1//= ProgramState.cpp - Path-Sensitive "State" for tracking values --*- 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 implements ProgramState and ProgramStateManager.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
14#include "clang/Analysis/CFG.h"
15#include "clang/Basic/JsonSupport.h"
16#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
17#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
18#include "clang/StaticAnalyzer/Core/PathSensitive/DynamicType.h"
19#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
20#include "llvm/Support/raw_ostream.h"
21#include <optional>
22
23using namespace clang;
24using namespace ento;
25
26namespace clang { namespace ento {
27/// Increments the number of times this state is referenced.
28
29void ProgramStateRetain(const ProgramState *state) {
30 ++const_cast<ProgramState*>(state)->refCount;
31}
32
33/// Decrement the number of times this state is referenced.
34void ProgramStateRelease(const ProgramState *state) {
35 assert(state->refCount > 0);
36 ProgramState *s = const_cast<ProgramState*>(state);
37 if (--s->refCount == 0) {
38 ProgramStateManager &Mgr = s->getStateManager();
39 Mgr.StateSet.RemoveNode(N: s);
40 s->~ProgramState();
41 Mgr.freeStates.push_back(x: s);
42 }
43}
44}}
45
46ProgramState::ProgramState(ProgramStateManager *mgr, const Environment& env,
47 StoreRef st, GenericDataMap gdm)
48 : stateMgr(mgr),
49 Env(env),
50 store(st.getStore()),
51 GDM(gdm),
52 refCount(0) {
53 stateMgr->getStoreManager().incrementReferenceCount(store);
54}
55
56ProgramState::ProgramState(const ProgramState &RHS)
57 : stateMgr(RHS.stateMgr), Env(RHS.Env), store(RHS.store), GDM(RHS.GDM),
58 PosteriorlyOverconstrained(RHS.PosteriorlyOverconstrained), refCount(0) {
59 stateMgr->getStoreManager().incrementReferenceCount(store);
60}
61
62ProgramState::~ProgramState() {
63 if (store)
64 stateMgr->getStoreManager().decrementReferenceCount(store);
65}
66
67int64_t ProgramState::getID() const {
68 return getStateManager().Alloc.identifyKnownAlignedObject<ProgramState>(Ptr: this);
69}
70
71ProgramStateManager::ProgramStateManager(ASTContext &Ctx,
72 StoreManagerCreator CreateSMgr,
73 ConstraintManagerCreator CreateCMgr,
74 llvm::BumpPtrAllocator &alloc,
75 ExprEngine *ExprEng)
76 : Eng(ExprEng), EnvMgr(alloc), GDMFactory(alloc),
77 svalBuilder(createSimpleSValBuilder(alloc, context&: Ctx, stateMgr&: *this)),
78 CallEventMgr(new CallEventManager(alloc)), Alloc(alloc) {
79 StoreMgr = (*CreateSMgr)(*this);
80 ConstraintMgr = (*CreateCMgr)(*this, ExprEng);
81}
82
83
84ProgramStateManager::~ProgramStateManager() {
85 for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end();
86 I!=E; ++I)
87 I->second.second(I->second.first);
88}
89
90ProgramStateRef ProgramStateManager::removeDeadBindingsFromEnvironmentAndStore(
91 ProgramStateRef state, const StackFrame *SF, SymbolReaper &SymReaper) {
92
93 // This code essentially performs a "mark-and-sweep" of the VariableBindings.
94 // The roots are any Block-level exprs and Decls that our liveness algorithm
95 // tells us are live. We then see what Decls they may reference, and keep
96 // those around. This code more than likely can be made faster, and the
97 // frequency of which this method is called should be experimented with
98 // for optimum performance.
99 ProgramState NewState = *state;
100
101 NewState.Env = EnvMgr.removeDeadBindings(Env: NewState.Env, SymReaper, state);
102
103 // Clean up the store.
