RetainCountChecker.cpp revision 70cbf3cc09eb21db1108396d30a414ea66d842cc
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/Calls.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 43namespace { 44/// Wrapper around different kinds of node builder, so that helper functions 45/// can have a common interface. 46class GenericNodeBuilderRefCount { 47 CheckerContext *C; 48 const ProgramPointTag *tag; 49public: 50 GenericNodeBuilderRefCount(CheckerContext &c, 51 const ProgramPointTag *t = 0) 52 : C(&c), tag(t){} 53 54 ExplodedNode *MakeNode(ProgramStateRef state, ExplodedNode *Pred, 55 bool MarkAsSink = false) { 56 return C->addTransition(state, Pred, tag, MarkAsSink); 57 } 58}; 59} // end anonymous namespace 60 61//===----------------------------------------------------------------------===// 62// Primitives used for constructing summaries for function/method calls. 63//===----------------------------------------------------------------------===// 64 65/// ArgEffect is used to summarize a function/method call's effect on a 66/// particular argument. 67enum ArgEffect { DoNothing, Autorelease, Dealloc, DecRef, DecRefMsg, 68 DecRefBridgedTransfered, 69 DecRefAndStopTracking, DecRefMsgAndStopTracking, 70 IncRefMsg, IncRef, MakeCollectable, MayEscape, 71 NewAutoreleasePool, StopTracking }; 72 73namespace llvm { 74template <> struct FoldingSetTrait<ArgEffect> { 75static inline void Profile(const ArgEffect X, FoldingSetNodeID& ID) { 76 ID.AddInteger((unsigned) X); 77} 78}; 79} // end llvm namespace 80 81/// ArgEffects summarizes the effects of a function/method call on all of 82/// its arguments. 83typedef llvm::ImmutableMap<unsigned,ArgEffect> ArgEffects; 84 85namespace { 86 87/// RetEffect is used to summarize a function/method call's behavior with 88/// respect to its return value. 89class RetEffect { 90public: 91 enum Kind { NoRet, OwnedSymbol, OwnedAllocatedSymbol, 92 NotOwnedSymbol, GCNotOwnedSymbol, ARCNotOwnedSymbol, 93 OwnedWhenTrackedReceiver }; 94 95 enum ObjKind { CF, ObjC, AnyObj }; 96 97private: 98 Kind K; 99 ObjKind O; 100 101 RetEffect(Kind k, ObjKind o = AnyObj) : K(k), O(o) {} 102 103public: 104 Kind getKind() const { return K; } 105 106 ObjKind getObjKind() const { return O; } 107 108 bool isOwned() const { 109 return K == OwnedSymbol || K == OwnedAllocatedSymbol || 110 K == OwnedWhenTrackedReceiver; 111 } 112 113 bool operator==(const RetEffect &Other) const { 114 return K == Other.K && O == Other.O; 115 } 116 117 static RetEffect MakeOwnedWhenTrackedReceiver() { 118 return RetEffect(OwnedWhenTrackedReceiver, ObjC); 119 } 120 121 static RetEffect MakeOwned(ObjKind o, bool isAllocated = false) { 122 return RetEffect(isAllocated ? OwnedAllocatedSymbol : OwnedSymbol, o); 123 } 124 static RetEffect MakeNotOwned(ObjKind o) { 125 return RetEffect(NotOwnedSymbol, o); 126 } 127 static RetEffect MakeGCNotOwned() { 128 return RetEffect(GCNotOwnedSymbol, ObjC); 129 } 130 static RetEffect MakeARCNotOwned() { 131 return RetEffect(ARCNotOwnedSymbol, ObjC); 132 } 133 static RetEffect MakeNoRet() { 134 return RetEffect(NoRet); 135 } 136 137 void Profile(llvm::FoldingSetNodeID& ID) const { 138 ID.AddInteger((unsigned) K); 139 ID.AddInteger((unsigned) O); 140 } 141}; 142 143//===----------------------------------------------------------------------===// 144// Reference-counting logic (typestate + counts). 145//===----------------------------------------------------------------------===// 146 147class RefVal { 148public: 149 enum Kind { 150 Owned = 0, // Owning reference. 151 NotOwned, // Reference is not owned by still valid (not freed). 152 Released, // Object has been released. 153 ReturnedOwned, // Returned object passes ownership to caller. 154 ReturnedNotOwned, // Return object does not pass ownership to caller. 155 ERROR_START, 156 ErrorDeallocNotOwned, // -dealloc called on non-owned object. 157 ErrorDeallocGC, // Calling -dealloc with GC enabled. 158 ErrorUseAfterRelease, // Object used after released. 159 ErrorReleaseNotOwned, // Release of an object that was not owned. 160 ERROR_LEAK_START, 161 ErrorLeak, // A memory leak due to excessive reference counts. 162 ErrorLeakReturned, // A memory leak due to the returning method not having 163 // the correct naming conventions. 164 ErrorGCLeakReturned, 165 ErrorOverAutorelease, 166 ErrorReturnedNotOwned 167 }; 168 169private: 170 Kind kind; 171 RetEffect::ObjKind okind; 172 unsigned Cnt; 173 unsigned ACnt; 174 QualType T; 175 176 RefVal(Kind k, RetEffect::ObjKind o, unsigned cnt, unsigned acnt, QualType t) 177 : kind(k), okind(o), Cnt(cnt), ACnt(acnt), T(t) {} 178 179public: 180 Kind getKind() const { return kind; } 181 182 RetEffect::ObjKind getObjKind() const { return okind; } 183 184 unsigned getCount() const { return Cnt; } 185 unsigned getAutoreleaseCount() const { return ACnt; } 186 unsigned getCombinedCounts() const { return Cnt + ACnt; } 187 void clearCounts() { Cnt = 0; ACnt = 0; } 188 void setCount(unsigned i) { Cnt = i; } 189 void setAutoreleaseCount(unsigned i) { ACnt = i; } 190 191 QualType getType() const { return T; } 192 193 bool isOwned() const { 194 return getKind() == Owned; 195 } 196 197 bool isNotOwned() const { 198 return getKind() == NotOwned; 199 } 200 201 bool isReturnedOwned() const { 202 return getKind() == ReturnedOwned; 203 } 204 205 bool isReturnedNotOwned() const { 206 return getKind() == ReturnedNotOwned; 207 } 208 209 static RefVal makeOwned(RetEffect::ObjKind o, QualType t, 210 unsigned Count = 1) { 211 return RefVal(Owned, o, Count, 0, t); 212 } 213 214 static RefVal makeNotOwned(RetEffect::ObjKind o, QualType t, 215 unsigned Count = 0) { 216 return RefVal(NotOwned, o, Count, 0, t); 217 } 218 219 // Comparison, profiling, and pretty-printing. 220 221 bool operator==(const RefVal& X) const { 222 return kind == X.kind && Cnt == X.Cnt && T == X.T && ACnt == X.ACnt; 223 } 224 225 RefVal operator-(size_t i) const { 226 return RefVal(getKind(), getObjKind(), getCount() - i, 227 getAutoreleaseCount(), getType()); 228 } 229 230 RefVal operator+(size_t i) const { 231 return RefVal(getKind(), getObjKind(), getCount() + i, 232 getAutoreleaseCount(), getType()); 233 } 234 235 RefVal operator^(Kind k) const { 236 return RefVal(k, getObjKind(), getCount(), getAutoreleaseCount(), 237 getType()); 238 } 239 240 RefVal autorelease() const { 241 return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount()+1, 242 getType()); 243 } 244 245 void Profile(llvm::FoldingSetNodeID& ID) const { 246 ID.AddInteger((unsigned) kind); 247 ID.AddInteger(Cnt); 248 ID.AddInteger(ACnt); 249 ID.Add(T); 250 } 251 252 void print(raw_ostream &Out) const; 253}; 254 255void RefVal::print(raw_ostream &Out) const { 256 if (!T.isNull()) 257 Out << "Tracked " << T.getAsString() << '/'; 258 259 switch (getKind()) { 260 default: llvm_unreachable("Invalid RefVal kind"); 261 case Owned: { 262 Out << "Owned"; 263 unsigned cnt = getCount(); 264 if (cnt) Out << " (+ " << cnt << ")"; 265 break; 266 } 267 268 case NotOwned: { 269 Out << "NotOwned"; 270 unsigned cnt = getCount(); 271 if (cnt) Out << " (+ " << cnt << ")"; 272 break; 273 } 274 275 case ReturnedOwned: { 276 Out << "ReturnedOwned"; 277 unsigned cnt = getCount(); 278 if (cnt) Out << " (+ " << cnt << ")"; 279 break; 280 } 281 282 case ReturnedNotOwned: { 283 Out << "ReturnedNotOwned"; 284 unsigned cnt = getCount(); 285 if (cnt) Out << " (+ " << cnt << ")"; 286 break; 287 } 288 289 case Released: 290 Out << "Released"; 291 break; 292 293 case ErrorDeallocGC: 294 Out << "-dealloc (GC)"; 295 break; 296 297 case ErrorDeallocNotOwned: 298 Out << "-dealloc (not-owned)"; 299 break; 300 301 case ErrorLeak: 302 Out << "Leaked"; 303 break; 304 305 case ErrorLeakReturned: 306 Out << "Leaked (Bad naming)"; 307 break; 308 309 case ErrorGCLeakReturned: 310 Out << "Leaked (GC-ed at return)"; 311 break; 312 313 case ErrorUseAfterRelease: 314 Out << "Use-After-Release [ERROR]"; 315 break; 316 317 case ErrorReleaseNotOwned: 318 Out << "Release of Not-Owned [ERROR]"; 319 break; 320 321 case RefVal::ErrorOverAutorelease: 322 Out << "Over autoreleased"; 323 break; 324 325 case RefVal::ErrorReturnedNotOwned: 326 Out << "Non-owned object returned instead of owned"; 327 break; 328 } 329 330 if (ACnt) { 331 Out << " [ARC +" << ACnt << ']'; 332 } 333} 334} //end anonymous namespace 335 336//===----------------------------------------------------------------------===// 337// RefBindings - State used to track object reference counts. 338//===----------------------------------------------------------------------===// 339 340typedef llvm::ImmutableMap<SymbolRef, RefVal> RefBindings; 341 342namespace clang { 343namespace ento { 344template<> 345struct ProgramStateTrait<RefBindings> 346 : public ProgramStatePartialTrait<RefBindings> { 347 static void *GDMIndex() { 348 static int RefBIndex = 0; 349 return &RefBIndex; 350 } 351}; 352} 353} 354 355//===----------------------------------------------------------------------===// 356// Function/Method behavior summaries. 357//===----------------------------------------------------------------------===// 358 359namespace { 360class RetainSummary { 361 /// Args - a map of (index, ArgEffect) pairs, where index 362 /// specifies the argument (starting from 0). This can be sparsely 363 /// populated; arguments with no entry in Args use 'DefaultArgEffect'. 364 ArgEffects Args; 365 366 /// DefaultArgEffect - The default ArgEffect to apply to arguments that 367 /// do not have an entry in Args. 368 ArgEffect DefaultArgEffect; 369 370 /// Receiver - If this summary applies to an Objective-C message expression, 371 /// this is the effect applied to the state of the receiver. 372 ArgEffect Receiver; 373 374 /// Ret - The effect on the return value. Used to indicate if the 375 /// function/method call returns a new tracked symbol. 376 RetEffect Ret; 377 378public: 379 RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff, 380 ArgEffect ReceiverEff) 381 : Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {} 382 383 /// getArg - Return the argument effect on the argument specified by 384 /// idx (starting from 0). 385 ArgEffect getArg(unsigned idx) const { 386 if (const ArgEffect *AE = Args.lookup(idx)) 387 return *AE; 388 389 return DefaultArgEffect; 390 } 391 392 void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) { 393 Args = af.add(Args, idx, e); 394 } 395 396 /// setDefaultArgEffect - Set the default argument effect. 397 void setDefaultArgEffect(ArgEffect E) { 398 DefaultArgEffect = E; 399 } 400 401 /// getRetEffect - Returns the effect on the return value of the call. 402 RetEffect getRetEffect() const { return Ret; } 403 404 /// setRetEffect - Set the effect of the return value of the call. 405 void setRetEffect(RetEffect E) { Ret = E; } 406 407 408 /// Sets the effect on the receiver of the message. 409 void setReceiverEffect(ArgEffect e) { Receiver = e; } 410 411 /// getReceiverEffect - Returns the effect on the receiver of the call. 412 /// This is only meaningful if the summary applies to an ObjCMessageExpr*. 413 ArgEffect getReceiverEffect() const { return Receiver; } 414 415 /// Test if two retain summaries are identical. Note that merely equivalent 416 /// summaries are not necessarily identical (for example, if an explicit 417 /// argument effect matches the default effect). 418 bool operator==(const RetainSummary &Other) const { 419 return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect && 420 Receiver == Other.Receiver && Ret == Other.Ret; 421 } 422 423 /// Profile this summary for inclusion in a FoldingSet. 424 void Profile(llvm::FoldingSetNodeID& ID) const { 425 ID.Add(Args); 426 ID.Add(DefaultArgEffect); 427 ID.Add(Receiver); 428 ID.Add(Ret); 429 } 430 431 /// A retain summary is simple if it has no ArgEffects other than the default. 432 bool isSimple() const { 433 return Args.isEmpty(); 434 } 435 436private: 437 ArgEffects getArgEffects() const { return Args; } 438 ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; } 439 440 friend class RetainSummaryManager; 441}; 442} // end anonymous namespace 443 444//===----------------------------------------------------------------------===// 445// Data structures for constructing summaries. 446//===----------------------------------------------------------------------===// 447 448namespace { 449class ObjCSummaryKey { 450 IdentifierInfo* II; 451 Selector S; 452public: 453 ObjCSummaryKey(IdentifierInfo* ii, Selector s) 454 : II(ii), S(s) {} 455 456 ObjCSummaryKey(const ObjCInterfaceDecl *d, Selector s) 457 : II(d ? d->getIdentifier() : 0), S(s) {} 458 459 ObjCSummaryKey(Selector s) 460 : II(0), S(s) {} 461 462 IdentifierInfo *getIdentifier() const { return II; } 463 Selector getSelector() const { return S; } 464}; 465} 466 467namespace llvm { 468template <> struct DenseMapInfo<ObjCSummaryKey> { 469 static inline ObjCSummaryKey getEmptyKey() { 470 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getEmptyKey(), 471 DenseMapInfo<Selector>::getEmptyKey()); 472 } 473 474 static inline ObjCSummaryKey getTombstoneKey() { 475 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getTombstoneKey(), 476 DenseMapInfo<Selector>::getTombstoneKey()); 477 } 478 479 static unsigned getHashValue(const ObjCSummaryKey &V) { 480 typedef std::pair<IdentifierInfo*, Selector> PairTy; 481 return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(), 482 V.getSelector())); 483 } 484 485 static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) { 486 return LHS.getIdentifier() == RHS.getIdentifier() && 487 LHS.getSelector() == RHS.getSelector(); 488 } 489 490}; 491template <> 492struct isPodLike<ObjCSummaryKey> { static const bool value = true; }; 493} // end llvm namespace 494 495namespace { 496class ObjCSummaryCache { 497 typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy; 498 MapTy M; 499public: 500 ObjCSummaryCache() {} 501 502 const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) { 503 // Do a lookup with the (D,S) pair. If we find a match return 504 // the iterator. 505 ObjCSummaryKey K(D, S); 506 MapTy::iterator I = M.find(K); 507 508 if (I != M.end()) 509 return I->second; 510 if (!D) 511 return NULL; 512 513 // Walk the super chain. If we find a hit with a parent, we'll end 514 // up returning that summary. We actually allow that key (null,S), as 515 // we cache summaries for the null ObjCInterfaceDecl* to allow us to 516 // generate initial summaries without having to worry about NSObject 517 // being declared. 518 // FIXME: We may change this at some point. 519 for (ObjCInterfaceDecl *C=D->getSuperClass() ;; C=C->getSuperClass()) { 520 if ((I = M.find(ObjCSummaryKey(C, S))) != M.end()) 521 break; 522 523 if (!C) 524 return NULL; 525 } 526 527 // Cache the summary with original key to make the next lookup faster 528 // and return the iterator. 529 const RetainSummary *Summ = I->second; 530 M[K] = Summ; 531 return Summ; 532 } 533 534 const RetainSummary *find(IdentifierInfo* II, Selector S) { 535 // FIXME: Class method lookup. Right now we dont' have a good way 536 // of going between IdentifierInfo* and the class hierarchy. 537 MapTy::iterator I = M.find(ObjCSummaryKey(II, S)); 538 539 if (I == M.end()) 540 I = M.find(ObjCSummaryKey(S)); 541 542 return I == M.end() ? NULL : I->second; 543 } 544 545 const RetainSummary *& operator[](ObjCSummaryKey K) { 546 return M[K]; 547 } 548 549 const RetainSummary *& operator[](Selector S) { 550 return M[ ObjCSummaryKey(S) ]; 551 } 552}; 553} // end anonymous namespace 554 555//===----------------------------------------------------------------------===// 556// Data structures for managing collections of summaries. 