RetainCountChecker.cpp revision fdaa33818cf9bad8d092136e73bd2e489cb821ba
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_CXXMemberOperator: 949 case CE_Block: 950 case CE_CXXConstructor: 951 case CE_CXXAllocator: 952 // FIXME: These calls are currently unsupported. 953 return getPersistentStopSummary(); 954 case CE_ObjCMessage: 955 case CE_ObjCPropertyAccess: { 956 const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call); 957 if (Msg.isInstanceMessage()) 958 Summ = getInstanceMethodSummary(Msg, State); 959 else 960 Summ = getClassMethodSummary(Msg); 961 break; 962 } 963 } 964 965 updateSummaryForCall(Summ, Call); 966 967 assert(Summ && "Unknown call type?"); 968 return Summ; 969} 970 971const RetainSummary * 972RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) { 973 // If we don't know what function we're calling, use our default summary. 974 if (!FD) 975 return getDefaultSummary(); 976 977 // Look up a summary in our cache of FunctionDecls -> Summaries. 978 FuncSummariesTy::iterator I = FuncSummaries.find(FD); 979 if (I != FuncSummaries.end()) 980 return I->second; 981 982 // No summary? Generate one. 983 const RetainSummary *S = 0; 984 985 do { 986 // We generate "stop" summaries for implicitly defined functions. 987 if (FD->isImplicit()) { 988 S = getPersistentStopSummary(); 989 break; 990 } 991 992 // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the 993 // function's type. 994 const FunctionType* FT = FD->getType()->getAs<FunctionType>(); 995 const IdentifierInfo *II = FD->getIdentifier(); 996 if (!II) 997 break; 998 999 StringRef FName = II->getName(); 1000 1001 // Strip away preceding '_'. Doing this here will effect all the checks 1002 // down below. 1003 FName = FName.substr(FName.find_first_not_of('_')); 1004 1005 // Inspect the result type. 1006 QualType RetTy = FT->getResultType(); 1007 1008 // FIXME: This should all be refactored into a chain of "summary lookup" 1009 // filters. 1010 assert(ScratchArgs.isEmpty()); 1011 1012 if (FName == "pthread_create" || FName == "pthread_setspecific") { 1013 // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>. 1014 // This will be addressed better with IPA. 1015 S = getPersistentStopSummary(); 1016 } else if (FName == "NSMakeCollectable") { 1017 // Handle: id NSMakeCollectable(CFTypeRef) 1018 S = (RetTy->isObjCIdType()) 1019 ? getUnarySummary(FT, cfmakecollectable) 1020 : getPersistentStopSummary(); 1021 } else if (FName == "IOBSDNameMatching" || 1022 FName == "IOServiceMatching" || 1023 FName == "IOServiceNameMatching" || 1024 FName == "IORegistryEntrySearchCFProperty" || 1025 FName == "IORegistryEntryIDMatching" || 1026 FName == "IOOpenFirmwarePathMatching") { 1027 // Part of <rdar://problem/6961230>. (IOKit) 1028 // This should be addressed using a API table. 1029 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1030 DoNothing, DoNothing); 1031 } else if (FName == "IOServiceGetMatchingService" || 1032 FName == "IOServiceGetMatchingServices") { 1033 // FIXES: <rdar://problem/6326900> 1034 // This should be addressed using a API table. This strcmp is also 1035 // a little gross, but there is no need to super optimize here. 1036 ScratchArgs = AF.add(ScratchArgs, 1, DecRef); 1037 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1038 } else if (FName == "IOServiceAddNotification" || 1039 FName == "IOServiceAddMatchingNotification") { 1040 // Part of <rdar://problem/6961230>. (IOKit) 1041 // This should be addressed using a API table. 1042 ScratchArgs = AF.add(ScratchArgs, 2, DecRef); 1043 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1044 } else if (FName == "CVPixelBufferCreateWithBytes") { 1045 // FIXES: <rdar://problem/7283567> 1046 // Eventually this can be improved by recognizing that the pixel 1047 // buffer passed to CVPixelBufferCreateWithBytes is released via 1048 // a callback and doing full IPA to make sure this is done correctly. 1049 // FIXME: This function has an out parameter that returns an 1050 // allocated object. 1051 ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); 1052 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1053 } else if (FName == "CGBitmapContextCreateWithData") { 1054 // FIXES: <rdar://problem/7358899> 1055 // Eventually this can be improved by recognizing that 'releaseInfo' 1056 // passed to CGBitmapContextCreateWithData is released via 1057 // a callback and doing full IPA to make sure this is done correctly. 1058 ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); 1059 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1060 DoNothing, DoNothing); 1061 } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { 1062 // FIXES: <rdar://problem/7283567> 1063 // Eventually this can be improved by recognizing that the pixel 1064 // buffer passed to CVPixelBufferCreateWithPlanarBytes is released 1065 // via a callback and doing full IPA to make sure this is done 1066 // correctly. 1067 ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); 1068 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1069 } else if (FName == "dispatch_set_context") { 1070 // <rdar://problem/11059275> - The analyzer currently doesn't have 1071 // a good way to reason about the finalizer function for libdispatch. 1072 // If we pass a context object that is memory managed, stop tracking it. 1073 // FIXME: this hack should possibly go away once we can handle 1074 // libdispatch finalizers. 1075 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1076 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1077 } else if (FName.startswith("NSLog")) { 1078 S = getDoNothingSummary(); 1079 } else if (FName.startswith("NS") && 1080 (FName.find("Insert") != StringRef::npos)) { 1081 // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 1082 // be deallocated by NSMapRemove. (radar://11152419) 1083 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1084 ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); 1085 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1086 } 1087 1088 // Did we get a summary? 1089 if (S) 1090 break; 1091 1092 // Enable this code once the semantics of NSDeallocateObject are resolved 1093 // for GC. <rdar://problem/6619988> 1094#if 0 1095 // Handle: NSDeallocateObject(id anObject); 1096 // This method does allow 'nil' (although we don't check it now). 1097 if (strcmp(FName, "NSDeallocateObject") == 0) { 1098 return RetTy == Ctx.VoidTy 1099 ? getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, Dealloc) 1100 : getPersistentStopSummary(); 1101 } 1102#endif 1103 1104 if (RetTy->isPointerType()) { 1105 // For CoreFoundation ('CF') types. 1106 if (cocoa::isRefType(RetTy, "CF", FName)) { 1107 if (isRetain(FD, FName)) 1108 S = getUnarySummary(FT, cfretain); 1109 else if (isMakeCollectable(FD, FName)) 1110 S = getUnarySummary(FT, cfmakecollectable); 1111 else 1112 S = getCFCreateGetRuleSummary(FD); 1113 1114 break; 1115 } 1116 1117 // For CoreGraphics ('CG') types. 1118 if (cocoa::isRefType(RetTy, "CG", FName)) { 1119 if (isRetain(FD, FName)) 1120 S = getUnarySummary(FT, cfretain); 1121 else 1122 S = getCFCreateGetRuleSummary(FD); 1123 1124 break; 1125 } 1126 1127 // For the Disk Arbitration API (DiskArbitration/DADisk.h) 1128 if (cocoa::isRefType(RetTy, "DADisk") || 1129 cocoa::isRefType(RetTy, "DADissenter") || 1130 cocoa::isRefType(RetTy, "DASessionRef")) { 1131 S = getCFCreateGetRuleSummary(FD); 1132 break; 1133 } 1134 1135 break; 1136 } 1137 1138 // Check for release functions, the only kind of functions that we care 1139 // about that don't return a pointer type. 1140 if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { 1141 // Test for 'CGCF'. 1142 FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); 1143 1144 if (isRelease(FD, FName)) 1145 S = getUnarySummary(FT, cfrelease); 1146 else { 1147 assert (ScratchArgs.isEmpty()); 1148 // Remaining CoreFoundation and CoreGraphics functions. 1149 // We use to assume that they all strictly followed the ownership idiom 1150 // and that ownership cannot be transferred. While this is technically 1151 // correct, many methods allow a tracked object to escape. For example: 1152 // 1153 // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); 1154 // CFDictionaryAddValue(y, key, x); 1155 // CFRelease(x); 1156 // ... it is okay to use 'x' since 'y' has a reference to it 1157 // 1158 // We handle this and similar cases with the follow heuristic. If the 1159 // function name contains "InsertValue", "SetValue", "AddValue", 1160 // "AppendValue", or "SetAttribute", then we assume that arguments may 1161 // "escape." This means that something else holds on to the object, 1162 // allowing it be used even after its local retain count drops to 0. 1163 ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| 1164 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 1165 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 1166 StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| 1167 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) 1168 ? MayEscape : DoNothing; 1169 1170 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); 1171 } 1172 } 1173 } 1174 while (0); 1175 1176 // If we got all the way here without any luck, use a default summary. 1177 if (!S) 1178 S = getDefaultSummary(); 1179 1180 // Annotations override defaults. 1181 updateSummaryFromAnnotations(S, FD); 1182 1183 FuncSummaries[FD] = S; 1184 return S; 1185} 1186 1187const RetainSummary * 1188RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { 1189 if (coreFoundation::followsCreateRule(FD)) 1190 return getCFSummaryCreateRule(FD); 1191 1192 return getCFSummaryGetRule(FD); 1193} 1194 1195const RetainSummary * 1196RetainSummaryManager::getUnarySummary(const FunctionType* FT, 1197 UnaryFuncKind func) { 1198 1199 // Sanity check that this is *really* a unary function. This can 1200 // happen if people do weird things. 1201 const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); 1202 if (!FTP || FTP->getNumArgs() != 1) 1203 return getPersistentStopSummary(); 1204 1205 assert (ScratchArgs.isEmpty()); 1206 1207 ArgEffect Effect; 1208 switch (func) { 1209 case cfretain: Effect = IncRef; break; 1210 case cfrelease: Effect = DecRef; break; 1211 case cfmakecollectable: Effect = MakeCollectable; break; 1212 } 1213 1214 ScratchArgs = AF.add(ScratchArgs, 0, Effect); 1215 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1216} 1217 1218const RetainSummary * 1219RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { 1220 assert (ScratchArgs.isEmpty()); 1221 1222 return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1223} 1224 1225const RetainSummary * 1226RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { 1227 assert (ScratchArgs.isEmpty()); 1228 return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), 1229 DoNothing, DoNothing); 1230} 1231 1232//===----------------------------------------------------------------------===// 1233// Summary creation for Selectors. 1234//===----------------------------------------------------------------------===// 1235 1236void 1237RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1238 const FunctionDecl *FD) { 1239 if (!FD) 1240 return; 1241 1242 assert(Summ && "Must have a summary to add annotations to."); 1243 RetainSummaryTemplate Template(Summ, *this); 1244 1245 // Effects on the parameters. 1246 unsigned parm_idx = 0; 1247 for (FunctionDecl::param_const_iterator pi = FD->param_begin(), 1248 pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { 1249 const ParmVarDecl *pd = *pi; 1250 if (pd->getAttr<NSConsumedAttr>()) { 1251 if (!GCEnabled) { 1252 Template->addArg(AF, parm_idx, DecRef); 1253 } 1254 } else if (pd->getAttr<CFConsumedAttr>()) { 1255 Template->addArg(AF, parm_idx, DecRef); 1256 } 1257 } 1258 1259 QualType RetTy = FD->getResultType(); 1260 1261 // Determine if there is a special return effect for this method. 