1	//== RegionStore.cpp - Field-sensitive store model --------------*- C++ -*--==//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This file defines a basic region store model. In this model, we do have field
10	// sensitivity. But we assume nothing about the heap shape. So recursive data
11	// structures are largely ignored. Basically we do 1-limiting analysis.
12	// Parameter pointers are assumed with no aliasing. Pointee objects of
13	// parameters are created lazily.
14	//
15	//===----------------------------------------------------------------------===//
16
17	#include "clang/AST/Attr.h"
18	#include "clang/AST/CharUnits.h"
19	#include "clang/ASTMatchers/ASTMatchFinder.h"
20	#include "clang/Analysis/Analyses/LiveVariables.h"
21	#include "clang/Analysis/AnalysisDeclContext.h"
22	#include "clang/Basic/JsonSupport.h"
23	#include "clang/Basic/TargetInfo.h"
24	#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
25	#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
26	#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
27	#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
28	#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
29	#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
30	#include "llvm/ADT/ImmutableMap.h"
31	#include "llvm/ADT/STLExtras.h"
32	#include "llvm/Support/raw_ostream.h"
33	#include <optional>
34	#include <utility>
35
36	using namespace clang;
37	using namespace ento;
38
39	//===----------------------------------------------------------------------===//
40	// Representation of binding keys.
41	//===----------------------------------------------------------------------===//
42
43	namespace {
44	class BindingKey {
45	public:
46	enum Kind { Default = 0x0, Direct = 0x1 };
47	private:
48	enum { Symbolic = 0x2 };
49
50	llvm::PointerIntPair<const MemRegion *, 2> P;
51	uint64_t Data;
52
53	/// Create a key for a binding to region \p r, which has a symbolic offset
54	/// from region \p Base.
55	explicit BindingKey(const SubRegion *r, const SubRegion *Base, Kind k)
56	: P(r, k | Symbolic), Data(reinterpret_cast<uintptr_t>(Base)) {
57	assert(r && Base && "Must have known regions.");
58	assert(getConcreteOffsetRegion() == Base && "Failed to store base region");
59	}
60
61	/// Create a key for a binding at \p offset from base region \p r.
62	explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
63	: P(r, k), Data(offset) {
64	assert(r && "Must have known regions.");
65	assert(getOffset() == offset && "Failed to store offset");
66	assert((r == r->getBaseRegion() ||
67	isa<ObjCIvarRegion, CXXDerivedObjectRegion>(r)) &&
68	"Not a base");
69	}
70	public:
71
72	bool isDirect() const { return P.getInt() & Direct; }
73	bool hasSymbolicOffset() const { return P.getInt() & Symbolic; }
74
75	const MemRegion *getRegion() const { return P.getPointer(); }
76	uint64_t getOffset() const {
77	assert(!hasSymbolicOffset());
78	return Data;
79	}
80
81	const SubRegion *getConcreteOffsetRegion() const {
82	assert(hasSymbolicOffset());
83	return reinterpret_cast<const SubRegion *>(static_cast<uintptr_t>(Data));
84	}
85
86	const MemRegion *getBaseRegion() const {
87	if (hasSymbolicOffset())
88	return getConcreteOffsetRegion()->getBaseRegion();
89	return getRegion()->getBaseRegion();
90	}
91
92	void Profile(llvm::FoldingSetNodeID& ID) const {
93	ID.AddPointer(Ptr: P.getOpaqueValue());
94	ID.AddInteger(I: Data);
95	}
96
97	static BindingKey Make(const MemRegion *R, Kind k);
98
99	bool operator<(const BindingKey &X) const {
100	if (P.getOpaqueValue() < X.P.getOpaqueValue())
101	return true;
102	if (P.getOpaqueValue() > X.P.getOpaqueValue())
103	return false;
104	return Data < X.Data;
105	}
106
107	bool operator==(const BindingKey &X) const {
108	return P.getOpaqueValue() == X.P.getOpaqueValue() &&
109	Data == X.Data;
110	}
111
112	LLVM_DUMP_METHOD void dump() const;
113	};
114	} // end anonymous namespace
115
116	BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
117	const RegionOffset &RO = R->getAsOffset();
118	if (RO.hasSymbolicOffset())
119	return BindingKey(cast<SubRegion>(Val: R), cast<SubRegion>(Val: RO.getRegion()), k);
120
121	return BindingKey(RO.getRegion(), RO.getOffset(), k);
122	}
123
124	namespace llvm {
125	static inline raw_ostream &operator<<(raw_ostream &Out, BindingKey K) {
126	Out << "\"kind\": \"" << (K.isDirect() ? "Direct" : "Default")
127	<< "\", \"offset\": ";
128
129	if (!K.hasSymbolicOffset())
130	Out << K.getOffset();
131	else
132	Out << "null";
133
134	return Out;
135	}
136
137	} // namespace llvm
138
139	#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
140	void BindingKey::dump() const { llvm::errs() << *this; }
141	#endif
142
143	//===----------------------------------------------------------------------===//
144	// Actual Store type.
145	//===----------------------------------------------------------------------===//
146
147	typedef llvm::ImmutableMap<BindingKey, SVal> ClusterBindings;
148	typedef llvm::ImmutableMapRef<BindingKey, SVal> ClusterBindingsRef;
149	typedef std::pair<BindingKey, SVal> BindingPair;
150
151	typedef llvm::ImmutableMap<const MemRegion *, ClusterBindings>
152	RegionBindings;
153
154	namespace {
155	class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
156	ClusterBindings> {
157	ClusterBindings::Factory *CBFactory;
158
159	// This flag indicates whether the current bindings are within the analysis
160	// that has started from main(). It affects how we perform loads from
161	// global variables that have initializers: if we have observed the
162	// program execution from the start and we know that these variables
163	// have not been overwritten yet, we can be sure that their initializers
164	// are still relevant. This flag never gets changed when the bindings are
165	// updated, so it could potentially be moved into RegionStoreManager
166	// (as if it's the same bindings but a different loading procedure)
167	// however that would have made the manager needlessly stateful.
168	bool IsMainAnalysis;
169
170	public:
171	typedef llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>
172	ParentTy;
173
174	RegionBindingsRef(ClusterBindings::Factory &CBFactory,
175	const RegionBindings::TreeTy *T,
176	RegionBindings::TreeTy::Factory *F,
177	bool IsMainAnalysis)
178	: llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(T, F),
179	CBFactory(&CBFactory), IsMainAnalysis(IsMainAnalysis) {}
180
181	RegionBindingsRef(const ParentTy &P,
182	ClusterBindings::Factory &CBFactory,
183	bool IsMainAnalysis)
184	: llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(P),
185	CBFactory(&CBFactory), IsMainAnalysis(IsMainAnalysis) {}
186
187	RegionBindingsRef add(key_type_ref K, data_type_ref D) const {
188	return RegionBindingsRef(static_cast<const ParentTy *>(this)->add(K, D),
189	*CBFactory, IsMainAnalysis);
190	}
191
192	RegionBindingsRef remove(key_type_ref K) const {
193	return RegionBindingsRef(static_cast<const ParentTy *>(this)->remove(K),
194	*CBFactory, IsMainAnalysis);
195	}
196
197	RegionBindingsRef addBinding(BindingKey K, SVal V) const;
198
199	RegionBindingsRef addBinding(const MemRegion *R,
200	BindingKey::Kind k, SVal V) const;
201
202	const SVal *lookup(BindingKey K) const;
203	const SVal *lookup(const MemRegion *R, BindingKey::Kind k) const;
204	using llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>::lookup;
205
206	RegionBindingsRef removeBinding(BindingKey K);
207
208	RegionBindingsRef removeBinding(const MemRegion *R,
209	BindingKey::Kind k);
210
211	RegionBindingsRef removeBinding(const MemRegion *R) {
212	return removeBinding(R, k: BindingKey::Direct).
213	removeBinding(R, k: BindingKey::Default);
214	}
215
216	std::optional<SVal> getDirectBinding(const MemRegion *R) const;
217
218	/// getDefaultBinding - Returns an SVal* representing an optional default
219	/// binding associated with a region and its subregions.
220	std::optional<SVal> getDefaultBinding(const MemRegion *R) const;
221
222	/// Return the internal tree as a Store.
223	Store asStore() const {
224	llvm::PointerIntPair<Store, 1, bool> Ptr = {
225	asImmutableMap().getRootWithoutRetain(), IsMainAnalysis};
226	return reinterpret_cast<Store>(Ptr.getOpaqueValue());
227	}
228
229	bool isMainAnalysis() const {
230	return IsMainAnalysis;
231	}
232
233	void printJson(raw_ostream &Out, const char *NL = "\n",
234	unsigned int Space = 0, bool IsDot = false) const {
235	for (iterator I = begin(), E = end(); I != E; ++I) {
236	// TODO: We might need a .printJson for I.getKey() as well.
237	Indent(Out, Space, IsDot)
238	<< "{ \"cluster\": \"" << I.getKey() << "\", \"pointer\": \""
239	<< (const void *)I.getKey() << "\", \"items\": [" << NL;
240
241	++Space;
242	const ClusterBindings &CB = I.getData();
243	for (ClusterBindings::iterator CI = CB.begin(), CE = CB.end(); CI != CE;
244	++CI) {
245	Indent(Out, Space, IsDot) << "{ " << CI.getKey() << ", \"value\": ";
246	CI.getData().printJson(Out, /*AddQuotes=*/true);
247	Out << " }";
248	if (std::next(x: CI) != CE)
249	Out << ',';
250	Out << NL;
251	}
252
253	--Space;
254	Indent(Out, Space, IsDot) << "]}";
255	if (std::next(x: I) != E)
256	Out << ',';
257	Out << NL;
258	}
259	}
260
261	LLVM_DUMP_METHOD void dump() const { printJson(Out&: llvm::errs()); }
262	};
263	} // end anonymous namespace
264
265	typedef const RegionBindingsRef& RegionBindingsConstRef;
266
267	std::optional<SVal>
268	RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
269	const SVal *V = lookup(R, k: BindingKey::Direct);
270	return V ? std::optional<SVal>(*V) : std::nullopt;
271	}
272
273	std::optional<SVal>
274	RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
275	const SVal *V = lookup(R, k: BindingKey::Default);
276	return V ? std::optional<SVal>(*V) : std::nullopt;
277	}
278
279	RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
280	const MemRegion *Base = K.getBaseRegion();
281
282	const ClusterBindings *ExistingCluster = lookup(K: Base);
283	ClusterBindings Cluster =
284	(ExistingCluster ? *ExistingCluster : CBFactory->getEmptyMap());
285
286	ClusterBindings NewCluster = CBFactory->add(Old: Cluster, K, D: V);
287	return add(K: Base, D: NewCluster);
288	}
289
290
291	RegionBindingsRef RegionBindingsRef::addBinding(const MemRegion *R,
292	BindingKey::Kind k,
293	SVal V) const {
294	return addBinding(K: BindingKey::Make(R, k), V);
295	}
296
297	const SVal *RegionBindingsRef::lookup(BindingKey K) const {
298	const ClusterBindings *Cluster = lookup(K: K.getBaseRegion());
299	if (!Cluster)
300	return nullptr;
301	return Cluster->lookup(K);
302	}
303
304	const SVal *RegionBindingsRef::lookup(const MemRegion *R,
305	BindingKey::Kind k) const {
306	return lookup(K: BindingKey::Make(R, k));
307	}
308
309	RegionBindingsRef RegionBindingsRef::removeBinding(BindingKey K) {
310	const MemRegion *Base = K.getBaseRegion();
311	const ClusterBindings *Cluster = lookup(K: Base);
312	if (!Cluster)
313	return *this;
314
315	ClusterBindings NewCluster = CBFactory->remove(Old: *Cluster, K);
316	if (NewCluster.isEmpty())
317	return remove(K: Base);
318	return add(K: Base, D: NewCluster);
319	}
320
321	RegionBindingsRef RegionBindingsRef::removeBinding(const MemRegion *R,
322	BindingKey::Kind k){
323	return removeBinding(K: BindingKey::Make(R, k));
324	}
325
326	//===----------------------------------------------------------------------===//
327	// Main RegionStore logic.
328	//===----------------------------------------------------------------------===//
329
330	namespace {
331	class InvalidateRegionsWorker;
332
333	class RegionStoreManager : public StoreManager {
334	public:
335	RegionBindings::Factory RBFactory;
336	mutable ClusterBindings::Factory CBFactory;
337
338	typedef std::vector<SVal> SValListTy;
339	private:
340	typedef llvm::DenseMap<const LazyCompoundValData *,
341	SValListTy> LazyBindingsMapTy;
342	LazyBindingsMapTy LazyBindingsMap;
343
344	/// The largest number of fields a struct can have and still be
345	/// considered "small".
346	///
347	/// This is currently used to decide whether or not it is worth "forcing" a
348	/// LazyCompoundVal on bind.
349	///
350	/// This is controlled by 'region-store-small-struct-limit' option.
351	/// To disable all small-struct-dependent behavior, set the option to "0".
352	unsigned SmallStructLimit;
353
354	/// The largest number of element an array can have and still be
355	/// considered "small".
356	///
357	/// This is currently used to decide whether or not it is worth "forcing" a
358	/// LazyCompoundVal on bind.
359	///
360	/// This is controlled by 'region-store-small-struct-limit' option.
361	/// To disable all small-struct-dependent behavior, set the option to "0".
362	unsigned SmallArrayLimit;
363
364	/// A helper used to populate the work list with the given set of
365	/// regions.
366	void populateWorkList(InvalidateRegionsWorker &W,
367	ArrayRef<SVal> Values,
368	InvalidatedRegions *TopLevelRegions);
369
370	public:
371	RegionStoreManager(ProgramStateManager &mgr)
372	: StoreManager(mgr), RBFactory(mgr.getAllocator()),
373	CBFactory(mgr.getAllocator()), SmallStructLimit(0), SmallArrayLimit(0) {
374	ExprEngine &Eng = StateMgr.getOwningEngine();
375	AnalyzerOptions &Options = Eng.getAnalysisManager().options;
376	SmallStructLimit = Options.RegionStoreSmallStructLimit;
377	SmallArrayLimit = Options.RegionStoreSmallArrayLimit;
378	}
379
380	/// setImplicitDefaultValue - Set the default binding for the provided
381	/// MemRegion to the value implicitly defined for compound literals when
382	/// the value is not specified.
383	RegionBindingsRef setImplicitDefaultValue(RegionBindingsConstRef B,
384	const MemRegion *R, QualType T);
385
386	/// ArrayToPointer - Emulates the "decay" of an array to a pointer
387	/// type. 'Array' represents the lvalue of the array being decayed
388	/// to a pointer, and the returned SVal represents the decayed
389	/// version of that lvalue (i.e., a pointer to the first element of
390	/// the array). This is called by ExprEngine when evaluating
391	/// casts from arrays to pointers.
