RetainCountChecker.cpp revision 4a25f3056416aaffa7852985c2045634e5275876
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 == "IOBSDNameMatching" || 1078 FName == "IOServiceMatching" || 1079 FName == "IOServiceNameMatching" || 1080 FName == "IORegistryEntrySearchCFProperty" || 1081 FName == "IORegistryEntryIDMatching" || 1082 FName == "IOOpenFirmwarePathMatching") { 1083 // Part of <rdar://problem/6961230>. (IOKit) 1084 // This should be addressed using a API table. 1085 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1086 DoNothing, DoNothing); 1087 } else if (FName == "IOServiceGetMatchingService" || 1088 FName == "IOServiceGetMatchingServices") { 1089 // FIXES: <rdar://problem/6326900> 1090 // This should be addressed using a API table. This strcmp is also 1091 // a little gross, but there is no need to super optimize here. 1092 ScratchArgs = AF.add(ScratchArgs, 1, DecRef); 1093 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1094 } else if (FName == "IOServiceAddNotification" || 1095 FName == "IOServiceAddMatchingNotification") { 1096 // Part of <rdar://problem/6961230>. (IOKit) 1097 // This should be addressed using a API table. 1098 ScratchArgs = AF.add(ScratchArgs, 2, DecRef); 1099 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1100 } else if (FName == "CVPixelBufferCreateWithBytes") { 1101 // FIXES: <rdar://problem/7283567> 1102 // Eventually this can be improved by recognizing that the pixel 1103 // buffer passed to CVPixelBufferCreateWithBytes is released via 1104 // a callback and doing full IPA to make sure this is done correctly. 1105 // FIXME: This function has an out parameter that returns an 1106 // allocated object. 1107 ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); 1108 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1109 } else if (FName == "CGBitmapContextCreateWithData") { 1110 // FIXES: <rdar://problem/7358899> 1111 // Eventually this can be improved by recognizing that 'releaseInfo' 1112 // passed to CGBitmapContextCreateWithData is released via 1113 // a callback and doing full IPA to make sure this is done correctly. 1114 ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); 1115 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1116 DoNothing, DoNothing); 1117 } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { 1118 // FIXES: <rdar://problem/7283567> 1119 // Eventually this can be improved by recognizing that the pixel 1120 // buffer passed to CVPixelBufferCreateWithPlanarBytes is released 1121 // via a callback and doing full IPA to make sure this is done 1122 // correctly. 1123 ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); 1124 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1125 } else if (FName == "dispatch_set_context") { 1126 // <rdar://problem/11059275> - The analyzer currently doesn't have 1127 // a good way to reason about the finalizer function for libdispatch. 1128 // If we pass a context object that is memory managed, stop tracking it. 1129 // FIXME: this hack should possibly go away once we can handle 1130 // libdispatch finalizers. 1131 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1132 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1133 } else if (FName.startswith("NSLog")) { 1134 S = getDoNothingSummary(); 1135 } else if (FName.startswith("NS") && 1136 (FName.find("Insert") != StringRef::npos)) { 1137 // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 1138 // be deallocated by NSMapRemove. (radar://11152419) 1139 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1140 ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); 1141 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1142 } 1143 1144 // Did we get a summary? 1145 if (S) 1146 break; 1147 1148 if (RetTy->isPointerType()) { 1149 if (FD->getAttr<CFAuditedTransferAttr>()) { 1150 S = getCFCreateGetRuleSummary(FD); 1151 break; 1152 } 1153 1154 // For CoreFoundation ('CF') types. 1155 if (cocoa::isRefType(RetTy, "CF", FName)) { 1156 if (isRetain(FD, FName)) 1157 S = getUnarySummary(FT, cfretain); 1158 else if (isMakeCollectable(FD, FName)) 1159 S = getUnarySummary(FT, cfmakecollectable); 1160 else 1161 S = getCFCreateGetRuleSummary(FD); 1162 1163 break; 1164 } 1165 1166 // For CoreGraphics ('CG') types. 1167 if (cocoa::isRefType(RetTy, "CG", FName)) { 1168 if (isRetain(FD, FName)) 1169 S = getUnarySummary(FT, cfretain); 1170 else 1171 S = getCFCreateGetRuleSummary(FD); 1172 1173 break; 1174 } 1175 1176 // For the Disk Arbitration API (DiskArbitration/DADisk.h) 1177 if (cocoa::isRefType(RetTy, "DADisk") || 1178 cocoa::isRefType(RetTy, "DADissenter") || 1179 cocoa::isRefType(RetTy, "DASessionRef")) { 1180 S = getCFCreateGetRuleSummary(FD); 1181 break; 1182 } 1183 1184 break; 1185 } 1186 1187 // Check for release functions, the only kind of functions that we care 1188 // about that don't return a pointer type. 1189 if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { 1190 // Test for 'CGCF'. 1191 FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); 1192 1193 if (isRelease(FD, FName)) 1194 S = getUnarySummary(FT, cfrelease); 1195 else { 1196 assert (ScratchArgs.isEmpty()); 1197 // Remaining CoreFoundation and CoreGraphics functions. 1198 // We use to assume that they all strictly followed the ownership idiom 1199 // and that ownership cannot be transferred. While this is technically 1200 // correct, many methods allow a tracked object to escape. For example: 1201 // 1202 // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); 1203 // CFDictionaryAddValue(y, key, x); 1204 // CFRelease(x); 1205 // ... it is okay to use 'x' since 'y' has a reference to it 1206 // 1207 // We handle this and similar cases with the follow heuristic. If the 1208 // function name contains "InsertValue", "SetValue", "AddValue", 1209 // "AppendValue", or "SetAttribute", then we assume that arguments may 1210 // "escape." This means that something else holds on to the object, 1211 // allowing it be used even after its local retain count drops to 0. 1212 ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| 1213 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 1214 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 1215 StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| 1216 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) 1217 ? MayEscape : DoNothing; 1218 1219 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); 1220 } 1221 } 1222 } 1223 while (0); 1224 1225 // If we got all the way here without any luck, use a default summary. 1226 if (!S) 1227 S = getDefaultSummary(); 1228 1229 // Annotations override defaults. 1230 if (AllowAnnotations) 1231 updateSummaryFromAnnotations(S, FD); 1232 1233 FuncSummaries[FD] = S; 1234 return S; 1235} 1236 1237const RetainSummary * 1238RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { 1239 if (coreFoundation::followsCreateRule(FD)) 1240 return getCFSummaryCreateRule(FD); 1241 1242 return getCFSummaryGetRule(FD); 1243} 1244 1245const RetainSummary * 1246RetainSummaryManager::getUnarySummary(const FunctionType* FT, 1247 UnaryFuncKind func) { 1248 1249 // Sanity check that this is *really* a unary function. This can 1250 // happen if people do weird things. 1251 const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); 1252 if (!FTP || FTP->getNumArgs() != 1) 1253 return getPersistentStopSummary(); 1254 1255 assert (ScratchArgs.isEmpty()); 1256 1257 ArgEffect Effect; 1258 switch (func) { 1259 case cfretain: Effect = IncRef; break; 1260 case cfrelease: Effect = DecRef; break; 1261 case cfmakecollectable: Effect = MakeCollectable; break; 1262 } 1263 1264 ScratchArgs = AF.add(ScratchArgs, 0, Effect); 1265 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1266} 1267 1268const RetainSummary * 1269RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { 1270 assert (ScratchArgs.isEmpty()); 1271 1272 return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1273} 1274 1275const RetainSummary * 1276RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { 1277 assert (ScratchArgs.isEmpty()); 1278 return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), 1279 DoNothing, DoNothing); 1280} 1281 1282//===----------------------------------------------------------------------===// 1283// Summary creation for Selectors. 1284//===----------------------------------------------------------------------===// 1285 1286void 1287RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1288 const FunctionDecl *FD) { 1289 if (!FD) 1290 return; 1291 1292 assert(Summ && "Must have a summary to add annotations to."); 1293 RetainSummaryTemplate Template(Summ, *this); 1294 1295 // Effects on the parameters. 1296 unsigned parm_idx = 0; 1297 for (FunctionDecl::param_const_iterator pi = FD->param_begin(), 1298 pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { 1299 const ParmVarDecl *pd = *pi; 1300 if (pd->getAttr<NSConsumedAttr>()) { 1301 if (!GCEnabled) { 1302 Template->addArg(AF, parm_idx, DecRef); 1303 } 1304 } else if (pd->getAttr<CFConsumedAttr>()) { 1305 Template->addArg(AF, parm_idx, DecRef); 1306 } 1307 } 1308 1309 QualType RetTy = FD->getResultType(); 1310 1311 // Determine if there is a special return effect for this method. 1312 if (cocoa::isCocoaObjectRef(RetTy)) { 1313 if (FD->getAttr<NSReturnsRetainedAttr>()) { 1314 Template->setRetEffect(ObjCAllocRetE); 1315 } 1316 else if (FD->getAttr<CFReturnsRetainedAttr>()) { 1317 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1318 } 1319 else if (FD->getAttr<NSReturnsNotRetainedAttr>()) { 1320 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1321 } 1322 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1323 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1324 } 1325 } else if (RetTy->getAs<PointerType>()) { 1326 if (FD->getAttr<CFReturnsRetainedAttr>()) { 1327 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1328 } 1329 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1330 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1331 } 1332 } 1333} 1334 1335void 1336RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1337 const ObjCMethodDecl *MD) { 1338 if (!MD) 1339 return; 1340 1341 assert(Summ && "Must have a valid summary to add annotations to"); 1342 RetainSummaryTemplate Template(Summ, *this); 1343 bool isTrackedLoc = false; 1344 1345 // Effects on the receiver. 1346 if (MD->getAttr<NSConsumesSelfAttr>()) { 1347 if (!GCEnabled) 1348 Template->setReceiverEffect(DecRefMsg); 1349 } 1350 1351 // Effects on the parameters. 1352 unsigned parm_idx = 0; 1353 for (ObjCMethodDecl::param_const_iterator 1354 pi=MD->param_begin(), pe=MD->param_end(); 1355 pi != pe; ++pi, ++parm_idx) { 1356 const ParmVarDecl *pd = *pi; 1357 if (pd->getAttr<NSConsumedAttr>()) { 1358 if (!GCEnabled) 1359 Template->addArg(AF, parm_idx, DecRef); 1360 } 1361 else if(pd->getAttr<CFConsumedAttr>()) { 1362 Template->addArg(AF, parm_idx, DecRef); 1363 } 1364 } 1365 1366 // Determine if there is a special return effect for this method. 