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/Optional.h"
32#include "llvm/Support/raw_ostream.h"
33#include <utility>
34
35using namespace clang;
36using namespace ento;
37
38//===----------------------------------------------------------------------===//
39// Representation of binding keys.
40//===----------------------------------------------------------------------===//
41
42namespace {
43class BindingKey {
44public:
45 enum Kind { Default = 0x0, Direct = 0x1 };
46private:
47 enum { Symbolic = 0x2 };
48
49 llvm::PointerIntPair<const MemRegion *, 2> P;
50 uint64_t Data;
51
52 /// Create a key for a binding to region \p r, which has a symbolic offset
53 /// from region \p Base.
54 explicit BindingKey(const SubRegion *r, const SubRegion *Base, Kind k)
55 : P(r, k | Symbolic), Data(reinterpret_cast<uintptr_t>(Base)) {
56 assert(r && Base && "Must have known regions.");
57 assert(getConcreteOffsetRegion() == Base && "Failed to store base region");
58 }
59
60 /// Create a key for a binding at \p offset from base region \p r.
61 explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
62 : P(r, k), Data(offset) {
63 assert(r && "Must have known regions.");
64 assert(getOffset() == offset && "Failed to store offset");
65 assert((r == r->getBaseRegion() ||
66 isa<ObjCIvarRegion, CXXDerivedObjectRegion>(r)) &&
67 "Not a base");
68 }
69public:
70
71 bool isDirect() const { return P.getInt() & Direct; }
72 bool hasSymbolicOffset() const { return P.getInt() & Symbolic; }
73
74 const MemRegion *getRegion() const { return P.getPointer(); }
75 uint64_t getOffset() const {
76 assert(!hasSymbolicOffset());
77 return Data;
78 }
79
80 const SubRegion *getConcreteOffsetRegion() const {
81 assert(hasSymbolicOffset());
82 return reinterpret_cast<const SubRegion *>(static_cast<uintptr_t>(Data));
83 }
84
85 const MemRegion *getBaseRegion() const {
86 if (hasSymbolicOffset())
87 return getConcreteOffsetRegion()->getBaseRegion();
88 return getRegion()->getBaseRegion();
89 }
90
91 void Profile(llvm::FoldingSetNodeID& ID) const {
92 ID.AddPointer(P.getOpaqueValue());
93 ID.AddInteger(Data);
94 }
95
96 static BindingKey Make(const MemRegion *R, Kind k);
97
98 bool operator<(const BindingKey &X) const {
99 if (P.getOpaqueValue() < X.P.getOpaqueValue())
100 return true;
101 if (P.getOpaqueValue() > X.P.getOpaqueValue())
102 return false;
103 return Data < X.Data;
104 }
105
106 bool operator==(const BindingKey &X) const {
107 return P.getOpaqueValue() == X.P.getOpaqueValue() &&
108 Data == X.Data;
109 }
110
111 LLVM_DUMP_METHOD void dump() const;
112};
113} // end anonymous namespace
114
115BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
116 const RegionOffset &RO = R->getAsOffset();
117 if (RO.hasSymbolicOffset())
118 return BindingKey(cast<SubRegion>(R), cast<SubRegion>(RO.getRegion()), k);
119
120 return BindingKey(RO.getRegion(), RO.getOffset(), k);
121}
122
123namespace llvm {
124static inline raw_ostream &operator<<(raw_ostream &Out, BindingKey K) {
125 Out << "\"kind\": \"" << (K.isDirect() ? "Direct" : "Default")
126 << "\", \"offset\": ";
127
128 if (!K.hasSymbolicOffset())
129 Out << K.getOffset();
130 else
131 Out << "null";
132
133 return Out;
134}
135
136} // namespace llvm
137
138#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
139void BindingKey::dump() const { llvm::errs() << *this; }
140#endif
141
142//===----------------------------------------------------------------------===//
143// Actual Store type.
144//===----------------------------------------------------------------------===//
145
146typedef llvm::ImmutableMap<BindingKey, SVal> ClusterBindings;
147typedef llvm::ImmutableMapRef<BindingKey, SVal> ClusterBindingsRef;
148typedef std::pair<BindingKey, SVal> BindingPair;
149
150typedef llvm::ImmutableMap<const MemRegion *, ClusterBindings>
151 RegionBindings;
152
153namespace {
154class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
155 ClusterBindings> {
156 ClusterBindings::Factory *CBFactory;
157
158 // This flag indicates whether the current bindings are within the analysis
159 // that has started from main(). It affects how we perform loads from
160 // global variables that have initializers: if we have observed the
161 // program execution from the start and we know that these variables
162 // have not been overwritten yet, we can be sure that their initializers
163 // are still relevant. This flag never gets changed when the bindings are
164 // updated, so it could potentially be moved into RegionStoreManager
165 // (as if it's the same bindings but a different loading procedure)
166 // however that would have made the manager needlessly stateful.
167 bool IsMainAnalysis;
168
169public:
170 typedef llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>
171 ParentTy;
172
173 RegionBindingsRef(ClusterBindings::Factory &CBFactory,
174 const RegionBindings::TreeTy *T,
175 RegionBindings::TreeTy::Factory *F,
176 bool IsMainAnalysis)
177 : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(T, F),
178 CBFactory(&CBFactory), IsMainAnalysis(IsMainAnalysis) {}
179
180 RegionBindingsRef(const ParentTy &P,
181 ClusterBindings::Factory &CBFactory,
182 bool IsMainAnalysis)
183 : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(P),
184 CBFactory(&CBFactory), IsMainAnalysis(IsMainAnalysis) {}
185
186 RegionBindingsRef add(key_type_ref K, data_type_ref D) const {
187 return RegionBindingsRef(static_cast<const ParentTy *>(this)->add(K, D),
188 *CBFactory, IsMainAnalysis);
189 }
190
191 RegionBindingsRef remove(key_type_ref K) const {
192 return RegionBindingsRef(static_cast<const ParentTy *>(this)->remove(K),
193 *CBFactory, IsMainAnalysis);
194 }
195
196 RegionBindingsRef addBinding(BindingKey K, SVal V) const;
197
198 RegionBindingsRef addBinding(const MemRegion *R,
199 BindingKey::Kind k, SVal V) const;
200
201 const SVal *lookup(BindingKey K) const;
202 const SVal *lookup(const MemRegion *R, BindingKey::Kind k) const;
203 using llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>::lookup;
204
205 RegionBindingsRef removeBinding(BindingKey K);
206
207 RegionBindingsRef removeBinding(const MemRegion *R,
208 BindingKey::Kind k);
209
210 RegionBindingsRef removeBinding(const MemRegion *R) {
211 return removeBinding(R, BindingKey::Direct).
212 removeBinding(R, BindingKey::Default);
213 }
214
215 Optional<SVal> getDirectBinding(const MemRegion *R) const;
216
217 /// getDefaultBinding - Returns an SVal* representing an optional default
218 /// binding associated with a region and its subregions.
219 Optional<SVal> getDefaultBinding(const MemRegion *R) const;
220
221 /// Return the internal tree as a Store.
222 Store asStore() const {
223 llvm::PointerIntPair<Store, 1, bool> Ptr = {
224 asImmutableMap().getRootWithoutRetain(), IsMainAnalysis};
225 return reinterpret_cast<Store>(Ptr.getOpaqueValue());
226 }
227
228 bool isMainAnalysis() const {
229 return IsMainAnalysis;
230 }
231
232 void printJson(raw_ostream &Out, const char *NL = "\n",
233 unsigned int Space = 0, bool IsDot = false) const {
234 for (iterator I = begin(); I != end(); ++I) {
235 // TODO: We might need a .printJson for I.getKey() as well.
236 Indent(Out, Space, IsDot)
237 << "{ \"cluster\": \"" << I.getKey() << "\", \"pointer\": \""
238 << (const void *)I.getKey() << "\", \"items\": [" << NL;
239
240 ++Space;
241 const ClusterBindings &CB = I.getData();
242 for (ClusterBindings::iterator CI = CB.begin(); CI != CB.end(); ++CI) {
243 Indent(Out, Space, IsDot) << "{ " << CI.getKey() << ", \"value\": ";
244 CI.getData().printJson(Out, /*AddQuotes=*/true);
245 Out << " }";
246 if (std::next(CI) != CB.end())
247 Out << ',';
248 Out << NL;
249 }
250
251 --Space;
252 Indent(Out, Space, IsDot) << "]}";
253 if (std::next(I) != end())
254 Out << ',';
255 Out << NL;
256 }
257 }
258
259 LLVM_DUMP_METHOD void dump() const { printJson(llvm::errs()); }
260};
261} // end anonymous namespace
262
263typedef const RegionBindingsRef& RegionBindingsConstRef;
264
265Optional<SVal> RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
266 return Optional<SVal>::create(lookup(R, BindingKey::Direct));
267}
268
269Optional<SVal> RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
270 return Optional<SVal>::create(lookup(R, BindingKey::Default));
271}
272
273RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
274 const MemRegion *Base = K.getBaseRegion();
275
276 const ClusterBindings *ExistingCluster = lookup(Base);
277 ClusterBindings Cluster =
278 (ExistingCluster ? *ExistingCluster : CBFactory->getEmptyMap());
279
280 ClusterBindings NewCluster = CBFactory->add(Cluster, K, V);
281 return add(Base, NewCluster);
282}
283
284
285RegionBindingsRef RegionBindingsRef::addBinding(const MemRegion *R,
286 BindingKey::Kind k,
287 SVal V) const {
288 return addBinding(BindingKey::Make(R, k), V);
289}
290
291const SVal *RegionBindingsRef::lookup(BindingKey K) const {
292 const ClusterBindings *Cluster = lookup(K.getBaseRegion());
293 if (!Cluster)
294 return nullptr;
295 return Cluster->lookup(K);
296}
297
298const SVal *RegionBindingsRef::lookup(const MemRegion *R,
299 BindingKey::Kind k) const {
300 return lookup(BindingKey::Make(R, k));
301}
302
303RegionBindingsRef RegionBindingsRef::removeBinding(BindingKey K) {
304 const MemRegion *Base = K.getBaseRegion();
305 const ClusterBindings *Cluster = lookup(Base);
306 if (!Cluster)
307 return *this;
308
309 ClusterBindings NewCluster = CBFactory->remove(*Cluster, K);
310 if (NewCluster.isEmpty())
311 return remove(Base);
312 return add(Base, NewCluster);
313}
314
315RegionBindingsRef RegionBindingsRef::removeBinding(const MemRegion *R,
316 BindingKey::Kind k){
317 return removeBinding(BindingKey::Make(R, k));
318}
319
320//===----------------------------------------------------------------------===//
321// Main RegionStore logic.
322//===----------------------------------------------------------------------===//
323
324namespace {
325class InvalidateRegionsWorker;
326
327class RegionStoreManager : public StoreManager {
328public:
329 RegionBindings::Factory RBFactory;
330 mutable ClusterBindings::Factory CBFactory;
331
332 typedef std::vector<SVal> SValListTy;
333private:
334 typedef llvm::DenseMap<const LazyCompoundValData *,
335 SValListTy> LazyBindingsMapTy;
336 LazyBindingsMapTy LazyBindingsMap;
337
338 /// The largest number of fields a struct can have and still be
339 /// considered "small".
340 ///
341 /// This is currently used to decide whether or not it is worth "forcing" a
342 /// LazyCompoundVal on bind.
343 ///
344 /// This is controlled by 'region-store-small-struct-limit' option.
345 /// To disable all small-struct-dependent behavior, set the option to "0".
346 unsigned SmallStructLimit;
347
348 /// The largest number of element an array can have and still be
349 /// considered "small".
350 ///
351 /// This is currently used to decide whether or not it is worth "forcing" a
352 /// LazyCompoundVal on bind.
353 ///
354 /// This is controlled by 'region-store-small-struct-limit' option.
355 /// To disable all small-struct-dependent behavior, set the option to "0".
356 unsigned SmallArrayLimit;
357
358 /// A helper used to populate the work list with the given set of
359 /// regions.
360 void populateWorkList(InvalidateRegionsWorker &W,
361 ArrayRef<SVal> Values,
362 InvalidatedRegions *TopLevelRegions);
363
364public:
365 RegionStoreManager(ProgramStateManager &mgr)
366 : StoreManager(mgr), RBFactory(mgr.getAllocator()),
367 CBFactory(mgr.getAllocator()), SmallStructLimit(0), SmallArrayLimit(0) {
368 ExprEngine &Eng = StateMgr.getOwningEngine();
369 AnalyzerOptions &Options = Eng.getAnalysisManager().options;
370 SmallStructLimit = Options.RegionStoreSmallStructLimit;
371 SmallArrayLimit = Options.RegionStoreSmallArrayLimit;
372 }
373
374 /// setImplicitDefaultValue - Set the default binding for the provided
375 /// MemRegion to the value implicitly defined for compound literals when
376 /// the value is not specified.
377 RegionBindingsRef setImplicitDefaultValue(RegionBindingsConstRef B,
378 const MemRegion *R, QualType T);
379
380 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
381 /// type. 'Array' represents the lvalue of the array being decayed
382 /// to a pointer, and the returned SVal represents the decayed
383 /// version of that lvalue (i.e., a pointer to the first element of
384 /// the array). This is called by ExprEngine when evaluating
385 /// casts from arrays to pointers.
386 SVal ArrayToPointer(Loc Array, QualType ElementTy) override;
387
388 /// Creates the Store that correctly represents memory contents before
389 /// the beginning of the analysis of the given top-level stack frame.
