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/AnalysisContext.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
137 LLVM_DUMP_METHOD void BindingKey::dump() const { llvm::errs() << *this; }
139 //===----------------------------------------------------------------------===//
140 // Actual Store type.
141 //===----------------------------------------------------------------------===//
143 typedef llvm::ImmutableMap<BindingKey, SVal> ClusterBindings;
144 typedef llvm::ImmutableMapRef<BindingKey, SVal> ClusterBindingsRef;
145 typedef std::pair<BindingKey, SVal> BindingPair;
147 typedef llvm::ImmutableMap<const MemRegion *, ClusterBindings>
151 class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
153 ClusterBindings::Factory *CBFactory;
156 typedef llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>
159 RegionBindingsRef(ClusterBindings::Factory &CBFactory,
160 const RegionBindings::TreeTy *T,
161 RegionBindings::TreeTy::Factory *F)
162 : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(T, F),
163 CBFactory(&CBFactory) {}
165 RegionBindingsRef(const ParentTy &P, ClusterBindings::Factory &CBFactory)
166 : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(P),
167 CBFactory(&CBFactory) {}
169 RegionBindingsRef add(key_type_ref K, data_type_ref D) const {
170 return RegionBindingsRef(static_cast<const ParentTy *>(this)->add(K, D),
174 RegionBindingsRef remove(key_type_ref K) const {
175 return RegionBindingsRef(static_cast<const ParentTy *>(this)->remove(K),
179 RegionBindingsRef addBinding(BindingKey K, SVal V) const;
181 RegionBindingsRef addBinding(const MemRegion *R,
182 BindingKey::Kind k, SVal V) const;
184 const SVal *lookup(BindingKey K) const;
185 const SVal *lookup(const MemRegion *R, BindingKey::Kind k) const;
186 using llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>::lookup;
188 RegionBindingsRef removeBinding(BindingKey K);
190 RegionBindingsRef removeBinding(const MemRegion *R,
193 RegionBindingsRef removeBinding(const MemRegion *R) {
194 return removeBinding(R, BindingKey::Direct).
195 removeBinding(R, BindingKey::Default);
198 Optional<SVal> getDirectBinding(const MemRegion *R) const;
200 /// getDefaultBinding - Returns an SVal* representing an optional default
201 /// binding associated with a region and its subregions.
202 Optional<SVal> getDefaultBinding(const MemRegion *R) const;
204 /// Return the internal tree as a Store.
205 Store asStore() const {
206 return asImmutableMap().getRootWithoutRetain();
209 void dump(raw_ostream &OS, const char *nl) const {
210 for (iterator I = begin(), E = end(); I != E; ++I) {
211 const ClusterBindings &Cluster = I.getData();
212 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
214 OS << ' ' << CI.getKey() << " : " << CI.getData() << nl;
220 LLVM_DUMP_METHOD void dump() const { dump(llvm::errs(), "\n"); }
222 } // end anonymous namespace
224 typedef const RegionBindingsRef& RegionBindingsConstRef;
226 Optional<SVal> RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
227 return Optional<SVal>::create(lookup(R, BindingKey::Direct));
230 Optional<SVal> RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
231 if (R->isBoundable())
232 if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R))
233 if (TR->getValueType()->isUnionType())
236 return Optional<SVal>::create(lookup(R, BindingKey::Default));
239 RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
240 const MemRegion *Base = K.getBaseRegion();
242 const ClusterBindings *ExistingCluster = lookup(Base);
243 ClusterBindings Cluster =
244 (ExistingCluster ? *ExistingCluster : CBFactory->getEmptyMap());
246 ClusterBindings NewCluster = CBFactory->add(Cluster, K, V);
247 return add(Base, NewCluster);
251 RegionBindingsRef RegionBindingsRef::addBinding(const MemRegion *R,
254 return addBinding(BindingKey::Make(R, k), V);
257 const SVal *RegionBindingsRef::lookup(BindingKey K) const {
258 const ClusterBindings *Cluster = lookup(K.getBaseRegion());
261 return Cluster->lookup(K);
264 const SVal *RegionBindingsRef::lookup(const MemRegion *R,
265 BindingKey::Kind k) const {
266 return lookup(BindingKey::Make(R, k));
269 RegionBindingsRef RegionBindingsRef::removeBinding(BindingKey K) {
270 const MemRegion *Base = K.getBaseRegion();
271 const ClusterBindings *Cluster = lookup(Base);
275 ClusterBindings NewCluster = CBFactory->remove(*Cluster, K);
276 if (NewCluster.isEmpty())
278 return add(Base, NewCluster);
281 RegionBindingsRef RegionBindingsRef::removeBinding(const MemRegion *R,
283 return removeBinding(BindingKey::Make(R, k));
286 //===----------------------------------------------------------------------===//
287 // Fine-grained control of RegionStoreManager.
288 //===----------------------------------------------------------------------===//
291 struct minimal_features_tag {};
292 struct maximal_features_tag {};
294 class RegionStoreFeatures {
297 RegionStoreFeatures(minimal_features_tag) :
298 SupportsFields(false) {}
300 RegionStoreFeatures(maximal_features_tag) :
301 SupportsFields(true) {}
303 void enableFields(bool t) { SupportsFields = t; }
305 bool supportsFields() const { return SupportsFields; }
309 //===----------------------------------------------------------------------===//
310 // Main RegionStore logic.
311 //===----------------------------------------------------------------------===//
314 class invalidateRegionsWorker;
316 class RegionStoreManager : public StoreManager {
318 const RegionStoreFeatures Features;
320 RegionBindings::Factory RBFactory;
321 mutable ClusterBindings::Factory CBFactory;
323 typedef std::vector<SVal> SValListTy;
325 typedef llvm::DenseMap<const LazyCompoundValData *,
326 SValListTy> LazyBindingsMapTy;
327 LazyBindingsMapTy LazyBindingsMap;
329 /// The largest number of fields a struct can have and still be
330 /// considered "small".
332 /// This is currently used to decide whether or not it is worth "forcing" a
333 /// LazyCompoundVal on bind.
335 /// This is controlled by 'region-store-small-struct-limit' option.
336 /// To disable all small-struct-dependent behavior, set the option to "0".
337 unsigned SmallStructLimit;
339 /// \brief A helper used to populate the work list with the given set of
341 void populateWorkList(invalidateRegionsWorker &W,
342 ArrayRef<SVal> Values,
343 InvalidatedRegions *TopLevelRegions);
346 RegionStoreManager(ProgramStateManager& mgr, const RegionStoreFeatures &f)
347 : StoreManager(mgr), Features(f),
348 RBFactory(mgr.getAllocator()), CBFactory(mgr.getAllocator()),
349 SmallStructLimit(0) {
350 if (SubEngine *Eng = StateMgr.getOwningEngine()) {
351 AnalyzerOptions &Options = Eng->getAnalysisManager().options;
353 Options.getOptionAsInteger("region-store-small-struct-limit", 2);
358 /// setImplicitDefaultValue - Set the default binding for the provided
359 /// MemRegion to the value implicitly defined for compound literals when
360 /// the value is not specified.
361 RegionBindingsRef setImplicitDefaultValue(RegionBindingsConstRef B,
362 const MemRegion *R, QualType T);
364 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
365 /// type. 'Array' represents the lvalue of the array being decayed
366 /// to a pointer, and the returned SVal represents the decayed
367 /// version of that lvalue (i.e., a pointer to the first element of
368 /// the array). This is called by ExprEngine when evaluating
369 /// casts from arrays to pointers.
370 SVal ArrayToPointer(Loc Array, QualType ElementTy) override;
372 StoreRef getInitialStore(const LocationContext *InitLoc) override {
373 return StoreRef(RBFactory.getEmptyMap().getRootWithoutRetain(), *this);
376 //===-------------------------------------------------------------------===//
377 // Binding values to regions.
378 //===-------------------------------------------------------------------===//
379 RegionBindingsRef invalidateGlobalRegion(MemRegion::Kind K,
382 const LocationContext *LCtx,
384 InvalidatedRegions *Invalidated);
386 StoreRef invalidateRegions(Store store,
387 ArrayRef<SVal> Values,
388 const Expr *E, unsigned Count,
389 const LocationContext *LCtx,
390 const CallEvent *Call,
391 InvalidatedSymbols &IS,
392 RegionAndSymbolInvalidationTraits &ITraits,
393 InvalidatedRegions *Invalidated,
394 InvalidatedRegions *InvalidatedTopLevel) override;
396 bool scanReachableSymbols(Store S, const MemRegion *R,
397 ScanReachableSymbols &Callbacks) override;
399 RegionBindingsRef removeSubRegionBindings(RegionBindingsConstRef B,
402 public: // Part of public interface to class.