1262 if (cocoa::isCocoaObjectRef(RetTy)) { 1263 if (FD->getAttr<NSReturnsRetainedAttr>()) { 1264 Template->setRetEffect(ObjCAllocRetE); 1265 } 1266 else if (FD->getAttr<CFReturnsRetainedAttr>()) { 1267 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1268 } 1269 else if (FD->getAttr<NSReturnsNotRetainedAttr>()) { 1270 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1271 } 1272 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1273 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1274 } 1275 } else if (RetTy->getAs<PointerType>()) { 1276 if (FD->getAttr<CFReturnsRetainedAttr>()) { 1277 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1278 } 1279 else if (FD->getAttr<CFReturnsNotRetainedAttr>()) { 1280 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1281 } 1282 } 1283} 1284 1285void 1286RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1287 const ObjCMethodDecl *MD) { 1288 if (!MD) 1289 return; 1290 1291 assert(Summ && "Must have a valid summary to add annotations to"); 1292 RetainSummaryTemplate Template(Summ, *this); 1293 bool isTrackedLoc = false; 1294 1295 // Effects on the receiver. 1296 if (MD->getAttr<NSConsumesSelfAttr>()) { 1297 if (!GCEnabled) 1298 Template->setReceiverEffect(DecRefMsg); 1299 } 1300 1301 // Effects on the parameters. 1302 unsigned parm_idx = 0; 1303 for (ObjCMethodDecl::param_const_iterator 1304 pi=MD->param_begin(), pe=MD->param_end(); 1305 pi != pe; ++pi, ++parm_idx) { 1306 const ParmVarDecl *pd = *pi; 1307 if (pd->getAttr<NSConsumedAttr>()) { 1308 if (!GCEnabled) 1309 Template->addArg(AF, parm_idx, DecRef); 1310 } 1311 else if(pd->getAttr<CFConsumedAttr>()) { 1312 Template->addArg(AF, parm_idx, DecRef); 1313 } 1314 } 1315 1316 // Determine if there is a special return effect for this method. 1317 if (cocoa::isCocoaObjectRef(MD->getResultType())) { 1318 if (MD->getAttr<NSReturnsRetainedAttr>()) { 1319 Template->setRetEffect(ObjCAllocRetE); 1320 return; 1321 } 1322 if (MD->getAttr<NSReturnsNotRetainedAttr>()) { 1323 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::ObjC)); 1324 return; 1325 } 1326 1327 isTrackedLoc = true; 1328 } else { 1329 isTrackedLoc = MD->getResultType()->getAs<PointerType>() != NULL; 1330 } 1331 1332 if (isTrackedLoc) { 1333 if (MD->getAttr<CFReturnsRetainedAttr>()) 1334 Template->setRetEffect(RetEffect::MakeOwned(RetEffect::CF, true)); 1335 else if (MD->getAttr<CFReturnsNotRetainedAttr>()) 1336 Template->setRetEffect(RetEffect::MakeNotOwned(RetEffect::CF)); 1337 } 1338} 1339 1340const RetainSummary * 1341RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, 1342 Selector S, QualType RetTy) { 1343 1344 if (MD) { 1345 // Scan the method decl for 'void*' arguments. These should be treated 1346 // as 'StopTracking' because they are often used with delegates. 1347 // Delegates are a frequent form of false positives with the retain 1348 // count checker. 1349 unsigned i = 0; 1350 for (ObjCMethodDecl::param_const_iterator I = MD->param_begin(), 1351 E = MD->param_end(); I != E; ++I, ++i) 1352 if (const ParmVarDecl *PD = *I) { 1353 QualType Ty = Ctx.getCanonicalType(PD->getType()); 1354 if (Ty.getLocalUnqualifiedType() == Ctx.VoidPtrTy) 1355 ScratchArgs = AF.add(ScratchArgs, i, StopTracking); 1356 } 1357 } 1358 1359 // Any special effects? 1360 ArgEffect ReceiverEff = DoNothing; 1361 RetEffect ResultEff = RetEffect::MakeNoRet(); 1362 1363 // Check the method family, and apply any default annotations. 1364 switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { 1365 case OMF_None: 1366 case OMF_performSelector: 1367 // Assume all Objective-C methods follow Cocoa Memory Management rules. 1368 // FIXME: Does the non-threaded performSelector family really belong here? 1369 // The selector could be, say, @selector(copy). 1370 if (cocoa::isCocoaObjectRef(RetTy)) 1371 ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); 1372 else if (coreFoundation::isCFObjectRef(RetTy)) { 1373 // ObjCMethodDecl currently doesn't consider CF objects as valid return 1374 // values for alloc, new, copy, or mutableCopy, so we have to 1375 // double-check with the selector. This is ugly, but there aren't that 1376 // many Objective-C methods that return CF objects, right? 1377 if (MD) { 1378 switch (S.getMethodFamily()) { 1379 case OMF_alloc: 1380 case OMF_new: 1381 case OMF_copy: 1382 case OMF_mutableCopy: 1383 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1384 break; 1385 default: 1386 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1387 break; 1388 } 1389 } else { 1390 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1391 } 1392 } 1393 break; 1394 case OMF_init: 1395 ResultEff = ObjCInitRetE; 1396 ReceiverEff = DecRefMsg; 1397 break; 1398 case OMF_alloc: 1399 case OMF_new: 1400 case OMF_copy: 1401 case OMF_mutableCopy: 1402 if (cocoa::isCocoaObjectRef(RetTy)) 1403 ResultEff = ObjCAllocRetE; 1404 else if (coreFoundation::isCFObjectRef(RetTy)) 1405 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1406 break; 1407 case OMF_autorelease: 1408 ReceiverEff = Autorelease; 1409 break; 1410 case OMF_retain: 1411 ReceiverEff = IncRefMsg; 1412 break; 1413 case OMF_release: 1414 ReceiverEff = DecRefMsg; 1415 break; 1416 case OMF_dealloc: 1417 ReceiverEff = Dealloc; 1418 break; 1419 case OMF_self: 1420 // -self is handled specially by the ExprEngine to propagate the receiver. 1421 break; 1422 case OMF_retainCount: 1423 case OMF_finalize: 1424 // These methods don't return objects. 1425 break; 1426 } 1427 1428 // If one of the arguments in the selector has the keyword 'delegate' we 1429 // should stop tracking the reference count for the receiver. This is 1430 // because the reference count is quite possibly handled by a delegate 1431 // method. 1432 if (S.isKeywordSelector()) { 1433 for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { 1434 StringRef Slot = S.getNameForSlot(i); 1435 if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { 1436 if (ResultEff == ObjCInitRetE) 1437 ResultEff = RetEffect::MakeNoRet(); 1438 else 1439 ReceiverEff = StopTracking; 1440 } 1441 } 1442 } 1443 1444 if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && 1445 ResultEff.getKind() == RetEffect::NoRet) 1446 return getDefaultSummary(); 1447 1448 return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); 1449} 1450 1451const RetainSummary * 1452RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, 1453 ProgramStateRef State) { 1454 const ObjCInterfaceDecl *ReceiverClass = 0; 1455 1456 // We do better tracking of the type of the object than the core ExprEngine. 1457 // See if we have its type in our private state. 1458 // FIXME: Eventually replace the use of state->get<RefBindings> with 1459 // a generic API for reasoning about the Objective-C types of symbolic 1460 // objects. 1461 SVal ReceiverV = Msg.getReceiverSVal(); 1462 if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) 1463 if (const RefVal *T = State->get<RefBindings>(Sym)) 1464 if (const ObjCObjectPointerType *PT = 1465 T->getType()->getAs<ObjCObjectPointerType>()) 1466 ReceiverClass = PT->getInterfaceDecl(); 1467 1468 // If we don't know what kind of object this is, fall back to its static type. 1469 if (!ReceiverClass) 1470 ReceiverClass = Msg.getReceiverInterface(); 1471 1472 // FIXME: The receiver could be a reference to a class, meaning that 1473 // we should use the class method. 1474 // id x = [NSObject class]; 1475 // [x performSelector:... withObject:... afterDelay:...]; 1476 Selector S = Msg.getSelector(); 1477 const ObjCMethodDecl *Method = Msg.getDecl(); 1478 if (!Method && ReceiverClass) 1479 Method = ReceiverClass->getInstanceMethod(S); 1480 1481 return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), 1482 ObjCMethodSummaries); 1483} 1484 1485const RetainSummary * 1486RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 1487 const ObjCMethodDecl *MD, QualType RetTy, 1488 ObjCMethodSummariesTy &CachedSummaries) { 1489 1490 // Look up a summary in our summary cache. 1491 const RetainSummary *Summ = CachedSummaries.find(ID, S); 1492 1493 if (!Summ) { 1494 Summ = getStandardMethodSummary(MD, S, RetTy); 1495 1496 // Annotations override defaults. 1497 updateSummaryFromAnnotations(Summ, MD); 1498 1499 // Memoize the summary. 1500 CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; 1501 } 1502 1503 return Summ; 1504} 1505 1506void RetainSummaryManager::InitializeClassMethodSummaries() { 1507 assert(ScratchArgs.isEmpty()); 1508 // Create the [NSAssertionHandler currentHander] summary. 1509 addClassMethSummary("NSAssertionHandler", "currentHandler", 1510 getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); 1511 1512 // Create the [NSAutoreleasePool addObject:] summary. 1513 ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); 1514 addClassMethSummary("NSAutoreleasePool", "addObject", 1515 getPersistentSummary(RetEffect::MakeNoRet(), 1516 DoNothing, Autorelease)); 1517} 1518 1519void RetainSummaryManager::InitializeMethodSummaries() { 1520 1521 assert (ScratchArgs.isEmpty()); 1522 1523 // Create the "init" selector. It just acts as a pass-through for the 1524 // receiver. 1525 const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); 1526 addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); 1527 1528 // awakeAfterUsingCoder: behaves basically like an 'init' method. It 1529 // claims the receiver and returns a retained object. 1530 addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), 1531 InitSumm); 1532 1533 // The next methods are allocators. 1534 const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); 1535 const RetainSummary *CFAllocSumm = 1536 getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1537 1538 // Create the "retain" selector. 1539 RetEffect NoRet = RetEffect::MakeNoRet(); 1540 const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); 1541 addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); 1542 1543 // Create the "release" selector. 1544 Summ = getPersistentSummary(NoRet, DecRefMsg); 1545 addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); 1546 1547 // Create the "drain" selector. 1548 Summ = getPersistentSummary(NoRet, isGCEnabled() ? DoNothing : DecRef); 1549 addNSObjectMethSummary(GetNullarySelector("drain", Ctx), Summ); 1550 1551 // Create the -dealloc summary. 1552 Summ = getPersistentSummary(NoRet, Dealloc); 1553 addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); 1554 1555 // Create the "autorelease" selector. 1556 Summ = getPersistentSummary(NoRet, Autorelease); 1557 addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); 1558 1559 // Specially handle NSAutoreleasePool. 1560 addInstMethSummary("NSAutoreleasePool", "init", 1561 getPersistentSummary(NoRet, NewAutoreleasePool)); 1562 1563 // For NSWindow, allocated objects are (initially) self-owned. 1564 // FIXME: For now we opt for false negatives with NSWindow, as these objects 1565 // self-own themselves. However, they only do this once they are displayed. 1566 // Thus, we need to track an NSWindow's display status. 1567 // This is tracked in <rdar://problem/6062711>. 1568 // See also http://llvm.org/bugs/show_bug.cgi?id=3714. 1569 const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), 1570 StopTracking, 1571 StopTracking); 1572 1573 addClassMethSummary("NSWindow", "alloc", NoTrackYet); 1574 1575#if 0 1576 addInstMethSummary("NSWindow", NoTrackYet, "initWithContentRect", 1577 "styleMask", "backing", "defer", NULL); 1578 1579 addInstMethSummary("NSWindow", NoTrackYet, "initWithContentRect", 1580 "styleMask", "backing", "defer", "screen", NULL); 1581#endif 1582 1583 // For NSPanel (which subclasses NSWindow), allocated objects are not 1584 // self-owned. 1585 // FIXME: For now we don't track NSPanels. object for the same reason 1586 // as for NSWindow objects. 1587 addClassMethSummary("NSPanel", "alloc", NoTrackYet); 1588 1589#if 0 1590 addInstMethSummary("NSPanel", NoTrackYet, "initWithContentRect", 1591 "styleMask", "backing", "defer", NULL); 1592 1593 addInstMethSummary("NSPanel", NoTrackYet, "initWithContentRect", 1594 "styleMask", "backing", "defer", "screen", NULL); 1595#endif 1596 1597 // Don't track allocated autorelease pools yet, as it is okay to prematurely 1598 // exit a method. 