390 StoreRef getInitialStore(const LocationContext *InitLoc) override {
391 bool IsMainAnalysis = false;
392 if (const auto *FD = dyn_cast<FunctionDecl>(InitLoc->getDecl()))
393 IsMainAnalysis = FD->isMain() && !Ctx.getLangOpts().CPlusPlus;
394 return StoreRef(RegionBindingsRef(
395 RegionBindingsRef::ParentTy(RBFactory.getEmptyMap(), RBFactory),
396 CBFactory, IsMainAnalysis).asStore(), *this);
397 }
398
399 //===-------------------------------------------------------------------===//
400 // Binding values to regions.
401 //===-------------------------------------------------------------------===//
402 RegionBindingsRef invalidateGlobalRegion(MemRegion::Kind K,
403 const Expr *Ex,
404 unsigned Count,
405 const LocationContext *LCtx,
406 RegionBindingsRef B,
407 InvalidatedRegions *Invalidated);
408
409 StoreRef invalidateRegions(Store store,
410 ArrayRef<SVal> Values,
411 const Expr *E, unsigned Count,
412 const LocationContext *LCtx,
413 const CallEvent *Call,
414 InvalidatedSymbols &IS,
415 RegionAndSymbolInvalidationTraits &ITraits,
416 InvalidatedRegions *Invalidated,
417 InvalidatedRegions *InvalidatedTopLevel) override;
418
419 bool scanReachableSymbols(Store S, const MemRegion *R,
420 ScanReachableSymbols &Callbacks) override;
421
422 RegionBindingsRef removeSubRegionBindings(RegionBindingsConstRef B,
423 const SubRegion *R);
424 Optional<SVal>
425 getConstantValFromConstArrayInitializer(RegionBindingsConstRef B,
426 const ElementRegion *R);
427 Optional<SVal>
428 getSValFromInitListExpr(const InitListExpr *ILE,
429 const SmallVector<uint64_t, 2> &ConcreteOffsets,
430 QualType ElemT);
431 SVal getSValFromStringLiteral(const StringLiteral *SL, uint64_t Offset,
432 QualType ElemT);
433
434public: // Part of public interface to class.
435
436 StoreRef Bind(Store store, Loc LV, SVal V) override {
437 return StoreRef(bind(getRegionBindings(store), LV, V).asStore(), *this);
438 }
439
440 RegionBindingsRef bind(RegionBindingsConstRef B, Loc LV, SVal V);
441
442 // BindDefaultInitial is only used to initialize a region with
443 // a default value.
444 StoreRef BindDefaultInitial(Store store, const MemRegion *R,
445 SVal V) override {
446 RegionBindingsRef B = getRegionBindings(store);
447 // Use other APIs when you have to wipe the region that was initialized
448 // earlier.
449 assert(!(B.getDefaultBinding(R) || B.getDirectBinding(R)) &&
450 "Double initialization!");
451 B = B.addBinding(BindingKey::Make(R, BindingKey::Default), V);
452 return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
453 }
454
455 // BindDefaultZero is used for zeroing constructors that may accidentally
456 // overwrite existing bindings.
457 StoreRef BindDefaultZero(Store store, const MemRegion *R) override {
458 // FIXME: The offsets of empty bases can be tricky because of
459 // of the so called "empty base class optimization".
460 // If a base class has been optimized out
461 // we should not try to create a binding, otherwise we should.
462 // Unfortunately, at the moment ASTRecordLayout doesn't expose
463 // the actual sizes of the empty bases
464 // and trying to infer them from offsets/alignments
465 // seems to be error-prone and non-trivial because of the trailing padding.
466 // As a temporary mitigation we don't create bindings for empty bases.
467 if (const auto *BR = dyn_cast<CXXBaseObjectRegion>(R))
468 if (BR->getDecl()->isEmpty())
469 return StoreRef(store, *this);
470
471 RegionBindingsRef B = getRegionBindings(store);
472 SVal V = svalBuilder.makeZeroVal(Ctx.CharTy);
473 B = removeSubRegionBindings(B, cast<SubRegion>(R));
474 B = B.addBinding(BindingKey::Make(R, BindingKey::Default), V);
475 return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
476 }
477
478 /// Attempt to extract the fields of \p LCV and bind them to the struct region
479 /// \p R.
480 ///
481 /// This path is used when it seems advantageous to "force" loading the values
482 /// within a LazyCompoundVal to bind memberwise to the struct region, rather
483 /// than using a Default binding at the base of the entire region. This is a
484 /// heuristic attempting to avoid building long chains of LazyCompoundVals.
485 ///
486 /// \returns The updated store bindings, or \c None if binding non-lazily
487 /// would be too expensive.
488 Optional<RegionBindingsRef> tryBindSmallStruct(RegionBindingsConstRef B,
489 const TypedValueRegion *R,
490 const RecordDecl *RD,
491 nonloc::LazyCompoundVal LCV);
492
493 /// BindStruct - Bind a compound value to a structure.
494 RegionBindingsRef bindStruct(RegionBindingsConstRef B,
495 const TypedValueRegion* R, SVal V);
496
497 /// BindVector - Bind a compound value to a vector.
498 RegionBindingsRef bindVector(RegionBindingsConstRef B,
499 const TypedValueRegion* R, SVal V);
500
501 Optional<RegionBindingsRef> tryBindSmallArray(RegionBindingsConstRef B,
502 const TypedValueRegion *R,
503 const ArrayType *AT,
504 nonloc::LazyCompoundVal LCV);
505
506 RegionBindingsRef bindArray(RegionBindingsConstRef B,
507 const TypedValueRegion* R,
508 SVal V);
509
510 /// Clears out all bindings in the given region and assigns a new value
511 /// as a Default binding.
512 RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
513 const TypedRegion *R,
514 SVal DefaultVal);
515
516 /// Create a new store with the specified binding removed.
517 /// \param ST the original store, that is the basis for the new store.
518 /// \param L the location whose binding should be removed.
519 StoreRef killBinding(Store ST, Loc L) override;
520
521 void incrementReferenceCount(Store store) override {
522 getRegionBindings(store).manualRetain();
523 }
524
525 /// If the StoreManager supports it, decrement the reference count of
526 /// the specified Store object. If the reference count hits 0, the memory
527 /// associated with the object is recycled.
528 void decrementReferenceCount(Store store) override {
529 getRegionBindings(store).manualRelease();
530 }
531
532 bool includedInBindings(Store store, const MemRegion *region) const override;
533
534 /// Return the value bound to specified location in a given state.
535 ///
536 /// The high level logic for this method is this:
537 /// getBinding (L)
538 /// if L has binding
539 /// return L's binding
540 /// else if L is in killset
541 /// return unknown
542 /// else
543 /// if L is on stack or heap
544 /// return undefined
545 /// else
546 /// return symbolic
547 SVal getBinding(Store S, Loc L, QualType T) override {
548 return getBinding(getRegionBindings(S), L, T);
549 }
550
551 Optional<SVal> getDefaultBinding(Store S, const MemRegion *R) override {
552 RegionBindingsRef B = getRegionBindings(S);
553 // Default bindings are always applied over a base region so look up the
554 // base region's default binding, otherwise the lookup will fail when R
555 // is at an offset from R->getBaseRegion().
556 return B.getDefaultBinding(R->getBaseRegion());
557 }
558
559 SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());
560
561 SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);
562
563 SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);
564
565 SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);
566
567 SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);
568
569 SVal getBindingForLazySymbol(const TypedValueRegion *R);
570
571 SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
572 const TypedValueRegion *R,
573 QualType Ty);
574
575 SVal getLazyBinding(const SubRegion *LazyBindingRegion,
576 RegionBindingsRef LazyBinding);
577
578 /// Get bindings for the values in a struct and return a CompoundVal, used
579 /// when doing struct copy:
580 /// struct s x, y;
581 /// x = y;
582 /// y's value is retrieved by this method.
583 SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
584 SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
585 NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);
586
587 /// Used to lazily generate derived symbols for bindings that are defined
588 /// implicitly by default bindings in a super region.
589 ///
590 /// Note that callers may need to specially handle LazyCompoundVals, which
591 /// are returned as is in case the caller needs to treat them differently.
592 Optional<SVal> getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
593 const MemRegion *superR,
594 const TypedValueRegion *R,
595 QualType Ty);
596
597 /// Get the state and region whose binding this region \p R corresponds to.
598 ///
599 /// If there is no lazy binding for \p R, the returned value will have a null
600 /// \c second. Note that a null pointer can represents a valid Store.
601 std::pair<Store, const SubRegion *>
602 findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
603 const SubRegion *originalRegion);
604
605 /// Returns the cached set of interesting SVals contained within a lazy
606 /// binding.
607 ///
608 /// The precise value of "interesting" is determined for the purposes of
609 /// RegionStore's internal analysis. It must always contain all regions and
610 /// symbols, but may omit constants and other kinds of SVal.
611 const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);
612
613 //===------------------------------------------------------------------===//
614 // State pruning.
615 //===------------------------------------------------------------------===//
616
617 /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
618 /// It returns a new Store with these values removed.
619 StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
620 SymbolReaper& SymReaper) override;
621
622 //===------------------------------------------------------------------===//
623 // Utility methods.
624 //===------------------------------------------------------------------===//
625
626 RegionBindingsRef getRegionBindings(Store store) const {
627 llvm::PointerIntPair<Store, 1, bool> Ptr;
628 Ptr.setFromOpaqueValue(const_cast<void *>(store));
629 return RegionBindingsRef(
630 CBFactory,
631 static_cast<const RegionBindings::TreeTy *>(Ptr.getPointer()),
632 RBFactory.getTreeFactory(),
633 Ptr.getInt());
634 }
635
636 void printJson(raw_ostream &Out, Store S, const char *NL = "\n",
637 unsigned int Space = 0, bool IsDot = false) const override;
638
639 void iterBindings(Store store, BindingsHandler& f) override {
640 RegionBindingsRef B = getRegionBindings(store);
641 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
642 const ClusterBindings &Cluster = I.getData();
643 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
644 CI != CE; ++CI) {
645 const BindingKey &K = CI.getKey();
646 if (!K.isDirect())
647 continue;
648 if (const SubRegion *R = dyn_cast<SubRegion>(K.getRegion())) {
649 // FIXME: Possibly incorporate the offset?
650 if (!f.HandleBinding(*this, store, R, CI.getData()))
651 return;
652 }
653 }
654 }
655 }
656};
657
658} // end anonymous namespace
659
660//===----------------------------------------------------------------------===//
661// RegionStore creation.
662//===----------------------------------------------------------------------===//
663
664std::unique_ptr<StoreManager>
665ento::CreateRegionStoreManager(ProgramStateManager &StMgr) {
666 return std::make_unique<RegionStoreManager>(StMgr);
667}
668
669//===----------------------------------------------------------------------===//
670// Region Cluster analysis.
671//===----------------------------------------------------------------------===//
672
673namespace {
674/// Used to determine which global regions are automatically included in the
675/// initial worklist of a ClusterAnalysis.
676enum GlobalsFilterKind {
677 /// Don't include any global regions.
678 GFK_None,
679 /// Only include system globals.
680 GFK_SystemOnly,
681 /// Include all global regions.
682 GFK_All
683};
684
685template <typename DERIVED>
686class ClusterAnalysis {
687protected:
688 typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
689 typedef const MemRegion * WorkListElement;
690 typedef SmallVector<WorkListElement, 10> WorkList;
691
692 llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
693
694 WorkList WL;
695
696 RegionStoreManager &RM;
697 ASTContext &Ctx;
698 SValBuilder &svalBuilder;
699
700 RegionBindingsRef B;
701
702
703protected:
704 const ClusterBindings *getCluster(const MemRegion *R) {
705 return B.lookup(R);
706 }
707
708 /// Returns true if all clusters in the given memspace should be initially
709 /// included in the cluster analysis. Subclasses may provide their
710 /// own implementation.
711 bool includeEntireMemorySpace(const MemRegion *Base) {
712 return false;
713 }
714
715public:
716 ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
717 RegionBindingsRef b)
718 : RM(rm), Ctx(StateMgr.getContext()),
719 svalBuilder(StateMgr.getSValBuilder()), B(std::move(b)) {}
720
721 RegionBindingsRef getRegionBindings() const { return B; }
722
723 bool isVisited(const MemRegion *R) {
724 return Visited.count(getCluster(R));
725 }
726
727 void GenerateClusters() {
728 // Scan the entire set of bindings and record the region clusters.
729 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
730 RI != RE; ++RI){
731 const MemRegion *Base = RI.getKey();
732
733 const ClusterBindings &Cluster = RI.getData();
734 assert(!Cluster.isEmpty() && "Empty clusters should be removed");
735 static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);
736
737 // If the base's memspace should be entirely invalidated, add the cluster
738 // to the workspace up front.
739 if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
740 AddToWorkList(WorkListElement(Base), &Cluster);
741 }
742 }
743
744 bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
745 if (C && !Visited.insert(C).second)
746 return false;
747 WL.push_back(E);
748 return true;
749 }
750
751 bool AddToWorkList(const MemRegion *R) {
752 return static_cast<DERIVED*>(this)->AddToWorkList(R);
753 }
754
755 void RunWorkList() {
756 while (!WL.empty()) {
757 WorkListElement E = WL.pop_back_val();
758 const MemRegion *BaseR = E;
759
760 static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
761 }
762 }
763
764 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
765 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}
766
767 void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
768 bool Flag) {
769 static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
770 }
771};
772}
773
774//===----------------------------------------------------------------------===//
775// Binding invalidation.
