1 //== RegionStore.cpp - Field-sensitive store model --------------*- C++ -*--==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a basic region store model. In this model, we do have field
11 // sensitivity. But we assume nothing about the heap shape. So recursive data
12 // structures are largely ignored. Basically we do 1-limiting analysis.
13 // Parameter pointers are assumed with no aliasing. Pointee objects of
14 // parameters are created lazily.
16 //===----------------------------------------------------------------------===//
18 #include "clang/AST/Attr.h"
19 #include "clang/AST/CharUnits.h"
20 #include "clang/Analysis/Analyses/LiveVariables.h"
21 #include "clang/Analysis/AnalysisDeclContext.h"
22 #include "clang/Basic/TargetInfo.h"
23 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
24 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
25 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
26 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
27 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
28 #include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
29 #include "llvm/ADT/ImmutableMap.h"
30 #include "llvm/ADT/Optional.h"
31 #include "llvm/Support/raw_ostream.h"
34 using namespace clang;
37 //===----------------------------------------------------------------------===//
38 // Representation of binding keys.
39 //===----------------------------------------------------------------------===//
44 enum Kind { Default = 0x0, Direct = 0x1 };
46 enum { Symbolic = 0x2 };
48 llvm::PointerIntPair<const MemRegion *, 2> P;
51 /// Create a key for a binding to region \p r, which has a symbolic offset
52 /// from region \p Base.
53 explicit BindingKey(const SubRegion *r, const SubRegion *Base, Kind k)
54 : P(r, k | Symbolic), Data(reinterpret_cast<uintptr_t>(Base)) {
55 assert(r && Base && "Must have known regions.");
56 assert(getConcreteOffsetRegion() == Base && "Failed to store base region");
59 /// Create a key for a binding at \p offset from base region \p r.
60 explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
61 : P(r, k), Data(offset) {
62 assert(r && "Must have known regions.");
63 assert(getOffset() == offset && "Failed to store offset");
64 assert((r == r->getBaseRegion() || isa<ObjCIvarRegion>(r)) && "Not a base");
68 bool isDirect() const { return P.getInt() & Direct; }
69 bool hasSymbolicOffset() const { return P.getInt() & Symbolic; }
71 const MemRegion *getRegion() const { return P.getPointer(); }
72 uint64_t getOffset() const {
73 assert(!hasSymbolicOffset());
77 const SubRegion *getConcreteOffsetRegion() const {
78 assert(hasSymbolicOffset());
79 return reinterpret_cast<const SubRegion *>(static_cast<uintptr_t>(Data));
82 const MemRegion *getBaseRegion() const {
83 if (hasSymbolicOffset())
84 return getConcreteOffsetRegion()->getBaseRegion();
85 return getRegion()->getBaseRegion();
88 void Profile(llvm::FoldingSetNodeID& ID) const {
89 ID.AddPointer(P.getOpaqueValue());
93 static BindingKey Make(const MemRegion *R, Kind k);
95 bool operator<(const BindingKey &X) const {
96 if (P.getOpaqueValue() < X.P.getOpaqueValue())
98 if (P.getOpaqueValue() > X.P.getOpaqueValue())
100 return Data < X.Data;
103 bool operator==(const BindingKey &X) const {
104 return P.getOpaqueValue() == X.P.getOpaqueValue() &&
110 } // end anonymous namespace
112 BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
113 const RegionOffset &RO = R->getAsOffset();
114 if (RO.hasSymbolicOffset())
115 return BindingKey(cast<SubRegion>(R), cast<SubRegion>(RO.getRegion()), k);
117 return BindingKey(RO.getRegion(), RO.getOffset(), k);
122 raw_ostream &operator<<(raw_ostream &os, BindingKey K) {
123 os << '(' << K.getRegion();
124 if (!K.hasSymbolicOffset())
125 os << ',' << K.getOffset();
126 os << ',' << (K.isDirect() ? "direct" : "default")
131 template <typename T> struct isPodLike;
132 template <> struct isPodLike<BindingKey> {
133 static const bool value = true;
135 } // end llvm namespace
138 LLVM_DUMP_METHOD void BindingKey::dump() const { llvm::errs() << *this; }
141 //===----------------------------------------------------------------------===//
142 // Actual Store type.
143 //===----------------------------------------------------------------------===//
145 typedef llvm::ImmutableMap<BindingKey, SVal> ClusterBindings;
146 typedef llvm::ImmutableMapRef<BindingKey, SVal> ClusterBindingsRef;
147 typedef std::pair<BindingKey, SVal> BindingPair;
149 typedef llvm::ImmutableMap<const MemRegion *, ClusterBindings>
153 class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
155 ClusterBindings::Factory *CBFactory;
158 typedef llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>
161 RegionBindingsRef(ClusterBindings::Factory &CBFactory,
162 const RegionBindings::TreeTy *T,
163 RegionBindings::TreeTy::Factory *F)
164 : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(T, F),
165 CBFactory(&CBFactory) {}
167 RegionBindingsRef(const ParentTy &P, ClusterBindings::Factory &CBFactory)
168 : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(P),
169 CBFactory(&CBFactory) {}
171 RegionBindingsRef add(key_type_ref K, data_type_ref D) const {
172 return RegionBindingsRef(static_cast<const ParentTy *>(this)->add(K, D),
176 RegionBindingsRef remove(key_type_ref K) const {
177 return RegionBindingsRef(static_cast<const ParentTy *>(this)->remove(K),
181 RegionBindingsRef addBinding(BindingKey K, SVal V) const;
183 RegionBindingsRef addBinding(const MemRegion *R,
184 BindingKey::Kind k, SVal V) const;
186 const SVal *lookup(BindingKey K) const;
187 const SVal *lookup(const MemRegion *R, BindingKey::Kind k) const;
188 using llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>::lookup;
190 RegionBindingsRef removeBinding(BindingKey K);
192 RegionBindingsRef removeBinding(const MemRegion *R,
195 RegionBindingsRef removeBinding(const MemRegion *R) {
196 return removeBinding(R, BindingKey::Direct).
197 removeBinding(R, BindingKey::Default);
200 Optional<SVal> getDirectBinding(const MemRegion *R) const;
202 /// getDefaultBinding - Returns an SVal* representing an optional default
203 /// binding associated with a region and its subregions.
204 Optional<SVal> getDefaultBinding(const MemRegion *R) const;
206 /// Return the internal tree as a Store.
207 Store asStore() const {
208 return asImmutableMap().getRootWithoutRetain();
211 void dump(raw_ostream &OS, const char *nl) const {
212 for (iterator I = begin(), E = end(); I != E; ++I) {
213 const ClusterBindings &Cluster = I.getData();
214 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
216 OS << ' ' << CI.getKey() << " : " << CI.getData() << nl;
222 LLVM_DUMP_METHOD void dump() const { dump(llvm::errs(), "\n"); }
224 } // end anonymous namespace
226 typedef const RegionBindingsRef& RegionBindingsConstRef;
228 Optional<SVal> RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
229 return Optional<SVal>::create(lookup(R, BindingKey::Direct));
232 Optional<SVal> RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
233 if (R->isBoundable())
234 if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R))
235 if (TR->getValueType()->isUnionType())
238 return Optional<SVal>::create(lookup(R, BindingKey::Default));
241 RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
242 const MemRegion *Base = K.getBaseRegion();
244 const ClusterBindings *ExistingCluster = lookup(Base);
245 ClusterBindings Cluster =
246 (ExistingCluster ? *ExistingCluster : CBFactory->getEmptyMap());
248 ClusterBindings NewCluster = CBFactory->add(Cluster, K, V);
249 return add(Base, NewCluster);
253 RegionBindingsRef RegionBindingsRef::addBinding(const MemRegion *R,
256 return addBinding(BindingKey::Make(R, k), V);
259 const SVal *RegionBindingsRef::lookup(BindingKey K) const {
260 const ClusterBindings *Cluster = lookup(K.getBaseRegion());
263 return Cluster->lookup(K);
266 const SVal *RegionBindingsRef::lookup(const MemRegion *R,
267 BindingKey::Kind k) const {
268 return lookup(BindingKey::Make(R, k));
271 RegionBindingsRef RegionBindingsRef::removeBinding(BindingKey K) {
272 const MemRegion *Base = K.getBaseRegion();
273 const ClusterBindings *Cluster = lookup(Base);
277 ClusterBindings NewCluster = CBFactory->remove(*Cluster, K);
278 if (NewCluster.isEmpty())
280 return add(Base, NewCluster);
283 RegionBindingsRef RegionBindingsRef::removeBinding(const MemRegion *R,
285 return removeBinding(BindingKey::Make(R, k));
288 //===----------------------------------------------------------------------===//
289 // Fine-grained control of RegionStoreManager.
290 //===----------------------------------------------------------------------===//
293 struct minimal_features_tag {};
294 struct maximal_features_tag {};
296 class RegionStoreFeatures {
299 RegionStoreFeatures(minimal_features_tag) :
300 SupportsFields(false) {}
302 RegionStoreFeatures(maximal_features_tag) :
303 SupportsFields(true) {}
305 void enableFields(bool t) { SupportsFields = t; }
307 bool supportsFields() const { return SupportsFields; }
311 //===----------------------------------------------------------------------===//
312 // Main RegionStore logic.
