clang  8.0.0svn
ProgramState.cpp
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1 //= ProgramState.cpp - Path-Sensitive "State" for tracking values --*- 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 implements ProgramState and ProgramStateManager.
11 //
12 //===----------------------------------------------------------------------===//
13 
16 #include "clang/Analysis/CFG.h"
22 #include "llvm/Support/raw_ostream.h"
23 
24 using namespace clang;
25 using namespace ento;
26 
27 namespace clang { namespace ento {
28 /// Increments the number of times this state is referenced.
29 
31  ++const_cast<ProgramState*>(state)->refCount;
32 }
33 
34 /// Decrement the number of times this state is referenced.
36  assert(state->refCount > 0);
37  ProgramState *s = const_cast<ProgramState*>(state);
38  if (--s->refCount == 0) {
40  Mgr.StateSet.RemoveNode(s);
41  s->~ProgramState();
42  Mgr.freeStates.push_back(s);
43  }
44 }
45 }}
46 
48  StoreRef st, GenericDataMap gdm)
49  : stateMgr(mgr),
50  Env(env),
51  store(st.getStore()),
52  GDM(gdm),
53  refCount(0) {
54  stateMgr->getStoreManager().incrementReferenceCount(store);
55 }
56 
58  : llvm::FoldingSetNode(),
59  stateMgr(RHS.stateMgr),
60  Env(RHS.Env),
61  store(RHS.store),
62  GDM(RHS.GDM),
63  refCount(0) {
64  stateMgr->getStoreManager().incrementReferenceCount(store);
65 }
66 
68  if (store)
69  stateMgr->getStoreManager().decrementReferenceCount(store);
70 }
71 
72 int64_t ProgramState::getID() const {
73  return getStateManager().Alloc.identifyKnownAlignedObject<ProgramState>(this);
74 }
75 
77  StoreManagerCreator CreateSMgr,
78  ConstraintManagerCreator CreateCMgr,
79  llvm::BumpPtrAllocator &alloc,
80  SubEngine *SubEng)
81  : Eng(SubEng), EnvMgr(alloc), GDMFactory(alloc),
82  svalBuilder(createSimpleSValBuilder(alloc, Ctx, *this)),
83  CallEventMgr(new CallEventManager(alloc)), Alloc(alloc) {
84  StoreMgr = (*CreateSMgr)(*this);
85  ConstraintMgr = (*CreateCMgr)(*this, SubEng);
86 }
87 
88 
90  for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end();
91  I!=E; ++I)
92  I->second.second(I->second.first);
93 }
94 
97  const StackFrameContext *LCtx,
98  SymbolReaper& SymReaper) {
99 
100  // This code essentially performs a "mark-and-sweep" of the VariableBindings.
101  // The roots are any Block-level exprs and Decls that our liveness algorithm
102  // tells us are live. We then see what Decls they may reference, and keep
103  // those around. This code more than likely can be made faster, and the
104  // frequency of which this method is called should be experimented with
105  // for optimum performance.
106  ProgramState NewState = *state;
107 
108  NewState.Env = EnvMgr.removeDeadBindings(NewState.Env, SymReaper, state);
109 
110  // Clean up the store.
111  StoreRef newStore = StoreMgr->removeDeadBindings(NewState.getStore(), LCtx,
112  SymReaper);
113  NewState.setStore(newStore);
114  SymReaper.setReapedStore(newStore);
115 
116  ProgramStateRef Result = getPersistentState(NewState);
117  return ConstraintMgr->removeDeadBindings(Result, SymReaper);
118 }
119 
121  SVal V,
122  const LocationContext *LCtx,
123  bool notifyChanges) const {
124  ProgramStateManager &Mgr = getStateManager();
125  ProgramStateRef newState = makeWithStore(Mgr.StoreMgr->Bind(getStore(),
126  LV, V));
127  const MemRegion *MR = LV.getAsRegion();
128  if (MR && Mgr.getOwningEngine() && notifyChanges)
129  return Mgr.getOwningEngine()->processRegionChange(newState, MR, LCtx);
130 
131  return newState;
132 }
133 
136  const LocationContext *LCtx) const {
137  ProgramStateManager &Mgr = getStateManager();
138  const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion();
139  const StoreRef &newStore = Mgr.StoreMgr->BindDefaultInitial(getStore(), R, V);
140  ProgramStateRef new_state = makeWithStore(newStore);
141  return Mgr.getOwningEngine()
142  ? Mgr.getOwningEngine()->processRegionChange(new_state, R, LCtx)
143  : new_state;
144 }
145 
148  ProgramStateManager &Mgr = getStateManager();
149  const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion();
150  const StoreRef &newStore = Mgr.StoreMgr->BindDefaultZero(getStore(), R);
151  ProgramStateRef new_state = makeWithStore(newStore);
152  return Mgr.getOwningEngine()
153  ? Mgr.getOwningEngine()->processRegionChange(new_state, R, LCtx)
154  : new_state;
155 }
156 
159 