392	SVal ArrayToPointer(Loc Array, QualType ElementTy) override;
393
394	/// Creates the Store that correctly represents memory contents before
395	/// the beginning of the analysis of the given top-level stack frame.
396	StoreRef getInitialStore(const LocationContext *InitLoc) override {
397	bool IsMainAnalysis = false;
398	if (const auto *FD = dyn_cast<FunctionDecl>(Val: InitLoc->getDecl()))
399	IsMainAnalysis = FD->isMain() && !Ctx.getLangOpts().CPlusPlus;
400	return StoreRef(RegionBindingsRef(
401	RegionBindingsRef::ParentTy(RBFactory.getEmptyMap(), RBFactory),
402	CBFactory, IsMainAnalysis).asStore(), *this);
403	}
404
405	//===-------------------------------------------------------------------===//
406	// Binding values to regions.
407	//===-------------------------------------------------------------------===//
408	RegionBindingsRef invalidateGlobalRegion(MemRegion::Kind K,
409	const Expr *Ex,
410	unsigned Count,
411	const LocationContext *LCtx,
412	RegionBindingsRef B,
413	InvalidatedRegions *Invalidated);
414
415	StoreRef invalidateRegions(Store store,
416	ArrayRef<SVal> Values,
417	const Expr *E, unsigned Count,
418	const LocationContext *LCtx,
419	const CallEvent *Call,
420	InvalidatedSymbols &IS,
421	RegionAndSymbolInvalidationTraits &ITraits,
422	InvalidatedRegions *Invalidated,
423	InvalidatedRegions *InvalidatedTopLevel) override;
424
425	bool scanReachableSymbols(Store S, const MemRegion *R,
426	ScanReachableSymbols &Callbacks) override;
427
428	RegionBindingsRef removeSubRegionBindings(RegionBindingsConstRef B,
429	const SubRegion *R);
430	std::optional<SVal>
431	getConstantValFromConstArrayInitializer(RegionBindingsConstRef B,
432	const ElementRegion *R);
433	std::optional<SVal>
434	getSValFromInitListExpr(const InitListExpr *ILE,
435	const SmallVector<uint64_t, 2> &ConcreteOffsets,
436	QualType ElemT);
437	SVal getSValFromStringLiteral(const StringLiteral *SL, uint64_t Offset,
438	QualType ElemT);
439
440	public: // Part of public interface to class.
441
442	StoreRef Bind(Store store, Loc LV, SVal V) override {
443	return StoreRef(bind(B: getRegionBindings(store), LV, V).asStore(), *this);
444	}
445
446	RegionBindingsRef bind(RegionBindingsConstRef B, Loc LV, SVal V);
447
448	// BindDefaultInitial is only used to initialize a region with
449	// a default value.
450	StoreRef BindDefaultInitial(Store store, const MemRegion *R,
451	SVal V) override {
452	RegionBindingsRef B = getRegionBindings(store);
453	// Use other APIs when you have to wipe the region that was initialized
454	// earlier.
455	assert(!(B.getDefaultBinding(R) || B.getDirectBinding(R)) &&
456	"Double initialization!");
457	B = B.addBinding(K: BindingKey::Make(R, k: BindingKey::Default), V);
458	return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
459	}
460
461	// BindDefaultZero is used for zeroing constructors that may accidentally
462	// overwrite existing bindings.
463	StoreRef BindDefaultZero(Store store, const MemRegion *R) override {
464	// FIXME: The offsets of empty bases can be tricky because of
465	// of the so called "empty base class optimization".
466	// If a base class has been optimized out
467	// we should not try to create a binding, otherwise we should.
468	// Unfortunately, at the moment ASTRecordLayout doesn't expose
469	// the actual sizes of the empty bases
470	// and trying to infer them from offsets/alignments
471	// seems to be error-prone and non-trivial because of the trailing padding.
472	// As a temporary mitigation we don't create bindings for empty bases.
473	if (const auto *BR = dyn_cast<CXXBaseObjectRegion>(Val: R))
474	if (BR->getDecl()->isEmpty())
475	return StoreRef(store, *this);
476
477	RegionBindingsRef B = getRegionBindings(store);
478	SVal V = svalBuilder.makeZeroVal(type: Ctx.CharTy);
479	B = removeSubRegionBindings(B, R: cast<SubRegion>(Val: R));
480	B = B.addBinding(K: BindingKey::Make(R, k: BindingKey::Default), V);
481	return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
482	}
483
484	/// Attempt to extract the fields of \p LCV and bind them to the struct region
485	/// \p R.
486	///
487	/// This path is used when it seems advantageous to "force" loading the values
488	/// within a LazyCompoundVal to bind memberwise to the struct region, rather
489	/// than using a Default binding at the base of the entire region. This is a
490	/// heuristic attempting to avoid building long chains of LazyCompoundVals.
491	///
492	/// \returns The updated store bindings, or \c std::nullopt if binding
493	/// non-lazily would be too expensive.
494	std::optional<RegionBindingsRef>
495	tryBindSmallStruct(RegionBindingsConstRef B, const TypedValueRegion *R,
496	const RecordDecl *RD, nonloc::LazyCompoundVal LCV);
497
498	/// BindStruct - Bind a compound value to a structure.
499	RegionBindingsRef bindStruct(RegionBindingsConstRef B,
500	const TypedValueRegion* R, SVal V);
501
502	/// BindVector - Bind a compound value to a vector.
503	RegionBindingsRef bindVector(RegionBindingsConstRef B,
504	const TypedValueRegion* R, SVal V);
505
506	std::optional<RegionBindingsRef>
507	tryBindSmallArray(RegionBindingsConstRef B, const TypedValueRegion *R,
508	const ArrayType *AT, nonloc::LazyCompoundVal LCV);
509
510	RegionBindingsRef bindArray(RegionBindingsConstRef B,
511	const TypedValueRegion* R,
512	SVal V);
513
514	/// Clears out all bindings in the given region and assigns a new value
515	/// as a Default binding.
516	RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
517	const TypedRegion *R,
518	SVal DefaultVal);
519
520	/// Create a new store with the specified binding removed.
521	/// \param ST the original store, that is the basis for the new store.
522	/// \param L the location whose binding should be removed.
523	StoreRef killBinding(Store ST, Loc L) override;
524
525	void incrementReferenceCount(Store store) override {
526	getRegionBindings(store).manualRetain();
527	}
528
529	/// If the StoreManager supports it, decrement the reference count of
530	/// the specified Store object. If the reference count hits 0, the memory
531	/// associated with the object is recycled.
532	void decrementReferenceCount(Store store) override {
533	getRegionBindings(store).manualRelease();
534	}
535
536	bool includedInBindings(Store store, const MemRegion *region) const override;
537
538	/// Return the value bound to specified location in a given state.
539	///
540	/// The high level logic for this method is this:
541	/// getBinding (L)
542	/// if L has binding
543	/// return L's binding
544	/// else if L is in killset
545	/// return unknown
546	/// else
547	/// if L is on stack or heap
548	/// return undefined
549	/// else
550	/// return symbolic
551	SVal getBinding(Store S, Loc L, QualType T) override {
552	return getBinding(B: getRegionBindings(store: S), L, T);
553	}
554
555	std::optional<SVal> getDefaultBinding(Store S, const MemRegion *R) override {
556	RegionBindingsRef B = getRegionBindings(store: S);
557	// Default bindings are always applied over a base region so look up the
558	// base region's default binding, otherwise the lookup will fail when R
559	// is at an offset from R->getBaseRegion().
560	return B.getDefaultBinding(R: R->getBaseRegion());
561	}
562
563	SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());
564
565	SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);
566
567	SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);
568
569	SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);
570
571	SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);
572
573	SVal getBindingForLazySymbol(const TypedValueRegion *R);
574
575	SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
576	const TypedValueRegion *R,
577	QualType Ty);
578
579	SVal getLazyBinding(const SubRegion *LazyBindingRegion,
580	RegionBindingsRef LazyBinding);
581
582	/// Get bindings for the values in a struct and return a CompoundVal, used
583	/// when doing struct copy:
584	/// struct s x, y;
585	/// x = y;
586	/// y's value is retrieved by this method.
587	SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
588	SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
589	NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);
590
591	/// Used to lazily generate derived symbols for bindings that are defined
592	/// implicitly by default bindings in a super region.
593	///
594	/// Note that callers may need to specially handle LazyCompoundVals, which
595	/// are returned as is in case the caller needs to treat them differently.
596	std::optional<SVal>
597	getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
598	const MemRegion *superR,
599	const TypedValueRegion *R, QualType Ty);
600
601	/// Get the state and region whose binding this region \p R corresponds to.
602	///
603	/// If there is no lazy binding for \p R, the returned value will have a null
604	/// \c second. Note that a null pointer can represents a valid Store.
605	std::pair<Store, const SubRegion *>
606	findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
607	const SubRegion *originalRegion);
608
609	/// Returns the cached set of interesting SVals contained within a lazy
610	/// binding.
611	///
612	/// The precise value of "interesting" is determined for the purposes of
613	/// RegionStore's internal analysis. It must always contain all regions and
614	/// symbols, but may omit constants and other kinds of SVal.
615	///
616	/// In contrast to compound values, LazyCompoundVals are also added
617	/// to the 'interesting values' list in addition to the child interesting
618	/// values.
619	const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);
620
621	//===------------------------------------------------------------------===//
622	// State pruning.
623	//===------------------------------------------------------------------===//
624
625	/// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
626	/// It returns a new Store with these values removed.
627	StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
628	SymbolReaper& SymReaper) override;
629
630	//===------------------------------------------------------------------===//
631	// Utility methods.
632	//===------------------------------------------------------------------===//
633
634	RegionBindingsRef getRegionBindings(Store store) const {
635	llvm::PointerIntPair<Store, 1, bool> Ptr;
636	Ptr.setFromOpaqueValue(const_cast<void *>(store));
637	return RegionBindingsRef(
638	CBFactory,
639	static_cast<const RegionBindings::TreeTy *>(Ptr.getPointer()),
640	RBFactory.getTreeFactory(),
641	Ptr.getInt());
642	}
643
644	void printJson(raw_ostream &Out, Store S, const char *NL = "\n",
645	unsigned int Space = 0, bool IsDot = false) const override;
646
647	void iterBindings(Store store, BindingsHandler& f) override {
648	RegionBindingsRef B = getRegionBindings(store);
649	for (const auto &[Region, Cluster] : B) {
650	for (const auto &[Key, Value] : Cluster) {
651	if (!Key.isDirect())
652	continue;
653	if (const SubRegion *R = dyn_cast<SubRegion>(Val: Key.getRegion())) {
654	// FIXME: Possibly incorporate the offset?
655	if (!f.HandleBinding(SMgr&: *this, store, region: R, val: Value))
656	return;
657	}
658	}
659	}
660	}
661	};
662
663	} // end anonymous namespace
664
665	//===----------------------------------------------------------------------===//
666	// RegionStore creation.
667	//===----------------------------------------------------------------------===//
668
669	std::unique_ptr<StoreManager>
670	ento::CreateRegionStoreManager(ProgramStateManager &StMgr) {
671	return std::make_unique<RegionStoreManager>(args&: StMgr);
672	}
673
674	//===----------------------------------------------------------------------===//
675	// Region Cluster analysis.
676	//===----------------------------------------------------------------------===//
677
678	namespace {
679	/// Used to determine which global regions are automatically included in the
680	/// initial worklist of a ClusterAnalysis.
681	enum GlobalsFilterKind {
682	/// Don't include any global regions.
683	GFK_None,
684	/// Only include system globals.
685	GFK_SystemOnly,
686	/// Include all global regions.
687	GFK_All
688	};
689
690	template <typename DERIVED>
691	class ClusterAnalysis {
692	protected:
693	typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
694	typedef const MemRegion * WorkListElement;
695	typedef SmallVector<WorkListElement, 10> WorkList;
696
697	llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
698
699	WorkList WL;
700
701	RegionStoreManager &RM;
702	ASTContext &Ctx;
703	SValBuilder &svalBuilder;
704
705	RegionBindingsRef B;
706
707
708	protected:
709	const ClusterBindings *getCluster(const MemRegion *R) {
710	return B.lookup(K: R);
711	}
712
713	/// Returns true if all clusters in the given memspace should be initially
714	/// included in the cluster analysis. Subclasses may provide their
715	/// own implementation.
716	bool includeEntireMemorySpace(const MemRegion *Base) {
717	return false;
718	}
719
720	public:
721	ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
722	RegionBindingsRef b)
723	: RM(rm), Ctx(StateMgr.getContext()),
724	svalBuilder(StateMgr.getSValBuilder()), B(std::move(b)) {}
725
726	RegionBindingsRef getRegionBindings() const { return B; }
727
728	bool isVisited(const MemRegion *R) {
729	return Visited.count(Ptr: getCluster(R));
730	}
731
732	void GenerateClusters() {
733	// Scan the entire set of bindings and record the region clusters.
734	for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
735	RI != RE; ++RI){
736	const MemRegion *Base = RI.getKey();
737
738	const ClusterBindings &Cluster = RI.getData();
739	assert(!Cluster.isEmpty() && "Empty clusters should be removed");
740	static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);
741
742	// If the base's memspace should be entirely invalidated, add the cluster
743	// to the workspace up front.
744	if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
745	AddToWorkList(WorkListElement(Base), &Cluster);
746	}
747	}
748
749	bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
750	if (C && !Visited.insert(Ptr: C).second)
751	return false;
752	WL.push_back(Elt: E);
753	return true;
754	}
755
756	bool AddToWorkList(const MemRegion *R) {
757	return static_cast<DERIVED*>(this)->AddToWorkList(R);
758	}
759
760	void RunWorkList() {
761	while (!WL.empty()) {
762	WorkListElement E = WL.pop_back_val();
763	const MemRegion *BaseR = E;
764
765	static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(R: BaseR));
766	}
767	}
768
769	void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
770	void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}
771
772	void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
773	bool Flag) {
774	static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
775	}
776	};
777	}
778
779	//===----------------------------------------------------------------------===//
780	// Binding invalidation.