557//===----------------------------------------------------------------------===// 558 559namespace { 560class RetainSummaryManager { 561 562 //==-----------------------------------------------------------------==// 563 // Typedefs. 564 //==-----------------------------------------------------------------==// 565 566 typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *> 567 FuncSummariesTy; 568 569 typedef ObjCSummaryCache ObjCMethodSummariesTy; 570 571 typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode; 572 573 //==-----------------------------------------------------------------==// 574 // Data. 575 //==-----------------------------------------------------------------==// 576 577 /// Ctx - The ASTContext object for the analyzed ASTs. 578 ASTContext &Ctx; 579 580 /// GCEnabled - Records whether or not the analyzed code runs in GC mode. 581 const bool GCEnabled; 582 583 /// Records whether or not the analyzed code runs in ARC mode. 584 const bool ARCEnabled; 585 586 /// FuncSummaries - A map from FunctionDecls to summaries. 587 FuncSummariesTy FuncSummaries; 588 589 /// ObjCClassMethodSummaries - A map from selectors (for instance methods) 590 /// to summaries. 591 ObjCMethodSummariesTy ObjCClassMethodSummaries; 592 593 /// ObjCMethodSummaries - A map from selectors to summaries. 594 ObjCMethodSummariesTy ObjCMethodSummaries; 595 596 /// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects, 597 /// and all other data used by the checker. 598 llvm::BumpPtrAllocator BPAlloc; 599 600 /// AF - A factory for ArgEffects objects. 601 ArgEffects::Factory AF; 602 603 /// ScratchArgs - A holding buffer for construct ArgEffects. 604 ArgEffects ScratchArgs; 605 606 /// ObjCAllocRetE - Default return effect for methods returning Objective-C 607 /// objects. 608 RetEffect ObjCAllocRetE; 609 610 /// ObjCInitRetE - Default return effect for init methods returning 611 /// Objective-C objects. 612 RetEffect ObjCInitRetE; 613 614 /// SimpleSummaries - Used for uniquing summaries that don't have special 615 /// effects. 616 llvm::FoldingSet<CachedSummaryNode> SimpleSummaries; 617 618 //==-----------------------------------------------------------------==// 619 // Methods. 620 //==-----------------------------------------------------------------==// 621 622 /// getArgEffects - Returns a persistent ArgEffects object based on the 623 /// data in ScratchArgs. 624 ArgEffects getArgEffects(); 625 626 enum UnaryFuncKind { cfretain, cfrelease, cfmakecollectable }; 627 628 const RetainSummary *getUnarySummary(const FunctionType* FT, 629 UnaryFuncKind func); 630 631 const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD); 632 const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD); 633 const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD); 634 635 const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm); 636 637 const RetainSummary *getPersistentSummary(RetEffect RetEff, 638 ArgEffect ReceiverEff = DoNothing, 639 ArgEffect DefaultEff = MayEscape) { 640 RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff); 641 return getPersistentSummary(Summ); 642 } 643 644 const RetainSummary *getDoNothingSummary() { 645 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 646 } 647 648 const RetainSummary *getDefaultSummary() { 649 return getPersistentSummary(RetEffect::MakeNoRet(), 650 DoNothing, MayEscape); 651 } 652 653 const RetainSummary *getPersistentStopSummary() { 654 return getPersistentSummary(RetEffect::MakeNoRet(), 655 StopTracking, StopTracking); 656 } 657 658 void InitializeClassMethodSummaries(); 659 void InitializeMethodSummaries(); 660private: 661 void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) { 662 ObjCClassMethodSummaries[S] = Summ; 663 } 664 665 void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) { 666 ObjCMethodSummaries[S] = Summ; 667 } 668 669 void addClassMethSummary(const char* Cls, const char* name, 670 const RetainSummary *Summ, bool isNullary = true) { 671 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 672 Selector S = isNullary ? GetNullarySelector(name, Ctx) 673 : GetUnarySelector(name, Ctx); 674 ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 675 } 676 677 void addInstMethSummary(const char* Cls, const char* nullaryName, 678 const RetainSummary *Summ) { 679 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 680 Selector S = GetNullarySelector(nullaryName, Ctx); 681 ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 682 } 683 684 Selector generateSelector(va_list argp) { 685 SmallVector<IdentifierInfo*, 10> II; 686 687 while (const char* s = va_arg(argp, const char*)) 688 II.push_back(&Ctx.Idents.get(s)); 689 690 return Ctx.Selectors.getSelector(II.size(), &II[0]); 691 } 692 693 void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy& Summaries, 694 const RetainSummary * Summ, va_list argp) { 695 Selector S = generateSelector(argp); 696 Summaries[ObjCSummaryKey(ClsII, S)] = Summ; 697 } 698 699 void addInstMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 700 va_list argp; 701 va_start(argp, Summ); 702 addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp); 703 va_end(argp); 704 } 705 706 void addClsMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 707 va_list argp; 708 va_start(argp, Summ); 709 addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp); 710 va_end(argp); 711 } 712 713 void addClsMethSummary(IdentifierInfo *II, const RetainSummary * Summ, ...) { 714 va_list argp; 715 va_start(argp, Summ); 716 addMethodSummary(II, ObjCClassMethodSummaries, Summ, argp); 717 va_end(argp); 718 } 719 720public: 721 722 RetainSummaryManager(ASTContext &ctx, bool gcenabled, bool usesARC) 723 : Ctx(ctx), 724 GCEnabled(gcenabled), 725 ARCEnabled(usesARC), 726 AF(BPAlloc), ScratchArgs(AF.getEmptyMap()), 727 ObjCAllocRetE(gcenabled 728 ? RetEffect::MakeGCNotOwned() 729 : (usesARC ? RetEffect::MakeARCNotOwned() 730 : RetEffect::MakeOwned(RetEffect::ObjC, true))), 731 ObjCInitRetE(gcenabled 732 ? RetEffect::MakeGCNotOwned() 733 : (usesARC ? RetEffect::MakeARCNotOwned() 734 : RetEffect::MakeOwnedWhenTrackedReceiver())) { 735 InitializeClassMethodSummaries(); 736 InitializeMethodSummaries(); 737 } 738 739 const RetainSummary *getSummary(const CallEvent &Call, 740 ProgramStateRef State = 0); 741 742 const RetainSummary *getFunctionSummary(const FunctionDecl *FD); 743 744 const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 745 const ObjCMethodDecl *MD, 746 QualType RetTy, 747 ObjCMethodSummariesTy &CachedSummaries); 748 749 const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M, 750 ProgramStateRef State); 751 752 const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) { 753 assert(!M.isInstanceMessage()); 754 const ObjCInterfaceDecl *Class = M.getReceiverInterface(); 755 756 return getMethodSummary(M.getSelector(), Class, M.getDecl(), 757 M.getResultType(), ObjCClassMethodSummaries); 758 } 759 760 /// getMethodSummary - This version of getMethodSummary is used to query 761 /// the summary for the current method being analyzed. 762 const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) { 763 const ObjCInterfaceDecl *ID = MD->getClassInterface(); 764 Selector S = MD->getSelector(); 765 QualType ResultTy = MD->getResultType(); 766 767 ObjCMethodSummariesTy *CachedSummaries; 768 if (MD->isInstanceMethod()) 769 CachedSummaries = &ObjCMethodSummaries; 770 else 771 CachedSummaries = &ObjCClassMethodSummaries; 772 773 return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries); 774 } 775 776 const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD, 777 Selector S, QualType RetTy); 778 779 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 780 const ObjCMethodDecl *MD); 781 782 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 783 const FunctionDecl *FD); 784 785 void updateSummaryForCall(const RetainSummary *&Summ, 786 const CallEvent &Call); 787 788 bool isGCEnabled() const { return GCEnabled; } 789 790 bool isARCEnabled() const { return ARCEnabled; } 791 792 bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; } 793 794 RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; } 795 796 friend class RetainSummaryTemplate; 797}; 798 799// Used to avoid allocating long-term (BPAlloc'd) memory for default retain 800// summaries. If a function or method looks like it has a default summary, but 801// it has annotations, the annotations are added to the stack-based template 802// and then copied into managed memory. 803class RetainSummaryTemplate { 804 RetainSummaryManager &Manager; 805 const RetainSummary *&RealSummary; 806 RetainSummary ScratchSummary; 807 bool Accessed; 808public: 809 RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr) 810 : Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {} 811 812 ~RetainSummaryTemplate() { 813 if (Accessed) 814 RealSummary = Manager.getPersistentSummary(ScratchSummary); 815 } 816 817 RetainSummary &operator*() { 818 Accessed = true; 819 return ScratchSummary; 820 } 821 822 RetainSummary *operator->() { 823 Accessed = true; 824 return &ScratchSummary; 825 } 826}; 827 828} // end anonymous namespace 829 830//===----------------------------------------------------------------------===// 831// Implementation of checker data structures. 832//===----------------------------------------------------------------------===// 833 834ArgEffects RetainSummaryManager::getArgEffects() { 835 ArgEffects AE = ScratchArgs; 836 ScratchArgs = AF.getEmptyMap(); 837 return AE; 838} 839 840const RetainSummary * 841RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) { 842 // Unique "simple" summaries -- those without ArgEffects. 843 if (OldSumm.isSimple()) { 844 llvm::FoldingSetNodeID ID; 845 OldSumm.Profile(ID); 846 847 void *Pos; 848 CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos); 849 850 if (!N) { 851 N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>(); 852 new (N) CachedSummaryNode(OldSumm); 853 SimpleSummaries.InsertNode(N, Pos); 854 } 855 856 return &N->getValue(); 857 } 858 859 RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>(); 860 new (Summ) RetainSummary(OldSumm); 861 return Summ; 862} 863 864//===----------------------------------------------------------------------===// 865// Summary creation for functions (largely uses of Core Foundation). 866//===----------------------------------------------------------------------===// 867 868static bool isRetain(const FunctionDecl *FD, StringRef FName) { 869 return FName.endswith("Retain"); 870} 871 872static bool isRelease(const FunctionDecl *FD, StringRef FName) { 873 return FName.endswith("Release"); 874} 875 876static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) { 877 // FIXME: Remove FunctionDecl parameter. 878 // FIXME: Is it really okay if MakeCollectable isn't a suffix? 879 return FName.find("MakeCollectable") != StringRef::npos; 880} 881 882static ArgEffect getStopTrackingEquivalent(ArgEffect E) { 883 switch (E) { 884 case DoNothing: 885 case Autorelease: 886 case DecRefBridgedTransfered: 887 case IncRef: 888 case IncRefMsg: 889 case MakeCollectable: 890 case MayEscape: 891 case NewAutoreleasePool: 892 case StopTracking: 893 return StopTracking; 894 case DecRef: 895 case DecRefAndStopTracking: 896 return DecRefAndStopTracking; 897 case DecRefMsg: 898 case DecRefMsgAndStopTracking: 899 return DecRefMsgAndStopTracking; 900 case Dealloc: 901 return Dealloc; 902 } 903 904 llvm_unreachable("Unknown ArgEffect kind"); 905} 906 907void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S, 908 const CallEvent &Call) { 909 if (Call.hasNonZeroCallbackArg()) { 910 ArgEffect RecEffect = getStopTrackingEquivalent(S->getReceiverEffect()); 911 ArgEffect DefEffect = getStopTrackingEquivalent(S->getDefaultArgEffect()); 912 913 ArgEffects CustomArgEffects = S->getArgEffects(); 914 for (ArgEffects::iterator I = CustomArgEffects.begin(), 915 E = CustomArgEffects.end(); 916 I != E; ++I) { 917 ArgEffect Translated = getStopTrackingEquivalent(I->second); 918 if (Translated != DefEffect) 919 ScratchArgs = AF.add(ScratchArgs, I->first, Translated); 920 } 921 922 RetEffect RE = RetEffect::MakeNoRet(); 923 924 // Special cases where the callback argument CANNOT free the return value. 925 // This can generally only happen if we know that the callback will only be 926 // called when the return value is already being deallocated. 927 if (const FunctionCall *FC = dyn_cast<FunctionCall>(&Call)) { 928 IdentifierInfo *Name = FC->getDecl()->getIdentifier(); 929 930 // This callback frees the associated buffer. 931 if (Name->isStr("CGBitmapContextCreateWithData")) 932 RE = S->getRetEffect(); 933 } 934 935 S = getPersistentSummary(RE, RecEffect, DefEffect); 936 } 937} 938 939const RetainSummary * 940RetainSummaryManager::getSummary(const CallEvent &Call, 941 ProgramStateRef State) { 942 const RetainSummary *Summ; 943 switch (Call.getKind()) { 944 case CE_Function: 945 Summ = getFunctionSummary(cast<FunctionCall>(Call).getDecl()); 946 break; 947 case CE_CXXMember: 948 case CE_Block: 949 case CE_CXXConstructor: 950 case CE_CXXAllocator: 951 // FIXME: These calls are currently unsupported. 952 return getPersistentStopSummary(); 953 case CE_ObjCMessage: 954 case CE_ObjCPropertyAccess: { 955 const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call); 956 if (Msg.isInstanceMessage()) 957 Summ = getInstanceMethodSummary(Msg, State); 958 else 959 Summ = getClassMethodSummary(Msg); 960 break; 961 } 962 } 963 964 updateSummaryForCall(Summ, Call); 965 966 assert(Summ && "Unknown call type?"); 967 return Summ; 968} 969 970const RetainSummary * 971RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) { 972 // If we don't know what function we're calling, use our default summary. 973 if (!FD) 974 return getDefaultSummary(); 975 976 // Look up a summary in our cache of FunctionDecls -> Summaries. 977 FuncSummariesTy::iterator I = FuncSummaries.find(FD); 978 if (I != FuncSummaries.end()) 979 return I->second; 980 981 // No summary? Generate one. 982 const RetainSummary *S = 0; 983 984 do { 985 // We generate "stop" summaries for implicitly defined functions. 986 if (FD->isImplicit()) { 987 S = getPersistentStopSummary(); 988 break; 989 } 990 991 // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the 992 // function's type. 993 const FunctionType* FT = FD->getType()->getAs<FunctionType>(); 994 const IdentifierInfo *II = FD->getIdentifier(); 995 if (!II) 996 break; 997 998 StringRef FName = II->getName(); 999 1000 // Strip away preceding '_'. Doing this here will effect all the checks 1001 // down below. 1002 FName = FName.substr(FName.find_first_not_of('_')); 1003 1004 // Inspect the result type. 1005 QualType RetTy = FT->getResultType(); 1006 1007 // FIXME: This should all be refactored into a chain of "summary lookup" 1008 // filters. 1009 assert(ScratchArgs.isEmpty()); 1010 1011 if (FName == "pthread_create" || FName == "pthread_setspecific") { 1012 // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>. 1013 // This will be addressed better with IPA. 1014 S = getPersistentStopSummary(); 1015 } else if (FName == "NSMakeCollectable") { 1016 // Handle: id NSMakeCollectable(CFTypeRef) 1017 S = (RetTy->isObjCIdType()) 1018 ? getUnarySummary(FT, cfmakecollectable) 1019 : getPersistentStopSummary(); 1020 } else if (FName == "IOBSDNameMatching" || 1021 FName == "IOServiceMatching" || 1022 FName == "IOServiceNameMatching" || 1023 FName == "IORegistryEntrySearchCFProperty" || 1024 FName == "IORegistryEntryIDMatching" || 1025 FName == "IOOpenFirmwarePathMatching") { 1026 // Part of <rdar://problem/6961230>. (IOKit) 1027 // This should be addressed using a API table. 