1367 if (cocoa::isCocoaObjectRef(MD->getResultType())) { 1368 if (MD->getAttr<NSReturnsRetainedAttr>()) { 1369 Template->setRetEffect(ObjCAllocRetE); 1370 return; 1371 } 1372 if (MD->getAttr<NSReturnsNotRetainedAttr>()) { 1373 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1374 return; 1375 } 1376 1377 isTrackedLoc = true; 1378 } else { 1379 isTrackedLoc = MD->getResultType()->getAs<PointerType>() != NULL; 1380 } 1381 1382 if (isTrackedLoc) { 1383 if (MD->getAttr<CFReturnsRetainedAttr>()) 1384 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1385 else if (MD->getAttr<CFReturnsNotRetainedAttr>()) 1386 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1387 } 1388} 1389 1390const RetainSummary * 1391RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, 1392 Selector S, QualType RetTy) { 1393 // Any special effects? 1394 ArgEffect ReceiverEff = DoNothing; 1395 RetEffect ResultEff = RetEffect::MakeNoRet(); 1396 1397 // Check the method family, and apply any default annotations. 1398 switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { 1399 case OMF_None: 1400 case OMF_performSelector: 1401 // Assume all Objective-C methods follow Cocoa Memory Management rules. 1402 // FIXME: Does the non-threaded performSelector family really belong here? 1403 // The selector could be, say, @selector(copy). 1404 if (cocoa::isCocoaObjectRef(RetTy)) 1405 ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); 1406 else if (coreFoundation::isCFObjectRef(RetTy)) { 1407 // ObjCMethodDecl currently doesn't consider CF objects as valid return 1408 // values for alloc, new, copy, or mutableCopy, so we have to 1409 // double-check with the selector. This is ugly, but there aren't that 1410 // many Objective-C methods that return CF objects, right? 1411 if (MD) { 1412 switch (S.getMethodFamily()) { 1413 case OMF_alloc: 1414 case OMF_new: 1415 case OMF_copy: 1416 case OMF_mutableCopy: 1417 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1418 break; 1419 default: 1420 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1421 break; 1422 } 1423 } else { 1424 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1425 } 1426 } 1427 break; 1428 case OMF_init: 1429 ResultEff = ObjCInitRetE; 1430 ReceiverEff = DecRefMsg; 1431 break; 1432 case OMF_alloc: 1433 case OMF_new: 1434 case OMF_copy: 1435 case OMF_mutableCopy: 1436 if (cocoa::isCocoaObjectRef(RetTy)) 1437 ResultEff = ObjCAllocRetE; 1438 else if (coreFoundation::isCFObjectRef(RetTy)) 1439 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1440 break; 1441 case OMF_autorelease: 1442 ReceiverEff = Autorelease; 1443 break; 1444 case OMF_retain: 1445 ReceiverEff = IncRefMsg; 1446 break; 1447 case OMF_release: 1448 ReceiverEff = DecRefMsg; 1449 break; 1450 case OMF_dealloc: 1451 ReceiverEff = Dealloc; 1452 break; 1453 case OMF_self: 1454 // -self is handled specially by the ExprEngine to propagate the receiver. 1455 break; 1456 case OMF_retainCount: 1457 case OMF_finalize: 1458 // These methods don't return objects. 1459 break; 1460 } 1461 1462 // If one of the arguments in the selector has the keyword 'delegate' we 1463 // should stop tracking the reference count for the receiver. This is 1464 // because the reference count is quite possibly handled by a delegate 1465 // method. 1466 if (S.isKeywordSelector()) { 1467 for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { 1468 StringRef Slot = S.getNameForSlot(i); 1469 if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { 1470 if (ResultEff == ObjCInitRetE) 1471 ResultEff = RetEffect::MakeNoRetHard(); 1472 else 1473 ReceiverEff = StopTrackingHard; 1474 } 1475 } 1476 } 1477 1478 if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && 1479 ResultEff.getKind() == RetEffect::NoRet) 1480 return getDefaultSummary(); 1481 1482 return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); 1483} 1484 1485const RetainSummary * 1486RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, 1487 ProgramStateRef State) { 1488 const ObjCInterfaceDecl *ReceiverClass = 0; 1489 1490 // We do better tracking of the type of the object than the core ExprEngine. 1491 // See if we have its type in our private state. 1492 // FIXME: Eventually replace the use of state->get<RefBindings> with 1493 // a generic API for reasoning about the Objective-C types of symbolic 1494 // objects. 1495 SVal ReceiverV = Msg.getReceiverSVal(); 1496 if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) 1497 if (const RefVal *T = getRefBinding(State, Sym)) 1498 if (const ObjCObjectPointerType *PT = 1499 T->getType()->getAs<ObjCObjectPointerType>()) 1500 ReceiverClass = PT->getInterfaceDecl(); 1501 1502 // If we don't know what kind of object this is, fall back to its static type. 1503 if (!ReceiverClass) 1504 ReceiverClass = Msg.getReceiverInterface(); 1505 1506 // FIXME: The receiver could be a reference to a class, meaning that 1507 // we should use the class method. 1508 // id x = [NSObject class]; 1509 // [x performSelector:... withObject:... afterDelay:...]; 1510 Selector S = Msg.getSelector(); 1511 const ObjCMethodDecl *Method = Msg.getDecl(); 1512 if (!Method && ReceiverClass) 1513 Method = ReceiverClass->getInstanceMethod(S); 1514 1515 return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), 1516 ObjCMethodSummaries); 1517} 1518 1519const RetainSummary * 1520RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 1521 const ObjCMethodDecl *MD, QualType RetTy, 1522 ObjCMethodSummariesTy &CachedSummaries) { 1523 1524 // Look up a summary in our summary cache. 1525 const RetainSummary *Summ = CachedSummaries.find(ID, S); 1526 1527 if (!Summ) { 1528 Summ = getStandardMethodSummary(MD, S, RetTy); 1529 1530 // Annotations override defaults. 1531 updateSummaryFromAnnotations(Summ, MD); 1532 1533 // Memoize the summary. 1534 CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; 1535 } 1536 1537 return Summ; 1538} 1539 1540void RetainSummaryManager::InitializeClassMethodSummaries() { 1541 assert(ScratchArgs.isEmpty()); 1542 // Create the [NSAssertionHandler currentHander] summary. 1543 addClassMethSummary("NSAssertionHandler", "currentHandler", 1544 getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); 1545 1546 // Create the [NSAutoreleasePool addObject:] summary. 1547 ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); 1548 addClassMethSummary("NSAutoreleasePool", "addObject", 1549 getPersistentSummary(RetEffect::MakeNoRet(), 1550 DoNothing, Autorelease)); 1551} 1552 1553void RetainSummaryManager::InitializeMethodSummaries() { 1554 1555 assert (ScratchArgs.isEmpty()); 1556 1557 // Create the "init" selector. It just acts as a pass-through for the 1558 // receiver. 1559 const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); 1560 addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); 1561 1562 // awakeAfterUsingCoder: behaves basically like an 'init' method. It 1563 // claims the receiver and returns a retained object. 1564 addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), 1565 InitSumm); 1566 1567 // The next methods are allocators. 1568 const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); 1569 const RetainSummary *CFAllocSumm = 1570 getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1571 1572 // Create the "retain" selector. 1573 RetEffect NoRet = RetEffect::MakeNoRet(); 1574 const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); 1575 addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); 1576 1577 // Create the "release" selector. 1578 Summ = getPersistentSummary(NoRet, DecRefMsg); 1579 addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); 1580 1581 // Create the "drain" selector. 1582 Summ = getPersistentSummary(NoRet, isGCEnabled() ? DoNothing : DecRef); 1583 addNSObjectMethSummary(GetNullarySelector("drain", Ctx), Summ); 1584 1585 // Create the -dealloc summary. 1586 Summ = getPersistentSummary(NoRet, Dealloc); 1587 addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); 1588 1589 // Create the "autorelease" selector. 1590 Summ = getPersistentSummary(NoRet, Autorelease); 1591 addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); 1592 1593 // Specially handle NSAutoreleasePool. 1594 addInstMethSummary("NSAutoreleasePool", "init", 1595 getPersistentSummary(NoRet, NewAutoreleasePool)); 1596 1597 // For NSWindow, allocated objects are (initially) self-owned. 1598 // FIXME: For now we opt for false negatives with NSWindow, as these objects 1599 // self-own themselves. However, they only do this once they are displayed. 1600 // Thus, we need to track an NSWindow's display status. 1601 // This is tracked in <rdar://problem/6062711>. 1602 // See also http://llvm.org/bugs/show_bug.cgi?id=3714. 1603 const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), 1604 StopTracking, 1605 StopTracking); 1606 1607 addClassMethSummary("NSWindow", "alloc", NoTrackYet); 1608 1609 // For NSPanel (which subclasses NSWindow), allocated objects are not 1610 // self-owned. 1611 // FIXME: For now we don't track NSPanels. object for the same reason 1612 // as for NSWindow objects. 1613 addClassMethSummary("NSPanel", "alloc", NoTrackYet); 1614 1615 // Don't track allocated autorelease pools yet, as it is okay to prematurely 1616 // exit a method. 1617 addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); 1618 addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); 1619 1620 // Create summaries QCRenderer/QCView -createSnapShotImageOfType: 1621 addInstMethSummary("QCRenderer", AllocSumm, 1622 "createSnapshotImageOfType", NULL); 1623 addInstMethSummary("QCView", AllocSumm, 1624 "createSnapshotImageOfType", NULL); 1625 1626 // Create summaries for CIContext, 'createCGImage' and 1627 // 'createCGLayerWithSize'. These objects are CF objects, and are not 1628 // automatically garbage collected. 1629 addInstMethSummary("CIContext", CFAllocSumm, 1630 "createCGImage", "fromRect", NULL); 1631 addInstMethSummary("CIContext", CFAllocSumm, 1632 "createCGImage", "fromRect", "format", "colorSpace", NULL); 1633 addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", 1634 "info", NULL); 1635} 1636 1637//===----------------------------------------------------------------------===// 1638// Error reporting. 1639//===----------------------------------------------------------------------===// 1640namespace { 1641 typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> 1642 SummaryLogTy; 1643 1644 //===-------------===// 1645 // Bug Descriptions. // 1646 //===-------------===// 1647 1648 class CFRefBug : public BugType { 1649 protected: 1650 CFRefBug(StringRef name) 1651 : BugType(name, categories::MemoryCoreFoundationObjectiveC) {} 1652 public: 1653 1654 // FIXME: Eventually remove. 