781	//===----------------------------------------------------------------------===//
782
783	bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
784	ScanReachableSymbols &Callbacks) {
785	assert(R == R->getBaseRegion() && "Should only be called for base regions");
786	RegionBindingsRef B = getRegionBindings(store: S);
787	const ClusterBindings *Cluster = B.lookup(K: R);
788
789	if (!Cluster)
790	return true;
791
792	for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
793	RI != RE; ++RI) {
794	if (!Callbacks.scan(val: RI.getData()))
795	return false;
796	}
797
798	return true;
799	}
800
801	static inline bool isUnionField(const FieldRegion *FR) {
802	return FR->getDecl()->getParent()->isUnion();
803	}
804
805	typedef SmallVector<const FieldDecl *, 8> FieldVector;
806
807	static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
808	assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
809
810	const MemRegion *Base = K.getConcreteOffsetRegion();
811	const MemRegion *R = K.getRegion();
812
813	while (R != Base) {
814	if (const FieldRegion *FR = dyn_cast<FieldRegion>(Val: R))
815	if (!isUnionField(FR))
816	Fields.push_back(Elt: FR->getDecl());
817
818	R = cast<SubRegion>(Val: R)->getSuperRegion();
819	}
820	}
821
822	static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
823	assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
824
825	if (Fields.empty())
826	return true;
827
828	FieldVector FieldsInBindingKey;
829	getSymbolicOffsetFields(K, Fields&: FieldsInBindingKey);
830
831	ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
832	if (Delta >= 0)
833	return std::equal(first1: FieldsInBindingKey.begin() + Delta,
834	last1: FieldsInBindingKey.end(),
835	first2: Fields.begin());
836	else
837	return std::equal(first1: FieldsInBindingKey.begin(), last1: FieldsInBindingKey.end(),
838	first2: Fields.begin() - Delta);
839	}
840
841	/// Collects all bindings in \p Cluster that may refer to bindings within
842	/// \p Top.
843	///
844	/// Each binding is a pair whose \c first is the key (a BindingKey) and whose
845	/// \c second is the value (an SVal).
846	///
847	/// The \p IncludeAllDefaultBindings parameter specifies whether to include
848	/// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
849	/// an aggregate within a larger aggregate with a default binding.
850	static void
851	collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
852	SValBuilder &SVB, const ClusterBindings &Cluster,
853	const SubRegion *Top, BindingKey TopKey,
854	bool IncludeAllDefaultBindings) {
855	FieldVector FieldsInSymbolicSubregions;
856	if (TopKey.hasSymbolicOffset()) {
857	getSymbolicOffsetFields(K: TopKey, Fields&: FieldsInSymbolicSubregions);
858	Top = TopKey.getConcreteOffsetRegion();
859	TopKey = BindingKey::Make(R: Top, k: BindingKey::Default);
860	}
861
862	// Find the length (in bits) of the region being invalidated.
863	uint64_t Length = UINT64_MAX;
864	SVal Extent = Top->getMemRegionManager().getStaticSize(MR: Top, SVB);
865	if (std::optional<nonloc::ConcreteInt> ExtentCI =
866	Extent.getAs<nonloc::ConcreteInt>()) {
867	const llvm::APSInt &ExtentInt = ExtentCI->getValue();
868	assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
869	// Extents are in bytes but region offsets are in bits. Be careful!
870	Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
871	} else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Val: Top)) {
872	if (FR->getDecl()->isBitField())
873	Length = FR->getDecl()->getBitWidthValue(Ctx: SVB.getContext());
874	}
875
876	for (const auto &StoreEntry : Cluster) {
877	BindingKey NextKey = StoreEntry.first;
878	if (NextKey.getRegion() == TopKey.getRegion()) {
879	// FIXME: This doesn't catch the case where we're really invalidating a
880	// region with a symbolic offset. Example:
881	// R: points[i].y
882	// Next: points[0].x
883
884	if (NextKey.getOffset() > TopKey.getOffset() &&
885	NextKey.getOffset() - TopKey.getOffset() < Length) {
886	// Case 1: The next binding is inside the region we're invalidating.
887	// Include it.
888	Bindings.push_back(Elt: StoreEntry);
889
890	} else if (NextKey.getOffset() == TopKey.getOffset()) {
891	// Case 2: The next binding is at the same offset as the region we're
892	// invalidating. In this case, we need to leave default bindings alone,
893	// since they may be providing a default value for a regions beyond what
894	// we're invalidating.
895	// FIXME: This is probably incorrect; consider invalidating an outer
896	// struct whose first field is bound to a LazyCompoundVal.
897	if (IncludeAllDefaultBindings || NextKey.isDirect())
898	Bindings.push_back(Elt: StoreEntry);
899	}
900
901	} else if (NextKey.hasSymbolicOffset()) {
902	const MemRegion *Base = NextKey.getConcreteOffsetRegion();
903	if (Top->isSubRegionOf(R: Base) && Top != Base) {
904	// Case 3: The next key is symbolic and we just changed something within
905	// its concrete region. We don't know if the binding is still valid, so
906	// we'll be conservative and include it.
907	if (IncludeAllDefaultBindings || NextKey.isDirect())
908	if (isCompatibleWithFields(K: NextKey, Fields: FieldsInSymbolicSubregions))
909	Bindings.push_back(Elt: StoreEntry);
910	} else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Val: Base)) {
911	// Case 4: The next key is symbolic, but we changed a known
912	// super-region. In this case the binding is certainly included.
913	if (BaseSR->isSubRegionOf(R: Top))
914	if (isCompatibleWithFields(K: NextKey, Fields: FieldsInSymbolicSubregions))
915	Bindings.push_back(Elt: StoreEntry);
916	}
917	}
918	}
919	}
920
921	static void
922	collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
923	SValBuilder &SVB, const ClusterBindings &Cluster,
924	const SubRegion *Top, bool IncludeAllDefaultBindings) {
925	collectSubRegionBindings(Bindings, SVB, Cluster, Top,
926	TopKey: BindingKey::Make(R: Top, k: BindingKey::Default),
927	IncludeAllDefaultBindings);
928	}
929
930	RegionBindingsRef
931	RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
932	const SubRegion *Top) {
933	BindingKey TopKey = BindingKey::Make(R: Top, k: BindingKey::Default);
934	const MemRegion *ClusterHead = TopKey.getBaseRegion();
935
936	if (Top == ClusterHead) {
937	// We can remove an entire cluster's bindings all in one go.
938	return B.remove(K: Top);
939	}
940
941	const ClusterBindings *Cluster = B.lookup(K: ClusterHead);
942	if (!Cluster) {
943	// If we're invalidating a region with a symbolic offset, we need to make
944	// sure we don't treat the base region as uninitialized anymore.
945	if (TopKey.hasSymbolicOffset()) {
946	const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
947	return B.addBinding(R: Concrete, k: BindingKey::Default, V: UnknownVal());
948	}
949	return B;
950	}
951
952	SmallVector<BindingPair, 32> Bindings;
953	collectSubRegionBindings(Bindings, SVB&: svalBuilder, Cluster: *Cluster, Top, TopKey,
954	/*IncludeAllDefaultBindings=*/false);
955
956	ClusterBindingsRef Result(*Cluster, CBFactory);
957	for (BindingKey Key : llvm::make_first_range(c&: Bindings))
958	Result = Result.remove(K: Key);
959
960	// If we're invalidating a region with a symbolic offset, we need to make sure
961	// we don't treat the base region as uninitialized anymore.
962	// FIXME: This isn't very precise; see the example in
963	// collectSubRegionBindings.
964	if (TopKey.hasSymbolicOffset()) {
965	const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
966	Result = Result.add(K: BindingKey::Make(R: Concrete, k: BindingKey::Default),
967	D: UnknownVal());
968	}
969
970	if (Result.isEmpty())
971	return B.remove(K: ClusterHead);
972	return B.add(K: ClusterHead, D: Result.asImmutableMap());
973	}
974
975	namespace {
976	class InvalidateRegionsWorker : public ClusterAnalysis<InvalidateRegionsWorker>
977	{
978	const Expr *Ex;
979	unsigned Count;
980	const LocationContext *LCtx;
981	InvalidatedSymbols &IS;
982	RegionAndSymbolInvalidationTraits &ITraits;
983	StoreManager::InvalidatedRegions *Regions;
984	GlobalsFilterKind GlobalsFilter;
985	public:
986	InvalidateRegionsWorker(RegionStoreManager &rm,
987	ProgramStateManager &stateMgr,
988	RegionBindingsRef b,
989	const Expr *ex, unsigned count,
990	const LocationContext *lctx,
991	InvalidatedSymbols &is,
992	RegionAndSymbolInvalidationTraits &ITraitsIn,
993	StoreManager::InvalidatedRegions *r,
994	GlobalsFilterKind GFK)
995	: ClusterAnalysis<InvalidateRegionsWorker>(rm, stateMgr, b),
996	Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
997	GlobalsFilter(GFK) {}
998
999	void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
1000	void VisitBinding(SVal V);
1001
1002	using ClusterAnalysis::AddToWorkList;
1003
1004	bool AddToWorkList(const MemRegion *R);
1005
1006	/// Returns true if all clusters in the memory space for \p Base should be
1007	/// be invalidated.
1008	bool includeEntireMemorySpace(const MemRegion *Base);
1009
1010	/// Returns true if the memory space of the given region is one of the global
1011	/// regions specially included at the start of invalidation.
1012	bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
1013	};
1014	}
1015
1016	bool InvalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
1017	bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1018	MR: R, IK: RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
1019	const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
1020	return AddToWorkList(E: WorkListElement(BaseR), C: getCluster(R: BaseR));
1021	}
1022
1023	void InvalidateRegionsWorker::VisitBinding(SVal V) {
1024	// A symbol? Mark it touched by the invalidation.
1025	if (SymbolRef Sym = V.getAsSymbol())
1026	IS.insert(V: Sym);
1027
1028	if (const MemRegion *R = V.getAsRegion()) {
1029	AddToWorkList(R);
1030	return;
1031	}
1032
1033	// Is it a LazyCompoundVal? All references get invalidated as well.
1034	if (std::optional<nonloc::LazyCompoundVal> LCS =
1035	V.getAs<nonloc::LazyCompoundVal>()) {
1036
1037	// `getInterestingValues()` returns SVals contained within LazyCompoundVals,
1038	// so there is no need to visit them.
1039	for (SVal V : RM.getInterestingValues(LCV: *LCS))
1040	if (!isa<nonloc::LazyCompoundVal>(Val: V))
1041	VisitBinding(V);
1042
1043	return;
1044	}
1045	}
1046
1047	void InvalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
1048	const ClusterBindings *C) {
1049
1050	bool PreserveRegionsContents =
1051	ITraits.hasTrait(MR: baseR,
1052	IK: RegionAndSymbolInvalidationTraits::TK_PreserveContents);
1053
1054	if (C) {
1055	for (SVal Val : llvm::make_second_range(c: *C))
1056	VisitBinding(V: Val);
1057
1058	// Invalidate regions contents.
1059	if (!PreserveRegionsContents)
1060	B = B.remove(K: baseR);
1061	}
1062
1063	if (const auto *TO = dyn_cast<TypedValueRegion>(Val: baseR)) {
1064	if (const auto *RD = TO->getValueType()->getAsCXXRecordDecl()) {
1065
1066	// Lambdas can affect all static local variables without explicitly
1067	// capturing those.
1068	// We invalidate all static locals referenced inside the lambda body.
1069	if (RD->isLambda() && RD->getLambdaCallOperator()->getBody()) {
1070	using namespace ast_matchers;
1071
1072	const char *DeclBind = "DeclBind";
1073	StatementMatcher RefToStatic = stmt(hasDescendant(declRefExpr(
1074	to(InnerMatcher: varDecl(hasStaticStorageDuration()).bind(ID: DeclBind)))));
1075	auto Matches =
1076	match(RefToStatic, *RD->getLambdaCallOperator()->getBody(),
1077	RD->getASTContext());
1078
1079	for (BoundNodes &Match : Matches) {
1080	auto *VD = Match.getNodeAs<VarDecl>(DeclBind);
1081	const VarRegion *ToInvalidate =
1082	RM.getRegionManager().getVarRegion(VD, LCtx);
1083	AddToWorkList(ToInvalidate);
1084	}
1085	}
1086	}
1087	}
1088
1089	// BlockDataRegion? If so, invalidate captured variables that are passed
1090	// by reference.
1091	if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(Val: baseR)) {
1092	for (auto Var : BR->referenced_vars()) {
1093	const VarRegion *VR = Var.getCapturedRegion();
1094	const VarDecl *VD = VR->getDecl();
1095	if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
1096	AddToWorkList(R: VR);
1097	}
1098	else if (Loc::isLocType(T: VR->getValueType())) {
1099	// Map the current bindings to a Store to retrieve the value
1100	// of the binding. If that binding itself is a region, we should
1101	// invalidate that region. This is because a block may capture
1102	// a pointer value, but the thing pointed by that pointer may
1103	// get invalidated.
1104	SVal V = RM.getBinding(B, L: loc::MemRegionVal(VR));
1105	if (std::optional<Loc> L = V.getAs<Loc>()) {
1106	if (const MemRegion *LR = L->getAsRegion())
1107	AddToWorkList(R: LR);
1108	}
1109	}
1110	}
1111	return;
1112	}
1113
1114	// Symbolic region?
1115	if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Val: baseR))
1116	IS.insert(V: SR->getSymbol());
1117
1118	// Nothing else should be done in the case when we preserve regions context.
1119	if (PreserveRegionsContents)
1120	return;
1121
1122	// Otherwise, we have a normal data region. Record that we touched the region.
1123	if (Regions)
1124	Regions->push_back(Elt: baseR);
1125
1126	if (isa<AllocaRegion, SymbolicRegion>(Val: baseR)) {
1127	// Invalidate the region by setting its default value to
1128	// conjured symbol. The type of the symbol is irrelevant.
1129	DefinedOrUnknownSVal V =
1130	svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
1131	B = B.addBinding(R: baseR, k: BindingKey::Default, V);
1132	return;
1133	}
1134
1135	if (!baseR->isBoundable())
1136	return;
1137
1138	const TypedValueRegion *TR = cast<TypedValueRegion>(Val: baseR);
1139	QualType T = TR->getValueType();
1140
1141	if (isInitiallyIncludedGlobalRegion(R: baseR)) {
1142	// If the region is a global and we are invalidating all globals,
1143	// erasing the entry is good enough. This causes all globals to be lazily
1144	// symbolicated from the same base symbol.
1145	return;
1146	}
1147
1148	if (T->isRecordType()) {
1149	// Invalidate the region by setting its default value to
1150	// conjured symbol. The type of the symbol is irrelevant.
1151	DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1152	Ctx.IntTy, Count);
1153	B = B.addBinding(R: baseR, k: BindingKey::Default, V);
1154	return;
1155	}
1156
1157	if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
1158	bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1159	MR: baseR,
1160	IK: RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
1161
1162	if (doNotInvalidateSuperRegion) {
1163	// We are not doing blank invalidation of the whole array region so we
1164	// have to manually invalidate each elements.
1165	std::optional<uint64_t> NumElements;
1166
1167	// Compute lower and upper offsets for region within array.
1168	if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(Val: AT))
1169	NumElements = CAT->getZExtSize();
1170	if (!NumElements) // We are not dealing with a constant size array
1171	goto conjure_default;
1172	QualType ElementTy = AT->getElementType();
1173	uint64_t ElemSize = Ctx.getTypeSize(T: ElementTy);
1174	const RegionOffset &RO = baseR->getAsOffset();
1175	const MemRegion *SuperR = baseR->getBaseRegion();
1176	if (RO.hasSymbolicOffset()) {
1177	// If base region has a symbolic offset,
1178	// we revert to invalidating the super region.
