RetainCountChecker.cpp revision 166d502d5367ceacd1313a33cac43b1048b8524d
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 345REGISTER_MAP_WITH_PROGRAMSTATE(RefBindings, SymbolRef, RefVal) 346 347static inline const RefVal *getRefBinding(ProgramStateRef State, 348 SymbolRef Sym) { 349 return State->get<RefBindings>(Sym); 350} 351 352static inline ProgramStateRef setRefBinding(ProgramStateRef State, 353 SymbolRef Sym, RefVal Val) { 354 return State->set<RefBindings>(Sym, Val); 355} 356 357static ProgramStateRef removeRefBinding(ProgramStateRef State, SymbolRef Sym) { 358 return State->remove<RefBindings>(Sym); 359} 360 361//===----------------------------------------------------------------------===// 362// Function/Method behavior summaries. 363//===----------------------------------------------------------------------===// 364 365namespace { 366class RetainSummary { 367 /// Args - a map of (index, ArgEffect) pairs, where index 368 /// specifies the argument (starting from 0). This can be sparsely 369 /// populated; arguments with no entry in Args use 'DefaultArgEffect'. 370 ArgEffects Args; 371 372 /// DefaultArgEffect - The default ArgEffect to apply to arguments that 373 /// do not have an entry in Args. 374 ArgEffect DefaultArgEffect; 375 376 /// Receiver - If this summary applies to an Objective-C message expression, 377 /// this is the effect applied to the state of the receiver. 378 ArgEffect Receiver; 379 380 /// Ret - The effect on the return value. Used to indicate if the 381 /// function/method call returns a new tracked symbol. 382 RetEffect Ret; 383 384public: 385 RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff, 386 ArgEffect ReceiverEff) 387 : Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {} 388 389 /// getArg - Return the argument effect on the argument specified by 390 /// idx (starting from 0). 391 ArgEffect getArg(unsigned idx) const { 392 if (const ArgEffect *AE = Args.lookup(idx)) 393 return *AE; 394 395 return DefaultArgEffect; 396 } 397 398 void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) { 399 Args = af.add(Args, idx, e); 400 } 401 402 /// setDefaultArgEffect - Set the default argument effect. 403 void setDefaultArgEffect(ArgEffect E) { 404 DefaultArgEffect = E; 405 } 406 407 /// getRetEffect - Returns the effect on the return value of the call. 408 RetEffect getRetEffect() const { return Ret; } 409 410 /// setRetEffect - Set the effect of the return value of the call. 411 void setRetEffect(RetEffect E) { Ret = E; } 412 413 414 /// Sets the effect on the receiver of the message. 415 void setReceiverEffect(ArgEffect e) { Receiver = e; } 416 417 /// getReceiverEffect - Returns the effect on the receiver of the call. 418 /// This is only meaningful if the summary applies to an ObjCMessageExpr*. 419 ArgEffect getReceiverEffect() const { return Receiver; } 420 421 /// Test if two retain summaries are identical. Note that merely equivalent 422 /// summaries are not necessarily identical (for example, if an explicit 423 /// argument effect matches the default effect). 424 bool operator==(const RetainSummary &Other) const { 425 return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect && 426 Receiver == Other.Receiver && Ret == Other.Ret; 427 } 428 429 /// Profile this summary for inclusion in a FoldingSet. 430 void Profile(llvm::FoldingSetNodeID& ID) const { 431 ID.Add(Args); 432 ID.Add(DefaultArgEffect); 433 ID.Add(Receiver); 434 ID.Add(Ret); 435 } 436 437 /// A retain summary is simple if it has no ArgEffects other than the default. 438 bool isSimple() const { 439 return Args.isEmpty(); 440 } 441 442private: 443 ArgEffects getArgEffects() const { return Args; } 444 ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; } 445 446 friend class RetainSummaryManager; 447}; 448} // end anonymous namespace 449 450//===----------------------------------------------------------------------===// 451// Data structures for constructing summaries. 452//===----------------------------------------------------------------------===// 453 454namespace { 455class ObjCSummaryKey { 456 IdentifierInfo* II; 457 Selector S; 458public: 459 ObjCSummaryKey(IdentifierInfo* ii, Selector s) 460 : II(ii), S(s) {} 461 462 ObjCSummaryKey(const ObjCInterfaceDecl *d, Selector s) 463 : II(d ? d->getIdentifier() : 0), S(s) {} 464 465 ObjCSummaryKey(Selector s) 466 : II(0), S(s) {} 467 468 IdentifierInfo *getIdentifier() const { return II; } 469 Selector getSelector() const { return S; } 470}; 471} 472 473namespace llvm { 474template <> struct DenseMapInfo<ObjCSummaryKey> { 475 static inline ObjCSummaryKey getEmptyKey() { 476 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getEmptyKey(), 477 DenseMapInfo<Selector>::getEmptyKey()); 478 } 479 480 static inline ObjCSummaryKey getTombstoneKey() { 481 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getTombstoneKey(), 482 DenseMapInfo<Selector>::getTombstoneKey()); 483 } 484 485 static unsigned getHashValue(const ObjCSummaryKey &V) { 486 typedef std::pair<IdentifierInfo*, Selector> PairTy; 487 return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(), 488 V.getSelector())); 489 } 490 491 static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) { 492 return LHS.getIdentifier() == RHS.getIdentifier() && 493 LHS.getSelector() == RHS.getSelector(); 494 } 495 496}; 497template <> 498struct isPodLike<ObjCSummaryKey> { static const bool value = true; }; 499} // end llvm namespace 500 501namespace { 502class ObjCSummaryCache { 503 typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy; 504 MapTy M; 505public: 506 ObjCSummaryCache() {} 507 508 const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) { 509 // Do a lookup with the (D,S) pair. If we find a match return 510 // the iterator. 511 ObjCSummaryKey K(D, S); 512 MapTy::iterator I = M.find(K); 513 514 if (I != M.end()) 515 return I->second; 516 if (!D) 517 return NULL; 518 519 // Walk the super chain. If we find a hit with a parent, we'll end 520 // up returning that summary. We actually allow that key (null,S), as 521 // we cache summaries for the null ObjCInterfaceDecl* to allow us to 522 // generate initial summaries without having to worry about NSObject 523 // being declared. 524 // FIXME: We may change this at some point. 525 for (ObjCInterfaceDecl *C=D->getSuperClass() ;; C=C->getSuperClass()) { 526 if ((I = M.find(ObjCSummaryKey(C, S))) != M.end()) 527 break; 528 529 if (!C) 530 return NULL; 531 } 532 533 // Cache the summary with original key to make the next lookup faster 534 // and return the iterator. 535 const RetainSummary *Summ = I->second; 536 M[K] = Summ; 537 return Summ; 538 } 539 540 const RetainSummary *find(IdentifierInfo* II, Selector S) { 541 // FIXME: Class method lookup. Right now we dont' have a good way 542 // of going between IdentifierInfo* and the class hierarchy. 543 MapTy::iterator I = M.find(ObjCSummaryKey(II, S)); 544 545 if (I == M.end()) 546 I = M.find(ObjCSummaryKey(S)); 547 548 return I == M.end() ? NULL : I->second; 549 } 550 551 const RetainSummary *& operator[](ObjCSummaryKey K) { 552 return M[K]; 553 } 554 555 const RetainSummary *& operator[](Selector S) { 556 return M[ ObjCSummaryKey(S) ]; 557 } 558}; 559} // end anonymous namespace 560 561//===----------------------------------------------------------------------===// 562// Data structures for managing collections of summaries. 563//===----------------------------------------------------------------------===// 564 565namespace { 566class RetainSummaryManager { 567 568 //==-----------------------------------------------------------------==// 569 // Typedefs. 570 //==-----------------------------------------------------------------==// 571 572 typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *> 573 FuncSummariesTy; 574 575 typedef ObjCSummaryCache ObjCMethodSummariesTy; 576 577 typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode; 578 579 //==-----------------------------------------------------------------==// 580 // Data. 581 //==-----------------------------------------------------------------==// 582 583 /// Ctx - The ASTContext object for the analyzed ASTs. 584 ASTContext &Ctx; 585 586 /// GCEnabled - Records whether or not the analyzed code runs in GC mode. 587 const bool GCEnabled; 588 589 /// Records whether or not the analyzed code runs in ARC mode. 590 const bool ARCEnabled; 591 592 /// FuncSummaries - A map from FunctionDecls to summaries. 593 FuncSummariesTy FuncSummaries; 594 595 /// ObjCClassMethodSummaries - A map from selectors (for instance methods) 596 /// to summaries. 597 ObjCMethodSummariesTy ObjCClassMethodSummaries; 598 599 /// ObjCMethodSummaries - A map from selectors to summaries. 600 ObjCMethodSummariesTy ObjCMethodSummaries; 601 602 /// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects, 603 /// and all other data used by the checker. 604 llvm::BumpPtrAllocator BPAlloc; 605 606 /// AF - A factory for ArgEffects objects. 607 ArgEffects::Factory AF; 608 609 /// ScratchArgs - A holding buffer for construct ArgEffects. 610 ArgEffects ScratchArgs; 611 612 /// ObjCAllocRetE - Default return effect for methods returning Objective-C 613 /// objects. 614 RetEffect ObjCAllocRetE; 615 616 /// ObjCInitRetE - Default return effect for init methods returning 617 /// Objective-C objects. 618 RetEffect ObjCInitRetE; 619 620 /// SimpleSummaries - Used for uniquing summaries that don't have special 621 /// effects. 622 llvm::FoldingSet<CachedSummaryNode> SimpleSummaries; 623 624 //==-----------------------------------------------------------------==// 625 // Methods. 626 //==-----------------------------------------------------------------==// 627 628 /// getArgEffects - Returns a persistent ArgEffects object based on the 629 /// data in ScratchArgs. 630 ArgEffects getArgEffects(); 631 632 enum UnaryFuncKind { cfretain, cfrelease, cfmakecollectable }; 633 634 const RetainSummary *getUnarySummary(const FunctionType* FT, 635 UnaryFuncKind func); 636 637 const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD); 638 const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD); 639 const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD); 640 641 const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm); 642 643 const RetainSummary *getPersistentSummary(RetEffect RetEff, 644 ArgEffect ReceiverEff = DoNothing, 645 ArgEffect DefaultEff = MayEscape) { 646 RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff); 647 return getPersistentSummary(Summ); 648 } 649 650 const RetainSummary *getDoNothingSummary() { 651 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 652 } 653 654 const RetainSummary *getDefaultSummary() { 655 return getPersistentSummary(RetEffect::MakeNoRet(), 656 DoNothing, MayEscape); 657 } 658 659 const RetainSummary *getPersistentStopSummary() { 660 return getPersistentSummary(RetEffect::MakeNoRet(), 661 StopTracking, StopTracking); 662 } 663 664 void InitializeClassMethodSummaries(); 665 void InitializeMethodSummaries(); 666private: 667 void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) { 668 ObjCClassMethodSummaries[S] = Summ; 669 } 670 671 void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) { 672 ObjCMethodSummaries[S] = Summ; 673 } 674 675 void addClassMethSummary(const char* Cls, const char* name, 676 const RetainSummary *Summ, bool isNullary = true) { 677 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 678 Selector S = isNullary ? GetNullarySelector(name, Ctx) 679 : GetUnarySelector(name, Ctx); 680 ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 681 } 682 683 void addInstMethSummary(const char* Cls, const char* nullaryName, 684 const RetainSummary *Summ) { 685 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 686 Selector S = GetNullarySelector(nullaryName, Ctx); 687 ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 688 } 689 690 Selector generateSelector(va_list argp) { 691 SmallVector<IdentifierInfo*, 10> II; 692 693 while (const char* s = va_arg(argp, const char*)) 694 II.push_back(&Ctx.Idents.get(s)); 695 696 return Ctx.Selectors.getSelector(II.size(), &II[0]); 697 } 698 699 void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy& Summaries, 700 const RetainSummary * Summ, va_list argp) { 701 Selector S = generateSelector(argp); 702 Summaries[ObjCSummaryKey(ClsII, S)] = Summ; 703 } 704 705 void addInstMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 706 va_list argp; 707 va_start(argp, Summ); 708 addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp); 709 va_end(argp); 710 } 711 712 void addClsMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 713 va_list argp; 714 va_start(argp, Summ); 715 addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp); 716 va_end(argp); 717 } 718 719 void addClsMethSummary(IdentifierInfo *II, const RetainSummary * Summ, ...) { 720 va_list argp; 721 va_start(argp, Summ); 722 addMethodSummary(II, ObjCClassMethodSummaries, Summ, argp); 723 va_end(argp); 724 } 725 726public: 727 728 RetainSummaryManager(ASTContext &ctx, bool gcenabled, bool usesARC) 729 : Ctx(ctx), 730 GCEnabled(gcenabled), 731 ARCEnabled(usesARC), 732 AF(BPAlloc), ScratchArgs(AF.getEmptyMap()), 733 ObjCAllocRetE(gcenabled 734 ? RetEffect::MakeGCNotOwned() 735 : (usesARC ? RetEffect::MakeARCNotOwned() 736 : RetEffect::MakeOwned(RetEffect::ObjC, true))), 737 ObjCInitRetE(gcenabled 738 ? RetEffect::MakeGCNotOwned() 739 : (usesARC ? RetEffect::MakeARCNotOwned() 740 : RetEffect::MakeOwnedWhenTrackedReceiver())) { 741 InitializeClassMethodSummaries(); 742 InitializeMethodSummaries(); 743 } 744 745 const RetainSummary *getSummary(const CallEvent &Call, 746 ProgramStateRef State = 0); 747 748 const RetainSummary *getFunctionSummary(const FunctionDecl *FD); 749 750 const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 751 const ObjCMethodDecl *MD, 752 QualType RetTy, 753 ObjCMethodSummariesTy &CachedSummaries); 754 755 const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M, 756 ProgramStateRef State); 757 758 const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) { 759 assert(!M.isInstanceMessage()); 760 const ObjCInterfaceDecl *Class = M.getReceiverInterface(); 761 762 return getMethodSummary(M.getSelector(), Class, M.getDecl(), 763 M.getResultType(), ObjCClassMethodSummaries); 764 } 765 766 /// getMethodSummary - This version of getMethodSummary is used to query 767 /// the summary for the current method being analyzed. 