RetainCountChecker.cpp revision 063820655db8121f0022a7c51458463c7250324c
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//==-- RetainCountChecker.cpp - Checks for leaks and other issues -*- C++ -*--// 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The LLVM Compiler Infrastructure 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This file is distributed under the University of Illinois Open Source 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// License. See LICENSE.TXT for details. 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 102a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// This file defines the methods for RetainCountChecker, which implements 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// a reference count checker for Core Foundation and Cocoa on (Mac OS X). 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 155d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)#include "ClangSACheckers.h" 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/AST/Attr.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/AST/DeclCXX.h" 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/AST/DeclObjC.h" 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/AST/ParentMap.h" 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/Analysis/DomainSpecific/CocoaConventions.h" 212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "clang/Basic/LangOptions.h" 222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "clang/Basic/SourceManager.h" 235d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/Checker.h" 262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "clang/StaticAnalyzer/Core/CheckerManager.h" 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h" 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Checkers/ObjCRetainCount.h" 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/ADT/DenseMap.h" 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/ADT/FoldingSet.h" 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/ADT/ImmutableList.h" 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/ADT/ImmutableMap.h" 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/ADT/STLExtras.h" 372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "llvm/ADT/SmallString.h" 382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include "llvm/ADT/StringExtras.h" 392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include <cstdarg> 40d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles) 41d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)#include "AllocationDiagnostics.h" 42d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles) 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace clang; 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace ento; 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace objc_retain; 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using llvm::StrInStrNoCase; 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Adapters for FoldingSet. 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 512a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 522a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)namespace llvm { 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template <> struct FoldingSetTrait<ArgEffect> { 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static inline void Profile(const ArgEffect X, FoldingSetNodeID &ID) { 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ID.AddInteger((unsigned) X); 565d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)} 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 58ab8f6f0bd665d3c1ff476eb06c58c42630e462d4Ben Murdochtemplate <> struct FoldingSetTrait<RetEffect> { 5958537e28ecd584eab876aee8be7156509866d23aTorne (Richard Coles) static inline void Profile(const RetEffect &X, FoldingSetNodeID &ID) { 60d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles) ID.AddInteger((unsigned) X.getKind()); 61d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles) ID.AddInteger((unsigned) X.getObjKind()); 62d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)} 63d0247b1b59f9c528cb6df88b4f2b9afaf80d181eTorne (Richard Coles)}; 645d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)} // end llvm namespace 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 6658537e28ecd584eab876aee8be7156509866d23aTorne (Richard Coles)//===----------------------------------------------------------------------===// 6758537e28ecd584eab876aee8be7156509866d23aTorne (Richard Coles)// Reference-counting logic (typestate + counts). 6858537e28ecd584eab876aee8be7156509866d23aTorne (Richard Coles)//===----------------------------------------------------------------------===// 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// ArgEffects summarizes the effects of a function/method call on all of 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// its arguments. 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)typedef llvm::ImmutableMap<unsigned,ArgEffect> ArgEffects; 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 742a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)namespace { 752a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)class RefVal { 76f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)public: 77f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) enum Kind { 78f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) Owned = 0, // Owning reference. 79f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) NotOwned, // Reference is not owned by still valid (not freed). 80f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) Released, // Object has been released. 81f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) ReturnedOwned, // Returned object passes ownership to caller. 822a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) ReturnedNotOwned, // Return object does not pass ownership to caller. 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ERROR_START, 845d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) ErrorDeallocNotOwned, // -dealloc called on non-owned object. 85f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) ErrorDeallocGC, // Calling -dealloc with GC enabled. 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ErrorUseAfterRelease, // Object used after released. 872a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) ErrorReleaseNotOwned, // Release of an object that was not owned. 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ERROR_LEAK_START, 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ErrorLeak, // A memory leak due to excessive reference counts. 9058537e28ecd584eab876aee8be7156509866d23aTorne (Richard Coles) ErrorLeakReturned, // A memory leak due to the returning method not having 9158537e28ecd584eab876aee8be7156509866d23aTorne (Richard Coles) // the correct naming conventions. 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ErrorGCLeakReturned, 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ErrorOverAutorelease, 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ErrorReturnedNotOwned 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)private: 98 Kind kind; 99 RetEffect::ObjKind okind; 100 unsigned Cnt; 101 unsigned ACnt; 102 QualType T; 103 104 RefVal(Kind k, RetEffect::ObjKind o, unsigned cnt, unsigned acnt, QualType t) 105 : kind(k), okind(o), Cnt(cnt), ACnt(acnt), T(t) {} 106 107public: 108 Kind getKind() const { return kind; } 109 110 RetEffect::ObjKind getObjKind() const { return okind; } 111 112 unsigned getCount() const { return Cnt; } 113 unsigned getAutoreleaseCount() const { return ACnt; } 114 unsigned getCombinedCounts() const { return Cnt + ACnt; } 115 void clearCounts() { Cnt = 0; ACnt = 0; } 116 void setCount(unsigned i) { Cnt = i; } 117 void setAutoreleaseCount(unsigned i) { ACnt = i; } 118 119 QualType getType() const { return T; } 120 121 bool isOwned() const { 122 return getKind() == Owned; 123 } 124 125 bool isNotOwned() const { 126 return getKind() == NotOwned; 127 } 128 129 bool isReturnedOwned() const { 130 return getKind() == ReturnedOwned; 131 } 132 133 bool isReturnedNotOwned() const { 134 return getKind() == ReturnedNotOwned; 135 } 136 137 static RefVal makeOwned(RetEffect::ObjKind o, QualType t, 138 unsigned Count = 1) { 139 return RefVal(Owned, o, Count, 0, t); 140 } 141 142 static RefVal makeNotOwned(RetEffect::ObjKind o, QualType t, 143 unsigned Count = 0) { 144 return RefVal(NotOwned, o, Count, 0, t); 145 } 146 147 // Comparison, profiling, and pretty-printing. 148 149 bool operator==(const RefVal& X) const { 150 return kind == X.kind && Cnt == X.Cnt && T == X.T && ACnt == X.ACnt; 151 } 152 153 RefVal operator-(size_t i) const { 154 return RefVal(getKind(), getObjKind(), getCount() - i, 155 getAutoreleaseCount(), getType()); 156 } 157 158 RefVal operator+(size_t i) const { 159 return RefVal(getKind(), getObjKind(), getCount() + i, 160 getAutoreleaseCount(), getType()); 161 } 162 163 RefVal operator^(Kind k) const { 164 return RefVal(k, getObjKind(), getCount(), getAutoreleaseCount(), 165 getType()); 166 } 167 168 RefVal autorelease() const { 169 return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount()+1, 170 getType()); 171 } 172 173 void Profile(llvm::FoldingSetNodeID& ID) const { 174 ID.AddInteger((unsigned) kind); 175 ID.AddInteger(Cnt); 176 ID.AddInteger(ACnt); 177 ID.Add(T); 178 } 179 180 void print(raw_ostream &Out) const; 181}; 182 183void RefVal::print(raw_ostream &Out) const { 184 if (!T.isNull()) 185 Out << "Tracked " << T.getAsString() << '/'; 186 187 switch (getKind()) { 188 default: llvm_unreachable("Invalid RefVal kind"); 189 case Owned: { 190 Out << "Owned"; 191 unsigned cnt = getCount(); 192 if (cnt) Out << " (+ " << cnt << ")"; 193 break; 194 } 195 196 case NotOwned: { 197 Out << "NotOwned"; 198 unsigned cnt = getCount(); 199 if (cnt) Out << " (+ " << cnt << ")"; 200 break; 201 } 202 203 case ReturnedOwned: { 204 Out << "ReturnedOwned"; 205 unsigned cnt = getCount(); 206 if (cnt) Out << " (+ " << cnt << ")"; 207 break; 208 } 209 210 case ReturnedNotOwned: { 211 Out << "ReturnedNotOwned"; 212 unsigned cnt = getCount(); 213 if (cnt) Out << " (+ " << cnt << ")"; 214 break; 215 } 216 217 case Released: 218 Out << "Released"; 219 break; 220 221 case ErrorDeallocGC: 222 Out << "-dealloc (GC)"; 223 break; 224 225 case ErrorDeallocNotOwned: 226 Out << "-dealloc (not-owned)"; 227 break; 228 229 case ErrorLeak: 230 Out << "Leaked"; 231 break; 232 233 case ErrorLeakReturned: 234 Out << "Leaked (Bad naming)"; 235 break; 236 237 case ErrorGCLeakReturned: 238 Out << "Leaked (GC-ed at return)"; 239 break; 240 241 case ErrorUseAfterRelease: 242 Out << "Use-After-Release [ERROR]"; 243 break; 244 245 case ErrorReleaseNotOwned: 246 Out << "Release of Not-Owned [ERROR]"; 247 break; 248 249 case RefVal::ErrorOverAutorelease: 250 Out << "Over-autoreleased"; 251 break; 252 253 case RefVal::ErrorReturnedNotOwned: 254 Out << "Non-owned object returned instead of owned"; 255 break; 256 } 257 258 if (ACnt) { 259 Out << " [ARC +" << ACnt << ']'; 260 } 261} 262} //end anonymous namespace 263 264//===----------------------------------------------------------------------===// 265// RefBindings - State used to track object reference counts. 266//===----------------------------------------------------------------------===// 267 268REGISTER_MAP_WITH_PROGRAMSTATE(RefBindings, SymbolRef, RefVal) 269 270static inline const RefVal *getRefBinding(ProgramStateRef State, 271 SymbolRef Sym) { 272 return State->get<RefBindings>(Sym); 273} 274 275static inline ProgramStateRef setRefBinding(ProgramStateRef State, 276 SymbolRef Sym, RefVal Val) { 277 return State->set<RefBindings>(Sym, Val); 278} 279 280static ProgramStateRef removeRefBinding(ProgramStateRef State, SymbolRef Sym) { 281 return State->remove<RefBindings>(Sym); 282} 283 284//===----------------------------------------------------------------------===// 285// Function/Method behavior summaries. 286//===----------------------------------------------------------------------===// 287 288namespace { 289class RetainSummary { 290 /// Args - a map of (index, ArgEffect) pairs, where index 291 /// specifies the argument (starting from 0). This can be sparsely 292 /// populated; arguments with no entry in Args use 'DefaultArgEffect'. 293 ArgEffects Args; 294 295 /// DefaultArgEffect - The default ArgEffect to apply to arguments that 296 /// do not have an entry in Args. 297 ArgEffect DefaultArgEffect; 298 299 /// Receiver - If this summary applies to an Objective-C message expression, 300 /// this is the effect applied to the state of the receiver. 301 ArgEffect Receiver; 302 303 /// Ret - The effect on the return value. Used to indicate if the 304 /// function/method call returns a new tracked symbol. 305 RetEffect Ret; 306 307public: 308 RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff, 309 ArgEffect ReceiverEff) 310 : Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {} 311 312 /// getArg - Return the argument effect on the argument specified by 313 /// idx (starting from 0). 314 ArgEffect getArg(unsigned idx) const { 315 if (const ArgEffect *AE = Args.lookup(idx)) 316 return *AE; 317 318 return DefaultArgEffect; 319 } 320 321 void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) { 322 Args = af.add(Args, idx, e); 323 } 324 325 /// setDefaultArgEffect - Set the default argument effect. 326 void setDefaultArgEffect(ArgEffect E) { 327 DefaultArgEffect = E; 328 } 329 330 /// getRetEffect - Returns the effect on the return value of the call. 331 RetEffect getRetEffect() const { return Ret; } 332 333 /// setRetEffect - Set the effect of the return value of the call. 334 void setRetEffect(RetEffect E) { Ret = E; } 335 336 337 /// Sets the effect on the receiver of the message. 338 void setReceiverEffect(ArgEffect e) { Receiver = e; } 339 340 /// getReceiverEffect - Returns the effect on the receiver of the call. 341 /// This is only meaningful if the summary applies to an ObjCMessageExpr*. 342 ArgEffect getReceiverEffect() const { return Receiver; } 343 344 /// Test if two retain summaries are identical. Note that merely equivalent 345 /// summaries are not necessarily identical (for example, if an explicit 346 /// argument effect matches the default effect). 347 bool operator==(const RetainSummary &Other) const { 348 return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect && 349 Receiver == Other.Receiver && Ret == Other.Ret; 350 } 351 352 /// Profile this summary for inclusion in a FoldingSet. 353 void Profile(llvm::FoldingSetNodeID& ID) const { 354 ID.Add(Args); 355 ID.Add(DefaultArgEffect); 356 ID.Add(Receiver); 357 ID.Add(Ret); 358 } 359 360 /// A retain summary is simple if it has no ArgEffects other than the default. 361 bool isSimple() const { 362 return Args.isEmpty(); 363 } 364 365private: 366 ArgEffects getArgEffects() const { return Args; } 367 ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; } 368 369 friend class RetainSummaryManager; 370}; 371} // end anonymous namespace 372 373//===----------------------------------------------------------------------===// 374// Data structures for constructing summaries. 375//===----------------------------------------------------------------------===// 376 377namespace { 378class ObjCSummaryKey { 379 IdentifierInfo* II; 380 Selector S; 381public: 382 ObjCSummaryKey(IdentifierInfo* ii, Selector s) 383 : II(ii), S(s) {} 384 385 ObjCSummaryKey(const ObjCInterfaceDecl *d, Selector s) 386 : II(d ? d->getIdentifier() : 0), S(s) {} 387 388 ObjCSummaryKey(Selector s) 389 : II(0), S(s) {} 390 391 IdentifierInfo *getIdentifier() const { return II; } 392 Selector getSelector() const { return S; } 393}; 394} 395 396namespace llvm { 397template <> struct DenseMapInfo<ObjCSummaryKey> { 398 static inline ObjCSummaryKey getEmptyKey() { 399 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getEmptyKey(), 400 DenseMapInfo<Selector>::getEmptyKey()); 401 } 402 403 static inline ObjCSummaryKey getTombstoneKey() { 404 return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getTombstoneKey(), 405 DenseMapInfo<Selector>::getTombstoneKey()); 406 } 407 408 static unsigned getHashValue(const ObjCSummaryKey &V) { 409 typedef std::pair<IdentifierInfo*, Selector> PairTy; 410 return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(), 411 V.getSelector())); 412 } 413 414 static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) { 415 return LHS.getIdentifier() == RHS.getIdentifier() && 416 LHS.getSelector() == RHS.getSelector(); 417 } 418 419}; 420} // end llvm namespace 421 422namespace { 423class ObjCSummaryCache { 424 typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy; 425 MapTy M; 426public: 427 ObjCSummaryCache() {} 428 429 const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) { 430 // Do a lookup with the (D,S) pair. If we find a match return 431 // the iterator. 