313 //===----------------------------------------------------------------------===//
316 class invalidateRegionsWorker;
318 class RegionStoreManager : public StoreManager {
320 const RegionStoreFeatures Features;
322 RegionBindings::Factory RBFactory;
323 mutable ClusterBindings::Factory CBFactory;
325 typedef std::vector<SVal> SValListTy;
327 typedef llvm::DenseMap<const LazyCompoundValData *,
328 SValListTy> LazyBindingsMapTy;
329 LazyBindingsMapTy LazyBindingsMap;
331 /// The largest number of fields a struct can have and still be
332 /// considered "small".
334 /// This is currently used to decide whether or not it is worth "forcing" a
335 /// LazyCompoundVal on bind.
337 /// This is controlled by 'region-store-small-struct-limit' option.
338 /// To disable all small-struct-dependent behavior, set the option to "0".
339 unsigned SmallStructLimit;
341 /// \brief A helper used to populate the work list with the given set of
343 void populateWorkList(invalidateRegionsWorker &W,
344 ArrayRef<SVal> Values,
345 InvalidatedRegions *TopLevelRegions);
348 RegionStoreManager(ProgramStateManager& mgr, const RegionStoreFeatures &f)
349 : StoreManager(mgr), Features(f),
350 RBFactory(mgr.getAllocator()), CBFactory(mgr.getAllocator()),
351 SmallStructLimit(0) {
352 if (SubEngine *Eng = StateMgr.getOwningEngine()) {
353 AnalyzerOptions &Options = Eng->getAnalysisManager().options;
355 Options.getOptionAsInteger("region-store-small-struct-limit", 2);
360 /// setImplicitDefaultValue - Set the default binding for the provided
361 /// MemRegion to the value implicitly defined for compound literals when
362 /// the value is not specified.
363 RegionBindingsRef setImplicitDefaultValue(RegionBindingsConstRef B,
364 const MemRegion *R, QualType T);
366 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
367 /// type. 'Array' represents the lvalue of the array being decayed
368 /// to a pointer, and the returned SVal represents the decayed
369 /// version of that lvalue (i.e., a pointer to the first element of
370 /// the array). This is called by ExprEngine when evaluating
371 /// casts from arrays to pointers.
372 SVal ArrayToPointer(Loc Array, QualType ElementTy) override;
374 StoreRef getInitialStore(const LocationContext *InitLoc) override {
375 return StoreRef(RBFactory.getEmptyMap().getRootWithoutRetain(), *this);
378 //===-------------------------------------------------------------------===//
379 // Binding values to regions.
380 //===-------------------------------------------------------------------===//
381 RegionBindingsRef invalidateGlobalRegion(MemRegion::Kind K,
384 const LocationContext *LCtx,
386 InvalidatedRegions *Invalidated);
388 StoreRef invalidateRegions(Store store,
389 ArrayRef<SVal> Values,
390 const Expr *E, unsigned Count,
391 const LocationContext *LCtx,
392 const CallEvent *Call,
393 InvalidatedSymbols &IS,
394 RegionAndSymbolInvalidationTraits &ITraits,
395 InvalidatedRegions *Invalidated,
396 InvalidatedRegions *InvalidatedTopLevel) override;
398 bool scanReachableSymbols(Store S, const MemRegion *R,
399 ScanReachableSymbols &Callbacks) override;
401 RegionBindingsRef removeSubRegionBindings(RegionBindingsConstRef B,
404 public: // Part of public interface to class.
406 StoreRef Bind(Store store, Loc LV, SVal V) override {
407 return StoreRef(bind(getRegionBindings(store), LV, V).asStore(), *this);
410 RegionBindingsRef bind(RegionBindingsConstRef B, Loc LV, SVal V);
412 // BindDefault is only used to initialize a region with a default value.
413 StoreRef BindDefault(Store store, const MemRegion *R, SVal V) override {
414 // FIXME: The offsets of empty bases can be tricky because of
415 // of the so called "empty base class optimization".
416 // If a base class has been optimized out
417 // we should not try to create a binding, otherwise we should.
418 // Unfortunately, at the moment ASTRecordLayout doesn't expose
419 // the actual sizes of the empty bases
420 // and trying to infer them from offsets/alignments
421 // seems to be error-prone and non-trivial because of the trailing padding.
422 // As a temporary mitigation we don't create bindings for empty bases.
423 if (R->getKind() == MemRegion::CXXBaseObjectRegionKind &&
424 cast<CXXBaseObjectRegion>(R)->getDecl()->isEmpty())
425 return StoreRef(store, *this);
427 RegionBindingsRef B = getRegionBindings(store);
428 assert(!B.lookup(R, BindingKey::Direct));
430 BindingKey Key = BindingKey::Make(R, BindingKey::Default);
432 const SubRegion *SR = cast<SubRegion>(R);
433 assert(SR->getAsOffset().getOffset() ==
434 SR->getSuperRegion()->getAsOffset().getOffset() &&
435 "A default value must come from a super-region");
436 B = removeSubRegionBindings(B, SR);
438 B = B.addBinding(Key, V);
441 return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
444 /// Attempt to extract the fields of \p LCV and bind them to the struct region
447 /// This path is used when it seems advantageous to "force" loading the values
448 /// within a LazyCompoundVal to bind memberwise to the struct region, rather
449 /// than using a Default binding at the base of the entire region. This is a
450 /// heuristic attempting to avoid building long chains of LazyCompoundVals.
452 /// \returns The updated store bindings, or \c None if binding non-lazily
453 /// would be too expensive.
454 Optional<RegionBindingsRef> tryBindSmallStruct(RegionBindingsConstRef B,
455 const TypedValueRegion *R,
456 const RecordDecl *RD,
457 nonloc::LazyCompoundVal LCV);
459 /// BindStruct - Bind a compound value to a structure.
460 RegionBindingsRef bindStruct(RegionBindingsConstRef B,
461 const TypedValueRegion* R, SVal V);
463 /// BindVector - Bind a compound value to a vector.
464 RegionBindingsRef bindVector(RegionBindingsConstRef B,
465 const TypedValueRegion* R, SVal V);
467 RegionBindingsRef bindArray(RegionBindingsConstRef B,
468 const TypedValueRegion* R,
471 /// Clears out all bindings in the given region and assigns a new value
472 /// as a Default binding.
473 RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
474 const TypedRegion *R,
477 /// \brief Create a new store with the specified binding removed.
478 /// \param ST the original store, that is the basis for the new store.
479 /// \param L the location whose binding should be removed.
480 StoreRef killBinding(Store ST, Loc L) override;
482 void incrementReferenceCount(Store store) override {
483 getRegionBindings(store).manualRetain();
486 /// If the StoreManager supports it, decrement the reference count of
487 /// the specified Store object. If the reference count hits 0, the memory
488 /// associated with the object is recycled.
489 void decrementReferenceCount(Store store) override {
490 getRegionBindings(store).manualRelease();
493 bool includedInBindings(Store store, const MemRegion *region) const override;
495 /// \brief Return the value bound to specified location in a given state.
497 /// The high level logic for this method is this:
500 /// return L's binding
501 /// else if L is in killset
504 /// if L is on stack or heap
508 SVal getBinding(Store S, Loc L, QualType T) override {
509 return getBinding(getRegionBindings(S), L, T);
512 Optional<SVal> getDefaultBinding(Store S, const MemRegion *R) override {
513 RegionBindingsRef B = getRegionBindings(S);
514 // Default bindings are always applied over a base region so look up the
515 // base region's default binding, otherwise the lookup will fail when R
516 // is at an offset from R->getBaseRegion().
517 return B.getDefaultBinding(R->getBaseRegion());
520 SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());
522 SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);
524 SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);
526 SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);
528 SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);
530 SVal getBindingForLazySymbol(const TypedValueRegion *R);
532 SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
533 const TypedValueRegion *R,
536 SVal getLazyBinding(const SubRegion *LazyBindingRegion,
537 RegionBindingsRef LazyBinding);
539 /// Get bindings for the values in a struct and return a CompoundVal, used
540 /// when doing struct copy:
543 /// y's value is retrieved by this method.
544 SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
545 SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
546 NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);
548 /// Used to lazily generate derived symbols for bindings that are defined
549 /// implicitly by default bindings in a super region.
551 /// Note that callers may need to specially handle LazyCompoundVals, which
552 /// are returned as is in case the caller needs to treat them differently.
553 Optional<SVal> getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
554 const MemRegion *superR,
555 const TypedValueRegion *R,
558 /// Get the state and region whose binding this region \p R corresponds to.
560 /// If there is no lazy binding for \p R, the returned value will have a null
561 /// \c second. Note that a null pointer can represents a valid Store.
562 std::pair<Store, const SubRegion *>
563 findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
564 const SubRegion *originalRegion);
566 /// Returns the cached set of interesting SVals contained within a lazy
569 /// The precise value of "interesting" is determined for the purposes of
570 /// RegionStore's internal analysis. It must always contain all regions and
571 /// symbols, but may omit constants and other kinds of SVal.
572 const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);
574 //===------------------------------------------------------------------===//
576 //===------------------------------------------------------------------===//
578 /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
579 /// It returns a new Store with these values removed.
580 StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
581 SymbolReaper& SymReaper) override;
583 //===------------------------------------------------------------------===//
585 //===------------------------------------------------------------------===//
587 // FIXME: This method will soon be eliminated; see the note in Store.h.