768 const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) { 769 const ObjCInterfaceDecl *ID = MD->getClassInterface(); 770 Selector S = MD->getSelector(); 771 QualType ResultTy = MD->getResultType(); 772 773 ObjCMethodSummariesTy *CachedSummaries; 774 if (MD->isInstanceMethod()) 775 CachedSummaries = &ObjCMethodSummaries; 776 else 777 CachedSummaries = &ObjCClassMethodSummaries; 778 779 return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries); 780 } 781 782 const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD, 783 Selector S, QualType RetTy); 784 785 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 786 const ObjCMethodDecl *MD); 787 788 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 789 const FunctionDecl *FD); 790 791 void updateSummaryForCall(const RetainSummary *&Summ, 792 const CallEvent &Call); 793 794 bool isGCEnabled() const { return GCEnabled; } 795 796 bool isARCEnabled() const { return ARCEnabled; } 797 798 bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; } 799 800 RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; } 801 802 friend class RetainSummaryTemplate; 803}; 804 805// Used to avoid allocating long-term (BPAlloc'd) memory for default retain 806// summaries. If a function or method looks like it has a default summary, but 807// it has annotations, the annotations are added to the stack-based template 808// and then copied into managed memory. 809class RetainSummaryTemplate { 810 RetainSummaryManager &Manager; 811 const RetainSummary *&RealSummary; 812 RetainSummary ScratchSummary; 813 bool Accessed; 814public: 815 RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr) 816 : Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {} 817 818 ~RetainSummaryTemplate() { 819 if (Accessed) 820 RealSummary = Manager.getPersistentSummary(ScratchSummary); 821 } 822 823 RetainSummary &operator*() { 824 Accessed = true; 825 return ScratchSummary; 826 } 827 828 RetainSummary *operator->() { 829 Accessed = true; 830 return &ScratchSummary; 831 } 832}; 833 834} // end anonymous namespace 835 836//===----------------------------------------------------------------------===// 837// Implementation of checker data structures. 838//===----------------------------------------------------------------------===// 839 840ArgEffects RetainSummaryManager::getArgEffects() { 841 ArgEffects AE = ScratchArgs; 842 ScratchArgs = AF.getEmptyMap(); 843 return AE; 844} 845 846const RetainSummary * 847RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) { 848 // Unique "simple" summaries -- those without ArgEffects. 849 if (OldSumm.isSimple()) { 850 llvm::FoldingSetNodeID ID; 851 OldSumm.Profile(ID); 852 853 void *Pos; 854 CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos); 855 856 if (!N) { 857 N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>(); 858 new (N) CachedSummaryNode(OldSumm); 859 SimpleSummaries.InsertNode(N, Pos); 860 } 861 862 return &N->getValue(); 863 } 864 865 RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>(); 866 new (Summ) RetainSummary(OldSumm); 867 return Summ; 868} 869 870//===----------------------------------------------------------------------===// 871// Summary creation for functions (largely uses of Core Foundation). 872//===----------------------------------------------------------------------===// 873 874static bool isRetain(const FunctionDecl *FD, StringRef FName) { 875 return FName.endswith("Retain"); 876} 877 878static bool isRelease(const FunctionDecl *FD, StringRef FName) { 879 return FName.endswith("Release"); 880} 881 882static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) { 883 // FIXME: Remove FunctionDecl parameter. 884 // FIXME: Is it really okay if MakeCollectable isn't a suffix? 885 return FName.find("MakeCollectable") != StringRef::npos; 886} 887 888static ArgEffect getStopTrackingHardEquivalent(ArgEffect E) { 889 switch (E) { 890 case DoNothing: 891 case Autorelease: 892 case DecRefBridgedTransfered: 893 case IncRef: 894 case IncRefMsg: 895 case MakeCollectable: 896 case MayEscape: 897 case NewAutoreleasePool: 898 case StopTracking: 899 case StopTrackingHard: 900 return StopTrackingHard; 901 case DecRef: 902 case DecRefAndStopTrackingHard: 903 return DecRefAndStopTrackingHard; 904 case DecRefMsg: 905 case DecRefMsgAndStopTrackingHard: 906 return DecRefMsgAndStopTrackingHard; 907 case Dealloc: 908 return Dealloc; 909 } 910 911 llvm_unreachable("Unknown ArgEffect kind"); 912} 913 914void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S, 915 const CallEvent &Call) { 916 if (Call.hasNonZeroCallbackArg()) { 917 ArgEffect RecEffect = 918 getStopTrackingHardEquivalent(S->getReceiverEffect()); 919 ArgEffect DefEffect = 920 getStopTrackingHardEquivalent(S->getDefaultArgEffect()); 921 922 ArgEffects CustomArgEffects = S->getArgEffects(); 923 for (ArgEffects::iterator I = CustomArgEffects.begin(), 924 E = CustomArgEffects.end(); 925 I != E; ++I) { 926 ArgEffect Translated = getStopTrackingHardEquivalent(I->second); 927 if (Translated != DefEffect) 928 ScratchArgs = AF.add(ScratchArgs, I->first, Translated); 929 } 930 931 RetEffect RE = RetEffect::MakeNoRetHard(); 932 933 // Special cases where the callback argument CANNOT free the return value. 934 // This can generally only happen if we know that the callback will only be 935 // called when the return value is already being deallocated. 936 if (const FunctionCall *FC = dyn_cast<FunctionCall>(&Call)) { 937 if (IdentifierInfo *Name = FC->getDecl()->getIdentifier()) { 938 // When the CGBitmapContext is deallocated, the callback here will free 939 // the associated data buffer. 940 if (Name->isStr("CGBitmapContextCreateWithData")) 941 RE = S->getRetEffect(); 942 } 943 } 944 945 S = getPersistentSummary(RE, RecEffect, DefEffect); 946 } 947 948 // Special case '[super init];' and '[self init];' 949 // 950 // Even though calling '[super init]' without assigning the result to self 951 // and checking if the parent returns 'nil' is a bad pattern, it is common. 952 // Additionally, our Self Init checker already warns about it. To avoid 953 // overwhelming the user with messages from both checkers, we model the case 954 // of '[super init]' in cases when it is not consumed by another expression 955 // as if the call preserves the value of 'self'; essentially, assuming it can 956 // never fail and return 'nil'. 957 // Note, we don't want to just stop tracking the value since we want the 958 // RetainCount checker to report leaks and use-after-free if SelfInit checker 959 // is turned off. 960 if (const ObjCMethodCall *MC = dyn_cast<ObjCMethodCall>(&Call)) { 961 if (MC->getMethodFamily() == OMF_init && MC->isReceiverSelfOrSuper()) { 962 963 // Check if the message is not consumed, we know it will not be used in 964 // an assignment, ex: "self = [super init]". 965 const Expr *ME = MC->getOriginExpr(); 966 const LocationContext *LCtx = MC->getLocationContext(); 967 ParentMap &PM = LCtx->getAnalysisDeclContext()->getParentMap(); 968 if (!PM.isConsumedExpr(ME)) { 969 RetainSummaryTemplate ModifiableSummaryTemplate(S, *this); 970 ModifiableSummaryTemplate->setReceiverEffect(DoNothing); 971 ModifiableSummaryTemplate->setRetEffect(RetEffect::MakeNoRet()); 972 } 973 } 974 975 } 976} 977 978const RetainSummary * 979RetainSummaryManager::getSummary(const CallEvent &Call, 980 ProgramStateRef State) { 981 const RetainSummary *Summ; 982 switch (Call.getKind()) { 983 case CE_Function: 984 Summ = getFunctionSummary(cast<FunctionCall>(Call).getDecl()); 985 break; 986 case CE_CXXMember: 987 case CE_CXXMemberOperator: 988 case CE_Block: 989 case CE_CXXConstructor: 990 case CE_CXXDestructor: 991 case CE_CXXAllocator: 992 // FIXME: These calls are currently unsupported. 993 return getPersistentStopSummary(); 994 case CE_ObjCMessage: { 995 const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call); 996 if (Msg.isInstanceMessage()) 997 Summ = getInstanceMethodSummary(Msg, State); 998 else 999 Summ = getClassMethodSummary(Msg); 1000 break; 1001 } 1002 } 1003 1004 updateSummaryForCall(Summ, Call); 1005 1006 assert(Summ && "Unknown call type?"); 1007 return Summ; 1008} 1009 1010const RetainSummary * 1011RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) { 1012 // If we don't know what function we're calling, use our default summary. 1013 if (!FD) 1014 return getDefaultSummary(); 1015 1016 // Look up a summary in our cache of FunctionDecls -> Summaries. 1017 FuncSummariesTy::iterator I = FuncSummaries.find(FD); 1018 if (I != FuncSummaries.end()) 1019 return I->second; 1020 1021 // No summary? Generate one. 1022 const RetainSummary *S = 0; 1023 bool AllowAnnotations = true; 1024 1025 do { 1026 // We generate "stop" summaries for implicitly defined functions. 1027 if (FD->isImplicit()) { 1028 S = getPersistentStopSummary(); 1029 break; 1030 } 1031 1032 // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the 1033 // function's type. 1034 const FunctionType* FT = FD->getType()->getAs<FunctionType>(); 1035 const IdentifierInfo *II = FD->getIdentifier(); 1036 if (!II) 1037 break; 1038 1039 StringRef FName = II->getName(); 1040 1041 // Strip away preceding '_'. Doing this here will effect all the checks 1042 // down below. 1043 FName = FName.substr(FName.find_first_not_of('_')); 1044 1045 // Inspect the result type. 1046 QualType RetTy = FT->getResultType(); 1047 1048 // FIXME: This should all be refactored into a chain of "summary lookup" 1049 // filters. 1050 assert(ScratchArgs.isEmpty()); 1051 1052 if (FName == "pthread_create" || FName == "pthread_setspecific") { 1053 // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>. 1054 // This will be addressed better with IPA. 1055 S = getPersistentStopSummary(); 1056 } else if (FName == "NSMakeCollectable") { 1057 // Handle: id NSMakeCollectable(CFTypeRef) 1058 S = (RetTy->isObjCIdType()) 1059 ? getUnarySummary(FT, cfmakecollectable) 1060 : getPersistentStopSummary(); 1061 // The headers on OS X 10.8 use cf_consumed/ns_returns_retained, 1062 // but we can fully model NSMakeCollectable ourselves. 1063 AllowAnnotations = false; 1064 } else if (FName == "CFPlugInInstanceCreate") { 1065 S = getPersistentSummary(RetEffect::MakeNoRet()); 1066 } else if (FName == "IOBSDNameMatching" || 1067 FName == "IOServiceMatching" || 1068 FName == "IOServiceNameMatching" || 1069 FName == "IORegistryEntrySearchCFProperty" || 1070 FName == "IORegistryEntryIDMatching" || 1071 FName == "IOOpenFirmwarePathMatching") { 1072 // Part of <rdar://problem/6961230>. (IOKit) 1073 // This should be addressed using a API table. 1074 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1075 DoNothing, DoNothing); 1076 } else if (FName == "IOServiceGetMatchingService" || 1077 FName == "IOServiceGetMatchingServices") { 1078 // FIXES: <rdar://problem/6326900> 1079 // This should be addressed using a API table. This strcmp is also 1080 // a little gross, but there is no need to super optimize here. 1081 ScratchArgs = AF.add(ScratchArgs, 1, DecRef); 1082 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1083 } else if (FName == "IOServiceAddNotification" || 1084 FName == "IOServiceAddMatchingNotification") { 1085 // Part of <rdar://problem/6961230>. (IOKit) 1086 // This should be addressed using a API table. 1087 ScratchArgs = AF.add(ScratchArgs, 2, DecRef); 1088 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1089 } else if (FName == "CVPixelBufferCreateWithBytes") { 1090 // FIXES: <rdar://problem/7283567> 1091 // Eventually this can be improved by recognizing that the pixel 1092 // buffer passed to CVPixelBufferCreateWithBytes is released via 1093 // a callback and doing full IPA to make sure this is done correctly. 1094 // FIXME: This function has an out parameter that returns an 1095 // allocated object. 1096 ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); 1097 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1098 } else if (FName == "CGBitmapContextCreateWithData") { 1099 // FIXES: <rdar://problem/7358899> 1100 // Eventually this can be improved by recognizing that 'releaseInfo' 1101 // passed to CGBitmapContextCreateWithData is released via 1102 // a callback and doing full IPA to make sure this is done correctly. 