432 ObjCSummaryKey K(D, S); 433 MapTy::iterator I = M.find(K); 434 435 if (I != M.end()) 436 return I->second; 437 if (!D) 438 return NULL; 439 440 // Walk the super chain. If we find a hit with a parent, we'll end 441 // up returning that summary. We actually allow that key (null,S), as 442 // we cache summaries for the null ObjCInterfaceDecl* to allow us to 443 // generate initial summaries without having to worry about NSObject 444 // being declared. 445 // FIXME: We may change this at some point. 446 for (ObjCInterfaceDecl *C=D->getSuperClass() ;; C=C->getSuperClass()) { 447 if ((I = M.find(ObjCSummaryKey(C, S))) != M.end()) 448 break; 449 450 if (!C) 451 return NULL; 452 } 453 454 // Cache the summary with original key to make the next lookup faster 455 // and return the iterator. 456 const RetainSummary *Summ = I->second; 457 M[K] = Summ; 458 return Summ; 459 } 460 461 const RetainSummary *find(IdentifierInfo* II, Selector S) { 462 // FIXME: Class method lookup. Right now we dont' have a good way 463 // of going between IdentifierInfo* and the class hierarchy. 464 MapTy::iterator I = M.find(ObjCSummaryKey(II, S)); 465 466 if (I == M.end()) 467 I = M.find(ObjCSummaryKey(S)); 468 469 return I == M.end() ? NULL : I->second; 470 } 471 472 const RetainSummary *& operator[](ObjCSummaryKey K) { 473 return M[K]; 474 } 475 476 const RetainSummary *& operator[](Selector S) { 477 return M[ ObjCSummaryKey(S) ]; 478 } 479}; 480} // end anonymous namespace 481 482//===----------------------------------------------------------------------===// 483// Data structures for managing collections of summaries. 484//===----------------------------------------------------------------------===// 485 486namespace { 487class RetainSummaryManager { 488 489 //==-----------------------------------------------------------------==// 490 // Typedefs. 491 //==-----------------------------------------------------------------==// 492 493 typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *> 494 FuncSummariesTy; 495 496 typedef ObjCSummaryCache ObjCMethodSummariesTy; 497 498 typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode; 499 500 //==-----------------------------------------------------------------==// 501 // Data. 502 //==-----------------------------------------------------------------==// 503 504 /// Ctx - The ASTContext object for the analyzed ASTs. 505 ASTContext &Ctx; 506 507 /// GCEnabled - Records whether or not the analyzed code runs in GC mode. 508 const bool GCEnabled; 509 510 /// Records whether or not the analyzed code runs in ARC mode. 511 const bool ARCEnabled; 512 513 /// FuncSummaries - A map from FunctionDecls to summaries. 514 FuncSummariesTy FuncSummaries; 515 516 /// ObjCClassMethodSummaries - A map from selectors (for instance methods) 517 /// to summaries. 518 ObjCMethodSummariesTy ObjCClassMethodSummaries; 519 520 /// ObjCMethodSummaries - A map from selectors to summaries. 521 ObjCMethodSummariesTy ObjCMethodSummaries; 522 523 /// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects, 524 /// and all other data used by the checker. 525 llvm::BumpPtrAllocator BPAlloc; 526 527 /// AF - A factory for ArgEffects objects. 528 ArgEffects::Factory AF; 529 530 /// ScratchArgs - A holding buffer for construct ArgEffects. 531 ArgEffects ScratchArgs; 532 533 /// ObjCAllocRetE - Default return effect for methods returning Objective-C 534 /// objects. 535 RetEffect ObjCAllocRetE; 536 537 /// ObjCInitRetE - Default return effect for init methods returning 538 /// Objective-C objects. 539 RetEffect ObjCInitRetE; 540 541 /// SimpleSummaries - Used for uniquing summaries that don't have special 542 /// effects. 543 llvm::FoldingSet<CachedSummaryNode> SimpleSummaries; 544 545 //==-----------------------------------------------------------------==// 546 // Methods. 547 //==-----------------------------------------------------------------==// 548 549 /// getArgEffects - Returns a persistent ArgEffects object based on the 550 /// data in ScratchArgs. 551 ArgEffects getArgEffects(); 552 553 enum UnaryFuncKind { cfretain, cfrelease, cfautorelease, cfmakecollectable }; 554 555 const RetainSummary *getUnarySummary(const FunctionType* FT, 556 UnaryFuncKind func); 557 558 const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD); 559 const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD); 560 const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD); 561 562 const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm); 563 564 const RetainSummary *getPersistentSummary(RetEffect RetEff, 565 ArgEffect ReceiverEff = DoNothing, 566 ArgEffect DefaultEff = MayEscape) { 567 RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff); 568 return getPersistentSummary(Summ); 569 } 570 571 const RetainSummary *getDoNothingSummary() { 572 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 573 } 574 575 const RetainSummary *getDefaultSummary() { 576 return getPersistentSummary(RetEffect::MakeNoRet(), 577 DoNothing, MayEscape); 578 } 579 580 const RetainSummary *getPersistentStopSummary() { 581 return getPersistentSummary(RetEffect::MakeNoRet(), 582 StopTracking, StopTracking); 583 } 584 585 void InitializeClassMethodSummaries(); 586 void InitializeMethodSummaries(); 587private: 588 void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) { 589 ObjCClassMethodSummaries[S] = Summ; 590 } 591 592 void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) { 593 ObjCMethodSummaries[S] = Summ; 594 } 595 596 void addClassMethSummary(const char* Cls, const char* name, 597 const RetainSummary *Summ, bool isNullary = true) { 598 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 599 Selector S = isNullary ? GetNullarySelector(name, Ctx) 600 : GetUnarySelector(name, Ctx); 601 ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 602 } 603 604 void addInstMethSummary(const char* Cls, const char* nullaryName, 605 const RetainSummary *Summ) { 606 IdentifierInfo* ClsII = &Ctx.Idents.get(Cls); 607 Selector S = GetNullarySelector(nullaryName, Ctx); 608 ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ; 609 } 610 611 Selector generateSelector(va_list argp) { 612 SmallVector<IdentifierInfo*, 10> II; 613 614 while (const char* s = va_arg(argp, const char*)) 615 II.push_back(&Ctx.Idents.get(s)); 616 617 return Ctx.Selectors.getSelector(II.size(), &II[0]); 618 } 619 620 void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy& Summaries, 621 const RetainSummary * Summ, va_list argp) { 622 Selector S = generateSelector(argp); 623 Summaries[ObjCSummaryKey(ClsII, S)] = Summ; 624 } 625 626 void addInstMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 627 va_list argp; 628 va_start(argp, Summ); 629 addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp); 630 va_end(argp); 631 } 632 633 void addClsMethSummary(const char* Cls, const RetainSummary * Summ, ...) { 634 va_list argp; 635 va_start(argp, Summ); 636 addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp); 637 va_end(argp); 638 } 639 640 void addClsMethSummary(IdentifierInfo *II, const RetainSummary * Summ, ...) { 641 va_list argp; 642 va_start(argp, Summ); 643 addMethodSummary(II, ObjCClassMethodSummaries, Summ, argp); 644 va_end(argp); 645 } 646 647public: 648 649 RetainSummaryManager(ASTContext &ctx, bool gcenabled, bool usesARC) 650 : Ctx(ctx), 651 GCEnabled(gcenabled), 652 ARCEnabled(usesARC), 653 AF(BPAlloc), ScratchArgs(AF.getEmptyMap()), 654 ObjCAllocRetE(gcenabled 655 ? RetEffect::MakeGCNotOwned() 656 : (usesARC ? RetEffect::MakeARCNotOwned() 657 : RetEffect::MakeOwned(RetEffect::ObjC, true))), 658 ObjCInitRetE(gcenabled 659 ? RetEffect::MakeGCNotOwned() 660 : (usesARC ? RetEffect::MakeARCNotOwned() 661 : RetEffect::MakeOwnedWhenTrackedReceiver())) { 662 InitializeClassMethodSummaries(); 663 InitializeMethodSummaries(); 664 } 665 666 const RetainSummary *getSummary(const CallEvent &Call, 667 ProgramStateRef State = 0); 668 669 const RetainSummary *getFunctionSummary(const FunctionDecl *FD); 670 671 const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 672 const ObjCMethodDecl *MD, 673 QualType RetTy, 674 ObjCMethodSummariesTy &CachedSummaries); 675 676 const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M, 677 ProgramStateRef State); 678 679 const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) { 680 assert(!M.isInstanceMessage()); 681 const ObjCInterfaceDecl *Class = M.getReceiverInterface(); 682 683 return getMethodSummary(M.getSelector(), Class, M.getDecl(), 684 M.getResultType(), ObjCClassMethodSummaries); 685 } 686 687 /// getMethodSummary - This version of getMethodSummary is used to query 688 /// the summary for the current method being analyzed. 689 const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) { 690 const ObjCInterfaceDecl *ID = MD->getClassInterface(); 691 Selector S = MD->getSelector(); 692 QualType ResultTy = MD->getResultType(); 693 694 ObjCMethodSummariesTy *CachedSummaries; 695 if (MD->isInstanceMethod()) 696 CachedSummaries = &ObjCMethodSummaries; 697 else 698 CachedSummaries = &ObjCClassMethodSummaries; 699 700 return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries); 701 } 702 703 const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD, 704 Selector S, QualType RetTy); 705 706 /// Determine if there is a special return effect for this function or method. 707 Optional<RetEffect> getRetEffectFromAnnotations(QualType RetTy, 708 const Decl *D); 709 710 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 711 const ObjCMethodDecl *MD); 712 713 void updateSummaryFromAnnotations(const RetainSummary *&Summ, 714 const FunctionDecl *FD); 715 716 void updateSummaryForCall(const RetainSummary *&Summ, 717 const CallEvent &Call); 718 719 bool isGCEnabled() const { return GCEnabled; } 720 721 bool isARCEnabled() const { return ARCEnabled; } 722 723 bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; } 724 725 RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; } 726 727 friend class RetainSummaryTemplate; 728}; 729 730// Used to avoid allocating long-term (BPAlloc'd) memory for default retain 731// summaries. If a function or method looks like it has a default summary, but 732// it has annotations, the annotations are added to the stack-based template 733// and then copied into managed memory. 734class RetainSummaryTemplate { 735 RetainSummaryManager &Manager; 736 const RetainSummary *&RealSummary; 737 RetainSummary ScratchSummary; 738 bool Accessed; 739public: 740 RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr) 741 : Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {} 742 743 ~RetainSummaryTemplate() { 744 if (Accessed) 745 RealSummary = Manager.getPersistentSummary(ScratchSummary); 746 } 747 748 RetainSummary &operator*() { 749 Accessed = true; 750 return ScratchSummary; 751 } 752 753 RetainSummary *operator->() { 754 Accessed = true; 755 return &ScratchSummary; 756 } 757}; 758 759} // end anonymous namespace 760 761//===----------------------------------------------------------------------===// 762// Implementation of checker data structures. 763//===----------------------------------------------------------------------===// 764 765ArgEffects RetainSummaryManager::getArgEffects() { 766 ArgEffects AE = ScratchArgs; 767 ScratchArgs = AF.getEmptyMap(); 768 return AE; 769} 770 771const RetainSummary * 772RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) { 773 // Unique "simple" summaries -- those without ArgEffects. 774 if (OldSumm.isSimple()) { 775 llvm::FoldingSetNodeID ID; 776 OldSumm.Profile(ID); 777 778 void *Pos; 779 CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos); 780 781 if (!N) { 782 N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>(); 783 new (N) CachedSummaryNode(OldSumm); 784 SimpleSummaries.InsertNode(N, Pos); 785 } 786 787 return &N->getValue(); 788 } 789 790 RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>(); 791 new (Summ) RetainSummary(OldSumm); 792 return Summ; 793} 794 795//===----------------------------------------------------------------------===// 796// Summary creation for functions (largely uses of Core Foundation). 797//===----------------------------------------------------------------------===// 798 799static bool isRetain(const FunctionDecl *FD, StringRef FName) { 800 return FName.endswith("Retain"); 801} 802 803static bool isRelease(const FunctionDecl *FD, StringRef FName) { 804 return FName.endswith("Release"); 805} 806 807static bool isAutorelease(const FunctionDecl *FD, StringRef FName) { 808 return FName.endswith("Autorelease"); 809} 810 811static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) { 812 // FIXME: Remove FunctionDecl parameter. 813 // FIXME: Is it really okay if MakeCollectable isn't a suffix? 814 return FName.find("MakeCollectable") != StringRef::npos; 815} 816 817static ArgEffect getStopTrackingHardEquivalent(ArgEffect E) { 818 switch (E) { 819 case DoNothing: 820 case Autorelease: 821 case DecRefBridgedTransferred: 822 case IncRef: 823 case IncRefMsg: 824 case MakeCollectable: 825 case MayEscape: 826 case StopTracking: 827 case StopTrackingHard: 828 return StopTrackingHard; 829 case DecRef: 830 case DecRefAndStopTrackingHard: 831 return DecRefAndStopTrackingHard; 832 case DecRefMsg: 833 case DecRefMsgAndStopTrackingHard: 834 return DecRefMsgAndStopTrackingHard; 835 case Dealloc: 836 return Dealloc; 837 } 838 839 llvm_unreachable("Unknown ArgEffect kind"); 840} 841 842void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S, 843 const CallEvent &Call) { 844 if (Call.hasNonZeroCallbackArg()) { 845 ArgEffect RecEffect = 846 getStopTrackingHardEquivalent(S->getReceiverEffect()); 847 ArgEffect DefEffect = 848 getStopTrackingHardEquivalent(S->getDefaultArgEffect()); 849 850 ArgEffects CustomArgEffects = S->getArgEffects(); 851 for (ArgEffects::iterator I = CustomArgEffects.begin(), 852 E = CustomArgEffects.end(); 853 I != E; ++I) { 854 ArgEffect Translated = getStopTrackingHardEquivalent(I->second); 855 if (Translated != DefEffect) 856 ScratchArgs = AF.add(ScratchArgs, I->first, Translated); 857 } 858 859 RetEffect RE = RetEffect::MakeNoRetHard(); 860 861 // Special cases where the callback argument CANNOT free the return value. 862 // This can generally only happen if we know that the callback will only be 863 // called when the return value is already being deallocated. 864 if (const FunctionCall *FC = dyn_cast<FunctionCall>(&Call)) { 865 if (IdentifierInfo *Name = FC->getDecl()->getIdentifier()) { 866 // When the CGBitmapContext is deallocated, the callback here will free 867 // the associated data buffer. 868 if (Name->isStr("CGBitmapContextCreateWithData")) 869 RE = S->getRetEffect(); 870 } 871 } 872 873 S = getPersistentSummary(RE, RecEffect, DefEffect); 874 } 875 876 // Special case '[super init];' and '[self init];' 877 // 878 // Even though calling '[super init]' without assigning the result to self 879 // and checking if the parent returns 'nil' is a bad pattern, it is common. 880 // Additionally, our Self Init checker already warns about it. To avoid 881 // overwhelming the user with messages from both checkers, we model the case 882 // of '[super init]' in cases when it is not consumed by another expression 883 // as if the call preserves the value of 'self'; essentially, assuming it can 884 // never fail and return 'nil'. 885 // Note, we don't want to just stop tracking the value since we want the 886 // RetainCount checker to report leaks and use-after-free if SelfInit checker 887 // is turned off. 888 if (const ObjCMethodCall *MC = dyn_cast<ObjCMethodCall>(&Call)) { 889 if (MC->getMethodFamily() == OMF_init && MC->isReceiverSelfOrSuper()) { 890 891 // Check if the message is not consumed, we know it will not be used in 892 // an assignment, ex: "self = [super init]". 