1655 virtual const char *getDescription() const = 0; 1656 1657 virtual bool isLeak() const { return false; } 1658 }; 1659 1660 class UseAfterRelease : public CFRefBug { 1661 public: 1662 UseAfterRelease() : CFRefBug("Use-after-release") {} 1663 1664 const char *getDescription() const { 1665 return "Reference-counted object is used after it is released"; 1666 } 1667 }; 1668 1669 class BadRelease : public CFRefBug { 1670 public: 1671 BadRelease() : CFRefBug("Bad release") {} 1672 1673 const char *getDescription() const { 1674 return "Incorrect decrement of the reference count of an object that is " 1675 "not owned at this point by the caller"; 1676 } 1677 }; 1678 1679 class DeallocGC : public CFRefBug { 1680 public: 1681 DeallocGC() 1682 : CFRefBug("-dealloc called while using garbage collection") {} 1683 1684 const char *getDescription() const { 1685 return "-dealloc called while using garbage collection"; 1686 } 1687 }; 1688 1689 class DeallocNotOwned : public CFRefBug { 1690 public: 1691 DeallocNotOwned() 1692 : CFRefBug("-dealloc sent to non-exclusively owned object") {} 1693 1694 const char *getDescription() const { 1695 return "-dealloc sent to object that may be referenced elsewhere"; 1696 } 1697 }; 1698 1699 class OverAutorelease : public CFRefBug { 1700 public: 1701 OverAutorelease() 1702 : CFRefBug("Object sent -autorelease too many times") {} 1703 1704 const char *getDescription() const { 1705 return "Object sent -autorelease too many times"; 1706 } 1707 }; 1708 1709 class ReturnedNotOwnedForOwned : public CFRefBug { 1710 public: 1711 ReturnedNotOwnedForOwned() 1712 : CFRefBug("Method should return an owned object") {} 1713 1714 const char *getDescription() const { 1715 return "Object with a +0 retain count returned to caller where a +1 " 1716 "(owning) retain count is expected"; 1717 } 1718 }; 1719 1720 class Leak : public CFRefBug { 1721 public: 1722 Leak(StringRef name) 1723 : CFRefBug(name) { 1724 // Leaks should not be reported if they are post-dominated by a sink. 1725 setSuppressOnSink(true); 1726 } 1727 1728 const char *getDescription() const { return ""; } 1729 1730 bool isLeak() const { return true; } 1731 }; 1732 1733 //===---------===// 1734 // Bug Reports. // 1735 //===---------===// 1736 1737 class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> { 1738 protected: 1739 SymbolRef Sym; 1740 const SummaryLogTy &SummaryLog; 1741 bool GCEnabled; 1742 1743 public: 1744 CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) 1745 : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} 1746 1747 virtual void Profile(llvm::FoldingSetNodeID &ID) const { 1748 static int x = 0; 1749 ID.AddPointer(&x); 1750 ID.AddPointer(Sym); 1751 } 1752 1753 virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N, 1754 const ExplodedNode *PrevN, 1755 BugReporterContext &BRC, 1756 BugReport &BR); 1757 1758 virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1759 const ExplodedNode *N, 1760 BugReport &BR); 1761 }; 1762 1763 class CFRefLeakReportVisitor : public CFRefReportVisitor { 1764 public: 1765 CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, 1766 const SummaryLogTy &log) 1767 : CFRefReportVisitor(sym, GCEnabled, log) {} 1768 1769 PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1770 const ExplodedNode *N, 1771 BugReport &BR); 1772 1773 virtual BugReporterVisitor *clone() const { 1774 // The curiously-recurring template pattern only works for one level of 1775 // subclassing. Rather than make a new template base for 1776 // CFRefReportVisitor, we simply override clone() to do the right thing. 1777 // This could be trouble someday if BugReporterVisitorImpl is ever 1778 // used for something else besides a convenient implementation of clone(). 1779 return new CFRefLeakReportVisitor(*this); 1780 } 1781 }; 1782 1783 class CFRefReport : public BugReport { 1784 void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); 1785 1786 public: 1787 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1788 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1789 bool registerVisitor = true) 1790 : BugReport(D, D.getDescription(), n) { 1791 if (registerVisitor) 1792 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1793 addGCModeDescription(LOpts, GCEnabled); 1794 } 1795 1796 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1797 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1798 StringRef endText) 1799 : BugReport(D, D.getDescription(), endText, n) { 1800 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1801 addGCModeDescription(LOpts, GCEnabled); 1802 } 1803 1804 virtual std::pair<ranges_iterator, ranges_iterator> getRanges() { 1805 const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); 1806 if (!BugTy.isLeak()) 1807 return BugReport::getRanges(); 1808 else 1809 return std::make_pair(ranges_iterator(), ranges_iterator()); 1810 } 1811 }; 1812 1813 class CFRefLeakReport : public CFRefReport { 1814 const MemRegion* AllocBinding; 1815 1816 public: 1817 CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1818 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1819 CheckerContext &Ctx); 1820 1821 PathDiagnosticLocation getLocation(const SourceManager &SM) const { 1822 assert(Location.isValid()); 1823 return Location; 1824 } 1825 }; 1826} // end anonymous namespace 1827 1828void CFRefReport::addGCModeDescription(const LangOptions &LOpts, 1829 bool GCEnabled) { 1830 const char *GCModeDescription = 0; 1831 1832 switch (LOpts.getGC()) { 1833 case LangOptions::GCOnly: 1834 assert(GCEnabled); 1835 GCModeDescription = "Code is compiled to only use garbage collection"; 1836 break; 1837 1838 case LangOptions::NonGC: 1839 assert(!GCEnabled); 1840 GCModeDescription = "Code is compiled to use reference counts"; 1841 break; 1842 1843 case LangOptions::HybridGC: 1844 if (GCEnabled) { 1845 GCModeDescription = "Code is compiled to use either garbage collection " 1846 "(GC) or reference counts (non-GC). The bug occurs " 1847 "with GC enabled"; 1848 break; 1849 } else { 1850 GCModeDescription = "Code is compiled to use either garbage collection " 1851 "(GC) or reference counts (non-GC). The bug occurs " 1852 "in non-GC mode"; 1853 break; 1854 } 1855 } 1856 1857 assert(GCModeDescription && "invalid/unknown GC mode"); 1858 addExtraText(GCModeDescription); 1859} 1860 1861// FIXME: This should be a method on SmallVector. 1862static inline bool contains(const SmallVectorImpl<ArgEffect>& V, 1863 ArgEffect X) { 1864 for (SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end(); 1865 I!=E; ++I) 1866 if (*I == X) return true; 1867 1868 return false; 1869} 1870 1871static bool isNumericLiteralExpression(const Expr *E) { 1872 // FIXME: This set of cases was copied from SemaExprObjC. 1873 return isa<IntegerLiteral>(E) || 1874 isa<CharacterLiteral>(E) || 1875 isa<FloatingLiteral>(E) || 1876 isa<ObjCBoolLiteralExpr>(E) || 1877 isa<CXXBoolLiteralExpr>(E); 1878} 1879 1880PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N, 1881 const ExplodedNode *PrevN, 1882 BugReporterContext &BRC, 1883 BugReport &BR) { 1884 // FIXME: We will eventually need to handle non-statement-based events 1885 // (__attribute__((cleanup))). 1886 if (!isa<StmtPoint>(N->getLocation())) 1887 return NULL; 1888 1889 // Check if the type state has changed. 1890 ProgramStateRef PrevSt = PrevN->getState(); 1891 ProgramStateRef CurrSt = N->getState(); 1892 const LocationContext *LCtx = N->getLocationContext(); 1893 1894 const RefVal* CurrT = getRefBinding(CurrSt, Sym); 1895 if (!CurrT) return NULL; 1896 1897 const RefVal &CurrV = *CurrT; 1898 const RefVal *PrevT = getRefBinding(PrevSt, Sym); 1899 1900 // Create a string buffer to constain all the useful things we want 1901 // to tell the user. 1902 std::string sbuf; 1903 llvm::raw_string_ostream os(sbuf); 1904 1905 // This is the allocation site since the previous node had no bindings 1906 // for this symbol. 1907 if (!PrevT) { 1908 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 1909 1910 if (isa<ObjCArrayLiteral>(S)) { 1911 os << "NSArray literal is an object with a +0 retain count"; 1912 } 1913 else if (isa<ObjCDictionaryLiteral>(S)) { 1914 os << "NSDictionary literal is an object with a +0 retain count"; 1915 } 1916 else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { 1917 if (isNumericLiteralExpression(BL->getSubExpr())) 1918 os << "NSNumber literal is an object with a +0 retain count"; 1919 else { 1920 const ObjCInterfaceDecl *BoxClass = 0; 1921 if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) 1922 BoxClass = Method->getClassInterface(); 1923 1924 // We should always be able to find the boxing class interface, 1925 // but consider this future-proofing. 1926 if (BoxClass) 1927 os << *BoxClass << " b"; 1928 else 1929 os << "B"; 1930 1931 os << "oxed expression produces an object with a +0 retain count"; 1932 } 1933 } 1934 else { 1935 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1936 // Get the name of the callee (if it is available). 1937 SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); 1938 if (const FunctionDecl *FD = X.getAsFunctionDecl()) 1939 os << "Call to function '" << *FD << '\''; 1940 else 1941 os << "function call"; 1942 } 1943 else { 1944 assert(isa<ObjCMessageExpr>(S)); 1945 CallEventManager &Mgr = CurrSt->getStateManager().getCallEventManager(); 1946 CallEventRef<ObjCMethodCall> Call 1947 = Mgr.getObjCMethodCall(cast<ObjCMessageExpr>(S), CurrSt, LCtx); 1948 1949 switch (Call->getMessageKind()) { 1950 case OCM_Message: 1951 os << "Method"; 1952 break; 1953 case OCM_PropertyAccess: 1954 os << "Property"; 1955 break; 1956 case OCM_Subscript: 1957 os << "Subscript"; 1958 break; 1959 } 1960 } 1961 1962 if (CurrV.getObjKind() == RetEffect::CF) { 1963 os << " returns a Core Foundation object with a "; 1964 } 1965 else { 1966 assert (CurrV.getObjKind() == RetEffect::ObjC); 1967 os << " returns an Objective-C object with a "; 1968 } 1969 1970 if (CurrV.isOwned()) { 1971 os << "+1 retain count"; 1972 1973 if (GCEnabled) { 1974 assert(CurrV.getObjKind() == RetEffect::CF); 1975 os << ". " 1976 "Core Foundation objects are not automatically garbage collected."; 1977 } 1978 } 1979 else { 1980 assert (CurrV.isNotOwned()); 1981 os << "+0 retain count"; 1982 } 1983 } 1984 1985 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 1986 N->getLocationContext()); 1987 return new PathDiagnosticEventPiece(Pos, os.str()); 1988 } 1989 1990 // Gather up the effects that were performed on the object at this 1991 // program point 1992 SmallVector<ArgEffect, 2> AEffects; 1993 1994 const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); 1995 if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { 1996 // We only have summaries attached to nodes after evaluating CallExpr and 1997 // ObjCMessageExprs. 1998 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 1999 2000 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 2001 // Iterate through the parameter expressions and see if the symbol 2002 // was ever passed as an argument. 2003 unsigned i = 0; 2004 2005 for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); 2006 AI!=AE; ++AI, ++i) { 2007 2008 // Retrieve the value of the argument. Is it the symbol 2009 // we are interested in? 2010 if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) 2011 continue; 2012 2013 // We have an argument. Get the effect! 2014 AEffects.push_back(Summ->getArg(i)); 2015 } 2016 } 2017 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { 2018 if (const Expr *receiver = ME->getInstanceReceiver()) 2019 if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) 2020 .getAsLocSymbol() == Sym) { 2021 // The symbol we are tracking is the receiver. 2022 AEffects.push_back(Summ->getReceiverEffect()); 2023 } 2024 } 2025 } 2026 2027 do { 2028 // Get the previous type state. 2029 RefVal PrevV = *PrevT; 2030 2031 // Specially handle -dealloc. 2032 if (!GCEnabled && contains(AEffects, Dealloc)) { 2033 // Determine if the object's reference count was pushed to zero. 2034 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2035 // We may not have transitioned to 'release' if we hit an error. 2036 // This case is handled elsewhere. 