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 StackFrameContext *LCtx,
92 SymbolReaper &SymReaper) {
93
94 // This code essentially performs a "mark-and-sweep" of the VariableBindings.
95 // The roots are any Block-level exprs and Decls that our liveness algorithm
96 // tells us are live. We then see what Decls they may reference, and keep
97 // those around. This code more than likely can be made faster, and the
98 // frequency of which this method is called should be experimented with
99 // for optimum performance.
100 ProgramState NewState = *state;
101
102 NewState.Env = EnvMgr.removeDeadBindings(Env: NewState.Env, SymReaper, state);
103
104 // Clean up the store.
105 StoreRef newStore = StoreMgr->removeDeadBindings(store: NewState.getStore(), LCtx,
106 SymReaper);
107 NewState.setStore(newStore);
108 SymReaper.setReapedStore(newStore);
109
110 return getPersistentState(Impl&: NewState);
111}
112
113ProgramStateRef ProgramState::bindLoc(Loc LV,
114 SVal V,
115 const LocationContext *LCtx,
116 bool notifyChanges) const {
117 ProgramStateManager &Mgr = getStateManager();
118 ExprEngine &Eng = Mgr.getOwningEngine();
119 ProgramStateRef State = makeWithStore(BindRes: Mgr.StoreMgr->Bind(store: getStore(), loc: LV, val: V));
120 const MemRegion *MR = LV.getAsRegion();
121
122 if (MR && notifyChanges)
123 return Eng.processRegionChange(state: State, MR, LCtx);
124
125 return State;
126}
127
128ProgramStateRef
129ProgramState::bindDefaultInitial(SVal loc, SVal V,
130 const LocationContext *LCtx) const {
131 ProgramStateManager &Mgr = getStateManager();
132 const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion();
133 BindResult BindRes = Mgr.StoreMgr->BindDefaultInitial(store: getStore(), R, V);
134 ProgramStateRef State = makeWithStore(BindRes);
135 return Mgr.getOwningEngine().processRegionChange(state: State, MR: R, LCtx);
136}
137
138ProgramStateRef
139ProgramState::bindDefaultZero(SVal loc, const LocationContext *LCtx) const {
140 ProgramStateManager &Mgr = getStateManager();
141 const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion();
142 BindResult BindRes = Mgr.StoreMgr->BindDefaultZero(store: getStore(), R);
143 ProgramStateRef State = makeWithStore(BindRes);
144 return Mgr.getOwningEngine().processRegionChange(state: State, MR: R, LCtx);
145}
146
147typedef ArrayRef<const MemRegion *> RegionList;
148typedef ArrayRef<SVal> ValueList;
149
150ProgramStateRef ProgramState::invalidateRegions(
151 RegionList Regions, ConstCFGElementRef Elem, unsigned Count,
152 const LocationContext *LCtx, bool CausedByPointerEscape,
153 InvalidatedSymbols *IS, const CallEvent *Call,
154 RegionAndSymbolInvalidationTraits *ITraits) const {
155 SmallVector<SVal, 8> Values;
156 for (const MemRegion *Reg : Regions)
157 Values.push_back(Elt: loc::MemRegionVal(Reg));
158
159 return invalidateRegions(Values, Elem, BlockCount: Count, LCtx, CausesPointerEscape: CausedByPointerEscape, IS,
160 Call, ITraits);
161}
162
163ProgramStateRef ProgramState::invalidateRegions(
164 ValueList Values, ConstCFGElementRef Elem, unsigned Count,
165 const LocationContext *LCtx, bool CausedByPointerEscape,
166 InvalidatedSymbols *IS, const CallEvent *Call,
167 RegionAndSymbolInvalidationTraits *ITraits) const {
168
169 ProgramStateManager &Mgr = getStateManager();
170 ExprEngine &Eng = Mgr.getOwningEngine();
171
172 InvalidatedSymbols InvalidatedSyms;
173 if (!IS)
174 IS = &InvalidatedSyms;
175
176 RegionAndSymbolInvalidationTraits ITraitsLocal;
177 if (!ITraits)
178 ITraits = &ITraitsLocal;
179
180 StoreManager::InvalidatedRegions TopLevelInvalidated;
181 StoreManager::InvalidatedRegions Invalidated;
182 const StoreRef &NewStore = Mgr.StoreMgr->invalidateRegions(
183 store: getStore(), Values, Elem, Count, LCtx, Call, IS&: *IS, ITraits&: *ITraits,
184 TopLevelRegions: &TopLevelInvalidated, Invalidated: &Invalidated);
185
186 ProgramStateRef NewState = makeWithStore(store: NewStore);
187
188 if (CausedByPointerEscape) {
189 NewState = Eng.notifyCheckersOfPointerEscape(
190 State: NewState, Invalidated: IS, ExplicitRegions: TopLevelInvalidated, Call, ITraits&: *ITraits);
191 }
192
193 return Eng.processRegionChanges(state: NewState, invalidated: IS, ExplicitRegions: TopLevelInvalidated,
194 Regions: Invalidated, LCtx, Call);
195}
196
197ProgramStateRef ProgramState::killBinding(Loc LV) const {
198 Store OldStore = getStore();
199 const StoreRef &newStore =
200 getStateManager().StoreMgr->killBinding(ST: OldStore, L: LV);
201
202 if (newStore.getStore() == OldStore)
203 return this;
204
205 return makeWithStore(store: newStore);
206}
207
208/// We should never form a MemRegion that would wrap a TypedValueRegion of a
209/// reference type. What we actually wanted was to create a MemRegion refering
210/// to the pointee of that reference.
