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 //===----------------------------------------------------------------------===//
17 #include "clang/AST/CharUnits.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/ExprCXX.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/GRState.h"
24 #include "clang/StaticAnalyzer/Core/PathSensitive/GRStateTrait.h"
25 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
26 #include "llvm/ADT/ImmutableList.h"
27 #include "llvm/ADT/ImmutableMap.h"
28 #include "llvm/ADT/Optional.h"
29 #include "llvm/Support/raw_ostream.h"
31 using namespace clang;
35 //===----------------------------------------------------------------------===//
36 // Representation of binding keys.
37 //===----------------------------------------------------------------------===//
42 enum Kind { Direct = 0x0, Default = 0x1 };
44 llvm ::PointerIntPair<const MemRegion*, 1> P;
47 explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
48 : P(r, (unsigned) k), Offset(offset) {}
51 bool isDirect() const { return P.getInt() == Direct; }
53 const MemRegion *getRegion() const { return P.getPointer(); }
54 uint64_t getOffset() const { return Offset; }
56 void Profile(llvm::FoldingSetNodeID& ID) const {
57 ID.AddPointer(P.getOpaqueValue());
58 ID.AddInteger(Offset);
61 static BindingKey Make(const MemRegion *R, Kind k);
63 bool operator<(const BindingKey &X) const {
64 if (P.getOpaqueValue() < X.P.getOpaqueValue())
66 if (P.getOpaqueValue() > X.P.getOpaqueValue())
68 return Offset < X.Offset;
71 bool operator==(const BindingKey &X) const {
72 return P.getOpaqueValue() == X.P.getOpaqueValue() &&
76 bool isValid() const {
77 return getRegion() != NULL;
80 } // end anonymous namespace
82 BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
83 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
84 const RegionRawOffset &O = ER->getAsArrayOffset();
86 // FIXME: There are some ElementRegions for which we cannot compute
87 // raw offsets yet, including regions with symbolic offsets. These will be
88 // ignored by the store.
89 return BindingKey(O.getRegion(), O.getOffset().getQuantity(), k);
92 return BindingKey(R, 0, k);
97 llvm::raw_ostream& operator<<(llvm::raw_ostream& os, BindingKey K) {
98 os << '(' << K.getRegion() << ',' << K.getOffset()
99 << ',' << (K.isDirect() ? "direct" : "default")
103 } // end llvm namespace
105 //===----------------------------------------------------------------------===//
106 // Actual Store type.
107 //===----------------------------------------------------------------------===//
109 typedef llvm::ImmutableMap<BindingKey, SVal> RegionBindings;
111 //===----------------------------------------------------------------------===//
112 // Fine-grained control of RegionStoreManager.
113 //===----------------------------------------------------------------------===//
116 struct minimal_features_tag {};
117 struct maximal_features_tag {};
119 class RegionStoreFeatures {
122 RegionStoreFeatures(minimal_features_tag) :
123 SupportsFields(false) {}
125 RegionStoreFeatures(maximal_features_tag) :
126 SupportsFields(true) {}
128 void enableFields(bool t) { SupportsFields = t; }
130 bool supportsFields() const { return SupportsFields; }
134 //===----------------------------------------------------------------------===//
135 // Main RegionStore logic.
136 //===----------------------------------------------------------------------===//
140 class RegionStoreSubRegionMap : public SubRegionMap {
142 typedef llvm::ImmutableSet<const MemRegion*> Set;
143 typedef llvm::DenseMap<const MemRegion*, Set> Map;
148 bool add(const MemRegion* Parent, const MemRegion* SubRegion) {
149 Map::iterator I = M.find(Parent);
152 M.insert(std::make_pair(Parent, F.add(F.getEmptySet(), SubRegion)));
156 I->second = F.add(I->second, SubRegion);
160 void process(llvm::SmallVectorImpl<const SubRegion*> &WL, const SubRegion *R);
162 ~RegionStoreSubRegionMap() {}
164 const Set *getSubRegions(const MemRegion *Parent) const {
165 Map::const_iterator I = M.find(Parent);
166 return I == M.end() ? NULL : &I->second;
169 bool iterSubRegions(const MemRegion* Parent, Visitor& V) const {
170 Map::const_iterator I = M.find(Parent);
176 for (Set::iterator SI=S.begin(),SE=S.end(); SI != SE; ++SI) {
177 if (!V.Visit(Parent, *SI))
186 RegionStoreSubRegionMap::process(llvm::SmallVectorImpl<const SubRegion*> &WL,
187 const SubRegion *R) {
188 const MemRegion *superR = R->getSuperRegion();
190 if (const SubRegion *sr = dyn_cast<SubRegion>(superR))
194 class RegionStoreManager : public StoreManager {
195 const RegionStoreFeatures Features;
196 RegionBindings::Factory RBFactory;
199 RegionStoreManager(GRStateManager& mgr, const RegionStoreFeatures &f)
202 RBFactory(mgr.getAllocator()) {}
204 SubRegionMap *getSubRegionMap(Store store) {
205 return getRegionStoreSubRegionMap(store);
208 RegionStoreSubRegionMap *getRegionStoreSubRegionMap(Store store);
210 Optional<SVal> getDirectBinding(RegionBindings B, const MemRegion *R);
211 /// getDefaultBinding - Returns an SVal* representing an optional default
212 /// binding associated with a region and its subregions.
213 Optional<SVal> getDefaultBinding(RegionBindings B, const MemRegion *R);
215 /// setImplicitDefaultValue - Set the default binding for the provided
216 /// MemRegion to the value implicitly defined for compound literals when
217 /// the value is not specified.
218 StoreRef setImplicitDefaultValue(Store store, const MemRegion *R, QualType T);
220 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
221 /// type. 'Array' represents the lvalue of the array being decayed
222 /// to a pointer, and the returned SVal represents the decayed
223 /// version of that lvalue (i.e., a pointer to the first element of
224 /// the array). This is called by ExprEngine when evaluating
225 /// casts from arrays to pointers.
226 SVal ArrayToPointer(Loc Array);
228 /// For DerivedToBase casts, create a CXXBaseObjectRegion and return it.
229 virtual SVal evalDerivedToBase(SVal derived, QualType basePtrType);
231 StoreRef getInitialStore(const LocationContext *InitLoc) {
232 return StoreRef(RBFactory.getEmptyMap().getRootWithoutRetain(), *this);
235 //===-------------------------------------------------------------------===//
236 // Binding values to regions.
237 //===-------------------------------------------------------------------===//
239 StoreRef invalidateRegions(Store store,
240 const MemRegion * const *Begin,
241 const MemRegion * const *End,
242 const Expr *E, unsigned Count,
243 InvalidatedSymbols *IS,
244 bool invalidateGlobals,
245 InvalidatedRegions *Regions);
247 public: // Made public for helper classes.
249 void RemoveSubRegionBindings(RegionBindings &B, const MemRegion *R,
250 RegionStoreSubRegionMap &M);
252 RegionBindings addBinding(RegionBindings B, BindingKey K, SVal V);
254 RegionBindings addBinding(RegionBindings B, const MemRegion *R,
255 BindingKey::Kind k, SVal V);
257 const SVal *lookup(RegionBindings B, BindingKey K);
258 const SVal *lookup(RegionBindings B, const MemRegion *R, BindingKey::Kind k);
260 RegionBindings removeBinding(RegionBindings B, BindingKey K);
261 RegionBindings removeBinding(RegionBindings B, const MemRegion *R,
264 RegionBindings removeBinding(RegionBindings B, const MemRegion *R) {
265 return removeBinding(removeBinding(B, R, BindingKey::Direct), R,
266 BindingKey::Default);
269 public: // Part of public interface to class.