1103 ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); 1104 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1105 DoNothing, DoNothing); 1106 } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { 1107 // FIXES: <rdar://problem/7283567> 1108 // Eventually this can be improved by recognizing that the pixel 1109 // buffer passed to CVPixelBufferCreateWithPlanarBytes is released 1110 // via a callback and doing full IPA to make sure this is done 1111 // correctly. 1112 ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); 1113 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1114 } else if (FName == "dispatch_set_context") { 1115 // <rdar://problem/11059275> - The analyzer currently doesn't have 1116 // a good way to reason about the finalizer function for libdispatch. 1117 // If we pass a context object that is memory managed, stop tracking it. 1118 // FIXME: this hack should possibly go away once we can handle 1119 // libdispatch finalizers. 1120 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1121 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1122 } else if (FName.startswith("NSLog")) { 1123 S = getDoNothingSummary(); 1124 } else if (FName.startswith("NS") && 1125 (FName.find("Insert") != StringRef::npos)) { 1126 // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 1127 // be deallocated by NSMapRemove. (radar://11152419) 1128 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1129 ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); 1130 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1131 } 1132 1133 // Did we get a summary? 1134 if (S) 1135 break; 1136 1137 if (RetTy->isPointerType()) { 1138 if (FD->getAttr<CFAuditedTransferAttr>()) { 1139 S = getCFCreateGetRuleSummary(FD); 1140 break; 1141 } 1142 1143 // For CoreFoundation ('CF') types. 1144 if (cocoa::isRefType(RetTy, "CF", FName)) { 1145 if (isRetain(FD, FName)) 1146 S = getUnarySummary(FT, cfretain); 1147 else if (isMakeCollectable(FD, FName)) 1148 S = getUnarySummary(FT, cfmakecollectable); 1149 else 1150 S = getCFCreateGetRuleSummary(FD); 1151 1152 break; 1153 } 1154 1155 // For CoreGraphics ('CG') types. 1156 if (cocoa::isRefType(RetTy, "CG", FName)) { 1157 if (isRetain(FD, FName)) 1158 S = getUnarySummary(FT, cfretain); 1159 else 1160 S = getCFCreateGetRuleSummary(FD); 1161 1162 break; 1163 } 1164 1165 // For the Disk Arbitration API (DiskArbitration/DADisk.h) 1166 if (cocoa::isRefType(RetTy, "DADisk") || 1167 cocoa::isRefType(RetTy, "DADissenter") || 1168 cocoa::isRefType(RetTy, "DASessionRef")) { 1169 S = getCFCreateGetRuleSummary(FD); 1170 break; 1171 } 1172 1173 break; 1174 } 1175 1176 // Check for release functions, the only kind of functions that we care 1177 // about that don't return a pointer type. 1178 if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { 1179 // Test for 'CGCF'. 1180 FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); 1181 1182 if (isRelease(FD, FName)) 1183 S = getUnarySummary(FT, cfrelease); 1184 else { 1185 assert (ScratchArgs.isEmpty()); 1186 // Remaining CoreFoundation and CoreGraphics functions. 1187 // We use to assume that they all strictly followed the ownership idiom 1188 // and that ownership cannot be transferred. While this is technically 1189 // correct, many methods allow a tracked object to escape. For example: 1190 // 1191 // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); 1192 // CFDictionaryAddValue(y, key, x); 1193 // CFRelease(x); 1194 // ... it is okay to use 'x' since 'y' has a reference to it 1195 // 1196 // We handle this and similar cases with the follow heuristic. If the 1197 // function name contains "InsertValue", "SetValue", "AddValue", 1198 // "AppendValue", or "SetAttribute", then we assume that arguments may 1199 // "escape." This means that something else holds on to the object, 1200 // allowing it be used even after its local retain count drops to 0. 1201 ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| 1202 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 1203 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 1204 StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| 1205 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) 1206 ? MayEscape : DoNothing; 1207 1208 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); 1209 } 1210 } 1211 } 1212 while (0); 1213 1214 // If we got all the way here without any luck, use a default summary. 1215 if (!S) 1216 S = getDefaultSummary(); 1217 1218 // Annotations override defaults. 1219 if (AllowAnnotations) 1220 updateSummaryFromAnnotations(S, FD); 1221 1222 FuncSummaries[FD] = S; 1223 return S; 1224} 1225 1226const RetainSummary * 1227RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { 1228 if (coreFoundation::followsCreateRule(FD)) 1229 return getCFSummaryCreateRule(FD); 1230 1231 return getCFSummaryGetRule(FD); 1232} 1233 1234const RetainSummary * 1235RetainSummaryManager::getUnarySummary(const FunctionType* FT, 1236 UnaryFuncKind func) { 1237 1238 // Sanity check that this is *really* a unary function. This can 1239 // happen if people do weird things. 1240 const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); 1241 if (!FTP || FTP->getNumArgs() != 1) 1242 return getPersistentStopSummary(); 1243 1244 assert (ScratchArgs.isEmpty()); 1245 1246 ArgEffect Effect; 1247 switch (func) { 1248 case cfretain: Effect = IncRef; break; 1249 case cfrelease: Effect = DecRef; break; 1250 case cfmakecollectable: Effect = MakeCollectable; break; 1251 } 1252 1253 ScratchArgs = AF.add(ScratchArgs, 0, Effect); 1254 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1255} 1256 1257const RetainSummary * 1258RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { 1259 assert (ScratchArgs.isEmpty()); 1260 1261 return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1262} 1263 1264const RetainSummary * 1265RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { 1266 assert (ScratchArgs.isEmpty()); 1267 return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), 1268 DoNothing, DoNothing); 1269} 1270 1271//===----------------------------------------------------------------------===// 1272// Summary creation for Selectors. 1273//===----------------------------------------------------------------------===// 1274 1275void 1276RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1277 const FunctionDecl *FD) { 1278 if (!FD) 1279 return; 1280 1281 assert(Summ && "Must have a summary to add annotations to."); 1282 RetainSummaryTemplate Template(Summ, *this); 1283 1284 // Effects on the parameters. 1285 unsigned parm_idx = 0; 1286 for (FunctionDecl::param_const_iterator pi = FD->param_begin(), 1287 pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { 1288 const ParmVarDecl *pd = *pi; 1289 if (pd->getAttr<NSConsumedAttr>()) { 1290 if (!GCEnabled) { 1291 Template->addArg(AF, parm_idx, DecRef); 1292 } 1293 } else if (pd->getAttr<CFConsumedAttr>()) { 1294 Template->addArg(AF, parm_idx, DecRef); 1295 } 1296 } 1297 1298 QualType RetTy = FD->getResultType(); 1299 1300 // Determine if there is a special return effect for this method. 1301 if (cocoa::isCocoaObjectRef(RetTy)) { 1302 if (FD->getAttr<NSReturnsRetainedAttr>()) { 1303 Template->setRetEffect(ObjCAllocRetE); 1304 } 1305 else if (FD->getAttr<CFReturnsRetainedAttr>()) { 1306 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1307 } 1308 else if (FD->getAttr<NSReturnsNotRetainedAttr>()) { 1309 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1310 } 1311 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1312 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1313 } 1314 } else if (RetTy->getAs<PointerType>()) { 1315 if (FD->getAttr<CFReturnsRetainedAttr>()) { 1316 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1317 } 1318 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1319 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1320 } 1321 } 1322} 1323 1324void 1325RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1326 const ObjCMethodDecl *MD) { 1327 if (!MD) 1328 return; 1329 1330 assert(Summ && "Must have a valid summary to add annotations to"); 1331 RetainSummaryTemplate Template(Summ, *this); 1332 bool isTrackedLoc = false; 1333 1334 // Effects on the receiver. 1335 if (MD->getAttr<NSConsumesSelfAttr>()) { 1336 if (!GCEnabled) 1337 Template->setReceiverEffect(DecRefMsg); 1338 } 1339 1340 // Effects on the parameters. 1341 unsigned parm_idx = 0; 1342 for (ObjCMethodDecl::param_const_iterator 1343 pi=MD->param_begin(), pe=MD->param_end(); 1344 pi != pe; ++pi, ++parm_idx) { 1345 const ParmVarDecl *pd = *pi; 1346 if (pd->getAttr<NSConsumedAttr>()) { 1347 if (!GCEnabled) 1348 Template->addArg(AF, parm_idx, DecRef); 1349 } 1350 else if(pd->getAttr<CFConsumedAttr>()) { 1351 Template->addArg(AF, parm_idx, DecRef); 1352 } 1353 } 1354 1355 // Determine if there is a special return effect for this method. 1356 if (cocoa::isCocoaObjectRef(MD->getResultType())) { 1357 if (MD->getAttr<NSReturnsRetainedAttr>()) { 1358 Template->setRetEffect(ObjCAllocRetE); 1359 return; 1360 } 1361 if (MD->getAttr<NSReturnsNotRetainedAttr>()) { 1362 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1363 return; 1364 } 1365 1366 isTrackedLoc = true; 1367 } else { 1368 isTrackedLoc = MD->getResultType()->getAs<PointerType>() != NULL; 1369 } 1370 1371 if (isTrackedLoc) { 1372 if (MD->getAttr<CFReturnsRetainedAttr>()) 1373 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1374 else if (MD->getAttr<CFReturnsNotRetainedAttr>()) 1375 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1376 } 1377} 1378 1379const RetainSummary * 1380RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, 1381 Selector S, QualType RetTy) { 1382 // Any special effects? 1383 ArgEffect ReceiverEff = DoNothing; 1384 RetEffect ResultEff = RetEffect::MakeNoRet(); 1385 1386 // Check the method family, and apply any default annotations. 1387 switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { 1388 case OMF_None: 1389 case OMF_performSelector: 1390 // Assume all Objective-C methods follow Cocoa Memory Management rules. 1391 // FIXME: Does the non-threaded performSelector family really belong here? 1392 // The selector could be, say, @selector(copy). 1393 if (cocoa::isCocoaObjectRef(RetTy)) 1394 ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); 1395 else if (coreFoundation::isCFObjectRef(RetTy)) { 1396 // ObjCMethodDecl currently doesn't consider CF objects as valid return 1397 // values for alloc, new, copy, or mutableCopy, so we have to 1398 // double-check with the selector. This is ugly, but there aren't that 1399 // many Objective-C methods that return CF objects, right? 1400 if (MD) { 1401 switch (S.getMethodFamily()) { 1402 case OMF_alloc: 1403 case OMF_new: 1404 case OMF_copy: 1405 case OMF_mutableCopy: 1406 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1407 break; 1408 default: 1409 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1410 break; 1411 } 1412 } else { 1413 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1414 } 1415 } 1416 break; 1417 case OMF_init: 1418 ResultEff = ObjCInitRetE; 1419 ReceiverEff = DecRefMsg; 1420 break; 1421 case OMF_alloc: 1422 case OMF_new: 1423 case OMF_copy: 1424 case OMF_mutableCopy: 1425 if (cocoa::isCocoaObjectRef(RetTy)) 1426 ResultEff = ObjCAllocRetE; 1427 else if (coreFoundation::isCFObjectRef(RetTy)) 1428 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1429 break; 1430 case OMF_autorelease: 1431 ReceiverEff = Autorelease; 1432 break; 1433 case OMF_retain: 1434 ReceiverEff = IncRefMsg; 1435 break; 1436 case OMF_release: 1437 ReceiverEff = DecRefMsg; 1438 break; 1439 case OMF_dealloc: 1440 ReceiverEff = Dealloc; 1441 break; 1442 case OMF_self: 1443 // -self is handled specially by the ExprEngine to propagate the receiver. 1444 break; 1445 case OMF_retainCount: 1446 case OMF_finalize: 1447 // These methods don't return objects. 1448 break; 1449 } 1450 1451 // If one of the arguments in the selector has the keyword 'delegate' we 1452 // should stop tracking the reference count for the receiver. This is 1453 // because the reference count is quite possibly handled by a delegate 1454 // method. 1455 if (S.isKeywordSelector()) { 1456 for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { 1457 StringRef Slot = S.getNameForSlot(i); 1458 if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { 1459 if (ResultEff == ObjCInitRetE) 1460 ResultEff = RetEffect::MakeNoRetHard(); 1461 else 1462 ReceiverEff = StopTrackingHard; 1463 } 1464 } 1465 } 1466 1467 if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && 1468 ResultEff.getKind() == RetEffect::NoRet) 1469 return getDefaultSummary(); 1470 1471 return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); 1472} 1473 1474const RetainSummary * 1475RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, 1476 ProgramStateRef State) { 1477 const ObjCInterfaceDecl *ReceiverClass = 0; 1478 1479 // We do better tracking of the type of the object than the core ExprEngine. 1480 // See if we have its type in our private state. 1481 // FIXME: Eventually replace the use of state->get<RefBindings> with 1482 // a generic API for reasoning about the Objective-C types of symbolic 1483 // objects. 1484 SVal ReceiverV = Msg.getReceiverSVal(); 1485 if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) 1486 if (const RefVal *T = getRefBinding(State, Sym)) 1487 if (const ObjCObjectPointerType *PT = 1488 T->getType()->getAs<ObjCObjectPointerType>()) 1489 ReceiverClass = PT->getInterfaceDecl(); 1490 1491 // If we don't know what kind of object this is, fall back to its static type. 1492 if (!ReceiverClass) 1493 ReceiverClass = Msg.getReceiverInterface(); 1494 1495 // FIXME: The receiver could be a reference to a class, meaning that 1496 // we should use the class method. 