588 DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state,
590 QualType EleTy) override;
592 //===------------------------------------------------------------------===//
594 //===------------------------------------------------------------------===//
596 RegionBindingsRef getRegionBindings(Store store) const {
597 return RegionBindingsRef(CBFactory,
598 static_cast<const RegionBindings::TreeTy*>(store),
599 RBFactory.getTreeFactory());
602 void print(Store store, raw_ostream &Out, const char* nl,
603 const char *sep) override;
605 void iterBindings(Store store, BindingsHandler& f) override {
606 RegionBindingsRef B = getRegionBindings(store);
607 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
608 const ClusterBindings &Cluster = I.getData();
609 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
611 const BindingKey &K = CI.getKey();
614 if (const SubRegion *R = dyn_cast<SubRegion>(K.getRegion())) {
615 // FIXME: Possibly incorporate the offset?
616 if (!f.HandleBinding(*this, store, R, CI.getData()))
624 } // end anonymous namespace
626 //===----------------------------------------------------------------------===//
627 // RegionStore creation.
628 //===----------------------------------------------------------------------===//
630 std::unique_ptr<StoreManager>
631 ento::CreateRegionStoreManager(ProgramStateManager &StMgr) {
632 RegionStoreFeatures F = maximal_features_tag();
633 return llvm::make_unique<RegionStoreManager>(StMgr, F);
636 std::unique_ptr<StoreManager>
637 ento::CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr) {
638 RegionStoreFeatures F = minimal_features_tag();
639 F.enableFields(true);
640 return llvm::make_unique<RegionStoreManager>(StMgr, F);
644 //===----------------------------------------------------------------------===//
645 // Region Cluster analysis.
646 //===----------------------------------------------------------------------===//
649 /// Used to determine which global regions are automatically included in the
650 /// initial worklist of a ClusterAnalysis.
651 enum GlobalsFilterKind {
652 /// Don't include any global regions.
654 /// Only include system globals.
656 /// Include all global regions.
660 template <typename DERIVED>
661 class ClusterAnalysis {
663 typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
664 typedef const MemRegion * WorkListElement;
665 typedef SmallVector<WorkListElement, 10> WorkList;
667 llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
671 RegionStoreManager &RM;
673 SValBuilder &svalBuilder;
679 const ClusterBindings *getCluster(const MemRegion *R) {
683 /// Returns true if all clusters in the given memspace should be initially
684 /// included in the cluster analysis. Subclasses may provide their
685 /// own implementation.
686 bool includeEntireMemorySpace(const MemRegion *Base) {
691 ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
693 : RM(rm), Ctx(StateMgr.getContext()),
694 svalBuilder(StateMgr.getSValBuilder()), B(std::move(b)) {}
696 RegionBindingsRef getRegionBindings() const { return B; }
698 bool isVisited(const MemRegion *R) {
699 return Visited.count(getCluster(R));
702 void GenerateClusters() {
703 // Scan the entire set of bindings and record the region clusters.
704 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
706 const MemRegion *Base = RI.getKey();
708 const ClusterBindings &Cluster = RI.getData();
709 assert(!Cluster.isEmpty() && "Empty clusters should be removed");
710 static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);
712 // If the base's memspace should be entirely invalidated, add the cluster
713 // to the workspace up front.
714 if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
715 AddToWorkList(WorkListElement(Base), &Cluster);
719 bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
720 if (C && !Visited.insert(C).second)
726 bool AddToWorkList(const MemRegion *R) {
727 return static_cast<DERIVED*>(this)->AddToWorkList(R);
731 while (!WL.empty()) {
732 WorkListElement E = WL.pop_back_val();
733 const MemRegion *BaseR = E;
735 static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
739 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
740 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}
742 void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
744 static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
749 //===----------------------------------------------------------------------===//
750 // Binding invalidation.
751 //===----------------------------------------------------------------------===//
753 bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
754 ScanReachableSymbols &Callbacks) {
755 assert(R == R->getBaseRegion() && "Should only be called for base regions");
756 RegionBindingsRef B = getRegionBindings(S);
757 const ClusterBindings *Cluster = B.lookup(R);
762 for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
764 if (!Callbacks.scan(RI.getData()))
771 static inline bool isUnionField(const FieldRegion *FR) {
772 return FR->getDecl()->getParent()->isUnion();
775 typedef SmallVector<const FieldDecl *, 8> FieldVector;
777 static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
778 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
780 const MemRegion *Base = K.getConcreteOffsetRegion();
781 const MemRegion *R = K.getRegion();
784 if (const FieldRegion *FR = dyn_cast<FieldRegion>(R))
785 if (!isUnionField(FR))
786 Fields.push_back(FR->getDecl());
788 R = cast<SubRegion>(R)->getSuperRegion();
792 static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
793 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
798 FieldVector FieldsInBindingKey;
799 getSymbolicOffsetFields(K, FieldsInBindingKey);
801 ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
803 return std::equal(FieldsInBindingKey.begin() + Delta,
804 FieldsInBindingKey.end(),
807 return std::equal(FieldsInBindingKey.begin(), FieldsInBindingKey.end(),
808 Fields.begin() - Delta);
811 /// Collects all bindings in \p Cluster that may refer to bindings within
814 /// Each binding is a pair whose \c first is the key (a BindingKey) and whose
815 /// \c second is the value (an SVal).
817 /// The \p IncludeAllDefaultBindings parameter specifies whether to include
818 /// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
819 /// an aggregate within a larger aggregate with a default binding.
821 collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
822 SValBuilder &SVB, const ClusterBindings &Cluster,
823 const SubRegion *Top, BindingKey TopKey,
824 bool IncludeAllDefaultBindings) {
825 FieldVector FieldsInSymbolicSubregions;
826 if (TopKey.hasSymbolicOffset()) {
827 getSymbolicOffsetFields(TopKey, FieldsInSymbolicSubregions);
828 Top = cast<SubRegion>(TopKey.getConcreteOffsetRegion());
829 TopKey = BindingKey::Make(Top, BindingKey::Default);
832 // Find the length (in bits) of the region being invalidated.
833 uint64_t Length = UINT64_MAX;
834 SVal Extent = Top->getExtent(SVB);
835 if (Optional<nonloc::ConcreteInt> ExtentCI =
836 Extent.getAs<nonloc::ConcreteInt>()) {
837 const llvm::APSInt &ExtentInt = ExtentCI->getValue();
838 assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
839 // Extents are in bytes but region offsets are in bits. Be careful!
840 Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
841 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Top)) {
842 if (FR->getDecl()->isBitField())
843 Length = FR->getDecl()->getBitWidthValue(SVB.getContext());
846 for (ClusterBindings::iterator I = Cluster.begin(), E = Cluster.end();
848 BindingKey NextKey = I.getKey();
849 if (NextKey.getRegion() == TopKey.getRegion()) {
850 // FIXME: This doesn't catch the case where we're really invalidating a
851 // region with a symbolic offset. Example:
855 if (NextKey.getOffset() > TopKey.getOffset() &&
856 NextKey.getOffset() - TopKey.getOffset() < Length) {
857 // Case 1: The next binding is inside the region we're invalidating.
859 Bindings.push_back(*I);
861 } else if (NextKey.getOffset() == TopKey.getOffset()) {
862 // Case 2: The next binding is at the same offset as the region we're
863 // invalidating. In this case, we need to leave default bindings alone,
864 // since they may be providing a default value for a regions beyond what
865 // we're invalidating.
866 // FIXME: This is probably incorrect; consider invalidating an outer
867 // struct whose first field is bound to a LazyCompoundVal.
868 if (IncludeAllDefaultBindings || NextKey.isDirect())
869 Bindings.push_back(*I);
872 } else if (NextKey.hasSymbolicOffset()) {
873 const MemRegion *Base = NextKey.getConcreteOffsetRegion();
874 if (Top->isSubRegionOf(Base)) {
875 // Case 3: The next key is symbolic and we just changed something within
876 // its concrete region. We don't know if the binding is still valid, so
877 // we'll be conservative and include it.
878 if (IncludeAllDefaultBindings || NextKey.isDirect())
879 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
880 Bindings.push_back(*I);
881 } else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Base)) {
882 // Case 4: The next key is symbolic, but we changed a known
883 // super-region. In this case the binding is certainly included.
884 if (Top == Base || BaseSR->isSubRegionOf(Top))
885 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
886 Bindings.push_back(*I);
893 collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
894 SValBuilder &SVB, const ClusterBindings &Cluster,
895 const SubRegion *Top, bool IncludeAllDefaultBindings) {
896 collectSubRegionBindings(Bindings, SVB, Cluster, Top,
897 BindingKey::Make(Top, BindingKey::Default),
898 IncludeAllDefaultBindings);
902 RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
903 const SubRegion *Top) {
904 BindingKey TopKey = BindingKey::Make(Top, BindingKey::Default);
905 const MemRegion *ClusterHead = TopKey.getBaseRegion();
907 if (Top == ClusterHead) {
908 // We can remove an entire cluster's bindings all in one go.
909 return B.remove(Top);
912 const ClusterBindings *Cluster = B.lookup(ClusterHead);
914 // If we're invalidating a region with a symbolic offset, we need to make
915 // sure we don't treat the base region as uninitialized anymore.
916 if (TopKey.hasSymbolicOffset()) {
917 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
918 return B.addBinding(Concrete, BindingKey::Default, UnknownVal());
923 SmallVector<BindingPair, 32> Bindings;
924 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, Top, TopKey,
925 /*IncludeAllDefaultBindings=*/false);
927 ClusterBindingsRef Result(*Cluster, CBFactory);
928 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
931 Result = Result.remove(I->first);
933 // If we're invalidating a region with a symbolic offset, we need to make sure
934 // we don't treat the base region as uninitialized anymore.
