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 // FIXME: The offsets of empty bases can be tricky because of
413 // of the so called "empty base class optimization".
414 // If a base class has been optimized out
415 // we should not try to create a binding, otherwise we should.
416 // Unfortunately, at the moment ASTRecordLayout doesn't expose
417 // the actual sizes of the empty bases
418 // and trying to infer them from offsets/alignments
419 // seems to be error-prone and non-trivial because of the trailing padding.
420 // As a temporary mitigation we don't create bindings for empty bases.
421 if (R->getKind() == MemRegion::CXXBaseObjectRegionKind &&
422 cast<CXXBaseObjectRegion>(R)->getDecl()->isEmpty())
423 return StoreRef(store, *this);
425 RegionBindingsRef B = getRegionBindings(store);
426 assert(!B.lookup(R, BindingKey::Direct));
428 BindingKey Key = BindingKey::Make(R, BindingKey::Default);
430 const SubRegion *SR = cast<SubRegion>(R);
431 assert(SR->getAsOffset().getOffset() ==
432 SR->getSuperRegion()->getAsOffset().getOffset() &&
433 "A default value must come from a super-region");
434 B = removeSubRegionBindings(B, SR);
436 B = B.addBinding(Key, V);
439 return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
442 /// Attempt to extract the fields of \p LCV and bind them to the struct region
445 /// This path is used when it seems advantageous to "force" loading the values
446 /// within a LazyCompoundVal to bind memberwise to the struct region, rather
447 /// than using a Default binding at the base of the entire region. This is a
448 /// heuristic attempting to avoid building long chains of LazyCompoundVals.
450 /// \returns The updated store bindings, or \c None if binding non-lazily
451 /// would be too expensive.
452 Optional<RegionBindingsRef> tryBindSmallStruct(RegionBindingsConstRef B,
453 const TypedValueRegion *R,
454 const RecordDecl *RD,
455 nonloc::LazyCompoundVal LCV);
457 /// BindStruct - Bind a compound value to a structure.
458 RegionBindingsRef bindStruct(RegionBindingsConstRef B,
459 const TypedValueRegion* R, SVal V);
461 /// BindVector - Bind a compound value to a vector.
462 RegionBindingsRef bindVector(RegionBindingsConstRef B,
463 const TypedValueRegion* R, SVal V);
465 RegionBindingsRef bindArray(RegionBindingsConstRef B,
466 const TypedValueRegion* R,
469 /// Clears out all bindings in the given region and assigns a new value
470 /// as a Default binding.
471 RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
472 const TypedRegion *R,
475 /// \brief Create a new store with the specified binding removed.
476 /// \param ST the original store, that is the basis for the new store.
477 /// \param L the location whose binding should be removed.
478 StoreRef killBinding(Store ST, Loc L) override;
480 void incrementReferenceCount(Store store) override {
481 getRegionBindings(store).manualRetain();
484 /// If the StoreManager supports it, decrement the reference count of
485 /// the specified Store object. If the reference count hits 0, the memory
486 /// associated with the object is recycled.
487 void decrementReferenceCount(Store store) override {
488 getRegionBindings(store).manualRelease();
491 bool includedInBindings(Store store, const MemRegion *region) const override;
493 /// \brief Return the value bound to specified location in a given state.
495 /// The high level logic for this method is this:
498 /// return L's binding
499 /// else if L is in killset
502 /// if L is on stack or heap
506 SVal getBinding(Store S, Loc L, QualType T) override {
507 return getBinding(getRegionBindings(S), L, T);
510 Optional<SVal> getDefaultBinding(Store S, const MemRegion *R) override {
511 RegionBindingsRef B = getRegionBindings(S);
512 // Default bindings are always applied over a base region so look up the
513 // base region's default binding, otherwise the lookup will fail when R
514 // is at an offset from R->getBaseRegion().
515 return B.getDefaultBinding(R->getBaseRegion());
518 SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());
520 SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);
522 SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);
524 SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);
526 SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);
528 SVal getBindingForLazySymbol(const TypedValueRegion *R);
530 SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
531 const TypedValueRegion *R,
534 SVal getLazyBinding(const SubRegion *LazyBindingRegion,
535 RegionBindingsRef LazyBinding);
537 /// Get bindings for the values in a struct and return a CompoundVal, used
538 /// when doing struct copy:
541 /// y's value is retrieved by this method.
542 SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
543 SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
544 NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);
546 /// Used to lazily generate derived symbols for bindings that are defined
547 /// implicitly by default bindings in a super region.
549 /// Note that callers may need to specially handle LazyCompoundVals, which
550 /// are returned as is in case the caller needs to treat them differently.
551 Optional<SVal> getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
552 const MemRegion *superR,
553 const TypedValueRegion *R,
556 /// Get the state and region whose binding this region \p R corresponds to.
558 /// If there is no lazy binding for \p R, the returned value will have a null
559 /// \c second. Note that a null pointer can represents a valid Store.
560 std::pair<Store, const SubRegion *>
561 findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
562 const SubRegion *originalRegion);
564 /// Returns the cached set of interesting SVals contained within a lazy
567 /// The precise value of "interesting" is determined for the purposes of
568 /// RegionStore's internal analysis. It must always contain all regions and
569 /// symbols, but may omit constants and other kinds of SVal.
570 const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);
572 //===------------------------------------------------------------------===//
574 //===------------------------------------------------------------------===//
576 /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
577 /// It returns a new Store with these values removed.
578 StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
579 SymbolReaper& SymReaper) override;
581 //===------------------------------------------------------------------===//
583 //===------------------------------------------------------------------===//
585 // FIXME: This method will soon be eliminated; see the note in Store.h.
586 DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state,
588 QualType EleTy) override;
590 //===------------------------------------------------------------------===//
592 //===------------------------------------------------------------------===//
594 RegionBindingsRef getRegionBindings(Store store) const {
595 return RegionBindingsRef(CBFactory,
596 static_cast<const RegionBindings::TreeTy*>(store),
597 RBFactory.getTreeFactory());
600 void print(Store store, raw_ostream &Out, const char* nl,
601 const char *sep) override;
603 void iterBindings(Store store, BindingsHandler& f) override {
604 RegionBindingsRef B = getRegionBindings(store);
605 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
606 const ClusterBindings &Cluster = I.getData();
607 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
609 const BindingKey &K = CI.getKey();
612 if (const SubRegion *R = dyn_cast<SubRegion>(K.getRegion())) {
613 // FIXME: Possibly incorporate the offset?
614 if (!f.HandleBinding(*this, store, R, CI.getData()))
622 } // end anonymous namespace
624 //===----------------------------------------------------------------------===//
625 // RegionStore creation.
626 //===----------------------------------------------------------------------===//
628 std::unique_ptr<StoreManager>
629 ento::CreateRegionStoreManager(ProgramStateManager &StMgr) {
630 RegionStoreFeatures F = maximal_features_tag();
631 return llvm::make_unique<RegionStoreManager>(StMgr, F);
634 std::unique_ptr<StoreManager>
635 ento::CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr) {
636 RegionStoreFeatures F = minimal_features_tag();
637 F.enableFields(true);
638 return llvm::make_unique<RegionStoreManager>(StMgr, F);
642 //===----------------------------------------------------------------------===//
643 // Region Cluster analysis.
644 //===----------------------------------------------------------------------===//
647 /// Used to determine which global regions are automatically included in the
648 /// initial worklist of a ClusterAnalysis.
649 enum GlobalsFilterKind {
650 /// Don't include any global regions.
652 /// Only include system globals.
654 /// Include all global regions.
658 template <typename DERIVED>
659 class ClusterAnalysis {
661 typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
662 typedef const MemRegion * WorkListElement;
663 typedef SmallVector<WorkListElement, 10> WorkList;
665 llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
669 RegionStoreManager &RM;
671 SValBuilder &svalBuilder;
677 const ClusterBindings *getCluster(const MemRegion *R) {
681 /// Returns true if all clusters in the given memspace should be initially
682 /// included in the cluster analysis. Subclasses may provide their
683 /// own implementation.
