clang  3.9.0
RetainCountChecker.cpp
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1 //==-- RetainCountChecker.cpp - Checks for leaks and other issues -*- C++ -*--//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the methods for RetainCountChecker, which implements
11 // a reference count checker for Core Foundation and Cocoa on (Mac OS X).
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "AllocationDiagnostics.h"
16 #include "ClangSACheckers.h"
17 #include "SelectorExtras.h"
18 #include "clang/AST/Attr.h"
19 #include "clang/AST/DeclCXX.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "clang/AST/ParentMap.h"
34 #include "llvm/ADT/DenseMap.h"
35 #include "llvm/ADT/FoldingSet.h"
36 #include "llvm/ADT/ImmutableList.h"
37 #include "llvm/ADT/ImmutableMap.h"
38 #include "llvm/ADT/STLExtras.h"
39 #include "llvm/ADT/SmallString.h"
40 #include "llvm/ADT/StringExtras.h"
41 #include <cstdarg>
42 #include <utility>
43 
44 using namespace clang;
45 using namespace ento;
46 using namespace objc_retain;
47 using llvm::StrInStrNoCase;
48 
49 //===----------------------------------------------------------------------===//
50 // Adapters for FoldingSet.
51 //===----------------------------------------------------------------------===//
52 
53 namespace llvm {
54 template <> struct FoldingSetTrait<ArgEffect> {
55 static inline void Profile(const ArgEffect X, FoldingSetNodeID &ID) {
56  ID.AddInteger((unsigned) X);
57 }
58 };
59 template <> struct FoldingSetTrait<RetEffect> {
60  static inline void Profile(const RetEffect &X, FoldingSetNodeID &ID) {
61  ID.AddInteger((unsigned) X.getKind());
62  ID.AddInteger((unsigned) X.getObjKind());
63 }
64 };
65 } // end llvm namespace
66 
67 //===----------------------------------------------------------------------===//
68 // Reference-counting logic (typestate + counts).
69 //===----------------------------------------------------------------------===//
70 
71 /// ArgEffects summarizes the effects of a function/method call on all of
72 /// its arguments.
74 
75 namespace {
76 class RefVal {
77 public:
78  enum Kind {
79  Owned = 0, // Owning reference.
80  NotOwned, // Reference is not owned by still valid (not freed).
81  Released, // Object has been released.
82  ReturnedOwned, // Returned object passes ownership to caller.
83  ReturnedNotOwned, // Return object does not pass ownership to caller.
84  ERROR_START,
85  ErrorDeallocNotOwned, // -dealloc called on non-owned object.
86  ErrorDeallocGC, // Calling -dealloc with GC enabled.
87  ErrorUseAfterRelease, // Object used after released.
88  ErrorReleaseNotOwned, // Release of an object that was not owned.
89  ERROR_LEAK_START,
90  ErrorLeak, // A memory leak due to excessive reference counts.
91  ErrorLeakReturned, // A memory leak due to the returning method not having
92  // the correct naming conventions.
93  ErrorGCLeakReturned,
94  ErrorOverAutorelease,
95  ErrorReturnedNotOwned
96  };
97 
98  /// Tracks how an object referenced by an ivar has been used.
99  ///
100  /// This accounts for us not knowing if an arbitrary ivar is supposed to be
101  /// stored at +0 or +1.
102  enum class IvarAccessHistory {
103  None,
104  AccessedDirectly,
105  ReleasedAfterDirectAccess
106  };
107 
108 private:
109  /// The number of outstanding retains.
110  unsigned Cnt;
111  /// The number of outstanding autoreleases.
112  unsigned ACnt;
113  /// The (static) type of the object at the time we started tracking it.
114  QualType T;
115 
116  /// The current state of the object.
117  ///
118  /// See the RefVal::Kind enum for possible values.
119  unsigned RawKind : 5;
120 
121  /// The kind of object being tracked (CF or ObjC), if known.
122  ///
123  /// See the RetEffect::ObjKind enum for possible values.
124  unsigned RawObjectKind : 2;
125 
126  /// True if the current state and/or retain count may turn out to not be the
127  /// best possible approximation of the reference counting state.
128  ///
129  /// If true, the checker may decide to throw away ("override") this state
130  /// in favor of something else when it sees the object being used in new ways.
131  ///
132  /// This setting should not be propagated to state derived from this state.
133  /// Once we start deriving new states, it would be inconsistent to override
134  /// them.
135  unsigned RawIvarAccessHistory : 2;
136 
137  RefVal(Kind k, RetEffect::ObjKind o, unsigned cnt, unsigned acnt, QualType t,
138  IvarAccessHistory IvarAccess)
139  : Cnt(cnt), ACnt(acnt), T(t), RawKind(static_cast<unsigned>(k)),
140  RawObjectKind(static_cast<unsigned>(o)),
141  RawIvarAccessHistory(static_cast<unsigned>(IvarAccess)) {
142  assert(getKind() == k && "not enough bits for the kind");
143  assert(getObjKind() == o && "not enough bits for the object kind");
144  assert(getIvarAccessHistory() == IvarAccess && "not enough bits");
145  }
146 
147 public:
148  Kind getKind() const { return static_cast<Kind>(RawKind); }
149 
150  RetEffect::ObjKind getObjKind() const {
151  return static_cast<RetEffect::ObjKind>(RawObjectKind);
152  }
153 
154  unsigned getCount() const { return Cnt; }
155  unsigned getAutoreleaseCount() const { return ACnt; }
156  unsigned getCombinedCounts() const { return Cnt + ACnt; }
157  void clearCounts() {
158  Cnt = 0;
159  ACnt = 0;
160  }
161  void setCount(unsigned i) {
162  Cnt = i;
163  }
164  void setAutoreleaseCount(unsigned i) {
165  ACnt = i;
166  }
167 
168  QualType getType() const { return T; }
169 
170  /// Returns what the analyzer knows about direct accesses to a particular
171  /// instance variable.
172  ///
173  /// If the object with this refcount wasn't originally from an Objective-C
174  /// ivar region, this should always return IvarAccessHistory::None.
175  IvarAccessHistory getIvarAccessHistory() const {
176  return static_cast<IvarAccessHistory>(RawIvarAccessHistory);
177  }
178 
179  bool isOwned() const {
180  return getKind() == Owned;
181  }
182 
183  bool isNotOwned() const {
184  return getKind() == NotOwned;
185  }
186 
187  bool isReturnedOwned() const {
188  return getKind() == ReturnedOwned;
189  }
190 
191  bool isReturnedNotOwned() const {
192  return getKind() == ReturnedNotOwned;
193  }
194 
195  /// Create a state for an object whose lifetime is the responsibility of the
196  /// current function, at least partially.
197  ///
198  /// Most commonly, this is an owned object with a retain count of +1.
199  static RefVal makeOwned(RetEffect::ObjKind o, QualType t,
200  unsigned Count = 1) {
201  return RefVal(Owned, o, Count, 0, t, IvarAccessHistory::None);
202  }
203 
204  /// Create a state for an object whose lifetime is not the responsibility of
205  /// the current function.
206  ///
207  /// Most commonly, this is an unowned object with a retain count of +0.
208  static RefVal makeNotOwned(RetEffect::ObjKind o, QualType t,
209  unsigned Count = 0) {
210  return RefVal(NotOwned, o, Count, 0, t, IvarAccessHistory::None);
211  }
212 
213  RefVal operator-(size_t i) const {
214  return RefVal(getKind(), getObjKind(), getCount() - i,
215  getAutoreleaseCount(), getType(), getIvarAccessHistory());
216  }
217 
218  RefVal operator+(size_t i) const {
219  return RefVal(getKind(), getObjKind(), getCount() + i,
220  getAutoreleaseCount(), getType(), getIvarAccessHistory());
221  }
222 
223  RefVal operator^(Kind k) const {
224  return RefVal(k, getObjKind(), getCount(), getAutoreleaseCount(),
225  getType(), getIvarAccessHistory());
226  }
227 
228  RefVal autorelease() const {
229  return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount()+1,
230  getType(), getIvarAccessHistory());
231  }
232 
233  RefVal withIvarAccess() const {
234  assert(getIvarAccessHistory() == IvarAccessHistory::None);
235  return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount(),
236  getType(), IvarAccessHistory::AccessedDirectly);
237  }
238 
239  RefVal releaseViaIvar() const {
240  assert(getIvarAccessHistory() == IvarAccessHistory::AccessedDirectly);
241  return RefVal(getKind(), getObjKind(), getCount(), getAutoreleaseCount(),
242  getType(), IvarAccessHistory::ReleasedAfterDirectAccess);
243  }
244 
245  // Comparison, profiling, and pretty-printing.
246 
247  bool hasSameState(const RefVal &X) const {
248  return getKind() == X.getKind() && Cnt == X.Cnt && ACnt == X.ACnt &&
249  getIvarAccessHistory() == X.getIvarAccessHistory();
250  }
251 
252  bool operator==(const RefVal& X) const {
253  return T == X.T && hasSameState(X) && getObjKind() == X.getObjKind();
254  }
255 
256  void Profile(llvm::FoldingSetNodeID& ID) const {
257  ID.Add(T);
258  ID.AddInteger(RawKind);
259  ID.AddInteger(Cnt);
260  ID.AddInteger(ACnt);
261  ID.AddInteger(RawObjectKind);
262  ID.AddInteger(RawIvarAccessHistory);
263  }
264 
265  void print(raw_ostream &Out) const;
266 };
267 
268 void RefVal::print(raw_ostream &Out) const {
269  if (!T.isNull())
270  Out << "Tracked " << T.getAsString() << '/';
271 
272  switch (getKind()) {
273  default: llvm_unreachable("Invalid RefVal kind");
274  case Owned: {
275  Out << "Owned";
276  unsigned cnt = getCount();
277  if (cnt) Out << " (+ " << cnt << ")";
278  break;
279  }
280 
281  case NotOwned: {
282  Out << "NotOwned";
283  unsigned cnt = getCount();
284  if (cnt) Out << " (+ " << cnt << ")";
285  break;
286  }
287 
288  case ReturnedOwned: {
289  Out << "ReturnedOwned";
290  unsigned cnt = getCount();
291  if (cnt) Out << " (+ " << cnt << ")";
292  break;
293  }
294 
295  case ReturnedNotOwned: {
296  Out << "ReturnedNotOwned";
297  unsigned cnt = getCount();
298  if (cnt) Out << " (+ " << cnt << ")";
299  break;
300  }
301 
302  case Released:
303  Out << "Released";
304  break;
305 
306  case ErrorDeallocGC:
307  Out << "-dealloc (GC)";
308  break;
309 
310  case ErrorDeallocNotOwned:
311  Out << "-dealloc (not-owned)";
312  break;
313 
314  case ErrorLeak:
315  Out << "Leaked";
316  break;
317 
318  case ErrorLeakReturned:
319  Out << "Leaked (Bad naming)";
320  break;
321 
322  case ErrorGCLeakReturned:
323  Out << "Leaked (GC-ed at return)";
324  break;
325 
326  case ErrorUseAfterRelease:
327  Out << "Use-After-Release [ERROR]";
328  break;
329 
330  case ErrorReleaseNotOwned:
331  Out << "Release of Not-Owned [ERROR]";
332  break;
333 
334  case RefVal::ErrorOverAutorelease:
335  Out << "Over-autoreleased";
336  break;
337 
338  case RefVal::ErrorReturnedNotOwned:
339  Out << "Non-owned object returned instead of owned";
340  break;
341  }
342 
343  switch (getIvarAccessHistory()) {
345  break;
346  case IvarAccessHistory::AccessedDirectly:
347  Out << " [direct ivar access]";
348  break;
349  case IvarAccessHistory::ReleasedAfterDirectAccess:
350  Out << " [released after direct ivar access]";
351  }
352 
353  if (ACnt) {
354  Out << " [autorelease -" << ACnt << ']';
355  }
356 }
357 } //end anonymous namespace
358 
359 //===----------------------------------------------------------------------===//
360 // RefBindings - State used to track object reference counts.
361 //===----------------------------------------------------------------------===//
362 
363 REGISTER_MAP_WITH_PROGRAMSTATE(RefBindings, SymbolRef, RefVal)
364 
365 static inline const RefVal *getRefBinding(ProgramStateRef State,
366  SymbolRef Sym) {
367  return State->get<RefBindings>(Sym);
368 }
369 
371  SymbolRef Sym, RefVal Val) {
372  return State->set<RefBindings>(Sym, Val);
373 }
374 
376  return State->remove<RefBindings>(Sym);
377 }
378 
379 //===----------------------------------------------------------------------===//
380 // Function/Method behavior summaries.
381 //===----------------------------------------------------------------------===//
382 
383 namespace {
384 class RetainSummary {
385  /// Args - a map of (index, ArgEffect) pairs, where index
386  /// specifies the argument (starting from 0). This can be sparsely
387  /// populated; arguments with no entry in Args use 'DefaultArgEffect'.
388  ArgEffects Args;
389 
390  /// DefaultArgEffect - The default ArgEffect to apply to arguments that
391  /// do not have an entry in Args.
392  ArgEffect DefaultArgEffect;
393 
394  /// Receiver - If this summary applies to an Objective-C message expression,
395  /// this is the effect applied to the state of the receiver.
396  ArgEffect Receiver;
397 
398  /// Ret - The effect on the return value. Used to indicate if the
399  /// function/method call returns a new tracked symbol.
400  RetEffect Ret;
401 
402 public:
403  RetainSummary(ArgEffects A, RetEffect R, ArgEffect defaultEff,
404  ArgEffect ReceiverEff)
405  : Args(A), DefaultArgEffect(defaultEff), Receiver(ReceiverEff), Ret(R) {}
406 
407  /// getArg - Return the argument effect on the argument specified by
408  /// idx (starting from 0).
409  ArgEffect getArg(unsigned idx) const {
410  if (const ArgEffect *AE = Args.lookup(idx))
411  return *AE;
412 
413  return DefaultArgEffect;
414  }
415 
416  void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) {
417  Args = af.add(Args, idx, e);
418  }
419 
420  /// setDefaultArgEffect - Set the default argument effect.
421  void setDefaultArgEffect(ArgEffect E) {
422  DefaultArgEffect = E;
423  }
424 
425  /// getRetEffect - Returns the effect on the return value of the call.
426  RetEffect getRetEffect() const { return Ret; }
427 
428  /// setRetEffect - Set the effect of the return value of the call.
429  void setRetEffect(RetEffect E) { Ret = E; }
430 
431 
432  /// Sets the effect on the receiver of the message.
433  void setReceiverEffect(ArgEffect e) { Receiver = e; }
434 
435  /// getReceiverEffect - Returns the effect on the receiver of the call.
436  /// This is only meaningful if the summary applies to an ObjCMessageExpr*.
437  ArgEffect getReceiverEffect() const { return Receiver; }
438 
439  /// Test if two retain summaries are identical. Note that merely equivalent
440  /// summaries are not necessarily identical (for example, if an explicit
441  /// argument effect matches the default effect).
442  bool operator==(const RetainSummary &Other) const {
443  return Args == Other.Args && DefaultArgEffect == Other.DefaultArgEffect &&
444  Receiver == Other.Receiver && Ret == Other.Ret;
445  }
446 
447  /// Profile this summary for inclusion in a FoldingSet.
448  void Profile(llvm::FoldingSetNodeID& ID) const {
449  ID.Add(Args);
450  ID.Add(DefaultArgEffect);
451  ID.Add(Receiver);
452  ID.Add(Ret);
453  }
454 
455  /// A retain summary is simple if it has no ArgEffects other than the default.
456  bool isSimple() const {
457  return Args.isEmpty();
458  }
459 
460 private:
461  ArgEffects getArgEffects() const { return Args; }
462  ArgEffect getDefaultArgEffect() const { return DefaultArgEffect; }
463 
464  friend class RetainSummaryManager;
465 };
466 } // end anonymous namespace
467 
468 //===----------------------------------------------------------------------===//
469 // Data structures for constructing summaries.
470 //===----------------------------------------------------------------------===//
471 
472 namespace {
473 class ObjCSummaryKey {
474  IdentifierInfo* II;
475  Selector S;
476 public:
477  ObjCSummaryKey(IdentifierInfo* ii, Selector s)
478  : II(ii), S(s) {}
479 
480  ObjCSummaryKey(const ObjCInterfaceDecl *d, Selector s)
481  : II(d ? d->getIdentifier() : nullptr), S(s) {}
482 
483  ObjCSummaryKey(Selector s)
484  : II(nullptr), S(s) {}
485 
486  IdentifierInfo *getIdentifier() const { return II; }
487  Selector getSelector() const { return S; }
488 };
489 } // end anonymous namespace
490 
491 namespace llvm {
492 template <> struct DenseMapInfo<ObjCSummaryKey> {
493  static inline ObjCSummaryKey getEmptyKey() {
494  return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getEmptyKey(),
496  }
497 
498  static inline ObjCSummaryKey getTombstoneKey() {
499  return ObjCSummaryKey(DenseMapInfo<IdentifierInfo*>::getTombstoneKey(),
501  }
502 
503  static unsigned getHashValue(const ObjCSummaryKey &V) {
504  typedef std::pair<IdentifierInfo*, Selector> PairTy;
505  return DenseMapInfo<PairTy>::getHashValue(PairTy(V.getIdentifier(),
506  V.getSelector()));
507  }
508 
509  static bool isEqual(const ObjCSummaryKey& LHS, const ObjCSummaryKey& RHS) {
510  return LHS.getIdentifier() == RHS.getIdentifier() &&
511  LHS.getSelector() == RHS.getSelector();
512  }
513 
514 };
515 } // end llvm namespace
516 
517 namespace {
518 class ObjCSummaryCache {
519  typedef llvm::DenseMap<ObjCSummaryKey, const RetainSummary *> MapTy;
520  MapTy M;
521 public:
522  ObjCSummaryCache() {}
523 
524  const RetainSummary * find(const ObjCInterfaceDecl *D, Selector S) {
525  // Do a lookup with the (D,S) pair. If we find a match return
526  // the iterator.
527  ObjCSummaryKey K(D, S);
528  MapTy::iterator I = M.find(K);
529 
530  if (I != M.end())
531  return I->second;
532  if (!D)
533  return nullptr;
534 
535  // Walk the super chain. If we find a hit with a parent, we'll end
536  // up returning that summary. We actually allow that key (null,S), as
537  // we cache summaries for the null ObjCInterfaceDecl* to allow us to
538  // generate initial summaries without having to worry about NSObject
539  // being declared.
540  // FIXME: We may change this at some point.
541  for (ObjCInterfaceDecl *C=D->getSuperClass() ;; C=C->getSuperClass()) {
542  if ((I = M.find(ObjCSummaryKey(C, S))) != M.end())
543  break;
544 
545  if (!C)
546  return nullptr;
547  }
548 
549  // Cache the summary with original key to make the next lookup faster
550  // and return the iterator.
551  const RetainSummary *Summ = I->second;
552  M[K] = Summ;
553  return Summ;
554  }
555 
556  const RetainSummary *find(IdentifierInfo* II, Selector S) {
557  // FIXME: Class method lookup. Right now we dont' have a good way
558  // of going between IdentifierInfo* and the class hierarchy.
559  MapTy::iterator I = M.find(ObjCSummaryKey(II, S));
560 
561  if (I == M.end())
562  I = M.find(ObjCSummaryKey(S));
563 
564  return I == M.end() ? nullptr : I->second;
565  }
566 
567  const RetainSummary *& operator[](ObjCSummaryKey K) {
568  return M[K];
569  }
570 
571  const RetainSummary *& operator[](Selector S) {
572  return M[ ObjCSummaryKey(S) ];
573  }
574 };
575 } // end anonymous namespace
576 
577 //===----------------------------------------------------------------------===//
578 // Data structures for managing collections of summaries.
579 //===----------------------------------------------------------------------===//
580 
581 namespace {
582 class RetainSummaryManager {
583 
584  //==-----------------------------------------------------------------==//
585  // Typedefs.
586  //==-----------------------------------------------------------------==//
587 
588  typedef llvm::DenseMap<const FunctionDecl*, const RetainSummary *>
589  FuncSummariesTy;
590 
591  typedef ObjCSummaryCache ObjCMethodSummariesTy;
592 
593  typedef llvm::FoldingSetNodeWrapper<RetainSummary> CachedSummaryNode;
594 
595  //==-----------------------------------------------------------------==//
596  // Data.
597  //==-----------------------------------------------------------------==//
598 
599  /// Ctx - The ASTContext object for the analyzed ASTs.
600  ASTContext &Ctx;
601 
602  /// GCEnabled - Records whether or not the analyzed code runs in GC mode.
603  const bool GCEnabled;
604 
605  /// Records whether or not the analyzed code runs in ARC mode.
606  const bool ARCEnabled;
607 
608  /// FuncSummaries - A map from FunctionDecls to summaries.
609  FuncSummariesTy FuncSummaries;
610 
611  /// ObjCClassMethodSummaries - A map from selectors (for instance methods)
612  /// to summaries.
613  ObjCMethodSummariesTy ObjCClassMethodSummaries;
614 
615  /// ObjCMethodSummaries - A map from selectors to summaries.
616  ObjCMethodSummariesTy ObjCMethodSummaries;
617 
618  /// BPAlloc - A BumpPtrAllocator used for allocating summaries, ArgEffects,
619  /// and all other data used by the checker.
620  llvm::BumpPtrAllocator BPAlloc;
621 
622  /// AF - A factory for ArgEffects objects.
623  ArgEffects::Factory AF;
624 
625  /// ScratchArgs - A holding buffer for construct ArgEffects.
626  ArgEffects ScratchArgs;
627 
628  /// ObjCAllocRetE - Default return effect for methods returning Objective-C
629  /// objects.
630  RetEffect ObjCAllocRetE;
631 
632  /// ObjCInitRetE - Default return effect for init methods returning
633  /// Objective-C objects.
634  RetEffect ObjCInitRetE;
635 
636  /// SimpleSummaries - Used for uniquing summaries that don't have special
637  /// effects.
638  llvm::FoldingSet<CachedSummaryNode> SimpleSummaries;
639 
640  //==-----------------------------------------------------------------==//
641  // Methods.
