clang  9.0.0svn
RetainCountChecker.cpp
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1 //==-- RetainCountChecker.cpp - Checks for leaks and other issues -*- C++ -*--//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the methods for RetainCountChecker, which implements
10 // a reference count checker for Core Foundation and Cocoa on (Mac OS X).
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "RetainCountChecker.h"
16 
17 using namespace clang;
18 using namespace ento;
19 using namespace retaincountchecker;
20 using llvm::StrInStrNoCase;
21 
22 REGISTER_MAP_WITH_PROGRAMSTATE(RefBindings, SymbolRef, RefVal)
23 
24 namespace clang {
25 namespace ento {
26 namespace retaincountchecker {
27 
29  return State->get<RefBindings>(Sym);
30 }
31 
32 } // end namespace retaincountchecker
33 } // end namespace ento
34 } // end namespace clang
35 
37  RefVal Val) {
38  assert(Sym != nullptr);
39  return State->set<RefBindings>(Sym, Val);
40 }
41 
43  return State->remove<RefBindings>(Sym);
44 }
45 
46 void RefVal::print(raw_ostream &Out) const {
47  if (!T.isNull())
48  Out << "Tracked " << T.getAsString() << " | ";
49 
50  switch (getKind()) {
51  default: llvm_unreachable("Invalid RefVal kind");
52  case Owned: {
53  Out << "Owned";
54  unsigned cnt = getCount();
55  if (cnt) Out << " (+ " << cnt << ")";
56  break;
57  }
58 
59  case NotOwned: {
60  Out << "NotOwned";
61  unsigned cnt = getCount();
62  if (cnt) Out << " (+ " << cnt << ")";
63  break;
64  }
65 
66  case ReturnedOwned: {
67  Out << "ReturnedOwned";
68  unsigned cnt = getCount();
69  if (cnt) Out << " (+ " << cnt << ")";
70  break;
71  }
72 
73  case ReturnedNotOwned: {
74  Out << "ReturnedNotOwned";
75  unsigned cnt = getCount();
76  if (cnt) Out << " (+ " << cnt << ")";
77  break;
78  }
79 
80  case Released:
81  Out << "Released";
82  break;
83 
84  case ErrorDeallocNotOwned:
85  Out << "-dealloc (not-owned)";
86  break;
87 
88  case ErrorLeak:
89  Out << "Leaked";
90  break;
91 
92  case ErrorLeakReturned:
93  Out << "Leaked (Bad naming)";
94  break;
95 
96  case ErrorUseAfterRelease:
97  Out << "Use-After-Release [ERROR]";
98  break;
99 
100  case ErrorReleaseNotOwned:
101  Out << "Release of Not-Owned [ERROR]";
102  break;
103 
105  Out << "Over-autoreleased";
106  break;
107 
109  Out << "Non-owned object returned instead of owned";
110  break;
111  }
112 
113  switch (getIvarAccessHistory()) {
115  break;
116  case IvarAccessHistory::AccessedDirectly:
117  Out << " [direct ivar access]";
118  break;
119  case IvarAccessHistory::ReleasedAfterDirectAccess:
120  Out << " [released after direct ivar access]";
121  }
122 
123  if (ACnt) {
124  Out << " [autorelease -" << ACnt << ']';
125  }
126 }
127 
128 namespace {
129 class StopTrackingCallback final : public SymbolVisitor {
131 public:
132  StopTrackingCallback(ProgramStateRef st) : state(std::move(st)) {}
133  ProgramStateRef getState() const { return state; }
134 
135  bool VisitSymbol(SymbolRef sym) override {
136  state = removeRefBinding(state, sym);
137  return true;
138  }
139 };
140 } // end anonymous namespace
141 
142 //===----------------------------------------------------------------------===//
143 // Handle statements that may have an effect on refcounts.
144 //===----------------------------------------------------------------------===//
145 
147  CheckerContext &C) const {
148 
149  // Scan the BlockDecRefExprs for any object the retain count checker
150  // may be tracking.
151  if (!BE->getBlockDecl()->hasCaptures())
152  return;
153 
155  auto *R = cast<BlockDataRegion>(C.getSVal(BE).getAsRegion());
156 
157  BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(),
158  E = R->referenced_vars_end();
159 
160  if (I == E)
161  return;
162 
163  // FIXME: For now we invalidate the tracking of all symbols passed to blocks
164  // via captured variables, even though captured variables result in a copy
165  // and in implicit increment/decrement of a retain count.
167  const LocationContext *LC = C.getLocationContext();
169 
170  for ( ; I != E; ++I) {
171  const VarRegion *VR = I.getCapturedRegion();
172  if (VR->getSuperRegion() == R) {
173  VR = MemMgr.getVarRegion(VR->getDecl(), LC);
174  }
175  Regions.push_back(VR);
176  }
177 
178  state = state->scanReachableSymbols<StopTrackingCallback>(Regions).getState();
179  C.addTransition(state);
180 }
181 
183  CheckerContext &C) const {
184  const ObjCBridgedCastExpr *BE = dyn_cast<ObjCBridgedCastExpr>(CE);
185  if (!BE)
186  return;
187 
188  QualType QT = CE->getType();
189  ObjKind K;
190  if (QT->isObjCObjectPointerType()) {
191  K = ObjKind::ObjC;
192  } else {
193  K = ObjKind::CF;
194  }
195 
196  ArgEffect AE = ArgEffect(IncRef, K);
197 
198  switch (BE->getBridgeKind()) {
199  case OBC_Bridge:
200  // Do nothing.
201  return;
202  case OBC_BridgeRetained:
203  AE = AE.withKind(IncRef);
204  break;
205  case OBC_BridgeTransfer:
207  break;
208  }
209 
211  SymbolRef Sym = C.getSVal(CE).getAsLocSymbol();
212  if (!Sym)
213  return;
214  const RefVal* T = getRefBinding(state, Sym);
215  if (!T)
216  return;
217 
218  RefVal::Kind hasErr = (RefVal::Kind) 0;
219  state = updateSymbol(state, Sym, *T, AE, hasErr, C);
220 
221  if (hasErr) {
222  // FIXME: If we get an error during a bridge cast, should we report it?
223  return;
224  }
225 
226  C.addTransition(state);
227 }
228 
230  const Expr *Ex) const {
232  const ExplodedNode *pred = C.getPredecessor();
233  for (const Stmt *Child : Ex->children()) {
234  SVal V = pred->getSVal(Child);
235  if (SymbolRef sym = V.getAsSymbol())
236  if (const RefVal* T = getRefBinding(state, sym)) {
237  RefVal::Kind hasErr = (RefVal::Kind) 0;
238  state = updateSymbol(state, sym, *T,
239  ArgEffect(MayEscape, ObjKind::ObjC), hasErr, C);
240  if (hasErr) {
241  processNonLeakError(state, Child->getSourceRange(), hasErr, sym, C);
242  return;
243  }
244  }
245  }
246 
247  // Return the object as autoreleased.
248  // RetEffect RE = RetEffect::MakeNotOwned(ObjKind::ObjC);
249  if (SymbolRef sym =
250  state->getSVal(Ex, pred->getLocationContext()).getAsSymbol()) {
251  QualType ResultTy = Ex->getType();
252  state = setRefBinding(state, sym,
254  }
255 
256  C.addTransition(state);
257 }
258 
260  CheckerContext &C) const {
261  // Apply the 'MayEscape' to all values.
262  processObjCLiterals(C, AL);
263 }
264 
266  CheckerContext &C) const {
267  // Apply the 'MayEscape' to all keys and values.
268  processObjCLiterals(C, DL);
269 }
270 
272  CheckerContext &C) const {
273  const ExplodedNode *Pred = C.getPredecessor();
274  ProgramStateRef State = Pred->getState();
275 
276  if (SymbolRef Sym = Pred->getSVal(Ex).getAsSymbol()) {
277  QualType ResultTy = Ex->getType();
278  State = setRefBinding(State, Sym,
280  }
281 
282  C.addTransition(State);
283 }
284 
286  CheckerContext &C) const {
287  Optional<Loc> IVarLoc = C.getSVal(IRE).getAs<Loc>();
288  if (!IVarLoc)
289  return;
290 
292  SymbolRef Sym = State->getSVal(*IVarLoc).getAsSymbol();
293  if (!Sym || !dyn_cast_or_null<ObjCIvarRegion>(Sym->getOriginRegion()))
294  return;
295 
296  // Accessing an ivar directly is unusual. If we've done that, be more
297  // forgiving about what the surrounding code is allowed to do.