935 // FIXME: This isn't very precise; see the example in
936 // collectSubRegionBindings.
937 if (TopKey.hasSymbolicOffset()) {
938 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
939 Result = Result.add(BindingKey::Make(Concrete, BindingKey::Default),
943 if (Result.isEmpty())
944 return B.remove(ClusterHead);
945 return B.add(ClusterHead, Result.asImmutableMap());
949 class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
953 const LocationContext *LCtx;
954 InvalidatedSymbols &IS;
955 RegionAndSymbolInvalidationTraits &ITraits;
956 StoreManager::InvalidatedRegions *Regions;
957 GlobalsFilterKind GlobalsFilter;
959 invalidateRegionsWorker(RegionStoreManager &rm,
960 ProgramStateManager &stateMgr,
962 const Expr *ex, unsigned count,
963 const LocationContext *lctx,
964 InvalidatedSymbols &is,
965 RegionAndSymbolInvalidationTraits &ITraitsIn,
966 StoreManager::InvalidatedRegions *r,
967 GlobalsFilterKind GFK)
968 : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b),
969 Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
970 GlobalsFilter(GFK) {}
972 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
973 void VisitBinding(SVal V);
975 using ClusterAnalysis::AddToWorkList;
977 bool AddToWorkList(const MemRegion *R);
979 /// Returns true if all clusters in the memory space for \p Base should be
981 bool includeEntireMemorySpace(const MemRegion *Base);
983 /// Returns true if the memory space of the given region is one of the global
984 /// regions specially included at the start of invalidation.
985 bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
989 bool invalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
990 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
991 R, RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
992 const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
993 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
996 void invalidateRegionsWorker::VisitBinding(SVal V) {
997 // A symbol? Mark it touched by the invalidation.
998 if (SymbolRef Sym = V.getAsSymbol())
1001 if (const MemRegion *R = V.getAsRegion()) {
1006 // Is it a LazyCompoundVal? All references get invalidated as well.
1007 if (Optional<nonloc::LazyCompoundVal> LCS =
1008 V.getAs<nonloc::LazyCompoundVal>()) {
1010 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
1012 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
1021 void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
1022 const ClusterBindings *C) {
1024 bool PreserveRegionsContents =
1025 ITraits.hasTrait(baseR,
1026 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
1029 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
1030 VisitBinding(I.getData());
1032 // Invalidate regions contents.
1033 if (!PreserveRegionsContents)
1034 B = B.remove(baseR);
1037 // BlockDataRegion? If so, invalidate captured variables that are passed
1039 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
1040 for (BlockDataRegion::referenced_vars_iterator
1041 BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
1043 const VarRegion *VR = BI.getCapturedRegion();
1044 const VarDecl *VD = VR->getDecl();
1045 if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
1048 else if (Loc::isLocType(VR->getValueType())) {
1049 // Map the current bindings to a Store to retrieve the value
1050 // of the binding. If that binding itself is a region, we should
1051 // invalidate that region. This is because a block may capture
1052 // a pointer value, but the thing pointed by that pointer may
1054 SVal V = RM.getBinding(B, loc::MemRegionVal(VR));
1055 if (Optional<Loc> L = V.getAs<Loc>()) {
1056 if (const MemRegion *LR = L->getAsRegion())
1065 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
1066 IS.insert(SR->getSymbol());
1068 // Nothing else should be done in the case when we preserve regions context.
1069 if (PreserveRegionsContents)
1072 // Otherwise, we have a normal data region. Record that we touched the region.
1074 Regions->push_back(baseR);
1076 if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
1077 // Invalidate the region by setting its default value to
1078 // conjured symbol. The type of the symbol is irrelevant.
1079 DefinedOrUnknownSVal V =
1080 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
1081 B = B.addBinding(baseR, BindingKey::Default, V);
1085 if (!baseR->isBoundable())
1088 const TypedValueRegion *TR = cast<TypedValueRegion>(baseR);
1089 QualType T = TR->getValueType();
1091 if (isInitiallyIncludedGlobalRegion(baseR)) {
1092 // If the region is a global and we are invalidating all globals,
1093 // erasing the entry is good enough. This causes all globals to be lazily
1094 // symbolicated from the same base symbol.
1098 if (T->isStructureOrClassType()) {
1099 // Invalidate the region by setting its default value to
1100 // conjured symbol. The type of the symbol is irrelevant.
1101 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1103 B = B.addBinding(baseR, BindingKey::Default, V);
1107 if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
1108 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1110 RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
1112 if (doNotInvalidateSuperRegion) {
1113 // We are not doing blank invalidation of the whole array region so we
1114 // have to manually invalidate each elements.
1115 Optional<uint64_t> NumElements;
1117 // Compute lower and upper offsets for region within array.
1118 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
1119 NumElements = CAT->getSize().getZExtValue();
1120 if (!NumElements) // We are not dealing with a constant size array
1121 goto conjure_default;
1122 QualType ElementTy = AT->getElementType();
1123 uint64_t ElemSize = Ctx.getTypeSize(ElementTy);
1124 const RegionOffset &RO = baseR->getAsOffset();
1125 const MemRegion *SuperR = baseR->getBaseRegion();
1126 if (RO.hasSymbolicOffset()) {
1127 // If base region has a symbolic offset,
1128 // we revert to invalidating the super region.
1130 AddToWorkList(SuperR);
1131 goto conjure_default;
1134 uint64_t LowerOffset = RO.getOffset();
1135 uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
1136 bool UpperOverflow = UpperOffset < LowerOffset;
1138 // Invalidate regions which are within array boundaries,
1139 // or have a symbolic offset.
1141 goto conjure_default;
1143 const ClusterBindings *C = B.lookup(SuperR);
1145 goto conjure_default;
1147 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E;
1149 const BindingKey &BK = I.getKey();
1150 Optional<uint64_t> ROffset =
1151 BK.hasSymbolicOffset() ? Optional<uint64_t>() : BK.getOffset();
1153 // Check offset is not symbolic and within array's boundaries.
1154 // Handles arrays of 0 elements and of 0-sized elements as well.
1156 ((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
1158 (*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
1159 (LowerOffset == UpperOffset && *ROffset == LowerOffset))) {
1160 B = B.removeBinding(I.getKey());
1161 // Bound symbolic regions need to be invalidated for dead symbol
1163 SVal V = I.getData();
1164 const MemRegion *R = V.getAsRegion();
1165 if (R && isa<SymbolicRegion>(R))
1171 // Set the default value of the array to conjured symbol.
1172 DefinedOrUnknownSVal V =
1173 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1174 AT->getElementType(), Count);
1175 B = B.addBinding(baseR, BindingKey::Default, V);
1179 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1181 assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
1182 B = B.addBinding(baseR, BindingKey::Direct, V);
1185 bool invalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
1186 const MemRegion *R) {
1187 switch (GlobalsFilter) {
1190 case GFK_SystemOnly:
1191 return isa<GlobalSystemSpaceRegion>(R->getMemorySpace());
1193 return isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace());
1196 llvm_unreachable("unknown globals filter");
1199 bool invalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
1200 if (isInitiallyIncludedGlobalRegion(Base))
1203 const MemSpaceRegion *MemSpace = Base->getMemorySpace();
1204 return ITraits.hasTrait(MemSpace,
1205 RegionAndSymbolInvalidationTraits::TK_EntireMemSpace);
1209 RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
1212 const LocationContext *LCtx,
1213 RegionBindingsRef B,
1214 InvalidatedRegions *Invalidated) {
1215 // Bind the globals memory space to a new symbol that we will use to derive
1216 // the bindings for all globals.
1217 const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
1218 SVal V = svalBuilder.conjureSymbolVal(/* SymbolTag = */ (const void*) GS, Ex, LCtx,
1219 /* type does not matter */ Ctx.IntTy,
1222 B = B.removeBinding(GS)
1223 .addBinding(BindingKey::Make(GS, BindingKey::Default), V);
1225 // Even if there are no bindings in the global scope, we still need to
1226 // record that we touched it.
1228 Invalidated->push_back(GS);
1233 void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
1234 ArrayRef<SVal> Values,
1235 InvalidatedRegions *TopLevelRegions) {
1236 for (ArrayRef<SVal>::iterator I = Values.begin(),
1237 E = Values.end(); I != E; ++I) {
1239 if (Optional<nonloc::LazyCompoundVal> LCS =
1240 V.getAs<nonloc::LazyCompoundVal>()) {
1242 const SValListTy &Vals = getInterestingValues(*LCS);
1244 for (SValListTy::const_iterator I = Vals.begin(),
1245 E = Vals.end(); I != E; ++I) {
1246 // Note: the last argument is false here because these are
1247 // non-top-level regions.
1248 if (const MemRegion *R = (*I).getAsRegion())
1254 if (const MemRegion *R = V.getAsRegion()) {
1255 if (TopLevelRegions)
1256 TopLevelRegions->push_back(R);
1264 RegionStoreManager::invalidateRegions(Store store,
1265 ArrayRef<SVal> Values,
1266 const Expr *Ex, unsigned Count,
1267 const LocationContext *LCtx,
1268 const CallEvent *Call,
1269 InvalidatedSymbols &IS,
1270 RegionAndSymbolInvalidationTraits &ITraits,
1271 InvalidatedRegions *TopLevelRegions,
1272 InvalidatedRegions *Invalidated) {
1273 GlobalsFilterKind GlobalsFilter;
1275 if (Call->isInSystemHeader())
1276 GlobalsFilter = GFK_SystemOnly;
1278 GlobalsFilter = GFK_All;
1280 GlobalsFilter = GFK_None;
1283 RegionBindingsRef B = getRegionBindings(store);
1284 invalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
1285 Invalidated, GlobalsFilter);
1287 // Scan the bindings and generate the clusters.