642  //==-----------------------------------------------------------------==//
643 
644  /// getArgEffects - Returns a persistent ArgEffects object based on the
645  /// data in ScratchArgs.
646  ArgEffects getArgEffects();
647 
648  enum UnaryFuncKind { cfretain, cfrelease, cfautorelease, cfmakecollectable };
649 
650  const RetainSummary *getUnarySummary(const FunctionType* FT,
651  UnaryFuncKind func);
652 
653  const RetainSummary *getCFSummaryCreateRule(const FunctionDecl *FD);
654  const RetainSummary *getCFSummaryGetRule(const FunctionDecl *FD);
655  const RetainSummary *getCFCreateGetRuleSummary(const FunctionDecl *FD);
656 
657  const RetainSummary *getPersistentSummary(const RetainSummary &OldSumm);
658 
659  const RetainSummary *getPersistentSummary(RetEffect RetEff,
660  ArgEffect ReceiverEff = DoNothing,
661  ArgEffect DefaultEff = MayEscape) {
662  RetainSummary Summ(getArgEffects(), RetEff, DefaultEff, ReceiverEff);
663  return getPersistentSummary(Summ);
664  }
665 
666  const RetainSummary *getDoNothingSummary() {
667  return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
668  }
669 
670  const RetainSummary *getDefaultSummary() {
671  return getPersistentSummary(RetEffect::MakeNoRet(),
673  }
674 
675  const RetainSummary *getPersistentStopSummary() {
676  return getPersistentSummary(RetEffect::MakeNoRet(),
678  }
679 
680  void InitializeClassMethodSummaries();
681  void InitializeMethodSummaries();
682 private:
683  void addNSObjectClsMethSummary(Selector S, const RetainSummary *Summ) {
684  ObjCClassMethodSummaries[S] = Summ;
685  }
686 
687  void addNSObjectMethSummary(Selector S, const RetainSummary *Summ) {
688  ObjCMethodSummaries[S] = Summ;
689  }
690 
691  void addClassMethSummary(const char* Cls, const char* name,
692  const RetainSummary *Summ, bool isNullary = true) {
693  IdentifierInfo* ClsII = &Ctx.Idents.get(Cls);
694  Selector S = isNullary ? GetNullarySelector(name, Ctx)
695  : GetUnarySelector(name, Ctx);
696  ObjCClassMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
697  }
698 
699  void addInstMethSummary(const char* Cls, const char* nullaryName,
700  const RetainSummary *Summ) {
701  IdentifierInfo* ClsII = &Ctx.Idents.get(Cls);
702  Selector S = GetNullarySelector(nullaryName, Ctx);
703  ObjCMethodSummaries[ObjCSummaryKey(ClsII, S)] = Summ;
704  }
705 
706  void addMethodSummary(IdentifierInfo *ClsII, ObjCMethodSummariesTy &Summaries,
707  const RetainSummary *Summ, va_list argp) {
708  Selector S = getKeywordSelector(Ctx, argp);
709  Summaries[ObjCSummaryKey(ClsII, S)] = Summ;
710  }
711 
712  void addInstMethSummary(const char* Cls, const RetainSummary * Summ, ...) {
713  va_list argp;
714  va_start(argp, Summ);
715  addMethodSummary(&Ctx.Idents.get(Cls), ObjCMethodSummaries, Summ, argp);
716  va_end(argp);
717  }
718 
719  void addClsMethSummary(const char* Cls, const RetainSummary * Summ, ...) {
720  va_list argp;
721  va_start(argp, Summ);
722  addMethodSummary(&Ctx.Idents.get(Cls),ObjCClassMethodSummaries, Summ, argp);
723  va_end(argp);
724  }
725 
726  void addClsMethSummary(IdentifierInfo *II, const RetainSummary * Summ, ...) {
727  va_list argp;
728  va_start(argp, Summ);
729  addMethodSummary(II, ObjCClassMethodSummaries, Summ, argp);
730  va_end(argp);
731  }
732 
733 public:
734 
735  RetainSummaryManager(ASTContext &ctx, bool gcenabled, bool usesARC)
736  : Ctx(ctx),
737  GCEnabled(gcenabled),
738  ARCEnabled(usesARC),
739  AF(BPAlloc), ScratchArgs(AF.getEmptyMap()),
740  ObjCAllocRetE(gcenabled
741  ? RetEffect::MakeGCNotOwned()
742  : (usesARC ? RetEffect::MakeNotOwned(RetEffect::ObjC)
743  : RetEffect::MakeOwned(RetEffect::ObjC, true))),
744  ObjCInitRetE(gcenabled
745  ? RetEffect::MakeGCNotOwned()
746  : (usesARC ? RetEffect::MakeNotOwned(RetEffect::ObjC)
747  : RetEffect::MakeOwnedWhenTrackedReceiver())) {
748  InitializeClassMethodSummaries();
749  InitializeMethodSummaries();
750  }
751 
752  const RetainSummary *getSummary(const CallEvent &Call,
753  ProgramStateRef State = nullptr);
754 
755  const RetainSummary *getFunctionSummary(const FunctionDecl *FD);
756 
757  const RetainSummary *getMethodSummary(Selector S, const ObjCInterfaceDecl *ID,
758  const ObjCMethodDecl *MD,
759  QualType RetTy,
760  ObjCMethodSummariesTy &CachedSummaries);
761 
762  const RetainSummary *getInstanceMethodSummary(const ObjCMethodCall &M,
764 
765  const RetainSummary *getClassMethodSummary(const ObjCMethodCall &M) {
766  assert(!M.isInstanceMessage());
768 
769  return getMethodSummary(M.getSelector(), Class, M.getDecl(),
770  M.getResultType(), ObjCClassMethodSummaries);
771  }
772 
773  /// getMethodSummary - This version of getMethodSummary is used to query
774  /// the summary for the current method being analyzed.
775  const RetainSummary *getMethodSummary(const ObjCMethodDecl *MD) {
776  const ObjCInterfaceDecl *ID = MD->getClassInterface();
777  Selector S = MD->getSelector();
778  QualType ResultTy = MD->getReturnType();
779 
780  ObjCMethodSummariesTy *CachedSummaries;
781  if (MD->isInstanceMethod())
782  CachedSummaries = &ObjCMethodSummaries;
783  else
784  CachedSummaries = &ObjCClassMethodSummaries;
785 
786  return getMethodSummary(S, ID, MD, ResultTy, *CachedSummaries);
787  }
788 
789  const RetainSummary *getStandardMethodSummary(const ObjCMethodDecl *MD,
790  Selector S, QualType RetTy);
791 
792  /// Determine if there is a special return effect for this function or method.
793  Optional<RetEffect> getRetEffectFromAnnotations(QualType RetTy,
794  const Decl *D);
795 
796  void updateSummaryFromAnnotations(const RetainSummary *&Summ,
797  const ObjCMethodDecl *MD);
798 
799  void updateSummaryFromAnnotations(const RetainSummary *&Summ,
800  const FunctionDecl *FD);
801 
802  void updateSummaryForCall(const RetainSummary *&Summ,
803  const CallEvent &Call);
804 
805  bool isGCEnabled() const { return GCEnabled; }
806 
807  bool isARCEnabled() const { return ARCEnabled; }
808 
809  bool isARCorGCEnabled() const { return GCEnabled || ARCEnabled; }
810 
811  RetEffect getObjAllocRetEffect() const { return ObjCAllocRetE; }
812 
813  friend class RetainSummaryTemplate;
814 };
815 
816 // Used to avoid allocating long-term (BPAlloc'd) memory for default retain
817 // summaries. If a function or method looks like it has a default summary, but
818 // it has annotations, the annotations are added to the stack-based template
819 // and then copied into managed memory.
820 class RetainSummaryTemplate {
821  RetainSummaryManager &Manager;
822  const RetainSummary *&RealSummary;
823  RetainSummary ScratchSummary;
824  bool Accessed;
825 public:
826  RetainSummaryTemplate(const RetainSummary *&real, RetainSummaryManager &mgr)
827  : Manager(mgr), RealSummary(real), ScratchSummary(*real), Accessed(false) {}
828 
829  ~RetainSummaryTemplate() {
830  if (Accessed)
831  RealSummary = Manager.getPersistentSummary(ScratchSummary);
832  }
833 
834  RetainSummary &operator*() {
835  Accessed = true;
836  return ScratchSummary;
837  }
838 
839  RetainSummary *operator->() {
840  Accessed = true;
841  return &ScratchSummary;
842  }
843 };
844 
845 } // end anonymous namespace
846 
847 //===----------------------------------------------------------------------===//
848 // Implementation of checker data structures.
849 //===----------------------------------------------------------------------===//
850 
851 ArgEffects RetainSummaryManager::getArgEffects() {
852  ArgEffects AE = ScratchArgs;
853  ScratchArgs = AF.getEmptyMap();
854  return AE;
855 }
856 
857 const RetainSummary *
858 RetainSummaryManager::getPersistentSummary(const RetainSummary &OldSumm) {
859  // Unique "simple" summaries -- those without ArgEffects.
860  if (OldSumm.isSimple()) {
861  llvm::FoldingSetNodeID ID;
862  OldSumm.Profile(ID);
863 
864  void *Pos;
865  CachedSummaryNode *N = SimpleSummaries.FindNodeOrInsertPos(ID, Pos);
866 
867  if (!N) {
868  N = (CachedSummaryNode *) BPAlloc.Allocate<CachedSummaryNode>();
869  new (N) CachedSummaryNode(OldSumm);
870  SimpleSummaries.InsertNode(N, Pos);
871  }
872 
873  return &N->getValue();
874  }
875 
876  RetainSummary *Summ = (RetainSummary *) BPAlloc.Allocate<RetainSummary>();
877  new (Summ) RetainSummary(OldSumm);
878  return Summ;
879 }
880 
881 //===----------------------------------------------------------------------===//
882 // Summary creation for functions (largely uses of Core Foundation).
883 //===----------------------------------------------------------------------===//
884 
885 static bool isRetain(const FunctionDecl *FD, StringRef FName) {
886  return FName.endswith("Retain");
887 }
888 
889 static bool isRelease(const FunctionDecl *FD, StringRef FName) {
890  return FName.endswith("Release");
891 }
892 
893 static bool isAutorelease(const FunctionDecl *FD, StringRef FName) {
894  return FName.endswith("Autorelease");
895 }
896 
897 static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) {
898  // FIXME: Remove FunctionDecl parameter.
899  // FIXME: Is it really okay if MakeCollectable isn't a suffix?
900  return FName.find("MakeCollectable") != StringRef::npos;
901 }
902 
904  switch (E) {
905  case DoNothing:
906  case Autorelease:
908  case IncRef:
909  case IncRefMsg:
910  case MakeCollectable:
913  case MayEscape:
914  case StopTracking:
915  case StopTrackingHard:
916  return StopTrackingHard;
917  case DecRef:
920  case DecRefMsg:
923  case Dealloc:
924  return Dealloc;
925  }
926 
927  llvm_unreachable("Unknown ArgEffect kind");
928 }
929 
930 void RetainSummaryManager::updateSummaryForCall(const RetainSummary *&S,
931  const CallEvent &Call) {
932  if (Call.hasNonZeroCallbackArg()) {
933  ArgEffect RecEffect =
934  getStopTrackingHardEquivalent(S->getReceiverEffect());
935  ArgEffect DefEffect =
936  getStopTrackingHardEquivalent(S->getDefaultArgEffect());
937 
938  ArgEffects CustomArgEffects = S->getArgEffects();
939  for (ArgEffects::iterator I = CustomArgEffects.begin(),
940  E = CustomArgEffects.end();
941  I != E; ++I) {
942  ArgEffect Translated = getStopTrackingHardEquivalent(I->second);
943  if (Translated != DefEffect)
944  ScratchArgs = AF.add(ScratchArgs, I->first, Translated);
945  }
946 
948 
949  // Special cases where the callback argument CANNOT free the return value.
950  // This can generally only happen if we know that the callback will only be
951  // called when the return value is already being deallocated.
952  if (const SimpleFunctionCall *FC = dyn_cast<SimpleFunctionCall>(&Call)) {
953  if (IdentifierInfo *Name = FC->getDecl()->getIdentifier()) {
954  // When the CGBitmapContext is deallocated, the callback here will free
955  // the associated data buffer.
956  if (Name->isStr("CGBitmapContextCreateWithData"))
957  RE = S->getRetEffect();
958  }
959  }
960 
961  S = getPersistentSummary(RE, RecEffect, DefEffect);
962  }
963 
964  // Special case '[super init];' and '[self init];'
965  //
966  // Even though calling '[super init]' without assigning the result to self
967  // and checking if the parent returns 'nil' is a bad pattern, it is common.
968  // Additionally, our Self Init checker already warns about it. To avoid
969  // overwhelming the user with messages from both checkers, we model the case
970  // of '[super init]' in cases when it is not consumed by another expression
971  // as if the call preserves the value of 'self'; essentially, assuming it can
972  // never fail and return 'nil'.
973  // Note, we don't want to just stop tracking the value since we want the
974  // RetainCount checker to report leaks and use-after-free if SelfInit checker
975  // is turned off.
976  if (const ObjCMethodCall *MC = dyn_cast<ObjCMethodCall>(&Call)) {
977  if (MC->getMethodFamily() == OMF_init && MC->isReceiverSelfOrSuper()) {
978 
979  // Check if the message is not consumed, we know it will not be used in
980  // an assignment, ex: "self = [super init]".
981  const Expr *ME = MC->getOriginExpr();
982  const LocationContext *LCtx = MC->getLocationContext();
984  if (!PM.isConsumedExpr(ME)) {
985  RetainSummaryTemplate ModifiableSummaryTemplate(S, *this);
986  ModifiableSummaryTemplate->setReceiverEffect(DoNothing);
987  ModifiableSummaryTemplate->setRetEffect(RetEffect::MakeNoRet());
988  }
989  }
990  }
991 }
992 
993 const RetainSummary *
994 RetainSummaryManager::getSummary(const CallEvent &Call,
996  const RetainSummary *Summ;
997  switch (Call.getKind()) {
998  case CE_Function:
999  Summ = getFunctionSummary(cast<SimpleFunctionCall>(Call).getDecl());
1000  break;
1001  case CE_CXXMember:
1002  case CE_CXXMemberOperator:
1003  case CE_Block:
1004  case CE_CXXConstructor:
1005  case CE_CXXDestructor:
1006  case CE_CXXAllocator:
1007  // FIXME: These calls are currently unsupported.
1008  return getPersistentStopSummary();
1009  case CE_ObjCMessage: {
1010  const ObjCMethodCall &Msg = cast<ObjCMethodCall>(Call);
1011  if (Msg.isInstanceMessage())
1012  Summ = getInstanceMethodSummary(Msg, State);
1013  else
1014  Summ = getClassMethodSummary(Msg);
1015  break;
1016  }
1017  }
1018 
1019  updateSummaryForCall(Summ, Call);
1020 
1021  assert(Summ && "Unknown call type?");
1022  return Summ;
1023 }
1024 
1025 const RetainSummary *
1026 RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) {
1027  // If we don't know what function we're calling, use our default summary.
1028  if (!FD)
1029  return getDefaultSummary();
1030 
1031  // Look up a summary in our cache of FunctionDecls -> Summaries.
1032  FuncSummariesTy::iterator I = FuncSummaries.find(FD);
1033  if (I != FuncSummaries.end())
1034  return I->second;
1035 
1036  // No summary? Generate one.
1037  const RetainSummary *S = nullptr;
1038  bool AllowAnnotations = true;
1039 
1040  do {
1041  // We generate "stop" summaries for implicitly defined functions.
1042  if (FD->isImplicit()) {
1043  S = getPersistentStopSummary();
1044  break;
1045  }
1046 
1047  // [PR 3337] Use 'getAs<FunctionType>' to strip away any typedefs on the
1048  // function's type.
1049  const FunctionType* FT = FD->getType()->getAs<FunctionType>();
1050  const IdentifierInfo *II = FD->getIdentifier();
1051  if (!II)
1052  break;
1053 
1054  StringRef FName = II->getName();
1055 
1056  // Strip away preceding '_'. Doing this here will effect all the checks
1057  // down below.
1058  FName = FName.substr(FName.find_first_not_of('_'));
1059 
1060  // Inspect the result type.
1061  QualType RetTy = FT->getReturnType();
1062 
1063  // FIXME: This should all be refactored into a chain of "summary lookup"
1064  // filters.
1065  assert(ScratchArgs.isEmpty());
1066 
1067  if (FName == "pthread_create" || FName == "pthread_setspecific") {
1068  // Part of: <rdar://problem/7299394> and <rdar://problem/11282706>.
1069  // This will be addressed better with IPA.
1070  S = getPersistentStopSummary();
1071  } else if (FName == "NSMakeCollectable") {
1072  // Handle: id NSMakeCollectable(CFTypeRef)
1073  S = (RetTy->isObjCIdType())
1074  ? getUnarySummary(FT, cfmakecollectable)
1075  : getPersistentStopSummary();
1076  // The headers on OS X 10.8 use cf_consumed/ns_returns_retained,
1077  // but we can fully model NSMakeCollectable ourselves.
1078  AllowAnnotations = false;
1079  } else if (FName == "CFPlugInInstanceCreate") {
1080  S = getPersistentSummary(RetEffect::MakeNoRet());
1081  } else if (FName == "IOBSDNameMatching" ||
1082  FName == "IOServiceMatching" ||
1083  FName == "IOServiceNameMatching" ||
1084  FName == "IORegistryEntrySearchCFProperty" ||
1085  FName == "IORegistryEntryIDMatching" ||
1086  FName == "IOOpenFirmwarePathMatching") {
1087  // Part of <rdar://problem/6961230>. (IOKit)
1088  // This should be addressed using a API table.
1089  S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true),
1090  DoNothing, DoNothing);
1091  } else if (FName == "IOServiceGetMatchingService" ||
1092  FName == "IOServiceGetMatchingServices") {
1093  // FIXES: <rdar://problem/6326900>
1094  // This should be addressed using a API table. This strcmp is also
1095  // a little gross, but there is no need to super optimize here.
1096  ScratchArgs = AF.add(ScratchArgs, 1, DecRef);
1097  S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
1098  } else if (FName == "IOServiceAddNotification" ||
1099  FName == "IOServiceAddMatchingNotification") {
1100  // Part of <rdar://problem/6961230>. (IOKit)
1101  // This should be addressed using a API table.
1102  ScratchArgs = AF.add(ScratchArgs, 2, DecRef);
1103  S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
1104  } else if (FName == "CVPixelBufferCreateWithBytes") {
1105  // FIXES: <rdar://problem/7283567>
1106  // Eventually this can be improved by recognizing that the pixel
1107  // buffer passed to CVPixelBufferCreateWithBytes is released via
1108  // a callback and doing full IPA to make sure this is done correctly.
1109  // FIXME: This function has an out parameter that returns an
1110  // allocated object.
1111  ScratchArgs = AF.add(ScratchArgs, 7, StopTracking);
1112  S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
1113  } else if (FName == "CGBitmapContextCreateWithData") {
1114  // FIXES: <rdar://problem/7358899>
1115  // Eventually this can be improved by recognizing that 'releaseInfo'
1116  // passed to CGBitmapContextCreateWithData is released via
1117  // a callback and doing full IPA to make sure this is done correctly.
1118  ScratchArgs = AF.add(ScratchArgs, 8, StopTracking);
1119  S = getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true),
1120  DoNothing, DoNothing);
1121  } else if (FName == "CVPixelBufferCreateWithPlanarBytes") {
1122  // FIXES: <rdar://problem/7283567>
1123  // Eventually this can be improved by recognizing that the pixel
1124  // buffer passed to CVPixelBufferCreateWithPlanarBytes is released
1125  // via a callback and doing full IPA to make sure this is done
1126  // correctly.
1127  ScratchArgs = AF.add(ScratchArgs, 12, StopTracking);
1128  S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
1129  } else if (FName == "dispatch_set_context" ||
1130  FName == "xpc_connection_set_context") {
1131  // <rdar://problem/11059275> - The analyzer currently doesn't have
1132  // a good way to reason about the finalizer function for libdispatch.
1133  // If we pass a context object that is memory managed, stop tracking it.
1134  // <rdar://problem/13783514> - Same problem, but for XPC.
1135  // FIXME: this hack should possibly go away once we can handle
1136  // libdispatch and XPC finalizers.
1137  ScratchArgs = AF.add(ScratchArgs, 1, StopTracking);
1138  S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
1139  } else if (FName.startswith("NSLog")) {
1140  S = getDoNothingSummary();
1141  } else if (FName.startswith("NS") &&
1142  (FName.find("Insert") != StringRef::npos)) {
1143  // Whitelist NSXXInsertXX, for example NSMapInsertIfAbsent, since they can
1144  // be deallocated by NSMapRemove. (radar://11152419)
1145  ScratchArgs = AF.add(ScratchArgs, 1, StopTracking);
1146  ScratchArgs = AF.add(ScratchArgs, 2, StopTracking);
1147  S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
1148  }
1149 
1150  // Did we get a summary?
1151  if (S)
1152  break;
1153 
1154  if (RetTy->isPointerType()) {
1155  // For CoreFoundation ('CF') types.
1156  if (cocoa::isRefType(RetTy, "CF", FName)) {
1157  if (isRetain(FD, FName)) {
1158  S = getUnarySummary(FT, cfretain);
1159  } else if (isAutorelease(FD, FName)) {
1160  S = getUnarySummary(FT, cfautorelease);
1161  // The headers use cf_consumed, but we can fully model CFAutorelease
1162  // ourselves.
1163  AllowAnnotations = false;
1164  } else if (isMakeCollectable(FD, FName)) {
1165  S = getUnarySummary(FT, cfmakecollectable);
1166  AllowAnnotations = false;
1167  } else {
1168  S = getCFCreateGetRuleSummary(FD);
1169  }
1170 
1171  break;
1172  }
1173 
1174  // For CoreGraphics ('CG') types.