776//===----------------------------------------------------------------------===//
777
778bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
779 ScanReachableSymbols &Callbacks) {
780 assert(R == R->getBaseRegion() && "Should only be called for base regions");
781 RegionBindingsRef B = getRegionBindings(S);
782 const ClusterBindings *Cluster = B.lookup(R);
783
784 if (!Cluster)
785 return true;
786
787 for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
788 RI != RE; ++RI) {
789 if (!Callbacks.scan(RI.getData()))
790 return false;
791 }
792
793 return true;
794}
795
796static inline bool isUnionField(const FieldRegion *FR) {
797 return FR->getDecl()->getParent()->isUnion();
798}
799
800typedef SmallVector<const FieldDecl *, 8> FieldVector;
801
802static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
803 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
804
805 const MemRegion *Base = K.getConcreteOffsetRegion();
806 const MemRegion *R = K.getRegion();
807
808 while (R != Base) {
809 if (const FieldRegion *FR = dyn_cast<FieldRegion>(R))
810 if (!isUnionField(FR))
811 Fields.push_back(FR->getDecl());
812
813 R = cast<SubRegion>(R)->getSuperRegion();
814 }
815}
816
817static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
818 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
819
820 if (Fields.empty())
821 return true;
822
823 FieldVector FieldsInBindingKey;
824 getSymbolicOffsetFields(K, FieldsInBindingKey);
825
826 ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
827 if (Delta >= 0)
828 return std::equal(FieldsInBindingKey.begin() + Delta,
829 FieldsInBindingKey.end(),
830 Fields.begin());
831 else
832 return std::equal(FieldsInBindingKey.begin(), FieldsInBindingKey.end(),
833 Fields.begin() - Delta);
834}
835
836/// Collects all bindings in \p Cluster that may refer to bindings within
837/// \p Top.
838///
839/// Each binding is a pair whose \c first is the key (a BindingKey) and whose
840/// \c second is the value (an SVal).
841///
842/// The \p IncludeAllDefaultBindings parameter specifies whether to include
843/// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
844/// an aggregate within a larger aggregate with a default binding.
845static void
846collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
847 SValBuilder &SVB, const ClusterBindings &Cluster,
848 const SubRegion *Top, BindingKey TopKey,
849 bool IncludeAllDefaultBindings) {
850 FieldVector FieldsInSymbolicSubregions;
851 if (TopKey.hasSymbolicOffset()) {
852 getSymbolicOffsetFields(TopKey, FieldsInSymbolicSubregions);
853 Top = TopKey.getConcreteOffsetRegion();
854 TopKey = BindingKey::Make(Top, BindingKey::Default);
855 }
856
857 // Find the length (in bits) of the region being invalidated.
858 uint64_t Length = UINT64_MAX;
859 SVal Extent = Top->getMemRegionManager().getStaticSize(Top, SVB);
860 if (Optional<nonloc::ConcreteInt> ExtentCI =
861 Extent.getAs<nonloc::ConcreteInt>()) {
862 const llvm::APSInt &ExtentInt = ExtentCI->getValue();
863 assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
864 // Extents are in bytes but region offsets are in bits. Be careful!
865 Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
866 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Top)) {
867 if (FR->getDecl()->isBitField())
868 Length = FR->getDecl()->getBitWidthValue(SVB.getContext());
869 }
870
871 for (ClusterBindings::iterator I = Cluster.begin(), E = Cluster.end();
872 I != E; ++I) {
873 BindingKey NextKey = I.getKey();
874 if (NextKey.getRegion() == TopKey.getRegion()) {
875 // FIXME: This doesn't catch the case where we're really invalidating a
876 // region with a symbolic offset. Example:
877 // R: points[i].y
878 // Next: points[0].x
879
880 if (NextKey.getOffset() > TopKey.getOffset() &&
881 NextKey.getOffset() - TopKey.getOffset() < Length) {
882 // Case 1: The next binding is inside the region we're invalidating.
883 // Include it.
884 Bindings.push_back(*I);
885
886 } else if (NextKey.getOffset() == TopKey.getOffset()) {
887 // Case 2: The next binding is at the same offset as the region we're
888 // invalidating. In this case, we need to leave default bindings alone,
889 // since they may be providing a default value for a regions beyond what
890 // we're invalidating.
891 // FIXME: This is probably incorrect; consider invalidating an outer
892 // struct whose first field is bound to a LazyCompoundVal.
893 if (IncludeAllDefaultBindings || NextKey.isDirect())
894 Bindings.push_back(*I);
895 }
896
897 } else if (NextKey.hasSymbolicOffset()) {
898 const MemRegion *Base = NextKey.getConcreteOffsetRegion();
899 if (Top->isSubRegionOf(Base) && Top != Base) {
900 // Case 3: The next key is symbolic and we just changed something within
901 // its concrete region. We don't know if the binding is still valid, so
902 // we'll be conservative and include it.
903 if (IncludeAllDefaultBindings || NextKey.isDirect())
904 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
905 Bindings.push_back(*I);
906 } else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Base)) {
907 // Case 4: The next key is symbolic, but we changed a known
908 // super-region. In this case the binding is certainly included.
909 if (BaseSR->isSubRegionOf(Top))
910 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
911 Bindings.push_back(*I);
912 }
913 }
914 }
915}
916
917static void
918collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
919 SValBuilder &SVB, const ClusterBindings &Cluster,
920 const SubRegion *Top, bool IncludeAllDefaultBindings) {
921 collectSubRegionBindings(Bindings, SVB, Cluster, Top,
922 BindingKey::Make(Top, BindingKey::Default),
923 IncludeAllDefaultBindings);
924}
925
926RegionBindingsRef
927RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
928 const SubRegion *Top) {
929 BindingKey TopKey = BindingKey::Make(Top, BindingKey::Default);
930 const MemRegion *ClusterHead = TopKey.getBaseRegion();
931
932 if (Top == ClusterHead) {
933 // We can remove an entire cluster's bindings all in one go.
934 return B.remove(Top);
935 }
936
937 const ClusterBindings *Cluster = B.lookup(ClusterHead);
938 if (!Cluster) {
939 // If we're invalidating a region with a symbolic offset, we need to make
940 // sure we don't treat the base region as uninitialized anymore.
941 if (TopKey.hasSymbolicOffset()) {
942 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
943 return B.addBinding(Concrete, BindingKey::Default, UnknownVal());
944 }
945 return B;
946 }
947
948 SmallVector<BindingPair, 32> Bindings;
949 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, Top, TopKey,
950 /*IncludeAllDefaultBindings=*/false);
951
952 ClusterBindingsRef Result(*Cluster, CBFactory);
953 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
954 E = Bindings.end();
955 I != E; ++I)
956 Result = Result.remove(I->first);
957
958 // If we're invalidating a region with a symbolic offset, we need to make sure
959 // we don't treat the base region as uninitialized anymore.
960 // FIXME: This isn't very precise; see the example in
961 // collectSubRegionBindings.
962 if (TopKey.hasSymbolicOffset()) {
963 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
964 Result = Result.add(BindingKey::Make(Concrete, BindingKey::Default),
965 UnknownVal());
966 }
967
968 if (Result.isEmpty())
969 return B.remove(ClusterHead);
970 return B.add(ClusterHead, Result.asImmutableMap());
971}
972
973namespace {
974class InvalidateRegionsWorker : public ClusterAnalysis<InvalidateRegionsWorker>
975{
976 const Expr *Ex;
977 unsigned Count;
978 const LocationContext *LCtx;
979 InvalidatedSymbols &IS;
980 RegionAndSymbolInvalidationTraits &ITraits;
981 StoreManager::InvalidatedRegions *Regions;
982 GlobalsFilterKind GlobalsFilter;
983public:
984 InvalidateRegionsWorker(RegionStoreManager &rm,
985 ProgramStateManager &stateMgr,
986 RegionBindingsRef b,
987 const Expr *ex, unsigned count,
988 const LocationContext *lctx,
989 InvalidatedSymbols &is,
990 RegionAndSymbolInvalidationTraits &ITraitsIn,
991 StoreManager::InvalidatedRegions *r,
992 GlobalsFilterKind GFK)
993 : ClusterAnalysis<InvalidateRegionsWorker>(rm, stateMgr, b),
994 Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
995 GlobalsFilter(GFK) {}
996
997 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
998 void VisitBinding(SVal V);
999
1000 using ClusterAnalysis::AddToWorkList;
1001
1002 bool AddToWorkList(const MemRegion *R);
1003
1004 /// Returns true if all clusters in the memory space for \p Base should be
1005 /// be invalidated.
1006 bool includeEntireMemorySpace(const MemRegion *Base);
1007
1008 /// Returns true if the memory space of the given region is one of the global
1009 /// regions specially included at the start of invalidation.
1010 bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
1011};
1012}
1013
1014bool InvalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
1015 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1016 R, RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
1017 const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
1018 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
1019}
1020
1021void InvalidateRegionsWorker::VisitBinding(SVal V) {
1022 // A symbol? Mark it touched by the invalidation.
1023 if (SymbolRef Sym = V.getAsSymbol())
1024 IS.insert(Sym);
1025
1026 if (const MemRegion *R = V.getAsRegion()) {
1027 AddToWorkList(R);
1028 return;
1029 }
1030
1031 // Is it a LazyCompoundVal? All references get invalidated as well.
1032 if (Optional<nonloc::LazyCompoundVal> LCS =
1033 V.getAs<nonloc::LazyCompoundVal>()) {
1034
1035 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
1036
1037 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
1038 E = Vals.end();
1039 I != E; ++I)
1040 VisitBinding(*I);
1041
1042 return;
1043 }
1044}
1045
1046void InvalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
1047 const ClusterBindings *C) {
1048
1049 bool PreserveRegionsContents =
1050 ITraits.hasTrait(baseR,
1051 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
1052
1053 if (C) {
1054 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
1055 VisitBinding(I.getData());
1056
1057 // Invalidate regions contents.
1058 if (!PreserveRegionsContents)
1059 B = B.remove(baseR);
1060 }
1061
1062 if (const auto *TO = dyn_cast<TypedValueRegion>(baseR)) {
1063 if (const auto *RD = TO->getValueType()->getAsCXXRecordDecl()) {
1064
1065 // Lambdas can affect all static local variables without explicitly
1066 // capturing those.
1067 // We invalidate all static locals referenced inside the lambda body.
1068 if (RD->isLambda() && RD->getLambdaCallOperator()->getBody()) {
1069 using namespace ast_matchers;
1070
1071 const char *DeclBind = "DeclBind";
1072 StatementMatcher RefToStatic = stmt(hasDescendant(declRefExpr(
1073 to(varDecl(hasStaticStorageDuration()).bind(DeclBind)))));
1074 auto Matches =
1075 match(RefToStatic, *RD->getLambdaCallOperator()->getBody(),
1076 RD->getASTContext());
1077
1078 for (BoundNodes &Match : Matches) {
1079 auto *VD = Match.getNodeAs<VarDecl>(DeclBind);
1080 const VarRegion *ToInvalidate =
1081 RM.getRegionManager().getVarRegion(VD, LCtx);
1082 AddToWorkList(ToInvalidate);
1083 }
1084 }
1085 }
1086 }
1087
1088 // BlockDataRegion? If so, invalidate captured variables that are passed
1089 // by reference.
1090 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
1091 for (BlockDataRegion::referenced_vars_iterator
1092 BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
1093 BI != BE; ++BI) {
1094 const VarRegion *VR = BI.getCapturedRegion();
1095 const VarDecl *VD = VR->getDecl();
1096 if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
1097 AddToWorkList(VR);
1098 }
1099 else if (Loc::isLocType(VR->getValueType())) {
1100 // Map the current bindings to a Store to retrieve the value
1101 // of the binding. If that binding itself is a region, we should
1102 // invalidate that region. This is because a block may capture
1103 // a pointer value, but the thing pointed by that pointer may
1104 // get invalidated.
1105 SVal V = RM.getBinding(B, loc::MemRegionVal(VR));
1106 if (Optional<Loc> L = V.getAs<Loc>()) {
1107 if (const MemRegion *LR = L->getAsRegion())
1108 AddToWorkList(LR);
1109 }
1110 }
1111 }
1112 return;
1113 }
1114
1115 // Symbolic region?
1116 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
1117 IS.insert(SR->getSymbol());
1118
1119 // Nothing else should be done in the case when we preserve regions context.
1120 if (PreserveRegionsContents)
1121 return;
1122
1123 // Otherwise, we have a normal data region. Record that we touched the region.
1124 if (Regions)
1125 Regions->push_back(baseR);
1126
1127 if (isa<AllocaRegion, SymbolicRegion>(baseR)) {
1128 // Invalidate the region by setting its default value to
1129 // conjured symbol. The type of the symbol is irrelevant.
1130 DefinedOrUnknownSVal V =
1131 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
1132 B = B.addBinding(baseR, BindingKey::Default, V);
1133 return;
1134 }
1135
1136 if (!baseR->isBoundable())
1137 return;
1138
1139 const TypedValueRegion *TR = cast<TypedValueRegion>(baseR);
1140 QualType T = TR->getValueType();
1141
1142 if (isInitiallyIncludedGlobalRegion(baseR)) {
1143 // If the region is a global and we are invalidating all globals,
1144 // erasing the entry is good enough. This causes all globals to be lazily
1145 // symbolicated from the same base symbol.
1146 return;
1147 }
1148
1149 if (T->isRecordType()) {
1150 // Invalidate the region by setting its default value to
1151 // conjured symbol. The type of the symbol is irrelevant.
1152 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1153 Ctx.IntTy, Count);
1154 B = B.addBinding(baseR, BindingKey::Default, V);
1155 return;
1156 }
1157
1158 if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
1159 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1160 baseR,
1161 RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
1162
1163 if (doNotInvalidateSuperRegion) {
1164 // We are not doing blank invalidation of the whole array region so we
1165 // have to manually invalidate each elements.
1166 Optional<uint64_t> NumElements;
1167
1168 // Compute lower and upper offsets for region within array.
1169 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
1170 NumElements = CAT->getSize().getZExtValue();
1171 if (!NumElements) // We are not dealing with a constant size array
1172 goto conjure_default;
1173 QualType ElementTy = AT->getElementType();
1174 uint64_t ElemSize = Ctx.getTypeSize(ElementTy);
1175 const RegionOffset &RO = baseR->getAsOffset();
1176 const MemRegion *SuperR = baseR->getBaseRegion();
1177 if (RO.hasSymbolicOffset()) {
1178 // If base region has a symbolic offset,
1179 // we revert to invalidating the super region.