1497 // id x = [NSObject class]; 1498 // [x performSelector:... withObject:... afterDelay:...]; 1499 Selector S = Msg.getSelector(); 1500 const ObjCMethodDecl *Method = Msg.getDecl(); 1501 if (!Method && ReceiverClass) 1502 Method = ReceiverClass->getInstanceMethod(S); 1503 1504 return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), 1505 ObjCMethodSummaries); 1506} 1507 1508const RetainSummary * 1509RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 1510 const ObjCMethodDecl *MD, QualType RetTy, 1511 ObjCMethodSummariesTy &CachedSummaries) { 1512 1513 // Look up a summary in our summary cache. 1514 const RetainSummary *Summ = CachedSummaries.find(ID, S); 1515 1516 if (!Summ) { 1517 Summ = getStandardMethodSummary(MD, S, RetTy); 1518 1519 // Annotations override defaults. 1520 updateSummaryFromAnnotations(Summ, MD); 1521 1522 // Memoize the summary. 1523 CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; 1524 } 1525 1526 return Summ; 1527} 1528 1529void RetainSummaryManager::InitializeClassMethodSummaries() { 1530 assert(ScratchArgs.isEmpty()); 1531 // Create the [NSAssertionHandler currentHander] summary. 1532 addClassMethSummary("NSAssertionHandler", "currentHandler", 1533 getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); 1534 1535 // Create the [NSAutoreleasePool addObject:] summary. 1536 ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); 1537 addClassMethSummary("NSAutoreleasePool", "addObject", 1538 getPersistentSummary(RetEffect::MakeNoRet(), 1539 DoNothing, Autorelease)); 1540} 1541 1542void RetainSummaryManager::InitializeMethodSummaries() { 1543 1544 assert (ScratchArgs.isEmpty()); 1545 1546 // Create the "init" selector. It just acts as a pass-through for the 1547 // receiver. 1548 const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); 1549 addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); 1550 1551 // awakeAfterUsingCoder: behaves basically like an 'init' method. It 1552 // claims the receiver and returns a retained object. 1553 addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), 1554 InitSumm); 1555 1556 // The next methods are allocators. 1557 const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); 1558 const RetainSummary *CFAllocSumm = 1559 getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1560 1561 // Create the "retain" selector. 1562 RetEffect NoRet = RetEffect::MakeNoRet(); 1563 const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); 1564 addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); 1565 1566 // Create the "release" selector. 1567 Summ = getPersistentSummary(NoRet, DecRefMsg); 1568 addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); 1569 1570 // Create the "drain" selector. 1571 Summ = getPersistentSummary(NoRet, isGCEnabled() ? DoNothing : DecRef); 1572 addNSObjectMethSummary(GetNullarySelector("drain", Ctx), Summ); 1573 1574 // Create the -dealloc summary. 1575 Summ = getPersistentSummary(NoRet, Dealloc); 1576 addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); 1577 1578 // Create the "autorelease" selector. 1579 Summ = getPersistentSummary(NoRet, Autorelease); 1580 addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); 1581 1582 // Specially handle NSAutoreleasePool. 1583 addInstMethSummary("NSAutoreleasePool", "init", 1584 getPersistentSummary(NoRet, NewAutoreleasePool)); 1585 1586 // For NSWindow, allocated objects are (initially) self-owned. 1587 // FIXME: For now we opt for false negatives with NSWindow, as these objects 1588 // self-own themselves. However, they only do this once they are displayed. 1589 // Thus, we need to track an NSWindow's display status. 1590 // This is tracked in <rdar://problem/6062711>. 1591 // See also http://llvm.org/bugs/show_bug.cgi?id=3714. 1592 const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), 1593 StopTracking, 1594 StopTracking); 1595 1596 addClassMethSummary("NSWindow", "alloc", NoTrackYet); 1597 1598 // For NSPanel (which subclasses NSWindow), allocated objects are not 1599 // self-owned. 1600 // FIXME: For now we don't track NSPanels. object for the same reason 1601 // as for NSWindow objects. 1602 addClassMethSummary("NSPanel", "alloc", NoTrackYet); 1603 1604 // Don't track allocated autorelease pools yet, as it is okay to prematurely 1605 // exit a method. 1606 addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); 1607 addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); 1608 1609 // Create summaries QCRenderer/QCView -createSnapShotImageOfType: 1610 addInstMethSummary("QCRenderer", AllocSumm, 1611 "createSnapshotImageOfType", NULL); 1612 addInstMethSummary("QCView", AllocSumm, 1613 "createSnapshotImageOfType", NULL); 1614 1615 // Create summaries for CIContext, 'createCGImage' and 1616 // 'createCGLayerWithSize'. These objects are CF objects, and are not 1617 // automatically garbage collected. 1618 addInstMethSummary("CIContext", CFAllocSumm, 1619 "createCGImage", "fromRect", NULL); 1620 addInstMethSummary("CIContext", CFAllocSumm, 1621 "createCGImage", "fromRect", "format", "colorSpace", NULL); 1622 addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", 1623 "info", NULL); 1624} 1625 1626//===----------------------------------------------------------------------===// 1627// Error reporting. 1628//===----------------------------------------------------------------------===// 1629namespace { 1630 typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> 1631 SummaryLogTy; 1632 1633 //===-------------===// 1634 // Bug Descriptions. // 1635 //===-------------===// 1636 1637 class CFRefBug : public BugType { 1638 protected: 1639 CFRefBug(StringRef name) 1640 : BugType(name, categories::MemoryCoreFoundationObjectiveC) {} 1641 public: 1642 1643 // FIXME: Eventually remove. 1644 virtual const char *getDescription() const = 0; 1645 1646 virtual bool isLeak() const { return false; } 1647 }; 1648 1649 class UseAfterRelease : public CFRefBug { 1650 public: 1651 UseAfterRelease() : CFRefBug("Use-after-release") {} 1652 1653 const char *getDescription() const { 1654 return "Reference-counted object is used after it is released"; 1655 } 1656 }; 1657 1658 class BadRelease : public CFRefBug { 1659 public: 1660 BadRelease() : CFRefBug("Bad release") {} 1661 1662 const char *getDescription() const { 1663 return "Incorrect decrement of the reference count of an object that is " 1664 "not owned at this point by the caller"; 1665 } 1666 }; 1667 1668 class DeallocGC : public CFRefBug { 1669 public: 1670 DeallocGC() 1671 : CFRefBug("-dealloc called while using garbage collection") {} 1672 1673 const char *getDescription() const { 1674 return "-dealloc called while using garbage collection"; 1675 } 1676 }; 1677 1678 class DeallocNotOwned : public CFRefBug { 1679 public: 1680 DeallocNotOwned() 1681 : CFRefBug("-dealloc sent to non-exclusively owned object") {} 1682 1683 const char *getDescription() const { 1684 return "-dealloc sent to object that may be referenced elsewhere"; 1685 } 1686 }; 1687 1688 class OverAutorelease : public CFRefBug { 1689 public: 1690 OverAutorelease() 1691 : CFRefBug("Object sent -autorelease too many times") {} 1692 1693 const char *getDescription() const { 1694 return "Object sent -autorelease too many times"; 1695 } 1696 }; 1697 1698 class ReturnedNotOwnedForOwned : public CFRefBug { 1699 public: 1700 ReturnedNotOwnedForOwned() 1701 : CFRefBug("Method should return an owned object") {} 1702 1703 const char *getDescription() const { 1704 return "Object with a +0 retain count returned to caller where a +1 " 1705 "(owning) retain count is expected"; 1706 } 1707 }; 1708 1709 class Leak : public CFRefBug { 1710 public: 1711 Leak(StringRef name) 1712 : CFRefBug(name) { 1713 // Leaks should not be reported if they are post-dominated by a sink. 1714 setSuppressOnSink(true); 1715 } 1716 1717 const char *getDescription() const { return ""; } 1718 1719 bool isLeak() const { return true; } 1720 }; 1721 1722 //===---------===// 1723 // Bug Reports. // 1724 //===---------===// 1725 1726 class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> { 1727 protected: 1728 SymbolRef Sym; 1729 const SummaryLogTy &SummaryLog; 1730 bool GCEnabled; 1731 1732 public: 1733 CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) 1734 : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} 1735 1736 virtual void Profile(llvm::FoldingSetNodeID &ID) const { 1737 static int x = 0; 1738 ID.AddPointer(&x); 1739 ID.AddPointer(Sym); 1740 } 1741 1742 virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N, 1743 const ExplodedNode *PrevN, 1744 BugReporterContext &BRC, 1745 BugReport &BR); 1746 1747 virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1748 const ExplodedNode *N, 1749 BugReport &BR); 1750 }; 1751 1752 class CFRefLeakReportVisitor : public CFRefReportVisitor { 1753 public: 1754 CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, 1755 const SummaryLogTy &log) 1756 : CFRefReportVisitor(sym, GCEnabled, log) {} 1757 1758 PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1759 const ExplodedNode *N, 1760 BugReport &BR); 1761 1762 virtual BugReporterVisitor *clone() const { 1763 // The curiously-recurring template pattern only works for one level of 1764 // subclassing. Rather than make a new template base for 1765 // CFRefReportVisitor, we simply override clone() to do the right thing. 1766 // This could be trouble someday if BugReporterVisitorImpl is ever 1767 // used for something else besides a convenient implementation of clone(). 1768 return new CFRefLeakReportVisitor(*this); 1769 } 1770 }; 1771 1772 class CFRefReport : public BugReport { 1773 void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); 1774 1775 public: 1776 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1777 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1778 bool registerVisitor = true) 1779 : BugReport(D, D.getDescription(), n) { 1780 if (registerVisitor) 1781 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1782 addGCModeDescription(LOpts, GCEnabled); 1783 } 1784 1785 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1786 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1787 StringRef endText) 1788 : BugReport(D, D.getDescription(), endText, n) { 1789 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1790 addGCModeDescription(LOpts, GCEnabled); 1791 } 1792 1793 virtual std::pair<ranges_iterator, ranges_iterator> getRanges() { 1794 const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); 1795 if (!BugTy.isLeak()) 1796 return BugReport::getRanges(); 1797 else 1798 return std::make_pair(ranges_iterator(), ranges_iterator()); 1799 } 1800 }; 1801 1802 class CFRefLeakReport : public CFRefReport { 1803 const MemRegion* AllocBinding; 1804 1805 public: 1806 CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1807 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1808 CheckerContext &Ctx); 1809 1810 PathDiagnosticLocation getLocation(const SourceManager &SM) const { 1811 assert(Location.isValid()); 1812 return Location; 1813 } 1814 }; 1815} // end anonymous namespace 1816 1817void CFRefReport::addGCModeDescription(const LangOptions &LOpts, 1818 bool GCEnabled) { 1819 const char *GCModeDescription = 0; 1820 1821 switch (LOpts.getGC()) { 1822 case LangOptions::GCOnly: 1823 assert(GCEnabled); 1824 GCModeDescription = "Code is compiled to only use garbage collection"; 1825 break; 1826 1827 case LangOptions::NonGC: 1828 assert(!GCEnabled); 1829 GCModeDescription = "Code is compiled to use reference counts"; 1830 break; 1831 1832 case LangOptions::HybridGC: 1833 if (GCEnabled) { 1834 GCModeDescription = "Code is compiled to use either garbage collection " 1835 "(GC) or reference counts (non-GC). The bug occurs " 1836 "with GC enabled"; 1837 break; 1838 } else { 1839 GCModeDescription = "Code is compiled to use either garbage collection " 1840 "(GC) or reference counts (non-GC). The bug occurs " 1841 "in non-GC mode"; 1842 break; 1843 } 1844 } 1845 1846 assert(GCModeDescription && "invalid/unknown GC mode"); 1847 addExtraText(GCModeDescription); 1848} 1849 1850// FIXME: This should be a method on SmallVector. 1851static inline bool contains(const SmallVectorImpl<ArgEffect>& V, 1852 ArgEffect X) { 1853 for (SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end(); 1854 I!=E; ++I) 1855 if (*I == X) return true; 1856 1857 return false; 1858} 1859 1860static bool isNumericLiteralExpression(const Expr *E) { 1861 // FIXME: This set of cases was copied from SemaExprObjC. 1862 return isa<IntegerLiteral>(E) || 1863 isa<CharacterLiteral>(E) || 1864 isa<FloatingLiteral>(E) || 1865 isa<ObjCBoolLiteralExpr>(E) || 1866 isa<CXXBoolLiteralExpr>(E); 1867} 1868 1869PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N, 1870 const ExplodedNode *PrevN, 1871 BugReporterContext &BRC, 1872 BugReport &BR) { 1873 // FIXME: We will eventually need to handle non-statement-based events 1874 // (__attribute__((cleanup))). 1875 if (!isa<StmtPoint>(N->getLocation())) 1876 return NULL; 1877 1878 // Check if the type state has changed. 