1288 W.GenerateClusters();
1290 // Add the regions to the worklist.
1291 populateWorkList(W, Values, TopLevelRegions);
1295 // Return the new bindings.
1296 B = W.getRegionBindings();
1298 // For calls, determine which global regions should be invalidated and
1299 // invalidate them. (Note that function-static and immutable globals are never
1300 // invalidated by this.)
1301 // TODO: This could possibly be more precise with modules.
1302 switch (GlobalsFilter) {
1304 B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
1305 Ex, Count, LCtx, B, Invalidated);
1307 case GFK_SystemOnly:
1308 B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
1309 Ex, Count, LCtx, B, Invalidated);
1315 return StoreRef(B.asStore(), *this);
1318 //===----------------------------------------------------------------------===//
1319 // Extents for regions.
1320 //===----------------------------------------------------------------------===//
1322 DefinedOrUnknownSVal
1323 RegionStoreManager::getSizeInElements(ProgramStateRef state,
1326 SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
1327 const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
1329 return UnknownVal();
1331 CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());
1333 if (Ctx.getAsVariableArrayType(EleTy)) {
1334 // FIXME: We need to track extra state to properly record the size
1335 // of VLAs. Returning UnknownVal here, however, is a stop-gap so that
1336 // we don't have a divide-by-zero below.
1337 return UnknownVal();
1340 CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);
1342 // If a variable is reinterpreted as a type that doesn't fit into a larger
1343 // type evenly, round it down.
1344 // This is a signed value, since it's used in arithmetic with signed indices.
1345 return svalBuilder.makeIntVal(RegionSize / EleSize, false);
1348 //===----------------------------------------------------------------------===//
1349 // Location and region casting.
1350 //===----------------------------------------------------------------------===//
1352 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
1353 /// type. 'Array' represents the lvalue of the array being decayed
1354 /// to a pointer, and the returned SVal represents the decayed
1355 /// version of that lvalue (i.e., a pointer to the first element of
1356 /// the array). This is called by ExprEngine when evaluating casts
1357 /// from arrays to pointers.
1358 SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
1359 if (Array.getAs<loc::ConcreteInt>())
1362 if (!Array.getAs<loc::MemRegionVal>())
1363 return UnknownVal();
1365 const SubRegion *R =
1366 cast<SubRegion>(Array.castAs<loc::MemRegionVal>().getRegion());
1367 NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
1368 return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
1371 //===----------------------------------------------------------------------===//
1372 // Loading values from regions.
1373 //===----------------------------------------------------------------------===//
1375 SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
1376 assert(!L.getAs<UnknownVal>() && "location unknown");
1377 assert(!L.getAs<UndefinedVal>() && "location undefined");
1379 // For access to concrete addresses, return UnknownVal. Checks
1380 // for null dereferences (and similar errors) are done by checkers, not
1382 // FIXME: We can consider lazily symbolicating such memory, but we really
1383 // should defer this when we can reason easily about symbolicating arrays
1385 if (L.getAs<loc::ConcreteInt>()) {
1386 return UnknownVal();
1388 if (!L.getAs<loc::MemRegionVal>()) {
1389 return UnknownVal();
1392 const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();
1394 if (isa<BlockDataRegion>(MR)) {
1395 return UnknownVal();
1398 if (!isa<TypedValueRegion>(MR)) {
1400 if (const TypedRegion *TR = dyn_cast<TypedRegion>(MR))
1401 T = TR->getLocationType()->getPointeeType();
1402 else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
1403 T = SR->getSymbol()->getType()->getPointeeType();
1404 else if (isa<AllocaRegion>(MR))
1407 assert(!T.isNull() && "Unable to auto-detect binding type!");
1408 assert(!T->isVoidType() && "Attempting to dereference a void pointer!");
1409 MR = GetElementZeroRegion(cast<SubRegion>(MR), T);
1412 // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
1413 // instead of 'Loc', and have the other Loc cases handled at a higher level.
1414 const TypedValueRegion *R = cast<TypedValueRegion>(MR);
1415 QualType RTy = R->getValueType();
1417 // FIXME: we do not yet model the parts of a complex type, so treat the
1418 // whole thing as "unknown".
1419 if (RTy->isAnyComplexType())
1420 return UnknownVal();
1422 // FIXME: We should eventually handle funny addressing. e.g.:
1426 // char *q = (char*) p;
1427 // char c = *q; // returns the first byte of 'x'.
1429 // Such funny addressing will occur due to layering of regions.
1430 if (RTy->isStructureOrClassType())
1431 return getBindingForStruct(B, R);
1433 // FIXME: Handle unions.
1434 if (RTy->isUnionType())
1435 return createLazyBinding(B, R);
1437 if (RTy->isArrayType()) {
1438 if (RTy->isConstantArrayType())
1439 return getBindingForArray(B, R);
1441 return UnknownVal();
1444 // FIXME: handle Vector types.
1445 if (RTy->isVectorType())
1446 return UnknownVal();
1448 if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
1449 return CastRetrievedVal(getBindingForField(B, FR), FR, T, false);
1451 if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
1452 // FIXME: Here we actually perform an implicit conversion from the loaded
1453 // value to the element type. Eventually we want to compose these values
1454 // more intelligently. For example, an 'element' can encompass multiple
1455 // bound regions (e.g., several bound bytes), or could be a subset of
1457 return CastRetrievedVal(getBindingForElement(B, ER), ER, T, false);
1460 if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
1461 // FIXME: Here we actually perform an implicit conversion from the loaded
1462 // value to the ivar type. What we should model is stores to ivars
1463 // that blow past the extent of the ivar. If the address of the ivar is
1464 // reinterpretted, it is possible we stored a different value that could
1465 // fit within the ivar. Either we need to cast these when storing them
1466 // or reinterpret them lazily (as we do here).
1467 return CastRetrievedVal(getBindingForObjCIvar(B, IVR), IVR, T, false);
1470 if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
1471 // FIXME: Here we actually perform an implicit conversion from the loaded
1472 // value to the variable type. What we should model is stores to variables
1473 // that blow past the extent of the variable. If the address of the
1474 // variable is reinterpretted, it is possible we stored a different value
1475 // that could fit within the variable. Either we need to cast these when
1476 // storing them or reinterpret them lazily (as we do here).
1477 return CastRetrievedVal(getBindingForVar(B, VR), VR, T, false);
1480 const SVal *V = B.lookup(R, BindingKey::Direct);
1482 // Check if the region has a binding.
1486 // The location does not have a bound value. This means that it has
1487 // the value it had upon its creation and/or entry to the analyzed
1488 // function/method. These are either symbolic values or 'undefined'.
1489 if (R->hasStackNonParametersStorage()) {
1490 // All stack variables are considered to have undefined values
1491 // upon creation. All heap allocated blocks are considered to
1492 // have undefined values as well unless they are explicitly bound
1493 // to specific values.
1494 return UndefinedVal();
1497 // All other values are symbolic.
1498 return svalBuilder.getRegionValueSymbolVal(R);
1501 static QualType getUnderlyingType(const SubRegion *R) {
1503 if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
1504 RegionTy = TVR->getValueType();
1506 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
1507 RegionTy = SR->getSymbol()->getType();
1512 /// Checks to see if store \p B has a lazy binding for region \p R.
1514 /// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
1515 /// if there are additional bindings within \p R.
1517 /// Note that unlike RegionStoreManager::findLazyBinding, this will not search
1518 /// for lazy bindings for super-regions of \p R.
1519 static Optional<nonloc::LazyCompoundVal>
1520 getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
1521 const SubRegion *R, bool AllowSubregionBindings) {
1522 Optional<SVal> V = B.getDefaultBinding(R);
1526 Optional<nonloc::LazyCompoundVal> LCV = V->getAs<nonloc::LazyCompoundVal>();
1530 // If the LCV is for a subregion, the types might not match, and we shouldn't
1531 // reuse the binding.
1532 QualType RegionTy = getUnderlyingType(R);
1533 if (!RegionTy.isNull() &&
1534 !RegionTy->isVoidPointerType()) {
1535 QualType SourceRegionTy = LCV->getRegion()->getValueType();
1536 if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
1540 if (!AllowSubregionBindings) {
1541 // If there are any other bindings within this region, we shouldn't reuse
1542 // the top-level binding.
1543 SmallVector<BindingPair, 16> Bindings;
1544 collectSubRegionBindings(Bindings, SVB, *B.lookup(R->getBaseRegion()), R,
1545 /*IncludeAllDefaultBindings=*/true);
1546 if (Bindings.size() > 1)
1554 std::pair<Store, const SubRegion *>
1555 RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
1557 const SubRegion *originalRegion) {
1558 if (originalRegion != R) {
1559 if (Optional<nonloc::LazyCompoundVal> V =
1560 getExistingLazyBinding(svalBuilder, B, R, true))
1561 return std::make_pair(V->getStore(), V->getRegion());
1564 typedef std::pair<Store, const SubRegion *> StoreRegionPair;
1565 StoreRegionPair Result = StoreRegionPair();
1567 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1568 Result = findLazyBinding(B, cast<SubRegion>(ER->getSuperRegion()),
1572 Result.second = MRMgr.getElementRegionWithSuper(ER, Result.second);
1574 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
1575 Result = findLazyBinding(B, cast<SubRegion>(FR->getSuperRegion()),
1579 Result.second = MRMgr.getFieldRegionWithSuper(FR, Result.second);
1581 } else if (const CXXBaseObjectRegion *BaseReg =
1582 dyn_cast<CXXBaseObjectRegion>(R)) {
1583 // C++ base object region is another kind of region that we should blast
1584 // through to look for lazy compound value. It is like a field region.
