (for instance methods) 609 /// to summaries. 610 ObjCMethodSummariesTy ObjCClassMethodSummaries; 611 612 /// ObjCMethodSummaries - A map from selectors to summaries. 613 ObjCMethodSummariesTy ObjCMethodSummaries; 614 615 /// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects, 616 /// and all other data used by the checker. 617 llvm::BumpPtrAllocator BPAlloc; 618 619 /// AF - A factory for ArgEffects objects. 620 ArgEffects::Factory AF; 621 622 /// ScratchArgs - A holding buffer for construct ArgEffects. 623 ArgEffects ScratchArgs; 624 625 /// ObjCAllocRetE - Default return effect for methods returning Objective-C 626 /// objects. 627 RetEffect ObjCAllocRetE; 628 629 /// ObjCInitRetE - Default return effect for init methods returning 630 /// Objective-C objects. 631 RetEffect ObjCInitRetE; 632 633 /// SimpleSummaries - Used for uniquing summaries that don't have special 634 /// effects. 635 llvm::FoldingSet<CachedSummaryNode> SimpleSummaries; 636 637 //==-----------------------------------------------------------------==// 638 // Methods. 639 //==-----------------------------------------------------------------==// 640 641 /// getArgEffects - Returns a persistent ArgEffects object based on the 642 /// data in ScratchArgs. 643 ArgEffects getArgEffects(); 644 645 enum UnaryFuncKind { cfretain, cfrelease, cfmakecollectable }; 646 647 const RetainSummary *getUnarySummary(const FunctionType* FT, 648 UnaryFuncKind func); 649 650 const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD); 651 const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD); 652 const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD); 653 654 const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm); 655 656 const RetainSummary *getPersistentSummary(RetEffect RetEff, 657 ArgEffect ReceiverEff = DoNothing, 658 ArgEffect DefaultEff = MayEscape) { 659 RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff); 660 return getPersistentSummary(Summ); 661 } 662 663 const RetainSummary *getDoNothingSummary() { 664 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 665 } 666 667 const RetainSummary *getDefaultSummary() { 668 return getPersistentSummary(RetEffect::MakeNoRet(), 669 DoNothing, MayEscape); 670 } 671 672 const RetainSummary *getPersistentStopSummary() { 673 return getPersistentSummary(RetEffect::MakeNoRet(), 674 StopTracking, StopTracking); 675 } 676 677 void InitializeClassMethodSummaries(); 678 void InitializeMethodSummaries(); 679private: 680 void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) { 681 ObjCClassMethodSummaries[S] = Summ; 682 } 683 684 void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) { 685 ObjCMethodSummaries[S] = Summ; 686 } 687 688 void addClassMethSummary(const char* Cls, const char* name, 689 const RetainSummary *Summ, bool isNullary = true) { 690 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 691 Selector S = isNullary ? GetNullarySelector(name, Ctx) 692 : GetUnarySelector(name, Ctx); 693 ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 694 } 695 696 void addInstMethSummary(const char* Cls, const char* nullaryName, 697 const RetainSummary *Summ) { 698 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 699 Selector S = GetNullarySelector(nullaryName, Ctx); 700 ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 701 } 702 703 Selector generateSelector(va_list argp) { 704 SmallVector<IdentifierInfo*, 10> II; 705 706 while (const char* s = va_arg(argp, const char*)) 707 II.push_back(&Ctx.Idents.get(s)); 708 709 return Ctx.Selectors.getSelector(II.size(), &II[0]); 710 } 711 712 void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy& Summaries, 713 const RetainSummary * Summ, va_list argp) { 714 Selector S = generateSelector(argp); 715 Summaries[ObjCSummaryKey(ClsII, S)] = Summ; 716 } 717 718 void addInstMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 719 va_list argp; 720 va_start(argp, Summ); 721 addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp); 722 va_end(argp); 723 } 724 725 void addClsMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 726 va_list argp; 727 va_start(argp, Summ); 728 addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp); 729 va_end(argp); 730 } 731 732 void addClsMethSummary(IdentifierInfo *II, const RetainSummary * Summ, ...) { 733 va_list argp; 734 va_start(argp, Summ); 735 addMethodSummary(II, ObjCClassMethodSummaries, Summ, argp); 736 va_end(argp); 737 } 738 739public: 740 741 RetainSummaryManager(ASTContext &ctx, bool gcenabled, bool usesARC) 742 : Ctx(ctx), 743 GCEnabled(gcenabled), 744 ARCEnabled(usesARC), 745 AF(BPAlloc), ScratchArgs(AF.getEmptyMap()), 746 ObjCAllocRetE(gcenabled 747 ? RetEffect::MakeGCNotOwned() 748 : (usesARC ? RetEffect::MakeARCNotOwned() 749 : RetEffect::MakeOwned(RetEffect::ObjC, true))), 750 ObjCInitRetE(gcenabled 751 ? RetEffect::MakeGCNotOwned() 752 : (usesARC ? RetEffect::MakeARCNotOwned() 753 : RetEffect::MakeOwnedWhenTrackedReceiver())) { 754 InitializeClassMethodSummaries(); 755 InitializeMethodSummaries(); 756 } 757 758 const RetainSummary *getSummary(const CallEvent &Call, 759 ProgramStateRef State = 0); 760 761 const RetainSummary *getFunctionSummary(const FunctionDecl *FD); 762 763 const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 764 const ObjCMethodDecl *MD, 765 QualType RetTy, 766 ObjCMethodSummariesTy &CachedSummaries); 767 768 const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M, 769 ProgramStateRef State); 770 771 const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) { 772 assert(!M.isInstanceMessage()); 773 const ObjCInterfaceDecl *Class = M.getReceiverInterface(); 774 775 return getMethodSummary(M.getSelector(), Class, M.getDecl(), 776 M.getResultType(), ObjCClassMethodSummaries); 777 } 778 779 /// getMethodSummary - This version of getMethodSummary is used to query 780 /// the summary for the current method being analyzed. 781 const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) { 782 const ObjCInterfaceDecl *ID = MD->getClassInterface(); 783 Selector S = MD->getSelector(); 784 QualType ResultTy = MD->getResultType(); 785 786 ObjCMethodSummariesTy *CachedSummaries; 787 if (MD->isInstanceMethod()) 788 CachedSummaries = &ObjCMethodSummaries; 789 else 790 CachedSummaries = &ObjCClassMethodSummaries; 791 792 return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries); 793 } 794 795 const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD, 796 Selector S, QualType RetTy); 797 798 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 799 const ObjCMethodDecl *MD); 800 801 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 802 const FunctionDecl *FD); 803 804 void updateSummaryForCall(const RetainSummary *&Summ, 805 const CallEvent &Call); 806 807 bool isGCEnabled() const { return GCEnabled; } 808 809 bool isARCEnabled() const { return ARCEnabled; } 810 811 bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; } 812 813 RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; } 814 815 friend class RetainSummaryTemplate; 816}; 817 818// Used to avoid allocating long-term (BPAlloc'd) memory for default retain 819// summaries. If a function or method looks like it has a default summary, but 820// it has annotations, the annotations are added to the stack-based template 821// and then copied into managed memory. 822class RetainSummaryTemplate { 823 RetainSummaryManager &Manager; 824 const RetainSummary *&RealSummary; 825 RetainSummary ScratchSummary; 826 bool Accessed; 827public: 828 RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr) 829 : Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {} 830 831 ~RetainSummaryTemplate() { 832 if (Accessed) 833 RealSummary = Manager.getPersistentSummary(ScratchSummary); 834 } 835 836 RetainSummary &operator*() { 837 Accessed = true; 838 return ScratchSummary; 839 } 840 841 RetainSummary *operator->() { 842 Accessed = true; 843 return &ScratchSummary; 844 } 845}; 846 847} // end anonymous namespace 848 849//===----------------------------------------------------------------------===// 850// Implementation of checker data structures. 851//===----------------------------------------------------------------------===// 852 853ArgEffects RetainSummaryManager::getArgEffects() { 854 ArgEffects AE = ScratchArgs; 855 ScratchArgs = AF.getEmptyMap(); 856 return AE; 857} 858 859const RetainSummary * 860RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) { 861 // Unique "simple" summaries -- those without ArgEffects. 862 if (OldSumm.isSimple()) { 863 llvm::FoldingSetNodeID ID; 864 OldSumm.Profile(ID); 865 866 void *Pos; 867 CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos); 868 869 if (!N) { 870 N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>(); 871 new (N) CachedSummaryNode(OldSumm); 872 SimpleSummaries.InsertNode(N, Pos); 873 } 874 875 return &N->getValue(); 876 } 877 878 RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>(); 879 new (Summ) RetainSummary(OldSumm); 880 return Summ; 881} 882 883//===----------------------------------------------------------------------===// 884// Summary creation for functions (largely uses of Core Foundation). 885//===----------------------------------------------------------------------===// 886 887static bool isRetain(const FunctionDecl *FD, StringRef FName) { 888 return FName.endswith("Retain"); 889} 890 891static bool isRelease(const FunctionDecl *FD, StringRef FName) { 892 return FName.endswith("Release"); 893} 894 895static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) { 896 // FIXME: Remove FunctionDecl parameter. 897 // FIXME: Is it really okay if MakeCollectable isn't a suffix? 898 return FName.find("MakeCollectable") != StringRef::npos; 899} 900 901static ArgEffect getStopTrackingHardEquivalent(ArgEffect E) { 902 switch (E) { 903 case DoNothing: 904 case Autorelease: 905 case DecRefBridgedTransfered: 906 case IncRef: 907 case IncRefMsg: 908 case MakeCollectable: 909 case MayEscape: 910 case NewAutoreleasePool: 911 case StopTracking: 912 case StopTrackingHard: 913 return StopTrackingHard; 914 case DecRef: 915 case DecRefAndStopTrackingHard: 916 return DecRefAndStopTrackingHard; 917 case DecRefMsg: 918 case DecRefMsgAndStopTrackingHard: 919 return DecRefMsgAndStopTrackingHard; 920 case Dealloc: 921 return Dealloc; 922 } 923 924 llvm_unreachable("Unknown ArgEffect kind"); 925} 926 927void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S, 928 const CallEvent &Call) { 929 if (Call.hasNonZeroCallbackArg()) { 930 ArgEffect RecEffect = 931 getStopTrackingHardEquivalent(S->getReceiverEffect()); 932 ArgEffect DefEffect = 933 getStopTrackingHardEquivalent(S->getDefaultArgEffect()); 934 935 ArgEffects CustomArgEffects = S->getArgEffects(); 936 for (ArgEffects::iterator I = CustomArgEffects.begin(), 937 E = CustomArgEffects.end(); 938 I != E; ++I) { 939 ArgEffect Translated = getStopTrackingHardEquivalent(I->second); 940 if (Translated != DefEffect) 941 ScratchArgs = AF.add(ScratchArgs, I->first, Translated); 942 } 943 944 RetEffect RE = RetEffect::MakeNoRetHard(); 945 946 // Special cases where the callback argument CANNOT free the return value. 947 // This can generally only happen if we know that the callback will only be 948 // called when the return value is already being deallocated. 949 if (const FunctionCall *FC = dyn_cast<FunctionCall>(&Call)) { 950 if (IdentifierInfo *Name = FC->getDecl()->getIdentifier()) { 951 // When the CGBitmapContext is deallocated, the callback here will free 952 // the associated data buffer. 953 if (Name->isStr("CGBitmapContextCreateWithData")) 954 RE = S->getRetEffect(); 955 } 956 } 957 958 S = getPersistentSummary(RE, RecEffect, DefEffect); 959 } 960 961 // Special case '[super init];' and '[self init];' 962 // 963 // Even though calling '[super init]' without assigning the result to self 964 // and checking if the parent returns 'nil' is a bad pattern, it is common. 965 // Additionally, our Self Init checker already warns about it. To avoid 966 // overwhelming the user with messages from both checkers, we model the case 967 // of '[super init]' in cases when it is not consumed by another expression 968 // as if the call preserves the value of 'self'; essentially, assuming it can 969 // never fail and return 'nil'. 