1179	if (SuperR)
1180	AddToWorkList(R: SuperR);
1181	goto conjure_default;
1182	}
1183
1184	uint64_t LowerOffset = RO.getOffset();
1185	uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
1186	bool UpperOverflow = UpperOffset < LowerOffset;
1187
1188	// Invalidate regions which are within array boundaries,
1189	// or have a symbolic offset.
1190	if (!SuperR)
1191	goto conjure_default;
1192
1193	const ClusterBindings *C = B.lookup(K: SuperR);
1194	if (!C)
1195	goto conjure_default;
1196
1197	for (const auto &[BK, V] : *C) {
1198	std::optional<uint64_t> ROffset =
1199	BK.hasSymbolicOffset() ? std::optional<uint64_t>() : BK.getOffset();
1200
1201	// Check offset is not symbolic and within array's boundaries.
1202	// Handles arrays of 0 elements and of 0-sized elements as well.
1203	if (!ROffset ||
1204	((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
1205	(UpperOverflow &&
1206	(*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
1207	(LowerOffset == UpperOffset && *ROffset == LowerOffset))) {
1208	B = B.removeBinding(K: BK);
1209	// Bound symbolic regions need to be invalidated for dead symbol
1210	// detection.
1211	const MemRegion *R = V.getAsRegion();
1212	if (isa_and_nonnull<SymbolicRegion>(Val: R))
1213	VisitBinding(V);
1214	}
1215	}
1216	}
1217	conjure_default:
1218	// Set the default value of the array to conjured symbol.
1219	DefinedOrUnknownSVal V =
1220	svalBuilder.conjureSymbolVal(symbolTag: baseR, expr: Ex, LCtx,
1221	type: AT->getElementType(), count: Count);
1222	B = B.addBinding(R: baseR, k: BindingKey::Default, V);
1223	return;
1224	}
1225
1226	DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(symbolTag: baseR, expr: Ex, LCtx,
1227	type: T,count: Count);
1228	assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
1229	B = B.addBinding(R: baseR, k: BindingKey::Direct, V);
1230	}
1231
1232	bool InvalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
1233	const MemRegion *R) {
1234	switch (GlobalsFilter) {
1235	case GFK_None:
1236	return false;
1237	case GFK_SystemOnly:
1238	return isa<GlobalSystemSpaceRegion>(Val: R->getMemorySpace());
1239	case GFK_All:
1240	return isa<NonStaticGlobalSpaceRegion>(Val: R->getMemorySpace());
1241	}
1242
1243	llvm_unreachable("unknown globals filter");
1244	}
1245
1246	bool InvalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
1247	if (isInitiallyIncludedGlobalRegion(R: Base))
1248	return true;
1249
1250	const MemSpaceRegion *MemSpace = Base->getMemorySpace();
1251	return ITraits.hasTrait(MR: MemSpace,
1252	IK: RegionAndSymbolInvalidationTraits::TK_EntireMemSpace);
1253	}
1254
1255	RegionBindingsRef
1256	RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
1257	const Expr *Ex,
1258	unsigned Count,
1259	const LocationContext *LCtx,
1260	RegionBindingsRef B,
1261	InvalidatedRegions *Invalidated) {
1262	// Bind the globals memory space to a new symbol that we will use to derive
1263	// the bindings for all globals.
1264	const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
1265	SVal V = svalBuilder.conjureSymbolVal(/* symbolTag = */ (const void*) GS, Ex, LCtx,
1266	/* type does not matter */ Ctx.IntTy,
1267	Count);
1268
1269	B = B.removeBinding(R: GS)
1270	.addBinding(K: BindingKey::Make(R: GS, k: BindingKey::Default), V);
1271
1272	// Even if there are no bindings in the global scope, we still need to
1273	// record that we touched it.
1274	if (Invalidated)
1275	Invalidated->push_back(Elt: GS);
1276
1277	return B;
1278	}
1279
1280	void RegionStoreManager::populateWorkList(InvalidateRegionsWorker &W,
1281	ArrayRef<SVal> Values,
1282	InvalidatedRegions *TopLevelRegions) {
1283	for (SVal V : Values) {
1284	if (auto LCS = V.getAs<nonloc::LazyCompoundVal>()) {
1285	for (SVal S : getInterestingValues(LCV: *LCS))
1286	if (const MemRegion *R = S.getAsRegion())
1287	W.AddToWorkList(R);
1288
1289	continue;
1290	}
1291
1292	if (const MemRegion *R = V.getAsRegion()) {
1293	if (TopLevelRegions)
1294	TopLevelRegions->push_back(Elt: R);
1295	W.AddToWorkList(R);
1296	continue;
1297	}
1298	}
1299	}
1300
1301	StoreRef
1302	RegionStoreManager::invalidateRegions(Store store,
1303	ArrayRef<SVal> Values,
1304	const Expr *Ex, unsigned Count,
1305	const LocationContext *LCtx,
1306	const CallEvent *Call,
1307	InvalidatedSymbols &IS,
1308	RegionAndSymbolInvalidationTraits &ITraits,
1309	InvalidatedRegions *TopLevelRegions,
1310	InvalidatedRegions *Invalidated) {
1311	GlobalsFilterKind GlobalsFilter;
1312	if (Call) {
1313	if (Call->isInSystemHeader())
1314	GlobalsFilter = GFK_SystemOnly;
1315	else
1316	GlobalsFilter = GFK_All;
1317	} else {
1318	GlobalsFilter = GFK_None;
1319	}
1320
1321	RegionBindingsRef B = getRegionBindings(store);
1322	InvalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
1323	Invalidated, GlobalsFilter);
1324
1325	// Scan the bindings and generate the clusters.
1326	W.GenerateClusters();
1327
1328	// Add the regions to the worklist.
1329	populateWorkList(W, Values, TopLevelRegions);
1330
1331	W.RunWorkList();
1332
1333	// Return the new bindings.
1334	B = W.getRegionBindings();
1335
1336	// For calls, determine which global regions should be invalidated and
1337	// invalidate them. (Note that function-static and immutable globals are never
1338	// invalidated by this.)
1339	// TODO: This could possibly be more precise with modules.
1340	switch (GlobalsFilter) {
1341	case GFK_All:
1342	B = invalidateGlobalRegion(K: MemRegion::GlobalInternalSpaceRegionKind,
1343	Ex, Count, LCtx, B, Invalidated);
1344	[[fallthrough]];
1345	case GFK_SystemOnly:
1346	B = invalidateGlobalRegion(K: MemRegion::GlobalSystemSpaceRegionKind,
1347	Ex, Count, LCtx, B, Invalidated);
1348	[[fallthrough]];
1349	case GFK_None:
1350	break;
1351	}
1352
1353	return StoreRef(B.asStore(), *this);
1354	}
1355
1356	//===----------------------------------------------------------------------===//
1357	// Location and region casting.
1358	//===----------------------------------------------------------------------===//
1359
1360	/// ArrayToPointer - Emulates the "decay" of an array to a pointer
1361	/// type. 'Array' represents the lvalue of the array being decayed
1362	/// to a pointer, and the returned SVal represents the decayed
1363	/// version of that lvalue (i.e., a pointer to the first element of
1364	/// the array). This is called by ExprEngine when evaluating casts
1365	/// from arrays to pointers.
1366	SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
1367	if (isa<loc::ConcreteInt>(Val: Array))
1368	return Array;
1369
1370	if (!isa<loc::MemRegionVal>(Val: Array))
1371	return UnknownVal();
1372
1373	const SubRegion *R =
1374	cast<SubRegion>(Val: Array.castAs<loc::MemRegionVal>().getRegion());
1375	NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
1376	return loc::MemRegionVal(MRMgr.getElementRegion(elementType: T, Idx: ZeroIdx, superRegion: R, Ctx));
1377	}
1378
1379	//===----------------------------------------------------------------------===//
1380	// Loading values from regions.
1381	//===----------------------------------------------------------------------===//
1382
1383	SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
1384	assert(!isa<UnknownVal>(L) && "location unknown");
1385	assert(!isa<UndefinedVal>(L) && "location undefined");
1386
1387	// For access to concrete addresses, return UnknownVal. Checks
1388	// for null dereferences (and similar errors) are done by checkers, not
1389	// the Store.
1390	// FIXME: We can consider lazily symbolicating such memory, but we really
1391	// should defer this when we can reason easily about symbolicating arrays
1392	// of bytes.
1393	if (L.getAs<loc::ConcreteInt>()) {
1394	return UnknownVal();
1395	}
1396	if (!L.getAs<loc::MemRegionVal>()) {
1397	return UnknownVal();
1398	}
1399
1400	const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();
1401
1402	if (isa<BlockDataRegion>(Val: MR)) {
1403	return UnknownVal();
1404	}
1405
1406	// Auto-detect the binding type.
1407	if (T.isNull()) {
1408	if (const auto *TVR = dyn_cast<TypedValueRegion>(Val: MR))
1409	T = TVR->getValueType();
1410	else if (const auto *TR = dyn_cast<TypedRegion>(Val: MR))
1411	T = TR->getLocationType()->getPointeeType();
1412	else if (const auto *SR = dyn_cast<SymbolicRegion>(Val: MR))
1413	T = SR->getPointeeStaticType();
1414	}
1415	assert(!T.isNull() && "Unable to auto-detect binding type!");
1416	assert(!T->isVoidType() && "Attempting to dereference a void pointer!");
1417
1418	if (!isa<TypedValueRegion>(Val: MR))
1419	MR = GetElementZeroRegion(R: cast<SubRegion>(Val: MR), T);
1420
1421	// FIXME: Perhaps this method should just take a 'const MemRegion*' argument
1422	// instead of 'Loc', and have the other Loc cases handled at a higher level.
1423	const TypedValueRegion *R = cast<TypedValueRegion>(Val: MR);
1424	QualType RTy = R->getValueType();
1425
1426	// FIXME: we do not yet model the parts of a complex type, so treat the
1427	// whole thing as "unknown".
1428	if (RTy->isAnyComplexType())
1429	return UnknownVal();
1430
1431	// FIXME: We should eventually handle funny addressing. e.g.:
1432	//
1433	// int x = ...;
1434	// int *p = &x;
1435	// char *q = (char*) p;
1436	// char c = *q; // returns the first byte of 'x'.
1437	//
1438	// Such funny addressing will occur due to layering of regions.
1439	if (RTy->isStructureOrClassType())
1440	return getBindingForStruct(B, R);
1441
1442	// FIXME: Handle unions.
1443	if (RTy->isUnionType())
1444	return createLazyBinding(B, R);
1445
1446	if (RTy->isArrayType()) {
1447	if (RTy->isConstantArrayType())
1448	return getBindingForArray(B, R);
1449	else
1450	return UnknownVal();
1451	}
1452
1453	// FIXME: handle Vector types.
1454	if (RTy->isVectorType())
1455	return UnknownVal();
1456
1457	if (const FieldRegion* FR = dyn_cast<FieldRegion>(Val: R))
1458	return svalBuilder.evalCast(V: getBindingForField(B, R: FR), CastTy: T, OriginalTy: QualType{});
1459
1460	if (const ElementRegion* ER = dyn_cast<ElementRegion>(Val: R)) {
1461	// FIXME: Here we actually perform an implicit conversion from the loaded
1462	// value to the element type. Eventually we want to compose these values
1463	// more intelligently. For example, an 'element' can encompass multiple
1464	// bound regions (e.g., several bound bytes), or could be a subset of
1465	// a larger value.
1466	return svalBuilder.evalCast(V: getBindingForElement(B, R: ER), CastTy: T, OriginalTy: QualType{});
1467	}
1468
1469	if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(Val: R)) {
1470	// FIXME: Here we actually perform an implicit conversion from the loaded
1471	// value to the ivar type. What we should model is stores to ivars
1472	// that blow past the extent of the ivar. If the address of the ivar is
1473	// reinterpretted, it is possible we stored a different value that could
1474	// fit within the ivar. Either we need to cast these when storing them
1475	// or reinterpret them lazily (as we do here).
1476	return svalBuilder.evalCast(V: getBindingForObjCIvar(B, R: IVR), CastTy: T, OriginalTy: QualType{});
1477	}
1478
1479	if (const VarRegion *VR = dyn_cast<VarRegion>(Val: R)) {
1480	// FIXME: Here we actually perform an implicit conversion from the loaded
1481	// value to the variable type. What we should model is stores to variables
1482	// that blow past the extent of the variable. If the address of the
1483	// variable is reinterpretted, it is possible we stored a different value
1484	// that could fit within the variable. Either we need to cast these when
1485	// storing them or reinterpret them lazily (as we do here).
1486	return svalBuilder.evalCast(V: getBindingForVar(B, R: VR), CastTy: T, OriginalTy: QualType{});
1487	}
1488
1489	const SVal *V = B.lookup(R, k: BindingKey::Direct);
1490
1491	// Check if the region has a binding.
1492	if (V)
1493	return *V;
1494
1495	// The location does not have a bound value. This means that it has
1496	// the value it had upon its creation and/or entry to the analyzed
1497	// function/method. These are either symbolic values or 'undefined'.
1498	if (R->hasStackNonParametersStorage()) {
1499	// All stack variables are considered to have undefined values
1500	// upon creation. All heap allocated blocks are considered to
1501	// have undefined values as well unless they are explicitly bound
1502	// to specific values.
1503	return UndefinedVal();
1504	}
1505
1506	// All other values are symbolic.
1507	return svalBuilder.getRegionValueSymbolVal(region: R);
1508	}
1509
1510	static QualType getUnderlyingType(const SubRegion *R) {
1511	QualType RegionTy;
1512	if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(Val: R))
1513	RegionTy = TVR->getValueType();
1514
1515	if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Val: R))
1516	RegionTy = SR->getSymbol()->getType();
1517
1518	return RegionTy;
1519	}
1520
1521	/// Checks to see if store \p B has a lazy binding for region \p R.
1522	///
1523	/// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
1524	/// if there are additional bindings within \p R.
1525	///
1526	/// Note that unlike RegionStoreManager::findLazyBinding, this will not search
1527	/// for lazy bindings for super-regions of \p R.
1528	static std::optional<nonloc::LazyCompoundVal>
1529	getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
1530	const SubRegion *R, bool AllowSubregionBindings) {
1531	std::optional<SVal> V = B.getDefaultBinding(R);
1532	if (!V)
1533	return std::nullopt;
1534
1535	std::optional<nonloc::LazyCompoundVal> LCV =
1536	V->getAs<nonloc::LazyCompoundVal>();
1537	if (!LCV)
1538	return std::nullopt;
1539
1540	// If the LCV is for a subregion, the types might not match, and we shouldn't
1541	// reuse the binding.