684 bool includeEntireMemorySpace(const MemRegion *Base) {
689 ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
691 : RM(rm), Ctx(StateMgr.getContext()),
692 svalBuilder(StateMgr.getSValBuilder()), B(std::move(b)) {}
694 RegionBindingsRef getRegionBindings() const { return B; }
696 bool isVisited(const MemRegion *R) {
697 return Visited.count(getCluster(R));
700 void GenerateClusters() {
701 // Scan the entire set of bindings and record the region clusters.
702 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
704 const MemRegion *Base = RI.getKey();
706 const ClusterBindings &Cluster = RI.getData();
707 assert(!Cluster.isEmpty() && "Empty clusters should be removed");
708 static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);
710 // If the base's memspace should be entirely invalidated, add the cluster
711 // to the workspace up front.
712 if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
713 AddToWorkList(WorkListElement(Base), &Cluster);
717 bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
718 if (C && !Visited.insert(C).second)
724 bool AddToWorkList(const MemRegion *R) {
725 return static_cast<DERIVED*>(this)->AddToWorkList(R);
729 while (!WL.empty()) {
730 WorkListElement E = WL.pop_back_val();
731 const MemRegion *BaseR = E;
733 static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
737 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
738 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}
740 void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
742 static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
747 //===----------------------------------------------------------------------===//
748 // Binding invalidation.
749 //===----------------------------------------------------------------------===//
751 bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
752 ScanReachableSymbols &Callbacks) {
753 assert(R == R->getBaseRegion() && "Should only be called for base regions");
754 RegionBindingsRef B = getRegionBindings(S);
755 const ClusterBindings *Cluster = B.lookup(R);
760 for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
762 if (!Callbacks.scan(RI.getData()))
769 static inline bool isUnionField(const FieldRegion *FR) {
770 return FR->getDecl()->getParent()->isUnion();
773 typedef SmallVector<const FieldDecl *, 8> FieldVector;
775 static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
776 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
778 const MemRegion *Base = K.getConcreteOffsetRegion();
779 const MemRegion *R = K.getRegion();
782 if (const FieldRegion *FR = dyn_cast<FieldRegion>(R))
783 if (!isUnionField(FR))
784 Fields.push_back(FR->getDecl());
786 R = cast<SubRegion>(R)->getSuperRegion();
790 static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
791 assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
796 FieldVector FieldsInBindingKey;
797 getSymbolicOffsetFields(K, FieldsInBindingKey);
799 ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
801 return std::equal(FieldsInBindingKey.begin() + Delta,
802 FieldsInBindingKey.end(),
805 return std::equal(FieldsInBindingKey.begin(), FieldsInBindingKey.end(),
806 Fields.begin() - Delta);
809 /// Collects all bindings in \p Cluster that may refer to bindings within
812 /// Each binding is a pair whose \c first is the key (a BindingKey) and whose
813 /// \c second is the value (an SVal).
815 /// The \p IncludeAllDefaultBindings parameter specifies whether to include
816 /// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
817 /// an aggregate within a larger aggregate with a default binding.
819 collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
820 SValBuilder &SVB, const ClusterBindings &Cluster,
821 const SubRegion *Top, BindingKey TopKey,
822 bool IncludeAllDefaultBindings) {
823 FieldVector FieldsInSymbolicSubregions;
824 if (TopKey.hasSymbolicOffset()) {
825 getSymbolicOffsetFields(TopKey, FieldsInSymbolicSubregions);
826 Top = cast<SubRegion>(TopKey.getConcreteOffsetRegion());
827 TopKey = BindingKey::Make(Top, BindingKey::Default);
830 // Find the length (in bits) of the region being invalidated.
831 uint64_t Length = UINT64_MAX;
832 SVal Extent = Top->getExtent(SVB);
833 if (Optional<nonloc::ConcreteInt> ExtentCI =
834 Extent.getAs<nonloc::ConcreteInt>()) {
835 const llvm::APSInt &ExtentInt = ExtentCI->getValue();
836 assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
837 // Extents are in bytes but region offsets are in bits. Be careful!
838 Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
839 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Top)) {
840 if (FR->getDecl()->isBitField())
841 Length = FR->getDecl()->getBitWidthValue(SVB.getContext());
844 for (ClusterBindings::iterator I = Cluster.begin(), E = Cluster.end();
846 BindingKey NextKey = I.getKey();
847 if (NextKey.getRegion() == TopKey.getRegion()) {
848 // FIXME: This doesn't catch the case where we're really invalidating a
849 // region with a symbolic offset. Example:
853 if (NextKey.getOffset() > TopKey.getOffset() &&
854 NextKey.getOffset() - TopKey.getOffset() < Length) {
855 // Case 1: The next binding is inside the region we're invalidating.
857 Bindings.push_back(*I);
859 } else if (NextKey.getOffset() == TopKey.getOffset()) {
860 // Case 2: The next binding is at the same offset as the region we're
861 // invalidating. In this case, we need to leave default bindings alone,
862 // since they may be providing a default value for a regions beyond what
863 // we're invalidating.
864 // FIXME: This is probably incorrect; consider invalidating an outer
865 // struct whose first field is bound to a LazyCompoundVal.
866 if (IncludeAllDefaultBindings || NextKey.isDirect())
867 Bindings.push_back(*I);
870 } else if (NextKey.hasSymbolicOffset()) {
871 const MemRegion *Base = NextKey.getConcreteOffsetRegion();
872 if (Top->isSubRegionOf(Base)) {
873 // Case 3: The next key is symbolic and we just changed something within
874 // its concrete region. We don't know if the binding is still valid, so
875 // we'll be conservative and include it.
876 if (IncludeAllDefaultBindings || NextKey.isDirect())
877 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
878 Bindings.push_back(*I);
879 } else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Base)) {
880 // Case 4: The next key is symbolic, but we changed a known
881 // super-region. In this case the binding is certainly included.
882 if (Top == Base || BaseSR->isSubRegionOf(Top))
883 if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
884 Bindings.push_back(*I);
891 collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
892 SValBuilder &SVB, const ClusterBindings &Cluster,
893 const SubRegion *Top, bool IncludeAllDefaultBindings) {
894 collectSubRegionBindings(Bindings, SVB, Cluster, Top,
895 BindingKey::Make(Top, BindingKey::Default),
896 IncludeAllDefaultBindings);
900 RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
901 const SubRegion *Top) {
902 BindingKey TopKey = BindingKey::Make(Top, BindingKey::Default);
903 const MemRegion *ClusterHead = TopKey.getBaseRegion();
905 if (Top == ClusterHead) {
906 // We can remove an entire cluster's bindings all in one go.
907 return B.remove(Top);
910 const ClusterBindings *Cluster = B.lookup(ClusterHead);
912 // If we're invalidating a region with a symbolic offset, we need to make
913 // sure we don't treat the base region as uninitialized anymore.
914 if (TopKey.hasSymbolicOffset()) {
915 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
916 return B.addBinding(Concrete, BindingKey::Default, UnknownVal());
921 SmallVector<BindingPair, 32> Bindings;
922 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, Top, TopKey,
923 /*IncludeAllDefaultBindings=*/false);
925 ClusterBindingsRef Result(*Cluster, CBFactory);
926 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
929 Result = Result.remove(I->first);
931 // If we're invalidating a region with a symbolic offset, we need to make sure
932 // we don't treat the base region as uninitialized anymore.
933 // FIXME: This isn't very precise; see the example in
934 // collectSubRegionBindings.