404 StoreRef Bind(Store store, Loc LV, SVal V) override {
405 return StoreRef(bind(getRegionBindings(store), LV, V).asStore(), *this);
408 RegionBindingsRef bind(RegionBindingsConstRef B, Loc LV, SVal V);
410 // BindDefault is only used to initialize a region with a default value.
411 StoreRef BindDefault(Store store, const MemRegion *R, SVal V) override {
412 RegionBindingsRef B = getRegionBindings(store);
413 assert(!B.lookup(R, BindingKey::Direct));
415 BindingKey Key = BindingKey::Make(R, BindingKey::Default);
417 const SubRegion *SR = cast<SubRegion>(R);
418 assert(SR->getAsOffset().getOffset() ==
419 SR->getSuperRegion()->getAsOffset().getOffset() &&
420 "A default value must come from a super-region");
421 B = removeSubRegionBindings(B, SR);
423 B = B.addBinding(Key, V);
426 return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
429 /// Attempt to extract the fields of \p LCV and bind them to the struct region
432 /// This path is used when it seems advantageous to "force" loading the values
433 /// within a LazyCompoundVal to bind memberwise to the struct region, rather
434 /// than using a Default binding at the base of the entire region. This is a
435 /// heuristic attempting to avoid building long chains of LazyCompoundVals.
437 /// \returns The updated store bindings, or \c None if binding non-lazily
438 /// would be too expensive.
439 Optional<RegionBindingsRef> tryBindSmallStruct(RegionBindingsConstRef B,
440 const TypedValueRegion *R,
441 const RecordDecl *RD,
442 nonloc::LazyCompoundVal LCV);
444 /// BindStruct - Bind a compound value to a structure.
445 RegionBindingsRef bindStruct(RegionBindingsConstRef B,
446 const TypedValueRegion* R, SVal V);
448 /// BindVector - Bind a compound value to a vector.
449 RegionBindingsRef bindVector(RegionBindingsConstRef B,
450 const TypedValueRegion* R, SVal V);
452 RegionBindingsRef bindArray(RegionBindingsConstRef B,
453 const TypedValueRegion* R,
456 /// Clears out all bindings in the given region and assigns a new value
457 /// as a Default binding.
458 RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
459 const TypedRegion *R,
462 /// \brief Create a new store with the specified binding removed.
463 /// \param ST the original store, that is the basis for the new store.
464 /// \param L the location whose binding should be removed.
465 StoreRef killBinding(Store ST, Loc L) override;
467 void incrementReferenceCount(Store store) override {
468 getRegionBindings(store).manualRetain();
471 /// If the StoreManager supports it, decrement the reference count of
472 /// the specified Store object. If the reference count hits 0, the memory
473 /// associated with the object is recycled.
474 void decrementReferenceCount(Store store) override {
475 getRegionBindings(store).manualRelease();
478 bool includedInBindings(Store store, const MemRegion *region) const override;
480 /// \brief Return the value bound to specified location in a given state.
482 /// The high level logic for this method is this:
485 /// return L's binding
486 /// else if L is in killset
489 /// if L is on stack or heap
493 SVal getBinding(Store S, Loc L, QualType T) override {
494 return getBinding(getRegionBindings(S), L, T);
497 Optional<SVal> getDefaultBinding(Store S, const MemRegion *R) override {
498 RegionBindingsRef B = getRegionBindings(S);
499 // Default bindings are always applied over a base region so look up the
500 // base region's default binding, otherwise the lookup will fail when R
501 // is at an offset from R->getBaseRegion().
502 return B.getDefaultBinding(R->getBaseRegion());
505 SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());
507 SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);
509 SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);
511 SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);
513 SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);
515 SVal getBindingForLazySymbol(const TypedValueRegion *R);
517 SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
518 const TypedValueRegion *R,
521 SVal getLazyBinding(const SubRegion *LazyBindingRegion,
522 RegionBindingsRef LazyBinding);
524 /// Get bindings for the values in a struct and return a CompoundVal, used
525 /// when doing struct copy:
528 /// y's value is retrieved by this method.
529 SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
530 SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
531 NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);
533 /// Used to lazily generate derived symbols for bindings that are defined
534 /// implicitly by default bindings in a super region.
536 /// Note that callers may need to specially handle LazyCompoundVals, which
537 /// are returned as is in case the caller needs to treat them differently.
538 Optional<SVal> getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
539 const MemRegion *superR,
540 const TypedValueRegion *R,
543 /// Get the state and region whose binding this region \p R corresponds to.
545 /// If there is no lazy binding for \p R, the returned value will have a null
546 /// \c second. Note that a null pointer can represents a valid Store.
547 std::pair<Store, const SubRegion *>
548 findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
549 const SubRegion *originalRegion);
551 /// Returns the cached set of interesting SVals contained within a lazy
554 /// The precise value of "interesting" is determined for the purposes of
555 /// RegionStore's internal analysis. It must always contain all regions and
556 /// symbols, but may omit constants and other kinds of SVal.
557 const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);
559 //===------------------------------------------------------------------===//
561 //===------------------------------------------------------------------===//
563 /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
564 /// It returns a new Store with these values removed.
565 StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
566 SymbolReaper& SymReaper) override;
568 //===------------------------------------------------------------------===//
570 //===------------------------------------------------------------------===//
572 // FIXME: This method will soon be eliminated; see the note in Store.h.
573 DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state,
575 QualType EleTy) override;
577 //===------------------------------------------------------------------===//
579 //===------------------------------------------------------------------===//
581 RegionBindingsRef getRegionBindings(Store store) const {
582 return RegionBindingsRef(CBFactory,
583 static_cast<const RegionBindings::TreeTy*>(store),
584 RBFactory.getTreeFactory());
587 void print(Store store, raw_ostream &Out, const char* nl,
588 const char *sep) override;
590 void iterBindings(Store store, BindingsHandler& f) override {
591 RegionBindingsRef B = getRegionBindings(store);
592 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
593 const ClusterBindings &Cluster = I.getData();
594 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
596 const BindingKey &K = CI.getKey();
599 if (const SubRegion *R = dyn_cast<SubRegion>(K.getRegion())) {
600 // FIXME: Possibly incorporate the offset?
601 if (!f.HandleBinding(*this, store, R, CI.getData()))
609 } // end anonymous namespace
611 //===----------------------------------------------------------------------===//
612 // RegionStore creation.
613 //===----------------------------------------------------------------------===//
615 std::unique_ptr<StoreManager>
616 ento::CreateRegionStoreManager(ProgramStateManager &StMgr) {
617 RegionStoreFeatures F = maximal_features_tag();
618 return llvm::make_unique<RegionStoreManager>(StMgr, F);
621 std::unique_ptr<StoreManager>
622 ento::CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr) {
623 RegionStoreFeatures F = minimal_features_tag();
624 F.enableFields(true);
625 return llvm::make_unique<RegionStoreManager>(StMgr, F);
629 //===----------------------------------------------------------------------===//
630 // Region Cluster analysis.
631 //===----------------------------------------------------------------------===//
634 /// Used to determine which global regions are automatically included in the
635 /// initial worklist of a ClusterAnalysis.
636 enum GlobalsFilterKind {
637 /// Don't include any global regions.
639 /// Only include system globals.
641 /// Include all global regions.
645 template <typename DERIVED>
646 class ClusterAnalysis {
648 typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
649 typedef const MemRegion * WorkListElement;
650 typedef SmallVector<WorkListElement, 10> WorkList;
652 llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
656 RegionStoreManager &RM;
658 SValBuilder &svalBuilder;
664 const ClusterBindings *getCluster(const MemRegion *R) {
668 /// Returns true if all clusters in the given memspace should be initially
669 /// included in the cluster analysis. Subclasses may provide their
670 /// own implementation.
671 bool includeEntireMemorySpace(const MemRegion *Base) {
676 ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
678 : RM(rm), Ctx(StateMgr.getContext()),
679 svalBuilder(StateMgr.getSValBuilder()), B(std::move(b)) {}
681 RegionBindingsRef getRegionBindings() const { return B; }
683 bool isVisited(const MemRegion *R) {
684 return Visited.count(getCluster(R));
687 void GenerateClusters() {
688 // Scan the entire set of bindings and record the region clusters.
689 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
691 const MemRegion *Base = RI.getKey();
693 const ClusterBindings &Cluster = RI.getData();
694 assert(!Cluster.isEmpty() && "Empty clusters should be removed");
695 static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);
697 // If the base's memspace should be entirely invalidated, add the cluster
698 // to the workspace up front.
699 if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
700 AddToWorkList(WorkListElement(Base), &Cluster);
704 bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
705 if (C && !Visited.insert(C).second)
711 bool AddToWorkList(const MemRegion *R) {
712 return static_cast<DERIVED*>(this)->AddToWorkList(R);
716 while (!WL.empty()) {
717 WorkListElement E = WL.pop_back_val();
718 const MemRegion *BaseR = E;
720 static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
724 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
725 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}
727 void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
729 static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
734 //===----------------------------------------------------------------------===//
735 // Binding invalidation.
