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 && 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().processRegionChange(new_state, R, LCtx);
142 }
143 
146  ProgramStateManager &Mgr = getStateManager();
147  const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion();
148  const StoreRef &newStore = Mgr.StoreMgr->BindDefaultZero(getStore(), R);
149  ProgramStateRef new_state = makeWithStore(newStore);
150  return Mgr.getOwningEngine().processRegionChange(new_state, R, LCtx);
151 }
152 
155 
158  const Expr *E, unsigned Count,
159  const LocationContext *LCtx,
160  bool CausedByPointerEscape,
161  InvalidatedSymbols *IS,
162  const CallEvent *Call,
163  RegionAndSymbolInvalidationTraits *ITraits) const {
164  SmallVector<SVal, 8> Values;
165  for (RegionList::const_iterator I = Regions.begin(),
166  End = Regions.end(); I != End; ++I)
167  Values.push_back(loc::MemRegionVal(*I));
168 
169  return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape,
170  IS, ITraits, Call);
171 }
172 
175  const Expr *E, unsigned Count,
176  const LocationContext *LCtx,
177  bool CausedByPointerEscape,
178  InvalidatedSymbols *IS,
179  const CallEvent *Call,
180  RegionAndSymbolInvalidationTraits *ITraits) const {
181 
182  return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape,
183  IS, ITraits, Call);
184 }
185 
187 ProgramState::invalidateRegionsImpl(ValueList Values,
188  const Expr *E, unsigned Count,
189  const LocationContext *LCtx,
190  bool CausedByPointerEscape,
191  InvalidatedSymbols *IS,
192  RegionAndSymbolInvalidationTraits *ITraits,
193  const CallEvent *Call) const {
194  ProgramStateManager &Mgr = getStateManager();
195  SubEngine &Eng = Mgr.getOwningEngine();
196 
197  InvalidatedSymbols InvalidatedSyms;
198  if (!IS)
199  IS = &InvalidatedSyms;
200 
201  RegionAndSymbolInvalidationTraits ITraitsLocal;
202  if (!ITraits)
203  ITraits = &ITraitsLocal;
204 
205  StoreManager::InvalidatedRegions TopLevelInvalidated;
207  const StoreRef &newStore
208  = Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call,
209  *IS, *ITraits, &TopLevelInvalidated,
210  &Invalidated);
211 
212  ProgramStateRef newState = makeWithStore(newStore);
213 
214  if (CausedByPointerEscape) {
215  newState = Eng.notifyCheckersOfPointerEscape(newState, IS,
216  TopLevelInvalidated,
217  Call,
218  *ITraits);
219  }
220 
221  return Eng.processRegionChanges(newState, IS, TopLevelInvalidated,
222  Invalidated, LCtx, Call);
223 }
224 
226  assert(!LV.getAs<loc::MemRegionVal>() && "Use invalidateRegion instead.");
227 
228  Store OldStore = getStore();
229  const StoreRef &newStore =
230  getStateManager().StoreMgr->killBinding(OldStore, LV);
231 
232  if (newStore.getStore() == OldStore)
233  return this;
234 
235  return makeWithStore(newStore);
236 }
237 
240  const StackFrameContext *CalleeCtx) const {
241  const StoreRef &NewStore =
242  getStateManager().StoreMgr->enterStackFrame(getStore(), Call, CalleeCtx);
243  return makeWithStore(NewStore);
244 }
245 
247  // We only want to do fetches from regions that we can actually bind
248  // values. For example, SymbolicRegions of type 'id<...>' cannot
249  // have direct bindings (but their can be bindings on their subregions).
250  if (!R->isBoundable())
251  return UnknownVal();
252 
253  if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) {
254  QualType T = TR->getValueType();
256  return getSVal(R);
257  }
258 
259  return UnknownVal();
260 }
261 
262 SVal ProgramState::getSVal(Loc location, QualType T) const {
263  SVal V = getRawSVal(location, T);
264 
265  // If 'V' is a symbolic value that is *perfectly* constrained to
266  // be a constant value, use that value instead to lessen the burden
267  // on later analysis stages (so we have less symbolic values to reason
268  // about).
269  // We only go into this branch if we can convert the APSInt value we have
270  // to the type of T, which is not always the case (e.g. for void).
271  if (!T.isNull() && (T->isIntegralOrEnumerationType() || Loc::isLocType(T))) {
272  if (SymbolRef sym = V.getAsSymbol()) {
273  if (const llvm::APSInt *Int = getStateManager()
274  .getConstraintManager()
275  .getSymVal(this, sym)) {
276  // FIXME: Because we don't correctly model (yet) sign-extension
277  // and truncation of symbolic values, we need to convert
278  // the integer value to the correct signedness and bitwidth.