162  const Expr *E, unsigned Count,
163  const LocationContext *LCtx,
164  bool CausedByPointerEscape,
165  InvalidatedSymbols *IS,
166  const CallEvent *Call,
167  RegionAndSymbolInvalidationTraits *ITraits) const {
168  SmallVector<SVal, 8> Values;
169  for (RegionList::const_iterator I = Regions.begin(),
170  End = Regions.end(); I != End; ++I)
171  Values.push_back(loc::MemRegionVal(*I));
172 
173  return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape,
174  IS, ITraits, Call);
175 }
176 
179  const Expr *E, unsigned Count,
180  const LocationContext *LCtx,
181  bool CausedByPointerEscape,
182  InvalidatedSymbols *IS,
183  const CallEvent *Call,
184  RegionAndSymbolInvalidationTraits *ITraits) const {
185 
186  return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape,
187  IS, ITraits, Call);
188 }
189 
191 ProgramState::invalidateRegionsImpl(ValueList Values,
192  const Expr *E, unsigned Count,
193  const LocationContext *LCtx,
194  bool CausedByPointerEscape,
195  InvalidatedSymbols *IS,
196  RegionAndSymbolInvalidationTraits *ITraits,
197  const CallEvent *Call) const {
198  ProgramStateManager &Mgr = getStateManager();
199  SubEngine* Eng = Mgr.getOwningEngine();
200 
201  InvalidatedSymbols Invalidated;
202  if (!IS)
203  IS = &Invalidated;
204 
205  RegionAndSymbolInvalidationTraits ITraitsLocal;
206  if (!ITraits)
207  ITraits = &ITraitsLocal;
208 
209  if (Eng) {
210  StoreManager::InvalidatedRegions TopLevelInvalidated;
212  const StoreRef &newStore
213  = Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call,
214  *IS, *ITraits, &TopLevelInvalidated,
215  &Invalidated);
216 
217  ProgramStateRef newState = makeWithStore(newStore);
218 
219  if (CausedByPointerEscape) {
220  newState = Eng->notifyCheckersOfPointerEscape(newState, IS,
221  TopLevelInvalidated,
222  Call,
223  *ITraits);
224  }
225 
226  return Eng->processRegionChanges(newState, IS, TopLevelInvalidated,
227  Invalidated, LCtx, Call);
228  }
229 
230  const StoreRef &newStore =
231  Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call,
232  *IS, *ITraits, nullptr, nullptr);
233  return makeWithStore(newStore);
234 }
235 
237  assert(!LV.getAs<loc::MemRegionVal>() && "Use invalidateRegion instead.");
238 
239  Store OldStore = getStore();
240  const StoreRef &newStore =
241  getStateManager().StoreMgr->killBinding(OldStore, LV);
242 
243  if (newStore.getStore() == OldStore)
244  return this;
245 
246  return makeWithStore(newStore);
247 }
248 
251  const StackFrameContext *CalleeCtx) const {
252  const StoreRef &NewStore =
253  getStateManager().StoreMgr->enterStackFrame(getStore(), Call, CalleeCtx);
254  return makeWithStore(NewStore);
255 }
256 
258  // We only want to do fetches from regions that we can actually bind
259  // values. For example, SymbolicRegions of type 'id<...>' cannot
260  // have direct bindings (but their can be bindings on their subregions).
261  if (!R->isBoundable())
262  return UnknownVal();
263 
264  if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) {
265  QualType T = TR->getValueType();
267  return getSVal(R);
268  }
269 
270  return UnknownVal();
271 }
272 
273 SVal ProgramState::getSVal(Loc location, QualType T) const {
274  SVal V = getRawSVal(location, T);
275 
276  // If 'V' is a symbolic value that is *perfectly* constrained to
277  // be a constant value, use that value instead to lessen the burden
278  // on later analysis stages (so we have less symbolic values to reason
279  // about).
280  // We only go into this branch if we can convert the APSInt value we have
281  // to the type of T, which is not always the case (e.g. for void).
282  if (!T.isNull() && (T->isIntegralOrEnumerationType() || Loc::isLocType(T))) {
283  if (SymbolRef sym = V.getAsSymbol()) {
284  if (const llvm::APSInt *Int = getStateManager()
285  .getConstraintManager()
286  .getSymVal(this, sym)) {
287  // FIXME: Because we don't correctly model (yet) sign-extension
288  // and truncation of symbolic values, we need to convert
289  // the integer value to the correct signedness and bitwidth.
290  //
291  // This shows up in the following:
292  //
293  // char foo();
294  // unsigned x = foo();
295  // if (x == 54)
296  // ...
297  //
298  // The symbolic value stored to 'x' is actually the conjured
299  // symbol for the call to foo(); the type of that symbol is 'char',
300  // not unsigned.