1180 if (SuperR)
1181 AddToWorkList(SuperR);
1182 goto conjure_default;
1183 }
1184
1185 uint64_t LowerOffset = RO.getOffset();
1186 uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
1187 bool UpperOverflow = UpperOffset < LowerOffset;
1188
1189 // Invalidate regions which are within array boundaries,
1190 // or have a symbolic offset.
1191 if (!SuperR)
1192 goto conjure_default;
1193
1194 const ClusterBindings *C = B.lookup(SuperR);
1195 if (!C)
1196 goto conjure_default;
1197
1198 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E;
1199 ++I) {
1200 const BindingKey &BK = I.getKey();
1201 Optional<uint64_t> ROffset =
1202 BK.hasSymbolicOffset() ? Optional<uint64_t>() : BK.getOffset();
1203
1204 // Check offset is not symbolic and within array's boundaries.
1205 // Handles arrays of 0 elements and of 0-sized elements as well.
1206 if (!ROffset ||
1207 ((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
1208 (UpperOverflow &&
1209 (*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
1210 (LowerOffset == UpperOffset && *ROffset == LowerOffset))) {
1211 B = B.removeBinding(I.getKey());
1212 // Bound symbolic regions need to be invalidated for dead symbol
1213 // detection.
1214 SVal V = I.getData();
1215 const MemRegion *R = V.getAsRegion();
1216 if (isa_and_nonnull<SymbolicRegion>(R))
1217 VisitBinding(V);
1218 }
1219 }
1220 }
1221 conjure_default:
1222 // Set the default value of the array to conjured symbol.
1223 DefinedOrUnknownSVal V =
1224 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1225 AT->getElementType(), Count);
1226 B = B.addBinding(baseR, BindingKey::Default, V);
1227 return;
1228 }
1229
1230 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1231 T,Count);
1232 assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
1233 B = B.addBinding(baseR, BindingKey::Direct, V);
1234}
1235
1236bool InvalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
1237 const MemRegion *R) {
1238 switch (GlobalsFilter) {
1239 case GFK_None:
1240 return false;
1241 case GFK_SystemOnly:
1242 return isa<GlobalSystemSpaceRegion>(R->getMemorySpace());
1243 case GFK_All:
1244 return isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace());
1245 }
1246
1247 llvm_unreachable("unknown globals filter");
1248}
1249
1250bool InvalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
1251 if (isInitiallyIncludedGlobalRegion(Base))
1252 return true;
1253
1254 const MemSpaceRegion *MemSpace = Base->getMemorySpace();
1255 return ITraits.hasTrait(MemSpace,
1256 RegionAndSymbolInvalidationTraits::TK_EntireMemSpace);
1257}
1258
1259RegionBindingsRef
1260RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
1261 const Expr *Ex,
1262 unsigned Count,
1263 const LocationContext *LCtx,
1264 RegionBindingsRef B,
1265 InvalidatedRegions *Invalidated) {
1266 // Bind the globals memory space to a new symbol that we will use to derive
1267 // the bindings for all globals.
1268 const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
1269 SVal V = svalBuilder.conjureSymbolVal(/* symbolTag = */ (const void*) GS, Ex, LCtx,
1270 /* type does not matter */ Ctx.IntTy,
1271 Count);
1272
1273 B = B.removeBinding(GS)
1274 .addBinding(BindingKey::Make(GS, BindingKey::Default), V);
1275
1276 // Even if there are no bindings in the global scope, we still need to
1277 // record that we touched it.
1278 if (Invalidated)
1279 Invalidated->push_back(GS);
1280
1281 return B;
1282}
1283
1284void RegionStoreManager::populateWorkList(InvalidateRegionsWorker &W,
1285 ArrayRef<SVal> Values,
1286 InvalidatedRegions *TopLevelRegions) {
1287 for (ArrayRef<SVal>::iterator I = Values.begin(),
1288 E = Values.end(); I != E; ++I) {
1289 SVal V = *I;
1290 if (Optional<nonloc::LazyCompoundVal> LCS =
1291 V.getAs<nonloc::LazyCompoundVal>()) {
1292
1293 const SValListTy &Vals = getInterestingValues(*LCS);
1294
1295 for (SValListTy::const_iterator I = Vals.begin(),
1296 E = Vals.end(); I != E; ++I) {
1297 // Note: the last argument is false here because these are
1298 // non-top-level regions.
1299 if (const MemRegion *R = (*I).getAsRegion())
1300 W.AddToWorkList(R);
1301 }
1302 continue;
1303 }
1304
1305 if (const MemRegion *R = V.getAsRegion()) {
1306 if (TopLevelRegions)
1307 TopLevelRegions->push_back(R);
1308 W.AddToWorkList(R);
1309 continue;
1310 }
1311 }
1312}
1313
1314StoreRef
1315RegionStoreManager::invalidateRegions(Store store,
1316 ArrayRef<SVal> Values,
1317 const Expr *Ex, unsigned Count,
1318 const LocationContext *LCtx,
1319 const CallEvent *Call,
1320 InvalidatedSymbols &IS,
1321 RegionAndSymbolInvalidationTraits &ITraits,
1322 InvalidatedRegions *TopLevelRegions,
1323 InvalidatedRegions *Invalidated) {
1324 GlobalsFilterKind GlobalsFilter;
1325 if (Call) {
1326 if (Call->isInSystemHeader())
1327 GlobalsFilter = GFK_SystemOnly;
1328 else
1329 GlobalsFilter = GFK_All;
1330 } else {
1331 GlobalsFilter = GFK_None;
1332 }
1333
1334 RegionBindingsRef B = getRegionBindings(store);
1335 InvalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
1336 Invalidated, GlobalsFilter);
1337
1338 // Scan the bindings and generate the clusters.
1339 W.GenerateClusters();
1340
1341 // Add the regions to the worklist.
1342 populateWorkList(W, Values, TopLevelRegions);
1343
1344 W.RunWorkList();
1345
1346 // Return the new bindings.
1347 B = W.getRegionBindings();
1348
1349 // For calls, determine which global regions should be invalidated and
1350 // invalidate them. (Note that function-static and immutable globals are never
1351 // invalidated by this.)
1352 // TODO: This could possibly be more precise with modules.
1353 switch (GlobalsFilter) {
1354 case GFK_All:
1355 B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
1356 Ex, Count, LCtx, B, Invalidated);
1357 [[fallthrough]];
1358 case GFK_SystemOnly:
1359 B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
1360 Ex, Count, LCtx, B, Invalidated);
1361 [[fallthrough]];
1362 case GFK_None:
1363 break;
1364 }
1365
1366 return StoreRef(B.asStore(), *this);
1367}
1368
1369//===----------------------------------------------------------------------===//
1370// Location and region casting.
1371//===----------------------------------------------------------------------===//
1372
1373/// ArrayToPointer - Emulates the "decay" of an array to a pointer
1374/// type. 'Array' represents the lvalue of the array being decayed
1375/// to a pointer, and the returned SVal represents the decayed
1376/// version of that lvalue (i.e., a pointer to the first element of
1377/// the array). This is called by ExprEngine when evaluating casts
1378/// from arrays to pointers.
1379SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
1380 if (isa<loc::ConcreteInt>(Array))
1381 return Array;
1382
1383 if (!isa<loc::MemRegionVal>(Array))
1384 return UnknownVal();
1385
1386 const SubRegion *R =
1387 cast<SubRegion>(Array.castAs<loc::MemRegionVal>().getRegion());
1388 NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
1389 return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
1390}
1391
1392//===----------------------------------------------------------------------===//
1393// Loading values from regions.
1394//===----------------------------------------------------------------------===//
1395
1396SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
1397 assert(!isa<UnknownVal>(L) && "location unknown");
1398 assert(!isa<UndefinedVal>(L) && "location undefined");
1399
1400 // For access to concrete addresses, return UnknownVal. Checks
1401 // for null dereferences (and similar errors) are done by checkers, not
1402 // the Store.
1403 // FIXME: We can consider lazily symbolicating such memory, but we really
1404 // should defer this when we can reason easily about symbolicating arrays
1405 // of bytes.
1406 if (L.getAs<loc::ConcreteInt>()) {
1407 return UnknownVal();
1408 }
1409 if (!L.getAs<loc::MemRegionVal>()) {
1410 return UnknownVal();
1411 }
1412
1413 const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();
1414
1415 if (isa<BlockDataRegion>(MR)) {
1416 return UnknownVal();
1417 }
1418
1419 if (!isa<TypedValueRegion>(MR)) {
1420 if (T.isNull()) {
1421 if (const TypedRegion *TR = dyn_cast<TypedRegion>(MR))
1422 T = TR->getLocationType()->getPointeeType();
1423 else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
1424 T = SR->getSymbol()->getType()->getPointeeType();
1425 }
1426 assert(!T.isNull() && "Unable to auto-detect binding type!");
1427 assert(!T->isVoidType() && "Attempting to dereference a void pointer!");
1428 MR = GetElementZeroRegion(cast<SubRegion>(MR), T);
1429 } else {
1430 T = cast<TypedValueRegion>(MR)->getValueType();
1431 }
1432
1433 // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
1434 // instead of 'Loc', and have the other Loc cases handled at a higher level.
1435 const TypedValueRegion *R = cast<TypedValueRegion>(MR);
1436 QualType RTy = R->getValueType();
1437
1438 // FIXME: we do not yet model the parts of a complex type, so treat the
1439 // whole thing as "unknown".
1440 if (RTy->isAnyComplexType())
1441 return UnknownVal();
1442
1443 // FIXME: We should eventually handle funny addressing. e.g.:
1444 //
1445 // int x = ...;
1446 // int *p = &x;
1447 // char *q = (char*) p;
1448 // char c = *q; // returns the first byte of 'x'.
1449 //
1450 // Such funny addressing will occur due to layering of regions.
1451 if (RTy->isStructureOrClassType())
1452 return getBindingForStruct(B, R);
1453
1454 // FIXME: Handle unions.
1455 if (RTy->isUnionType())
1456 return createLazyBinding(B, R);
1457
1458 if (RTy->isArrayType()) {
1459 if (RTy->isConstantArrayType())
1460 return getBindingForArray(B, R);
1461 else
1462 return UnknownVal();
1463 }
1464
1465 // FIXME: handle Vector types.
1466 if (RTy->isVectorType())
1467 return UnknownVal();
1468
1469 if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
1470 return svalBuilder.evalCast(getBindingForField(B, FR), T, QualType{});
1471
1472 if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
1473 // FIXME: Here we actually perform an implicit conversion from the loaded
1474 // value to the element type. Eventually we want to compose these values
1475 // more intelligently. For example, an 'element' can encompass multiple
1476 // bound regions (e.g., several bound bytes), or could be a subset of
1477 // a larger value.
1478 return svalBuilder.evalCast(getBindingForElement(B, ER), T, QualType{});
1479 }
1480
1481 if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
1482 // FIXME: Here we actually perform an implicit conversion from the loaded
1483 // value to the ivar type. What we should model is stores to ivars
1484 // that blow past the extent of the ivar. If the address of the ivar is
1485 // reinterpretted, it is possible we stored a different value that could
1486 // fit within the ivar. Either we need to cast these when storing them
1487 // or reinterpret them lazily (as we do here).
1488 return svalBuilder.evalCast(getBindingForObjCIvar(B, IVR), T, QualType{});
1489 }
1490
1491 if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
1492 // FIXME: Here we actually perform an implicit conversion from the loaded
1493 // value to the variable type. What we should model is stores to variables
1494 // that blow past the extent of the variable. If the address of the
1495 // variable is reinterpretted, it is possible we stored a different value
1496 // that could fit within the variable. Either we need to cast these when
1497 // storing them or reinterpret them lazily (as we do here).
1498 return svalBuilder.evalCast(getBindingForVar(B, VR), T, QualType{});
1499 }
1500
1501 const SVal *V = B.lookup(R, BindingKey::Direct);
1502
1503 // Check if the region has a binding.
1504 if (V)
1505 return *V;
1506
1507 // The location does not have a bound value. This means that it has
1508 // the value it had upon its creation and/or entry to the analyzed
1509 // function/method. These are either symbolic values or 'undefined'.
1510 if (R->hasStackNonParametersStorage()) {
1511 // All stack variables are considered to have undefined values
1512 // upon creation. All heap allocated blocks are considered to
1513 // have undefined values as well unless they are explicitly bound
1514 // to specific values.
1515 return UndefinedVal();
1516 }
1517
1518 // All other values are symbolic.
1519 return svalBuilder.getRegionValueSymbolVal(R);
1520}
1521
1522static QualType getUnderlyingType(const SubRegion *R) {
1523 QualType RegionTy;
1524 if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
1525 RegionTy = TVR->getValueType();
1526
1527 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
1528 RegionTy = SR->getSymbol()->getType();
1529
1530 return RegionTy;
1531}
1532
1533/// Checks to see if store \p B has a lazy binding for region \p R.
1534///
1535/// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
1536/// if there are additional bindings within \p R.
1537///
1538/// Note that unlike RegionStoreManager::findLazyBinding, this will not search
1539/// for lazy bindings for super-regions of \p R.
1540static Optional<nonloc::LazyCompoundVal>
1541getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
1542 const SubRegion *R, bool AllowSubregionBindings) {
1543 Optional<SVal> V = B.getDefaultBinding(R);
1544 if (!V)
1545 return None;
1546
1547 Optional<nonloc::LazyCompoundVal> LCV = V->getAs<nonloc::LazyCompoundVal>();
1548 if (!LCV)
1549 return None;
1550
1551 // If the LCV is for a subregion, the types might not match, and we shouldn't
1552 // reuse the binding.