935 if (TopKey.hasSymbolicOffset()) {
936 const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
937 Result = Result.add(BindingKey::Make(Concrete, BindingKey::Default),
941 if (Result.isEmpty())
942 return B.remove(ClusterHead);
943 return B.add(ClusterHead, Result.asImmutableMap());
947 class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
951 const LocationContext *LCtx;
952 InvalidatedSymbols &IS;
953 RegionAndSymbolInvalidationTraits &ITraits;
954 StoreManager::InvalidatedRegions *Regions;
955 GlobalsFilterKind GlobalsFilter;
957 invalidateRegionsWorker(RegionStoreManager &rm,
958 ProgramStateManager &stateMgr,
960 const Expr *ex, unsigned count,
961 const LocationContext *lctx,
962 InvalidatedSymbols &is,
963 RegionAndSymbolInvalidationTraits &ITraitsIn,
964 StoreManager::InvalidatedRegions *r,
965 GlobalsFilterKind GFK)
966 : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b),
967 Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
968 GlobalsFilter(GFK) {}
970 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
971 void VisitBinding(SVal V);
973 using ClusterAnalysis::AddToWorkList;
975 bool AddToWorkList(const MemRegion *R);
977 /// Returns true if all clusters in the memory space for \p Base should be
979 bool includeEntireMemorySpace(const MemRegion *Base);
981 /// Returns true if the memory space of the given region is one of the global
982 /// regions specially included at the start of invalidation.
983 bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
987 bool invalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
988 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
989 R, RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
990 const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
991 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
994 void invalidateRegionsWorker::VisitBinding(SVal V) {
995 // A symbol? Mark it touched by the invalidation.
996 if (SymbolRef Sym = V.getAsSymbol())
999 if (const MemRegion *R = V.getAsRegion()) {
1004 // Is it a LazyCompoundVal? All references get invalidated as well.
1005 if (Optional<nonloc::LazyCompoundVal> LCS =
1006 V.getAs<nonloc::LazyCompoundVal>()) {
1008 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
1010 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
1019 void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
1020 const ClusterBindings *C) {
1022 bool PreserveRegionsContents =
1023 ITraits.hasTrait(baseR,
1024 RegionAndSymbolInvalidationTraits::TK_PreserveContents);
1027 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
1028 VisitBinding(I.getData());
1030 // Invalidate regions contents.
1031 if (!PreserveRegionsContents)
1032 B = B.remove(baseR);
1035 // BlockDataRegion? If so, invalidate captured variables that are passed
1037 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
1038 for (BlockDataRegion::referenced_vars_iterator
1039 BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
1041 const VarRegion *VR = BI.getCapturedRegion();
1042 const VarDecl *VD = VR->getDecl();
1043 if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
1046 else if (Loc::isLocType(VR->getValueType())) {
1047 // Map the current bindings to a Store to retrieve the value
1048 // of the binding. If that binding itself is a region, we should
1049 // invalidate that region. This is because a block may capture
1050 // a pointer value, but the thing pointed by that pointer may
1052 SVal V = RM.getBinding(B, loc::MemRegionVal(VR));
1053 if (Optional<Loc> L = V.getAs<Loc>()) {
1054 if (const MemRegion *LR = L->getAsRegion())
1063 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
1064 IS.insert(SR->getSymbol());
1066 // Nothing else should be done in the case when we preserve regions context.
1067 if (PreserveRegionsContents)
1070 // Otherwise, we have a normal data region. Record that we touched the region.
1072 Regions->push_back(baseR);
1074 if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
1075 // Invalidate the region by setting its default value to
1076 // conjured symbol. The type of the symbol is irrelevant.
1077 DefinedOrUnknownSVal V =
1078 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
1079 B = B.addBinding(baseR, BindingKey::Default, V);
1083 if (!baseR->isBoundable())
1086 const TypedValueRegion *TR = cast<TypedValueRegion>(baseR);
1087 QualType T = TR->getValueType();
1089 if (isInitiallyIncludedGlobalRegion(baseR)) {
1090 // If the region is a global and we are invalidating all globals,
1091 // erasing the entry is good enough. This causes all globals to be lazily
1092 // symbolicated from the same base symbol.
1096 if (T->isStructureOrClassType()) {
1097 // Invalidate the region by setting its default value to
1098 // conjured symbol. The type of the symbol is irrelevant.
1099 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1101 B = B.addBinding(baseR, BindingKey::Default, V);
1105 if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
1106 bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1108 RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
1110 if (doNotInvalidateSuperRegion) {
1111 // We are not doing blank invalidation of the whole array region so we
1112 // have to manually invalidate each elements.
1113 Optional<uint64_t> NumElements;
1115 // Compute lower and upper offsets for region within array.
1116 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
1117 NumElements = CAT->getSize().getZExtValue();
1118 if (!NumElements) // We are not dealing with a constant size array
1119 goto conjure_default;
1120 QualType ElementTy = AT->getElementType();
1121 uint64_t ElemSize = Ctx.getTypeSize(ElementTy);
1122 const RegionOffset &RO = baseR->getAsOffset();
1123 const MemRegion *SuperR = baseR->getBaseRegion();
1124 if (RO.hasSymbolicOffset()) {
1125 // If base region has a symbolic offset,
1126 // we revert to invalidating the super region.
1128 AddToWorkList(SuperR);
1129 goto conjure_default;
1132 uint64_t LowerOffset = RO.getOffset();
1133 uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
1134 bool UpperOverflow = UpperOffset < LowerOffset;
1136 // Invalidate regions which are within array boundaries,
1137 // or have a symbolic offset.
1139 goto conjure_default;
1141 const ClusterBindings *C = B.lookup(SuperR);
1143 goto conjure_default;
1145 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E;
1147 const BindingKey &BK = I.getKey();
1148 Optional<uint64_t> ROffset =
1149 BK.hasSymbolicOffset() ? Optional<uint64_t>() : BK.getOffset();
1151 // Check offset is not symbolic and within array's boundaries.
1152 // Handles arrays of 0 elements and of 0-sized elements as well.
1154 ((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
1156 (*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
1157 (LowerOffset == UpperOffset && *ROffset == LowerOffset))) {
1158 B = B.removeBinding(I.getKey());
1159 // Bound symbolic regions need to be invalidated for dead symbol
1161 SVal V = I.getData();
1162 const MemRegion *R = V.getAsRegion();
1163 if (R && isa<SymbolicRegion>(R))
1169 // Set the default value of the array to conjured symbol.
1170 DefinedOrUnknownSVal V =
1171 svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1172 AT->getElementType(), Count);
1173 B = B.addBinding(baseR, BindingKey::Default, V);
1177 DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1179 assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
1180 B = B.addBinding(baseR, BindingKey::Direct, V);
1183 bool invalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
1184 const MemRegion *R) {
1185 switch (GlobalsFilter) {
1188 case GFK_SystemOnly:
1189 return isa<GlobalSystemSpaceRegion>(R->getMemorySpace());
1191 return isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace());
1194 llvm_unreachable("unknown globals filter");
1197 bool invalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
1198 if (isInitiallyIncludedGlobalRegion(Base))
1201 const MemSpaceRegion *MemSpace = Base->getMemorySpace();
1202 return ITraits.hasTrait(MemSpace,
1203 RegionAndSymbolInvalidationTraits::TK_EntireMemSpace);
1207 RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
1210 const LocationContext *LCtx,
1211 RegionBindingsRef B,
1212 InvalidatedRegions *Invalidated) {
1213 // Bind the globals memory space to a new symbol that we will use to derive
1214 // the bindings for all globals.
1215 const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
1216 SVal V = svalBuilder.conjureSymbolVal(/* SymbolTag = */ (const void*) GS, Ex, LCtx,
1217 /* type does not matter */ Ctx.IntTy,
1220 B = B.removeBinding(GS)
1221 .addBinding(BindingKey::Make(GS, BindingKey::Default), V);
1223 // Even if there are no bindings in the global scope, we still need to
1224 // record that we touched it.