298 
299  QualType Ty = Sym->getType();
300  ObjKind Kind;
301  if (Ty->isObjCRetainableType())
302  Kind = ObjKind::ObjC;
303  else if (coreFoundation::isCFObjectRef(Ty))
304  Kind = ObjKind::CF;
305  else
306  return;
307 
308  // If the value is already known to be nil, don't bother tracking it.
309  ConstraintManager &CMgr = State->getConstraintManager();
310  if (CMgr.isNull(State, Sym).isConstrainedTrue())
311  return;
312 
313  if (const RefVal *RV = getRefBinding(State, Sym)) {
314  // If we've seen this symbol before, or we're only seeing it now because
315  // of something the analyzer has synthesized, don't do anything.
316  if (RV->getIvarAccessHistory() != RefVal::IvarAccessHistory::None ||
318  return;
319  }
320 
321  // Note that this value has been loaded from an ivar.
322  C.addTransition(setRefBinding(State, Sym, RV->withIvarAccess()));
323  return;
324  }
325 
326  RefVal PlusZero = RefVal::makeNotOwned(Kind, Ty);
327 
328  // In a synthesized accessor, the effective retain count is +0.
330  C.addTransition(setRefBinding(State, Sym, PlusZero));
331  return;
332  }
333 
334  State = setRefBinding(State, Sym, PlusZero.withIvarAccess());
335  C.addTransition(State);
336 }
337 
338 static bool isReceiverUnconsumedSelf(const CallEvent &Call) {
339  if (const auto *MC = dyn_cast<ObjCMethodCall>(&Call)) {
340 
341  // Check if the message is not consumed, we know it will not be used in
342  // an assignment, ex: "self = [super init]".
343  return MC->getMethodFamily() == OMF_init && MC->isReceiverSelfOrSuper() &&
344  !Call.getLocationContext()
346  ->getParentMap()
347  .isConsumedExpr(Call.getOriginExpr());
348  }
349  return false;
350 }
351 
352 const static RetainSummary *getSummary(RetainSummaryManager &Summaries,
353  const CallEvent &Call,
354  QualType ReceiverType) {
355  const Expr *CE = Call.getOriginExpr();
356  AnyCall C =
357  CE ? *AnyCall::forExpr(CE)
358  : AnyCall(cast<CXXDestructorDecl>(Call.getDecl()));
359  return Summaries.getSummary(C, Call.hasNonZeroCallbackArg(),
360  isReceiverUnconsumedSelf(Call), ReceiverType);
361 }
362 
364  CheckerContext &C) const {
365  RetainSummaryManager &Summaries = getSummaryManager(C);
366 
367  // Leave null if no receiver.
368  QualType ReceiverType;
369  if (const auto *MC = dyn_cast<ObjCMethodCall>(&Call)) {
370  if (MC->isInstanceMessage()) {
371  SVal ReceiverV = MC->getReceiverSVal();
372  if (SymbolRef Sym = ReceiverV.getAsLocSymbol())
373  if (const RefVal *T = getRefBinding(C.getState(), Sym))
374  ReceiverType = T->getType();
375  }
376  }
377 
378  const RetainSummary *Summ = getSummary(Summaries, Call, ReceiverType);
379 
380  if (C.wasInlined) {
381  processSummaryOfInlined(*Summ, Call, C);
382  return;
383  }
384  checkSummary(*Summ, Call, C);
385 }
386 
387 /// GetReturnType - Used to get the return type of a message expression or
388 /// function call with the intention of affixing that type to a tracked symbol.
389 /// While the return type can be queried directly from RetEx, when
390 /// invoking class methods we augment to the return type to be that of
391 /// a pointer to the class (as opposed it just being id).
392 // FIXME: We may be able to do this with related result types instead.
393 // This function is probably overestimating.
394 static QualType GetReturnType(const Expr *RetE, ASTContext &Ctx) {
395  QualType RetTy = RetE->getType();
396  // If RetE is not a message expression just return its type.
397  // If RetE is a message expression, return its types if it is something
398  /// more specific than id.
399  if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RetE))
400  if (const ObjCObjectPointerType *PT = RetTy->getAs<ObjCObjectPointerType>())
401  if (PT->isObjCQualifiedIdType() || PT->isObjCIdType() ||
402  PT->isObjCClassType()) {
403  // At this point we know the return type of the message expression is
404  // id, id<...>, or Class. If we have an ObjCInterfaceDecl, we know this
405  // is a call to a class method whose type we can resolve. In such
406  // cases, promote the return type to XXX* (where XXX is the class).
407  const ObjCInterfaceDecl *D = ME->getReceiverInterface();
408  return !D ? RetTy :
410  }
411 
412  return RetTy;
413 }
414 
416  QualType ResultTy) {
417  if (RE.isOwned()) {
418  return RefVal::makeOwned(RE.getObjKind(), ResultTy);
419  } else if (RE.notOwned()) {
420  return RefVal::makeNotOwned(RE.getObjKind(), ResultTy);
421  }
422 
423  return None;
424 }
425 
426 static bool isPointerToObject(QualType QT) {
427  QualType PT = QT->getPointeeType();
428  if (!PT.isNull())
429  if (PT->getAsCXXRecordDecl())
430  return true;
431  return false;
432 }
433 
434 /// Whether the tracked value should be escaped on a given call.
435 /// OSObjects are escaped when passed to void * / etc.
436 static bool shouldEscapeOSArgumentOnCall(const CallEvent &CE, unsigned ArgIdx,
437  const RefVal *TrackedValue) {
438  if (TrackedValue->getObjKind() != ObjKind::OS)
439  return false;
440  if (ArgIdx >= CE.parameters().size())
441  return false;
442  return !isPointerToObject(CE.parameters()[ArgIdx]->getType());
443 }
444 
445 // We don't always get the exact modeling of the function with regards to the
446 // retain count checker even when the function is inlined. For example, we need
447 // to stop tracking the symbols which were marked with StopTrackingHard.
448 void RetainCountChecker::processSummaryOfInlined(const RetainSummary &Summ,
449  const CallEvent &CallOrMsg,
450  CheckerContext &C) const {
452 
453  // Evaluate the effect of the arguments.
454  for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) {
455  SVal V = CallOrMsg.getArgSVal(idx);
456 
457  if (SymbolRef Sym = V.getAsLocSymbol()) {
458  bool ShouldRemoveBinding = Summ.getArg(idx).getKind() == StopTrackingHard;
459  if (const RefVal *T = getRefBinding(state, Sym))
460  if (shouldEscapeOSArgumentOnCall(CallOrMsg, idx, T))
461  ShouldRemoveBinding = true;
462 
463  if (ShouldRemoveBinding)
464  state = removeRefBinding(state, Sym);
465  }
466  }
467 
468  // Evaluate the effect on the message receiver.
469  if (const auto *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg)) {
470  if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) {
471  if (Summ.getReceiverEffect().getKind() == StopTrackingHard) {
472  state = removeRefBinding(state, Sym);
473  }
474  }
475  }
476 
477  // Consult the summary for the return value.
478  RetEffect RE = Summ.getRetEffect();
479 
480  if (SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol()) {
481  if (RE.getKind() == RetEffect::NoRetHard)
482  state = removeRefBinding(state, Sym);
483  }
484 
485  C.addTransition(state);
486 }
487 
488 static bool isSmartPtrField(const MemRegion *MR) {
489  const auto *TR = dyn_cast<TypedValueRegion>(
490  cast<SubRegion>(MR)->getSuperRegion());
491  return TR && RetainSummaryManager::isKnownSmartPointer(TR->getValueType());
492 }
493 
494 
495 /// A value escapes in these possible cases:
496 ///
497 /// - binding to something that is not a memory region.
498 /// - binding to a memregion that does not have stack storage
499 /// - binding to a variable that has a destructor attached using CleanupAttr
500 ///
501 /// We do not currently model what happens when a symbol is
502 /// assigned to a struct field, unless it is a known smart pointer
503 /// implementation, about which we know that it is inlined.
504 /// FIXME: This could definitely be improved upon.