970 // Note, we don't want to just stop tracking the value since we want the 971 // RetainCount checker to report leaks and use-after-free if SelfInit checker 972 // is turned off. 973 if (const ObjCMethodCall *MC = dyn_cast<ObjCMethodCall>(&Call)) { 974 if (MC->getMethodFamily() == OMF_init && MC->isReceiverSelfOrSuper()) { 975 976 // Check if the message is not consumed, we know it will not be used in 977 // an assignment, ex: "self = [super init]". 978 const Expr *ME = MC->getOriginExpr(); 979 const LocationContext *LCtx = MC->getLocationContext(); 980 ParentMap &PM = LCtx->getAnalysisDeclContext()->getParentMap(); 981 if (!PM.isConsumedExpr(ME)) { 982 RetainSummaryTemplate ModifiableSummaryTemplate(S, *this); 983 ModifiableSummaryTemplate->setReceiverEffect(DoNothing); 984 ModifiableSummaryTemplate->setRetEffect(RetEffect::MakeNoRet()); 985 } 986 } 987 988 } 989} 990 991const RetainSummary * 992RetainSummaryManager::getSummary(const CallEvent &Call, 993 ProgramStateRef State) { 994 const RetainSummary *Summ; 995 switch (Call.getKind()) { 996 case CE_Function: 997 Summ = getFunctionSummary(cast<FunctionCall>(Call).getDecl()); 998 break; 999 case CE_CXXMember: 1000 case CE_CXXMemberOperator: 1001 case CE_Block: 1002 case CE_CXXConstructor: 1003 case CE_CXXDestructor: 1004 case CE_CXXAllocator: 1005 // FIXME: These calls are currently unsupported. 1006 return getPersistentStopSummary(); 1007 case CE_ObjCMessage: { 1008 const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call); 1009 if (Msg.isInstanceMessage()) 1010 Summ = getInstanceMethodSummary(Msg, State); 1011 else 1012 Summ = getClassMethodSummary(Msg); 1013 break; 1014 } 1015 } 1016 1017 updateSummaryForCall(Summ, Call); 1018 1019 assert(Summ && "Unknown call type?"); 1020 return Summ; 1021} 1022 1023const RetainSummary * 1024RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) { 1025 // If we don't know what function we're calling, use our default summary. 1026 if (!FD) 1027 return getDefaultSummary(); 1028 1029 // Look up a summary in our cache of FunctionDecls -> Summaries. 1030 FuncSummariesTy::iterator I = FuncSummaries.find(FD); 1031 if (I != FuncSummaries.end()) 1032 return I->second; 1033 1034 // No summary? Generate one. 1035 const RetainSummary *S = 0; 1036 bool AllowAnnotations = true; 1037 1038 do { 1039 // We generate "stop" summaries for implicitly defined functions. 1040 if (FD->isImplicit()) { 1041 S = getPersistentStopSummary(); 1042 break; 1043 } 1044 1045 // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the 1046 // function's type. 1047 const FunctionType* FT = FD->getType()->getAs<FunctionType>(); 1048 const IdentifierInfo *II = FD->getIdentifier(); 1049 if (!II) 1050 break; 1051 1052 StringRef FName = II->getName(); 1053 1054 // Strip away preceding '_'. Doing this here will effect all the checks 1055 // down below. 1056 FName = FName.substr(FName.find_first_not_of('_')); 1057 1058 // Inspect the result type. 1059 QualType RetTy = FT->getResultType(); 1060 1061 // FIXME: This should all be refactored into a chain of "summary lookup" 1062 // filters. 1063 assert(ScratchArgs.isEmpty()); 1064 1065 if (FName == "pthread_create" || FName == "pthread_setspecific") { 1066 // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>. 1067 // This will be addressed better with IPA. 1068 S = getPersistentStopSummary(); 1069 } else if (FName == "NSMakeCollectable") { 1070 // Handle: id NSMakeCollectable(CFTypeRef) 1071 S = (RetTy->isObjCIdType()) 1072 ? getUnarySummary(FT, cfmakecollectable) 1073 : getPersistentStopSummary(); 1074 // The headers on OS X 10.8 use cf_consumed/ns_returns_retained, 1075 // but we can fully model NSMakeCollectable ourselves. 1076 AllowAnnotations = false; 1077 } else if (FName == "CFPlugInInstanceCreate") { 1078 S = getPersistentSummary(RetEffect::MakeNoRet()); 1079 } else if (FName == "IOBSDNameMatching" || 1080 FName == "IOServiceMatching" || 1081 FName == "IOServiceNameMatching" || 1082 FName == "IORegistryEntrySearchCFProperty" || 1083 FName == "IORegistryEntryIDMatching" || 1084 FName == "IOOpenFirmwarePathMatching") { 1085 // Part of <rdar://problem/6961230>. (IOKit) 1086 // This should be addressed using a API table. 1087 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1088 DoNothing, DoNothing); 1089 } else if (FName == "IOServiceGetMatchingService" || 1090 FName == "IOServiceGetMatchingServices") { 1091 // FIXES: <rdar://problem/6326900> 1092 // This should be addressed using a API table. This strcmp is also 1093 // a little gross, but there is no need to super optimize here. 1094 ScratchArgs = AF.add(ScratchArgs, 1, DecRef); 1095 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1096 } else if (FName == "IOServiceAddNotification" || 1097 FName == "IOServiceAddMatchingNotification") { 1098 // Part of <rdar://problem/6961230>. (IOKit) 1099 // This should be addressed using a API table. 1100 ScratchArgs = AF.add(ScratchArgs, 2, DecRef); 1101 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1102 } else if (FName == "CVPixelBufferCreateWithBytes") { 1103 // FIXES: <rdar://problem/7283567> 1104 // Eventually this can be improved by recognizing that the pixel 1105 // buffer passed to CVPixelBufferCreateWithBytes is released via 1106 // a callback and doing full IPA to make sure this is done correctly. 1107 // FIXME: This function has an out parameter that returns an 1108 // allocated object. 1109 ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); 1110 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1111 } else if (FName == "CGBitmapContextCreateWithData") { 1112 // FIXES: <rdar://problem/7358899> 1113 // Eventually this can be improved by recognizing that 'releaseInfo' 1114 // passed to CGBitmapContextCreateWithData is released via 1115 // a callback and doing full IPA to make sure this is done correctly. 1116 ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); 1117 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1118 DoNothing, DoNothing); 1119 } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { 1120 // FIXES: <rdar://problem/7283567> 1121 // Eventually this can be improved by recognizing that the pixel 1122 // buffer passed to CVPixelBufferCreateWithPlanarBytes is released 1123 // via a callback and doing full IPA to make sure this is done 1124 // correctly. 1125 ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); 1126 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1127 } else if (FName == "dispatch_set_context") { 1128 // <rdar://problem/11059275> - The analyzer currently doesn't have 1129 // a good way to reason about the finalizer function for libdispatch. 1130 // If we pass a context object that is memory managed, stop tracking it. 1131 // FIXME: this hack should possibly go away once we can handle 1132 // libdispatch finalizers. 1133 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1134 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1135 } else if (FName.startswith("NSLog")) { 1136 S = getDoNothingSummary(); 1137 } else if (FName.startswith("NS") && 1138 (FName.find("Insert") != StringRef::npos)) { 1139 // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 1140 // be deallocated by NSMapRemove. (radar://11152419) 1141 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1142 ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); 1143 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1144 } 1145 1146 // Did we get a summary? 1147 if (S) 1148 break; 1149 1150 if (RetTy->isPointerType()) { 1151 if (FD->getAttr<CFAuditedTransferAttr>()) { 1152 S = getCFCreateGetRuleSummary(FD); 1153 break; 1154 } 1155 1156 // For CoreFoundation ('CF') types. 1157 if (cocoa::isRefType(RetTy, "CF", FName)) { 1158 if (isRetain(FD, FName)) 1159 S = getUnarySummary(FT, cfretain); 1160 else if (isMakeCollectable(FD, FName)) 1161 S = getUnarySummary(FT, cfmakecollectable); 1162 else 1163 S = getCFCreateGetRuleSummary(FD); 1164 1165 break; 1166 } 1167 1168 // For CoreGraphics ('CG') types. 1169 if (cocoa::isRefType(RetTy, "CG", FName)) { 1170 if (isRetain(FD, FName)) 1171 S = getUnarySummary(FT, cfretain); 1172 else 1173 S = getCFCreateGetRuleSummary(FD); 1174 1175 break; 1176 } 1177 1178 // For the Disk Arbitration API (DiskArbitration/DADisk.h) 1179 if (cocoa::isRefType(RetTy, "DADisk") || 1180 cocoa::isRefType(RetTy, "DADissenter") || 1181 cocoa::isRefType(RetTy, "DASessionRef")) { 1182 S = getCFCreateGetRuleSummary(FD); 1183 break; 1184 } 1185 1186 break; 1187 } 1188 1189 // Check for release functions, the only kind of functions that we care 1190 // about that don't return a pointer type. 1191 if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { 1192 // Test for 'CGCF'. 1193 FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); 1194 1195 if (isRelease(FD, FName)) 1196 S = getUnarySummary(FT, cfrelease); 1197 else { 1198 assert (ScratchArgs.isEmpty()); 1199 // Remaining CoreFoundation and CoreGraphics functions. 1200 // We use to assume that they all strictly followed the ownership idiom 1201 // and that ownership cannot be transferred. While this is technically 1202 // correct, many methods allow a tracked object to escape. For example: 1203 // 1204 // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); 1205 // CFDictionaryAddValue(y, key, x); 1206 // CFRelease(x); 1207 // ... it is okay to use 'x' since 'y' has a reference to it 1208 // 1209 // We handle this and similar cases with the follow heuristic. If the 1210 // function name contains "InsertValue", "SetValue", "AddValue", 1211 // "AppendValue", or "SetAttribute", then we assume that arguments may 1212 // "escape." This means that something else holds on to the object, 1213 // allowing it be used even after its local retain count drops to 0. 1214 ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| 1215 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 1216 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 1217 StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| 1218 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) 1219 ? MayEscape : DoNothing; 1220 1221 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); 1222 } 1223 } 1224 } 1225 while (0); 1226 1227 // If we got all the way here without any luck, use a default summary. 1228 if (!S) 1229 S = getDefaultSummary(); 1230 1231 // Annotations override defaults. 1232 if (AllowAnnotations) 1233 updateSummaryFromAnnotations(S, FD); 1234 1235 FuncSummaries[FD] = S; 1236 return S; 1237} 1238 1239const RetainSummary * 1240RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { 1241 if (coreFoundation::followsCreateRule(FD)) 1242 return getCFSummaryCreateRule(FD); 1243 1244 return getCFSummaryGetRule(FD); 1245} 1246 1247const RetainSummary * 1248RetainSummaryManager::getUnarySummary(const FunctionType* FT, 1249 UnaryFuncKind func) { 1250 1251 // Sanity check that this is *really* a unary function. This can 1252 // happen if people do weird things. 1253 const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); 1254 if (!FTP || FTP->getNumArgs() != 1) 1255 return getPersistentStopSummary(); 1256 1257 assert (ScratchArgs.isEmpty()); 1258 1259 ArgEffect Effect; 1260 switch (func) { 1261 case cfretain: Effect = IncRef; break; 1262 case cfrelease: Effect = DecRef; break; 1263 case cfmakecollectable: Effect = MakeCollectable; break; 1264 } 1265 1266 ScratchArgs = AF.add(ScratchArgs, 0, Effect); 1267 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1268} 1269 1270const RetainSummary * 1271RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { 1272 assert (ScratchArgs.isEmpty()); 1273 1274 return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1275} 1276 1277const RetainSummary * 1278RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { 1279 assert (ScratchArgs.isEmpty()); 1280 return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), 1281 DoNothing, DoNothing); 1282} 1283 1284//===----------------------------------------------------------------------===// 1285// Summary creation for Selectors. 1286//===----------------------------------------------------------------------===// 1287 1288void 1289RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1290 const FunctionDecl *FD) { 1291 if (!FD) 1292 return; 1293 1294 assert(Summ && "Must have a summary to add annotations to."); 1295 RetainSummaryTemplate Template(Summ, *this); 1296 1297 // Effects on the parameters. 