271 StoreRef Bind(Store store, Loc LV, SVal V);
273 // BindDefault is only used to initialize a region with a default value.
274 StoreRef BindDefault(Store store, const MemRegion *R, SVal V) {
275 RegionBindings B = GetRegionBindings(store);
276 assert(!lookup(B, R, BindingKey::Default));
277 assert(!lookup(B, R, BindingKey::Direct));
278 return StoreRef(addBinding(B, R, BindingKey::Default, V).getRootWithoutRetain(), *this);
281 StoreRef BindCompoundLiteral(Store store, const CompoundLiteralExpr* CL,
282 const LocationContext *LC, SVal V);
284 StoreRef BindDecl(Store store, const VarRegion *VR, SVal InitVal);
286 StoreRef BindDeclWithNoInit(Store store, const VarRegion *) {
287 return StoreRef(store, *this);
290 /// BindStruct - Bind a compound value to a structure.
291 StoreRef BindStruct(Store store, const TypedRegion* R, SVal V);
293 StoreRef BindArray(Store store, const TypedRegion* R, SVal V);
295 /// KillStruct - Set the entire struct to unknown.
296 StoreRef KillStruct(Store store, const TypedRegion* R, SVal DefaultVal);
298 StoreRef Remove(Store store, Loc LV);
300 void incrementReferenceCount(Store store) {
301 GetRegionBindings(store).manualRetain();
304 /// If the StoreManager supports it, decrement the reference count of
305 /// the specified Store object. If the reference count hits 0, the memory
306 /// associated with the object is recycled.
307 void decrementReferenceCount(Store store) {
308 GetRegionBindings(store).manualRelease();
311 //===------------------------------------------------------------------===//
312 // Loading values from regions.
313 //===------------------------------------------------------------------===//
315 /// The high level logic for this method is this:
318 /// return L's binding
319 /// else if L is in killset
322 /// if L is on stack or heap
326 SVal Retrieve(Store store, Loc L, QualType T = QualType());
328 SVal RetrieveElement(Store store, const ElementRegion *R);
330 SVal RetrieveField(Store store, const FieldRegion *R);
332 SVal RetrieveObjCIvar(Store store, const ObjCIvarRegion *R);
334 SVal RetrieveVar(Store store, const VarRegion *R);
336 SVal RetrieveLazySymbol(const TypedRegion *R);
338 SVal RetrieveFieldOrElementCommon(Store store, const TypedRegion *R,
339 QualType Ty, const MemRegion *superR);
341 /// Retrieve the values in a struct and return a CompoundVal, used when doing
345 /// y's value is retrieved by this method.
346 SVal RetrieveStruct(Store store, const TypedRegion* R);
348 SVal RetrieveArray(Store store, const TypedRegion* R);
350 /// Used to lazily generate derived symbols for bindings that are defined
351 /// implicitly by default bindings in a super region.
352 Optional<SVal> RetrieveDerivedDefaultValue(RegionBindings B,
353 const MemRegion *superR,
354 const TypedRegion *R, QualType Ty);
356 /// Get the state and region whose binding this region R corresponds to.
357 std::pair<Store, const MemRegion*>
358 GetLazyBinding(RegionBindings B, const MemRegion *R);
360 StoreRef CopyLazyBindings(nonloc::LazyCompoundVal V, Store store,
361 const TypedRegion *R);
363 //===------------------------------------------------------------------===//
365 //===------------------------------------------------------------------===//
367 /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
368 /// It returns a new Store with these values removed.
369 StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
370 SymbolReaper& SymReaper,
371 llvm::SmallVectorImpl<const MemRegion*>& RegionRoots);
373 StoreRef enterStackFrame(const GRState *state, const StackFrameContext *frame);
375 //===------------------------------------------------------------------===//
377 //===------------------------------------------------------------------===//
379 // FIXME: This method will soon be eliminated; see the note in Store.h.
380 DefinedOrUnknownSVal getSizeInElements(const GRState *state,
381 const MemRegion* R, QualType EleTy);
383 //===------------------------------------------------------------------===//
385 //===------------------------------------------------------------------===//
387 static inline RegionBindings GetRegionBindings(Store store) {
388 return RegionBindings(static_cast<const RegionBindings::TreeTy*>(store));
391 void print(Store store, llvm::raw_ostream& Out, const char* nl,
394 void iterBindings(Store store, BindingsHandler& f) {
395 RegionBindings B = GetRegionBindings(store);
396 for (RegionBindings::iterator I=B.begin(), E=B.end(); I!=E; ++I) {
397 const BindingKey &K = I.getKey();
400 if (const SubRegion *R = dyn_cast<SubRegion>(I.getKey().getRegion())) {
401 // FIXME: Possibly incorporate the offset?
402 if (!f.HandleBinding(*this, store, R, I.getData()))
409 } // end anonymous namespace
411 //===----------------------------------------------------------------------===//
412 // RegionStore creation.
413 //===----------------------------------------------------------------------===//
415 StoreManager *ento::CreateRegionStoreManager(GRStateManager& StMgr) {
416 RegionStoreFeatures F = maximal_features_tag();
417 return new RegionStoreManager(StMgr, F);
420 StoreManager *ento::CreateFieldsOnlyRegionStoreManager(GRStateManager &StMgr) {
421 RegionStoreFeatures F = minimal_features_tag();
422 F.enableFields(true);
423 return new RegionStoreManager(StMgr, F);
427 RegionStoreSubRegionMap*
428 RegionStoreManager::getRegionStoreSubRegionMap(Store store) {
429 RegionBindings B = GetRegionBindings(store);
430 RegionStoreSubRegionMap *M = new RegionStoreSubRegionMap();
432 llvm::SmallVector<const SubRegion*, 10> WL;
434 for (RegionBindings::iterator I=B.begin(), E=B.end(); I!=E; ++I)
435 if (const SubRegion *R = dyn_cast<SubRegion>(I.getKey().getRegion()))
438 // We also need to record in the subregion map "intermediate" regions that
439 // don't have direct bindings but are super regions of those that do.
440 while (!WL.empty()) {
441 const SubRegion *R = WL.back();
449 //===----------------------------------------------------------------------===//
450 // Region Cluster analysis.
451 //===----------------------------------------------------------------------===//
454 template <typename DERIVED>
455 class ClusterAnalysis {
457 typedef BumpVector<BindingKey> RegionCluster;
458 typedef llvm::DenseMap<const MemRegion *, RegionCluster *> ClusterMap;
459 llvm::DenseMap<const RegionCluster*, unsigned> Visited;
460 typedef llvm::SmallVector<std::pair<const MemRegion *, RegionCluster*>, 10>
463 BumpVectorContext BVC;
467 RegionStoreManager &RM;
469 SValBuilder &svalBuilder;
473 const bool includeGlobals;
476 ClusterAnalysis(RegionStoreManager &rm, GRStateManager &StateMgr,
477 RegionBindings b, const bool includeGlobals)
478 : RM(rm), Ctx(StateMgr.getContext()),
479 svalBuilder(StateMgr.getSValBuilder()),
480 B(b), includeGlobals(includeGlobals) {}
482 RegionBindings getRegionBindings() const { return B; }
484 RegionCluster &AddToCluster(BindingKey K) {
485 const MemRegion *R = K.getRegion();
486 const MemRegion *baseR = R->getBaseRegion();
487 RegionCluster &C = getCluster(baseR);
489 static_cast<DERIVED*>(this)->VisitAddedToCluster(baseR, C);
493 bool isVisited(const MemRegion *R) {
494 return (bool) Visited[&getCluster(R->getBaseRegion())];
497 RegionCluster& getCluster(const MemRegion *R) {
498 RegionCluster *&CRef = ClusterM[R];
500 void *Mem = BVC.getAllocator().template Allocate<RegionCluster>();
501 CRef = new (Mem) RegionCluster(BVC, 10);
506 void GenerateClusters() {
507 // Scan the entire set of bindings and make the region clusters.