1542	QualType RegionTy = getUnderlyingType(R);
1543	if (!RegionTy.isNull() &&
1544	!RegionTy->isVoidPointerType()) {
1545	QualType SourceRegionTy = LCV->getRegion()->getValueType();
1546	if (!SVB.getContext().hasSameUnqualifiedType(T1: RegionTy, T2: SourceRegionTy))
1547	return std::nullopt;
1548	}
1549
1550	if (!AllowSubregionBindings) {
1551	// If there are any other bindings within this region, we shouldn't reuse
1552	// the top-level binding.
1553	SmallVector<BindingPair, 16> Bindings;
1554	collectSubRegionBindings(Bindings, SVB, Cluster: *B.lookup(K: R->getBaseRegion()), Top: R,
1555	/*IncludeAllDefaultBindings=*/true);
1556	if (Bindings.size() > 1)
1557	return std::nullopt;
1558	}
1559
1560	return *LCV;
1561	}
1562
1563	std::pair<Store, const SubRegion *>
1564	RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
1565	const SubRegion *R,
1566	const SubRegion *originalRegion) {
1567	if (originalRegion != R) {
1568	if (std::optional<nonloc::LazyCompoundVal> V =
1569	getExistingLazyBinding(SVB&: svalBuilder, B, R, AllowSubregionBindings: true))
1570	return std::make_pair(x: V->getStore(), y: V->getRegion());
1571	}
1572
1573	typedef std::pair<Store, const SubRegion *> StoreRegionPair;
1574	StoreRegionPair Result = StoreRegionPair();
1575
1576	if (const ElementRegion *ER = dyn_cast<ElementRegion>(Val: R)) {
1577	Result = findLazyBinding(B, R: cast<SubRegion>(ER->getSuperRegion()),
1578	originalRegion);
1579
1580	if (Result.second)
1581	Result.second = MRMgr.getElementRegionWithSuper(ER, superRegion: Result.second);
1582
1583	} else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Val: R)) {
1584	Result = findLazyBinding(B, R: cast<SubRegion>(Val: FR->getSuperRegion()),
1585	originalRegion);
1586
1587	if (Result.second)
1588	Result.second = MRMgr.getFieldRegionWithSuper(FR, superRegion: Result.second);
1589
1590	} else if (const CXXBaseObjectRegion *BaseReg =
1591	dyn_cast<CXXBaseObjectRegion>(Val: R)) {
1592	// C++ base object region is another kind of region that we should blast
1593	// through to look for lazy compound value. It is like a field region.
1594	Result = findLazyBinding(B, R: cast<SubRegion>(Val: BaseReg->getSuperRegion()),
1595	originalRegion);
1596
1597	if (Result.second)
1598	Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(baseReg: BaseReg,
1599	superRegion: Result.second);
1600	}
1601
1602	return Result;
1603	}
1604
1605	/// This is a helper function for `getConstantValFromConstArrayInitializer`.
1606	///
1607	/// Return an array of extents of the declared array type.
1608	///
1609	/// E.g. for `int x[1][2][3];` returns { 1, 2, 3 }.
1610	static SmallVector<uint64_t, 2>
1611	getConstantArrayExtents(const ConstantArrayType *CAT) {
1612	assert(CAT && "ConstantArrayType should not be null");
1613	CAT = cast<ConstantArrayType>(CAT->getCanonicalTypeInternal());
1614	SmallVector<uint64_t, 2> Extents;
1615	do {
1616	Extents.push_back(Elt: CAT->getZExtSize());
1617	} while ((CAT = dyn_cast<ConstantArrayType>(CAT->getElementType())));
1618	return Extents;
1619	}
1620
1621	/// This is a helper function for `getConstantValFromConstArrayInitializer`.
1622	///
1623	/// Return an array of offsets from nested ElementRegions and a root base
1624	/// region. The array is never empty and a base region is never null.
1625	///
1626	/// E.g. for `Element{Element{Element{VarRegion},1},2},3}` returns { 3, 2, 1 }.
1627	/// This represents an access through indirection: `arr[1][2][3];`
1628	///
1629	/// \param ER The given (possibly nested) ElementRegion.
1630	///
1631	/// \note The result array is in the reverse order of indirection expression:
1632	/// arr[1][2][3] -> { 3, 2, 1 }. This helps to provide complexity O(n), where n
1633	/// is a number of indirections. It may not affect performance in real-life
1634	/// code, though.
1635	static std::pair<SmallVector<SVal, 2>, const MemRegion *>
1636	getElementRegionOffsetsWithBase(const ElementRegion *ER) {
1637	assert(ER && "ConstantArrayType should not be null");
1638	const MemRegion *Base;
1639	SmallVector<SVal, 2> SValOffsets;
1640	do {
1641	SValOffsets.push_back(Elt: ER->getIndex());
1642	Base = ER->getSuperRegion();
1643	ER = dyn_cast<ElementRegion>(Val: Base);
1644	} while (ER);
1645	return {SValOffsets, Base};
1646	}
1647
1648	/// This is a helper function for `getConstantValFromConstArrayInitializer`.
1649	///
1650	/// Convert array of offsets from `SVal` to `uint64_t` in consideration of
1651	/// respective array extents.
1652	/// \param SrcOffsets [in] The array of offsets of type `SVal` in reversed
1653	/// order (expectedly received from `getElementRegionOffsetsWithBase`).
1654	/// \param ArrayExtents [in] The array of extents.
1655	/// \param DstOffsets [out] The array of offsets of type `uint64_t`.
1656	/// \returns:
1657	/// - `std::nullopt` for successful convertion.
1658	/// - `UndefinedVal` or `UnknownVal` otherwise. It's expected that this SVal
1659	/// will be returned as a suitable value of the access operation.
1660	/// which should be returned as a correct
1661	///
1662	/// \example:
1663	/// const int arr[10][20][30] = {}; // ArrayExtents { 10, 20, 30 }
1664	/// int x1 = arr[4][5][6]; // SrcOffsets { NonLoc(6), NonLoc(5), NonLoc(4) }
1665	/// // DstOffsets { 4, 5, 6 }
1666	/// // returns std::nullopt
1667	/// int x2 = arr[42][5][-6]; // returns UndefinedVal
1668	/// int x3 = arr[4][5][x2]; // returns UnknownVal
1669	static std::optional<SVal>
1670	convertOffsetsFromSvalToUnsigneds(const SmallVector<SVal, 2> &SrcOffsets,
1671	const SmallVector<uint64_t, 2> ArrayExtents,
1672	SmallVector<uint64_t, 2> &DstOffsets) {
1673	// Check offsets for being out of bounds.
1674	// C++20 [expr.add] 7.6.6.4 (excerpt):
1675	// If P points to an array element i of an array object x with n
1676	// elements, where i < 0 or i > n, the behavior is undefined.
1677	// Dereferencing is not allowed on the "one past the last
1678	// element", when i == n.
1679	// Example:
1680	// const int arr[3][2] = {{1, 2}, {3, 4}};
1681	// arr[0][0]; // 1
1682	// arr[0][1]; // 2
1683	// arr[0][2]; // UB
1684	// arr[1][0]; // 3
1685	// arr[1][1]; // 4
1686	// arr[1][-1]; // UB
1687	// arr[2][0]; // 0
1688	// arr[2][1]; // 0
1689	// arr[-2][0]; // UB
1690	DstOffsets.resize(N: SrcOffsets.size());
1691	auto ExtentIt = ArrayExtents.begin();
1692	auto OffsetIt = DstOffsets.begin();
1693	// Reverse `SValOffsets` to make it consistent with `ArrayExtents`.
1694	for (SVal V : llvm::reverse(C: SrcOffsets)) {
1695	if (auto CI = V.getAs<nonloc::ConcreteInt>()) {
1696	// When offset is out of array's bounds, result is UB.
1697	const llvm::APSInt &Offset = CI->getValue();
1698	if (Offset.isNegative() || Offset.uge(RHS: *(ExtentIt++)))
1699	return UndefinedVal();
1700	// Store index in a reversive order.
1701	*(OffsetIt++) = Offset.getZExtValue();
1702	continue;
1703	}
1704	// Symbolic index presented. Return Unknown value.
1705	// FIXME: We also need to take ElementRegions with symbolic indexes into
1706	// account.
1707	return UnknownVal();
1708	}
1709	return std::nullopt;
1710	}
1711
1712	std::optional<SVal> RegionStoreManager::getConstantValFromConstArrayInitializer(
1713	RegionBindingsConstRef B, const ElementRegion *R) {
1714	assert(R && "ElementRegion should not be null");
1715
1716	// Treat an n-dimensional array.
1717	SmallVector<SVal, 2> SValOffsets;
1718	const MemRegion *Base;
1719	std::tie(args&: SValOffsets, args&: Base) = getElementRegionOffsetsWithBase(ER: R);
1720	const VarRegion *VR = dyn_cast<VarRegion>(Val: Base);
1721	if (!VR)
1722	return std::nullopt;
1723
1724	assert(!SValOffsets.empty() && "getElementRegionOffsets guarantees the "
1725	"offsets vector is not empty.");
1726
1727	// Check if the containing array has an initialized value that we can trust.
1728	// We can trust a const value or a value of a global initializer in main().
1729	const VarDecl *VD = VR->getDecl();
1730	if (!VD->getType().isConstQualified() &&
1731	!R->getElementType().isConstQualified() &&
1732	(!B.isMainAnalysis() || !VD->hasGlobalStorage()))
1733	return std::nullopt;
1734
1735	// Array's declaration should have `ConstantArrayType` type, because only this
1736	// type contains an array extent. It may happen that array type can be of
1737	// `IncompleteArrayType` type. To get the declaration of `ConstantArrayType`
1738	// type, we should find the declaration in the redeclarations chain that has
1739	// the initialization expression.
1740	// NOTE: `getAnyInitializer` has an out-parameter, which returns a new `VD`
1741	// from which an initializer is obtained. We replace current `VD` with the new
1742	// `VD`. If the return value of the function is null than `VD` won't be
1743	// replaced.
1744	const Expr *Init = VD->getAnyInitializer(D&: VD);
1745	// NOTE: If `Init` is non-null, then a new `VD` is non-null for sure. So check
1746	// `Init` for null only and don't worry about the replaced `VD`.
1747	if (!Init)
1748	return std::nullopt;
1749
1750	// Array's declaration should have ConstantArrayType type, because only this
1751	// type contains an array extent.
1752	const ConstantArrayType *CAT = Ctx.getAsConstantArrayType(T: VD->getType());
1753	if (!CAT)
1754	return std::nullopt;
1755
1756	// Get array extents.
1757	SmallVector<uint64_t, 2> Extents = getConstantArrayExtents(CAT);
1758
1759	// The number of offsets should equal to the numbers of extents,
1760	// otherwise wrong type punning occurred. For instance:
1761	// int arr[1][2][3];
1762	// auto ptr = (int(*)[42])arr;
1763	// auto x = ptr[4][2]; // UB
1764	// FIXME: Should return UndefinedVal.
1765	if (SValOffsets.size() != Extents.size())
1766	return std::nullopt;
1767
1768	SmallVector<uint64_t, 2> ConcreteOffsets;
1769	if (std::optional<SVal> V = convertOffsetsFromSvalToUnsigneds(
1770	SrcOffsets: SValOffsets, ArrayExtents: Extents, DstOffsets&: ConcreteOffsets))
1771	return *V;
1772
1773	// Handle InitListExpr.
1774	// Example:
1775	// const char arr[4][2] = { { 1, 2 }, { 3 }, 4, 5 };
1776	if (const auto *ILE = dyn_cast<InitListExpr>(Val: Init))
1777	return getSValFromInitListExpr(ILE, ConcreteOffsets, ElemT: R->getElementType());
1778
1779	// Handle StringLiteral.
1780	// Example:
1781	// const char arr[] = "abc";
1782	if (const auto *SL = dyn_cast<StringLiteral>(Val: Init))
1783	return getSValFromStringLiteral(SL, Offset: ConcreteOffsets.front(),
1784	ElemT: R->getElementType());
1785
1786	// FIXME: Handle CompoundLiteralExpr.
1787
1788	return std::nullopt;
1789	}
1790
1791	/// Returns an SVal, if possible, for the specified position of an
1792	/// initialization list.
1793	///
1794	/// \param ILE The given initialization list.
1795	/// \param Offsets The array of unsigned offsets. E.g. for the expression
1796	/// `int x = arr[1][2][3];` an array should be { 1, 2, 3 }.
1797	/// \param ElemT The type of the result SVal expression.
1798	/// \return Optional SVal for the particular position in the initialization
1799	/// list. E.g. for the list `{{1, 2},[3, 4],{5, 6}, {}}` offsets:
1800	/// - {1, 1} returns SVal{4}, because it's the second position in the second
1801	/// sublist;
1802	/// - {3, 0} returns SVal{0}, because there's no explicit value at this
1803	/// position in the sublist.
1804	///
1805	/// NOTE: Inorder to get a valid SVal, a caller shall guarantee valid offsets
1806	/// for the given initialization list. Otherwise SVal can be an equivalent to 0
1807	/// or lead to assertion.
1808	std::optional<SVal> RegionStoreManager::getSValFromInitListExpr(
1809	const InitListExpr *ILE, const SmallVector<uint64_t, 2> &Offsets,
1810	QualType ElemT) {
1811	assert(ILE && "InitListExpr should not be null");
1812
1813	for (uint64_t Offset : Offsets) {
1814	// C++20 [dcl.init.string] 9.4.2.1:
1815	// An array of ordinary character type [...] can be initialized by [...]
1816	// an appropriately-typed string-literal enclosed in braces.
1817	// Example:
1818	// const char arr[] = { "abc" };
1819	if (ILE->isStringLiteralInit())
1820	if (const auto *SL = dyn_cast<StringLiteral>(Val: ILE->getInit(Init: 0)))
1821	return getSValFromStringLiteral(SL, Offset, ElemT);
1822
1823	// C++20 [expr.add] 9.4.17.5 (excerpt):
1824	// i-th array element is value-initialized for each k < i ≤ n,
1825	// where k is an expression-list size and n is an array extent.
1826	if (Offset >= ILE->getNumInits())
1827	return svalBuilder.makeZeroVal(type: ElemT);
1828
1829	const Expr *E = ILE->getInit(Init: Offset);
1830	const auto *IL = dyn_cast<InitListExpr>(Val: E);
1831	if (!IL)
1832	// Return a constant value, if it is presented.
1833	// FIXME: Support other SVals.
1834	return svalBuilder.getConstantVal(E);
1835
1836	// Go to the nested initializer list.
1837	ILE = IL;
1838	}
1839
1840	assert(ILE);
1841
1842	// FIXME: Unhandeled InitListExpr sub-expression, possibly constructing an
1843	// enum?
1844	return std::nullopt;
1845	}
1846
1847	/// Returns an SVal, if possible, for the specified position in a string
1848	/// literal.
1849	///
1850	/// \param SL The given string literal.
1851	/// \param Offset The unsigned offset. E.g. for the expression
1852	/// `char x = str[42];` an offset should be 42.
1853	/// E.g. for the string "abc" offset:
1854	/// - 1 returns SVal{b}, because it's the second position in the string.