1298 unsigned parm_idx = 0; 1299 for (FunctionDecl::param_const_iterator pi = FD->param_begin(), 1300 pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { 1301 const ParmVarDecl *pd = *pi; 1302 if (pd->getAttr<NSConsumedAttr>()) { 1303 if (!GCEnabled) { 1304 Template->addArg(AF, parm_idx, DecRef); 1305 } 1306 } else if (pd->getAttr<CFConsumedAttr>()) { 1307 Template->addArg(AF, parm_idx, DecRef); 1308 } 1309 } 1310 1311 QualType RetTy = FD->getResultType(); 1312 1313 // Determine if there is a special return effect for this method. 1314 if (cocoa::isCocoaObjectRef(RetTy)) { 1315 if (FD->getAttr<NSReturnsRetainedAttr>()) { 1316 Template->setRetEffect(ObjCAllocRetE); 1317 } 1318 else if (FD->getAttr<CFReturnsRetainedAttr>()) { 1319 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1320 } 1321 else if (FD->getAttr<NSReturnsNotRetainedAttr>()) { 1322 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1323 } 1324 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1325 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1326 } 1327 } else if (RetTy->getAs<PointerType>()) { 1328 if (FD->getAttr<CFReturnsRetainedAttr>()) { 1329 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1330 } 1331 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1332 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1333 } 1334 } 1335} 1336 1337void 1338RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1339 const ObjCMethodDecl *MD) { 1340 if (!MD) 1341 return; 1342 1343 assert(Summ && "Must have a valid summary to add annotations to"); 1344 RetainSummaryTemplate Template(Summ, *this); 1345 bool isTrackedLoc = false; 1346 1347 // Effects on the receiver. 1348 if (MD->getAttr<NSConsumesSelfAttr>()) { 1349 if (!GCEnabled) 1350 Template->setReceiverEffect(DecRefMsg); 1351 } 1352 1353 // Effects on the parameters. 1354 unsigned parm_idx = 0; 1355 for (ObjCMethodDecl::param_const_iterator 1356 pi=MD->param_begin(), pe=MD->param_end(); 1357 pi != pe; ++pi, ++parm_idx) { 1358 const ParmVarDecl *pd = *pi; 1359 if (pd->getAttr<NSConsumedAttr>()) { 1360 if (!GCEnabled) 1361 Template->addArg(AF, parm_idx, DecRef); 1362 } 1363 else if(pd->getAttr<CFConsumedAttr>()) { 1364 Template->addArg(AF, parm_idx, DecRef); 1365 } 1366 } 1367 1368 // Determine if there is a special return effect for this method. 1369 if (cocoa::isCocoaObjectRef(MD->getResultType())) { 1370 if (MD->getAttr<NSReturnsRetainedAttr>()) { 1371 Template->setRetEffect(ObjCAllocRetE); 1372 return; 1373 } 1374 if (MD->getAttr<NSReturnsNotRetainedAttr>()) { 1375 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1376 return; 1377 } 1378 1379 isTrackedLoc = true; 1380 } else { 1381 isTrackedLoc = MD->getResultType()->getAs<PointerType>() != NULL; 1382 } 1383 1384 if (isTrackedLoc) { 1385 if (MD->getAttr<CFReturnsRetainedAttr>()) 1386 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1387 else if (MD->getAttr<CFReturnsNotRetainedAttr>()) 1388 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1389 } 1390} 1391 1392const RetainSummary * 1393RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, 1394 Selector S, QualType RetTy) { 1395 // Any special effects? 1396 ArgEffect ReceiverEff = DoNothing; 1397 RetEffect ResultEff = RetEffect::MakeNoRet(); 1398 1399 // Check the method family, and apply any default annotations. 1400 switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { 1401 case OMF_None: 1402 case OMF_performSelector: 1403 // Assume all Objective-C methods follow Cocoa Memory Management rules. 1404 // FIXME: Does the non-threaded performSelector family really belong here? 1405 // The selector could be, say, @selector(copy). 1406 if (cocoa::isCocoaObjectRef(RetTy)) 1407 ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); 1408 else if (coreFoundation::isCFObjectRef(RetTy)) { 1409 // ObjCMethodDecl currently doesn't consider CF objects as valid return 1410 // values for alloc, new, copy, or mutableCopy, so we have to 1411 // double-check with the selector. This is ugly, but there aren't that 1412 // many Objective-C methods that return CF objects, right? 1413 if (MD) { 1414 switch (S.getMethodFamily()) { 1415 case OMF_alloc: 1416 case OMF_new: 1417 case OMF_copy: 1418 case OMF_mutableCopy: 1419 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1420 break; 1421 default: 1422 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1423 break; 1424 } 1425 } else { 1426 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1427 } 1428 } 1429 break; 1430 case OMF_init: 1431 ResultEff = ObjCInitRetE; 1432 ReceiverEff = DecRefMsg; 1433 break; 1434 case OMF_alloc: 1435 case OMF_new: 1436 case OMF_copy: 1437 case OMF_mutableCopy: 1438 if (cocoa::isCocoaObjectRef(RetTy)) 1439 ResultEff = ObjCAllocRetE; 1440 else if (coreFoundation::isCFObjectRef(RetTy)) 1441 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1442 break; 1443 case OMF_autorelease: 1444 ReceiverEff = Autorelease; 1445 break; 1446 case OMF_retain: 1447 ReceiverEff = IncRefMsg; 1448 break; 1449 case OMF_release: 1450 ReceiverEff = DecRefMsg; 1451 break; 1452 case OMF_dealloc: 1453 ReceiverEff = Dealloc; 1454 break; 1455 case OMF_self: 1456 // -self is handled specially by the ExprEngine to propagate the receiver. 1457 break; 1458 case OMF_retainCount: 1459 case OMF_finalize: 1460 // These methods don't return objects. 1461 break; 1462 } 1463 1464 // If one of the arguments in the selector has the keyword 'delegate' we 1465 // should stop tracking the reference count for the receiver. This is 1466 // because the reference count is quite possibly handled by a delegate 1467 // method. 1468 if (S.isKeywordSelector()) { 1469 for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { 1470 StringRef Slot = S.getNameForSlot(i); 1471 if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { 1472 if (ResultEff == ObjCInitRetE) 1473 ResultEff = RetEffect::MakeNoRetHard(); 1474 else 1475 ReceiverEff = StopTrackingHard; 1476 } 1477 } 1478 } 1479 1480 if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && 1481 ResultEff.getKind() == RetEffect::NoRet) 1482 return getDefaultSummary(); 1483 1484 return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); 1485} 1486 1487const RetainSummary * 1488RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, 1489 ProgramStateRef State) { 1490 const ObjCInterfaceDecl *ReceiverClass = 0; 1491 1492 // We do better tracking of the type of the object than the core ExprEngine. 1493 // See if we have its type in our private state. 1494 // FIXME: Eventually replace the use of state->get<RefBindings> with 1495 // a generic API for reasoning about the Objective-C types of symbolic 1496 // objects. 1497 SVal ReceiverV = Msg.getReceiverSVal(); 1498 if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) 1499 if (const RefVal *T = getRefBinding(State, Sym)) 1500 if (const ObjCObjectPointerType *PT = 1501 T->getType()->getAs<ObjCObjectPointerType>()) 1502 ReceiverClass = PT->getInterfaceDecl(); 1503 1504 // If we don't know what kind of object this is, fall back to its static type. 1505 if (!ReceiverClass) 1506 ReceiverClass = Msg.getReceiverInterface(); 1507 1508 // FIXME: The receiver could be a reference to a class, meaning that 1509 // we should use the class method. 1510 // id x = [NSObject class]; 1511 // [x performSelector:... withObject:... afterDelay:...]; 1512 Selector S = Msg.getSelector(); 1513 const ObjCMethodDecl *Method = Msg.getDecl(); 1514 if (!Method && ReceiverClass) 1515 Method = ReceiverClass->getInstanceMethod(S); 1516 1517 return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), 1518 ObjCMethodSummaries); 1519} 1520 1521const RetainSummary * 1522RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 1523 const ObjCMethodDecl *MD, QualType RetTy, 1524 ObjCMethodSummariesTy &CachedSummaries) { 1525 1526 // Look up a summary in our summary cache. 1527 const RetainSummary *Summ = CachedSummaries.find(ID, S); 1528 1529 if (!Summ) { 1530 Summ = getStandardMethodSummary(MD, S, RetTy); 1531 1532 // Annotations override defaults. 1533 updateSummaryFromAnnotations(Summ, MD); 1534 1535 // Memoize the summary. 1536 CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; 1537 } 1538 1539 return Summ; 1540} 1541 1542void RetainSummaryManager::InitializeClassMethodSummaries() { 1543 assert(ScratchArgs.isEmpty()); 1544 // Create the [NSAssertionHandler currentHander] summary. 1545 addClassMethSummary("NSAssertionHandler", "currentHandler", 1546 getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); 1547 1548 // Create the [NSAutoreleasePool addObject:] summary. 1549 ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); 1550 addClassMethSummary("NSAutoreleasePool", "addObject", 1551 getPersistentSummary(RetEffect::MakeNoRet(), 1552 DoNothing, Autorelease)); 1553} 1554 1555void RetainSummaryManager::InitializeMethodSummaries() { 1556 1557 assert (ScratchArgs.isEmpty()); 1558 1559 // Create the "init" selector. It just acts as a pass-through for the 1560 // receiver. 1561 const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); 1562 addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); 1563 1564 // awakeAfterUsingCoder: behaves basically like an 'init' method. It 1565 // claims the receiver and returns a retained object. 1566 addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), 1567 InitSumm); 1568 1569 // The next methods are allocators. 1570 const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); 1571 const RetainSummary *CFAllocSumm = 1572 getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1573 1574 // Create the "retain" selector. 1575 RetEffect NoRet = RetEffect::MakeNoRet(); 1576 const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); 1577 addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); 1578 1579 // Create the "release" selector. 1580 Summ = getPersistentSummary(NoRet, DecRefMsg); 1581 addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); 1582 1583 // Create the "drain" selector. 1584 Summ = getPersistentSummary(NoRet, isGCEnabled() ? DoNothing : DecRef); 1585 addNSObjectMethSummary(GetNullarySelector("drain", Ctx), Summ); 1586 1587 // Create the -dealloc summary. 1588 Summ = getPersistentSummary(NoRet, Dealloc); 1589 addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); 1590 1591 // Create the "autorelease" selector. 1592 Summ = getPersistentSummary(NoRet, Autorelease); 1593 addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); 1594 1595 // Specially handle NSAutoreleasePool. 1596 addInstMethSummary("NSAutoreleasePool", "init", 1597 getPersistentSummary(NoRet, NewAutoreleasePool)); 1598 1599 // For NSWindow, allocated objects are (initially) self-owned. 1600 // FIXME: For now we opt for false negatives with NSWindow, as these objects 1601 // self-own themselves. However, they only do this once they are displayed. 1602 // Thus, we need to track an NSWindow's display status. 1603 // This is tracked in <rdar://problem/6062711>. 1604 // See also http://llvm.org/bugs/show_bug.cgi?id=3714. 1605 const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), 1606 StopTracking, 1607 StopTracking); 1608 1609 addClassMethSummary("NSWindow", "alloc", NoTrackYet); 1610 1611 // For NSPanel (which subclasses NSWindow), allocated objects are not 1612 // self-owned. 1613 // FIXME: For now we don't track NSPanels. object for the same reason 1614 // as for NSWindow objects. 1615 addClassMethSummary("NSPanel", "alloc", NoTrackYet); 1616 1617 // Don't track allocated autorelease pools yet, as it is okay to prematurely 1618 // exit a method. 1619 addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); 1620 addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); 1621 1622 // Create summaries QCRenderer/QCView -createSnapShotImageOfType: 1623 addInstMethSummary("QCRenderer", AllocSumm, 1624 "createSnapshotImageOfType", NULL); 1625 addInstMethSummary("QCView", AllocSumm, 1626 "createSnapshotImageOfType", NULL); 1627 1628 // Create summaries for CIContext, 'createCGImage' and 1629 // 'createCGLayerWithSize'. These objects are CF objects, and are not 1630 // automatically garbage collected. 1631 addInstMethSummary("CIContext", CFAllocSumm, 1632 "createCGImage", "fromRect", NULL); 1633 addInstMethSummary("CIContext", CFAllocSumm, 1634 "createCGImage", "fromRect", "format", "colorSpace", NULL); 1635 addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", 1636 "info", NULL); 1637} 1638 1639//===----------------------------------------------------------------------===// 1640// Error reporting. 