1028 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1029 DoNothing, DoNothing); 1030 } else if (FName == "IOServiceGetMatchingService" || 1031 FName == "IOServiceGetMatchingServices") { 1032 // FIXES: <rdar://problem/6326900> 1033 // This should be addressed using a API table. This strcmp is also 1034 // a little gross, but there is no need to super optimize here. 1035 ScratchArgs = AF.add(ScratchArgs, 1, DecRef); 1036 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1037 } else if (FName == "IOServiceAddNotification" || 1038 FName == "IOServiceAddMatchingNotification") { 1039 // Part of <rdar://problem/6961230>. (IOKit) 1040 // This should be addressed using a API table. 1041 ScratchArgs = AF.add(ScratchArgs, 2, DecRef); 1042 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1043 } else if (FName == "CVPixelBufferCreateWithBytes") { 1044 // FIXES: <rdar://problem/7283567> 1045 // Eventually this can be improved by recognizing that the pixel 1046 // buffer passed to CVPixelBufferCreateWithBytes is released via 1047 // a callback and doing full IPA to make sure this is done correctly. 1048 // FIXME: This function has an out parameter that returns an 1049 // allocated object. 1050 ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); 1051 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1052 } else if (FName == "CGBitmapContextCreateWithData") { 1053 // FIXES: <rdar://problem/7358899> 1054 // Eventually this can be improved by recognizing that 'releaseInfo' 1055 // passed to CGBitmapContextCreateWithData is released via 1056 // a callback and doing full IPA to make sure this is done correctly. 1057 ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); 1058 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1059 DoNothing, DoNothing); 1060 } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { 1061 // FIXES: <rdar://problem/7283567> 1062 // Eventually this can be improved by recognizing that the pixel 1063 // buffer passed to CVPixelBufferCreateWithPlanarBytes is released 1064 // via a callback and doing full IPA to make sure this is done 1065 // correctly. 1066 ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); 1067 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1068 } else if (FName == "dispatch_set_context") { 1069 // <rdar://problem/11059275> - The analyzer currently doesn't have 1070 // a good way to reason about the finalizer function for libdispatch. 1071 // If we pass a context object that is memory managed, stop tracking it. 1072 // FIXME: this hack should possibly go away once we can handle 1073 // libdispatch finalizers. 1074 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1075 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1076 } else if (FName.startswith("NSLog")) { 1077 S = getDoNothingSummary(); 1078 } else if (FName.startswith("NS") && 1079 (FName.find("Insert") != StringRef::npos)) { 1080 // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 1081 // be deallocated by NSMapRemove. (radar://11152419) 1082 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1083 ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); 1084 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1085 } 1086 1087 // Did we get a summary? 1088 if (S) 1089 break; 1090 1091 // Enable this code once the semantics of NSDeallocateObject are resolved 1092 // for GC. <rdar://problem/6619988> 1093#if 0 1094 // Handle: NSDeallocateObject(id anObject); 1095 // This method does allow 'nil' (although we don't check it now). 1096 if (strcmp(FName, "NSDeallocateObject") == 0) { 1097 return RetTy == Ctx.VoidTy 1098 ? getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, Dealloc) 1099 : getPersistentStopSummary(); 1100 } 1101#endif 1102 1103 if (RetTy->isPointerType()) { 1104 // For CoreFoundation ('CF') types. 1105 if (cocoa::isRefType(RetTy, "CF", FName)) { 1106 if (isRetain(FD, FName)) 1107 S = getUnarySummary(FT, cfretain); 1108 else if (isMakeCollectable(FD, FName)) 1109 S = getUnarySummary(FT, cfmakecollectable); 1110 else 1111 S = getCFCreateGetRuleSummary(FD); 1112 1113 break; 1114 } 1115 1116 // For CoreGraphics ('CG') types. 1117 if (cocoa::isRefType(RetTy, "CG", FName)) { 1118 if (isRetain(FD, FName)) 1119 S = getUnarySummary(FT, cfretain); 1120 else 1121 S = getCFCreateGetRuleSummary(FD); 1122 1123 break; 1124 } 1125 1126 // For the Disk Arbitration API (DiskArbitration/DADisk.h) 1127 if (cocoa::isRefType(RetTy, "DADisk") || 1128 cocoa::isRefType(RetTy, "DADissenter") || 1129 cocoa::isRefType(RetTy, "DASessionRef")) { 1130 S = getCFCreateGetRuleSummary(FD); 1131 break; 1132 } 1133 1134 break; 1135 } 1136 1137 // Check for release functions, the only kind of functions that we care 1138 // about that don't return a pointer type. 1139 if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { 1140 // Test for 'CGCF'. 1141 FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); 1142 1143 if (isRelease(FD, FName)) 1144 S = getUnarySummary(FT, cfrelease); 1145 else { 1146 assert (ScratchArgs.isEmpty()); 1147 // Remaining CoreFoundation and CoreGraphics functions. 1148 // We use to assume that they all strictly followed the ownership idiom 1149 // and that ownership cannot be transferred. While this is technically 1150 // correct, many methods allow a tracked object to escape. For example: 1151 // 1152 // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); 1153 // CFDictionaryAddValue(y, key, x); 1154 // CFRelease(x); 1155 // ... it is okay to use 'x' since 'y' has a reference to it 1156 // 1157 // We handle this and similar cases with the follow heuristic. If the 1158 // function name contains "InsertValue", "SetValue", "AddValue", 1159 // "AppendValue", or "SetAttribute", then we assume that arguments may 1160 // "escape." This means that something else holds on to the object, 1161 // allowing it be used even after its local retain count drops to 0. 1162 ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| 1163 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 1164 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 1165 StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| 1166 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) 1167 ? MayEscape : DoNothing; 1168 1169 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); 1170 } 1171 } 1172 } 1173 while (0); 1174 1175 // If we got all the way here without any luck, use a default summary. 1176 if (!S) 1177 S = getDefaultSummary(); 1178 1179 // Annotations override defaults. 1180 updateSummaryFromAnnotations(S, FD); 1181 1182 FuncSummaries[FD] = S; 1183 return S; 1184} 1185 1186const RetainSummary * 1187RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { 1188 if (coreFoundation::followsCreateRule(FD)) 1189 return getCFSummaryCreateRule(FD); 1190 1191 return getCFSummaryGetRule(FD); 1192} 1193 1194const RetainSummary * 1195RetainSummaryManager::getUnarySummary(const FunctionType* FT, 1196 UnaryFuncKind func) { 1197 1198 // Sanity check that this is *really* a unary function. This can 1199 // happen if people do weird things. 1200 const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); 1201 if (!FTP || FTP->getNumArgs() != 1) 1202 return getPersistentStopSummary(); 1203 1204 assert (ScratchArgs.isEmpty()); 1205 1206 ArgEffect Effect; 1207 switch (func) { 1208 case cfretain: Effect = IncRef; break; 1209 case cfrelease: Effect = DecRef; break; 1210 case cfmakecollectable: Effect = MakeCollectable; break; 1211 } 1212 1213 ScratchArgs = AF.add(ScratchArgs, 0, Effect); 1214 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1215} 1216 1217const RetainSummary * 1218RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { 1219 assert (ScratchArgs.isEmpty()); 1220 1221 return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1222} 1223 1224const RetainSummary * 1225RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { 1226 assert (ScratchArgs.isEmpty()); 1227 return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), 1228 DoNothing, DoNothing); 1229} 1230 1231//===----------------------------------------------------------------------===// 1232// Summary creation for Selectors. 1233//===----------------------------------------------------------------------===// 1234 1235void 1236RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1237 const FunctionDecl *FD) { 1238 if (!FD) 1239 return; 1240 1241 assert(Summ && "Must have a summary to add annotations to."); 1242 RetainSummaryTemplate Template(Summ, *this); 1243 1244 // Effects on the parameters. 1245 unsigned parm_idx = 0; 1246 for (FunctionDecl::param_const_iterator pi = FD->param_begin(), 1247 pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { 1248 const ParmVarDecl *pd = *pi; 1249 if (pd->getAttr<NSConsumedAttr>()) { 1250 if (!GCEnabled) { 1251 Template->addArg(AF, parm_idx, DecRef); 1252 } 1253 } else if (pd->getAttr<CFConsumedAttr>()) { 1254 Template->addArg(AF, parm_idx, DecRef); 1255 } 1256 } 1257 1258 QualType RetTy = FD->getResultType(); 1259 1260 // Determine if there is a special return effect for this method. 1261 if (cocoa::isCocoaObjectRef(RetTy)) { 1262 if (FD->getAttr<NSReturnsRetainedAttr>()) { 1263 Template->setRetEffect(ObjCAllocRetE); 1264 } 1265 else if (FD->getAttr<CFReturnsRetainedAttr>()) { 1266 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1267 } 1268 else if (FD->getAttr<NSReturnsNotRetainedAttr>()) { 1269 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1270 } 1271 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1272 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1273 } 1274 } else if (RetTy->getAs<PointerType>()) { 1275 if (FD->getAttr<CFReturnsRetainedAttr>()) { 1276 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1277 } 1278 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1279 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1280 } 1281 } 1282} 1283 1284void 1285RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1286 const ObjCMethodDecl *MD) { 1287 if (!MD) 1288 return; 1289 1290 assert(Summ && "Must have a valid summary to add annotations to"); 1291 RetainSummaryTemplate Template(Summ, *this); 1292 bool isTrackedLoc = false; 1293 1294 // Effects on the receiver. 1295 if (MD->getAttr<NSConsumesSelfAttr>()) { 1296 if (!GCEnabled) 1297 Template->setReceiverEffect(DecRefMsg); 1298 } 1299 1300 // Effects on the parameters. 1301 unsigned parm_idx = 0; 1302 for (ObjCMethodDecl::param_const_iterator 1303 pi=MD->param_begin(), pe=MD->param_end(); 1304 pi != pe; ++pi, ++parm_idx) { 1305 const ParmVarDecl *pd = *pi; 1306 if (pd->getAttr<NSConsumedAttr>()) { 1307 if (!GCEnabled) 1308 Template->addArg(AF, parm_idx, DecRef); 1309 } 1310 else if(pd->getAttr<CFConsumedAttr>()) { 1311 Template->addArg(AF, parm_idx, DecRef); 1312 } 1313 } 1314 1315 // Determine if there is a special return effect for this method. 1316 if (cocoa::isCocoaObjectRef(MD->getResultType())) { 1317 if (MD->getAttr<NSReturnsRetainedAttr>()) { 1318 Template->setRetEffect(ObjCAllocRetE); 1319 return; 1320 } 1321 if (MD->getAttr<NSReturnsNotRetainedAttr>()) { 1322 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1323 return; 1324 } 1325 1326 isTrackedLoc = true; 1327 } else { 1328 isTrackedLoc = MD->getResultType()->getAs<PointerType>() != NULL; 1329 } 1330 1331 if (isTrackedLoc) { 1332 if (MD->getAttr<CFReturnsRetainedAttr>()) 1333 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1334 else if (MD->getAttr<CFReturnsNotRetainedAttr>()) 1335 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1336 } 1337} 1338 1339const RetainSummary * 1340RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, 1341 Selector S, QualType RetTy) { 1342 1343 if (MD) { 1344 // Scan the method decl for 'void*' arguments. These should be treated 1345 // as 'StopTracking' because they are often used with delegates. 1346 // Delegates are a frequent form of false positives with the retain 1347 // count checker. 1348 unsigned i = 0; 1349 for (ObjCMethodDecl::param_const_iterator I = MD->param_begin(), 1350 E = MD->param_end(); I != E; ++I, ++i) 1351 if (const ParmVarDecl *PD = *I) { 1352 QualType Ty = Ctx.getCanonicalType(PD->getType()); 1353 if (Ty.getLocalUnqualifiedType() == Ctx.VoidPtrTy) 1354 ScratchArgs = AF.add(ScratchArgs, i, StopTracking); 1355 } 1356 } 1357 1358 // Any special effects? 1359 ArgEffect ReceiverEff = DoNothing; 1360 RetEffect ResultEff = RetEffect::MakeNoRet(); 1361 1362 // Check the method family, and apply any default annotations. 1363 switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { 1364 case OMF_None: 1365 case OMF_performSelector: 1366 // Assume all Objective-C methods follow Cocoa Memory Management rules. 1367 // FIXME: Does the non-threaded performSelector family really belong here? 1368 // The selector could be, say, @selector(copy). 1369 if (cocoa::isCocoaObjectRef(RetTy)) 1370 ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); 1371 else if (coreFoundation::isCFObjectRef(RetTy)) { 1372 // ObjCMethodDecl currently doesn't consider CF objects as valid return 1373 // values for alloc, new, copy, or mutableCopy, so we have to 1374 // double-check with the selector. This is ugly, but there aren't that 1375 // many Objective-C methods that return CF objects, right? 1376 if (MD) { 1377 switch (S.getMethodFamily()) { 1378 case OMF_alloc: 1379 case OMF_new: 1380 case OMF_copy: 1381 case OMF_mutableCopy: 1382 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1383 break; 1384 default: 1385 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1386 break; 1387 } 1388 } else { 1389 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1390 } 1391 } 1392 break; 1393 case OMF_init: 1394 ResultEff = ObjCInitRetE; 1395 ReceiverEff = DecRefMsg; 1396 break; 1397 case OMF_alloc: 1398 case OMF_new: 1399 case OMF_copy: 1400 case OMF_mutableCopy: 1401 if (cocoa::isCocoaObjectRef(RetTy)) 1402 ResultEff = ObjCAllocRetE; 1403 else if (coreFoundation::isCFObjectRef(RetTy)) 1404 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1405 break; 1406 case OMF_autorelease: 1407 ReceiverEff = Autorelease; 1408 break; 1409 case OMF_retain: 1410 ReceiverEff = IncRefMsg; 1411 break; 1412 case OMF_release: 1413 ReceiverEff = DecRefMsg; 1414 break; 1415 case OMF_dealloc: 1416 ReceiverEff = Dealloc; 1417 break; 1418 case OMF_self: 1419 // -self is handled specially by the ExprEngine to propagate the receiver. 1420 break; 1421 case OMF_retainCount: 1422 case OMF_finalize: 1423 // These methods don't return objects. 1424 break; 1425 } 1426 1427 // If one of the arguments in the selector has the keyword 'delegate' we 1428 // should stop tracking the reference count for the receiver. This is 1429 // because the reference count is quite possibly handled by a delegate 1430 // method. 1431 if (S.isKeywordSelector()) { 1432 for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { 1433 StringRef Slot = S.getNameForSlot(i); 1434 if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { 1435 if (ResultEff == ObjCInitRetE) 1436 ResultEff = RetEffect::MakeNoRet(); 1437 else 1438 ReceiverEff = StopTracking; 1439 } 1440 } 1441 } 1442 1443 if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && 1444 ResultEff.getKind() == RetEffect::NoRet) 1445 return getDefaultSummary(); 1446 1447 return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); 1448} 1449 1450const RetainSummary * 1451RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, 1452 ProgramStateRef State) { 1453 const ObjCInterfaceDecl *ReceiverClass = 0; 1454 1455 // We do better tracking of the type of the object than the core ExprEngine. 