211SVal ProgramState::desugarReference(SVal Val) const {
212 const auto *TyReg = dyn_cast_or_null<TypedValueRegion>(Val: Val.getAsRegion());
213 if (!TyReg || !TyReg->getValueType()->isReferenceType())
214 return Val;
215 return getSVal(R: TyReg);
216}
217
218/// SymbolicRegions are expected to be wrapped by an ElementRegion as a
219/// canonical representation. As a canonical representation, SymbolicRegions
220/// should be wrapped by ElementRegions before getting a FieldRegion.
221/// See f8643a9b31c4029942f67d4534c9139b45173504 why.
222SVal ProgramState::wrapSymbolicRegion(SVal Val) const {
223 const auto *BaseReg = dyn_cast_or_null<SymbolicRegion>(Val: Val.getAsRegion());
224 if (!BaseReg)
225 return Val;
226
227 StoreManager &SM = getStateManager().getStoreManager();
228 QualType ElemTy = BaseReg->getPointeeStaticType();
229 return loc::MemRegionVal{SM.GetElementZeroRegion(R: BaseReg, T: ElemTy)};
230}
231
232ProgramStateRef
233ProgramState::enterStackFrame(const CallEvent &Call,
234 const StackFrameContext *CalleeCtx) const {
235 return makeWithStore(
236 BindRes: getStateManager().StoreMgr->enterStackFrame(store: getStore(), Call, CalleeCtx));
237}
238
239SVal ProgramState::getSelfSVal(const LocationContext *LCtx) const {
240 const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl();
241 if (!SelfDecl)
242 return SVal();
243 return getSVal(R: getRegion(D: SelfDecl, LC: LCtx));
244}
245
246SVal ProgramState::getSValAsScalarOrLoc(const MemRegion *R) const {
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>(Val: R)) {
254 QualType T = TR->getValueType();
255 if (Loc::isLocType(T) || T->isIntegralOrEnumerationType())
256 return getSVal(R);
257 }
258
259 return UnknownVal();
260}
261
262SVal ProgramState::getSVal(Loc location, QualType T) const {
263 SVal V = getRawSVal(LV: 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(state: 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 APSIntPtr NewV = getBasicVals().Convert(T, From: *Int);
291 if (V.getAs<Loc>())
292 return loc::ConcreteInt(NewV);
293 return nonloc::ConcreteInt(NewV);
294 }
295 }
296 }
297
298 return V;
299}
300
301ProgramStateRef ProgramState::BindExpr(const Stmt *S,
302 const LocationContext *LCtx,
303 SVal V, bool Invalidate) const{
304 Environment NewEnv =
305 getStateManager().EnvMgr.bindExpr(Env, E: EnvironmentEntry(S, LCtx), V,
306 Invalidate);
307 if (NewEnv == Env)
308 return this;
309
310 ProgramState NewSt = *this;
311 NewSt.Env = NewEnv;
312 return getStateManager().getPersistentState(Impl&: NewSt);
313}
314
315[[nodiscard]] std::pair<ProgramStateRef, ProgramStateRef>
316ProgramState::assumeInBoundDual(DefinedOrUnknownSVal Idx,
317 DefinedOrUnknownSVal UpperBound,
318 QualType indexTy) const {
319 if (Idx.isUnknown() || UpperBound.isUnknown())
320 return {this, this};
321
322 // Build an expression for 0 <= Idx < UpperBound.
323 // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed.
324 // FIXME: This should probably be part of SValBuilder.