279  //
280  // This shows up in the following:
281  //
282  // char foo();
283  // unsigned x = foo();
284  // if (x == 54)
285  // ...
286  //
287  // The symbolic value stored to 'x' is actually the conjured
288  // symbol for the call to foo(); the type of that symbol is 'char',
289  // not unsigned.
290  const llvm::APSInt &NewV = getBasicVals().Convert(T, *Int);
291 
292  if (V.getAs<Loc>())
293  return loc::ConcreteInt(NewV);
294  else
295  return nonloc::ConcreteInt(NewV);
296  }
297  }
298  }
299 
300  return V;
301 }
302 
304  const LocationContext *LCtx,
305  SVal V, bool Invalidate) const{
306  Environment NewEnv =
307  getStateManager().EnvMgr.bindExpr(Env, EnvironmentEntry(S, LCtx), V,
308  Invalidate);
309  if (NewEnv == Env)
310  return this;
311 
312  ProgramState NewSt = *this;
313  NewSt.Env = NewEnv;
314  return getStateManager().getPersistentState(NewSt);
315 }
316 
318  DefinedOrUnknownSVal UpperBound,
319  bool Assumption,
320  QualType indexTy) const {
321  if (Idx.isUnknown() || UpperBound.isUnknown())
322  return this;
323 
324  // Build an expression for 0 <= Idx < UpperBound.
325  // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed.
326  // FIXME: This should probably be part of SValBuilder.
327  ProgramStateManager &SM = getStateManager();
328  SValBuilder &svalBuilder = SM.getSValBuilder();
329  ASTContext &Ctx = svalBuilder.getContext();
330 
331  // Get the offset: the minimum value of the array index type.
332  BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
333  if (indexTy.isNull())
334  indexTy = svalBuilder.getArrayIndexType();
335  nonloc::ConcreteInt Min(BVF.getMinValue(indexTy));
336 
337  // Adjust the index.
338  SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add,
339  Idx.castAs<NonLoc>(), Min, indexTy);
340  if (newIdx.isUnknownOrUndef())
341  return this;
342 
343  // Adjust the upper bound.
344  SVal newBound =
345  svalBuilder.evalBinOpNN(this, BO_Add, UpperBound.castAs<NonLoc>(),
346  Min, indexTy);
347 
348  if (newBound.isUnknownOrUndef())
349  return this;
350 
351  // Build the actual comparison.
352  SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, newIdx.castAs<NonLoc>(),
353  newBound.castAs<NonLoc>(), Ctx.IntTy);
354  if (inBound.isUnknownOrUndef())
355  return this;
356 
357  // Finally, let the constraint manager take care of it.
359  return CM.assume(this, inBound.castAs<DefinedSVal>(), Assumption);
360 }
361 
363  ConditionTruthVal IsNull = isNull(V);
364  if (IsNull.isUnderconstrained())
365  return IsNull;
366  return ConditionTruthVal(!IsNull.getValue());
367 }
368 
370  return stateMgr->getSValBuilder().areEqual(this, Lhs, Rhs);
371 }
372 
374  if (V.isZeroConstant())
375  return true;
376 
377  if (V.isConstant())
378  return false;
379 
380  SymbolRef Sym = V.getAsSymbol(/* IncludeBaseRegion */ true);
381  if (!Sym)
382  return ConditionTruthVal();
383 
384  return getStateManager().ConstraintMgr->isNull(this, Sym);
385 }
386 
388  ProgramState State(this,
389  EnvMgr.getInitialEnvironment(),
390  StoreMgr->getInitialStore(InitLoc),
391  GDMFactory.getEmptyMap());
392 
393  return getPersistentState(State);
394 }
395 
397  ProgramStateRef FromState,
398  ProgramStateRef GDMState) {
399  ProgramState NewState(*FromState);
400  NewState.GDM = GDMState->GDM;
401  return getPersistentState(NewState);
402 }
403 
405 
406  llvm::FoldingSetNodeID ID;
407  State.Profile(ID);
408  void *InsertPos;
409 
410  if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos))
411  return I;
412 
413  ProgramState *newState = nullptr;
414  if (!freeStates.empty()) {
415  newState = freeStates.back();
416  freeStates.pop_back();
417  }
418  else {
419  newState = (ProgramState*) Alloc.Allocate<ProgramState>();
420  }
421  new (newState) ProgramState(State);
422  StateSet.InsertNode(newState, InsertPos);
423  return newState;
424 }
425 
426 ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const {
427  ProgramState NewSt(*this);
428  NewSt.setStore(store);
429  return getStateManager().getPersistentState(NewSt);
430 }
431 
432 void ProgramState::setStore(const StoreRef &newStore) {
433  Store newStoreStore = newStore.getStore();
434  if (newStoreStore)
435  stateMgr->getStoreManager().incrementReferenceCount(newStoreStore);
436  if (store)
437  stateMgr->getStoreManager().decrementReferenceCount(store);
438  store = newStoreStore;
439 }
440 
441 //===----------------------------------------------------------------------===//
442 // State pretty-printing.