508 for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
509 RegionCluster &C = AddToCluster(RI.getKey());
510 if (const MemRegion *R = RI.getData().getAsRegion()) {
511 // Generate a cluster, but don't add the region to the cluster
512 // if there aren't any bindings.
513 getCluster(R->getBaseRegion());
515 if (includeGlobals) {
516 const MemRegion *R = RI.getKey().getRegion();
517 if (isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace()))
523 bool AddToWorkList(const MemRegion *R, RegionCluster &C) {
524 if (unsigned &visited = Visited[&C])
529 WL.push_back(std::make_pair(R, &C));
533 bool AddToWorkList(BindingKey K) {
534 return AddToWorkList(K.getRegion());
537 bool AddToWorkList(const MemRegion *R) {
538 const MemRegion *baseR = R->getBaseRegion();
539 return AddToWorkList(baseR, getCluster(baseR));
543 while (!WL.empty()) {
544 const MemRegion *baseR;
546 llvm::tie(baseR, C) = WL.back();
549 // First visit the cluster.
550 static_cast<DERIVED*>(this)->VisitCluster(baseR, C->begin(), C->end());
552 // Next, visit the base region.
553 static_cast<DERIVED*>(this)->VisitBaseRegion(baseR);
558 void VisitAddedToCluster(const MemRegion *baseR, RegionCluster &C) {}
559 void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E) {}
560 void VisitBaseRegion(const MemRegion *baseR) {}
564 //===----------------------------------------------------------------------===//
565 // Binding invalidation.
566 //===----------------------------------------------------------------------===//
568 void RegionStoreManager::RemoveSubRegionBindings(RegionBindings &B,
570 RegionStoreSubRegionMap &M) {
572 if (const RegionStoreSubRegionMap::Set *S = M.getSubRegions(R))
573 for (RegionStoreSubRegionMap::Set::iterator I = S->begin(), E = S->end();
575 RemoveSubRegionBindings(B, *I, M);
577 B = removeBinding(B, R);
581 class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
585 StoreManager::InvalidatedSymbols *IS;
586 StoreManager::InvalidatedRegions *Regions;
588 invalidateRegionsWorker(RegionStoreManager &rm,
589 GRStateManager &stateMgr,
591 const Expr *ex, unsigned count,
592 StoreManager::InvalidatedSymbols *is,
593 StoreManager::InvalidatedRegions *r,
595 : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b, includeGlobals),
596 Ex(ex), Count(count), IS(is), Regions(r) {}
598 void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E);
599 void VisitBaseRegion(const MemRegion *baseR);
602 void VisitBinding(SVal V);
606 void invalidateRegionsWorker::VisitBinding(SVal V) {
607 // A symbol? Mark it touched by the invalidation.
609 if (SymbolRef Sym = V.getAsSymbol())
612 if (const MemRegion *R = V.getAsRegion()) {
617 // Is it a LazyCompoundVal? All references get invalidated as well.
618 if (const nonloc::LazyCompoundVal *LCS =
619 dyn_cast<nonloc::LazyCompoundVal>(&V)) {
621 const MemRegion *LazyR = LCS->getRegion();
622 RegionBindings B = RegionStoreManager::GetRegionBindings(LCS->getStore());
624 for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
625 const SubRegion *baseR = dyn_cast<SubRegion>(RI.getKey().getRegion());
626 if (baseR && baseR->isSubRegionOf(LazyR))
627 VisitBinding(RI.getData());
634 void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
635 BindingKey *I, BindingKey *E) {
636 for ( ; I != E; ++I) {
637 // Get the old binding. Is it a region? If so, add it to the worklist.
638 const BindingKey &K = *I;
639 if (const SVal *V = RM.lookup(B, K))
642 B = RM.removeBinding(B, K);
646 void invalidateRegionsWorker::VisitBaseRegion(const MemRegion *baseR) {
648 // Symbolic region? Mark that symbol touched by the invalidation.
649 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
650 IS->insert(SR->getSymbol());
653 // BlockDataRegion? If so, invalidate captured variables that are passed
655 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
656 for (BlockDataRegion::referenced_vars_iterator
657 BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
659 const VarRegion *VR = *BI;
660 const VarDecl *VD = VR->getDecl();
661 if (VD->getAttr<BlocksAttr>() || !VD->hasLocalStorage())
667 // Otherwise, we have a normal data region. Record that we touched the region.
669 Regions->push_back(baseR);
671 if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
672 // Invalidate the region by setting its default value to
673 // conjured symbol. The type of the symbol is irrelavant.
674 DefinedOrUnknownSVal V =
675 svalBuilder.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy, Count);
676 B = RM.addBinding(B, baseR, BindingKey::Default, V);
680 if (!baseR->isBoundable())
683 const TypedRegion *TR = cast<TypedRegion>(baseR);
684 QualType T = TR->getValueType();
686 // Invalidate the binding.
687 if (T->isStructureType()) {
688 // Invalidate the region by setting its default value to
689 // conjured symbol. The type of the symbol is irrelavant.
690 DefinedOrUnknownSVal V = svalBuilder.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy,
692 B = RM.addBinding(B, baseR, BindingKey::Default, V);
696 if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
697 // Set the default value of the array to conjured symbol.
698 DefinedOrUnknownSVal V =
699 svalBuilder.getConjuredSymbolVal(baseR, Ex, AT->getElementType(), Count);
700 B = RM.addBinding(B, baseR, BindingKey::Default, V);
704 if (includeGlobals &&
705 isa<NonStaticGlobalSpaceRegion>(baseR->getMemorySpace())) {
706 // If the region is a global and we are invalidating all globals,
707 // just erase the entry. This causes all globals to be lazily
708 // symbolicated from the same base symbol.
709 B = RM.removeBinding(B, baseR);
714 DefinedOrUnknownSVal V = svalBuilder.getConjuredSymbolVal(baseR, Ex, T, Count);
715 assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
716 B = RM.addBinding(B, baseR, BindingKey::Direct, V);
719 StoreRef RegionStoreManager::invalidateRegions(Store store,
720 const MemRegion * const *I,
721 const MemRegion * const *E,
722 const Expr *Ex, unsigned Count,
723 InvalidatedSymbols *IS,
724 bool invalidateGlobals,
725 InvalidatedRegions *Regions) {
726 invalidateRegionsWorker W(*this, StateMgr,
727 RegionStoreManager::GetRegionBindings(store),
728 Ex, Count, IS, Regions, invalidateGlobals);
730 // Scan the bindings and generate the clusters.