2037 if (CurrV.getKind() == RefVal::Released) { 2038 assert(CurrV.getCombinedCounts() == 0); 2039 os << "Object released by directly sending the '-dealloc' message"; 2040 break; 2041 } 2042 } 2043 2044 // Specially handle CFMakeCollectable and friends. 2045 if (contains(AEffects, MakeCollectable)) { 2046 // Get the name of the function. 2047 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2048 SVal X = 2049 CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); 2050 const FunctionDecl *FD = X.getAsFunctionDecl(); 2051 2052 if (GCEnabled) { 2053 // Determine if the object's reference count was pushed to zero. 2054 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2055 2056 os << "In GC mode a call to '" << *FD 2057 << "' decrements an object's retain count and registers the " 2058 "object with the garbage collector. "; 2059 2060 if (CurrV.getKind() == RefVal::Released) { 2061 assert(CurrV.getCount() == 0); 2062 os << "Since it now has a 0 retain count the object can be " 2063 "automatically collected by the garbage collector."; 2064 } 2065 else 2066 os << "An object must have a 0 retain count to be garbage collected. " 2067 "After this call its retain count is +" << CurrV.getCount() 2068 << '.'; 2069 } 2070 else 2071 os << "When GC is not enabled a call to '" << *FD 2072 << "' has no effect on its argument."; 2073 2074 // Nothing more to say. 2075 break; 2076 } 2077 2078 // Determine if the typestate has changed. 2079 if (!(PrevV == CurrV)) 2080 switch (CurrV.getKind()) { 2081 case RefVal::Owned: 2082 case RefVal::NotOwned: 2083 2084 if (PrevV.getCount() == CurrV.getCount()) { 2085 // Did an autorelease message get sent? 2086 if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) 2087 return 0; 2088 2089 assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); 2090 os << "Object sent -autorelease message"; 2091 break; 2092 } 2093 2094 if (PrevV.getCount() > CurrV.getCount()) 2095 os << "Reference count decremented."; 2096 else 2097 os << "Reference count incremented."; 2098 2099 if (unsigned Count = CurrV.getCount()) 2100 os << " The object now has a +" << Count << " retain count."; 2101 2102 if (PrevV.getKind() == RefVal::Released) { 2103 assert(GCEnabled && CurrV.getCount() > 0); 2104 os << " The object is not eligible for garbage collection until " 2105 "the retain count reaches 0 again."; 2106 } 2107 2108 break; 2109 2110 case RefVal::Released: 2111 os << "Object released."; 2112 break; 2113 2114 case RefVal::ReturnedOwned: 2115 // Autoreleases can be applied after marking a node ReturnedOwned. 2116 if (CurrV.getAutoreleaseCount()) 2117 return NULL; 2118 2119 os << "Object returned to caller as an owning reference (single " 2120 "retain count transferred to caller)"; 2121 break; 2122 2123 case RefVal::ReturnedNotOwned: 2124 os << "Object returned to caller with a +0 retain count"; 2125 break; 2126 2127 default: 2128 return NULL; 2129 } 2130 2131 // Emit any remaining diagnostics for the argument effects (if any). 2132 for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), 2133 E=AEffects.end(); I != E; ++I) { 2134 2135 // A bunch of things have alternate behavior under GC. 2136 if (GCEnabled) 2137 switch (*I) { 2138 default: break; 2139 case Autorelease: 2140 os << "In GC mode an 'autorelease' has no effect."; 2141 continue; 2142 case IncRefMsg: 2143 os << "In GC mode the 'retain' message has no effect."; 2144 continue; 2145 case DecRefMsg: 2146 os << "In GC mode the 'release' message has no effect."; 2147 continue; 2148 } 2149 } 2150 } while (0); 2151 2152 if (os.str().empty()) 2153 return 0; // We have nothing to say! 2154 2155 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2156 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2157 N->getLocationContext()); 2158 PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str()); 2159 2160 // Add the range by scanning the children of the statement for any bindings 2161 // to Sym. 2162 for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); 2163 I!=E; ++I) 2164 if (const Expr *Exp = dyn_cast_or_null<Expr>(*I)) 2165 if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { 2166 P->addRange(Exp->getSourceRange()); 2167 break; 2168 } 2169 2170 return P; 2171} 2172 2173// Find the first node in the current function context that referred to the 2174// tracked symbol and the memory location that value was stored to. Note, the 2175// value is only reported if the allocation occurred in the same function as 2176// the leak. 2177static std::pair<const ExplodedNode*,const MemRegion*> 2178GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, 2179 SymbolRef Sym) { 2180 const ExplodedNode *Last = N; 2181 const MemRegion* FirstBinding = 0; 2182 const LocationContext *LeakContext = N->getLocationContext(); 2183 2184 while (N) { 2185 ProgramStateRef St = N->getState(); 2186 2187 if (!getRefBinding(St, Sym)) 2188 break; 2189 2190 StoreManager::FindUniqueBinding FB(Sym); 2191 StateMgr.iterBindings(St, FB); 2192 if (FB) FirstBinding = FB.getRegion(); 2193 2194 // Allocation node, is the last node in the current context in which the 2195 // symbol was tracked. 2196 if (N->getLocationContext() == LeakContext) 2197 Last = N; 2198 2199 N = N->pred_empty() ? NULL : *(N->pred_begin()); 2200 } 2201 2202 // If allocation happened in a function different from the leak node context, 2203 // do not report the binding. 2204 if (N->getLocationContext() != LeakContext) { 2205 FirstBinding = 0; 2206 } 2207 2208 return std::make_pair(Last, FirstBinding); 2209} 2210 2211PathDiagnosticPiece* 2212CFRefReportVisitor::getEndPath(BugReporterContext &BRC, 2213 const ExplodedNode *EndN, 2214 BugReport &BR) { 2215 BR.markInteresting(Sym); 2216 return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); 2217} 2218 2219PathDiagnosticPiece* 2220CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, 2221 const ExplodedNode *EndN, 2222 BugReport &BR) { 2223 2224 // Tell the BugReporterContext to report cases when the tracked symbol is 2225 // assigned to different variables, etc. 2226 BR.markInteresting(Sym); 2227 2228 // We are reporting a leak. Walk up the graph to get to the first node where 2229 // the symbol appeared, and also get the first VarDecl that tracked object 2230 // is stored to. 2231 const ExplodedNode *AllocNode = 0; 2232 const MemRegion* FirstBinding = 0; 2233 2234 llvm::tie(AllocNode, FirstBinding) = 2235 GetAllocationSite(BRC.getStateManager(), EndN, Sym); 2236 2237 SourceManager& SM = BRC.getSourceManager(); 2238 2239 // Compute an actual location for the leak. Sometimes a leak doesn't 2240 // occur at an actual statement (e.g., transition between blocks; end 2241 // of function) so we need to walk the graph and compute a real location. 2242 const ExplodedNode *LeakN = EndN; 2243 PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); 2244 2245 std::string sbuf; 2246 llvm::raw_string_ostream os(sbuf); 2247 2248 os << "Object leaked: "; 2249 2250 if (FirstBinding) { 2251 os << "object allocated and stored into '" 2252 << FirstBinding->getString() << '\''; 2253 } 2254 else 2255 os << "allocated object"; 2256 2257 // Get the retain count. 2258 const RefVal* RV = getRefBinding(EndN->getState(), Sym); 2259 2260 if (RV->getKind() == RefVal::ErrorLeakReturned) { 2261 // FIXME: Per comments in rdar://6320065, "create" only applies to CF 2262 // objects. Only "copy", "alloc", "retain" and "new" transfer ownership 2263 // to the caller for NS objects. 2264 const Decl *D = &EndN->getCodeDecl(); 2265 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 2266 os << " is returned from a method whose name ('" 2267 << MD->getSelector().getAsString() 2268 << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'." 2269 " This violates the naming convention rules" 2270 " given in the Memory Management Guide for Cocoa"; 2271 } 2272 else { 2273 const FunctionDecl *FD = cast<FunctionDecl>(D); 2274 os << " is returned from a function whose name ('" 2275 << *FD 2276 << "') does not contain 'Copy' or 'Create'. This violates the naming" 2277 " convention rules given in the Memory Management Guide for Core" 2278 " Foundation"; 2279 } 2280 } 2281 else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { 2282 ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); 2283 os << " and returned from method '" << MD.getSelector().getAsString() 2284 << "' is potentially leaked when using garbage collection. Callers " 2285 "of this method do not expect a returned object with a +1 retain " 2286 "count since they expect the object to be managed by the garbage " 2287 "collector"; 2288 } 2289 else 2290 os << " is not referenced later in this execution path and has a retain " 2291 "count of +" << RV->getCount(); 2292 2293 return new PathDiagnosticEventPiece(L, os.str()); 2294} 2295 2296CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, 2297 bool GCEnabled, const SummaryLogTy &Log, 2298 ExplodedNode *n, SymbolRef sym, 2299 CheckerContext &Ctx) 2300: CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { 2301 2302 // Most bug reports are cached at the location where they occurred. 2303 // With leaks, we want to unique them by the location where they were 2304 // allocated, and only report a single path. To do this, we need to find 2305 // the allocation site of a piece of tracked memory, which we do via a 2306 // call to GetAllocationSite. This will walk the ExplodedGraph backwards. 2307 // Note that this is *not* the trimmed graph; we are guaranteed, however, 2308 // that all ancestor nodes that represent the allocation site have the 2309 // same SourceLocation. 2310 const ExplodedNode *AllocNode = 0; 2311 2312 const SourceManager& SMgr = Ctx.getSourceManager(); 2313 2314 llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding. 2315 GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); 2316 2317 // Get the SourceLocation for the allocation site. 2318 // FIXME: This will crash the analyzer if an allocation comes from an 2319 // implicit call. (Currently there are no such allocations in Cocoa, though.) 2320 const Stmt *AllocStmt; 2321 ProgramPoint P = AllocNode->getLocation(); 2322 if (CallExitEnd *Exit = dyn_cast<CallExitEnd>(&P)) 2323 AllocStmt = Exit->getCalleeContext()->getCallSite(); 2324 else 2325 AllocStmt = cast<PostStmt>(P).getStmt(); 2326 assert(AllocStmt && "All allocations must come from explicit calls"); 2327 Location = PathDiagnosticLocation::createBegin(AllocStmt, SMgr, 2328 n->getLocationContext()); 2329 // Fill in the description of the bug. 2330 Description.clear(); 2331 llvm::raw_string_ostream os(Description); 2332 os << "Potential leak "; 2333 if (GCEnabled) 2334 os << "(when using garbage collection) "; 2335 os << "of an object"; 2336 2337 // FIXME: AllocBinding doesn't get populated for RegionStore yet. 2338 if (AllocBinding) 2339 os << " stored into '" << AllocBinding->getString() << '\''; 2340 2341 addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log)); 2342} 2343 2344//===----------------------------------------------------------------------===// 2345// Main checker logic. 