1855	/// - 42 returns SVal{0}, because there's no explicit value at this
1856	/// position in the string.
1857	/// \param ElemT The type of the result SVal expression.
1858	///
1859	/// NOTE: We return `0` for every offset >= the literal length for array
1860	/// declarations, like:
1861	/// const char str[42] = "123"; // Literal length is 4.
1862	/// char c = str[41]; // Offset is 41.
1863	/// FIXME: Nevertheless, we can't do the same for pointer declaraions, like:
1864	/// const char * const str = "123"; // Literal length is 4.
1865	/// char c = str[41]; // Offset is 41. Returns `0`, but Undef
1866	/// // expected.
1867	/// It should be properly handled before reaching this point.
1868	/// The main problem is that we can't distinguish between these declarations,
1869	/// because in case of array we can get the Decl from VarRegion, but in case
1870	/// of pointer the region is a StringRegion, which doesn't contain a Decl.
1871	/// Possible solution could be passing an array extent along with the offset.
1872	SVal RegionStoreManager::getSValFromStringLiteral(const StringLiteral *SL,
1873	uint64_t Offset,
1874	QualType ElemT) {
1875	assert(SL && "StringLiteral should not be null");
1876	// C++20 [dcl.init.string] 9.4.2.3:
1877	// If there are fewer initializers than there are array elements, each
1878	// element not explicitly initialized shall be zero-initialized [dcl.init].
1879	uint32_t Code = (Offset >= SL->getLength()) ? 0 : SL->getCodeUnit(i: Offset);
1880	return svalBuilder.makeIntVal(integer: Code, type: ElemT);
1881	}
1882
1883	static std::optional<SVal> getDerivedSymbolForBinding(
1884	RegionBindingsConstRef B, const TypedValueRegion *BaseRegion,
1885	const TypedValueRegion *SubReg, const ASTContext &Ctx, SValBuilder &SVB) {
1886	assert(BaseRegion);
1887	QualType BaseTy = BaseRegion->getValueType();
1888	QualType Ty = SubReg->getValueType();
1889	if (BaseTy->isScalarType() && Ty->isScalarType()) {
1890	if (Ctx.getTypeSizeInChars(T: BaseTy) >= Ctx.getTypeSizeInChars(T: Ty)) {
1891	if (const std::optional<SVal> &ParentValue =
1892	B.getDirectBinding(R: BaseRegion)) {
1893	if (SymbolRef ParentValueAsSym = ParentValue->getAsSymbol())
1894	return SVB.getDerivedRegionValueSymbolVal(parentSymbol: ParentValueAsSym, region: SubReg);
1895
1896	if (ParentValue->isUndef())
1897	return UndefinedVal();
1898
1899	// Other cases: give up. We are indexing into a larger object
1900	// that has some value, but we don't know how to handle that yet.
1901	return UnknownVal();
1902	}
1903	}
1904	}
1905	return std::nullopt;
1906	}
1907
1908	SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
1909	const ElementRegion* R) {
1910	// Check if the region has a binding.
1911	if (const std::optional<SVal> &V = B.getDirectBinding(R))
1912	return *V;
1913
1914	const MemRegion* superR = R->getSuperRegion();
1915
1916	// Check if the region is an element region of a string literal.
1917	if (const StringRegion *StrR = dyn_cast<StringRegion>(Val: superR)) {
1918	// FIXME: Handle loads from strings where the literal is treated as
1919	// an integer, e.g., *((unsigned int*)"hello"). Such loads are UB according
1920	// to C++20 7.2.1.11 [basic.lval].
1921	QualType T = Ctx.getAsArrayType(T: StrR->getValueType())->getElementType();
1922	if (!Ctx.hasSameUnqualifiedType(T1: T, T2: R->getElementType()))
1923	return UnknownVal();
1924	if (const auto CI = R->getIndex().getAs<nonloc::ConcreteInt>()) {
1925	const llvm::APSInt &Idx = CI->getValue();
1926	if (Idx < 0)
1927	return UndefinedVal();
1928	const StringLiteral *SL = StrR->getStringLiteral();
1929	return getSValFromStringLiteral(SL, Offset: Idx.getZExtValue(), ElemT: T);
1930	}
1931	} else if (isa<ElementRegion, VarRegion>(Val: superR)) {
1932	if (std::optional<SVal> V = getConstantValFromConstArrayInitializer(B, R))
1933	return *V;
1934	}
1935
1936	// Check for loads from a code text region. For such loads, just give up.
1937	if (isa<CodeTextRegion>(Val: superR))
1938	return UnknownVal();
1939
1940	// Handle the case where we are indexing into a larger scalar object.
1941	// For example, this handles:
1942	// int x = ...
1943	// char *y = &x;
1944	// return *y;
1945	// FIXME: This is a hack, and doesn't do anything really intelligent yet.
1946	const RegionRawOffset &O = R->getAsArrayOffset();
1947
1948	// If we cannot reason about the offset, return an unknown value.
1949	if (!O.getRegion())
1950	return UnknownVal();
1951
1952	if (const TypedValueRegion *baseR = dyn_cast<TypedValueRegion>(Val: O.getRegion()))
1953	if (auto V = getDerivedSymbolForBinding(B, baseR, R, Ctx, svalBuilder))
1954	return *V;
1955
1956	return getBindingForFieldOrElementCommon(B, R, R->getElementType());
1957	}
1958
1959	SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
1960	const FieldRegion* R) {
1961
1962	// Check if the region has a binding.
1963	if (const std::optional<SVal> &V = B.getDirectBinding(R))
1964	return *V;
1965
1966	// If the containing record was initialized, try to get its constant value.
1967	const FieldDecl *FD = R->getDecl();
1968	QualType Ty = FD->getType();
1969	const MemRegion* superR = R->getSuperRegion();
1970	if (const auto *VR = dyn_cast<VarRegion>(Val: superR)) {
1971	const VarDecl *VD = VR->getDecl();
1972	QualType RecordVarTy = VD->getType();
1973	unsigned Index = FD->getFieldIndex();
1974	// Either the record variable or the field has an initializer that we can
1975	// trust. We trust initializers of constants and, additionally, respect
1976	// initializers of globals when analyzing main().
1977	if (RecordVarTy.isConstQualified() || Ty.isConstQualified() ||
1978	(B.isMainAnalysis() && VD->hasGlobalStorage()))
1979	if (const Expr *Init = VD->getAnyInitializer())
1980	if (const auto *InitList = dyn_cast<InitListExpr>(Val: Init)) {
1981	if (Index < InitList->getNumInits()) {
1982	if (const Expr *FieldInit = InitList->getInit(Init: Index))
1983	if (std::optional<SVal> V = svalBuilder.getConstantVal(E: FieldInit))
1984	return *V;
1985	} else {
1986	return svalBuilder.makeZeroVal(type: Ty);
1987	}
1988	}
1989	}
1990
1991	// Handle the case where we are accessing into a larger scalar object.
1992	// For example, this handles:
1993	// struct header {
1994	// unsigned a : 1;
1995	// unsigned b : 1;
1996	// };
1997	// struct parse_t {
1998	// unsigned bits0 : 1;
1999	// unsigned bits2 : 2; // <-- header
2000	// unsigned bits4 : 4;
2001	// };
2002	// int parse(parse_t *p) {
2003	// unsigned copy = p->bits2;
2004	// header *bits = (header *)&copy;
2005	// return bits->b; <-- here
2006	// }
2007	if (const auto *Base = dyn_cast<TypedValueRegion>(Val: R->getBaseRegion()))
2008	if (auto V = getDerivedSymbolForBinding(B, BaseRegion: Base, SubReg: R, Ctx, SVB&: svalBuilder))
2009	return *V;
2010
2011	return getBindingForFieldOrElementCommon(B, R, Ty);
2012	}
2013
2014	std::optional<SVal> RegionStoreManager::getBindingForDerivedDefaultValue(
2015	RegionBindingsConstRef B, const MemRegion *superR,
2016	const TypedValueRegion *R, QualType Ty) {
2017
2018	if (const std::optional<SVal> &D = B.getDefaultBinding(R: superR)) {
2019	SVal val = *D;
2020	if (SymbolRef parentSym = val.getAsSymbol())
2021	return svalBuilder.getDerivedRegionValueSymbolVal(parentSymbol: parentSym, region: R);
2022
2023	if (val.isZeroConstant())
2024	return svalBuilder.makeZeroVal(type: Ty);
2025
2026	if (val.isUnknownOrUndef())
2027	return val;
2028
2029	// Lazy bindings are usually handled through getExistingLazyBinding().
2030	// We should unify these two code paths at some point.
2031	if (isa<nonloc::LazyCompoundVal, nonloc::CompoundVal>(Val: val))
2032	return val;
2033
2034	llvm_unreachable("Unknown default value");
2035	}
2036
2037	return std::nullopt;
2038	}
2039
2040	SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
2041	RegionBindingsRef LazyBinding) {
2042	SVal Result;
2043	if (const ElementRegion *ER = dyn_cast<ElementRegion>(Val: LazyBindingRegion))
2044	Result = getBindingForElement(B: LazyBinding, R: ER);
2045	else
2046	Result = getBindingForField(B: LazyBinding,
2047	R: cast<FieldRegion>(Val: LazyBindingRegion));
2048
2049	// FIXME: This is a hack to deal with RegionStore's inability to distinguish a
2050	// default value for /part/ of an aggregate from a default value for the
2051	// /entire/ aggregate. The most common case of this is when struct Outer
2052	// has as its first member a struct Inner, which is copied in from a stack
2053	// variable. In this case, even if the Outer's default value is symbolic, 0,
2054	// or unknown, it gets overridden by the Inner's default value of undefined.
2055	//
2056	// This is a general problem -- if the Inner is zero-initialized, the Outer
2057	// will now look zero-initialized. The proper way to solve this is with a
2058	// new version of RegionStore that tracks the extent of a binding as well
2059	// as the offset.
2060	//
2061	// This hack only takes care of the undefined case because that can very
2062	// quickly result in a warning.
2063	if (Result.isUndef())
2064	Result = UnknownVal();
2065
2066	return Result;
2067	}
2068
2069	SVal
2070	RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
2071	const TypedValueRegion *R,
2072	QualType Ty) {
2073
2074	// At this point we have already checked in either getBindingForElement or
2075	// getBindingForField if 'R' has a direct binding.
2076
2077	// Lazy binding?
2078	Store lazyBindingStore = nullptr;
2079	const SubRegion *lazyBindingRegion = nullptr;
2080	std::tie(args&: lazyBindingStore, args&: lazyBindingRegion) = findLazyBinding(B, R, originalRegion: R);
2081	if (lazyBindingRegion)
2082	return getLazyBinding(LazyBindingRegion: lazyBindingRegion,
2083	LazyBinding: getRegionBindings(store: lazyBindingStore));
2084
2085	// Record whether or not we see a symbolic index. That can completely
2086	// be out of scope of our lookup.
2087	bool hasSymbolicIndex = false;
2088
2089	// FIXME: This is a hack to deal with RegionStore's inability to distinguish a
2090	// default value for /part/ of an aggregate from a default value for the
2091	// /entire/ aggregate. The most common case of this is when struct Outer
2092	// has as its first member a struct Inner, which is copied in from a stack
2093	// variable. In this case, even if the Outer's default value is symbolic, 0,
2094	// or unknown, it gets overridden by the Inner's default value of undefined.
2095	//
2096	// This is a general problem -- if the Inner is zero-initialized, the Outer
2097	// will now look zero-initialized. The proper way to solve this is with a
2098	// new version of RegionStore that tracks the extent of a binding as well
2099	// as the offset.
2100	//
2101	// This hack only takes care of the undefined case because that can very
2102	// quickly result in a warning.
2103	bool hasPartialLazyBinding = false;
2104
2105	const SubRegion *SR = R;
2106	while (SR) {
2107	const MemRegion *Base = SR->getSuperRegion();
2108	if (std::optional<SVal> D =
2109	getBindingForDerivedDefaultValue(B, superR: Base, R, Ty)) {
2110	if (D->getAs<nonloc::LazyCompoundVal>()) {
2111	hasPartialLazyBinding = true;
2112	break;
2113	}
2114
2115	return *D;
2116	}
2117
2118	if (const ElementRegion *ER = dyn_cast<ElementRegion>(Val: Base)) {
2119	NonLoc index = ER->getIndex();
2120	if (!index.isConstant())
2121	hasSymbolicIndex = true;
2122	}
2123
2124	// If our super region is a field or element itself, walk up the region
2125	// hierarchy to see if there is a default value installed in an ancestor.
2126	SR = dyn_cast<SubRegion>(Val: Base);
2127	}
2128
2129	if (R->hasStackNonParametersStorage()) {
2130	if (isa<ElementRegion>(Val: R)) {
2131	// Currently we don't reason specially about Clang-style vectors. Check
2132	// if superR is a vector and if so return Unknown.
2133	if (const TypedValueRegion *typedSuperR =
2134	dyn_cast<TypedValueRegion>(Val: R->getSuperRegion())) {
2135	if (typedSuperR->getValueType()->isVectorType())
2136	return UnknownVal();
2137	}
2138	}
2139
2140	// FIXME: We also need to take ElementRegions with symbolic indexes into
2141	// account. This case handles both directly accessing an ElementRegion
2142	// with a symbolic offset, but also fields within an element with
2143	// a symbolic offset.
2144	if (hasSymbolicIndex)
2145	return UnknownVal();
2146
2147	// Additionally allow introspection of a block's internal layout.
2148	// Try to get direct binding if all other attempts failed thus far.
2149	// Else, return UndefinedVal()
2150	if (!hasPartialLazyBinding && !isa<BlockDataRegion>(Val: R->getBaseRegion())) {
2151	if (const std::optional<SVal> &V = B.getDefaultBinding(R))
2152	return *V;
2153	return UndefinedVal();
2154	}
2155	}
2156
2157	// All other values are symbolic.
2158	return svalBuilder.getRegionValueSymbolVal(region: R);
2159	}
2160
2161	SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
2162	const ObjCIvarRegion* R) {
2163	// Check if the region has a binding.
2164	if (const std::optional<SVal> &V = B.getDirectBinding(R))
2165	return *V;
2166
2167	const MemRegion *superR = R->getSuperRegion();
2168
2169	// Check if the super region has a default binding.
2170	if (const std::optional<SVal> &V = B.getDefaultBinding(R: superR)) {
2171	if (SymbolRef parentSym = V->getAsSymbol())
2172	return svalBuilder.getDerivedRegionValueSymbolVal(parentSymbol: parentSym, region: R);
2173
2174	// Other cases: give up.
2175	return UnknownVal();
2176	}
2177
2178	return getBindingForLazySymbol(R);
2179	}
2180
2181	SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
2182	const VarRegion *R) {
2183
2184	// Check if the region has a binding.