1599 addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); 1600 addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); 1601 1602 // Create summaries QCRenderer/QCView -createSnapShotImageOfType: 1603 addInstMethSummary("QCRenderer", AllocSumm, 1604 "createSnapshotImageOfType", NULL); 1605 addInstMethSummary("QCView", AllocSumm, 1606 "createSnapshotImageOfType", NULL); 1607 1608 // Create summaries for CIContext, 'createCGImage' and 1609 // 'createCGLayerWithSize'. These objects are CF objects, and are not 1610 // automatically garbage collected. 1611 addInstMethSummary("CIContext", CFAllocSumm, 1612 "createCGImage", "fromRect", NULL); 1613 addInstMethSummary("CIContext", CFAllocSumm, 1614 "createCGImage", "fromRect", "format", "colorSpace", NULL); 1615 addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", 1616 "info", NULL); 1617} 1618 1619//===----------------------------------------------------------------------===// 1620// AutoreleaseBindings - State used to track objects in autorelease pools. 1621//===----------------------------------------------------------------------===// 1622 1623typedef llvm::ImmutableMap<SymbolRef, unsigned> ARCounts; 1624typedef llvm::ImmutableMap<SymbolRef, ARCounts> ARPoolContents; 1625typedef llvm::ImmutableList<SymbolRef> ARStack; 1626 1627static int AutoRCIndex = 0; 1628static int AutoRBIndex = 0; 1629 1630namespace { class AutoreleasePoolContents {}; } 1631namespace { class AutoreleaseStack {}; } 1632 1633namespace clang { 1634namespace ento { 1635template<> struct ProgramStateTrait<AutoreleaseStack> 1636 : public ProgramStatePartialTrait<ARStack> { 1637 static inline void *GDMIndex() { return &AutoRBIndex; } 1638}; 1639 1640template<> struct ProgramStateTrait<AutoreleasePoolContents> 1641 : public ProgramStatePartialTrait<ARPoolContents> { 1642 static inline void *GDMIndex() { return &AutoRCIndex; } 1643}; 1644} // end GR namespace 1645} // end clang namespace 1646 1647static SymbolRef GetCurrentAutoreleasePool(ProgramStateRef state) { 1648 ARStack stack = state->get<AutoreleaseStack>(); 1649 return stack.isEmpty() ? SymbolRef() : stack.getHead(); 1650} 1651 1652static ProgramStateRef 1653SendAutorelease(ProgramStateRef state, 1654 ARCounts::Factory &F, 1655 SymbolRef sym) { 1656 SymbolRef pool = GetCurrentAutoreleasePool(state); 1657 const ARCounts *cnts = state->get<AutoreleasePoolContents>(pool); 1658 ARCounts newCnts(0); 1659 1660 if (cnts) { 1661 const unsigned *cnt = (*cnts).lookup(sym); 1662 newCnts = F.add(*cnts, sym, cnt ? *cnt + 1 : 1); 1663 } 1664 else 1665 newCnts = F.add(F.getEmptyMap(), sym, 1); 1666 1667 return state->set<AutoreleasePoolContents>(pool, newCnts); 1668} 1669 1670//===----------------------------------------------------------------------===// 1671// Error reporting. 1672//===----------------------------------------------------------------------===// 1673namespace { 1674 typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> 1675 SummaryLogTy; 1676 1677 //===-------------===// 1678 // Bug Descriptions. // 1679 //===-------------===// 1680 1681 class CFRefBug : public BugType { 1682 protected: 1683 CFRefBug(StringRef name) 1684 : BugType(name, categories::MemoryCoreFoundationObjectiveC) {} 1685 public: 1686 1687 // FIXME: Eventually remove. 1688 virtual const char *getDescription() const = 0; 1689 1690 virtual bool isLeak() const { return false; } 1691 }; 1692 1693 class UseAfterRelease : public CFRefBug { 1694 public: 1695 UseAfterRelease() : CFRefBug("Use-after-release") {} 1696 1697 const char *getDescription() const { 1698 return "Reference-counted object is used after it is released"; 1699 } 1700 }; 1701 1702 class BadRelease : public CFRefBug { 1703 public: 1704 BadRelease() : CFRefBug("Bad release") {} 1705 1706 const char *getDescription() const { 1707 return "Incorrect decrement of the reference count of an object that is " 1708 "not owned at this point by the caller"; 1709 } 1710 }; 1711 1712 class DeallocGC : public CFRefBug { 1713 public: 1714 DeallocGC() 1715 : CFRefBug("-dealloc called while using garbage collection") {} 1716 1717 const char *getDescription() const { 1718 return "-dealloc called while using garbage collection"; 1719 } 1720 }; 1721 1722 class DeallocNotOwned : public CFRefBug { 1723 public: 1724 DeallocNotOwned() 1725 : CFRefBug("-dealloc sent to non-exclusively owned object") {} 1726 1727 const char *getDescription() const { 1728 return "-dealloc sent to object that may be referenced elsewhere"; 1729 } 1730 }; 1731 1732 class OverAutorelease : public CFRefBug { 1733 public: 1734 OverAutorelease() 1735 : CFRefBug("Object sent -autorelease too many times") {} 1736 1737 const char *getDescription() const { 1738 return "Object sent -autorelease too many times"; 1739 } 1740 }; 1741 1742 class ReturnedNotOwnedForOwned : public CFRefBug { 1743 public: 1744 ReturnedNotOwnedForOwned() 1745 : CFRefBug("Method should return an owned object") {} 1746 1747 const char *getDescription() const { 1748 return "Object with a +0 retain count returned to caller where a +1 " 1749 "(owning) retain count is expected"; 1750 } 1751 }; 1752 1753 class Leak : public CFRefBug { 1754 public: 1755 Leak(StringRef name) 1756 : CFRefBug(name) { 1757 // Leaks should not be reported if they are post-dominated by a sink. 1758 setSuppressOnSink(true); 1759 } 1760 1761 const char *getDescription() const { return ""; } 1762 1763 bool isLeak() const { return true; } 1764 }; 1765 1766 //===---------===// 1767 // Bug Reports. // 1768 //===---------===// 1769 1770 class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> { 1771 protected: 1772 SymbolRef Sym; 1773 const SummaryLogTy &SummaryLog; 1774 bool GCEnabled; 1775 1776 public: 1777 CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) 1778 : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} 1779 1780 virtual void Profile(llvm::FoldingSetNodeID &ID) const { 1781 static int x = 0; 1782 ID.AddPointer(&x); 1783 ID.AddPointer(Sym); 1784 } 1785 1786 virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N, 1787 const ExplodedNode *PrevN, 1788 BugReporterContext &BRC, 1789 BugReport &BR); 1790 1791 virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1792 const ExplodedNode *N, 1793 BugReport &BR); 1794 }; 1795 1796 class CFRefLeakReportVisitor : public CFRefReportVisitor { 1797 public: 1798 CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, 1799 const SummaryLogTy &log) 1800 : CFRefReportVisitor(sym, GCEnabled, log) {} 1801 1802 PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1803 const ExplodedNode *N, 1804 BugReport &BR); 1805 1806 virtual BugReporterVisitor *clone() const { 1807 // The curiously-recurring template pattern only works for one level of 1808 // subclassing. Rather than make a new template base for 1809 // CFRefReportVisitor, we simply override clone() to do the right thing. 1810 // This could be trouble someday if BugReporterVisitorImpl is ever 1811 // used for something else besides a convenient implementation of clone(). 1812 return new CFRefLeakReportVisitor(*this); 1813 } 1814 }; 1815 1816 class CFRefReport : public BugReport { 1817 void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); 1818 1819 public: 1820 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1821 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1822 bool registerVisitor = true) 1823 : BugReport(D, D.getDescription(), n) { 1824 if (registerVisitor) 1825 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1826 addGCModeDescription(LOpts, GCEnabled); 1827 } 1828 1829 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1830 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1831 StringRef endText) 1832 : BugReport(D, D.getDescription(), endText, n) { 1833 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1834 addGCModeDescription(LOpts, GCEnabled); 1835 } 1836 1837 virtual std::pair<ranges_iterator, ranges_iterator> getRanges() { 1838 const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); 1839 if (!BugTy.isLeak()) 1840 return BugReport::getRanges(); 1841 else 1842 return std::make_pair(ranges_iterator(), ranges_iterator()); 1843 } 1844 }; 1845 1846 class CFRefLeakReport : public CFRefReport { 1847 const MemRegion* AllocBinding; 1848 1849 public: 1850 CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1851 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1852 CheckerContext &Ctx); 1853 1854 PathDiagnosticLocation getLocation(const SourceManager &SM) const { 1855 assert(Location.isValid()); 1856 return Location; 1857 } 1858 }; 1859} // end anonymous namespace 1860 1861void CFRefReport::addGCModeDescription(const LangOptions &LOpts, 1862 bool GCEnabled) { 1863 const char *GCModeDescription = 0; 1864 1865 switch (LOpts.getGC()) { 1866 case LangOptions::GCOnly: 1867 assert(GCEnabled); 1868 GCModeDescription = "Code is compiled to only use garbage collection"; 1869 break; 1870 1871 case LangOptions::NonGC: 1872 assert(!GCEnabled); 1873 GCModeDescription = "Code is compiled to use reference counts"; 1874 break; 1875 1876 case LangOptions::HybridGC: 1877 if (GCEnabled) { 1878 GCModeDescription = "Code is compiled to use either garbage collection " 1879 "(GC) or reference counts (non-GC). The bug occurs " 1880 "with GC enabled"; 1881 break; 1882 } else { 1883 GCModeDescription = "Code is compiled to use either garbage collection " 1884 "(GC) or reference counts (non-GC). The bug occurs " 1885 "in non-GC mode"; 1886 break; 1887 } 1888 } 1889 1890 assert(GCModeDescription && "invalid/unknown GC mode"); 1891 addExtraText(GCModeDescription); 1892} 1893 1894// FIXME: This should be a method on SmallVector. 1895static inline bool contains(const SmallVectorImpl<ArgEffect>& V, 1896 ArgEffect X) { 1897 for (SmallVectorImpl<ArgEffect>::const_iterator I=V.begin(), E=V.end(); 1898 I!=E; ++I) 1899 if (*I == X) return true; 1900 1901 return false; 1902} 1903 1904static bool isNumericLiteralExpression(const Expr *E) { 1905 // FIXME: This set of cases was copied from SemaExprObjC. 1906 return isa<IntegerLiteral>(E) || 1907 isa<CharacterLiteral>(E) || 1908 isa<FloatingLiteral>(E) || 1909 isa<ObjCBoolLiteralExpr>(E) || 1910 isa<CXXBoolLiteralExpr>(E); 1911} 1912 1913static bool isPropertyAccess(const Stmt *S, ParentMap &PM) { 1914 unsigned maxDepth = 4; 1915 while (S && maxDepth) { 1916 if (const PseudoObjectExpr *PO = dyn_cast<PseudoObjectExpr>(S)) { 1917 if (!isa<ObjCMessageExpr>(PO->getSyntacticForm())) 1918 return true; 1919 return false; 1920 } 1921 S = PM.getParent(S); 1922 --maxDepth; 1923 } 1924 return false; 1925} 1926 1927PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N, 1928 const ExplodedNode *PrevN, 1929 BugReporterContext &BRC, 1930 BugReport &BR) { 1931 1932 if (!isa<StmtPoint>(N->getLocation())) 1933 return NULL; 1934 1935 // Check if the type state has changed. 1936 ProgramStateRef PrevSt = PrevN->getState(); 1937 ProgramStateRef CurrSt = N->getState(); 1938 const LocationContext *LCtx = N->getLocationContext(); 1939 1940 const RefVal* CurrT = CurrSt->get<RefBindings>(Sym); 1941 if (!CurrT) return NULL; 1942 1943 const RefVal &CurrV = *CurrT; 1944 const RefVal *PrevT = PrevSt->get<RefBindings>(Sym); 1945 1946 // Create a string buffer to constain all the useful things we want 1947 // to tell the user. 1948 std::string sbuf; 1949 llvm::raw_string_ostream os(sbuf); 1950 1951 // This is the allocation site since the previous node had no bindings 1952 // for this symbol. 1953 if (!PrevT) { 1954 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 1955 1956 if (isa<ObjCArrayLiteral>(S)) { 1957 os << "NSArray literal is an object with a +0 retain count"; 1958 } 1959 else if (isa<ObjCDictionaryLiteral>(S)) { 1960 os << "NSDictionary literal is an object with a +0 retain count"; 1961 } 1962 else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { 1963 if (isNumericLiteralExpression(BL->getSubExpr())) 1964 os << "NSNumber literal is an object with a +0 retain count"; 1965 else { 1966 const ObjCInterfaceDecl *BoxClass = 0; 1967 if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) 1968 BoxClass = Method->getClassInterface(); 1969 1970 // We should always be able to find the boxing class interface, 1971 // but consider this future-proofing. 