2346//===----------------------------------------------------------------------===// 2347 2348namespace { 2349class RetainCountChecker 2350 : public Checker< check::Bind, 2351 check::DeadSymbols, 2352 check::EndAnalysis, 2353 check::EndPath, 2354 check::PostStmt<BlockExpr>, 2355 check::PostStmt<CastExpr>, 2356 check::PostStmt<ObjCArrayLiteral>, 2357 check::PostStmt<ObjCDictionaryLiteral>, 2358 check::PostStmt<ObjCBoxedExpr>, 2359 check::PostCall, 2360 check::PreStmt<ReturnStmt>, 2361 check::RegionChanges, 2362 eval::Assume, 2363 eval::Call > { 2364 mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned; 2365 mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned; 2366 mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned; 2367 mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn; 2368 mutable OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; 2369 2370 typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap; 2371 2372 // This map is only used to ensure proper deletion of any allocated tags. 2373 mutable SymbolTagMap DeadSymbolTags; 2374 2375 mutable OwningPtr<RetainSummaryManager> Summaries; 2376 mutable OwningPtr<RetainSummaryManager> SummariesGC; 2377 mutable SummaryLogTy SummaryLog; 2378 mutable bool ShouldResetSummaryLog; 2379 2380public: 2381 RetainCountChecker() : ShouldResetSummaryLog(false) {} 2382 2383 virtual ~RetainCountChecker() { 2384 DeleteContainerSeconds(DeadSymbolTags); 2385 } 2386 2387 void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, 2388 ExprEngine &Eng) const { 2389 // FIXME: This is a hack to make sure the summary log gets cleared between 2390 // analyses of different code bodies. 2391 // 2392 // Why is this necessary? Because a checker's lifetime is tied to a 2393 // translation unit, but an ExplodedGraph's lifetime is just a code body. 2394 // Once in a blue moon, a new ExplodedNode will have the same address as an 2395 // old one with an associated summary, and the bug report visitor gets very 2396 // confused. (To make things worse, the summary lifetime is currently also 2397 // tied to a code body, so we get a crash instead of incorrect results.) 2398 // 2399 // Why is this a bad solution? Because if the lifetime of the ExplodedGraph 2400 // changes, things will start going wrong again. Really the lifetime of this 2401 // log needs to be tied to either the specific nodes in it or the entire 2402 // ExplodedGraph, not to a specific part of the code being analyzed. 2403 // 2404 // (Also, having stateful local data means that the same checker can't be 2405 // used from multiple threads, but a lot of checkers have incorrect 2406 // assumptions about that anyway. So that wasn't a priority at the time of 2407 // this fix.) 2408 // 2409 // This happens at the end of analysis, but bug reports are emitted /after/ 2410 // this point. So we can't just clear the summary log now. Instead, we mark 2411 // that the next time we access the summary log, it should be cleared. 2412 2413 // If we never reset the summary log during /this/ code body analysis, 2414 // there were no new summaries. There might still have been summaries from 2415 // the /last/ analysis, so clear them out to make sure the bug report 2416 // visitors don't get confused. 2417 if (ShouldResetSummaryLog) 2418 SummaryLog.clear(); 2419 2420 ShouldResetSummaryLog = !SummaryLog.empty(); 2421 } 2422 2423 CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, 2424 bool GCEnabled) const { 2425 if (GCEnabled) { 2426 if (!leakWithinFunctionGC) 2427 leakWithinFunctionGC.reset(new Leak("Leak of object when using " 2428 "garbage collection")); 2429 return leakWithinFunctionGC.get(); 2430 } else { 2431 if (!leakWithinFunction) { 2432 if (LOpts.getGC() == LangOptions::HybridGC) { 2433 leakWithinFunction.reset(new Leak("Leak of object when not using " 2434 "garbage collection (GC) in " 2435 "dual GC/non-GC code")); 2436 } else { 2437 leakWithinFunction.reset(new Leak("Leak")); 2438 } 2439 } 2440 return leakWithinFunction.get(); 2441 } 2442 } 2443 2444 CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { 2445 if (GCEnabled) { 2446 if (!leakAtReturnGC) 2447 leakAtReturnGC.reset(new Leak("Leak of returned object when using " 2448 "garbage collection")); 2449 return leakAtReturnGC.get(); 2450 } else { 2451 if (!leakAtReturn) { 2452 if (LOpts.getGC() == LangOptions::HybridGC) { 2453 leakAtReturn.reset(new Leak("Leak of returned object when not using " 2454 "garbage collection (GC) in dual " 2455 "GC/non-GC code")); 2456 } else { 2457 leakAtReturn.reset(new Leak("Leak of returned object")); 2458 } 2459 } 2460 return leakAtReturn.get(); 2461 } 2462 } 2463 2464 RetainSummaryManager &getSummaryManager(ASTContext &Ctx, 2465 bool GCEnabled) const { 2466 // FIXME: We don't support ARC being turned on and off during one analysis. 2467 // (nor, for that matter, do we support changing ASTContexts) 2468 bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; 2469 if (GCEnabled) { 2470 if (!SummariesGC) 2471 SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); 2472 else 2473 assert(SummariesGC->isARCEnabled() == ARCEnabled); 2474 return *SummariesGC; 2475 } else { 2476 if (!Summaries) 2477 Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); 2478 else 2479 assert(Summaries->isARCEnabled() == ARCEnabled); 2480 return *Summaries; 2481 } 2482 } 2483 2484 RetainSummaryManager &getSummaryManager(CheckerContext &C) const { 2485 return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); 2486 } 2487 2488 void printState(raw_ostream &Out, ProgramStateRef State, 2489 const char *NL, const char *Sep) const; 2490 2491 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; 2492 void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; 2493 void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; 2494 2495 void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; 2496 void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; 2497 void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; 2498 2499 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 2500 2501 void checkSummary(const RetainSummary &Summ, const CallEvent &Call, 2502 CheckerContext &C) const; 2503 2504 void processSummaryOfInlined(const RetainSummary &Summ, 2505 const CallEvent &Call, 2506 CheckerContext &C) const; 2507 2508 bool evalCall(const CallExpr *CE, CheckerContext &C) const; 2509 2510 ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, 2511 bool Assumption) const; 2512 2513 ProgramStateRef 2514 checkRegionChanges(ProgramStateRef state, 2515 const StoreManager::InvalidatedSymbols *invalidated, 2516 ArrayRef<const MemRegion *> ExplicitRegions, 2517 ArrayRef<const MemRegion *> Regions, 2518 const CallEvent *Call) const; 2519 2520 bool wantsRegionChangeUpdate(ProgramStateRef state) const { 2521 return true; 2522 } 2523 2524 void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; 2525 void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, 2526 ExplodedNode *Pred, RetEffect RE, RefVal X, 2527 SymbolRef Sym, ProgramStateRef state) const; 2528 2529 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 2530 void checkEndPath(CheckerContext &C) const; 2531 2532 ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, 2533 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2534 CheckerContext &C) const; 2535 2536 void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, 2537 RefVal::Kind ErrorKind, SymbolRef Sym, 2538 CheckerContext &C) const; 2539 2540 void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; 2541 2542 const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; 2543 2544 ProgramStateRef handleSymbolDeath(ProgramStateRef state, 2545 SymbolRef sid, RefVal V, 2546 SmallVectorImpl<SymbolRef> &Leaked) const; 2547 2548 std::pair<ExplodedNode *, ProgramStateRef > 2549 handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred, 2550 const ProgramPointTag *Tag, CheckerContext &Ctx, 2551 SymbolRef Sym, RefVal V) const; 2552 2553 ExplodedNode *processLeaks(ProgramStateRef state, 2554 SmallVectorImpl<SymbolRef> &Leaked, 2555 CheckerContext &Ctx, 2556 ExplodedNode *Pred = 0) const; 2557}; 2558} // end anonymous namespace 2559 2560namespace { 2561class StopTrackingCallback : public SymbolVisitor { 2562 ProgramStateRef state; 2563public: 2564 StopTrackingCallback(ProgramStateRef st) : state(st) {} 2565 ProgramStateRef getState() const { return state; } 2566 2567 bool VisitSymbol(SymbolRef sym) { 2568 state = state->remove<RefBindings>(sym); 2569 return true; 2570 } 2571}; 2572} // end anonymous namespace 2573 2574//===----------------------------------------------------------------------===// 2575// Handle statements that may have an effect on refcounts. 2576//===----------------------------------------------------------------------===// 2577 2578void RetainCountChecker::checkPostStmt(const BlockExpr *BE, 2579 CheckerContext &C) const { 2580 2581 // Scan the BlockDecRefExprs for any object the retain count checker 2582 // may be tracking. 2583 if (!BE->getBlockDecl()->hasCaptures()) 2584 return; 2585 2586 ProgramStateRef state = C.getState(); 2587 const BlockDataRegion *R = 2588 cast<BlockDataRegion>(state->getSVal(BE, 2589 C.getLocationContext()).getAsRegion()); 2590 2591 BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), 2592 E = R->referenced_vars_end(); 2593 2594 if (I == E) 2595 return; 2596 2597 // FIXME: For now we invalidate the tracking of all symbols passed to blocks 2598 // via captured variables, even though captured variables result in a copy 2599 // and in implicit increment/decrement of a retain count. 2600 SmallVector<const MemRegion*, 10> Regions; 2601 const LocationContext *LC = C.getLocationContext(); 2602 MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); 2603 2604 for ( ; I != E; ++I) { 2605 const VarRegion *VR = *I; 2606 if (VR->getSuperRegion() == R) { 2607 VR = MemMgr.getVarRegion(VR->getDecl(), LC); 2608 } 2609 Regions.push_back(VR); 2610 } 2611 2612 state = 2613 state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), 2614 Regions.data() + Regions.size()).getState(); 2615 C.addTransition(state); 2616} 2617 2618void RetainCountChecker::checkPostStmt(const CastExpr *CE, 2619 CheckerContext &C) const { 2620 const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); 2621 if (!BE) 2622 return; 2623 2624 ArgEffect AE = IncRef; 2625 2626 switch (BE->getBridgeKind()) { 2627 case clang::OBC_Bridge: 2628 // Do nothing. 2629 return; 2630 case clang::OBC_BridgeRetained: 2631 AE = IncRef; 2632 break; 2633 case clang::OBC_BridgeTransfer: 2634 AE = DecRefBridgedTransfered; 2635 break; 2636 } 2637 2638 ProgramStateRef state = C.getState(); 2639 SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol(); 2640 if (!Sym) 2641 return; 2642 const RefVal* T = getRefBinding(state, Sym); 2643 if (!T) 2644 return; 2645 2646 RefVal::Kind hasErr = (RefVal::Kind) 0; 2647 state = updateSymbol(state, Sym, *T, AE, hasErr, C); 2648 2649 if (hasErr) { 2650 // FIXME: If we get an error during a bridge cast, should we report it? 2651 // Should we assert that there is no error? 2652 return; 2653 } 2654 2655 C.addTransition(state); 2656} 2657 2658void RetainCountChecker::processObjCLiterals(CheckerContext &C, 2659 const Expr *Ex) const { 2660 ProgramStateRef state = C.getState(); 2661 const ExplodedNode *pred = C.getPredecessor(); 2662 for (Stmt::const_child_iterator it = Ex->child_begin(), et = Ex->child_end() ; 2663 it != et ; ++it) { 2664 const Stmt *child = *it; 2665 SVal V = state->getSVal(child, pred->getLocationContext()); 2666 if (SymbolRef sym = V.getAsSymbol()) 2667 if (const RefVal* T = getRefBinding(state, sym)) { 2668 RefVal::Kind hasErr = (RefVal::Kind) 0; 2669 state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); 2670 if (hasErr) { 2671 processNonLeakError(state, child->getSourceRange(), hasErr, sym, C); 2672 return; 2673 } 2674 } 2675 } 2676 2677 // Return the object as autoreleased. 