301  const llvm::APSInt &NewV = getBasicVals().Convert(T, *Int);
302 
303  if (V.getAs<Loc>())
304  return loc::ConcreteInt(NewV);
305  else
306  return nonloc::ConcreteInt(NewV);
307  }
308  }
309  }
310 
311  return V;
312 }
313 
315  const LocationContext *LCtx,
316  SVal V, bool Invalidate) const{
317  Environment NewEnv =
318  getStateManager().EnvMgr.bindExpr(Env, EnvironmentEntry(S, LCtx), V,
319  Invalidate);
320  if (NewEnv == Env)
321  return this;
322 
323  ProgramState NewSt = *this;
324  NewSt.Env = NewEnv;
325  return getStateManager().getPersistentState(NewSt);
326 }
327 
329  DefinedOrUnknownSVal UpperBound,
330  bool Assumption,
331  QualType indexTy) const {
332  if (Idx.isUnknown() || UpperBound.isUnknown())
333  return this;
334 
335  // Build an expression for 0 <= Idx < UpperBound.
336  // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed.
337  // FIXME: This should probably be part of SValBuilder.
338  ProgramStateManager &SM = getStateManager();
339  SValBuilder &svalBuilder = SM.getSValBuilder();
340  ASTContext &Ctx = svalBuilder.getContext();
341 
342  // Get the offset: the minimum value of the array index type.
343  BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
344  if (indexTy.isNull())
345  indexTy = svalBuilder.getArrayIndexType();
346  nonloc::ConcreteInt Min(BVF.getMinValue(indexTy));
347 
348  // Adjust the index.
349  SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add,
350  Idx.castAs<NonLoc>(), Min, indexTy);
351  if (newIdx.isUnknownOrUndef())
352  return this;
353 
354  // Adjust the upper bound.
355  SVal newBound =
356  svalBuilder.evalBinOpNN(this, BO_Add, UpperBound.castAs<NonLoc>(),
357  Min, indexTy);
358 
359  if (newBound.isUnknownOrUndef())
360  return this;
361 
362  // Build the actual comparison.
363  SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, newIdx.castAs<NonLoc>(),
364  newBound.castAs<NonLoc>(), Ctx.IntTy);
365  if (inBound.isUnknownOrUndef())
366  return this;
367 
368  // Finally, let the constraint manager take care of it.
370  return CM.assume(this, inBound.castAs<DefinedSVal>(), Assumption);
371 }
372 
374  ConditionTruthVal IsNull = isNull(V);
375  if (IsNull.isUnderconstrained())
376  return IsNull;
377  return ConditionTruthVal(!IsNull.getValue());
378 }
379 
381  return stateMgr->getSValBuilder().areEqual(this, Lhs, Rhs);
382 }
383 
385  if (V.isZeroConstant())
386  return true;
387 
388  if (V.isConstant())
389  return false;
390 
391  SymbolRef Sym = V.getAsSymbol(/* IncludeBaseRegion */ true);
392  if (!Sym)
393  return ConditionTruthVal();
394 
395  return getStateManager().ConstraintMgr->isNull(this, Sym);
396 }
397 
399  ProgramState State(this,
400  EnvMgr.getInitialEnvironment(),
401  StoreMgr->getInitialStore(InitLoc),
402  GDMFactory.getEmptyMap());
403 
404  return getPersistentState(State);
405 }
406 
408  ProgramStateRef FromState,
409  ProgramStateRef GDMState) {
410  ProgramState NewState(*FromState);
411  NewState.GDM = GDMState->GDM;
412  return getPersistentState(NewState);
413 }
414 
416 
417  llvm::FoldingSetNodeID ID;
418  State.Profile(ID);
419  void *InsertPos;
420 
421  if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos))
422  return I;
423 
424  ProgramState *newState = nullptr;
425  if (!freeStates.empty()) {
426  newState = freeStates.back();
427  freeStates.pop_back();
428  }
429  else {
430  newState = (ProgramState*) Alloc.Allocate<ProgramState>();
431  }
432  new (newState) ProgramState(State);
433  StateSet.InsertNode(newState, InsertPos);
434  return newState;
435 }
436 
437 ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const {
438  ProgramState NewSt(*this);
439  NewSt.setStore(store);
440  return getStateManager().getPersistentState(NewSt);
441 }
442 
443 void ProgramState::setStore(const StoreRef &newStore) {
444  Store newStoreStore = newStore.getStore();
445  if (newStoreStore)
446  stateMgr->getStoreManager().incrementReferenceCount(newStoreStore);
447  if (store)
448  stateMgr->getStoreManager().decrementReferenceCount(store);
449  store = newStoreStore;
450 }
451 
452 //===----------------------------------------------------------------------===//
453 // State pretty-printing.
454 //===----------------------------------------------------------------------===//
455 
456 void ProgramState::print(raw_ostream &Out,
457  const char *NL, const char *Sep,
458  const LocationContext *LC) const {
459  // Print the store.
460  ProgramStateManager &Mgr = getStateManager();
461  const ASTContext &Context = getStateManager().getContext();
462  Mgr.getStoreManager().print(getStore(), Out, NL);
463 
464  // Print out the environment.
465  Env.print(Out, NL, Sep, Context, LC);
466 
467  // Print out the constraints.