2185	if (std::optional<SVal> V = B.getDirectBinding(R))
2186	return *V;
2187
2188	if (std::optional<SVal> V = B.getDefaultBinding(R))
2189	return *V;
2190
2191	// Lazily derive a value for the VarRegion.
2192	const VarDecl *VD = R->getDecl();
2193	const MemSpaceRegion *MS = R->getMemorySpace();
2194
2195	// Arguments are always symbolic.
2196	if (isa<StackArgumentsSpaceRegion>(Val: MS))
2197	return svalBuilder.getRegionValueSymbolVal(region: R);
2198
2199	// Is 'VD' declared constant? If so, retrieve the constant value.
2200	if (VD->getType().isConstQualified()) {
2201	if (const Expr *Init = VD->getAnyInitializer()) {
2202	if (std::optional<SVal> V = svalBuilder.getConstantVal(E: Init))
2203	return *V;
2204
2205	// If the variable is const qualified and has an initializer but
2206	// we couldn't evaluate initializer to a value, treat the value as
2207	// unknown.
2208	return UnknownVal();
2209	}
2210	}
2211
2212	// This must come after the check for constants because closure-captured
2213	// constant variables may appear in UnknownSpaceRegion.
2214	if (isa<UnknownSpaceRegion>(Val: MS))
2215	return svalBuilder.getRegionValueSymbolVal(region: R);
2216
2217	if (isa<GlobalsSpaceRegion>(Val: MS)) {
2218	QualType T = VD->getType();
2219
2220	// If we're in main(), then global initializers have not become stale yet.
2221	if (B.isMainAnalysis())
2222	if (const Expr *Init = VD->getAnyInitializer())
2223	if (std::optional<SVal> V = svalBuilder.getConstantVal(E: Init))
2224	return *V;
2225
2226	// Function-scoped static variables are default-initialized to 0; if they
2227	// have an initializer, it would have been processed by now.
2228	// FIXME: This is only true when we're starting analysis from main().
2229	// We're losing a lot of coverage here.
2230	if (isa<StaticGlobalSpaceRegion>(Val: MS))
2231	return svalBuilder.makeZeroVal(type: T);
2232
2233	if (std::optional<SVal> V = getBindingForDerivedDefaultValue(B, superR: MS, R, Ty: T)) {
2234	assert(!V->getAs<nonloc::LazyCompoundVal>());
2235	return *V;
2236	}
2237
2238	return svalBuilder.getRegionValueSymbolVal(region: R);
2239	}
2240
2241	return UndefinedVal();
2242	}
2243
2244	SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
2245	// All other values are symbolic.
2246	return svalBuilder.getRegionValueSymbolVal(region: R);
2247	}
2248
2249	const RegionStoreManager::SValListTy &
2250	RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
2251	// First, check the cache.
2252	LazyBindingsMapTy::iterator I = LazyBindingsMap.find(Val: LCV.getCVData());
2253	if (I != LazyBindingsMap.end())
2254	return I->second;
2255
2256	// If we don't have a list of values cached, start constructing it.
2257	SValListTy List;
2258
2259	const SubRegion *LazyR = LCV.getRegion();
2260	RegionBindingsRef B = getRegionBindings(store: LCV.getStore());
2261
2262	// If this region had /no/ bindings at the time, there are no interesting
2263	// values to return.
2264	const ClusterBindings *Cluster = B.lookup(K: LazyR->getBaseRegion());
2265	if (!Cluster)
2266	return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
2267
2268	SmallVector<BindingPair, 32> Bindings;
2269	collectSubRegionBindings(Bindings, SVB&: svalBuilder, Cluster: *Cluster, Top: LazyR,
2270	/*IncludeAllDefaultBindings=*/true);
2271	for (SVal V : llvm::make_second_range(c&: Bindings)) {
2272	if (V.isUnknownOrUndef() || V.isConstant())
2273	continue;
2274
2275	if (auto InnerLCV = V.getAs<nonloc::LazyCompoundVal>()) {
2276	const SValListTy &InnerList = getInterestingValues(LCV: *InnerLCV);
2277	List.insert(position: List.end(), first: InnerList.begin(), last: InnerList.end());
2278	}
2279
2280	List.push_back(x: V);
2281	}
2282
2283	return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
2284	}
2285
2286	NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
2287	const TypedValueRegion *R) {
2288	if (std::optional<nonloc::LazyCompoundVal> V =
2289	getExistingLazyBinding(SVB&: svalBuilder, B, R, AllowSubregionBindings: false))
2290	return *V;
2291
2292	return svalBuilder.makeLazyCompoundVal(store: StoreRef(B.asStore(), *this), region: R);
2293	}
2294
2295	static bool isRecordEmpty(const RecordDecl *RD) {
2296	if (!RD->field_empty())
2297	return false;
2298	if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(Val: RD))
2299	return CRD->getNumBases() == 0;
2300	return true;
2301	}
2302
2303	SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
2304	const TypedValueRegion *R) {
2305	const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
2306	if (!RD->getDefinition() || isRecordEmpty(RD))
2307	return UnknownVal();
2308
2309	return createLazyBinding(B, R);
2310	}
2311
2312	SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
2313	const TypedValueRegion *R) {
2314	assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
2315	"Only constant array types can have compound bindings.");
2316
2317	return createLazyBinding(B, R);
2318	}
2319
2320	bool RegionStoreManager::includedInBindings(Store store,
2321	const MemRegion *region) const {
2322	RegionBindingsRef B = getRegionBindings(store);
2323	region = region->getBaseRegion();
2324
2325	// Quick path: if the base is the head of a cluster, the region is live.
2326	if (B.lookup(K: region))
2327	return true;
2328
2329	// Slow path: if the region is the VALUE of any binding, it is live.
2330	for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
2331	const ClusterBindings &Cluster = RI.getData();
2332	for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
2333	CI != CE; ++CI) {
2334	SVal D = CI.getData();
2335	if (const MemRegion *R = D.getAsRegion())
2336	if (R->getBaseRegion() == region)
2337	return true;
2338	}
2339	}
2340
2341	return false;
2342	}
2343
2344	//===----------------------------------------------------------------------===//
2345	// Binding values to regions.
2346	//===----------------------------------------------------------------------===//
2347
2348	StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
2349	if (std::optional<loc::MemRegionVal> LV = L.getAs<loc::MemRegionVal>())
2350	if (const MemRegion* R = LV->getRegion())
2351	return StoreRef(getRegionBindings(store: ST).removeBinding(R)
2352	.asImmutableMap()
2353	.getRootWithoutRetain(),
2354	*this);
2355
2356	return StoreRef(ST, *this);
2357	}
2358
2359	RegionBindingsRef
2360	RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
2361	// We only care about region locations.
2362	auto MemRegVal = L.getAs<loc::MemRegionVal>();
2363	if (!MemRegVal)
2364	return B;
2365
2366	const MemRegion *R = MemRegVal->getRegion();
2367
2368	// Check if the region is a struct region.
2369	if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(Val: R)) {
2370	QualType Ty = TR->getValueType();
2371	if (Ty->isArrayType())
2372	return bindArray(B, R: TR, V);
2373	if (Ty->isStructureOrClassType())
2374	return bindStruct(B, R: TR, V);
2375	if (Ty->isVectorType())
2376	return bindVector(B, R: TR, V);
2377	if (Ty->isUnionType())
2378	return bindAggregate(B, R: TR, DefaultVal: V);
2379	}
2380
2381	// Binding directly to a symbolic region should be treated as binding
2382	// to element 0.
2383	if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Val: R))
2384	R = GetElementZeroRegion(R: SR, T: SR->getPointeeStaticType());
2385
2386	assert((!isa<CXXThisRegion>(R) || !B.lookup(R)) &&
2387	"'this' pointer is not an l-value and is not assignable");
2388
2389	// Clear out bindings that may overlap with this binding.
2390	RegionBindingsRef NewB = removeSubRegionBindings(B, Top: cast<SubRegion>(Val: R));
2391
2392	// LazyCompoundVals should be always bound as 'default' bindings.
2393	auto KeyKind = isa<nonloc::LazyCompoundVal>(Val: V) ? BindingKey::Default
2394	: BindingKey::Direct;
2395	return NewB.addBinding(K: BindingKey::Make(R, k: KeyKind), V);
2396	}
2397
2398	RegionBindingsRef
2399	RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
2400	const MemRegion *R,
2401	QualType T) {
2402	SVal V;
2403
2404	if (Loc::isLocType(T))
2405	V = svalBuilder.makeNullWithType(type: T);
2406	else if (T->isIntegralOrEnumerationType())
2407	V = svalBuilder.makeZeroVal(type: T);
2408	else if (T->isStructureOrClassType() || T->isArrayType()) {
2409	// Set the default value to a zero constant when it is a structure
2410	// or array. The type doesn't really matter.
2411	V = svalBuilder.makeZeroVal(type: Ctx.IntTy);
2412	}
2413	else {
2414	// We can't represent values of this type, but we still need to set a value
2415	// to record that the region has been initialized.
2416	// If this assertion ever fires, a new case should be added above -- we
2417	// should know how to default-initialize any value we can symbolicate.
2418	assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
2419	V = UnknownVal();
2420	}
2421
2422	return B.addBinding(R, k: BindingKey::Default, V);
2423	}
2424
2425	std::optional<RegionBindingsRef> RegionStoreManager::tryBindSmallArray(
2426	RegionBindingsConstRef B, const TypedValueRegion *R, const ArrayType *AT,
2427	nonloc::LazyCompoundVal LCV) {
2428
2429	auto CAT = dyn_cast<ConstantArrayType>(Val: AT);
2430
2431	// If we don't know the size, create a lazyCompoundVal instead.
2432	if (!CAT)
2433	return std::nullopt;
2434
2435	QualType Ty = CAT->getElementType();
2436	if (!(Ty->isScalarType() || Ty->isReferenceType()))
2437	return std::nullopt;
2438
2439	// If the array is too big, create a LCV instead.
2440	uint64_t ArrSize = CAT->getLimitedSize();
2441	if (ArrSize > SmallArrayLimit)
2442	return std::nullopt;
2443
2444	RegionBindingsRef NewB = B;
2445
2446	for (uint64_t i = 0; i < ArrSize; ++i) {
2447	auto Idx = svalBuilder.makeArrayIndex(idx: i);
2448	const ElementRegion *SrcER =
2449	MRMgr.getElementRegion(elementType: Ty, Idx, superRegion: LCV.getRegion(), Ctx);
2450	SVal V = getBindingForElement(B: getRegionBindings(store: LCV.getStore()), R: SrcER);
2451
2452	const ElementRegion *DstER = MRMgr.getElementRegion(elementType: Ty, Idx, superRegion: R, Ctx);
2453	NewB = bind(B: NewB, L: loc::MemRegionVal(DstER), V);
2454	}
2455
2456	return NewB;
2457	}
2458
2459	RegionBindingsRef
2460	RegionStoreManager::bindArray(RegionBindingsConstRef B,
2461	const TypedValueRegion* R,
2462	SVal Init) {
2463
2464	const ArrayType *AT =cast<ArrayType>(Val: Ctx.getCanonicalType(T: R->getValueType()));
2465	QualType ElementTy = AT->getElementType();
2466	std::optional<uint64_t> Size;
2467
2468	if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(Val: AT))
2469	Size = CAT->getZExtSize();
2470
2471	// Check if the init expr is a literal. If so, bind the rvalue instead.
2472	// FIXME: It's not responsibility of the Store to transform this lvalue
2473	// to rvalue. ExprEngine or maybe even CFG should do this before binding.
2474	if (std::optional<loc::MemRegionVal> MRV = Init.getAs<loc::MemRegionVal>()) {
2475	SVal V = getBinding(S: B.asStore(), L: *MRV, T: R->getValueType());
2476	return bindAggregate(B, R, DefaultVal: V);
2477	}
2478
2479	// Handle lazy compound values.
2480	if (std::optional<nonloc::LazyCompoundVal> LCV =
2481	Init.getAs<nonloc::LazyCompoundVal>()) {
2482	if (std::optional<RegionBindingsRef> NewB =
2483	tryBindSmallArray(B, R, AT, LCV: *LCV))
2484	return *NewB;
2485
2486	return bindAggregate(B, R, DefaultVal: Init);
2487	}
2488
2489	if (Init.isUnknown())
2490	return bindAggregate(B, R, DefaultVal: UnknownVal());
2491
2492	// Remaining case: explicit compound values.
2493	const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
2494	nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2495	uint64_t i = 0;
2496
2497	RegionBindingsRef NewB(B);
2498
2499	for (; Size ? i < *Size : true; ++i, ++VI) {
2500	// The init list might be shorter than the array length.
2501	if (VI == VE)
2502	break;
2503
2504	NonLoc Idx = svalBuilder.makeArrayIndex(idx: i);
2505	const ElementRegion *ER = MRMgr.getElementRegion(elementType: ElementTy, Idx, superRegion: R, Ctx);
2506
2507	if (ElementTy->isStructureOrClassType())
2508	NewB = bindStruct(NewB, ER, *VI);
2509	else if (ElementTy->isArrayType())
2510	NewB = bindArray(NewB, ER, *VI);
2511	else
2512	NewB = bind(B: NewB, L: loc::MemRegionVal(ER), V: *VI);
2513	}
2514
2515	// If the init list is shorter than the array length (or the array has
2516	// variable length), set the array default value. Values that are already set
2517	// are not overwritten.
2518	if (!Size || i < *Size)
2519	NewB = setImplicitDefaultValue(B: NewB, R, T: ElementTy);
2520
2521	return NewB;
2522	}
2523
2524	RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
2525	const TypedValueRegion* R,
2526	SVal V) {
2527	QualType T = R->getValueType();
2528	const VectorType *VT = T->castAs<VectorType>(); // Use castAs for typedefs.
2529
2530	// Handle lazy compound values and symbolic values.
2531	if (isa<nonloc::LazyCompoundVal, nonloc::SymbolVal>(Val: V))
2532	return bindAggregate(B, R, DefaultVal: V);
2533
2534	// We may get non-CompoundVal accidentally due to imprecise cast logic or
2535	// that we are binding symbolic struct value. Kill the field values, and if
2536	// the value is symbolic go and bind it as a "default" binding.