104 StoreRef newStore =
105 StoreMgr->removeDeadBindings(store: NewState.getStore(), SF, SymReaper);
106 NewState.setStore(newStore);
107 SymReaper.setReapedStore(newStore);
108
109 return getPersistentState(Impl&: NewState);
110}
111
112ProgramStateRef ProgramState::bindLoc(Loc LV, SVal V, const StackFrame *SF,
113 bool notifyChanges) const {
114 ProgramStateManager &Mgr = getStateManager();
115 ExprEngine &Eng = Mgr.getOwningEngine();
116 ProgramStateRef State = makeWithStore(BindRes: Mgr.StoreMgr->Bind(store: getStore(), loc: LV, val: V));
117 const MemRegion *MR = LV.getAsRegion();
118
119 if (MR && notifyChanges)
120 return Eng.processRegionChange(state: State, MR, SF);
121
122 return State;
123}
124
125ProgramStateRef ProgramState::bindDefaultInitial(SVal loc, SVal V,
126 const StackFrame *SF) const {
127 ProgramStateManager &Mgr = getStateManager();
128 const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion();
129 BindResult BindRes = Mgr.StoreMgr->BindDefaultInitial(store: getStore(), R, V);
130 ProgramStateRef State = makeWithStore(BindRes);
131 return Mgr.getOwningEngine().processRegionChange(state: State, MR: R, SF);
132}
133
134ProgramStateRef ProgramState::bindDefaultZero(SVal loc,
135 const StackFrame *SF) const {
136 ProgramStateManager &Mgr = getStateManager();
137 const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion();
138 BindResult BindRes = Mgr.StoreMgr->BindDefaultZero(store: getStore(), R);
139 ProgramStateRef State = makeWithStore(BindRes);
140 return Mgr.getOwningEngine().processRegionChange(state: State, MR: R, SF);
141}
142
143typedef ArrayRef<const MemRegion *> RegionList;
144typedef ArrayRef<SVal> ValueList;
145
146ProgramStateRef ProgramState::invalidateRegions(
147 RegionList Regions, ConstCFGElementRef Elem, unsigned Count,
148 const StackFrame *SF, bool CausedByPointerEscape, InvalidatedSymbols *IS,
149 const CallEvent *Call, RegionAndSymbolInvalidationTraits *ITraits) const {
150 SmallVector<SVal, 8> Values;
151 for (const MemRegion *Reg : Regions)
152 Values.push_back(Elt: loc::MemRegionVal(Reg));
153
154 return invalidateRegions(Values, Elem, BlockCount: Count, SF, CausesPointerEscape: CausedByPointerEscape, IS,
155 Call, ITraits);
156}
157
158ProgramStateRef ProgramState::invalidateRegions(
159 ValueList Values, ConstCFGElementRef Elem, unsigned Count,
160 const StackFrame *SF, bool CausedByPointerEscape, InvalidatedSymbols *IS,
161 const CallEvent *Call, RegionAndSymbolInvalidationTraits *ITraits) const {
162
163 ProgramStateManager &Mgr = getStateManager();
164 ExprEngine &Eng = Mgr.getOwningEngine();
165
166 InvalidatedSymbols InvalidatedSyms;
167 if (!IS)
168 IS = &InvalidatedSyms;
169
170 RegionAndSymbolInvalidationTraits ITraitsLocal;
171 if (!ITraits)
172 ITraits = &ITraitsLocal;
173
174 StoreManager::InvalidatedRegions TopLevelInvalidated;
175 StoreManager::InvalidatedRegions Invalidated;
176 const StoreRef &NewStore = Mgr.StoreMgr->invalidateRegions(
177 store: getStore(), Values, Elem, Count, SF, Call, IS&: *IS, ITraits&: *ITraits,
178 TopLevelRegions: &TopLevelInvalidated, Invalidated: &Invalidated);
179
180 ProgramStateRef NewState = makeWithStore(store: NewStore);
181
182 if (CausedByPointerEscape) {
183 NewState = Eng.notifyCheckersOfPointerEscape(
184 State: NewState, Invalidated: IS, ExplicitRegions: TopLevelInvalidated, Call, ITraits&: *ITraits);
185 }
186
187 return Eng.processRegionChanges(state: NewState, invalidated: IS, ExplicitRegions: TopLevelInvalidated,
188 Regions: Invalidated, SF, Call);
189}
190
191ProgramStateRef ProgramState::killBinding(Loc LV) const {
192 Store OldStore = getStore();
193 const StoreRef &newStore =
194 getStateManager().StoreMgr->killBinding(ST: OldStore, L: LV);
195
196 if (newStore.getStore() == OldStore)
197 return this;
198
199 return makeWithStore(store: newStore);
200}
201
202/// We should never form a MemRegion that would wrap a TypedValueRegion of a
203/// reference type. What we actually wanted was to create a MemRegion refering
204/// to the pointee of that reference.