1972 if (BoxClass) 1973 os << *BoxClass << " b"; 1974 else 1975 os << "B"; 1976 1977 os << "oxed expression produces an object with a +0 retain count"; 1978 } 1979 } 1980 else { 1981 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1982 // Get the name of the callee (if it is available). 1983 SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); 1984 if (const FunctionDecl *FD = X.getAsFunctionDecl()) 1985 os << "Call to function '" << *FD << '\''; 1986 else 1987 os << "function call"; 1988 } 1989 else { 1990 assert(isa<ObjCMessageExpr>(S)); 1991 // The message expression may have between written directly or as 1992 // a property access. Lazily determine which case we are looking at. 1993 os << (isPropertyAccess(S, N->getParentMap()) ? "Property" : "Method"); 1994 } 1995 1996 if (CurrV.getObjKind() == RetEffect::CF) { 1997 os << " returns a Core Foundation object with a "; 1998 } 1999 else { 2000 assert (CurrV.getObjKind() == RetEffect::ObjC); 2001 os << " returns an Objective-C object with a "; 2002 } 2003 2004 if (CurrV.isOwned()) { 2005 os << "+1 retain count"; 2006 2007 if (GCEnabled) { 2008 assert(CurrV.getObjKind() == RetEffect::CF); 2009 os << ". " 2010 "Core Foundation objects are not automatically garbage collected."; 2011 } 2012 } 2013 else { 2014 assert (CurrV.isNotOwned()); 2015 os << "+0 retain count"; 2016 } 2017 } 2018 2019 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2020 N->getLocationContext()); 2021 return new PathDiagnosticEventPiece(Pos, os.str()); 2022 } 2023 2024 // Gather up the effects that were performed on the object at this 2025 // program point 2026 SmallVector<ArgEffect, 2> AEffects; 2027 2028 const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); 2029 if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { 2030 // We only have summaries attached to nodes after evaluating CallExpr and 2031 // ObjCMessageExprs. 2032 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2033 2034 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 2035 // Iterate through the parameter expressions and see if the symbol 2036 // was ever passed as an argument. 2037 unsigned i = 0; 2038 2039 for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); 2040 AI!=AE; ++AI, ++i) { 2041 2042 // Retrieve the value of the argument. Is it the symbol 2043 // we are interested in? 2044 if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) 2045 continue; 2046 2047 // We have an argument. Get the effect! 2048 AEffects.push_back(Summ->getArg(i)); 2049 } 2050 } 2051 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { 2052 if (const Expr *receiver = ME->getInstanceReceiver()) 2053 if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) 2054 .getAsLocSymbol() == Sym) { 2055 // The symbol we are tracking is the receiver. 2056 AEffects.push_back(Summ->getReceiverEffect()); 2057 } 2058 } 2059 } 2060 2061 do { 2062 // Get the previous type state. 2063 RefVal PrevV = *PrevT; 2064 2065 // Specially handle -dealloc. 2066 if (!GCEnabled && contains(AEffects, Dealloc)) { 2067 // Determine if the object's reference count was pushed to zero. 2068 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2069 // We may not have transitioned to 'release' if we hit an error. 2070 // This case is handled elsewhere. 2071 if (CurrV.getKind() == RefVal::Released) { 2072 assert(CurrV.getCombinedCounts() == 0); 2073 os << "Object released by directly sending the '-dealloc' message"; 2074 break; 2075 } 2076 } 2077 2078 // Specially handle CFMakeCollectable and friends. 2079 if (contains(AEffects, MakeCollectable)) { 2080 // Get the name of the function. 2081 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2082 SVal X = 2083 CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); 2084 const FunctionDecl *FD = X.getAsFunctionDecl(); 2085 2086 if (GCEnabled) { 2087 // Determine if the object's reference count was pushed to zero. 2088 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 2089 2090 os << "In GC mode a call to '" << *FD 2091 << "' decrements an object's retain count and registers the " 2092 "object with the garbage collector. "; 2093 2094 if (CurrV.getKind() == RefVal::Released) { 2095 assert(CurrV.getCount() == 0); 2096 os << "Since it now has a 0 retain count the object can be " 2097 "automatically collected by the garbage collector."; 2098 } 2099 else 2100 os << "An object must have a 0 retain count to be garbage collected. " 2101 "After this call its retain count is +" << CurrV.getCount() 2102 << '.'; 2103 } 2104 else 2105 os << "When GC is not enabled a call to '" << *FD 2106 << "' has no effect on its argument."; 2107 2108 // Nothing more to say. 2109 break; 2110 } 2111 2112 // Determine if the typestate has changed. 2113 if (!(PrevV == CurrV)) 2114 switch (CurrV.getKind()) { 2115 case RefVal::Owned: 2116 case RefVal::NotOwned: 2117 2118 if (PrevV.getCount() == CurrV.getCount()) { 2119 // Did an autorelease message get sent? 2120 if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) 2121 return 0; 2122 2123 assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); 2124 os << "Object sent -autorelease message"; 2125 break; 2126 } 2127 2128 if (PrevV.getCount() > CurrV.getCount()) 2129 os << "Reference count decremented."; 2130 else 2131 os << "Reference count incremented."; 2132 2133 if (unsigned Count = CurrV.getCount()) 2134 os << " The object now has a +" << Count << " retain count."; 2135 2136 if (PrevV.getKind() == RefVal::Released) { 2137 assert(GCEnabled && CurrV.getCount() > 0); 2138 os << " The object is not eligible for garbage collection until " 2139 "the retain count reaches 0 again."; 2140 } 2141 2142 break; 2143 2144 case RefVal::Released: 2145 os << "Object released."; 2146 break; 2147 2148 case RefVal::ReturnedOwned: 2149 // Autoreleases can be applied after marking a node ReturnedOwned. 2150 if (CurrV.getAutoreleaseCount()) 2151 return NULL; 2152 2153 os << "Object returned to caller as an owning reference (single " 2154 "retain count transferred to caller)"; 2155 break; 2156 2157 case RefVal::ReturnedNotOwned: 2158 os << "Object returned to caller with a +0 retain count"; 2159 break; 2160 2161 default: 2162 return NULL; 2163 } 2164 2165 // Emit any remaining diagnostics for the argument effects (if any). 2166 for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), 2167 E=AEffects.end(); I != E; ++I) { 2168 2169 // A bunch of things have alternate behavior under GC. 2170 if (GCEnabled) 2171 switch (*I) { 2172 default: break; 2173 case Autorelease: 2174 os << "In GC mode an 'autorelease' has no effect."; 2175 continue; 2176 case IncRefMsg: 2177 os << "In GC mode the 'retain' message has no effect."; 2178 continue; 2179 case DecRefMsg: 2180 os << "In GC mode the 'release' message has no effect."; 2181 continue; 2182 } 2183 } 2184 } while (0); 2185 2186 if (os.str().empty()) 2187 return 0; // We have nothing to say! 2188 2189 const Stmt *S = cast<StmtPoint>(N->getLocation()).getStmt(); 2190 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2191 N->getLocationContext()); 2192 PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str()); 2193 2194 // Add the range by scanning the children of the statement for any bindings 2195 // to Sym. 2196 for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); 2197 I!=E; ++I) 2198 if (const Expr *Exp = dyn_cast_or_null<Expr>(*I)) 2199 if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { 2200 P->addRange(Exp->getSourceRange()); 2201 break; 2202 } 2203 2204 return P; 2205} 2206 2207// Find the first node in the current function context that referred to the 2208// tracked symbol and the memory location that value was stored to. Note, the 2209// value is only reported if the allocation occurred in the same function as 2210// the leak. 2211static std::pair<const ExplodedNode*,const MemRegion*> 2212GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, 2213 SymbolRef Sym) { 2214 const ExplodedNode *Last = N; 2215 const MemRegion* FirstBinding = 0; 2216 const LocationContext *LeakContext = N->getLocationContext(); 2217 2218 while (N) { 2219 ProgramStateRef St = N->getState(); 2220 RefBindings B = St->get<RefBindings>(); 2221 2222 if (!B.lookup(Sym)) 2223 break; 2224 2225 StoreManager::FindUniqueBinding FB(Sym); 2226 StateMgr.iterBindings(St, FB); 2227 if (FB) FirstBinding = FB.getRegion(); 2228 2229 // Allocation node, is the last node in the current context in which the 2230 // symbol was tracked. 2231 if (N->getLocationContext() == LeakContext) 2232 Last = N; 2233 2234 N = N->pred_empty() ? NULL : *(N->pred_begin()); 2235 } 2236 2237 // If allocation happened in a function different from the leak node context, 2238 // do not report the binding. 2239 if (N->getLocationContext() != LeakContext) { 2240 FirstBinding = 0; 2241 } 2242 2243 return std::make_pair(Last, FirstBinding); 2244} 2245 2246PathDiagnosticPiece* 2247CFRefReportVisitor::getEndPath(BugReporterContext &BRC, 2248 const ExplodedNode *EndN, 2249 BugReport &BR) { 2250 BR.markInteresting(Sym); 2251 return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); 2252} 2253 2254PathDiagnosticPiece* 2255CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, 2256 const ExplodedNode *EndN, 2257 BugReport &BR) { 2258 2259 // Tell the BugReporterContext to report cases when the tracked symbol is 2260 // assigned to different variables, etc. 2261 BR.markInteresting(Sym); 2262 2263 // We are reporting a leak. Walk up the graph to get to the first node where 2264 // the symbol appeared, and also get the first VarDecl that tracked object 2265 // is stored to. 2266 const ExplodedNode *AllocNode = 0; 2267 const MemRegion* FirstBinding = 0; 2268 2269 llvm::tie(AllocNode, FirstBinding) = 2270 GetAllocationSite(BRC.getStateManager(), EndN, Sym); 2271 2272 SourceManager& SM = BRC.getSourceManager(); 2273 2274 // Compute an actual location for the leak. Sometimes a leak doesn't 2275 // occur at an actual statement (e.g., transition between blocks; end 2276 // of function) so we need to walk the graph and compute a real location. 2277 const ExplodedNode *LeakN = EndN; 2278 PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); 2279 2280 std::string sbuf; 2281 llvm::raw_string_ostream os(sbuf); 2282 2283 os << "Object leaked: "; 2284 2285 if (FirstBinding) { 2286 os << "object allocated and stored into '" 2287 << FirstBinding->getString() << '\''; 2288 } 2289 else 2290 os << "allocated object"; 2291 2292 // Get the retain count. 2293 const RefVal* RV = EndN->getState()->get<RefBindings>(Sym); 2294 2295 if (RV->getKind() == RefVal::ErrorLeakReturned) { 2296 // FIXME: Per comments in rdar://6320065, "create" only applies to CF 2297 // objects. Only "copy", "alloc", "retain" and "new" transfer ownership 2298 // to the caller for NS objects. 2299 const Decl *D = &EndN->getCodeDecl(); 2300 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 2301 os << " is returned from a method whose name ('" 2302 << MD->getSelector().getAsString() 2303 << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'." 2304 " This violates the naming convention rules" 2305 " given in the Memory Management Guide for Cocoa"; 2306 } 2307 else { 2308 const FunctionDecl *FD = cast<FunctionDecl>(D); 2309 os << " is returned from a function whose name ('" 2310 << *FD 2311 << "') does not contain 'Copy' or 'Create'. This violates the naming" 2312 " convention rules given in the Memory Management Guide for Core" 2313 " Foundation"; 2314 } 2315 } 2316 else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { 2317 ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); 2318 os << " and returned from method '" << MD.getSelector().getAsString() 2319 << "' is potentially leaked when using garbage collection. Callers " 2320 "of this method do not expect a returned object with a +1 retain " 2321 "count since they expect the object to be managed by the garbage " 2322 "collector"; 2323 } 2324 else 2325 os << " is not referenced later in this execution path and has a retain " 2326 "count of +" << RV->getCount(); 2327 2328 return new PathDiagnosticEventPiece(L, os.str()); 2329} 2330 2331CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, 2332 bool GCEnabled, const SummaryLogTy &Log, 2333 ExplodedNode *n, SymbolRef sym, 2334 CheckerContext &Ctx) 2335: CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { 2336 2337 // Most bug reports are cached at the location where they occurred. 