1879 ProgramStateRef PrevSt = PrevN->getState(); 1880 ProgramStateRef CurrSt = N->getState(); 1881 const LocationContext *LCtx = N->getLocationContext(); 1882 1883 const RefVal* CurrT = getRefBinding(CurrSt, Sym); 1884 if (!CurrT) return NULL; 1885 1886 const RefVal &CurrV = *CurrT; 1887 const RefVal *PrevT = getRefBinding(PrevSt, Sym); 1888 1889 // Create a string buffer to constain all the useful things we want 1890 // to tell the user. 1891 std::string sbuf; 1892 llvm::raw_string_ostream os(sbuf); 1893 1894 // This is the allocation site since the previous node had no bindings 1895 // for this symbol. 1896 if (!PrevT) { 1897 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 1898 1899 if (isa<ObjCArrayLiteral>(S)) { 1900 os << "NSArray literal is an object with a +0 retain count"; 1901 } 1902 else if (isa<ObjCDictionaryLiteral>(S)) { 1903 os << "NSDictionary literal is an object with a +0 retain count"; 1904 } 1905 else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { 1906 if (isNumericLiteralExpression(BL->getSubExpr())) 1907 os << "NSNumber literal is an object with a +0 retain count"; 1908 else { 1909 const ObjCInterfaceDecl *BoxClass = 0; 1910 if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) 1911 BoxClass = Method->getClassInterface(); 1912 1913 // We should always be able to find the boxing class interface, 1914 // but consider this future-proofing. 1915 if (BoxClass) 1916 os << *BoxClass << " b"; 1917 else 1918 os << "B"; 1919 1920 os << "oxed expression produces an object with a +0 retain count"; 1921 } 1922 } 1923 else { 1924 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1925 // Get the name of the callee (if it is available). 1926 SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); 1927 if (const FunctionDecl *FD = X.getAsFunctionDecl()) 1928 os << "Call to function '" << *FD << '\''; 1929 else 1930 os << "function call"; 1931 } 1932 else { 1933 assert(isa<ObjCMessageExpr>(S)); 1934 CallEventManager &Mgr = CurrSt->getStateManager().getCallEventManager(); 1935 CallEventRef<ObjCMethodCall> Call 1936 = Mgr.getObjCMethodCall(cast<ObjCMessageExpr>(S), CurrSt, LCtx); 1937 1938 switch (Call->getMessageKind()) { 1939 case OCM_Message: 1940 os << "Method"; 1941 break; 1942 case OCM_PropertyAccess: 1943 os << "Property"; 1944 break; 1945 case OCM_Subscript: 1946 os << "Subscript"; 1947 break; 1948 } 1949 } 1950 1951 if (CurrV.getObjKind() == RetEffect::CF) { 1952 os << " returns a Core Foundation object with a "; 1953 } 1954 else { 1955 assert (CurrV.getObjKind() == RetEffect::ObjC); 1956 os << " returns an Objective-C object with a "; 1957 } 1958 1959 if (CurrV.isOwned()) { 1960 os << "+1 retain count"; 1961 1962 if (GCEnabled) { 1963 assert(CurrV.getObjKind() == RetEffect::CF); 1964 os << ". " 1965 "Core Foundation objects are not automatically garbage collected."; 1966 } 1967 } 1968 else { 1969 assert (CurrV.isNotOwned()); 1970 os << "+0 retain count"; 1971 } 1972 } 1973 1974 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 1975 N->getLocationContext()); 1976 return new PathDiagnosticEventPiece(Pos, os.str()); 1977 } 1978 1979 // Gather up the effects that were performed on the object at this 1980 // program point 1981 SmallVector<ArgEffect, 2> AEffects; 1982 1983 const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); 1984 if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { 1985 // We only have summaries attached to nodes after evaluating CallExpr and 1986 // ObjCMessageExprs. 1987 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 1988 1989 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1990 // Iterate through the parameter expressions and see if the symbol 1991 // was ever passed as an argument. 1992 unsigned i = 0; 1993 1994 for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); 1995 AI!=AE; ++AI, ++i) { 1996 1997 // Retrieve the value of the argument. Is it the symbol 1998 // we are interested in? 1999 if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) 2000 continue; 2001 2002 // We have an argument. Get the effect! 2003 AEffects.push_back(Summ->getArg(i)); 2004 } 2005 } 2006 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { 2007 if (const Expr *receiver = ME->getInstanceReceiver()) 2008 if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) 2009 .getAsLocSymbol() == Sym) { 2010 // The symbol we are tracking is the receiver. 2011 AEffects.push_back(Summ->getReceiverEffect()); 2012 } 2013 } 2014 } 2015 2016 do { 2017 // Get the previous type state. 2018 RefVal PrevV = *PrevT; 2019 2020 // Specially handle -dealloc. 2021 if (!GCEnabled && contains(AEffects, Dealloc)) { 2022 // Determine if the object's reference count was pushed to zero. 2023 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2024 // We may not have transitioned to 'release' if we hit an error. 2025 // This case is handled elsewhere. 2026 if (CurrV.getKind() == RefVal::Released) { 2027 assert(CurrV.getCombinedCounts() == 0); 2028 os << "Object released by directly sending the '-dealloc' message"; 2029 break; 2030 } 2031 } 2032 2033 // Specially handle CFMakeCollectable and friends. 2034 if (contains(AEffects, MakeCollectable)) { 2035 // Get the name of the function. 2036 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2037 SVal X = 2038 CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); 2039 const FunctionDecl *FD = X.getAsFunctionDecl(); 2040 2041 if (GCEnabled) { 2042 // Determine if the object's reference count was pushed to zero. 2043 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2044 2045 os << "In GC mode a call to '" << *FD 2046 << "' decrements an object's retain count and registers the " 2047 "object with the garbage collector. "; 2048 2049 if (CurrV.getKind() == RefVal::Released) { 2050 assert(CurrV.getCount() == 0); 2051 os << "Since it now has a 0 retain count the object can be " 2052 "automatically collected by the garbage collector."; 2053 } 2054 else 2055 os << "An object must have a 0 retain count to be garbage collected. " 2056 "After this call its retain count is +" << CurrV.getCount() 2057 << '.'; 2058 } 2059 else 2060 os << "When GC is not enabled a call to '" << *FD 2061 << "' has no effect on its argument."; 2062 2063 // Nothing more to say. 2064 break; 2065 } 2066 2067 // Determine if the typestate has changed. 2068 if (!(PrevV == CurrV)) 2069 switch (CurrV.getKind()) { 2070 case RefVal::Owned: 2071 case RefVal::NotOwned: 2072 2073 if (PrevV.getCount() == CurrV.getCount()) { 2074 // Did an autorelease message get sent? 2075 if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) 2076 return 0; 2077 2078 assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); 2079 os << "Object sent -autorelease message"; 2080 break; 2081 } 2082 2083 if (PrevV.getCount() > CurrV.getCount()) 2084 os << "Reference count decremented."; 2085 else 2086 os << "Reference count incremented."; 2087 2088 if (unsigned Count = CurrV.getCount()) 2089 os << " The object now has a +" << Count << " retain count."; 2090 2091 if (PrevV.getKind() == RefVal::Released) { 2092 assert(GCEnabled && CurrV.getCount() > 0); 2093 os << " The object is not eligible for garbage collection until " 2094 "the retain count reaches 0 again."; 2095 } 2096 2097 break; 2098 2099 case RefVal::Released: 2100 os << "Object released."; 2101 break; 2102 2103 case RefVal::ReturnedOwned: 2104 // Autoreleases can be applied after marking a node ReturnedOwned. 2105 if (CurrV.getAutoreleaseCount()) 2106 return NULL; 2107 2108 os << "Object returned to caller as an owning reference (single " 2109 "retain count transferred to caller)"; 2110 break; 2111 2112 case RefVal::ReturnedNotOwned: 2113 os << "Object returned to caller with a +0 retain count"; 2114 break; 2115 2116 default: 2117 return NULL; 2118 } 2119 2120 // Emit any remaining diagnostics for the argument effects (if any). 2121 for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), 2122 E=AEffects.end(); I != E; ++I) { 2123 2124 // A bunch of things have alternate behavior under GC. 2125 if (GCEnabled) 2126 switch (*I) { 2127 default: break; 2128 case Autorelease: 2129 os << "In GC mode an 'autorelease' has no effect."; 2130 continue; 2131 case IncRefMsg: 2132 os << "In GC mode the 'retain' message has no effect."; 2133 continue; 2134 case DecRefMsg: 2135 os << "In GC mode the 'release' message has no effect."; 2136 continue; 2137 } 2138 } 2139 } while (0); 2140 2141 if (os.str().empty()) 2142 return 0; // We have nothing to say! 2143 2144 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2145 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2146 N->getLocationContext()); 2147 PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str()); 2148 2149 // Add the range by scanning the children of the statement for any bindings 2150 // to Sym. 2151 for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); 2152 I!=E; ++I) 2153 if (const Expr *Exp = dyn_cast_or_null<Expr>(*I)) 2154 if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { 2155 P->addRange(Exp->getSourceRange()); 2156 break; 2157 } 2158 2159 return P; 2160} 2161 2162// Find the first node in the current function context that referred to the 2163// tracked symbol and the memory location that value was stored to. Note, the 2164// value is only reported if the allocation occurred in the same function as 2165// the leak. 2166static std::pair<const ExplodedNode*,const MemRegion*> 2167GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, 2168 SymbolRef Sym) { 2169 const ExplodedNode *Last = N; 2170 const MemRegion* FirstBinding = 0; 2171 const LocationContext *LeakContext = N->getLocationContext(); 2172 2173 while (N) { 2174 ProgramStateRef St = N->getState(); 2175 2176 if (!getRefBinding(St, Sym)) 2177 break; 2178 2179 StoreManager::FindUniqueBinding FB(Sym); 2180 StateMgr.iterBindings(St, FB); 2181 if (FB) FirstBinding = FB.getRegion(); 2182 2183 // Allocation node, is the last node in the current context in which the 2184 // symbol was tracked. 2185 if (N->getLocationContext() == LeakContext) 2186 Last = N; 2187 2188 N = N->pred_empty() ? NULL : *(N->pred_begin()); 2189 } 2190 2191 // If allocation happened in a function different from the leak node context, 2192 // do not report the binding. 2193 assert(N && "Could not find allocation node"); 2194 if (N->getLocationContext() != LeakContext) { 2195 FirstBinding = 0; 2196 } 2197 2198 return std::make_pair(Last, FirstBinding); 2199} 2200 2201PathDiagnosticPiece* 2202CFRefReportVisitor::getEndPath(BugReporterContext &BRC, 2203 const ExplodedNode *EndN, 2204 BugReport &BR) { 2205 BR.markInteresting(Sym); 2206 return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); 2207} 2208 2209PathDiagnosticPiece* 2210CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, 2211 const ExplodedNode *EndN, 2212 BugReport &BR) { 2213 2214 // Tell the BugReporterContext to report cases when the tracked symbol is 2215 // assigned to different variables, etc. 2216 BR.markInteresting(Sym); 2217 2218 // We are reporting a leak. Walk up the graph to get to the first node where 2219 // the symbol appeared, and also get the first VarDecl that tracked object 2220 // is stored to. 2221 const ExplodedNode *AllocNode = 0; 2222 const MemRegion* FirstBinding = 0; 2223 2224 llvm::tie(AllocNode, FirstBinding) = 2225 GetAllocationSite(BRC.getStateManager(), EndN, Sym); 2226 2227 SourceManager& SM = BRC.getSourceManager(); 2228 2229 // Compute an actual location for the leak. Sometimes a leak doesn't 2230 // occur at an actual statement (e.g., transition between blocks; end 2231 // of function) so we need to walk the graph and compute a real location. 2232 const ExplodedNode *LeakN = EndN; 2233 PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); 2234 2235 std::string sbuf; 2236 llvm::raw_string_ostream os(sbuf); 2237 2238 os << "Object leaked: "; 2239 2240 if (FirstBinding) { 2241 os << "object allocated and stored into '" 2242 << FirstBinding->getString() << '\''; 2243 } 2244 else 2245 os << "allocated object"; 2246 2247 // Get the retain count. 2248 const RefVal* RV = getRefBinding(EndN->getState(), Sym); 2249 assert(RV); 2250 2251 if (RV->getKind() == RefVal::ErrorLeakReturned) { 2252 // FIXME: Per comments in rdar://6320065, "create" only applies to CF 2253 // objects. Only "copy", "alloc", "retain" and "new" transfer ownership 2254 // to the caller for NS objects. 2255 const Decl *D = &EndN->getCodeDecl(); 2256 2257 os << (isa<ObjCMethodDecl>(D) ? " is returned from a method " 2258 : " is returned from a function "); 2259 2260 if (D->getAttr<CFReturnsNotRetainedAttr>()) 2261 os << "that is annotated as CF_RETURNS_NOT_RETAINED"; 2262 else if (D->getAttr<NSReturnsNotRetainedAttr>()) 2263 os << "that is annotated as NS_RETURNS_NOT_RETAINED"; 2264 else { 2265 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 2266 os << "whose name ('" << MD->getSelector().getAsString() 2267 << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'." 2268 " This violates the naming convention rules" 2269 " given in the Memory Management Guide for Cocoa"; 2270 } 2271 else { 2272 const FunctionDecl *FD = cast<FunctionDecl>(D); 2273 os << "whose name ('" << *FD 2274 << "') does not contain 'Copy' or 'Create'. This violates the naming" 2275 " convention rules given in the Memory Management Guide for Core" 2276 " Foundation"; 2277 } 2278 } 2279 } 2280 else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { 2281 ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); 2282 os << " and returned from method '" << MD.getSelector().getAsString() 2283 << "' is potentially leaked when using garbage collection. Callers " 2284 "of this method do not expect a returned object with a +1 retain " 2285 "count since they expect the object to be managed by the garbage " 2286 "collector"; 2287 } 2288 else 2289 os << " is not referenced later in this execution path and has a retain " 2290 "count of +" << RV->getCount(); 2291 2292 return new PathDiagnosticEventPiece(L, os.str()); 2293} 2294 2295CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, 2296 bool GCEnabled, const SummaryLogTy &Log, 2297 ExplodedNode *n, SymbolRef sym, 2298 CheckerContext &Ctx) 2299: CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { 2300 2301 // Most bug reports are cached at the location where they occurred. 