1226 Invalidated->push_back(GS);
1231 void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
1232 ArrayRef<SVal> Values,
1233 InvalidatedRegions *TopLevelRegions) {
1234 for (ArrayRef<SVal>::iterator I = Values.begin(),
1235 E = Values.end(); I != E; ++I) {
1237 if (Optional<nonloc::LazyCompoundVal> LCS =
1238 V.getAs<nonloc::LazyCompoundVal>()) {
1240 const SValListTy &Vals = getInterestingValues(*LCS);
1242 for (SValListTy::const_iterator I = Vals.begin(),
1243 E = Vals.end(); I != E; ++I) {
1244 // Note: the last argument is false here because these are
1245 // non-top-level regions.
1246 if (const MemRegion *R = (*I).getAsRegion())
1252 if (const MemRegion *R = V.getAsRegion()) {
1253 if (TopLevelRegions)
1254 TopLevelRegions->push_back(R);
1262 RegionStoreManager::invalidateRegions(Store store,
1263 ArrayRef<SVal> Values,
1264 const Expr *Ex, unsigned Count,
1265 const LocationContext *LCtx,
1266 const CallEvent *Call,
1267 InvalidatedSymbols &IS,
1268 RegionAndSymbolInvalidationTraits &ITraits,
1269 InvalidatedRegions *TopLevelRegions,
1270 InvalidatedRegions *Invalidated) {
1271 GlobalsFilterKind GlobalsFilter;
1273 if (Call->isInSystemHeader())
1274 GlobalsFilter = GFK_SystemOnly;
1276 GlobalsFilter = GFK_All;
1278 GlobalsFilter = GFK_None;
1281 RegionBindingsRef B = getRegionBindings(store);
1282 invalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
1283 Invalidated, GlobalsFilter);
1285 // Scan the bindings and generate the clusters.
1286 W.GenerateClusters();
1288 // Add the regions to the worklist.
1289 populateWorkList(W, Values, TopLevelRegions);
1293 // Return the new bindings.
1294 B = W.getRegionBindings();
1296 // For calls, determine which global regions should be invalidated and
1297 // invalidate them. (Note that function-static and immutable globals are never
1298 // invalidated by this.)
1299 // TODO: This could possibly be more precise with modules.
1300 switch (GlobalsFilter) {
1302 B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
1303 Ex, Count, LCtx, B, Invalidated);
1305 case GFK_SystemOnly:
1306 B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
1307 Ex, Count, LCtx, B, Invalidated);
1313 return StoreRef(B.asStore(), *this);
1316 //===----------------------------------------------------------------------===//
1317 // Extents for regions.
1318 //===----------------------------------------------------------------------===//
1320 DefinedOrUnknownSVal
1321 RegionStoreManager::getSizeInElements(ProgramStateRef state,
1324 SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
1325 const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
1327 return UnknownVal();
1329 CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());
1331 if (Ctx.getAsVariableArrayType(EleTy)) {
1332 // FIXME: We need to track extra state to properly record the size
1333 // of VLAs. Returning UnknownVal here, however, is a stop-gap so that
1334 // we don't have a divide-by-zero below.
1335 return UnknownVal();
1338 CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);
1340 // If a variable is reinterpreted as a type that doesn't fit into a larger
1341 // type evenly, round it down.
1342 // This is a signed value, since it's used in arithmetic with signed indices.
1343 return svalBuilder.makeIntVal(RegionSize / EleSize, false);
1346 //===----------------------------------------------------------------------===//
1347 // Location and region casting.
1348 //===----------------------------------------------------------------------===//
1350 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
1351 /// type. 'Array' represents the lvalue of the array being decayed
1352 /// to a pointer, and the returned SVal represents the decayed
1353 /// version of that lvalue (i.e., a pointer to the first element of
1354 /// the array). This is called by ExprEngine when evaluating casts
1355 /// from arrays to pointers.
1356 SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
1357 if (Array.getAs<loc::ConcreteInt>())
1360 if (!Array.getAs<loc::MemRegionVal>())
1361 return UnknownVal();
1363 const SubRegion *R =
1364 cast<SubRegion>(Array.castAs<loc::MemRegionVal>().getRegion());
1365 NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
1366 return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
1369 //===----------------------------------------------------------------------===//
1370 // Loading values from regions.
1371 //===----------------------------------------------------------------------===//
1373 SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
1374 assert(!L.getAs<UnknownVal>() && "location unknown");
1375 assert(!L.getAs<UndefinedVal>() && "location undefined");
1377 // For access to concrete addresses, return UnknownVal. Checks
1378 // for null dereferences (and similar errors) are done by checkers, not
1380 // FIXME: We can consider lazily symbolicating such memory, but we really
1381 // should defer this when we can reason easily about symbolicating arrays
1383 if (L.getAs<loc::ConcreteInt>()) {
1384 return UnknownVal();
1386 if (!L.getAs<loc::MemRegionVal>()) {
1387 return UnknownVal();
1390 const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();
1392 if (isa<BlockDataRegion>(MR)) {
1393 return UnknownVal();
1396 if (isa<AllocaRegion>(MR) ||
1397 isa<SymbolicRegion>(MR) ||
1398 isa<CodeTextRegion>(MR)) {
1400 if (const TypedRegion *TR = dyn_cast<TypedRegion>(MR))
1401 T = TR->getLocationType();
1403 const SymbolicRegion *SR = cast<SymbolicRegion>(MR);
1404 T = SR->getSymbol()->getType();
1407 MR = GetElementZeroRegion(cast<SubRegion>(MR), T);
1410 // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
1411 // instead of 'Loc', and have the other Loc cases handled at a higher level.
1412 const TypedValueRegion *R = cast<TypedValueRegion>(MR);
1413 QualType RTy = R->getValueType();
1415 // FIXME: we do not yet model the parts of a complex type, so treat the
1416 // whole thing as "unknown".
1417 if (RTy->isAnyComplexType())
1418 return UnknownVal();
1420 // FIXME: We should eventually handle funny addressing. e.g.:
1424 // char *q = (char*) p;
1425 // char c = *q; // returns the first byte of 'x'.
1427 // Such funny addressing will occur due to layering of regions.
1428 if (RTy->isStructureOrClassType())
1429 return getBindingForStruct(B, R);
1431 // FIXME: Handle unions.
1432 if (RTy->isUnionType())
1433 return createLazyBinding(B, R);
1435 if (RTy->isArrayType()) {
1436 if (RTy->isConstantArrayType())
1437 return getBindingForArray(B, R);
1439 return UnknownVal();
1442 // FIXME: handle Vector types.
1443 if (RTy->isVectorType())
1444 return UnknownVal();
1446 if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
1447 return CastRetrievedVal(getBindingForField(B, FR), FR, T, false);
1449 if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
1450 // FIXME: Here we actually perform an implicit conversion from the loaded
1451 // value to the element type. Eventually we want to compose these values
1452 // more intelligently. For example, an 'element' can encompass multiple
1453 // bound regions (e.g., several bound bytes), or could be a subset of
1455 return CastRetrievedVal(getBindingForElement(B, ER), ER, T, false);
1458 if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
1459 // FIXME: Here we actually perform an implicit conversion from the loaded
1460 // value to the ivar type. What we should model is stores to ivars
1461 // that blow past the extent of the ivar. If the address of the ivar is
1462 // reinterpretted, it is possible we stored a different value that could
1463 // fit within the ivar. Either we need to cast these when storing them
1464 // or reinterpret them lazily (as we do here).
1465 return CastRetrievedVal(getBindingForObjCIvar(B, IVR), IVR, T, false);
1468 if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
1469 // FIXME: Here we actually perform an implicit conversion from the loaded
1470 // value to the variable type. What we should model is stores to variables
1471 // that blow past the extent of the variable. If the address of the
1472 // variable is reinterpretted, it is possible we stored a different value
1473 // that could fit within the variable. Either we need to cast these when
1474 // storing them or reinterpret them lazily (as we do here).