2338 // With leaks, we want to unique them by the location where they were 2339 // allocated, and only report a single path. To do this, we need to find 2340 // the allocation site of a piece of tracked memory, which we do via a 2341 // call to GetAllocationSite. This will walk the ExplodedGraph backwards. 2342 // Note that this is *not* the trimmed graph; we are guaranteed, however, 2343 // that all ancestor nodes that represent the allocation site have the 2344 // same SourceLocation. 2345 const ExplodedNode *AllocNode = 0; 2346 2347 const SourceManager& SMgr = Ctx.getSourceManager(); 2348 2349 llvm::tie(AllocNode, AllocBinding) = // Set AllocBinding. 2350 GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); 2351 2352 // Get the SourceLocation for the allocation site. 2353 ProgramPoint P = AllocNode->getLocation(); 2354 const Stmt *AllocStmt = cast<PostStmt>(P).getStmt(); 2355 Location = PathDiagnosticLocation::createBegin(AllocStmt, SMgr, 2356 n->getLocationContext()); 2357 // Fill in the description of the bug. 2358 Description.clear(); 2359 llvm::raw_string_ostream os(Description); 2360 os << "Potential leak "; 2361 if (GCEnabled) 2362 os << "(when using garbage collection) "; 2363 os << "of an object"; 2364 2365 // FIXME: AllocBinding doesn't get populated for RegionStore yet. 2366 if (AllocBinding) 2367 os << " stored into '" << AllocBinding->getString() << '\''; 2368 2369 addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log)); 2370} 2371 2372//===----------------------------------------------------------------------===// 2373// Main checker logic. 2374//===----------------------------------------------------------------------===// 2375 2376namespace { 2377class RetainCountChecker 2378 : public Checker< check::Bind, 2379 check::DeadSymbols, 2380 check::EndAnalysis, 2381 check::EndPath, 2382 check::PostStmt<BlockExpr>, 2383 check::PostStmt<CastExpr>, 2384 check::PostStmt<ObjCArrayLiteral>, 2385 check::PostStmt<ObjCDictionaryLiteral>, 2386 check::PostStmt<ObjCBoxedExpr>, 2387 check::PostCall, 2388 check::PreStmt<ReturnStmt>, 2389 check::RegionChanges, 2390 eval::Assume, 2391 eval::Call > { 2392 mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned; 2393 mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned; 2394 mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned; 2395 mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn; 2396 mutable OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; 2397 2398 typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap; 2399 2400 // This map is only used to ensure proper deletion of any allocated tags. 2401 mutable SymbolTagMap DeadSymbolTags; 2402 2403 mutable OwningPtr<RetainSummaryManager> Summaries; 2404 mutable OwningPtr<RetainSummaryManager> SummariesGC; 2405 2406 mutable ARCounts::Factory ARCountFactory; 2407 2408 mutable SummaryLogTy SummaryLog; 2409 mutable bool ShouldResetSummaryLog; 2410 2411public: 2412 RetainCountChecker() : ShouldResetSummaryLog(false) {} 2413 2414 virtual ~RetainCountChecker() { 2415 DeleteContainerSeconds(DeadSymbolTags); 2416 } 2417 2418 void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, 2419 ExprEngine &Eng) const { 2420 // FIXME: This is a hack to make sure the summary log gets cleared between 2421 // analyses of different code bodies. 2422 // 2423 // Why is this necessary? Because a checker's lifetime is tied to a 2424 // translation unit, but an ExplodedGraph's lifetime is just a code body. 2425 // Once in a blue moon, a new ExplodedNode will have the same address as an 2426 // old one with an associated summary, and the bug report visitor gets very 2427 // confused. (To make things worse, the summary lifetime is currently also 2428 // tied to a code body, so we get a crash instead of incorrect results.) 2429 // 2430 // Why is this a bad solution? Because if the lifetime of the ExplodedGraph 2431 // changes, things will start going wrong again. Really the lifetime of this 2432 // log needs to be tied to either the specific nodes in it or the entire 2433 // ExplodedGraph, not to a specific part of the code being analyzed. 2434 // 2435 // (Also, having stateful local data means that the same checker can't be 2436 // used from multiple threads, but a lot of checkers have incorrect 2437 // assumptions about that anyway. So that wasn't a priority at the time of 2438 // this fix.) 2439 // 2440 // This happens at the end of analysis, but bug reports are emitted /after/ 2441 // this point. So we can't just clear the summary log now. Instead, we mark 2442 // that the next time we access the summary log, it should be cleared. 2443 2444 // If we never reset the summary log during /this/ code body analysis, 2445 // there were no new summaries. There might still have been summaries from 2446 // the /last/ analysis, so clear them out to make sure the bug report 2447 // visitors don't get confused. 2448 if (ShouldResetSummaryLog) 2449 SummaryLog.clear(); 2450 2451 ShouldResetSummaryLog = !SummaryLog.empty(); 2452 } 2453 2454 CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, 2455 bool GCEnabled) const { 2456 if (GCEnabled) { 2457 if (!leakWithinFunctionGC) 2458 leakWithinFunctionGC.reset(new Leak("Leak of object when using " 2459 "garbage collection")); 2460 return leakWithinFunctionGC.get(); 2461 } else { 2462 if (!leakWithinFunction) { 2463 if (LOpts.getGC() == LangOptions::HybridGC) { 2464 leakWithinFunction.reset(new Leak("Leak of object when not using " 2465 "garbage collection (GC) in " 2466 "dual GC/non-GC code")); 2467 } else { 2468 leakWithinFunction.reset(new Leak("Leak")); 2469 } 2470 } 2471 return leakWithinFunction.get(); 2472 } 2473 } 2474 2475 CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { 2476 if (GCEnabled) { 2477 if (!leakAtReturnGC) 2478 leakAtReturnGC.reset(new Leak("Leak of returned object when using " 2479 "garbage collection")); 2480 return leakAtReturnGC.get(); 2481 } else { 2482 if (!leakAtReturn) { 2483 if (LOpts.getGC() == LangOptions::HybridGC) { 2484 leakAtReturn.reset(new Leak("Leak of returned object when not using " 2485 "garbage collection (GC) in dual " 2486 "GC/non-GC code")); 2487 } else { 2488 leakAtReturn.reset(new Leak("Leak of returned object")); 2489 } 2490 } 2491 return leakAtReturn.get(); 2492 } 2493 } 2494 2495 RetainSummaryManager &getSummaryManager(ASTContext &Ctx, 2496 bool GCEnabled) const { 2497 // FIXME: We don't support ARC being turned on and off during one analysis. 2498 // (nor, for that matter, do we support changing ASTContexts) 2499 bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; 2500 if (GCEnabled) { 2501 if (!SummariesGC) 2502 SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); 2503 else 2504 assert(SummariesGC->isARCEnabled() == ARCEnabled); 2505 return *SummariesGC; 2506 } else { 2507 if (!Summaries) 2508 Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); 2509 else 2510 assert(Summaries->isARCEnabled() == ARCEnabled); 2511 return *Summaries; 2512 } 2513 } 2514 2515 RetainSummaryManager &getSummaryManager(CheckerContext &C) const { 2516 return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); 2517 } 2518 2519 void printState(raw_ostream &Out, ProgramStateRef State, 2520 const char *NL, const char *Sep) const; 2521 2522 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; 2523 void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; 2524 void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; 2525 2526 void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; 2527 void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; 2528 void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; 2529 2530 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 2531 2532 void checkSummary(const RetainSummary &Summ, const CallEvent &Call, 2533 CheckerContext &C) const; 2534 2535 bool evalCall(const CallExpr *CE, CheckerContext &C) const; 2536 2537 ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, 2538 bool Assumption) const; 2539 2540 ProgramStateRef 2541 checkRegionChanges(ProgramStateRef state, 2542 const StoreManager::InvalidatedSymbols *invalidated, 2543 ArrayRef<const MemRegion *> ExplicitRegions, 2544 ArrayRef<const MemRegion *> Regions, 2545 const CallEvent *Call) const; 2546 2547 bool wantsRegionChangeUpdate(ProgramStateRef state) const { 2548 return true; 2549 } 2550 2551 void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; 2552 void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, 2553 ExplodedNode *Pred, RetEffect RE, RefVal X, 2554 SymbolRef Sym, ProgramStateRef state) const; 2555 2556 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 2557 void checkEndPath(CheckerContext &C) const; 2558 2559 ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, 2560 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2561 CheckerContext &C) const; 2562 2563 void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, 2564 RefVal::Kind ErrorKind, SymbolRef Sym, 2565 CheckerContext &C) const; 2566 2567 void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; 2568 2569 const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; 2570 2571 ProgramStateRef handleSymbolDeath(ProgramStateRef state, 2572 SymbolRef sid, RefVal V, 2573 SmallVectorImpl<SymbolRef> &Leaked) const; 2574 2575 std::pair<ExplodedNode *, ProgramStateRef > 2576 handleAutoreleaseCounts(ProgramStateRef state, 2577 GenericNodeBuilderRefCount Bd, ExplodedNode *Pred, 2578 CheckerContext &Ctx, SymbolRef Sym, RefVal V) const; 2579 2580 ExplodedNode *processLeaks(ProgramStateRef state, 2581 SmallVectorImpl<SymbolRef> &Leaked, 2582 GenericNodeBuilderRefCount &Builder, 2583 CheckerContext &Ctx, 2584 ExplodedNode *Pred = 0) const; 2585}; 2586} // end anonymous namespace 2587 2588namespace { 2589class StopTrackingCallback : public SymbolVisitor { 2590 ProgramStateRef state; 2591public: 2592 StopTrackingCallback(ProgramStateRef st) : state(st) {} 2593 ProgramStateRef getState() const { return state; } 2594 2595 bool VisitSymbol(SymbolRef sym) { 2596 state = state->remove<RefBindings>(sym); 2597 return true; 2598 } 2599}; 2600} // end anonymous namespace 2601 2602//===----------------------------------------------------------------------===// 2603// Handle statements that may have an effect on refcounts. 2604//===----------------------------------------------------------------------===// 2605 2606void RetainCountChecker::checkPostStmt(const BlockExpr *BE, 2607 CheckerContext &C) const { 2608 2609 // Scan the BlockDecRefExprs for any object the retain count checker 2610 // may be tracking. 2611 if (!BE->getBlockDecl()->hasCaptures()) 2612 return; 2613 2614 ProgramStateRef state = C.getState(); 2615 const BlockDataRegion *R = 2616 cast<BlockDataRegion>(state->getSVal(BE, 2617 C.getLocationContext()).getAsRegion()); 2618 2619 BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), 2620 E = R->referenced_vars_end(); 2621 2622 if (I == E) 2623 return; 2624 2625 // FIXME: For now we invalidate the tracking of all symbols passed to blocks 2626 // via captured variables, even though captured variables result in a copy 2627 // and in implicit increment/decrement of a retain count. 