893 const Expr *ME = MC->getOriginExpr(); 894 const LocationContext *LCtx = MC->getLocationContext(); 895 ParentMap &PM = LCtx->getAnalysisDeclContext()->getParentMap(); 896 if (!PM.isConsumedExpr(ME)) { 897 RetainSummaryTemplate ModifiableSummaryTemplate(S, *this); 898 ModifiableSummaryTemplate->setReceiverEffect(DoNothing); 899 ModifiableSummaryTemplate->setRetEffect(RetEffect::MakeNoRet()); 900 } 901 } 902 903 } 904} 905 906const RetainSummary * 907RetainSummaryManager::getSummary(const CallEvent &Call, 908 ProgramStateRef State) { 909 const RetainSummary *Summ; 910 switch (Call.getKind()) { 911 case CE_Function: 912 Summ = getFunctionSummary(cast<FunctionCall>(Call).getDecl()); 913 break; 914 case CE_CXXMember: 915 case CE_CXXMemberOperator: 916 case CE_Block: 917 case CE_CXXConstructor: 918 case CE_CXXDestructor: 919 case CE_CXXAllocator: 920 // FIXME: These calls are currently unsupported. 921 return getPersistentStopSummary(); 922 case CE_ObjCMessage: { 923 const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call); 924 if (Msg.isInstanceMessage()) 925 Summ = getInstanceMethodSummary(Msg, State); 926 else 927 Summ = getClassMethodSummary(Msg); 928 break; 929 } 930 } 931 932 updateSummaryForCall(Summ, Call); 933 934 assert(Summ && "Unknown call type?"); 935 return Summ; 936} 937 938const RetainSummary * 939RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) { 940 // If we don't know what function we're calling, use our default summary. 941 if (!FD) 942 return getDefaultSummary(); 943 944 // Look up a summary in our cache of FunctionDecls -> Summaries. 945 FuncSummariesTy::iterator I = FuncSummaries.find(FD); 946 if (I != FuncSummaries.end()) 947 return I->second; 948 949 // No summary? Generate one. 950 const RetainSummary *S = 0; 951 bool AllowAnnotations = true; 952 953 do { 954 // We generate "stop" summaries for implicitly defined functions. 955 if (FD->isImplicit()) { 956 S = getPersistentStopSummary(); 957 break; 958 } 959 960 // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the 961 // function's type. 962 const FunctionType* FT = FD->getType()->getAs<FunctionType>(); 963 const IdentifierInfo *II = FD->getIdentifier(); 964 if (!II) 965 break; 966 967 StringRef FName = II->getName(); 968 969 // Strip away preceding '_'. Doing this here will effect all the checks 970 // down below. 971 FName = FName.substr(FName.find_first_not_of('_')); 972 973 // Inspect the result type. 974 QualType RetTy = FT->getResultType(); 975 976 // FIXME: This should all be refactored into a chain of "summary lookup" 977 // filters. 978 assert(ScratchArgs.isEmpty()); 979 980 if (FName == "pthread_create" || FName == "pthread_setspecific") { 981 // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>. 982 // This will be addressed better with IPA. 983 S = getPersistentStopSummary(); 984 } else if (FName == "NSMakeCollectable") { 985 // Handle: id NSMakeCollectable(CFTypeRef) 986 S = (RetTy->isObjCIdType()) 987 ? getUnarySummary(FT, cfmakecollectable) 988 : getPersistentStopSummary(); 989 // The headers on OS X 10.8 use cf_consumed/ns_returns_retained, 990 // but we can fully model NSMakeCollectable ourselves. 991 AllowAnnotations = false; 992 } else if (FName == "CFPlugInInstanceCreate") { 993 S = getPersistentSummary(RetEffect::MakeNoRet()); 994 } else if (FName == "IOBSDNameMatching" || 995 FName == "IOServiceMatching" || 996 FName == "IOServiceNameMatching" || 997 FName == "IORegistryEntrySearchCFProperty" || 998 FName == "IORegistryEntryIDMatching" || 999 FName == "IOOpenFirmwarePathMatching") { 1000 // Part of <rdar://problem/6961230>. (IOKit) 1001 // This should be addressed using a API table. 1002 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1003 DoNothing, DoNothing); 1004 } else if (FName == "IOServiceGetMatchingService" || 1005 FName == "IOServiceGetMatchingServices") { 1006 // FIXES: <rdar://problem/6326900> 1007 // This should be addressed using a API table. This strcmp is also 1008 // a little gross, but there is no need to super optimize here. 1009 ScratchArgs = AF.add(ScratchArgs, 1, DecRef); 1010 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1011 } else if (FName == "IOServiceAddNotification" || 1012 FName == "IOServiceAddMatchingNotification") { 1013 // Part of <rdar://problem/6961230>. (IOKit) 1014 // This should be addressed using a API table. 1015 ScratchArgs = AF.add(ScratchArgs, 2, DecRef); 1016 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1017 } else if (FName == "CVPixelBufferCreateWithBytes") { 1018 // FIXES: <rdar://problem/7283567> 1019 // Eventually this can be improved by recognizing that the pixel 1020 // buffer passed to CVPixelBufferCreateWithBytes is released via 1021 // a callback and doing full IPA to make sure this is done correctly. 1022 // FIXME: This function has an out parameter that returns an 1023 // allocated object. 1024 ScratchArgs = AF.add(ScratchArgs, 7, StopTracking); 1025 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1026 } else if (FName == "CGBitmapContextCreateWithData") { 1027 // FIXES: <rdar://problem/7358899> 1028 // Eventually this can be improved by recognizing that 'releaseInfo' 1029 // passed to CGBitmapContextCreateWithData is released via 1030 // a callback and doing full IPA to make sure this is done correctly. 1031 ScratchArgs = AF.add(ScratchArgs, 8, StopTracking); 1032 S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true), 1033 DoNothing, DoNothing); 1034 } else if (FName == "CVPixelBufferCreateWithPlanarBytes") { 1035 // FIXES: <rdar://problem/7283567> 1036 // Eventually this can be improved by recognizing that the pixel 1037 // buffer passed to CVPixelBufferCreateWithPlanarBytes is released 1038 // via a callback and doing full IPA to make sure this is done 1039 // correctly. 1040 ScratchArgs = AF.add(ScratchArgs, 12, StopTracking); 1041 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1042 } else if (FName == "dispatch_set_context" || 1043 FName == "xpc_connection_set_context") { 1044 // <rdar://problem/11059275> - The analyzer currently doesn't have 1045 // a good way to reason about the finalizer function for libdispatch. 1046 // If we pass a context object that is memory managed, stop tracking it. 1047 // <rdar://problem/13783514> - Same problem, but for XPC. 1048 // FIXME: this hack should possibly go away once we can handle 1049 // libdispatch and XPC finalizers. 1050 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1051 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1052 } else if (FName.startswith("NSLog")) { 1053 S = getDoNothingSummary(); 1054 } else if (FName.startswith("NS") && 1055 (FName.find("Insert") != StringRef::npos)) { 1056 // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 1057 // be deallocated by NSMapRemove. (radar://11152419) 1058 ScratchArgs = AF.add(ScratchArgs, 1, StopTracking); 1059 ScratchArgs = AF.add(ScratchArgs, 2, StopTracking); 1060 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1061 } 1062 1063 // Did we get a summary? 1064 if (S) 1065 break; 1066 1067 if (RetTy->isPointerType()) { 1068 // For CoreFoundation ('CF') types. 1069 if (cocoa::isRefType(RetTy, "CF", FName)) { 1070 if (isRetain(FD, FName)) { 1071 S = getUnarySummary(FT, cfretain); 1072 } else if (isAutorelease(FD, FName)) { 1073 S = getUnarySummary(FT, cfautorelease); 1074 // The headers use cf_consumed, but we can fully model CFAutorelease 1075 // ourselves. 1076 AllowAnnotations = false; 1077 } else if (isMakeCollectable(FD, FName)) { 1078 S = getUnarySummary(FT, cfmakecollectable); 1079 AllowAnnotations = false; 1080 } else { 1081 S = getCFCreateGetRuleSummary(FD); 1082 } 1083 1084 break; 1085 } 1086 1087 // For CoreGraphics ('CG') types. 1088 if (cocoa::isRefType(RetTy, "CG", FName)) { 1089 if (isRetain(FD, FName)) 1090 S = getUnarySummary(FT, cfretain); 1091 else 1092 S = getCFCreateGetRuleSummary(FD); 1093 1094 break; 1095 } 1096 1097 // For the Disk Arbitration API (DiskArbitration/DADisk.h) 1098 if (cocoa::isRefType(RetTy, "DADisk") || 1099 cocoa::isRefType(RetTy, "DADissenter") || 1100 cocoa::isRefType(RetTy, "DASessionRef")) { 1101 S = getCFCreateGetRuleSummary(FD); 1102 break; 1103 } 1104 1105 if (FD->getAttr<CFAuditedTransferAttr>()) { 1106 S = getCFCreateGetRuleSummary(FD); 1107 break; 1108 } 1109 1110 break; 1111 } 1112 1113 // Check for release functions, the only kind of functions that we care 1114 // about that don't return a pointer type. 1115 if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) { 1116 // Test for 'CGCF'. 1117 FName = FName.substr(FName.startswith("CGCF") ? 4 : 2); 1118 1119 if (isRelease(FD, FName)) 1120 S = getUnarySummary(FT, cfrelease); 1121 else { 1122 assert (ScratchArgs.isEmpty()); 1123 // Remaining CoreFoundation and CoreGraphics functions. 1124 // We use to assume that they all strictly followed the ownership idiom 1125 // and that ownership cannot be transferred. While this is technically 1126 // correct, many methods allow a tracked object to escape. For example: 1127 // 1128 // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...); 1129 // CFDictionaryAddValue(y, key, x); 1130 // CFRelease(x); 1131 // ... it is okay to use 'x' since 'y' has a reference to it 1132 // 1133 // We handle this and similar cases with the follow heuristic. If the 1134 // function name contains "InsertValue", "SetValue", "AddValue", 1135 // "AppendValue", or "SetAttribute", then we assume that arguments may 1136 // "escape." This means that something else holds on to the object, 1137 // allowing it be used even after its local retain count drops to 0. 1138 ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos|| 1139 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 1140 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 1141 StrInStrNoCase(FName, "AppendValue") != StringRef::npos|| 1142 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos) 1143 ? MayEscape : DoNothing; 1144 1145 S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E); 1146 } 1147 } 1148 } 1149 while (0); 1150 1151 // If we got all the way here without any luck, use a default summary. 1152 if (!S) 1153 S = getDefaultSummary(); 1154 1155 // Annotations override defaults. 1156 if (AllowAnnotations) 1157 updateSummaryFromAnnotations(S, FD); 1158 1159 FuncSummaries[FD] = S; 1160 return S; 1161} 1162 1163const RetainSummary * 1164RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) { 1165 if (coreFoundation::followsCreateRule(FD)) 1166 return getCFSummaryCreateRule(FD); 1167 1168 return getCFSummaryGetRule(FD); 1169} 1170 1171const RetainSummary * 1172RetainSummaryManager::getUnarySummary(const FunctionType* FT, 1173 UnaryFuncKind func) { 1174 1175 // Sanity check that this is *really* a unary function. This can 1176 // happen if people do weird things. 1177 const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT); 1178 if (!FTP || FTP->getNumArgs() != 1) 1179 return getPersistentStopSummary(); 1180 1181 assert (ScratchArgs.isEmpty()); 1182 1183 ArgEffect Effect; 1184 switch (func) { 1185 case cfretain: Effect = IncRef; break; 1186 case cfrelease: Effect = DecRef; break; 1187 case cfautorelease: Effect = Autorelease; break; 1188 case cfmakecollectable: Effect = MakeCollectable; break; 1189 } 1190 1191 ScratchArgs = AF.add(ScratchArgs, 0, Effect); 1192 return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing); 1193} 1194 1195const RetainSummary * 1196RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) { 1197 assert (ScratchArgs.isEmpty()); 1198 1199 return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1200} 1201 1202const RetainSummary * 1203RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) { 1204 assert (ScratchArgs.isEmpty()); 1205 return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF), 1206 DoNothing, DoNothing); 1207} 1208 1209//===----------------------------------------------------------------------===// 1210// Summary creation for Selectors. 1211//===----------------------------------------------------------------------===// 1212 1213Optional<RetEffect> 1214RetainSummaryManager::getRetEffectFromAnnotations(QualType RetTy, 1215 const Decl *D) { 1216 if (cocoa::isCocoaObjectRef(RetTy)) { 1217 if (D->getAttr<NSReturnsRetainedAttr>()) 1218 return ObjCAllocRetE; 1219 1220 if (D->getAttr<NSReturnsNotRetainedAttr>() || 1221 D->getAttr<NSReturnsAutoreleasedAttr>()) 1222 return RetEffect::MakeNotOwned(RetEffect::ObjC); 1223 1224 } else if (!RetTy->isPointerType()) { 1225 return None; 1226 } 1227 1228 if (D->getAttr<CFReturnsRetainedAttr>()) 1229 return RetEffect::MakeOwned(RetEffect::CF, true); 1230 1231 if (D->getAttr<CFReturnsNotRetainedAttr>()) 1232 return RetEffect::MakeNotOwned(RetEffect::CF); 1233 1234 return None; 1235} 1236 1237void 1238RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1239 const FunctionDecl *FD) { 1240 if (!FD) 1241 return; 1242 1243 assert(Summ && "Must have a summary to add annotations to."); 1244 RetainSummaryTemplate Template(Summ, *this); 1245 1246 // Effects on the parameters. 1247 unsigned parm_idx = 0; 1248 for (FunctionDecl::param_const_iterator pi = FD->param_begin(), 1249 pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) { 1250 const ParmVarDecl *pd = *pi; 1251 if (pd->getAttr<NSConsumedAttr>()) 1252 Template->addArg(AF, parm_idx, DecRefMsg); 1253 else if (pd->getAttr<CFConsumedAttr>()) 1254 Template->addArg(AF, parm_idx, DecRef); 1255 } 1256 1257 QualType RetTy = FD->getResultType(); 1258 if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, FD)) 1259 Template->setRetEffect(*RetE); 1260} 1261 1262void 1263RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ, 1264 const ObjCMethodDecl *MD) { 1265 if (!MD) 1266 return; 1267 1268 assert(Summ && "Must have a valid summary to add annotations to"); 1269 RetainSummaryTemplate Template(Summ, *this); 1270 1271 // Effects on the receiver. 1272 if (MD->getAttr<NSConsumesSelfAttr>()) 1273 Template->setReceiverEffect(DecRefMsg); 1274 1275 // Effects on the parameters. 1276 unsigned parm_idx = 0; 1277 for (ObjCMethodDecl::param_const_iterator 1278 pi=MD->param_begin(), pe=MD->param_end(); 1279 pi != pe; ++pi, ++parm_idx) { 1280 const ParmVarDecl *pd = *pi; 1281 if (pd->getAttr<NSConsumedAttr>()) 1282 Template->addArg(AF, parm_idx, DecRefMsg); 1283 else if (pd->getAttr<CFConsumedAttr>()) { 1284 Template->addArg(AF, parm_idx, DecRef); 1285 } 1286 } 1287 1288 QualType RetTy = MD->getResultType(); 1289 if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, MD)) 1290 Template->setRetEffect(*RetE); 1291} 1292 1293const RetainSummary * 1294RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD, 1295 Selector S, QualType RetTy) { 1296 // Any special effects? 1297 ArgEffect ReceiverEff = DoNothing; 1298 RetEffect ResultEff = RetEffect::MakeNoRet(); 1299 1300 // Check the method family, and apply any default annotations. 1301 switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) { 1302 case OMF_None: 1303 case OMF_performSelector: 1304 // Assume all Objective-C methods follow Cocoa Memory Management rules. 1305 // FIXME: Does the non-threaded performSelector family really belong here? 1306 // The selector could be, say, @selector(copy). 1307 if (cocoa::isCocoaObjectRef(RetTy)) 1308 ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC); 1309 else if (coreFoundation::isCFObjectRef(RetTy)) { 1310 // ObjCMethodDecl currently doesn't consider CF objects as valid return 1311 // values for alloc, new, copy, or mutableCopy, so we have to 1312 // double-check with the selector. This is ugly, but there aren't that 1313 // many Objective-C methods that return CF objects, right? 1314 if (MD) { 1315 switch (S.getMethodFamily()) { 1316 case OMF_alloc: 1317 case OMF_new: 1318 case OMF_copy: 1319 case OMF_mutableCopy: 1320 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1321 break; 1322 default: 1323 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1324 break; 1325 } 1326 } else { 1327 ResultEff = RetEffect::MakeNotOwned(RetEffect::CF); 1328 } 1329 } 1330 break; 1331 case OMF_init: 1332 ResultEff = ObjCInitRetE; 1333 ReceiverEff = DecRefMsg; 1334 break; 1335 case OMF_alloc: 1336 case OMF_new: 1337 case OMF_copy: 1338 case OMF_mutableCopy: 1339 if (cocoa::isCocoaObjectRef(RetTy)) 1340 ResultEff = ObjCAllocRetE; 1341 else if (coreFoundation::isCFObjectRef(RetTy)) 1342 ResultEff = RetEffect::MakeOwned(RetEffect::CF, true); 1343 break; 1344 case OMF_autorelease: 1345 ReceiverEff = Autorelease; 1346 break; 1347 case OMF_retain: 1348 ReceiverEff = IncRefMsg; 1349 break; 1350 case OMF_release: 1351 ReceiverEff = DecRefMsg; 1352 break; 1353 case OMF_dealloc: 1354 ReceiverEff = Dealloc; 1355 break; 1356 case OMF_self: 1357 // -self is handled specially by the ExprEngine to propagate the receiver. 