736 //===----------------------------------------------------------------------===//
738 bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
739 ScanReachableSymbols &Callbacks) {
740 assert(R == R->getBaseRegion() && "Should only be called for base regions");
741 RegionBindingsRef B = getRegionBindings(S);
742 const ClusterBindings *Cluster = B.lookup(R);
747 for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
749 if (!Callbacks.scan(RI.getData()))
756 static inline bool isUnionField(const FieldRegion *FR) {
757 return FR->getDecl()->getParent()->isUnion();
760 typedef SmallVector<const FieldDecl *, 8> FieldVector;
762 static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
763 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
765 const MemRegion *Base = K.getConcreteOffsetRegion();
766 const MemRegion *R = K.getRegion();
769 if (const FieldRegion *FR = dyn_cast<FieldRegion>(R))
770 if (!isUnionField(FR))
771 Fields.push_back(FR->getDecl());
773 R = cast<SubRegion>(R)->getSuperRegion();
777 static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
778 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
783 FieldVector FieldsInBindingKey;
784 getSymbolicOffsetFields(K, FieldsInBindingKey);
786 ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
788 return std::equal(FieldsInBindingKey.begin() + Delta,
789 FieldsInBindingKey.end(),
792 return std::equal(FieldsInBindingKey.begin(), FieldsInBindingKey.end(),
793 Fields.begin() - Delta);
796 /// Collects all bindings in \p Cluster that may refer to bindings within
799 /// Each binding is a pair whose \c first is the key (a BindingKey) and whose
800 /// \c second is the value (an SVal).
802 /// The \p IncludeAllDefaultBindings parameter specifies whether to include
803 /// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
804 /// an aggregate within a larger aggregate with a default binding.
806 collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
807 SValBuilder &SVB, const ClusterBindings &Cluster,
808 const SubRegion *Top, BindingKey TopKey,
809 bool IncludeAllDefaultBindings) {
810 FieldVector FieldsInSymbolicSubregions;
811 if (TopKey.hasSymbolicOffset()) {
812 getSymbolicOffsetFields(TopKey, FieldsInSymbolicSubregions);
813 Top = cast<SubRegion>(TopKey.getConcreteOffsetRegion());
814 TopKey = BindingKey::Make(Top, BindingKey::Default);
817 // Find the length (in bits) of the region being invalidated.
818 uint64_t Length = UINT64_MAX;
819 SVal Extent = Top->getExtent(SVB);
820 if (Optional<nonloc::ConcreteInt> ExtentCI =
821 Extent.getAs<nonloc::ConcreteInt>()) {
822 const llvm::APSInt &ExtentInt = ExtentCI->getValue();
823 assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
824 // Extents are in bytes but region offsets are in bits. Be careful!
825 Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
826 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Top)) {
827 if (FR->getDecl()->isBitField())
828 Length = FR->getDecl()->getBitWidthValue(SVB.getContext());
831 for (ClusterBindings::iterator I = Cluster.begin(), E = Cluster.end();
833 BindingKey NextKey = I.getKey();
834 if (NextKey.getRegion() == TopKey.getRegion()) {
835 // FIXME: This doesn't catch the case where we're really invalidating a
836 // region with a symbolic offset. Example:
840 if (NextKey.getOffset() > TopKey.getOffset() &&
841 NextKey.getOffset() - TopKey.getOffset() < Length) {
842 // Case 1: The next binding is inside the region we're invalidating.
844 Bindings.push_back(*I);
846 } else if (NextKey.getOffset() == TopKey.getOffset()) {
847 // Case 2: The next binding is at the same offset as the region we're
848 // invalidating. In this case, we need to leave default bindings alone,
849 // since they may be providing a default value for a regions beyond what
850 // we're invalidating.
851 // FIXME: This is probably incorrect; consider invalidating an outer
852 // struct whose first field is bound to a LazyCompoundVal.
853 if (IncludeAllDefaultBindings || NextKey.isDirect())
854 Bindings.push_back(*I);
857 } else if (NextKey.hasSymbolicOffset()) {
858 const MemRegion *Base = NextKey.getConcreteOffsetRegion();
859 if (Top->isSubRegionOf(Base)) {
860 // Case 3: The next key is symbolic and we just changed something within
861 // its concrete region. We don't know if the binding is still valid, so
862 // we'll be conservative and include it.
863 if (IncludeAllDefaultBindings || NextKey.isDirect())
864 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
865 Bindings.push_back(*I);
866 } else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Base)) {
867 // Case 4: The next key is symbolic, but we changed a known
868 // super-region. In this case the binding is certainly included.
869 if (Top == Base || BaseSR->isSubRegionOf(Top))
870 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
871 Bindings.push_back(*I);
878 collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
879 SValBuilder &SVB, const ClusterBindings &Cluster,
880 const SubRegion *Top, bool IncludeAllDefaultBindings) {
881 collectSubRegionBindings(Bindings, SVB, Cluster, Top,
882 BindingKey::Make(Top, BindingKey::Default),
883 IncludeAllDefaultBindings);
887 RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
888 const SubRegion *Top) {
889 BindingKey TopKey = BindingKey::Make(Top, BindingKey::Default);
890 const MemRegion *ClusterHead = TopKey.getBaseRegion();
892 if (Top == ClusterHead) {
893 // We can remove an entire cluster's bindings all in one go.
894 return B.remove(Top);
897 const ClusterBindings *Cluster = B.lookup(ClusterHead);
899 // If we're invalidating a region with a symbolic offset, we need to make
900 // sure we don't treat the base region as uninitialized anymore.
901 if (TopKey.hasSymbolicOffset()) {
902 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
903 return B.addBinding(Concrete, BindingKey::Default, UnknownVal());
908 SmallVector<BindingPair, 32> Bindings;
909 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, Top, TopKey,
910 /*IncludeAllDefaultBindings=*/false);
912 ClusterBindingsRef Result(*Cluster, CBFactory);
913 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
916 Result = Result.remove(I->first);
918 // If we're invalidating a region with a symbolic offset, we need to make sure
919 // we don't treat the base region as uninitialized anymore.
920 // FIXME: This isn't very precise; see the example in
921 // collectSubRegionBindings.
922 if (TopKey.hasSymbolicOffset()) {
923 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
924 Result = Result.add(BindingKey::Make(Concrete, BindingKey::Default),
928 if (Result.isEmpty())
929 return B.remove(ClusterHead);
930 return B.add(ClusterHead, Result.asImmutableMap());
934 class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
938 const LocationContext *LCtx;
939 InvalidatedSymbols &IS;
940 RegionAndSymbolInvalidationTraits &ITraits;
941 StoreManager::InvalidatedRegions *Regions;
942 GlobalsFilterKind GlobalsFilter;
944 invalidateRegionsWorker(RegionStoreManager &rm,
945 ProgramStateManager &stateMgr,
947 const Expr *ex, unsigned count,
948 const LocationContext *lctx,
949 InvalidatedSymbols &is,
950 RegionAndSymbolInvalidationTraits &ITraitsIn,
951 StoreManager::InvalidatedRegions *r,
952 GlobalsFilterKind GFK)
953 : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b),
954 Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
955 GlobalsFilter(GFK) {}
957 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
958 void VisitBinding(SVal V);
960 using ClusterAnalysis::AddToWorkList;
962 bool AddToWorkList(const MemRegion *R);
964 /// Returns true if all clusters in the memory space for \p Base should be
966 bool includeEntireMemorySpace(const MemRegion *Base);
968 /// Returns true if the memory space of the given region is one of the global
969 /// regions specially included at the start of invalidation.
970 bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
974 bool invalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
975 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
976 R, RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
977 const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
978 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
981 void invalidateRegionsWorker::VisitBinding(SVal V) {
982 // A symbol? Mark it touched by the invalidation.
983 if (SymbolRef Sym = V.getAsSymbol())
986 if (const MemRegion *R = V.getAsRegion()) {
991 // Is it a LazyCompoundVal? All references get invalidated as well.
992 if (Optional<nonloc::LazyCompoundVal> LCS =
993 V.getAs<nonloc::LazyCompoundVal>()) {
995 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
997 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
1006 void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
1007 const ClusterBindings *C) {
1009 bool PreserveRegionsContents =
1010 ITraits.hasTrait(baseR,
1011 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
1014 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
1015 VisitBinding(I.getData());
1017 // Invalidate regions contents.