1641//===----------------------------------------------------------------------===// 1642namespace { 1643 typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> 1644 SummaryLogTy; 1645 1646 //===-------------===// 1647 // Bug Descriptions. // 1648 //===-------------===// 1649 1650 class CFRefBug : public BugType { 1651 protected: 1652 CFRefBug(StringRef name) 1653 : BugType(name, categories::MemoryCoreFoundationObjectiveC) {} 1654 public: 1655 1656 // FIXME: Eventually remove. 1657 virtual const char *getDescription() const = 0; 1658 1659 virtual bool isLeak() const { return false; } 1660 }; 1661 1662 class UseAfterRelease : public CFRefBug { 1663 public: 1664 UseAfterRelease() : CFRefBug("Use-after-release") {} 1665 1666 const char *getDescription() const { 1667 return "Reference-counted object is used after it is released"; 1668 } 1669 }; 1670 1671 class BadRelease : public CFRefBug { 1672 public: 1673 BadRelease() : CFRefBug("Bad release") {} 1674 1675 const char *getDescription() const { 1676 return "Incorrect decrement of the reference count of an object that is " 1677 "not owned at this point by the caller"; 1678 } 1679 }; 1680 1681 class DeallocGC : public CFRefBug { 1682 public: 1683 DeallocGC() 1684 : CFRefBug("-dealloc called while using garbage collection") {} 1685 1686 const char *getDescription() const { 1687 return "-dealloc called while using garbage collection"; 1688 } 1689 }; 1690 1691 class DeallocNotOwned : public CFRefBug { 1692 public: 1693 DeallocNotOwned() 1694 : CFRefBug("-dealloc sent to non-exclusively owned object") {} 1695 1696 const char *getDescription() const { 1697 return "-dealloc sent to object that may be referenced elsewhere"; 1698 } 1699 }; 1700 1701 class OverAutorelease : public CFRefBug { 1702 public: 1703 OverAutorelease() 1704 : CFRefBug("Object sent -autorelease too many times") {} 1705 1706 const char *getDescription() const { 1707 return "Object sent -autorelease too many times"; 1708 } 1709 }; 1710 1711 class ReturnedNotOwnedForOwned : public CFRefBug { 1712 public: 1713 ReturnedNotOwnedForOwned() 1714 : CFRefBug("Method should return an owned object") {} 1715 1716 const char *getDescription() const { 1717 return "Object with a +0 retain count returned to caller where a +1 " 1718 "(owning) retain count is expected"; 1719 } 1720 }; 1721 1722 class Leak : public CFRefBug { 1723 public: 1724 Leak(StringRef name) 1725 : CFRefBug(name) { 1726 // Leaks should not be reported if they are post-dominated by a sink. 1727 setSuppressOnSink(true); 1728 } 1729 1730 const char *getDescription() const { return ""; } 1731 1732 bool isLeak() const { return true; } 1733 }; 1734 1735 //===---------===// 1736 // Bug Reports. // 1737 //===---------===// 1738 1739 class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> { 1740 protected: 1741 SymbolRef Sym; 1742 const SummaryLogTy &SummaryLog; 1743 bool GCEnabled; 1744 1745 public: 1746 CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) 1747 : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} 1748 1749 virtual void Profile(llvm::FoldingSetNodeID &ID) const { 1750 static int x = 0; 1751 ID.AddPointer(&x); 1752 ID.AddPointer(Sym); 1753 } 1754 1755 virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N, 1756 const ExplodedNode *PrevN, 1757 BugReporterContext &BRC, 1758 BugReport &BR); 1759 1760 virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1761 const ExplodedNode *N, 1762 BugReport &BR); 1763 }; 1764 1765 class CFRefLeakReportVisitor : public CFRefReportVisitor { 1766 public: 1767 CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, 1768 const SummaryLogTy &log) 1769 : CFRefReportVisitor(sym, GCEnabled, log) {} 1770 1771 PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1772 const ExplodedNode *N, 1773 BugReport &BR); 1774 1775 virtual BugReporterVisitor *clone() const { 1776 // The curiously-recurring template pattern only works for one level of 1777 // subclassing. Rather than make a new template base for 1778 // CFRefReportVisitor, we simply override clone() to do the right thing. 1779 // This could be trouble someday if BugReporterVisitorImpl is ever 1780 // used for something else besides a convenient implementation of clone(). 1781 return new CFRefLeakReportVisitor(*this); 1782 } 1783 }; 1784 1785 class CFRefReport : public BugReport { 1786 void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); 1787 1788 public: 1789 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1790 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1791 bool registerVisitor = true) 1792 : BugReport(D, D.getDescription(), n) { 1793 if (registerVisitor) 1794 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1795 addGCModeDescription(LOpts, GCEnabled); 1796 } 1797 1798 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1799 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1800 StringRef endText) 1801 : BugReport(D, D.getDescription(), endText, n) { 1802 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1803 addGCModeDescription(LOpts, GCEnabled); 1804 } 1805 1806 virtual std::pair<ranges_iterator, ranges_iterator> getRanges() { 1807 const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); 1808 if (!BugTy.isLeak()) 1809 return BugReport::getRanges(); 1810 else 1811 return std::make_pair(ranges_iterator(), ranges_iterator()); 1812 } 1813 }; 1814 1815 class CFRefLeakReport : public CFRefReport { 1816 const MemRegion* AllocBinding; 1817 1818 public: 1819 CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1820 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1821 CheckerContext &Ctx); 1822 1823 PathDiagnosticLocation getLocation(const SourceManager &SM) const { 1824 assert(Location.isValid()); 1825 return Location; 1826 } 1827 }; 1828} // end anonymous namespace 1829 1830void CFRefReport::addGCModeDescription(const LangOptions &LOpts, 1831 bool GCEnabled) { 1832 const char *GCModeDescription = 0; 1833 1834 switch (LOpts.getGC()) { 1835 case LangOptions::GCOnly: 1836 assert(GCEnabled); 1837 GCModeDescription = "Code is compiled to only use garbage collection"; 1838 break; 1839 1840 case LangOptions::NonGC: 1841 assert(!GCEnabled); 1842 GCModeDescription = "Code is compiled to use reference counts"; 1843 break; 1844 1845 case LangOptions::HybridGC: 1846 if (GCEnabled) { 1847 GCModeDescription = "Code is compiled to use either garbage collection " 1848 "(GC) or reference counts (non-GC). The bug occurs " 1849 "with GC enabled"; 1850 break; 1851 } else { 1852 GCModeDescription = "Code is compiled to use either garbage collection " 1853 "(GC) or reference counts (non-GC). The bug occurs " 1854 "in non-GC mode"; 1855 break; 1856 } 1857 } 1858 1859 assert(GCModeDescription && "invalid/unknown GC mode"); 1860 addExtraText(GCModeDescription); 1861} 1862 1863// FIXME: This should be a method on SmallVector. 1864static inline bool contains(const SmallVectorImpl<ArgEffect>& V, 1865 ArgEffect X) { 1866 for (SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end(); 1867 I!=E; ++I) 1868 if (*I == X) return true; 1869 1870 return false; 1871} 1872 1873static bool isNumericLiteralExpression(const Expr *E) { 1874 // FIXME: This set of cases was copied from SemaExprObjC. 1875 return isa<IntegerLiteral>(E) || 1876 isa<CharacterLiteral>(E) || 1877 isa<FloatingLiteral>(E) || 1878 isa<ObjCBoolLiteralExpr>(E) || 1879 isa<CXXBoolLiteralExpr>(E); 1880} 1881 1882PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N, 1883 const ExplodedNode *PrevN, 1884 BugReporterContext &BRC, 1885 BugReport &BR) { 1886 // FIXME: We will eventually need to handle non-statement-based events 1887 // (__attribute__((cleanup))). 1888 if (!isa<StmtPoint>(N->getLocation())) 1889 return NULL; 1890 1891 // Check if the type state has changed. 1892 ProgramStateRef PrevSt = PrevN->getState(); 1893 ProgramStateRef CurrSt = N->getState(); 1894 const LocationContext *LCtx = N->getLocationContext(); 1895 1896 const RefVal* CurrT = getRefBinding(CurrSt, Sym); 1897 if (!CurrT) return NULL; 1898 1899 const RefVal &CurrV = *CurrT; 1900 const RefVal *PrevT = getRefBinding(PrevSt, Sym); 1901 1902 // Create a string buffer to constain all the useful things we want 1903 // to tell the user. 1904 std::string sbuf; 1905 llvm::raw_string_ostream os(sbuf); 1906 1907 // This is the allocation site since the previous node had no bindings 1908 // for this symbol. 1909 if (!PrevT) { 1910 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 1911 1912 if (isa<ObjCArrayLiteral>(S)) { 1913 os << "NSArray literal is an object with a +0 retain count"; 1914 } 1915 else if (isa<ObjCDictionaryLiteral>(S)) { 1916 os << "NSDictionary literal is an object with a +0 retain count"; 1917 } 1918 else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { 1919 if (isNumericLiteralExpression(BL->getSubExpr())) 1920 os << "NSNumber literal is an object with a +0 retain count"; 1921 else { 1922 const ObjCInterfaceDecl *BoxClass = 0; 1923 if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) 1924 BoxClass = Method->getClassInterface(); 1925 1926 // We should always be able to find the boxing class interface, 1927 // but consider this future-proofing. 1928 if (BoxClass) 1929 os << *BoxClass << " b"; 1930 else 1931 os << "B"; 1932 1933 os << "oxed expression produces an object with a +0 retain count"; 1934 } 1935 } 1936 else { 1937 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1938 // Get the name of the callee (if it is available). 1939 SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); 1940 if (const FunctionDecl *FD = X.getAsFunctionDecl()) 1941 os << "Call to function '" << *FD << '\''; 1942 else 1943 os << "function call"; 1944 } 1945 else { 1946 assert(isa<ObjCMessageExpr>(S)); 1947 CallEventManager &Mgr = CurrSt->getStateManager().getCallEventManager(); 1948 CallEventRef<ObjCMethodCall> Call 1949 = Mgr.getObjCMethodCall(cast<ObjCMessageExpr>(S), CurrSt, LCtx); 1950 1951 switch (Call->getMessageKind()) { 1952 case OCM_Message: 1953 os << "Method"; 1954 break; 1955 case OCM_PropertyAccess: 1956 os << "Property"; 1957 break; 1958 case OCM_Subscript: 1959 os << "Subscript"; 1960 break; 1961 } 1962 } 1963 1964 if (CurrV.getObjKind() == RetEffect::CF) { 1965 os << " returns a Core Foundation object with a "; 1966 } 1967 else { 1968 assert (CurrV.getObjKind() == RetEffect::ObjC); 1969 os << " returns an Objective-C object with a "; 1970 } 1971 1972 if (CurrV.isOwned()) { 1973 os << "+1 retain count"; 1974 1975 if (GCEnabled) { 1976 assert(CurrV.getObjKind() == RetEffect::CF); 1977 os << ". " 1978 "Core Foundation objects are not automatically garbage collected."; 1979 } 1980 } 1981 else { 1982 assert (CurrV.isNotOwned()); 1983 os << "+0 retain count"; 1984 } 1985 } 1986 1987 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 1988 N->getLocationContext()); 1989 return new PathDiagnosticEventPiece(Pos, os.str()); 1990 } 1991 1992 // Gather up the effects that were performed on the object at this 1993 // program point 1994 SmallVector<ArgEffect, 2> AEffects; 1995 1996 const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); 1997 if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { 1998 // We only have summaries attached to nodes after evaluating CallExpr and 1999 // ObjCMessageExprs. 2000 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2001 2002 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 2003 // Iterate through the parameter expressions and see if the symbol 2004 // was ever passed as an argument. 2005 unsigned i = 0; 2006 2007 for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); 2008 AI!=AE; ++AI, ++i) { 2009 2010 // Retrieve the value of the argument. Is it the symbol 2011 // we are interested in? 2012 if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) 2013 continue; 2014 2015 // We have an argument. Get the effect! 2016 AEffects.push_back(Summ->getArg(i)); 2017 } 2018 } 2019 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { 2020 if (const Expr *receiver = ME->getInstanceReceiver()) 2021 if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) 2022 .getAsLocSymbol() == Sym) { 2023 // The symbol we are tracking is the receiver. 2024 AEffects.push_back(Summ->getReceiverEffect()); 2025 } 2026 } 2027 } 2028 2029 do { 2030 // Get the previous type state. 