1358 break; 1359 case OMF_retainCount: 1360 case OMF_finalize: 1361 // These methods don't return objects. 1362 break; 1363 } 1364 1365 // If one of the arguments in the selector has the keyword 'delegate' we 1366 // should stop tracking the reference count for the receiver. This is 1367 // because the reference count is quite possibly handled by a delegate 1368 // method. 1369 if (S.isKeywordSelector()) { 1370 for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) { 1371 StringRef Slot = S.getNameForSlot(i); 1372 if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) { 1373 if (ResultEff == ObjCInitRetE) 1374 ResultEff = RetEffect::MakeNoRetHard(); 1375 else 1376 ReceiverEff = StopTrackingHard; 1377 } 1378 } 1379 } 1380 1381 if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing && 1382 ResultEff.getKind() == RetEffect::NoRet) 1383 return getDefaultSummary(); 1384 1385 return getPersistentSummary(ResultEff, ReceiverEff, MayEscape); 1386} 1387 1388const RetainSummary * 1389RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg, 1390 ProgramStateRef State) { 1391 const ObjCInterfaceDecl *ReceiverClass = 0; 1392 1393 // We do better tracking of the type of the object than the core ExprEngine. 1394 // See if we have its type in our private state. 1395 // FIXME: Eventually replace the use of state->get<RefBindings> with 1396 // a generic API for reasoning about the Objective-C types of symbolic 1397 // objects. 1398 SVal ReceiverV = Msg.getReceiverSVal(); 1399 if (SymbolRef Sym = ReceiverV.getAsLocSymbol()) 1400 if (const RefVal *T = getRefBinding(State, Sym)) 1401 if (const ObjCObjectPointerType *PT = 1402 T->getType()->getAs<ObjCObjectPointerType>()) 1403 ReceiverClass = PT->getInterfaceDecl(); 1404 1405 // If we don't know what kind of object this is, fall back to its static type. 1406 if (!ReceiverClass) 1407 ReceiverClass = Msg.getReceiverInterface(); 1408 1409 // FIXME: The receiver could be a reference to a class, meaning that 1410 // we should use the class method. 1411 // id x = [NSObject class]; 1412 // [x performSelector:... withObject:... afterDelay:...]; 1413 Selector S = Msg.getSelector(); 1414 const ObjCMethodDecl *Method = Msg.getDecl(); 1415 if (!Method && ReceiverClass) 1416 Method = ReceiverClass->getInstanceMethod(S); 1417 1418 return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(), 1419 ObjCMethodSummaries); 1420} 1421 1422const RetainSummary * 1423RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID, 1424 const ObjCMethodDecl *MD, QualType RetTy, 1425 ObjCMethodSummariesTy &CachedSummaries) { 1426 1427 // Look up a summary in our summary cache. 1428 const RetainSummary *Summ = CachedSummaries.find(ID, S); 1429 1430 if (!Summ) { 1431 Summ = getStandardMethodSummary(MD, S, RetTy); 1432 1433 // Annotations override defaults. 1434 updateSummaryFromAnnotations(Summ, MD); 1435 1436 // Memoize the summary. 1437 CachedSummaries[ObjCSummaryKey(ID, S)] = Summ; 1438 } 1439 1440 return Summ; 1441} 1442 1443void RetainSummaryManager::InitializeClassMethodSummaries() { 1444 assert(ScratchArgs.isEmpty()); 1445 // Create the [NSAssertionHandler currentHander] summary. 1446 addClassMethSummary("NSAssertionHandler", "currentHandler", 1447 getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC))); 1448 1449 // Create the [NSAutoreleasePool addObject:] summary. 1450 ScratchArgs = AF.add(ScratchArgs, 0, Autorelease); 1451 addClassMethSummary("NSAutoreleasePool", "addObject", 1452 getPersistentSummary(RetEffect::MakeNoRet(), 1453 DoNothing, Autorelease)); 1454} 1455 1456void RetainSummaryManager::InitializeMethodSummaries() { 1457 1458 assert (ScratchArgs.isEmpty()); 1459 1460 // Create the "init" selector. It just acts as a pass-through for the 1461 // receiver. 1462 const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg); 1463 addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm); 1464 1465 // awakeAfterUsingCoder: behaves basically like an 'init' method. It 1466 // claims the receiver and returns a retained object. 1467 addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx), 1468 InitSumm); 1469 1470 // The next methods are allocators. 1471 const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE); 1472 const RetainSummary *CFAllocSumm = 1473 getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true)); 1474 1475 // Create the "retain" selector. 1476 RetEffect NoRet = RetEffect::MakeNoRet(); 1477 const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg); 1478 addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ); 1479 1480 // Create the "release" selector. 1481 Summ = getPersistentSummary(NoRet, DecRefMsg); 1482 addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ); 1483 1484 // Create the -dealloc summary. 1485 Summ = getPersistentSummary(NoRet, Dealloc); 1486 addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ); 1487 1488 // Create the "autorelease" selector. 1489 Summ = getPersistentSummary(NoRet, Autorelease); 1490 addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ); 1491 1492 // For NSWindow, allocated objects are (initially) self-owned. 1493 // FIXME: For now we opt for false negatives with NSWindow, as these objects 1494 // self-own themselves. However, they only do this once they are displayed. 1495 // Thus, we need to track an NSWindow's display status. 1496 // This is tracked in <rdar://problem/6062711>. 1497 // See also http://llvm.org/bugs/show_bug.cgi?id=3714. 1498 const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(), 1499 StopTracking, 1500 StopTracking); 1501 1502 addClassMethSummary("NSWindow", "alloc", NoTrackYet); 1503 1504 // For NSPanel (which subclasses NSWindow), allocated objects are not 1505 // self-owned. 1506 // FIXME: For now we don't track NSPanels. object for the same reason 1507 // as for NSWindow objects. 1508 addClassMethSummary("NSPanel", "alloc", NoTrackYet); 1509 1510 // Don't track allocated autorelease pools, as it is okay to prematurely 1511 // exit a method. 1512 addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet); 1513 addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false); 1514 addClassMethSummary("NSAutoreleasePool", "new", NoTrackYet); 1515 1516 // Create summaries QCRenderer/QCView -createSnapShotImageOfType: 1517 addInstMethSummary("QCRenderer", AllocSumm, 1518 "createSnapshotImageOfType", NULL); 1519 addInstMethSummary("QCView", AllocSumm, 1520 "createSnapshotImageOfType", NULL); 1521 1522 // Create summaries for CIContext, 'createCGImage' and 1523 // 'createCGLayerWithSize'. These objects are CF objects, and are not 1524 // automatically garbage collected. 1525 addInstMethSummary("CIContext", CFAllocSumm, 1526 "createCGImage", "fromRect", NULL); 1527 addInstMethSummary("CIContext", CFAllocSumm, 1528 "createCGImage", "fromRect", "format", "colorSpace", NULL); 1529 addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", 1530 "info", NULL); 1531} 1532 1533//===----------------------------------------------------------------------===// 1534// Error reporting. 1535//===----------------------------------------------------------------------===// 1536namespace { 1537 typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *> 1538 SummaryLogTy; 1539 1540 //===-------------===// 1541 // Bug Descriptions. // 1542 //===-------------===// 1543 1544 class CFRefBug : public BugType { 1545 protected: 1546 CFRefBug(StringRef name) 1547 : BugType(name, categories::MemoryCoreFoundationObjectiveC) {} 1548 public: 1549 1550 // FIXME: Eventually remove. 1551 virtual const char *getDescription() const = 0; 1552 1553 virtual bool isLeak() const { return false; } 1554 }; 1555 1556 class UseAfterRelease : public CFRefBug { 1557 public: 1558 UseAfterRelease() : CFRefBug("Use-after-release") {} 1559 1560 const char *getDescription() const { 1561 return "Reference-counted object is used after it is released"; 1562 } 1563 }; 1564 1565 class BadRelease : public CFRefBug { 1566 public: 1567 BadRelease() : CFRefBug("Bad release") {} 1568 1569 const char *getDescription() const { 1570 return "Incorrect decrement of the reference count of an object that is " 1571 "not owned at this point by the caller"; 1572 } 1573 }; 1574 1575 class DeallocGC : public CFRefBug { 1576 public: 1577 DeallocGC() 1578 : CFRefBug("-dealloc called while using garbage collection") {} 1579 1580 const char *getDescription() const { 1581 return "-dealloc called while using garbage collection"; 1582 } 1583 }; 1584 1585 class DeallocNotOwned : public CFRefBug { 1586 public: 1587 DeallocNotOwned() 1588 : CFRefBug("-dealloc sent to non-exclusively owned object") {} 1589 1590 const char *getDescription() const { 1591 return "-dealloc sent to object that may be referenced elsewhere"; 1592 } 1593 }; 1594 1595 class OverAutorelease : public CFRefBug { 1596 public: 1597 OverAutorelease() 1598 : CFRefBug("Object autoreleased too many times") {} 1599 1600 const char *getDescription() const { 1601 return "Object autoreleased too many times"; 1602 } 1603 }; 1604 1605 class ReturnedNotOwnedForOwned : public CFRefBug { 1606 public: 1607 ReturnedNotOwnedForOwned() 1608 : CFRefBug("Method should return an owned object") {} 1609 1610 const char *getDescription() const { 1611 return "Object with a +0 retain count returned to caller where a +1 " 1612 "(owning) retain count is expected"; 1613 } 1614 }; 1615 1616 class Leak : public CFRefBug { 1617 public: 1618 Leak(StringRef name) 1619 : CFRefBug(name) { 1620 // Leaks should not be reported if they are post-dominated by a sink. 1621 setSuppressOnSink(true); 1622 } 1623 1624 const char *getDescription() const { return ""; } 1625 1626 bool isLeak() const { return true; } 1627 }; 1628 1629 //===---------===// 1630 // Bug Reports. // 1631 //===---------===// 1632 1633 class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> { 1634 protected: 1635 SymbolRef Sym; 1636 const SummaryLogTy &SummaryLog; 1637 bool GCEnabled; 1638 1639 public: 1640 CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log) 1641 : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {} 1642 1643 virtual void Profile(llvm::FoldingSetNodeID &ID) const { 1644 static int x = 0; 1645 ID.AddPointer(&x); 1646 ID.AddPointer(Sym); 1647 } 1648 1649 virtual PathDiagnosticPiece *VisitNode(const ExplodedNode *N, 1650 const ExplodedNode *PrevN, 1651 BugReporterContext &BRC, 1652 BugReport &BR); 1653 1654 virtual PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1655 const ExplodedNode *N, 1656 BugReport &BR); 1657 }; 1658 1659 class CFRefLeakReportVisitor : public CFRefReportVisitor { 1660 public: 1661 CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled, 1662 const SummaryLogTy &log) 1663 : CFRefReportVisitor(sym, GCEnabled, log) {} 1664 1665 PathDiagnosticPiece *getEndPath(BugReporterContext &BRC, 1666 const ExplodedNode *N, 1667 BugReport &BR); 1668 1669 virtual BugReporterVisitor *clone() const { 1670 // The curiously-recurring template pattern only works for one level of 1671 // subclassing. Rather than make a new template base for 1672 // CFRefReportVisitor, we simply override clone() to do the right thing. 1673 // This could be trouble someday if BugReporterVisitorImpl is ever 1674 // used for something else besides a convenient implementation of clone(). 1675 return new CFRefLeakReportVisitor(*this); 1676 } 1677 }; 1678 1679 class CFRefReport : public BugReport { 1680 void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled); 1681 1682 public: 1683 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1684 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1685 bool registerVisitor = true) 1686 : BugReport(D, D.getDescription(), n) { 1687 if (registerVisitor) 1688 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1689 addGCModeDescription(LOpts, GCEnabled); 1690 } 1691 1692 CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1693 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1694 StringRef endText) 1695 : BugReport(D, D.getDescription(), endText, n) { 1696 addVisitor(new CFRefReportVisitor(sym, GCEnabled, Log)); 1697 addGCModeDescription(LOpts, GCEnabled); 1698 } 1699 1700 virtual std::pair<ranges_iterator, ranges_iterator> getRanges() { 1701 const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType()); 1702 if (!BugTy.isLeak()) 1703 return BugReport::getRanges(); 1704 else 1705 return std::make_pair(ranges_iterator(), ranges_iterator()); 1706 } 1707 }; 1708 1709 class CFRefLeakReport : public CFRefReport { 1710 const MemRegion* AllocBinding; 1711 public: 1712 CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled, 1713 const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym, 1714 CheckerContext &Ctx, 1715 bool IncludeAllocationLine); 1716 1717 PathDiagnosticLocation getLocation(const SourceManager &SM) const { 1718 assert(Location.isValid()); 1719 return Location; 1720 } 1721 }; 1722} // end anonymous namespace 1723 1724void CFRefReport::addGCModeDescription(const LangOptions &LOpts, 1725 bool GCEnabled) { 1726 const char *GCModeDescription = 0; 1727 1728 switch (LOpts.getGC()) { 1729 case LangOptions::GCOnly: 1730 assert(GCEnabled); 1731 GCModeDescription = "Code is compiled to only use garbage collection"; 1732 break; 1733 1734 case LangOptions::NonGC: 1735 assert(!GCEnabled); 1736 GCModeDescription = "Code is compiled to use reference counts"; 1737 break; 1738 1739 case LangOptions::HybridGC: 1740 if (GCEnabled) { 1741 GCModeDescription = "Code is compiled to use either garbage collection " 1742 "(GC) or reference counts (non-GC). The bug occurs " 1743 "with GC enabled"; 1744 break; 1745 } else { 1746 GCModeDescription = "Code is compiled to use either garbage collection " 1747 "(GC) or reference counts (non-GC). The bug occurs " 1748 "in non-GC mode"; 1749 break; 1750 } 1751 } 1752 1753 assert(GCModeDescription && "invalid/unknown GC mode"); 1754 addExtraText(GCModeDescription); 1755} 1756 1757static bool isNumericLiteralExpression(const Expr *E) { 1758 // FIXME: This set of cases was copied from SemaExprObjC. 1759 return isa<IntegerLiteral>(E) || 1760 isa<CharacterLiteral>(E) || 1761 isa<FloatingLiteral>(E) || 1762 isa<ObjCBoolLiteralExpr>(E) || 1763 isa<CXXBoolLiteralExpr>(E); 1764} 1765 1766PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N, 1767 const ExplodedNode *PrevN, 1768 BugReporterContext &BRC, 1769 BugReport &BR) { 1770 // FIXME: We will eventually need to handle non-statement-based events 1771 // (__attribute__((cleanup))). 1772 if (!N->getLocation().getAs<StmtPoint>()) 1773 return NULL; 1774 1775 // Check if the type state has changed. 1776 ProgramStateRef PrevSt = PrevN->getState(); 1777 ProgramStateRef CurrSt = N->getState(); 1778 const LocationContext *LCtx = N->getLocationContext(); 1779 1780 const RefVal* CurrT = getRefBinding(CurrSt, Sym); 1781 if (!CurrT) return NULL; 1782 1783 const RefVal &CurrV = *CurrT; 1784 const RefVal *PrevT = getRefBinding(PrevSt, Sym); 1785 1786 // Create a string buffer to constain all the useful things we want 1787 // to tell the user. 1788 std::string sbuf; 1789 llvm::raw_string_ostream os(sbuf); 1790 1791 // This is the allocation site since the previous node had no bindings 1792 // for this symbol. 1793 if (!PrevT) { 1794 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 1795 1796 if (isa<ObjCArrayLiteral>(S)) { 1797 os << "NSArray literal is an object with a +0 retain count"; 1798 } 1799 else if (isa<ObjCDictionaryLiteral>(S)) { 1800 os << "NSDictionary literal is an object with a +0 retain count"; 1801 } 1802 else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) { 1803 if (isNumericLiteralExpression(BL->getSubExpr())) 1804 os << "NSNumber literal is an object with a +0 retain count"; 1805 else { 1806 const ObjCInterfaceDecl *BoxClass = 0; 1807 if (const ObjCMethodDecl *Method = BL->getBoxingMethod()) 1808 BoxClass = Method->getClassInterface(); 1809 1810 // We should always be able to find the boxing class interface, 1811 // but consider this future-proofing. 