1175  if (cocoa::isRefType(RetTy, "CG", FName)) {
1176  if (isRetain(FD, FName))
1177  S = getUnarySummary(FT, cfretain);
1178  else
1179  S = getCFCreateGetRuleSummary(FD);
1180 
1181  break;
1182  }
1183 
1184  // For the Disk Arbitration API (DiskArbitration/DADisk.h)
1185  if (cocoa::isRefType(RetTy, "DADisk") ||
1186  cocoa::isRefType(RetTy, "DADissenter") ||
1187  cocoa::isRefType(RetTy, "DASessionRef")) {
1188  S = getCFCreateGetRuleSummary(FD);
1189  break;
1190  }
1191 
1192  if (FD->hasAttr<CFAuditedTransferAttr>()) {
1193  S = getCFCreateGetRuleSummary(FD);
1194  break;
1195  }
1196 
1197  break;
1198  }
1199 
1200  // Check for release functions, the only kind of functions that we care
1201  // about that don't return a pointer type.
1202  if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) {
1203  // Test for 'CGCF'.
1204  FName = FName.substr(FName.startswith("CGCF") ? 4 : 2);
1205 
1206  if (isRelease(FD, FName))
1207  S = getUnarySummary(FT, cfrelease);
1208  else {
1209  assert (ScratchArgs.isEmpty());
1210  // Remaining CoreFoundation and CoreGraphics functions.
1211  // We use to assume that they all strictly followed the ownership idiom
1212  // and that ownership cannot be transferred. While this is technically
1213  // correct, many methods allow a tracked object to escape. For example:
1214  //
1215  // CFMutableDictionaryRef x = CFDictionaryCreateMutable(...);
1216  // CFDictionaryAddValue(y, key, x);
1217  // CFRelease(x);
1218  // ... it is okay to use 'x' since 'y' has a reference to it
1219  //
1220  // We handle this and similar cases with the follow heuristic. If the
1221  // function name contains "InsertValue", "SetValue", "AddValue",
1222  // "AppendValue", or "SetAttribute", then we assume that arguments may
1223  // "escape." This means that something else holds on to the object,
1224  // allowing it be used even after its local retain count drops to 0.
1225  ArgEffect E = (StrInStrNoCase(FName, "InsertValue") != StringRef::npos||
1226  StrInStrNoCase(FName, "AddValue") != StringRef::npos ||
1227  StrInStrNoCase(FName, "SetValue") != StringRef::npos ||
1228  StrInStrNoCase(FName, "AppendValue") != StringRef::npos||
1229  StrInStrNoCase(FName, "SetAttribute") != StringRef::npos)
1230  ? MayEscape : DoNothing;
1231 
1232  S = getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, E);
1233  }
1234  }
1235  }
1236  while (0);
1237 
1238  // If we got all the way here without any luck, use a default summary.
1239  if (!S)
1240  S = getDefaultSummary();
1241 
1242  // Annotations override defaults.
1243  if (AllowAnnotations)
1244  updateSummaryFromAnnotations(S, FD);
1245 
1246  FuncSummaries[FD] = S;
1247  return S;
1248 }
1249 
1250 const RetainSummary *
1251 RetainSummaryManager::getCFCreateGetRuleSummary(const FunctionDecl *FD) {
1253  return getCFSummaryCreateRule(FD);
1254 
1255  return getCFSummaryGetRule(FD);
1256 }
1257 
1258 const RetainSummary *
1259 RetainSummaryManager::getUnarySummary(const FunctionType* FT,
1260  UnaryFuncKind func) {
1261 
1262  // Sanity check that this is *really* a unary function. This can
1263  // happen if people do weird things.
1264  const FunctionProtoType* FTP = dyn_cast<FunctionProtoType>(FT);
1265  if (!FTP || FTP->getNumParams() != 1)
1266  return getPersistentStopSummary();
1267 
1268  assert (ScratchArgs.isEmpty());
1269 
1270  ArgEffect Effect;
1271  switch (func) {
1272  case cfretain: Effect = IncRef; break;
1273  case cfrelease: Effect = DecRef; break;
1274  case cfautorelease: Effect = Autorelease; break;
1275  case cfmakecollectable: Effect = MakeCollectable; break;
1276  }
1277 
1278  ScratchArgs = AF.add(ScratchArgs, 0, Effect);
1279  return getPersistentSummary(RetEffect::MakeNoRet(), DoNothing, DoNothing);
1280 }
1281 
1282 const RetainSummary *
1283 RetainSummaryManager::getCFSummaryCreateRule(const FunctionDecl *FD) {
1284  assert (ScratchArgs.isEmpty());
1285 
1286  return getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true));
1287 }
1288 
1289 const RetainSummary *
1290 RetainSummaryManager::getCFSummaryGetRule(const FunctionDecl *FD) {
1291  assert (ScratchArgs.isEmpty());
1292  return getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::CF),
1293  DoNothing, DoNothing);
1294 }
1295 
1296 //===----------------------------------------------------------------------===//
1297 // Summary creation for Selectors.
1298 //===----------------------------------------------------------------------===//
1299 
1301 RetainSummaryManager::getRetEffectFromAnnotations(QualType RetTy,
1302  const Decl *D) {
1303  if (cocoa::isCocoaObjectRef(RetTy)) {
1304  if (D->hasAttr<NSReturnsRetainedAttr>())
1305  return ObjCAllocRetE;
1306 
1307  if (D->hasAttr<NSReturnsNotRetainedAttr>() ||
1308  D->hasAttr<NSReturnsAutoreleasedAttr>())
1309  return RetEffect::MakeNotOwned(RetEffect::ObjC);
1310 
1311  } else if (!RetTy->isPointerType()) {
1312  return None;
1313  }
1314 
1315  if (D->hasAttr<CFReturnsRetainedAttr>())
1316  return RetEffect::MakeOwned(RetEffect::CF, true);
1317 
1318  if (D->hasAttr<CFReturnsNotRetainedAttr>())
1319  return RetEffect::MakeNotOwned(RetEffect::CF);
1320 
1321  return None;
1322 }
1323 
1324 void
1325 RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ,
1326  const FunctionDecl *FD) {
1327  if (!FD)
1328  return;
1329 
1330  assert(Summ && "Must have a summary to add annotations to.");
1331  RetainSummaryTemplate Template(Summ, *this);
1332 
1333  // Effects on the parameters.
1334  unsigned parm_idx = 0;
1336  pe = FD->param_end(); pi != pe; ++pi, ++parm_idx) {
1337  const ParmVarDecl *pd = *pi;
1338  if (pd->hasAttr<NSConsumedAttr>())
1339  Template->addArg(AF, parm_idx, DecRefMsg);
1340  else if (pd->hasAttr<CFConsumedAttr>())
1341  Template->addArg(AF, parm_idx, DecRef);
1342  else if (pd->hasAttr<CFReturnsRetainedAttr>()) {
1343  QualType PointeeTy = pd->getType()->getPointeeType();
1344  if (!PointeeTy.isNull())
1345  if (coreFoundation::isCFObjectRef(PointeeTy))
1346  Template->addArg(AF, parm_idx, RetainedOutParameter);
1347  } else if (pd->hasAttr<CFReturnsNotRetainedAttr>()) {
1348  QualType PointeeTy = pd->getType()->getPointeeType();
1349  if (!PointeeTy.isNull())
1350  if (coreFoundation::isCFObjectRef(PointeeTy))
1351  Template->addArg(AF, parm_idx, UnretainedOutParameter);
1352  }
1353  }
1354 
1355  QualType RetTy = FD->getReturnType();
1356  if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, FD))
1357  Template->setRetEffect(*RetE);
1358 }
1359 
1360 void
1361 RetainSummaryManager::updateSummaryFromAnnotations(const RetainSummary *&Summ,
1362  const ObjCMethodDecl *MD) {
1363  if (!MD)
1364  return;
1365 
1366  assert(Summ && "Must have a valid summary to add annotations to");
1367  RetainSummaryTemplate Template(Summ, *this);
1368 
1369  // Effects on the receiver.
1370  if (MD->hasAttr<NSConsumesSelfAttr>())
1371  Template->setReceiverEffect(DecRefMsg);
1372 
1373  // Effects on the parameters.
1374  unsigned parm_idx = 0;
1376  pi=MD->param_begin(), pe=MD->param_end();
1377  pi != pe; ++pi, ++parm_idx) {
1378  const ParmVarDecl *pd = *pi;
1379  if (pd->hasAttr<NSConsumedAttr>())
1380  Template->addArg(AF, parm_idx, DecRefMsg);
1381  else if (pd->hasAttr<CFConsumedAttr>()) {
1382  Template->addArg(AF, parm_idx, DecRef);
1383  } else if (pd->hasAttr<CFReturnsRetainedAttr>()) {
1384  QualType PointeeTy = pd->getType()->getPointeeType();
1385  if (!PointeeTy.isNull())
1386  if (coreFoundation::isCFObjectRef(PointeeTy))
1387  Template->addArg(AF, parm_idx, RetainedOutParameter);
1388  } else if (pd->hasAttr<CFReturnsNotRetainedAttr>()) {
1389  QualType PointeeTy = pd->getType()->getPointeeType();
1390  if (!PointeeTy.isNull())
1391  if (coreFoundation::isCFObjectRef(PointeeTy))
1392  Template->addArg(AF, parm_idx, UnretainedOutParameter);
1393  }
1394  }
1395 
1396  QualType RetTy = MD->getReturnType();
1397  if (Optional<RetEffect> RetE = getRetEffectFromAnnotations(RetTy, MD))
1398  Template->setRetEffect(*RetE);
1399 }
1400 
1401 const RetainSummary *
1402 RetainSummaryManager::getStandardMethodSummary(const ObjCMethodDecl *MD,
1403  Selector S, QualType RetTy) {
1404  // Any special effects?
1405  ArgEffect ReceiverEff = DoNothing;
1406  RetEffect ResultEff = RetEffect::MakeNoRet();
1407 
1408  // Check the method family, and apply any default annotations.
1409  switch (MD ? MD->getMethodFamily() : S.getMethodFamily()) {
1410  case OMF_None:
1411  case OMF_initialize:
1412  case OMF_performSelector:
1413  // Assume all Objective-C methods follow Cocoa Memory Management rules.
1414  // FIXME: Does the non-threaded performSelector family really belong here?
1415  // The selector could be, say, @selector(copy).
1416  if (cocoa::isCocoaObjectRef(RetTy))
1417  ResultEff = RetEffect::MakeNotOwned(RetEffect::ObjC);
1418  else if (coreFoundation::isCFObjectRef(RetTy)) {
1419  // ObjCMethodDecl currently doesn't consider CF objects as valid return
1420  // values for alloc, new, copy, or mutableCopy, so we have to
1421  // double-check with the selector. This is ugly, but there aren't that
1422  // many Objective-C methods that return CF objects, right?
1423  if (MD) {
1424  switch (S.getMethodFamily()) {
1425  case OMF_alloc:
1426  case OMF_new:
1427  case OMF_copy:
1428  case OMF_mutableCopy:
1429  ResultEff = RetEffect::MakeOwned(RetEffect::CF, true);
1430  break;
1431  default:
1432  ResultEff = RetEffect::MakeNotOwned(RetEffect::CF);
1433  break;
1434  }
1435  } else {
1436  ResultEff = RetEffect::MakeNotOwned(RetEffect::CF);
1437  }
1438  }
1439  break;
1440  case OMF_init:
1441  ResultEff = ObjCInitRetE;
1442  ReceiverEff = DecRefMsg;
1443  break;
1444  case OMF_alloc:
1445  case OMF_new:
1446  case OMF_copy:
1447  case OMF_mutableCopy:
1448  if (cocoa::isCocoaObjectRef(RetTy))
1449  ResultEff = ObjCAllocRetE;
1450  else if (coreFoundation::isCFObjectRef(RetTy))
1451  ResultEff = RetEffect::MakeOwned(RetEffect::CF, true);
1452  break;
1453  case OMF_autorelease:
1454  ReceiverEff = Autorelease;
1455  break;
1456  case OMF_retain:
1457  ReceiverEff = IncRefMsg;
1458  break;
1459  case OMF_release:
1460  ReceiverEff = DecRefMsg;
1461  break;
1462  case OMF_dealloc:
1463  ReceiverEff = Dealloc;
1464  break;
1465  case OMF_self:
1466  // -self is handled specially by the ExprEngine to propagate the receiver.
1467  break;
1468  case OMF_retainCount:
1469  case OMF_finalize:
1470  // These methods don't return objects.
1471  break;
1472  }
1473 
1474  // If one of the arguments in the selector has the keyword 'delegate' we
1475  // should stop tracking the reference count for the receiver. This is
1476  // because the reference count is quite possibly handled by a delegate
1477  // method.
1478  if (S.isKeywordSelector()) {
1479  for (unsigned i = 0, e = S.getNumArgs(); i != e; ++i) {
1480  StringRef Slot = S.getNameForSlot(i);
1481  if (Slot.substr(Slot.size() - 8).equals_lower("delegate")) {
1482  if (ResultEff == ObjCInitRetE)
1483  ResultEff = RetEffect::MakeNoRetHard();
1484  else
1485  ReceiverEff = StopTrackingHard;
1486  }
1487  }
1488  }
1489 
1490  if (ScratchArgs.isEmpty() && ReceiverEff == DoNothing &&
1491  ResultEff.getKind() == RetEffect::NoRet)
1492  return getDefaultSummary();
1493 
1494  return getPersistentSummary(ResultEff, ReceiverEff, MayEscape);
1495 }
1496 
1497 const RetainSummary *
1498 RetainSummaryManager::getInstanceMethodSummary(const ObjCMethodCall &Msg,
1499  ProgramStateRef State) {
1500  const ObjCInterfaceDecl *ReceiverClass = nullptr;
1501 
1502  // We do better tracking of the type of the object than the core ExprEngine.
1503  // See if we have its type in our private state.
1504  // FIXME: Eventually replace the use of state->get<RefBindings> with
1505  // a generic API for reasoning about the Objective-C types of symbolic
1506  // objects.
1507  SVal ReceiverV = Msg.getReceiverSVal();
1508  if (SymbolRef Sym = ReceiverV.getAsLocSymbol())
1509  if (const RefVal *T = getRefBinding(State, Sym))
1510  if (const ObjCObjectPointerType *PT =
1511  T->getType()->getAs<ObjCObjectPointerType>())
1512  ReceiverClass = PT->getInterfaceDecl();
1513 
1514  // If we don't know what kind of object this is, fall back to its static type.
1515  if (!ReceiverClass)
1516  ReceiverClass = Msg.getReceiverInterface();
1517 
1518  // FIXME: The receiver could be a reference to a class, meaning that
1519  // we should use the class method.
1520  // id x = [NSObject class];
1521  // [x performSelector:... withObject:... afterDelay:...];
1522  Selector S = Msg.getSelector();
1523  const ObjCMethodDecl *Method = Msg.getDecl();
1524  if (!Method && ReceiverClass)
1525  Method = ReceiverClass->getInstanceMethod(S);
1526 
1527  return getMethodSummary(S, ReceiverClass, Method, Msg.getResultType(),
1528  ObjCMethodSummaries);
1529 }
1530 
1531 const RetainSummary *
1532 RetainSummaryManager::getMethodSummary(Selector S, const ObjCInterfaceDecl *ID,
1533  const ObjCMethodDecl *MD, QualType RetTy,
1534  ObjCMethodSummariesTy &CachedSummaries) {
1535 
1536  // Look up a summary in our summary cache.
1537  const RetainSummary *Summ = CachedSummaries.find(ID, S);
1538 
1539  if (!Summ) {
1540  Summ = getStandardMethodSummary(MD, S, RetTy);
1541 
1542  // Annotations override defaults.
1543  updateSummaryFromAnnotations(Summ, MD);
1544 
1545  // Memoize the summary.
1546  CachedSummaries[ObjCSummaryKey(ID, S)] = Summ;
1547  }
1548 
1549  return Summ;
1550 }
1551 
1552 void RetainSummaryManager::InitializeClassMethodSummaries() {
1553  assert(ScratchArgs.isEmpty());
1554  // Create the [NSAssertionHandler currentHander] summary.
1555  addClassMethSummary("NSAssertionHandler", "currentHandler",
1556  getPersistentSummary(RetEffect::MakeNotOwned(RetEffect::ObjC)));
1557 
1558  // Create the [NSAutoreleasePool addObject:] summary.
1559  ScratchArgs = AF.add(ScratchArgs, 0, Autorelease);
1560  addClassMethSummary("NSAutoreleasePool", "addObject",
1561  getPersistentSummary(RetEffect::MakeNoRet(),
1563 }
1564 
1565 void RetainSummaryManager::InitializeMethodSummaries() {
1566 
1567  assert (ScratchArgs.isEmpty());
1568 
1569  // Create the "init" selector. It just acts as a pass-through for the
1570  // receiver.
1571  const RetainSummary *InitSumm = getPersistentSummary(ObjCInitRetE, DecRefMsg);
1572  addNSObjectMethSummary(GetNullarySelector("init", Ctx), InitSumm);
1573 
1574  // awakeAfterUsingCoder: behaves basically like an 'init' method. It
1575  // claims the receiver and returns a retained object.
1576  addNSObjectMethSummary(GetUnarySelector("awakeAfterUsingCoder", Ctx),
1577  InitSumm);
1578 
1579  // The next methods are allocators.
1580  const RetainSummary *AllocSumm = getPersistentSummary(ObjCAllocRetE);
1581  const RetainSummary *CFAllocSumm =
1582  getPersistentSummary(RetEffect::MakeOwned(RetEffect::CF, true));
1583 
1584  // Create the "retain" selector.
1585  RetEffect NoRet = RetEffect::MakeNoRet();
1586  const RetainSummary *Summ = getPersistentSummary(NoRet, IncRefMsg);
1587  addNSObjectMethSummary(GetNullarySelector("retain", Ctx), Summ);
1588 
1589  // Create the "release" selector.
1590  Summ = getPersistentSummary(NoRet, DecRefMsg);
1591  addNSObjectMethSummary(GetNullarySelector("release", Ctx), Summ);
1592 
1593  // Create the -dealloc summary.
1594  Summ = getPersistentSummary(NoRet, Dealloc);
1595  addNSObjectMethSummary(GetNullarySelector("dealloc", Ctx), Summ);
1596 
1597  // Create the "autorelease" selector.
1598  Summ = getPersistentSummary(NoRet, Autorelease);
1599  addNSObjectMethSummary(GetNullarySelector("autorelease", Ctx), Summ);
1600 
1601  // For NSWindow, allocated objects are (initially) self-owned.
1602  // FIXME: For now we opt for false negatives with NSWindow, as these objects
1603  // self-own themselves. However, they only do this once they are displayed.
1604  // Thus, we need to track an NSWindow's display status.
1605  // This is tracked in <rdar://problem/6062711>.
1606  // See also http://llvm.org/bugs/show_bug.cgi?id=3714.
1607  const RetainSummary *NoTrackYet = getPersistentSummary(RetEffect::MakeNoRet(),
1608  StopTracking,
1609  StopTracking);
1610 
1611  addClassMethSummary("NSWindow", "alloc", NoTrackYet);
1612 
1613  // For NSPanel (which subclasses NSWindow), allocated objects are not
1614  // self-owned.
1615  // FIXME: For now we don't track NSPanels. object for the same reason
1616  // as for NSWindow objects.
1617  addClassMethSummary("NSPanel", "alloc", NoTrackYet);
1618 
1619  // For NSNull, objects returned by +null are singletons that ignore
1620  // retain/release semantics. Just don't track them.
1621  // <rdar://problem/12858915>
1622  addClassMethSummary("NSNull", "null", NoTrackYet);
1623 
1624  // Don't track allocated autorelease pools, as it is okay to prematurely
1625  // exit a method.
1626  addClassMethSummary("NSAutoreleasePool", "alloc", NoTrackYet);
1627  addClassMethSummary("NSAutoreleasePool", "allocWithZone", NoTrackYet, false);
1628  addClassMethSummary("NSAutoreleasePool", "new", NoTrackYet);
1629 
1630  // Create summaries QCRenderer/QCView -createSnapShotImageOfType:
1631  addInstMethSummary("QCRenderer", AllocSumm,
1632  "createSnapshotImageOfType", nullptr);
1633  addInstMethSummary("QCView", AllocSumm,
1634  "createSnapshotImageOfType", nullptr);
1635 
1636  // Create summaries for CIContext, 'createCGImage' and
1637  // 'createCGLayerWithSize'. These objects are CF objects, and are not
1638  // automatically garbage collected.
1639  addInstMethSummary("CIContext", CFAllocSumm,
1640  "createCGImage", "fromRect", nullptr);
1641  addInstMethSummary("CIContext", CFAllocSumm, "createCGImage", "fromRect",
1642  "format", "colorSpace", nullptr);
1643  addInstMethSummary("CIContext", CFAllocSumm, "createCGLayerWithSize", "info",
1644  nullptr);
1645 }
1646 
1647 //===----------------------------------------------------------------------===//
1648 // Error reporting.
1649 //===----------------------------------------------------------------------===//
1650 namespace {
1651  typedef llvm::DenseMap<const ExplodedNode *, const RetainSummary *>
1652  SummaryLogTy;
1653 
1654  //===-------------===//
1655  // Bug Descriptions. //
1656  //===-------------===//
1657 
1658  class CFRefBug : public BugType {
1659  protected:
1660  CFRefBug(const CheckerBase *checker, StringRef name)
1661  : BugType(checker, name, categories::MemoryCoreFoundationObjectiveC) {}
1662 
1663  public:
1664 
1665  // FIXME: Eventually remove.