2537	if (!isa<nonloc::CompoundVal>(Val: V)) {
2538	return bindAggregate(B, R, DefaultVal: UnknownVal());
2539	}
2540
2541	QualType ElemType = VT->getElementType();
2542	nonloc::CompoundVal CV = V.castAs<nonloc::CompoundVal>();
2543	nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2544	unsigned index = 0, numElements = VT->getNumElements();
2545	RegionBindingsRef NewB(B);
2546
2547	for ( ; index != numElements ; ++index) {
2548	if (VI == VE)
2549	break;
2550
2551	NonLoc Idx = svalBuilder.makeArrayIndex(idx: index);
2552	const ElementRegion *ER = MRMgr.getElementRegion(elementType: ElemType, Idx, superRegion: R, Ctx);
2553
2554	if (ElemType->isArrayType())
2555	NewB = bindArray(NewB, ER, *VI);
2556	else if (ElemType->isStructureOrClassType())
2557	NewB = bindStruct(NewB, ER, *VI);
2558	else
2559	NewB = bind(B: NewB, L: loc::MemRegionVal(ER), V: *VI);
2560	}
2561	return NewB;
2562	}
2563
2564	std::optional<RegionBindingsRef> RegionStoreManager::tryBindSmallStruct(
2565	RegionBindingsConstRef B, const TypedValueRegion *R, const RecordDecl *RD,
2566	nonloc::LazyCompoundVal LCV) {
2567	FieldVector Fields;
2568
2569	if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Val: RD))
2570	if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
2571	return std::nullopt;
2572
2573	for (const auto *FD : RD->fields()) {
2574	if (FD->isUnnamedBitField())
2575	continue;
2576
2577	// If there are too many fields, or if any of the fields are aggregates,
2578	// just use the LCV as a default binding.
2579	if (Fields.size() == SmallStructLimit)
2580	return std::nullopt;
2581
2582	QualType Ty = FD->getType();
2583
2584	// Zero length arrays are basically no-ops, so we also ignore them here.
2585	if (Ty->isConstantArrayType() &&
2586	Ctx.getConstantArrayElementCount(CA: Ctx.getAsConstantArrayType(T: Ty)) == 0)
2587	continue;
2588
2589	if (!(Ty->isScalarType() || Ty->isReferenceType()))
2590	return std::nullopt;
2591
2592	Fields.push_back(Elt: FD);
2593	}
2594
2595	RegionBindingsRef NewB = B;
2596
2597	for (const FieldDecl *Field : Fields) {
2598	const FieldRegion *SourceFR = MRMgr.getFieldRegion(fd: Field, superRegion: LCV.getRegion());
2599	SVal V = getBindingForField(B: getRegionBindings(store: LCV.getStore()), R: SourceFR);
2600
2601	const FieldRegion *DestFR = MRMgr.getFieldRegion(fd: Field, superRegion: R);
2602	NewB = bind(B: NewB, L: loc::MemRegionVal(DestFR), V);
2603	}
2604
2605	return NewB;
2606	}
2607
2608	RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
2609	const TypedValueRegion *R,
2610	SVal V) {
2611	QualType T = R->getValueType();
2612	assert(T->isStructureOrClassType());
2613
2614	const RecordType* RT = T->castAs<RecordType>();
2615	const RecordDecl *RD = RT->getDecl();
2616
2617	if (!RD->isCompleteDefinition())
2618	return B;
2619
2620	// Handle lazy compound values and symbolic values.
2621	if (std::optional<nonloc::LazyCompoundVal> LCV =
2622	V.getAs<nonloc::LazyCompoundVal>()) {
2623	if (std::optional<RegionBindingsRef> NewB =
2624	tryBindSmallStruct(B, R, RD, LCV: *LCV))
2625	return *NewB;
2626	return bindAggregate(B, R, DefaultVal: V);
2627	}
2628	if (isa<nonloc::SymbolVal>(Val: V))
2629	return bindAggregate(B, R, DefaultVal: V);
2630
2631	// We may get non-CompoundVal accidentally due to imprecise cast logic or
2632	// that we are binding symbolic struct value. Kill the field values, and if
2633	// the value is symbolic go and bind it as a "default" binding.
2634	if (V.isUnknown() || !isa<nonloc::CompoundVal>(Val: V))
2635	return bindAggregate(B, R, DefaultVal: UnknownVal());
2636
2637	// The raw CompoundVal is essentially a symbolic InitListExpr: an (immutable)
2638	// list of other values. It appears pretty much only when there's an actual
2639	// initializer list expression in the program, and the analyzer tries to
2640	// unwrap it as soon as possible.
2641	// This code is where such unwrap happens: when the compound value is put into
2642	// the object that it was supposed to initialize (it's an *initializer* list,
2643	// after all), instead of binding the whole value to the whole object, we bind
2644	// sub-values to sub-objects. Sub-values may themselves be compound values,
2645	// and in this case the procedure becomes recursive.
2646	// FIXME: The annoying part about compound values is that they don't carry
2647	// any sort of information about which value corresponds to which sub-object.
2648	// It's simply a list of values in the middle of nowhere; we expect to match
2649	// them to sub-objects, essentially, "by index": first value binds to
2650	// the first field, second value binds to the second field, etc.
2651	// It would have been much safer to organize non-lazy compound values as
2652	// a mapping from fields/bases to values.
2653	const nonloc::CompoundVal& CV = V.castAs<nonloc::CompoundVal>();
2654	nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2655
2656	RegionBindingsRef NewB(B);
2657
2658	// In C++17 aggregates may have base classes, handle those as well.
2659	// They appear before fields in the initializer list / compound value.
2660	if (const auto *CRD = dyn_cast<CXXRecordDecl>(Val: RD)) {
2661	// If the object was constructed with a constructor, its value is a
2662	// LazyCompoundVal. If it's a raw CompoundVal, it means that we're
2663	// performing aggregate initialization. The only exception from this
2664	// rule is sending an Objective-C++ message that returns a C++ object
2665	// to a nil receiver; in this case the semantics is to return a
2666	// zero-initialized object even if it's a C++ object that doesn't have
2667	// this sort of constructor; the CompoundVal is empty in this case.
2668	assert((CRD->isAggregate() || (Ctx.getLangOpts().ObjC && VI == VE)) &&
2669	"Non-aggregates are constructed with a constructor!");
2670
2671	for (const auto &B : CRD->bases()) {
2672	// (Multiple inheritance is fine though.)
2673	assert(!B.isVirtual() && "Aggregates cannot have virtual base classes!");
2674
2675	if (VI == VE)
2676	break;
2677
2678	QualType BTy = B.getType();
2679	assert(BTy->isStructureOrClassType() && "Base classes must be classes!");
2680
2681	const CXXRecordDecl *BRD = BTy->getAsCXXRecordDecl();
2682	assert(BRD && "Base classes must be C++ classes!");
2683
2684	const CXXBaseObjectRegion *BR =
2685	MRMgr.getCXXBaseObjectRegion(BaseClass: BRD, Super: R, /*IsVirtual=*/false);
2686
2687	NewB = bindStruct(B: NewB, R: BR, V: *VI);
2688
2689	++VI;
2690	}
2691	}
2692
2693	RecordDecl::field_iterator FI, FE;
2694
2695	for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {
2696
2697	if (VI == VE)
2698	break;
2699
2700	// Skip any unnamed bitfields to stay in sync with the initializers.
2701	if (FI->isUnnamedBitField())
2702	continue;
2703
2704	QualType FTy = FI->getType();
2705	const FieldRegion* FR = MRMgr.getFieldRegion(fd: *FI, superRegion: R);
2706
2707	if (FTy->isArrayType())
2708	NewB = bindArray(B: NewB, R: FR, Init: *VI);
2709	else if (FTy->isStructureOrClassType())
2710	NewB = bindStruct(B: NewB, R: FR, V: *VI);
2711	else
2712	NewB = bind(B: NewB, L: loc::MemRegionVal(FR), V: *VI);
2713	++VI;
2714	}
2715
2716	// There may be fewer values in the initialize list than the fields of struct.
2717	if (FI != FE) {
2718	NewB = NewB.addBinding(R, k: BindingKey::Default,
2719	V: svalBuilder.makeIntVal(integer: 0, isUnsigned: false));
2720	}
2721
2722	return NewB;
2723	}
2724
2725	RegionBindingsRef
2726	RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
2727	const TypedRegion *R,
2728	SVal Val) {
2729	// Remove the old bindings, using 'R' as the root of all regions
2730	// we will invalidate. Then add the new binding.
2731	return removeSubRegionBindings(B, Top: R).addBinding(R, k: BindingKey::Default, V: Val);
2732	}
2733
2734	//===----------------------------------------------------------------------===//
2735	// State pruning.
2736	//===----------------------------------------------------------------------===//
2737
2738	namespace {
2739	class RemoveDeadBindingsWorker
2740	: public ClusterAnalysis<RemoveDeadBindingsWorker> {
2741	SmallVector<const SymbolicRegion *, 12> Postponed;
2742	SymbolReaper &SymReaper;
2743	const StackFrameContext *CurrentLCtx;
2744
2745	public:
2746	RemoveDeadBindingsWorker(RegionStoreManager &rm,
2747	ProgramStateManager &stateMgr,
2748	RegionBindingsRef b, SymbolReaper &symReaper,
2749	const StackFrameContext *LCtx)
2750	: ClusterAnalysis<RemoveDeadBindingsWorker>(rm, stateMgr, b),
2751	SymReaper(symReaper), CurrentLCtx(LCtx) {}
2752
2753	// Called by ClusterAnalysis.
2754	void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
2755	void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
2756	using ClusterAnalysis<RemoveDeadBindingsWorker>::VisitCluster;
2757
2758	using ClusterAnalysis::AddToWorkList;
2759
2760	bool AddToWorkList(const MemRegion *R);
2761
2762	bool UpdatePostponed();
2763	void VisitBinding(SVal V);
2764	};
2765	}
2766
2767	bool RemoveDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
2768	const MemRegion *BaseR = R->getBaseRegion();
2769	return AddToWorkList(E: WorkListElement(BaseR), C: getCluster(R: BaseR));
2770	}
2771
2772	void RemoveDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
2773	const ClusterBindings &C) {
2774
2775	if (const VarRegion *VR = dyn_cast<VarRegion>(Val: baseR)) {
2776	if (SymReaper.isLive(VR))
2777	AddToWorkList(E: baseR, C: &C);
2778
2779	return;
2780	}
2781
2782	if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Val: baseR)) {
2783	if (SymReaper.isLive(sym: SR->getSymbol()))
2784	AddToWorkList(E: SR, C: &C);
2785	else
2786	Postponed.push_back(Elt: SR);
2787
2788	return;
2789	}
2790
2791	if (isa<NonStaticGlobalSpaceRegion>(Val: baseR)) {
2792	AddToWorkList(E: baseR, C: &C);
2793	return;
2794	}
2795
2796	// CXXThisRegion in the current or parent location context is live.
2797	if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(Val: baseR)) {
2798	const auto *StackReg =
2799	cast<StackArgumentsSpaceRegion>(Val: TR->getSuperRegion());
2800	const StackFrameContext *RegCtx = StackReg->getStackFrame();
2801	if (CurrentLCtx &&
2802	(RegCtx == CurrentLCtx || RegCtx->isParentOf(LC: CurrentLCtx)))
2803	AddToWorkList(E: TR, C: &C);
2804	}
2805	}
2806
2807	void RemoveDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
2808	const ClusterBindings *C) {
2809	if (!C)
2810	return;
2811
2812	// Mark the symbol for any SymbolicRegion with live bindings as live itself.
2813	// This means we should continue to track that symbol.
2814	if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(Val: baseR))
2815	SymReaper.markLive(sym: SymR->getSymbol());
2816
2817	for (const auto &[Key, Val] : *C) {
2818	// Element index of a binding key is live.
2819	SymReaper.markElementIndicesLive(region: Key.getRegion());
2820
2821	VisitBinding(V: Val);
2822	}
2823	}
2824
2825	void RemoveDeadBindingsWorker::VisitBinding(SVal V) {
2826	// Is it a LazyCompoundVal? All referenced regions are live as well.
2827	// The LazyCompoundVal itself is not live but should be readable.
2828	if (auto LCS = V.getAs<nonloc::LazyCompoundVal>()) {
2829	SymReaper.markLazilyCopied(region: LCS->getRegion());
2830
2831	for (SVal V : RM.getInterestingValues(LCV: *LCS)) {
2832	if (auto DepLCS = V.getAs<nonloc::LazyCompoundVal>())
2833	SymReaper.markLazilyCopied(region: DepLCS->getRegion());
2834	else
2835	VisitBinding(V);
2836	}
2837
2838	return;
2839	}
2840
2841	// If V is a region, then add it to the worklist.
2842	if (const MemRegion *R = V.getAsRegion()) {
2843	AddToWorkList(R);
2844	SymReaper.markLive(region: R);
2845
2846	// All regions captured by a block are also live.
2847	if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(Val: R)) {
2848	for (auto Var : BR->referenced_vars())
2849	AddToWorkList(R: Var.getCapturedRegion());
2850	}
2851	}
2852
2853
2854	// Update the set of live symbols.
2855	for (SymbolRef Sym : V.symbols())
2856	SymReaper.markLive(sym: Sym);
2857	}
2858
2859	bool RemoveDeadBindingsWorker::UpdatePostponed() {
2860	// See if any postponed SymbolicRegions are actually live now, after
2861	// having done a scan.
2862	bool Changed = false;
2863
2864	for (const SymbolicRegion *SR : Postponed) {
2865	if (SymReaper.isLive(sym: SR->getSymbol())) {
2866	Changed |= AddToWorkList(R: SR);
2867	SR = nullptr;
2868	}
2869	}
2870
2871	return Changed;
2872	}
2873
2874	StoreRef RegionStoreManager::removeDeadBindings(Store store,
2875	const StackFrameContext *LCtx,
2876	SymbolReaper& SymReaper) {
2877	RegionBindingsRef B = getRegionBindings(store);
2878	RemoveDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
2879	W.GenerateClusters();
2880
2881	// Enqueue the region roots onto the worklist.
2882	for (const MemRegion *Reg : SymReaper.regions()) {
2883	W.AddToWorkList(R: Reg);
2884	}
2885
2886	do W.RunWorkList(); while (W.UpdatePostponed());
2887
2888	// We have now scanned the store, marking reachable regions and symbols
2889	// as live. We now remove all the regions that are dead from the store
2890	// as well as update DSymbols with the set symbols that are now dead.
2891	for (const MemRegion *Base : llvm::make_first_range(c&: B)) {
2892	// If the cluster has been visited, we know the region has been marked.
2893	// Otherwise, remove the dead entry.
2894	if (!W.isVisited(R: Base))
2895	B = B.remove(K: Base);
2896	}
2897
2898	return StoreRef(B.asStore(), *this);
2899	}
2900
2901	//===----------------------------------------------------------------------===//
2902	// Utility methods.
2903	//===----------------------------------------------------------------------===//
2904
2905	void RegionStoreManager::printJson(raw_ostream &Out, Store S, const char *NL,
2906	unsigned int Space, bool IsDot) const {
2907	RegionBindingsRef Bindings = getRegionBindings(store: S);
2908
2909	Indent(Out, Space, IsDot) << "\"store\": ";
2910
2911	if (Bindings.isEmpty()) {
2912	Out << "null," << NL;
2913	return;
2914	}
2915
2916	Out << "{ \"pointer\": \"" << Bindings.asStore() << "\", \"items\": [" << NL;
2917	Bindings.printJson(Out, NL, Space: Space + 1, IsDot);
2918	Indent(Out, Space, IsDot) << "]}," << NL;
2919	}
2920