505 static bool shouldEscapeRegion(const MemRegion *R) {
506  if (isSmartPtrField(R))
507  return false;
508 
509  const auto *VR = dyn_cast<VarRegion>(R);
510 
511  if (!R->hasStackStorage() || !VR)
512  return true;
513 
514  const VarDecl *VD = VR->getDecl();
515  if (!VD->hasAttr<CleanupAttr>())
516  return false; // CleanupAttr attaches destructors, which cause escaping.
517  return true;
518 }
519 
521 updateOutParameters(ProgramStateRef State, const RetainSummary &Summ,
522  const CallEvent &CE) {
523 
524  SVal L = CE.getReturnValue();
525 
526  // Splitting is required to support out parameters,
527  // as out parameters might be created only on the "success" branch.
528  // We want to avoid eagerly splitting unless out parameters are actually
529  // needed.
530  bool SplitNecessary = false;
531  for (auto &P : Summ.getArgEffects())
532  if (P.second.getKind() == RetainedOutParameterOnNonZero ||
533  P.second.getKind() == RetainedOutParameterOnZero)
534  SplitNecessary = true;
535 
536  ProgramStateRef AssumeNonZeroReturn = State;
537  ProgramStateRef AssumeZeroReturn = State;
538 
539  if (SplitNecessary) {
540  if (auto DL = L.getAs<DefinedOrUnknownSVal>()) {
541  AssumeNonZeroReturn = AssumeNonZeroReturn->assume(*DL, true);
542  AssumeZeroReturn = AssumeZeroReturn->assume(*DL, false);
543  }
544  }
545 
546  for (unsigned idx = 0, e = CE.getNumArgs(); idx != e; ++idx) {
547  SVal ArgVal = CE.getArgSVal(idx);
548  ArgEffect AE = Summ.getArg(idx);
549 
550  auto *ArgRegion = dyn_cast_or_null<TypedValueRegion>(ArgVal.getAsRegion());
551  if (!ArgRegion)
552  continue;
553 
554  QualType PointeeTy = ArgRegion->getValueType();
555  SVal PointeeVal = State->getSVal(ArgRegion);
556  SymbolRef Pointee = PointeeVal.getAsLocSymbol();
557  if (!Pointee)
558  continue;
559 
560  if (shouldEscapeRegion(ArgRegion))
561  continue;
562 
563  auto makeNotOwnedParameter = [&](ProgramStateRef St) {
564  return setRefBinding(St, Pointee,
565  RefVal::makeNotOwned(AE.getObjKind(), PointeeTy));
566  };
567  auto makeOwnedParameter = [&](ProgramStateRef St) {
568  return setRefBinding(St, Pointee,
569  RefVal::makeOwned(ObjKind::OS, PointeeTy));
570  };
571 
572  switch (AE.getKind()) {
574  AssumeNonZeroReturn = makeNotOwnedParameter(AssumeNonZeroReturn);
575  AssumeZeroReturn = makeNotOwnedParameter(AssumeZeroReturn);
576  break;
578  AssumeNonZeroReturn = makeOwnedParameter(AssumeNonZeroReturn);
579  AssumeZeroReturn = makeOwnedParameter(AssumeZeroReturn);
580  break;
582  AssumeNonZeroReturn = makeOwnedParameter(AssumeNonZeroReturn);
583  break;
585  AssumeZeroReturn = makeOwnedParameter(AssumeZeroReturn);
586  break;
587  default:
588  break;
589  }
590  }
591 
592  if (SplitNecessary) {
593  return {AssumeNonZeroReturn, AssumeZeroReturn};
594  } else {
595  assert(AssumeZeroReturn == AssumeNonZeroReturn);
596  return {AssumeZeroReturn};
597  }
598 }
599 
600 void RetainCountChecker::checkSummary(const RetainSummary &Summ,
601  const CallEvent &CallOrMsg,
602  CheckerContext &C) const {
604 
605  // Evaluate the effect of the arguments.
606  RefVal::Kind hasErr = (RefVal::Kind) 0;
607  SourceRange ErrorRange;
608  SymbolRef ErrorSym = nullptr;
609 
610  // Helper tag for providing diagnostics: indicate whether dealloc was sent
611  // at this location.
612  bool DeallocSent = false;
613 
614  for (unsigned idx = 0, e = CallOrMsg.getNumArgs(); idx != e; ++idx) {
615  SVal V = CallOrMsg.getArgSVal(idx);
616 
617  ArgEffect Effect = Summ.getArg(idx);
618  if (SymbolRef Sym = V.getAsLocSymbol()) {
619  if (const RefVal *T = getRefBinding(state, Sym)) {
620 
621  if (shouldEscapeOSArgumentOnCall(CallOrMsg, idx, T))
623 
624  state = updateSymbol(state, Sym, *T, Effect, hasErr, C);
625  if (hasErr) {
626  ErrorRange = CallOrMsg.getArgSourceRange(idx);
627  ErrorSym = Sym;
628  break;
629  } else if (Effect.getKind() == Dealloc) {
630  DeallocSent = true;
631  }
632  }
633  }
634  }
635 
636  // Evaluate the effect on the message receiver / `this` argument.
637  bool ReceiverIsTracked = false;
638  if (!hasErr) {
639  if (const auto *MsgInvocation = dyn_cast<ObjCMethodCall>(&CallOrMsg)) {
640  if (SymbolRef Sym = MsgInvocation->getReceiverSVal().getAsLocSymbol()) {
641  if (const RefVal *T = getRefBinding(state, Sym)) {
642  ReceiverIsTracked = true;
643  state = updateSymbol(state, Sym, *T,
644  Summ.getReceiverEffect(), hasErr, C);
645  if (hasErr) {
646  ErrorRange = MsgInvocation->getOriginExpr()->getReceiverRange();
647  ErrorSym = Sym;
648  } else if (Summ.getReceiverEffect().getKind() == Dealloc) {
649  DeallocSent = true;
650  }
651  }
652  }
653  } else if (const auto *MCall = dyn_cast<CXXMemberCall>(&CallOrMsg)) {
654  if (SymbolRef Sym = MCall->getCXXThisVal().getAsLocSymbol()) {
655  if (const RefVal *T = getRefBinding(state, Sym)) {
656  state = updateSymbol(state, Sym, *T, Summ.getThisEffect(),
657  hasErr, C);
658  if (hasErr) {
659  ErrorRange = MCall->getOriginExpr()->getSourceRange();
660  ErrorSym = Sym;
661  }
662  }
663  }
664  }
665  }
666 
667  // Process any errors.
668  if (hasErr) {
669  processNonLeakError(state, ErrorRange, hasErr, ErrorSym, C);
670  return;
671  }
672 
673  // Consult the summary for the return value.
674  RetEffect RE = Summ.getRetEffect();
675 
677  if (ReceiverIsTracked)
678  RE = getSummaryManager(C).getObjAllocRetEffect();
679  else
680  RE = RetEffect::MakeNoRet();
681  }
682 
683  if (SymbolRef Sym = CallOrMsg.getReturnValue().getAsSymbol()) {
684  QualType ResultTy = CallOrMsg.getResultType();
685  if (RE.notOwned()) {
686  const Expr *Ex = CallOrMsg.getOriginExpr();
687  assert(Ex);
688  ResultTy = GetReturnType(Ex, C.getASTContext());
689  }
690  if (Optional<RefVal> updatedRefVal = refValFromRetEffect(RE, ResultTy))
691  state = setRefBinding(state, Sym, *updatedRefVal);
692  }
693 
695  updateOutParameters(state, Summ, CallOrMsg);
696 
697  for (ProgramStateRef St : Out) {
698  if (DeallocSent) {
699  C.addTransition(St, C.getPredecessor(), &DeallocSentTag);
700  } else {
701  C.addTransition(St);
702  }
703  }
704 }
705 
707  SymbolRef sym, RefVal V,
708  ArgEffect AE,
709  RefVal::Kind &hasErr,
710  CheckerContext &C) const {
711  bool IgnoreRetainMsg = (bool)C.getASTContext().getLangOpts().ObjCAutoRefCount;
712  if (AE.getObjKind() == ObjKind::ObjC && IgnoreRetainMsg) {
713  switch (AE.getKind()) {
714  default:
715  break;
716  case IncRef:
717  AE = AE.withKind(DoNothing);
718  break;
719  case DecRef:
720  AE = AE.withKind(DoNothing);
721  break;
723  AE = AE.withKind(StopTracking);
724  break;
725  }
726  }
727 
728  // Handle all use-after-releases.