2678 // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); 2679 if (SymbolRef sym = 2680 state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { 2681 QualType ResultTy = Ex->getType(); 2682 state = setRefBinding(state, sym, 2683 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2684 } 2685 2686 C.addTransition(state); 2687} 2688 2689void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, 2690 CheckerContext &C) const { 2691 // Apply the 'MayEscape' to all values. 2692 processObjCLiterals(C, AL); 2693} 2694 2695void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 2696 CheckerContext &C) const { 2697 // Apply the 'MayEscape' to all keys and values. 2698 processObjCLiterals(C, DL); 2699} 2700 2701void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, 2702 CheckerContext &C) const { 2703 const ExplodedNode *Pred = C.getPredecessor(); 2704 const LocationContext *LCtx = Pred->getLocationContext(); 2705 ProgramStateRef State = Pred->getState(); 2706 2707 if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) { 2708 QualType ResultTy = Ex->getType(); 2709 State = setRefBinding(State, Sym, 2710 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2711 } 2712 2713 C.addTransition(State); 2714} 2715 2716void RetainCountChecker::checkPostCall(const CallEvent &Call, 2717 CheckerContext &C) const { 2718 RetainSummaryManager &Summaries = getSummaryManager(C); 2719 const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); 2720 2721 if (C.wasInlined) { 2722 processSummaryOfInlined(*Summ, Call, C); 2723 return; 2724 } 2725 checkSummary(*Summ, Call, C); 2726} 2727 2728/// GetReturnType - Used to get the return type of a message expression or 2729/// function call with the intention of affixing that type to a tracked symbol. 2730/// While the return type can be queried directly from RetEx, when 2731/// invoking class methods we augment to the return type to be that of 2732/// a pointer to the class (as opposed it just being id). 2733// FIXME: We may be able to do this with related result types instead. 2734// This function is probably overestimating. 2735static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { 2736 QualType RetTy = RetE->getType(); 2737 // If RetE is not a message expression just return its type. 2738 // If RetE is a message expression, return its types if it is something 2739 /// more specific than id. 2740 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) 2741 if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) 2742 if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || 2743 PT->isObjCClassType()) { 2744 // At this point we know the return type of the message expression is 2745 // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this 2746 // is a call to a class method whose type we can resolve. In such 2747 // cases, promote the return type to XXX* (where XXX is the class). 2748 const ObjCInterfaceDecl *D = ME->getReceiverInterface(); 2749 return !D ? RetTy : 2750 Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); 2751 } 2752 2753 return RetTy; 2754} 2755 2756// We don't always get the exact modeling of the function with regards to the 2757// retain count checker even when the function is inlined. For example, we need 2758// to stop tracking the symbols which were marked with StopTrackingHard. 2759void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ, 2760 const CallEvent &CallOrMsg, 2761 CheckerContext &C) const { 2762 ProgramStateRef state = C.getState(); 2763 2764 // Evaluate the effect of the arguments. 2765 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2766 if (Summ.getArg(idx) == StopTrackingHard) { 2767 SVal V = CallOrMsg.getArgSVal(idx); 2768 if (SymbolRef Sym = V.getAsLocSymbol()) { 2769 state = removeRefBinding(state, Sym); 2770 } 2771 } 2772 } 2773 2774 // Evaluate the effect on the message receiver. 2775 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2776 if (MsgInvocation) { 2777 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2778 if (Summ.getReceiverEffect() == StopTrackingHard) { 2779 state = removeRefBinding(state, Sym); 2780 } 2781 } 2782 } 2783 2784 // Consult the summary for the return value. 2785 RetEffect RE = Summ.getRetEffect(); 2786 if (RE.getKind() == RetEffect::NoRetHard) { 2787 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2788 C.getLocationContext()).getAsSymbol(); 2789 if (Sym) 2790 state = removeRefBinding(state, Sym); 2791 } 2792 2793 C.addTransition(state); 2794} 2795 2796void RetainCountChecker::checkSummary(const RetainSummary &Summ, 2797 const CallEvent &CallOrMsg, 2798 CheckerContext &C) const { 2799 ProgramStateRef state = C.getState(); 2800 2801 // Evaluate the effect of the arguments. 2802 RefVal::Kind hasErr = (RefVal::Kind) 0; 2803 SourceRange ErrorRange; 2804 SymbolRef ErrorSym = 0; 2805 2806 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2807 SVal V = CallOrMsg.getArgSVal(idx); 2808 2809 if (SymbolRef Sym = V.getAsLocSymbol()) { 2810 if (const RefVal *T = getRefBinding(state, Sym)) { 2811 state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C); 2812 if (hasErr) { 2813 ErrorRange = CallOrMsg.getArgSourceRange(idx); 2814 ErrorSym = Sym; 2815 break; 2816 } 2817 } 2818 } 2819 } 2820 2821 // Evaluate the effect on the message receiver. 2822 bool ReceiverIsTracked = false; 2823 if (!hasErr) { 2824 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2825 if (MsgInvocation) { 2826 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2827 if (const RefVal *T = getRefBinding(state, Sym)) { 2828 ReceiverIsTracked = true; 2829 state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), 2830 hasErr, C); 2831 if (hasErr) { 2832 ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange(); 2833 ErrorSym = Sym; 2834 } 2835 } 2836 } 2837 } 2838 } 2839 2840 // Process any errors. 2841 if (hasErr) { 2842 processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); 2843 return; 2844 } 2845 2846 // Consult the summary for the return value. 2847 RetEffect RE = Summ.getRetEffect(); 2848 2849 if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { 2850 if (ReceiverIsTracked) 2851 RE = getSummaryManager(C).getObjAllocRetEffect(); 2852 else 2853 RE = RetEffect::MakeNoRet(); 2854 } 2855 2856 switch (RE.getKind()) { 2857 default: 2858 llvm_unreachable("Unhandled RetEffect."); 2859 2860 case RetEffect::NoRet: 2861 case RetEffect::NoRetHard: 2862 // No work necessary. 2863 break; 2864 2865 case RetEffect::OwnedAllocatedSymbol: 2866 case RetEffect::OwnedSymbol: { 2867 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2868 C.getLocationContext()).getAsSymbol(); 2869 if (!Sym) 2870 break; 2871 2872 // Use the result type from the CallEvent as it automatically adjusts 2873 // for methods/functions that return references. 2874 QualType ResultTy = CallOrMsg.getResultType(); 2875 state = setRefBinding(state, Sym, RefVal::makeOwned(RE.getObjKind(), 2876 ResultTy)); 2877 2878 // FIXME: Add a flag to the checker where allocations are assumed to 2879 // *not* fail. 2880 break; 2881 } 2882 2883 case RetEffect::GCNotOwnedSymbol: 2884 case RetEffect::ARCNotOwnedSymbol: 2885 case RetEffect::NotOwnedSymbol: { 2886 const Expr *Ex = CallOrMsg.getOriginExpr(); 2887 SymbolRef Sym = state->getSVal(Ex, C.getLocationContext()).getAsSymbol(); 2888 if (!Sym) 2889 break; 2890 2891 // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. 2892 QualType ResultTy = GetReturnType(Ex, C.getASTContext()); 2893 state = setRefBinding(state, Sym, RefVal::makeNotOwned(RE.getObjKind(), 2894 ResultTy)); 2895 break; 2896 } 2897 } 2898 2899 // This check is actually necessary; otherwise the statement builder thinks 2900 // we've hit a previously-found path. 2901 // Normally addTransition takes care of this, but we want the node pointer. 2902 ExplodedNode *NewNode; 2903 if (state == C.getState()) { 2904 NewNode = C.getPredecessor(); 2905 } else { 2906 NewNode = C.addTransition(state); 2907 } 2908 2909 // Annotate the node with summary we used. 2910 if (NewNode) { 2911 // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. 2912 if (ShouldResetSummaryLog) { 2913 SummaryLog.clear(); 2914 ShouldResetSummaryLog = false; 2915 } 2916 SummaryLog[NewNode] = &Summ; 2917 } 2918} 2919 2920 2921ProgramStateRef 2922RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, 2923 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2924 CheckerContext &C) const { 2925 // In GC mode [... release] and [... retain] do nothing. 2926 // In ARC mode they shouldn't exist at all, but we just ignore them. 2927 bool IgnoreRetainMsg = C.isObjCGCEnabled(); 2928 if (!IgnoreRetainMsg) 2929 IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; 2930 2931 switch (E) { 2932 default: 2933 break; 2934 case IncRefMsg: 2935 E = IgnoreRetainMsg ? DoNothing : IncRef; 2936 break; 2937 case DecRefMsg: 2938 E = IgnoreRetainMsg ? DoNothing : DecRef; 2939 break; 2940 case DecRefMsgAndStopTrackingHard: 2941 E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTrackingHard; 2942 break; 2943 case MakeCollectable: 2944 E = C.isObjCGCEnabled() ? DecRef : DoNothing; 2945 break; 2946 case NewAutoreleasePool: 2947 E = C.isObjCGCEnabled() ? DoNothing : NewAutoreleasePool; 2948 break; 2949 } 2950 2951 // Handle all use-after-releases. 2952 if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { 2953 V = V ^ RefVal::ErrorUseAfterRelease; 2954 hasErr = V.getKind(); 2955 return setRefBinding(state, sym, V); 2956 } 2957 2958 switch (E) { 2959 case DecRefMsg: 2960 case IncRefMsg: 2961 case MakeCollectable: 2962 case DecRefMsgAndStopTrackingHard: 2963 llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); 2964 2965 case Dealloc: 2966 // Any use of -dealloc in GC is *bad*. 2967 if (C.isObjCGCEnabled()) { 2968 V = V ^ RefVal::ErrorDeallocGC; 2969 hasErr = V.getKind(); 2970 break; 2971 } 2972 2973 switch (V.getKind()) { 2974 default: 2975 llvm_unreachable("Invalid RefVal state for an explicit dealloc."); 2976 case RefVal::Owned: 2977 // The object immediately transitions to the released state. 2978 V = V ^ RefVal::Released; 2979 V.clearCounts(); 2980 return setRefBinding(state, sym, V); 2981 case RefVal::NotOwned: 2982 V = V ^ RefVal::ErrorDeallocNotOwned; 2983 hasErr = V.getKind(); 2984 break; 2985 } 2986 break; 2987 2988 case NewAutoreleasePool: 2989 assert(!C.isObjCGCEnabled()); 2990 return state; 2991 2992 case MayEscape: 2993 if (V.getKind() == RefVal::Owned) { 2994 V = V ^ RefVal::NotOwned; 2995 break; 2996 } 2997 2998 // Fall-through. 2999 3000 case DoNothing: 3001 return state; 3002 3003 case Autorelease: 3004 if (C.isObjCGCEnabled()) 3005 return state; 3006 // Update the autorelease counts. 3007 V = V.autorelease(); 3008 break; 3009 3010 case StopTracking: 3011 case StopTrackingHard: 3012 return removeRefBinding(state, sym); 3013 3014 case IncRef: 3015 switch (V.getKind()) { 3016 default: 3017 llvm_unreachable("Invalid RefVal state for a retain."); 3018 case RefVal::Owned: 3019 case RefVal::NotOwned: 3020 V = V + 1; 3021 break; 3022 case RefVal::Released: 3023 // Non-GC cases are handled above. 