1475 return CastRetrievedVal(getBindingForVar(B, VR), VR, T, false);
1478 const SVal *V = B.lookup(R, BindingKey::Direct);
1480 // Check if the region has a binding.
1484 // The location does not have a bound value. This means that it has
1485 // the value it had upon its creation and/or entry to the analyzed
1486 // function/method. These are either symbolic values or 'undefined'.
1487 if (R->hasStackNonParametersStorage()) {
1488 // All stack variables are considered to have undefined values
1489 // upon creation. All heap allocated blocks are considered to
1490 // have undefined values as well unless they are explicitly bound
1491 // to specific values.
1492 return UndefinedVal();
1495 // All other values are symbolic.
1496 return svalBuilder.getRegionValueSymbolVal(R);
1499 static QualType getUnderlyingType(const SubRegion *R) {
1501 if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
1502 RegionTy = TVR->getValueType();
1504 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
1505 RegionTy = SR->getSymbol()->getType();
1510 /// Checks to see if store \p B has a lazy binding for region \p R.
1512 /// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
1513 /// if there are additional bindings within \p R.
1515 /// Note that unlike RegionStoreManager::findLazyBinding, this will not search
1516 /// for lazy bindings for super-regions of \p R.
1517 static Optional<nonloc::LazyCompoundVal>
1518 getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
1519 const SubRegion *R, bool AllowSubregionBindings) {
1520 Optional<SVal> V = B.getDefaultBinding(R);
1524 Optional<nonloc::LazyCompoundVal> LCV = V->getAs<nonloc::LazyCompoundVal>();
1528 // If the LCV is for a subregion, the types might not match, and we shouldn't
1529 // reuse the binding.
1530 QualType RegionTy = getUnderlyingType(R);
1531 if (!RegionTy.isNull() &&
1532 !RegionTy->isVoidPointerType()) {
1533 QualType SourceRegionTy = LCV->getRegion()->getValueType();
1534 if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
1538 if (!AllowSubregionBindings) {
1539 // If there are any other bindings within this region, we shouldn't reuse
1540 // the top-level binding.
1541 SmallVector<BindingPair, 16> Bindings;
1542 collectSubRegionBindings(Bindings, SVB, *B.lookup(R->getBaseRegion()), R,
1543 /*IncludeAllDefaultBindings=*/true);
1544 if (Bindings.size() > 1)
1552 std::pair<Store, const SubRegion *>
1553 RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
1555 const SubRegion *originalRegion) {
1556 if (originalRegion != R) {
1557 if (Optional<nonloc::LazyCompoundVal> V =
1558 getExistingLazyBinding(svalBuilder, B, R, true))
1559 return std::make_pair(V->getStore(), V->getRegion());
1562 typedef std::pair<Store, const SubRegion *> StoreRegionPair;
1563 StoreRegionPair Result = StoreRegionPair();
1565 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1566 Result = findLazyBinding(B, cast<SubRegion>(ER->getSuperRegion()),
1570 Result.second = MRMgr.getElementRegionWithSuper(ER, Result.second);
1572 } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
1573 Result = findLazyBinding(B, cast<SubRegion>(FR->getSuperRegion()),
1577 Result.second = MRMgr.getFieldRegionWithSuper(FR, Result.second);
1579 } else if (const CXXBaseObjectRegion *BaseReg =
1580 dyn_cast<CXXBaseObjectRegion>(R)) {
1581 // C++ base object region is another kind of region that we should blast
1582 // through to look for lazy compound value. It is like a field region.
1583 Result = findLazyBinding(B, cast<SubRegion>(BaseReg->getSuperRegion()),
1587 Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(BaseReg,
1594 SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
1595 const ElementRegion* R) {
1596 // We do not currently model bindings of the CompoundLiteralregion.
1597 if (isa<CompoundLiteralRegion>(R->getBaseRegion()))
1598 return UnknownVal();
1600 // Check if the region has a binding.
1601 if (const Optional<SVal> &V = B.getDirectBinding(R))
1604 const MemRegion* superR = R->getSuperRegion();
1606 // Check if the region is an element region of a string literal.
1607 if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
1608 // FIXME: Handle loads from strings where the literal is treated as
1609 // an integer, e.g., *((unsigned int*)"hello")
1610 QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
1611 if (!Ctx.hasSameUnqualifiedType(T, R->getElementType()))
1612 return UnknownVal();
1614 const StringLiteral *Str = StrR->getStringLiteral();
1615 SVal Idx = R->getIndex();
1616 if (Optional<nonloc::ConcreteInt> CI = Idx.getAs<nonloc::ConcreteInt>()) {
1617 int64_t i = CI->getValue().getSExtValue();
1618 // Abort on string underrun. This can be possible by arbitrary
1619 // clients of getBindingForElement().
1621 return UndefinedVal();
1622 int64_t length = Str->getLength();
1623 // Technically, only i == length is guaranteed to be null.
1624 // However, such overflows should be caught before reaching this point;
1625 // the only time such an access would be made is if a string literal was
1626 // used to initialize a larger array.
1627 char c = (i >= length) ? '\0' : Str->getCodeUnit(i);
1628 return svalBuilder.makeIntVal(c, T);
1632 // Check for loads from a code text region. For such loads, just give up.
1633 if (isa<CodeTextRegion>(superR))
1634 return UnknownVal();
1636 // Handle the case where we are indexing into a larger scalar object.
1637 // For example, this handles:
1641 // FIXME: This is a hack, and doesn't do anything really intelligent yet.
1642 const RegionRawOffset &O = R->getAsArrayOffset();
1644 // If we cannot reason about the offset, return an unknown value.
1646 return UnknownVal();
1648 if (const TypedValueRegion *baseR =
1649 dyn_cast_or_null<TypedValueRegion>(O.getRegion())) {
1650 QualType baseT = baseR->getValueType();
1651 if (baseT->isScalarType()) {
1652 QualType elemT = R->getElementType();
1653 if (elemT->isScalarType()) {
1654 if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
1655 if (const Optional<SVal> &V = B.getDirectBinding(superR)) {
1656 if (SymbolRef parentSym = V->getAsSymbol())
1657 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1659 if (V->isUnknownOrUndef())
1661 // Other cases: give up. We are indexing into a larger object
1662 // that has some value, but we don't know how to handle that yet.
1663 return UnknownVal();
1669 return getBindingForFieldOrElementCommon(B, R, R->getElementType());
1672 SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
1673 const FieldRegion* R) {
1675 // Check if the region has a binding.
1676 if (const Optional<SVal> &V = B.getDirectBinding(R))
1679 QualType Ty = R->getValueType();
1680 return getBindingForFieldOrElementCommon(B, R, Ty);
1684 RegionStoreManager::getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
1685 const MemRegion *superR,
1686 const TypedValueRegion *R,
1689 if (const Optional<SVal> &D = B.getDefaultBinding(superR)) {
1690 const SVal &val = D.getValue();
1691 if (SymbolRef parentSym = val.getAsSymbol())
1692 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1694 if (val.isZeroConstant())
1695 return svalBuilder.makeZeroVal(Ty);
1697 if (val.isUnknownOrUndef())
1700 // Lazy bindings are usually handled through getExistingLazyBinding().
1701 // We should unify these two code paths at some point.
1702 if (val.getAs<nonloc::LazyCompoundVal>() ||
1703 val.getAs<nonloc::CompoundVal>())
1706 llvm_unreachable("Unknown default value");
1712 SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
1713 RegionBindingsRef LazyBinding) {
1715 if (const ElementRegion *ER = dyn_cast<ElementRegion>(LazyBindingRegion))
1716 Result = getBindingForElement(LazyBinding, ER);
1718 Result = getBindingForField(LazyBinding,
1719 cast<FieldRegion>(LazyBindingRegion));
1721 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1722 // default value for /part/ of an aggregate from a default value for the
1723 // /entire/ aggregate. The most common case of this is when struct Outer
1724 // has as its first member a struct Inner, which is copied in from a stack
1725 // variable. In this case, even if the Outer's default value is symbolic, 0,
1726 // or unknown, it gets overridden by the Inner's default value of undefined.