1018 if (!PreserveRegionsContents)
1019 B = B.remove(baseR);
1022 // BlockDataRegion? If so, invalidate captured variables that are passed
1024 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
1025 for (BlockDataRegion::referenced_vars_iterator
1026 BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
1028 const VarRegion *VR = BI.getCapturedRegion();
1029 const VarDecl *VD = VR->getDecl();
1030 if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
1033 else if (Loc::isLocType(VR->getValueType())) {
1034 // Map the current bindings to a Store to retrieve the value
1035 // of the binding. If that binding itself is a region, we should
1036 // invalidate that region. This is because a block may capture
1037 // a pointer value, but the thing pointed by that pointer may
1039 SVal V = RM.getBinding(B, loc::MemRegionVal(VR));
1040 if (Optional<Loc> L = V.getAs<Loc>()) {
1041 if (const MemRegion *LR = L->getAsRegion())
1050 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
1051 IS.insert(SR->getSymbol());
1053 // Nothing else should be done in the case when we preserve regions context.
1054 if (PreserveRegionsContents)
1057 // Otherwise, we have a normal data region. Record that we touched the region.
1059 Regions->push_back(baseR);
1061 if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
1062 // Invalidate the region by setting its default value to
1063 // conjured symbol. The type of the symbol is irrelevant.
1064 DefinedOrUnknownSVal V =
1065 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
1066 B = B.addBinding(baseR, BindingKey::Default, V);
1070 if (!baseR->isBoundable())
1073 const TypedValueRegion *TR = cast<TypedValueRegion>(baseR);
1074 QualType T = TR->getValueType();
1076 if (isInitiallyIncludedGlobalRegion(baseR)) {
1077 // If the region is a global and we are invalidating all globals,
1078 // erasing the entry is good enough. This causes all globals to be lazily
1079 // symbolicated from the same base symbol.
1083 if (T->isStructureOrClassType()) {
1084 // Invalidate the region by setting its default value to
1085 // conjured symbol. The type of the symbol is irrelevant.
1086 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1088 B = B.addBinding(baseR, BindingKey::Default, V);
1092 if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
1093 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1095 RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
1097 if (doNotInvalidateSuperRegion) {
1098 // We are not doing blank invalidation of the whole array region so we
1099 // have to manually invalidate each elements.
1100 Optional<uint64_t> NumElements;
1102 // Compute lower and upper offsets for region within array.
1103 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
1104 NumElements = CAT->getSize().getZExtValue();
1105 if (!NumElements) // We are not dealing with a constant size array
1106 goto conjure_default;
1107 QualType ElementTy = AT->getElementType();
1108 uint64_t ElemSize = Ctx.getTypeSize(ElementTy);
1109 const RegionOffset &RO = baseR->getAsOffset();
1110 const MemRegion *SuperR = baseR->getBaseRegion();
1111 if (RO.hasSymbolicOffset()) {
1112 // If base region has a symbolic offset,
1113 // we revert to invalidating the super region.
1115 AddToWorkList(SuperR);
1116 goto conjure_default;
1119 uint64_t LowerOffset = RO.getOffset();
1120 uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
1121 bool UpperOverflow = UpperOffset < LowerOffset;
1123 // Invalidate regions which are within array boundaries,
1124 // or have a symbolic offset.
1126 goto conjure_default;
1128 const ClusterBindings *C = B.lookup(SuperR);
1130 goto conjure_default;
1132 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E;
1134 const BindingKey &BK = I.getKey();
1135 Optional<uint64_t> ROffset =
1136 BK.hasSymbolicOffset() ? Optional<uint64_t>() : BK.getOffset();
1138 // Check offset is not symbolic and within array's boundaries.
1139 // Handles arrays of 0 elements and of 0-sized elements as well.
1141 ((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
1143 (*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
1144 (LowerOffset == UpperOffset && *ROffset == LowerOffset))) {
1145 B = B.removeBinding(I.getKey());
1146 // Bound symbolic regions need to be invalidated for dead symbol
1148 SVal V = I.getData();
1149 const MemRegion *R = V.getAsRegion();
1150 if (R && isa<SymbolicRegion>(R))
1156 // Set the default value of the array to conjured symbol.
1157 DefinedOrUnknownSVal V =
1158 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1159 AT->getElementType(), Count);
1160 B = B.addBinding(baseR, BindingKey::Default, V);
1164 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1166 assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
1167 B = B.addBinding(baseR, BindingKey::Direct, V);
1170 bool invalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
1171 const MemRegion *R) {
1172 switch (GlobalsFilter) {
1175 case GFK_SystemOnly:
1176 return isa<GlobalSystemSpaceRegion>(R->getMemorySpace());
1178 return isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace());
1181 llvm_unreachable("unknown globals filter");
1184 bool invalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
1185 if (isInitiallyIncludedGlobalRegion(Base))
1188 const MemSpaceRegion *MemSpace = Base->getMemorySpace();
1189 return ITraits.hasTrait(MemSpace,
1190 RegionAndSymbolInvalidationTraits::TK_EntireMemSpace);
1194 RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
1197 const LocationContext *LCtx,
1198 RegionBindingsRef B,
1199 InvalidatedRegions *Invalidated) {
1200 // Bind the globals memory space to a new symbol that we will use to derive
1201 // the bindings for all globals.
1202 const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
1203 SVal V = svalBuilder.conjureSymbolVal(/* SymbolTag = */ (const void*) GS, Ex, LCtx,
1204 /* type does not matter */ Ctx.IntTy,
1207 B = B.removeBinding(GS)
1208 .addBinding(BindingKey::Make(GS, BindingKey::Default), V);
1210 // Even if there are no bindings in the global scope, we still need to
1211 // record that we touched it.
1213 Invalidated->push_back(GS);
1218 void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
1219 ArrayRef<SVal> Values,
1220 InvalidatedRegions *TopLevelRegions) {
1221 for (ArrayRef<SVal>::iterator I = Values.begin(),
1222 E = Values.end(); I != E; ++I) {
1224 if (Optional<nonloc::LazyCompoundVal> LCS =
1225 V.getAs<nonloc::LazyCompoundVal>()) {
1227 const SValListTy &Vals = getInterestingValues(*LCS);
1229 for (SValListTy::const_iterator I = Vals.begin(),
1230 E = Vals.end(); I != E; ++I) {
1231 // Note: the last argument is false here because these are
1232 // non-top-level regions.
1233 if (const MemRegion *R = (*I).getAsRegion())
1239 if (const MemRegion *R = V.getAsRegion()) {
1240 if (TopLevelRegions)
1241 TopLevelRegions->push_back(R);
1249 RegionStoreManager::invalidateRegions(Store store,
1250 ArrayRef<SVal> Values,
1251 const Expr *Ex, unsigned Count,
1252 const LocationContext *LCtx,
1253 const CallEvent *Call,
1254 InvalidatedSymbols &IS,
1255 RegionAndSymbolInvalidationTraits &ITraits,
1256 InvalidatedRegions *TopLevelRegions,
1257 InvalidatedRegions *Invalidated) {
1258 GlobalsFilterKind GlobalsFilter;
1260 if (Call->isInSystemHeader())
1261 GlobalsFilter = GFK_SystemOnly;
1263 GlobalsFilter = GFK_All;
1265 GlobalsFilter = GFK_None;
1268 RegionBindingsRef B = getRegionBindings(store);
1269 invalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
1270 Invalidated, GlobalsFilter);
1272 // Scan the bindings and generate the clusters.
1273 W.GenerateClusters();
1275 // Add the regions to the worklist.
1276 populateWorkList(W, Values, TopLevelRegions);
1280 // Return the new bindings.
1281 B = W.getRegionBindings();
1283 // For calls, determine which global regions should be invalidated and
1284 // invalidate them. (Note that function-static and immutable globals are never
1285 // invalidated by this.)
1286 // TODO: This could possibly be more precise with modules.
1287 switch (GlobalsFilter) {
1289 B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
1290 Ex, Count, LCtx, B, Invalidated);
1292 case GFK_SystemOnly:
1293 B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
1294 Ex, Count, LCtx, B, Invalidated);
1300 return StoreRef(B.asStore(), *this);
1303 //===----------------------------------------------------------------------===//
1304 // Extents for regions.
1305 //===----------------------------------------------------------------------===//
1307 DefinedOrUnknownSVal
1308 RegionStoreManager::getSizeInElements(ProgramStateRef state,
1311 SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
1312 const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
1314 return UnknownVal();
1316 CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());
1318 if (Ctx.getAsVariableArrayType(EleTy)) {
1319 // FIXME: We need to track extra state to properly record the size
1320 // of VLAs. Returning UnknownVal here, however, is a stop-gap so that
1321 // we don't have a divide-by-zero below.
1322 return UnknownVal();
1325 CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);
1327 // If a variable is reinterpreted as a type that doesn't fit into a larger
1328 // type evenly, round it down.
1329 // This is a signed value, since it's used in arithmetic with signed indices.
1330 return svalBuilder.makeIntVal(RegionSize / EleSize, false);
1333 //===----------------------------------------------------------------------===//
1334 // Location and region casting.