729  if (V.getKind() == RefVal::Released) {
731  hasErr = V.getKind();
732  return setRefBinding(state, sym, V);
733  }
734 
735  switch (AE.getKind()) {
740  llvm_unreachable("Applies to pointer-to-pointer parameters, which should "
741  "not have ref state.");
742 
743  case Dealloc: // NB. we only need to add a note in a non-error case.
744  switch (V.getKind()) {
745  default:
746  llvm_unreachable("Invalid RefVal state for an explicit dealloc.");
747  case RefVal::Owned:
748  // The object immediately transitions to the released state.
749  V = V ^ RefVal::Released;
750  V.clearCounts();
751  return setRefBinding(state, sym, V);
752  case RefVal::NotOwned:
754  hasErr = V.getKind();
755  break;
756  }
757  break;
758 
759  case MayEscape:
760  if (V.getKind() == RefVal::Owned) {
761  V = V ^ RefVal::NotOwned;
762  break;
763  }
764 
765  LLVM_FALLTHROUGH;
766 
767  case DoNothing:
768  return state;
769 
770  case Autorelease:
771  // Update the autorelease counts.
772  V = V.autorelease();
773  break;
774 
775  case StopTracking:
776  case StopTrackingHard:
777  return removeRefBinding(state, sym);
778 
779  case IncRef:
780  switch (V.getKind()) {
781  default:
782  llvm_unreachable("Invalid RefVal state for a retain.");
783  case RefVal::Owned:
784  case RefVal::NotOwned:
785  V = V + 1;
786  break;
787  }
788  break;
789 
790  case DecRef:
793  switch (V.getKind()) {
794  default:
795  // case 'RefVal::Released' handled above.
796  llvm_unreachable("Invalid RefVal state for a release.");
797 
798  case RefVal::Owned:
799  assert(V.getCount() > 0);
800  if (V.getCount() == 1) {
801  if (AE.getKind() == DecRefBridgedTransferred ||
802  V.getIvarAccessHistory() ==
804  V = V ^ RefVal::NotOwned;
805  else
806  V = V ^ RefVal::Released;
807  } else if (AE.getKind() == DecRefAndStopTrackingHard) {
808  return removeRefBinding(state, sym);
809  }
810 
811  V = V - 1;
812  break;
813 
814  case RefVal::NotOwned:
815  if (V.getCount() > 0) {
817  return removeRefBinding(state, sym);
818  V = V - 1;
819  } else if (V.getIvarAccessHistory() ==
821  // Assume that the instance variable was holding on the object at
822  // +1, and we just didn't know.
824  return removeRefBinding(state, sym);
826  } else {
828  hasErr = V.getKind();
829  }
830  break;
831  }
832  break;
833  }
834  return setRefBinding(state, sym, V);
835 }
836 
837 const RefCountBug &
839  SymbolRef Sym) const {
840  switch (ErrorKind) {
842  return useAfterRelease;
844  return releaseNotOwned;
846  if (Sym->getType()->getPointeeCXXRecordDecl())
847  return freeNotOwned;
848  return deallocNotOwned;
849  default:
850  llvm_unreachable("Unhandled error.");
851  }
852 }
853 
855  SourceRange ErrorRange,
857  SymbolRef Sym,
858  CheckerContext &C) const {
859  // HACK: Ignore retain-count issues on values accessed through ivars,
860  // because of cases like this:
861  // [_contentView retain];
862  // [_contentView removeFromSuperview];
863  // [self addSubview:_contentView]; // invalidates 'self'
864  // [_contentView release];
865  if (const RefVal *RV = getRefBinding(St, Sym))
866  if (RV->getIvarAccessHistory() != RefVal::IvarAccessHistory::None)
867  return;
868 
869  ExplodedNode *N = C.generateErrorNode(St);
870  if (!N)
871  return;
872 
873  auto report = llvm::make_unique<RefCountReport>(
874  errorKindToBugKind(ErrorKind, Sym),
875  C.getASTContext().getLangOpts(), N, Sym);
876  report->addRange(ErrorRange);
877  C.emitReport(std::move(report));
878 }
879 
880 //===----------------------------------------------------------------------===//
881 // Handle the return values of retain-count-related functions.
882 //===----------------------------------------------------------------------===//
883 
886  const FunctionDecl *FD = C.getCalleeDecl(CE);
887  if (!FD)
888  return false;
889 
890  RetainSummaryManager &SmrMgr = getSummaryManager(C);
891  QualType ResultTy = CE->getCallReturnType(C.getASTContext());
892 
893  // See if the function has 'rc_ownership_trusted_implementation'
894  // annotate attribute. If it does, we will not inline it.
895  bool hasTrustedImplementationAnnotation = false;
896 
897  const LocationContext *LCtx = C.getLocationContext();
898 
899  using BehaviorSummary = RetainSummaryManager::BehaviorSummary;
901  SmrMgr.canEval(CE, FD, hasTrustedImplementationAnnotation);
902 
903  // See if it's one of the specific functions we know how to eval.
904  if (!BSmr)
905  return false;
906 
907  // Bind the return value.
908  if (BSmr == BehaviorSummary::Identity ||
909  BSmr == BehaviorSummary::IdentityOrZero ||
910  BSmr == BehaviorSummary::IdentityThis) {
911 
912  const Expr *BindReturnTo =
913  (BSmr == BehaviorSummary::IdentityThis)
914  ? cast<CXXMemberCallExpr>(CE)->getImplicitObjectArgument()
915  : CE->getArg(0);
916  SVal RetVal = state->getSVal(BindReturnTo, LCtx);
917 
918  // If the receiver is unknown or the function has
919  // 'rc_ownership_trusted_implementation' annotate attribute, conjure a
920  // return value.
921  // FIXME: this branch is very strange.
922  if (RetVal.isUnknown() ||
923  (hasTrustedImplementationAnnotation && !ResultTy.isNull())) {
924  SValBuilder &SVB = C.getSValBuilder();
925  RetVal =
926  SVB.conjureSymbolVal(nullptr, CE, LCtx, ResultTy, C.blockCount());
927  }
928 
929  // Bind the value.
930  state = state->BindExpr(CE, LCtx, RetVal, /*Invalidate=*/false);
931 
932  if (BSmr == BehaviorSummary::IdentityOrZero) {
933  // Add a branch where the output is zero.
934  ProgramStateRef NullOutputState = C.getState();
935 
936  // Assume that output is zero on the other branch.
937  NullOutputState = NullOutputState->BindExpr(
938  CE, LCtx, C.getSValBuilder().makeNull(), /*Invalidate=*/false);
939  C.addTransition(NullOutputState, &CastFailTag);
940 
941  // And on the original branch assume that both input and
942  // output are non-zero.
943  if (auto L = RetVal.getAs<DefinedOrUnknownSVal>())
944  state = state->assume(*L, /*Assumption=*/true);
945 
946  }
947  }
948 
949  C.addTransition(state);
950  return true;
951 }
952 
953 ExplodedNode * RetainCountChecker::processReturn(const ReturnStmt *S,
954  CheckerContext &C) const {
955  ExplodedNode *Pred = C.getPredecessor();
956 
957  // Only adjust the reference count if this is the top-level call frame,
958  // and not the result of inlining. In the future, we should do
959  // better checking even for inlined calls, and see if they match
960  // with their expected semantics (e.g., the method should return a retained
961  // object, etc.).
962  if (!C.inTopFrame())
963  return Pred;
964 
965  if (!S)
966  return Pred;
967 
968  const Expr *RetE = S->getRetValue();
969  if (!RetE)
970  return Pred;
971 
973  SymbolRef Sym =
974  state->getSValAsScalarOrLoc(RetE, C.getLocationContext()).getAsLocSymbol();
975  if (!Sym)
976  return Pred;
977 
978  // Get the reference count binding (if any).
979  const RefVal *T = getRefBinding(state, Sym);
980  if (!T)
981  return Pred;
982 
983  // Change the reference count.