325 ProgramStateManager &SM = getStateManager();
326 SValBuilder &svalBuilder = SM.getSValBuilder();
327 ASTContext &Ctx = svalBuilder.getContext();
328
329 // Get the offset: the minimum value of the array index type.
330 BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
331 if (indexTy.isNull())
332 indexTy = svalBuilder.getArrayIndexType();
333 nonloc::ConcreteInt Min(BVF.getMinValue(T: indexTy));
334
335 // Adjust the index.
336 SVal newIdx = svalBuilder.evalBinOpNN(state: this, op: BO_Add,
337 lhs: Idx.castAs<NonLoc>(), rhs: Min, resultTy: indexTy);
338 if (newIdx.isUnknownOrUndef())
339 return {this, this};
340
341 // Adjust the upper bound.
342 SVal newBound =
343 svalBuilder.evalBinOpNN(state: this, op: BO_Add, lhs: UpperBound.castAs<NonLoc>(),
344 rhs: Min, resultTy: indexTy);
345
346 if (newBound.isUnknownOrUndef())
347 return {this, this};
348
349 // Build the actual comparison.
350 SVal inBound = svalBuilder.evalBinOpNN(state: this, op: BO_LT, lhs: newIdx.castAs<NonLoc>(),
351 rhs: newBound.castAs<NonLoc>(), resultTy: Ctx.IntTy);
352 if (inBound.isUnknownOrUndef())
353 return {this, this};
354
355 // Finally, let the constraint manager take care of it.
356 ConstraintManager &CM = SM.getConstraintManager();
357 return CM.assumeDual(State: this, Cond: inBound.castAs<DefinedSVal>());
358}
359
360ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx,
361 DefinedOrUnknownSVal UpperBound,
362 bool Assumption,
363 QualType indexTy) const {
364 std::pair<ProgramStateRef, ProgramStateRef> R =
365 assumeInBoundDual(Idx, UpperBound, indexTy);
366 return Assumption ? R.first : R.second;
367}
368
369ConditionTruthVal ProgramState::isNonNull(SVal V) const {
370 ConditionTruthVal IsNull = isNull(V);
371 if (IsNull.isUnderconstrained())
372 return IsNull;
373 return ConditionTruthVal(!IsNull.getValue());
374}
375
376ConditionTruthVal ProgramState::areEqual(SVal Lhs, SVal Rhs) const {
377 return stateMgr->getSValBuilder().areEqual(state: this, lhs: Lhs, rhs: Rhs);
378}
379
380ConditionTruthVal ProgramState::isNull(SVal V) const {
381 if (V.isZeroConstant())
382 return true;
383
384 if (V.isConstant())
385 return false;
386
387 SymbolRef Sym = V.getAsSymbol(/* IncludeBaseRegion */ IncludeBaseRegions: true);
388 if (!Sym)
389 return ConditionTruthVal();
390
391 return getStateManager().ConstraintMgr->isNull(State: this, Sym);
392}
393
394ProgramStateRef ProgramStateManager::getInitialState(const LocationContext *InitLoc) {
395 ProgramState State(this,
396 EnvMgr.getInitialEnvironment(),
397 StoreMgr->getInitialStore(InitLoc),
398 GDMFactory.getEmptyMap());
399
400 return getPersistentState(Impl&: State);
401}
402
403ProgramStateRef ProgramStateManager::getPersistentStateWithGDM(
404 ProgramStateRef FromState,
405 ProgramStateRef GDMState) {
406 ProgramState NewState(*FromState);
407 NewState.GDM = GDMState->GDM;
408 return getPersistentState(Impl&: NewState);
409}
410
411ProgramStateRef ProgramStateManager::getPersistentState(ProgramState &State) {
412
413 llvm::FoldingSetNodeID ID;
414 State.Profile(ID);
415 void *InsertPos;
416
417 if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos))
418 return I;
419
420 ProgramState *newState = nullptr;
421 if (!freeStates.empty()) {
422 newState = freeStates.back();
423 freeStates.pop_back();
424 }
425 else {
426 newState = Alloc.Allocate<ProgramState>();
427 }
428 new (newState) ProgramState(State);
429 StateSet.InsertNode(N: newState, InsertPos);
430 return newState;
431}
432
433ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const {
434 ProgramState NewSt(*this);
435 NewSt.setStore(store);
436 return getStateManager().getPersistentState(State&: NewSt);
437}
438
439ProgramStateRef ProgramState::makeWithStore(const BindResult &BindRes) const {
440 ExprEngine &Eng = getStateManager().getOwningEngine();
441 ProgramStateRef State = makeWithStore(store: BindRes.ResultingStore);
442
443 // We must always notify the checkers for failing binds because otherwise they
444 // may keep stale traits for these symbols.