468  Mgr.getConstraintManager().print(this, Out, NL, Sep);
469 
470  // Print out the tracked dynamic types.
471  printDynamicTypeInfo(this, Out, NL, Sep);
472 
473  // Print out tainted symbols.
474  printTaint(Out, NL);
475 
476  // Print checker-specific data.
477  Mgr.getOwningEngine()->printState(Out, this, NL, Sep, LC);
478 }
479 
480 void ProgramState::printDOT(raw_ostream &Out,
481  const LocationContext *LC) const {
482  print(Out, "\\l", "\\|", LC);
483 }
484 
485 LLVM_DUMP_METHOD void ProgramState::dump() const {
486  print(llvm::errs());
487 }
488 
489 void ProgramState::printTaint(raw_ostream &Out,
490  const char *NL) const {
491  TaintMapImpl TM = get<TaintMap>();
492 
493  if (!TM.isEmpty())
494  Out <<"Tainted symbols:" << NL;
495 
496  for (TaintMapImpl::iterator I = TM.begin(), E = TM.end(); I != E; ++I) {
497  Out << I->first << " : " << I->second << NL;
498  }
499 }
500 
502  printTaint(llvm::errs());
503 }
504 
506  return stateMgr->getOwningEngine()->getAnalysisManager();
507 }
508 
509 //===----------------------------------------------------------------------===//
510 // Generic Data Map.
511 //===----------------------------------------------------------------------===//
512 
513 void *const* ProgramState::FindGDM(void *K) const {
514  return GDM.lookup(K);
515 }
516 
517 void*
519  void *(*CreateContext)(llvm::BumpPtrAllocator&),
520  void (*DeleteContext)(void*)) {
521 
522  std::pair<void*, void (*)(void*)>& p = GDMContexts[K];
523  if (!p.first) {
524  p.first = CreateContext(Alloc);
525  p.second = DeleteContext;
526  }
527 
528  return p.first;
529 }
530 
532  ProgramState::GenericDataMap M1 = St->getGDM();
533  ProgramState::GenericDataMap M2 = GDMFactory.add(M1, Key, Data);
534 
535  if (M1 == M2)
536  return St;
537 
538  ProgramState NewSt = *St;
539  NewSt.GDM = M2;
540  return getPersistentState(NewSt);
541 }
542 
544  ProgramState::GenericDataMap OldM = state->getGDM();
545  ProgramState::GenericDataMap NewM = GDMFactory.remove(OldM, Key);
546 
547  if (NewM == OldM)
548  return state;
549 
550  ProgramState NewState = *state;
551  NewState.GDM = NewM;
552  return getPersistentState(NewState);
553 }
554 
556  bool wasVisited = !visited.insert(val.getCVData()).second;
557  if (wasVisited)
558  return true;
559 
560  StoreManager &StoreMgr = state->getStateManager().getStoreManager();
561  // FIXME: We don't really want to use getBaseRegion() here because pointer
562  // arithmetic doesn't apply, but scanReachableSymbols only accepts base
563  // regions right now.
564  const MemRegion *R = val.getRegion()->getBaseRegion();
565  return StoreMgr.scanReachableSymbols(val.getStore(), R, *this);
566 }
567 
569  for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I)
570  if (!scan(*I))
571  return false;
572 
573  return true;
574 }
575 
577  for (SymExpr::symbol_iterator SI = sym->symbol_begin(),
578  SE = sym->symbol_end();
579  SI != SE; ++SI) {
580  bool wasVisited = !visited.insert(*SI).second;
581  if (wasVisited)
582  continue;
583 
584  if (!visitor.VisitSymbol(*SI))
585  return false;
586  }
587 
588  return true;
589 }
590 
593  return scan(X->getRegion());
594 
597  return scan(*X);
598 
600  return scan(X->getLoc());
601 
602  if (SymbolRef Sym = val.getAsSymbol())
603  return scan(Sym);
604 
605  if (const SymExpr *Sym = val.getAsSymbolicExpression())
606  return scan(Sym);
607 
609  return scan(*X);
610 
611  return true;
612 }
613 
615  if (isa<MemSpaceRegion>(R))
616  return true;
617 
618  bool wasVisited = !visited.insert(R).second;
619  if (wasVisited)
620  return true;
621 
622  if (!visitor.VisitMemRegion(R))
623  return false;
624 
625  // If this is a symbolic region, visit the symbol for the region.
626  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
627  if (!visitor.VisitSymbol(SR->getSymbol()))
628  return false;
629 
630  // If this is a subregion, also visit the parent regions.
631  if (const SubRegion *SR = dyn_cast<SubRegion>(R)) {
632  const MemRegion *Super = SR->getSuperRegion();
633  if (!scan(Super))
634  return false;
635 
636  // When we reach the topmost region, scan all symbols in it.
637  if (isa<MemSpaceRegion>(Super)) {
638  StoreManager &StoreMgr = state->getStateManager().getStoreManager();
639  if (!StoreMgr.scanReachableSymbols(state->getStore(), SR, *this))
640  return false;
641  }
642  }
643 
644  // Regions captured by a block are also implicitly reachable.