731 W.GenerateClusters();
733 // Add I .. E to the worklist.
739 // Return the new bindings.
740 RegionBindings B = W.getRegionBindings();
742 if (invalidateGlobals) {
743 // Bind the non-static globals memory space to a new symbol that we will
744 // use to derive the bindings for all non-static globals.
745 const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion();
747 svalBuilder.getConjuredSymbolVal(/* SymbolTag = */ (void*) GS, Ex,
748 /* symbol type, doesn't matter */ Ctx.IntTy,
750 B = addBinding(B, BindingKey::Make(GS, BindingKey::Default), V);
752 // Even if there are no bindings in the global scope, we still need to
753 // record that we touched it.
755 Regions->push_back(GS);
758 return StoreRef(B.getRootWithoutRetain(), *this);
761 //===----------------------------------------------------------------------===//
762 // Extents for regions.
763 //===----------------------------------------------------------------------===//
765 DefinedOrUnknownSVal RegionStoreManager::getSizeInElements(const GRState *state,
768 SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
769 const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
773 CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());
775 if (Ctx.getAsVariableArrayType(EleTy)) {
776 // FIXME: We need to track extra state to properly record the size
777 // of VLAs. Returning UnknownVal here, however, is a stop-gap so that
778 // we don't have a divide-by-zero below.
782 CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);
784 // If a variable is reinterpreted as a type that doesn't fit into a larger
785 // type evenly, round it down.
786 // This is a signed value, since it's used in arithmetic with signed indices.
787 return svalBuilder.makeIntVal(RegionSize / EleSize, false);
790 //===----------------------------------------------------------------------===//
791 // Location and region casting.
792 //===----------------------------------------------------------------------===//
794 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
795 /// type. 'Array' represents the lvalue of the array being decayed
796 /// to a pointer, and the returned SVal represents the decayed
797 /// version of that lvalue (i.e., a pointer to the first element of
798 /// the array). This is called by ExprEngine when evaluating casts
799 /// from arrays to pointers.
800 SVal RegionStoreManager::ArrayToPointer(Loc Array) {
801 if (!isa<loc::MemRegionVal>(Array))
804 const MemRegion* R = cast<loc::MemRegionVal>(&Array)->getRegion();
805 const TypedRegion* ArrayR = dyn_cast<TypedRegion>(R);
810 // Strip off typedefs from the ArrayRegion's ValueType.
811 QualType T = ArrayR->getValueType().getDesugaredType(Ctx);
812 const ArrayType *AT = cast<ArrayType>(T);
813 T = AT->getElementType();
815 NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
816 return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, ArrayR, Ctx));
819 SVal RegionStoreManager::evalDerivedToBase(SVal derived, QualType baseType) {
820 const CXXRecordDecl *baseDecl;
821 if (baseType->isPointerType())
822 baseDecl = baseType->getCXXRecordDeclForPointerType();
824 baseDecl = baseType->getAsCXXRecordDecl();
826 assert(baseDecl && "not a CXXRecordDecl?");
828 loc::MemRegionVal *derivedRegVal = dyn_cast<loc::MemRegionVal>(&derived);
832 const MemRegion *baseReg =
833 MRMgr.getCXXBaseObjectRegion(baseDecl, derivedRegVal->getRegion());
835 return loc::MemRegionVal(baseReg);
838 //===----------------------------------------------------------------------===//
839 // Loading values from regions.
840 //===----------------------------------------------------------------------===//
842 Optional<SVal> RegionStoreManager::getDirectBinding(RegionBindings B,
843 const MemRegion *R) {
845 if (const SVal *V = lookup(B, R, BindingKey::Direct))
848 return Optional<SVal>();
851 Optional<SVal> RegionStoreManager::getDefaultBinding(RegionBindings B,
852 const MemRegion *R) {
853 if (R->isBoundable())
854 if (const TypedRegion *TR = dyn_cast<TypedRegion>(R))
855 if (TR->getValueType()->isUnionType())
858 if (const SVal *V = lookup(B, R, BindingKey::Default))
861 return Optional<SVal>();
864 SVal RegionStoreManager::Retrieve(Store store, Loc L, QualType T) {
865 assert(!isa<UnknownVal>(L) && "location unknown");
866 assert(!isa<UndefinedVal>(L) && "location undefined");
868 // For access to concrete addresses, return UnknownVal. Checks
869 // for null dereferences (and similar errors) are done by checkers, not
871 // FIXME: We can consider lazily symbolicating such memory, but we really
872 // should defer this when we can reason easily about symbolicating arrays
874 if (isa<loc::ConcreteInt>(L)) {
877 if (!isa<loc::MemRegionVal>(L)) {
881 const MemRegion *MR = cast<loc::MemRegionVal>(L).getRegion();
883 if (isa<AllocaRegion>(MR) || isa<SymbolicRegion>(MR)) {
885 const SymbolicRegion *SR = cast<SymbolicRegion>(MR);
886 T = SR->getSymbol()->getType(Ctx);
888 MR = GetElementZeroRegion(MR, T);
891 if (isa<CodeTextRegion>(MR)) {
892 assert(0 && "Why load from a code text region?");
896 // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
897 // instead of 'Loc', and have the other Loc cases handled at a higher level.
898 const TypedRegion *R = cast<TypedRegion>(MR);
899 QualType RTy = R->getValueType();
901 // FIXME: We should eventually handle funny addressing. e.g.:
905 // char *q = (char*) p;
906 // char c = *q; // returns the first byte of 'x'.
908 // Such funny addressing will occur due to layering of regions.
910 if (RTy->isStructureOrClassType())
911 return RetrieveStruct(store, R);
913 // FIXME: Handle unions.
914 if (RTy->isUnionType())
917 if (RTy->isArrayType())
918 return RetrieveArray(store, R);
920 // FIXME: handle Vector types.
921 if (RTy->isVectorType())
924 if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
925 return CastRetrievedVal(RetrieveField(store, FR), FR, T, false);
927 if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
928 // FIXME: Here we actually perform an implicit conversion from the loaded
929 // value to the element type. Eventually we want to compose these values
930 // more intelligently. For example, an 'element' can encompass multiple
931 // bound regions (e.g., several bound bytes), or could be a subset of
933 return CastRetrievedVal(RetrieveElement(store, ER), ER, T, false);
936 if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
937 // FIXME: Here we actually perform an implicit conversion from the loaded
938 // value to the ivar type. What we should model is stores to ivars
939 // that blow past the extent of the ivar. If the address of the ivar is
940 // reinterpretted, it is possible we stored a different value that could
941 // fit within the ivar. Either we need to cast these when storing them
942 // or reinterpret them lazily (as we do here).
943 return CastRetrievedVal(RetrieveObjCIvar(store, IVR), IVR, T, false);
946 if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
947 // FIXME: Here we actually perform an implicit conversion from the loaded
948 // value to the variable type. What we should model is stores to variables
949 // that blow past the extent of the variable. If the address of the
950 // variable is reinterpretted, it is possible we stored a different value
951 // that could fit within the variable. Either we need to cast these when
952 // storing them or reinterpret them lazily (as we do here).
953 return CastRetrievedVal(RetrieveVar(store, VR), VR, T, false);
956 RegionBindings B = GetRegionBindings(store);
957 const SVal *V = lookup(B, R, BindingKey::Direct);
959 // Check if the region has a binding.