2031 RefVal PrevV = *PrevT; 2032 2033 // Specially handle -dealloc. 2034 if (!GCEnabled && contains(AEffects, Dealloc)) { 2035 // Determine if the object's reference count was pushed to zero. 2036 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2037 // We may not have transitioned to 'release' if we hit an error. 2038 // This case is handled elsewhere. 2039 if (CurrV.getKind() == RefVal::Released) { 2040 assert(CurrV.getCombinedCounts() == 0); 2041 os << "Object released by directly sending the '-dealloc' message"; 2042 break; 2043 } 2044 } 2045 2046 // Specially handle CFMakeCollectable and friends. 2047 if (contains(AEffects, MakeCollectable)) { 2048 // Get the name of the function. 2049 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2050 SVal X = 2051 CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); 2052 const FunctionDecl *FD = X.getAsFunctionDecl(); 2053 2054 if (GCEnabled) { 2055 // Determine if the object's reference count was pushed to zero. 2056 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2057 2058 os << "In GC mode a call to '" << *FD 2059 << "' decrements an object's retain count and registers the " 2060 "object with the garbage collector. "; 2061 2062 if (CurrV.getKind() == RefVal::Released) { 2063 assert(CurrV.getCount() == 0); 2064 os << "Since it now has a 0 retain count the object can be " 2065 "automatically collected by the garbage collector."; 2066 } 2067 else 2068 os << "An object must have a 0 retain count to be garbage collected. " 2069 "After this call its retain count is +" << CurrV.getCount() 2070 << '.'; 2071 } 2072 else 2073 os << "When GC is not enabled a call to '" << *FD 2074 << "' has no effect on its argument."; 2075 2076 // Nothing more to say. 2077 break; 2078 } 2079 2080 // Determine if the typestate has changed. 2081 if (!(PrevV == CurrV)) 2082 switch (CurrV.getKind()) { 2083 case RefVal::Owned: 2084 case RefVal::NotOwned: 2085 2086 if (PrevV.getCount() == CurrV.getCount()) { 2087 // Did an autorelease message get sent? 2088 if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) 2089 return 0; 2090 2091 assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); 2092 os << "Object sent -autorelease message"; 2093 break; 2094 } 2095 2096 if (PrevV.getCount() > CurrV.getCount()) 2097 os << "Reference count decremented."; 2098 else 2099 os << "Reference count incremented."; 2100 2101 if (unsigned Count = CurrV.getCount()) 2102 os << " The object now has a +" << Count << " retain count."; 2103 2104 if (PrevV.getKind() == RefVal::Released) { 2105 assert(GCEnabled && CurrV.getCount() > 0); 2106 os << " The object is not eligible for garbage collection until " 2107 "the retain count reaches 0 again."; 2108 } 2109 2110 break; 2111 2112 case RefVal::Released: 2113 os << "Object released."; 2114 break; 2115 2116 case RefVal::ReturnedOwned: 2117 // Autoreleases can be applied after marking a node ReturnedOwned. 2118 if (CurrV.getAutoreleaseCount()) 2119 return NULL; 2120 2121 os << "Object returned to caller as an owning reference (single " 2122 "retain count transferred to caller)"; 2123 break; 2124 2125 case RefVal::ReturnedNotOwned: 2126 os << "Object returned to caller with a +0 retain count"; 2127 break; 2128 2129 default: 2130 return NULL; 2131 } 2132 2133 // Emit any remaining diagnostics for the argument effects (if any). 2134 for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), 2135 E=AEffects.end(); I != E; ++I) { 2136 2137 // A bunch of things have alternate behavior under GC. 2138 if (GCEnabled) 2139 switch (*I) { 2140 default: break; 2141 case Autorelease: 2142 os << "In GC mode an 'autorelease' has no effect."; 2143 continue; 2144 case IncRefMsg: 2145 os << "In GC mode the 'retain' message has no effect."; 2146 continue; 2147 case DecRefMsg: 2148 os << "In GC mode the 'release' message has no effect."; 2149 continue; 2150 } 2151 } 2152 } while (0); 2153 2154 if (os.str().empty()) 2155 return 0; // We have nothing to say! 2156 2157 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2158 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2159 N->getLocationContext()); 2160 PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str()); 2161 2162 // Add the range by scanning the children of the statement for any bindings 2163 // to Sym. 2164 for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); 2165 I!=E; ++I) 2166 if (const Expr *Exp = dyn_cast_or_null<Expr>(*I)) 2167 if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { 2168 P->addRange(Exp->getSourceRange()); 2169 break; 2170 } 2171 2172 return P; 2173} 2174 2175// Find the first node in the current function context that referred to the 2176// tracked symbol and the memory location that value was stored to. Note, the 2177// value is only reported if the allocation occurred in the same function as 2178// the leak. 2179static std::pair<const ExplodedNode*,const MemRegion*> 2180GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, 2181 SymbolRef Sym) { 2182 const ExplodedNode *Last = N; 2183 const MemRegion* FirstBinding = 0; 2184 const LocationContext *LeakContext = N->getLocationContext(); 2185 2186 while (N) { 2187 ProgramStateRef St = N->getState(); 2188 2189 if (!getRefBinding(St, Sym)) 2190 break; 2191 2192 StoreManager::FindUniqueBinding FB(Sym); 2193 StateMgr.iterBindings(St, FB); 2194 if (FB) FirstBinding = FB.getRegion(); 2195 2196 // Allocation node, is the last node in the current context in which the 2197 // symbol was tracked. 2198 if (N->getLocationContext() == LeakContext) 2199 Last = N; 2200 2201 N = N->pred_empty() ? NULL : *(N->pred_begin()); 2202 } 2203 2204 // If allocation happened in a function different from the leak node context, 2205 // do not report the binding. 2206 assert(N && "Could not find allocation node"); 2207 if (N->getLocationContext() != LeakContext) { 2208 FirstBinding = 0; 2209 } 2210 2211 return std::make_pair(Last, FirstBinding); 2212} 2213 2214PathDiagnosticPiece* 2215CFRefReportVisitor::getEndPath(BugReporterContext &BRC, 2216 const ExplodedNode *EndN, 2217 BugReport &BR) { 2218 BR.markInteresting(Sym); 2219 return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); 2220} 2221 2222PathDiagnosticPiece* 2223CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, 2224 const ExplodedNode *EndN, 2225 BugReport &BR) { 2226 2227 // Tell the BugReporterContext to report cases when the tracked symbol is 2228 // assigned to different variables, etc. 2229 BR.markInteresting(Sym); 2230 2231 // We are reporting a leak. Walk up the graph to get to the first node where 2232 // the symbol appeared, and also get the first VarDecl that tracked object 2233 // is stored to. 2234 const ExplodedNode *AllocNode = 0; 2235 const MemRegion* FirstBinding = 0; 2236 2237 llvm::tie(AllocNode, FirstBinding) = 2238 GetAllocationSite(BRC.getStateManager(), EndN, Sym); 2239 2240 SourceManager& SM = BRC.getSourceManager(); 2241 2242 // Compute an actual location for the leak. Sometimes a leak doesn't 2243 // occur at an actual statement (e.g., transition between blocks; end 2244 // of function) so we need to walk the graph and compute a real location. 2245 const ExplodedNode *LeakN = EndN; 2246 PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); 2247 2248 std::string sbuf; 2249 llvm::raw_string_ostream os(sbuf); 2250 2251 os << "Object leaked: "; 2252 2253 if (FirstBinding) { 2254 os << "object allocated and stored into '" 2255 << FirstBinding->getString() << '\''; 2256 } 2257 else 2258 os << "allocated object"; 2259 2260 // Get the retain count. 2261 const RefVal* RV = getRefBinding(EndN->getState(), Sym); 2262 assert(RV); 2263 2264 if (RV->getKind() == RefVal::ErrorLeakReturned) { 2265 // FIXME: Per comments in rdar://6320065, "create" only applies to CF 2266 // objects. Only "copy", "alloc", "retain" and "new" transfer ownership 2267 // to the caller for NS objects. 2268 const Decl *D = &EndN->getCodeDecl(); 2269 2270 os << (isa<ObjCMethodDecl>(D) ? " is returned from a method " 2271 : " is returned from a function "); 2272 2273 if (D->getAttr<CFReturnsNotRetainedAttr>()) 2274 os << "that is annotated as CF_RETURNS_NOT_RETAINED"; 2275 else if (D->getAttr<NSReturnsNotRetainedAttr>()) 2276 os << "that is annotated as NS_RETURNS_NOT_RETAINED"; 2277 else { 2278 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 2279 os << "whose name ('" << MD->getSelector().getAsString() 2280 << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'." 2281 " This violates the naming convention rules" 2282 " given in the Memory Management Guide for Cocoa"; 2283 } 2284 else { 2285 const FunctionDecl *FD = cast<FunctionDecl>(D); 2286 os << "whose name ('" << *FD 2287 << "') does not contain 'Copy' or 'Create'. This violates the naming" 2288 " convention rules given in the Memory Management Guide for Core" 2289 " Foundation"; 2290 } 2291 } 2292 } 2293 else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { 2294 ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); 2295 os << " and returned from method '" << MD.getSelector().getAsString() 2296 << "' is potentially leaked when using garbage collection. Callers " 2297 "of this method do not expect a returned object with a +1 retain " 2298 "count since they expect the object to be managed by the garbage " 2299 "collector"; 2300 } 2301 else 2302 os << " is not referenced later in this execution path and has a retain " 2303 "count of +" << RV->getCount(); 2304 2305 return new PathDiagnosticEventPiece(L, os.str()); 2306} 2307 2308CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, 2309 bool GCEnabled, const SummaryLogTy &Log, 2310 ExplodedNode *n, SymbolRef sym, 2311 CheckerContext &Ctx) 2312: CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { 2313 2314 // Most bug reports are cached at the location where they occurred. 2315 // With leaks, we want to unique them by the location where they were 2316 // allocated, and only report a single path. To do this, we need to find 2317 // the allocation site of a piece of tracked memory, which we do via a 2318 // call to GetAllocationSite. This will walk the ExplodedGraph backwards. 2319 // Note that this is *not* the trimmed graph; we are guaranteed, however, 2320 // that all ancestor nodes that represent the allocation site have the 2321 // same SourceLocation. 2322 const ExplodedNode *AllocNode = 0; 2323 2324 const SourceManager& SMgr = Ctx.getSourceManager(); 2325 2326 llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding. 2327 GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); 2328 2329 // Get the SourceLocation for the allocation site. 2330 // FIXME: This will crash the analyzer if an allocation comes from an 2331 // implicit call. (Currently there are no such allocations in Cocoa, though.) 2332 const Stmt *AllocStmt; 2333 ProgramPoint P = AllocNode->getLocation(); 2334 if (CallExitEnd *Exit = dyn_cast<CallExitEnd>(&P)) 2335 AllocStmt = Exit->getCalleeContext()->getCallSite(); 2336 else 2337 AllocStmt = cast<PostStmt>(P).getStmt(); 2338 assert(AllocStmt && "All allocations must come from explicit calls"); 2339 Location = PathDiagnosticLocation::createBegin(AllocStmt, SMgr, 2340 n->getLocationContext()); 2341 // Fill in the description of the bug. 2342 Description.clear(); 2343 llvm::raw_string_ostream os(Description); 2344 os << "Potential leak "; 2345 if (GCEnabled) 2346 os << "(when using garbage collection) "; 2347 os << "of an object"; 2348 2349 // FIXME: AllocBinding doesn't get populated for RegionStore yet. 2350 if (AllocBinding) 2351 os << " stored into '" << AllocBinding->getString() << '\''; 2352 2353 addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log)); 2354} 2355 2356//===----------------------------------------------------------------------===// 2357// Main checker logic. 