1585 Result = findLazyBinding(B, cast<SubRegion>(BaseReg->getSuperRegion()),
1589 Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(BaseReg,
1596 SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
1597 const ElementRegion* R) {
1598 // We do not currently model bindings of the CompoundLiteralregion.
1599 if (isa<CompoundLiteralRegion>(R->getBaseRegion()))
1600 return UnknownVal();
1602 // Check if the region has a binding.
1603 if (const Optional<SVal> &V = B.getDirectBinding(R))
1606 const MemRegion* superR = R->getSuperRegion();
1608 // Check if the region is an element region of a string literal.
1609 if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
1610 // FIXME: Handle loads from strings where the literal is treated as
1611 // an integer, e.g., *((unsigned int*)"hello")
1612 QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
1613 if (!Ctx.hasSameUnqualifiedType(T, R->getElementType()))
1614 return UnknownVal();
1616 const StringLiteral *Str = StrR->getStringLiteral();
1617 SVal Idx = R->getIndex();
1618 if (Optional<nonloc::ConcreteInt> CI = Idx.getAs<nonloc::ConcreteInt>()) {
1619 int64_t i = CI->getValue().getSExtValue();
1620 // Abort on string underrun. This can be possible by arbitrary
1621 // clients of getBindingForElement().
1623 return UndefinedVal();
1624 int64_t length = Str->getLength();
1625 // Technically, only i == length is guaranteed to be null.
1626 // However, such overflows should be caught before reaching this point;
1627 // the only time such an access would be made is if a string literal was
1628 // used to initialize a larger array.
1629 char c = (i >= length) ? '\0' : Str->getCodeUnit(i);
1630 return svalBuilder.makeIntVal(c, T);
1634 // Check for loads from a code text region. For such loads, just give up.
1635 if (isa<CodeTextRegion>(superR))
1636 return UnknownVal();
1638 // Handle the case where we are indexing into a larger scalar object.
1639 // For example, this handles:
1643 // FIXME: This is a hack, and doesn't do anything really intelligent yet.
1644 const RegionRawOffset &O = R->getAsArrayOffset();
1646 // If we cannot reason about the offset, return an unknown value.
1648 return UnknownVal();
1650 if (const TypedValueRegion *baseR =
1651 dyn_cast_or_null<TypedValueRegion>(O.getRegion())) {
1652 QualType baseT = baseR->getValueType();
1653 if (baseT->isScalarType()) {
1654 QualType elemT = R->getElementType();
1655 if (elemT->isScalarType()) {
1656 if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
1657 if (const Optional<SVal> &V = B.getDirectBinding(superR)) {
1658 if (SymbolRef parentSym = V->getAsSymbol())
1659 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1661 if (V->isUnknownOrUndef())
1663 // Other cases: give up. We are indexing into a larger object
1664 // that has some value, but we don't know how to handle that yet.
1665 return UnknownVal();
1671 return getBindingForFieldOrElementCommon(B, R, R->getElementType());
1674 SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
1675 const FieldRegion* R) {
1677 // Check if the region has a binding.
1678 if (const Optional<SVal> &V = B.getDirectBinding(R))
1681 QualType Ty = R->getValueType();
1682 return getBindingForFieldOrElementCommon(B, R, Ty);
1686 RegionStoreManager::getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
1687 const MemRegion *superR,
1688 const TypedValueRegion *R,
1691 if (const Optional<SVal> &D = B.getDefaultBinding(superR)) {
1692 const SVal &val = D.getValue();
1693 if (SymbolRef parentSym = val.getAsSymbol())
1694 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1696 if (val.isZeroConstant())
1697 return svalBuilder.makeZeroVal(Ty);
1699 if (val.isUnknownOrUndef())
1702 // Lazy bindings are usually handled through getExistingLazyBinding().
1703 // We should unify these two code paths at some point.
1704 if (val.getAs<nonloc::LazyCompoundVal>() ||
1705 val.getAs<nonloc::CompoundVal>())
1708 llvm_unreachable("Unknown default value");
1714 SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
1715 RegionBindingsRef LazyBinding) {
1717 if (const ElementRegion *ER = dyn_cast<ElementRegion>(LazyBindingRegion))
1718 Result = getBindingForElement(LazyBinding, ER);
1720 Result = getBindingForField(LazyBinding,
1721 cast<FieldRegion>(LazyBindingRegion));
1723 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1724 // default value for /part/ of an aggregate from a default value for the
1725 // /entire/ aggregate. The most common case of this is when struct Outer
1726 // has as its first member a struct Inner, which is copied in from a stack
1727 // variable. In this case, even if the Outer's default value is symbolic, 0,
1728 // or unknown, it gets overridden by the Inner's default value of undefined.
1730 // This is a general problem -- if the Inner is zero-initialized, the Outer
1731 // will now look zero-initialized. The proper way to solve this is with a
1732 // new version of RegionStore that tracks the extent of a binding as well
1735 // This hack only takes care of the undefined case because that can very
1736 // quickly result in a warning.
1737 if (Result.isUndef())
1738 Result = UnknownVal();
1744 RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
1745 const TypedValueRegion *R,
1748 // At this point we have already checked in either getBindingForElement or
1749 // getBindingForField if 'R' has a direct binding.
1752 Store lazyBindingStore = nullptr;
1753 const SubRegion *lazyBindingRegion = nullptr;
1754 std::tie(lazyBindingStore, lazyBindingRegion) = findLazyBinding(B, R, R);
1755 if (lazyBindingRegion)
1756 return getLazyBinding(lazyBindingRegion,
1757 getRegionBindings(lazyBindingStore));
1759 // Record whether or not we see a symbolic index. That can completely
1760 // be out of scope of our lookup.
1761 bool hasSymbolicIndex = false;
1763 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1764 // default value for /part/ of an aggregate from a default value for the
1765 // /entire/ aggregate. The most common case of this is when struct Outer
1766 // has as its first member a struct Inner, which is copied in from a stack
1767 // variable. In this case, even if the Outer's default value is symbolic, 0,
1768 // or unknown, it gets overridden by the Inner's default value of undefined.
1770 // This is a general problem -- if the Inner is zero-initialized, the Outer
1771 // will now look zero-initialized. The proper way to solve this is with a
1772 // new version of RegionStore that tracks the extent of a binding as well
1775 // This hack only takes care of the undefined case because that can very
1776 // quickly result in a warning.
1777 bool hasPartialLazyBinding = false;
1779 const SubRegion *SR = dyn_cast<SubRegion>(R);
1781 const MemRegion *Base = SR->getSuperRegion();
1782 if (Optional<SVal> D = getBindingForDerivedDefaultValue(B, Base, R, Ty)) {
1783 if (D->getAs<nonloc::LazyCompoundVal>()) {
1784 hasPartialLazyBinding = true;
1791 if (const ElementRegion *ER = dyn_cast<ElementRegion>(Base)) {
1792 NonLoc index = ER->getIndex();
1793 if (!index.isConstant())
1794 hasSymbolicIndex = true;
1797 // If our super region is a field or element itself, walk up the region
1798 // hierarchy to see if there is a default value installed in an ancestor.
1799 SR = dyn_cast<SubRegion>(Base);
1802 if (R->hasStackNonParametersStorage()) {
1803 if (isa<ElementRegion>(R)) {
1804 // Currently we don't reason specially about Clang-style vectors. Check
1805 // if superR is a vector and if so return Unknown.
1806 if (const TypedValueRegion *typedSuperR =
1807 dyn_cast<TypedValueRegion>(R->getSuperRegion())) {
1808 if (typedSuperR->getValueType()->isVectorType())
1809 return UnknownVal();
1813 // FIXME: We also need to take ElementRegions with symbolic indexes into
1814 // account. This case handles both directly accessing an ElementRegion
1815 // with a symbolic offset, but also fields within an element with
1816 // a symbolic offset.
1817 if (hasSymbolicIndex)
1818 return UnknownVal();
1820 if (!hasPartialLazyBinding)
1821 return UndefinedVal();
1824 // All other values are symbolic.
1825 return svalBuilder.getRegionValueSymbolVal(R);
1828 SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
1829 const ObjCIvarRegion* R) {
1830 // Check if the region has a binding.
1831 if (const Optional<SVal> &V = B.getDirectBinding(R))
1834 const MemRegion *superR = R->getSuperRegion();
1836 // Check if the super region has a default binding.
1837 if (const Optional<SVal> &V = B.getDefaultBinding(superR)) {
1838 if (SymbolRef parentSym = V->getAsSymbol())
1839 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1841 // Other cases: give up.
1842 return UnknownVal();
1845 return getBindingForLazySymbol(R);
1848 SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
1849 const VarRegion *R) {
1851 // Check if the region has a binding.
1852 if (const Optional<SVal> &V = B.getDirectBinding(R))
1855 // Lazily derive a value for the VarRegion.