3024 assert(C.isObjCGCEnabled()); 3025 V = (V ^ RefVal::Owned) + 1; 3026 break; 3027 } 3028 break; 3029 3030 case DecRef: 3031 case DecRefBridgedTransfered: 3032 case DecRefAndStopTrackingHard: 3033 switch (V.getKind()) { 3034 default: 3035 // case 'RefVal::Released' handled above. 3036 llvm_unreachable("Invalid RefVal state for a release."); 3037 3038 case RefVal::Owned: 3039 assert(V.getCount() > 0); 3040 if (V.getCount() == 1) 3041 V = V ^ (E == DecRefBridgedTransfered ? 3042 RefVal::NotOwned : RefVal::Released); 3043 else if (E == DecRefAndStopTrackingHard) 3044 return removeRefBinding(state, sym); 3045 3046 V = V - 1; 3047 break; 3048 3049 case RefVal::NotOwned: 3050 if (V.getCount() > 0) { 3051 if (E == DecRefAndStopTrackingHard) 3052 return removeRefBinding(state, sym); 3053 V = V - 1; 3054 } else { 3055 V = V ^ RefVal::ErrorReleaseNotOwned; 3056 hasErr = V.getKind(); 3057 } 3058 break; 3059 3060 case RefVal::Released: 3061 // Non-GC cases are handled above. 3062 assert(C.isObjCGCEnabled()); 3063 V = V ^ RefVal::ErrorUseAfterRelease; 3064 hasErr = V.getKind(); 3065 break; 3066 } 3067 break; 3068 } 3069 return setRefBinding(state, sym, V); 3070} 3071 3072void RetainCountChecker::processNonLeakError(ProgramStateRef St, 3073 SourceRange ErrorRange, 3074 RefVal::Kind ErrorKind, 3075 SymbolRef Sym, 3076 CheckerContext &C) const { 3077 ExplodedNode *N = C.generateSink(St); 3078 if (!N) 3079 return; 3080 3081 CFRefBug *BT; 3082 switch (ErrorKind) { 3083 default: 3084 llvm_unreachable("Unhandled error."); 3085 case RefVal::ErrorUseAfterRelease: 3086 if (!useAfterRelease) 3087 useAfterRelease.reset(new UseAfterRelease()); 3088 BT = &*useAfterRelease; 3089 break; 3090 case RefVal::ErrorReleaseNotOwned: 3091 if (!releaseNotOwned) 3092 releaseNotOwned.reset(new BadRelease()); 3093 BT = &*releaseNotOwned; 3094 break; 3095 case RefVal::ErrorDeallocGC: 3096 if (!deallocGC) 3097 deallocGC.reset(new DeallocGC()); 3098 BT = &*deallocGC; 3099 break; 3100 case RefVal::ErrorDeallocNotOwned: 3101 if (!deallocNotOwned) 3102 deallocNotOwned.reset(new DeallocNotOwned()); 3103 BT = &*deallocNotOwned; 3104 break; 3105 } 3106 3107 assert(BT); 3108 CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOpts(), 3109 C.isObjCGCEnabled(), SummaryLog, 3110 N, Sym); 3111 report->addRange(ErrorRange); 3112 C.EmitReport(report); 3113} 3114 3115//===----------------------------------------------------------------------===// 3116// Handle the return values of retain-count-related functions. 3117//===----------------------------------------------------------------------===// 3118 3119bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { 3120 // Get the callee. We're only interested in simple C functions. 3121 ProgramStateRef state = C.getState(); 3122 const FunctionDecl *FD = C.getCalleeDecl(CE); 3123 if (!FD) 3124 return false; 3125 3126 IdentifierInfo *II = FD->getIdentifier(); 3127 if (!II) 3128 return false; 3129 3130 // For now, we're only handling the functions that return aliases of their 3131 // arguments: CFRetain and CFMakeCollectable (and their families). 3132 // Eventually we should add other functions we can model entirely, 3133 // such as CFRelease, which don't invalidate their arguments or globals. 3134 if (CE->getNumArgs() != 1) 3135 return false; 3136 3137 // Get the name of the function. 3138 StringRef FName = II->getName(); 3139 FName = FName.substr(FName.find_first_not_of('_')); 3140 3141 // See if it's one of the specific functions we know how to eval. 3142 bool canEval = false; 3143 3144 QualType ResultTy = CE->getCallReturnType(); 3145 if (ResultTy->isObjCIdType()) { 3146 // Handle: id NSMakeCollectable(CFTypeRef) 3147 canEval = II->isStr("NSMakeCollectable"); 3148 } else if (ResultTy->isPointerType()) { 3149 // Handle: (CF|CG)Retain 3150 // CFMakeCollectable 3151 // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). 3152 if (cocoa::isRefType(ResultTy, "CF", FName) || 3153 cocoa::isRefType(ResultTy, "CG", FName)) { 3154 canEval = isRetain(FD, FName) || isMakeCollectable(FD, FName); 3155 } 3156 } 3157 3158 if (!canEval) 3159 return false; 3160 3161 // Bind the return value. 3162 const LocationContext *LCtx = C.getLocationContext(); 3163 SVal RetVal = state->getSVal(CE->getArg(0), LCtx); 3164 if (RetVal.isUnknown()) { 3165 // If the receiver is unknown, conjure a return value. 3166 SValBuilder &SVB = C.getSValBuilder(); 3167 RetVal = SVB.conjureSymbolVal(0, CE, LCtx, ResultTy, C.blockCount()); 3168 } 3169 state = state->BindExpr(CE, LCtx, RetVal, false); 3170 3171 // FIXME: This should not be necessary, but otherwise the argument seems to be 3172 // considered alive during the next statement. 3173 if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { 3174 // Save the refcount status of the argument. 3175 SymbolRef Sym = RetVal.getAsLocSymbol(); 3176 const RefVal *Binding = 0; 3177 if (Sym) 3178 Binding = getRefBinding(state, Sym); 3179 3180 // Invalidate the argument region. 3181 state = state->invalidateRegions(ArgRegion, CE, C.blockCount(), LCtx); 3182 3183 // Restore the refcount status of the argument. 3184 if (Binding) 3185 state = setRefBinding(state, Sym, *Binding); 3186 } 3187 3188 C.addTransition(state); 3189 return true; 3190} 3191 3192//===----------------------------------------------------------------------===// 3193// Handle return statements. 3194//===----------------------------------------------------------------------===// 3195 3196// Return true if the current LocationContext has no caller context. 3197static bool inTopFrame(CheckerContext &C) { 3198 const LocationContext *LC = C.getLocationContext(); 3199 return LC->getParent() == 0; 3200} 3201 3202void RetainCountChecker::checkPreStmt(const ReturnStmt *S, 3203 CheckerContext &C) const { 3204 3205 // Only adjust the reference count if this is the top-level call frame, 3206 // and not the result of inlining. In the future, we should do 3207 // better checking even for inlined calls, and see if they match 3208 // with their expected semantics (e.g., the method should return a retained 3209 // object, etc.). 3210 if (!inTopFrame(C)) 3211 return; 3212 3213 const Expr *RetE = S->getRetValue(); 3214 if (!RetE) 3215 return; 3216 3217 ProgramStateRef state = C.getState(); 3218 SymbolRef Sym = 3219 state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); 3220 if (!Sym) 3221 return; 3222 3223 // Get the reference count binding (if any). 3224 const RefVal *T = getRefBinding(state, Sym); 3225 if (!T) 3226 return; 3227 3228 // Change the reference count. 3229 RefVal X = *T; 3230 3231 switch (X.getKind()) { 3232 case RefVal::Owned: { 3233 unsigned cnt = X.getCount(); 3234 assert(cnt > 0); 3235 X.setCount(cnt - 1); 3236 X = X ^ RefVal::ReturnedOwned; 3237 break; 3238 } 3239 3240 case RefVal::NotOwned: { 3241 unsigned cnt = X.getCount(); 3242 if (cnt) { 3243 X.setCount(cnt - 1); 3244 X = X ^ RefVal::ReturnedOwned; 3245 } 3246 else { 3247 X = X ^ RefVal::ReturnedNotOwned; 3248 } 3249 break; 3250 } 3251 3252 default: 3253 return; 3254 } 3255 3256 // Update the binding. 3257 state = setRefBinding(state, Sym, X); 3258 ExplodedNode *Pred = C.addTransition(state); 3259 3260 // At this point we have updated the state properly. 3261 // Everything after this is merely checking to see if the return value has 3262 // been over- or under-retained. 3263 3264 // Did we cache out? 3265 if (!Pred) 3266 return; 3267 3268 // Update the autorelease counts. 3269 static SimpleProgramPointTag 3270 AutoreleaseTag("RetainCountChecker : Autorelease"); 3271 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, 3272 C, Sym, X); 3273 3274 // Did we cache out? 3275 if (!Pred) 3276 return; 3277 3278 // Get the updated binding. 3279 T = getRefBinding(state, Sym); 3280 assert(T); 3281 X = *T; 3282 3283 // Consult the summary of the enclosing method. 3284 RetainSummaryManager &Summaries = getSummaryManager(C); 3285 const Decl *CD = &Pred->getCodeDecl(); 3286 RetEffect RE = RetEffect::MakeNoRet(); 3287 3288 // FIXME: What is the convention for blocks? Is there one? 3289 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) { 3290 const RetainSummary *Summ = Summaries.getMethodSummary(MD); 3291 RE = Summ->getRetEffect(); 3292 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) { 3293 if (!isa<CXXMethodDecl>(FD)) { 3294 const RetainSummary *Summ = Summaries.getFunctionSummary(FD); 3295 RE = Summ->getRetEffect(); 3296 } 3297 } 3298 3299 checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state); 3300} 3301 3302void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S, 3303 CheckerContext &C, 3304 ExplodedNode *Pred, 3305 RetEffect RE, RefVal X, 3306 SymbolRef Sym, 3307 ProgramStateRef state) const { 3308 // Any leaks or other errors? 3309 if (X.isReturnedOwned() && X.getCount() == 0) { 3310 if (RE.getKind() != RetEffect::NoRet) { 3311 bool hasError = false; 3312 if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) { 3313 // Things are more complicated with garbage collection. If the 3314 // returned object is suppose to be an Objective-C object, we have 3315 // a leak (as the caller expects a GC'ed object) because no 3316 // method should return ownership unless it returns a CF object. 3317 hasError = true; 3318 X = X ^ RefVal::ErrorGCLeakReturned; 3319 } 3320 else if (!RE.isOwned()) { 3321 // Either we are using GC and the returned object is a CF type 3322 // or we aren't using GC. In either case, we expect that the 3323 // enclosing method is expected to return ownership. 3324 hasError = true; 3325 X = X ^ RefVal::ErrorLeakReturned; 3326 } 3327 3328 if (hasError) { 3329 // Generate an error node. 3330 state = setRefBinding(state, Sym, X); 3331 3332 static SimpleProgramPointTag 3333 ReturnOwnLeakTag("RetainCountChecker : ReturnsOwnLeak"); 3334 ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag); 3335 if (N) { 3336 const LangOptions &LOpts = C.getASTContext().getLangOpts(); 3337 bool GCEnabled = C.isObjCGCEnabled(); 3338 CFRefReport *report = 3339 new CFRefLeakReport(*getLeakAtReturnBug(LOpts, GCEnabled), 3340 LOpts, GCEnabled, SummaryLog, 3341 N, Sym, C); 3342 C.EmitReport(report); 3343 } 3344 } 3345 } 3346 } else if (X.isReturnedNotOwned()) { 3347 if (RE.isOwned()) { 3348 // Trying to return a not owned object to a caller expecting an 3349 // owned object. 3350 state = setRefBinding(state, Sym, X ^ RefVal::ErrorReturnedNotOwned); 3351 3352 static SimpleProgramPointTag 3353 ReturnNotOwnedTag("RetainCountChecker : ReturnNotOwnedForOwned"); 3354 ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag); 3355 if (N) { 3356 if (!returnNotOwnedForOwned) 3357 returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned()); 3358 3359 CFRefReport *report = 3360 new CFRefReport(*returnNotOwnedForOwned, 3361 C.getASTContext().getLangOpts(), 3362 C.isObjCGCEnabled(), SummaryLog, N, Sym); 3363 C.EmitReport(report); 3364 } 3365 } 3366 } 3367} 3368 3369//===----------------------------------------------------------------------===// 3370// Check various ways a symbol can be invalidated. 