2628 SmallVector<const MemRegion*, 10> Regions; 2629 const LocationContext *LC = C.getLocationContext(); 2630 MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); 2631 2632 for ( ; I != E; ++I) { 2633 const VarRegion *VR = *I; 2634 if (VR->getSuperRegion() == R) { 2635 VR = MemMgr.getVarRegion(VR->getDecl(), LC); 2636 } 2637 Regions.push_back(VR); 2638 } 2639 2640 state = 2641 state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), 2642 Regions.data() + Regions.size()).getState(); 2643 C.addTransition(state); 2644} 2645 2646void RetainCountChecker::checkPostStmt(const CastExpr *CE, 2647 CheckerContext &C) const { 2648 const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); 2649 if (!BE) 2650 return; 2651 2652 ArgEffect AE = IncRef; 2653 2654 switch (BE->getBridgeKind()) { 2655 case clang::OBC_Bridge: 2656 // Do nothing. 2657 return; 2658 case clang::OBC_BridgeRetained: 2659 AE = IncRef; 2660 break; 2661 case clang::OBC_BridgeTransfer: 2662 AE = DecRefBridgedTransfered; 2663 break; 2664 } 2665 2666 ProgramStateRef state = C.getState(); 2667 SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol(); 2668 if (!Sym) 2669 return; 2670 const RefVal* T = state->get<RefBindings>(Sym); 2671 if (!T) 2672 return; 2673 2674 RefVal::Kind hasErr = (RefVal::Kind) 0; 2675 state = updateSymbol(state, Sym, *T, AE, hasErr, C); 2676 2677 if (hasErr) { 2678 // FIXME: If we get an error during a bridge cast, should we report it? 2679 // Should we assert that there is no error? 2680 return; 2681 } 2682 2683 C.addTransition(state); 2684} 2685 2686void RetainCountChecker::processObjCLiterals(CheckerContext &C, 2687 const Expr *Ex) const { 2688 ProgramStateRef state = C.getState(); 2689 const ExplodedNode *pred = C.getPredecessor(); 2690 for (Stmt::const_child_iterator it = Ex->child_begin(), et = Ex->child_end() ; 2691 it != et ; ++it) { 2692 const Stmt *child = *it; 2693 SVal V = state->getSVal(child, pred->getLocationContext()); 2694 if (SymbolRef sym = V.getAsSymbol()) 2695 if (const RefVal* T = state->get<RefBindings>(sym)) { 2696 RefVal::Kind hasErr = (RefVal::Kind) 0; 2697 state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); 2698 if (hasErr) { 2699 processNonLeakError(state, child->getSourceRange(), hasErr, sym, C); 2700 return; 2701 } 2702 } 2703 } 2704 2705 // Return the object as autoreleased. 2706 // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); 2707 if (SymbolRef sym = 2708 state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { 2709 QualType ResultTy = Ex->getType(); 2710 state = state->set<RefBindings>(sym, RefVal::makeNotOwned(RetEffect::ObjC, 2711 ResultTy)); 2712 } 2713 2714 C.addTransition(state); 2715} 2716 2717void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, 2718 CheckerContext &C) const { 2719 // Apply the 'MayEscape' to all values. 2720 processObjCLiterals(C, AL); 2721} 2722 2723void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 2724 CheckerContext &C) const { 2725 // Apply the 'MayEscape' to all keys and values. 2726 processObjCLiterals(C, DL); 2727} 2728 2729void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, 2730 CheckerContext &C) const { 2731 const ExplodedNode *Pred = C.getPredecessor(); 2732 const LocationContext *LCtx = Pred->getLocationContext(); 2733 ProgramStateRef State = Pred->getState(); 2734 2735 if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) { 2736 QualType ResultTy = Ex->getType(); 2737 State = State->set<RefBindings>(Sym, RefVal::makeNotOwned(RetEffect::ObjC, 2738 ResultTy)); 2739 } 2740 2741 C.addTransition(State); 2742} 2743 2744void RetainCountChecker::checkPostCall(const CallEvent &Call, 2745 CheckerContext &C) const { 2746 if (C.wasInlined) 2747 return; 2748 2749 RetainSummaryManager &Summaries = getSummaryManager(C); 2750 const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); 2751 checkSummary(*Summ, Call, C); 2752} 2753 2754/// GetReturnType - Used to get the return type of a message expression or 2755/// function call with the intention of affixing that type to a tracked symbol. 2756/// While the the return type can be queried directly from RetEx, when 2757/// invoking class methods we augment to the return type to be that of 2758/// a pointer to the class (as opposed it just being id). 2759// FIXME: We may be able to do this with related result types instead. 2760// This function is probably overestimating. 2761static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { 2762 QualType RetTy = RetE->getType(); 2763 // If RetE is not a message expression just return its type. 2764 // If RetE is a message expression, return its types if it is something 2765 /// more specific than id. 2766 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) 2767 if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) 2768 if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || 2769 PT->isObjCClassType()) { 2770 // At this point we know the return type of the message expression is 2771 // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this 2772 // is a call to a class method whose type we can resolve. In such 2773 // cases, promote the return type to XXX* (where XXX is the class). 2774 const ObjCInterfaceDecl *D = ME->getReceiverInterface(); 2775 return !D ? RetTy : 2776 Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); 2777 } 2778 2779 return RetTy; 2780} 2781 2782void RetainCountChecker::checkSummary(const RetainSummary &Summ, 2783 const CallEvent &CallOrMsg, 2784 CheckerContext &C) const { 2785 ProgramStateRef state = C.getState(); 2786 2787 // Evaluate the effect of the arguments. 2788 RefVal::Kind hasErr = (RefVal::Kind) 0; 2789 SourceRange ErrorRange; 2790 SymbolRef ErrorSym = 0; 2791 2792 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2793 SVal V = CallOrMsg.getArgSVal(idx); 2794 2795 if (SymbolRef Sym = V.getAsLocSymbol()) { 2796 if (RefBindings::data_type *T = state->get<RefBindings>(Sym)) { 2797 state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C); 2798 if (hasErr) { 2799 ErrorRange = CallOrMsg.getArgSourceRange(idx); 2800 ErrorSym = Sym; 2801 break; 2802 } 2803 } 2804 } 2805 } 2806 2807 // Evaluate the effect on the message receiver. 2808 bool ReceiverIsTracked = false; 2809 if (!hasErr) { 2810 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2811 if (MsgInvocation) { 2812 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2813 if (const RefVal *T = state->get<RefBindings>(Sym)) { 2814 ReceiverIsTracked = true; 2815 state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), 2816 hasErr, C); 2817 if (hasErr) { 2818 ErrorRange = MsgInvocation->getReceiverSourceRange(); 2819 ErrorSym = Sym; 2820 } 2821 } 2822 } 2823 } 2824 } 2825 2826 // Process any errors. 2827 if (hasErr) { 2828 processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); 2829 return; 2830 } 2831 2832 // Consult the summary for the return value. 2833 RetEffect RE = Summ.getRetEffect(); 2834 2835 if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { 2836 if (ReceiverIsTracked) 2837 RE = getSummaryManager(C).getObjAllocRetEffect(); 2838 else 2839 RE = RetEffect::MakeNoRet(); 2840 } 2841 2842 switch (RE.getKind()) { 2843 default: 2844 llvm_unreachable("Unhandled RetEffect."); 2845 2846 case RetEffect::NoRet: 2847 // No work necessary. 2848 break; 2849 2850 case RetEffect::OwnedAllocatedSymbol: 2851 case RetEffect::OwnedSymbol: { 2852 SymbolRef Sym = state->getSVal(CallOrMsg.getOriginExpr(), 2853 C.getLocationContext()).getAsSymbol(); 2854 if (!Sym) 2855 break; 2856 2857 // Use the result type from the CallEvent as it automatically adjusts 2858 // for methods/functions that return references. 2859 QualType ResultTy = CallOrMsg.getResultType(); 2860 state = state->set<RefBindings>(Sym, RefVal::makeOwned(RE.getObjKind(), 2861 ResultTy)); 2862 2863 // FIXME: Add a flag to the checker where allocations are assumed to 2864 // *not* fail. (The code below is out-of-date, though.) 2865#if 0 2866 if (RE.getKind() == RetEffect::OwnedAllocatedSymbol) { 2867 bool isFeasible; 2868 state = state.assume(loc::SymbolVal(Sym), true, isFeasible); 2869 assert(isFeasible && "Cannot assume fresh symbol is non-null."); 2870 } 2871#endif 2872 2873 break; 2874 } 2875 2876 case RetEffect::GCNotOwnedSymbol: 2877 case RetEffect::ARCNotOwnedSymbol: 2878 case RetEffect::NotOwnedSymbol: { 2879 const Expr *Ex = CallOrMsg.getOriginExpr(); 2880 SymbolRef Sym = state->getSVal(Ex, C.getLocationContext()).getAsSymbol(); 2881 if (!Sym) 2882 break; 2883 2884 // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. 2885 QualType ResultTy = GetReturnType(Ex, C.getASTContext()); 2886 state = state->set<RefBindings>(Sym, RefVal::makeNotOwned(RE.getObjKind(), 2887 ResultTy)); 2888 break; 2889 } 2890 } 2891 2892 // This check is actually necessary; otherwise the statement builder thinks 2893 // we've hit a previously-found path. 2894 // Normally addTransition takes care of this, but we want the node pointer. 2895 ExplodedNode *NewNode; 2896 if (state == C.getState()) { 2897 NewNode = C.getPredecessor(); 2898 } else { 2899 NewNode = C.addTransition(state); 2900 } 2901 2902 // Annotate the node with summary we used. 2903 if (NewNode) { 2904 // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. 2905 if (ShouldResetSummaryLog) { 2906 SummaryLog.clear(); 2907 ShouldResetSummaryLog = false; 2908 } 2909 SummaryLog[NewNode] = &Summ; 2910 } 2911} 2912 2913 2914ProgramStateRef 2915RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, 2916 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2917 CheckerContext &C) const { 2918 // In GC mode [... release] and [... retain] do nothing. 2919 // In ARC mode they shouldn't exist at all, but we just ignore them. 2920 bool IgnoreRetainMsg = C.isObjCGCEnabled(); 2921 if (!IgnoreRetainMsg) 2922 IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; 2923 2924 switch (E) { 2925 default: 2926 break; 2927 case IncRefMsg: 2928 E = IgnoreRetainMsg ? DoNothing : IncRef; 2929 break; 2930 case DecRefMsg: 2931 E = IgnoreRetainMsg ? DoNothing : DecRef; 2932 break; 2933 case DecRefMsgAndStopTracking: 2934 E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTracking; 2935 break; 2936 case MakeCollectable: 2937 E = C.isObjCGCEnabled() ? DecRef : DoNothing; 2938 break; 2939 case NewAutoreleasePool: 2940 E = C.isObjCGCEnabled() ? DoNothing : NewAutoreleasePool; 2941 break; 2942 } 2943 2944 // Handle all use-after-releases. 2945 if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { 2946 V = V ^ RefVal::ErrorUseAfterRelease; 2947 hasErr = V.getKind(); 2948 return state->set<RefBindings>(sym, V); 2949 } 2950 2951 switch (E) { 2952 case DecRefMsg: 2953 case IncRefMsg: 2954 case MakeCollectable: 2955 case DecRefMsgAndStopTracking: 2956 llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); 2957 2958 case Dealloc: 2959 // Any use of -dealloc in GC is *bad*. 2960 if (C.isObjCGCEnabled()) { 2961 V = V ^ RefVal::ErrorDeallocGC; 2962 hasErr = V.getKind(); 2963 break; 2964 } 2965 2966 switch (V.getKind()) { 2967 default: 2968 llvm_unreachable("Invalid RefVal state for an explicit dealloc."); 2969 case RefVal::Owned: 2970 // The object immediately transitions to the released state. 2971 V = V ^ RefVal::Released; 2972 V.clearCounts(); 2973 return state->set<RefBindings>(sym, V); 2974 case RefVal::NotOwned: 2975 V = V ^ RefVal::ErrorDeallocNotOwned; 2976 hasErr = V.getKind(); 2977 break; 2978 } 2979 break; 2980 2981 case NewAutoreleasePool: 2982 assert(!C.isObjCGCEnabled()); 2983 return state->add<AutoreleaseStack>(sym); 2984 2985 case MayEscape: 2986 if (V.getKind() == RefVal::Owned) { 2987 V = V ^ RefVal::NotOwned; 2988 break; 2989 } 2990 2991 // Fall-through. 2992 2993 case DoNothing: 2994 return state; 2995 2996 case Autorelease: 2997 if (C.isObjCGCEnabled()) 2998 return state; 2999 3000 // Update the autorelease counts. 3001 state = SendAutorelease(state, ARCountFactory, sym); 3002 V = V.autorelease(); 3003 break; 3004 3005 case StopTracking: 3006 return state->remove<RefBindings>(sym); 3007 3008 case IncRef: 3009 switch (V.getKind()) { 3010 default: 3011 llvm_unreachable("Invalid RefVal state for a retain."); 3012 case RefVal::Owned: 3013 case RefVal::NotOwned: 3014 V = V + 1; 3015 break; 3016 case RefVal::Released: 3017 // Non-GC cases are handled above. 