443 //===----------------------------------------------------------------------===//
444 
445 void ProgramState::print(raw_ostream &Out,
446  const char *NL, const char *Sep,
447  const LocationContext *LC) const {
448  // Print the store.
449  ProgramStateManager &Mgr = getStateManager();
450  const ASTContext &Context = getStateManager().getContext();
451  Mgr.getStoreManager().print(getStore(), Out, NL);
452 
453  // Print out the environment.
454  Env.print(Out, NL, Sep, Context, LC);
455 
456  // Print out the constraints.
457  Mgr.getConstraintManager().print(this, Out, NL, Sep);
458 
459  // Print out the tracked dynamic types.
460  printDynamicTypeInfo(this, Out, NL, Sep);
461 
462  // Print out tainted symbols.
463  printTaint(Out, NL);
464 
465  // Print checker-specific data.
466  Mgr.getOwningEngine().printState(Out, this, NL, Sep, LC);
467 }
468 
469 void ProgramState::printDOT(raw_ostream &Out,
470  const LocationContext *LC) const {
471  print(Out, "\\l", "\\|", LC);
472 }
473 
474 LLVM_DUMP_METHOD void ProgramState::dump() const {
475  print(llvm::errs());
476 }
477 
478 void ProgramState::printTaint(raw_ostream &Out,
479  const char *NL) const {
480  TaintMapImpl TM = get<TaintMap>();
481 
482  if (!TM.isEmpty())
483  Out <<"Tainted symbols:" << NL;
484 
485  for (TaintMapImpl::iterator I = TM.begin(), E = TM.end(); I != E; ++I) {
486  Out << I->first << " : " << I->second << NL;
487  }
488 }
489 
491  printTaint(llvm::errs());
492 }
493 
495  return stateMgr->getOwningEngine().getAnalysisManager();
496 }
497 
498 //===----------------------------------------------------------------------===//
499 // Generic Data Map.
500 //===----------------------------------------------------------------------===//
501 
502 void *const* ProgramState::FindGDM(void *K) const {
503  return GDM.lookup(K);
504 }
505 
506 void*
508  void *(*CreateContext)(llvm::BumpPtrAllocator&),
509  void (*DeleteContext)(void*)) {
510 
511  std::pair<void*, void (*)(void*)>& p = GDMContexts[K];
512  if (!p.first) {
513  p.first = CreateContext(Alloc);
514  p.second = DeleteContext;
515  }
516 
517  return p.first;
518 }
519 
521  ProgramState::GenericDataMap M1 = St->getGDM();
522  ProgramState::GenericDataMap M2 = GDMFactory.add(M1, Key, Data);
523 
524  if (M1 == M2)
525  return St;
526 
527  ProgramState NewSt = *St;
528  NewSt.GDM = M2;
529  return getPersistentState(NewSt);
530 }
531 
533  ProgramState::GenericDataMap OldM = state->getGDM();
534  ProgramState::GenericDataMap NewM = GDMFactory.remove(OldM, Key);
535 
536  if (NewM == OldM)
537  return state;
538 
539  ProgramState NewState = *state;
540  NewState.GDM = NewM;
541  return getPersistentState(NewState);
542 }
543 
545  bool wasVisited = !visited.insert(val.getCVData()).second;
546  if (wasVisited)
547  return true;
548 
549  StoreManager &StoreMgr = state->getStateManager().getStoreManager();
550  // FIXME: We don't really want to use getBaseRegion() here because pointer
551  // arithmetic doesn't apply, but scanReachableSymbols only accepts base
552  // regions right now.