205SVal ProgramState::desugarReference(SVal Val) const {
206 const auto *TyReg = dyn_cast_or_null<TypedValueRegion>(Val: Val.getAsRegion());
207 if (!TyReg || !TyReg->getValueType()->isReferenceType())
208 return Val;
209 return getSVal(R: TyReg);
210}
211
212/// SymbolicRegions are expected to be wrapped by an ElementRegion as a
213/// canonical representation. As a canonical representation, SymbolicRegions
214/// should be wrapped by ElementRegions before getting a FieldRegion.
215/// See f8643a9b31c4029942f67d4534c9139b45173504 why.
216SVal ProgramState::wrapSymbolicRegion(SVal Val) const {
217 const auto *BaseReg = dyn_cast_or_null<SymbolicRegion>(Val: Val.getAsRegion());
218 if (!BaseReg)
219 return Val;
220
221 StoreManager &SM = getStateManager().getStoreManager();
222 QualType ElemTy = BaseReg->getPointeeStaticType();
223 return loc::MemRegionVal{SM.GetElementZeroRegion(R: BaseReg, T: ElemTy)};
224}
225
226ProgramStateRef
227ProgramState::enterStackFrame(const CallEvent &Call,
228 const StackFrame *CalleeCtx) const {
229 return makeWithStore(
230 BindRes: getStateManager().StoreMgr->enterStackFrame(store: getStore(), Call, CalleeSF: CalleeCtx));
231}
232
233SVal ProgramState::getSelfSVal(const StackFrame *SF) const {
234 const ImplicitParamDecl *SelfDecl = SF->getSelfDecl();
235 if (!SelfDecl)
236 return SVal();
237 return getSVal(R: getRegion(D: SelfDecl, SF));
238}
239
240SVal ProgramState::getSValAsScalarOrLoc(const MemRegion *R) const {
241 // We only want to do fetches from regions that we can actually bind
242 // values. For example, SymbolicRegions of type 'id<...>' cannot
243 // have direct bindings (but their can be bindings on their subregions).
244 if (!R->isBoundable())
245 return UnknownVal();
246
247 if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(Val: R)) {
248 QualType T = TR->getValueType();
249 if (Loc::isLocType(T) || T->isIntegralOrEnumerationType())
250 return getSVal(R);
251 }
252
253 return UnknownVal();
254}
255
256SVal ProgramState::getSVal(Loc location, QualType T) const {
257 SVal V = getRawSVal(LV: location, T);
258
259 // If 'V' is a symbolic value that is *perfectly* constrained to
260 // be a constant value, use that value instead to lessen the burden
261 // on later analysis stages (so we have less symbolic values to reason
262 // about).
263 // We only go into this branch if we can convert the APSInt value we have
264 // to the type of T, which is not always the case (e.g. for void).
265 if (!T.isNull() && (T->isIntegralOrEnumerationType() || Loc::isLocType(T))) {
266 if (SymbolRef sym = V.getAsSymbol()) {
267 if (const llvm::APSInt *Int = getStateManager()
268 .getConstraintManager()
269 .getSymVal(state: this, sym)) {
270 // FIXME: Because we don't correctly model (yet) sign-extension
271 // and truncation of symbolic values, we need to convert
272 // the integer value to the correct signedness and bitwidth.