963 // The location does not have a bound value. This means that it has
964 // the value it had upon its creation and/or entry to the analyzed
965 // function/method. These are either symbolic values or 'undefined'.
966 if (R->hasStackNonParametersStorage()) {
967 // All stack variables are considered to have undefined values
968 // upon creation. All heap allocated blocks are considered to
969 // have undefined values as well unless they are explicitly bound
970 // to specific values.
971 return UndefinedVal();
974 // All other values are symbolic.
975 return svalBuilder.getRegionValueSymbolVal(R);
978 std::pair<Store, const MemRegion *>
979 RegionStoreManager::GetLazyBinding(RegionBindings B, const MemRegion *R) {
980 if (Optional<SVal> OV = getDirectBinding(B, R))
981 if (const nonloc::LazyCompoundVal *V =
982 dyn_cast<nonloc::LazyCompoundVal>(OV.getPointer()))
983 return std::make_pair(V->getStore(), V->getRegion());
985 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
986 const std::pair<Store, const MemRegion *> &X =
987 GetLazyBinding(B, ER->getSuperRegion());
990 return std::make_pair(X.first,
991 MRMgr.getElementRegionWithSuper(ER, X.second));
993 else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
994 const std::pair<Store, const MemRegion *> &X =
995 GetLazyBinding(B, FR->getSuperRegion());
998 return std::make_pair(X.first,
999 MRMgr.getFieldRegionWithSuper(FR, X.second));
1001 // C++ base object region is another kind of region that we should blast
1002 // through to look for lazy compound value. It is like a field region.
1003 else if (const CXXBaseObjectRegion *baseReg =
1004 dyn_cast<CXXBaseObjectRegion>(R)) {
1005 const std::pair<Store, const MemRegion *> &X =
1006 GetLazyBinding(B, baseReg->getSuperRegion());
1009 return std::make_pair(X.first,
1010 MRMgr.getCXXBaseObjectRegionWithSuper(baseReg, X.second));
1012 // The NULL MemRegion indicates an non-existent lazy binding. A NULL Store is
1013 // possible for a valid lazy binding.
1014 return std::make_pair((Store) 0, (const MemRegion *) 0);
1017 SVal RegionStoreManager::RetrieveElement(Store store,
1018 const ElementRegion* R) {
1019 // Check if the region has a binding.
1020 RegionBindings B = GetRegionBindings(store);
1021 if (const Optional<SVal> &V = getDirectBinding(B, R))
1024 const MemRegion* superR = R->getSuperRegion();
1026 // Check if the region is an element region of a string literal.
1027 if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
1028 // FIXME: Handle loads from strings where the literal is treated as
1029 // an integer, e.g., *((unsigned int*)"hello")
1030 QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
1031 if (T != Ctx.getCanonicalType(R->getElementType()))
1032 return UnknownVal();
1034 const StringLiteral *Str = StrR->getStringLiteral();
1035 SVal Idx = R->getIndex();
1036 if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&Idx)) {
1037 int64_t i = CI->getValue().getSExtValue();
1038 int64_t byteLength = Str->getByteLength();
1039 // Technically, only i == byteLength is guaranteed to be null.
1040 // However, such overflows should be caught before reaching this point;
1041 // the only time such an access would be made is if a string literal was
1042 // used to initialize a larger array.
1043 char c = (i >= byteLength) ? '\0' : Str->getString()[i];
1044 return svalBuilder.makeIntVal(c, T);
1048 // Check for loads from a code text region. For such loads, just give up.
1049 if (isa<CodeTextRegion>(superR))
1050 return UnknownVal();
1052 // Handle the case where we are indexing into a larger scalar object.
1053 // For example, this handles:
1057 // FIXME: This is a hack, and doesn't do anything really intelligent yet.
1058 const RegionRawOffset &O = R->getAsArrayOffset();
1059 if (const TypedRegion *baseR = dyn_cast_or_null<TypedRegion>(O.getRegion())) {
1060 QualType baseT = baseR->getValueType();
1061 if (baseT->isScalarType()) {
1062 QualType elemT = R->getElementType();
1063 if (elemT->isScalarType()) {
1064 if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
1065 if (const Optional<SVal> &V = getDirectBinding(B, superR)) {
1066 if (SymbolRef parentSym = V->getAsSymbol())
1067 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1069 if (V->isUnknownOrUndef())
1071 // Other cases: give up. We are indexing into a larger object
1072 // that has some value, but we don't know how to handle that yet.
1073 return UnknownVal();
1079 return RetrieveFieldOrElementCommon(store, R, R->getElementType(), superR);
1082 SVal RegionStoreManager::RetrieveField(Store store,
1083 const FieldRegion* R) {
1085 // Check if the region has a binding.
1086 RegionBindings B = GetRegionBindings(store);
1087 if (const Optional<SVal> &V = getDirectBinding(B, R))
1090 QualType Ty = R->getValueType();
1091 return RetrieveFieldOrElementCommon(store, R, Ty, R->getSuperRegion());
1095 RegionStoreManager::RetrieveDerivedDefaultValue(RegionBindings B,
1096 const MemRegion *superR,
1097 const TypedRegion *R,
1100 if (const Optional<SVal> &D = getDefaultBinding(B, superR)) {
1101 if (SymbolRef parentSym = D->getAsSymbol())
1102 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1104 if (D->isZeroConstant())
1105 return svalBuilder.makeZeroVal(Ty);
1107 if (D->isUnknownOrUndef())
1110 assert(0 && "Unknown default value");
1113 return Optional<SVal>();
1116 SVal RegionStoreManager::RetrieveFieldOrElementCommon(Store store,
1117 const TypedRegion *R,
1119 const MemRegion *superR) {
1121 // At this point we have already checked in either RetrieveElement or
1122 // RetrieveField if 'R' has a direct binding.
1124 RegionBindings B = GetRegionBindings(store);
1127 if (const Optional<SVal> &D =
1128 RetrieveDerivedDefaultValue(B, superR, R, Ty))
1131 // If our super region is a field or element itself, walk up the region
1132 // hierarchy to see if there is a default value installed in an ancestor.
1133 if (const SubRegion *SR = dyn_cast<SubRegion>(superR)) {
1134 superR = SR->getSuperRegion();
1141 Store lazyBindingStore = NULL;
1142 const MemRegion *lazyBindingRegion = NULL;
1143 llvm::tie(lazyBindingStore, lazyBindingRegion) = GetLazyBinding(B, R);
1145 if (lazyBindingRegion) {
1146 if (const ElementRegion *ER = dyn_cast<ElementRegion>(lazyBindingRegion))
1147 return RetrieveElement(lazyBindingStore, ER);
1148 return RetrieveField(lazyBindingStore,
1149 cast<FieldRegion>(lazyBindingRegion));
1152 if (R->hasStackNonParametersStorage()) {
1153 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1154 // Currently we don't reason specially about Clang-style vectors. Check
1155 // if superR is a vector and if so return Unknown.
1156 if (const TypedRegion *typedSuperR = dyn_cast<TypedRegion>(superR)) {
1157 if (typedSuperR->getValueType()->isVectorType())
1158 return UnknownVal();
1161 // FIXME: We also need to take ElementRegions with symbolic indexes into
1163 if (!ER->getIndex().isConstant())
1164 return UnknownVal();
1167 return UndefinedVal();
1170 // All other values are symbolic.