1335 //===----------------------------------------------------------------------===//
1337 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
1338 /// type. 'Array' represents the lvalue of the array being decayed
1339 /// to a pointer, and the returned SVal represents the decayed
1340 /// version of that lvalue (i.e., a pointer to the first element of
1341 /// the array). This is called by ExprEngine when evaluating casts
1342 /// from arrays to pointers.
1343 SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
1344 if (Array.getAs<loc::ConcreteInt>())
1347 if (!Array.getAs<loc::MemRegionVal>())
1348 return UnknownVal();
1350 const SubRegion *R =
1351 cast<SubRegion>(Array.castAs<loc::MemRegionVal>().getRegion());
1352 NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
1353 return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
1356 //===----------------------------------------------------------------------===//
1357 // Loading values from regions.
1358 //===----------------------------------------------------------------------===//
1360 SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
1361 assert(!L.getAs<UnknownVal>() && "location unknown");
1362 assert(!L.getAs<UndefinedVal>() && "location undefined");
1364 // For access to concrete addresses, return UnknownVal. Checks
1365 // for null dereferences (and similar errors) are done by checkers, not
1367 // FIXME: We can consider lazily symbolicating such memory, but we really
1368 // should defer this when we can reason easily about symbolicating arrays
1370 if (L.getAs<loc::ConcreteInt>()) {
1371 return UnknownVal();
1373 if (!L.getAs<loc::MemRegionVal>()) {
1374 return UnknownVal();
1377 const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();
1379 if (isa<BlockDataRegion>(MR)) {
1380 return UnknownVal();
1383 if (isa<AllocaRegion>(MR) ||
1384 isa<SymbolicRegion>(MR) ||
1385 isa<CodeTextRegion>(MR)) {
1387 if (const TypedRegion *TR = dyn_cast<TypedRegion>(MR))
1388 T = TR->getLocationType();
1390 const SymbolicRegion *SR = cast<SymbolicRegion>(MR);
1391 T = SR->getSymbol()->getType();
1394 MR = GetElementZeroRegion(cast<SubRegion>(MR), T);
1397 // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
1398 // instead of 'Loc', and have the other Loc cases handled at a higher level.
1399 const TypedValueRegion *R = cast<TypedValueRegion>(MR);
1400 QualType RTy = R->getValueType();
1402 // FIXME: we do not yet model the parts of a complex type, so treat the
1403 // whole thing as "unknown".
1404 if (RTy->isAnyComplexType())
1405 return UnknownVal();
1407 // FIXME: We should eventually handle funny addressing. e.g.:
1411 // char *q = (char*) p;
1412 // char c = *q; // returns the first byte of 'x'.
1414 // Such funny addressing will occur due to layering of regions.
1415 if (RTy->isStructureOrClassType())
1416 return getBindingForStruct(B, R);
1418 // FIXME: Handle unions.
1419 if (RTy->isUnionType())
1420 return createLazyBinding(B, R);
1422 if (RTy->isArrayType()) {
1423 if (RTy->isConstantArrayType())
1424 return getBindingForArray(B, R);
1426 return UnknownVal();
1429 // FIXME: handle Vector types.
1430 if (RTy->isVectorType())
1431 return UnknownVal();
1433 if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
1434 return CastRetrievedVal(getBindingForField(B, FR), FR, T, false);
1436 if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
1437 // FIXME: Here we actually perform an implicit conversion from the loaded
1438 // value to the element type. Eventually we want to compose these values
1439 // more intelligently. For example, an 'element' can encompass multiple
1440 // bound regions (e.g., several bound bytes), or could be a subset of
1442 return CastRetrievedVal(getBindingForElement(B, ER), ER, T, false);
1445 if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
1446 // FIXME: Here we actually perform an implicit conversion from the loaded
1447 // value to the ivar type. What we should model is stores to ivars
1448 // that blow past the extent of the ivar. If the address of the ivar is
1449 // reinterpretted, it is possible we stored a different value that could
1450 // fit within the ivar. Either we need to cast these when storing them
1451 // or reinterpret them lazily (as we do here).
1452 return CastRetrievedVal(getBindingForObjCIvar(B, IVR), IVR, T, false);
1455 if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
1456 // FIXME: Here we actually perform an implicit conversion from the loaded
1457 // value to the variable type. What we should model is stores to variables
1458 // that blow past the extent of the variable. If the address of the
1459 // variable is reinterpretted, it is possible we stored a different value
1460 // that could fit within the variable. Either we need to cast these when
1461 // storing them or reinterpret them lazily (as we do here).
1462 return CastRetrievedVal(getBindingForVar(B, VR), VR, T, false);
1465 const SVal *V = B.lookup(R, BindingKey::Direct);
1467 // Check if the region has a binding.
1471 // The location does not have a bound value. This means that it has
1472 // the value it had upon its creation and/or entry to the analyzed
1473 // function/method. These are either symbolic values or 'undefined'.
1474 if (R->hasStackNonParametersStorage()) {
1475 // All stack variables are considered to have undefined values
1476 // upon creation. All heap allocated blocks are considered to
1477 // have undefined values as well unless they are explicitly bound
1478 // to specific values.
1479 return UndefinedVal();
1482 // All other values are symbolic.
1483 return svalBuilder.getRegionValueSymbolVal(R);
1486 static QualType getUnderlyingType(const SubRegion *R) {
1488 if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
1489 RegionTy = TVR->getValueType();
1491 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
1492 RegionTy = SR->getSymbol()->getType();
1497 /// Checks to see if store \p B has a lazy binding for region \p R.
1499 /// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
1500 /// if there are additional bindings within \p R.
1502 /// Note that unlike RegionStoreManager::findLazyBinding, this will not search
1503 /// for lazy bindings for super-regions of \p R.
1504 static Optional<nonloc::LazyCompoundVal>
1505 getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
1506 const SubRegion *R, bool AllowSubregionBindings) {
1507 Optional<SVal> V = B.getDefaultBinding(R);
1511 Optional<nonloc::LazyCompoundVal> LCV = V->getAs<nonloc::LazyCompoundVal>();
1515 // If the LCV is for a subregion, the types might not match, and we shouldn't
1516 // reuse the binding.
1517 QualType RegionTy = getUnderlyingType(R);
1518 if (!RegionTy.isNull() &&
1519 !RegionTy->isVoidPointerType()) {
1520 QualType SourceRegionTy = LCV->getRegion()->getValueType();
1521 if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
1525 if (!AllowSubregionBindings) {
1526 // If there are any other bindings within this region, we shouldn't reuse
1527 // the top-level binding.
1528 SmallVector<BindingPair, 16> Bindings;
1529 collectSubRegionBindings(Bindings, SVB, *B.lookup(R->getBaseRegion()), R,
1530 /*IncludeAllDefaultBindings=*/true);
1531 if (Bindings.size() > 1)
1539 std::pair<Store, const SubRegion *>
1540 RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
1542 const SubRegion *originalRegion) {
1543 if (originalRegion != R) {
1544 if (Optional<nonloc::LazyCompoundVal> V =
1545 getExistingLazyBinding(svalBuilder, B, R, true))
1546 return std::make_pair(V->getStore(), V->getRegion());
1549 typedef std::pair<Store, const SubRegion *> StoreRegionPair;
1550 StoreRegionPair Result = StoreRegionPair();
1552 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1553 Result = findLazyBinding(B, cast<SubRegion>(ER->getSuperRegion()),
1557 Result.second = MRMgr.getElementRegionWithSuper(ER, Result.second);
1559 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
1560 Result = findLazyBinding(B, cast<SubRegion>(FR->getSuperRegion()),
1564 Result.second = MRMgr.getFieldRegionWithSuper(FR, Result.second);
1566 } else if (const CXXBaseObjectRegion *BaseReg =
1567 dyn_cast<CXXBaseObjectRegion>(R)) {
1568 // C++ base object region is another kind of region that we should blast
1569 // through to look for lazy compound value. It is like a field region.
1570 Result = findLazyBinding(B, cast<SubRegion>(BaseReg->getSuperRegion()),
1574 Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(BaseReg,
1581 SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
1582 const ElementRegion* R) {
1583 // We do not currently model bindings of the CompoundLiteralregion.
1584 if (isa<CompoundLiteralRegion>(R->getBaseRegion()))
1585 return UnknownVal();
1587 // Check if the region has a binding.
1588 if (const Optional<SVal> &V = B.getDirectBinding(R))
1591 const MemRegion* superR = R->getSuperRegion();
1593 // Check if the region is an element region of a string literal.
1594 if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
1595 // FIXME: Handle loads from strings where the literal is treated as
1596 // an integer, e.g., *((unsigned int*)"hello")
1597 QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
1598 if (!Ctx.hasSameUnqualifiedType(T, R->getElementType()))
1599 return UnknownVal();
1601 const StringLiteral *Str = StrR->getStringLiteral();
1602 SVal Idx = R->getIndex();
1603 if (Optional<nonloc::ConcreteInt> CI = Idx.getAs<nonloc::ConcreteInt>()) {
1604 int64_t i = CI->getValue().getSExtValue();
1605 // Abort on string underrun. This can be possible by arbitrary
1606 // clients of getBindingForElement().