1553 QualType RegionTy = getUnderlyingType(R);
1554 if (!RegionTy.isNull() &&
1555 !RegionTy->isVoidPointerType()) {
1556 QualType SourceRegionTy = LCV->getRegion()->getValueType();
1557 if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
1558 return None;
1559 }
1560
1561 if (!AllowSubregionBindings) {
1562 // If there are any other bindings within this region, we shouldn't reuse
1563 // the top-level binding.
1564 SmallVector<BindingPair, 16> Bindings;
1565 collectSubRegionBindings(Bindings, SVB, *B.lookup(R->getBaseRegion()), R,
1566 /*IncludeAllDefaultBindings=*/true);
1567 if (Bindings.size() > 1)
1568 return None;
1569 }
1570
1571 return *LCV;
1572}
1573
1574
1575std::pair<Store, const SubRegion *>
1576RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
1577 const SubRegion *R,
1578 const SubRegion *originalRegion) {
1579 if (originalRegion != R) {
1580 if (Optional<nonloc::LazyCompoundVal> V =
1581 getExistingLazyBinding(svalBuilder, B, R, true))
1582 return std::make_pair(V->getStore(), V->getRegion());
1583 }
1584
1585 typedef std::pair<Store, const SubRegion *> StoreRegionPair;
1586 StoreRegionPair Result = StoreRegionPair();
1587
1588 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1589 Result = findLazyBinding(B, cast<SubRegion>(ER->getSuperRegion()),
1590 originalRegion);
1591
1592 if (Result.second)
1593 Result.second = MRMgr.getElementRegionWithSuper(ER, Result.second);
1594
1595 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
1596 Result = findLazyBinding(B, cast<SubRegion>(FR->getSuperRegion()),
1597 originalRegion);
1598
1599 if (Result.second)
1600 Result.second = MRMgr.getFieldRegionWithSuper(FR, Result.second);
1601
1602 } else if (const CXXBaseObjectRegion *BaseReg =
1603 dyn_cast<CXXBaseObjectRegion>(R)) {
1604 // C++ base object region is another kind of region that we should blast
1605 // through to look for lazy compound value. It is like a field region.
1606 Result = findLazyBinding(B, cast<SubRegion>(BaseReg->getSuperRegion()),
1607 originalRegion);
1608
1609 if (Result.second)
1610 Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(BaseReg,
1611 Result.second);
1612 }
1613
1614 return Result;
1615}
1616
1617/// This is a helper function for `getConstantValFromConstArrayInitializer`.
1618///
1619/// Return an array of extents of the declared array type.
1620///
1621/// E.g. for `int x[1][2][3];` returns { 1, 2, 3 }.
1622static SmallVector<uint64_t, 2>
1623getConstantArrayExtents(const ConstantArrayType *CAT) {
1624 assert(CAT && "ConstantArrayType should not be null");
1625 CAT = cast<ConstantArrayType>(CAT->getCanonicalTypeInternal());
1626 SmallVector<uint64_t, 2> Extents;
1627 do {
1628 Extents.push_back(CAT->getSize().getZExtValue());
1629 } while ((CAT = dyn_cast<ConstantArrayType>(CAT->getElementType())));
1630 return Extents;
1631}
1632
1633/// This is a helper function for `getConstantValFromConstArrayInitializer`.
1634///
1635/// Return an array of offsets from nested ElementRegions and a root base
1636/// region. The array is never empty and a base region is never null.
1637///
1638/// E.g. for `Element{Element{Element{VarRegion},1},2},3}` returns { 3, 2, 1 }.
1639/// This represents an access through indirection: `arr[1][2][3];`
1640///
1641/// \param ER The given (possibly nested) ElementRegion.
1642///
1643/// \note The result array is in the reverse order of indirection expression:
1644/// arr[1][2][3] -> { 3, 2, 1 }. This helps to provide complexity O(n), where n
1645/// is a number of indirections. It may not affect performance in real-life
1646/// code, though.
1647static std::pair<SmallVector<SVal, 2>, const MemRegion *>
1648getElementRegionOffsetsWithBase(const ElementRegion *ER) {
1649 assert(ER && "ConstantArrayType should not be null");
1650 const MemRegion *Base;
1651 SmallVector<SVal, 2> SValOffsets;
1652 do {
1653 SValOffsets.push_back(ER->getIndex());
1654 Base = ER->getSuperRegion();
1655 ER = dyn_cast<ElementRegion>(Base);
1656 } while (ER);
1657 return {SValOffsets, Base};
1658}
1659
1660/// This is a helper function for `getConstantValFromConstArrayInitializer`.
1661///
1662/// Convert array of offsets from `SVal` to `uint64_t` in consideration of
1663/// respective array extents.
1664/// \param SrcOffsets [in] The array of offsets of type `SVal` in reversed
1665/// order (expectedly received from `getElementRegionOffsetsWithBase`).
1666/// \param ArrayExtents [in] The array of extents.
1667/// \param DstOffsets [out] The array of offsets of type `uint64_t`.
1668/// \returns:
1669/// - `None` for successful convertion.
1670/// - `UndefinedVal` or `UnknownVal` otherwise. It's expected that this SVal
1671/// will be returned as a suitable value of the access operation.
1672/// which should be returned as a correct
1673///
1674/// \example:
1675/// const int arr[10][20][30] = {}; // ArrayExtents { 10, 20, 30 }
1676/// int x1 = arr[4][5][6]; // SrcOffsets { NonLoc(6), NonLoc(5), NonLoc(4) }
1677/// // DstOffsets { 4, 5, 6 }
1678/// // returns None
1679/// int x2 = arr[42][5][-6]; // returns UndefinedVal
1680/// int x3 = arr[4][5][x2]; // returns UnknownVal
1681static Optional<SVal>
1682convertOffsetsFromSvalToUnsigneds(const SmallVector<SVal, 2> &SrcOffsets,
1683 const SmallVector<uint64_t, 2> ArrayExtents,
1684 SmallVector<uint64_t, 2> &DstOffsets) {
1685 // Check offsets for being out of bounds.
1686 // C++20 [expr.add] 7.6.6.4 (excerpt):
1687 // If P points to an array element i of an array object x with n
1688 // elements, where i < 0 or i > n, the behavior is undefined.
1689 // Dereferencing is not allowed on the "one past the last
1690 // element", when i == n.
1691 // Example:
1692 // const int arr[3][2] = {{1, 2}, {3, 4}};
1693 // arr[0][0]; // 1
1694 // arr[0][1]; // 2
1695 // arr[0][2]; // UB
1696 // arr[1][0]; // 3
1697 // arr[1][1]; // 4
1698 // arr[1][-1]; // UB
1699 // arr[2][0]; // 0
1700 // arr[2][1]; // 0
1701 // arr[-2][0]; // UB
1702 DstOffsets.resize(SrcOffsets.size());
1703 auto ExtentIt = ArrayExtents.begin();
1704 auto OffsetIt = DstOffsets.begin();
1705 // Reverse `SValOffsets` to make it consistent with `ArrayExtents`.
1706 for (SVal V : llvm::reverse(SrcOffsets)) {
1707 if (auto CI = V.getAs<nonloc::ConcreteInt>()) {
1708 // When offset is out of array's bounds, result is UB.
1709 const llvm::APSInt &Offset = CI->getValue();
1710 if (Offset.isNegative() || Offset.uge(*(ExtentIt++)))
1711 return UndefinedVal();
1712 // Store index in a reversive order.
1713 *(OffsetIt++) = Offset.getZExtValue();
1714 continue;
1715 }
1716 // Symbolic index presented. Return Unknown value.
1717 // FIXME: We also need to take ElementRegions with symbolic indexes into
1718 // account.
1719 return UnknownVal();
1720 }
1721 return None;
1722}
1723
1724Optional<SVal> RegionStoreManager::getConstantValFromConstArrayInitializer(
1725 RegionBindingsConstRef B, const ElementRegion *R) {
1726 assert(R && "ElementRegion should not be null");
1727
1728 // Treat an n-dimensional array.
1729 SmallVector<SVal, 2> SValOffsets;
1730 const MemRegion *Base;
1731 std::tie(SValOffsets, Base) = getElementRegionOffsetsWithBase(R);
1732 const VarRegion *VR = dyn_cast<VarRegion>(Base);
1733 if (!VR)
1734 return None;
1735
1736 assert(!SValOffsets.empty() && "getElementRegionOffsets guarantees the "
1737 "offsets vector is not empty.");
1738
1739 // Check if the containing array has an initialized value that we can trust.
1740 // We can trust a const value or a value of a global initializer in main().
1741 const VarDecl *VD = VR->getDecl();
1742 if (!VD->getType().isConstQualified() &&
1743 !R->getElementType().isConstQualified() &&
1744 (!B.isMainAnalysis() || !VD->hasGlobalStorage()))
1745 return None;
1746
1747 // Array's declaration should have `ConstantArrayType` type, because only this
1748 // type contains an array extent. It may happen that array type can be of
1749 // `IncompleteArrayType` type. To get the declaration of `ConstantArrayType`
1750 // type, we should find the declaration in the redeclarations chain that has
1751 // the initialization expression.
1752 // NOTE: `getAnyInitializer` has an out-parameter, which returns a new `VD`
1753 // from which an initializer is obtained. We replace current `VD` with the new
1754 // `VD`. If the return value of the function is null than `VD` won't be
1755 // replaced.
1756 const Expr *Init = VD->getAnyInitializer(VD);
1757 // NOTE: If `Init` is non-null, then a new `VD` is non-null for sure. So check
1758 // `Init` for null only and don't worry about the replaced `VD`.
1759 if (!Init)
1760 return None;
1761
1762 // Array's declaration should have ConstantArrayType type, because only this
1763 // type contains an array extent.
1764 const ConstantArrayType *CAT = Ctx.getAsConstantArrayType(VD->getType());
1765 if (!CAT)
1766 return None;
1767
1768 // Get array extents.
1769 SmallVector<uint64_t, 2> Extents = getConstantArrayExtents(CAT);
1770
1771 // The number of offsets should equal to the numbers of extents,
1772 // otherwise wrong type punning occurred. For instance:
1773 // int arr[1][2][3];
1774 // auto ptr = (int(*)[42])arr;
1775 // auto x = ptr[4][2]; // UB
1776 // FIXME: Should return UndefinedVal.
1777 if (SValOffsets.size() != Extents.size())
1778 return None;
1779
1780 SmallVector<uint64_t, 2> ConcreteOffsets;
1781 if (Optional<SVal> V = convertOffsetsFromSvalToUnsigneds(SValOffsets, Extents,
1782 ConcreteOffsets))
1783 return *V;
1784
1785 // Handle InitListExpr.
1786 // Example:
1787 // const char arr[4][2] = { { 1, 2 }, { 3 }, 4, 5 };
1788 if (const auto *ILE = dyn_cast<InitListExpr>(Init))
1789 return getSValFromInitListExpr(ILE, ConcreteOffsets, R->getElementType());
1790
1791 // Handle StringLiteral.
1792 // Example:
1793 // const char arr[] = "abc";
1794 if (const auto *SL = dyn_cast<StringLiteral>(Init))
1795 return getSValFromStringLiteral(SL, ConcreteOffsets.front(),
1796 R->getElementType());
1797
1798 // FIXME: Handle CompoundLiteralExpr.
1799
1800 return None;
1801}
1802
1803/// Returns an SVal, if possible, for the specified position of an
1804/// initialization list.
1805///
1806/// \param ILE The given initialization list.
1807/// \param Offsets The array of unsigned offsets. E.g. for the expression
1808/// `int x = arr[1][2][3];` an array should be { 1, 2, 3 }.
1809/// \param ElemT The type of the result SVal expression.
1810/// \return Optional SVal for the particular position in the initialization
1811/// list. E.g. for the list `{{1, 2},[3, 4],{5, 6}, {}}` offsets:
1812/// - {1, 1} returns SVal{4}, because it's the second position in the second
1813/// sublist;
1814/// - {3, 0} returns SVal{0}, because there's no explicit value at this
1815/// position in the sublist.
1816///
1817/// NOTE: Inorder to get a valid SVal, a caller shall guarantee valid offsets
1818/// for the given initialization list. Otherwise SVal can be an equivalent to 0
1819/// or lead to assertion.
1820Optional<SVal> RegionStoreManager::getSValFromInitListExpr(
1821 const InitListExpr *ILE, const SmallVector<uint64_t, 2> &Offsets,
1822 QualType ElemT) {
1823 assert(ILE && "InitListExpr should not be null");
1824
1825 for (uint64_t Offset : Offsets) {
1826 // C++20 [dcl.init.string] 9.4.2.1:
1827 // An array of ordinary character type [...] can be initialized by [...]
1828 // an appropriately-typed string-literal enclosed in braces.
1829 // Example:
1830 // const char arr[] = { "abc" };
1831 if (ILE->isStringLiteralInit())
1832 if (const auto *SL = dyn_cast<StringLiteral>(ILE->getInit(0)))
1833 return getSValFromStringLiteral(SL, Offset, ElemT);
1834
1835 // C++20 [expr.add] 9.4.17.5 (excerpt):
1836 // i-th array element is value-initialized for each k < i ≤ n,
1837 // where k is an expression-list size and n is an array extent.
1838 if (Offset >= ILE->getNumInits())
1839 return svalBuilder.makeZeroVal(ElemT);
1840
1841 const Expr *E = ILE->getInit(Offset);
1842 const auto *IL = dyn_cast<InitListExpr>(E);
1843 if (!IL)
1844 // Return a constant value, if it is presented.
1845 // FIXME: Support other SVals.
1846 return svalBuilder.getConstantVal(E);
1847
1848 // Go to the nested initializer list.