2302 // With leaks, we want to unique them by the location where they were 2303 // allocated, and only report a single path. To do this, we need to find 2304 // the allocation site of a piece of tracked memory, which we do via a 2305 // call to GetAllocationSite. This will walk the ExplodedGraph backwards. 2306 // Note that this is *not* the trimmed graph; we are guaranteed, however, 2307 // that all ancestor nodes that represent the allocation site have the 2308 // same SourceLocation. 2309 const ExplodedNode *AllocNode = 0; 2310 2311 const SourceManager& SMgr = Ctx.getSourceManager(); 2312 2313 llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding. 2314 GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); 2315 2316 // Get the SourceLocation for the allocation site. 2317 // FIXME: This will crash the analyzer if an allocation comes from an 2318 // implicit call. (Currently there are no such allocations in Cocoa, though.) 2319 const Stmt *AllocStmt; 2320 ProgramPoint P = AllocNode->getLocation(); 2321 if (CallExitEnd *Exit = dyn_cast<CallExitEnd>(&P)) 2322 AllocStmt = Exit->getCalleeContext()->getCallSite(); 2323 else 2324 AllocStmt = cast<PostStmt>(P).getStmt(); 2325 assert(AllocStmt && "All allocations must come from explicit calls"); 2326 Location = PathDiagnosticLocation::createBegin(AllocStmt, SMgr, 2327 n->getLocationContext()); 2328 // Fill in the description of the bug. 2329 Description.clear(); 2330 llvm::raw_string_ostream os(Description); 2331 os << "Potential leak "; 2332 if (GCEnabled) 2333 os << "(when using garbage collection) "; 2334 os << "of an object"; 2335 2336 // FIXME: AllocBinding doesn't get populated for RegionStore yet. 2337 if (AllocBinding) 2338 os << " stored into '" << AllocBinding->getString() << '\''; 2339 2340 addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log)); 2341} 2342 2343//===----------------------------------------------------------------------===// 2344// Main checker logic. 2345//===----------------------------------------------------------------------===// 2346 2347namespace { 2348class RetainCountChecker 2349 : public Checker< check::Bind, 2350 check::DeadSymbols, 2351 check::EndAnalysis, 2352 check::EndPath, 2353 check::PostStmt<BlockExpr>, 2354 check::PostStmt<CastExpr>, 2355 check::PostStmt<ObjCArrayLiteral>, 2356 check::PostStmt<ObjCDictionaryLiteral>, 2357 check::PostStmt<ObjCBoxedExpr>, 2358 check::PostCall, 2359 check::PreStmt<ReturnStmt>, 2360 check::RegionChanges, 2361 eval::Assume, 2362 eval::Call > { 2363 mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned; 2364 mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned; 2365 mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned; 2366 mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn; 2367 mutable OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; 2368 2369 typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap; 2370 2371 // This map is only used to ensure proper deletion of any allocated tags. 2372 mutable SymbolTagMap DeadSymbolTags; 2373 2374 mutable OwningPtr<RetainSummaryManager> Summaries; 2375 mutable OwningPtr<RetainSummaryManager> SummariesGC; 2376 mutable SummaryLogTy SummaryLog; 2377 mutable bool ShouldResetSummaryLog; 2378 2379public: 2380 RetainCountChecker() : ShouldResetSummaryLog(false) {} 2381 2382 virtual ~RetainCountChecker() { 2383 DeleteContainerSeconds(DeadSymbolTags); 2384 } 2385 2386 void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, 2387 ExprEngine &Eng) const { 2388 // FIXME: This is a hack to make sure the summary log gets cleared between 2389 // analyses of different code bodies. 2390 // 2391 // Why is this necessary? Because a checker's lifetime is tied to a 2392 // translation unit, but an ExplodedGraph's lifetime is just a code body. 2393 // Once in a blue moon, a new ExplodedNode will have the same address as an 2394 // old one with an associated summary, and the bug report visitor gets very 2395 // confused. (To make things worse, the summary lifetime is currently also 2396 // tied to a code body, so we get a crash instead of incorrect results.) 2397 // 2398 // Why is this a bad solution? Because if the lifetime of the ExplodedGraph 2399 // changes, things will start going wrong again. Really the lifetime of this 2400 // log needs to be tied to either the specific nodes in it or the entire 2401 // ExplodedGraph, not to a specific part of the code being analyzed. 2402 // 2403 // (Also, having stateful local data means that the same checker can't be 2404 // used from multiple threads, but a lot of checkers have incorrect 2405 // assumptions about that anyway. So that wasn't a priority at the time of 2406 // this fix.) 2407 // 2408 // This happens at the end of analysis, but bug reports are emitted /after/ 2409 // this point. So we can't just clear the summary log now. Instead, we mark 2410 // that the next time we access the summary log, it should be cleared. 2411 2412 // If we never reset the summary log during /this/ code body analysis, 2413 // there were no new summaries. There might still have been summaries from 2414 // the /last/ analysis, so clear them out to make sure the bug report 2415 // visitors don't get confused. 2416 if (ShouldResetSummaryLog) 2417 SummaryLog.clear(); 2418 2419 ShouldResetSummaryLog = !SummaryLog.empty(); 2420 } 2421 2422 CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, 2423 bool GCEnabled) const { 2424 if (GCEnabled) { 2425 if (!leakWithinFunctionGC) 2426 leakWithinFunctionGC.reset(new Leak("Leak of object when using " 2427 "garbage collection")); 2428 return leakWithinFunctionGC.get(); 2429 } else { 2430 if (!leakWithinFunction) { 2431 if (LOpts.getGC() == LangOptions::HybridGC) { 2432 leakWithinFunction.reset(new Leak("Leak of object when not using " 2433 "garbage collection (GC) in " 2434 "dual GC/non-GC code")); 2435 } else { 2436 leakWithinFunction.reset(new Leak("Leak")); 2437 } 2438 } 2439 return leakWithinFunction.get(); 2440 } 2441 } 2442 2443 CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { 2444 if (GCEnabled) { 2445 if (!leakAtReturnGC) 2446 leakAtReturnGC.reset(new Leak("Leak of returned object when using " 2447 "garbage collection")); 2448 return leakAtReturnGC.get(); 2449 } else { 2450 if (!leakAtReturn) { 2451 if (LOpts.getGC() == LangOptions::HybridGC) { 2452 leakAtReturn.reset(new Leak("Leak of returned object when not using " 2453 "garbage collection (GC) in dual " 2454 "GC/non-GC code")); 2455 } else { 2456 leakAtReturn.reset(new Leak("Leak of returned object")); 2457 } 2458 } 2459 return leakAtReturn.get(); 2460 } 2461 } 2462 2463 RetainSummaryManager &getSummaryManager(ASTContext &Ctx, 2464 bool GCEnabled) const { 2465 // FIXME: We don't support ARC being turned on and off during one analysis. 2466 // (nor, for that matter, do we support changing ASTContexts) 2467 bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; 2468 if (GCEnabled) { 2469 if (!SummariesGC) 2470 SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); 2471 else 2472 assert(SummariesGC->isARCEnabled() == ARCEnabled); 2473 return *SummariesGC; 2474 } else { 2475 if (!Summaries) 2476 Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); 2477 else 2478 assert(Summaries->isARCEnabled() == ARCEnabled); 2479 return *Summaries; 2480 } 2481 } 2482 2483 RetainSummaryManager &getSummaryManager(CheckerContext &C) const { 2484 return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); 2485 } 2486 2487 void printState(raw_ostream &Out, ProgramStateRef State, 2488 const char *NL, const char *Sep) const; 2489 2490 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; 2491 void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; 2492 void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; 2493 2494 void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; 2495 void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; 2496 void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; 2497 2498 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 2499 2500 void checkSummary(const RetainSummary &Summ, const CallEvent &Call, 2501 CheckerContext &C) const; 2502 2503 void processSummaryOfInlined(const RetainSummary &Summ, 2504 const CallEvent &Call, 2505 CheckerContext &C) const; 2506 2507 bool evalCall(const CallExpr *CE, CheckerContext &C) const; 2508 2509 ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, 2510 bool Assumption) const; 2511 2512 ProgramStateRef 2513 checkRegionChanges(ProgramStateRef state, 2514 const StoreManager::InvalidatedSymbols *invalidated, 2515 ArrayRef<const MemRegion *> ExplicitRegions, 2516 ArrayRef<const MemRegion *> Regions, 2517 const CallEvent *Call) const; 2518 2519 bool wantsRegionChangeUpdate(ProgramStateRef state) const { 2520 return true; 2521 } 2522 2523 void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; 2524 void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, 2525 ExplodedNode *Pred, RetEffect RE, RefVal X, 2526 SymbolRef Sym, ProgramStateRef state) const; 2527 2528 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 2529 void checkEndPath(CheckerContext &C) const; 2530 2531 ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, 2532 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2533 CheckerContext &C) const; 2534 2535 void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, 2536 RefVal::Kind ErrorKind, SymbolRef Sym, 2537 CheckerContext &C) const; 2538 2539 void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; 2540 2541 const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; 2542 2543 ProgramStateRef handleSymbolDeath(ProgramStateRef state, 2544 SymbolRef sid, RefVal V, 2545 SmallVectorImpl<SymbolRef> &Leaked) const; 2546 2547 std::pair<ExplodedNode *, ProgramStateRef > 2548 handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred, 2549 const ProgramPointTag *Tag, CheckerContext &Ctx, 2550 SymbolRef Sym, RefVal V) const; 2551 2552 ExplodedNode *processLeaks(ProgramStateRef state, 2553 SmallVectorImpl<SymbolRef> &Leaked, 2554 CheckerContext &Ctx, 2555 ExplodedNode *Pred = 0) const; 2556}; 2557} // end anonymous namespace 2558 2559namespace { 2560class StopTrackingCallback : public SymbolVisitor { 2561 ProgramStateRef state; 2562public: 2563 StopTrackingCallback(ProgramStateRef st) : state(st) {} 2564 ProgramStateRef getState() const { return state; } 2565 2566 bool VisitSymbol(SymbolRef sym) { 2567 state = state->remove<RefBindings>(sym); 2568 return true; 2569 } 2570}; 2571} // end anonymous namespace 2572 2573//===----------------------------------------------------------------------===// 2574// Handle statements that may have an effect on refcounts. 2575//===----------------------------------------------------------------------===// 2576 2577void RetainCountChecker::checkPostStmt(const BlockExpr *BE, 2578 CheckerContext &C) const { 2579 2580 // Scan the BlockDecRefExprs for any object the retain count checker 2581 // may be tracking. 2582 if (!BE->getBlockDecl()->hasCaptures()) 2583 return; 2584 2585 ProgramStateRef state = C.getState(); 2586 const BlockDataRegion *R = 2587 cast<BlockDataRegion>(state->getSVal(BE, 2588 C.getLocationContext()).getAsRegion()); 2589 2590 BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), 2591 E = R->referenced_vars_end(); 2592 2593 if (I == E) 2594 return; 2595 2596 // FIXME: For now we invalidate the tracking of all symbols passed to blocks 2597 // via captured variables, even though captured variables result in a copy 2598 // and in implicit increment/decrement of a retain count. 2599 SmallVector<const MemRegion*, 10> Regions; 2600 const LocationContext *LC = C.getLocationContext(); 2601 MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); 2602 2603 for ( ; I != E; ++I) { 2604 const VarRegion *VR = *I; 2605 if (VR->getSuperRegion() == R) { 2606 VR = MemMgr.getVarRegion(VR->getDecl(), LC); 2607 } 2608 Regions.push_back(VR); 2609 } 2610 2611 state = 2612 state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), 2613 Regions.data() + Regions.size()).getState(); 2614 C.addTransition(state); 2615} 2616 2617void RetainCountChecker::checkPostStmt(const CastExpr *CE, 2618 CheckerContext &C) const { 2619 const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); 2620 if (!BE) 2621 return; 2622 2623 ArgEffect AE = IncRef; 2624 2625 switch (BE->getBridgeKind()) { 2626 case clang::OBC_Bridge: 2627 // Do nothing. 2628 return; 2629 case clang::OBC_BridgeRetained: 2630 AE = IncRef; 2631 break; 2632 case clang::OBC_BridgeTransfer: 2633 AE = DecRefBridgedTransfered; 2634 break; 2635 } 2636 2637 ProgramStateRef state = C.getState(); 2638 SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol(); 2639 if (!Sym) 2640 return; 2641 const RefVal* T = getRefBinding(state, Sym); 2642 if (!T) 2643 return; 2644 2645 RefVal::Kind hasErr = (RefVal::Kind) 0; 2646 state = updateSymbol(state, Sym, *T, AE, hasErr, C); 2647 2648 if (hasErr) { 2649 // FIXME: If we get an error during a bridge cast, should we report it? 2650 // Should we assert that there is no error? 