1608 return UndefinedVal();
1609 int64_t length = Str->getLength();
1610 // Technically, only i == length is guaranteed to be null.
1611 // However, such overflows should be caught before reaching this point;
1612 // the only time such an access would be made is if a string literal was
1613 // used to initialize a larger array.
1614 char c = (i >= length) ? '\0' : Str->getCodeUnit(i);
1615 return svalBuilder.makeIntVal(c, T);
1619 // Check for loads from a code text region. For such loads, just give up.
1620 if (isa<CodeTextRegion>(superR))
1621 return UnknownVal();
1623 // Handle the case where we are indexing into a larger scalar object.
1624 // For example, this handles:
1628 // FIXME: This is a hack, and doesn't do anything really intelligent yet.
1629 const RegionRawOffset &O = R->getAsArrayOffset();
1631 // If we cannot reason about the offset, return an unknown value.
1633 return UnknownVal();
1635 if (const TypedValueRegion *baseR =
1636 dyn_cast_or_null<TypedValueRegion>(O.getRegion())) {
1637 QualType baseT = baseR->getValueType();
1638 if (baseT->isScalarType()) {
1639 QualType elemT = R->getElementType();
1640 if (elemT->isScalarType()) {
1641 if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
1642 if (const Optional<SVal> &V = B.getDirectBinding(superR)) {
1643 if (SymbolRef parentSym = V->getAsSymbol())
1644 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1646 if (V->isUnknownOrUndef())
1648 // Other cases: give up. We are indexing into a larger object
1649 // that has some value, but we don't know how to handle that yet.
1650 return UnknownVal();
1656 return getBindingForFieldOrElementCommon(B, R, R->getElementType());
1659 SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
1660 const FieldRegion* R) {
1662 // Check if the region has a binding.
1663 if (const Optional<SVal> &V = B.getDirectBinding(R))
1666 QualType Ty = R->getValueType();
1667 return getBindingForFieldOrElementCommon(B, R, Ty);
1671 RegionStoreManager::getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
1672 const MemRegion *superR,
1673 const TypedValueRegion *R,
1676 if (const Optional<SVal> &D = B.getDefaultBinding(superR)) {
1677 const SVal &val = D.getValue();
1678 if (SymbolRef parentSym = val.getAsSymbol())
1679 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1681 if (val.isZeroConstant())
1682 return svalBuilder.makeZeroVal(Ty);
1684 if (val.isUnknownOrUndef())
1687 // Lazy bindings are usually handled through getExistingLazyBinding().
1688 // We should unify these two code paths at some point.
1689 if (val.getAs<nonloc::LazyCompoundVal>() ||
1690 val.getAs<nonloc::CompoundVal>())
1693 llvm_unreachable("Unknown default value");
1699 SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
1700 RegionBindingsRef LazyBinding) {
1702 if (const ElementRegion *ER = dyn_cast<ElementRegion>(LazyBindingRegion))
1703 Result = getBindingForElement(LazyBinding, ER);
1705 Result = getBindingForField(LazyBinding,
1706 cast<FieldRegion>(LazyBindingRegion));
1708 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1709 // default value for /part/ of an aggregate from a default value for the
1710 // /entire/ aggregate. The most common case of this is when struct Outer
1711 // has as its first member a struct Inner, which is copied in from a stack
1712 // variable. In this case, even if the Outer's default value is symbolic, 0,
1713 // or unknown, it gets overridden by the Inner's default value of undefined.
1715 // This is a general problem -- if the Inner is zero-initialized, the Outer
1716 // will now look zero-initialized. The proper way to solve this is with a
1717 // new version of RegionStore that tracks the extent of a binding as well
1720 // This hack only takes care of the undefined case because that can very
1721 // quickly result in a warning.
1722 if (Result.isUndef())
1723 Result = UnknownVal();
1729 RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
1730 const TypedValueRegion *R,
1733 // At this point we have already checked in either getBindingForElement or
1734 // getBindingForField if 'R' has a direct binding.
1737 Store lazyBindingStore = nullptr;
1738 const SubRegion *lazyBindingRegion = nullptr;
1739 std::tie(lazyBindingStore, lazyBindingRegion) = findLazyBinding(B, R, R);
1740 if (lazyBindingRegion)
1741 return getLazyBinding(lazyBindingRegion,
1742 getRegionBindings(lazyBindingStore));
1744 // Record whether or not we see a symbolic index. That can completely
1745 // be out of scope of our lookup.
1746 bool hasSymbolicIndex = false;
1748 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1749 // default value for /part/ of an aggregate from a default value for the
1750 // /entire/ aggregate. The most common case of this is when struct Outer
1751 // has as its first member a struct Inner, which is copied in from a stack
1752 // variable. In this case, even if the Outer's default value is symbolic, 0,
1753 // or unknown, it gets overridden by the Inner's default value of undefined.
1755 // This is a general problem -- if the Inner is zero-initialized, the Outer
1756 // will now look zero-initialized. The proper way to solve this is with a
1757 // new version of RegionStore that tracks the extent of a binding as well
1760 // This hack only takes care of the undefined case because that can very
1761 // quickly result in a warning.
1762 bool hasPartialLazyBinding = false;
1764 const SubRegion *SR = dyn_cast<SubRegion>(R);
1766 const MemRegion *Base = SR->getSuperRegion();
1767 if (Optional<SVal> D = getBindingForDerivedDefaultValue(B, Base, R, Ty)) {
1768 if (D->getAs<nonloc::LazyCompoundVal>()) {
1769 hasPartialLazyBinding = true;
1776 if (const ElementRegion *ER = dyn_cast<ElementRegion>(Base)) {
1777 NonLoc index = ER->getIndex();
1778 if (!index.isConstant())
1779 hasSymbolicIndex = true;
1782 // If our super region is a field or element itself, walk up the region
1783 // hierarchy to see if there is a default value installed in an ancestor.
1784 SR = dyn_cast<SubRegion>(Base);
1787 if (R->hasStackNonParametersStorage()) {
1788 if (isa<ElementRegion>(R)) {
1789 // Currently we don't reason specially about Clang-style vectors. Check
1790 // if superR is a vector and if so return Unknown.
1791 if (const TypedValueRegion *typedSuperR =
1792 dyn_cast<TypedValueRegion>(R->getSuperRegion())) {
1793 if (typedSuperR->getValueType()->isVectorType())
1794 return UnknownVal();
1798 // FIXME: We also need to take ElementRegions with symbolic indexes into
1799 // account. This case handles both directly accessing an ElementRegion
1800 // with a symbolic offset, but also fields within an element with
1801 // a symbolic offset.
1802 if (hasSymbolicIndex)
1803 return UnknownVal();
1805 if (!hasPartialLazyBinding)
1806 return UndefinedVal();
1809 // All other values are symbolic.
1810 return svalBuilder.getRegionValueSymbolVal(R);
1813 SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
1814 const ObjCIvarRegion* R) {
1815 // Check if the region has a binding.
1816 if (const Optional<SVal> &V = B.getDirectBinding(R))
1819 const MemRegion *superR = R->getSuperRegion();
1821 // Check if the super region has a default binding.
1822 if (const Optional<SVal> &V = B.getDefaultBinding(superR)) {
1823 if (SymbolRef parentSym = V->getAsSymbol())
1824 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1826 // Other cases: give up.
1827 return UnknownVal();
1830 return getBindingForLazySymbol(R);
1833 SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
1834 const VarRegion *R) {
1836 // Check if the region has a binding.
1837 if (const Optional<SVal> &V = B.getDirectBinding(R))
1840 // Lazily derive a value for the VarRegion.
1841 const VarDecl *VD = R->getDecl();
1842 const MemSpaceRegion *MS = R->getMemorySpace();
1844 // Arguments are always symbolic.
1845 if (isa<StackArgumentsSpaceRegion>(MS))
1846 return svalBuilder.getRegionValueSymbolVal(R);
1848 // Is 'VD' declared constant? If so, retrieve the constant value.
1849 if (VD->getType().isConstQualified())
1850 if (const Expr *Init = VD->getInit())
1851 if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
1854 // This must come after the check for constants because closure-captured
1855 // constant variables may appear in UnknownSpaceRegion.
1856 if (isa<UnknownSpaceRegion>(MS))
1857 return svalBuilder.getRegionValueSymbolVal(R);
1859 if (isa<GlobalsSpaceRegion>(MS)) {
1860 QualType T = VD->getType();
1862 // Function-scoped static variables are default-initialized to 0; if they
1863 // have an initializer, it would have been processed by now.
1864 // FIXME: This is only true when we're starting analysis from main().
1865 // We're losing a lot of coverage here.