553  const MemRegion *R = val.getRegion()->getBaseRegion();
554  return StoreMgr.scanReachableSymbols(val.getStore(), R, *this);
555 }
556 
558  for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I)
559  if (!scan(*I))
560  return false;
561 
562  return true;
563 }
564 
566  for (SymExpr::symbol_iterator SI = sym->symbol_begin(),
567  SE = sym->symbol_end();
568  SI != SE; ++SI) {
569  bool wasVisited = !visited.insert(*SI).second;
570  if (wasVisited)
571  continue;
572 
573  if (!visitor.VisitSymbol(*SI))
574  return false;
575  }
576 
577  return true;
578 }
579 
582  return scan(X->getRegion());
583 
586  return scan(*X);
587 
589  return scan(X->getLoc());
590 
591  if (SymbolRef Sym = val.getAsSymbol())
592  return scan(Sym);
593 
594  if (const SymExpr *Sym = val.getAsSymbolicExpression())
595  return scan(Sym);
596 
598  return scan(*X);
599 
600  return true;
601 }
602 
604  if (isa<MemSpaceRegion>(R))
605  return true;
606 
607  bool wasVisited = !visited.insert(R).second;
608  if (wasVisited)
609  return true;
610 
611  if (!visitor.VisitMemRegion(R))
612  return false;
613 
614  // If this is a symbolic region, visit the symbol for the region.
615  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
616  if (!visitor.VisitSymbol(SR->getSymbol()))
617  return false;
618 
619  // If this is a subregion, also visit the parent regions.
620  if (const SubRegion *SR = dyn_cast<SubRegion>(R)) {
621  const MemRegion *Super = SR->getSuperRegion();
622  if (!scan(Super))
623  return false;
624 
625  // When we reach the topmost region, scan all symbols in it.
626  if (isa<MemSpaceRegion>(Super)) {
627  StoreManager &StoreMgr = state->getStateManager().getStoreManager();
628  if (!StoreMgr.scanReachableSymbols(state->getStore(), SR, *this))
629  return false;
630  }
631  }
632 
633  // Regions captured by a block are also implicitly reachable.
634  if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) {
635  BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(),
636  E = BDR->referenced_vars_end();
637  for ( ; I != E; ++I) {
638  if (!scan(I.getCapturedRegion()))
639  return false;
640  }
641  }
642 
643  return true;
644 }
645 
647  ScanReachableSymbols S(this, visitor);
648  return S.scan(val);
649 }
650 
652  llvm::iterator_range<region_iterator> Reachable,
653  SymbolVisitor &visitor) const {
654  ScanReachableSymbols S(this, visitor);
655  for (const MemRegion *R : Reachable) {
656  if (!S.scan(R))
657  return false;
658  }
659  return true;
660 }
661 
663  const LocationContext *LCtx,
664  TaintTagType Kind) const {
665  if (const Expr *E = dyn_cast_or_null<Expr>(S))
666  S = E->IgnoreParens();
667 
668  return addTaint(getSVal(S, LCtx), Kind);
669 }
670 
672  TaintTagType Kind) const {
673  SymbolRef Sym = V.getAsSymbol();
674  if (Sym)
675  return addTaint(Sym, Kind);
676 
677  // If the SVal represents a structure, try to mass-taint all values within the
678  // structure. For now it only works efficiently on lazy compound values that
679  // were conjured during a conservative evaluation of a function - either as
680  // return values of functions that return structures or arrays by value, or as
681  // values of structures or arrays passed into the function by reference,
682  // directly or through pointer aliasing. Such lazy compound values are
683  // characterized by having exactly one binding in their captured store within
684  // their parent region, which is a conjured symbol default-bound to the base
685  // region of the parent region.
686  if (auto LCV = V.getAs<nonloc::LazyCompoundVal>()) {
687  if (Optional<SVal> binding = getStateManager().StoreMgr->getDefaultBinding(*LCV)) {
688  if (SymbolRef Sym = binding->getAsSymbol())
689  return addPartialTaint(Sym, LCV->getRegion(), Kind);
690  }
691  }
692 
693  const MemRegion *R = V.getAsRegion();
694  return addTaint(R, Kind);
695 }
696 
698  TaintTagType Kind) const {
699  if (const SymbolicRegion *SR = dyn_cast_or_null<SymbolicRegion>(R))
700  return addTaint(SR->getSymbol(), Kind);
701  return this;
702 }
703 
705  TaintTagType Kind) const {
706  // If this is a symbol cast, remove the cast before adding the taint. Taint
707  // is cast agnostic.