645  if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) {
646  BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(),
647  E = BDR->referenced_vars_end();
648  for ( ; I != E; ++I) {
649  if (!scan(I.getCapturedRegion()))
650  return false;
651  }
652  }
653 
654  return true;
655 }
656 
658  ScanReachableSymbols S(this, visitor);
659  return S.scan(val);
660 }
661 
663  llvm::iterator_range<region_iterator> Reachable,
664  SymbolVisitor &visitor) const {
665  ScanReachableSymbols S(this, visitor);
666  for (const MemRegion *R : Reachable) {
667  if (!S.scan(R))
668  return false;
669  }
670  return true;
671 }
672 
674  const LocationContext *LCtx,
675  TaintTagType Kind) const {
676  if (const Expr *E = dyn_cast_or_null<Expr>(S))
677  S = E->IgnoreParens();
678 
679  return addTaint(getSVal(S, LCtx), Kind);
680 }
681 
683  TaintTagType Kind) const {
684  SymbolRef Sym = V.getAsSymbol();
685  if (Sym)
686  return addTaint(Sym, Kind);
687 
688  // If the SVal represents a structure, try to mass-taint all values within the
689  // structure. For now it only works efficiently on lazy compound values that
690  // were conjured during a conservative evaluation of a function - either as
691  // return values of functions that return structures or arrays by value, or as
692  // values of structures or arrays passed into the function by reference,
693  // directly or through pointer aliasing. Such lazy compound values are
694  // characterized by having exactly one binding in their captured store within
695  // their parent region, which is a conjured symbol default-bound to the base
696  // region of the parent region.
697  if (auto LCV = V.getAs<nonloc::LazyCompoundVal>()) {
698  if (Optional<SVal> binding = getStateManager().StoreMgr->getDefaultBinding(*LCV)) {
699  if (SymbolRef Sym = binding->getAsSymbol())
700  return addPartialTaint(Sym, LCV->getRegion(), Kind);
701  }
702  }
703 
704  const MemRegion *R = V.getAsRegion();
705  return addTaint(R, Kind);
706 }
707 
709  TaintTagType Kind) const {
710  if (const SymbolicRegion *SR = dyn_cast_or_null<SymbolicRegion>(R))
711  return addTaint(SR->getSymbol(), Kind);
712  return this;
713 }
714 
716  TaintTagType Kind) const {
717  // If this is a symbol cast, remove the cast before adding the taint. Taint
718  // is cast agnostic.
719  while (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym))
720  Sym = SC->getOperand();
721 
722  ProgramStateRef NewState = set<TaintMap>(Sym, Kind);
723  assert(NewState);
724  return NewState;
725 }
726 
728  const SubRegion *SubRegion,
729  TaintTagType Kind) const {
730  // Ignore partial taint if the entire parent symbol is already tainted.
731  if (contains<TaintMap>(ParentSym) && *get<TaintMap>(ParentSym) == Kind)
732  return this;
733 
734  // Partial taint applies if only a portion of the symbol is tainted.
735  if (SubRegion == SubRegion->getBaseRegion())
736  return addTaint(ParentSym, Kind);
737 
738  const TaintedSubRegions *SavedRegs = get<DerivedSymTaint>(ParentSym);
739  TaintedSubRegions Regs =
740  SavedRegs ? *SavedRegs : stateMgr->TSRFactory.getEmptyMap();
741 
742  Regs = stateMgr->TSRFactory.add(Regs, SubRegion, Kind);
743  ProgramStateRef NewState = set<DerivedSymTaint>(ParentSym, Regs);
744  assert(NewState);
745  return NewState;
746 }
747 
748 bool ProgramState::isTainted(const Stmt *S, const LocationContext *LCtx,
749  TaintTagType Kind) const {
750  if (const Expr *E = dyn_cast_or_null<Expr>(S))
751  S = E->IgnoreParens();
752 
753  SVal val = getSVal(S, LCtx);
754  return isTainted(val, Kind);
755 }
756 
757 bool ProgramState::isTainted(SVal V, TaintTagType Kind) const {
758  if (const SymExpr *Sym = V.getAsSymExpr())
759  return isTainted(Sym, Kind);
760  if (const MemRegion *Reg = V.getAsRegion())
761  return isTainted(Reg, Kind);
762  return false;
763 }
764 
765 bool ProgramState::isTainted(const MemRegion *Reg, TaintTagType K) const {
766  if (!Reg)
767  return false;
768 
769  // Element region (array element) is tainted if either the base or the offset
770  // are tainted.
771  if (const ElementRegion *ER = dyn_cast<ElementRegion>(Reg))
772  return isTainted(ER->getSuperRegion(), K) || isTainted(ER->getIndex(), K);
773 
774  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg))
775  return isTainted(SR->getSymbol(), K);
776 
777  if (const SubRegion *ER = dyn_cast<SubRegion>(Reg))
778  return isTainted(ER->getSuperRegion(), K);
779 
780  return false;
781 }
782 
783 bool ProgramState::isTainted(SymbolRef Sym, TaintTagType Kind) const {
784  if (!Sym)
785  return false;
786 
787  // Traverse all the symbols this symbol depends on to see if any are tainted.