2358//===----------------------------------------------------------------------===// 2359 2360namespace { 2361class RetainCountChecker 2362 : public Checker< check::Bind, 2363 check::DeadSymbols, 2364 check::EndAnalysis, 2365 check::EndPath, 2366 check::PostStmt<BlockExpr>, 2367 check::PostStmt<CastExpr>, 2368 check::PostStmt<ObjCArrayLiteral>, 2369 check::PostStmt<ObjCDictionaryLiteral>, 2370 check::PostStmt<ObjCBoxedExpr>, 2371 check::PostCall, 2372 check::PreStmt<ReturnStmt>, 2373 check::RegionChanges, 2374 eval::Assume, 2375 eval::Call > { 2376 mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned; 2377 mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned; 2378 mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned; 2379 mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn; 2380 mutable OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; 2381 2382 typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap; 2383 2384 // This map is only used to ensure proper deletion of any allocated tags. 2385 mutable SymbolTagMap DeadSymbolTags; 2386 2387 mutable OwningPtr<RetainSummaryManager> Summaries; 2388 mutable OwningPtr<RetainSummaryManager> SummariesGC; 2389 mutable SummaryLogTy SummaryLog; 2390 mutable bool ShouldResetSummaryLog; 2391 2392public: 2393 RetainCountChecker() : ShouldResetSummaryLog(false) {} 2394 2395 virtual ~RetainCountChecker() { 2396 DeleteContainerSeconds(DeadSymbolTags); 2397 } 2398 2399 void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, 2400 ExprEngine &Eng) const { 2401 // FIXME: This is a hack to make sure the summary log gets cleared between 2402 // analyses of different code bodies. 2403 // 2404 // Why is this necessary? Because a checker's lifetime is tied to a 2405 // translation unit, but an ExplodedGraph's lifetime is just a code body. 2406 // Once in a blue moon, a new ExplodedNode will have the same address as an 2407 // old one with an associated summary, and the bug report visitor gets very 2408 // confused. (To make things worse, the summary lifetime is currently also 2409 // tied to a code body, so we get a crash instead of incorrect results.) 2410 // 2411 // Why is this a bad solution? Because if the lifetime of the ExplodedGraph 2412 // changes, things will start going wrong again. Really the lifetime of this 2413 // log needs to be tied to either the specific nodes in it or the entire 2414 // ExplodedGraph, not to a specific part of the code being analyzed. 2415 // 2416 // (Also, having stateful local data means that the same checker can't be 2417 // used from multiple threads, but a lot of checkers have incorrect 2418 // assumptions about that anyway. So that wasn't a priority at the time of 2419 // this fix.) 2420 // 2421 // This happens at the end of analysis, but bug reports are emitted /after/ 2422 // this point. So we can't just clear the summary log now. Instead, we mark 2423 // that the next time we access the summary log, it should be cleared. 2424 2425 // If we never reset the summary log during /this/ code body analysis, 2426 // there were no new summaries. There might still have been summaries from 2427 // the /last/ analysis, so clear them out to make sure the bug report 2428 // visitors don't get confused. 2429 if (ShouldResetSummaryLog) 2430 SummaryLog.clear(); 2431 2432 ShouldResetSummaryLog = !SummaryLog.empty(); 2433 } 2434 2435 CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, 2436 bool GCEnabled) const { 2437 if (GCEnabled) { 2438 if (!leakWithinFunctionGC) 2439 leakWithinFunctionGC.reset(new Leak("Leak of object when using " 2440 "garbage collection")); 2441 return leakWithinFunctionGC.get(); 2442 } else { 2443 if (!leakWithinFunction) { 2444 if (LOpts.getGC() == LangOptions::HybridGC) { 2445 leakWithinFunction.reset(new Leak("Leak of object when not using " 2446 "garbage collection (GC) in " 2447 "dual GC/non-GC code")); 2448 } else { 2449 leakWithinFunction.reset(new Leak("Leak")); 2450 } 2451 } 2452 return leakWithinFunction.get(); 2453 } 2454 } 2455 2456 CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { 2457 if (GCEnabled) { 2458 if (!leakAtReturnGC) 2459 leakAtReturnGC.reset(new Leak("Leak of returned object when using " 2460 "garbage collection")); 2461 return leakAtReturnGC.get(); 2462 } else { 2463 if (!leakAtReturn) { 2464 if (LOpts.getGC() == LangOptions::HybridGC) { 2465 leakAtReturn.reset(new Leak("Leak of returned object when not using " 2466 "garbage collection (GC) in dual " 2467 "GC/non-GC code")); 2468 } else { 2469 leakAtReturn.reset(new Leak("Leak of returned object")); 2470 } 2471 } 2472 return leakAtReturn.get(); 2473 } 2474 } 2475 2476 RetainSummaryManager &getSummaryManager(ASTContext &Ctx, 2477 bool GCEnabled) const { 2478 // FIXME: We don't support ARC being turned on and off during one analysis. 2479 // (nor, for that matter, do we support changing ASTContexts) 2480 bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; 2481 if (GCEnabled) { 2482 if (!SummariesGC) 2483 SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); 2484 else 2485 assert(SummariesGC->isARCEnabled() == ARCEnabled); 2486 return *SummariesGC; 2487 } else { 2488 if (!Summaries) 2489 Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); 2490 else 2491 assert(Summaries->isARCEnabled() == ARCEnabled); 2492 return *Summaries; 2493 } 2494 } 2495 2496 RetainSummaryManager &getSummaryManager(CheckerContext &C) const { 2497 return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); 2498 } 2499 2500 void printState(raw_ostream &Out, ProgramStateRef State, 2501 const char *NL, const char *Sep) const; 2502 2503 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; 2504 void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; 2505 void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; 2506 2507 void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; 2508 void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; 2509 void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; 2510 2511 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 2512 2513 void checkSummary(const RetainSummary &Summ, const CallEvent &Call, 2514 CheckerContext &C) const; 2515 2516 void processSummaryOfInlined(const RetainSummary &Summ, 2517 const CallEvent &Call, 2518 CheckerContext &C) const; 2519 2520 bool evalCall(const CallExpr *CE, CheckerContext &C) const; 2521 2522 ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, 2523 bool Assumption) const; 2524 2525 ProgramStateRef 2526 checkRegionChanges(ProgramStateRef state, 2527 const StoreManager::InvalidatedSymbols *invalidated, 2528 ArrayRef<const MemRegion *> ExplicitRegions, 2529 ArrayRef<const MemRegion *> Regions, 2530 const CallEvent *Call) const; 2531 2532 bool wantsRegionChangeUpdate(ProgramStateRef state) const { 2533 return true; 2534 } 2535 2536 void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; 2537 void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, 2538 ExplodedNode *Pred, RetEffect RE, RefVal X, 2539 SymbolRef Sym, ProgramStateRef state) const; 2540 2541 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 2542 void checkEndPath(CheckerContext &C) const; 2543 2544 ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, 2545 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2546 CheckerContext &C) const; 2547 2548 void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, 2549 RefVal::Kind ErrorKind, SymbolRef Sym, 2550 CheckerContext &C) const; 2551 2552 void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; 2553 2554 const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; 2555 2556 ProgramStateRef handleSymbolDeath(ProgramStateRef state, 2557 SymbolRef sid, RefVal V, 2558 SmallVectorImpl<SymbolRef> &Leaked) const; 2559 2560 std::pair<ExplodedNode *, ProgramStateRef > 2561 handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred, 2562 const ProgramPointTag *Tag, CheckerContext &Ctx, 2563 SymbolRef Sym, RefVal V) const; 2564 2565 ExplodedNode *processLeaks(ProgramStateRef state, 2566 SmallVectorImpl<SymbolRef> &Leaked, 2567 CheckerContext &Ctx, 2568 ExplodedNode *Pred = 0) const; 2569}; 2570} // end anonymous namespace 2571 2572namespace { 2573class StopTrackingCallback : public SymbolVisitor { 2574 ProgramStateRef state; 2575public: 2576 StopTrackingCallback(ProgramStateRef st) : state(st) {} 2577 ProgramStateRef getState() const { return state; } 2578 2579 bool VisitSymbol(SymbolRef sym) { 2580 state = state->remove<RefBindings>(sym); 2581 return true; 2582 } 2583}; 2584} // end anonymous namespace 2585 2586//===----------------------------------------------------------------------===// 2587// Handle statements that may have an effect on refcounts. 2588//===----------------------------------------------------------------------===// 2589 2590void RetainCountChecker::checkPostStmt(const BlockExpr *BE, 2591 CheckerContext &C) const { 2592 2593 // Scan the BlockDecRefExprs for any object the retain count checker 2594 // may be tracking. 2595 if (!BE->getBlockDecl()->hasCaptures()) 2596 return; 2597 2598 ProgramStateRef state = C.getState(); 2599 const BlockDataRegion *R = 2600 cast<BlockDataRegion>(state->getSVal(BE, 2601 C.getLocationContext()).getAsRegion()); 2602 2603 BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), 2604 E = R->referenced_vars_end(); 2605 2606 if (I == E) 2607 return; 2608 2609 // FIXME: For now we invalidate the tracking of all symbols passed to blocks 2610 // via captured variables, even though captured variables result in a copy 2611 // and in implicit increment/decrement of a retain count. 2612 SmallVector<const MemRegion*, 10> Regions; 2613 const LocationContext *LC = C.getLocationContext(); 2614 MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); 2615 2616 for ( ; I != E; ++I) { 2617 const VarRegion *VR = *I; 2618 if (VR->getSuperRegion() == R) { 2619 VR = MemMgr.getVarRegion(VR->getDecl(), LC); 2620 } 2621 Regions.push_back(VR); 2622 } 2623 2624 state = 2625 state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), 2626 Regions.data() + Regions.size()).getState(); 2627 C.addTransition(state); 2628} 2629 2630void RetainCountChecker::checkPostStmt(const CastExpr *CE, 2631 CheckerContext &C) const { 2632 const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); 2633 if (!BE) 2634 return; 2635 2636 ArgEffect AE = IncRef; 2637 2638 switch (BE->getBridgeKind()) { 2639 case clang::OBC_Bridge: 2640 // Do nothing. 2641 return; 2642 case clang::OBC_BridgeRetained: 2643 AE = IncRef; 2644 break; 2645 case clang::OBC_BridgeTransfer: 2646 AE = DecRefBridgedTransfered; 2647 break; 2648 } 2649 2650 ProgramStateRef state = C.getState(); 2651 SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol(); 2652 if (!Sym) 2653 return; 2654 const RefVal* T = getRefBinding(state, Sym); 2655 if (!T) 2656 return; 2657 2658 RefVal::Kind hasErr = (RefVal::Kind) 0; 2659 state = updateSymbol(state, Sym, *T, AE, hasErr, C); 2660 2661 if (hasErr) { 2662 // FIXME: If we get an error during a bridge cast, should we report it? 2663 // Should we assert that there is no error? 2664 return; 2665 } 2666 2667 C.addTransition(state); 2668} 2669 2670void RetainCountChecker::processObjCLiterals(CheckerContext &C, 2671 const Expr *Ex) const { 2672 ProgramStateRef state = C.getState(); 2673 const ExplodedNode *pred = C.getPredecessor(); 2674 for (Stmt::const_child_iterator it = Ex->child_begin(), et = Ex->child_end() ; 2675 it != et ; ++it) { 2676 const Stmt *child = *it; 2677 SVal V = state->getSVal(child, pred->getLocationContext()); 2678 if (SymbolRef sym = V.getAsSymbol()) 2679 if (const RefVal* T = getRefBinding(state, sym)) { 2680 RefVal::Kind hasErr = (RefVal::Kind) 0; 2681 state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); 2682 if (hasErr) { 2683 processNonLeakError(state, child->getSourceRange(), hasErr, sym, C); 2684 return; 2685 } 2686 } 2687 } 2688 2689 // Return the object as autoreleased. 2690 // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); 2691 if (SymbolRef sym = 2692 state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { 2693 QualType ResultTy = Ex->getType(); 2694 state = setRefBinding(state, sym, 2695 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2696 } 2697 2698 C.addTransition(state); 2699} 2700 2701void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, 2702 CheckerContext &C) const { 2703 // Apply the 'MayEscape' to all values. 2704 processObjCLiterals(C, AL); 2705} 2706 2707void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 2708 CheckerContext &C) const { 2709 // Apply the 'MayEscape' to all keys and values. 