1666  virtual const char *getDescription() const = 0;
1667 
1668  virtual bool isLeak() const { return false; }
1669  };
1670 
1671  class UseAfterRelease : public CFRefBug {
1672  public:
1673  UseAfterRelease(const CheckerBase *checker)
1674  : CFRefBug(checker, "Use-after-release") {}
1675 
1676  const char *getDescription() const override {
1677  return "Reference-counted object is used after it is released";
1678  }
1679  };
1680 
1681  class BadRelease : public CFRefBug {
1682  public:
1683  BadRelease(const CheckerBase *checker) : CFRefBug(checker, "Bad release") {}
1684 
1685  const char *getDescription() const override {
1686  return "Incorrect decrement of the reference count of an object that is "
1687  "not owned at this point by the caller";
1688  }
1689  };
1690 
1691  class DeallocGC : public CFRefBug {
1692  public:
1693  DeallocGC(const CheckerBase *checker)
1694  : CFRefBug(checker, "-dealloc called while using garbage collection") {}
1695 
1696  const char *getDescription() const override {
1697  return "-dealloc called while using garbage collection";
1698  }
1699  };
1700 
1701  class DeallocNotOwned : public CFRefBug {
1702  public:
1703  DeallocNotOwned(const CheckerBase *checker)
1704  : CFRefBug(checker, "-dealloc sent to non-exclusively owned object") {}
1705 
1706  const char *getDescription() const override {
1707  return "-dealloc sent to object that may be referenced elsewhere";
1708  }
1709  };
1710 
1711  class OverAutorelease : public CFRefBug {
1712  public:
1713  OverAutorelease(const CheckerBase *checker)
1714  : CFRefBug(checker, "Object autoreleased too many times") {}
1715 
1716  const char *getDescription() const override {
1717  return "Object autoreleased too many times";
1718  }
1719  };
1720 
1721  class ReturnedNotOwnedForOwned : public CFRefBug {
1722  public:
1723  ReturnedNotOwnedForOwned(const CheckerBase *checker)
1724  : CFRefBug(checker, "Method should return an owned object") {}
1725 
1726  const char *getDescription() const override {
1727  return "Object with a +0 retain count returned to caller where a +1 "
1728  "(owning) retain count is expected";
1729  }
1730  };
1731 
1732  class Leak : public CFRefBug {
1733  public:
1734  Leak(const CheckerBase *checker, StringRef name) : CFRefBug(checker, name) {
1735  // Leaks should not be reported if they are post-dominated by a sink.
1736  setSuppressOnSink(true);
1737  }
1738 
1739  const char *getDescription() const override { return ""; }
1740 
1741  bool isLeak() const override { return true; }
1742  };
1743 
1744  //===---------===//
1745  // Bug Reports. //
1746  //===---------===//
1747 
1748  class CFRefReportVisitor : public BugReporterVisitorImpl<CFRefReportVisitor> {
1749  protected:
1750  SymbolRef Sym;
1751  const SummaryLogTy &SummaryLog;
1752  bool GCEnabled;
1753 
1754  public:
1755  CFRefReportVisitor(SymbolRef sym, bool gcEnabled, const SummaryLogTy &log)
1756  : Sym(sym), SummaryLog(log), GCEnabled(gcEnabled) {}
1757 
1758  void Profile(llvm::FoldingSetNodeID &ID) const override {
1759  static int x = 0;
1760  ID.AddPointer(&x);
1761  ID.AddPointer(Sym);
1762  }
1763 
1764  PathDiagnosticPiece *VisitNode(const ExplodedNode *N,
1765  const ExplodedNode *PrevN,
1766  BugReporterContext &BRC,
1767  BugReport &BR) override;
1768 
1769  std::unique_ptr<PathDiagnosticPiece> getEndPath(BugReporterContext &BRC,
1770  const ExplodedNode *N,
1771  BugReport &BR) override;
1772  };
1773 
1774  class CFRefLeakReportVisitor : public CFRefReportVisitor {
1775  public:
1776  CFRefLeakReportVisitor(SymbolRef sym, bool GCEnabled,
1777  const SummaryLogTy &log)
1778  : CFRefReportVisitor(sym, GCEnabled, log) {}
1779 
1780  std::unique_ptr<PathDiagnosticPiece> getEndPath(BugReporterContext &BRC,
1781  const ExplodedNode *N,
1782  BugReport &BR) override;
1783 
1784  std::unique_ptr<BugReporterVisitor> clone() const override {
1785  // The curiously-recurring template pattern only works for one level of
1786  // subclassing. Rather than make a new template base for
1787  // CFRefReportVisitor, we simply override clone() to do the right thing.
1788  // This could be trouble someday if BugReporterVisitorImpl is ever
1789  // used for something else besides a convenient implementation of clone().
1790  return llvm::make_unique<CFRefLeakReportVisitor>(*this);
1791  }
1792  };
1793 
1794  class CFRefReport : public BugReport {
1795  void addGCModeDescription(const LangOptions &LOpts, bool GCEnabled);
1796 
1797  public:
1798  CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled,
1799  const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym,
1800  bool registerVisitor = true)
1801  : BugReport(D, D.getDescription(), n) {
1802  if (registerVisitor)
1803  addVisitor(llvm::make_unique<CFRefReportVisitor>(sym, GCEnabled, Log));
1804  addGCModeDescription(LOpts, GCEnabled);
1805  }
1806 
1807  CFRefReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled,
1808  const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym,
1809  StringRef endText)
1810  : BugReport(D, D.getDescription(), endText, n) {
1811  addVisitor(llvm::make_unique<CFRefReportVisitor>(sym, GCEnabled, Log));
1812  addGCModeDescription(LOpts, GCEnabled);
1813  }
1814 
1815  llvm::iterator_range<ranges_iterator> getRanges() override {
1816  const CFRefBug& BugTy = static_cast<CFRefBug&>(getBugType());
1817  if (!BugTy.isLeak())
1818  return BugReport::getRanges();
1819  return llvm::make_range(ranges_iterator(), ranges_iterator());
1820  }
1821  };
1822 
1823  class CFRefLeakReport : public CFRefReport {
1824  const MemRegion* AllocBinding;
1825  public:
1826  CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts, bool GCEnabled,
1827  const SummaryLogTy &Log, ExplodedNode *n, SymbolRef sym,
1828  CheckerContext &Ctx,
1829  bool IncludeAllocationLine);
1830 
1831  PathDiagnosticLocation getLocation(const SourceManager &SM) const override {
1832  assert(Location.isValid());
1833  return Location;
1834  }
1835  };
1836 } // end anonymous namespace
1837 
1838 void CFRefReport::addGCModeDescription(const LangOptions &LOpts,
1839  bool GCEnabled) {
1840  const char *GCModeDescription = nullptr;
1841 
1842  switch (LOpts.getGC()) {
1843  case LangOptions::GCOnly:
1844  assert(GCEnabled);
1845  GCModeDescription = "Code is compiled to only use garbage collection";
1846  break;
1847 
1848  case LangOptions::NonGC:
1849  assert(!GCEnabled);
1850  GCModeDescription = "Code is compiled to use reference counts";
1851  break;
1852 
1853  case LangOptions::HybridGC:
1854  if (GCEnabled) {
1855  GCModeDescription = "Code is compiled to use either garbage collection "
1856  "(GC) or reference counts (non-GC). The bug occurs "
1857  "with GC enabled";
1858  break;
1859  } else {
1860  GCModeDescription = "Code is compiled to use either garbage collection "
1861  "(GC) or reference counts (non-GC). The bug occurs "
1862  "in non-GC mode";
1863  break;
1864  }
1865  }
1866 
1867  assert(GCModeDescription && "invalid/unknown GC mode");
1868  addExtraText(GCModeDescription);
1869 }
1870 
1871 static bool isNumericLiteralExpression(const Expr *E) {
1872  // FIXME: This set of cases was copied from SemaExprObjC.
1873  return isa<IntegerLiteral>(E) ||
1874  isa<CharacterLiteral>(E) ||
1875  isa<FloatingLiteral>(E) ||
1876  isa<ObjCBoolLiteralExpr>(E) ||
1877  isa<CXXBoolLiteralExpr>(E);
1878 }
1879 
1880 /// Returns true if this stack frame is for an Objective-C method that is a
1881 /// property getter or setter whose body has been synthesized by the analyzer.
1882 static bool isSynthesizedAccessor(const StackFrameContext *SFC) {
1883  auto Method = dyn_cast_or_null<ObjCMethodDecl>(SFC->getDecl());
1884  if (!Method || !Method->isPropertyAccessor())
1885  return false;
1886 
1888 }
1889 
1890 PathDiagnosticPiece *CFRefReportVisitor::VisitNode(const ExplodedNode *N,
1891  const ExplodedNode *PrevN,
1892  BugReporterContext &BRC,
1893  BugReport &BR) {
1894  // FIXME: We will eventually need to handle non-statement-based events
1895  // (__attribute__((cleanup))).
1896  if (!N->getLocation().getAs<StmtPoint>())
1897  return nullptr;
1898 
1899  // Check if the type state has changed.
1900  ProgramStateRef PrevSt = PrevN->getState();
1901  ProgramStateRef CurrSt = N->getState();
1902  const LocationContext *LCtx = N->getLocationContext();
1903 
1904  const RefVal* CurrT = getRefBinding(CurrSt, Sym);
1905  if (!CurrT) return nullptr;
1906 
1907  const RefVal &CurrV = *CurrT;
1908  const RefVal *PrevT = getRefBinding(PrevSt, Sym);
1909 
1910  // Create a string buffer to constain all the useful things we want
1911  // to tell the user.
1912  std::string sbuf;
1913  llvm::raw_string_ostream os(sbuf);
1914 
1915  // This is the allocation site since the previous node had no bindings
1916  // for this symbol.
1917  if (!PrevT) {
1918  const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt();
1919 
1920  if (isa<ObjCIvarRefExpr>(S) &&
1922  S = LCtx->getCurrentStackFrame()->getCallSite();
1923  }
1924 
1925  if (isa<ObjCArrayLiteral>(S)) {
1926  os << "NSArray literal is an object with a +0 retain count";
1927  }
1928  else if (isa<ObjCDictionaryLiteral>(S)) {
1929  os << "NSDictionary literal is an object with a +0 retain count";
1930  }
1931  else if (const ObjCBoxedExpr *BL = dyn_cast<ObjCBoxedExpr>(S)) {
1932  if (isNumericLiteralExpression(BL->getSubExpr()))
1933  os << "NSNumber literal is an object with a +0 retain count";
1934  else {
1935  const ObjCInterfaceDecl *BoxClass = nullptr;
1936  if (const ObjCMethodDecl *Method = BL->getBoxingMethod())
1937  BoxClass = Method->getClassInterface();
1938 
1939  // We should always be able to find the boxing class interface,
1940  // but consider this future-proofing.
1941  if (BoxClass)
1942  os << *BoxClass << " b";
1943  else
1944  os << "B";
1945 
1946  os << "oxed expression produces an object with a +0 retain count";
1947  }
1948  }
1949  else if (isa<ObjCIvarRefExpr>(S)) {
1950  os << "Object loaded from instance variable";
1951  }
1952  else {
1953  if (const CallExpr *CE = dyn_cast<CallExpr>(S)) {
1954  // Get the name of the callee (if it is available).
1955  SVal X = CurrSt->getSValAsScalarOrLoc(CE->getCallee(), LCtx);
1956  if (const FunctionDecl *FD = X.getAsFunctionDecl())
1957  os << "Call to function '" << *FD << '\'';
1958  else
1959  os << "function call";
1960  }
1961  else {
1962  assert(isa<ObjCMessageExpr>(S));
1963  CallEventManager &Mgr = CurrSt->getStateManager().getCallEventManager();
1965  = Mgr.getObjCMethodCall(cast<ObjCMessageExpr>(S), CurrSt, LCtx);
1966 
1967  switch (Call->getMessageKind()) {
1968  case OCM_Message:
1969  os << "Method";
1970  break;
1971  case OCM_PropertyAccess:
1972  os << "Property";
1973  break;
1974  case OCM_Subscript:
1975  os << "Subscript";
1976  break;
1977  }
1978  }
1979 
1980  if (CurrV.getObjKind() == RetEffect::CF) {
1981  os << " returns a Core Foundation object with a ";
1982  }
1983  else {
1984  assert (CurrV.getObjKind() == RetEffect::ObjC);
1985  os << " returns an Objective-C object with a ";
1986  }
1987 
1988  if (CurrV.isOwned()) {
1989  os << "+1 retain count";
1990 
1991  if (GCEnabled) {
1992  assert(CurrV.getObjKind() == RetEffect::CF);
1993  os << ". "
1994  "Core Foundation objects are not automatically garbage collected.";
1995  }
1996  }
1997  else {
1998  assert (CurrV.isNotOwned());
1999  os << "+0 retain count";
2000  }
2001  }
2002 
2004  N->getLocationContext());
2005  return new PathDiagnosticEventPiece(Pos, os.str());
2006  }
2007 
2008  // Gather up the effects that were performed on the object at this
2009  // program point
2010  SmallVector<ArgEffect, 2> AEffects;
2011 
2012  const ExplodedNode *OrigNode = BRC.getNodeResolver().getOriginalNode(N);
2013  if (const RetainSummary *Summ = SummaryLog.lookup(OrigNode)) {
2014  // We only have summaries attached to nodes after evaluating CallExpr and
2015  // ObjCMessageExprs.
2016  const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt();
2017 
2018  if (const CallExpr *CE = dyn_cast<CallExpr>(S)) {
2019  // Iterate through the parameter expressions and see if the symbol
2020  // was ever passed as an argument.
2021  unsigned i = 0;
2022 
2023  for (CallExpr::const_arg_iterator AI=CE->arg_begin(), AE=CE->arg_end();
2024  AI!=AE; ++AI, ++i) {
2025 
2026  // Retrieve the value of the argument. Is it the symbol
2027  // we are interested in?
2028  if (CurrSt->getSValAsScalarOrLoc(*AI, LCtx).getAsLocSymbol() != Sym)
2029  continue;
2030 
2031  // We have an argument. Get the effect!
2032  AEffects.push_back(Summ->getArg(i));
2033  }
2034  }
2035  else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S)) {
2036  if (const Expr *receiver = ME->getInstanceReceiver())
2037  if (CurrSt->getSValAsScalarOrLoc(receiver, LCtx)
2038  .getAsLocSymbol() == Sym) {
2039  // The symbol we are tracking is the receiver.
2040  AEffects.push_back(Summ->getReceiverEffect());
2041  }
2042  }
2043  }
2044 
2045  do {
2046  // Get the previous type state.
2047  RefVal PrevV = *PrevT;
2048 
2049  // Specially handle -dealloc.
2050  if (!GCEnabled && std::find(AEffects.begin(), AEffects.end(), Dealloc) !=
2051  AEffects.end()) {
2052  // Determine if the object's reference count was pushed to zero.
2053  assert(!PrevV.hasSameState(CurrV) && "The state should have changed.");
2054  // We may not have transitioned to 'release' if we hit an error.
2055  // This case is handled elsewhere.
2056  if (CurrV.getKind() == RefVal::Released) {
2057  assert(CurrV.getCombinedCounts() == 0);
2058  os << "Object released by directly sending the '-dealloc' message";
2059  break;
2060  }
2061  }
2062 
2063  // Specially handle CFMakeCollectable and friends.
2064  if (std::find(AEffects.begin(), AEffects.end(), MakeCollectable) !=
2065  AEffects.end()) {
2066  // Get the name of the function.
2067  const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt();
2068  SVal X =
2069  CurrSt->getSValAsScalarOrLoc(cast<CallExpr>(S)->getCallee(), LCtx);
2070  const FunctionDecl *FD = X.getAsFunctionDecl();
2071 
2072  if (GCEnabled) {
2073  // Determine if the object's reference count was pushed to zero.
2074  assert(!PrevV.hasSameState(CurrV) && "The state should have changed.");
2075 
2076  os << "In GC mode a call to '" << *FD
2077  << "' decrements an object's retain count and registers the "
2078  "object with the garbage collector. ";
2079 
2080  if (CurrV.getKind() == RefVal::Released) {
2081  assert(CurrV.getCount() == 0);
2082  os << "Since it now has a 0 retain count the object can be "
2083  "automatically collected by the garbage collector.";
2084  }
2085  else
2086  os << "An object must have a 0 retain count to be garbage collected. "
2087  "After this call its retain count is +" << CurrV.getCount()
2088  << '.';
2089  }
2090  else
2091  os << "When GC is not enabled a call to '" << *FD
2092  << "' has no effect on its argument.";
2093 
2094  // Nothing more to say.
2095  break;
2096  }
2097 
2098  // Determine if the typestate has changed.
2099  if (!PrevV.hasSameState(CurrV))
2100  switch (CurrV.getKind()) {
2101  case RefVal::Owned:
2102  case RefVal::NotOwned:
2103  if (PrevV.getCount() == CurrV.getCount()) {
2104  // Did an autorelease message get sent?
2105  if (PrevV.getAutoreleaseCount() == CurrV.getAutoreleaseCount())
2106  return nullptr;
2107 
2108  assert(PrevV.getAutoreleaseCount() < CurrV.getAutoreleaseCount());
2109  os << "Object autoreleased";
2110  break;
2111  }
2112 
2113  if (PrevV.getCount() > CurrV.getCount())
2114  os << "Reference count decremented.";
2115  else
2116  os << "Reference count incremented.";
2117 
2118  if (unsigned Count = CurrV.getCount())
2119  os << " The object now has a +" << Count << " retain count.";
2120 
2121  if (PrevV.getKind() == RefVal::Released) {
2122  assert(GCEnabled && CurrV.getCount() > 0);
2123  os << " The object is not eligible for garbage collection until "
2124  "the retain count reaches 0 again.";
2125  }
2126 
2127  break;
2128 
2129  case RefVal::Released:
2130  if (CurrV.getIvarAccessHistory() ==
2131  RefVal::IvarAccessHistory::ReleasedAfterDirectAccess &&
2132  CurrV.getIvarAccessHistory() != PrevV.getIvarAccessHistory()) {
2133  os << "Strong instance variable relinquished. ";
2134  }
2135  os << "Object released.";
2136  break;
2137 
2138  case RefVal::ReturnedOwned:
2139  // Autoreleases can be applied after marking a node ReturnedOwned.
2140  if (CurrV.getAutoreleaseCount())
2141  return nullptr;
2142 
2143  os << "Object returned to caller as an owning reference (single "
2144  "retain count transferred to caller)";
2145  break;
2146 
2147  case RefVal::ReturnedNotOwned:
2148  os << "Object returned to caller with a +0 retain count";
2149  break;
2150 
2151  default:
2152  return nullptr;
2153  }
2154 
2155  // Emit any remaining diagnostics for the argument effects (if any).
2156  for (SmallVectorImpl<ArgEffect>::iterator I=AEffects.begin(),
2157  E=AEffects.end(); I != E; ++I) {
2158 
2159  // A bunch of things have alternate behavior under GC.
2160  if (GCEnabled)
2161  switch (*I) {
2162  default: break;
2163  case Autorelease:
2164  os << "In GC mode an 'autorelease' has no effect.";
2165  continue;
2166  case IncRefMsg:
2167  os << "In GC mode the 'retain' message has no effect.";
2168  continue;
2169  case DecRefMsg:
2170  os << "In GC mode the 'release' message has no effect.";
2171  continue;
2172  }
2173  }
2174  } while (0);
2175 
2176  if (os.str().empty())
2177  return nullptr; // We have nothing to say!
2178 
2179  const Stmt *S = N->getLocation().castAs<StmtPoint>().getStmt();
2181  N->getLocationContext());
2182  PathDiagnosticPiece *P = new PathDiagnosticEventPiece(Pos, os.str());
2183 
2184  // Add the range by scanning the children of the statement for any bindings
2185  // to Sym.
2186  for (const Stmt *Child : S->children())
2187  if (const Expr *Exp = dyn_cast_or_null<Expr>(Child))
2188  if (CurrSt->getSValAsScalarOrLoc(Exp, LCtx).getAsLocSymbol() == Sym) {
2189  P->addRange(Exp->getSourceRange());
2190  break;
2191  }
2192 
2193  return P;
2194 }
2195 
2196 namespace {
2197 // Find the first node in the current function context that referred to the
2198 // tracked symbol and the memory location that value was stored to. Note, the
2199 // value is only reported if the allocation occurred in the same function as
2200 // the leak. The function can also return a location context, which should be
2201 // treated as interesting.
2202 struct AllocationInfo {
2203  const ExplodedNode* N;
2204  const MemRegion *R;
2205  const LocationContext *InterestingMethodContext;
2206  AllocationInfo(const ExplodedNode *InN,
2207  const MemRegion *InR,
2208  const LocationContext *InInterestingMethodContext) :
2209  N(InN), R(InR), InterestingMethodContext(InInterestingMethodContext) {}
2210 };
2211 } // end anonymous namespace
2212 
2213 static AllocationInfo
2215  SymbolRef Sym) {
2216  const ExplodedNode *AllocationNode = N;
2217  const ExplodedNode *AllocationNodeInCurrentOrParentContext = N;
2218  const MemRegion *FirstBinding = nullptr;
2219  const LocationContext *LeakContext = N->getLocationContext();
2220 
2221  // The location context of the init method called on the leaked object, if
2222  // available.
2223  const LocationContext *InitMethodContext = nullptr;
2224 
2225  while (N) {
2226  ProgramStateRef St = N->getState();
2227  const LocationContext *NContext = N->getLocationContext();
2228 
2229  if (!getRefBinding(St, Sym))
2230  break;
2231 
2233  StateMgr.iterBindings(St, FB);
2234 
2235  if (FB) {
2236  const MemRegion *R = FB.getRegion();
2237  const VarRegion *VR = R->getBaseRegion()->getAs<VarRegion>();
2238  // Do not show local variables belonging to a function other than
2239  // where the error is reported.
2240  if (!VR || VR->getStackFrame() == LeakContext->getCurrentStackFrame())
2241  FirstBinding = R;
2242  }
2243 
2244  // AllocationNode is the last node in which the symbol was tracked.
2245  AllocationNode = N;
2246 
2247  // AllocationNodeInCurrentContext, is the last node in the current or
2248  // parent context in which the symbol was tracked.
2249  //
2250  // Note that the allocation site might be in the parent conext. For example,
2251  // the case where an allocation happens in a block that captures a reference
2252  // to it and that reference is overwritten/dropped by another call to
2253  // the block.
2254  if (NContext == LeakContext || NContext->isParentOf(LeakContext))
2255  AllocationNodeInCurrentOrParentContext = N;
2256 
2257  // Find the last init that was called on the given symbol and store the
2258  // init method's location context.