984  RefVal X = *T;
985 
986  switch (X.getKind()) {
987  case RefVal::Owned: {
988  unsigned cnt = X.getCount();
989  assert(cnt > 0);
990  X.setCount(cnt - 1);
991  X = X ^ RefVal::ReturnedOwned;
992  break;
993  }
994 
995  case RefVal::NotOwned: {
996  unsigned cnt = X.getCount();
997  if (cnt) {
998  X.setCount(cnt - 1);
999  X = X ^ RefVal::ReturnedOwned;
1000  } else {
1001  X = X ^ RefVal::ReturnedNotOwned;
1002  }
1003  break;
1004  }
1005 
1006  default:
1007  return Pred;
1008  }
1009 
1010  // Update the binding.
1011  state = setRefBinding(state, Sym, X);
1012  Pred = C.addTransition(state);
1013 
1014  // At this point we have updated the state properly.
1015  // Everything after this is merely checking to see if the return value has
1016  // been over- or under-retained.
1017 
1018  // Did we cache out?
1019  if (!Pred)
1020  return nullptr;
1021 
1022  // Update the autorelease counts.
1023  static CheckerProgramPointTag AutoreleaseTag(this, "Autorelease");
1024  state = handleAutoreleaseCounts(state, Pred, &AutoreleaseTag, C, Sym, X, S);
1025 
1026  // Have we generated a sink node?
1027  if (!state)
1028  return nullptr;
1029 
1030  // Get the updated binding.
1031  T = getRefBinding(state, Sym);
1032  assert(T);
1033  X = *T;
1034 
1035  // Consult the summary of the enclosing method.
1036  RetainSummaryManager &Summaries = getSummaryManager(C);
1037  const Decl *CD = &Pred->getCodeDecl();
1039 
1040  // FIXME: What is the convention for blocks? Is there one?
1041  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CD)) {
1042  const RetainSummary *Summ = Summaries.getSummary(AnyCall(MD));
1043  RE = Summ->getRetEffect();
1044  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CD)) {
1045  if (!isa<CXXMethodDecl>(FD)) {
1046  const RetainSummary *Summ = Summaries.getSummary(AnyCall(FD));
1047  RE = Summ->getRetEffect();
1048  }
1049  }
1050 
1051  return checkReturnWithRetEffect(S, C, Pred, RE, X, Sym, state);
1052 }
1053 
1055  CheckerContext &C,
1056  ExplodedNode *Pred,
1057  RetEffect RE, RefVal X,
1058  SymbolRef Sym,
1059  ProgramStateRef state) const {
1060  // HACK: Ignore retain-count issues on values accessed through ivars,
1061  // because of cases like this:
1062  // [_contentView retain];
1063  // [_contentView removeFromSuperview];
1064  // [self addSubview:_contentView]; // invalidates 'self'
1065  // [_contentView release];
1067  return Pred;
1068 
1069  // Any leaks or other errors?
1070  if (X.isReturnedOwned() && X.getCount() == 0) {
1071  if (RE.getKind() != RetEffect::NoRet) {
1072  if (!RE.isOwned()) {
1073 
1074  // The returning type is a CF, we expect the enclosing method should
1075  // return ownership.
1076  X = X ^ RefVal::ErrorLeakReturned;
1077 
1078  // Generate an error node.
1079  state = setRefBinding(state, Sym, X);
1080 
1081  static CheckerProgramPointTag ReturnOwnLeakTag(this, "ReturnsOwnLeak");
1082  ExplodedNode *N = C.addTransition(state, Pred, &ReturnOwnLeakTag);
1083  if (N) {
1084  const LangOptions &LOpts = C.getASTContext().getLangOpts();
1085  auto R =
1086  llvm::make_unique<RefLeakReport>(leakAtReturn, LOpts, N, Sym, C);
1087  C.emitReport(std::move(R));
1088  }
1089  return N;
1090  }
1091  }
1092  } else if (X.isReturnedNotOwned()) {
1093  if (RE.isOwned()) {
1094  if (X.getIvarAccessHistory() ==
1096  // Assume the method was trying to transfer a +1 reference from a
1097  // strong ivar to the caller.
1098  state = setRefBinding(state, Sym,
1100  } else {
1101  // Trying to return a not owned object to a caller expecting an
1102  // owned object.
1103  state = setRefBinding(state, Sym, X ^ RefVal::ErrorReturnedNotOwned);
1104 
1105  static CheckerProgramPointTag
1106  ReturnNotOwnedTag(this, "ReturnNotOwnedForOwned");
1107 
1108  ExplodedNode *N = C.addTransition(state, Pred, &ReturnNotOwnedTag);
1109  if (N) {
1110  auto R = llvm::make_unique<RefCountReport>(
1111  returnNotOwnedForOwned, C.getASTContext().getLangOpts(), N, Sym);
1112  C.emitReport(std::move(R));
1113  }
1114  return N;
1115  }
1116  }
1117  }
1118  return Pred;
1119 }
1120 
1121 //===----------------------------------------------------------------------===//
1122 // Check various ways a symbol can be invalidated.
1123 //===----------------------------------------------------------------------===//
1124 
1126  CheckerContext &C) const {
1128  const MemRegion *MR = loc.getAsRegion();
1129 
1130  // Find all symbols referenced by 'val' that we are tracking
1131  // and stop tracking them.
1132  if (MR && shouldEscapeRegion(MR)) {
1133  state = state->scanReachableSymbols<StopTrackingCallback>(val).getState();
1134  C.addTransition(state);
1135  }
1136 }
1137 
1139  SVal Cond,
1140  bool Assumption) const {
1141  // FIXME: We may add to the interface of evalAssume the list of symbols
1142  // whose assumptions have changed. For now we just iterate through the
1143  // bindings and check if any of the tracked symbols are NULL. This isn't
1144  // too bad since the number of symbols we will track in practice are
1145  // probably small and evalAssume is only called at branches and a few
1146  // other places.
1147  RefBindingsTy B = state->get<RefBindings>();
1148 
1149  if (B.isEmpty())
1150  return state;
1151 
1152  bool changed = false;
1153  RefBindingsTy::Factory &RefBFactory = state->get_context<RefBindings>();
1154  ConstraintManager &CMgr = state->getConstraintManager();
1155 
1156  for (auto &I : B) {
1157  // Check if the symbol is null stop tracking the symbol.
1158  ConditionTruthVal AllocFailed = CMgr.isNull(state, I.first);
1159  if (AllocFailed.isConstrainedTrue()) {
1160  changed = true;
1161  B = RefBFactory.remove(B, I.first);
1162  }
1163  }
1164 
1165  if (changed)
1166  state = state->set<RefBindings>(B);
1167 
1168  return state;
1169 }
1170 
1172  ProgramStateRef state, const InvalidatedSymbols *invalidated,
1173  ArrayRef<const MemRegion *> ExplicitRegions,
1174  ArrayRef<const MemRegion *> Regions, const LocationContext *LCtx,
1175  const CallEvent *Call) const {
1176  if (!invalidated)
1177  return state;
1178 
1179  llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols;
1180 
1181  for (const MemRegion *I : ExplicitRegions)
1182  if (const SymbolicRegion *SR = I->StripCasts()->getAs<SymbolicRegion>())
1183  WhitelistedSymbols.insert(SR->getSymbol());
1184 
1185  for (SymbolRef sym : *invalidated) {
1186  if (WhitelistedSymbols.count(sym))
1187  continue;
1188  // Remove any existing reference-count binding.
1189  state = removeRefBinding(state, sym);
1190  }
1191  return state;
1192 }
1193 
1196  ExplodedNode *Pred,
1197  const ProgramPointTag *Tag,
1198  CheckerContext &Ctx,
1199  SymbolRef Sym,
1200  RefVal V,
1201  const ReturnStmt *S) const {
1202  unsigned ACnt = V.getAutoreleaseCount();
1203 
1204  // No autorelease counts? Nothing to be done.
1205  if (!ACnt)
1206  return state;
1207 
1208  unsigned Cnt = V.getCount();
1209 
1210  // FIXME: Handle sending 'autorelease' to already released object.
1211 
1212  if (V.getKind() == RefVal::ReturnedOwned)
1213  ++Cnt;
1214 
1215  // If we would over-release here, but we know the value came from an ivar,
1216  // assume it was a strong ivar that's just been relinquished.