1456 // See if we have its type in our private state. 1457 // FIXME: Eventually replace the use of state->get<RefBindings> with 1458 // a generic API for reasoning about the Objective-C types of symbolic 1459 // objects. 1460 SVal ReceiverV = Msg.getReceiverSVal(); 1461 if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) 1462 if (const RefVal *T = State->get<RefBindings>(Sym)) 1463 if (const ObjCObjectPointerType *PT = 1464 T->getType()->getAs<ObjCObjectPointerType>()) 1465 ReceiverClass = PT->getInterfaceDecl(); 1466 1467 // If we don't know what kind of object this is, fall back to its static type. 1468 if (!ReceiverClass) 1469 ReceiverClass = Msg.getReceiverInterface(); 1470 1471 // FIXME: The receiver could be a reference to a class, meaning that 1472 // we should use the class method. 1473 // id x = [NSObject class]; 1474 // [x performSelector:... withObject:... afterDelay:...]; 1475 Selector S = Msg.getSelector(); 1476 const ObjCMethodDecl *Method = Msg.getDecl(); 1477 if (!Method && ReceiverClass) 1478 Method = ReceiverClass->getInstanceMethod(S); 1479 1480 return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), 1481 ObjCMethodSummaries); 1482} 1483 1484const RetainSummary * 1485RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 1486 const ObjCMethodDecl *MD, QualType RetTy, 1487 ObjCMethodSummariesTy &CachedSummaries) { 1488 1489 // Look up a summary in our summary cache. 1490 const RetainSummary *Summ = CachedSummaries.find(ID, S); 1491 1492 if (!Summ) { 1493 Summ = getStandardMethodSummary(MD, S, RetTy); 1494 1495 // Annotations override defaults. 1496 updateSummaryFromAnnotations(Summ, MD); 1497 1498 // Memoize the summary. 1499 CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; 1500 } 1501 1502 return Summ; 1503} 1504 1505void RetainSummaryManager::InitializeClassMethodSummaries() { 1506 assert(ScratchArgs.isEmpty()); 1507 // Create the [NSAssertionHandler currentHander] summary. 1508 addClassMethSummary("NSAssertionHandler", "currentHandler", 1509 getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); 1510 1511 // Create the [NSAutoreleasePool addObject:] summary. 1512 ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); 1513 addClassMethSummary("NSAutoreleasePool", "addObject", 1514 getPersistentSummary(RetEffect::MakeNoRet(), 1515 DoNothing, Autorelease)); 1516} 1517 1518void RetainSummaryManager::InitializeMethodSummaries() { 1519 1520 assert (ScratchArgs.isEmpty()); 1521 1522 // Create the "init" selector. It just acts as a pass-through for the 1523 // receiver. 1524 const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); 1525 addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); 1526 1527 // awakeAfterUsingCoder: behaves basically like an 'init' method. It 1528 // claims the receiver and returns a retained object. 1529 addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), 1530 InitSumm); 1531 1532 // The next methods are allocators. 1533 const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); 1534 const RetainSummary *CFAllocSumm = 1535 getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1536 1537 // Create the "retain" selector. 1538 RetEffect NoRet = RetEffect::MakeNoRet(); 1539 const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); 1540 addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); 1541 1542 // Create the "release" selector. 1543 Summ = getPersistentSummary(NoRet, DecRefMsg); 1544 addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); 1545 1546 // Create the "drain" selector. 1547 Summ = getPersistentSummary(NoRet, isGCEnabled() ? DoNothing : DecRef); 1548 addNSObjectMethSummary(GetNullarySelector("drain", Ctx), Summ); 1549 1550 // Create the -dealloc summary. 1551 Summ = getPersistentSummary(NoRet, Dealloc); 1552 addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); 1553 1554 // Create the "autorelease" selector. 1555 Summ = getPersistentSummary(NoRet, Autorelease); 1556 addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); 1557 1558 // Specially handle NSAutoreleasePool. 1559 addInstMethSummary("NSAutoreleasePool", "init", 1560 getPersistentSummary(NoRet, NewAutoreleasePool)); 1561 1562 // For NSWindow, allocated objects are (initially) self-owned. 1563 // FIXME: For now we opt for false negatives with NSWindow, as these objects 1564 // self-own themselves. However, they only do this once they are displayed. 1565 // Thus, we need to track an NSWindow's display status. 1566 // This is tracked in <rdar://problem/6062711>. 1567 // See also http://llvm.org/bugs/show_bug.cgi?id=3714. 1568 const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), 1569 StopTracking, 1570 StopTracking); 1571 1572 addClassMethSummary("NSWindow", "alloc", NoTrackYet); 1573 1574#if 0 1575 addInstMethSummary("NSWindow", NoTrackYet, "initWithContentRect", 1576 "styleMask", "backing", "defer", NULL); 1577 1578 addInstMethSummary("NSWindow", NoTrackYet, "initWithContentRect", 1579 "styleMask", "backing", "defer", "screen", NULL); 1580#endif 1581 1582 // For NSPanel (which subclasses NSWindow), allocated objects are not 1583 // self-owned. 1584 // FIXME: For now we don't track NSPanels. object for the same reason 1585 // as for NSWindow objects. 1586 addClassMethSummary("NSPanel", "alloc", NoTrackYet); 1587 1588#if 0 1589 addInstMethSummary("NSPanel", NoTrackYet, "initWithContentRect", 1590 "styleMask", "backing", "defer", NULL); 1591 1592 addInstMethSummary("NSPanel", NoTrackYet, "initWithContentRect", 1593 "styleMask", "backing", "defer", "screen", NULL); 1594#endif 1595 1596 // Don't track allocated autorelease pools yet, as it is okay to prematurely 1597 // exit a method. 1598 addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); 1599 addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); 1600 1601 // Create summaries QCRenderer/QCView -createSnapShotImageOfType: 1602 addInstMethSummary("QCRenderer", AllocSumm, 1603 "createSnapshotImageOfType", NULL); 1604 addInstMethSummary("QCView", AllocSumm, 1605 "createSnapshotImageOfType", NULL); 1606 1607 // Create summaries for CIContext, 'createCGImage' and 1608 // 'createCGLayerWithSize'. These objects are CF objects, and are not 1609 // automatically garbage collected. 1610 addInstMethSummary("CIContext", CFAllocSumm, 1611 "createCGImage", "fromRect", NULL); 1612 addInstMethSummary("CIContext", CFAllocSumm, 1613 "createCGImage", "fromRect", "format", "colorSpace", NULL); 1614 addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", 1615 "info", NULL); 1616} 1617 1618//===----------------------------------------------------------------------===// 1619// AutoreleaseBindings - State used to track objects in autorelease pools. 1620//===----------------------------------------------------------------------===// 1621 1622typedef llvm::ImmutableMap<SymbolRef, unsigned> ARCounts; 1623typedef llvm::ImmutableMap<SymbolRef, ARCounts> ARPoolContents; 1624typedef llvm::ImmutableList<SymbolRef> ARStack; 1625 1626static int AutoRCIndex = 0; 1627static int AutoRBIndex = 0; 1628 1629namespace { class AutoreleasePoolContents {}; } 1630namespace { class AutoreleaseStack {}; } 1631 1632namespace clang { 1633namespace ento { 1634template<> struct ProgramStateTrait<AutoreleaseStack> 1635 : public ProgramStatePartialTrait<ARStack> { 1636 static inline void *GDMIndex() { return &AutoRBIndex; } 1637}; 1638 1639template<> struct ProgramStateTrait<AutoreleasePoolContents> 1640 : public ProgramStatePartialTrait<ARPoolContents> { 1641 static inline void *GDMIndex() { return &AutoRCIndex; } 1642}; 1643} // end GR namespace 1644} // end clang namespace 1645 1646static SymbolRef GetCurrentAutoreleasePool(ProgramStateRef state) { 1647 ARStack stack = state->get<AutoreleaseStack>(); 1648 return stack.isEmpty() ? SymbolRef() : stack.getHead(); 1649} 1650 1651static ProgramStateRef 1652SendAutorelease(ProgramStateRef state, 1653 ARCounts::Factory &F, 1654 SymbolRef sym) { 1655 SymbolRef pool = GetCurrentAutoreleasePool(state); 1656 const ARCounts *cnts = state->get<AutoreleasePoolContents>(pool); 1657 ARCounts newCnts(0); 1658 1659 if (cnts) { 1660 const unsigned *cnt = (*cnts).lookup(sym); 1661 newCnts = F.add(*cnts, sym, cnt ? *cnt + 1 : 1); 1662 } 1663 else 1664 newCnts = F.add(F.getEmptyMap(), sym, 1); 1665 1666 return state->set<AutoreleasePoolContents>(pool, newCnts); 1667} 1668 1669//===----------------------------------------------------------------------===// 1670// Error reporting. 1671//===----------------------------------------------------------------------===// 1672namespace { 1673 typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> 1674 SummaryLogTy; 1675 1676 //===-------------===// 1677 // Bug Descriptions. // 1678 //===-------------===// 1679 1680 class CFRefBug : public BugType { 1681 protected: 1682 CFRefBug(StringRef name) 1683 : BugType(name, categories::MemoryCoreFoundationObjectiveC) {} 1684 public: 1685 1686 // FIXME: Eventually remove. 1687 virtual const char *getDescription() const = 0; 1688 1689 virtual bool isLeak() const { return false; } 1690 }; 1691 1692 class UseAfterRelease : public CFRefBug { 1693 public: 1694 UseAfterRelease() : CFRefBug("Use-after-release") {} 1695 1696 const char *getDescription() const { 1697 return "Reference-counted object is used after it is released"; 1698 } 1699 }; 1700 1701 class BadRelease : public CFRefBug { 1702 public: 1703 BadRelease() : CFRefBug("Bad release") {} 1704 1705 const char *getDescription() const { 1706 return "Incorrect decrement of the reference count of an object that is " 1707 "not owned at this point by the caller"; 1708 } 1709 }; 1710 1711 class DeallocGC : public CFRefBug { 1712 public: 1713 DeallocGC() 1714 : CFRefBug("-dealloc called while using garbage collection") {} 1715 1716 const char *getDescription() const { 1717 return "-dealloc called while using garbage collection"; 1718 } 1719 }; 1720 1721 class DeallocNotOwned : public CFRefBug { 1722 public: 1723 DeallocNotOwned() 1724 : CFRefBug("-dealloc sent to non-exclusively owned object") {} 1725 1726 const char *getDescription() const { 1727 return "-dealloc sent to object that may be referenced elsewhere"; 1728 } 1729 }; 1730 1731 class OverAutorelease : public CFRefBug { 1732 public: 1733 OverAutorelease() 1734 : CFRefBug("Object sent -autorelease too many times") {} 1735 1736 const char *getDescription() const { 1737 return "Object sent -autorelease too many times"; 1738 } 1739 }; 1740 1741 class ReturnedNotOwnedForOwned : public CFRefBug { 1742 public: 1743 ReturnedNotOwnedForOwned() 1744 : CFRefBug("Method should return an owned object") {} 1745 1746 const char *getDescription() const { 1747 return "Object with a +0 retain count returned to caller where a +1 " 1748 "(owning) retain count is expected"; 1749 } 1750 }; 1751 1752 class Leak : public CFRefBug { 1753 public: 1754 Leak(StringRef name) 1755 : CFRefBug(name) { 1756 // Leaks should not be reported if they are post-dominated by a sink. 1757 setSuppressOnSink(true); 1758 } 1759 1760 const char *getDescription() const { return ""; } 1761 1762 bool isLeak() const { return true; } 1763 }; 1764 1765 //===---------===// 1766 // Bug Reports. // 1767 //===---------===// 1768 1769 class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> { 1770 protected: 1771 SymbolRef Sym; 1772 const SummaryLogTy &SummaryLog; 1773 bool GCEnabled; 1774 1775 public: 1776 CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) 1777 : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} 1778 1779 virtual void Profile(llvm::FoldingSetNodeID &ID) const { 1780 static int x = 0; 1781 ID.AddPointer(&x); 1782 ID.AddPointer(Sym); 1783 } 1784 1785 virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N, 1786 const ExplodedNode *PrevN, 1787 BugReporterContext &BRC, 1788 BugReport &BR); 1789 1790 virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1791 const ExplodedNode *N, 1792 BugReport &BR); 1793 }; 1794 1795 class CFRefLeakReportVisitor : public CFRefReportVisitor { 1796 public: 1797 CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, 1798 const SummaryLogTy &log) 1799 : CFRefReportVisitor(sym, GCEnabled, log) {} 1800 1801 PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1802 const ExplodedNode *N, 1803 BugReport &BR); 1804 1805 virtual BugReporterVisitor *clone() const { 1806 // The curiously-recurring template pattern only works for one level of 1807 // subclassing. Rather than make a new template base for 1808 // CFRefReportVisitor, we simply override clone() to do the right thing. 1809 // This could be trouble someday if BugReporterVisitorImpl is ever 1810 // used for something else besides a convenient implementation of clone(). 1811 return new CFRefLeakReportVisitor(*this); 1812 } 1813 }; 1814 1815 class CFRefReport : public BugReport { 1816 void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); 1817 1818 public: 1819 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1820 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1821 bool registerVisitor = true) 1822 : BugReport(D, D.getDescription(), n) { 1823 if (registerVisitor) 1824 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1825 addGCModeDescription(LOpts, GCEnabled); 1826 } 1827 1828 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1829 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1830 StringRef endText) 1831 : BugReport(D, D.getDescription(), endText, n) { 1832 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1833 addGCModeDescription(LOpts, GCEnabled); 1834 } 1835 1836 virtual std::pair<ranges_iterator, ranges_iterator> getRanges() { 1837 const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); 1838 if (!BugTy.isLeak()) 1839 return BugReport::getRanges(); 1840 else 1841 return std::make_pair(ranges_iterator(), ranges_iterator()); 1842 } 1843 }; 1844 1845 class CFRefLeakReport : public CFRefReport { 1846 const MemRegion* AllocBinding; 1847 1848 public: 1849 CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1850 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1851 CheckerContext &Ctx); 1852 1853 PathDiagnosticLocation getLocation(const SourceManager &SM) const { 1854 assert(Location.isValid()); 1855 return Location; 1856 } 1857 }; 1858} // end anonymous namespace 1859 1860void CFRefReport::addGCModeDescription(const LangOptions &LOpts, 1861 bool GCEnabled) { 1862 const char *GCModeDescription = 0; 1863 1864 switch (LOpts.getGC()) { 1865 case LangOptions::GCOnly: 1866 assert(GCEnabled); 1867 GCModeDescription = "Code is compiled to only use garbage collection"; 1868 break; 1869 1870 case LangOptions::NonGC: 1871 assert(!GCEnabled); 1872 GCModeDescription = "Code is compiled to use reference counts"; 1873 break; 1874 1875 case LangOptions::HybridGC: 1876 if (GCEnabled) { 1877 GCModeDescription = "Code is compiled to use either garbage collection " 1878 "(GC) or reference counts (non-GC). The bug occurs " 1879 "with GC enabled"; 1880 break; 1881 } else { 1882 GCModeDescription = "Code is compiled to use either garbage collection " 1883 "(GC) or reference counts (non-GC). The bug occurs " 1884 "in non-GC mode"; 1885 break; 1886 } 1887 } 1888 1889 assert(GCModeDescription && "invalid/unknown GC mode"); 1890 addExtraText(GCModeDescription); 1891} 1892 1893// FIXME: This should be a method on SmallVector. 1894static inline bool contains(const SmallVectorImpl<ArgEffect>& V, 1895 ArgEffect X) { 1896 for (SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end(); 1897 I!