788  for (SymExpr::symbol_iterator SI = Sym->symbol_begin(), SE =Sym->symbol_end();
789  SI != SE; ++SI) {
790  if (!isa<SymbolData>(*SI))
791  continue;
792 
793  if (const TaintTagType *Tag = get<TaintMap>(*SI)) {
794  if (*Tag == Kind)
795  return true;
796  }
797 
798  if (const SymbolDerived *SD = dyn_cast<SymbolDerived>(*SI)) {
799  // If this is a SymbolDerived with a tainted parent, it's also tainted.
800  if (isTainted(SD->getParentSymbol(), Kind))
801  return true;
802 
803  // If this is a SymbolDerived with the same parent symbol as another
804  // tainted SymbolDerived and a region that's a sub-region of that tainted
805  // symbol, it's also tainted.
806  if (const TaintedSubRegions *Regs =
807  get<DerivedSymTaint>(SD->getParentSymbol())) {
808  const TypedValueRegion *R = SD->getRegion();
809  for (auto I : *Regs) {
810  // FIXME: The logic to identify tainted regions could be more
811  // complete. For example, this would not currently identify
812  // overlapping fields in a union as tainted. To identify this we can
813  // check for overlapping/nested byte offsets.
814  if (Kind == I.second && R->isSubRegionOf(I.first))
815  return true;
816  }
817  }
818  }
819 
820  // If memory region is tainted, data is also tainted.
821  if (const SymbolRegionValue *SRV = dyn_cast<SymbolRegionValue>(*SI)) {
822  if (isTainted(SRV->getRegion(), Kind))
823  return true;
824  }
825 
826  // If this is a SymbolCast from a tainted value, it's also tainted.
827  if (const SymbolCast *SC = dyn_cast<SymbolCast>(*SI)) {
828  if (isTainted(SC->getOperand(), Kind))
829  return true;
830  }
831  }
832 
833  return false;
834 }
virtual ProgramStateRef assume(ProgramStateRef state, DefinedSVal Cond, bool Assumption)=0
LLVM_NODISCARD ProgramStateRef addPartialTaint(SymbolRef ParentSym, const SubRegion *SubRegion, TaintTagType Kind=TaintTagGeneric) const
Create a new state in a which a sub-region of a given symbol is tainted.
ProgramStateRef addGDM(ProgramStateRef St, void *Key, void *Data)
TypedValueRegion - An abstract class representing regions having a typed value.
Definition: MemRegion.h:529
ProgramStateRef processRegionChange(ProgramStateRef state, const MemRegion *MR, const LocationContext *LCtx)
Definition: SubEngine.h:146
if(T->getSizeExpr()) TRY_TO(TraverseStmt(T -> getSizeExpr()))
QualType getArrayIndexType() const
Definition: SValBuilder.h:165
A (possibly-)qualified type.
Definition: Type.h:638
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:94
bool isUnderconstrained() const
Return true if the constrained is underconstrained and we do not know if the constraint is true of va...
Store getStore() const
Definition: StoreRef.h:47
LLVM_NODISCARD ProgramStateRef enterStackFrame(const CallEvent &Call, const StackFrameContext *CalleeCtx) const
enterStackFrame - Returns the state for entry to the given stack frame, preserving the current state...
llvm::DenseSet< SymbolRef > InvalidatedSymbols
Definition: Store.h:52
DominatorTree GraphTraits specialization so the DominatorTree can be iterable by generic graph iterat...
Definition: Dominators.h:30
SValBuilder * createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context, ProgramStateManager &stateMgr)
Stmt - This represents one statement.
Definition: Stmt.h:66
BasicValueFactory & getBasicVals()
Definition: ProgramState.h:538
Manages the lifetime of CallEvent objects.
Definition: CallEvent.h:1087
IntrusiveRefCntPtr< const ProgramState > ProgramStateRef
Value representing integer constant.
Definition: SVals.h:377
ConditionTruthVal isNonNull(SVal V) const
Check if the given SVal is not constrained to zero and is not a zero constant.
A utility class that visits the reachable symbols using a custom SymbolVisitor.
Definition: ProgramState.h:889
const void * Store
Store - This opaque type encapsulates an immutable mapping from locations to values.
Definition: StoreRef.h:28
ProgramStateRef removeDeadBindings(ProgramStateRef St, const StackFrameContext *LCtx, SymbolReaper &SymReaper)
Store getStore() const
Return the store associated with this state.
Definition: ProgramState.h:128
LLVM_NODISCARD ProgramStateRef bindDefaultInitial(SVal loc, SVal V, const LocationContext *LCtx) const
Initializes the region of memory represented by loc with an initial value.
Symbolic value.