1217  if (ACnt > Cnt &&
1219  V = V.releaseViaIvar();
1220  --ACnt;
1221  }
1222 
1223  if (ACnt <= Cnt) {
1224  if (ACnt == Cnt) {
1225  V.clearCounts();
1226  if (V.getKind() == RefVal::ReturnedOwned) {
1227  V = V ^ RefVal::ReturnedNotOwned;
1228  } else {
1229  V = V ^ RefVal::NotOwned;
1230  }
1231  } else {
1232  V.setCount(V.getCount() - ACnt);
1233  V.setAutoreleaseCount(0);
1234  }
1235  return setRefBinding(state, Sym, V);
1236  }
1237 
1238  // HACK: Ignore retain-count issues on values accessed through ivars,
1239  // because of cases like this:
1240  // [_contentView retain];
1241  // [_contentView removeFromSuperview];
1242  // [self addSubview:_contentView]; // invalidates 'self'
1243  // [_contentView release];
1245  return state;
1246 
1247  // Woah! More autorelease counts then retain counts left.
1248  // Emit hard error.
1250  state = setRefBinding(state, Sym, V);
1251 
1252  ExplodedNode *N = Ctx.generateSink(state, Pred, Tag);
1253  if (N) {
1254  SmallString<128> sbuf;
1255  llvm::raw_svector_ostream os(sbuf);
1256  os << "Object was autoreleased ";
1257  if (V.getAutoreleaseCount() > 1)
1258  os << V.getAutoreleaseCount() << " times but the object ";
1259  else
1260  os << "but ";
1261  os << "has a +" << V.getCount() << " retain count";
1262 
1263  const LangOptions &LOpts = Ctx.getASTContext().getLangOpts();
1264  auto R = llvm::make_unique<RefCountReport>(overAutorelease, LOpts, N, Sym,
1265  os.str());
1266  Ctx.emitReport(std::move(R));
1267  }
1268 
1269  return nullptr;
1270 }
1271 
1274  SymbolRef sid, RefVal V,
1275  SmallVectorImpl<SymbolRef> &Leaked) const {
1276  bool hasLeak;
1277 
1278  // HACK: Ignore retain-count issues on values accessed through ivars,
1279  // because of cases like this:
1280  // [_contentView retain];
1281  // [_contentView removeFromSuperview];
1282  // [self addSubview:_contentView]; // invalidates 'self'
1283  // [_contentView release];
1285  hasLeak = false;
1286  else if (V.isOwned())
1287  hasLeak = true;
1288  else if (V.isNotOwned() || V.isReturnedOwned())
1289  hasLeak = (V.getCount() > 0);
1290  else
1291  hasLeak = false;
1292 
1293  if (!hasLeak)
1294  return removeRefBinding(state, sid);
1295 
1296  Leaked.push_back(sid);
1297  return setRefBinding(state, sid, V ^ RefVal::ErrorLeak);
1298 }
1299 
1300 ExplodedNode *
1303  CheckerContext &Ctx,
1304  ExplodedNode *Pred) const {
1305  // Generate an intermediate node representing the leak point.
1306  ExplodedNode *N = Ctx.addTransition(state, Pred);
1307  const LangOptions &LOpts = Ctx.getASTContext().getLangOpts();
1308 
1309  if (N) {
1310  for (SymbolRef L : Leaked) {
1311  const RefCountBug &BT = Pred ? leakWithinFunction : leakAtReturn;
1312  Ctx.emitReport(llvm::make_unique<RefLeakReport>(BT, LOpts, N, L, Ctx));
1313  }
1314  }
1315 
1316  return N;
1317 }
1318 
1320  if (!Ctx.inTopFrame())
1321  return;
1322 
1323  RetainSummaryManager &SmrMgr = getSummaryManager(Ctx);
1324  const LocationContext *LCtx = Ctx.getLocationContext();
1325  const Decl *D = LCtx->getDecl();
1326  Optional<AnyCall> C = AnyCall::forDecl(D);
1327 
1328  if (!C || SmrMgr.isTrustedReferenceCountImplementation(D))
1329  return;
1330 
1331  ProgramStateRef state = Ctx.getState();
1332  const RetainSummary *FunctionSummary = SmrMgr.getSummary(*C);
1333  ArgEffects CalleeSideArgEffects = FunctionSummary->getArgEffects();
1334 
1335  for (unsigned idx = 0, e = C->param_size(); idx != e; ++idx) {
1336  const ParmVarDecl *Param = C->parameters()[idx];
1337  SymbolRef Sym = state->getSVal(state->getRegion(Param, LCtx)).getAsSymbol();
1338 
1339  QualType Ty = Param->getType();
1340  const ArgEffect *AE = CalleeSideArgEffects.lookup(idx);
1341  if (AE) {
1342  ObjKind K = AE->getObjKind();
1343  if (K == ObjKind::Generalized || K == ObjKind::OS ||
1344  (TrackNSCFStartParam && (K == ObjKind::ObjC || K == ObjKind::CF))) {
1345  RefVal NewVal = AE->getKind() == DecRef ? RefVal::makeOwned(K, Ty)
1346  : RefVal::makeNotOwned(K, Ty);
1347  state = setRefBinding(state, Sym, NewVal);
1348  }
1349  }
1350  }
1351 
1352  Ctx.addTransition(state);
1353 }
1354 
1356  CheckerContext &Ctx) const {
1357  ExplodedNode *Pred = processReturn(RS, Ctx);
1358 
1359  // Created state cached out.
1360  if (!Pred) {
1361  return;
1362  }
1363 
1364  ProgramStateRef state = Pred->getState();
1365  RefBindingsTy B = state->get<RefBindings>();
1366 
1367  // Don't process anything within synthesized bodies.
1368  const LocationContext *LCtx = Pred->getLocationContext();
1369  if (LCtx->getAnalysisDeclContext()->isBodyAutosynthesized()) {
1370  assert(!LCtx->inTopFrame());
1371  return;
1372  }
1373 
1374  for (auto &I : B) {
1375  state = handleAutoreleaseCounts(state, Pred, /*Tag=*/nullptr, Ctx,
1376  I.first, I.second);
1377  if (!state)
1378  return;
1379  }
1380 
1381  // If the current LocationContext has a parent, don't check for leaks.
1382  // We will do that later.
1383  // FIXME: we should instead check for imbalances of the retain/releases,
1384  // and suggest annotations.
1385  if (LCtx->getParent())
1386  return;
1387 
1388  B = state->get<RefBindings>();
1390 
1391  for (auto &I : B)
1392  state = handleSymbolDeath(state, I.first, I.second, Leaked);
1393 
1394  processLeaks(state, Leaked, Ctx, Pred);
1395 }
1396 
1398  CheckerContext &C) const {
1399  ExplodedNode *Pred = C.getPredecessor();
1400 
1403 
1404  // Update counts from autorelease pools
1405  for (const auto &I: state->get<RefBindings>()) {
1406  SymbolRef Sym = I.first;
1407  if (SymReaper.isDead(Sym)) {
1408  static CheckerProgramPointTag Tag(this, "DeadSymbolAutorelease");
1409  const RefVal &V = I.second;
1410  state = handleAutoreleaseCounts(state, Pred, &Tag, C, Sym, V);
1411  if (!state)
1412  return;
1413 
1414  // Fetch the new reference count from the state, and use it to handle
1415  // this symbol.
1416  state = handleSymbolDeath(state, Sym, *getRefBinding(state, Sym), Leaked);
1417  }
1418  }
1419 
1420  if (Leaked.empty()) {
1421  C.addTransition(state);
1422  return;
1423  }
1424 
1425  Pred = processLeaks(state, Leaked, C, Pred);
1426 
1427  // Did we cache out?
1428  if (!Pred)
1429  return;
1430 
1431  // Now generate a new node that nukes the old bindings.
1432  // The only bindings left at this point are the leaked symbols.
1433  RefBindingsTy::Factory &F = state->get_context<RefBindings>();
1434  RefBindingsTy B = state->get<RefBindings>();
1435 
1436  for (SymbolRef L : Leaked)
1437  B = F.remove(B, L);
1438 
1439  state = state->set<RefBindings>(B);
1440  C.addTransition(state, Pred);
1441 }
1442 
1444  const char *NL, const char *Sep) const {
1445 
1446  RefBindingsTy B = State->get<RefBindings>();
1447 
1448  if (B.isEmpty())
1449  return;
1450 
1451  Out << Sep << NL;
1452 
1453  for (auto &I : B) {
1454  Out << I.first << " : ";
1455  I.second.print(Out);
1456  Out << NL;
1457  }
1458 }
1459 
1460 //===----------------------------------------------------------------------===//
1461 // Checker registration.