2651 return; 2652 } 2653 2654 C.addTransition(state); 2655} 2656 2657void RetainCountChecker::processObjCLiterals(CheckerContext &C, 2658 const Expr *Ex) const { 2659 ProgramStateRef state = C.getState(); 2660 const ExplodedNode *pred = C.getPredecessor(); 2661 for (Stmt::const_child_iterator it = Ex->child_begin(), et = Ex->child_end() ; 2662 it != et ; ++it) { 2663 const Stmt *child = *it; 2664 SVal V = state->getSVal(child, pred->getLocationContext()); 2665 if (SymbolRef sym = V.getAsSymbol()) 2666 if (const RefVal* T = getRefBinding(state, sym)) { 2667 RefVal::Kind hasErr = (RefVal::Kind) 0; 2668 state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); 2669 if (hasErr) { 2670 processNonLeakError(state, child->getSourceRange(), hasErr, sym, C); 2671 return; 2672 } 2673 } 2674 } 2675 2676 // Return the object as autoreleased. 2677 // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); 2678 if (SymbolRef sym = 2679 state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { 2680 QualType ResultTy = Ex->getType(); 2681 state = setRefBinding(state, sym, 2682 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2683 } 2684 2685 C.addTransition(state); 2686} 2687 2688void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, 2689 CheckerContext &C) const { 2690 // Apply the 'MayEscape' to all values. 2691 processObjCLiterals(C, AL); 2692} 2693 2694void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 2695 CheckerContext &C) const { 2696 // Apply the 'MayEscape' to all keys and values. 2697 processObjCLiterals(C, DL); 2698} 2699 2700void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, 2701 CheckerContext &C) const { 2702 const ExplodedNode *Pred = C.getPredecessor(); 2703 const LocationContext *LCtx = Pred->getLocationContext(); 2704 ProgramStateRef State = Pred->getState(); 2705 2706 if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) { 2707 QualType ResultTy = Ex->getType(); 2708 State = setRefBinding(State, Sym, 2709 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2710 } 2711 2712 C.addTransition(State); 2713} 2714 2715void RetainCountChecker::checkPostCall(const CallEvent &Call, 2716 CheckerContext &C) const { 2717 RetainSummaryManager &Summaries = getSummaryManager(C); 2718 const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); 2719 2720 if (C.wasInlined) { 2721 processSummaryOfInlined(*Summ, Call, C); 2722 return; 2723 } 2724 checkSummary(*Summ, Call, C); 2725} 2726 2727/// GetReturnType - Used to get the return type of a message expression or 2728/// function call with the intention of affixing that type to a tracked symbol. 2729/// While the return type can be queried directly from RetEx, when 2730/// invoking class methods we augment to the return type to be that of 2731/// a pointer to the class (as opposed it just being id). 2732// FIXME: We may be able to do this with related result types instead. 2733// This function is probably overestimating. 2734static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { 2735 QualType RetTy = RetE->getType(); 2736 // If RetE is not a message expression just return its type. 2737 // If RetE is a message expression, return its types if it is something 2738 /// more specific than id. 2739 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) 2740 if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) 2741 if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || 2742 PT->isObjCClassType()) { 2743 // At this point we know the return type of the message expression is 2744 // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this 2745 // is a call to a class method whose type we can resolve. In such 2746 // cases, promote the return type to XXX* (where XXX is the class). 2747 const ObjCInterfaceDecl *D = ME->getReceiverInterface(); 2748 return !D ? RetTy : 2749 Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); 2750 } 2751 2752 return RetTy; 2753} 2754 2755// We don't always get the exact modeling of the function with regards to the 2756// retain count checker even when the function is inlined. For example, we need 2757// to stop tracking the symbols which were marked with StopTrackingHard. 2758void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ, 2759 const CallEvent &CallOrMsg, 2760 CheckerContext &C) const { 2761 ProgramStateRef state = C.getState(); 2762 2763 // Evaluate the effect of the arguments. 2764 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2765 if (Summ.getArg(idx) == StopTrackingHard) { 2766 SVal V = CallOrMsg.getArgSVal(idx); 2767 if (SymbolRef Sym = V.getAsLocSymbol()) { 2768 state = removeRefBinding(state, Sym); 2769 } 2770 } 2771 } 2772 2773 // Evaluate the effect on the message receiver. 2774 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2775 if (MsgInvocation) { 2776 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2777 if (Summ.getReceiverEffect() == StopTrackingHard) { 2778 state = removeRefBinding(state, Sym); 2779 } 2780 } 2781 } 2782 2783 // Consult the summary for the return value. 2784 RetEffect RE = Summ.getRetEffect(); 2785 if (RE.getKind() == RetEffect::NoRetHard) { 2786 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2787 C.getLocationContext()).getAsSymbol(); 2788 if (Sym) 2789 state = removeRefBinding(state, Sym); 2790 } 2791 2792 C.addTransition(state); 2793} 2794 2795void RetainCountChecker::checkSummary(const RetainSummary &Summ, 2796 const CallEvent &CallOrMsg, 2797 CheckerContext &C) const { 2798 ProgramStateRef state = C.getState(); 2799 2800 // Evaluate the effect of the arguments. 2801 RefVal::Kind hasErr = (RefVal::Kind) 0; 2802 SourceRange ErrorRange; 2803 SymbolRef ErrorSym = 0; 2804 2805 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2806 SVal V = CallOrMsg.getArgSVal(idx); 2807 2808 if (SymbolRef Sym = V.getAsLocSymbol()) { 2809 if (const RefVal *T = getRefBinding(state, Sym)) { 2810 state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C); 2811 if (hasErr) { 2812 ErrorRange = CallOrMsg.getArgSourceRange(idx); 2813 ErrorSym = Sym; 2814 break; 2815 } 2816 } 2817 } 2818 } 2819 2820 // Evaluate the effect on the message receiver. 2821 bool ReceiverIsTracked = false; 2822 if (!hasErr) { 2823 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2824 if (MsgInvocation) { 2825 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2826 if (const RefVal *T = getRefBinding(state, Sym)) { 2827 ReceiverIsTracked = true; 2828 state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), 2829 hasErr, C); 2830 if (hasErr) { 2831 ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange(); 2832 ErrorSym = Sym; 2833 } 2834 } 2835 } 2836 } 2837 } 2838 2839 // Process any errors. 2840 if (hasErr) { 2841 processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); 2842 return; 2843 } 2844 2845 // Consult the summary for the return value. 2846 RetEffect RE = Summ.getRetEffect(); 2847 2848 if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { 2849 if (ReceiverIsTracked) 2850 RE = getSummaryManager(C).getObjAllocRetEffect(); 2851 else 2852 RE = RetEffect::MakeNoRet(); 2853 } 2854 2855 switch (RE.getKind()) { 2856 default: 2857 llvm_unreachable("Unhandled RetEffect."); 2858 2859 case RetEffect::NoRet: 2860 case RetEffect::NoRetHard: 2861 // No work necessary. 2862 break; 2863 2864 case RetEffect::OwnedAllocatedSymbol: 2865 case RetEffect::OwnedSymbol: { 2866 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2867 C.getLocationContext()).getAsSymbol(); 2868 if (!Sym) 2869 break; 2870 2871 // Use the result type from the CallEvent as it automatically adjusts 2872 // for methods/functions that return references. 2873 QualType ResultTy = CallOrMsg.getResultType(); 2874 state = setRefBinding(state, Sym, RefVal::makeOwned(RE.getObjKind(), 2875 ResultTy)); 2876 2877 // FIXME: Add a flag to the checker where allocations are assumed to 2878 // *not* fail. 2879 break; 2880 } 2881 2882 case RetEffect::GCNotOwnedSymbol: 2883 case RetEffect::ARCNotOwnedSymbol: 2884 case RetEffect::NotOwnedSymbol: { 2885 const Expr *Ex = CallOrMsg.getOriginExpr(); 2886 SymbolRef Sym = state->getSVal(Ex, C.getLocationContext()).getAsSymbol(); 2887 if (!Sym) 2888 break; 2889 assert(Ex); 2890 // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. 2891 QualType ResultTy = GetReturnType(Ex, C.getASTContext()); 2892 state = setRefBinding(state, Sym, RefVal::makeNotOwned(RE.getObjKind(), 2893 ResultTy)); 2894 break; 2895 } 2896 } 2897 2898 // This check is actually necessary; otherwise the statement builder thinks 2899 // we've hit a previously-found path. 2900 // Normally addTransition takes care of this, but we want the node pointer. 2901 ExplodedNode *NewNode; 2902 if (state == C.getState()) { 2903 NewNode = C.getPredecessor(); 2904 } else { 2905 NewNode = C.addTransition(state); 2906 } 2907 2908 // Annotate the node with summary we used. 2909 if (NewNode) { 2910 // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. 2911 if (ShouldResetSummaryLog) { 2912 SummaryLog.clear(); 2913 ShouldResetSummaryLog = false; 2914 } 2915 SummaryLog[NewNode] = &Summ; 2916 } 2917} 2918 2919 2920ProgramStateRef 2921RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, 2922 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2923 CheckerContext &C) const { 2924 // In GC mode [... release] and [... retain] do nothing. 2925 // In ARC mode they shouldn't exist at all, but we just ignore them. 2926 bool IgnoreRetainMsg = C.isObjCGCEnabled(); 2927 if (!IgnoreRetainMsg) 2928 IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; 2929 2930 switch (E) { 2931 default: 2932 break; 2933 case IncRefMsg: 2934 E = IgnoreRetainMsg ? DoNothing : IncRef; 2935 break; 2936 case DecRefMsg: 2937 E = IgnoreRetainMsg ? DoNothing : DecRef; 2938 break; 2939 case DecRefMsgAndStopTrackingHard: 2940 E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTrackingHard; 2941 break; 2942 case MakeCollectable: 2943 E = C.isObjCGCEnabled() ? DecRef : DoNothing; 2944 break; 2945 case NewAutoreleasePool: 2946 E = C.isObjCGCEnabled() ? DoNothing : NewAutoreleasePool; 2947 break; 2948 } 2949 2950 // Handle all use-after-releases. 2951 if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { 2952 V = V ^ RefVal::ErrorUseAfterRelease; 2953 hasErr = V.getKind(); 2954 return setRefBinding(state, sym, V); 2955 } 2956 2957 switch (E) { 2958 case DecRefMsg: 2959 case IncRefMsg: 2960 case MakeCollectable: 2961 case DecRefMsgAndStopTrackingHard: 2962 llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); 2963 2964 case Dealloc: 2965 // Any use of -dealloc in GC is *bad*. 2966 if (C.isObjCGCEnabled()) { 2967 V = V ^ RefVal::ErrorDeallocGC; 2968 hasErr = V.getKind(); 2969 break; 2970 } 2971 2972 switch (V.getKind()) { 2973 default: 2974 llvm_unreachable("Invalid RefVal state for an explicit dealloc."); 2975 case RefVal::Owned: 2976 // The object immediately transitions to the released state. 2977 V = V ^ RefVal::Released; 2978 V.clearCounts(); 2979 return setRefBinding(state, sym, V); 2980 case RefVal::NotOwned: 2981 V = V ^ RefVal::ErrorDeallocNotOwned; 2982 hasErr = V.getKind(); 2983 break; 2984 } 2985 break; 2986 2987 case NewAutoreleasePool: 2988 assert(!C.isObjCGCEnabled()); 2989 return state; 2990 2991 case MayEscape: 2992 if (V.getKind() == RefVal::Owned) { 2993 V = V ^ RefVal::NotOwned; 2994 break; 2995 } 2996 2997 // Fall-through. 2998 2999 case DoNothing: 3000 return state; 3001 3002 case Autorelease: 3003 if (C.isObjCGCEnabled()) 3004 return state; 3005 // Update the autorelease counts. 3006 V = V.autorelease(); 3007 break; 3008 3009 case StopTracking: 3010 case StopTrackingHard: 3011 return removeRefBinding(state, sym); 3012 3013 case IncRef: 3014 switch (V.getKind()) { 3015 default: 3016 llvm_unreachable("Invalid RefVal state for a retain."); 3017 case RefVal::Owned: 3018 case RefVal::NotOwned: 3019 V = V + 1; 3020 break; 3021 case RefVal::Released: 3022 // Non-GC cases are handled above. 3023 assert(C.isObjCGCEnabled()); 3024 V = (V ^ RefVal::Owned) + 1; 3025 break; 3026 } 3027 break; 3028 3029 case DecRef: 3030 case DecRefBridgedTransfered: 3031 case DecRefAndStopTrackingHard: 3032 switch (V.getKind()) { 3033 default: 3034 // case 'RefVal::Released' handled above. 3035 llvm_unreachable("Invalid RefVal state for a release."); 3036 3037 case RefVal::Owned: 3038 assert(V.getCount() > 0); 3039 if (V.getCount() == 1) 3040 V = V ^ (E == DecRefBridgedTransfered ? 3041 RefVal::NotOwned : RefVal::Released); 3042 else if (E == DecRefAndStopTrackingHard) 3043 return removeRefBinding(state, sym); 3044 3045 V = V - 1; 3046 break; 3047 3048 case RefVal::NotOwned: 3049 if (V.getCount() > 0) { 3050 if (E == DecRefAndStopTrackingHard) 3051 return removeRefBinding(state, sym); 3052 V = V - 1; 3053 } else { 3054 V = V ^ RefVal::ErrorReleaseNotOwned; 3055 hasErr = V.getKind(); 3056 } 3057 break; 3058 3059 case RefVal::Released: 3060 // Non-GC cases are handled above. 