1849 ILE = IL;
1850 }
1851 llvm_unreachable(
1852 "Unhandled InitListExpr sub-expressions or invalid offsets.");
1853}
1854
1855/// Returns an SVal, if possible, for the specified position in a string
1856/// literal.
1857///
1858/// \param SL The given string literal.
1859/// \param Offset The unsigned offset. E.g. for the expression
1860/// `char x = str[42];` an offset should be 42.
1861/// E.g. for the string "abc" offset:
1862/// - 1 returns SVal{b}, because it's the second position in the string.
1863/// - 42 returns SVal{0}, because there's no explicit value at this
1864/// position in the string.
1865/// \param ElemT The type of the result SVal expression.
1866///
1867/// NOTE: We return `0` for every offset >= the literal length for array
1868/// declarations, like:
1869/// const char str[42] = "123"; // Literal length is 4.
1870/// char c = str[41]; // Offset is 41.
1871/// FIXME: Nevertheless, we can't do the same for pointer declaraions, like:
1872/// const char * const str = "123"; // Literal length is 4.
1873/// char c = str[41]; // Offset is 41. Returns `0`, but Undef
1874/// // expected.
1875/// It should be properly handled before reaching this point.
1876/// The main problem is that we can't distinguish between these declarations,
1877/// because in case of array we can get the Decl from VarRegion, but in case
1878/// of pointer the region is a StringRegion, which doesn't contain a Decl.
1879/// Possible solution could be passing an array extent along with the offset.
1880SVal RegionStoreManager::getSValFromStringLiteral(const StringLiteral *SL,
1881 uint64_t Offset,
1882 QualType ElemT) {
1883 assert(SL && "StringLiteral should not be null");
1884 // C++20 [dcl.init.string] 9.4.2.3:
1885 // If there are fewer initializers than there are array elements, each
1886 // element not explicitly initialized shall be zero-initialized [dcl.init].
1887 uint32_t Code = (Offset >= SL->getLength()) ? 0 : SL->getCodeUnit(Offset);
1888 return svalBuilder.makeIntVal(Code, ElemT);
1889}
1890
1891static Optional<SVal> getDerivedSymbolForBinding(
1892 RegionBindingsConstRef B, const TypedValueRegion *BaseRegion,
1893 const TypedValueRegion *SubReg, const ASTContext &Ctx, SValBuilder &SVB) {
1894 assert(BaseRegion);
1895 QualType BaseTy = BaseRegion->getValueType();
1896 QualType Ty = SubReg->getValueType();
1897 if (BaseTy->isScalarType() && Ty->isScalarType()) {
1898 if (Ctx.getTypeSizeInChars(BaseTy) >= Ctx.getTypeSizeInChars(Ty)) {
1899 if (const Optional<SVal> &ParentValue = B.getDirectBinding(BaseRegion)) {
1900 if (SymbolRef ParentValueAsSym = ParentValue->getAsSymbol())
1901 return SVB.getDerivedRegionValueSymbolVal(ParentValueAsSym, SubReg);
1902
1903 if (ParentValue->isUndef())
1904 return UndefinedVal();
1905
1906 // Other cases: give up. We are indexing into a larger object
1907 // that has some value, but we don't know how to handle that yet.
1908 return UnknownVal();
1909 }
1910 }
1911 }
1912 return None;
1913}
1914
1915SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
1916 const ElementRegion* R) {
1917 // Check if the region has a binding.
1918 if (const Optional<SVal> &V = B.getDirectBinding(R))
1919 return *V;
1920
1921 const MemRegion* superR = R->getSuperRegion();
1922
1923 // Check if the region is an element region of a string literal.
1924 if (const StringRegion *StrR = dyn_cast<StringRegion>(superR)) {
1925 // FIXME: Handle loads from strings where the literal is treated as
1926 // an integer, e.g., *((unsigned int*)"hello"). Such loads are UB according
1927 // to C++20 7.2.1.11 [basic.lval].
1928 QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
1929 if (!Ctx.hasSameUnqualifiedType(T, R->getElementType()))
1930 return UnknownVal();
1931 if (const auto CI = R->getIndex().getAs<nonloc::ConcreteInt>()) {
1932 const llvm::APSInt &Idx = CI->getValue();
1933 if (Idx < 0)
1934 return UndefinedVal();
1935 const StringLiteral *SL = StrR->getStringLiteral();
1936 return getSValFromStringLiteral(SL, Idx.getZExtValue(), T);
1937 }
1938 } else if (isa<ElementRegion, VarRegion>(superR)) {
1939 if (Optional<SVal> V = getConstantValFromConstArrayInitializer(B, R))
1940 return *V;
1941 }
1942
1943 // Check for loads from a code text region. For such loads, just give up.
1944 if (isa<CodeTextRegion>(superR))
1945 return UnknownVal();
1946
1947 // Handle the case where we are indexing into a larger scalar object.
1948 // For example, this handles:
1949 // int x = ...
1950 // char *y = &x;
1951 // return *y;
1952 // FIXME: This is a hack, and doesn't do anything really intelligent yet.
1953 const RegionRawOffset &O = R->getAsArrayOffset();
1954
1955 // If we cannot reason about the offset, return an unknown value.
1956 if (!O.getRegion())
1957 return UnknownVal();
1958
1959 if (const TypedValueRegion *baseR = dyn_cast<TypedValueRegion>(O.getRegion()))
1960 if (auto V = getDerivedSymbolForBinding(B, baseR, R, Ctx, svalBuilder))
1961 return *V;
1962
1963 return getBindingForFieldOrElementCommon(B, R, R->getElementType());
1964}
1965
1966SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
1967 const FieldRegion* R) {
1968
1969 // Check if the region has a binding.
1970 if (const Optional<SVal> &V = B.getDirectBinding(R))
1971 return *V;
1972
1973 // If the containing record was initialized, try to get its constant value.
1974 const FieldDecl *FD = R->getDecl();
1975 QualType Ty = FD->getType();
1976 const MemRegion* superR = R->getSuperRegion();
1977 if (const auto *VR = dyn_cast<VarRegion>(superR)) {
1978 const VarDecl *VD = VR->getDecl();
1979 QualType RecordVarTy = VD->getType();
1980 unsigned Index = FD->getFieldIndex();
1981 // Either the record variable or the field has an initializer that we can
1982 // trust. We trust initializers of constants and, additionally, respect
1983 // initializers of globals when analyzing main().
1984 if (RecordVarTy.isConstQualified() || Ty.isConstQualified() ||
1985 (B.isMainAnalysis() && VD->hasGlobalStorage()))
1986 if (const Expr *Init = VD->getAnyInitializer())
1987 if (const auto *InitList = dyn_cast<InitListExpr>(Init)) {
1988 if (Index < InitList->getNumInits()) {
1989 if (const Expr *FieldInit = InitList->getInit(Index))
1990 if (Optional<SVal> V = svalBuilder.getConstantVal(FieldInit))
1991 return *V;
1992 } else {
1993 return svalBuilder.makeZeroVal(Ty);
1994 }
1995 }
1996 }
1997
1998 // Handle the case where we are accessing into a larger scalar object.
1999 // For example, this handles:
2000 // struct header {
2001 // unsigned a : 1;
2002 // unsigned b : 1;
2003 // };
2004 // struct parse_t {
2005 // unsigned bits0 : 1;
2006 // unsigned bits2 : 2; // <-- header
2007 // unsigned bits4 : 4;
2008 // };
2009 // int parse(parse_t *p) {
2010 // unsigned copy = p->bits2;
2011 // header *bits = (header *)&copy;
2012 // return bits->b; <-- here
2013 // }
2014 if (const auto *Base = dyn_cast<TypedValueRegion>(R->getBaseRegion()))
2015 if (auto V = getDerivedSymbolForBinding(B, Base, R, Ctx, svalBuilder))
2016 return *V;
2017
2018 return getBindingForFieldOrElementCommon(B, R, Ty);
2019}
2020
2021Optional<SVal>
2022RegionStoreManager::getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
2023 const MemRegion *superR,
2024 const TypedValueRegion *R,
2025 QualType Ty) {
2026
2027 if (const Optional<SVal> &D = B.getDefaultBinding(superR)) {
2028 const SVal &val = *D;
2029 if (SymbolRef parentSym = val.getAsSymbol())
2030 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
2031
2032 if (val.isZeroConstant())
2033 return svalBuilder.makeZeroVal(Ty);
2034
2035 if (val.isUnknownOrUndef())
2036 return val;
2037
2038 // Lazy bindings are usually handled through getExistingLazyBinding().
2039 // We should unify these two code paths at some point.
2040 if (isa<nonloc::LazyCompoundVal, nonloc::CompoundVal>(val))
2041 return val;
2042
2043 llvm_unreachable("Unknown default value");
2044 }
2045
2046 return None;
2047}
2048
2049SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
2050 RegionBindingsRef LazyBinding) {
2051 SVal Result;
2052 if (const ElementRegion *ER = dyn_cast<ElementRegion>(LazyBindingRegion))
2053 Result = getBindingForElement(LazyBinding, ER);
2054 else
2055 Result = getBindingForField(LazyBinding,
2056 cast<FieldRegion>(LazyBindingRegion));
2057
2058 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
2059 // default value for /part/ of an aggregate from a default value for the
2060 // /entire/ aggregate. The most common case of this is when struct Outer
2061 // has as its first member a struct Inner, which is copied in from a stack
2062 // variable. In this case, even if the Outer's default value is symbolic, 0,
2063 // or unknown, it gets overridden by the Inner's default value of undefined.
2064 //
2065 // This is a general problem -- if the Inner is zero-initialized, the Outer
2066 // will now look zero-initialized. The proper way to solve this is with a
2067 // new version of RegionStore that tracks the extent of a binding as well
2068 // as the offset.
2069 //
2070 // This hack only takes care of the undefined case because that can very
2071 // quickly result in a warning.
2072 if (Result.isUndef())
2073 Result = UnknownVal();
2074
2075 return Result;
2076}
2077
2078SVal
2079RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
2080 const TypedValueRegion *R,
2081 QualType Ty) {
2082
2083 // At this point we have already checked in either getBindingForElement or
2084 // getBindingForField if 'R' has a direct binding.
2085
2086 // Lazy binding?
2087 Store lazyBindingStore = nullptr;
2088 const SubRegion *lazyBindingRegion = nullptr;
2089 std::tie(lazyBindingStore, lazyBindingRegion) = findLazyBinding(B, R, R);
2090 if (lazyBindingRegion)
2091 return getLazyBinding(lazyBindingRegion,
2092 getRegionBindings(lazyBindingStore));
2093
2094 // Record whether or not we see a symbolic index. That can completely
2095 // be out of scope of our lookup.
2096 bool hasSymbolicIndex = false;
2097
2098 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
2099 // default value for /part/ of an aggregate from a default value for the
2100 // /entire/ aggregate. The most common case of this is when struct Outer
2101 // has as its first member a struct Inner, which is copied in from a stack
2102 // variable. In this case, even if the Outer's default value is symbolic, 0,
2103 // or unknown, it gets overridden by the Inner's default value of undefined.
2104 //
2105 // This is a general problem -- if the Inner is zero-initialized, the Outer
2106 // will now look zero-initialized. The proper way to solve this is with a
2107 // new version of RegionStore that tracks the extent of a binding as well
2108 // as the offset.
2109 //
2110 // This hack only takes care of the undefined case because that can very
2111 // quickly result in a warning.
2112 bool hasPartialLazyBinding = false;
2113
2114 const SubRegion *SR = R;
2115 while (SR) {
2116 const MemRegion *Base = SR->getSuperRegion();
2117 if (Optional<SVal> D = getBindingForDerivedDefaultValue(B, Base, R, Ty)) {
2118 if (D->getAs<nonloc::LazyCompoundVal>()) {
2119 hasPartialLazyBinding = true;
2120 break;
2121 }
2122
2123 return *D;
2124 }
2125
2126 if (const ElementRegion *ER = dyn_cast<ElementRegion>(Base)) {
2127 NonLoc index = ER->getIndex();
2128 if (!index.isConstant())
2129 hasSymbolicIndex = true;
2130 }
2131
2132 // If our super region is a field or element itself, walk up the region
2133 // hierarchy to see if there is a default value installed in an ancestor.
2134 SR = dyn_cast<SubRegion>(Base);
2135 }
2136
2137 if (R->hasStackNonParametersStorage()) {
2138 if (isa<ElementRegion>(R)) {
2139 // Currently we don't reason specially about Clang-style vectors. Check
2140 // if superR is a vector and if so return Unknown.
2141 if (const TypedValueRegion *typedSuperR =
2142 dyn_cast<TypedValueRegion>(R->getSuperRegion())) {
2143 if (typedSuperR->getValueType()->isVectorType())
2144 return UnknownVal();
2145 }
2146 }
2147
2148 // FIXME: We also need to take ElementRegions with symbolic indexes into
2149 // account. This case handles both directly accessing an ElementRegion
2150 // with a symbolic offset, but also fields within an element with
2151 // a symbolic offset.
2152 if (hasSymbolicIndex)
2153 return UnknownVal();
2154
2155 // Additionally allow introspection of a block's internal layout.
2156 // Try to get direct binding if all other attempts failed thus far.
2157 // Else, return UndefinedVal()
2158 if (!hasPartialLazyBinding && !isa<BlockDataRegion>(R->getBaseRegion())) {
2159 if (const Optional<SVal> &V = B.getDefaultBinding(R))
2160 return *V;
2161 return UndefinedVal();
2162 }
2163 }
2164
2165 // All other values are symbolic.
2166 return svalBuilder.getRegionValueSymbolVal(R);
2167}
2168
2169SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
2170 const ObjCIvarRegion* R) {
2171 // Check if the region has a binding.