273 //
274 // This shows up in the following:
275 //
276 // char foo();
277 // unsigned x = foo();
278 // if (x == 54)
279 // ...
280 //
281 // The symbolic value stored to 'x' is actually the conjured
282 // symbol for the call to foo(); the type of that symbol is 'char',
283 // not unsigned.
284 APSIntPtr NewV = getBasicVals().Convert(T, From: *Int);
285 if (V.getAs<Loc>())
286 return loc::ConcreteInt(NewV);
287 return nonloc::ConcreteInt(NewV);
288 }
289 }
290 }
291
292 return V;
293}
294
295ProgramStateRef ProgramState::BindExpr(const Expr *E, const StackFrame *SF,
296 SVal V, bool Invalidate) const {
297 Environment NewEnv = getStateManager().EnvMgr.bindExpr(
298 Env, E: EnvironmentEntry(E, SF), V, Invalidate);
299 if (NewEnv == Env)
300 return this;
301
302 ProgramState NewSt = *this;
303 NewSt.Env = std::move(NewEnv);
304 return getStateManager().getPersistentState(Impl&: NewSt);
305}
306
307[[nodiscard]] std::pair<ProgramStateRef, ProgramStateRef>
308ProgramState::assumeInBoundDual(DefinedOrUnknownSVal Idx,
309 DefinedOrUnknownSVal UpperBound,
310 QualType indexTy) const {
311 if (Idx.isUnknown() || UpperBound.isUnknown())
312 return {this, this};
313
314 // Build an expression for 0 <= Idx < UpperBound.
315 // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed.
316 // FIXME: This should probably be part of SValBuilder.
317 ProgramStateManager &SM = getStateManager();
318 SValBuilder &svalBuilder = SM.getSValBuilder();
319 ASTContext &Ctx = svalBuilder.getContext();
320
321 // Get the offset: the minimum value of the array index type.
322 BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
323 if (indexTy.isNull())
324 indexTy = svalBuilder.getArrayIndexType();
325 nonloc::ConcreteInt Min(BVF.getMinValue(T: indexTy));
326
327 // Adjust the index.
328 SVal newIdx = svalBuilder.evalBinOpNN(state: this, op: BO_Add,
329 lhs: Idx.castAs<NonLoc>(), rhs: Min, resultTy: indexTy);
330 if (newIdx.isUnknownOrUndef())
331 return {this, this};
332
333 // Adjust the upper bound.
334 SVal newBound =
335 svalBuilder.evalBinOpNN(state: this, op: BO_Add, lhs: UpperBound.castAs<NonLoc>(),
336 rhs: Min, resultTy: indexTy);
337
338 if (newBound.isUnknownOrUndef())
339 return {this, this};
340
341 // Build the actual comparison.
342 SVal inBound = svalBuilder.evalBinOpNN(state: this, op: BO_LT, lhs: newIdx.castAs<NonLoc>(),
343 rhs: newBound.castAs<NonLoc>(), resultTy: Ctx.IntTy);
344 if (inBound.isUnknownOrUndef())
345 return {this, this};
346
347 // Finally, let the constraint manager take care of it.