=E; ++I) 1898 if (*I == X) return true; 1899 1900 return false; 1901} 1902 1903static bool isNumericLiteralExpression(const Expr *E) { 1904 // FIXME: This set of cases was copied from SemaExprObjC. 1905 return isa<IntegerLiteral>(E) || 1906 isa<CharacterLiteral>(E) || 1907 isa<FloatingLiteral>(E) || 1908 isa<ObjCBoolLiteralExpr>(E) || 1909 isa<CXXBoolLiteralExpr>(E); 1910} 1911 1912static bool isPropertyAccess(const Stmt *S, ParentMap &PM) { 1913 unsigned maxDepth = 4; 1914 while (S && maxDepth) { 1915 if (const PseudoObjectExpr *PO = dyn_cast<PseudoObjectExpr>(S)) { 1916 if (!isa<ObjCMessageExpr>(PO->getSyntacticForm())) 1917 return true; 1918 return false; 1919 } 1920 S = PM.getParent(S); 1921 --maxDepth; 1922 } 1923 return false; 1924} 1925 1926PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N, 1927 const ExplodedNode *PrevN, 1928 BugReporterContext &BRC, 1929 BugReport &BR) { 1930 1931 if (!isa<StmtPoint>(N->getLocation())) 1932 return NULL; 1933 1934 // Check if the type state has changed. 1935 ProgramStateRef PrevSt = PrevN->getState(); 1936 ProgramStateRef CurrSt = N->getState(); 1937 const LocationContext *LCtx = N->getLocationContext(); 1938 1939 const RefVal* CurrT = CurrSt->get<RefBindings>(Sym); 1940 if (!CurrT) return NULL; 1941 1942 const RefVal &CurrV = *CurrT; 1943 const RefVal *PrevT = PrevSt->get<RefBindings>(Sym); 1944 1945 // Create a string buffer to constain all the useful things we want 1946 // to tell the user. 1947 std::string sbuf; 1948 llvm::raw_string_ostream os(sbuf); 1949 1950 // This is the allocation site since the previous node had no bindings 1951 // for this symbol. 1952 if (!PrevT) { 1953 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 1954 1955 if (isa<ObjCArrayLiteral>(S)) { 1956 os << "NSArray literal is an object with a +0 retain count"; 1957 } 1958 else if (isa<ObjCDictionaryLiteral>(S)) { 1959 os << "NSDictionary literal is an object with a +0 retain count"; 1960 } 1961 else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { 1962 if (isNumericLiteralExpression(BL->getSubExpr())) 1963 os << "NSNumber literal is an object with a +0 retain count"; 1964 else { 1965 const ObjCInterfaceDecl *BoxClass = 0; 1966 if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) 1967 BoxClass = Method->getClassInterface(); 1968 1969 // We should always be able to find the boxing class interface, 1970 // but consider this future-proofing. 1971 if (BoxClass) 1972 os << *BoxClass << " b"; 1973 else 1974 os << "B"; 1975 1976 os << "oxed expression produces an object with a +0 retain count"; 1977 } 1978 } 1979 else { 1980 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1981 // Get the name of the callee (if it is available). 1982 SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); 1983 if (const FunctionDecl *FD = X.getAsFunctionDecl()) 1984 os << "Call to function '" << *FD << '\''; 1985 else 1986 os << "function call"; 1987 } 1988 else { 1989 assert(isa<ObjCMessageExpr>(S)); 1990 // The message expression may have between written directly or as 1991 // a property access. Lazily determine which case we are looking at. 1992 os << (isPropertyAccess(S, N->getParentMap()) ? "Property" : "Method"); 1993 } 1994 1995 if (CurrV.getObjKind() == RetEffect::CF) { 1996 os << " returns a Core Foundation object with a "; 1997 } 1998 else { 1999 assert (CurrV.getObjKind() == RetEffect::ObjC); 2000 os << " returns an Objective-C object with a "; 2001 } 2002 2003 if (CurrV.isOwned()) { 2004 os << "+1 retain count"; 2005 2006 if (GCEnabled) { 2007 assert(CurrV.getObjKind() == RetEffect::CF); 2008 os << ". " 2009 "Core Foundation objects are not automatically garbage collected."; 2010 } 2011 } 2012 else { 2013 assert (CurrV.isNotOwned()); 2014 os << "+0 retain count"; 2015 } 2016 } 2017 2018 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2019 N->getLocationContext()); 2020 return new PathDiagnosticEventPiece(Pos, os.str()); 2021 } 2022 2023 // Gather up the effects that were performed on the object at this 2024 // program point 2025 SmallVector<ArgEffect, 2> AEffects; 2026 2027 const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); 2028 if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { 2029 // We only have summaries attached to nodes after evaluating CallExpr and 2030 // ObjCMessageExprs. 2031 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2032 2033 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 2034 // Iterate through the parameter expressions and see if the symbol 2035 // was ever passed as an argument. 2036 unsigned i = 0; 2037 2038 for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); 2039 AI!=AE; ++AI, ++i) { 2040 2041 // Retrieve the value of the argument. Is it the symbol 2042 // we are interested in? 2043 if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) 2044 continue; 2045 2046 // We have an argument. Get the effect! 2047 AEffects.push_back(Summ->getArg(i)); 2048 } 2049 } 2050 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { 2051 if (const Expr *receiver = ME->getInstanceReceiver()) 2052 if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) 2053 .getAsLocSymbol() == Sym) { 2054 // The symbol we are tracking is the receiver. 2055 AEffects.push_back(Summ->getReceiverEffect()); 2056 } 2057 } 2058 } 2059 2060 do { 2061 // Get the previous type state. 2062 RefVal PrevV = *PrevT; 2063 2064 // Specially handle -dealloc. 2065 if (!GCEnabled && contains(AEffects, Dealloc)) { 2066 // Determine if the object's reference count was pushed to zero. 2067 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2068 // We may not have transitioned to 'release' if we hit an error. 2069 // This case is handled elsewhere. 2070 if (CurrV.getKind() == RefVal::Released) { 2071 assert(CurrV.getCombinedCounts() == 0); 2072 os << "Object released by directly sending the '-dealloc' message"; 2073 break; 2074 } 2075 } 2076 2077 // Specially handle CFMakeCollectable and friends. 2078 if (contains(AEffects, MakeCollectable)) { 2079 // Get the name of the function. 2080 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2081 SVal X = 2082 CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); 2083 const FunctionDecl *FD = X.getAsFunctionDecl(); 2084 2085 if (GCEnabled) { 2086 // Determine if the object's reference count was pushed to zero. 2087 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2088 2089 os << "In GC mode a call to '" << *FD 2090 << "' decrements an object's retain count and registers the " 2091 "object with the garbage collector. "; 2092 2093 if (CurrV.getKind() == RefVal::Released) { 2094 assert(CurrV.getCount() == 0); 2095 os << "Since it now has a 0 retain count the object can be " 2096 "automatically collected by the garbage collector."; 2097 } 2098 else 2099 os << "An object must have a 0 retain count to be garbage collected. " 2100 "After this call its retain count is +" << CurrV.getCount() 2101 << '.'; 2102 } 2103 else 2104 os << "When GC is not enabled a call to '" << *FD 2105 << "' has no effect on its argument."; 2106 2107 // Nothing more to say. 2108 break; 2109 } 2110 2111 // Determine if the typestate has changed. 2112 if (!(PrevV == CurrV)) 2113 switch (CurrV.getKind()) { 2114 case RefVal::Owned: 2115 case RefVal::NotOwned: 2116 2117 if (PrevV.getCount() == CurrV.getCount()) { 2118 // Did an autorelease message get sent? 2119 if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) 2120 return 0; 2121 2122 assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); 2123 os << "Object sent -autorelease message"; 2124 break; 2125 } 2126 2127 if (PrevV.getCount() > CurrV.getCount()) 2128 os << "Reference count decremented."; 2129 else 2130 os << "Reference count incremented."; 2131 2132 if (unsigned Count = CurrV.getCount()) 2133 os << " The object now has a +" << Count << " retain count."; 2134 2135 if (PrevV.getKind() == RefVal::Released) { 2136 assert(GCEnabled && CurrV.getCount() > 0); 2137 os << " The object is not eligible for garbage collection until " 2138 "the retain count reaches 0 again."; 2139 } 2140 2141 break; 2142 2143 case RefVal::Released: 2144 os << "Object released."; 2145 break; 2146 2147 case RefVal::ReturnedOwned: 2148 // Autoreleases can be applied after marking a node ReturnedOwned. 2149 if (CurrV.getAutoreleaseCount()) 2150 return NULL; 2151 2152 os << "Object returned to caller as an owning reference (single " 2153 "retain count transferred to caller)"; 2154 break; 2155 2156 case RefVal::ReturnedNotOwned: 2157 os << "Object returned to caller with a +0 retain count"; 2158 break; 2159 2160 default: 2161 return NULL; 2162 } 2163 2164 // Emit any remaining diagnostics for the argument effects (if any). 2165 for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), 2166 E=AEffects.end(); I != E; ++I) { 2167 2168 // A bunch of things have alternate behavior under GC. 2169 if (GCEnabled) 2170 switch (*I) { 2171 default: break; 2172 case Autorelease: 2173 os << "In GC mode an 'autorelease' has no effect."; 2174 continue; 2175 case IncRefMsg: 2176 os << "In GC mode the 'retain' message has no effect."; 2177 continue; 2178 case DecRefMsg: 2179 os << "In GC mode the 'release' message has no effect."; 2180 continue; 2181 } 2182 } 2183 } while (0); 2184 2185 if (os.str().empty()) 2186 return 0; // We have nothing to say! 2187 2188 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2189 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2190 N->getLocationContext()); 2191 PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str()); 2192 2193 // Add the range by scanning the children of the statement for any bindings 2194 // to Sym. 2195 for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); 2196 I!=E; ++I) 2197 if (const Expr *Exp = dyn_cast_or_null<Expr>(*I)) 2198 if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { 2199 P->addRange(Exp->getSourceRange()); 2200 break; 2201 } 2202 2203 return P; 2204} 2205 2206// Find the first node in the current function context that referred to the 2207// tracked symbol and the memory location that value was stored to. Note, the 2208// value is only reported if the allocation occurred in the same function as 2209// the leak. 2210static std::pair<const ExplodedNode*,const MemRegion*> 2211GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, 2212 SymbolRef Sym) { 2213 const ExplodedNode *Last = N; 2214 const MemRegion* FirstBinding = 0; 2215 const LocationContext *LeakContext = N->getLocationContext(); 2216 2217 while (N) { 2218 ProgramStateRef St = N->getState(); 2219 RefBindings B = St->get<RefBindings>(); 2220 2221 if (!B.lookup(Sym)) 2222 break; 2223 2224 StoreManager::FindUniqueBinding FB(Sym); 2225 StateMgr.iterBindings(St, FB); 2226 if (FB) FirstBinding = FB.getRegion(); 2227 2228 // Allocation node, is the last node in the current context in which the 2229 // symbol was tracked. 2230 if (N->getLocationContext() == LeakContext) 2231 Last = N; 2232 2233 N = N->pred_empty() ? NULL : *(N->pred_begin()); 2234 } 2235 2236 // If allocation happened in a function different from the leak node context, 2237 // do not report the binding. 2238 if (N->getLocationContext() != LeakContext) { 2239 FirstBinding = 0; 2240 } 2241 2242 return std::make_pair(Last, FirstBinding); 2243} 2244 2245PathDiagnosticPiece* 2246CFRefReportVisitor::getEndPath(BugReporterContext &BRC, 2247 const ExplodedNode *EndN, 2248 BugReport &BR) { 2249 BR.markInteresting(Sym); 2250 return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); 2251} 2252 2253PathDiagnosticPiece* 2254CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, 2255 const ExplodedNode *EndN, 2256 BugReport &BR) { 2257 2258 // Tell the BugReporterContext to report cases when the tracked symbol is 2259 // assigned to different variables, etc. 2260 BR.markInteresting(Sym); 2261 2262 // We are reporting a leak. Walk up the graph to get to the first node where 2263 // the symbol appeared, and also get the first VarDecl that tracked object 2264 // is stored to. 2265 const ExplodedNode *AllocNode = 0; 2266 const MemRegion* FirstBinding = 0; 2267 2268 llvm::tie(AllocNode, FirstBinding) = 2269 GetAllocationSite(BRC.getStateManager(), EndN, Sym); 2270 2271 SourceManager& SM = BRC.getSourceManager(); 2272 2273 // Compute an actual location for the leak. Sometimes a leak doesn't 2274 // occur at an actual statement (e.g., transition between blocks; end 2275 // of function) so we need to walk the graph and compute a real location. 2276 const ExplodedNode *LeakN = EndN; 2277 PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); 2278 2279 std::string sbuf; 2280 llvm::raw_string_ostream os(sbuf); 2281 2282 os << "Object leaked: "; 2283 2284 if (FirstBinding) { 2285 os << "object allocated and stored into '" 2286 << FirstBinding->getString() << '\''; 2287 } 2288 else 2289 os << "allocated object"; 2290 2291 // Get the retain count. 2292 const RefVal* RV = EndN->getState()->get<RefBindings>(Sym); 2293 2294 if (RV->getKind() == RefVal::ErrorLeakReturned) { 2295 // FIXME: Per comments in rdar://6320065, "create" only applies to CF 2296 // objects. Only "copy", "alloc", "retain" and "new" transfer ownership 2297 // to the caller for NS objects. 2298 const Decl *D = &EndN->getCodeDecl(); 2299 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 2300 os << " is returned from a method whose name ('" 2301 << MD->getSelector().getAsString() 2302 << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'." 2303 " This violates the naming convention rules" 2304 " given in the Memory Management Guide for Cocoa"; 2305 } 2306 else { 2307 const FunctionDecl *FD = cast<FunctionDecl>(D); 2308 os << " is returned from a function whose name ('" 2309 << *FD 2310 << "') does not contain 'Copy' or 'Create'. This violates the naming" 2311 " convention rules given in the Memory Management Guide for Core" 2312 " Foundation"; 2313 } 2314 } 2315 else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { 2316 ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); 2317 os << " and returned from method '" << MD.getSelector().getAsString() 2318 << "' is potentially leaked when using garbage collection. Callers " 2319 "of this method do not expect a returned object with a +1 retain " 2320 "count since they expect the object to be managed by the garbage " 2321 "collector"; 2322 } 2323 else 2324 os << " is not referenced later in this execution path and has a retain " 2325 "count of +" << RV->getCount(); 2326 2327 return new PathDiagnosticEventPiece(L, os.str()); 2328} 2329 2330CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, 2331 bool GCEnabled, const SummaryLogTy &Log, 2332 ExplodedNode *n, SymbolRef sym, 2333 CheckerContext &Ctx) 2334: CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { 2335 2336 // Most bug reports are cached at the location where they occurred. 2337 // With leaks, we want to unique them by the location where they were 2338 // allocated, and only report a single path. To do this, we need to find 2339 // the allocation site of a piece of tracked memory, which we do via a 2340 // call to GetAllocationSite. This will walk the ExplodedGraph backwards. 2341 // Note that this is *not* the trimmed graph; we are guaranteed, however, 2342 // that all ancestor nodes that represent the allocation site have the 2343 // same SourceLocation. 