1866 if (isa<StaticGlobalSpaceRegion>(MS))
1867 return svalBuilder.makeZeroVal(T);
1869 if (Optional<SVal> V = getBindingForDerivedDefaultValue(B, MS, R, T)) {
1870 assert(!V->getAs<nonloc::LazyCompoundVal>());
1871 return V.getValue();
1874 return svalBuilder.getRegionValueSymbolVal(R);
1877 return UndefinedVal();
1880 SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
1881 // All other values are symbolic.
1882 return svalBuilder.getRegionValueSymbolVal(R);
1885 const RegionStoreManager::SValListTy &
1886 RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
1887 // First, check the cache.
1888 LazyBindingsMapTy::iterator I = LazyBindingsMap.find(LCV.getCVData());
1889 if (I != LazyBindingsMap.end())
1892 // If we don't have a list of values cached, start constructing it.
1895 const SubRegion *LazyR = LCV.getRegion();
1896 RegionBindingsRef B = getRegionBindings(LCV.getStore());
1898 // If this region had /no/ bindings at the time, there are no interesting
1899 // values to return.
1900 const ClusterBindings *Cluster = B.lookup(LazyR->getBaseRegion());
1902 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1904 SmallVector<BindingPair, 32> Bindings;
1905 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, LazyR,
1906 /*IncludeAllDefaultBindings=*/true);
1907 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
1911 if (V.isUnknownOrUndef() || V.isConstant())
1914 if (Optional<nonloc::LazyCompoundVal> InnerLCV =
1915 V.getAs<nonloc::LazyCompoundVal>()) {
1916 const SValListTy &InnerList = getInterestingValues(*InnerLCV);
1917 List.insert(List.end(), InnerList.begin(), InnerList.end());
1924 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1927 NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
1928 const TypedValueRegion *R) {
1929 if (Optional<nonloc::LazyCompoundVal> V =
1930 getExistingLazyBinding(svalBuilder, B, R, false))
1933 return svalBuilder.makeLazyCompoundVal(StoreRef(B.asStore(), *this), R);
1936 static bool isRecordEmpty(const RecordDecl *RD) {
1937 if (!RD->field_empty())
1939 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD))
1940 return CRD->getNumBases() == 0;
1944 SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
1945 const TypedValueRegion *R) {
1946 const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
1947 if (!RD->getDefinition() || isRecordEmpty(RD))
1948 return UnknownVal();
1950 return createLazyBinding(B, R);
1953 SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
1954 const TypedValueRegion *R) {
1955 assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
1956 "Only constant array types can have compound bindings.");
1958 return createLazyBinding(B, R);
1961 bool RegionStoreManager::includedInBindings(Store store,
1962 const MemRegion *region) const {
1963 RegionBindingsRef B = getRegionBindings(store);
1964 region = region->getBaseRegion();
1966 // Quick path: if the base is the head of a cluster, the region is live.
1967 if (B.lookup(region))
1970 // Slow path: if the region is the VALUE of any binding, it is live.
1971 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
1972 const ClusterBindings &Cluster = RI.getData();
1973 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
1975 const SVal &D = CI.getData();
1976 if (const MemRegion *R = D.getAsRegion())
1977 if (R->getBaseRegion() == region)
1985 //===----------------------------------------------------------------------===//
1986 // Binding values to regions.
1987 //===----------------------------------------------------------------------===//
1989 StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
1990 if (Optional<loc::MemRegionVal> LV = L.getAs<loc::MemRegionVal>())
1991 if (const MemRegion* R = LV->getRegion())
1992 return StoreRef(getRegionBindings(ST).removeBinding(R)
1994 .getRootWithoutRetain(),
1997 return StoreRef(ST, *this);
2001 RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
2002 if (L.getAs<loc::ConcreteInt>())
2005 // If we get here, the location should be a region.
2006 const MemRegion *R = L.castAs<loc::MemRegionVal>().getRegion();
2008 // Check if the region is a struct region.
2009 if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(R)) {
2010 QualType Ty = TR->getValueType();
2011 if (Ty->isArrayType())
2012 return bindArray(B, TR, V);
2013 if (Ty->isStructureOrClassType())
2014 return bindStruct(B, TR, V);
2015 if (Ty->isVectorType())
2016 return bindVector(B, TR, V);
2017 if (Ty->isUnionType())
2018 return bindAggregate(B, TR, V);
2021 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
2022 // Binding directly to a symbolic region should be treated as binding
2024 QualType T = SR->getSymbol()->getType();
2025 if (T->isAnyPointerType() || T->isReferenceType())
2026 T = T->getPointeeType();
2028 R = GetElementZeroRegion(SR, T);
2031 // Clear out bindings that may overlap with this binding.
2032 RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
2033 return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
2037 RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
2042 if (Loc::isLocType(T))
2043 V = svalBuilder.makeNull();
2044 else if (T->isIntegralOrEnumerationType())
2045 V = svalBuilder.makeZeroVal(T);
2046 else if (T->isStructureOrClassType() || T->isArrayType()) {
2047 // Set the default value to a zero constant when it is a structure
2048 // or array. The type doesn't really matter.
2049 V = svalBuilder.makeZeroVal(Ctx.IntTy);
2052 // We can't represent values of this type, but we still need to set a value
2053 // to record that the region has been initialized.
2054 // If this assertion ever fires, a new case should be added above -- we
2055 // should know how to default-initialize any value we can symbolicate.
2056 assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
2060 return B.addBinding(R, BindingKey::Default, V);
2064 RegionStoreManager::bindArray(RegionBindingsConstRef B,
2065 const TypedValueRegion* R,
2068 const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
2069 QualType ElementTy = AT->getElementType();
2070 Optional<uint64_t> Size;
2072 if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
2073 Size = CAT->getSize().getZExtValue();
2075 // Check if the init expr is a string literal.
2076 if (Optional<loc::MemRegionVal> MRV = Init.getAs<loc::MemRegionVal>()) {
2077 const StringRegion *S = cast<StringRegion>(MRV->getRegion());
2079 // Treat the string as a lazy compound value.
2080 StoreRef store(B.asStore(), *this);
2081 nonloc::LazyCompoundVal LCV = svalBuilder.makeLazyCompoundVal(store, S)
2082 .castAs<nonloc::LazyCompoundVal>();
2083 return bindAggregate(B, R, LCV);
2086 // Handle lazy compound values.
2087 if (Init.getAs<nonloc::LazyCompoundVal>())
2088 return bindAggregate(B, R, Init);
2090 if (Init.isUnknown())
2091 return bindAggregate(B, R, UnknownVal());
2093 // Remaining case: explicit compound values.
2094 const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
2095 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2098 RegionBindingsRef NewB(B);
2100 for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
2101 // The init list might be shorter than the array length.
2105 const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
2106 const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
2108 if (ElementTy->isStructureOrClassType())
2109 NewB = bindStruct(NewB, ER, *VI);
2110 else if (ElementTy->isArrayType())
2111 NewB = bindArray(NewB, ER, *VI);
2113 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2116 // If the init list is shorter than the array length, set the
2117 // array default value.
2118 if (Size.hasValue() && i < Size.getValue())
2119 NewB = setImplicitDefaultValue(NewB, R, ElementTy);
2124 RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
2125 const TypedValueRegion* R,
2127 QualType T = R->getValueType();
2128 assert(T->isVectorType());
2129 const VectorType *VT = T->getAs<VectorType>(); // Use getAs for typedefs.
2131 // Handle lazy compound values and symbolic values.
2132 if (V.getAs<nonloc::LazyCompoundVal>() || V.getAs<nonloc::SymbolVal>())
2133 return bindAggregate(B, R, V);
2135 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2136 // that we are binding symbolic struct value. Kill the field values, and if
2137 // the value is symbolic go and bind it as a "default" binding.
2138 if (!V.getAs<nonloc::CompoundVal>()) {
2139 return bindAggregate(B, R, UnknownVal());
2142 QualType ElemType = VT->getElementType();
2143 nonloc::CompoundVal CV = V.castAs<nonloc::CompoundVal>();
2144 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2145 unsigned index = 0, numElements = VT->getNumElements();
2146 RegionBindingsRef NewB(B);
2148 for ( ; index != numElements ; ++index) {
2152 NonLoc Idx = svalBuilder.makeArrayIndex(index);
2153 const ElementRegion *ER = MRMgr.getElementRegion(ElemType, Idx, R, Ctx);
2155 if (ElemType->isArrayType())
2156 NewB = bindArray(NewB, ER, *VI);
2157 else if (ElemType->isStructureOrClassType())
2158 NewB = bindStruct(NewB, ER, *VI);
2160 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2165 Optional<RegionBindingsRef>
2166 RegionStoreManager::tryBindSmallStruct(RegionBindingsConstRef B,
2167 const TypedValueRegion *R,
2168 const RecordDecl *RD,
2169 nonloc::LazyCompoundVal LCV) {
2172 if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(RD))
2173 if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
2176 for (const auto *FD : RD->fields()) {
2177 if (FD->isUnnamedBitfield())
2180 // If there are too many fields, or if any of the fields are aggregates,
2181 // just use the LCV as a default binding.