1728 // This is a general problem -- if the Inner is zero-initialized, the Outer
1729 // will now look zero-initialized. The proper way to solve this is with a
1730 // new version of RegionStore that tracks the extent of a binding as well
1733 // This hack only takes care of the undefined case because that can very
1734 // quickly result in a warning.
1735 if (Result.isUndef())
1736 Result = UnknownVal();
1742 RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
1743 const TypedValueRegion *R,
1746 // At this point we have already checked in either getBindingForElement or
1747 // getBindingForField if 'R' has a direct binding.
1750 Store lazyBindingStore = nullptr;
1751 const SubRegion *lazyBindingRegion = nullptr;
1752 std::tie(lazyBindingStore, lazyBindingRegion) = findLazyBinding(B, R, R);
1753 if (lazyBindingRegion)
1754 return getLazyBinding(lazyBindingRegion,
1755 getRegionBindings(lazyBindingStore));
1757 // Record whether or not we see a symbolic index. That can completely
1758 // be out of scope of our lookup.
1759 bool hasSymbolicIndex = false;
1761 // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1762 // default value for /part/ of an aggregate from a default value for the
1763 // /entire/ aggregate. The most common case of this is when struct Outer
1764 // has as its first member a struct Inner, which is copied in from a stack
1765 // variable. In this case, even if the Outer's default value is symbolic, 0,
1766 // or unknown, it gets overridden by the Inner's default value of undefined.
1768 // This is a general problem -- if the Inner is zero-initialized, the Outer
1769 // will now look zero-initialized. The proper way to solve this is with a
1770 // new version of RegionStore that tracks the extent of a binding as well
1773 // This hack only takes care of the undefined case because that can very
1774 // quickly result in a warning.
1775 bool hasPartialLazyBinding = false;
1777 const SubRegion *SR = dyn_cast<SubRegion>(R);
1779 const MemRegion *Base = SR->getSuperRegion();
1780 if (Optional<SVal> D = getBindingForDerivedDefaultValue(B, Base, R, Ty)) {
1781 if (D->getAs<nonloc::LazyCompoundVal>()) {
1782 hasPartialLazyBinding = true;
1789 if (const ElementRegion *ER = dyn_cast<ElementRegion>(Base)) {
1790 NonLoc index = ER->getIndex();
1791 if (!index.isConstant())
1792 hasSymbolicIndex = true;
1795 // If our super region is a field or element itself, walk up the region
1796 // hierarchy to see if there is a default value installed in an ancestor.
1797 SR = dyn_cast<SubRegion>(Base);
1800 if (R->hasStackNonParametersStorage()) {
1801 if (isa<ElementRegion>(R)) {
1802 // Currently we don't reason specially about Clang-style vectors. Check
1803 // if superR is a vector and if so return Unknown.
1804 if (const TypedValueRegion *typedSuperR =
1805 dyn_cast<TypedValueRegion>(R->getSuperRegion())) {
1806 if (typedSuperR->getValueType()->isVectorType())
1807 return UnknownVal();
1811 // FIXME: We also need to take ElementRegions with symbolic indexes into
1812 // account. This case handles both directly accessing an ElementRegion
1813 // with a symbolic offset, but also fields within an element with
1814 // a symbolic offset.
1815 if (hasSymbolicIndex)
1816 return UnknownVal();
1818 if (!hasPartialLazyBinding)
1819 return UndefinedVal();
1822 // All other values are symbolic.
1823 return svalBuilder.getRegionValueSymbolVal(R);
1826 SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
1827 const ObjCIvarRegion* R) {
1828 // Check if the region has a binding.
1829 if (const Optional<SVal> &V = B.getDirectBinding(R))
1832 const MemRegion *superR = R->getSuperRegion();
1834 // Check if the super region has a default binding.
1835 if (const Optional<SVal> &V = B.getDefaultBinding(superR)) {
1836 if (SymbolRef parentSym = V->getAsSymbol())
1837 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1839 // Other cases: give up.
1840 return UnknownVal();
1843 return getBindingForLazySymbol(R);
1846 SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
1847 const VarRegion *R) {
1849 // Check if the region has a binding.
1850 if (const Optional<SVal> &V = B.getDirectBinding(R))
1853 // Lazily derive a value for the VarRegion.
1854 const VarDecl *VD = R->getDecl();
1855 const MemSpaceRegion *MS = R->getMemorySpace();
1857 // Arguments are always symbolic.
1858 if (isa<StackArgumentsSpaceRegion>(MS))
1859 return svalBuilder.getRegionValueSymbolVal(R);
1861 // Is 'VD' declared constant? If so, retrieve the constant value.
1862 if (VD->getType().isConstQualified())
1863 if (const Expr *Init = VD->getInit())
1864 if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
1867 // This must come after the check for constants because closure-captured
1868 // constant variables may appear in UnknownSpaceRegion.
1869 if (isa<UnknownSpaceRegion>(MS))
1870 return svalBuilder.getRegionValueSymbolVal(R);
1872 if (isa<GlobalsSpaceRegion>(MS)) {
1873 QualType T = VD->getType();
1875 // Function-scoped static variables are default-initialized to 0; if they
1876 // have an initializer, it would have been processed by now.
1877 // FIXME: This is only true when we're starting analysis from main().
1878 // We're losing a lot of coverage here.
1879 if (isa<StaticGlobalSpaceRegion>(MS))
1880 return svalBuilder.makeZeroVal(T);
1882 if (Optional<SVal> V = getBindingForDerivedDefaultValue(B, MS, R, T)) {
1883 assert(!V->getAs<nonloc::LazyCompoundVal>());
1884 return V.getValue();
1887 return svalBuilder.getRegionValueSymbolVal(R);
1890 return UndefinedVal();
1893 SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
1894 // All other values are symbolic.
1895 return svalBuilder.getRegionValueSymbolVal(R);
1898 const RegionStoreManager::SValListTy &
1899 RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
1900 // First, check the cache.
1901 LazyBindingsMapTy::iterator I = LazyBindingsMap.find(LCV.getCVData());
1902 if (I != LazyBindingsMap.end())
1905 // If we don't have a list of values cached, start constructing it.
1908 const SubRegion *LazyR = LCV.getRegion();
1909 RegionBindingsRef B = getRegionBindings(LCV.getStore());
1911 // If this region had /no/ bindings at the time, there are no interesting
1912 // values to return.
1913 const ClusterBindings *Cluster = B.lookup(LazyR->getBaseRegion());
1915 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1917 SmallVector<BindingPair, 32> Bindings;
1918 collectSubRegionBindings(Bindings, svalBuilder, *Cluster, LazyR,
1919 /*IncludeAllDefaultBindings=*/true);
1920 for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
1924 if (V.isUnknownOrUndef() || V.isConstant())
1927 if (Optional<nonloc::LazyCompoundVal> InnerLCV =
1928 V.getAs<nonloc::LazyCompoundVal>()) {
1929 const SValListTy &InnerList = getInterestingValues(*InnerLCV);
1930 List.insert(List.end(), InnerList.begin(), InnerList.end());
1937 return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1940 NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
1941 const TypedValueRegion *R) {
1942 if (Optional<nonloc::LazyCompoundVal> V =
1943 getExistingLazyBinding(svalBuilder, B, R, false))
1946 return svalBuilder.makeLazyCompoundVal(StoreRef(B.asStore(), *this), R);
1949 static bool isRecordEmpty(const RecordDecl *RD) {
1950 if (!RD->field_empty())
1952 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD))
1953 return CRD->getNumBases() == 0;
1957 SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
1958 const TypedValueRegion *R) {
1959 const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
1960 if (!RD->getDefinition() || isRecordEmpty(RD))
1961 return UnknownVal();
1963 return createLazyBinding(B, R);
1966 SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
1967 const TypedValueRegion *R) {
1968 assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
1969 "Only constant array types can have compound bindings.");
1971 return createLazyBinding(B, R);
1974 bool RegionStoreManager::includedInBindings(Store store,
1975 const MemRegion *region) const {
1976 RegionBindingsRef B = getRegionBindings(store);
1977 region = region->getBaseRegion();
1979 // Quick path: if the base is the head of a cluster, the region is live.