2172 if (const Optional<SVal> &V = B.getDirectBinding(R))
2173 return *V;
2174
2175 const MemRegion *superR = R->getSuperRegion();
2176
2177 // Check if the super region has a default binding.
2178 if (const Optional<SVal> &V = B.getDefaultBinding(superR)) {
2179 if (SymbolRef parentSym = V->getAsSymbol())
2180 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
2181
2182 // Other cases: give up.
2183 return UnknownVal();
2184 }
2185
2186 return getBindingForLazySymbol(R);
2187}
2188
2189SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
2190 const VarRegion *R) {
2191
2192 // Check if the region has a binding.
2193 if (Optional<SVal> V = B.getDirectBinding(R))
2194 return *V;
2195
2196 if (Optional<SVal> V = B.getDefaultBinding(R))
2197 return *V;
2198
2199 // Lazily derive a value for the VarRegion.
2200 const VarDecl *VD = R->getDecl();
2201 const MemSpaceRegion *MS = R->getMemorySpace();
2202
2203 // Arguments are always symbolic.
2204 if (isa<StackArgumentsSpaceRegion>(MS))
2205 return svalBuilder.getRegionValueSymbolVal(R);
2206
2207 // Is 'VD' declared constant? If so, retrieve the constant value.
2208 if (VD->getType().isConstQualified()) {
2209 if (const Expr *Init = VD->getAnyInitializer()) {
2210 if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
2211 return *V;
2212
2213 // If the variable is const qualified and has an initializer but
2214 // we couldn't evaluate initializer to a value, treat the value as
2215 // unknown.
2216 return UnknownVal();
2217 }
2218 }
2219
2220 // This must come after the check for constants because closure-captured
2221 // constant variables may appear in UnknownSpaceRegion.
2222 if (isa<UnknownSpaceRegion>(MS))
2223 return svalBuilder.getRegionValueSymbolVal(R);
2224
2225 if (isa<GlobalsSpaceRegion>(MS)) {
2226 QualType T = VD->getType();
2227
2228 // If we're in main(), then global initializers have not become stale yet.
2229 if (B.isMainAnalysis())
2230 if (const Expr *Init = VD->getAnyInitializer())
2231 if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
2232 return *V;
2233
2234 // Function-scoped static variables are default-initialized to 0; if they
2235 // have an initializer, it would have been processed by now.
2236 // FIXME: This is only true when we're starting analysis from main().
2237 // We're losing a lot of coverage here.
2238 if (isa<StaticGlobalSpaceRegion>(MS))
2239 return svalBuilder.makeZeroVal(T);
2240
2241 if (Optional<SVal> V = getBindingForDerivedDefaultValue(B, MS, R, T)) {
2242 assert(!V->getAs<nonloc::LazyCompoundVal>());
2243 return *V;
2244 }
2245
2246 return svalBuilder.getRegionValueSymbolVal(R);
2247 }
2248
2249 return UndefinedVal();
2250}
2251
2252SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
2253 // All other values are symbolic.
2254 return svalBuilder.getRegionValueSymbolVal(R);
2255}
2256
2257const RegionStoreManager::SValListTy &
2258RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
2259 // First, check the cache.
2260 LazyBindingsMapTy::iterator I = LazyBindingsMap.find(LCV.getCVData());
2261 if (I != LazyBindingsMap.end())
2262 return I->second;
2263
2264 // If we don't have a list of values cached, start constructing it.
2265 SValListTy List;
2266
2267 const SubRegion *LazyR = LCV.getRegion();
2268 RegionBindingsRef B = getRegionBindings(LCV.getStore());
2269
2270 // If this region had /no/ bindings at the time, there are no interesting
2271 // values to return.
2272 const ClusterBindings *Cluster = B.lookup(LazyR->getBaseRegion());
2273 if (!Cluster)
2274 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
2275
2276 SmallVector<BindingPair, 32> Bindings;
2277 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, LazyR,
2278 /*IncludeAllDefaultBindings=*/true);
2279 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
2280 E = Bindings.end();
2281 I != E; ++I) {
2282 SVal V = I->second;
2283 if (V.isUnknownOrUndef() || V.isConstant())
2284 continue;
2285
2286 if (Optional<nonloc::LazyCompoundVal> InnerLCV =
2287 V.getAs<nonloc::LazyCompoundVal>()) {
2288 const SValListTy &InnerList = getInterestingValues(*InnerLCV);
2289 List.insert(List.end(), InnerList.begin(), InnerList.end());
2290 continue;
2291 }
2292
2293 List.push_back(V);
2294 }
2295
2296 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
2297}
2298
2299NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
2300 const TypedValueRegion *R) {
2301 if (Optional<nonloc::LazyCompoundVal> V =
2302 getExistingLazyBinding(svalBuilder, B, R, false))
2303 return *V;
2304
2305 return svalBuilder.makeLazyCompoundVal(StoreRef(B.asStore(), *this), R);
2306}
2307
2308static bool isRecordEmpty(const RecordDecl *RD) {
2309 if (!RD->field_empty())
2310 return false;
2311 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD))
2312 return CRD->getNumBases() == 0;
2313 return true;
2314}
2315
2316SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
2317 const TypedValueRegion *R) {
2318 const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
2319 if (!RD->getDefinition() || isRecordEmpty(RD))
2320 return UnknownVal();
2321
2322 return createLazyBinding(B, R);
2323}
2324
2325SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
2326 const TypedValueRegion *R) {
2327 assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
2328 "Only constant array types can have compound bindings.");
2329
2330 return createLazyBinding(B, R);
2331}
2332
2333bool RegionStoreManager::includedInBindings(Store store,
2334 const MemRegion *region) const {
2335 RegionBindingsRef B = getRegionBindings(store);
2336 region = region->getBaseRegion();
2337
2338 // Quick path: if the base is the head of a cluster, the region is live.
2339 if (B.lookup(region))
2340 return true;
2341
2342 // Slow path: if the region is the VALUE of any binding, it is live.
2343 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
2344 const ClusterBindings &Cluster = RI.getData();
2345 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
2346 CI != CE; ++CI) {
2347 const SVal &D = CI.getData();
2348 if (const MemRegion *R = D.getAsRegion())
2349 if (R->getBaseRegion() == region)
2350 return true;
2351 }
2352 }
2353
2354 return false;
2355}
2356
2357//===----------------------------------------------------------------------===//
2358// Binding values to regions.
2359//===----------------------------------------------------------------------===//
2360
2361StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
2362 if (Optional<loc::MemRegionVal> LV = L.getAs<loc::MemRegionVal>())
2363 if (const MemRegion* R = LV->getRegion())
2364 return StoreRef(getRegionBindings(ST).removeBinding(R)
2365 .asImmutableMap()
2366 .getRootWithoutRetain(),
2367 *this);
2368
2369 return StoreRef(ST, *this);
2370}
2371
2372RegionBindingsRef
2373RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
2374 if (L.getAs<loc::ConcreteInt>())
2375 return B;
2376
2377 // If we get here, the location should be a region.
2378 const MemRegion *R = L.castAs<loc::MemRegionVal>().getRegion();
2379
2380 // Check if the region is a struct region.
2381 if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(R)) {
2382 QualType Ty = TR->getValueType();
2383 if (Ty->isArrayType())
2384 return bindArray(B, TR, V);
2385 if (Ty->isStructureOrClassType())
2386 return bindStruct(B, TR, V);
2387 if (Ty->isVectorType())
2388 return bindVector(B, TR, V);
2389 if (Ty->isUnionType())
2390 return bindAggregate(B, TR, V);
2391 }
2392
2393 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
2394 // Binding directly to a symbolic region should be treated as binding
2395 // to element 0.
2396 QualType T = SR->getSymbol()->getType();
2397 if (T->isAnyPointerType() || T->isReferenceType())
2398 T = T->getPointeeType();
2399
2400 R = GetElementZeroRegion(SR, T);
2401 }
2402
2403 assert((!isa<CXXThisRegion>(R) || !B.lookup(R)) &&
2404 "'this' pointer is not an l-value and is not assignable");
2405
2406 // Clear out bindings that may overlap with this binding.
2407 RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
2408 return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
2409}
2410
2411RegionBindingsRef
2412RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
2413 const MemRegion *R,
2414 QualType T) {
2415 SVal V;
2416
2417 if (Loc::isLocType(T))
2418 V = svalBuilder.makeNullWithType(T);
2419 else if (T->isIntegralOrEnumerationType())
2420 V = svalBuilder.makeZeroVal(T);
2421 else if (T->isStructureOrClassType() || T->isArrayType()) {
2422 // Set the default value to a zero constant when it is a structure
2423 // or array. The type doesn't really matter.
2424 V = svalBuilder.makeZeroVal(Ctx.IntTy);
2425 }
2426 else {
2427 // We can't represent values of this type, but we still need to set a value
2428 // to record that the region has been initialized.
2429 // If this assertion ever fires, a new case should be added above -- we
2430 // should know how to default-initialize any value we can symbolicate.
2431 assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
2432 V = UnknownVal();
2433 }
2434
2435 return B.addBinding(R, BindingKey::Default, V);
2436}
2437
2438Optional<RegionBindingsRef> RegionStoreManager::tryBindSmallArray(
2439 RegionBindingsConstRef B, const TypedValueRegion *R, const ArrayType *AT,
2440 nonloc::LazyCompoundVal LCV) {
2441
2442 auto CAT = dyn_cast<ConstantArrayType>(AT);
2443
2444 // If we don't know the size, create a lazyCompoundVal instead.
2445 if (!CAT)
2446 return None;
2447
2448 QualType Ty = CAT->getElementType();
2449 if (!(Ty->isScalarType() || Ty->isReferenceType()))
2450 return None;
2451
2452 // If the array is too big, create a LCV instead.
2453 uint64_t ArrSize = CAT->getSize().getLimitedValue();
2454 if (ArrSize > SmallArrayLimit)
2455 return None;
2456
2457 RegionBindingsRef NewB = B;
2458
2459 for (uint64_t i = 0; i < ArrSize; ++i) {
2460 auto Idx = svalBuilder.makeArrayIndex(i);
2461 const ElementRegion *SrcER =
2462 MRMgr.getElementRegion(Ty, Idx, LCV.getRegion(), Ctx);
2463 SVal V = getBindingForElement(getRegionBindings(LCV.getStore()), SrcER);
2464
2465 const ElementRegion *DstER = MRMgr.getElementRegion(Ty, Idx, R, Ctx);
2466 NewB = bind(NewB, loc::MemRegionVal(DstER), V);
2467 }
2468
2469 return NewB;
2470}
2471
2472RegionBindingsRef
2473RegionStoreManager::bindArray(RegionBindingsConstRef B,
2474 const TypedValueRegion* R,
2475 SVal Init) {
2476
2477 const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
2478 QualType ElementTy = AT->getElementType();
2479 Optional<uint64_t> Size;
2480
2481 if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
2482 Size = CAT->getSize().getZExtValue();
2483
2484 // Check if the init expr is a literal. If so, bind the rvalue instead.
2485 // FIXME: It's not responsibility of the Store to transform this lvalue
2486 // to rvalue. ExprEngine or maybe even CFG should do this before binding.
2487 if (Optional<loc::MemRegionVal> MRV = Init.getAs<loc::MemRegionVal>()) {
2488 SVal V = getBinding(B.asStore(), *MRV, R->getValueType());
2489 return bindAggregate(B, R, V);
2490 }
2491
2492 // Handle lazy compound values.
2493 if (Optional<nonloc::LazyCompoundVal> LCV =
2494 Init.getAs<nonloc::LazyCompoundVal>()) {
2495 if (Optional<RegionBindingsRef> NewB = tryBindSmallArray(B, R, AT, *LCV))
2496 return *NewB;
2497
2498 return bindAggregate(B, R, Init);
2499 }
2500
2501 if (Init.isUnknown())
2502 return bindAggregate(B, R, UnknownVal());
2503
2504 // Remaining case: explicit compound values.
2505 const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
2506 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2507 uint64_t i = 0;
2508
2509 RegionBindingsRef NewB(B);
2510
2511 for (; Size ? i < *Size : true; ++i, ++VI) {
2512 // The init list might be shorter than the array length.
2513 if (VI == VE)
2514 break;
2515
2516 const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
2517 const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
2518
2519 if (ElementTy->isStructureOrClassType())
2520 NewB = bindStruct(NewB, ER, *VI);
2521 else if (ElementTy->isArrayType())
2522 NewB = bindArray(NewB, ER, *VI);
2523 else
2524 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2525 }
2526
2527 // If the init list is shorter than the array length (or the array has
2528 // variable length), set the array default value. Values that are already set
2529 // are not overwritten.
2530 if (!Size || i < *Size)
2531 NewB = setImplicitDefaultValue(NewB, R, ElementTy);
2532
2533 return NewB;
2534}
2535
2536RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
2537 const TypedValueRegion* R,
2538 SVal V) {
2539 QualType T = R->getValueType();
2540 const VectorType *VT = T->castAs<VectorType>(); // Use castAs for typedefs.
2541
2542 // Handle lazy compound values and symbolic values.
2543 if (isa<nonloc::LazyCompoundVal, nonloc::SymbolVal>(V))
2544 return bindAggregate(B, R, V);
2545
2546 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2547 // that we are binding symbolic struct value. Kill the field values, and if
2548 // the value is symbolic go and bind it as a "default" binding.