1856 const VarDecl *VD = R->getDecl();
1857 const MemSpaceRegion *MS = R->getMemorySpace();
1859 // Arguments are always symbolic.
1860 if (isa<StackArgumentsSpaceRegion>(MS))
1861 return svalBuilder.getRegionValueSymbolVal(R);
1863 // Is 'VD' declared constant? If so, retrieve the constant value.
1864 if (VD->getType().isConstQualified()) {
1865 if (const Expr *Init = VD->getInit()) {
1866 if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
1869 // If the variable is const qualified and has an initializer but
1870 // we couldn't evaluate initializer to a value, treat the value as
1872 return UnknownVal();
1876 // This must come after the check for constants because closure-captured
1877 // constant variables may appear in UnknownSpaceRegion.
1878 if (isa<UnknownSpaceRegion>(MS))
1879 return svalBuilder.getRegionValueSymbolVal(R);
1881 if (isa<GlobalsSpaceRegion>(MS)) {
1882 QualType T = VD->getType();
1884 // Function-scoped static variables are default-initialized to 0; if they
1885 // have an initializer, it would have been processed by now.
1886 // FIXME: This is only true when we're starting analysis from main().
1887 // We're losing a lot of coverage here.
1888 if (isa<StaticGlobalSpaceRegion>(MS))
1889 return svalBuilder.makeZeroVal(T);
1891 if (Optional<SVal> V = getBindingForDerivedDefaultValue(B, MS, R, T)) {
1892 assert(!V->getAs<nonloc::LazyCompoundVal>());
1893 return V.getValue();
1896 return svalBuilder.getRegionValueSymbolVal(R);
1899 return UndefinedVal();
1902 SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
1903 // All other values are symbolic.
1904 return svalBuilder.getRegionValueSymbolVal(R);
1907 const RegionStoreManager::SValListTy &
1908 RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
1909 // First, check the cache.
1910 LazyBindingsMapTy::iterator I = LazyBindingsMap.find(LCV.getCVData());
1911 if (I != LazyBindingsMap.end())
1914 // If we don't have a list of values cached, start constructing it.
1917 const SubRegion *LazyR = LCV.getRegion();
1918 RegionBindingsRef B = getRegionBindings(LCV.getStore());
1920 // If this region had /no/ bindings at the time, there are no interesting
1921 // values to return.
1922 const ClusterBindings *Cluster = B.lookup(LazyR->getBaseRegion());
1924 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1926 SmallVector<BindingPair, 32> Bindings;
1927 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, LazyR,
1928 /*IncludeAllDefaultBindings=*/true);
1929 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
1933 if (V.isUnknownOrUndef() || V.isConstant())
1936 if (Optional<nonloc::LazyCompoundVal> InnerLCV =
1937 V.getAs<nonloc::LazyCompoundVal>()) {
1938 const SValListTy &InnerList = getInterestingValues(*InnerLCV);
1939 List.insert(List.end(), InnerList.begin(), InnerList.end());
1946 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1949 NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
1950 const TypedValueRegion *R) {
1951 if (Optional<nonloc::LazyCompoundVal> V =
1952 getExistingLazyBinding(svalBuilder, B, R, false))
1955 return svalBuilder.makeLazyCompoundVal(StoreRef(B.asStore(), *this), R);
1958 static bool isRecordEmpty(const RecordDecl *RD) {
1959 if (!RD->field_empty())
1961 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD))
1962 return CRD->getNumBases() == 0;
1966 SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
1967 const TypedValueRegion *R) {
1968 const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
1969 if (!RD->getDefinition() || isRecordEmpty(RD))
1970 return UnknownVal();
1972 return createLazyBinding(B, R);
1975 SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
1976 const TypedValueRegion *R) {
1977 assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
1978 "Only constant array types can have compound bindings.");
1980 return createLazyBinding(B, R);
1983 bool RegionStoreManager::includedInBindings(Store store,
1984 const MemRegion *region) const {
1985 RegionBindingsRef B = getRegionBindings(store);
1986 region = region->getBaseRegion();
1988 // Quick path: if the base is the head of a cluster, the region is live.
1989 if (B.lookup(region))
1992 // Slow path: if the region is the VALUE of any binding, it is live.
1993 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
1994 const ClusterBindings &Cluster = RI.getData();
1995 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
1997 const SVal &D = CI.getData();
1998 if (const MemRegion *R = D.getAsRegion())
1999 if (R->getBaseRegion() == region)
2007 //===----------------------------------------------------------------------===//
2008 // Binding values to regions.
2009 //===----------------------------------------------------------------------===//
2011 StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
2012 if (Optional<loc::MemRegionVal> LV = L.getAs<loc::MemRegionVal>())
2013 if (const MemRegion* R = LV->getRegion())
2014 return StoreRef(getRegionBindings(ST).removeBinding(R)
2016 .getRootWithoutRetain(),
2019 return StoreRef(ST, *this);
2023 RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
2024 if (L.getAs<loc::ConcreteInt>())
2027 // If we get here, the location should be a region.
2028 const MemRegion *R = L.castAs<loc::MemRegionVal>().getRegion();
2030 // Check if the region is a struct region.
2031 if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(R)) {
2032 QualType Ty = TR->getValueType();
2033 if (Ty->isArrayType())
2034 return bindArray(B, TR, V);
2035 if (Ty->isStructureOrClassType())
2036 return bindStruct(B, TR, V);
2037 if (Ty->isVectorType())
2038 return bindVector(B, TR, V);
2039 if (Ty->isUnionType())
2040 return bindAggregate(B, TR, V);
2043 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
2044 // Binding directly to a symbolic region should be treated as binding
2046 QualType T = SR->getSymbol()->getType();
2047 if (T->isAnyPointerType() || T->isReferenceType())
2048 T = T->getPointeeType();
2050 R = GetElementZeroRegion(SR, T);
2053 // Clear out bindings that may overlap with this binding.
2054 RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
2055 return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
2059 RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
2064 if (Loc::isLocType(T))
2065 V = svalBuilder.makeNull();
2066 else if (T->isIntegralOrEnumerationType())
2067 V = svalBuilder.makeZeroVal(T);
2068 else if (T->isStructureOrClassType() || T->isArrayType()) {
2069 // Set the default value to a zero constant when it is a structure
2070 // or array. The type doesn't really matter.
2071 V = svalBuilder.makeZeroVal(Ctx.IntTy);
2074 // We can't represent values of this type, but we still need to set a value
2075 // to record that the region has been initialized.
2076 // If this assertion ever fires, a new case should be added above -- we
2077 // should know how to default-initialize any value we can symbolicate.
2078 assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
2082 return B.addBinding(R, BindingKey::Default, V);
2086 RegionStoreManager::bindArray(RegionBindingsConstRef B,
2087 const TypedValueRegion* R,
2090 const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
2091 QualType ElementTy = AT->getElementType();
2092 Optional<uint64_t> Size;
2094 if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
2095 Size = CAT->getSize().getZExtValue();
2097 // Check if the init expr is a literal. If so, bind the rvalue instead.
2098 // FIXME: It's not responsibility of the Store to transform this lvalue
2099 // to rvalue. ExprEngine or maybe even CFG should do this before binding.
2100 if (Optional<loc::MemRegionVal> MRV = Init.getAs<loc::MemRegionVal>()) {
2101 SVal V = getBinding(B.asStore(), *MRV, R->getValueType());
2102 return bindAggregate(B, R, V);
2105 // Handle lazy compound values.
2106 if (Init.getAs<nonloc::LazyCompoundVal>())
2107 return bindAggregate(B, R, Init);
2109 if (Init.isUnknown())
2110 return bindAggregate(B, R, UnknownVal());
2112 // Remaining case: explicit compound values.
2113 const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
2114 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2117 RegionBindingsRef NewB(B);
2119 for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
2120 // The init list might be shorter than the array length.
2124 const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
2125 const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
2127 if (ElementTy->isStructureOrClassType())
2128 NewB = bindStruct(NewB, ER, *VI);
2129 else if (ElementTy->isArrayType())
2130 NewB = bindArray(NewB, ER, *VI);
2132 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2135 // If the init list is shorter than the array length (or the array has
2136 // variable length), set the array default value. Values that are already set
2137 // are not overwritten.
2138 if (!Size.hasValue() || i < Size.getValue())
2139 NewB = setImplicitDefaultValue(NewB, R, ElementTy);
2144 RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
2145 const TypedValueRegion* R,
2147 QualType T = R->getValueType();
2148 assert(T->isVectorType());
2149 const VectorType *VT = T->getAs<VectorType>(); // Use getAs for typedefs.
2151 // Handle lazy compound values and symbolic values.
2152 if (V.getAs<nonloc::LazyCompoundVal>() || V.getAs<nonloc::SymbolVal>())
2153 return bindAggregate(B, R, V);
2155 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2156 // that we are binding symbolic struct value. Kill the field values, and if
2157 // the value is symbolic go and bind it as a "default" binding.