1462 //===----------------------------------------------------------------------===//
1463 
1464 void ento::registerRetainCountBase(CheckerManager &Mgr) {
1466 }
1467 
1468 bool ento::shouldRegisterRetainCountBase(const LangOptions &LO) {
1469  return true;
1470 }
1471 
1472 // FIXME: remove this, hack for backwards compatibility:
1473 // it should be possible to enable the NS/CF retain count checker as
1474 // osx.cocoa.RetainCount, and it should be possible to disable
1475 // osx.OSObjectRetainCount using osx.cocoa.RetainCount:CheckOSObject=false.
1476 static bool getOption(AnalyzerOptions &Options,
1477  StringRef Postfix,
1478  StringRef Value) {
1479  auto I = Options.Config.find(
1480  (StringRef("osx.cocoa.RetainCount:") + Postfix).str());
1481  if (I != Options.Config.end())
1482  return I->getValue() == Value;
1483  return false;
1484 }
1485 
1486 void ento::registerRetainCountChecker(CheckerManager &Mgr) {
1487  auto *Chk = Mgr.getChecker<RetainCountChecker>();
1488  Chk->TrackObjCAndCFObjects = true;
1489  Chk->TrackNSCFStartParam = getOption(Mgr.getAnalyzerOptions(),
1490  "TrackNSCFStartParam",
1491  "true");
1492 }
1493 
1494 bool ento::shouldRegisterRetainCountChecker(const LangOptions &LO) {
1495  return true;
1496 }
1497 
1498 void ento::registerOSObjectRetainCountChecker(CheckerManager &Mgr) {
1499  auto *Chk = Mgr.getChecker<RetainCountChecker>();
1500  if (!getOption(Mgr.getAnalyzerOptions(),
1501  "CheckOSObject",
1502  "false"))
1503  Chk->TrackOSObjects = true;
1504 }
1505 
1506 bool ento::shouldRegisterOSObjectRetainCountChecker(const LangOptions &LO) {
1507  return true;
1508 }
Indicates that the tracked object is a generalized object.
Indicates that the tracked object is a CF object.
const BlockDecl * getBlockDecl() const
Definition: Expr.h:5398
ProgramStateRef handleAutoreleaseCounts(ProgramStateRef state, ExplodedNode *Pred, const ProgramPointTag *Tag, CheckerContext &Ctx, SymbolRef Sym, RefVal V, const ReturnStmt *S=nullptr) const
Represents a function declaration or definition.
Definition: Decl.h:1737
TypedValueRegion - An abstract class representing regions having a typed value.
Definition: MemRegion.h:529
There is no effect.
ObjKind
Determines the object kind of a tracked object.
A (possibly-)qualified type.
Definition: Type.h:639
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:94
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:2586
bool hasCaptures() const
True if this block (or its nested blocks) captures anything of local storage from its enclosing scope...
Definition: Decl.h:3976
ProgramStateRef handleSymbolDeath(ProgramStateRef state, SymbolRef sid, RefVal V, SmallVectorImpl< SymbolRef > &Leaked) const
bool isDead(SymbolRef sym)
Returns whether or not a symbol has been confirmed dead.
The argument has its reference count decreased by 1 to model a transferred bridge cast under ARC...
bool evalCall(const CallExpr *CE, CheckerContext &C) const
Stmt - This represents one statement.
Definition: Stmt.h:65
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:505
Bridging via __bridge, which does nothing but reinterpret the bits.
static ProgramStateRef removeRefBinding(ProgramStateRef State, SymbolRef Sym)
All typestate tracking of the object ceases.
ExplodedNode * addTransition(ProgramStateRef State=nullptr, const ProgramPointTag *Tag=nullptr)
Generates a new transition in the program state graph (ExplodedGraph).
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
The argument has its reference count increased by 1.
StringRef P
static SmallVector< ProgramStateRef, 2 > updateOutParameters(ProgramStateRef State, const RetainSummary &Summ, const CallEvent &CE)
void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const
The argument is treated as if an -autorelease message had been sent to the referenced object...
const ProgramStateRef & getState() const
Indicates that no retain count information is tracked for the return value.
static bool isSmartPtrField(const MemRegion *MR)
static bool isPointerToObject(QualType QT)
const Expr * getOriginExpr() const
Returns the expression whose value will be the result of this call.
Definition: CallEvent.h:254
bool isConsumedExpr(Expr *E) const
Definition: ParentMap.cpp:159
static RetEffect MakeNoRet()
Represents a variable declaration or definition.
Definition: Decl.h:812
SymbolRef getAsLocSymbol(bool IncludeBaseRegions=false) const
If this SVal is a location and wraps a symbol, return that SymbolRef.
Definition: SVals.cpp:84
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6766
const FunctionDecl * getCalleeDecl(const CallExpr *CE) const
Get the declaration of the called function (path-sensitive).
const Decl & getCodeDecl() const
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:138
ExplodedNode * getPredecessor()
Returns the previous node in the exploded graph, which includes the state of the program before the c...
virtual const MemRegion * getOriginRegion() const
Find the region from which this symbol originates.
Definition: SymExpr.h:101
SVal getSVal(const Stmt *S) const
Get the value of arbitrary expressions at this point in the path.
Represents a parameter to a function.
Definition: Decl.h:1549
const bool wasInlined
If we are post visiting a call, this flag will be set if the call was inlined.
Symbolic value.
Definition: SymExpr.h:29
const MemRegion * getSuperRegion() const
Definition: MemRegion.h:447
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...
MemRegionManager & getRegionManager()
Definition: SValBuilder.h:174
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
LineState State
void processNonLeakError(ProgramStateRef St, SourceRange ErrorRange, RefVal::Kind ErrorKind, SymbolRef Sym, CheckerContext &C) const
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:49
ObjCArrayLiteral - used for objective-c array containers; as in: @["Hello", NSApp, [NSNumber numberWithInt:42]];.
Definition: ExprObjC.h:176
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
The argument has its reference count decreased by 1.
The argument is a pointer to a retain-counted object; on exit, the new value of the pointer is a +0 v...
static bool getOption(AnalyzerOptions &Options, StringRef Postfix, StringRef Value)
void checkPostCall(const CallEvent &Call, CheckerContext &C) const
bool hasNonZeroCallbackArg() const
Returns true if any of the arguments appear to represent callbacks.
Definition: CallEvent.cpp:153
Indicates that the return value is an owned object when the receiver is also a tracked object...
child_range children()
Definition: Stmt.cpp:212
const LocationContext * getLocationContext() const
The argument is a pointer to a retain-counted object; on exit, the new value of the pointer is a +1 v...
bool isUnknown() const
Definition: SVals.h:136
SVal getReturnValue() const
Returns the return value of the call.
Definition: CallEvent.cpp:426
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3036
Represents an ObjC class declaration.
Definition: DeclObjC.h:1171
Bridging via __bridge_transfer, which transfers ownership of an Objective-C pointer into ARC...
static bool shouldEscapeOSArgumentOnCall(const CallEvent &CE, unsigned ArgIdx, const RefVal *TrackedValue)
Whether the tracked value should be escaped on a given call.
virtual QualType getType() const =0
virtual ArrayRef< ParmVarDecl * > parameters() const =0
Return call&#39;s formal parameters.
static bool isReceiverUnconsumedSelf(const CallEvent &Call)
SymbolRef getAsSymbol(bool IncludeBaseRegions=false) const
If this SVal wraps a symbol return that SymbolRef.
Definition: SVals.cpp:126
bool hasAttr() const
Definition: DeclBase.h:533
bool isConstrainedTrue() const
Return true if the constraint is perfectly constrained to &#39;true&#39;.
return Out str()
void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1635
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...
static const RetainSummary * getSummary(RetainSummaryManager &Summaries, const CallEvent &Call, QualType ReceiverType)
IvarAccessHistory getIvarAccessHistory() const
Returns what the analyzer knows about direct accesses to a particular instance variable.
const RegionTy * getAs() const
Definition: MemRegion.h:1227
SymbolicRegion - A special, "non-concrete" region.