3018 assert(C.isObjCGCEnabled()); 3019 V = (V ^ RefVal::Owned) + 1; 3020 break; 3021 } 3022 break; 3023 3024 case DecRef: 3025 case DecRefBridgedTransfered: 3026 case DecRefAndStopTracking: 3027 switch (V.getKind()) { 3028 default: 3029 // case 'RefVal::Released' handled above. 3030 llvm_unreachable("Invalid RefVal state for a release."); 3031 3032 case RefVal::Owned: 3033 assert(V.getCount() > 0); 3034 if (V.getCount() == 1) 3035 V = V ^ (E == DecRefBridgedTransfered ? 3036 RefVal::NotOwned : RefVal::Released); 3037 else if (E == DecRefAndStopTracking) 3038 return state->remove<RefBindings>(sym); 3039 3040 V = V - 1; 3041 break; 3042 3043 case RefVal::NotOwned: 3044 if (V.getCount() > 0) { 3045 if (E == DecRefAndStopTracking) 3046 return state->remove<RefBindings>(sym); 3047 V = V - 1; 3048 } else { 3049 V = V ^ RefVal::ErrorReleaseNotOwned; 3050 hasErr = V.getKind(); 3051 } 3052 break; 3053 3054 case RefVal::Released: 3055 // Non-GC cases are handled above. 3056 assert(C.isObjCGCEnabled()); 3057 V = V ^ RefVal::ErrorUseAfterRelease; 3058 hasErr = V.getKind(); 3059 break; 3060 } 3061 break; 3062 } 3063 return state->set<RefBindings>(sym, V); 3064} 3065 3066void RetainCountChecker::processNonLeakError(ProgramStateRef St, 3067 SourceRange ErrorRange, 3068 RefVal::Kind ErrorKind, 3069 SymbolRef Sym, 3070 CheckerContext &C) const { 3071 ExplodedNode *N = C.generateSink(St); 3072 if (!N) 3073 return; 3074 3075 CFRefBug *BT; 3076 switch (ErrorKind) { 3077 default: 3078 llvm_unreachable("Unhandled error."); 3079 case RefVal::ErrorUseAfterRelease: 3080 if (!useAfterRelease) 3081 useAfterRelease.reset(new UseAfterRelease()); 3082 BT = &*useAfterRelease; 3083 break; 3084 case RefVal::ErrorReleaseNotOwned: 3085 if (!releaseNotOwned) 3086 releaseNotOwned.reset(new BadRelease()); 3087 BT = &*releaseNotOwned; 3088 break; 3089 case RefVal::ErrorDeallocGC: 3090 if (!deallocGC) 3091 deallocGC.reset(new DeallocGC()); 3092 BT = &*deallocGC; 3093 break; 3094 case RefVal::ErrorDeallocNotOwned: 3095 if (!deallocNotOwned) 3096 deallocNotOwned.reset(new DeallocNotOwned()); 3097 BT = &*deallocNotOwned; 3098 break; 3099 } 3100 3101 assert(BT); 3102 CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOpts(), 3103 C.isObjCGCEnabled(), SummaryLog, 3104 N, Sym); 3105 report->addRange(ErrorRange); 3106 C.EmitReport(report); 3107} 3108 3109//===----------------------------------------------------------------------===// 3110// Handle the return values of retain-count-related functions. 3111//===----------------------------------------------------------------------===// 3112 3113bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { 3114 // Get the callee. We're only interested in simple C functions. 3115 ProgramStateRef state = C.getState(); 3116 const FunctionDecl *FD = C.getCalleeDecl(CE); 3117 if (!FD) 3118 return false; 3119 3120 IdentifierInfo *II = FD->getIdentifier(); 3121 if (!II) 3122 return false; 3123 3124 // For now, we're only handling the functions that return aliases of their 3125 // arguments: CFRetain and CFMakeCollectable (and their families). 3126 // Eventually we should add other functions we can model entirely, 3127 // such as CFRelease, which don't invalidate their arguments or globals. 3128 if (CE->getNumArgs() != 1) 3129 return false; 3130 3131 // Get the name of the function. 3132 StringRef FName = II->getName(); 3133 FName = FName.substr(FName.find_first_not_of('_')); 3134 3135 // See if it's one of the specific functions we know how to eval. 3136 bool canEval = false; 3137 3138 QualType ResultTy = CE->getCallReturnType(); 3139 if (ResultTy->isObjCIdType()) { 3140 // Handle: id NSMakeCollectable(CFTypeRef) 3141 canEval = II->isStr("NSMakeCollectable"); 3142 } else if (ResultTy->isPointerType()) { 3143 // Handle: (CF|CG)Retain 3144 // CFMakeCollectable 3145 // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). 3146 if (cocoa::isRefType(ResultTy, "CF", FName) || 3147 cocoa::isRefType(ResultTy, "CG", FName)) { 3148 canEval = isRetain(FD, FName) || isMakeCollectable(FD, FName); 3149 } 3150 } 3151 3152 if (!canEval) 3153 return false; 3154 3155 // Bind the return value. 3156 const LocationContext *LCtx = C.getLocationContext(); 3157 SVal RetVal = state->getSVal(CE->getArg(0), LCtx); 3158 if (RetVal.isUnknown()) { 3159 // If the receiver is unknown, conjure a return value. 3160 SValBuilder &SVB = C.getSValBuilder(); 3161 unsigned Count = C.getCurrentBlockCount(); 3162 SVal RetVal = SVB.getConjuredSymbolVal(0, CE, LCtx, ResultTy, Count); 3163 } 3164 state = state->BindExpr(CE, LCtx, RetVal, false); 3165 3166 // FIXME: This should not be necessary, but otherwise the argument seems to be 3167 // considered alive during the next statement. 3168 if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { 3169 // Save the refcount status of the argument. 3170 SymbolRef Sym = RetVal.getAsLocSymbol(); 3171 RefBindings::data_type *Binding = 0; 3172 if (Sym) 3173 Binding = state->get<RefBindings>(Sym); 3174 3175 // Invalidate the argument region. 3176 unsigned Count = C.getCurrentBlockCount(); 3177 state = state->invalidateRegions(ArgRegion, CE, Count, LCtx); 3178 3179 // Restore the refcount status of the argument. 3180 if (Binding) 3181 state = state->set<RefBindings>(Sym, *Binding); 3182 } 3183 3184 C.addTransition(state); 3185 return true; 3186} 3187 3188//===----------------------------------------------------------------------===// 3189// Handle return statements. 3190//===----------------------------------------------------------------------===// 3191 3192// Return true if the current LocationContext has no caller context. 3193static bool inTopFrame(CheckerContext &C) { 3194 const LocationContext *LC = C.getLocationContext(); 3195 return LC->getParent() == 0; 3196} 3197 3198void RetainCountChecker::checkPreStmt(const ReturnStmt *S, 3199 CheckerContext &C) const { 3200 3201 // Only adjust the reference count if this is the top-level call frame, 3202 // and not the result of inlining. In the future, we should do 3203 // better checking even for inlined calls, and see if they match 3204 // with their expected semantics (e.g., the method should return a retained 3205 // object, etc.). 3206 if (!inTopFrame(C)) 3207 return; 3208 3209 const Expr *RetE = S->getRetValue(); 3210 if (!RetE) 3211 return; 3212 3213 ProgramStateRef state = C.getState(); 3214 SymbolRef Sym = 3215 state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); 3216 if (!Sym) 3217 return; 3218 3219 // Get the reference count binding (if any). 3220 const RefVal *T = state->get<RefBindings>(Sym); 3221 if (!T) 3222 return; 3223 3224 // Change the reference count. 3225 RefVal X = *T; 3226 3227 switch (X.getKind()) { 3228 case RefVal::Owned: { 3229 unsigned cnt = X.getCount(); 3230 assert(cnt > 0); 3231 X.setCount(cnt - 1); 3232 X = X ^ RefVal::ReturnedOwned; 3233 break; 3234 } 3235 3236 case RefVal::NotOwned: { 3237 unsigned cnt = X.getCount(); 3238 if (cnt) { 3239 X.setCount(cnt - 1); 3240 X = X ^ RefVal::ReturnedOwned; 3241 } 3242 else { 3243 X = X ^ RefVal::ReturnedNotOwned; 3244 } 3245 break; 3246 } 3247 3248 default: 3249 return; 3250 } 3251 3252 // Update the binding. 3253 state = state->set<RefBindings>(Sym, X); 3254 ExplodedNode *Pred = C.addTransition(state); 3255 3256 // At this point we have updated the state properly. 3257 // Everything after this is merely checking to see if the return value has 3258 // been over- or under-retained. 3259 3260 // Did we cache out? 3261 if (!Pred) 3262 return; 3263 3264 // Update the autorelease counts. 3265 static SimpleProgramPointTag 3266 AutoreleaseTag("RetainCountChecker : Autorelease"); 3267 GenericNodeBuilderRefCount Bd(C, &AutoreleaseTag); 3268 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, C, Sym, X); 3269 3270 // Did we cache out? 3271 if (!Pred) 3272 return; 3273 3274 // Get the updated binding. 3275 T = state->get<RefBindings>(Sym); 3276 assert(T); 3277 X = *T; 3278 3279 // Consult the summary of the enclosing method. 3280 RetainSummaryManager &Summaries = getSummaryManager(C); 3281 const Decl *CD = &Pred->getCodeDecl(); 3282 RetEffect RE = RetEffect::MakeNoRet(); 3283 3284 // FIXME: What is the convention for blocks? Is there one? 3285 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) { 3286 const RetainSummary *Summ = Summaries.getMethodSummary(MD); 3287 RE = Summ->getRetEffect(); 3288 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) { 3289 if (!isa<CXXMethodDecl>(FD)) { 3290 const RetainSummary *Summ = Summaries.getFunctionSummary(FD); 3291 RE = Summ->getRetEffect(); 3292 } 3293 } 3294 3295 checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state); 3296} 3297 3298void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S, 3299 CheckerContext &C, 3300 ExplodedNode *Pred, 3301 RetEffect RE, RefVal X, 3302 SymbolRef Sym, 3303 ProgramStateRef state) const { 3304 // Any leaks or other errors? 3305 if (X.isReturnedOwned() && X.getCount() == 0) { 3306 if (RE.getKind() != RetEffect::NoRet) { 3307 bool hasError = false; 3308 if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) { 3309 // Things are more complicated with garbage collection. If the 3310 // returned object is suppose to be an Objective-C object, we have 3311 // a leak (as the caller expects a GC'ed object) because no 3312 // method should return ownership unless it returns a CF object. 3313 hasError = true; 3314 X = X ^ RefVal::ErrorGCLeakReturned; 3315 } 3316 else if (!RE.isOwned()) { 3317 // Either we are using GC and the returned object is a CF type 3318 // or we aren't using GC. In either case, we expect that the 3319 // enclosing method is expected to return ownership. 3320 hasError = true; 3321 X = X ^ RefVal::ErrorLeakReturned; 3322 } 3323 3324 if (hasError) { 3325 // Generate an error node. 3326 state = state->set<RefBindings>(Sym, X); 3327 3328 static SimpleProgramPointTag 3329 ReturnOwnLeakTag("RetainCountChecker : ReturnsOwnLeak"); 3330 ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag); 3331 if (N) { 3332 const LangOptions &LOpts = C.getASTContext().getLangOpts(); 3333 bool GCEnabled = C.isObjCGCEnabled(); 3334 CFRefReport *report = 3335 new CFRefLeakReport(*getLeakAtReturnBug(LOpts, GCEnabled), 3336 LOpts, GCEnabled, SummaryLog, 3337 N, Sym, C); 3338 C.EmitReport(report); 3339 } 3340 } 3341 } 3342 } else if (X.isReturnedNotOwned()) { 3343 if (RE.isOwned()) { 3344 // Trying to return a not owned object to a caller expecting an 3345 // owned object. 3346 state = state->set<RefBindings>(Sym, X ^ RefVal::ErrorReturnedNotOwned); 3347 3348 static SimpleProgramPointTag 3349 ReturnNotOwnedTag("RetainCountChecker : ReturnNotOwnedForOwned"); 3350 ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag); 3351 if (N) { 3352 if (!returnNotOwnedForOwned) 3353 returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned()); 3354 3355 CFRefReport *report = 3356 new CFRefReport(*returnNotOwnedForOwned, 3357 C.getASTContext().getLangOpts(), 3358 C.isObjCGCEnabled(), SummaryLog, N, Sym); 3359 C.EmitReport(report); 3360 } 3361 } 3362 } 3363} 3364 3365//===----------------------------------------------------------------------===// 3366// Check various ways a symbol can be invalidated. 3367//===----------------------------------------------------------------------===// 3368 3369void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S, 3370 CheckerContext &C) const { 3371 // Are we storing to something that causes the value to "escape"? 3372 bool escapes = true; 3373 3374 // A value escapes in three possible cases (this may change): 3375 // 3376 // (1) we are binding to something that is not a memory region. 3377 // (2) we are binding to a memregion that does not have stack storage 3378 // (3) we are binding to a memregion with stack storage that the store 3379 // does not understand. 3380 ProgramStateRef state = C.getState(); 3381 3382 if (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) { 3383 escapes = !regionLoc->getRegion()->hasStackStorage(); 3384 3385 if (!escapes) { 3386 // To test (3), generate a new state with the binding added. If it is 3387 // the same state, then it escapes (since the store cannot represent 3388 // the binding). 