1171 return svalBuilder.getRegionValueSymbolVal(R);
1174 SVal RegionStoreManager::RetrieveObjCIvar(Store store, const ObjCIvarRegion* R){
1176 // Check if the region has a binding.
1177 RegionBindings B = GetRegionBindings(store);
1179 if (const Optional<SVal> &V = getDirectBinding(B, R))
1182 const MemRegion *superR = R->getSuperRegion();
1184 // Check if the super region has a default binding.
1185 if (const Optional<SVal> &V = getDefaultBinding(B, superR)) {
1186 if (SymbolRef parentSym = V->getAsSymbol())
1187 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1189 // Other cases: give up.
1190 return UnknownVal();
1193 return RetrieveLazySymbol(R);
1196 SVal RegionStoreManager::RetrieveVar(Store store, const VarRegion *R) {
1198 // Check if the region has a binding.
1199 RegionBindings B = GetRegionBindings(store);
1201 if (const Optional<SVal> &V = getDirectBinding(B, R))
1204 // Lazily derive a value for the VarRegion.
1205 const VarDecl *VD = R->getDecl();
1206 QualType T = VD->getType();
1207 const MemSpaceRegion *MS = R->getMemorySpace();
1209 if (isa<UnknownSpaceRegion>(MS) ||
1210 isa<StackArgumentsSpaceRegion>(MS))
1211 return svalBuilder.getRegionValueSymbolVal(R);
1213 if (isa<GlobalsSpaceRegion>(MS)) {
1214 if (isa<NonStaticGlobalSpaceRegion>(MS)) {
1215 // Is 'VD' declared constant? If so, retrieve the constant value.
1216 QualType CT = Ctx.getCanonicalType(T);
1217 if (CT.isConstQualified()) {
1218 const Expr *Init = VD->getInit();
1219 // Do the null check first, as we want to call 'IgnoreParenCasts'.
1221 if (const IntegerLiteral *IL =
1222 dyn_cast<IntegerLiteral>(Init->IgnoreParenCasts())) {
1223 const nonloc::ConcreteInt &V = svalBuilder.makeIntVal(IL);
1224 return svalBuilder.evalCast(V, Init->getType(), IL->getType());
1228 if (const Optional<SVal> &V = RetrieveDerivedDefaultValue(B, MS, R, CT))
1229 return V.getValue();
1231 return svalBuilder.getRegionValueSymbolVal(R);
1234 if (T->isIntegerType())
1235 return svalBuilder.makeIntVal(0, T);
1236 if (T->isPointerType())
1237 return svalBuilder.makeNull();
1239 return UnknownVal();
1242 return UndefinedVal();
1245 SVal RegionStoreManager::RetrieveLazySymbol(const TypedRegion *R) {
1246 // All other values are symbolic.
1247 return svalBuilder.getRegionValueSymbolVal(R);
1250 SVal RegionStoreManager::RetrieveStruct(Store store, const TypedRegion* R) {
1251 QualType T = R->getValueType();
1252 assert(T->isStructureOrClassType());
1253 return svalBuilder.makeLazyCompoundVal(store, R);
1256 SVal RegionStoreManager::RetrieveArray(Store store, const TypedRegion * R) {
1257 assert(Ctx.getAsConstantArrayType(R->getValueType()));
1258 return svalBuilder.makeLazyCompoundVal(store, R);
1261 //===----------------------------------------------------------------------===//
1262 // Binding values to regions.
1263 //===----------------------------------------------------------------------===//
1265 StoreRef RegionStoreManager::Remove(Store store, Loc L) {
1266 if (isa<loc::MemRegionVal>(L))
1267 if (const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion())
1268 return StoreRef(removeBinding(GetRegionBindings(store),
1269 R).getRootWithoutRetain(),
1272 return StoreRef(store, *this);
1275 StoreRef RegionStoreManager::Bind(Store store, Loc L, SVal V) {
1276 if (isa<loc::ConcreteInt>(L))
1277 return StoreRef(store, *this);
1279 // If we get here, the location should be a region.
1280 const MemRegion *R = cast<loc::MemRegionVal>(L).getRegion();
1282 // Check if the region is a struct region.
1283 if (const TypedRegion* TR = dyn_cast<TypedRegion>(R))
1284 if (TR->getValueType()->isStructureOrClassType())
1285 return BindStruct(store, TR, V);
1287 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1288 if (ER->getIndex().isZeroConstant()) {
1289 if (const TypedRegion *superR =
1290 dyn_cast<TypedRegion>(ER->getSuperRegion())) {
1291 QualType superTy = superR->getValueType();
1292 // For now, just invalidate the fields of the struct/union/class.
1293 // This is for test rdar_test_7185607 in misc-ps-region-store.m.
1294 // FIXME: Precisely handle the fields of the record.
1295 if (superTy->isStructureOrClassType())
1296 return KillStruct(store, superR, UnknownVal());
1300 else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
1301 // Binding directly to a symbolic region should be treated as binding
1303 QualType T = SR->getSymbol()->getType(Ctx);
1305 // FIXME: Is this the right way to handle symbols that are references?
1306 if (const PointerType *PT = T->getAs<PointerType>())
1307 T = PT->getPointeeType();
1309 T = T->getAs<ReferenceType>()->getPointeeType();
1311 R = GetElementZeroRegion(SR, T);
1314 // Perform the binding.
1315 RegionBindings B = GetRegionBindings(store);
1316 return StoreRef(addBinding(B, R, BindingKey::Direct,
1317 V).getRootWithoutRetain(), *this);
1320 StoreRef RegionStoreManager::BindDecl(Store store, const VarRegion *VR,
1323 QualType T = VR->getDecl()->getType();
1325 if (T->isArrayType())
1326 return BindArray(store, VR, InitVal);
1327 if (T->isStructureOrClassType())
1328 return BindStruct(store, VR, InitVal);
1330 return Bind(store, svalBuilder.makeLoc(VR), InitVal);
1333 // FIXME: this method should be merged into Bind().
1334 StoreRef RegionStoreManager::BindCompoundLiteral(Store store,
1335 const CompoundLiteralExpr *CL,
1336 const LocationContext *LC,
1338 return Bind(store, loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)),
1342 StoreRef RegionStoreManager::setImplicitDefaultValue(Store store,
1345 RegionBindings B = GetRegionBindings(store);
1348 if (Loc::isLocType(T))
1349 V = svalBuilder.makeNull();
1350 else if (T->isIntegerType())
1351 V = svalBuilder.makeZeroVal(T);
1352 else if (T->isStructureOrClassType() || T->isArrayType()) {
1353 // Set the default value to a zero constant when it is a structure
1354 // or array. The type doesn't really matter.
1355 V = svalBuilder.makeZeroVal(Ctx.IntTy);
1358 return StoreRef(store, *this);
1361 return StoreRef(addBinding(B, R, BindingKey::Default,
1362 V).getRootWithoutRetain(), *this);
1365 StoreRef RegionStoreManager::BindArray(Store store, const TypedRegion* R,
1368 const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
1369 QualType ElementTy = AT->getElementType();
1370 Optional<uint64_t> Size;
1372 if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
1373 Size = CAT->getSize().getZExtValue();
1375 // Check if the init expr is a string literal.
1376 if (loc::MemRegionVal *MRV = dyn_cast<loc::MemRegionVal>(&Init)) {
1377 const StringRegion *S = cast<StringRegion>(MRV->getRegion());
1379 // Treat the string as a lazy compound value.