2158 if (!V.getAs<nonloc::CompoundVal>()) {
2159 return bindAggregate(B, R, UnknownVal());
2162 QualType ElemType = VT->getElementType();
2163 nonloc::CompoundVal CV = V.castAs<nonloc::CompoundVal>();
2164 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2165 unsigned index = 0, numElements = VT->getNumElements();
2166 RegionBindingsRef NewB(B);
2168 for ( ; index != numElements ; ++index) {
2172 NonLoc Idx = svalBuilder.makeArrayIndex(index);
2173 const ElementRegion *ER = MRMgr.getElementRegion(ElemType, Idx, R, Ctx);
2175 if (ElemType->isArrayType())
2176 NewB = bindArray(NewB, ER, *VI);
2177 else if (ElemType->isStructureOrClassType())
2178 NewB = bindStruct(NewB, ER, *VI);
2180 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2185 Optional<RegionBindingsRef>
2186 RegionStoreManager::tryBindSmallStruct(RegionBindingsConstRef B,
2187 const TypedValueRegion *R,
2188 const RecordDecl *RD,
2189 nonloc::LazyCompoundVal LCV) {
2192 if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(RD))
2193 if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
2196 for (const auto *FD : RD->fields()) {
2197 if (FD->isUnnamedBitfield())
2200 // If there are too many fields, or if any of the fields are aggregates,
2201 // just use the LCV as a default binding.
2202 if (Fields.size() == SmallStructLimit)
2205 QualType Ty = FD->getType();
2206 if (!(Ty->isScalarType() || Ty->isReferenceType()))
2209 Fields.push_back(FD);
2212 RegionBindingsRef NewB = B;
2214 for (FieldVector::iterator I = Fields.begin(), E = Fields.end(); I != E; ++I){
2215 const FieldRegion *SourceFR = MRMgr.getFieldRegion(*I, LCV.getRegion());
2216 SVal V = getBindingForField(getRegionBindings(LCV.getStore()), SourceFR);
2218 const FieldRegion *DestFR = MRMgr.getFieldRegion(*I, R);
2219 NewB = bind(NewB, loc::MemRegionVal(DestFR), V);
2225 RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
2226 const TypedValueRegion* R,
2228 if (!Features.supportsFields())
2231 QualType T = R->getValueType();
2232 assert(T->isStructureOrClassType());
2234 const RecordType* RT = T->getAs<RecordType>();
2235 const RecordDecl *RD = RT->getDecl();
2237 if (!RD->isCompleteDefinition())
2240 // Handle lazy compound values and symbolic values.
2241 if (Optional<nonloc::LazyCompoundVal> LCV =
2242 V.getAs<nonloc::LazyCompoundVal>()) {
2243 if (Optional<RegionBindingsRef> NewB = tryBindSmallStruct(B, R, RD, *LCV))
2245 return bindAggregate(B, R, V);
2247 if (V.getAs<nonloc::SymbolVal>())
2248 return bindAggregate(B, R, V);
2250 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2251 // that we are binding symbolic struct value. Kill the field values, and if
2252 // the value is symbolic go and bind it as a "default" binding.
2253 if (V.isUnknown() || !V.getAs<nonloc::CompoundVal>())
2254 return bindAggregate(B, R, UnknownVal());
2256 const nonloc::CompoundVal& CV = V.castAs<nonloc::CompoundVal>();
2257 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2259 RecordDecl::field_iterator FI, FE;
2260 RegionBindingsRef NewB(B);
2262 for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {
2267 // Skip any unnamed bitfields to stay in sync with the initializers.
2268 if (FI->isUnnamedBitfield())
2271 QualType FTy = FI->getType();
2272 const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
2274 if (FTy->isArrayType())
2275 NewB = bindArray(NewB, FR, *VI);
2276 else if (FTy->isStructureOrClassType())
2277 NewB = bindStruct(NewB, FR, *VI);
2279 NewB = bind(NewB, loc::MemRegionVal(FR), *VI);
2283 // There may be fewer values in the initialize list than the fields of struct.
2285 NewB = NewB.addBinding(R, BindingKey::Default,
2286 svalBuilder.makeIntVal(0, false));
2293 RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
2294 const TypedRegion *R,
2296 // Remove the old bindings, using 'R' as the root of all regions
2297 // we will invalidate. Then add the new binding.
2298 return removeSubRegionBindings(B, R).addBinding(R, BindingKey::Default, Val);
2301 //===----------------------------------------------------------------------===//
2303 //===----------------------------------------------------------------------===//
2306 class removeDeadBindingsWorker :
2307 public ClusterAnalysis<removeDeadBindingsWorker> {
2308 SmallVector<const SymbolicRegion*, 12> Postponed;
2309 SymbolReaper &SymReaper;
2310 const StackFrameContext *CurrentLCtx;
2313 removeDeadBindingsWorker(RegionStoreManager &rm,
2314 ProgramStateManager &stateMgr,
2315 RegionBindingsRef b, SymbolReaper &symReaper,
2316 const StackFrameContext *LCtx)
2317 : ClusterAnalysis<removeDeadBindingsWorker>(rm, stateMgr, b),
2318 SymReaper(symReaper), CurrentLCtx(LCtx) {}
2320 // Called by ClusterAnalysis.
2321 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
2322 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
2323 using ClusterAnalysis<removeDeadBindingsWorker>::VisitCluster;
2325 using ClusterAnalysis::AddToWorkList;
2327 bool AddToWorkList(const MemRegion *R);
2329 bool UpdatePostponed();
2330 void VisitBinding(SVal V);
2334 bool removeDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
2335 const MemRegion *BaseR = R->getBaseRegion();
2336 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
2339 void removeDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
2340 const ClusterBindings &C) {
2342 if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
2343 if (SymReaper.isLive(VR))
2344 AddToWorkList(baseR, &C);
2349 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
2350 if (SymReaper.isLive(SR->getSymbol()))
2351 AddToWorkList(SR, &C);
2353 Postponed.push_back(SR);
2358 if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
2359 AddToWorkList(baseR, &C);
2363 // CXXThisRegion in the current or parent location context is live.
2364 if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
2365 const StackArgumentsSpaceRegion *StackReg =
2366 cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
2367 const StackFrameContext *RegCtx = StackReg->getStackFrame();
2369 (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx)))
2370 AddToWorkList(TR, &C);
2374 void removeDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
2375 const ClusterBindings *C) {
2379 // Mark the symbol for any SymbolicRegion with live bindings as live itself.
2380 // This means we should continue to track that symbol.
2381 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(baseR))
2382 SymReaper.markLive(SymR->getSymbol());
2384 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I) {
2385 // Element index of a binding key is live.
2386 SymReaper.markElementIndicesLive(I.getKey().getRegion());
2388 VisitBinding(I.getData());
2392 void removeDeadBindingsWorker::VisitBinding(SVal V) {
2393 // Is it a LazyCompoundVal? All referenced regions are live as well.
2394 if (Optional<nonloc::LazyCompoundVal> LCS =
2395 V.getAs<nonloc::LazyCompoundVal>()) {
2397 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
2399 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
2407 // If V is a region, then add it to the worklist.
2408 if (const MemRegion *R = V.getAsRegion()) {
2410 SymReaper.markLive(R);
2412 // All regions captured by a block are also live.
2413 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
2414 BlockDataRegion::referenced_vars_iterator I = BR->referenced_vars_begin(),
2415 E = BR->referenced_vars_end();
2416 for ( ; I != E; ++I)
2417 AddToWorkList(I.getCapturedRegion());
2422 // Update the set of live symbols.
2423 for (SymExpr::symbol_iterator SI = V.symbol_begin(), SE = V.symbol_end();
2425 SymReaper.markLive(*SI);
2428 bool removeDeadBindingsWorker::UpdatePostponed() {
2429 // See if any postponed SymbolicRegions are actually live now, after
2430 // having done a scan.
2431 bool changed = false;
2433 for (SmallVectorImpl<const SymbolicRegion*>::iterator
2434 I = Postponed.begin(), E = Postponed.end() ; I != E ; ++I) {
2435 if (const SymbolicRegion *SR = *I) {
2436 if (SymReaper.isLive(SR->getSymbol())) {
2437 changed |= AddToWorkList(SR);
2446 StoreRef RegionStoreManager::removeDeadBindings(Store store,
2447 const StackFrameContext *LCtx,
2448 SymbolReaper& SymReaper) {
2449 RegionBindingsRef B = getRegionBindings(store);
2450 removeDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
2451 W.GenerateClusters();
2453 // Enqueue the region roots onto the worklist.
2454 for (SymbolReaper::region_iterator I = SymReaper.region_begin(),
2455 E = SymReaper.region_end(); I != E; ++I) {
2456 W.AddToWorkList(*I);
2459 do W.RunWorkList(); while (W.UpdatePostponed());
2461 // We have now scanned the store, marking reachable regions and symbols
2462 // as live. We now remove all the regions that are dead from the store
2463 // as well as update DSymbols with the set symbols that are now dead.
2464 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
2465 const MemRegion *Base = I.getKey();
2467 // If the cluster has been visited, we know the region has been marked.
2468 if (W.isVisited(Base))
2471 // Remove the dead entry.
2474 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(Base))
2475 SymReaper.maybeDead(SymR->getSymbol());
2477 // Mark all non-live symbols that this binding references as dead.
2478 const ClusterBindings &Cluster = I.getData();
2479 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
2481 SVal X = CI.getData();
2482 SymExpr::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
2483 for (; SI != SE; ++SI)
2484 SymReaper.maybeDead(*SI);
2488 return StoreRef(B.asStore(), *this);
2491 //===----------------------------------------------------------------------===//
2493 //===----------------------------------------------------------------------===//
2495 void RegionStoreManager::print(Store store, raw_ostream &OS,
2496 const char* nl, const char *sep) {
2497 RegionBindingsRef B = getRegionBindings(store);
2498 OS << "Store (direct and default bindings), "