348 ConstraintManager &CM = SM.getConstraintManager();
349 return CM.assumeDual(State: this, Cond: inBound.castAs<DefinedSVal>());
350}
351
352ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx,
353 DefinedOrUnknownSVal UpperBound,
354 bool Assumption,
355 QualType indexTy) const {
356 std::pair<ProgramStateRef, ProgramStateRef> R =
357 assumeInBoundDual(Idx, UpperBound, indexTy);
358 return Assumption ? R.first : R.second;
359}
360
361ConditionTruthVal ProgramState::isNonNull(SVal V) const {
362 ConditionTruthVal IsNull = isNull(V);
363 if (IsNull.isUnderconstrained())
364 return IsNull;
365 return ConditionTruthVal(!IsNull.getValue());
366}
367
368ConditionTruthVal ProgramState::areEqual(SVal Lhs, SVal Rhs) const {
369 return stateMgr->getSValBuilder().areEqual(state: this, lhs: Lhs, rhs: Rhs);
370}
371
372ConditionTruthVal ProgramState::isNull(SVal V) const {
373 if (V.isZeroConstant())
374 return true;
375
376 if (V.isConstant())
377 return false;
378
379 SymbolRef Sym = V.getAsSymbol(/* IncludeBaseRegion */ IncludeBaseRegions: true);
380 if (!Sym)
381 return ConditionTruthVal();
382
383 return getStateManager().ConstraintMgr->isNull(State: this, Sym);
384}
385
386ProgramStateRef ProgramStateManager::getInitialState(const StackFrame *InitSF) {
387 ProgramState State(this, EnvMgr.getInitialEnvironment(),
388 StoreMgr->getInitialStore(InitSF),
389 GDMFactory.getEmptyMap());
390
391 return getPersistentState(Impl&: State);
392}
393
394ProgramStateRef ProgramStateManager::getPersistentStateWithGDM(
395 ProgramStateRef FromState,
396 ProgramStateRef GDMState) {
397 ProgramState NewState(*FromState);
398 NewState.GDM = GDMState->GDM;
399 return getPersistentState(Impl&: NewState);
400}
401
402ProgramStateRef ProgramStateManager::getPersistentState(ProgramState &State) {
403
404 llvm::FoldingSetNodeID ID;
405 State.Profile(ID);
406 void *InsertPos;
407
408 if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos))
409 return I;
410
411 ProgramState *newState = nullptr;
412 if (!freeStates.empty()) {
413 newState = freeStates.back();
414 freeStates.pop_back();
415 }
416 else {
417 newState = Alloc.Allocate<ProgramState>();
418 }
419 new (newState) ProgramState(State);
420 StateSet.InsertNode(N: newState, InsertPos);
421 return newState;
422}
423
424ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const {
425 ProgramState NewSt(*this);
426 NewSt.setStore(store);
427 return getStateManager().getPersistentState(State&: NewSt);
428}
429
430ProgramStateRef ProgramState::makeWithStore(const BindResult &BindRes) const {
431 ExprEngine &Eng = getStateManager().getOwningEngine();
432 ProgramStateRef State = makeWithStore(store: BindRes.ResultingStore);
433
434 // We must always notify the checkers for failing binds because otherwise they
435 // may keep stale traits for these symbols.
436 // Eg., Malloc checker may report leaks if we failed to bind that symbol.
437 if (BindRes.FailedToBindValues.empty())
438 return State;
439 return Eng.escapeValues(State, Vs: BindRes.FailedToBindValues, K: PSK_EscapeOnBind);
440}
441
442ProgramStateRef ProgramState::cloneAsPosteriorlyOverconstrained() const {
443 ProgramState NewSt(*this);
444 NewSt.PosteriorlyOverconstrained = true;
445 return getStateManager().getPersistentState(State&: NewSt);
446}
447
448void ProgramState::setStore(const StoreRef &newStore) {
449 Store newStoreStore = newStore.getStore();
450 if (newStoreStore)
451 stateMgr->getStoreManager().incrementReferenceCount(store: newStoreStore);
452 if (store)
453 stateMgr->getStoreManager().decrementReferenceCount(store);
454 store = newStoreStore;
455}
456
457SVal ProgramState::getLValue(const FieldDecl *D, SVal Base) const {
458 Base = desugarReference(Val: Base);
459 Base = wrapSymbolicRegion(Val: Base);
460 return getStateManager().StoreMgr->getLValueField(D, Base);
461}
462
463SVal ProgramState::getLValue(const IndirectFieldDecl *D, SVal Base) const {
464 StoreManager &SM = *getStateManager().StoreMgr;
465 Base = desugarReference(Val: Base);
466 Base = wrapSymbolicRegion(Val: Base);
467
468 // FIXME: This should work with `SM.getLValueField(D->getAnonField(), Base)`,
469 // but that would break some tests. There is probably a bug somewhere that it
470 // would expose.