445 // Eg., Malloc checker may report leaks if we failed to bind that symbol.
446 if (BindRes.FailedToBindValues.empty())
447 return State;
448 return Eng.escapeValues(State, Vs: BindRes.FailedToBindValues, K: PSK_EscapeOnBind);
449}
450
451ProgramStateRef ProgramState::cloneAsPosteriorlyOverconstrained() const {
452 ProgramState NewSt(*this);
453 NewSt.PosteriorlyOverconstrained = true;
454 return getStateManager().getPersistentState(State&: NewSt);
455}
456
457void ProgramState::setStore(const StoreRef &newStore) {
458 Store newStoreStore = newStore.getStore();
459 if (newStoreStore)
460 stateMgr->getStoreManager().incrementReferenceCount(store: newStoreStore);
461 if (store)
462 stateMgr->getStoreManager().decrementReferenceCount(store);
463 store = newStoreStore;
464}
465
466SVal ProgramState::getLValue(const FieldDecl *D, SVal Base) const {
467 Base = desugarReference(Val: Base);
468 Base = wrapSymbolicRegion(Val: Base);
469 return getStateManager().StoreMgr->getLValueField(D, Base);
470}
471
472SVal ProgramState::getLValue(const IndirectFieldDecl *D, SVal Base) const {
473 StoreManager &SM = *getStateManager().StoreMgr;
474 Base = desugarReference(Val: Base);
475 Base = wrapSymbolicRegion(Val: Base);
476
477 // FIXME: This should work with `SM.getLValueField(D->getAnonField(), Base)`,
478 // but that would break some tests. There is probably a bug somewhere that it
479 // would expose.
480 for (const auto *I : D->chain()) {
481 Base = SM.getLValueField(D: cast<FieldDecl>(Val: I), Base);
482 }
483 return Base;
484}
485
486//===----------------------------------------------------------------------===//
487// State pretty-printing.
488//===----------------------------------------------------------------------===//
489
490void ProgramState::printJson(raw_ostream &Out, const LocationContext *LCtx,
491 const char *NL, unsigned int Space,
492 bool IsDot) const {
493 Indent(Out, Space, IsDot) << "\"program_state\": {" << NL;
494 ++Space;
495
496 ProgramStateManager &Mgr = getStateManager();
497
498 // Print the store.
499 Mgr.getStoreManager().printJson(Out, S: getStore(), NL, Space, IsDot);
500
501 // Print out the environment.
502 Env.printJson(Out, Ctx: Mgr.getContext(), LCtx, NL, Space, IsDot);
503
504 // Print out the constraints.
505 Mgr.getConstraintManager().printJson(Out, State: this, NL, Space, IsDot);
506
507 // Print out the tracked dynamic types.
508 printDynamicTypeInfoJson(Out, State: this, NL, Space, IsDot);
509
510 // Print checker-specific data.
511 Mgr.getOwningEngine().printJson(Out, State: this, LCtx, NL, Space, IsDot);
512
513 --Space;
514 Indent(Out, Space, IsDot) << '}';
515}
516
517void ProgramState::printDOT(raw_ostream &Out, const LocationContext *LCtx,
518 unsigned int Space) const {
519 printJson(Out, LCtx, /*NL=*/"\\l", Space, /*IsDot=*/true);
520}
521
522LLVM_DUMP_METHOD void ProgramState::dump() const {
523 printJson(Out&: llvm::errs());
524}
525
526AnalysisManager& ProgramState::getAnalysisManager() const {
527 return stateMgr->getOwningEngine().getAnalysisManager();
528}
529
530//===----------------------------------------------------------------------===//
531// Generic Data Map.