1812 if (BoxClass) 1813 os << *BoxClass << " b"; 1814 else 1815 os << "B"; 1816 1817 os << "oxed expression produces an object with a +0 retain count"; 1818 } 1819 } 1820 else { 1821 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1822 // Get the name of the callee (if it is available). 1823 SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx); 1824 if (const FunctionDecl *FD = X.getAsFunctionDecl()) 1825 os << "Call to function '" << *FD << '\''; 1826 else 1827 os << "function call"; 1828 } 1829 else { 1830 assert(isa<ObjCMessageExpr>(S)); 1831 CallEventManager &Mgr = CurrSt->getStateManager().getCallEventManager(); 1832 CallEventRef<ObjCMethodCall> Call 1833 = Mgr.getObjCMethodCall(cast<ObjCMessageExpr>(S), CurrSt, LCtx); 1834 1835 switch (Call->getMessageKind()) { 1836 case OCM_Message: 1837 os << "Method"; 1838 break; 1839 case OCM_PropertyAccess: 1840 os << "Property"; 1841 break; 1842 case OCM_Subscript: 1843 os << "Subscript"; 1844 break; 1845 } 1846 } 1847 1848 if (CurrV.getObjKind() == RetEffect::CF) { 1849 os << " returns a Core Foundation object with a "; 1850 } 1851 else { 1852 assert (CurrV.getObjKind() == RetEffect::ObjC); 1853 os << " returns an Objective-C object with a "; 1854 } 1855 1856 if (CurrV.isOwned()) { 1857 os << "+1 retain count"; 1858 1859 if (GCEnabled) { 1860 assert(CurrV.getObjKind() == RetEffect::CF); 1861 os << ". " 1862 "Core Foundation objects are not automatically garbage collected."; 1863 } 1864 } 1865 else { 1866 assert (CurrV.isNotOwned()); 1867 os << "+0 retain count"; 1868 } 1869 } 1870 1871 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 1872 N->getLocationContext()); 1873 return new PathDiagnosticEventPiece(Pos, os.str()); 1874 } 1875 1876 // Gather up the effects that were performed on the object at this 1877 // program point 1878 SmallVector<ArgEffect, 2> AEffects; 1879 1880 const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N); 1881 if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) { 1882 // We only have summaries attached to nodes after evaluating CallExpr and 1883 // ObjCMessageExprs. 1884 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 1885 1886 if (const CallExpr *CE = dyn_cast<CallExpr>(S)) { 1887 // Iterate through the parameter expressions and see if the symbol 1888 // was ever passed as an argument. 1889 unsigned i = 0; 1890 1891 for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end(); 1892 AI!=AE; ++AI, ++i) { 1893 1894 // Retrieve the value of the argument. Is it the symbol 1895 // we are interested in? 1896 if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym) 1897 continue; 1898 1899 // We have an argument. Get the effect! 1900 AEffects.push_back(Summ->getArg(i)); 1901 } 1902 } 1903 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) { 1904 if (const Expr *receiver = ME->getInstanceReceiver()) 1905 if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx) 1906 .getAsLocSymbol() == Sym) { 1907 // The symbol we are tracking is the receiver. 1908 AEffects.push_back(Summ->getReceiverEffect()); 1909 } 1910 } 1911 } 1912 1913 do { 1914 // Get the previous type state. 1915 RefVal PrevV = *PrevT; 1916 1917 // Specially handle -dealloc. 1918 if (!GCEnabled && std::find(AEffects.begin(), AEffects.end(), Dealloc) != 1919 AEffects.end()) { 1920 // Determine if the object's reference count was pushed to zero. 1921 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 1922 // We may not have transitioned to 'release' if we hit an error. 1923 // This case is handled elsewhere. 1924 if (CurrV.getKind() == RefVal::Released) { 1925 assert(CurrV.getCombinedCounts() == 0); 1926 os << "Object released by directly sending the '-dealloc' message"; 1927 break; 1928 } 1929 } 1930 1931 // Specially handle CFMakeCollectable and friends. 1932 if (std::find(AEffects.begin(), AEffects.end(), MakeCollectable) != 1933 AEffects.end()) { 1934 // Get the name of the function. 1935 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 1936 SVal X = 1937 CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx); 1938 const FunctionDecl *FD = X.getAsFunctionDecl(); 1939 1940 if (GCEnabled) { 1941 // Determine if the object's reference count was pushed to zero. 1942 assert(!(PrevV == CurrV) && "The typestate *must* have changed."); 1943 1944 os << "In GC mode a call to '" << *FD 1945 << "' decrements an object's retain count and registers the " 1946 "object with the garbage collector. "; 1947 1948 if (CurrV.getKind() == RefVal::Released) { 1949 assert(CurrV.getCount() == 0); 1950 os << "Since it now has a 0 retain count the object can be " 1951 "automatically collected by the garbage collector."; 1952 } 1953 else 1954 os << "An object must have a 0 retain count to be garbage collected. " 1955 "After this call its retain count is +" << CurrV.getCount() 1956 << '.'; 1957 } 1958 else 1959 os << "When GC is not enabled a call to '" << *FD 1960 << "' has no effect on its argument."; 1961 1962 // Nothing more to say. 1963 break; 1964 } 1965 1966 // Determine if the typestate has changed. 1967 if (!(PrevV == CurrV)) 1968 switch (CurrV.getKind()) { 1969 case RefVal::Owned: 1970 case RefVal::NotOwned: 1971 1972 if (PrevV.getCount() == CurrV.getCount()) { 1973 // Did an autorelease message get sent? 1974 if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount()) 1975 return 0; 1976 1977 assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount()); 1978 os << "Object autoreleased"; 1979 break; 1980 } 1981 1982 if (PrevV.getCount() > CurrV.getCount()) 1983 os << "Reference count decremented."; 1984 else 1985 os << "Reference count incremented."; 1986 1987 if (unsigned Count = CurrV.getCount()) 1988 os << " The object now has a +" << Count << " retain count."; 1989 1990 if (PrevV.getKind() == RefVal::Released) { 1991 assert(GCEnabled && CurrV.getCount() > 0); 1992 os << " The object is not eligible for garbage collection until " 1993 "the retain count reaches 0 again."; 1994 } 1995 1996 break; 1997 1998 case RefVal::Released: 1999 os << "Object released."; 2000 break; 2001 2002 case RefVal::ReturnedOwned: 2003 // Autoreleases can be applied after marking a node ReturnedOwned. 2004 if (CurrV.getAutoreleaseCount()) 2005 return NULL; 2006 2007 os << "Object returned to caller as an owning reference (single " 2008 "retain count transferred to caller)"; 2009 break; 2010 2011 case RefVal::ReturnedNotOwned: 2012 os << "Object returned to caller with a +0 retain count"; 2013 break; 2014 2015 default: 2016 return NULL; 2017 } 2018 2019 // Emit any remaining diagnostics for the argument effects (if any). 2020 for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(), 2021 E=AEffects.end(); I != E; ++I) { 2022 2023 // A bunch of things have alternate behavior under GC. 2024 if (GCEnabled) 2025 switch (*I) { 2026 default: break; 2027 case Autorelease: 2028 os << "In GC mode an 'autorelease' has no effect."; 2029 continue; 2030 case IncRefMsg: 2031 os << "In GC mode the 'retain' message has no effect."; 2032 continue; 2033 case DecRefMsg: 2034 os << "In GC mode the 'release' message has no effect."; 2035 continue; 2036 } 2037 } 2038 } while (0); 2039 2040 if (os.str().empty()) 2041 return 0; // We have nothing to say! 2042 2043 const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt(); 2044 PathDiagnosticLocation Pos(S, BRC.getSourceManager(), 2045 N->getLocationContext()); 2046 PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str()); 2047 2048 // Add the range by scanning the children of the statement for any bindings 2049 // to Sym. 2050 for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end(); 2051 I!=E; ++I) 2052 if (const Expr *Exp = dyn_cast_or_null<Expr>(*I)) 2053 if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) { 2054 P->addRange(Exp->getSourceRange()); 2055 break; 2056 } 2057 2058 return P; 2059} 2060 2061// Find the first node in the current function context that referred to the 2062// tracked symbol and the memory location that value was stored to. Note, the 2063// value is only reported if the allocation occurred in the same function as 2064// the leak. The function can also return a location context, which should be 2065// treated as interesting. 2066struct AllocationInfo { 2067 const ExplodedNode* N; 2068 const MemRegion *R; 2069 const LocationContext *InterestingMethodContext; 2070 AllocationInfo(const ExplodedNode *InN, 2071 const MemRegion *InR, 2072 const LocationContext *InInterestingMethodContext) : 2073 N(InN), R(InR), InterestingMethodContext(InInterestingMethodContext) {} 2074}; 2075 2076static AllocationInfo 2077GetAllocationSite(ProgramStateManager& StateMgr, const ExplodedNode *N, 2078 SymbolRef Sym) { 2079 const ExplodedNode *AllocationNode = N; 2080 const ExplodedNode *AllocationNodeInCurrentContext = N; 2081 const MemRegion* FirstBinding = 0; 2082 const LocationContext *LeakContext = N->getLocationContext(); 2083 2084 // The location context of the init method called on the leaked object, if 2085 // available. 2086 const LocationContext *InitMethodContext = 0; 2087 2088 while (N) { 2089 ProgramStateRef St = N->getState(); 2090 const LocationContext *NContext = N->getLocationContext(); 2091 2092 if (!getRefBinding(St, Sym)) 2093 break; 2094 2095 StoreManager::FindUniqueBinding FB(Sym); 2096 StateMgr.iterBindings(St, FB); 2097 2098 if (FB) { 2099 const MemRegion *R = FB.getRegion(); 2100 const VarRegion *VR = R->getBaseRegion()->getAs<VarRegion>(); 2101 // Do not show local variables belonging to a function other than 2102 // where the error is reported. 2103 if (!VR || VR->getStackFrame() == LeakContext->getCurrentStackFrame()) 2104 FirstBinding = R; 2105 } 2106 2107 // AllocationNode is the last node in which the symbol was tracked. 2108 AllocationNode = N; 2109 2110 // AllocationNodeInCurrentContext, is the last node in the current context 2111 // in which the symbol was tracked. 2112 if (NContext == LeakContext) 2113 AllocationNodeInCurrentContext = N; 2114 2115 // Find the last init that was called on the given symbol and store the 2116 // init method's location context. 2117 if (!InitMethodContext) 2118 if (Optional<CallEnter> CEP = N->getLocation().getAs<CallEnter>()) { 2119 const Stmt *CE = CEP->getCallExpr(); 2120 if (const ObjCMessageExpr *ME = dyn_cast_or_null<ObjCMessageExpr>(CE)) { 2121 const Stmt *RecExpr = ME->getInstanceReceiver(); 2122 if (RecExpr) { 2123 SVal RecV = St->getSVal(RecExpr, NContext); 2124 if (ME->getMethodFamily() == OMF_init && RecV.getAsSymbol() == Sym) 2125 InitMethodContext = CEP->getCalleeContext(); 2126 } 2127 } 2128 } 2129 2130 N = N->pred_empty() ? NULL : *(N->pred_begin()); 2131 } 2132 2133 // If we are reporting a leak of the object that was allocated with alloc, 2134 // mark its init method as interesting. 2135 const LocationContext *InterestingMethodContext = 0; 2136 if (InitMethodContext) { 2137 const ProgramPoint AllocPP = AllocationNode->getLocation(); 2138 if (Optional<StmtPoint> SP = AllocPP.getAs<StmtPoint>()) 2139 if (const ObjCMessageExpr *ME = SP->getStmtAs<ObjCMessageExpr>()) 2140 if (ME->getMethodFamily() == OMF_alloc) 2141 InterestingMethodContext = InitMethodContext; 2142 } 2143 2144 // If allocation happened in a function different from the leak node context, 2145 // do not report the binding. 2146 assert(N && "Could not find allocation node"); 2147 if (N->getLocationContext() != LeakContext) { 2148 FirstBinding = 0; 2149 } 2150 2151 return AllocationInfo(AllocationNodeInCurrentContext, 2152 FirstBinding, 2153 InterestingMethodContext); 2154} 2155 2156PathDiagnosticPiece* 2157CFRefReportVisitor::getEndPath(BugReporterContext &BRC, 2158 const ExplodedNode *EndN, 2159 BugReport &BR) { 2160 BR.markInteresting(Sym); 2161 return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR); 2162} 2163 2164PathDiagnosticPiece* 2165CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC, 2166 const ExplodedNode *EndN, 2167 BugReport &BR) { 2168 2169 // Tell the BugReporterContext to report cases when the tracked symbol is 2170 // assigned to different variables, etc. 2171 BR.markInteresting(Sym); 2172 2173 // We are reporting a leak. Walk up the graph to get to the first node where 2174 // the symbol appeared, and also get the first VarDecl that tracked object 2175 // is stored to. 2176 AllocationInfo AllocI = 2177 GetAllocationSite(BRC.getStateManager(), EndN, Sym); 2178 2179 const MemRegion* FirstBinding = AllocI.R; 2180 BR.markInteresting(AllocI.InterestingMethodContext); 2181 2182 SourceManager& SM = BRC.getSourceManager(); 2183 2184 // Compute an actual location for the leak. Sometimes a leak doesn't 2185 // occur at an actual statement (e.g., transition between blocks; end 2186 // of function) so we need to walk the graph and compute a real location. 2187 const ExplodedNode *LeakN = EndN; 2188 PathDiagnosticLocation L = PathDiagnosticLocation::createEndOfPath(LeakN, SM); 2189 2190 std::string sbuf; 2191 llvm::raw_string_ostream os(sbuf); 2192 2193 os << "Object leaked: "; 2194 2195 if (FirstBinding) { 2196 os << "object allocated and stored into '" 2197 << FirstBinding->getString() << '\''; 2198 } 2199 else 2200 os << "allocated object"; 2201 2202 // Get the retain count. 2203 const RefVal* RV = getRefBinding(EndN->getState(), Sym); 2204 assert(RV); 2205 2206 if (RV->getKind() == RefVal::ErrorLeakReturned) { 2207 // FIXME: Per comments in rdar://6320065, "create" only applies to CF 2208 // objects. Only "copy", "alloc", "retain" and "new" transfer ownership 2209 // to the caller for NS objects. 2210 const Decl *D = &EndN->getCodeDecl(); 2211 2212 os << (isa<ObjCMethodDecl>(D) ? " is returned from a method " 2213 : " is returned from a function "); 2214 2215 if (D->getAttr<CFReturnsNotRetainedAttr>()) 2216 os << "that is annotated as CF_RETURNS_NOT_RETAINED"; 2217 else if (D->getAttr<NSReturnsNotRetainedAttr>()) 2218 os << "that is annotated as NS_RETURNS_NOT_RETAINED"; 2219 else { 2220 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 2221 os << "whose name ('" << MD->getSelector().getAsString() 2222 << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'." 2223 " This violates the naming convention rules" 2224 " given in the Memory Management Guide for Cocoa"; 2225 } 2226 else { 2227 const FunctionDecl *FD = cast<FunctionDecl>(D); 2228 os << "whose name ('" << *FD 2229 << "') does not contain 'Copy' or 'Create'. This violates the naming" 2230 " convention rules given in the Memory Management Guide for Core" 2231 " Foundation"; 2232 } 2233 } 2234 } 2235 else if (RV->getKind() == RefVal::ErrorGCLeakReturned) { 2236 const ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl()); 2237 os << " and returned from method '" << MD.getSelector().getAsString() 2238 << "' is potentially leaked when using garbage collection. Callers " 2239 "of this method do not expect a returned object with a +1 retain " 2240 "count since they expect the object to be managed by the garbage " 2241 "collector"; 2242 } 2243 else 2244 os << " is not referenced later in this execution path and has a retain " 2245 "count of +" << RV->getCount(); 2246 2247 return new PathDiagnosticEventPiece(L, os.str()); 2248} 2249 2250CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, 2251 bool GCEnabled, const SummaryLogTy &Log, 2252 ExplodedNode *n, SymbolRef sym, 2253 CheckerContext &Ctx, 2254 bool IncludeAllocationLine) 2255 : CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) { 2256 2257 // Most bug reports are cached at the location where they occurred. 2258 // With leaks, we want to unique them by the location where they were 2259 // allocated, and only report a single path. To do this, we need to find 2260 // the allocation site of a piece of tracked memory, which we do via a 2261 // call to GetAllocationSite. This will walk the ExplodedGraph backwards. 2262 // Note that this is *not* the trimmed graph; we are guaranteed, however, 2263 // that all ancestor nodes that represent the allocation site have the 2264 // same SourceLocation. 2265 const ExplodedNode *AllocNode = 0; 2266 2267 const SourceManager& SMgr = Ctx.getSourceManager(); 2268 2269 AllocationInfo AllocI = 2270 GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym); 2271 2272 AllocNode = AllocI.N; 2273 AllocBinding = AllocI.R; 2274 markInteresting(AllocI.InterestingMethodContext); 2275 2276 // Get the SourceLocation for the allocation site. 2277 // FIXME: This will crash the analyzer if an allocation comes from an 2278 // implicit call. (Currently there are no such allocations in Cocoa, though.) 