3389 // Do this only if we know that the store is not supposed to generate the 3390 // same state. 3391 SVal StoredVal = state->getSVal(regionLoc->getRegion()); 3392 if (StoredVal != val) 3393 escapes = (state == (state->bindLoc(*regionLoc, val))); 3394 } 3395 if (!escapes) { 3396 // Case 4: We do not currently model what happens when a symbol is 3397 // assigned to a struct field, so be conservative here and let the symbol 3398 // go. TODO: This could definitely be improved upon. 3399 escapes = !isa<VarRegion>(regionLoc->getRegion()); 3400 } 3401 } 3402 3403 // If our store can represent the binding and we aren't storing to something 3404 // that doesn't have local storage then just return and have the simulation 3405 // state continue as is. 3406 if (!escapes) 3407 return; 3408 3409 // Otherwise, find all symbols referenced by 'val' that we are tracking 3410 // and stop tracking them. 3411 state = state->scanReachableSymbols<StopTrackingCallback>(val).getState(); 3412 C.addTransition(state); 3413} 3414 3415ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state, 3416 SVal Cond, 3417 bool Assumption) const { 3418 3419 // FIXME: We may add to the interface of evalAssume the list of symbols 3420 // whose assumptions have changed. For now we just iterate through the 3421 // bindings and check if any of the tracked symbols are NULL. This isn't 3422 // too bad since the number of symbols we will track in practice are 3423 // probably small and evalAssume is only called at branches and a few 3424 // other places. 3425 RefBindings B = state->get<RefBindings>(); 3426 3427 if (B.isEmpty()) 3428 return state; 3429 3430 bool changed = false; 3431 RefBindings::Factory &RefBFactory = state->get_context<RefBindings>(); 3432 3433 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3434 // Check if the symbol is null (or equal to any constant). 3435 // If this is the case, stop tracking the symbol. 3436 if (state->getSymVal(I.getKey())) { 3437 changed = true; 3438 B = RefBFactory.remove(B, I.getKey()); 3439 } 3440 } 3441 3442 if (changed) 3443 state = state->set<RefBindings>(B); 3444 3445 return state; 3446} 3447 3448ProgramStateRef 3449RetainCountChecker::checkRegionChanges(ProgramStateRef state, 3450 const StoreManager::InvalidatedSymbols *invalidated, 3451 ArrayRef<const MemRegion *> ExplicitRegions, 3452 ArrayRef<const MemRegion *> Regions, 3453 const CallEvent *Call) const { 3454 if (!invalidated) 3455 return state; 3456 3457 llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols; 3458 for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(), 3459 E = ExplicitRegions.end(); I != E; ++I) { 3460 if (const SymbolicRegion *SR = (*I)->StripCasts()->getAs<SymbolicRegion>()) 3461 WhitelistedSymbols.insert(SR->getSymbol()); 3462 } 3463 3464 for (StoreManager::InvalidatedSymbols::const_iterator I=invalidated->begin(), 3465 E = invalidated->end(); I!=E; ++I) { 3466 SymbolRef sym = *I; 3467 if (WhitelistedSymbols.count(sym)) 3468 continue; 3469 // Remove any existing reference-count binding. 3470 state = state->remove<RefBindings>(sym); 3471 } 3472 return state; 3473} 3474 3475//===----------------------------------------------------------------------===// 3476// Handle dead symbols and end-of-path. 3477//===----------------------------------------------------------------------===// 3478 3479std::pair<ExplodedNode *, ProgramStateRef > 3480RetainCountChecker::handleAutoreleaseCounts(ProgramStateRef state, 3481 GenericNodeBuilderRefCount Bd, 3482 ExplodedNode *Pred, 3483 CheckerContext &Ctx, 3484 SymbolRef Sym, RefVal V) const { 3485 unsigned ACnt = V.getAutoreleaseCount(); 3486 3487 // No autorelease counts? Nothing to be done. 3488 if (!ACnt) 3489 return std::make_pair(Pred, state); 3490 3491 assert(!Ctx.isObjCGCEnabled() && "Autorelease counts in GC mode?"); 3492 unsigned Cnt = V.getCount(); 3493 3494 // FIXME: Handle sending 'autorelease' to already released object. 3495 3496 if (V.getKind() == RefVal::ReturnedOwned) 3497 ++Cnt; 3498 3499 if (ACnt <= Cnt) { 3500 if (ACnt == Cnt) { 3501 V.clearCounts(); 3502 if (V.getKind() == RefVal::ReturnedOwned) 3503 V = V ^ RefVal::ReturnedNotOwned; 3504 else 3505 V = V ^ RefVal::NotOwned; 3506 } else { 3507 V.setCount(Cnt - ACnt); 3508 V.setAutoreleaseCount(0); 3509 } 3510 state = state->set<RefBindings>(Sym, V); 3511 ExplodedNode *N = Bd.MakeNode(state, Pred); 3512 if (N == 0) 3513 state = 0; 3514 return std::make_pair(N, state); 3515 } 3516 3517 // Woah! More autorelease counts then retain counts left. 3518 // Emit hard error. 3519 V = V ^ RefVal::ErrorOverAutorelease; 3520 state = state->set<RefBindings>(Sym, V); 3521 3522 if (ExplodedNode *N = Bd.MakeNode(state, Pred, true)) { 3523 SmallString<128> sbuf; 3524 llvm::raw_svector_ostream os(sbuf); 3525 os << "Object over-autoreleased: object was sent -autorelease "; 3526 if (V.getAutoreleaseCount() > 1) 3527 os << V.getAutoreleaseCount() << " times "; 3528 os << "but the object has a +" << V.getCount() << " retain count"; 3529 3530 if (!overAutorelease) 3531 overAutorelease.reset(new OverAutorelease()); 3532 3533 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3534 CFRefReport *report = 3535 new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false, 3536 SummaryLog, N, Sym, os.str()); 3537 Ctx.EmitReport(report); 3538 } 3539 3540 return std::make_pair((ExplodedNode *)0, (ProgramStateRef )0); 3541} 3542 3543ProgramStateRef 3544RetainCountChecker::handleSymbolDeath(ProgramStateRef state, 3545 SymbolRef sid, RefVal V, 3546 SmallVectorImpl<SymbolRef> &Leaked) const { 3547 bool hasLeak = false; 3548 if (V.isOwned()) 3549 hasLeak = true; 3550 else if (V.isNotOwned() || V.isReturnedOwned()) 3551 hasLeak = (V.getCount() > 0); 3552 3553 if (!hasLeak) 3554 return state->remove<RefBindings>(sid); 3555 3556 Leaked.push_back(sid); 3557 return state->set<RefBindings>(sid, V ^ RefVal::ErrorLeak); 3558} 3559 3560ExplodedNode * 3561RetainCountChecker::processLeaks(ProgramStateRef state, 3562 SmallVectorImpl<SymbolRef> &Leaked, 3563 GenericNodeBuilderRefCount &Builder, 3564 CheckerContext &Ctx, 3565 ExplodedNode *Pred) const { 3566 if (Leaked.empty()) 3567 return Pred; 3568 3569 // Generate an intermediate node representing the leak point. 3570 ExplodedNode *N = Builder.MakeNode(state, Pred); 3571 3572 if (N) { 3573 for (SmallVectorImpl<SymbolRef>::iterator 3574 I = Leaked.begin(), E = Leaked.end(); I != E; ++I) { 3575 3576 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3577 bool GCEnabled = Ctx.isObjCGCEnabled(); 3578 CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled) 3579 : getLeakAtReturnBug(LOpts, GCEnabled); 3580 assert(BT && "BugType not initialized."); 3581 3582 CFRefLeakReport *report = new CFRefLeakReport(*BT, LOpts, GCEnabled, 3583 SummaryLog, N, *I, Ctx); 3584 Ctx.EmitReport(report); 3585 } 3586 } 3587 3588 return N; 3589} 3590 3591void RetainCountChecker::checkEndPath(CheckerContext &Ctx) const { 3592 ProgramStateRef state = Ctx.getState(); 3593 GenericNodeBuilderRefCount Bd(Ctx); 3594 RefBindings B = state->get<RefBindings>(); 3595 ExplodedNode *Pred = Ctx.getPredecessor(); 3596 3597 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3598 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, Ctx, 3599 I->first, I->second); 3600 if (!state) 3601 return; 3602 } 3603 3604 // If the current LocationContext has a parent, don't check for leaks. 3605 // We will do that later. 3606 // FIXME: we should instead check for imblances of the retain/releases, 3607 // and suggest annotations. 3608 if (Ctx.getLocationContext()->getParent()) 3609 return; 3610 3611 B = state->get<RefBindings>(); 3612 SmallVector<SymbolRef, 10> Leaked; 3613 3614 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) 3615 state = handleSymbolDeath(state, I->first, I->second, Leaked); 3616 3617 processLeaks(state, Leaked, Bd, Ctx, Pred); 3618} 3619 3620const ProgramPointTag * 3621RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const { 3622 const SimpleProgramPointTag *&tag = DeadSymbolTags[sym]; 3623 if (!tag) { 3624 SmallString<64> buf; 3625 llvm::raw_svector_ostream out(buf); 3626 out << "RetainCountChecker : Dead Symbol : "; 3627 sym->dumpToStream(out); 3628 tag = new SimpleProgramPointTag(out.str()); 3629 } 3630 return tag; 3631} 3632 3633void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper, 3634 CheckerContext &C) const { 3635 ExplodedNode *Pred = C.getPredecessor(); 3636 3637 ProgramStateRef state = C.getState(); 3638 RefBindings B = state->get<RefBindings>(); 3639 3640 // Update counts from autorelease pools 3641 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3642 E = SymReaper.dead_end(); I != E; ++I) { 3643 SymbolRef Sym = *I; 3644 if (const RefVal *T = B.lookup(Sym)){ 3645 // Use the symbol as the tag. 3646 // FIXME: This might not be as unique as we would like. 3647 GenericNodeBuilderRefCount Bd(C, getDeadSymbolTag(Sym)); 3648 llvm::tie(Pred, state) = handleAutoreleaseCounts(state, Bd, Pred, C, 3649 Sym, *T); 3650 if (!state) 3651 return; 3652 } 3653 } 3654 3655 B = state->get<RefBindings>(); 3656 SmallVector<SymbolRef, 10> Leaked; 3657 3658 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3659 E = SymReaper.dead_end(); I != E; ++I) { 3660 if (const RefVal *T = B.lookup(*I)) 3661 state = handleSymbolDeath(state, *I, *T, Leaked); 3662 } 3663 3664 { 3665 GenericNodeBuilderRefCount Bd(C, this); 3666 Pred = processLeaks(state, Leaked, Bd, C, Pred); 3667 } 3668 3669 // Did we cache out? 3670 if (!Pred) 3671 return; 3672 3673 // Now generate a new node that nukes the old bindings. 3674 RefBindings::Factory &F = state->get_context<RefBindings>(); 3675 3676 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3677 E = SymReaper.dead_end(); I != E; ++I) 3678 B = F.remove(B, *I); 3679 3680 state = state->set<RefBindings>(B); 3681 C.addTransition(state, Pred); 3682} 3683 3684//===----------------------------------------------------------------------===// 3685// Debug printing of refcount bindings and autorelease pools. 3686//===----------------------------------------------------------------------===// 3687 3688static void PrintPool(raw_ostream &Out, SymbolRef Sym, 3689 ProgramStateRef State) { 3690 Out << ' '; 3691 if (Sym) 3692 Sym->dumpToStream(Out); 3693 else 3694 Out << "<pool>"; 3695 Out << ":{"; 3696 3697 // Get the contents of the pool. 3698 if (const ARCounts *Cnts = State->get<AutoreleasePoolContents>(Sym)) 3699 for (ARCounts::iterator I = Cnts->begin(), E = Cnts->end(); I != E; ++I) 3700 Out << '(' << I.getKey() << ',' << I.getData() << ')'; 3701 3702 Out << '}'; 3703} 3704 3705static bool UsesAutorelease(ProgramStateRef state) { 3706 // A state uses autorelease if it allocated an autorelease pool or if it has 3707 // objects in the caller's autorelease pool. 3708 return !state->get<AutoreleaseStack>().isEmpty() || 3709 state->get<AutoreleasePoolContents>(SymbolRef()); 3710} 3711 3712void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State, 3713 const char *NL, const char *Sep) const { 3714 3715 RefBindings B = State->get<RefBindings>(); 3716 3717 if (!B.isEmpty()) 3718 Out << Sep << NL; 3719 3720 for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3721 Out << I->first << " : "; 3722 I->second.print(Out); 3723 Out << NL; 3724 } 3725 3726 // Print the autorelease stack. 3727 if (UsesAutorelease(State)) { 3728 Out << Sep << NL << "AR pool stack:"; 3729 ARStack Stack = State->get<AutoreleaseStack>(); 3730 3731 PrintPool(Out, SymbolRef(), State); // Print the caller's pool. 3732 for (ARStack::iterator I = Stack.begin(), E = Stack.end(); I != E; ++I) 3733 PrintPool(Out, *I, State); 3734 3735 Out << NL; 3736 } 3737} 3738 3739//===----------------------------------------------------------------------===// 3740// Checker registration. 3741//===----------------------------------------------------------------------===// 3742 3743void ento::registerRetainCountChecker(CheckerManager &Mgr) { 3744 Mgr.registerChecker<RetainCountChecker>(); 3745} 3746 3747