2259  if (!InitMethodContext)
2260  if (Optional<CallEnter> CEP = N->getLocation().getAs<CallEnter>()) {
2261  const Stmt *CE = CEP->getCallExpr();
2262  if (const ObjCMessageExpr *ME = dyn_cast_or_null<ObjCMessageExpr>(CE)) {
2263  const Stmt *RecExpr = ME->getInstanceReceiver();
2264  if (RecExpr) {
2265  SVal RecV = St->getSVal(RecExpr, NContext);
2266  if (ME->getMethodFamily() == OMF_init && RecV.getAsSymbol() == Sym)
2267  InitMethodContext = CEP->getCalleeContext();
2268  }
2269  }
2270  }
2271 
2272  N = N->pred_empty() ? nullptr : *(N->pred_begin());
2273  }
2274 
2275  // If we are reporting a leak of the object that was allocated with alloc,
2276  // mark its init method as interesting.
2277  const LocationContext *InterestingMethodContext = nullptr;
2278  if (InitMethodContext) {
2279  const ProgramPoint AllocPP = AllocationNode->getLocation();
2280  if (Optional<StmtPoint> SP = AllocPP.getAs<StmtPoint>())
2281  if (const ObjCMessageExpr *ME = SP->getStmtAs<ObjCMessageExpr>())
2282  if (ME->getMethodFamily() == OMF_alloc)
2283  InterestingMethodContext = InitMethodContext;
2284  }
2285 
2286  // If allocation happened in a function different from the leak node context,
2287  // do not report the binding.
2288  assert(N && "Could not find allocation node");
2289  if (N->getLocationContext() != LeakContext) {
2290  FirstBinding = nullptr;
2291  }
2292 
2293  return AllocationInfo(AllocationNodeInCurrentOrParentContext,
2294  FirstBinding,
2295  InterestingMethodContext);
2296 }
2297 
2298 std::unique_ptr<PathDiagnosticPiece>
2299 CFRefReportVisitor::getEndPath(BugReporterContext &BRC,
2300  const ExplodedNode *EndN, BugReport &BR) {
2301  BR.markInteresting(Sym);
2302  return BugReporterVisitor::getDefaultEndPath(BRC, EndN, BR);
2303 }
2304 
2305 std::unique_ptr<PathDiagnosticPiece>
2306 CFRefLeakReportVisitor::getEndPath(BugReporterContext &BRC,
2307  const ExplodedNode *EndN, BugReport &BR) {
2308 
2309  // Tell the BugReporterContext to report cases when the tracked symbol is
2310  // assigned to different variables, etc.
2311  BR.markInteresting(Sym);
2312 
2313  // We are reporting a leak. Walk up the graph to get to the first node where
2314  // the symbol appeared, and also get the first VarDecl that tracked object
2315  // is stored to.
2316  AllocationInfo AllocI =
2317  GetAllocationSite(BRC.getStateManager(), EndN, Sym);
2318 
2319  const MemRegion* FirstBinding = AllocI.R;
2320  BR.markInteresting(AllocI.InterestingMethodContext);
2321 
2323 
2324  // Compute an actual location for the leak. Sometimes a leak doesn't
2325  // occur at an actual statement (e.g., transition between blocks; end
2326  // of function) so we need to walk the graph and compute a real location.
2327  const ExplodedNode *LeakN = EndN;
2329 
2330  std::string sbuf;
2331  llvm::raw_string_ostream os(sbuf);
2332 
2333  os << "Object leaked: ";
2334 
2335  if (FirstBinding) {
2336  os << "object allocated and stored into '"
2337  << FirstBinding->getString() << '\'';
2338  }
2339  else
2340  os << "allocated object";
2341 
2342  // Get the retain count.
2343  const RefVal* RV = getRefBinding(EndN->getState(), Sym);
2344  assert(RV);
2345 
2346  if (RV->getKind() == RefVal::ErrorLeakReturned) {
2347  // FIXME: Per comments in rdar://6320065, "create" only applies to CF
2348  // objects. Only "copy", "alloc", "retain" and "new" transfer ownership
2349  // to the caller for NS objects.
2350  const Decl *D = &EndN->getCodeDecl();
2351 
2352  os << (isa<ObjCMethodDecl>(D) ? " is returned from a method "
2353  : " is returned from a function ");
2354 
2355  if (D->hasAttr<CFReturnsNotRetainedAttr>())
2356  os << "that is annotated as CF_RETURNS_NOT_RETAINED";
2357  else if (D->hasAttr<NSReturnsNotRetainedAttr>())
2358  os << "that is annotated as NS_RETURNS_NOT_RETAINED";
2359  else {
2360  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
2361  os << "whose name ('" << MD->getSelector().getAsString()
2362  << "') does not start with 'copy', 'mutableCopy', 'alloc' or 'new'."
2363  " This violates the naming convention rules"
2364  " given in the Memory Management Guide for Cocoa";
2365  }
2366  else {
2367  const FunctionDecl *FD = cast<FunctionDecl>(D);
2368  os << "whose name ('" << *FD
2369  << "') does not contain 'Copy' or 'Create'. This violates the naming"
2370  " convention rules given in the Memory Management Guide for Core"
2371  " Foundation";
2372  }
2373  }
2374  }
2375  else if (RV->getKind() == RefVal::ErrorGCLeakReturned) {
2376  const ObjCMethodDecl &MD = cast<ObjCMethodDecl>(EndN->getCodeDecl());
2377  os << " and returned from method '" << MD.getSelector().getAsString()
2378  << "' is potentially leaked when using garbage collection. Callers "
2379  "of this method do not expect a returned object with a +1 retain "
2380  "count since they expect the object to be managed by the garbage "
2381  "collector";
2382  }
2383  else
2384  os << " is not referenced later in this execution path and has a retain "
2385  "count of +" << RV->getCount();
2386 
2387  return llvm::make_unique<PathDiagnosticEventPiece>(L, os.str());
2388 }
2389 
2390 CFRefLeakReport::CFRefLeakReport(CFRefBug &D, const LangOptions &LOpts,
2391  bool GCEnabled, const SummaryLogTy &Log,
2392  ExplodedNode *n, SymbolRef sym,
2393  CheckerContext &Ctx,
2394  bool IncludeAllocationLine)
2395  : CFRefReport(D, LOpts, GCEnabled, Log, n, sym, false) {
2396 
2397  // Most bug reports are cached at the location where they occurred.
2398  // With leaks, we want to unique them by the location where they were
2399  // allocated, and only report a single path. To do this, we need to find
2400  // the allocation site of a piece of tracked memory, which we do via a
2401  // call to GetAllocationSite. This will walk the ExplodedGraph backwards.
2402  // Note that this is *not* the trimmed graph; we are guaranteed, however,
2403  // that all ancestor nodes that represent the allocation site have the
2404  // same SourceLocation.
2405  const ExplodedNode *AllocNode = nullptr;
2406 
2407  const SourceManager& SMgr = Ctx.getSourceManager();
2408 
2409  AllocationInfo AllocI =
2410  GetAllocationSite(Ctx.getStateManager(), getErrorNode(), sym);
2411 
2412  AllocNode = AllocI.N;
2413  AllocBinding = AllocI.R;
2414  markInteresting(AllocI.InterestingMethodContext);
2415 
2416  // Get the SourceLocation for the allocation site.
2417  // FIXME: This will crash the analyzer if an allocation comes from an
2418  // implicit call (ex: a destructor call).
2419  // (Currently there are no such allocations in Cocoa, though.)
2420  const Stmt *AllocStmt = nullptr;
2421  ProgramPoint P = AllocNode->getLocation();
2422  if (Optional<CallExitEnd> Exit = P.getAs<CallExitEnd>())
2423  AllocStmt = Exit->getCalleeContext()->getCallSite();
2424  else
2425  AllocStmt = P.castAs<PostStmt>().getStmt();
2426  assert(AllocStmt && "Cannot find allocation statement");
2427 
2428  PathDiagnosticLocation AllocLocation =
2429  PathDiagnosticLocation::createBegin(AllocStmt, SMgr,
2430  AllocNode->getLocationContext());
2431  Location = AllocLocation;
2432 
2433  // Set uniqieing info, which will be used for unique the bug reports. The
2434  // leaks should be uniqued on the allocation site.
2435  UniqueingLocation = AllocLocation;
2436  UniqueingDecl = AllocNode->getLocationContext()->getDecl();
2437 
2438  // Fill in the description of the bug.
2439  Description.clear();
2440  llvm::raw_string_ostream os(Description);
2441  os << "Potential leak ";
2442  if (GCEnabled)
2443  os << "(when using garbage collection) ";
2444  os << "of an object";
2445 
2446  if (AllocBinding) {
2447  os << " stored into '" << AllocBinding->getString() << '\'';
2448  if (IncludeAllocationLine) {
2449  FullSourceLoc SL(AllocStmt->getLocStart(), Ctx.getSourceManager());
2450  os << " (allocated on line " << SL.getSpellingLineNumber() << ")";
2451  }
2452  }
2453 
2454  addVisitor(llvm::make_unique<CFRefLeakReportVisitor>(sym, GCEnabled, Log));
2455 }
2456 
2457 //===----------------------------------------------------------------------===//
2458 // Main checker logic.
2459 //===----------------------------------------------------------------------===//
2460 
2461 namespace {
2462 class RetainCountChecker
2463  : public Checker< check::Bind,
2464  check::DeadSymbols,
2465  check::EndAnalysis,
2466  check::EndFunction,
2467  check::PostStmt<BlockExpr>,
2468  check::PostStmt<CastExpr>,
2469  check::PostStmt<ObjCArrayLiteral>,
2470  check::PostStmt<ObjCDictionaryLiteral>,
2471  check::PostStmt<ObjCBoxedExpr>,
2472  check::PostStmt<ObjCIvarRefExpr>,
2473  check::PostCall,
2474  check::PreStmt<ReturnStmt>,
2475  check::RegionChanges,
2476  eval::Assume,
2477  eval::Call > {
2478  mutable std::unique_ptr<CFRefBug> useAfterRelease, releaseNotOwned;
2479  mutable std::unique_ptr<CFRefBug> deallocGC, deallocNotOwned;
2480  mutable std::unique_ptr<CFRefBug> overAutorelease, returnNotOwnedForOwned;
2481  mutable std::unique_ptr<CFRefBug> leakWithinFunction, leakAtReturn;
2482  mutable std::unique_ptr<CFRefBug> leakWithinFunctionGC, leakAtReturnGC;
2483 
2484  typedef llvm::DenseMap<SymbolRef, const CheckerProgramPointTag *> SymbolTagMap;
2485 
2486  // This map is only used to ensure proper deletion of any allocated tags.
2487  mutable SymbolTagMap DeadSymbolTags;
2488 
2489  mutable std::unique_ptr<RetainSummaryManager> Summaries;
2490  mutable std::unique_ptr<RetainSummaryManager> SummariesGC;
2491  mutable SummaryLogTy SummaryLog;
2492  mutable bool ShouldResetSummaryLog;
2493 
2494  /// Optional setting to indicate if leak reports should include
2495  /// the allocation line.
2496  mutable bool IncludeAllocationLine;
2497 
2498 public:
2499  RetainCountChecker(AnalyzerOptions &AO)
2500  : ShouldResetSummaryLog(false),
2501  IncludeAllocationLine(shouldIncludeAllocationSiteInLeakDiagnostics(AO)) {}
2502 
2503  ~RetainCountChecker() override { DeleteContainerSeconds(DeadSymbolTags); }
2504 
2505  void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR,
2506  ExprEngine &Eng) const {
2507  // FIXME: This is a hack to make sure the summary log gets cleared between
2508  // analyses of different code bodies.
2509  //
2510  // Why is this necessary? Because a checker's lifetime is tied to a
2511  // translation unit, but an ExplodedGraph's lifetime is just a code body.
2512  // Once in a blue moon, a new ExplodedNode will have the same address as an
2513  // old one with an associated summary, and the bug report visitor gets very
2514  // confused. (To make things worse, the summary lifetime is currently also
2515  // tied to a code body, so we get a crash instead of incorrect results.)
2516  //
2517  // Why is this a bad solution? Because if the lifetime of the ExplodedGraph
2518  // changes, things will start going wrong again. Really the lifetime of this
2519  // log needs to be tied to either the specific nodes in it or the entire
2520  // ExplodedGraph, not to a specific part of the code being analyzed.
2521  //
2522  // (Also, having stateful local data means that the same checker can't be
2523  // used from multiple threads, but a lot of checkers have incorrect
2524  // assumptions about that anyway. So that wasn't a priority at the time of
2525  // this fix.)
2526  //
2527  // This happens at the end of analysis, but bug reports are emitted /after/
2528  // this point. So we can't just clear the summary log now. Instead, we mark
2529  // that the next time we access the summary log, it should be cleared.
2530 
2531  // If we never reset the summary log during /this/ code body analysis,
2532  // there were no new summaries. There might still have been summaries from
2533  // the /last/ analysis, so clear them out to make sure the bug report
2534  // visitors don't get confused.
2535  if (ShouldResetSummaryLog)
2536  SummaryLog.clear();
2537 
2538  ShouldResetSummaryLog = !SummaryLog.empty();
2539  }
2540 
2541  CFRefBug *getLeakWithinFunctionBug(const LangOptions &LOpts,
2542  bool GCEnabled) const {
2543  if (GCEnabled) {
2544  if (!leakWithinFunctionGC)
2545  leakWithinFunctionGC.reset(new Leak(this, "Leak of object when using "
2546  "garbage collection"));
2547  return leakWithinFunctionGC.get();
2548  } else {
2549  if (!leakWithinFunction) {
2550  if (LOpts.getGC() == LangOptions::HybridGC) {
2551  leakWithinFunction.reset(new Leak(this,
2552  "Leak of object when not using "
2553  "garbage collection (GC) in "
2554  "dual GC/non-GC code"));
2555  } else {
2556  leakWithinFunction.reset(new Leak(this, "Leak"));
2557  }
2558  }
2559  return leakWithinFunction.get();
2560  }
2561  }
2562 
2563  CFRefBug *getLeakAtReturnBug(const LangOptions &LOpts, bool GCEnabled) const {
2564  if (GCEnabled) {
2565  if (!leakAtReturnGC)
2566  leakAtReturnGC.reset(new Leak(this,
2567  "Leak of returned object when using "
2568  "garbage collection"));
2569  return leakAtReturnGC.get();
2570  } else {
2571  if (!leakAtReturn) {
2572  if (LOpts.getGC() == LangOptions::HybridGC) {
2573  leakAtReturn.reset(new Leak(this,
2574  "Leak of returned object when not using "
2575  "garbage collection (GC) in dual "
2576  "GC/non-GC code"));
2577  } else {
2578  leakAtReturn.reset(new Leak(this, "Leak of returned object"));
2579  }
2580  }
2581  return leakAtReturn.get();
2582  }
2583  }
2584 
2585  RetainSummaryManager &getSummaryManager(ASTContext &Ctx,
2586  bool GCEnabled) const {
2587  // FIXME: We don't support ARC being turned on and off during one analysis.
2588  // (nor, for that matter, do we support changing ASTContexts)
2589  bool ARCEnabled = (bool)Ctx.getLangOpts().ObjCAutoRefCount;
2590  if (GCEnabled) {
2591  if (!SummariesGC)
2592  SummariesGC.reset(new RetainSummaryManager(Ctx, true, ARCEnabled));
2593  else
2594  assert(SummariesGC->isARCEnabled() == ARCEnabled);
2595  return *SummariesGC;
2596  } else {
2597  if (!Summaries)
2598  Summaries.reset(new RetainSummaryManager(Ctx, false, ARCEnabled));
2599  else
2600  assert(Summaries->isARCEnabled() == ARCEnabled);
2601  return *Summaries;
2602  }
2603  }
2604 
2605  RetainSummaryManager &getSummaryManager(CheckerContext &C) const {
2606  return getSummaryManager(C.getASTContext(), C.isObjCGCEnabled());
2607  }
2608 
2609  void printState(raw_ostream &Out, ProgramStateRef State,
2610  const char *NL, const char *Sep) const override;
2611 
2612  void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const;
2613  void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
2614  void checkPostStmt(const CastExpr *CE, CheckerContext &C) const;
2615 
2616  void checkPostStmt(const ObjCArrayLiteral *AL, CheckerContext &C) const;
2617  void checkPostStmt(const ObjCDictionaryLiteral *DL, CheckerContext &C) const;
2618  void checkPostStmt(const ObjCBoxedExpr *BE, CheckerContext &C) const;
2619 
2620  void checkPostStmt(const ObjCIvarRefExpr *IRE, CheckerContext &C) const;
2621 
2622  void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
2623 
2624  void checkSummary(const RetainSummary &Summ, const CallEvent &Call,
2625  CheckerContext &C) const;
2626 
2627  void processSummaryOfInlined(const RetainSummary &Summ,
2628  const CallEvent &Call,
2629  CheckerContext &C) const;
2630 
2631  bool evalCall(const CallExpr *CE, CheckerContext &C) const;
2632 
2633  ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond,
2634  bool Assumption) const;
2635 
2637  checkRegionChanges(ProgramStateRef state,
2638  const InvalidatedSymbols *invalidated,
2639  ArrayRef<const MemRegion *> ExplicitRegions,
2641  const CallEvent *Call) const;
2642 
2643  bool wantsRegionChangeUpdate(ProgramStateRef state) const {
2644  return true;
2645  }
2646 
2647  void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const;
2648  void checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C,
2649  ExplodedNode *Pred, RetEffect RE, RefVal X,
2650  SymbolRef Sym, ProgramStateRef state) const;
2651 
2652  void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
2653  void checkEndFunction(CheckerContext &C) const;
2654 
2655  ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym,
2656  RefVal V, ArgEffect E, RefVal::Kind &hasErr,
2657  CheckerContext &C) const;
2658 
2659  void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange,
2660  RefVal::Kind ErrorKind, SymbolRef Sym,
2661  CheckerContext &C) const;
2662 
2663  void processObjCLiterals(CheckerContext &C, const Expr *Ex) const;
2664 
2665  const ProgramPointTag *getDeadSymbolTag(SymbolRef sym) const;
2666 
2667  ProgramStateRef handleSymbolDeath(ProgramStateRef state,
2668  SymbolRef sid, RefVal V,
2669  SmallVectorImpl<SymbolRef> &Leaked) const;
2670 
2672  handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred,
2673  const ProgramPointTag *Tag, CheckerContext &Ctx,
2674  SymbolRef Sym, RefVal V) const;
2675 
2676  ExplodedNode *processLeaks(ProgramStateRef state,
2678  CheckerContext &Ctx,
2679  ExplodedNode *Pred = nullptr) const;
2680 };
2681 } // end anonymous namespace
2682 
2683 namespace {
2684 class StopTrackingCallback final : public SymbolVisitor {
2686 public:
2687  StopTrackingCallback(ProgramStateRef st) : state(std::move(st)) {}
2688  ProgramStateRef getState() const { return state; }
2689 
2690  bool VisitSymbol(SymbolRef sym) override {
2691  state = state->remove<RefBindings>(sym);
2692  return true;
2693  }
2694 };
2695 } // end anonymous namespace
2696 
2697 //===----------------------------------------------------------------------===//
2698 // Handle statements that may have an effect on refcounts.
2699 //===----------------------------------------------------------------------===//
2700 
2701 void RetainCountChecker::checkPostStmt(const BlockExpr *BE,
2702  CheckerContext &C) const {
2703 
2704  // Scan the BlockDecRefExprs for any object the retain count checker
2705  // may be tracking.
2706  if (!BE->getBlockDecl()->hasCaptures())
2707  return;
2708 
2710  const BlockDataRegion *R =
2711  cast<BlockDataRegion>(state->getSVal(BE,
2712  C.getLocationContext()).getAsRegion());
2713 
2715  E = R->referenced_vars_end();
2716 
2717  if (I == E)
2718  return;
2719 
2720  // FIXME: For now we invalidate the tracking of all symbols passed to blocks
2721  // via captured variables, even though captured variables result in a copy
2722  // and in implicit increment/decrement of a retain count.
2724  const LocationContext *LC = C.getLocationContext();
2726 
2727  for ( ; I != E; ++I) {
2728  const VarRegion *VR = I.getCapturedRegion();
2729  if (VR->getSuperRegion() == R) {
2730  VR = MemMgr.getVarRegion(VR->getDecl(), LC);
2731  }
2732  Regions.push_back(VR);
2733  }
2734 
2735  state =
2736  state->scanReachableSymbols<StopTrackingCallback>(Regions.data(),
2737  Regions.data() + Regions.size()).getState();
2738  C.addTransition(state);
2739 }
2740 
2741 void RetainCountChecker::checkPostStmt(const CastExpr *CE,
2742  CheckerContext &C) const {
2743  const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE);
2744  if (!BE)
2745  return;
2746 
2747  ArgEffect AE = IncRef;
2748 
2749  switch (BE->getBridgeKind()) {
2750  case clang::OBC_Bridge:
2751  // Do nothing.
2752  return;
2754  AE = IncRef;
2755  break;
2758  break;
2759  }
2760 
2761  ProgramStateRef state = C.getState();
2762  SymbolRef Sym = state->getSVal(CE, C.getLocationContext()).getAsLocSymbol();
2763  if (!Sym)
2764  return;
2765  const RefVal* T = getRefBinding(state, Sym);
2766  if (!T)
2767  return;
2768 
2769  RefVal::Kind hasErr = (RefVal::Kind) 0;
2770  state = updateSymbol(state, Sym, *T, AE, hasErr, C);
2771 
2772  if (hasErr) {
2773  // FIXME: If we get an error during a bridge cast, should we report it?
2774  return;
2775  }
2776 
2777  C.addTransition(state);
2778 }
2779 
2780 void RetainCountChecker::processObjCLiterals(CheckerContext &C,
2781  const Expr *Ex) const {
2782  ProgramStateRef state = C.getState();
2783  const ExplodedNode *pred = C.getPredecessor();
2784  for (const Stmt *Child : Ex->children()) {
2785  SVal V = state->getSVal(Child, pred->getLocationContext());
2786  if (SymbolRef sym = V.getAsSymbol())
2787  if (const RefVal* T = getRefBinding(state, sym)) {
2788  RefVal::Kind hasErr = (RefVal::Kind) 0;
2789  state = updateSymbol(state, sym, *T, MayEscape, hasErr, C);
2790  if (hasErr) {
2791  processNonLeakError(state, Child->getSourceRange(), hasErr, sym, C);
2792  return;
2793  }
2794  }
2795  }
2796 
2797  // Return the object as autoreleased.