2279 const Stmt *AllocStmt; 2280 ProgramPoint P = AllocNode->getLocation(); 2281 if (Optional<CallExitEnd> Exit = P.getAs<CallExitEnd>()) 2282 AllocStmt = Exit->getCalleeContext()->getCallSite(); 2283 else 2284 AllocStmt = P.castAs<PostStmt>().getStmt(); 2285 assert(AllocStmt && "All allocations must come from explicit calls"); 2286 2287 PathDiagnosticLocation AllocLocation = 2288 PathDiagnosticLocation::createBegin(AllocStmt, SMgr, 2289 AllocNode->getLocationContext()); 2290 Location = AllocLocation; 2291 2292 // Set uniqieing info, which will be used for unique the bug reports. The 2293 // leaks should be uniqued on the allocation site. 2294 UniqueingLocation = AllocLocation; 2295 UniqueingDecl = AllocNode->getLocationContext()->getDecl(); 2296 2297 // Fill in the description of the bug. 2298 Description.clear(); 2299 llvm::raw_string_ostream os(Description); 2300 os << "Potential leak "; 2301 if (GCEnabled) 2302 os << "(when using garbage collection) "; 2303 os << "of an object"; 2304 2305 if (AllocBinding) { 2306 os << " stored into '" << AllocBinding->getString() << '\''; 2307 if (IncludeAllocationLine) { 2308 FullSourceLoc SL(AllocStmt->getLocStart(), Ctx.getSourceManager()); 2309 os << " (allocated on line " << SL.getSpellingLineNumber() << ")"; 2310 } 2311 } 2312 2313 addVisitor(new CFRefLeakReportVisitor(sym, GCEnabled, Log)); 2314} 2315 2316//===----------------------------------------------------------------------===// 2317// Main checker logic. 2318//===----------------------------------------------------------------------===// 2319 2320namespace { 2321class RetainCountChecker 2322 : public Checker< check::Bind, 2323 check::DeadSymbols, 2324 check::EndAnalysis, 2325 check::EndFunction, 2326 check::PostStmt<BlockExpr>, 2327 check::PostStmt<CastExpr>, 2328 check::PostStmt<ObjCArrayLiteral>, 2329 check::PostStmt<ObjCDictionaryLiteral>, 2330 check::PostStmt<ObjCBoxedExpr>, 2331 check::PostCall, 2332 check::PreStmt<ReturnStmt>, 2333 check::RegionChanges, 2334 eval::Assume, 2335 eval::Call > { 2336 mutable OwningPtr<CFRefBug> useAfterRelease, releaseNotOwned; 2337 mutable OwningPtr<CFRefBug> deallocGC, deallocNotOwned; 2338 mutable OwningPtr<CFRefBug> overAutorelease, returnNotOwnedForOwned; 2339 mutable OwningPtr<CFRefBug> leakWithinFunction, leakAtReturn; 2340 mutable OwningPtr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC; 2341 2342 typedef llvm::DenseMap<SymbolRef, const SimpleProgramPointTag *> SymbolTagMap; 2343 2344 // This map is only used to ensure proper deletion of any allocated tags. 2345 mutable SymbolTagMap DeadSymbolTags; 2346 2347 mutable OwningPtr<RetainSummaryManager> Summaries; 2348 mutable OwningPtr<RetainSummaryManager> SummariesGC; 2349 mutable SummaryLogTy SummaryLog; 2350 mutable bool ShouldResetSummaryLog; 2351 2352 /// Optional setting to indicate if leak reports should include 2353 /// the allocation line. 2354 mutable bool IncludeAllocationLine; 2355 2356public: 2357 RetainCountChecker(AnalyzerOptions &AO) 2358 : ShouldResetSummaryLog(false), 2359 IncludeAllocationLine(shouldIncludeAllocationSiteInLeakDiagnostics(AO)) {} 2360 2361 virtual ~RetainCountChecker() { 2362 DeleteContainerSeconds(DeadSymbolTags); 2363 } 2364 2365 void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR, 2366 ExprEngine &Eng) const { 2367 // FIXME: This is a hack to make sure the summary log gets cleared between 2368 // analyses of different code bodies. 2369 // 2370 // Why is this necessary? Because a checker's lifetime is tied to a 2371 // translation unit, but an ExplodedGraph's lifetime is just a code body. 2372 // Once in a blue moon, a new ExplodedNode will have the same address as an 2373 // old one with an associated summary, and the bug report visitor gets very 2374 // confused. (To make things worse, the summary lifetime is currently also 2375 // tied to a code body, so we get a crash instead of incorrect results.) 2376 // 2377 // Why is this a bad solution? Because if the lifetime of the ExplodedGraph 2378 // changes, things will start going wrong again. Really the lifetime of this 2379 // log needs to be tied to either the specific nodes in it or the entire 2380 // ExplodedGraph, not to a specific part of the code being analyzed. 2381 // 2382 // (Also, having stateful local data means that the same checker can't be 2383 // used from multiple threads, but a lot of checkers have incorrect 2384 // assumptions about that anyway. So that wasn't a priority at the time of 2385 // this fix.) 2386 // 2387 // This happens at the end of analysis, but bug reports are emitted /after/ 2388 // this point. So we can't just clear the summary log now. Instead, we mark 2389 // that the next time we access the summary log, it should be cleared. 2390 2391 // If we never reset the summary log during /this/ code body analysis, 2392 // there were no new summaries. There might still have been summaries from 2393 // the /last/ analysis, so clear them out to make sure the bug report 2394 // visitors don't get confused. 2395 if (ShouldResetSummaryLog) 2396 SummaryLog.clear(); 2397 2398 ShouldResetSummaryLog = !SummaryLog.empty(); 2399 } 2400 2401 CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts, 2402 bool GCEnabled) const { 2403 if (GCEnabled) { 2404 if (!leakWithinFunctionGC) 2405 leakWithinFunctionGC.reset(new Leak("Leak of object when using " 2406 "garbage collection")); 2407 return leakWithinFunctionGC.get(); 2408 } else { 2409 if (!leakWithinFunction) { 2410 if (LOpts.getGC() == LangOptions::HybridGC) { 2411 leakWithinFunction.reset(new Leak("Leak of object when not using " 2412 "garbage collection (GC) in " 2413 "dual GC/non-GC code")); 2414 } else { 2415 leakWithinFunction.reset(new Leak("Leak")); 2416 } 2417 } 2418 return leakWithinFunction.get(); 2419 } 2420 } 2421 2422 CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const { 2423 if (GCEnabled) { 2424 if (!leakAtReturnGC) 2425 leakAtReturnGC.reset(new Leak("Leak of returned object when using " 2426 "garbage collection")); 2427 return leakAtReturnGC.get(); 2428 } else { 2429 if (!leakAtReturn) { 2430 if (LOpts.getGC() == LangOptions::HybridGC) { 2431 leakAtReturn.reset(new Leak("Leak of returned object when not using " 2432 "garbage collection (GC) in dual " 2433 "GC/non-GC code")); 2434 } else { 2435 leakAtReturn.reset(new Leak("Leak of returned object")); 2436 } 2437 } 2438 return leakAtReturn.get(); 2439 } 2440 } 2441 2442 RetainSummaryManager &getSummaryManager(ASTContext &Ctx, 2443 bool GCEnabled) const { 2444 // FIXME: We don't support ARC being turned on and off during one analysis. 2445 // (nor, for that matter, do we support changing ASTContexts) 2446 bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount; 2447 if (GCEnabled) { 2448 if (!SummariesGC) 2449 SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled)); 2450 else 2451 assert(SummariesGC->isARCEnabled() == ARCEnabled); 2452 return *SummariesGC; 2453 } else { 2454 if (!Summaries) 2455 Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled)); 2456 else 2457 assert(Summaries->isARCEnabled() == ARCEnabled); 2458 return *Summaries; 2459 } 2460 } 2461 2462 RetainSummaryManager &getSummaryManager(CheckerContext &C) const { 2463 return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled()); 2464 } 2465 2466 void printState(raw_ostream &Out, ProgramStateRef State, 2467 const char *NL, const char *Sep) const; 2468 2469 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; 2470 void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const; 2471 void checkPostStmt(const CastExpr *CE, CheckerContext &C) const; 2472 2473 void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const; 2474 void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const; 2475 void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const; 2476 2477 void checkPostCall(const CallEvent &Call, CheckerContext &C) const; 2478 2479 void checkSummary(const RetainSummary &Summ, const CallEvent &Call, 2480 CheckerContext &C) const; 2481 2482 void processSummaryOfInlined(const RetainSummary &Summ, 2483 const CallEvent &Call, 2484 CheckerContext &C) const; 2485 2486 bool evalCall(const CallExpr *CE, CheckerContext &C) const; 2487 2488 ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, 2489 bool Assumption) const; 2490 2491 ProgramStateRef 2492 checkRegionChanges(ProgramStateRef state, 2493 const InvalidatedSymbols *invalidated, 2494 ArrayRef<const MemRegion *> ExplicitRegions, 2495 ArrayRef<const MemRegion *> Regions, 2496 const CallEvent *Call) const; 2497 2498 bool wantsRegionChangeUpdate(ProgramStateRef state) const { 2499 return true; 2500 } 2501 2502 void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const; 2503 void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, 2504 ExplodedNode *Pred, RetEffect RE, RefVal X, 2505 SymbolRef Sym, ProgramStateRef state) const; 2506 2507 void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const; 2508 void checkEndFunction(CheckerContext &C) const; 2509 2510 ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, 2511 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2512 CheckerContext &C) const; 2513 2514 void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, 2515 RefVal::Kind ErrorKind, SymbolRef Sym, 2516 CheckerContext &C) const; 2517 2518 void processObjCLiterals(CheckerContext &C, const Expr *Ex) const; 2519 2520 const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const; 2521 2522 ProgramStateRef handleSymbolDeath(ProgramStateRef state, 2523 SymbolRef sid, RefVal V, 2524 SmallVectorImpl<SymbolRef> &Leaked) const; 2525 2526 ProgramStateRef 2527 handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred, 2528 const ProgramPointTag *Tag, CheckerContext &Ctx, 2529 SymbolRef Sym, RefVal V) const; 2530 2531 ExplodedNode *processLeaks(ProgramStateRef state, 2532 SmallVectorImpl<SymbolRef> &Leaked, 2533 CheckerContext &Ctx, 2534 ExplodedNode *Pred = 0) const; 2535}; 2536} // end anonymous namespace 2537 2538namespace { 2539class StopTrackingCallback : public SymbolVisitor { 2540 ProgramStateRef state; 2541public: 2542 StopTrackingCallback(ProgramStateRef st) : state(st) {} 2543 ProgramStateRef getState() const { return state; } 2544 2545 bool VisitSymbol(SymbolRef sym) { 2546 state = state->remove<RefBindings>(sym); 2547 return true; 2548 } 2549}; 2550} // end anonymous namespace 2551 2552//===----------------------------------------------------------------------===// 2553// Handle statements that may have an effect on refcounts. 2554//===----------------------------------------------------------------------===// 2555 2556void RetainCountChecker::checkPostStmt(const BlockExpr *BE, 2557 CheckerContext &C) const { 2558 2559 // Scan the BlockDecRefExprs for any object the retain count checker 2560 // may be tracking. 2561 if (!BE->getBlockDecl()->hasCaptures()) 2562 return; 2563 2564 ProgramStateRef state = C.getState(); 2565 const BlockDataRegion *R = 2566 cast<BlockDataRegion>(state->getSVal(BE, 2567 C.getLocationContext()).getAsRegion()); 2568 2569 BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(), 2570 E = R->referenced_vars_end(); 2571 2572 if (I == E) 2573 return; 2574 2575 // FIXME: For now we invalidate the tracking of all symbols passed to blocks 2576 // via captured variables, even though captured variables result in a copy 2577 // and in implicit increment/decrement of a retain count. 2578 SmallVector<const MemRegion*, 10> Regions; 2579 const LocationContext *LC = C.getLocationContext(); 2580 MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager(); 2581 2582 for ( ; I != E; ++I) { 2583 const VarRegion *VR = I.getCapturedRegion(); 2584 if (VR->getSuperRegion() == R) { 2585 VR = MemMgr.getVarRegion(VR->getDecl(), LC); 2586 } 2587 Regions.push_back(VR); 2588 } 2589 2590 state = 2591 state->scanReachableSymbols<StopTrackingCallback>(Regions.data(), 2592 Regions.data() + Regions.size()).getState(); 2593 C.addTransition(state); 2594} 2595 2596void RetainCountChecker::checkPostStmt(const CastExpr *CE, 2597 CheckerContext &C) const { 2598 const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE); 2599 if (!BE) 2600 return; 2601 2602 ArgEffect AE = IncRef; 2603 2604 switch (BE->getBridgeKind()) { 2605 case clang::OBC_Bridge: 2606 // Do nothing. 2607 return; 2608 case clang::OBC_BridgeRetained: 2609 AE = IncRef; 2610 break; 2611 case clang::OBC_BridgeTransfer: 2612 AE = DecRefBridgedTransfered; 2613 break; 2614 } 2615 2616 ProgramStateRef state = C.getState(); 2617 SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol(); 2618 if (!Sym) 2619 return; 2620 const RefVal* T = getRefBinding(state, Sym); 2621 if (!T) 2622 return; 2623 2624 RefVal::Kind hasErr = (RefVal::Kind) 0; 2625 state = updateSymbol(state, Sym, *T, AE, hasErr, C); 2626 2627 if (hasErr) { 2628 // FIXME: If we get an error during a bridge cast, should we report it? 2629 // Should we assert that there is no error? 2630 return; 2631 } 2632 2633 C.addTransition(state); 2634} 2635 2636void RetainCountChecker::processObjCLiterals(CheckerContext &C, 2637 const Expr *Ex) const { 2638 ProgramStateRef state = C.getState(); 2639 const ExplodedNode *pred = C.getPredecessor(); 2640 for (Stmt::const_child_iterator it = Ex->child_begin(), et = Ex->child_end() ; 2641 it != et ; ++it) { 2642 const Stmt *child = *it; 2643 SVal V = state->getSVal(child, pred->getLocationContext()); 2644 if (SymbolRef sym = V.getAsSymbol()) 2645 if (const RefVal* T = getRefBinding(state, sym)) { 2646 RefVal::Kind hasErr = (RefVal::Kind) 0; 2647 state = updateSymbol(state, sym, *T, MayEscape, hasErr, C); 2648 if (hasErr) { 2649 processNonLeakError(state, child->getSourceRange(), hasErr, sym, C); 2650 return; 2651 } 2652 } 2653 } 2654 2655 // Return the object as autoreleased. 2656 // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC); 2657 if (SymbolRef sym = 2658 state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) { 2659 QualType ResultTy = Ex->getType(); 2660 state = setRefBinding(state, sym, 2661 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2662 } 2663 2664 C.addTransition(state); 2665} 2666 2667void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL, 2668 CheckerContext &C) const { 2669 // Apply the 'MayEscape' to all values. 2670 processObjCLiterals(C, AL); 2671} 2672 2673void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL, 2674 CheckerContext &C) const { 2675 // Apply the 'MayEscape' to all keys and values. 2676 processObjCLiterals(C, DL); 2677} 2678 2679void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex, 2680 CheckerContext &C) const { 2681 const ExplodedNode *Pred = C.getPredecessor(); 2682 const LocationContext *LCtx = Pred->getLocationContext(); 2683 ProgramStateRef State = Pred->getState(); 2684 2685 if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) { 2686 QualType ResultTy = Ex->getType(); 2687 State = setRefBinding(State, Sym, 2688 RefVal::makeNotOwned(RetEffect::ObjC, ResultTy)); 2689 } 2690 2691 C.addTransition(State); 2692} 2693 2694void RetainCountChecker::checkPostCall(const CallEvent &Call, 2695 CheckerContext &C) const { 2696 RetainSummaryManager &Summaries = getSummaryManager(C); 2697 const RetainSummary *Summ = Summaries.getSummary(Call, C.getState()); 2698 2699 if (C.wasInlined) { 2700 processSummaryOfInlined(*Summ, Call, C); 2701 return; 2702 } 2703 checkSummary(*Summ, Call, C); 2704} 2705 2706/// GetReturnType - Used to get the return type of a message expression or 2707/// function call with the intention of affixing that type to a tracked symbol. 2708/// While the return type can be queried directly from RetEx, when 2709/// invoking class methods we augment to the return type to be that of 2710/// a pointer to the class (as opposed it just being id). 2711// FIXME: We may be able to do this with related result types instead. 2712// This function is probably overestimating. 