Definition: SymExpr.h:30
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
LineState State
llvm::ImmutableList< SVal >::iterator iterator
Definition: SVals.h:465
llvm::ImmutableMap< SymbolRef, TaintTagType > TaintMapImpl
Definition: TaintManager.h:33
std::unique_ptr< StoreManager >(* StoreManagerCreator)(ProgramStateManager &)
Definition: ProgramState.h:45
symbol_iterator symbol_begin() const
Definition: SymExpr.h:87
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
const SymExpr * getAsSymbolicExpression() const
getAsSymbolicExpression - If this Sval wraps a symbolic expression then return that expression...
Definition: SVals.cpp:137
void setReapedStore(StoreRef st)
Set to the value of the symbolic store after StoreManager::removeDeadBindings has been called...
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6648
const llvm::APSInt & Convert(const llvm::APSInt &To, const llvm::APSInt &From)
Convert - Create a new persistent APSInt with the same value as &#39;From&#39; but with the bitwidth and sign...
static bool isLocType(QualType T)
Definition: SVals.h:327
ProgramStateManager & getStateManager() const
Return the ProgramStateManager associated with this state.
Definition: ProgramState.h:113
bool isTainted(const Stmt *S, const LocationContext *LCtx, TaintTagType Kind=TaintTagGeneric) const
Check if the statement is tainted in the current state.
BlockDataRegion - A region that represents a block instance.
Definition: MemRegion.h:672
AnalysisManager & getAnalysisManager() const
bool scanReachableSymbols(SVal val, SymbolVisitor &visitor) const
Visits the symbols reachable from the given SVal using the provided SymbolVisitor.
virtual void print(Store store, raw_ostream &Out, const char *nl)=0
bool isUnknown() const
Definition: SVals.h:137
virtual void decrementReferenceCount(Store store)
If the StoreManager supports it, decrement the reference count of the specified Store object...
Definition: Store.h:208
const LazyCompoundValData * getCVData() const
Definition: SVals.h:491
A symbol representing the value of a MemRegion whose parent region has symbolic value.
SmallVector< const MemRegion *, 8 > InvalidatedRegions
Definition: Store.h:210
bool isConstant() const
Definition: SVals.cpp:218
SVal getSVal(const Stmt *S, const LocationContext *LCtx) const
Returns the SVal bound to the statement &#39;S&#39; in the state&#39;s environment.
Definition: ProgramState.h:789
virtual void print(ProgramStateRef state, raw_ostream &Out, const char *nl, const char *sep)=0
LLVM_NODISCARD ProgramStateRef addTaint(const Stmt *S, const LocationContext *LCtx, TaintTagType Kind=TaintTagGeneric) const
Create a new state in which the statement is marked as tainted.
SymbolRef getAsSymbol(bool IncludeBaseRegions=false) const
If this SVal wraps a symbol return that SymbolRef.
Definition: SVals.cpp:127
std::unique_ptr< ConstraintManager >(* ConstraintManagerCreator)(ProgramStateManager &, SubEngine *)
Definition: ProgramState.h:43
LLVM_NODISCARD ProgramStateRef BindExpr(const Stmt *S, const LocationContext *LCtx, SVal V, bool Invalidate=true) const
Create a new state by binding the value &#39;V&#39; to the statement &#39;S&#39; in the state&#39;s environment.
llvm::ImmutableMap< void *, void * > GenericDataMap
Definition: ProgramState.h:78
SymbolicRegion - A special, "non-concrete" region.
Definition: MemRegion.h:763
ProgramState - This class encapsulates:
Definition: ProgramState.h:75
This represents one expression.
Definition: Expr.h:106
SourceLocation End
Represents a cast expression.
LLVM_NODISCARD ProgramStateRef bindDefaultZero(SVal loc, const LocationContext *LCtx) const
Performs C++ zero-initialization procedure on the region of memory represented by loc...
ConditionTruthVal isNull(SVal V) const
Check if the given SVal is constrained to zero or is a zero constant.
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:703
const SourceManager & SM
Definition: Format.cpp:1490
void *const * FindGDM(void *K) 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:112
LLVM_NODISCARD ProgramStateRef bindLoc(Loc location, SVal V, const LocationContext *LCtx, bool notifyChanges=true) const
virtual bool isBoundable() const
Definition: MemRegion.h:173
ProgramStateRef removeGDM(ProgramStateRef state, void *Key)
bool scan(nonloc::LazyCompoundVal val)
void print(raw_ostream &Out, const char *nl="\, const char *sep="", const LocationContext *CurrentLC=nullptr) const
Kind
ProgramStateRef getInitialState(const LocationContext *InitLoc)
const MemRegion * getAsRegion() const
Definition: SVals.cpp:151
bool isSubRegionOf(const MemRegion *R) const override
Check if the region is a subregion of the given region.
Definition: MemRegion.cpp:133
An entry in the environment consists of a Stmt and an LocationContext.
Definition: Environment.h:36
ASTContext & getContext()
Definition: SValBuilder.h:156
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:76
A class responsible for cleaning up unused symbols.