2710 processObjCLiterals(C, DL); 2711} 2712 2713void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, 2714 CheckerContext &C) const { 2715 const ExplodedNode *Pred = C.getPredecessor(); 2716 const LocationContext *LCtx = Pred->getLocationContext(); 2717 ProgramStateRef State = Pred->getState(); 2718 2719 if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) { 2720 QualType ResultTy = Ex->getType(); 2721 State = setRefBinding(State, Sym, 2722 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2723 } 2724 2725 C.addTransition(State); 2726} 2727 2728void RetainCountChecker::checkPostCall(const CallEvent &Call, 2729 CheckerContext &C) const { 2730 RetainSummaryManager &Summaries = getSummaryManager(C); 2731 const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); 2732 2733 if (C.wasInlined) { 2734 processSummaryOfInlined(*Summ, Call, C); 2735 return; 2736 } 2737 checkSummary(*Summ, Call, C); 2738} 2739 2740/// GetReturnType - Used to get the return type of a message expression or 2741/// function call with the intention of affixing that type to a tracked symbol. 2742/// While the return type can be queried directly from RetEx, when 2743/// invoking class methods we augment to the return type to be that of 2744/// a pointer to the class (as opposed it just being id). 2745// FIXME: We may be able to do this with related result types instead. 2746// This function is probably overestimating. 2747static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { 2748 QualType RetTy = RetE->getType(); 2749 // If RetE is not a message expression just return its type. 2750 // If RetE is a message expression, return its types if it is something 2751 /// more specific than id. 2752 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) 2753 if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) 2754 if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || 2755 PT->isObjCClassType()) { 2756 // At this point we know the return type of the message expression is 2757 // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this 2758 // is a call to a class method whose type we can resolve. In such 2759 // cases, promote the return type to XXX* (where XXX is the class). 2760 const ObjCInterfaceDecl *D = ME->getReceiverInterface(); 2761 return !D ? RetTy : 2762 Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); 2763 } 2764 2765 return RetTy; 2766} 2767 2768// We don't always get the exact modeling of the function with regards to the 2769// retain count checker even when the function is inlined. For example, we need 2770// to stop tracking the symbols which were marked with StopTrackingHard. 2771void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ, 2772 const CallEvent &CallOrMsg, 2773 CheckerContext &C) const { 2774 ProgramStateRef state = C.getState(); 2775 2776 // Evaluate the effect of the arguments. 2777 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2778 if (Summ.getArg(idx) == StopTrackingHard) { 2779 SVal V = CallOrMsg.getArgSVal(idx); 2780 if (SymbolRef Sym = V.getAsLocSymbol()) { 2781 state = removeRefBinding(state, Sym); 2782 } 2783 } 2784 } 2785 2786 // Evaluate the effect on the message receiver. 2787 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2788 if (MsgInvocation) { 2789 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2790 if (Summ.getReceiverEffect() == StopTrackingHard) { 2791 state = removeRefBinding(state, Sym); 2792 } 2793 } 2794 } 2795 2796 // Consult the summary for the return value. 2797 RetEffect RE = Summ.getRetEffect(); 2798 if (RE.getKind() == RetEffect::NoRetHard) { 2799 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2800 C.getLocationContext()).getAsSymbol(); 2801 if (Sym) 2802 state = removeRefBinding(state, Sym); 2803 } 2804 2805 C.addTransition(state); 2806} 2807 2808void RetainCountChecker::checkSummary(const RetainSummary &Summ, 2809 const CallEvent &CallOrMsg, 2810 CheckerContext &C) const { 2811 ProgramStateRef state = C.getState(); 2812 2813 // Evaluate the effect of the arguments. 2814 RefVal::Kind hasErr = (RefVal::Kind) 0; 2815 SourceRange ErrorRange; 2816 SymbolRef ErrorSym = 0; 2817 2818 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2819 SVal V = CallOrMsg.getArgSVal(idx); 2820 2821 if (SymbolRef Sym = V.getAsLocSymbol()) { 2822 if (const RefVal *T = getRefBinding(state, Sym)) { 2823 state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C); 2824 if (hasErr) { 2825 ErrorRange = CallOrMsg.getArgSourceRange(idx); 2826 ErrorSym = Sym; 2827 break; 2828 } 2829 } 2830 } 2831 } 2832 2833 // Evaluate the effect on the message receiver. 2834 bool ReceiverIsTracked = false; 2835 if (!hasErr) { 2836 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2837 if (MsgInvocation) { 2838 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2839 if (const RefVal *T = getRefBinding(state, Sym)) { 2840 ReceiverIsTracked = true; 2841 state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), 2842 hasErr, C); 2843 if (hasErr) { 2844 ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange(); 2845 ErrorSym = Sym; 2846 } 2847 } 2848 } 2849 } 2850 } 2851 2852 // Process any errors. 2853 if (hasErr) { 2854 processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); 2855 return; 2856 } 2857 2858 // Consult the summary for the return value. 2859 RetEffect RE = Summ.getRetEffect(); 2860 2861 if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { 2862 if (ReceiverIsTracked) 2863 RE = getSummaryManager(C).getObjAllocRetEffect(); 2864 else 2865 RE = RetEffect::MakeNoRet(); 2866 } 2867 2868 switch (RE.getKind()) { 2869 default: 2870 llvm_unreachable("Unhandled RetEffect."); 2871 2872 case RetEffect::NoRet: 2873 case RetEffect::NoRetHard: 2874 // No work necessary. 2875 break; 2876 2877 case RetEffect::OwnedAllocatedSymbol: 2878 case RetEffect::OwnedSymbol: { 2879 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2880 C.getLocationContext()).getAsSymbol(); 2881 if (!Sym) 2882 break; 2883 2884 // Use the result type from the CallEvent as it automatically adjusts 2885 // for methods/functions that return references. 2886 QualType ResultTy = CallOrMsg.getResultType(); 2887 state = setRefBinding(state, Sym, RefVal::makeOwned(RE.getObjKind(), 2888 ResultTy)); 2889 2890 // FIXME: Add a flag to the checker where allocations are assumed to 2891 // *not* fail. 2892 break; 2893 } 2894 2895 case RetEffect::GCNotOwnedSymbol: 2896 case RetEffect::ARCNotOwnedSymbol: 2897 case RetEffect::NotOwnedSymbol: { 2898 const Expr *Ex = CallOrMsg.getOriginExpr(); 2899 SymbolRef Sym = state->getSVal(Ex, C.getLocationContext()).getAsSymbol(); 2900 if (!Sym) 2901 break; 2902 assert(Ex); 2903 // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. 2904 QualType ResultTy = GetReturnType(Ex, C.getASTContext()); 2905 state = setRefBinding(state, Sym, RefVal::makeNotOwned(RE.getObjKind(), 2906 ResultTy)); 2907 break; 2908 } 2909 } 2910 2911 // This check is actually necessary; otherwise the statement builder thinks 2912 // we've hit a previously-found path. 2913 // Normally addTransition takes care of this, but we want the node pointer. 2914 ExplodedNode *NewNode; 2915 if (state == C.getState()) { 2916 NewNode = C.getPredecessor(); 2917 } else { 2918 NewNode = C.addTransition(state); 2919 } 2920 2921 // Annotate the node with summary we used. 2922 if (NewNode) { 2923 // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. 2924 if (ShouldResetSummaryLog) { 2925 SummaryLog.clear(); 2926 ShouldResetSummaryLog = false; 2927 } 2928 SummaryLog[NewNode] = &Summ; 2929 } 2930} 2931 2932 2933ProgramStateRef 2934RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, 2935 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2936 CheckerContext &C) const { 2937 // In GC mode [... release] and [... retain] do nothing. 2938 // In ARC mode they shouldn't exist at all, but we just ignore them. 2939 bool IgnoreRetainMsg = C.isObjCGCEnabled(); 2940 if (!IgnoreRetainMsg) 2941 IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; 2942 2943 switch (E) { 2944 default: 2945 break; 2946 case IncRefMsg: 2947 E = IgnoreRetainMsg ? DoNothing : IncRef; 2948 break; 2949 case DecRefMsg: 2950 E = IgnoreRetainMsg ? DoNothing : DecRef; 2951 break; 2952 case DecRefMsgAndStopTrackingHard: 2953 E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTrackingHard; 2954 break; 2955 case MakeCollectable: 2956 E = C.isObjCGCEnabled() ? DecRef : DoNothing; 2957 break; 2958 case NewAutoreleasePool: 2959 E = C.isObjCGCEnabled() ? DoNothing : NewAutoreleasePool; 2960 break; 2961 } 2962 2963 // Handle all use-after-releases. 2964 if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { 2965 V = V ^ RefVal::ErrorUseAfterRelease; 2966 hasErr = V.getKind(); 2967 return setRefBinding(state, sym, V); 2968 } 2969 2970 switch (E) { 2971 case DecRefMsg: 2972 case IncRefMsg: 2973 case MakeCollectable: 2974 case DecRefMsgAndStopTrackingHard: 2975 llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); 2976 2977 case Dealloc: 2978 // Any use of -dealloc in GC is *bad*. 2979 if (C.isObjCGCEnabled()) { 2980 V = V ^ RefVal::ErrorDeallocGC; 2981 hasErr = V.getKind(); 2982 break; 2983 } 2984 2985 switch (V.getKind()) { 2986 default: 2987 llvm_unreachable("Invalid RefVal state for an explicit dealloc."); 2988 case RefVal::Owned: 2989 // The object immediately transitions to the released state. 2990 V = V ^ RefVal::Released; 2991 V.clearCounts(); 2992 return setRefBinding(state, sym, V); 2993 case RefVal::NotOwned: 2994 V = V ^ RefVal::ErrorDeallocNotOwned; 2995 hasErr = V.getKind(); 2996 break; 2997 } 2998 break; 2999 3000 case NewAutoreleasePool: 3001 assert(!C.isObjCGCEnabled()); 3002 return state; 3003 3004 case MayEscape: 3005 if (V.getKind() == RefVal::Owned) { 3006 V = V ^ RefVal::NotOwned; 3007 break; 3008 } 3009 3010 // Fall-through. 3011 3012 case DoNothing: 3013 return state; 3014 3015 case Autorelease: 3016 if (C.isObjCGCEnabled()) 3017 return state; 3018 // Update the autorelease counts. 3019 V = V.autorelease(); 3020 break; 3021 3022 case StopTracking: 3023 case StopTrackingHard: 3024 return removeRefBinding(state, sym); 3025 3026 case IncRef: 3027 switch (V.getKind()) { 3028 default: 3029 llvm_unreachable("Invalid RefVal state for a retain."); 3030 case RefVal::Owned: 3031 case RefVal::NotOwned: 3032 V = V + 1; 3033 break; 3034 case RefVal::Released: 3035 // Non-GC cases are handled above. 3036 assert(C.isObjCGCEnabled()); 3037 V = (V ^ RefVal::Owned) + 1; 3038 break; 3039 } 3040 break; 3041 3042 case DecRef: 3043 case DecRefBridgedTransfered: 3044 case DecRefAndStopTrackingHard: 3045 switch (V.getKind()) { 3046 default: 3047 // case 'RefVal::Released' handled above. 3048 llvm_unreachable("Invalid RefVal state for a release."); 3049 3050 case RefVal::Owned: 3051 assert(V.getCount() > 0); 3052 if (V.getCount() == 1) 3053 V = V ^ (E == DecRefBridgedTransfered ? 3054 RefVal::NotOwned : RefVal::Released); 3055 else if (E == DecRefAndStopTrackingHard) 3056 return removeRefBinding(state, sym); 3057 3058 V = V - 1; 3059 break; 3060 3061 case RefVal::NotOwned: 3062 if (V.getCount() > 0) { 3063 if (E == DecRefAndStopTrackingHard) 3064 return removeRefBinding(state, sym); 3065 V = V - 1; 3066 } else { 3067 V = V ^ RefVal::ErrorReleaseNotOwned; 3068 hasErr = V.getKind(); 3069 } 3070 break; 3071 3072 case RefVal::Released: 3073 // Non-GC cases are handled above. 3074 assert(C.isObjCGCEnabled()); 3075 V = V ^ RefVal::ErrorUseAfterRelease; 3076 hasErr = V.getKind(); 3077 break; 3078 } 3079 break; 3080 } 3081 return setRefBinding(state, sym, V); 3082} 3083 3084void RetainCountChecker::processNonLeakError(ProgramStateRef St, 3085 SourceRange ErrorRange, 3086 RefVal::Kind ErrorKind, 3087 SymbolRef Sym, 3088 CheckerContext &C) const { 3089 ExplodedNode *N = C.generateSink(St); 3090 if (!N) 3091 return; 3092 3093 CFRefBug *BT; 3094 switch (ErrorKind) { 3095 default: 3096 llvm_unreachable("Unhandled error."); 3097 case RefVal::ErrorUseAfterRelease: 3098 if (!useAfterRelease) 3099 useAfterRelease.reset(new UseAfterRelease()); 3100 BT = &*useAfterRelease; 3101 break; 3102 case RefVal::ErrorReleaseNotOwned: 3103 if (!releaseNotOwned) 3104 releaseNotOwned.reset(new BadRelease()); 3105 BT = &*releaseNotOwned; 3106 break; 3107 case RefVal::ErrorDeallocGC: 3108 if (!deallocGC) 3109 deallocGC.reset(new DeallocGC()); 3110 BT = &*deallocGC; 3111 break; 3112 case RefVal::ErrorDeallocNotOwned: 3113 if (!deallocNotOwned) 3114 deallocNotOwned.reset(new DeallocNotOwned()); 3115 BT = &*deallocNotOwned; 3116 break; 3117 } 3118 3119 assert(BT); 3120 CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOpts(), 3121 C.isObjCGCEnabled(), SummaryLog, 3122 N, Sym); 3123 report->addRange(ErrorRange); 3124 C.emitReport(report); 3125} 3126 3127//===----------------------------------------------------------------------===// 3128// Handle the return values of retain-count-related functions. 