2713static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) { 2714 QualType RetTy = RetE->getType(); 2715 // If RetE is not a message expression just return its type. 2716 // If RetE is a message expression, return its types if it is something 2717 /// more specific than id. 2718 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE)) 2719 if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>()) 2720 if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() || 2721 PT->isObjCClassType()) { 2722 // At this point we know the return type of the message expression is 2723 // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this 2724 // is a call to a class method whose type we can resolve. In such 2725 // cases, promote the return type to XXX* (where XXX is the class). 2726 const ObjCInterfaceDecl *D = ME->getReceiverInterface(); 2727 return !D ? RetTy : 2728 Ctx.getObjCObjectPointerType(Ctx.getObjCInterfaceType(D)); 2729 } 2730 2731 return RetTy; 2732} 2733 2734// We don't always get the exact modeling of the function with regards to the 2735// retain count checker even when the function is inlined. For example, we need 2736// to stop tracking the symbols which were marked with StopTrackingHard. 2737void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ, 2738 const CallEvent &CallOrMsg, 2739 CheckerContext &C) const { 2740 ProgramStateRef state = C.getState(); 2741 2742 // Evaluate the effect of the arguments. 2743 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2744 if (Summ.getArg(idx) == StopTrackingHard) { 2745 SVal V = CallOrMsg.getArgSVal(idx); 2746 if (SymbolRef Sym = V.getAsLocSymbol()) { 2747 state = removeRefBinding(state, Sym); 2748 } 2749 } 2750 } 2751 2752 // Evaluate the effect on the message receiver. 2753 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2754 if (MsgInvocation) { 2755 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2756 if (Summ.getReceiverEffect() == StopTrackingHard) { 2757 state = removeRefBinding(state, Sym); 2758 } 2759 } 2760 } 2761 2762 // Consult the summary for the return value. 2763 RetEffect RE = Summ.getRetEffect(); 2764 if (RE.getKind() == RetEffect::NoRetHard) { 2765 SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); 2766 if (Sym) 2767 state = removeRefBinding(state, Sym); 2768 } 2769 2770 C.addTransition(state); 2771} 2772 2773void RetainCountChecker::checkSummary(const RetainSummary &Summ, 2774 const CallEvent &CallOrMsg, 2775 CheckerContext &C) const { 2776 ProgramStateRef state = C.getState(); 2777 2778 // Evaluate the effect of the arguments. 2779 RefVal::Kind hasErr = (RefVal::Kind) 0; 2780 SourceRange ErrorRange; 2781 SymbolRef ErrorSym = 0; 2782 2783 for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) { 2784 SVal V = CallOrMsg.getArgSVal(idx); 2785 2786 if (SymbolRef Sym = V.getAsLocSymbol()) { 2787 if (const RefVal *T = getRefBinding(state, Sym)) { 2788 state = updateSymbol(state, Sym, *T, Summ.getArg(idx), hasErr, C); 2789 if (hasErr) { 2790 ErrorRange = CallOrMsg.getArgSourceRange(idx); 2791 ErrorSym = Sym; 2792 break; 2793 } 2794 } 2795 } 2796 } 2797 2798 // Evaluate the effect on the message receiver. 2799 bool ReceiverIsTracked = false; 2800 if (!hasErr) { 2801 const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg); 2802 if (MsgInvocation) { 2803 if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) { 2804 if (const RefVal *T = getRefBinding(state, Sym)) { 2805 ReceiverIsTracked = true; 2806 state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(), 2807 hasErr, C); 2808 if (hasErr) { 2809 ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange(); 2810 ErrorSym = Sym; 2811 } 2812 } 2813 } 2814 } 2815 } 2816 2817 // Process any errors. 2818 if (hasErr) { 2819 processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C); 2820 return; 2821 } 2822 2823 // Consult the summary for the return value. 2824 RetEffect RE = Summ.getRetEffect(); 2825 2826 if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) { 2827 if (ReceiverIsTracked) 2828 RE = getSummaryManager(C).getObjAllocRetEffect(); 2829 else 2830 RE = RetEffect::MakeNoRet(); 2831 } 2832 2833 switch (RE.getKind()) { 2834 default: 2835 llvm_unreachable("Unhandled RetEffect."); 2836 2837 case RetEffect::NoRet: 2838 case RetEffect::NoRetHard: 2839 // No work necessary. 2840 break; 2841 2842 case RetEffect::OwnedAllocatedSymbol: 2843 case RetEffect::OwnedSymbol: { 2844 SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); 2845 if (!Sym) 2846 break; 2847 2848 // Use the result type from the CallEvent as it automatically adjusts 2849 // for methods/functions that return references. 2850 QualType ResultTy = CallOrMsg.getResultType(); 2851 state = setRefBinding(state, Sym, RefVal::makeOwned(RE.getObjKind(), 2852 ResultTy)); 2853 2854 // FIXME: Add a flag to the checker where allocations are assumed to 2855 // *not* fail. 2856 break; 2857 } 2858 2859 case RetEffect::GCNotOwnedSymbol: 2860 case RetEffect::ARCNotOwnedSymbol: 2861 case RetEffect::NotOwnedSymbol: { 2862 const Expr *Ex = CallOrMsg.getOriginExpr(); 2863 SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol(); 2864 if (!Sym) 2865 break; 2866 assert(Ex); 2867 // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *. 2868 QualType ResultTy = GetReturnType(Ex, C.getASTContext()); 2869 state = setRefBinding(state, Sym, RefVal::makeNotOwned(RE.getObjKind(), 2870 ResultTy)); 2871 break; 2872 } 2873 } 2874 2875 // This check is actually necessary; otherwise the statement builder thinks 2876 // we've hit a previously-found path. 2877 // Normally addTransition takes care of this, but we want the node pointer. 2878 ExplodedNode *NewNode; 2879 if (state == C.getState()) { 2880 NewNode = C.getPredecessor(); 2881 } else { 2882 NewNode = C.addTransition(state); 2883 } 2884 2885 // Annotate the node with summary we used. 2886 if (NewNode) { 2887 // FIXME: This is ugly. See checkEndAnalysis for why it's necessary. 2888 if (ShouldResetSummaryLog) { 2889 SummaryLog.clear(); 2890 ShouldResetSummaryLog = false; 2891 } 2892 SummaryLog[NewNode] = &Summ; 2893 } 2894} 2895 2896 2897ProgramStateRef 2898RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym, 2899 RefVal V, ArgEffect E, RefVal::Kind &hasErr, 2900 CheckerContext &C) const { 2901 // In GC mode [... release] and [... retain] do nothing. 2902 // In ARC mode they shouldn't exist at all, but we just ignore them. 2903 bool IgnoreRetainMsg = C.isObjCGCEnabled(); 2904 if (!IgnoreRetainMsg) 2905 IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount; 2906 2907 switch (E) { 2908 default: 2909 break; 2910 case IncRefMsg: 2911 E = IgnoreRetainMsg ? DoNothing : IncRef; 2912 break; 2913 case DecRefMsg: 2914 E = IgnoreRetainMsg ? DoNothing : DecRef; 2915 break; 2916 case DecRefMsgAndStopTrackingHard: 2917 E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTrackingHard; 2918 break; 2919 case MakeCollectable: 2920 E = C.isObjCGCEnabled() ? DecRef : DoNothing; 2921 break; 2922 } 2923 2924 // Handle all use-after-releases. 2925 if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) { 2926 V = V ^ RefVal::ErrorUseAfterRelease; 2927 hasErr = V.getKind(); 2928 return setRefBinding(state, sym, V); 2929 } 2930 2931 switch (E) { 2932 case DecRefMsg: 2933 case IncRefMsg: 2934 case MakeCollectable: 2935 case DecRefMsgAndStopTrackingHard: 2936 llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted"); 2937 2938 case Dealloc: 2939 // Any use of -dealloc in GC is *bad*. 2940 if (C.isObjCGCEnabled()) { 2941 V = V ^ RefVal::ErrorDeallocGC; 2942 hasErr = V.getKind(); 2943 break; 2944 } 2945 2946 switch (V.getKind()) { 2947 default: 2948 llvm_unreachable("Invalid RefVal state for an explicit dealloc."); 2949 case RefVal::Owned: 2950 // The object immediately transitions to the released state. 2951 V = V ^ RefVal::Released; 2952 V.clearCounts(); 2953 return setRefBinding(state, sym, V); 2954 case RefVal::NotOwned: 2955 V = V ^ RefVal::ErrorDeallocNotOwned; 2956 hasErr = V.getKind(); 2957 break; 2958 } 2959 break; 2960 2961 case MayEscape: 2962 if (V.getKind() == RefVal::Owned) { 2963 V = V ^ RefVal::NotOwned; 2964 break; 2965 } 2966 2967 // Fall-through. 2968 2969 case DoNothing: 2970 return state; 2971 2972 case Autorelease: 2973 if (C.isObjCGCEnabled()) 2974 return state; 2975 // Update the autorelease counts. 2976 V = V.autorelease(); 2977 break; 2978 2979 case StopTracking: 2980 case StopTrackingHard: 2981 return removeRefBinding(state, sym); 2982 2983 case IncRef: 2984 switch (V.getKind()) { 2985 default: 2986 llvm_unreachable("Invalid RefVal state for a retain."); 2987 case RefVal::Owned: 2988 case RefVal::NotOwned: 2989 V = V + 1; 2990 break; 2991 case RefVal::Released: 2992 // Non-GC cases are handled above. 2993 assert(C.isObjCGCEnabled()); 2994 V = (V ^ RefVal::Owned) + 1; 2995 break; 2996 } 2997 break; 2998 2999 case DecRef: 3000 case DecRefBridgedTransfered: 3001 case DecRefAndStopTrackingHard: 3002 switch (V.getKind()) { 3003 default: 3004 // case 'RefVal::Released' handled above. 3005 llvm_unreachable("Invalid RefVal state for a release."); 3006 3007 case RefVal::Owned: 3008 assert(V.getCount() > 0); 3009 if (V.getCount() == 1) 3010 V = V ^ (E == DecRefBridgedTransfered ? 3011 RefVal::NotOwned : RefVal::Released); 3012 else if (E == DecRefAndStopTrackingHard) 3013 return removeRefBinding(state, sym); 3014 3015 V = V - 1; 3016 break; 3017 3018 case RefVal::NotOwned: 3019 if (V.getCount() > 0) { 3020 if (E == DecRefAndStopTrackingHard) 3021 return removeRefBinding(state, sym); 3022 V = V - 1; 3023 } else { 3024 V = V ^ RefVal::ErrorReleaseNotOwned; 3025 hasErr = V.getKind(); 3026 } 3027 break; 3028 3029 case RefVal::Released: 3030 // Non-GC cases are handled above. 3031 assert(C.isObjCGCEnabled()); 3032 V = V ^ RefVal::ErrorUseAfterRelease; 3033 hasErr = V.getKind(); 3034 break; 3035 } 3036 break; 3037 } 3038 return setRefBinding(state, sym, V); 3039} 3040 3041void RetainCountChecker::processNonLeakError(ProgramStateRef St, 3042 SourceRange ErrorRange, 3043 RefVal::Kind ErrorKind, 3044 SymbolRef Sym, 3045 CheckerContext &C) const { 3046 ExplodedNode *N = C.generateSink(St); 3047 if (!N) 3048 return; 3049 3050 CFRefBug *BT; 3051 switch (ErrorKind) { 3052 default: 3053 llvm_unreachable("Unhandled error."); 3054 case RefVal::ErrorUseAfterRelease: 3055 if (!useAfterRelease) 3056 useAfterRelease.reset(new UseAfterRelease()); 3057 BT = &*useAfterRelease; 3058 break; 3059 case RefVal::ErrorReleaseNotOwned: 3060 if (!releaseNotOwned) 3061 releaseNotOwned.reset(new BadRelease()); 3062 BT = &*releaseNotOwned; 3063 break; 3064 case RefVal::ErrorDeallocGC: 3065 if (!deallocGC) 3066 deallocGC.reset(new DeallocGC()); 3067 BT = &*deallocGC; 3068 break; 3069 case RefVal::ErrorDeallocNotOwned: 3070 if (!deallocNotOwned) 3071 deallocNotOwned.reset(new DeallocNotOwned()); 3072 BT = &*deallocNotOwned; 3073 break; 3074 } 3075 3076 assert(BT); 3077 CFRefReport *report = new CFRefReport(*BT, C.getASTContext().getLangOpts(), 3078 C.isObjCGCEnabled(), SummaryLog, 3079 N, Sym); 3080 report->addRange(ErrorRange); 3081 C.emitReport(report); 3082} 3083 3084//===----------------------------------------------------------------------===// 3085// Handle the return values of retain-count-related functions. 3086//===----------------------------------------------------------------------===// 3087 3088bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const { 3089 // Get the callee. We're only interested in simple C functions. 3090 ProgramStateRef state = C.getState(); 3091 const FunctionDecl *FD = C.getCalleeDecl(CE); 3092 if (!FD) 3093 return false; 3094 3095 IdentifierInfo *II = FD->getIdentifier(); 3096 if (!II) 3097 return false; 3098 3099 // For now, we're only handling the functions that return aliases of their 3100 // arguments: CFRetain and CFMakeCollectable (and their families). 3101 // Eventually we should add other functions we can model entirely, 3102 // such as CFRelease, which don't invalidate their arguments or globals. 3103 if (CE->getNumArgs() != 1) 3104 return false; 3105 3106 // Get the name of the function. 3107 StringRef FName = II->getName(); 3108 FName = FName.substr(FName.find_first_not_of('_')); 3109 3110 // See if it's one of the specific functions we know how to eval. 3111 bool canEval = false; 3112 3113 QualType ResultTy = CE->getCallReturnType(); 3114 if (ResultTy->isObjCIdType()) { 3115 // Handle: id NSMakeCollectable(CFTypeRef) 3116 canEval = II->isStr("NSMakeCollectable"); 3117 } else if (ResultTy->isPointerType()) { 3118 // Handle: (CF|CG)Retain 3119 // CFAutorelease 3120 // CFMakeCollectable 3121 // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist). 3122 if (cocoa::isRefType(ResultTy, "CF", FName) || 3123 cocoa::isRefType(ResultTy, "CG", FName)) { 3124 canEval = isRetain(FD, FName) || isAutorelease(FD, FName) || 3125 isMakeCollectable(FD, FName); 3126 } 3127 } 3128 3129 if (!canEval) 3130 return false; 3131 3132 // Bind the return value. 3133 const LocationContext *LCtx = C.getLocationContext(); 3134 SVal RetVal = state->getSVal(CE->getArg(0), LCtx); 3135 if (RetVal.isUnknown()) { 3136 // If the receiver is unknown, conjure a return value. 3137 SValBuilder &SVB = C.getSValBuilder(); 3138 RetVal = SVB.conjureSymbolVal(0, CE, LCtx, ResultTy, C.blockCount()); 3139 } 3140 state = state->BindExpr(CE, LCtx, RetVal, false); 3141 3142 // FIXME: This should not be necessary, but otherwise the argument seems to be 3143 // considered alive during the next statement. 3144 if (const MemRegion *ArgRegion = RetVal.getAsRegion()) { 3145 // Save the refcount status of the argument. 3146 SymbolRef Sym = RetVal.getAsLocSymbol(); 3147 const RefVal *Binding = 0; 3148 if (Sym) 3149 Binding = getRefBinding(state, Sym); 3150 3151 // Invalidate the argument region. 3152 state = state->invalidateRegions(ArgRegion, CE, C.blockCount(), LCtx, 3153 /*CausesPointerEscape*/ false); 3154 3155 // Restore the refcount status of the argument. 3156 if (Binding) 3157 state = setRefBinding(state, Sym, *Binding); 3158 } 3159 3160 C.addTransition(state); 3161 return true; 3162} 3163 3164//===----------------------------------------------------------------------===// 3165// Handle return statements. 3166//===----------------------------------------------------------------------===// 3167 3168void RetainCountChecker::checkPreStmt(const ReturnStmt *S, 3169 CheckerContext &C) const { 3170 3171 // Only adjust the reference count if this is the top-level call frame, 3172 // and not the result of inlining. In the future, we should do 3173 // better checking even for inlined calls, and see if they match 3174 // with their expected semantics (e.g., the method should return a retained 3175 // object, etc.). 3176 if (!C.inTopFrame()) 3177 return; 3178 3179 const Expr *RetE = S->getRetValue(); 3180 if (!RetE) 3181 return; 3182 3183 ProgramStateRef state = C.getState(); 3184 SymbolRef Sym = 3185 state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol(); 3186 if (!Sym) 3187 return; 3188 3189 // Get the reference count binding (if any). 3190 const RefVal *T = getRefBinding(state, Sym); 3191 if (!T) 3192 return; 3193 3194 // Change the reference count. 3195 RefVal X = *T; 3196 3197 switch (X.getKind()) { 3198 case RefVal::Owned: { 3199 unsigned cnt = X.getCount(); 3200 assert(cnt > 0); 3201 X.setCount(cnt - 1); 3202 X = X ^ RefVal::ReturnedOwned; 3203 break; 3204 } 3205 3206 case RefVal::NotOwned: { 3207 unsigned cnt = X.getCount(); 3208 if (cnt) { 3209 X.setCount(cnt - 1); 3210 X = X ^ RefVal::ReturnedOwned; 3211 } 3212 else { 3213 X = X ^ RefVal::ReturnedNotOwned; 3214 } 3215 break; 3216 } 3217 3218 default: 3219 return; 3220 } 3221 3222 // Update the binding. 3223 state = setRefBinding(state, Sym, X); 3224 ExplodedNode *Pred = C.addTransition(state); 3225 3226 // At this point we have updated the state properly. 3227 // Everything after this is merely checking to see if the return value has 3228 // been over- or under-retained. 3229 3230 // Did we cache out? 3231 if (!Pred) 3232 return; 3233 3234 // Update the autorelease counts. 3235 static SimpleProgramPointTag 3236 AutoreleaseTag("RetainCountChecker : Autorelease"); 3237 state = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, C, Sym, X); 3238 3239 // Did we cache out? 3240 if (!state) 3241 return; 3242 3243 // Get the updated binding. 3244 T = getRefBinding(state, Sym); 3245 assert(T); 3246 X = *T; 3247 3248 // Consult the summary of the enclosing method. 