471 for (const auto *I : D->chain()) {
472 Base = SM.getLValueField(D: cast<FieldDecl>(Val: I), Base);
473 }
474 return Base;
475}
476
477//===----------------------------------------------------------------------===//
478// State pretty-printing.
479//===----------------------------------------------------------------------===//
480
481void ProgramState::printJson(raw_ostream &Out, const StackFrame *SF,
482 const char *NL, unsigned int Space,
483 bool IsDot) const {
484 Indent(Out, Space, IsDot) << "\"program_state\": {" << NL;
485 ++Space;
486
487 ProgramStateManager &Mgr = getStateManager();
488
489 // Print the store.
490 Mgr.getStoreManager().printJson(Out, S: getStore(), NL, Space, IsDot);
491
492 // Print out the environment.
493 Env.printJson(Out, Ctx: Mgr.getContext(), SF, NL, Space, IsDot);
494
495 // Print out the constraints.
496 Mgr.getConstraintManager().printJson(Out, State: this, NL, Space, IsDot);
497
498 // Print out the tracked dynamic types.
499 printDynamicTypeInfoJson(Out, State: this, NL, Space, IsDot);
500
501 // Print checker-specific data.
502 Mgr.getOwningEngine().printJson(Out, State: this, SF, NL, Space, IsDot);
503
504 --Space;
505 Indent(Out, Space, IsDot) << '}';
506}
507
508void ProgramState::printDOT(raw_ostream &Out, const StackFrame *SF,
509 unsigned int Space) const {
510 printJson(Out, SF, /*NL=*/"\\l", Space, /*IsDot=*/true);
511}
512
513LLVM_DUMP_METHOD void ProgramState::dump() const {
514 printJson(Out&: llvm::errs());
515}
516
517AnalysisManager& ProgramState::getAnalysisManager() const {
518 return stateMgr->getOwningEngine().getAnalysisManager();
519}
520
521//===----------------------------------------------------------------------===//
522// Generic Data Map.
523//===----------------------------------------------------------------------===//
524
525void *const *ProgramState::FindGDM(const void *K) const {
526 return GDM.lookup(K);
527}
528
529void *ProgramStateManager::FindGDMContext(
530 const void *K, void *(*CreateContext)(llvm::BumpPtrAllocator &),
531 void (*DeleteContext)(void *)) {
532
533 std::pair<void*, void (*)(void*)>& p = GDMContexts[K];
534 if (!p.first) {
535 p.first = CreateContext(Alloc);
536 p.second = DeleteContext;
537 }
538
539 return p.first;
540}
541
542ProgramStateRef ProgramStateManager::addGDM(ProgramStateRef St, const void *Key,
543 void *Data) {
544 ProgramState::GenericDataMap M1 = St->getGDM();
545 ProgramState::GenericDataMap M2 = GDMFactory.add(Old: M1, K: Key, D: Data);
546
547 if (M1 == M2)
548 return St;
549
550 ProgramState NewSt = *St;
551 NewSt.GDM = M2;
552 return getPersistentState(State&: NewSt);
553}
554
555ProgramStateRef ProgramStateManager::removeGDM(ProgramStateRef state,
556 const void *Key) {
557 ProgramState::GenericDataMap OldM = state->getGDM();
558 ProgramState::GenericDataMap NewM = GDMFactory.remove(Old: OldM, K: Key);
559
560 if (NewM == OldM)
561 return state;
562
563 ProgramState NewState = *state;
564 NewState.GDM = NewM;
565 return getPersistentState(State&: NewState);
566}
567
568bool ScanReachableSymbols::scan(nonloc::LazyCompoundVal val) {
569 bool wasVisited = !visited.insert(V: val.getCVData()).second;
570 if (wasVisited)
571 return true;
572
573 StoreManager &StoreMgr = state->getStateManager().getStoreManager();
574 // FIXME: We don't really want to use getBaseRegion() here because pointer
575 // arithmetic doesn't apply, but scanReachableSymbols only accepts base
576 // regions right now.