2798  // RetEffect RE = RetEffect::MakeNotOwned(RetEffect::ObjC);
2799  if (SymbolRef sym =
2800  state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) {
2801  QualType ResultTy = Ex->getType();
2802  state = setRefBinding(state, sym,
2803  RefVal::makeNotOwned(RetEffect::ObjC, ResultTy));
2804  }
2805 
2806  C.addTransition(state);
2807 }
2808 
2809 void RetainCountChecker::checkPostStmt(const ObjCArrayLiteral *AL,
2810  CheckerContext &C) const {
2811  // Apply the 'MayEscape' to all values.
2812  processObjCLiterals(C, AL);
2813 }
2814 
2815 void RetainCountChecker::checkPostStmt(const ObjCDictionaryLiteral *DL,
2816  CheckerContext &C) const {
2817  // Apply the 'MayEscape' to all keys and values.
2818  processObjCLiterals(C, DL);
2819 }
2820 
2821 void RetainCountChecker::checkPostStmt(const ObjCBoxedExpr *Ex,
2822  CheckerContext &C) const {
2823  const ExplodedNode *Pred = C.getPredecessor();
2824  const LocationContext *LCtx = Pred->getLocationContext();
2825  ProgramStateRef State = Pred->getState();
2826 
2827  if (SymbolRef Sym = State->getSVal(Ex, LCtx).getAsSymbol()) {
2828  QualType ResultTy = Ex->getType();
2829  State = setRefBinding(State, Sym,
2830  RefVal::makeNotOwned(RetEffect::ObjC, ResultTy));
2831  }
2832 
2833  C.addTransition(State);
2834 }
2835 
2836 void RetainCountChecker::checkPostStmt(const ObjCIvarRefExpr *IRE,
2837  CheckerContext &C) const {
2838  Optional<Loc> IVarLoc = C.getSVal(IRE).getAs<Loc>();
2839  if (!IVarLoc)
2840  return;
2841 
2842  ProgramStateRef State = C.getState();
2843  SymbolRef Sym = State->getSVal(*IVarLoc).getAsSymbol();
2844  if (!Sym || !dyn_cast_or_null<ObjCIvarRegion>(Sym->getOriginRegion()))
2845  return;
2846 
2847  // Accessing an ivar directly is unusual. If we've done that, be more
2848  // forgiving about what the surrounding code is allowed to do.
2849 
2850  QualType Ty = Sym->getType();
2852  if (Ty->isObjCRetainableType())
2853  Kind = RetEffect::ObjC;
2854  else if (coreFoundation::isCFObjectRef(Ty))
2855  Kind = RetEffect::CF;
2856  else
2857  return;
2858 
2859  // If the value is already known to be nil, don't bother tracking it.
2860  ConstraintManager &CMgr = State->getConstraintManager();
2861  if (CMgr.isNull(State, Sym).isConstrainedTrue())
2862  return;
2863 
2864  if (const RefVal *RV = getRefBinding(State, Sym)) {
2865  // If we've seen this symbol before, or we're only seeing it now because
2866  // of something the analyzer has synthesized, don't do anything.
2867  if (RV->getIvarAccessHistory() != RefVal::IvarAccessHistory::None ||
2869  return;
2870  }
2871 
2872  // Note that this value has been loaded from an ivar.
2873  C.addTransition(setRefBinding(State, Sym, RV->withIvarAccess()));
2874  return;
2875  }
2876 
2877  RefVal PlusZero = RefVal::makeNotOwned(Kind, Ty);
2878 
2879  // In a synthesized accessor, the effective retain count is +0.
2881  C.addTransition(setRefBinding(State, Sym, PlusZero));
2882  return;
2883  }
2884 
2885  State = setRefBinding(State, Sym, PlusZero.withIvarAccess());
2886  C.addTransition(State);
2887 }
2888 
2889 void RetainCountChecker::checkPostCall(const CallEvent &Call,
2890  CheckerContext &C) const {
2891  RetainSummaryManager &Summaries = getSummaryManager(C);
2892  const RetainSummary *Summ = Summaries.getSummary(Call, C.getState());
2893 
2894  if (C.wasInlined) {
2895  processSummaryOfInlined(*Summ, Call, C);
2896  return;
2897  }
2898  checkSummary(*Summ, Call, C);
2899 }
2900 
2901 /// GetReturnType - Used to get the return type of a message expression or
2902 /// function call with the intention of affixing that type to a tracked symbol.
2903 /// While the return type can be queried directly from RetEx, when
2904 /// invoking class methods we augment to the return type to be that of
2905 /// a pointer to the class (as opposed it just being id).
2906 // FIXME: We may be able to do this with related result types instead.
2907 // This function is probably overestimating.
2908 static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) {
2909  QualType RetTy = RetE->getType();
2910  // If RetE is not a message expression just return its type.
2911  // If RetE is a message expression, return its types if it is something
2912  /// more specific than id.
2913  if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE))
2914  if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>())
2915  if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() ||
2916  PT->isObjCClassType()) {
2917  // At this point we know the return type of the message expression is
2918  // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this
2919  // is a call to a class method whose type we can resolve. In such
2920  // cases, promote the return type to XXX* (where XXX is the class).
2921  const ObjCInterfaceDecl *D = ME->getReceiverInterface();
2922  return !D ? RetTy :
2924  }
2925 
2926  return RetTy;
2927 }
2928 
2929 // We don't always get the exact modeling of the function with regards to the
2930 // retain count checker even when the function is inlined. For example, we need
2931 // to stop tracking the symbols which were marked with StopTrackingHard.
2932 void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ,
2933  const CallEvent &CallOrMsg,
2934  CheckerContext &C) const {
2935  ProgramStateRef state = C.getState();
2936 
2937  // Evaluate the effect of the arguments.
2938  for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) {
2939  if (Summ.getArg(idx) == StopTrackingHard) {
2940  SVal V = CallOrMsg.getArgSVal(idx);
2941  if (SymbolRef Sym = V.getAsLocSymbol()) {
2942  state = removeRefBinding(state, Sym);
2943  }
2944  }
2945  }
2946 
2947  // Evaluate the effect on the message receiver.
2948  const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg);
2949  if (MsgInvocation) {
2950  if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) {
2951  if (Summ.getReceiverEffect() == StopTrackingHard) {
2952  state = removeRefBinding(state, Sym);
2953  }
2954  }
2955  }
2956 
2957  // Consult the summary for the return value.
2958  RetEffect RE = Summ.getRetEffect();
2959  if (RE.getKind() == RetEffect::NoRetHard) {
2960  SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol();
2961  if (Sym)
2962  state = removeRefBinding(state, Sym);
2963  }
2964 
2965  C.addTransition(state);
2966 }
2967 
2969  SVal ArgVal,
2970  ArgEffect Effect) {
2971  auto *ArgRegion = dyn_cast_or_null<TypedValueRegion>(ArgVal.getAsRegion());
2972  if (!ArgRegion)
2973  return State;
2974 
2975  QualType PointeeTy = ArgRegion->getValueType();
2976  if (!coreFoundation::isCFObjectRef(PointeeTy))
2977  return State;
2978 
2979  SVal PointeeVal = State->getSVal(ArgRegion);
2980  SymbolRef Pointee = PointeeVal.getAsLocSymbol();
2981  if (!Pointee)
2982  return State;
2983 
2984  switch (Effect) {
2986  State = setRefBinding(State, Pointee,
2987  RefVal::makeNotOwned(RetEffect::CF, PointeeTy));
2988  break;
2989  case RetainedOutParameter:
2990  // Do nothing. Retained out parameters will either point to a +1 reference
2991  // or NULL, but the way you check for failure differs depending on the API.
2992  // Consequently, we don't have a good way to track them yet.
2993  break;
2994 
2995  default:
2996  llvm_unreachable("only for out parameters");
2997  }
2998 
2999  return State;
3000 }
3001 
3002 void RetainCountChecker::checkSummary(const RetainSummary &Summ,
3003  const CallEvent &CallOrMsg,
3004  CheckerContext &C) const {
3005  ProgramStateRef state = C.getState();
3006 
3007  // Evaluate the effect of the arguments.
3008  RefVal::Kind hasErr = (RefVal::Kind) 0;
3009  SourceRange ErrorRange;
3010  SymbolRef ErrorSym = nullptr;
3011 
3012  for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) {
3013  SVal V = CallOrMsg.getArgSVal(idx);
3014 
3015  ArgEffect Effect = Summ.getArg(idx);
3016  if (Effect == RetainedOutParameter || Effect == UnretainedOutParameter) {
3017  state = updateOutParameter(state, V, Effect);
3018  } else if (SymbolRef Sym = V.getAsLocSymbol()) {
3019  if (const RefVal *T = getRefBinding(state, Sym)) {
3020  state = updateSymbol(state, Sym, *T, Effect, hasErr, C);
3021  if (hasErr) {
3022  ErrorRange = CallOrMsg.getArgSourceRange(idx);
3023  ErrorSym = Sym;
3024  break;
3025  }
3026  }
3027  }
3028  }
3029 
3030  // Evaluate the effect on the message receiver.
3031  bool ReceiverIsTracked = false;
3032  if (!hasErr) {
3033  const ObjCMethodCall *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg);
3034  if (MsgInvocation) {
3035  if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) {
3036  if (const RefVal *T = getRefBinding(state, Sym)) {
3037  ReceiverIsTracked = true;
3038  state = updateSymbol(state, Sym, *T, Summ.getReceiverEffect(),
3039  hasErr, C);
3040  if (hasErr) {
3041  ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange();
3042  ErrorSym = Sym;
3043  }
3044  }
3045  }
3046  }
3047  }
3048 
3049  // Process any errors.
3050  if (hasErr) {
3051  processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C);
3052  return;
3053  }
3054 
3055  // Consult the summary for the return value.
3056  RetEffect RE = Summ.getRetEffect();
3057 
3058  if (RE.getKind() == RetEffect::OwnedWhenTrackedReceiver) {
3059  if (ReceiverIsTracked)
3060  RE = getSummaryManager(C).getObjAllocRetEffect();
3061  else
3062  RE = RetEffect::MakeNoRet();
3063  }
3064 
3065  switch (RE.getKind()) {
3066  default:
3067  llvm_unreachable("Unhandled RetEffect.");
3068 
3069  case RetEffect::NoRet:
3070  case RetEffect::NoRetHard:
3071  // No work necessary.
3072  break;
3073 
3074  case RetEffect::OwnedAllocatedSymbol:
3075  case RetEffect::OwnedSymbol: {
3076  SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol();
3077  if (!Sym)
3078  break;
3079 
3080  // Use the result type from the CallEvent as it automatically adjusts
3081  // for methods/functions that return references.
3082  QualType ResultTy = CallOrMsg.getResultType();
3083  state = setRefBinding(state, Sym, RefVal::makeOwned(RE.getObjKind(),
3084  ResultTy));
3085 
3086  // FIXME: Add a flag to the checker where allocations are assumed to
3087  // *not* fail.
3088  break;
3089  }
3090 
3091  case RetEffect::GCNotOwnedSymbol:
3092  case RetEffect::NotOwnedSymbol: {
3093  const Expr *Ex = CallOrMsg.getOriginExpr();
3094  SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol();
3095  if (!Sym)
3096  break;
3097  assert(Ex);
3098  // Use GetReturnType in order to give [NSFoo alloc] the type NSFoo *.
3099  QualType ResultTy = GetReturnType(Ex, C.getASTContext());
3100  state = setRefBinding(state, Sym, RefVal::makeNotOwned(RE.getObjKind(),
3101  ResultTy));
3102  break;
3103  }
3104  }
3105 
3106  // This check is actually necessary; otherwise the statement builder thinks
3107  // we've hit a previously-found path.
3108  // Normally addTransition takes care of this, but we want the node pointer.
3109  ExplodedNode *NewNode;
3110  if (state == C.getState()) {
3111  NewNode = C.getPredecessor();
3112  } else {
3113  NewNode = C.addTransition(state);
3114  }
3115 
3116  // Annotate the node with summary we used.
3117  if (NewNode) {
3118  // FIXME: This is ugly. See checkEndAnalysis for why it's necessary.
3119  if (ShouldResetSummaryLog) {
3120  SummaryLog.clear();
3121  ShouldResetSummaryLog = false;
3122  }
3123  SummaryLog[NewNode] = &Summ;
3124  }
3125 }
3126 
3128 RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym,
3129  RefVal V, ArgEffect E, RefVal::Kind &hasErr,
3130  CheckerContext &C) const {
3131  // In GC mode [... release] and [... retain] do nothing.
3132  // In ARC mode they shouldn't exist at all, but we just ignore them.
3133  bool IgnoreRetainMsg = C.isObjCGCEnabled();
3134  if (!IgnoreRetainMsg)
3135  IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount;
3136 
3137  switch (E) {
3138  default:
3139  break;
3140  case IncRefMsg:
3141  E = IgnoreRetainMsg ? DoNothing : IncRef;
3142  break;
3143  case DecRefMsg:
3144  E = IgnoreRetainMsg ? DoNothing : DecRef;
3145  break;
3147  E = IgnoreRetainMsg ? StopTracking : DecRefAndStopTrackingHard;
3148  break;
3149  case MakeCollectable:
3150  E = C.isObjCGCEnabled() ? DecRef : DoNothing;
3151  break;
3152  }
3153 
3154  // Handle all use-after-releases.
3155  if (!C.isObjCGCEnabled() && V.getKind() == RefVal::Released) {
3156  V = V ^ RefVal::ErrorUseAfterRelease;
3157  hasErr = V.getKind();
3158  return setRefBinding(state, sym, V);
3159  }
3160 
3161  switch (E) {
3162  case DecRefMsg:
3163  case IncRefMsg:
3164  case MakeCollectable:
3166  llvm_unreachable("DecRefMsg/IncRefMsg/MakeCollectable already converted");
3167 
3169  case RetainedOutParameter:
3170  llvm_unreachable("Applies to pointer-to-pointer parameters, which should "
3171  "not have ref state.");
3172 
3173  case Dealloc:
3174  // Any use of -dealloc in GC is *bad*.
3175  if (C.isObjCGCEnabled()) {
3176  V = V ^ RefVal::ErrorDeallocGC;
3177  hasErr = V.getKind();
3178  break;
3179  }
3180 
3181  switch (V.getKind()) {
3182  default:
3183  llvm_unreachable("Invalid RefVal state for an explicit dealloc.");
3184  case RefVal::Owned:
3185  // The object immediately transitions to the released state.
3186  V = V ^ RefVal::Released;
3187  V.clearCounts();
3188  return setRefBinding(state, sym, V);
3189  case RefVal::NotOwned:
3190  V = V ^ RefVal::ErrorDeallocNotOwned;
3191  hasErr = V.getKind();
3192  break;
3193  }
3194  break;
3195 
3196  case MayEscape:
3197  if (V.getKind() == RefVal::Owned) {
3198  V = V ^ RefVal::NotOwned;
3199  break;
3200  }
3201 
3202  // Fall-through.
3203 
3204  case DoNothing:
3205  return state;
3206 
3207  case Autorelease:
3208  if (C.isObjCGCEnabled())
3209  return state;
3210  // Update the autorelease counts.
3211  V = V.autorelease();
3212  break;
3213 
3214  case StopTracking:
3215  case StopTrackingHard:
3216  return removeRefBinding(state, sym);
3217 
3218  case IncRef:
3219  switch (V.getKind()) {
3220  default:
3221  llvm_unreachable("Invalid RefVal state for a retain.");
3222  case RefVal::Owned:
3223  case RefVal::NotOwned:
3224  V = V + 1;
3225  break;
3226  case RefVal::Released:
3227  // Non-GC cases are handled above.
3228  assert(C.isObjCGCEnabled());
3229  V = (V ^ RefVal::Owned) + 1;
3230  break;
3231  }
3232  break;
3233 
3234  case DecRef:
3237  switch (V.getKind()) {
3238  default:
3239  // case 'RefVal::Released' handled above.
3240  llvm_unreachable("Invalid RefVal state for a release.");
3241 
3242  case RefVal::Owned:
3243  assert(V.getCount() > 0);
3244  if (V.getCount() == 1) {
3245  if (E == DecRefBridgedTransferred ||
3246  V.getIvarAccessHistory() ==
3247  RefVal::IvarAccessHistory::AccessedDirectly)
3248  V = V ^ RefVal::NotOwned;
3249  else
3250  V = V ^ RefVal::Released;
3251  } else if (E == DecRefAndStopTrackingHard) {
3252  return removeRefBinding(state, sym);
3253  }
3254 
3255  V = V - 1;
3256  break;
3257 
3258  case RefVal::NotOwned:
3259  if (V.getCount() > 0) {
3260  if (E == DecRefAndStopTrackingHard)
3261  return removeRefBinding(state, sym);
3262  V = V - 1;
3263  } else if (V.getIvarAccessHistory() ==
3264  RefVal::IvarAccessHistory::AccessedDirectly) {
3265  // Assume that the instance variable was holding on the object at
3266  // +1, and we just didn't know.
3267  if (E == DecRefAndStopTrackingHard)
3268  return removeRefBinding(state, sym);
3269  V = V.releaseViaIvar() ^ RefVal::Released;
3270  } else {
3271  V = V ^ RefVal::ErrorReleaseNotOwned;
3272  hasErr = V.getKind();
3273  }
3274  break;
3275 
3276  case RefVal::Released:
3277  // Non-GC cases are handled above.
3278  assert(C.isObjCGCEnabled());
3279  V = V ^ RefVal::ErrorUseAfterRelease;
3280  hasErr = V.getKind();
3281  break;
3282  }
3283  break;
3284  }
3285  return setRefBinding(state, sym, V);
3286 }
3287 
3288 void RetainCountChecker::processNonLeakError(ProgramStateRef St,
3289  SourceRange ErrorRange,
3290  RefVal::Kind ErrorKind,
3291  SymbolRef Sym,
3292  CheckerContext &C) const {
3293  // HACK: Ignore retain-count issues on values accessed through ivars,
3294  // because of cases like this:
3295  // [_contentView retain];
3296  // [_contentView removeFromSuperview];
3297  // [self addSubview:_contentView]; // invalidates 'self'
3298  // [_contentView release];
3299  if (const RefVal *RV = getRefBinding(St, Sym))
3300  if (RV->getIvarAccessHistory() != RefVal::IvarAccessHistory::None)
3301  return;
3302 
3303  ExplodedNode *N = C.generateErrorNode(St);
3304  if (!N)
3305  return;
3306 
3307  CFRefBug *BT;
3308  switch (ErrorKind) {
3309  default:
3310  llvm_unreachable("Unhandled error.");
3311  case RefVal::ErrorUseAfterRelease:
3312  if (!useAfterRelease)
3313  useAfterRelease.reset(new UseAfterRelease(this));
3314  BT = useAfterRelease.get();
3315  break;
3316  case RefVal::ErrorReleaseNotOwned:
3317  if (!releaseNotOwned)
3318  releaseNotOwned.reset(new BadRelease(this));
3319  BT = releaseNotOwned.get();
3320  break;
3321  case RefVal::ErrorDeallocGC:
3322  if (!deallocGC)
3323  deallocGC.reset(new DeallocGC(this));
3324  BT = deallocGC.get();
3325  break;
3326  case RefVal::ErrorDeallocNotOwned:
3327  if (!deallocNotOwned)
3328  deallocNotOwned.reset(new DeallocNotOwned(this));
3329  BT = deallocNotOwned.get();
3330  break;
3331  }
3332 
3333  assert(BT);
3334  auto report = std::unique_ptr<BugReport>(
3335  new CFRefReport(*BT, C.getASTContext().getLangOpts(), C.isObjCGCEnabled(),
3336  SummaryLog, N, Sym));
3337  report->addRange(ErrorRange);
3338  C.emitReport(std::move(report));
3339 }
3340 
3341 //===----------------------------------------------------------------------===//
3342 // Handle the return values of retain-count-related functions.
3343 //===----------------------------------------------------------------------===//
3344 
3345 bool RetainCountChecker::evalCall(const CallExpr *CE, CheckerContext &C) const {
3346  // Get the callee. We're only interested in simple C functions.
3347  ProgramStateRef state = C.getState();
3348  const FunctionDecl *FD = C.getCalleeDecl(CE);
3349  if (!FD)
3350  return false;
3351 
3352  IdentifierInfo *II = FD->getIdentifier();
3353  if (!II)
3354  return false;
3355 
3356  // For now, we're only handling the functions that return aliases of their
3357  // arguments: CFRetain and CFMakeCollectable (and their families).
3358  // Eventually we should add other functions we can model entirely,
3359  // such as CFRelease, which don't invalidate their arguments or globals.
3360  if (CE->getNumArgs() != 1)
3361  return false;
3362 
3363  // Get the name of the function.
3364  StringRef FName = II->getName();
3365  FName = FName.substr(FName.find_first_not_of('_'));
3366 
3367  // See if it's one of the specific functions we know how to eval.
3368  bool canEval = false;
3369 
3370  QualType ResultTy = CE->getCallReturnType(C.getASTContext());
3371  if (ResultTy->isObjCIdType()) {
3372  // Handle: id NSMakeCollectable(CFTypeRef)
3373  canEval = II->isStr("NSMakeCollectable");
3374  } else if (ResultTy->isPointerType()) {
3375  // Handle: (CF|CG)Retain
3376  // CFAutorelease
3377  // CFMakeCollectable
3378  // It's okay to be a little sloppy here (CGMakeCollectable doesn't exist).
3379  if (cocoa::isRefType(ResultTy, "CF", FName) ||
3380  cocoa::isRefType(ResultTy, "CG", FName)) {
3381  canEval = isRetain(FD, FName) || isAutorelease(FD, FName) ||
3382  isMakeCollectable(FD, FName);
3383  }
3384  }
3385 
3386  if (!canEval)
3387  return false;
3388 
3389  // Bind the return value.
3390  const LocationContext *LCtx = C.getLocationContext();
3391  SVal RetVal = state->getSVal(CE->getArg(0), LCtx);
3392  if (RetVal.isUnknown()) {
3393  // If the receiver is unknown, conjure a return value.