2344 const ExplodedNode *AllocNode = 0; 2345 2346 const SourceManager& SMgr = Ctx.getSourceManager(); 2347 2348 llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding. 2349 GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); 2350 2351 // Get the SourceLocation for the allocation site. 2352 ProgramPoint P = AllocNode->getLocation(); 2353 const Stmt *AllocStmt = cast<PostStmt>(P).getStmt(); 2354 Location = PathDiagnosticLocation::createBegin(AllocStmt, SMgr, 2355 n->getLocationContext()); 2356 // Fill in the description of the bug. 2357 Description.clear(); 2358 llvm::raw_string_ostream os(Description); 2359 os << "Potential leak "; 2360 if (GCEnabled) 2361 os << "(when using garbage collection) "; 2362 os << "of an object"; 2363 2364 // FIXME: AllocBinding doesn't get populated for RegionStore yet. 2365 if (AllocBinding) 2366 os << " stored into '" << AllocBinding->getString() << '\''; 2367 2368 addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log)); 2369} 2370 2371//===----------------------------------------------------------------------===// 2372// Main checker logic. 2373//===----------------------------------------------------------------------===// 2374 2375namespace { 2376class RetainCountChecker 2377 : public Checker< check::Bind, 2378 check::DeadSymbols, 2379 check::EndAnalysis, 2380 check::EndPath, 2381 check::PostStmt<BlockExpr>, 2382 check::PostStmt<CastExpr>, 2383 check::PostStmt<ObjCArrayLiteral>, 2384 check::PostStmt<ObjCDictionaryLiteral>, 2385 check::PostStmt<ObjCBoxedExpr>, 2386 check::PostCall, 2387 check::PreStmt<ReturnStmt>, 2388 check::RegionChanges, 2389 eval::Assume, 2390 eval::Call > { 2391 mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned; 2392 mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned; 2393 mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned; 2394 mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn; 2395 mutable OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; 2396 2397 typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap; 2398 2399 // This map is only used to ensure proper deletion of any allocated tags. 2400 mutable SymbolTagMap DeadSymbolTags; 2401 2402 mutable OwningPtr<RetainSummaryManager> Summaries; 2403 mutable OwningPtr<RetainSummaryManager> SummariesGC; 2404 2405 mutable ARCounts::Factory ARCountFactory; 2406 2407 mutable SummaryLogTy SummaryLog; 2408 mutable bool ShouldResetSummaryLog; 2409 2410public: 2411 RetainCountChecker() : ShouldResetSummaryLog(false) {} 2412 2413 virtual ~RetainCountChecker() { 2414 DeleteContainerSeconds(DeadSymbolTags); 2415 } 2416 2417 void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, 2418 ExprEngine &Eng) const { 2419 // FIXME: This is a hack to make sure the summary log gets cleared between 2420 // analyses of different code bodies. 2421 // 2422 // Why is this necessary? Because a checker's lifetime is tied to a 2423 // translation unit, but an ExplodedGraph's lifetime is just a code body. 2424 // Once in a blue moon, a new ExplodedNode will have the same address as an 2425 // old one with an associated summary, and the bug report visitor gets very 2426 // confused. (To make things worse, the summary lifetime is currently also 2427 // tied to a code body, so we get a crash instead of incorrect results.) 2428 // 2429 // Why is this a bad solution? Because if the lifetime of the ExplodedGraph 2430 // changes, things will start going wrong again. Really the lifetime of this 2431 // log needs to be tied to either the specific nodes in it or the entire 2432 // ExplodedGraph, not to a specific part of the code being analyzed. 2433 // 2434 // (Also, having stateful local data means that the same checker can't be 2435 // used from multiple threads, but a lot of checkers have incorrect 2436 // assumptions about that anyway. So that wasn't a priority at the time of 2437 // this fix.) 2438 // 2439 // This happens at the end of analysis, but bug reports are emitted /after/ 2440 // this point. So we can't just clear the summary log now. Instead, we mark 2441 // that the next time we access the summary log, it should be cleared. 2442 2443 // If we never reset the summary log during /this/ code body analysis, 2444 // there were no new summaries. There might still have been summaries from 2445 // the /last/ analysis, so clear them out to make sure the bug report 2446 // visitors don't get confused. 2447 if (ShouldResetSummaryLog) 2448 SummaryLog.clear(); 2449 2450 ShouldResetSummaryLog = !SummaryLog.empty(); 2451 } 2452 2453 CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, 2454 bool GCEnabled) const { 2455 if (GCEnabled) { 2456 if (!leakWithinFunctionGC) 2457 leakWithinFunctionGC.reset(new Leak("Leak of object when using " 2458 "garbage collection")); 2459 return leakWithinFunctionGC.get(); 2460 } else { 2461 if (!leakWithinFunction) { 2462 if (LOpts.getGC() == LangOptions::HybridGC) { 2463 leakWithinFunction.reset(new Leak("Leak of object when not using " 2464 "garbage collection (GC) in " 2465 "dual GC/non-GC code")); 2466 } else { 2467 leakWithinFunction.reset(new Leak("Leak")); 2468 } 2469 } 2470 return leakWithinFunction.get(); 2471 } 2472 } 2473 2474 CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { 2475 if (GCEnabled) { 2476 if (!leakAtReturnGC) 2477 leakAtReturnGC.reset(new Leak("Leak of returned object when using " 2478 "garbage collection")); 2479 return leakAtReturnGC.get(); 2480 } else { 2481 if (!leakAtReturn) { 2482 if (LOpts.getGC() == LangOptions::HybridGC) { 2483 leakAtReturn.reset(new Leak("Leak of returned object when not using " 2484 "garbage collection (GC) in dual " 2485 "GC/non-GC code")); 2486 } else { 2487 leakAtReturn.reset(new Leak("Leak of returned object")); 2488 } 2489 } 2490 return leakAtReturn.get(); 2491 } 2492 } 2493 2494 RetainSummaryManager &getSummaryManager(ASTContext &Ctx, 2495 bool GCEnabled) const { 2496 // FIXME: We don't support ARC being turned on and off during one analysis. 2497 // (nor, for that matter, do we support changing ASTContexts) 2498 bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; 2499 if (GCEnabled) { 2500 if (!SummariesGC) 2501 SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); 2502 else 2503 assert(SummariesGC->isARCEnabled() == ARCEnabled); 2504 return *SummariesGC; 2505 } else { 2506 if (!Summaries) 2507 Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); 2508 else 2509 assert(Summaries->isARCEnabled() == ARCEnabled); 2510 return *Summaries; 2511 } 2512 } 2513 2514 RetainSummaryManager &getSummaryManager(CheckerContext &C) const { 2515 return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); 2516 } 2517 2518 void printState(raw_ostream &Out, ProgramStateRef State, 2519 const char *NL, const char *Sep) const; 2520 2521 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; 2522 void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; 2523 void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; 2524 2525 void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; 2526 void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; 2527 void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; 2528 2529 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 2530 2531 void checkSummary(const RetainSummary &Summ, const CallEvent &Call, 2532 CheckerContext &C) const; 2533 2534 bool evalCall(const CallExpr *CE, CheckerContext &C) const; 2535 2536 ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, 2537 bool Assumption) const; 2538 2539 ProgramStateRef 2540 checkRegionChanges(ProgramStateRef state, 2541 const StoreManager::InvalidatedSymbols *invalidated, 2542 ArrayRef<const MemRegion *> ExplicitRegions, 2543 ArrayRef<const MemRegion *> Regions, 2544 const CallEvent *Call) const; 2545 2546 bool wantsRegionChangeUpdate(ProgramStateRef state) const { 2547 return true; 2548 } 2549 2550 void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; 2551 void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, 2552 ExplodedNode *Pred, RetEffect RE, RefVal X, 2553 SymbolRef Sym, ProgramStateRef state) const; 2554 2555 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 2556 void checkEndPath(CheckerContext &C) const; 2557 2558 ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, 2559 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2560 CheckerContext &C) const; 2561 2562 void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, 2563 RefVal::Kind ErrorKind, SymbolRef Sym, 2564 CheckerContext &C) const; 2565 2566 void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; 2567 2568 const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; 2569 2570 ProgramStateRef handleSymbolDeath(ProgramStateRef state, 2571 SymbolRef sid, RefVal V, 2572 SmallVectorImpl<SymbolRef> &Leaked) const; 2573 2574 std::pair<ExplodedNode *, ProgramStateRef > 2575 handleAutoreleaseCounts(ProgramStateRef state, 2576 GenericNodeBuilderRefCount Bd, ExplodedNode *Pred, 2577 CheckerContext &Ctx, SymbolRef Sym, RefVal V) const; 2578 2579 ExplodedNode *processLeaks(ProgramStateRef state, 2580 SmallVectorImpl<SymbolRef> &Leaked, 2581 GenericNodeBuilderRefCount &Builder, 2582 CheckerContext &Ctx, 2583 ExplodedNode *Pred = 0) const; 2584}; 2585} // end anonymous namespace 2586 2587namespace { 2588class StopTrackingCallback : public SymbolVisitor { 2589 ProgramStateRef state; 2590public: 2591 StopTrackingCallback(ProgramStateRef st) : state(st) {} 2592 ProgramStateRef getState() const { return state; } 2593 2594 bool VisitSymbol(SymbolRef sym) { 2595 state = state->remove<RefBindings>(sym); 2596 return true; 2597 } 2598}; 2599} // end anonymous namespace 2600 2601//===----------------------------------------------------------------------===// 2602// Handle statements that may have an effect on refcounts. 2603//===----------------------------------------------------------------------===// 2604 2605void RetainCountChecker::checkPostStmt(const BlockExpr *BE, 2606 CheckerContext &C) const { 2607 2608 // Scan the BlockDecRefExprs for any object the retain count checker 2609 // may be tracking. 2610 if (!BE->getBlockDecl()->hasCaptures()) 2611 return; 2612 2613 ProgramStateRef state = C.getState(); 2614 const BlockDataRegion *R = 2615 cast<BlockDataRegion>(state->getSVal(BE, 2616 C.getLocationContext()).getAsRegion()); 2617 2618 BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), 2619 E = R->referenced_vars_end(); 2620 2621 if (I == E) 2622 return; 2623 2624 // FIXME: For now we invalidate the tracking of all symbols passed to blocks 2625 // via captured variables, even though captured variables result in a copy 2626 // and in implicit increment/decrement of a retain count. 2627 SmallVector<const MemRegion*, 10> Regions; 2628 const LocationContext *LC = C.getLocationContext(); 2629 MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); 2630 2631 for ( ; I != E; ++I) { 2632 const VarRegion *VR = *I; 2633 if (VR->getSuperRegion() == R) { 2634 VR = MemMgr.getVarRegion(VR->getDecl(), LC); 2635 } 2636 Regions.push_back(VR); 2637 } 2638 2639 state = 2640 state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), 2641 Regions.data() + Regions.size()).getState(); 2642 C.addTransition(state); 2643} 2644 2645void RetainCountChecker::checkPostStmt(const CastExpr *CE, 2646 CheckerContext &C) const { 2647 const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); 2648 if (!BE) 2649 return; 2650 2651 ArgEffect AE = IncRef; 2652 2653 switch (BE->getBridgeKind()) { 2654 case clang::OBC_Bridge: 2655 // Do nothing. 2656 return; 2657 case clang::OBC_BridgeRetained: 2658 AE = IncRef; 2659 break; 2660 case clang::OBC_BridgeTransfer: 2661 AE = DecRefBridgedTransfered; 2662 break; 2663 } 2664 2665 ProgramStateRef state = C.getState(); 2666 SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol(); 2667 if (!Sym) 2668 return; 2669 const RefVal* T = state->get<RefBindings>(Sym); 2670 if (!T) 2671 return; 2672 2673 RefVal::Kind hasErr = (RefVal::Kind) 0; 2674 state = updateSymbol(state, Sym, *T, AE, hasErr, C); 2675 2676 if (hasErr) { 2677 // FIXME: If we get an error during a bridge cast, should we report it? 2678 // Should we assert that there is no error? 2679 return; 2680 } 2681 2682 C.addTransition(state); 2683} 2684 2685void RetainCountChecker::processObjCLiterals(CheckerContext &C, 2686 const Expr *Ex) const { 2687 ProgramStateRef state = C.getState(); 2688 const ExplodedNode *pred = C.getPredecessor(); 2689 for (Stmt::const_child_iterator it = Ex->child_begin(), et = Ex->child_end() ; 2690 it != et ; ++it) { 2691 const Stmt *child = *it; 2692 SVal V = state->getSVal(child, pred->getLocationContext()); 2693 if (SymbolRef sym = V.getAsSymbol()) 2694 if (const RefVal* T = state->get<RefBindings>(sym)) { 2695 RefVal::Kind hasErr = (RefVal::Kind) 0; 2696 state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); 2697 if (hasErr) { 2698 processNonLeakError(state, child->getSourceRange(), hasErr, sym, C); 2699 return; 2700 } 2701 } 2702 } 2703 2704 // Return the object as autoreleased. 2705 // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); 2706 if (SymbolRef sym = 2707 state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { 2708 QualType ResultTy = Ex->getType(); 2709 state = state->set<RefBindings>(sym, RefVal::makeNotOwned(RetEffect::ObjC, 2710 ResultTy)); 2711 } 2712 2713 C.addTransition(state); 2714} 2715 2716void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, 2717 CheckerContext &C) const { 2718 // Apply the 'MayEscape' to all values. 2719 processObjCLiterals(C, AL); 2720} 2721 2722void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 2723 CheckerContext &C) const { 2724 // Apply the 'MayEscape' to all keys and values. 2725 processObjCLiterals(C, DL); 2726} 2727 2728void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, 2729 CheckerContext &C) const { 2730 const ExplodedNode *Pred = C.getPredecessor(); 2731 const LocationContext *LCtx = Pred->getLocationContext(); 2732 ProgramStateRef State = Pred->getState(); 2733 2734 if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) { 2735 QualType ResultTy = Ex->getType(); 2736 State = State->set<RefBindings>(Sym, RefVal::makeNotOwned(RetEffect::ObjC, 2737 ResultTy)); 2738 } 2739 2740 C.addTransition(State); 2741} 2742 2743void RetainCountChecker::checkPostCall(const CallEvent &Call, 2744 CheckerContext &C) const { 2745 if (C.wasInlined) 2746 return; 2747 2748 RetainSummaryManager &Summaries = getSummaryManager(C); 2749 const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); 2750 checkSummary(*Summ, Call, C); 2751} 2752 2753/// GetReturnType - Used to get the return type of a message expression or 2754/// function call with the intention of affixing that type to a tracked symbol. 2755/// While the the return type can be queried directly from RetEx, when 2756/// invoking class methods we augment to the return type to be that of 2757/// a pointer to the class (as opposed it just being id). 2758// FIXME: We may be able to do this with related result types instead. 2759// This function is probably overestimating. 2760static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { 2761 QualType RetTy = RetE->getType(); 2762 // If RetE is not a message expression just return its type. 2763 // If RetE is a message expression, return its types if it is something 2764 /// more specific than id. 2765 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) 2766 if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) 2767 if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || 2768 PT->isObjCClassType()) { 2769 // At this point we know the return type of the message expression is 2770 // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this 2771 // is a call to a class method whose type we can resolve. In such 2772 // cases, promote the return type to XXX* (where XXX is the class). 