3249 RetainSummaryManager &Summaries = getSummaryManager(C); 3250 const Decl *CD = &Pred->getCodeDecl(); 3251 RetEffect RE = RetEffect::MakeNoRet(); 3252 3253 // FIXME: What is the convention for blocks? Is there one? 3254 if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) { 3255 const RetainSummary *Summ = Summaries.getMethodSummary(MD); 3256 RE = Summ->getRetEffect(); 3257 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) { 3258 if (!isa<CXXMethodDecl>(FD)) { 3259 const RetainSummary *Summ = Summaries.getFunctionSummary(FD); 3260 RE = Summ->getRetEffect(); 3261 } 3262 } 3263 3264 checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state); 3265} 3266 3267void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S, 3268 CheckerContext &C, 3269 ExplodedNode *Pred, 3270 RetEffect RE, RefVal X, 3271 SymbolRef Sym, 3272 ProgramStateRef state) const { 3273 // Any leaks or other errors? 3274 if (X.isReturnedOwned() && X.getCount() == 0) { 3275 if (RE.getKind() != RetEffect::NoRet) { 3276 bool hasError = false; 3277 if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) { 3278 // Things are more complicated with garbage collection. If the 3279 // returned object is suppose to be an Objective-C object, we have 3280 // a leak (as the caller expects a GC'ed object) because no 3281 // method should return ownership unless it returns a CF object. 3282 hasError = true; 3283 X = X ^ RefVal::ErrorGCLeakReturned; 3284 } 3285 else if (!RE.isOwned()) { 3286 // Either we are using GC and the returned object is a CF type 3287 // or we aren't using GC. In either case, we expect that the 3288 // enclosing method is expected to return ownership. 3289 hasError = true; 3290 X = X ^ RefVal::ErrorLeakReturned; 3291 } 3292 3293 if (hasError) { 3294 // Generate an error node. 3295 state = setRefBinding(state, Sym, X); 3296 3297 static SimpleProgramPointTag 3298 ReturnOwnLeakTag("RetainCountChecker : ReturnsOwnLeak"); 3299 ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag); 3300 if (N) { 3301 const LangOptions &LOpts = C.getASTContext().getLangOpts(); 3302 bool GCEnabled = C.isObjCGCEnabled(); 3303 CFRefReport *report = 3304 new CFRefLeakReport(*getLeakAtReturnBug(LOpts, GCEnabled), 3305 LOpts, GCEnabled, SummaryLog, 3306 N, Sym, C, IncludeAllocationLine); 3307 3308 C.emitReport(report); 3309 } 3310 } 3311 } 3312 } else if (X.isReturnedNotOwned()) { 3313 if (RE.isOwned()) { 3314 // Trying to return a not owned object to a caller expecting an 3315 // owned object. 3316 state = setRefBinding(state, Sym, X ^ RefVal::ErrorReturnedNotOwned); 3317 3318 static SimpleProgramPointTag 3319 ReturnNotOwnedTag("RetainCountChecker : ReturnNotOwnedForOwned"); 3320 ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag); 3321 if (N) { 3322 if (!returnNotOwnedForOwned) 3323 returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned()); 3324 3325 CFRefReport *report = 3326 new CFRefReport(*returnNotOwnedForOwned, 3327 C.getASTContext().getLangOpts(), 3328 C.isObjCGCEnabled(), SummaryLog, N, Sym); 3329 C.emitReport(report); 3330 } 3331 } 3332 } 3333} 3334 3335//===----------------------------------------------------------------------===// 3336// Check various ways a symbol can be invalidated. 3337//===----------------------------------------------------------------------===// 3338 3339void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S, 3340 CheckerContext &C) const { 3341 // Are we storing to something that causes the value to "escape"? 3342 bool escapes = true; 3343 3344 // A value escapes in three possible cases (this may change): 3345 // 3346 // (1) we are binding to something that is not a memory region. 3347 // (2) we are binding to a memregion that does not have stack storage 3348 // (3) we are binding to a memregion with stack storage that the store 3349 // does not understand. 3350 ProgramStateRef state = C.getState(); 3351 3352 if (Optional<loc::MemRegionVal> regionLoc = loc.getAs<loc::MemRegionVal>()) { 3353 escapes = !regionLoc->getRegion()->hasStackStorage(); 3354 3355 if (!escapes) { 3356 // To test (3), generate a new state with the binding added. If it is 3357 // the same state, then it escapes (since the store cannot represent 3358 // the binding). 3359 // Do this only if we know that the store is not supposed to generate the 3360 // same state. 3361 SVal StoredVal = state->getSVal(regionLoc->getRegion()); 3362 if (StoredVal != val) 3363 escapes = (state == (state->bindLoc(*regionLoc, val))); 3364 } 3365 if (!escapes) { 3366 // Case 4: We do not currently model what happens when a symbol is 3367 // assigned to a struct field, so be conservative here and let the symbol 3368 // go. TODO: This could definitely be improved upon. 3369 escapes = !isa<VarRegion>(regionLoc->getRegion()); 3370 } 3371 } 3372 3373 // If we are storing the value into an auto function scope variable annotated 3374 // with (__attribute__((cleanup))), stop tracking the value to avoid leak 3375 // false positives. 3376 if (const VarRegion *LVR = dyn_cast_or_null<VarRegion>(loc.getAsRegion())) { 3377 const VarDecl *VD = LVR->getDecl(); 3378 if (VD->getAttr<CleanupAttr>()) { 3379 escapes = true; 3380 } 3381 } 3382 3383 // If our store can represent the binding and we aren't storing to something 3384 // that doesn't have local storage then just return and have the simulation 3385 // state continue as is. 3386 if (!escapes) 3387 return; 3388 3389 // Otherwise, find all symbols referenced by 'val' that we are tracking 3390 // and stop tracking them. 3391 state = state->scanReachableSymbols<StopTrackingCallback>(val).getState(); 3392 C.addTransition(state); 3393} 3394 3395ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state, 3396 SVal Cond, 3397 bool Assumption) const { 3398 3399 // FIXME: We may add to the interface of evalAssume the list of symbols 3400 // whose assumptions have changed. For now we just iterate through the 3401 // bindings and check if any of the tracked symbols are NULL. This isn't 3402 // too bad since the number of symbols we will track in practice are 3403 // probably small and evalAssume is only called at branches and a few 3404 // other places. 3405 RefBindingsTy B = state->get<RefBindings>(); 3406 3407 if (B.isEmpty()) 3408 return state; 3409 3410 bool changed = false; 3411 RefBindingsTy::Factory &RefBFactory = state->get_context<RefBindings>(); 3412 3413 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3414 // Check if the symbol is null stop tracking the symbol. 3415 ConstraintManager &CMgr = state->getConstraintManager(); 3416 ConditionTruthVal AllocFailed = CMgr.isNull(state, I.getKey()); 3417 if (AllocFailed.isConstrainedTrue()) { 3418 changed = true; 3419 B = RefBFactory.remove(B, I.getKey()); 3420 } 3421 } 3422 3423 if (changed) 3424 state = state->set<RefBindings>(B); 3425 3426 return state; 3427} 3428 3429ProgramStateRef 3430RetainCountChecker::checkRegionChanges(ProgramStateRef state, 3431 const InvalidatedSymbols *invalidated, 3432 ArrayRef<const MemRegion *> ExplicitRegions, 3433 ArrayRef<const MemRegion *> Regions, 3434 const CallEvent *Call) const { 3435 if (!invalidated) 3436 return state; 3437 3438 llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols; 3439 for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(), 3440 E = ExplicitRegions.end(); I != E; ++I) { 3441 if (const SymbolicRegion *SR = (*I)->StripCasts()->getAs<SymbolicRegion>()) 3442 WhitelistedSymbols.insert(SR->getSymbol()); 3443 } 3444 3445 for (InvalidatedSymbols::const_iterator I=invalidated->begin(), 3446 E = invalidated->end(); I!=E; ++I) { 3447 SymbolRef sym = *I; 3448 if (WhitelistedSymbols.count(sym)) 3449 continue; 3450 // Remove any existing reference-count binding. 3451 state = removeRefBinding(state, sym); 3452 } 3453 return state; 3454} 3455 3456//===----------------------------------------------------------------------===// 3457// Handle dead symbols and end-of-path. 3458//===----------------------------------------------------------------------===// 3459 3460ProgramStateRef 3461RetainCountChecker::handleAutoreleaseCounts(ProgramStateRef state, 3462 ExplodedNode *Pred, 3463 const ProgramPointTag *Tag, 3464 CheckerContext &Ctx, 3465 SymbolRef Sym, RefVal V) const { 3466 unsigned ACnt = V.getAutoreleaseCount(); 3467 3468 // No autorelease counts? Nothing to be done. 3469 if (!ACnt) 3470 return state; 3471 3472 assert(!Ctx.isObjCGCEnabled() && "Autorelease counts in GC mode?"); 3473 unsigned Cnt = V.getCount(); 3474 3475 // FIXME: Handle sending 'autorelease' to already released object. 3476 3477 if (V.getKind() == RefVal::ReturnedOwned) 3478 ++Cnt; 3479 3480 if (ACnt <= Cnt) { 3481 if (ACnt == Cnt) { 3482 V.clearCounts(); 3483 if (V.getKind() == RefVal::ReturnedOwned) 3484 V = V ^ RefVal::ReturnedNotOwned; 3485 else 3486 V = V ^ RefVal::NotOwned; 3487 } else { 3488 V.setCount(V.getCount() - ACnt); 3489 V.setAutoreleaseCount(0); 3490 } 3491 return setRefBinding(state, Sym, V); 3492 } 3493 3494 // Woah! More autorelease counts then retain counts left. 3495 // Emit hard error. 3496 V = V ^ RefVal::ErrorOverAutorelease; 3497 state = setRefBinding(state, Sym, V); 3498 3499 ExplodedNode *N = Ctx.generateSink(state, Pred, Tag); 3500 if (N) { 3501 SmallString<128> sbuf; 3502 llvm::raw_svector_ostream os(sbuf); 3503 os << "Object was autoreleased "; 3504 if (V.getAutoreleaseCount() > 1) 3505 os << V.getAutoreleaseCount() << " times but the object "; 3506 else 3507 os << "but "; 3508 os << "has a +" << V.getCount() << " retain count"; 3509 3510 if (!overAutorelease) 3511 overAutorelease.reset(new OverAutorelease()); 3512 3513 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3514 CFRefReport *report = 3515 new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false, 3516 SummaryLog, N, Sym, os.str()); 3517 Ctx.emitReport(report); 3518 } 3519 3520 return 0; 3521} 3522 3523ProgramStateRef 3524RetainCountChecker::handleSymbolDeath(ProgramStateRef state, 3525 SymbolRef sid, RefVal V, 3526 SmallVectorImpl<SymbolRef> &Leaked) const { 3527 bool hasLeak = false; 3528 if (V.isOwned()) 3529 hasLeak = true; 3530 else if (V.isNotOwned() || V.isReturnedOwned()) 3531 hasLeak = (V.getCount() > 0); 3532 3533 if (!hasLeak) 3534 return removeRefBinding(state, sid); 3535 3536 Leaked.push_back(sid); 3537 return setRefBinding(state, sid, V ^ RefVal::ErrorLeak); 3538} 3539 3540ExplodedNode * 3541RetainCountChecker::processLeaks(ProgramStateRef state, 3542 SmallVectorImpl<SymbolRef> &Leaked, 3543 CheckerContext &Ctx, 3544 ExplodedNode *Pred) const { 3545 // Generate an intermediate node representing the leak point. 3546 ExplodedNode *N = Ctx.addTransition(state, Pred); 3547 3548 if (N) { 3549 for (SmallVectorImpl<SymbolRef>::iterator 3550 I = Leaked.begin(), E = Leaked.end(); I != E; ++I) { 3551 3552 const LangOptions &LOpts = Ctx.getASTContext().getLangOpts(); 3553 bool GCEnabled = Ctx.isObjCGCEnabled(); 3554 CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled) 3555 : getLeakAtReturnBug(LOpts, GCEnabled); 3556 assert(BT && "BugType not initialized."); 3557 3558 CFRefLeakReport *report = new CFRefLeakReport(*BT, LOpts, GCEnabled, 3559 SummaryLog, N, *I, Ctx, 3560 IncludeAllocationLine); 3561 Ctx.emitReport(report); 3562 } 3563 } 3564 3565 return N; 3566} 3567 3568void RetainCountChecker::checkEndFunction(CheckerContext &Ctx) const { 3569 ProgramStateRef state = Ctx.getState(); 3570 RefBindingsTy B = state->get<RefBindings>(); 3571 ExplodedNode *Pred = Ctx.getPredecessor(); 3572 3573 // Don't process anything within synthesized bodies. 3574 const LocationContext *LCtx = Pred->getLocationContext(); 3575 if (LCtx->getAnalysisDeclContext()->isBodyAutosynthesized()) { 3576 assert(LCtx->getParent()); 3577 return; 3578 } 3579 3580 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3581 state = handleAutoreleaseCounts(state, Pred, /*Tag=*/0, Ctx, 3582 I->first, I->second); 3583 if (!state) 3584 return; 3585 } 3586 3587 // If the current LocationContext has a parent, don't check for leaks. 3588 // We will do that later. 3589 // FIXME: we should instead check for imbalances of the retain/releases, 3590 // and suggest annotations. 3591 if (LCtx->getParent()) 3592 return; 3593 3594 B = state->get<RefBindings>(); 3595 SmallVector<SymbolRef, 10> Leaked; 3596 3597 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) 3598 state = handleSymbolDeath(state, I->first, I->second, Leaked); 3599 3600 processLeaks(state, Leaked, Ctx, Pred); 3601} 3602 3603const ProgramPointTag * 3604RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const { 3605 const SimpleProgramPointTag *&tag = DeadSymbolTags[sym]; 3606 if (!tag) { 3607 SmallString<64> buf; 3608 llvm::raw_svector_ostream out(buf); 3609 out << "RetainCountChecker : Dead Symbol : "; 3610 sym->dumpToStream(out); 3611 tag = new SimpleProgramPointTag(out.str()); 3612 } 3613 return tag; 3614} 3615 3616void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper, 3617 CheckerContext &C) const { 3618 ExplodedNode *Pred = C.getPredecessor(); 3619 3620 ProgramStateRef state = C.getState(); 3621 RefBindingsTy B = state->get<RefBindings>(); 3622 SmallVector<SymbolRef, 10> Leaked; 3623 3624 // Update counts from autorelease pools 3625 for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(), 3626 E = SymReaper.dead_end(); I != E; ++I) { 3627 SymbolRef Sym = *I; 3628 if (const RefVal *T = B.lookup(Sym)){ 3629 // Use the symbol as the tag. 3630 // FIXME: This might not be as unique as we would like. 3631 const ProgramPointTag *Tag = getDeadSymbolTag(Sym); 3632 state = handleAutoreleaseCounts(state, Pred, Tag, C, Sym, *T); 3633 if (!state) 3634 return; 3635 3636 // Fetch the new reference count from the state, and use it to handle 3637 // this symbol. 3638 state = handleSymbolDeath(state, *I, *getRefBinding(state, Sym), Leaked); 3639 } 3640 } 3641 3642 if (Leaked.empty()) { 3643 C.addTransition(state); 3644 return; 3645 } 3646 3647 Pred = processLeaks(state, Leaked, C, Pred); 3648 3649 // Did we cache out? 3650 if (!Pred) 3651 return; 3652 3653 // Now generate a new node that nukes the old bindings. 3654 // The only bindings left at this point are the leaked symbols. 3655 RefBindingsTy::Factory &F = state->get_context<RefBindings>(); 3656 B = state->get<RefBindings>(); 3657 3658 for (SmallVectorImpl<SymbolRef>::iterator I = Leaked.begin(), 3659 E = Leaked.end(); 3660 I != E; ++I) 3661 B = F.remove(B, *I); 3662 3663 state = state->set<RefBindings>(B); 3664 C.addTransition(state, Pred); 3665} 3666 3667void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State, 3668 const char *NL, const char *Sep) const { 3669 3670 RefBindingsTy B = State->get<RefBindings>(); 3671 3672 if (B.isEmpty()) 3673 return; 3674 3675 Out << Sep << NL; 3676 3677 for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { 3678 Out << I->first << " : "; 3679 I->second.print(Out); 3680 Out << NL; 3681 } 3682} 3683 3684//===----------------------------------------------------------------------===// 3685// Checker registration. 3686//===----------------------------------------------------------------------===// 3687 3688void ento::registerRetainCountChecker(CheckerManager &Mgr) { 3689 Mgr.registerChecker<RetainCountChecker>(Mgr.getAnalyzerOptions()); 3690} 3691 3692//===----------------------------------------------------------------------===// 3693// Implementation of the CallEffects API. 3694//===----------------------------------------------------------------------===// 3695 3696namespace clang { namespace ento { namespace objc_retain { 3697 3698// This is a bit gross, but it allows us to populate CallEffects without 3699// creating a bunch of accessors. This kind is very localized, so the 3700// damage of this macro is limited. 3701#define createCallEffect(D, KIND)\ 3702 ASTContext &Ctx = D->getASTContext();\ 3703 LangOptions L = Ctx.getLangOpts();\ 3704 RetainSummaryManager M(Ctx, L.GCOnly, L.ObjCAutoRefCount);\ 3705 const RetainSummary *S = M.get ## KIND ## Summary(D);\ 3706 CallEffects CE(S->getRetEffect());\ 3707 CE.Receiver = S->getReceiverEffect();\ 3708 unsigned N = D->param_size();\ 3709 for (unsigned i = 0; i < N; ++i) {\ 3710 CE.Args.push_back(S->getArg(i));\ 3711 } 3712 3713CallEffects CallEffects::getEffect(const ObjCMethodDecl *MD) { 3714 createCallEffect(MD, Method); 3715 return CE; 3716} 3717 3718CallEffects CallEffects::getEffect(const FunctionDecl *FD) { 3719 createCallEffect(FD, Function); 3720 return CE; 3721} 3722 3723#undef createCallEffect 3724 3725}}} 3726