3394  SValBuilder &SVB = C.getSValBuilder();
3395  RetVal = SVB.conjureSymbolVal(nullptr, CE, LCtx, ResultTy, C.blockCount());
3396  }
3397  state = state->BindExpr(CE, LCtx, RetVal, false);
3398 
3399  // FIXME: This should not be necessary, but otherwise the argument seems to be
3400  // considered alive during the next statement.
3401  if (const MemRegion *ArgRegion = RetVal.getAsRegion()) {
3402  // Save the refcount status of the argument.
3403  SymbolRef Sym = RetVal.getAsLocSymbol();
3404  const RefVal *Binding = nullptr;
3405  if (Sym)
3406  Binding = getRefBinding(state, Sym);
3407 
3408  // Invalidate the argument region.
3409  state = state->invalidateRegions(ArgRegion, CE, C.blockCount(), LCtx,
3410  /*CausesPointerEscape*/ false);
3411 
3412  // Restore the refcount status of the argument.
3413  if (Binding)
3414  state = setRefBinding(state, Sym, *Binding);
3415  }
3416 
3417  C.addTransition(state);
3418  return true;
3419 }
3420 
3421 //===----------------------------------------------------------------------===//
3422 // Handle return statements.
3423 //===----------------------------------------------------------------------===//
3424 
3425 void RetainCountChecker::checkPreStmt(const ReturnStmt *S,
3426  CheckerContext &C) const {
3427 
3428  // Only adjust the reference count if this is the top-level call frame,
3429  // and not the result of inlining. In the future, we should do
3430  // better checking even for inlined calls, and see if they match
3431  // with their expected semantics (e.g., the method should return a retained
3432  // object, etc.).
3433  if (!C.inTopFrame())
3434  return;
3435 
3436  const Expr *RetE = S->getRetValue();
3437  if (!RetE)
3438  return;
3439 
3440  ProgramStateRef state = C.getState();
3441  SymbolRef Sym =
3442  state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol();
3443  if (!Sym)
3444  return;
3445 
3446  // Get the reference count binding (if any).
3447  const RefVal *T = getRefBinding(state, Sym);
3448  if (!T)
3449  return;
3450 
3451  // Change the reference count.
3452  RefVal X = *T;
3453 
3454  switch (X.getKind()) {
3455  case RefVal::Owned: {
3456  unsigned cnt = X.getCount();
3457  assert(cnt > 0);
3458  X.setCount(cnt - 1);
3459  X = X ^ RefVal::ReturnedOwned;
3460  break;
3461  }
3462 
3463  case RefVal::NotOwned: {
3464  unsigned cnt = X.getCount();
3465  if (cnt) {
3466  X.setCount(cnt - 1);
3467  X = X ^ RefVal::ReturnedOwned;
3468  }
3469  else {
3470  X = X ^ RefVal::ReturnedNotOwned;
3471  }
3472  break;
3473  }
3474 
3475  default:
3476  return;
3477  }
3478 
3479  // Update the binding.
3480  state = setRefBinding(state, Sym, X);
3481  ExplodedNode *Pred = C.addTransition(state);
3482 
3483  // At this point we have updated the state properly.
3484  // Everything after this is merely checking to see if the return value has
3485  // been over- or under-retained.
3486 
3487  // Did we cache out?
3488  if (!Pred)
3489  return;
3490 
3491  // Update the autorelease counts.
3492  static CheckerProgramPointTag AutoreleaseTag(this, "Autorelease");
3493  state = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, C, Sym, X);
3494 
3495  // Did we cache out?
3496  if (!state)
3497  return;
3498 
3499  // Get the updated binding.
3500  T = getRefBinding(state, Sym);
3501  assert(T);
3502  X = *T;
3503 
3504  // Consult the summary of the enclosing method.
3505  RetainSummaryManager &Summaries = getSummaryManager(C);
3506  const Decl *CD = &Pred->getCodeDecl();
3507  RetEffect RE = RetEffect::MakeNoRet();
3508 
3509  // FIXME: What is the convention for blocks? Is there one?
3510  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) {
3511  const RetainSummary *Summ = Summaries.getMethodSummary(MD);
3512  RE = Summ->getRetEffect();
3513  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) {
3514  if (!isa<CXXMethodDecl>(FD)) {
3515  const RetainSummary *Summ = Summaries.getFunctionSummary(FD);
3516  RE = Summ->getRetEffect();
3517  }
3518  }
3519 
3520  checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state);
3521 }
3522 
3523 void RetainCountChecker::checkReturnWithRetEffect(const ReturnStmt *S,
3524  CheckerContext &C,
3525  ExplodedNode *Pred,
3526  RetEffect RE, RefVal X,
3527  SymbolRef Sym,
3528  ProgramStateRef state) const {
3529  // HACK: Ignore retain-count issues on values accessed through ivars,
3530  // because of cases like this:
3531  // [_contentView retain];
3532  // [_contentView removeFromSuperview];
3533  // [self addSubview:_contentView]; // invalidates 'self'
3534  // [_contentView release];
3535  if (X.getIvarAccessHistory() != RefVal::IvarAccessHistory::None)
3536  return;
3537 
3538  // Any leaks or other errors?
3539  if (X.isReturnedOwned() && X.getCount() == 0) {
3540  if (RE.getKind() != RetEffect::NoRet) {
3541  bool hasError = false;
3542  if (C.isObjCGCEnabled() && RE.getObjKind() == RetEffect::ObjC) {
3543  // Things are more complicated with garbage collection. If the
3544  // returned object is suppose to be an Objective-C object, we have
3545  // a leak (as the caller expects a GC'ed object) because no
3546  // method should return ownership unless it returns a CF object.
3547  hasError = true;
3548  X = X ^ RefVal::ErrorGCLeakReturned;
3549  }
3550  else if (!RE.isOwned()) {
3551  // Either we are using GC and the returned object is a CF type
3552  // or we aren't using GC. In either case, we expect that the
3553  // enclosing method is expected to return ownership.
3554  hasError = true;
3555  X = X ^ RefVal::ErrorLeakReturned;
3556  }
3557 
3558  if (hasError) {
3559  // Generate an error node.
3560  state = setRefBinding(state, Sym, X);
3561 
3562  static CheckerProgramPointTag ReturnOwnLeakTag(this, "ReturnsOwnLeak");
3563  ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag);
3564  if (N) {
3565  const LangOptions &LOpts = C.getASTContext().getLangOpts();
3566  bool GCEnabled = C.isObjCGCEnabled();
3567  C.emitReport(std::unique_ptr<BugReport>(new CFRefLeakReport(
3568  *getLeakAtReturnBug(LOpts, GCEnabled), LOpts, GCEnabled,
3569  SummaryLog, N, Sym, C, IncludeAllocationLine)));
3570  }
3571  }
3572  }
3573  } else if (X.isReturnedNotOwned()) {
3574  if (RE.isOwned()) {
3575  if (X.getIvarAccessHistory() ==
3576  RefVal::IvarAccessHistory::AccessedDirectly) {
3577  // Assume the method was trying to transfer a +1 reference from a
3578  // strong ivar to the caller.
3579  state = setRefBinding(state, Sym,
3580  X.releaseViaIvar() ^ RefVal::ReturnedOwned);
3581  } else {
3582  // Trying to return a not owned object to a caller expecting an
3583  // owned object.
3584  state = setRefBinding(state, Sym, X ^ RefVal::ErrorReturnedNotOwned);
3585 
3586  static CheckerProgramPointTag
3587  ReturnNotOwnedTag(this, "ReturnNotOwnedForOwned");
3588 
3589  ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag);
3590  if (N) {
3591  if (!returnNotOwnedForOwned)
3592  returnNotOwnedForOwned.reset(new ReturnedNotOwnedForOwned(this));
3593 
3594  C.emitReport(std::unique_ptr<BugReport>(new CFRefReport(
3595  *returnNotOwnedForOwned, C.getASTContext().getLangOpts(),
3596  C.isObjCGCEnabled(), SummaryLog, N, Sym)));
3597  }
3598  }
3599  }
3600  }
3601 }
3602 
3603 //===----------------------------------------------------------------------===//
3604 // Check various ways a symbol can be invalidated.
3605 //===----------------------------------------------------------------------===//
3606 
3607 void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S,
3608  CheckerContext &C) const {
3609  // Are we storing to something that causes the value to "escape"?
3610  bool escapes = true;
3611 
3612  // A value escapes in three possible cases (this may change):
3613  //
3614  // (1) we are binding to something that is not a memory region.
3615  // (2) we are binding to a memregion that does not have stack storage
3616  // (3) we are binding to a memregion with stack storage that the store
3617  // does not understand.
3618  ProgramStateRef state = C.getState();
3619 
3620  if (Optional<loc::MemRegionVal> regionLoc = loc.getAs<loc::MemRegionVal>()) {
3621  escapes = !regionLoc->getRegion()->hasStackStorage();
3622 
3623  if (!escapes) {
3624  // To test (3), generate a new state with the binding added. If it is
3625  // the same state, then it escapes (since the store cannot represent
3626  // the binding).
3627  // Do this only if we know that the store is not supposed to generate the
3628  // same state.
3629  SVal StoredVal = state->getSVal(regionLoc->getRegion());
3630  if (StoredVal != val)
3631  escapes = (state == (state->bindLoc(*regionLoc, val)));
3632  }
3633  if (!escapes) {
3634  // Case 4: We do not currently model what happens when a symbol is
3635  // assigned to a struct field, so be conservative here and let the symbol
3636  // go. TODO: This could definitely be improved upon.
3637  escapes = !isa<VarRegion>(regionLoc->getRegion());
3638  }
3639  }
3640 
3641  // If we are storing the value into an auto function scope variable annotated
3642  // with (__attribute__((cleanup))), stop tracking the value to avoid leak
3643  // false positives.
3644  if (const VarRegion *LVR = dyn_cast_or_null<VarRegion>(loc.getAsRegion())) {
3645  const VarDecl *VD = LVR->getDecl();
3646  if (VD->hasAttr<CleanupAttr>()) {
3647  escapes = true;
3648  }
3649  }
3650 
3651  // If our store can represent the binding and we aren't storing to something
3652  // that doesn't have local storage then just return and have the simulation
3653  // state continue as is.
3654  if (!escapes)
3655  return;
3656 
3657  // Otherwise, find all symbols referenced by 'val' that we are tracking
3658  // and stop tracking them.
3659  state = state->scanReachableSymbols<StopTrackingCallback>(val).getState();
3660  C.addTransition(state);
3661 }
3662 
3663 ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state,
3664  SVal Cond,
3665  bool Assumption) const {
3666  // FIXME: We may add to the interface of evalAssume the list of symbols
3667  // whose assumptions have changed. For now we just iterate through the
3668  // bindings and check if any of the tracked symbols are NULL. This isn't
3669  // too bad since the number of symbols we will track in practice are
3670  // probably small and evalAssume is only called at branches and a few
3671  // other places.
3672  RefBindingsTy B = state->get<RefBindings>();
3673 
3674  if (B.isEmpty())
3675  return state;
3676 
3677  bool changed = false;
3678  RefBindingsTy::Factory &RefBFactory = state->get_context<RefBindings>();
3679 
3680  for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) {
3681  // Check if the symbol is null stop tracking the symbol.
3682  ConstraintManager &CMgr = state->getConstraintManager();
3683  ConditionTruthVal AllocFailed = CMgr.isNull(state, I.getKey());
3684  if (AllocFailed.isConstrainedTrue()) {
3685  changed = true;
3686  B = RefBFactory.remove(B, I.getKey());
3687  }
3688  }
3689 
3690  if (changed)
3691  state = state->set<RefBindings>(B);
3692 
3693  return state;
3694 }
3695 
3697 RetainCountChecker::checkRegionChanges(ProgramStateRef state,
3698  const InvalidatedSymbols *invalidated,
3699  ArrayRef<const MemRegion *> ExplicitRegions,
3701  const CallEvent *Call) const {
3702  if (!invalidated)
3703  return state;
3704 
3705  llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols;
3706  for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(),
3707  E = ExplicitRegions.end(); I != E; ++I) {
3708  if (const SymbolicRegion *SR = (*I)->StripCasts()->getAs<SymbolicRegion>())
3709  WhitelistedSymbols.insert(SR->getSymbol());
3710  }
3711 
3712  for (InvalidatedSymbols::const_iterator I=invalidated->begin(),
3713  E = invalidated->end(); I!=E; ++I) {
3714  SymbolRef sym = *I;
3715  if (WhitelistedSymbols.count(sym))
3716  continue;
3717  // Remove any existing reference-count binding.
3718  state = removeRefBinding(state, sym);
3719  }
3720  return state;
3721 }
3722 
3723 //===----------------------------------------------------------------------===//
3724 // Handle dead symbols and end-of-path.
3725 //===----------------------------------------------------------------------===//
3726 
3728 RetainCountChecker::handleAutoreleaseCounts(ProgramStateRef state,
3729  ExplodedNode *Pred,
3730  const ProgramPointTag *Tag,
3731  CheckerContext &Ctx,
3732  SymbolRef Sym, RefVal V) const {
3733  unsigned ACnt = V.getAutoreleaseCount();
3734 
3735  // No autorelease counts? Nothing to be done.
3736  if (!ACnt)
3737  return state;
3738 
3739  assert(!Ctx.isObjCGCEnabled() && "Autorelease counts in GC mode?");
3740  unsigned Cnt = V.getCount();
3741 
3742  // FIXME: Handle sending 'autorelease' to already released object.
3743 
3744  if (V.getKind() == RefVal::ReturnedOwned)
3745  ++Cnt;
3746 
3747  // If we would over-release here, but we know the value came from an ivar,
3748  // assume it was a strong ivar that's just been relinquished.
3749  if (ACnt > Cnt &&
3750  V.getIvarAccessHistory() == RefVal::IvarAccessHistory::AccessedDirectly) {
3751  V = V.releaseViaIvar();
3752  --ACnt;
3753  }
3754 
3755  if (ACnt <= Cnt) {
3756  if (ACnt == Cnt) {
3757  V.clearCounts();
3758  if (V.getKind() == RefVal::ReturnedOwned)
3759  V = V ^ RefVal::ReturnedNotOwned;
3760  else
3761  V = V ^ RefVal::NotOwned;
3762  } else {
3763  V.setCount(V.getCount() - ACnt);
3764  V.setAutoreleaseCount(0);
3765  }
3766  return setRefBinding(state, Sym, V);
3767  }
3768 
3769  // HACK: Ignore retain-count issues on values accessed through ivars,
3770  // because of cases like this:
3771  // [_contentView retain];
3772  // [_contentView removeFromSuperview];
3773  // [self addSubview:_contentView]; // invalidates 'self'
3774  // [_contentView release];
3775  if (V.getIvarAccessHistory() != RefVal::IvarAccessHistory::None)
3776  return state;
3777 
3778  // Woah! More autorelease counts then retain counts left.
3779  // Emit hard error.
3780  V = V ^ RefVal::ErrorOverAutorelease;
3781  state = setRefBinding(state, Sym, V);
3782 
3783  ExplodedNode *N = Ctx.generateSink(state, Pred, Tag);
3784  if (N) {
3785  SmallString<128> sbuf;
3786  llvm::raw_svector_ostream os(sbuf);
3787  os << "Object was autoreleased ";
3788  if (V.getAutoreleaseCount() > 1)
3789  os << V.getAutoreleaseCount() << " times but the object ";
3790  else
3791  os << "but ";
3792  os << "has a +" << V.getCount() << " retain count";
3793 
3794  if (!overAutorelease)
3795  overAutorelease.reset(new OverAutorelease(this));
3796 
3797  const LangOptions &LOpts = Ctx.getASTContext().getLangOpts();
3798  Ctx.emitReport(std::unique_ptr<BugReport>(
3799  new CFRefReport(*overAutorelease, LOpts, /* GCEnabled = */ false,
3800  SummaryLog, N, Sym, os.str())));
3801  }
3802 
3803  return nullptr;
3804 }
3805 
3807 RetainCountChecker::handleSymbolDeath(ProgramStateRef state,
3808  SymbolRef sid, RefVal V,
3809  SmallVectorImpl<SymbolRef> &Leaked) const {
3810  bool hasLeak;
3811 
3812  // HACK: Ignore retain-count issues on values accessed through ivars,
3813  // because of cases like this:
3814  // [_contentView retain];
3815  // [_contentView removeFromSuperview];
3816  // [self addSubview:_contentView]; // invalidates 'self'
3817  // [_contentView release];
3818  if (V.getIvarAccessHistory() != RefVal::IvarAccessHistory::None)
3819  hasLeak = false;
3820  else if (V.isOwned())
3821  hasLeak = true;
3822  else if (V.isNotOwned() || V.isReturnedOwned())
3823  hasLeak = (V.getCount() > 0);
3824  else
3825  hasLeak = false;
3826 
3827  if (!hasLeak)
3828  return removeRefBinding(state, sid);
3829 
3830  Leaked.push_back(sid);
3831  return setRefBinding(state, sid, V ^ RefVal::ErrorLeak);
3832 }
3833 
3834 ExplodedNode *
3835 RetainCountChecker::processLeaks(ProgramStateRef state,
3837  CheckerContext &Ctx,
3838  ExplodedNode *Pred) const {
3839  // Generate an intermediate node representing the leak point.
3840  ExplodedNode *N = Ctx.addTransition(state, Pred);
3841 
3842  if (N) {
3844  I = Leaked.begin(), E = Leaked.end(); I != E; ++I) {
3845 
3846  const LangOptions &LOpts = Ctx.getASTContext().getLangOpts();
3847  bool GCEnabled = Ctx.isObjCGCEnabled();
3848  CFRefBug *BT = Pred ? getLeakWithinFunctionBug(LOpts, GCEnabled)
3849  : getLeakAtReturnBug(LOpts, GCEnabled);
3850  assert(BT && "BugType not initialized.");
3851 
3852  Ctx.emitReport(std::unique_ptr<BugReport>(
3853  new CFRefLeakReport(*BT, LOpts, GCEnabled, SummaryLog, N, *I, Ctx,
3854  IncludeAllocationLine)));
3855  }
3856  }
3857 
3858  return N;
3859 }
3860 
3861 void RetainCountChecker::checkEndFunction(CheckerContext &Ctx) const {
3862  ProgramStateRef state = Ctx.getState();
3863  RefBindingsTy B = state->get<RefBindings>();
3864  ExplodedNode *Pred = Ctx.getPredecessor();
3865 
3866  // Don't process anything within synthesized bodies.
3867  const LocationContext *LCtx = Pred->getLocationContext();
3869  assert(LCtx->getParent());
3870  return;
3871  }
3872 
3873  for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) {
3874  state = handleAutoreleaseCounts(state, Pred, /*Tag=*/nullptr, Ctx,
3875  I->first, I->second);
3876  if (!state)
3877  return;
3878  }
3879 
3880  // If the current LocationContext has a parent, don't check for leaks.
3881  // We will do that later.
3882  // FIXME: we should instead check for imbalances of the retain/releases,
3883  // and suggest annotations.
3884  if (LCtx->getParent())
3885  return;
3886 
3887  B = state->get<RefBindings>();
3889 
3890  for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I)
3891  state = handleSymbolDeath(state, I->first, I->second, Leaked);
3892 
3893  processLeaks(state, Leaked, Ctx, Pred);
3894 }
3895 
3896 const ProgramPointTag *
3897 RetainCountChecker::getDeadSymbolTag(SymbolRef sym) const {
3898  const CheckerProgramPointTag *&tag = DeadSymbolTags[sym];
3899  if (!tag) {
3900  SmallString<64> buf;
3901  llvm::raw_svector_ostream out(buf);
3902  out << "Dead Symbol : ";
3903  sym->dumpToStream(out);
3904  tag = new CheckerProgramPointTag(this, out.str());
3905  }
3906  return tag;
3907 }
3908 
3909 void RetainCountChecker::checkDeadSymbols(SymbolReaper &SymReaper,
3910  CheckerContext &C) const {
3911  ExplodedNode *Pred = C.getPredecessor();
3912 
3913  ProgramStateRef state = C.getState();
3914  RefBindingsTy B = state->get<RefBindings>();
3916 
3917  // Update counts from autorelease pools
3918  for (SymbolReaper::dead_iterator I = SymReaper.dead_begin(),
3919  E = SymReaper.dead_end(); I != E; ++I) {
3920  SymbolRef Sym = *I;
3921  if (const RefVal *T = B.lookup(Sym)){
3922  // Use the symbol as the tag.
3923  // FIXME: This might not be as unique as we would like.
3924  const ProgramPointTag *Tag = getDeadSymbolTag(Sym);
3925  state = handleAutoreleaseCounts(state, Pred, Tag, C, Sym, *T);
3926  if (!state)
3927  return;
3928 
3929  // Fetch the new reference count from the state, and use it to handle
3930  // this symbol.
3931  state = handleSymbolDeath(state, *I, *getRefBinding(state, Sym), Leaked);
3932  }
3933  }
3934 
3935  if (Leaked.empty()) {
3936  C.addTransition(state);
3937  return;
3938  }
3939 
3940  Pred = processLeaks(state, Leaked, C, Pred);
3941 
3942  // Did we cache out?
3943  if (!Pred)
3944  return;
3945 
3946  // Now generate a new node that nukes the old bindings.
3947  // The only bindings left at this point are the leaked symbols.
3948  RefBindingsTy::Factory &F = state->get_context<RefBindings>();
3949  B = state->get<RefBindings>();
3950 
3951  for (SmallVectorImpl<SymbolRef>::iterator I = Leaked.begin(),
3952  E = Leaked.end();
3953  I != E; ++I)
3954  B = F.remove(B, *I);
3955 
3956  state = state->set<RefBindings>(B);
3957  C.addTransition(state, Pred);
3958 }
3959 
3960 void RetainCountChecker::printState(raw_ostream &Out, ProgramStateRef State,
3961  const char *NL, const char *Sep) const {
3962 
3963  RefBindingsTy B = State->get<RefBindings>();
3964 
3965  if (B.isEmpty())
3966  return;
3967 
3968  Out << Sep << NL;
3969 
3970  for (RefBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) {
3971  Out << I->first << " : ";
3972  I->second.print(Out);
3973  Out << NL;
3974  }
3975 }
3976 
3977 //===----------------------------------------------------------------------===//
3978 // Checker registration.