2549 if (!isa<nonloc::CompoundVal>(V)) {
2550 return bindAggregate(B, R, UnknownVal());
2551 }
2552
2553 QualType ElemType = VT->getElementType();
2554 nonloc::CompoundVal CV = V.castAs<nonloc::CompoundVal>();
2555 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2556 unsigned index = 0, numElements = VT->getNumElements();
2557 RegionBindingsRef NewB(B);
2558
2559 for ( ; index != numElements ; ++index) {
2560 if (VI == VE)
2561 break;
2562
2563 NonLoc Idx = svalBuilder.makeArrayIndex(index);
2564 const ElementRegion *ER = MRMgr.getElementRegion(ElemType, Idx, R, Ctx);
2565
2566 if (ElemType->isArrayType())
2567 NewB = bindArray(NewB, ER, *VI);
2568 else if (ElemType->isStructureOrClassType())
2569 NewB = bindStruct(NewB, ER, *VI);
2570 else
2571 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2572 }
2573 return NewB;
2574}
2575
2576Optional<RegionBindingsRef>
2577RegionStoreManager::tryBindSmallStruct(RegionBindingsConstRef B,
2578 const TypedValueRegion *R,
2579 const RecordDecl *RD,
2580 nonloc::LazyCompoundVal LCV) {
2581 FieldVector Fields;
2582
2583 if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(RD))
2584 if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
2585 return None;
2586
2587 for (const auto *FD : RD->fields()) {
2588 if (FD->isUnnamedBitfield())
2589 continue;
2590
2591 // If there are too many fields, or if any of the fields are aggregates,
2592 // just use the LCV as a default binding.
2593 if (Fields.size() == SmallStructLimit)
2594 return None;
2595
2596 QualType Ty = FD->getType();
2597 if (!(Ty->isScalarType() || Ty->isReferenceType()))
2598 return None;
2599
2600 Fields.push_back(FD);
2601 }
2602
2603 RegionBindingsRef NewB = B;
2604
2605 for (FieldVector::iterator I = Fields.begin(), E = Fields.end(); I != E; ++I){
2606 const FieldRegion *SourceFR = MRMgr.getFieldRegion(*I, LCV.getRegion());
2607 SVal V = getBindingForField(getRegionBindings(LCV.getStore()), SourceFR);
2608
2609 const FieldRegion *DestFR = MRMgr.getFieldRegion(*I, R);
2610 NewB = bind(NewB, loc::MemRegionVal(DestFR), V);
2611 }
2612
2613 return NewB;
2614}
2615
2616RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
2617 const TypedValueRegion *R,
2618 SVal V) {
2619 QualType T = R->getValueType();
2620 assert(T->isStructureOrClassType());
2621
2622 const RecordType* RT = T->castAs<RecordType>();
2623 const RecordDecl *RD = RT->getDecl();
2624
2625 if (!RD->isCompleteDefinition())
2626 return B;
2627
2628 // Handle lazy compound values and symbolic values.
2629 if (Optional<nonloc::LazyCompoundVal> LCV =
2630 V.getAs<nonloc::LazyCompoundVal>()) {
2631 if (Optional<RegionBindingsRef> NewB = tryBindSmallStruct(B, R, RD, *LCV))
2632 return *NewB;
2633 return bindAggregate(B, R, V);
2634 }
2635 if (isa<nonloc::SymbolVal>(V))
2636 return bindAggregate(B, R, V);
2637
2638 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2639 // that we are binding symbolic struct value. Kill the field values, and if
2640 // the value is symbolic go and bind it as a "default" binding.
2641 if (V.isUnknown() || !isa<nonloc::CompoundVal>(V))
2642 return bindAggregate(B, R, UnknownVal());
2643
2644 // The raw CompoundVal is essentially a symbolic InitListExpr: an (immutable)
2645 // list of other values. It appears pretty much only when there's an actual
2646 // initializer list expression in the program, and the analyzer tries to
2647 // unwrap it as soon as possible.
2648 // This code is where such unwrap happens: when the compound value is put into
2649 // the object that it was supposed to initialize (it's an *initializer* list,
2650 // after all), instead of binding the whole value to the whole object, we bind
2651 // sub-values to sub-objects. Sub-values may themselves be compound values,
2652 // and in this case the procedure becomes recursive.
2653 // FIXME: The annoying part about compound values is that they don't carry
2654 // any sort of information about which value corresponds to which sub-object.
2655 // It's simply a list of values in the middle of nowhere; we expect to match
2656 // them to sub-objects, essentially, "by index": first value binds to
2657 // the first field, second value binds to the second field, etc.
2658 // It would have been much safer to organize non-lazy compound values as
2659 // a mapping from fields/bases to values.
2660 const nonloc::CompoundVal& CV = V.castAs<nonloc::CompoundVal>();
2661 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2662
2663 RegionBindingsRef NewB(B);
2664
2665 // In C++17 aggregates may have base classes, handle those as well.
2666 // They appear before fields in the initializer list / compound value.
2667 if (const auto *CRD = dyn_cast<CXXRecordDecl>(RD)) {
2668 // If the object was constructed with a constructor, its value is a
2669 // LazyCompoundVal. If it's a raw CompoundVal, it means that we're
2670 // performing aggregate initialization. The only exception from this
2671 // rule is sending an Objective-C++ message that returns a C++ object
2672 // to a nil receiver; in this case the semantics is to return a
2673 // zero-initialized object even if it's a C++ object that doesn't have
2674 // this sort of constructor; the CompoundVal is empty in this case.
2675 assert((CRD->isAggregate() || (Ctx.getLangOpts().ObjC && VI == VE)) &&
2676 "Non-aggregates are constructed with a constructor!");
2677
2678 for (const auto &B : CRD->bases()) {
2679 // (Multiple inheritance is fine though.)
2680 assert(!B.isVirtual() && "Aggregates cannot have virtual base classes!");
2681
2682 if (VI == VE)
2683 break;
2684
2685 QualType BTy = B.getType();
2686 assert(BTy->isStructureOrClassType() && "Base classes must be classes!");
2687
2688 const CXXRecordDecl *BRD = BTy->getAsCXXRecordDecl();
2689 assert(BRD && "Base classes must be C++ classes!");
2690
2691 const CXXBaseObjectRegion *BR =
2692 MRMgr.getCXXBaseObjectRegion(BRD, R, /*IsVirtual=*/false);
2693
2694 NewB = bindStruct(NewB, BR, *VI);
2695
2696 ++VI;
2697 }
2698 }
2699
2700 RecordDecl::field_iterator FI, FE;
2701
2702 for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {
2703
2704 if (VI == VE)
2705 break;
2706
2707 // Skip any unnamed bitfields to stay in sync with the initializers.
2708 if (FI->isUnnamedBitfield())
2709 continue;
2710
2711 QualType FTy = FI->getType();
2712 const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
2713
2714 if (FTy->isArrayType())
2715 NewB = bindArray(NewB, FR, *VI);
2716 else if (FTy->isStructureOrClassType())
2717 NewB = bindStruct(NewB, FR, *VI);
2718 else
2719 NewB = bind(NewB, loc::MemRegionVal(FR), *VI);
2720 ++VI;
2721 }
2722
2723 // There may be fewer values in the initialize list than the fields of struct.
2724 if (FI != FE) {
2725 NewB = NewB.addBinding(R, BindingKey::Default,
2726 svalBuilder.makeIntVal(0, false));
2727 }
2728
2729 return NewB;
2730}
2731
2732RegionBindingsRef
2733RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
2734 const TypedRegion *R,
2735 SVal Val) {
2736 // Remove the old bindings, using 'R' as the root of all regions
2737 // we will invalidate. Then add the new binding.
2738 return removeSubRegionBindings(B, R).addBinding(R, BindingKey::Default, Val);
2739}
2740
2741//===----------------------------------------------------------------------===//
2742// State pruning.
2743//===----------------------------------------------------------------------===//
2744
2745namespace {
2746class RemoveDeadBindingsWorker
2747 : public ClusterAnalysis<RemoveDeadBindingsWorker> {
2748 SmallVector<const SymbolicRegion *, 12> Postponed;
2749 SymbolReaper &SymReaper;
2750 const StackFrameContext *CurrentLCtx;
2751
2752public:
2753 RemoveDeadBindingsWorker(RegionStoreManager &rm,
2754 ProgramStateManager &stateMgr,
2755 RegionBindingsRef b, SymbolReaper &symReaper,
2756 const StackFrameContext *LCtx)
2757 : ClusterAnalysis<RemoveDeadBindingsWorker>(rm, stateMgr, b),
2758 SymReaper(symReaper), CurrentLCtx(LCtx) {}
2759
2760 // Called by ClusterAnalysis.
2761 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
2762 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
2763 using ClusterAnalysis<RemoveDeadBindingsWorker>::VisitCluster;
2764
2765 using ClusterAnalysis::AddToWorkList;
2766
2767 bool AddToWorkList(const MemRegion *R);
2768
2769 bool UpdatePostponed();
2770 void VisitBinding(SVal V);
2771};
2772}
2773
2774bool RemoveDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
2775 const MemRegion *BaseR = R->getBaseRegion();
2776 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
2777}
2778
2779void RemoveDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
2780 const ClusterBindings &C) {
2781
2782 if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
2783 if (SymReaper.isLive(VR))
2784 AddToWorkList(baseR, &C);
2785
2786 return;
2787 }
2788
2789 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
2790 if (SymReaper.isLive(SR->getSymbol()))
2791 AddToWorkList(SR, &C);
2792 else
2793 Postponed.push_back(SR);
2794
2795 return;
2796 }
2797
2798 if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
2799 AddToWorkList(baseR, &C);
2800 return;
2801 }
2802
2803 // CXXThisRegion in the current or parent location context is live.
2804 if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
2805 const auto *StackReg =
2806 cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
2807 const StackFrameContext *RegCtx = StackReg->getStackFrame();
2808 if (CurrentLCtx &&
2809 (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx)))
2810 AddToWorkList(TR, &C);
2811 }
2812}
2813
2814void RemoveDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
2815 const ClusterBindings *C) {
2816 if (!C)
2817 return;
2818
2819 // Mark the symbol for any SymbolicRegion with live bindings as live itself.
2820 // This means we should continue to track that symbol.
2821 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(baseR))
2822 SymReaper.markLive(SymR->getSymbol());
2823
2824 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I) {
2825 // Element index of a binding key is live.
2826 SymReaper.markElementIndicesLive(I.getKey().getRegion());
2827
2828 VisitBinding(I.getData());
2829 }
2830}
2831
2832void RemoveDeadBindingsWorker::VisitBinding(SVal V) {
2833 // Is it a LazyCompoundVal? All referenced regions are live as well.
2834 if (Optional<nonloc::LazyCompoundVal> LCS =
2835 V.getAs<nonloc::LazyCompoundVal>()) {
2836
2837 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
2838
2839 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
2840 E = Vals.end();
2841 I != E; ++I)
2842 VisitBinding(*I);
2843
2844 return;
2845 }
2846
2847 // If V is a region, then add it to the worklist.
2848 if (const MemRegion *R = V.getAsRegion()) {
2849 AddToWorkList(R);
2850 SymReaper.markLive(R);
2851
2852 // All regions captured by a block are also live.
2853 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
2854 BlockDataRegion::referenced_vars_iterator I = BR->referenced_vars_begin(),
2855 E = BR->referenced_vars_end();
2856 for ( ; I != E; ++I)
2857 AddToWorkList(I.getCapturedRegion());
2858 }
2859 }
2860
2861
2862 // Update the set of live symbols.
2863 for (auto SI = V.symbol_begin(), SE = V.symbol_end(); SI!=SE; ++SI)
2864 SymReaper.markLive(*SI);
2865}
2866
2867bool RemoveDeadBindingsWorker::UpdatePostponed() {
2868 // See if any postponed SymbolicRegions are actually live now, after
2869 // having done a scan.
2870 bool Changed = false;
2871
2872 for (auto I = Postponed.begin(), E = Postponed.end(); I != E; ++I) {
2873 if (const SymbolicRegion *SR = *I) {
2874 if (SymReaper.isLive(SR->getSymbol())) {
2875 Changed |= AddToWorkList(SR);
2876 *I = nullptr;
2877 }
2878 }
2879 }
2880
2881 return Changed;
2882}
2883
2884StoreRef RegionStoreManager::removeDeadBindings(Store store,
2885 const StackFrameContext *LCtx,
2886 SymbolReaper& SymReaper) {
2887 RegionBindingsRef B = getRegionBindings(store);
2888 RemoveDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
2889 W.GenerateClusters();
2890
2891 // Enqueue the region roots onto the worklist.
2892 for (SymbolReaper::region_iterator I = SymReaper.region_begin(),
2893 E = SymReaper.region_end(); I != E; ++I) {
2894 W.AddToWorkList(*I);
2895 }
2896
2897 do W.RunWorkList(); while (W.UpdatePostponed());
2898
2899 // We have now scanned the store, marking reachable regions and symbols
2900 // as live. We now remove all the regions that are dead from the store
2901 // as well as update DSymbols with the set symbols that are now dead.
2902 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
2903 const MemRegion *Base = I.getKey();
2904
2905 // If the cluster has been visited, we know the region has been marked.
2906 // Otherwise, remove the dead entry.
2907 if (!W.isVisited(Base))
2908 B = B.remove(Base);
2909 }
2910
2911 return StoreRef(B.asStore(), *this);
2912}
2913
2914//===----------------------------------------------------------------------===//
2915// Utility methods.
2916//===----------------------------------------------------------------------===//
2917
2918void RegionStoreManager::printJson(raw_ostream &Out, Store S, const char *NL,
2919 unsigned int Space, bool IsDot) const {
2920 RegionBindingsRef Bindings = getRegionBindings(S);
2921
2922 Indent(Out, Space, IsDot) << "\"store\": ";
2923
2924 if (Bindings.isEmpty()) {
2925 Out << "null," << NL;
2926 return;
2927 }
2928
2929 Out << "{ \"pointer\": \"" << Bindings.asStore() << "\", \"items\": [" << NL;
2930 Bindings.printJson(Out, NL, Space + 1, IsDot);
2931 Indent(Out, Space, IsDot) << "]}," << NL;
2932}
2933

source code of clang/lib/StaticAnalyzer/Core/RegionStore.cpp