ConditionTruthVal areEqual(SVal Lhs, SVal Rhs) const
llvm::ImmutableMap< const SubRegion *, TaintTagType > TaintedSubRegions
Definition: ProgramState.h:47
virtual void printState(raw_ostream &Out, ProgramStateRef State, const char *NL, const char *Sep, const LocationContext *LCtx=nullptr)=0
printState - Called by ProgramStateManager to print checker-specific data.
ProgramStateRef getPersistentStateWithGDM(ProgramStateRef FromState, ProgramStateRef GDMState)
virtual SVal evalBinOpNN(ProgramStateRef state, BinaryOperator::Opcode op, NonLoc lhs, NonLoc rhs, QualType resultTy)=0
Create a new value which represents a binary expression with two non- location operands.
An immutable map from EnvironemntEntries to SVals.
Definition: Environment.h:57
A symbol representing the value stored at a MemRegion.
Definition: SymbolManager.h:42
LLVM_NODISCARD ProgramStateRef invalidateRegions(ArrayRef< const MemRegion *> Regions, const Expr *E, unsigned BlockCount, const LocationContext *LCtx, bool CausesPointerEscape, InvalidatedSymbols *IS=nullptr, const CallEvent *Call=nullptr, RegionAndSymbolInvalidationTraits *ITraits=nullptr) const
Returns the state with bindings for the given regions cleared from the store.
Dataflow Directional Tag Classes.
void ProgramStateRelease(const ProgramState *state)
Decrement the number of times this state is referenced.
ArrayRef< const MemRegion * > RegionList
bool isZeroConstant() const
Definition: SVals.cpp:230
static symbol_iterator symbol_end()
Definition: SymExpr.h:88
LLVM_NODISCARD ProgramStateRef killBinding(Loc LV) const
const void * getStore() const
Definition: SVals.cpp:166
Represents an abstract call to a function or method along a particular path.
Definition: CallEvent.h:171
virtual bool scanReachableSymbols(Store S, const MemRegion *R, ScanReachableSymbols &Visitor)=0
Finds the transitive closure of symbols within the given region.
const llvm::APSInt & getMinValue(const llvm::APSInt &v)
ConstraintManager & getConstraintManager()
Definition: ProgramState.h:565
T castAs() const
Convert to the specified SVal type, asserting that this SVal is of the desired type.
Definition: SVals.h:104
BasicValueFactory & getBasicValueFactory()
Definition: SValBuilder.h:169
SubRegion - A region that subsets another larger region.
Definition: MemRegion.h:435
ProgramState(ProgramStateManager *mgr, const Environment &env, StoreRef st, GenericDataMap gdm)
This ctor is used when creating the first ProgramState object.
void ProgramStateRetain(const ProgramState *state)
Increments the number of times this state is referenced.
const SymExpr * getAsSymExpr() const
Definition: SVals.cpp:144
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:13961
void printTaint(raw_ostream &Out, const char *nl="\) const
ProgramStateManager(ASTContext &Ctx, StoreManagerCreator CreateStoreManager, ConstraintManagerCreator CreateConstraintManager, llvm::BumpPtrAllocator &alloc, SubEngine *subeng)
const TypedValueRegion * getRegion() const
Definition: SVals.cpp:170
Environment removeDeadBindings(Environment Env, SymbolReaper &SymReaper, ProgramStateRef state)
void printDOT(raw_ostream &Out, const LocationContext *CurrentLC=nullptr) const
void * FindGDMContext(void *index, void *(*CreateContext)(llvm::BumpPtrAllocator &), void(*DeleteContext)(void *))
const MemRegion * getBaseRegion() const
Definition: MemRegion.cpp:1159
virtual void incrementReferenceCount(Store store)
If the StoreManager supports it, increment the reference count of the specified Store object...
Definition: Store.h:203
unsigned TaintTagType
The type of taint, which helps to differentiate between different types of taint. ...
Definition: TaintTag.h:23
ElementRegion is used to represent both array elements and casts.
Definition: MemRegion.h:1085
CanQualType IntTy
Definition: ASTContext.h:1024
static void Profile(llvm::FoldingSetNodeID &ID, const ProgramState *V)
Profile - Profile the contents of a ProgramState object for use in a FoldingSet.
Definition: ProgramState.h:139
LLVM_NODISCARD ProgramStateRef assumeInBound(DefinedOrUnknownSVal idx, DefinedOrUnknownSVal upperBound, bool assumption, QualType IndexType=QualType()) const
ProgramStateRef getPersistentState(ProgramState &Impl)
SVal getSValAsScalarOrLoc(const Stmt *Ex, const LocationContext *LCtx) const
Definition: ProgramState.h:796
void printDynamicTypeInfo(ProgramStateRef State, raw_ostream &Out, const char *NL, const char *Sep)
bool isUnknownOrUndef() const
Definition: SVals.h:145
ArrayRef< SVal > ValueList
Expr * IgnoreParens() LLVM_READONLY
IgnoreParens - Ignore parentheses.
Definition: Expr.cpp:2525
Iterator over symbols that the current symbol depends on.
Definition: SymExpr.h:71