Definition: MemRegion.h:763
const LocationContext * getLocationContext() const
The context in which the call is being evaluated.
Definition: CallEvent.h:244
The argument is treated as potentially escaping, meaning that even when its reference count hits 0 it...
void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const
This represents one expression.
Definition: Expr.h:108
static bool shouldEscapeRegion(const MemRegion *R)
A value escapes in these possible cases:
const CXXRecordDecl * getPointeeCXXRecordDecl() const
If this is a pointer or reference to a RecordType, return the CXXRecordDecl that the type refers to...
Definition: Type.cpp:1620
bool isObjCRetainableType() const
Definition: Type.cpp:4000
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5384
#define bool
Definition: stdbool.h:31
ObjCDictionaryLiteral - AST node to represent objective-c dictionary literals; as in:"name" : NSUserN...
Definition: ExprObjC.h:287
void printState(raw_ostream &Out, ProgramStateRef State, const char *NL, const char *Sep) const override
See CheckerManager::runCheckersForPrintState.
QualType getType() const
Definition: Expr.h:130
virtual const Decl * getDecl() const
Returns the declaration of the function or method that will be called.
Definition: CallEvent.h:234
The argument is treated as if the referenced object was deallocated.
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:2476
ExplodedNode * checkReturnWithRetEffect(const ReturnStmt *S, CheckerContext &C, ExplodedNode *Pred, RetEffect RE, RefVal X, SymbolRef Sym, ProgramStateRef state) const
An expression that sends a message to the given Objective-C object or class.
Definition: ExprObjC.h:903
void processObjCLiterals(CheckerContext &C, const Expr *Ex) const
QualType getObjCInterfaceType(const ObjCInterfaceDecl *Decl, ObjCInterfaceDecl *PrevDecl=nullptr) const
getObjCInterfaceType - Return the unique reference to the type for the specified ObjC interface decl...
ObjCBridgeCastKind getBridgeKind() const
Determine which kind of bridge is being performed via this cast.
Definition: ExprObjC.h:1608
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:704
ProgramStateRef updateSymbol(ProgramStateRef state, SymbolRef sym, RefVal V, ArgEffect E, RefVal::Kind &hasErr, CheckerContext &C) const
Optional< T > getAs() const
Convert to the specified SVal type, returning None if this SVal is not of the desired type...
Definition: SVals.h:111
const VarDecl * getDecl() const
Definition: MemRegion.h:949
void emitReport(std::unique_ptr< BugReport > R)
Emit the diagnostics report.
Kind
ArgEffectKind getKind() const
DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag, const Expr *expr, const LocationContext *LCtx, unsigned count)
Create a new symbol with a unique &#39;name&#39;.
CHECKER * registerChecker(AT &&... Args)
Used to register checkers.
Expr * getRetValue()
Definition: Stmt.h:2509
ExplodedNode * generateSink(ProgramStateRef State, ExplodedNode *Pred, const ProgramPointTag *Tag=nullptr)
Generate a sink node.
#define REGISTER_MAP_WITH_PROGRAMSTATE(Name, Key, Value)
Declares an immutable map of type NameTy, suitable for placement into the ProgramState.
ProgramPoints can be "tagged" as representing points specific to a given analysis entity...
Definition: ProgramPoint.h:39
Indicates that the tracked object is an Objective-C object.
const MemRegion * getAsRegion() const
Definition: SVals.cpp:150
ConfigTable Config
A key-value table of use-specified configuration values.
ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond, bool Assumption) const
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:75
Performs the combined functionality of DecRef and StopTrackingHard.
bool isObjCObjectPointerType() const
Definition: Type.h:6403
A class responsible for cleaning up unused symbols.
SVal getSVal(const Stmt *S) const
Get the value of an arbitrary expression at this node.
ObjCBoxedExpr - used for generalized expression boxing.
Definition: ExprObjC.h:116
unsigned blockCount() const
Returns the number of times the current block has been visited along the analyzed path...
An Objective-C "bridged" cast expression, which casts between Objective-C pointers and C pointers...
Definition: ExprObjC.h:1581
static ProgramStateRef setRefBinding(ProgramStateRef State, SymbolRef Sym, RefVal Val)
Dataflow Directional Tag Classes.
virtual SourceRange getArgSourceRange(unsigned Index) const
Returns the source range for errors associated with this argument.
Definition: CallEvent.cpp:419
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:845
static Optional< RefVal > refValFromRetEffect(RetEffect RE, QualType ResultTy)
ProgramStateRef checkRegionChanges(ProgramStateRef state, const InvalidatedSymbols *invalidated, ArrayRef< const MemRegion *> ExplicitRegions, ArrayRef< const MemRegion *> Regions, const LocationContext *LCtx, const CallEvent *Call) const
ExplodedNode * processLeaks(ProgramStateRef state, SmallVectorImpl< SymbolRef > &Leaked, CheckerContext &Ctx, ExplodedNode *Pred=nullptr) const
const MemRegion * StripCasts(bool StripBaseAndDerivedCasts=true) const
Definition: MemRegion.cpp:1196
static RefVal makeOwned(ObjKind o, QualType t)
Create a state for an object whose lifetime is the responsibility of the current function, at least partially.
QualType getCallReturnType(const ASTContext &Ctx) const
getCallReturnType - Get the return type of the call expr.
Definition: Expr.cpp:1397
Represents an abstract call to a function or method along a particular path.
Definition: CallEvent.h:170
Bridging via __bridge_retain, which makes an ARC object available as a +1 C pointer.
AnalyzerOptions & getAnalyzerOptions()
const Decl * getDecl() const
Represents a pointer to an Objective C object.
Definition: Type.h:5804
const StackFrameContext * getStackFrame() const
Indicates that the tracking object is a descendant of a referenced-counted OSObject, used in the Darwin kernel.
const ProgramStateRef & getState() const
void checkEndFunction(const ReturnStmt *RS, CheckerContext &C) const
const RefVal * getRefBinding(ProgramStateRef State, SymbolRef Sym)
bool hasStackStorage() const
Definition: MemRegion.cpp:1140
Stores options for the analyzer from the command line.
ObjCIvarRefExpr - A reference to an ObjC instance variable.
Definition: ExprObjC.h:512
QualType getResultType() const
Returns the result type, adjusted for references.
Definition: CallEvent.cpp:69
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:14015
ArgEffect withKind(ArgEffectKind NewK)
All typestate tracking of the object ceases.
static RefVal makeNotOwned(ObjKind o, QualType t)
Create a state for an object whose lifetime is not the responsibility of the current function...
virtual unsigned getNumArgs() const =0
Returns the number of arguments (explicit and implicit).
The argument is a pointer to a retain-counted object; on exit, the new value of the pointer is a +1 v...
void checkSummary(const RetainSummary &Summ, const CallEvent &Call, CheckerContext &C) const
SValBuilder & getSValBuilder()
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2429
const RefCountBug & errorKindToBugKind(RefVal::Kind ErrorKind, SymbolRef Sym) const
static Decl::Kind getKind(const Decl *D)
Definition: DeclBase.cpp:957
The argument is a pointer to a retain-counted object; on exit, the new value of the pointer is a +1 v...
virtual SVal getArgSVal(unsigned Index) const
Returns the value of a given argument at the time of the call.
Definition: CallEvent.cpp:412
QualType getType() const
Definition: Decl.h:647
void processSummaryOfInlined(const RetainSummary &Summ, const CallEvent &Call, CheckerContext &C) const
A trivial tuple used to represent a source range.
An ArgEffect summarizes the retain count behavior on an argument or receiver to a function or method...
Tag that can use a checker name as a message provider (see SimpleProgramPointTag).
Definition: Checker.h:509
QualType getObjCObjectPointerType(QualType OIT) const
Return a ObjCObjectPointerType type for the given ObjCObjectType.
bool inTopFrame() const
Return true if the current LocationContext has no caller context.
AnalysisDeclContext * getAnalysisDeclContext() const
const LocationContext * getLocationContext() const
const LangOptions & getLangOpts() const
Definition: ASTContext.h:706
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...
RetEffect summarizes a call&#39;s retain/release behavior with respect to its return value.