2182 if (Fields.size() == SmallStructLimit)
2185 QualType Ty = FD->getType();
2186 if (!(Ty->isScalarType() || Ty->isReferenceType()))
2189 Fields.push_back(FD);
2192 RegionBindingsRef NewB = B;
2194 for (FieldVector::iterator I = Fields.begin(), E = Fields.end(); I != E; ++I){
2195 const FieldRegion *SourceFR = MRMgr.getFieldRegion(*I, LCV.getRegion());
2196 SVal V = getBindingForField(getRegionBindings(LCV.getStore()), SourceFR);
2198 const FieldRegion *DestFR = MRMgr.getFieldRegion(*I, R);
2199 NewB = bind(NewB, loc::MemRegionVal(DestFR), V);
2205 RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
2206 const TypedValueRegion* R,
2208 if (!Features.supportsFields())
2211 QualType T = R->getValueType();
2212 assert(T->isStructureOrClassType());
2214 const RecordType* RT = T->getAs<RecordType>();
2215 const RecordDecl *RD = RT->getDecl();
2217 if (!RD->isCompleteDefinition())
2220 // Handle lazy compound values and symbolic values.
2221 if (Optional<nonloc::LazyCompoundVal> LCV =
2222 V.getAs<nonloc::LazyCompoundVal>()) {
2223 if (Optional<RegionBindingsRef> NewB = tryBindSmallStruct(B, R, RD, *LCV))
2225 return bindAggregate(B, R, V);
2227 if (V.getAs<nonloc::SymbolVal>())
2228 return bindAggregate(B, R, V);
2230 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2231 // that we are binding symbolic struct value. Kill the field values, and if
2232 // the value is symbolic go and bind it as a "default" binding.
2233 if (V.isUnknown() || !V.getAs<nonloc::CompoundVal>())
2234 return bindAggregate(B, R, UnknownVal());
2236 const nonloc::CompoundVal& CV = V.castAs<nonloc::CompoundVal>();
2237 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2239 RecordDecl::field_iterator FI, FE;
2240 RegionBindingsRef NewB(B);
2242 for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {
2247 // Skip any unnamed bitfields to stay in sync with the initializers.
2248 if (FI->isUnnamedBitfield())
2251 QualType FTy = FI->getType();
2252 const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
2254 if (FTy->isArrayType())
2255 NewB = bindArray(NewB, FR, *VI);
2256 else if (FTy->isStructureOrClassType())
2257 NewB = bindStruct(NewB, FR, *VI);
2259 NewB = bind(NewB, loc::MemRegionVal(FR), *VI);
2263 // There may be fewer values in the initialize list than the fields of struct.
2265 NewB = NewB.addBinding(R, BindingKey::Default,
2266 svalBuilder.makeIntVal(0, false));
2273 RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
2274 const TypedRegion *R,
2276 // Remove the old bindings, using 'R' as the root of all regions
2277 // we will invalidate. Then add the new binding.
2278 return removeSubRegionBindings(B, R).addBinding(R, BindingKey::Default, Val);
2281 //===----------------------------------------------------------------------===//
2283 //===----------------------------------------------------------------------===//
2286 class removeDeadBindingsWorker :
2287 public ClusterAnalysis<removeDeadBindingsWorker> {
2288 SmallVector<const SymbolicRegion*, 12> Postponed;
2289 SymbolReaper &SymReaper;
2290 const StackFrameContext *CurrentLCtx;
2293 removeDeadBindingsWorker(RegionStoreManager &rm,
2294 ProgramStateManager &stateMgr,
2295 RegionBindingsRef b, SymbolReaper &symReaper,
2296 const StackFrameContext *LCtx)
2297 : ClusterAnalysis<removeDeadBindingsWorker>(rm, stateMgr, b),
2298 SymReaper(symReaper), CurrentLCtx(LCtx) {}
2300 // Called by ClusterAnalysis.
2301 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
2302 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
2303 using ClusterAnalysis<removeDeadBindingsWorker>::VisitCluster;
2305 using ClusterAnalysis::AddToWorkList;
2307 bool AddToWorkList(const MemRegion *R);
2309 bool UpdatePostponed();
2310 void VisitBinding(SVal V);
2314 bool removeDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
2315 const MemRegion *BaseR = R->getBaseRegion();
2316 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
2319 void removeDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
2320 const ClusterBindings &C) {
2322 if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
2323 if (SymReaper.isLive(VR))
2324 AddToWorkList(baseR, &C);
2329 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
2330 if (SymReaper.isLive(SR->getSymbol()))
2331 AddToWorkList(SR, &C);
2333 Postponed.push_back(SR);
2338 if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
2339 AddToWorkList(baseR, &C);
2343 // CXXThisRegion in the current or parent location context is live.
2344 if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
2345 const StackArgumentsSpaceRegion *StackReg =
2346 cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
2347 const StackFrameContext *RegCtx = StackReg->getStackFrame();
2349 (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx)))
2350 AddToWorkList(TR, &C);
2354 void removeDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
2355 const ClusterBindings *C) {
2359 // Mark the symbol for any SymbolicRegion with live bindings as live itself.
2360 // This means we should continue to track that symbol.
2361 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(baseR))
2362 SymReaper.markLive(SymR->getSymbol());
2364 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I) {
2365 // Element index of a binding key is live.
2366 SymReaper.markElementIndicesLive(I.getKey().getRegion());
2368 VisitBinding(I.getData());
2372 void removeDeadBindingsWorker::VisitBinding(SVal V) {
2373 // Is it a LazyCompoundVal? All referenced regions are live as well.
2374 if (Optional<nonloc::LazyCompoundVal> LCS =
2375 V.getAs<nonloc::LazyCompoundVal>()) {
2377 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
2379 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
2387 // If V is a region, then add it to the worklist.
2388 if (const MemRegion *R = V.getAsRegion()) {
2390 SymReaper.markLive(R);
2392 // All regions captured by a block are also live.
2393 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
2394 BlockDataRegion::referenced_vars_iterator I = BR->referenced_vars_begin(),
2395 E = BR->referenced_vars_end();
2396 for ( ; I != E; ++I)
2397 AddToWorkList(I.getCapturedRegion());
2402 // Update the set of live symbols.
2403 for (SymExpr::symbol_iterator SI = V.symbol_begin(), SE = V.symbol_end();
2405 SymReaper.markLive(*SI);
2408 bool removeDeadBindingsWorker::UpdatePostponed() {
2409 // See if any postponed SymbolicRegions are actually live now, after
2410 // having done a scan.
2411 bool changed = false;
2413 for (SmallVectorImpl<const SymbolicRegion*>::iterator
2414 I = Postponed.begin(), E = Postponed.end() ; I != E ; ++I) {
2415 if (const SymbolicRegion *SR = *I) {
2416 if (SymReaper.isLive(SR->getSymbol())) {
2417 changed |= AddToWorkList(SR);
2426 StoreRef RegionStoreManager::removeDeadBindings(Store store,
2427 const StackFrameContext *LCtx,
2428 SymbolReaper& SymReaper) {
2429 RegionBindingsRef B = getRegionBindings(store);
2430 removeDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
2431 W.GenerateClusters();
2433 // Enqueue the region roots onto the worklist.
2434 for (SymbolReaper::region_iterator I = SymReaper.region_begin(),
2435 E = SymReaper.region_end(); I != E; ++I) {
2436 W.AddToWorkList(*I);
2439 do W.RunWorkList(); while (W.UpdatePostponed());
2441 // We have now scanned the store, marking reachable regions and symbols
2442 // as live. We now remove all the regions that are dead from the store
2443 // as well as update DSymbols with the set symbols that are now dead.
2444 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
2445 const MemRegion *Base = I.getKey();
2447 // If the cluster has been visited, we know the region has been marked.
2448 if (W.isVisited(Base))
2451 // Remove the dead entry.
2454 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(Base))
2455 SymReaper.maybeDead(SymR->getSymbol());
2457 // Mark all non-live symbols that this binding references as dead.
2458 const ClusterBindings &Cluster = I.getData();
2459 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
2461 SVal X = CI.getData();
2462 SymExpr::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
2463 for (; SI != SE; ++SI)
2464 SymReaper.maybeDead(*SI);
2468 return StoreRef(B.asStore(), *this);
2471 //===----------------------------------------------------------------------===//
2473 //===----------------------------------------------------------------------===//
2475 void RegionStoreManager::print(Store store, raw_ostream &OS,
2476 const char* nl, const char *sep) {
2477 RegionBindingsRef B = getRegionBindings(store);
2478 OS << "Store (direct and default bindings), "