1380 nonloc::LazyCompoundVal LCV =
1381 cast<nonloc::LazyCompoundVal>(svalBuilder.makeLazyCompoundVal(store, S));
1382 return CopyLazyBindings(LCV, store, R);
1385 // Handle lazy compound values.
1386 if (nonloc::LazyCompoundVal *LCV = dyn_cast<nonloc::LazyCompoundVal>(&Init))
1387 return CopyLazyBindings(*LCV, store, R);
1389 // Remaining case: explicit compound values.
1391 if (Init.isUnknown())
1392 return setImplicitDefaultValue(store, R, ElementTy);
1394 nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(Init);
1395 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
1398 StoreRef newStore(store, *this);
1399 for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
1400 // The init list might be shorter than the array length.
1404 const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
1405 const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
1407 if (ElementTy->isStructureOrClassType())
1408 newStore = BindStruct(newStore.getStore(), ER, *VI);
1409 else if (ElementTy->isArrayType())
1410 newStore = BindArray(newStore.getStore(), ER, *VI);
1412 newStore = Bind(newStore.getStore(), svalBuilder.makeLoc(ER), *VI);
1415 // If the init list is shorter than the array length, set the
1416 // array default value.
1417 if (Size.hasValue() && i < Size.getValue())
1418 newStore = setImplicitDefaultValue(newStore.getStore(), R, ElementTy);
1423 StoreRef RegionStoreManager::BindStruct(Store store, const TypedRegion* R,
1426 if (!Features.supportsFields())
1427 return StoreRef(store, *this);
1429 QualType T = R->getValueType();
1430 assert(T->isStructureOrClassType());
1432 const RecordType* RT = T->getAs<RecordType>();
1433 RecordDecl* RD = RT->getDecl();
1435 if (!RD->isDefinition())
1436 return StoreRef(store, *this);
1438 // Handle lazy compound values.
1439 if (const nonloc::LazyCompoundVal *LCV=dyn_cast<nonloc::LazyCompoundVal>(&V))
1440 return CopyLazyBindings(*LCV, store, R);
1442 // We may get non-CompoundVal accidentally due to imprecise cast logic or
1443 // that we are binding symbolic struct value. Kill the field values, and if
1444 // the value is symbolic go and bind it as a "default" binding.
1445 if (V.isUnknown() || !isa<nonloc::CompoundVal>(V)) {
1446 SVal SV = isa<nonloc::SymbolVal>(V) ? V : UnknownVal();
1447 return KillStruct(store, R, SV);
1450 nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(V);
1451 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
1453 RecordDecl::field_iterator FI, FE;
1454 StoreRef newStore(store, *this);
1456 for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI, ++VI) {
1461 QualType FTy = (*FI)->getType();
1462 const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
1464 if (FTy->isArrayType())
1465 newStore = BindArray(newStore.getStore(), FR, *VI);
1466 else if (FTy->isStructureOrClassType())
1467 newStore = BindStruct(newStore.getStore(), FR, *VI);
1469 newStore = Bind(newStore.getStore(), svalBuilder.makeLoc(FR), *VI);
1472 // There may be fewer values in the initialize list than the fields of struct.
1474 RegionBindings B = GetRegionBindings(newStore.getStore());
1475 B = addBinding(B, R, BindingKey::Default, svalBuilder.makeIntVal(0, false));
1476 newStore = StoreRef(B.getRootWithoutRetain(), *this);
1482 StoreRef RegionStoreManager::KillStruct(Store store, const TypedRegion* R,
1484 BindingKey key = BindingKey::Make(R, BindingKey::Default);
1486 // The BindingKey may be "invalid" if we cannot handle the region binding
1487 // explicitly. One example is something like array[index], where index
1488 // is a symbolic value. In such cases, we want to invalidate the entire
1489 // array, as the index assignment could have been to any element. In
1490 // the case of nested symbolic indices, we need to march up the region
1491 // hierarchy untile we reach a region whose binding we can reason about.
1492 const SubRegion *subReg = R;
1494 while (!key.isValid()) {
1495 if (const SubRegion *tmp = dyn_cast<SubRegion>(subReg->getSuperRegion())) {
1497 key = BindingKey::Make(tmp, BindingKey::Default);
1503 // Remove the old bindings, using 'subReg' as the root of all regions
1504 // we will invalidate.
1505 RegionBindings B = GetRegionBindings(store);
1506 llvm::OwningPtr<RegionStoreSubRegionMap>
1507 SubRegions(getRegionStoreSubRegionMap(store));
1508 RemoveSubRegionBindings(B, subReg, *SubRegions);
1510 // Set the default value of the struct region to "unknown".
1512 return StoreRef(B.getRootWithoutRetain(), *this);
1514 return StoreRef(addBinding(B, key, DefaultVal).getRootWithoutRetain(), *this);
1517 StoreRef RegionStoreManager::CopyLazyBindings(nonloc::LazyCompoundVal V,
1519 const TypedRegion *R) {
1521 // Nuke the old bindings stemming from R.
1522 RegionBindings B = GetRegionBindings(store);
1524 llvm::OwningPtr<RegionStoreSubRegionMap>
1525 SubRegions(getRegionStoreSubRegionMap(store));
1527 // B and DVM are updated after the call to RemoveSubRegionBindings.
1528 RemoveSubRegionBindings(B, R, *SubRegions.get());
1530 // Now copy the bindings. This amounts to just binding 'V' to 'R'. This
1531 // results in a zero-copy algorithm.
1532 return StoreRef(addBinding(B, R, BindingKey::Direct,
1533 V).getRootWithoutRetain(), *this);
1536 //===----------------------------------------------------------------------===//
1537 // "Raw" retrievals and bindings.
1538 //===----------------------------------------------------------------------===//
1541 RegionBindings RegionStoreManager::addBinding(RegionBindings B, BindingKey K,
1545 return RBFactory.add(B, K, V);
1548 RegionBindings RegionStoreManager::addBinding(RegionBindings B,
1550 BindingKey::Kind k, SVal V) {
1551 return addBinding(B, BindingKey::Make(R, k), V);
1554 const SVal *RegionStoreManager::lookup(RegionBindings B, BindingKey K) {
1560 const SVal *RegionStoreManager::lookup(RegionBindings B,
1562 BindingKey::Kind k) {
1563 return lookup(B, BindingKey::Make(R, k));
1566 RegionBindings RegionStoreManager::removeBinding(RegionBindings B,
1570 return RBFactory.remove(B, K);
1573 RegionBindings RegionStoreManager::removeBinding(RegionBindings B,
1575 BindingKey::Kind k){
1576 return removeBinding(B, BindingKey::Make(R, k));
1579 //===----------------------------------------------------------------------===//
1581 //===----------------------------------------------------------------------===//
1584 class removeDeadBindingsWorker :
1585 public ClusterAnalysis<removeDeadBindingsWorker> {
1586 llvm::SmallVector<const SymbolicRegion*, 12> Postponed;
1587 SymbolReaper &SymReaper;
1588 const StackFrameContext *CurrentLCtx;
1591 removeDeadBindingsWorker(RegionStoreManager &rm, GRStateManager &stateMgr,
1592 RegionBindings b, SymbolReaper &symReaper,
1593 const StackFrameContext *LCtx)
1594 : ClusterAnalysis<removeDeadBindingsWorker>(rm, stateMgr, b,
1595 /* includeGlobals = */ false),
1596 SymReaper(symReaper), CurrentLCtx(LCtx) {}
1598 // Called by ClusterAnalysis.