1980 if (B.lookup(region))
1983 // Slow path: if the region is the VALUE of any binding, it is live.
1984 for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
1985 const ClusterBindings &Cluster = RI.getData();
1986 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
1988 const SVal &D = CI.getData();
1989 if (const MemRegion *R = D.getAsRegion())
1990 if (R->getBaseRegion() == region)
1998 //===----------------------------------------------------------------------===//
1999 // Binding values to regions.
2000 //===----------------------------------------------------------------------===//
2002 StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
2003 if (Optional<loc::MemRegionVal> LV = L.getAs<loc::MemRegionVal>())
2004 if (const MemRegion* R = LV->getRegion())
2005 return StoreRef(getRegionBindings(ST).removeBinding(R)
2007 .getRootWithoutRetain(),
2010 return StoreRef(ST, *this);
2014 RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
2015 if (L.getAs<loc::ConcreteInt>())
2018 // If we get here, the location should be a region.
2019 const MemRegion *R = L.castAs<loc::MemRegionVal>().getRegion();
2021 // Check if the region is a struct region.
2022 if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(R)) {
2023 QualType Ty = TR->getValueType();
2024 if (Ty->isArrayType())
2025 return bindArray(B, TR, V);
2026 if (Ty->isStructureOrClassType())
2027 return bindStruct(B, TR, V);
2028 if (Ty->isVectorType())
2029 return bindVector(B, TR, V);
2030 if (Ty->isUnionType())
2031 return bindAggregate(B, TR, V);
2034 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
2035 // Binding directly to a symbolic region should be treated as binding
2037 QualType T = SR->getSymbol()->getType();
2038 if (T->isAnyPointerType() || T->isReferenceType())
2039 T = T->getPointeeType();
2041 R = GetElementZeroRegion(SR, T);
2044 // Clear out bindings that may overlap with this binding.
2045 RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
2046 return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
2050 RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
2055 if (Loc::isLocType(T))
2056 V = svalBuilder.makeNull();
2057 else if (T->isIntegralOrEnumerationType())
2058 V = svalBuilder.makeZeroVal(T);
2059 else if (T->isStructureOrClassType() || T->isArrayType()) {
2060 // Set the default value to a zero constant when it is a structure
2061 // or array. The type doesn't really matter.
2062 V = svalBuilder.makeZeroVal(Ctx.IntTy);
2065 // We can't represent values of this type, but we still need to set a value
2066 // to record that the region has been initialized.
2067 // If this assertion ever fires, a new case should be added above -- we
2068 // should know how to default-initialize any value we can symbolicate.
2069 assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
2073 return B.addBinding(R, BindingKey::Default, V);
2077 RegionStoreManager::bindArray(RegionBindingsConstRef B,
2078 const TypedValueRegion* R,
2081 const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
2082 QualType ElementTy = AT->getElementType();
2083 Optional<uint64_t> Size;
2085 if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
2086 Size = CAT->getSize().getZExtValue();
2088 // Check if the init expr is a string literal.
2089 if (Optional<loc::MemRegionVal> MRV = Init.getAs<loc::MemRegionVal>()) {
2090 const StringRegion *S = cast<StringRegion>(MRV->getRegion());
2092 // Treat the string as a lazy compound value.
2093 StoreRef store(B.asStore(), *this);
2094 nonloc::LazyCompoundVal LCV = svalBuilder.makeLazyCompoundVal(store, S)
2095 .castAs<nonloc::LazyCompoundVal>();
2096 return bindAggregate(B, R, LCV);
2099 // Handle lazy compound values.
2100 if (Init.getAs<nonloc::LazyCompoundVal>())
2101 return bindAggregate(B, R, Init);
2103 if (Init.isUnknown())
2104 return bindAggregate(B, R, UnknownVal());
2106 // Remaining case: explicit compound values.
2107 const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
2108 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2111 RegionBindingsRef NewB(B);
2113 for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
2114 // The init list might be shorter than the array length.
2118 const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
2119 const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
2121 if (ElementTy->isStructureOrClassType())
2122 NewB = bindStruct(NewB, ER, *VI);
2123 else if (ElementTy->isArrayType())
2124 NewB = bindArray(NewB, ER, *VI);
2126 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2129 // If the init list is shorter than the array length, set the
2130 // array default value.
2131 if (Size.hasValue() && i < Size.getValue())
2132 NewB = setImplicitDefaultValue(NewB, R, ElementTy);
2137 RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
2138 const TypedValueRegion* R,
2140 QualType T = R->getValueType();
2141 assert(T->isVectorType());
2142 const VectorType *VT = T->getAs<VectorType>(); // Use getAs for typedefs.
2144 // Handle lazy compound values and symbolic values.
2145 if (V.getAs<nonloc::LazyCompoundVal>() || V.getAs<nonloc::SymbolVal>())
2146 return bindAggregate(B, R, V);
2148 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2149 // that we are binding symbolic struct value. Kill the field values, and if
2150 // the value is symbolic go and bind it as a "default" binding.
2151 if (!V.getAs<nonloc::CompoundVal>()) {
2152 return bindAggregate(B, R, UnknownVal());
2155 QualType ElemType = VT->getElementType();
2156 nonloc::CompoundVal CV = V.castAs<nonloc::CompoundVal>();
2157 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2158 unsigned index = 0, numElements = VT->getNumElements();
2159 RegionBindingsRef NewB(B);
2161 for ( ; index != numElements ; ++index) {
2165 NonLoc Idx = svalBuilder.makeArrayIndex(index);
2166 const ElementRegion *ER = MRMgr.getElementRegion(ElemType, Idx, R, Ctx);
2168 if (ElemType->isArrayType())
2169 NewB = bindArray(NewB, ER, *VI);
2170 else if (ElemType->isStructureOrClassType())
2171 NewB = bindStruct(NewB, ER, *VI);
2173 NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2178 Optional<RegionBindingsRef>
2179 RegionStoreManager::tryBindSmallStruct(RegionBindingsConstRef B,
2180 const TypedValueRegion *R,
2181 const RecordDecl *RD,
2182 nonloc::LazyCompoundVal LCV) {
2185 if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(RD))
2186 if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
2189 for (const auto *FD : RD->fields()) {
2190 if (FD->isUnnamedBitfield())
2193 // If there are too many fields, or if any of the fields are aggregates,
2194 // just use the LCV as a default binding.
2195 if (Fields.size() == SmallStructLimit)
2198 QualType Ty = FD->getType();
2199 if (!(Ty->isScalarType() || Ty->isReferenceType()))
2202 Fields.push_back(FD);
2205 RegionBindingsRef NewB = B;
2207 for (FieldVector::iterator I = Fields.begin(), E = Fields.end(); I != E; ++I){
2208 const FieldRegion *SourceFR = MRMgr.getFieldRegion(*I, LCV.getRegion());
2209 SVal V = getBindingForField(getRegionBindings(LCV.getStore()), SourceFR);
2211 const FieldRegion *DestFR = MRMgr.getFieldRegion(*I, R);
2212 NewB = bind(NewB, loc::MemRegionVal(DestFR), V);
2218 RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
2219 const TypedValueRegion* R,
2221 if (!Features.supportsFields())
2224 QualType T = R->getValueType();
2225 assert(T->isStructureOrClassType());
2227 const RecordType* RT = T->getAs<RecordType>();
2228 const RecordDecl *RD = RT->getDecl();
2230 if (!RD->isCompleteDefinition())
2233 // Handle lazy compound values and symbolic values.