532//===----------------------------------------------------------------------===//
533
534void *const* ProgramState::FindGDM(void *K) const {
535 return GDM.lookup(K);
536}
537
538void*
539ProgramStateManager::FindGDMContext(void *K,
540 void *(*CreateContext)(llvm::BumpPtrAllocator&),
541 void (*DeleteContext)(void*)) {
542
543 std::pair<void*, void (*)(void*)>& p = GDMContexts[K];
544 if (!p.first) {
545 p.first = CreateContext(Alloc);
546 p.second = DeleteContext;
547 }
548
549 return p.first;
550}
551
552ProgramStateRef ProgramStateManager::addGDM(ProgramStateRef St, void *Key, void *Data){
553 ProgramState::GenericDataMap M1 = St->getGDM();
554 ProgramState::GenericDataMap M2 = GDMFactory.add(Old: M1, K: Key, D: Data);
555
556 if (M1 == M2)
557 return St;
558
559 ProgramState NewSt = *St;
560 NewSt.GDM = M2;
561 return getPersistentState(State&: NewSt);
562}
563
564ProgramStateRef ProgramStateManager::removeGDM(ProgramStateRef state, void *Key) {
565 ProgramState::GenericDataMap OldM = state->getGDM();
566 ProgramState::GenericDataMap NewM = GDMFactory.remove(Old: OldM, K: Key);
567
568 if (NewM == OldM)
569 return state;
570
571 ProgramState NewState = *state;
572 NewState.GDM = NewM;
573 return getPersistentState(State&: NewState);
574}
575
576bool ScanReachableSymbols::scan(nonloc::LazyCompoundVal val) {
577 bool wasVisited = !visited.insert(V: val.getCVData()).second;
578 if (wasVisited)
579 return true;
580
581 StoreManager &StoreMgr = state->getStateManager().getStoreManager();
582 // FIXME: We don't really want to use getBaseRegion() here because pointer
583 // arithmetic doesn't apply, but scanReachableSymbols only accepts base
584 // regions right now.
585 const MemRegion *R = val.getRegion()->getBaseRegion();
586 return StoreMgr.scanReachableSymbols(S: val.getStore(), R, Visitor&: *this);
587}
588
589bool ScanReachableSymbols::scan(nonloc::CompoundVal val) {
590 for (SVal V : val)
591 if (!scan(val: V))
592 return false;
593
594 return true;
595}
596
597bool ScanReachableSymbols::scan(const SymExpr *sym) {
598 for (SymbolRef SubSym : sym->symbols()) {
599 bool wasVisited = !visited.insert(V: SubSym).second;
600 if (wasVisited)
601 continue;
602
603 if (!visitor.VisitSymbol(sym: SubSym))
604 return false;
605 }
606
607 return true;
608}
609
610bool ScanReachableSymbols::scan(SVal val) {
611 if (std::optional<loc::MemRegionVal> X = val.getAs<loc::MemRegionVal>())
612 return scan(R: X->getRegion());
613
614 if (std::optional<nonloc::LazyCompoundVal> X =
615 val.getAs<nonloc::LazyCompoundVal>())
616 return scan(val: *X);
617
618 if (std::optional<nonloc::LocAsInteger> X = val.getAs<nonloc::LocAsInteger>())
619 return scan(val: X->getLoc());
620
621 if (SymbolRef Sym = val.getAsSymbol())
622 return scan(sym: Sym);
623
624 if (std::optional<nonloc::CompoundVal> X = val.getAs<nonloc::CompoundVal>())
625 return scan(val: *X);
626
627 return true;
628}
629
630bool ScanReachableSymbols::scan(const MemRegion *R) {
631 if (isa<MemSpaceRegion>(Val: R))
632 return true;
633
634 bool wasVisited = !visited.insert(V: R).second;
635 if (wasVisited)
636 return true;
637
638 if (!visitor.VisitMemRegion(R))
639 return false;
640
641 // If this is a symbolic region, visit the symbol for the region.
642 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Val: R))
643 if (!visitor.VisitSymbol(sym: SR->getSymbol()))
644 return false;
645
646 // If this is a subregion, also visit the parent regions.
647 if (const SubRegion *SR = dyn_cast<SubRegion>(Val: R)) {
648 const MemRegion *Super = SR->getSuperRegion();
649 if (!scan(R: Super))
650 return false;
651
652 // When we reach the topmost region, scan all symbols in it.
653 if (isa<MemSpaceRegion>(Val: Super)) {
654 StoreManager &StoreMgr = state->getStateManager().getStoreManager();
655 if (!StoreMgr.scanReachableSymbols(S: state->getStore(), R: SR, Visitor&: *this))
656 return false;
657 }
658 }
659
660 // Regions captured by a block are also implicitly reachable.
661 if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(Val: R)) {
662 for (auto Var : BDR->referenced_vars()) {
663 if (!scan(R: Var.getCapturedRegion()))
664 return false;
665 }
666 }
667
668 return true;
669}
670
671bool ProgramState::scanReachableSymbols(SVal val, SymbolVisitor& visitor) const {
672 ScanReachableSymbols S(this, visitor);
673 return S.scan(val);
674}
675
676bool ProgramState::scanReachableSymbols(
677 llvm::iterator_range<region_iterator> Reachable,
678 SymbolVisitor &visitor) const {
679 ScanReachableSymbols S(this, visitor);
680 for (const MemRegion *R : Reachable) {
681 if (!S.scan(R))
682 return false;
683 }
684 return true;
685}
686