577 const MemRegion *R = val.getRegion()->getBaseRegion();
578 return StoreMgr.scanReachableSymbols(S: val.getStore(), R, Visitor&: *this);
579}
580
581bool ScanReachableSymbols::scan(nonloc::CompoundVal val) {
582 for (SVal V : val)
583 if (!scan(val: V))
584 return false;
585
586 return true;
587}
588
589bool ScanReachableSymbols::scan(const SymExpr *sym) {
590 for (SymbolRef SubSym : sym->symbols()) {
591 bool wasVisited = !visited.insert(V: SubSym).second;
592 if (wasVisited)
593 continue;
594
595 if (!visitor.VisitSymbol(sym: SubSym))
596 return false;
597 }
598
599 return true;
600}
601
602bool ScanReachableSymbols::scan(SVal val) {
603 if (std::optional<loc::MemRegionVal> X = val.getAs<loc::MemRegionVal>())
604 return scan(R: X->getRegion());
605
606 if (std::optional<nonloc::LazyCompoundVal> X =
607 val.getAs<nonloc::LazyCompoundVal>())
608 return scan(val: *X);
609
610 if (std::optional<nonloc::LocAsInteger> X = val.getAs<nonloc::LocAsInteger>())
611 return scan(val: X->getLoc());
612
613 if (SymbolRef Sym = val.getAsSymbol())
614 return scan(sym: Sym);
615
616 if (std::optional<nonloc::CompoundVal> X = val.getAs<nonloc::CompoundVal>())
617 return scan(val: *X);
618
619 return true;
620}
621
622bool ScanReachableSymbols::scan(const MemRegion *R) {
623 if (isa<MemSpaceRegion>(Val: R))
624 return true;
625
626 bool wasVisited = !visited.insert(V: R).second;
627 if (wasVisited)
628 return true;
629
630 if (!visitor.VisitMemRegion(R))
631 return false;
632
633 // If this is a symbolic region, visit the symbol for the region.
634 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Val: R))
635 if (!visitor.VisitSymbol(sym: SR->getSymbol()))
636 return false;
637
638 // If this is a subregion, also visit the parent regions.
639 if (const SubRegion *SR = dyn_cast<SubRegion>(Val: R)) {
640 const MemRegion *Super = SR->getSuperRegion();
641 if (!scan(R: Super))
642 return false;
643
644 // When we reach the topmost region, scan all symbols in it.
645 if (isa<MemSpaceRegion>(Val: Super)) {
646 StoreManager &StoreMgr = state->getStateManager().getStoreManager();
647 if (!StoreMgr.scanReachableSymbols(S: state->getStore(), R: SR, Visitor&: *this))
648 return false;
649 }
650 }
651
652 // Regions captured by a block are also implicitly reachable.
653 if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(Val: R)) {
654 for (auto Var : BDR->referenced_vars()) {
655 if (!scan(R: Var.getCapturedRegion()))
656 return false;
657 }
658 }
659
660 return true;
661}
662
663bool ProgramState::scanReachableSymbols(SVal val, SymbolVisitor& visitor) const {
664 ScanReachableSymbols S(this, visitor);
665 return S.scan(val);
666}
667
668bool ProgramState::scanReachableSymbols(
669 llvm::iterator_range<region_iterator> Reachable,
670 SymbolVisitor &visitor) const {
671 ScanReachableSymbols S(this, visitor);
672 for (const MemRegion *R : Reachable) {
673 if (!S.scan(R))
674 return false;
675 }
676 return true;
677}
678