1599 void VisitAddedToCluster(const MemRegion *baseR, RegionCluster &C);
1600 void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E);
1602 void VisitBindingKey(BindingKey K);
1603 bool UpdatePostponed();
1604 void VisitBinding(SVal V);
1608 void removeDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
1611 if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
1612 if (SymReaper.isLive(VR))
1613 AddToWorkList(baseR, C);
1618 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
1619 if (SymReaper.isLive(SR->getSymbol()))
1620 AddToWorkList(SR, C);
1622 Postponed.push_back(SR);
1627 if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
1628 AddToWorkList(baseR, C);
1632 // CXXThisRegion in the current or parent location context is live.
1633 if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
1634 const StackArgumentsSpaceRegion *StackReg =
1635 cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
1636 const StackFrameContext *RegCtx = StackReg->getStackFrame();
1637 if (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx))
1638 AddToWorkList(TR, C);
1642 void removeDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
1643 BindingKey *I, BindingKey *E) {
1644 for ( ; I != E; ++I)
1645 VisitBindingKey(*I);
1648 void removeDeadBindingsWorker::VisitBinding(SVal V) {
1649 // Is it a LazyCompoundVal? All referenced regions are live as well.
1650 if (const nonloc::LazyCompoundVal *LCS =
1651 dyn_cast<nonloc::LazyCompoundVal>(&V)) {
1653 const MemRegion *LazyR = LCS->getRegion();
1654 RegionBindings B = RegionStoreManager::GetRegionBindings(LCS->getStore());
1655 for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
1656 const SubRegion *baseR = dyn_cast<SubRegion>(RI.getKey().getRegion());
1657 if (baseR && baseR->isSubRegionOf(LazyR))
1658 VisitBinding(RI.getData());
1663 // If V is a region, then add it to the worklist.
1664 if (const MemRegion *R = V.getAsRegion())
1667 // Update the set of live symbols.
1668 for (SVal::symbol_iterator SI=V.symbol_begin(), SE=V.symbol_end();
1670 SymReaper.markLive(*SI);
1673 void removeDeadBindingsWorker::VisitBindingKey(BindingKey K) {
1674 const MemRegion *R = K.getRegion();
1676 // Mark this region "live" by adding it to the worklist. This will cause
1677 // use to visit all regions in the cluster (if we haven't visited them
1679 if (AddToWorkList(R)) {
1680 // Mark the symbol for any live SymbolicRegion as "live". This means we
1681 // should continue to track that symbol.
1682 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(R))
1683 SymReaper.markLive(SymR->getSymbol());
1685 // For BlockDataRegions, enqueue the VarRegions for variables marked
1686 // with __block (passed-by-reference).
1687 // via BlockDeclRefExprs.
1688 if (const BlockDataRegion *BD = dyn_cast<BlockDataRegion>(R)) {
1689 for (BlockDataRegion::referenced_vars_iterator
1690 RI = BD->referenced_vars_begin(), RE = BD->referenced_vars_end();
1692 if ((*RI)->getDecl()->getAttr<BlocksAttr>())
1696 // No possible data bindings on a BlockDataRegion.
1701 // Visit the data binding for K.
1702 if (const SVal *V = RM.lookup(B, K))
1706 bool removeDeadBindingsWorker::UpdatePostponed() {
1707 // See if any postponed SymbolicRegions are actually live now, after
1708 // having done a scan.
1709 bool changed = false;
1711 for (llvm::SmallVectorImpl<const SymbolicRegion*>::iterator
1712 I = Postponed.begin(), E = Postponed.end() ; I != E ; ++I) {
1713 if (const SymbolicRegion *SR = cast_or_null<SymbolicRegion>(*I)) {
1714 if (SymReaper.isLive(SR->getSymbol())) {
1715 changed |= AddToWorkList(SR);
1724 StoreRef RegionStoreManager::removeDeadBindings(Store store,
1725 const StackFrameContext *LCtx,
1726 SymbolReaper& SymReaper,
1727 llvm::SmallVectorImpl<const MemRegion*>& RegionRoots)
1729 RegionBindings B = GetRegionBindings(store);
1730 removeDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
1731 W.GenerateClusters();
1733 // Enqueue the region roots onto the worklist.
1734 for (llvm::SmallVectorImpl<const MemRegion*>::iterator I=RegionRoots.begin(),
1735 E=RegionRoots.end(); I!=E; ++I)
1736 W.AddToWorkList(*I);
1738 do W.RunWorkList(); while (W.UpdatePostponed());
1740 // We have now scanned the store, marking reachable regions and symbols
1741 // as live. We now remove all the regions that are dead from the store
1742 // as well as update DSymbols with the set symbols that are now dead.
1743 for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
1744 const BindingKey &K = I.getKey();
1746 // If the cluster has been visited, we know the region has been marked.
1747 if (W.isVisited(K.getRegion()))
1750 // Remove the dead entry.
1751 B = removeBinding(B, K);
1753 // Mark all non-live symbols that this binding references as dead.
1754 if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(K.getRegion()))
1755 SymReaper.maybeDead(SymR->getSymbol());
1757 SVal X = I.getData();
1758 SVal::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
1759 for (; SI != SE; ++SI)
1760 SymReaper.maybeDead(*SI);
1763 return StoreRef(B.getRootWithoutRetain(), *this);
1767 StoreRef RegionStoreManager::enterStackFrame(const GRState *state,
1768 const StackFrameContext *frame) {
1769 FunctionDecl const *FD = cast<FunctionDecl>(frame->getDecl());
1770 FunctionDecl::param_const_iterator PI = FD->param_begin(),
1771 PE = FD->param_end();
1772 StoreRef store = StoreRef(state->getStore(), *this);
1774 if (CallExpr const *CE = dyn_cast<CallExpr>(frame->getCallSite())) {
1775 CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end();
1777 // Copy the arg expression value to the arg variables. We check that
1778 // PI != PE because the actual number of arguments may be different than
1779 // the function declaration.
1780 for (; AI != AE && PI != PE; ++AI, ++PI) {
1781 SVal ArgVal = state->getSVal(*AI);
1782 store = Bind(store.getStore(),
1783 svalBuilder.makeLoc(MRMgr.getVarRegion(*PI, frame)), ArgVal);
1785 } else if (const CXXConstructExpr *CE =
1786 dyn_cast<CXXConstructExpr>(frame->getCallSite())) {
1787 CXXConstructExpr::const_arg_iterator AI = CE->arg_begin(),
1790 // Copy the arg expression value to the arg variables.
1791 for (; AI != AE; ++AI, ++PI) {
1792 SVal ArgVal = state->getSVal(*AI);
1793 store = Bind(store.getStore(),
1794 svalBuilder.makeLoc(MRMgr.getVarRegion(*PI,frame)), ArgVal);
1797 assert(isa<CXXDestructorDecl>(frame->getDecl()));
1802 //===----------------------------------------------------------------------===//
1804 //===----------------------------------------------------------------------===//
1806 void RegionStoreManager::print(Store store, llvm::raw_ostream& OS,
1807 const char* nl, const char *sep) {
1808 RegionBindings B = GetRegionBindings(store);
1809 OS << "Store (direct and default bindings):" << nl;
1811 for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I)
1812 OS << ' ' << I.getKey() << " : " << I.getData() << nl;