3371//===----------------------------------------------------------------------===// 3372 3373void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S, 3374 CheckerContext &C) const { 3375 // Are we storing to something that causes the value to "escape"? 3376 bool escapes = true; 3377 3378 // A value escapes in three possible cases (this may change): 3379 // 3380 // (1) we are binding to something that is not a memory region. 3381 // (2) we are binding to a memregion that does not have stack storage 3382 // (3) we are binding to a memregion with stack storage that the store 3383 // does not understand. 3384 ProgramStateRef state = C.getState(); 3385 3386 if (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) { 3387 escapes = !regionLoc->getRegion()->hasStackStorage(); 3388 3389 if (!escapes) { 3390 // To test (3), generate a new state with the binding added. If it is 3391 // the same state, then it escapes (since the store cannot represent 3392 // the binding). 3393 // Do this only if we know that the store is not supposed to generate the 3394 // same state. 3395 SVal StoredVal = state->getSVal(regionLoc->getRegion()); 3396 if (StoredVal != val) 3397 escapes = (state == (state->bindLoc(*regionLoc, val))); 3398 } 3399 if (!escapes) { 3400 // Case 4: We do not currently model what happens when a symbol is 3401 // assigned to a struct field, so be conservative here and let the symbol 3402 // go. TODO: This could definitely be improved upon. 3403 escapes = !isa<VarRegion>(regionLoc->getRegion()); 3404 } 3405 } 3406 3407 // If our store can represent the binding and we aren't storing to something 3408 // that doesn't have local storage then just return and have the simulation 3409 // state continue as is. 3410 if (!escapes) 3411 return; 3412 3413 // Otherwise, find all symbols referenced by 'val' that we are tracking 3414 // and stop tracking them. 3415 state = state->scanReachableSymbols<StopTrackingCallback>(val).getState(); 3416 C.addTransition(state); 3417} 3418 3419ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state, 3420 SVal Cond, 3421 bool Assumption) const { 3422 3423 // FIXME: We may add to the interface of evalAssume the list of symbols 3424 // whose assumptions have changed. For now we just iterate through the 3425 // bindings and check if any of the tracked symbols are NULL. This isn't 3426 // too bad since the number of symbols we will track in practice are 3427 // probably small and evalAssume is only called at branches and a few 3428 // other places. 3429 RefBindings B = state->get<RefBindings>(); 3430 3431 if (B.isEmpty()) 3432 return state; 3433 3434 bool changed = false; 3435 RefBindings::Factory &RefBFactory = state->get_context<RefBindings>(); 3436 3437 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3438 // Check if the symbol is null (or equal to any constant). 3439 // If this is the case, stop tracking the symbol. 3440 if (state->getSymVal(I.getKey())) { 3441 changed = true; 3442 B = RefBFactory.remove(B, I.getKey()); 3443 } 3444 } 3445 3446 if (changed) 3447 state = state->set<RefBindings>(B); 3448 3449 return state; 3450} 3451 3452ProgramStateRef 3453RetainCountChecker::checkRegionChanges(ProgramStateRef state, 3454 const StoreManager::InvalidatedSymbols *invalidated, 3455 ArrayRef<const MemRegion *> ExplicitRegions, 3456 ArrayRef<const MemRegion *> Regions, 3457 const CallEvent *Call) const { 3458 if (!invalidated) 3459 return state; 3460 3461 llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols; 3462 for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(), 3463 E = ExplicitRegions.end(); I != E; ++I) { 3464 if (const SymbolicRegion *SR = (*I)->StripCasts()->getAs<SymbolicRegion>()) 3465 WhitelistedSymbols.insert(SR->getSymbol()); 3466 } 3467 3468 for (StoreManager::InvalidatedSymbols::const_iterator I=invalidated->begin(), 3469 E = invalidated->end(); I!=E; ++I) { 3470 SymbolRef sym = *I; 3471 if (WhitelistedSymbols.count(sym)) 3472 continue; 3473 // Remove any existing reference-count binding. 3474 state = removeRefBinding(state, sym); 3475 } 3476 return state; 3477} 3478 3479//===----------------------------------------------------------------------===// 3480// Handle dead symbols and end-of-path. 3481//===----------------------------------------------------------------------===// 3482 3483std::pair<ExplodedNode *, ProgramStateRef > 3484RetainCountChecker::handleAutoreleaseCounts(ProgramStateRef state, 3485 ExplodedNode *Pred, 3486 const ProgramPointTag *Tag, 3487 CheckerContext &Ctx, 3488 SymbolRef Sym, RefVal V) const { 3489 unsigned ACnt = V.getAutoreleaseCount(); 3490 3491 // No autorelease counts? Nothing to be done. 3492 if (!ACnt) 3493 return std::make_pair(Pred, state); 3494 3495 assert(!Ctx.isObjCGCEnabled() && "Autorelease counts in GC mode?"); 3496 unsigned Cnt = V.getCount(); 3497 3498 // FIXME: Handle sending 'autorelease' to already released object. 3499 3500 if (V.getKind() == RefVal::ReturnedOwned) 3501 ++Cnt; 3502 3503 if (ACnt <= Cnt) { 3504 if (ACnt == Cnt) { 3505 V.clearCounts(); 3506 if (V.getKind() == RefVal::ReturnedOwned) 3507 V = V ^ RefVal::ReturnedNotOwned; 3508 else 3509 V = V ^ RefVal::NotOwned; 3510 } else { 3511 V.setCount(Cnt - ACnt); 3512 V.setAutoreleaseCount(0); 3513 } 3514 state = setRefBinding(state, Sym, V); 3515 ExplodedNode *N = Ctx.addTransition(state, Pred, Tag); 3516 if (N == 0) 3517 state = 0; 3518 return std::make_pair(N, state); 3519 } 3520 3521 // Woah! More autorelease counts then retain counts left. 3522 // Emit hard error. 3523 V = V ^ RefVal::ErrorOverAutorelease; 3524 state = setRefBinding(state, Sym, V); 3525 3526 ExplodedNode *N = Ctx.generateSink(state, Pred, Tag); 3527 if (N) { 3528 SmallString<128> sbuf; 3529 llvm::raw_svector_ostream os(sbuf); 3530 os << "Object over-autoreleased: object was sent -autorelease "; 3531 if (V.getAutoreleaseCount() > 1) 3532 os << V.getAutoreleaseCount() << " times "; 3533 os << "but the object has a +" << V.getCount() << " retain count"; 3534 3535 if (!overAutorelease) 3536 overAutorelease.reset(new OverAutorelease()); 3537 3538 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3539 CFRefReport *report = 3540 new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false, 3541 SummaryLog, N, Sym, os.str()); 3542 Ctx.EmitReport(report); 3543 } 3544 3545 return std::make_pair((ExplodedNode *)0, (ProgramStateRef )0); 3546} 3547 3548ProgramStateRef 3549RetainCountChecker::handleSymbolDeath(ProgramStateRef state, 3550 SymbolRef sid, RefVal V, 3551 SmallVectorImpl<SymbolRef> &Leaked) const { 3552 bool hasLeak = false; 3553 if (V.isOwned()) 3554 hasLeak = true; 3555 else if (V.isNotOwned() || V.isReturnedOwned()) 3556 hasLeak = (V.getCount() > 0); 3557 3558 if (!hasLeak) 3559 return removeRefBinding(state, sid); 3560 3561 Leaked.push_back(sid); 3562 return setRefBinding(state, sid, V ^ RefVal::ErrorLeak); 3563} 3564 3565ExplodedNode * 3566RetainCountChecker::processLeaks(ProgramStateRef state, 3567 SmallVectorImpl<SymbolRef> &Leaked, 3568 CheckerContext &Ctx, 3569 ExplodedNode *Pred) const { 3570 if (Leaked.empty()) 3571 return Pred; 3572 3573 // Generate an intermediate node representing the leak point. 3574 ExplodedNode *N = Ctx.addTransition(state, Pred); 3575 3576 if (N) { 3577 for (SmallVectorImpl<SymbolRef>::iterator 3578 I = Leaked.begin(), E = Leaked.end(); I != E; ++I) { 3579 3580 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3581 bool GCEnabled = Ctx.isObjCGCEnabled(); 3582 CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled) 3583 : getLeakAtReturnBug(LOpts, GCEnabled); 3584 assert(BT && "BugType not initialized."); 3585 3586 CFRefLeakReport *report = new CFRefLeakReport(*BT, LOpts, GCEnabled, 3587 SummaryLog, N, *I, Ctx); 3588 Ctx.EmitReport(report); 3589 } 3590 } 3591 3592 return N; 3593} 3594 3595void RetainCountChecker::checkEndPath(CheckerContext &Ctx) const { 3596 ProgramStateRef state = Ctx.getState(); 3597 RefBindings B = state->get<RefBindings>(); 3598 ExplodedNode *Pred = Ctx.getPredecessor(); 3599 3600 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3601 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Pred, /*Tag=*/0, 3602 Ctx, I->first, I->second); 3603 if (!state) 3604 return; 3605 } 3606 3607 // If the current LocationContext has a parent, don't check for leaks. 3608 // We will do that later. 3609 // FIXME: we should instead check for imbalances of the retain/releases, 3610 // and suggest annotations. 3611 if (Ctx.getLocationContext()->getParent()) 3612 return; 3613 3614 B = state->get<RefBindings>(); 3615 SmallVector<SymbolRef, 10> Leaked; 3616 3617 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) 3618 state = handleSymbolDeath(state, I->first, I->second, Leaked); 3619 3620 processLeaks(state, Leaked, Ctx, Pred); 3621} 3622 3623const ProgramPointTag * 3624RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const { 3625 const SimpleProgramPointTag *&tag = DeadSymbolTags[sym]; 3626 if (!tag) { 3627 SmallString<64> buf; 3628 llvm::raw_svector_ostream out(buf); 3629 out << "RetainCountChecker : Dead Symbol : "; 3630 sym->dumpToStream(out); 3631 tag = new SimpleProgramPointTag(out.str()); 3632 } 3633 return tag; 3634} 3635 3636void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper, 3637 CheckerContext &C) const { 3638 ExplodedNode *Pred = C.getPredecessor(); 3639 3640 ProgramStateRef state = C.getState(); 3641 RefBindings B = state->get<RefBindings>(); 3642 3643 // Update counts from autorelease pools 3644 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3645 E = SymReaper.dead_end(); I != E; ++I) { 3646 SymbolRef Sym = *I; 3647 if (const RefVal *T = B.lookup(Sym)){ 3648 // Use the symbol as the tag. 3649 // FIXME: This might not be as unique as we would like. 3650 const ProgramPointTag *Tag = getDeadSymbolTag(Sym); 3651 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Pred, Tag, C, 3652 Sym, *T); 3653 if (!state) 3654 return; 3655 } 3656 } 3657 3658 B = state->get<RefBindings>(); 3659 SmallVector<SymbolRef, 10> Leaked; 3660 3661 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3662 E = SymReaper.dead_end(); I != E; ++I) { 3663 if (const RefVal *T = B.lookup(*I)) 3664 state = handleSymbolDeath(state, *I, *T, Leaked); 3665 } 3666 3667 Pred = processLeaks(state, Leaked, C, Pred); 3668 3669 // Did we cache out? 3670 if (!Pred) 3671 return; 3672 3673 // Now generate a new node that nukes the old bindings. 3674 RefBindings::Factory &F = state->get_context<RefBindings>(); 3675 3676 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3677 E = SymReaper.dead_end(); I != E; ++I) 3678 B = F.remove(B, *I); 3679 3680 state = state->set<RefBindings>(B); 3681 C.addTransition(state, Pred); 3682} 3683 3684void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State, 3685 const char *NL, const char *Sep) const { 3686 3687 RefBindings B = State->get<RefBindings>(); 3688 3689 if (!B.isEmpty()) 3690 Out << Sep << NL; 3691 3692 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3693 Out << I->first << " : "; 3694 I->second.print(Out); 3695 Out << NL; 3696 } 3697} 3698 3699//===----------------------------------------------------------------------===// 3700// Checker registration. 3701//===----------------------------------------------------------------------===// 3702 3703void ento::registerRetainCountChecker(CheckerManager &Mgr) { 3704 Mgr.registerChecker<RetainCountChecker>(); 3705} 3706 3707