3129//===----------------------------------------------------------------------===// 3130 3131bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { 3132 // Get the callee. We're only interested in simple C functions. 3133 ProgramStateRef state = C.getState(); 3134 const FunctionDecl *FD = C.getCalleeDecl(CE); 3135 if (!FD) 3136 return false; 3137 3138 IdentifierInfo *II = FD->getIdentifier(); 3139 if (!II) 3140 return false; 3141 3142 // For now, we're only handling the functions that return aliases of their 3143 // arguments: CFRetain and CFMakeCollectable (and their families). 3144 // Eventually we should add other functions we can model entirely, 3145 // such as CFRelease, which don't invalidate their arguments or globals. 3146 if (CE->getNumArgs() != 1) 3147 return false; 3148 3149 // Get the name of the function. 3150 StringRef FName = II->getName(); 3151 FName = FName.substr(FName.find_first_not_of('_')); 3152 3153 // See if it's one of the specific functions we know how to eval. 3154 bool canEval = false; 3155 3156 QualType ResultTy = CE->getCallReturnType(); 3157 if (ResultTy->isObjCIdType()) { 3158 // Handle: id NSMakeCollectable(CFTypeRef) 3159 canEval = II->isStr("NSMakeCollectable"); 3160 } else if (ResultTy->isPointerType()) { 3161 // Handle: (CF|CG)Retain 3162 // CFMakeCollectable 3163 // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). 3164 if (cocoa::isRefType(ResultTy, "CF", FName) || 3165 cocoa::isRefType(ResultTy, "CG", FName)) { 3166 canEval = isRetain(FD, FName) || isMakeCollectable(FD, FName); 3167 } 3168 } 3169 3170 if (!canEval) 3171 return false; 3172 3173 // Bind the return value. 3174 const LocationContext *LCtx = C.getLocationContext(); 3175 SVal RetVal = state->getSVal(CE->getArg(0), LCtx); 3176 if (RetVal.isUnknown()) { 3177 // If the receiver is unknown, conjure a return value. 3178 SValBuilder &SVB = C.getSValBuilder(); 3179 RetVal = SVB.conjureSymbolVal(0, CE, LCtx, ResultTy, C.blockCount()); 3180 } 3181 state = state->BindExpr(CE, LCtx, RetVal, false); 3182 3183 // FIXME: This should not be necessary, but otherwise the argument seems to be 3184 // considered alive during the next statement. 3185 if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { 3186 // Save the refcount status of the argument. 3187 SymbolRef Sym = RetVal.getAsLocSymbol(); 3188 const RefVal *Binding = 0; 3189 if (Sym) 3190 Binding = getRefBinding(state, Sym); 3191 3192 // Invalidate the argument region. 3193 state = state->invalidateRegions(ArgRegion, CE, C.blockCount(), LCtx); 3194 3195 // Restore the refcount status of the argument. 3196 if (Binding) 3197 state = setRefBinding(state, Sym, *Binding); 3198 } 3199 3200 C.addTransition(state); 3201 return true; 3202} 3203 3204//===----------------------------------------------------------------------===// 3205// Handle return statements. 3206//===----------------------------------------------------------------------===// 3207 3208// Return true if the current LocationContext has no caller context. 3209static bool inTopFrame(CheckerContext &C) { 3210 const LocationContext *LC = C.getLocationContext(); 3211 return LC->getParent() == 0; 3212} 3213 3214void RetainCountChecker::checkPreStmt(const ReturnStmt *S, 3215 CheckerContext &C) const { 3216 3217 // Only adjust the reference count if this is the top-level call frame, 3218 // and not the result of inlining. In the future, we should do 3219 // better checking even for inlined calls, and see if they match 3220 // with their expected semantics (e.g., the method should return a retained 3221 // object, etc.). 3222 if (!inTopFrame(C)) 3223 return; 3224 3225 const Expr *RetE = S->getRetValue(); 3226 if (!RetE) 3227 return; 3228 3229 ProgramStateRef state = C.getState(); 3230 SymbolRef Sym = 3231 state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); 3232 if (!Sym) 3233 return; 3234 3235 // Get the reference count binding (if any). 3236 const RefVal *T = getRefBinding(state, Sym); 3237 if (!T) 3238 return; 3239 3240 // Change the reference count. 3241 RefVal X = *T; 3242 3243 switch (X.getKind()) { 3244 case RefVal::Owned: { 3245 unsigned cnt = X.getCount(); 3246 assert(cnt > 0); 3247 X.setCount(cnt - 1); 3248 X = X ^ RefVal::ReturnedOwned; 3249 break; 3250 } 3251 3252 case RefVal::NotOwned: { 3253 unsigned cnt = X.getCount(); 3254 if (cnt) { 3255 X.setCount(cnt - 1); 3256 X = X ^ RefVal::ReturnedOwned; 3257 } 3258 else { 3259 X = X ^ RefVal::ReturnedNotOwned; 3260 } 3261 break; 3262 } 3263 3264 default: 3265 return; 3266 } 3267 3268 // Update the binding. 3269 state = setRefBinding(state, Sym, X); 3270 ExplodedNode *Pred = C.addTransition(state); 3271 3272 // At this point we have updated the state properly. 3273 // Everything after this is merely checking to see if the return value has 3274 // been over- or under-retained. 3275 3276 // Did we cache out? 3277 if (!Pred) 3278 return; 3279 3280 // Update the autorelease counts. 3281 static SimpleProgramPointTag 3282 AutoreleaseTag("RetainCountChecker : Autorelease"); 3283 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, 3284 C, Sym, X); 3285 3286 // Did we cache out? 3287 if (!Pred) 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 (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) { 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 RefBindings B = state->get<RefBindings>(); 3442 3443 if (B.isEmpty()) 3444 return state; 3445 3446 bool changed = false; 3447 RefBindings::Factory &RefBFactory = state->get_context<RefBindings>(); 3448 3449 for (RefBindings::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 StoreManager::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 (StoreManager::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 3496std::pair<ExplodedNode *, ProgramStateRef > 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 std::make_pair(Pred, 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(Cnt - ACnt); 3525 V.setAutoreleaseCount(0); 3526 } 3527 state = setRefBinding(state, Sym, V); 3528 ExplodedNode *N = Ctx.addTransition(state, Pred, Tag); 3529 if (N == 0) 3530 state = 0; 3531 return std::make_pair(N, state); 3532 } 3533 3534 // Woah! More autorelease counts then retain counts left. 3535 // Emit hard error. 3536 V = V ^ RefVal::ErrorOverAutorelease; 3537 state = setRefBinding(state, Sym, V); 3538 3539 ExplodedNode *N = Ctx.generateSink(state, Pred, Tag); 3540 if (N) { 3541 SmallString<128> sbuf; 3542 llvm::raw_svector_ostream os(sbuf); 3543 os << "Object over-autoreleased: object was sent -autorelease "; 3544 if (V.getAutoreleaseCount() > 1) 3545 os << V.getAutoreleaseCount() << " times "; 3546 os << "but the object has a +" << V.getCount() << " retain count"; 3547 3548 if (!overAutorelease) 3549 overAutorelease.reset(new OverAutorelease()); 3550 3551 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3552 CFRefReport *report = 3553 new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false, 3554 SummaryLog, N, Sym, os.str()); 3555 Ctx.emitReport(report); 3556 } 3557 3558 return std::make_pair((ExplodedNode *)0, (ProgramStateRef )0); 3559} 3560 3561ProgramStateRef 3562RetainCountChecker::handleSymbolDeath(ProgramStateRef state, 3563 SymbolRef sid, RefVal V, 3564 SmallVectorImpl<SymbolRef> &Leaked) const { 3565 bool hasLeak = false; 3566 if (V.isOwned()) 3567 hasLeak = true; 3568 else if (V.isNotOwned() || V.isReturnedOwned()) 3569 hasLeak = (V.getCount() > 0); 3570 3571 if (!hasLeak) 3572 return removeRefBinding(state, sid); 3573 3574 Leaked.push_back(sid); 3575 return setRefBinding(state, sid, V ^ RefVal::ErrorLeak); 3576} 3577 3578ExplodedNode * 3579RetainCountChecker::processLeaks(ProgramStateRef state, 3580 SmallVectorImpl<SymbolRef> &Leaked, 3581 CheckerContext &Ctx, 3582 ExplodedNode *Pred) const { 3583 if (Leaked.empty()) 3584 return Pred; 3585 3586 // Generate an intermediate node representing the leak point. 3587 ExplodedNode *N = Ctx.addTransition(state, Pred); 3588 3589 if (N) { 3590 for (SmallVectorImpl<SymbolRef>::iterator 3591 I = Leaked.begin(), E = Leaked.end(); I != E; ++I) { 3592 3593 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3594 bool GCEnabled = Ctx.isObjCGCEnabled(); 3595 CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled) 3596 : getLeakAtReturnBug(LOpts, GCEnabled); 3597 assert(BT && "BugType not initialized."); 3598 3599 CFRefLeakReport *report = new CFRefLeakReport(*BT, LOpts, GCEnabled, 3600 SummaryLog, N, *I, Ctx); 3601 Ctx.emitReport(report); 3602 } 3603 } 3604 3605 return N; 3606} 3607 3608void RetainCountChecker::checkEndPath(CheckerContext &Ctx) const { 3609 ProgramStateRef state = Ctx.getState(); 3610 RefBindings B = state->get<RefBindings>(); 3611 ExplodedNode *Pred = Ctx.getPredecessor(); 3612 3613 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3614 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Pred, /*Tag=*/0, 3615 Ctx, I->first, I->second); 3616 if (!state) 3617 return; 3618 } 3619 3620 // If the current LocationContext has a parent, don't check for leaks. 3621 // We will do that later. 3622 // FIXME: we should instead check for imbalances of the retain/releases, 3623 // and suggest annotations. 3624 if (Ctx.getLocationContext()->getParent()) 3625 return; 3626 3627 B = state->get<RefBindings>(); 3628 SmallVector<SymbolRef, 10> Leaked; 3629 3630 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) 3631 state = handleSymbolDeath(state, I->first, I->second, Leaked); 3632 3633 processLeaks(state, Leaked, Ctx, Pred); 3634} 3635 3636const ProgramPointTag * 3637RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const { 3638 const SimpleProgramPointTag *&tag = DeadSymbolTags[sym]; 3639 if (!tag) { 3640 SmallString<64> buf; 3641 llvm::raw_svector_ostream out(buf); 3642 out << "RetainCountChecker : Dead Symbol : "; 3643 sym->dumpToStream(out); 3644 tag = new SimpleProgramPointTag(out.str()); 3645 } 3646 return tag; 3647} 3648 3649void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper, 3650 CheckerContext &C) const { 3651 ExplodedNode *Pred = C.getPredecessor(); 3652 3653 ProgramStateRef state = C.getState(); 3654 RefBindings B = state->get<RefBindings>(); 3655 3656 // Update counts from autorelease pools 3657 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3658 E = SymReaper.dead_end(); I != E; ++I) { 3659 SymbolRef Sym = *I; 3660 if (const RefVal *T = B.lookup(Sym)){ 3661 // Use the symbol as the tag. 3662 // FIXME: This might not be as unique as we would like. 3663 const ProgramPointTag *Tag = getDeadSymbolTag(Sym); 3664 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Pred, Tag, C, 3665 Sym, *T); 3666 if (!state) 3667 return; 3668 } 3669 } 3670 3671 B = state->get<RefBindings>(); 3672 SmallVector<SymbolRef, 10> Leaked; 3673 3674 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3675 E = SymReaper.dead_end(); I != E; ++I) { 3676 if (const RefVal *T = B.lookup(*I)) 3677 state = handleSymbolDeath(state, *I, *T, Leaked); 3678 } 3679 3680 Pred = processLeaks(state, Leaked, C, Pred); 3681 3682 // Did we cache out? 3683 if (!Pred) 3684 return; 3685 3686 // Now generate a new node that nukes the old bindings. 3687 RefBindings::Factory &F = state->get_context<RefBindings>(); 3688 3689 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3690 E = SymReaper.dead_end(); I != E; ++I) 3691 B = F.remove(B, *I); 3692 3693 state = state->set<RefBindings>(B); 3694 C.addTransition(state, Pred); 3695} 3696 3697void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State, 3698 const char *NL, const char *Sep) const { 3699 3700 RefBindings B = State->get<RefBindings>(); 3701 3702 if (!B.isEmpty()) 3703 Out << Sep << NL; 3704 3705 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3706 Out << I->first << " : "; 3707 I->second.print(Out); 3708 Out << NL; 3709 } 3710} 3711 3712//===----------------------------------------------------------------------===// 3713// Checker registration. 3714//===----------------------------------------------------------------------===// 3715 3716void ento::registerRetainCountChecker(CheckerManager &Mgr) { 3717 Mgr.registerChecker<RetainCountChecker>(); 3718} 3719 3720