2773 const ObjCInterfaceDecl *D = ME->getReceiverInterface(); 2774 return !D ? RetTy : 2775 Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); 2776 } 2777 2778 return RetTy; 2779} 2780 2781void RetainCountChecker::checkSummary(const RetainSummary &Summ, 2782 const CallEvent &CallOrMsg, 2783 CheckerContext &C) const { 2784 ProgramStateRef state = C.getState(); 2785 2786 // Evaluate the effect of the arguments. 2787 RefVal::Kind hasErr = (RefVal::Kind) 0; 2788 SourceRange ErrorRange; 2789 SymbolRef ErrorSym = 0; 2790 2791 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2792 SVal V = CallOrMsg.getArgSVal(idx); 2793 2794 if (SymbolRef Sym = V.getAsLocSymbol()) { 2795 if (RefBindings::data_type *T = state->get<RefBindings>(Sym)) { 2796 state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C); 2797 if (hasErr) { 2798 ErrorRange = CallOrMsg.getArgSourceRange(idx); 2799 ErrorSym = Sym; 2800 break; 2801 } 2802 } 2803 } 2804 } 2805 2806 // Evaluate the effect on the message receiver. 2807 bool ReceiverIsTracked = false; 2808 if (!hasErr) { 2809 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2810 if (MsgInvocation) { 2811 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2812 if (const RefVal *T = state->get<RefBindings>(Sym)) { 2813 ReceiverIsTracked = true; 2814 state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), 2815 hasErr, C); 2816 if (hasErr) { 2817 ErrorRange = MsgInvocation->getReceiverSourceRange(); 2818 ErrorSym = Sym; 2819 } 2820 } 2821 } 2822 } 2823 } 2824 2825 // Process any errors. 2826 if (hasErr) { 2827 processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); 2828 return; 2829 } 2830 2831 // Consult the summary for the return value. 2832 RetEffect RE = Summ.getRetEffect(); 2833 2834 if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { 2835 if (ReceiverIsTracked) 2836 RE = getSummaryManager(C).getObjAllocRetEffect(); 2837 else 2838 RE = RetEffect::MakeNoRet(); 2839 } 2840 2841 switch (RE.getKind()) { 2842 default: 2843 llvm_unreachable("Unhandled RetEffect."); 2844 2845 case RetEffect::NoRet: 2846 // No work necessary. 2847 break; 2848 2849 case RetEffect::OwnedAllocatedSymbol: 2850 case RetEffect::OwnedSymbol: { 2851 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2852 C.getLocationContext()).getAsSymbol(); 2853 if (!Sym) 2854 break; 2855 2856 // Use the result type from the CallEvent as it automatically adjusts 2857 // for methods/functions that return references. 2858 QualType ResultTy = CallOrMsg.getResultType(); 2859 state = state->set<RefBindings>(Sym, RefVal::makeOwned(RE.getObjKind(), 2860 ResultTy)); 2861 2862 // FIXME: Add a flag to the checker where allocations are assumed to 2863 // *not* fail. (The code below is out-of-date, though.) 2864#if 0 2865 if (RE.getKind() == RetEffect::OwnedAllocatedSymbol) { 2866 bool isFeasible; 2867 state = state.assume(loc::SymbolVal(Sym), true, isFeasible); 2868 assert(isFeasible && "Cannot assume fresh symbol is non-null."); 2869 } 2870#endif 2871 2872 break; 2873 } 2874 2875 case RetEffect::GCNotOwnedSymbol: 2876 case RetEffect::ARCNotOwnedSymbol: 2877 case RetEffect::NotOwnedSymbol: { 2878 const Expr *Ex = CallOrMsg.getOriginExpr(); 2879 SymbolRef Sym = state->getSVal(Ex, C.getLocationContext()).getAsSymbol(); 2880 if (!Sym) 2881 break; 2882 2883 // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. 2884 QualType ResultTy = GetReturnType(Ex, C.getASTContext()); 2885 state = state->set<RefBindings>(Sym, RefVal::makeNotOwned(RE.getObjKind(), 2886 ResultTy)); 2887 break; 2888 } 2889 } 2890 2891 // This check is actually necessary; otherwise the statement builder thinks 2892 // we've hit a previously-found path. 2893 // Normally addTransition takes care of this, but we want the node pointer. 2894 ExplodedNode *NewNode; 2895 if (state == C.getState()) { 2896 NewNode = C.getPredecessor(); 2897 } else { 2898 NewNode = C.addTransition(state); 2899 } 2900 2901 // Annotate the node with summary we used. 2902 if (NewNode) { 2903 // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. 2904 if (ShouldResetSummaryLog) { 2905 SummaryLog.clear(); 2906 ShouldResetSummaryLog = false; 2907 } 2908 SummaryLog[NewNode] = &Summ; 2909 } 2910} 2911 2912 2913ProgramStateRef 2914RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, 2915 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2916 CheckerContext &C) const { 2917 // In GC mode [... release] and [... retain] do nothing. 2918 // In ARC mode they shouldn't exist at all, but we just ignore them. 2919 bool IgnoreRetainMsg = C.isObjCGCEnabled(); 2920 if (!IgnoreRetainMsg) 2921 IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; 2922 2923 switch (E) { 2924 default: 2925 break; 2926 case IncRefMsg: 2927 E = IgnoreRetainMsg ? DoNothing : IncRef; 2928 break; 2929 case DecRefMsg: 2930 E = IgnoreRetainMsg ? DoNothing : DecRef; 2931 break; 2932 case DecRefMsgAndStopTracking: 2933 E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTracking; 2934 break; 2935 case MakeCollectable: 2936 E = C.isObjCGCEnabled() ? DecRef : DoNothing; 2937 break; 2938 case NewAutoreleasePool: 2939 E = C.isObjCGCEnabled() ? DoNothing : NewAutoreleasePool; 2940 break; 2941 } 2942 2943 // Handle all use-after-releases. 2944 if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { 2945 V = V ^ RefVal::ErrorUseAfterRelease; 2946 hasErr = V.getKind(); 2947 return state->set<RefBindings>(sym, V); 2948 } 2949 2950 switch (E) { 2951 case DecRefMsg: 2952 case IncRefMsg: 2953 case MakeCollectable: 2954 case DecRefMsgAndStopTracking: 2955 llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); 2956 2957 case Dealloc: 2958 // Any use of -dealloc in GC is *bad*. 2959 if (C.isObjCGCEnabled()) { 2960 V = V ^ RefVal::ErrorDeallocGC; 2961 hasErr = V.getKind(); 2962 break; 2963 } 2964 2965 switch (V.getKind()) { 2966 default: 2967 llvm_unreachable("Invalid RefVal state for an explicit dealloc."); 2968 case RefVal::Owned: 2969 // The object immediately transitions to the released state. 2970 V = V ^ RefVal::Released; 2971 V.clearCounts(); 2972 return state->set<RefBindings>(sym, V); 2973 case RefVal::NotOwned: 2974 V = V ^ RefVal::ErrorDeallocNotOwned; 2975 hasErr = V.getKind(); 2976 break; 2977 } 2978 break; 2979 2980 case NewAutoreleasePool: 2981 assert(!C.isObjCGCEnabled()); 2982 return state->add<AutoreleaseStack>(sym); 2983 2984 case MayEscape: 2985 if (V.getKind() == RefVal::Owned) { 2986 V = V ^ RefVal::NotOwned; 2987 break; 2988 } 2989 2990 // Fall-through. 2991 2992 case DoNothing: 2993 return state; 2994 2995 case Autorelease: 2996 if (C.isObjCGCEnabled()) 2997 return state; 2998 2999 // Update the autorelease counts. 3000 state = SendAutorelease(state, ARCountFactory, sym); 3001 V = V.autorelease(); 3002 break; 3003 3004 case StopTracking: 3005 return state->remove<RefBindings>(sym); 3006 3007 case IncRef: 3008 switch (V.getKind()) { 3009 default: 3010 llvm_unreachable("Invalid RefVal state for a retain."); 3011 case RefVal::Owned: 3012 case RefVal::NotOwned: 3013 V = V + 1; 3014 break; 3015 case RefVal::Released: 3016 // Non-GC cases are handled above. 3017 assert(C.isObjCGCEnabled()); 3018 V = (V ^ RefVal::Owned) + 1; 3019 break; 3020 } 3021 break; 3022 3023 case DecRef: 3024 case DecRefBridgedTransfered: 3025 case DecRefAndStopTracking: 3026 switch (V.getKind()) { 3027 default: 3028 // case 'RefVal::Released' handled above. 3029 llvm_unreachable("Invalid RefVal state for a release."); 3030 3031 case RefVal::Owned: 3032 assert(V.getCount() > 0); 3033 if (V.getCount() == 1) 3034 V = V ^ (E == DecRefBridgedTransfered ? 3035 RefVal::NotOwned : RefVal::Released); 3036 else if (E == DecRefAndStopTracking) 3037 return state->remove<RefBindings>(sym); 3038 3039 V = V - 1; 3040 break; 3041 3042 case RefVal::NotOwned: 3043 if (V.getCount() > 0) { 3044 if (E == DecRefAndStopTracking) 3045 return state->remove<RefBindings>(sym); 3046 V = V - 1; 3047 } else { 3048 V = V ^ RefVal::ErrorReleaseNotOwned; 3049 hasErr = V.getKind(); 3050 } 3051 break; 3052 3053 case RefVal::Released: 3054 // Non-GC cases are handled above. 3055 assert(C.isObjCGCEnabled()); 3056 V = V ^ RefVal::ErrorUseAfterRelease; 3057 hasErr = V.getKind(); 3058 break; 3059 } 3060 break; 3061 } 3062 return state->set<RefBindings>(sym, V); 3063} 3064 3065void RetainCountChecker::processNonLeakError(ProgramStateRef St, 3066 SourceRange ErrorRange, 3067 RefVal::Kind ErrorKind, 3068 SymbolRef Sym, 3069 CheckerContext &C) const { 3070 ExplodedNode *N = C.generateSink(St); 3071 if (!N) 3072 return; 3073 3074 CFRefBug *BT; 3075 switch (ErrorKind) { 3076 default: 3077 llvm_unreachable("Unhandled error."); 3078 case RefVal::ErrorUseAfterRelease: 3079 if (!useAfterRelease) 3080 useAfterRelease.reset(new UseAfterRelease()); 3081 BT = &*useAfterRelease; 3082 break; 3083 case RefVal::ErrorReleaseNotOwned: 3084 if (!releaseNotOwned) 3085 releaseNotOwned.reset(new BadRelease()); 3086 BT = &*releaseNotOwned; 3087 break; 3088 case RefVal::ErrorDeallocGC: 3089 if (!deallocGC) 3090 deallocGC.reset(new DeallocGC()); 3091 BT = &*deallocGC; 3092 break; 3093 case RefVal::ErrorDeallocNotOwned: 3094 if (!deallocNotOwned) 3095 deallocNotOwned.reset(new DeallocNotOwned()); 3096 BT = &*deallocNotOwned; 3097 break; 3098 } 3099 3100 assert(BT); 3101 CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOpts(), 3102 C.isObjCGCEnabled(), SummaryLog, 3103 N, Sym); 3104 report->addRange(ErrorRange); 3105 C.EmitReport(report); 3106} 3107 3108//===----------------------------------------------------------------------===// 3109// Handle the return values of retain-count-related functions. 3110//===----------------------------------------------------------------------===// 3111 3112bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { 3113 // Get the callee. We're only interested in simple C functions. 3114 ProgramStateRef state = C.getState(); 3115 const FunctionDecl *FD = C.getCalleeDecl(CE); 3116 if (!FD) 3117 return false; 3118 3119 IdentifierInfo *II = FD->getIdentifier(); 3120 if (!II) 3121 return false; 3122 3123 // For now, we're only handling the functions that return aliases of their 3124 // arguments: CFRetain and CFMakeCollectable (and their families). 3125 // Eventually we should add other functions we can model entirely, 3126 // such as CFRelease, which don't invalidate their arguments or globals. 3127 if (CE->getNumArgs() != 1) 3128 return false; 3129 3130 // Get the name of the function. 3131 StringRef FName = II->getName(); 3132 FName = FName.substr(FName.find_first_not_of('_')); 3133 3134 // See if it's one of the specific functions we know how to eval. 3135 bool canEval = false; 3136 3137 QualType ResultTy = CE->getCallReturnType(); 3138 if (ResultTy->isObjCIdType()) { 3139 // Handle: id NSMakeCollectable(CFTypeRef) 3140 canEval = II->isStr("NSMakeCollectable"); 3141 } else if (ResultTy->isPointerType()) { 3142 // Handle: (CF|CG)Retain 3143 // CFMakeCollectable 3144 // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). 3145 if (cocoa::isRefType(ResultTy, "CF", FName) || 3146 cocoa::isRefType(ResultTy, "CG", FName)) { 3147 canEval = isRetain(FD, FName) || isMakeCollectable(FD, FName); 3148 } 3149 } 3150 3151 if (!canEval) 3152 return false; 3153 3154 // Bind the return value. 3155 const LocationContext *LCtx = C.getLocationContext(); 3156 SVal RetVal = state->getSVal(CE->getArg(0), LCtx); 3157 if (RetVal.isUnknown()) { 3158 // If the receiver is unknown, conjure a return value. 3159 SValBuilder &SVB = C.getSValBuilder(); 3160 unsigned Count = C.getCurrentBlockCount(); 3161 SVal RetVal = SVB.getConjuredSymbolVal(0, CE, LCtx, ResultTy, Count); 3162 } 3163 state = state->BindExpr(CE, LCtx, RetVal, false); 3164 3165 // FIXME: This should not be necessary, but otherwise the argument seems to be 3166 // considered alive during the next statement. 3167 if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { 3168 // Save the refcount status of the argument. 3169 SymbolRef Sym = RetVal.getAsLocSymbol(); 3170 RefBindings::data_type *Binding = 0; 3171 if (Sym) 3172 Binding = state->get<RefBindings>(Sym); 3173 3174 // Invalidate the argument region. 3175 unsigned Count = C.getCurrentBlockCount(); 3176 state = state->invalidateRegions(ArgRegion, CE, Count, LCtx); 3177 3178 // Restore the refcount status of the argument. 3179 if (Binding) 3180 state = state->set<RefBindings>(Sym, *Binding); 3181 } 3182 3183 C.addTransition(state); 3184 return true; 3185} 3186 3187//===----------------------------------------------------------------------===// 3188// Handle return statements. 3189//===----------------------------------------------------------------------===// 3190 3191// Return true if the current LocationContext has no caller context. 3192static bool inTopFrame(CheckerContext &C) { 3193 const LocationContext *LC = C.getLocationContext(); 3194 return LC->getParent() == 0; 3195} 3196 3197void RetainCountChecker::checkPreStmt(const ReturnStmt *S, 3198 CheckerContext &C) const { 3199 3200 // Only adjust the reference count if this is the top-level call frame, 3201 // and not the result of inlining. In the future, we should do 3202 // better checking even for inlined calls, and see if they match 3203 // with their expected semantics (e.g., the method should return a retained 3204 // object, etc.). 3205 if (!inTopFrame(C)) 3206 return; 3207 3208 const Expr *RetE = S->getRetValue(); 3209 if (!RetE) 3210 return; 3211 3212 ProgramStateRef state = C.getState(); 3213 SymbolRef Sym = 3214 state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); 3215 if (!Sym) 3216 return; 3217 3218 // Get the reference count binding (if any). 3219 const RefVal *T = state->get<RefBindings>(Sym); 3220 if (!T) 3221 return; 3222 3223 // Change the reference count. 3224 RefVal X = *T; 3225 3226 switch (X.getKind()) { 3227 case RefVal::Owned: { 3228 unsigned cnt = X.getCount(); 3229 assert(cnt > 0); 3230 X.setCount(cnt - 1); 3231 X = X ^ RefVal::ReturnedOwned; 3232 break; 3233 } 3234 3235 case RefVal::NotOwned: { 3236 unsigned cnt = X.getCount(); 3237 if (cnt) { 3238 X.setCount(cnt - 1); 3239 X = X ^ RefVal::ReturnedOwned; 3240 } 3241 else { 3242 X = X ^ RefVal::ReturnedNotOwned; 3243 } 3244 break; 3245 } 3246 3247 default: 3248 return; 3249 } 3250 3251 // Update the binding. 3252 state = state->set<RefBindings>(Sym, X); 3253 ExplodedNode *Pred = C.addTransition(state); 3254 3255 // At this point we have updated the state properly. 3256 // Everything after this is merely checking to see if the return value has 3257 // been over- or under-retained. 3258 3259 // Did we cache out? 3260 if (!Pred) 3261 return; 3262 3263 // Update the autorelease counts. 3264 static SimpleProgramPointTag 3265 AutoreleaseTag("RetainCountChecker : Autorelease"); 3266 GenericNodeBuilderRefCount Bd(C, &AutoreleaseTag); 3267 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, C, Sym, X); 3268 3269 // Did we cache out? 3270 if (!Pred) 3271 return; 3272 3273 // Get the updated binding. 3274 T = state->get<RefBindings>(Sym); 3275 assert(T); 3276 X = *T; 3277 3278 // Consult the summary of the enclosing method. 3279 RetainSummaryManager &Summaries = getSummaryManager(C); 3280 const Decl *CD = &Pred->getCodeDecl(); 3281 RetEffect RE = RetEffect::MakeNoRet(); 3282 3283 // FIXME: What is the convention for blocks? Is there one? 3284 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) { 3285 const RetainSummary *Summ = Summaries.getMethodSummary(MD); 3286 RE = Summ->getRetEffect(); 3287 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) { 3288 if (!isa<CXXMethodDecl>(FD)) { 3289 const RetainSummary *Summ = Summaries.getFunctionSummary(FD); 3290 RE = Summ->getRetEffect(); 3291 } 3292 } 3293 3294 checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state); 3295} 3296 3297void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S, 3298 CheckerContext &C, 3299 ExplodedNode *Pred, 3300 RetEffect RE, RefVal X, 3301 SymbolRef Sym, 3302 ProgramStateRef state) const { 3303 // Any leaks or other errors? 