3979 //===----------------------------------------------------------------------===//
3980 
3981 void ento::registerRetainCountChecker(CheckerManager &Mgr) {
3982  Mgr.registerChecker<RetainCountChecker>(Mgr.getAnalyzerOptions());
3983 }
3984 
3985 //===----------------------------------------------------------------------===//
3986 // Implementation of the CallEffects API.
3987 //===----------------------------------------------------------------------===//
3988 
3989 namespace clang {
3990 namespace ento {
3991 namespace objc_retain {
3992 
3993 // This is a bit gross, but it allows us to populate CallEffects without
3994 // creating a bunch of accessors. This kind is very localized, so the
3995 // damage of this macro is limited.
3996 #define createCallEffect(D, KIND)\
3997  ASTContext &Ctx = D->getASTContext();\
3998  LangOptions L = Ctx.getLangOpts();\
3999  RetainSummaryManager M(Ctx, L.GCOnly, L.ObjCAutoRefCount);\
4000  const RetainSummary *S = M.get ## KIND ## Summary(D);\
4001  CallEffects CE(S->getRetEffect());\
4002  CE.Receiver = S->getReceiverEffect();\
4003  unsigned N = D->param_size();\
4004  for (unsigned i = 0; i < N; ++i) {\
4005  CE.Args.push_back(S->getArg(i));\
4006  }
4007 
4009  createCallEffect(MD, Method);
4010  return CE;
4011 }
4012 
4014  createCallEffect(FD, Function);
4015  return CE;
4016 }
4017 
4018 #undef createCallEffect
4019 
4020 } // end namespace objc_retain
4021 } // end namespace ento
4022 } // end namespace clang
virtual SVal getArgSVal(unsigned Index) const
Returns the value of a given argument at the time of the call.
Definition: CallEvent.cpp:223
param_const_iterator param_begin() const
Definition: DeclObjC.h:354
static Selector GetNullarySelector(StringRef name, ASTContext &Ctx)
Utility function for constructing a nullary selector.
Definition: ASTContext.h:2605
FunctionDecl - An instance of this class is created to represent a function declaration or definition...
Definition: Decl.h:1561
Smart pointer class that efficiently represents Objective-C method names.
A (possibly-)qualified type.
Definition: Type.h:598
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:79
ExplodedNode * generateErrorNode(ProgramStateRef State=nullptr, const ProgramPointTag *Tag=nullptr)
Generate a transition to a node that will be used to report an error.
Expr * getArg(unsigned Arg)
getArg - Return the specified argument.
Definition: Expr.h:2217
ObjCInterfaceDecl * getClassInterface()
Definition: DeclObjC.cpp:1071
#define va_end(ap)
Definition: stdarg.h:34
bool isInstanceMessage() const
Definition: CallEvent.h:917
static Selector GetUnarySelector(StringRef name, ASTContext &Ctx)
Utility function for constructing an unary selector.
Definition: ASTContext.h:2611
bool operator==(CanQual< T > x, CanQual< U > y)
IdentifierInfo * getIdentifier() const
getIdentifier - Get the identifier that names this declaration, if there is one.
Definition: Decl.h:232
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:2879
Bridging via __bridge, which does nothing but reinterpret the bits.
static ProgramStateRef removeRefBinding(ProgramStateRef State, SymbolRef Sym)
const StackFrameContext * getStackFrame() const
Definition: MemRegion.cpp:170
Defines the SourceManager interface.
The argument acts as if has been passed to CFMakeCollectable, which transfers the object to the Garba...
ProgramPoint getLocation() const
getLocation - Returns the edge associated with the given node.
ExplodedNode * addTransition(ProgramStateRef State=nullptr, const ProgramPointTag *Tag=nullptr)
Generates a new transition in the program state graph (ExplodedGraph).
Represents a point when we begin processing an inlined call.
Definition: ProgramPoint.h:584
Manages the lifetime of CallEvent objects.
Definition: CallEvent.h:993
The argument has its reference count decreased by 1.
StringRef P
const RegionTy * getAs() const
Definition: MemRegion.h:1106
bool isCocoaObjectRef(QualType T)
llvm::DenseMap< Stmt *, Stmt * > MapTy
Definition: ParentMap.cpp:22
static Selector getKeywordSelector(ASTContext &Ctx, va_list argp)
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:768
referenced_vars_iterator referenced_vars_begin() const
Definition: MemRegion.cpp:1479
bool hasCaptures() const
hasCaptures - True if this block (or its nested blocks) captures anything of local storage from its e...
Definition: Decl.h:3573
The argument is a pointer to a retain-counted object; on exit, the new value of the pointer is a +1 v...
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:113
ExplodedNode * getPredecessor()
Returns the previous node in the exploded graph, which includes the state of the program before the c...
const MemRegion * getBaseRegion() const
Definition: MemRegion.cpp:1129
virtual const MemRegion * getOriginRegion() const
Find the region from which this symbol originates.
Definition: SymExpr.h:92
ParmVarDecl - Represents a parameter to a function.
Definition: Decl.h:1377
bool isObjCRetainableType() const
Definition: Type.cpp:3699
const bool wasInlined
If we are post visiting a call, this flag will be set if the call was inlined.
const char *const MemoryCoreFoundationObjectiveC
referenced_vars_iterator referenced_vars_end() const
Definition: MemRegion.cpp:1496
Symbolic value.
Definition: SymExpr.h:29
unsigned getNumParams() const
Definition: Type.h:3271
ConditionTruthVal isNull(ProgramStateRef State, SymbolRef Sym)
Convenience method to query the state to see if a symbol is null or not null, or if neither assumptio...
const ObjCInterfaceDecl * getReceiverInterface() const
Get the interface for the receiver.
Definition: CallEvent.h:939
One of these records is kept for each identifier that is lexed.
MemRegionManager & getRegionManager()
Definition: SValBuilder.h:145
class LLVM_ALIGNAS(8) DependentTemplateSpecializationType const IdentifierInfo * Name
Represents a template specialization type whose template cannot be resolved, e.g. ...
Definition: Type.h:4549
bool isBodyAutosynthesized() const
Checks if the body of the Decl is generated by the BodyFarm.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:92
const FunctionDecl * getCalleeDecl(const CallExpr *CE) const
Get the declaration of the called function (path-sensitive).
LineState State
QualType getReturnType() const
Definition: Decl.h:2034
bool isKeywordSelector() const
This class provides a convenience implementation for clone() using the Curiously-Recurring Template P...
The argument is treated as if an -autorelease message had been sent to the referenced object...
AnalysisDeclContext * getAnalysisDeclContext() const
const Expr * getOriginExpr() const
Returns the expression whose value will be the result of this call.
Definition: CallEvent.h:223
SymbolRef getAsLocSymbol(bool IncludeBaseRegions=false) const
If this SVal is a location and wraps a symbol, return that SymbolRef.
Definition: SVals.cpp:69
unsigned blockCount() const
Returns the number of times the current block has been visited along the analyzed path...
clang::CharUnits operator*(clang::CharUnits::QuantityType Scale, const clang::CharUnits &CU)
Definition: CharUnits.h:208
const FunctionDecl * getAsFunctionDecl() const
getAsFunctionDecl - If this SVal is a MemRegionVal and wraps a CodeTextRegion wrapping a FunctionDecl...
Definition: SVals.cpp:51
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:48
ObjCArrayLiteral - used for objective-c array containers; as in: @["Hello", NSApp, [NSNumber numberWithInt:42]];.
Definition: ExprObjC.h:144
i32 captured_struct **param SharedsTy A type which contains references the shared variables *param Shareds Context with the list of shared variables from the p *TaskFunction *param Data Additional data for task generation like final * state
static bool isRetain(const FunctionDecl *FD, StringRef FName)
static AllocationInfo GetAllocationSite(ProgramStateManager &StateMgr, const ExplodedNode *N, SymbolRef Sym)
const VarDecl * getDecl() const
Definition: MemRegion.h:873
virtual llvm::iterator_range< ranges_iterator > getRanges()
Get the SourceRanges associated with the report.
static bool isEqual(const ObjCSummaryKey &LHS, const ObjCSummaryKey &RHS)
bool followsCreateRule(const FunctionDecl *FD)
BlockDataRegion - A region that represents a block instance.
Definition: MemRegion.h:627
Represents any expression that calls an Objective-C method.
Definition: CallEvent.h:881
virtual Kind getKind() const =0
Returns the kind of call this is.
SVal getReceiverSVal() const
Returns the value of the receiver at the time of this call.
Definition: CallEvent.cpp:712
const LangOptions & getLangOpts() const
Definition: ASTContext.h:604
ObjCBridgeCastKind getBridgeKind() const
Determine which kind of bridge is being performed via this cast.
Definition: ExprObjC.h:1546
static void Profile(const ArgEffect X, FoldingSetNodeID &ID)
ProgramStateManager & getStateManager()
The argument has its reference count increased by 1.
ObjCMethodFamily getMethodFamily() const
Determines the family of this method.
Definition: DeclObjC.cpp:913
QualType getReturnType() const
Definition: Type.h:3009
const TemplateArgument & getArg(unsigned Idx) const
Retrieve a specific template argument as a type.
const Stmt * getCallSite() const
bool isParentOf(const LocationContext *LC) const
dead_iterator dead_begin() const
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:2632
Represents an ObjC class declaration.
Definition: DeclObjC.h:1091
Bridging via __bridge_transfer, which transfers ownership of an Objective-C pointer into ARC...
static bool isNumericLiteralExpression(const Expr *E)
detail::InMemoryDirectory::const_iterator I
virtual BugReport::NodeResolver & getNodeResolver()=0
QualType getType() const
Definition: Decl.h:599
virtual QualType getType() const =0
virtual SourceRange getArgSourceRange(unsigned Index) const
Returns the source range for errors associated with this argument.
Definition: CallEvent.cpp:230
param_iterator param_begin()
Definition: Decl.h:2000
const MemRegion * getSuperRegion() const
Definition: MemRegion.h:417
const LocationContext * getLocationContext() const
ArrayRef< ParmVarDecl * >::const_iterator param_const_iterator
Definition: Decl.h:1998
ArgEffect
An ArgEffect summarizes the retain count behavior on an argument or receiver to a function or method...
const ParmVarDecl *const * param_const_iterator
Definition: DeclObjC.h:349
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3073
The argument is treated as potentially escaping, meaning that even when its reference count hits 0 it...
llvm::ImmutableMap< unsigned, ArgEffect > ArgEffects
ArgEffects summarizes the effects of a function/method call on all of its arguments.
#define REGISTER_MAP_WITH_PROGRAMSTATE(Name, Key, Value)
Declares an immutable map of type NameTy, suitable for placement into the ProgramState.
const MemRegion * StripCasts(bool StripBaseCasts=true) const
Definition: MemRegion.cpp:1155
Represents a point when we finish the call exit sequence (for inlined call).
Definition: ProgramPoint.h:638
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:415
QualType getObjCInterfaceType(const ObjCInterfaceDecl *Decl, ObjCInterfaceDecl *PrevDecl=nullptr) const
getObjCInterfaceType - Return the unique reference to the type for the specified ObjC interface decl...
SymbolicRegion - A special, "non-concrete" region.
Definition: MemRegion.h:707
bool inTopFrame() const
Return true if the current LocationContext has no caller context.
Expr - This represents one expression.
Definition: Expr.h:105
const ProgramStateRef & getState() const
Defines the clang::LangOptions interface.
Indicates that the tracked object is a CF object.
StringRef getName() const
Return the actual identifier string.
const ProgramStateRef & getState() const
unsigned getNumArgs() const
SourceRange getReceiverRange() const
Source range of the receiver.
Definition: ExprObjC.cpp:290
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:4567
bool shouldIncludeAllocationSiteInLeakDiagnostics(AnalyzerOptions &AOpts)
Returns true if leak diagnostics should directly reference the allocatin site (where possible)...
Optional< T > getAs() const
Convert to the specified SVal type, returning None if this SVal is not of the desired type...
Definition: SVals.h:86
SymbolSetTy::const_iterator dead_iterator
static CallEffects getEffect(const ObjCMethodDecl *MD)
Return the CallEfect for a given Objective-C method.
#define bool
Definition: stdbool.h:31
ObjCDictionaryLiteral - AST node to represent objective-c dictionary literals; as in:"name" : NSUserN...
Definition: ExprObjC.h:257
static bool isRelease(const FunctionDecl *FD, StringRef FName)
bool isObjCIdType() const
Definition: Type.h:5578
ObjKind
Determines the object kind of a tracked object.
bool isInstanceMethod() const
Definition: DeclObjC.h:414
static RetEffect MakeOwned(ObjKind o, bool isAllocated=false)
T castAs() const
Convert to the specified ProgramPoint type, asserting that this ProgramPoint is of the desired type...
Definition: ProgramPoint.h:139
static bool isAutorelease(const FunctionDecl *FD, StringRef FName)
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:1366
An expression that sends a message to the given Objective-C object or class.
Definition: ExprObjC.h:860
void markInteresting(SymbolRef sym)
CallEventRef< ObjCMethodCall > getObjCMethodCall(const ObjCMessageExpr *E, ProgramStateRef State, const LocationContext *LCtx)
Definition: CallEvent.h:1056
Represents a C function or static C++ member function call.
Definition: CallEvent.h:468
const SourceManager & SM
Definition: Format.cpp:1184
static bool isSynthesizedAccessor(const StackFrameContext *SFC)
Returns true if this stack frame is for an Objective-C method that is a property getter or setter who...
param_const_iterator param_end() const
Definition: DeclObjC.h:357
void emitReport(std::unique_ptr< BugReport > R)
Emit the diagnostics report.
BugReporter is a utility class for generating PathDiagnostics for analysis.
Definition: BugReporter.h:388
bool isConsumedExpr(Expr *E) const
Definition: ParentMap.cpp:159
#define log(__x)
Definition: tgmath.h:467
static std::unique_ptr< PathDiagnosticPiece > getDefaultEndPath(BugReporterContext &BRC, const ExplodedNode *N, BugReport &BR)
Generates the default final diagnostic piece.
#define false
Definition: stdbool.h:33
Kind
CHECKER * registerChecker()
Used to register checkers.
ConstExprIterator const_arg_iterator
Definition: Expr.h:2238
The argument has its reference count increased by 1.
DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag, const Expr *expr, const LocationContext *LCtx, unsigned count)
Create a new symbol with a unique 'name'.
const TemplateArgument * iterator
Definition: Type.h:4233
ExplodedNode * generateSink(ProgramStateRef State, ExplodedNode *Pred, const ProgramPointTag *Tag=nullptr)
Generate a sink node.
The argument has its reference count decreased by 1 to model a transferred bridge cast under ARC...
const StackFrameContext * getCurrentStackFrame() const
ProgramPoints can be "tagged" as representing points specific to a given analysis entity...
Definition: ProgramPoint.h:40
const std::string ID
StringRef getNameForSlot(unsigned argIndex) const
Retrieve the name at a given position in the selector.
static ProgramStateRef updateOutParameter(ProgramStateRef State, SVal ArgVal, ArgEffect Effect)
static const RefVal * getRefBinding(ProgramStateRef State, SymbolRef Sym)
static void Profile(const RetEffect &X, FoldingSetNodeID &ID)
unsigned getSpellingLineNumber(bool *Invalid=nullptr) const
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:46
Selector getSelector() const
Definition: CallEvent.h:923
void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx)
Definition: Type.h:4262
bool isPropertyAccessor() const
Definition: DeclObjC.h:421
dead_iterator dead_end() const
#define va_start(ap, param)
Definition: stdarg.h:33
std::string getAsString() const
Derive the full selector name (e.g.
const Decl * getDecl() const
A class responsible for cleaning up unused symbols.
QualType getReturnType() const
Definition: DeclObjC.h:330
const IdentifierInfo * getIdentifier() const
Definition: Type.h:4580
const StackFrameContext * getStackFrame() const
ObjCBoxedExpr - used for generalized expression boxing.
Definition: ExprObjC.h:94
const BlockDecl * getBlockDecl() const
Definition: Expr.h:4581
const ObjCMethodDecl * getDecl() const override
Definition: CallEvent.h:907
QualType getCallReturnType(const ASTContext &Ctx) const
getCallReturnType - Get the return type of the call expr.
Definition: Expr.cpp:1272
bool isStr(const char(&Str)[StrLen]) const
Return true if this is the identifier for the specified string.
An Objective-C "bridged" cast expression, which casts between Objective-C pointers and C pointers...
Definition: ExprObjC.h:1519
QualType getType() const
Definition: Expr.h:126
if(T->getSizeExpr()) TRY_TO(TraverseStmt(T-> getSizeExpr()))
static ProgramStateRef setRefBinding(ProgramStateRef State, SymbolRef Sym, RefVal Val)
const LocationContext * getParent() const
All typestate tracking of the object ceases.
bool isRefType(QualType RetTy, StringRef Prefix, StringRef Name=StringRef())
const Decl & getCodeDecl() const
virtual bool VisitSymbol(SymbolRef sym)=0
A visitor method invoked by ProgramStateManager::scanReachableSymbols.
ObjCMethodDecl * getInstanceMethod(Selector Sel, bool AllowHidden=false) const
Definition: DeclObjC.h:1007
The argument is treated as if an -dealloc message had been sent to the referenced object...
const VarRegion * getVarRegion(const VarDecl *D, const LocationContext *LC)
getVarRegion - Retrieve or create the memory region associated with a specified VarDecl and LocationC...
Definition: MemRegion.cpp:821
Performs the combined functionality of DecRef and StopTrackingHard.
__builtin_va_list va_list
Definition: stdarg.h:30
QualType getObjCObjectPointerType(QualType OIT) const
Return a ObjCObjectPointerType type for the given ObjCObjectType.
Selector getSelector() const
Definition: DeclObjC.h:328
detail::InMemoryDirectory::const_iterator E
const MemRegion * getAsRegion() const
Definition: SVals.cpp:135
ObjCMethodFamily getMethodFamily() const
Derive the conventional family of this method.
const Expr * getRetValue() const
Definition: Stmt.cpp:899
bool isConstrainedTrue() const
Return true if the constraint is perfectly constrained to 'true'.
unsigned getNumArgs() const
getNumArgs - Return the number of actual arguments to this call.
Definition: Expr.h:2205
Represents an abstract call to a function or method along a particular path.
Definition: CallEvent.h:138
Bridging via __bridge_retain, which makes an ARC object available as a +1 C pointer.
Optional< T > getAs() const
Convert to the specified ProgramPoint type, returning None if this ProgramPoint is not of the desired...
Definition: ProgramPoint.h:150
AnalyzerOptions & getAnalyzerOptions()
RetEffect summarizes a call's retain/release behavior with respect to its return value.
param_iterator param_end()
Definition: Decl.h:2001
static ArgEffect getStopTrackingHardEquivalent(ArgEffect E)
virtual void dumpToStream(raw_ostream &os) const
Definition: SymExpr.h:52
Represents a pointer to an Objective C object.
Definition: Type.h:4991
QualType getResultType() const
Returns the result type, adjusted for references.
Definition: CallEvent.cpp:28
const T * getAs() const
Member-template getAs<specific type>'.
Definition: Type.h:5818
#define createCallEffect(D, KIND)
bool isUnknown() const
Definition: SVals.h:117
Performs the combined functionality of DecRefMsg and StopTrackingHard.
ProgramStateManager & getStateManager()
Definition: BugReporter.h:538
The argument is a pointer to a retain-counted object; on exit, the new value of the pointer is a +0 v...
static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName)
ObjCIvarRefExpr - A reference to an ObjC instance variable.
Definition: ExprObjC.h:479
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:12171
No particular method family.
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
virtual void printState(raw_ostream &Out, ProgramStateRef State, const char *NL, const char *Sep) const
See CheckerManager::runCheckersForPrintState.
Definition: Checker.h:489
pred_iterator pred_begin()
SourceManager & getSourceManager()
virtual unsigned getNumArgs() const =0
Returns the number of arguments (explicit and implicit).
static PathDiagnosticLocation createEndOfPath(const ExplodedNode *N, const SourceManager &SM)
Create a location corresponding to the next valid ExplodedNode as end of path location.
SymbolRef getAsSymbol(bool IncludeBaseRegions=false) const
If this SVal wraps a symbol return that SymbolRef.
Definition: SVals.cpp:111
SValBuilder & getSValBuilder()
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2148
A SourceLocation and its associated SourceManager.
ObjCInterfaceDecl * getSuperClass() const
Definition: DeclObjC.cpp:314
static Decl::Kind getKind(const Decl *D)
Definition: DeclBase.cpp:810
virtual const ExplodedNode * getOriginalNode(const ExplodedNode *N)=0
All typestate tracking of the object ceases.
void iterBindings(ProgramStateRef state, StoreManager::BindingsHandler &F)
Definition: ProgramState.h:537
The argument has its reference count decreased by 1.
Encapsulates the retain count semantics on the arguments, return value, and receiver (if any) of a fu...
#define true
Definition: stdbool.h:32
A trivial tuple used to represent a source range.
Tag that can use a checker name as a message provider (see SimpleProgramPointTag).
Definition: Checker.h:498
This class provides an interface through which checkers can create individual bug reports...
Definition: BugReporter.h:55
bool hasNonZeroCallbackArg() const
Returns true if any of the arguments appear to represent callbacks.
Definition: CallEvent.cpp:113
static unsigned getHashValue(const ObjCSummaryKey &V)
bool isNull() const
Return true if this QualType doesn't point to a type yet.
Definition: Type.h:665
virtual const ObjCMessageExpr * getOriginExpr() const
Definition: CallEvent.h:904
SVal getReturnValue() const
Returns the return value of the call.
Definition: CallEvent.cpp:237
This class handles loading and caching of source files into memory.
SourceManager & getSourceManager()
Definition: BugReporter.h:550
static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx)
GetReturnType - Used to get the return type of a message expression or function call with the intenti...
const LocationContext * getLocationContext() const
SVal getSVal(const Stmt *S) const
Get the value of arbitrary expressions at this point in the path.
bool isPointerType() const
Definition: Type.h:5482