3061 assert(C.isObjCGCEnabled()); 3062 V = V ^ RefVal::ErrorUseAfterRelease; 3063 hasErr = V.getKind(); 3064 break; 3065 } 3066 break; 3067 } 3068 return setRefBinding(state, sym, V); 3069} 3070 3071void RetainCountChecker::processNonLeakError(ProgramStateRef St, 3072 SourceRange ErrorRange, 3073 RefVal::Kind ErrorKind, 3074 SymbolRef Sym, 3075 CheckerContext &C) const { 3076 ExplodedNode *N = C.generateSink(St); 3077 if (!N) 3078 return; 3079 3080 CFRefBug *BT; 3081 switch (ErrorKind) { 3082 default: 3083 llvm_unreachable("Unhandled error."); 3084 case RefVal::ErrorUseAfterRelease: 3085 if (!useAfterRelease) 3086 useAfterRelease.reset(new UseAfterRelease()); 3087 BT = &*useAfterRelease; 3088 break; 3089 case RefVal::ErrorReleaseNotOwned: 3090 if (!releaseNotOwned) 3091 releaseNotOwned.reset(new BadRelease()); 3092 BT = &*releaseNotOwned; 3093 break; 3094 case RefVal::ErrorDeallocGC: 3095 if (!deallocGC) 3096 deallocGC.reset(new DeallocGC()); 3097 BT = &*deallocGC; 3098 break; 3099 case RefVal::ErrorDeallocNotOwned: 3100 if (!deallocNotOwned) 3101 deallocNotOwned.reset(new DeallocNotOwned()); 3102 BT = &*deallocNotOwned; 3103 break; 3104 } 3105 3106 assert(BT); 3107 CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOpts(), 3108 C.isObjCGCEnabled(), SummaryLog, 3109 N, Sym); 3110 report->addRange(ErrorRange); 3111 C.emitReport(report); 3112} 3113 3114//===----------------------------------------------------------------------===// 3115// Handle the return values of retain-count-related functions. 3116//===----------------------------------------------------------------------===// 3117 3118bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { 3119 // Get the callee. We're only interested in simple C functions. 3120 ProgramStateRef state = C.getState(); 3121 const FunctionDecl *FD = C.getCalleeDecl(CE); 3122 if (!FD) 3123 return false; 3124 3125 IdentifierInfo *II = FD->getIdentifier(); 3126 if (!II) 3127 return false; 3128 3129 // For now, we're only handling the functions that return aliases of their 3130 // arguments: CFRetain and CFMakeCollectable (and their families). 3131 // Eventually we should add other functions we can model entirely, 3132 // such as CFRelease, which don't invalidate their arguments or globals. 3133 if (CE->getNumArgs() != 1) 3134 return false; 3135 3136 // Get the name of the function. 3137 StringRef FName = II->getName(); 3138 FName = FName.substr(FName.find_first_not_of('_')); 3139 3140 // See if it's one of the specific functions we know how to eval. 3141 bool canEval = false; 3142 3143 QualType ResultTy = CE->getCallReturnType(); 3144 if (ResultTy->isObjCIdType()) { 3145 // Handle: id NSMakeCollectable(CFTypeRef) 3146 canEval = II->isStr("NSMakeCollectable"); 3147 } else if (ResultTy->isPointerType()) { 3148 // Handle: (CF|CG)Retain 3149 // CFMakeCollectable 3150 // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). 3151 if (cocoa::isRefType(ResultTy, "CF", FName) || 3152 cocoa::isRefType(ResultTy, "CG", FName)) { 3153 canEval = isRetain(FD, FName) || isMakeCollectable(FD, FName); 3154 } 3155 } 3156 3157 if (!canEval) 3158 return false; 3159 3160 // Bind the return value. 3161 const LocationContext *LCtx = C.getLocationContext(); 3162 SVal RetVal = state->getSVal(CE->getArg(0), LCtx); 3163 if (RetVal.isUnknown()) { 3164 // If the receiver is unknown, conjure a return value. 3165 SValBuilder &SVB = C.getSValBuilder(); 3166 RetVal = SVB.conjureSymbolVal(0, CE, LCtx, ResultTy, C.blockCount()); 3167 } 3168 state = state->BindExpr(CE, LCtx, RetVal, false); 3169 3170 // FIXME: This should not be necessary, but otherwise the argument seems to be 3171 // considered alive during the next statement. 3172 if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { 3173 // Save the refcount status of the argument. 3174 SymbolRef Sym = RetVal.getAsLocSymbol(); 3175 const RefVal *Binding = 0; 3176 if (Sym) 3177 Binding = getRefBinding(state, Sym); 3178 3179 // Invalidate the argument region. 3180 state = state->invalidateRegions(ArgRegion, CE, C.blockCount(), LCtx); 3181 3182 // Restore the refcount status of the argument. 3183 if (Binding) 3184 state = setRefBinding(state, Sym, *Binding); 3185 } 3186 3187 C.addTransition(state); 3188 return true; 3189} 3190 3191//===----------------------------------------------------------------------===// 3192// Handle return statements. 3193//===----------------------------------------------------------------------===// 3194 3195// Return true if the current LocationContext has no caller context. 3196static bool inTopFrame(CheckerContext &C) { 3197 const LocationContext *LC = C.getLocationContext(); 3198 return LC->getParent() == 0; 3199} 3200 3201void RetainCountChecker::checkPreStmt(const ReturnStmt *S, 3202 CheckerContext &C) const { 3203 3204 // Only adjust the reference count if this is the top-level call frame, 3205 // and not the result of inlining. In the future, we should do 3206 // better checking even for inlined calls, and see if they match 3207 // with their expected semantics (e.g., the method should return a retained 3208 // object, etc.). 3209 if (!inTopFrame(C)) 3210 return; 3211 3212 const Expr *RetE = S->getRetValue(); 3213 if (!RetE) 3214 return; 3215 3216 ProgramStateRef state = C.getState(); 3217 SymbolRef Sym = 3218 state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); 3219 if (!Sym) 3220 return; 3221 3222 // Get the reference count binding (if any). 3223 const RefVal *T = getRefBinding(state, Sym); 3224 if (!T) 3225 return; 3226 3227 // Change the reference count. 3228 RefVal X = *T; 3229 3230 switch (X.getKind()) { 3231 case RefVal::Owned: { 3232 unsigned cnt = X.getCount(); 3233 assert(cnt > 0); 3234 X.setCount(cnt - 1); 3235 X = X ^ RefVal::ReturnedOwned; 3236 break; 3237 } 3238 3239 case RefVal::NotOwned: { 3240 unsigned cnt = X.getCount(); 3241 if (cnt) { 3242 X.setCount(cnt - 1); 3243 X = X ^ RefVal::ReturnedOwned; 3244 } 3245 else { 3246 X = X ^ RefVal::ReturnedNotOwned; 3247 } 3248 break; 3249 } 3250 3251 default: 3252 return; 3253 } 3254 3255 // Update the binding. 3256 state = setRefBinding(state, Sym, X); 3257 ExplodedNode *Pred = C.addTransition(state); 3258 3259 // At this point we have updated the state properly. 3260 // Everything after this is merely checking to see if the return value has 3261 // been over- or under-retained. 3262 3263 // Did we cache out? 3264 if (!Pred) 3265 return; 3266 3267 // Update the autorelease counts. 3268 static SimpleProgramPointTag 3269 AutoreleaseTag("RetainCountChecker : Autorelease"); 3270 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, 3271 C, Sym, X); 3272 3273 // Did we cache out? 3274 if (!Pred) 3275 return; 3276 3277 // Get the updated binding. 3278 T = getRefBinding(state, Sym); 3279 assert(T); 3280 X = *T; 3281 3282 // Consult the summary of the enclosing method. 3283 RetainSummaryManager &Summaries = getSummaryManager(C); 3284 const Decl *CD = &Pred->getCodeDecl(); 3285 RetEffect RE = RetEffect::MakeNoRet(); 3286 3287 // FIXME: What is the convention for blocks? Is there one? 3288 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) { 3289 const RetainSummary *Summ = Summaries.getMethodSummary(MD); 3290 RE = Summ->getRetEffect(); 3291 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) { 3292 if (!isa<CXXMethodDecl>(FD)) { 3293 const RetainSummary *Summ = Summaries.getFunctionSummary(FD); 3294 RE = Summ->getRetEffect(); 3295 } 3296 } 3297 3298 checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state); 3299} 3300 3301void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S, 3302 CheckerContext &C, 3303 ExplodedNode *Pred, 3304 RetEffect RE, RefVal X, 3305 SymbolRef Sym, 3306 ProgramStateRef state) const { 3307 // Any leaks or other errors? 3308 if (X.isReturnedOwned() && X.getCount() == 0) { 3309 if (RE.getKind() != RetEffect::NoRet) { 3310 bool hasError = false; 3311 if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) { 3312 // Things are more complicated with garbage collection. If the 3313 // returned object is suppose to be an Objective-C object, we have 3314 // a leak (as the caller expects a GC'ed object) because no 3315 // method should return ownership unless it returns a CF object. 3316 hasError = true; 3317 X = X ^ RefVal::ErrorGCLeakReturned; 3318 } 3319 else if (!RE.isOwned()) { 3320 // Either we are using GC and the returned object is a CF type 3321 // or we aren't using GC. In either case, we expect that the 3322 // enclosing method is expected to return ownership. 3323 hasError = true; 3324 X = X ^ RefVal::ErrorLeakReturned; 3325 } 3326 3327 if (hasError) { 3328 // Generate an error node. 3329 state = setRefBinding(state, Sym, X); 3330 3331 static SimpleProgramPointTag 3332 ReturnOwnLeakTag("RetainCountChecker : ReturnsOwnLeak"); 3333 ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag); 3334 if (N) { 3335 const LangOptions &LOpts = C.getASTContext().getLangOpts(); 3336 bool GCEnabled = C.isObjCGCEnabled(); 3337 CFRefReport *report = 3338 new CFRefLeakReport(*getLeakAtReturnBug(LOpts, GCEnabled), 3339 LOpts, GCEnabled, SummaryLog, 3340 N, Sym, C); 3341 C.emitReport(report); 3342 } 3343 } 3344 } 3345 } else if (X.isReturnedNotOwned()) { 3346 if (RE.isOwned()) { 3347 // Trying to return a not owned object to a caller expecting an 3348 // owned object. 3349 state = setRefBinding(state, Sym, X ^ RefVal::ErrorReturnedNotOwned); 3350 3351 static SimpleProgramPointTag 3352 ReturnNotOwnedTag("RetainCountChecker : ReturnNotOwnedForOwned"); 3353 ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag); 3354 if (N) { 3355 if (!returnNotOwnedForOwned) 3356 returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned()); 3357 3358 CFRefReport *report = 3359 new CFRefReport(*returnNotOwnedForOwned, 3360 C.getASTContext().getLangOpts(), 3361 C.isObjCGCEnabled(), SummaryLog, N, Sym); 3362 C.emitReport(report); 3363 } 3364 } 3365 } 3366} 3367 3368//===----------------------------------------------------------------------===// 3369// Check various ways a symbol can be invalidated. 3370//===----------------------------------------------------------------------===// 3371 3372void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S, 3373 CheckerContext &C) const { 3374 // Are we storing to something that causes the value to "escape"? 3375 bool escapes = true; 3376 3377 // A value escapes in three possible cases (this may change): 3378 // 3379 // (1) we are binding to something that is not a memory region. 3380 // (2) we are binding to a memregion that does not have stack storage 3381 // (3) we are binding to a memregion with stack storage that the store 3382 // does not understand. 3383 ProgramStateRef state = C.getState(); 3384 3385 if (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) { 3386 escapes = !regionLoc->getRegion()->hasStackStorage(); 3387 3388 if (!escapes) { 3389 // To test (3), generate a new state with the binding added. If it is 3390 // the same state, then it escapes (since the store cannot represent 3391 // the binding). 3392 // Do this only if we know that the store is not supposed to generate the 3393 // same state. 3394 SVal StoredVal = state->getSVal(regionLoc->getRegion()); 3395 if (StoredVal != val) 3396 escapes = (state == (state->bindLoc(*regionLoc, val))); 3397 } 3398 if (!escapes) { 3399 // Case 4: We do not currently model what happens when a symbol is 3400 // assigned to a struct field, so be conservative here and let the symbol 3401 // go. TODO: This could definitely be improved upon. 3402 escapes = !isa<VarRegion>(regionLoc->getRegion()); 3403 } 3404 } 3405 3406 // If our store can represent the binding and we aren't storing to something 3407 // that doesn't have local storage then just return and have the simulation 3408 // state continue as is. 3409 if (!escapes) 3410 return; 3411 3412 // Otherwise, find all symbols referenced by 'val' that we are tracking 3413 // and stop tracking them. 3414 state = state->scanReachableSymbols<StopTrackingCallback>(val).getState(); 3415 C.addTransition(state); 3416} 3417 3418ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state, 3419 SVal Cond, 3420 bool Assumption) const { 3421 3422 // FIXME: We may add to the interface of evalAssume the list of symbols 3423 // whose assumptions have changed. For now we just iterate through the 3424 // bindings and check if any of the tracked symbols are NULL. This isn't 3425 // too bad since the number of symbols we will track in practice are 3426 // probably small and evalAssume is only called at branches and a few 3427 // other places. 3428 RefBindingsTy B = state->get<RefBindings>(); 3429 3430 if (B.isEmpty()) 3431 return state; 3432 3433 bool changed = false; 3434 RefBindingsTy::Factory &RefBFactory = state->get_context<RefBindings>(); 3435 3436 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3437 // Check if the symbol is null stop tracking the symbol. 3438 ConstraintManager &CMgr = state->getConstraintManager(); 3439 ConditionTruthVal AllocFailed = CMgr.isNull(state, I.getKey()); 3440 if (AllocFailed.isConstrainedTrue()) { 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 RefBindingsTy B = state->get<RefBindings>(); 3598 ExplodedNode *Pred = Ctx.getPredecessor(); 3599 3600 for (RefBindingsTy::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 (RefBindingsTy::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 RefBindingsTy 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 RefBindingsTy::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 RefBindingsTy B = State->get<RefBindings>(); 3688 3689 if (!B.isEmpty()) 3690 Out << Sep << NL; 3691 3692 for (RefBindingsTy::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