3304 if (X.isReturnedOwned() && X.getCount() == 0) { 3305 if (RE.getKind() != RetEffect::NoRet) { 3306 bool hasError = false; 3307 if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) { 3308 // Things are more complicated with garbage collection. If the 3309 // returned object is suppose to be an Objective-C object, we have 3310 // a leak (as the caller expects a GC'ed object) because no 3311 // method should return ownership unless it returns a CF object. 3312 hasError = true; 3313 X = X ^ RefVal::ErrorGCLeakReturned; 3314 } 3315 else if (!RE.isOwned()) { 3316 // Either we are using GC and the returned object is a CF type 3317 // or we aren't using GC. In either case, we expect that the 3318 // enclosing method is expected to return ownership. 3319 hasError = true; 3320 X = X ^ RefVal::ErrorLeakReturned; 3321 } 3322 3323 if (hasError) { 3324 // Generate an error node. 3325 state = state->set<RefBindings>(Sym, X); 3326 3327 static SimpleProgramPointTag 3328 ReturnOwnLeakTag("RetainCountChecker : ReturnsOwnLeak"); 3329 ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag); 3330 if (N) { 3331 const LangOptions &LOpts = C.getASTContext().getLangOpts(); 3332 bool GCEnabled = C.isObjCGCEnabled(); 3333 CFRefReport *report = 3334 new CFRefLeakReport(*getLeakAtReturnBug(LOpts, GCEnabled), 3335 LOpts, GCEnabled, SummaryLog, 3336 N, Sym, C); 3337 C.EmitReport(report); 3338 } 3339 } 3340 } 3341 } else if (X.isReturnedNotOwned()) { 3342 if (RE.isOwned()) { 3343 // Trying to return a not owned object to a caller expecting an 3344 // owned object. 3345 state = state->set<RefBindings>(Sym, X ^ RefVal::ErrorReturnedNotOwned); 3346 3347 static SimpleProgramPointTag 3348 ReturnNotOwnedTag("RetainCountChecker : ReturnNotOwnedForOwned"); 3349 ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag); 3350 if (N) { 3351 if (!returnNotOwnedForOwned) 3352 returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned()); 3353 3354 CFRefReport *report = 3355 new CFRefReport(*returnNotOwnedForOwned, 3356 C.getASTContext().getLangOpts(), 3357 C.isObjCGCEnabled(), SummaryLog, N, Sym); 3358 C.EmitReport(report); 3359 } 3360 } 3361 } 3362} 3363 3364//===----------------------------------------------------------------------===// 3365// Check various ways a symbol can be invalidated. 3366//===----------------------------------------------------------------------===// 3367 3368void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S, 3369 CheckerContext &C) const { 3370 // Are we storing to something that causes the value to "escape"? 3371 bool escapes = true; 3372 3373 // A value escapes in three possible cases (this may change): 3374 // 3375 // (1) we are binding to something that is not a memory region. 3376 // (2) we are binding to a memregion that does not have stack storage 3377 // (3) we are binding to a memregion with stack storage that the store 3378 // does not understand. 3379 ProgramStateRef state = C.getState(); 3380 3381 if (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) { 3382 escapes = !regionLoc->getRegion()->hasStackStorage(); 3383 3384 if (!escapes) { 3385 // To test (3), generate a new state with the binding added. If it is 3386 // the same state, then it escapes (since the store cannot represent 3387 // the binding). 3388 // Do this only if we know that the store is not supposed to generate the 3389 // same state. 3390 SVal StoredVal = state->getSVal(regionLoc->getRegion()); 3391 if (StoredVal != val) 3392 escapes = (state == (state->bindLoc(*regionLoc, val))); 3393 } 3394 if (!escapes) { 3395 // Case 4: We do not currently model what happens when a symbol is 3396 // assigned to a struct field, so be conservative here and let the symbol 3397 // go. TODO: This could definitely be improved upon. 3398 escapes = !isa<VarRegion>(regionLoc->getRegion()); 3399 } 3400 } 3401 3402 // If our store can represent the binding and we aren't storing to something 3403 // that doesn't have local storage then just return and have the simulation 3404 // state continue as is. 3405 if (!escapes) 3406 return; 3407 3408 // Otherwise, find all symbols referenced by 'val' that we are tracking 3409 // and stop tracking them. 3410 state = state->scanReachableSymbols<StopTrackingCallback>(val).getState(); 3411 C.addTransition(state); 3412} 3413 3414ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state, 3415 SVal Cond, 3416 bool Assumption) const { 3417 3418 // FIXME: We may add to the interface of evalAssume the list of symbols 3419 // whose assumptions have changed. For now we just iterate through the 3420 // bindings and check if any of the tracked symbols are NULL. This isn't 3421 // too bad since the number of symbols we will track in practice are 3422 // probably small and evalAssume is only called at branches and a few 3423 // other places. 3424 RefBindings B = state->get<RefBindings>(); 3425 3426 if (B.isEmpty()) 3427 return state; 3428 3429 bool changed = false; 3430 RefBindings::Factory &RefBFactory = state->get_context<RefBindings>(); 3431 3432 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3433 // Check if the symbol is null (or equal to any constant). 3434 // If this is the case, stop tracking the symbol. 3435 if (state->getSymVal(I.getKey())) { 3436 changed = true; 3437 B = RefBFactory.remove(B, I.getKey()); 3438 } 3439 } 3440 3441 if (changed) 3442 state = state->set<RefBindings>(B); 3443 3444 return state; 3445} 3446 3447ProgramStateRef 3448RetainCountChecker::checkRegionChanges(ProgramStateRef state, 3449 const StoreManager::InvalidatedSymbols *invalidated, 3450 ArrayRef<const MemRegion *> ExplicitRegions, 3451 ArrayRef<const MemRegion *> Regions, 3452 const CallEvent *Call) const { 3453 if (!invalidated) 3454 return state; 3455 3456 llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols; 3457 for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(), 3458 E = ExplicitRegions.end(); I != E; ++I) { 3459 if (const SymbolicRegion *SR = (*I)->StripCasts()->getAs<SymbolicRegion>()) 3460 WhitelistedSymbols.insert(SR->getSymbol()); 3461 } 3462 3463 for (StoreManager::InvalidatedSymbols::const_iterator I=invalidated->begin(), 3464 E = invalidated->end(); I!=E; ++I) { 3465 SymbolRef sym = *I; 3466 if (WhitelistedSymbols.count(sym)) 3467 continue; 3468 // Remove any existing reference-count binding. 3469 state = state->remove<RefBindings>(sym); 3470 } 3471 return state; 3472} 3473 3474//===----------------------------------------------------------------------===// 3475// Handle dead symbols and end-of-path. 3476//===----------------------------------------------------------------------===// 3477 3478std::pair<ExplodedNode *, ProgramStateRef > 3479RetainCountChecker::handleAutoreleaseCounts(ProgramStateRef state, 3480 GenericNodeBuilderRefCount Bd, 3481 ExplodedNode *Pred, 3482 CheckerContext &Ctx, 3483 SymbolRef Sym, RefVal V) const { 3484 unsigned ACnt = V.getAutoreleaseCount(); 3485 3486 // No autorelease counts? Nothing to be done. 3487 if (!ACnt) 3488 return std::make_pair(Pred, state); 3489 3490 assert(!Ctx.isObjCGCEnabled() && "Autorelease counts in GC mode?"); 3491 unsigned Cnt = V.getCount(); 3492 3493 // FIXME: Handle sending 'autorelease' to already released object. 3494 3495 if (V.getKind() == RefVal::ReturnedOwned) 3496 ++Cnt; 3497 3498 if (ACnt <= Cnt) { 3499 if (ACnt == Cnt) { 3500 V.clearCounts(); 3501 if (V.getKind() == RefVal::ReturnedOwned) 3502 V = V ^ RefVal::ReturnedNotOwned; 3503 else 3504 V = V ^ RefVal::NotOwned; 3505 } else { 3506 V.setCount(Cnt - ACnt); 3507 V.setAutoreleaseCount(0); 3508 } 3509 state = state->set<RefBindings>(Sym, V); 3510 ExplodedNode *N = Bd.MakeNode(state, Pred); 3511 if (N == 0) 3512 state = 0; 3513 return std::make_pair(N, state); 3514 } 3515 3516 // Woah! More autorelease counts then retain counts left. 3517 // Emit hard error. 3518 V = V ^ RefVal::ErrorOverAutorelease; 3519 state = state->set<RefBindings>(Sym, V); 3520 3521 if (ExplodedNode *N = Bd.MakeNode(state, Pred, true)) { 3522 SmallString<128> sbuf; 3523 llvm::raw_svector_ostream os(sbuf); 3524 os << "Object over-autoreleased: object was sent -autorelease "; 3525 if (V.getAutoreleaseCount() > 1) 3526 os << V.getAutoreleaseCount() << " times "; 3527 os << "but the object has a +" << V.getCount() << " retain count"; 3528 3529 if (!overAutorelease) 3530 overAutorelease.reset(new OverAutorelease()); 3531 3532 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3533 CFRefReport *report = 3534 new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false, 3535 SummaryLog, N, Sym, os.str()); 3536 Ctx.EmitReport(report); 3537 } 3538 3539 return std::make_pair((ExplodedNode *)0, (ProgramStateRef )0); 3540} 3541 3542ProgramStateRef 3543RetainCountChecker::handleSymbolDeath(ProgramStateRef state, 3544 SymbolRef sid, RefVal V, 3545 SmallVectorImpl<SymbolRef> &Leaked) const { 3546 bool hasLeak = false; 3547 if (V.isOwned()) 3548 hasLeak = true; 3549 else if (V.isNotOwned() || V.isReturnedOwned()) 3550 hasLeak = (V.getCount() > 0); 3551 3552 if (!hasLeak) 3553 return state->remove<RefBindings>(sid); 3554 3555 Leaked.push_back(sid); 3556 return state->set<RefBindings>(sid, V ^ RefVal::ErrorLeak); 3557} 3558 3559ExplodedNode * 3560RetainCountChecker::processLeaks(ProgramStateRef state, 3561 SmallVectorImpl<SymbolRef> &Leaked, 3562 GenericNodeBuilderRefCount &Builder, 3563 CheckerContext &Ctx, 3564 ExplodedNode *Pred) const { 3565 if (Leaked.empty()) 3566 return Pred; 3567 3568 // Generate an intermediate node representing the leak point. 3569 ExplodedNode *N = Builder.MakeNode(state, Pred); 3570 3571 if (N) { 3572 for (SmallVectorImpl<SymbolRef>::iterator 3573 I = Leaked.begin(), E = Leaked.end(); I != E; ++I) { 3574 3575 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3576 bool GCEnabled = Ctx.isObjCGCEnabled(); 3577 CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled) 3578 : getLeakAtReturnBug(LOpts, GCEnabled); 3579 assert(BT && "BugType not initialized."); 3580 3581 CFRefLeakReport *report = new CFRefLeakReport(*BT, LOpts, GCEnabled, 3582 SummaryLog, N, *I, Ctx); 3583 Ctx.EmitReport(report); 3584 } 3585 } 3586 3587 return N; 3588} 3589 3590void RetainCountChecker::checkEndPath(CheckerContext &Ctx) const { 3591 ProgramStateRef state = Ctx.getState(); 3592 GenericNodeBuilderRefCount Bd(Ctx); 3593 RefBindings B = state->get<RefBindings>(); 3594 ExplodedNode *Pred = Ctx.getPredecessor(); 3595 3596 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3597 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, Ctx, 3598 I->first, I->second); 3599 if (!state) 3600 return; 3601 } 3602 3603 // If the current LocationContext has a parent, don't check for leaks. 3604 // We will do that later. 3605 // FIXME: we should instead check for imblances of the retain/releases, 3606 // and suggest annotations. 3607 if (Ctx.getLocationContext()->getParent()) 3608 return; 3609 3610 B = state->get<RefBindings>(); 3611 SmallVector<SymbolRef, 10> Leaked; 3612 3613 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) 3614 state = handleSymbolDeath(state, I->first, I->second, Leaked); 3615 3616 processLeaks(state, Leaked, Bd, Ctx, Pred); 3617} 3618 3619const ProgramPointTag * 3620RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const { 3621 const SimpleProgramPointTag *&tag = DeadSymbolTags[sym]; 3622 if (!tag) { 3623 SmallString<64> buf; 3624 llvm::raw_svector_ostream out(buf); 3625 out << "RetainCountChecker : Dead Symbol : "; 3626 sym->dumpToStream(out); 3627 tag = new SimpleProgramPointTag(out.str()); 3628 } 3629 return tag; 3630} 3631 3632void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper, 3633 CheckerContext &C) const { 3634 ExplodedNode *Pred = C.getPredecessor(); 3635 3636 ProgramStateRef state = C.getState(); 3637 RefBindings B = state->get<RefBindings>(); 3638 3639 // Update counts from autorelease pools 3640 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3641 E = SymReaper.dead_end(); I != E; ++I) { 3642 SymbolRef Sym = *I; 3643 if (const RefVal *T = B.lookup(Sym)){ 3644 // Use the symbol as the tag. 3645 // FIXME: This might not be as unique as we would like. 3646 GenericNodeBuilderRefCount Bd(C, getDeadSymbolTag(Sym)); 3647 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, C, 3648 Sym, *T); 3649 if (!state) 3650 return; 3651 } 3652 } 3653 3654 B = state->get<RefBindings>(); 3655 SmallVector<SymbolRef, 10> Leaked; 3656 3657 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3658 E = SymReaper.dead_end(); I != E; ++I) { 3659 if (const RefVal *T = B.lookup(*I)) 3660 state = handleSymbolDeath(state, *I, *T, Leaked); 3661 } 3662 3663 { 3664 GenericNodeBuilderRefCount Bd(C, this); 3665 Pred = processLeaks(state, Leaked, Bd, C, Pred); 3666 } 3667 3668 // Did we cache out? 3669 if (!Pred) 3670 return; 3671 3672 // Now generate a new node that nukes the old bindings. 3673 RefBindings::Factory &F = state->get_context<RefBindings>(); 3674 3675 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3676 E = SymReaper.dead_end(); I != E; ++I) 3677 B = F.remove(B, *I); 3678 3679 state = state->set<RefBindings>(B); 3680 C.addTransition(state, Pred); 3681} 3682 3683//===----------------------------------------------------------------------===// 3684// Debug printing of refcount bindings and autorelease pools. 3685//===----------------------------------------------------------------------===// 3686 3687static void PrintPool(raw_ostream &Out, SymbolRef Sym, 3688 ProgramStateRef State) { 3689 Out << ' '; 3690 if (Sym) 3691 Sym->dumpToStream(Out); 3692 else 3693 Out << "<pool>"; 3694 Out << ":{"; 3695 3696 // Get the contents of the pool. 3697 if (const ARCounts *Cnts = State->get<AutoreleasePoolContents>(Sym)) 3698 for (ARCounts::iterator I = Cnts->begin(), E = Cnts->end(); I != E; ++I) 3699 Out << '(' << I.getKey() << ',' << I.getData() << ')'; 3700 3701 Out << '}'; 3702} 3703 3704static bool UsesAutorelease(ProgramStateRef state) { 3705 // A state uses autorelease if it allocated an autorelease pool or if it has 3706 // objects in the caller's autorelease pool. 3707 return !state->get<AutoreleaseStack>().isEmpty() || 3708 state->get<AutoreleasePoolContents>(SymbolRef()); 3709} 3710 3711void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State, 3712 const char *NL, const char *Sep) const { 3713 3714 RefBindings B = State->get<RefBindings>(); 3715 3716 if (!B.isEmpty()) 3717 Out << Sep << NL; 3718 3719 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3720 Out << I->first << " : "; 3721 I->second.print(Out); 3722 Out << NL; 3723 } 3724 3725 // Print the autorelease stack. 3726 if (UsesAutorelease(State)) { 3727 Out << Sep << NL << "AR pool stack:"; 3728 ARStack Stack = State->get<AutoreleaseStack>(); 3729 3730 PrintPool(Out, SymbolRef(), State); // Print the caller's pool. 3731 for (ARStack::iterator I = Stack.begin(), E = Stack.end(); I != E; ++I) 3732 PrintPool(Out, *I, State); 3733 3734 Out << NL; 3735 } 3736} 3737 3738//===----------------------------------------------------------------------===// 3739// Checker registration. 3740//===----------------------------------------------------------------------===// 3741 3742void ento::registerRetainCountChecker(CheckerManager &Mgr) { 3743 Mgr.registerChecker<RetainCountChecker>(); 3744} 3745 3746