2234 if (Optional<nonloc::LazyCompoundVal> LCV =
2235 V.getAs<nonloc::LazyCompoundVal>()) {
2236 if (Optional<RegionBindingsRef> NewB = tryBindSmallStruct(B, R, RD, *LCV))
2238 return bindAggregate(B, R, V);
2240 if (V.getAs<nonloc::SymbolVal>())
2241 return bindAggregate(B, R, V);
2243 // We may get non-CompoundVal accidentally due to imprecise cast logic or
2244 // that we are binding symbolic struct value. Kill the field values, and if
2245 // the value is symbolic go and bind it as a "default" binding.
2246 if (V.isUnknown() || !V.getAs<nonloc::CompoundVal>())
2247 return bindAggregate(B, R, UnknownVal());
2249 const nonloc::CompoundVal& CV = V.castAs<nonloc::CompoundVal>();
2250 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2252 RecordDecl::field_iterator FI, FE;
2253 RegionBindingsRef NewB(B);
2255 for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {
2260 // Skip any unnamed bitfields to stay in sync with the initializers.
2261 if (FI->isUnnamedBitfield())
2264 QualType FTy = FI->getType();
2265 const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
2267 if (FTy->isArrayType())
2268 NewB = bindArray(NewB, FR, *VI);
2269 else if (FTy->isStructureOrClassType())
2270 NewB = bindStruct(NewB, FR, *VI);
2272 NewB = bind(NewB, loc::MemRegionVal(FR), *VI);
2276 // There may be fewer values in the initialize list than the fields of struct.
2278 NewB = NewB.addBinding(R, BindingKey::Default,
2279 svalBuilder.makeIntVal(0, false));
2286 RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
2287 const TypedRegion *R,
2289 // Remove the old bindings, using 'R' as the root of all regions
2290 // we will invalidate. Then add the new binding.
2291 return removeSubRegionBindings(B, R).addBinding(R, BindingKey::Default, Val);
2294 //===----------------------------------------------------------------------===//
2296 //===----------------------------------------------------------------------===//
2299 class removeDeadBindingsWorker :
2300 public ClusterAnalysis<removeDeadBindingsWorker> {
2301 SmallVector<const SymbolicRegion*, 12> Postponed;
2302 SymbolReaper &SymReaper;
2303 const StackFrameContext *CurrentLCtx;
2306 removeDeadBindingsWorker(RegionStoreManager &rm,
2307 ProgramStateManager &stateMgr,
2308 RegionBindingsRef b, SymbolReaper &symReaper,
2309 const StackFrameContext *LCtx)
2310 : ClusterAnalysis<removeDeadBindingsWorker>(rm, stateMgr, b),
2311 SymReaper(symReaper), CurrentLCtx(LCtx) {}
2313 // Called by ClusterAnalysis.
2314 void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
2315 void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
2316 using ClusterAnalysis<removeDeadBindingsWorker>::VisitCluster;
2318 using ClusterAnalysis::AddToWorkList;
2320 bool AddToWorkList(const MemRegion *R);
2322 bool UpdatePostponed();
2323 void VisitBinding(SVal V);
2327 bool removeDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
2328 const MemRegion *BaseR = R->getBaseRegion();
2329 return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
2332 void removeDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
2333 const ClusterBindings &C) {
2335 if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
2336 if (SymReaper.isLive(VR))
2337 AddToWorkList(baseR, &C);
2342 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
2343 if (SymReaper.isLive(SR->getSymbol()))
2344 AddToWorkList(SR, &C);
2346 Postponed.push_back(SR);
2351 if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
2352 AddToWorkList(baseR, &C);
2356 // CXXThisRegion in the current or parent location context is live.
2357 if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
2358 const StackArgumentsSpaceRegion *StackReg =
2359 cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
2360 const StackFrameContext *RegCtx = StackReg->getStackFrame();
2362 (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx)))
2363 AddToWorkList(TR, &C);
2367 void removeDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
2368 const ClusterBindings *C) {
2372 // Mark the symbol for any SymbolicRegion with live bindings as live itself.
2373 // This means we should continue to track that symbol.
2374 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(baseR))
2375 SymReaper.markLive(SymR->getSymbol());
2377 for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I) {
2378 // Element index of a binding key is live.
2379 SymReaper.markElementIndicesLive(I.getKey().getRegion());
2381 VisitBinding(I.getData());
2385 void removeDeadBindingsWorker::VisitBinding(SVal V) {
2386 // Is it a LazyCompoundVal? All referenced regions are live as well.
2387 if (Optional<nonloc::LazyCompoundVal> LCS =
2388 V.getAs<nonloc::LazyCompoundVal>()) {
2390 const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
2392 for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
2400 // If V is a region, then add it to the worklist.
2401 if (const MemRegion *R = V.getAsRegion()) {
2403 SymReaper.markLive(R);
2405 // All regions captured by a block are also live.
2406 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
2407 BlockDataRegion::referenced_vars_iterator I = BR->referenced_vars_begin(),
2408 E = BR->referenced_vars_end();
2409 for ( ; I != E; ++I)
2410 AddToWorkList(I.getCapturedRegion());
2415 // Update the set of live symbols.
2416 for (SymExpr::symbol_iterator SI = V.symbol_begin(), SE = V.symbol_end();
2418 SymReaper.markLive(*SI);
2421 bool removeDeadBindingsWorker::UpdatePostponed() {
2422 // See if any postponed SymbolicRegions are actually live now, after
2423 // having done a scan.
2424 bool changed = false;
2426 for (SmallVectorImpl<const SymbolicRegion*>::iterator
2427 I = Postponed.begin(), E = Postponed.end() ; I != E ; ++I) {
2428 if (const SymbolicRegion *SR = *I) {
2429 if (SymReaper.isLive(SR->getSymbol())) {
2430 changed |= AddToWorkList(SR);
2439 StoreRef RegionStoreManager::removeDeadBindings(Store store,
2440 const StackFrameContext *LCtx,
2441 SymbolReaper& SymReaper) {
2442 RegionBindingsRef B = getRegionBindings(store);
2443 removeDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
2444 W.GenerateClusters();
2446 // Enqueue the region roots onto the worklist.
2447 for (SymbolReaper::region_iterator I = SymReaper.region_begin(),
2448 E = SymReaper.region_end(); I != E; ++I) {
2449 W.AddToWorkList(*I);
2452 do W.RunWorkList(); while (W.UpdatePostponed());
2454 // We have now scanned the store, marking reachable regions and symbols
2455 // as live. We now remove all the regions that are dead from the store
2456 // as well as update DSymbols with the set symbols that are now dead.
2457 for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
2458 const MemRegion *Base = I.getKey();
2460 // If the cluster has been visited, we know the region has been marked.
2461 if (W.isVisited(Base))
2464 // Remove the dead entry.
2467 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(Base))
2468 SymReaper.maybeDead(SymR->getSymbol());
2470 // Mark all non-live symbols that this binding references as dead.
2471 const ClusterBindings &Cluster = I.getData();
2472 for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
2474 SVal X = CI.getData();
2475 SymExpr::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
2476 for (; SI != SE; ++SI)
2477 SymReaper.maybeDead(*SI);
2481 return StoreRef(B.asStore(), *this);
2484 //===----------------------------------------------------------------------===//
2486 //===----------------------------------------------------------------------===//
2488 void RegionStoreManager::print(Store store, raw_ostream &OS,
2489 const char* nl, const char *sep) {
2490 RegionBindingsRef B = getRegionBindings(store);
2491 OS << "Store (direct and default bindings), "