708  while (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym))
709  Sym = SC->getOperand();
710 
711  ProgramStateRef NewState = set<TaintMap>(Sym, Kind);
712  assert(NewState);
713  return NewState;
714 }
715 
717  const SubRegion *SubRegion,
718  TaintTagType Kind) const {
719  // Ignore partial taint if the entire parent symbol is already tainted.
720  if (contains<TaintMap>(ParentSym) && *get<TaintMap>(ParentSym) == Kind)
721  return this;
722 
723  // Partial taint applies if only a portion of the symbol is tainted.
724  if (SubRegion == SubRegion->getBaseRegion())
725  return addTaint(ParentSym, Kind);
726 
727  const TaintedSubRegions *SavedRegs = get<DerivedSymTaint>(ParentSym);
728  TaintedSubRegions Regs =
729  SavedRegs ? *SavedRegs : stateMgr->TSRFactory.getEmptyMap();
730 
731  Regs = stateMgr->TSRFactory.add(Regs, SubRegion, Kind);
732  ProgramStateRef NewState = set<DerivedSymTaint>(ParentSym, Regs);
733  assert(NewState);
734  return NewState;
735 }
736 
737 bool ProgramState::isTainted(const Stmt *S, const LocationContext *LCtx,
738  TaintTagType Kind) const {
739  if (const Expr *E = dyn_cast_or_null<Expr>(S))
740  S = E->IgnoreParens();
741 
742  SVal val = getSVal(S, LCtx);
743  return isTainted(val, Kind);
744 }
745 
746 bool ProgramState::isTainted(SVal V, TaintTagType Kind) const {
747  if (const SymExpr *Sym = V.getAsSymExpr())
748  return isTainted(Sym, Kind);
749  if (const MemRegion *Reg = V.getAsRegion())
750  return isTainted(Reg, Kind);
751  return false;
752 }
753 
754 bool ProgramState::isTainted(const MemRegion *Reg, TaintTagType K) const {
755  if (!Reg)
756  return false;
757 
758  // Element region (array element) is tainted if either the base or the offset
759  // are tainted.
760  if (const ElementRegion *ER = dyn_cast<ElementRegion>(Reg))
761  return isTainted(ER->getSuperRegion(), K) || isTainted(ER->getIndex(), K);
762 
763  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg))
764  return isTainted(SR->getSymbol(), K);
765 
766  if (const SubRegion *ER = dyn_cast<SubRegion>(Reg))
767  return isTainted(ER->getSuperRegion(), K);
768 
769  return false;
770 }
771 
772 bool ProgramState::isTainted(SymbolRef Sym, TaintTagType Kind) const {
773  if (!Sym)
774  return false;
775 
776  // Traverse all the symbols this symbol depends on to see if any are tainted.
777  for (SymExpr::symbol_iterator SI = Sym->symbol_begin(), SE =Sym->symbol_end();
778  SI != SE; ++SI) {
779  if (!isa<SymbolData>(*SI))
780  continue;
781 
782  if (const TaintTagType *Tag = get<TaintMap>(*SI)) {
783  if (*Tag == Kind)
784  return true;
785  }
786 
787  if (const SymbolDerived *SD = dyn_cast<SymbolDerived>(*SI)) {
788  // If this is a SymbolDerived with a tainted parent, it's also tainted.
789  if (isTainted(SD->getParentSymbol(), Kind))
790  return true;
791 
792  // If this is a SymbolDerived with the same parent symbol as another
793  // tainted SymbolDerived and a region that's a sub-region of that tainted
794  // symbol, it's also tainted.
795  if (const TaintedSubRegions *Regs =
796  get<DerivedSymTaint>(SD->getParentSymbol())) {
797  const TypedValueRegion *R = SD->getRegion();
798  for (auto I : *Regs) {
799  // FIXME: The logic to identify tainted regions could be more
800  // complete. For example, this would not currently identify
801  // overlapping fields in a union as tainted. To identify this we can
802  // check for overlapping/nested byte offsets.
803  if (Kind == I.second && R->isSubRegionOf(I.first))
804  return true;
805  }
806  }
807  }
808 
809  // If memory region is tainted, data is also tainted.
810  if (const SymbolRegionValue *SRV = dyn_cast<SymbolRegionValue>(*SI)) {
811  if (isTainted(SRV->getRegion(), Kind))
812  return true;
813  }
814 
815  // If this is a SymbolCast from a tainted value, it's also tainted.
816  if (const SymbolCast *SC = dyn_cast<SymbolCast>(*SI)) {
817  if (isTainted(SC->getOperand(), Kind))
818  return true;
819  }
820  }
821 
822  return false;
823 }
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