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 SVal RetrieveLazyBinding(const MemRegion *lazyBindingRegion,
342 Store lazyBindingStore);
344 /// Retrieve the values in a struct and return a CompoundVal, used when doing
348 /// y's value is retrieved by this method.
349 SVal RetrieveStruct(Store store, const TypedRegion* R);
351 SVal RetrieveArray(Store store, const TypedRegion* R);
353 /// Used to lazily generate derived symbols for bindings that are defined
354 /// implicitly by default bindings in a super region.
355 Optional<SVal> RetrieveDerivedDefaultValue(RegionBindings B,
356 const MemRegion *superR,
357 const TypedRegion *R, QualType Ty);
359 /// Get the state and region whose binding this region R corresponds to.
360 std::pair<Store, const MemRegion*>
361 GetLazyBinding(RegionBindings B, const MemRegion *R,
362 const MemRegion *originalRegion);
364 StoreRef CopyLazyBindings(nonloc::LazyCompoundVal V, Store store,
365 const TypedRegion *R);
367 //===------------------------------------------------------------------===//
369 //===------------------------------------------------------------------===//
371 /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
372 /// It returns a new Store with these values removed.
373 StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
374 SymbolReaper& SymReaper,
375 llvm::SmallVectorImpl<const MemRegion*>& RegionRoots);
377 StoreRef enterStackFrame(const GRState *state, const StackFrameContext *frame);
379 //===------------------------------------------------------------------===//
381 //===------------------------------------------------------------------===//
383 // FIXME: This method will soon be eliminated; see the note in Store.h.
384 DefinedOrUnknownSVal getSizeInElements(const GRState *state,
385 const MemRegion* R, QualType EleTy);
387 //===------------------------------------------------------------------===//
389 //===------------------------------------------------------------------===//
391 static inline RegionBindings GetRegionBindings(Store store) {
392 return RegionBindings(static_cast<const RegionBindings::TreeTy*>(store));
395 void print(Store store, llvm::raw_ostream& Out, const char* nl,
398 void iterBindings(Store store, BindingsHandler& f) {
399 RegionBindings B = GetRegionBindings(store);
400 for (RegionBindings::iterator I=B.begin(), E=B.end(); I!=E; ++I) {
401 const BindingKey &K = I.getKey();
404 if (const SubRegion *R = dyn_cast<SubRegion>(I.getKey().getRegion())) {
405 // FIXME: Possibly incorporate the offset?
406 if (!f.HandleBinding(*this, store, R, I.getData()))
413 } // end anonymous namespace
415 //===----------------------------------------------------------------------===//
416 // RegionStore creation.
417 //===----------------------------------------------------------------------===//
419 StoreManager *ento::CreateRegionStoreManager(GRStateManager& StMgr) {
420 RegionStoreFeatures F = maximal_features_tag();
421 return new RegionStoreManager(StMgr, F);
424 StoreManager *ento::CreateFieldsOnlyRegionStoreManager(GRStateManager &StMgr) {
425 RegionStoreFeatures F = minimal_features_tag();
426 F.enableFields(true);
427 return new RegionStoreManager(StMgr, F);
431 RegionStoreSubRegionMap*
432 RegionStoreManager::getRegionStoreSubRegionMap(Store store) {
433 RegionBindings B = GetRegionBindings(store);
434 RegionStoreSubRegionMap *M = new RegionStoreSubRegionMap();
436 llvm::SmallVector<const SubRegion*, 10> WL;
438 for (RegionBindings::iterator I=B.begin(), E=B.end(); I!=E; ++I)
439 if (const SubRegion *R = dyn_cast<SubRegion>(I.getKey().getRegion()))
442 // We also need to record in the subregion map "intermediate" regions that
443 // don't have direct bindings but are super regions of those that do.
444 while (!WL.empty()) {
445 const SubRegion *R = WL.back();
453 //===----------------------------------------------------------------------===//
454 // Region Cluster analysis.
455 //===----------------------------------------------------------------------===//
458 template <typename DERIVED>
459 class ClusterAnalysis {
461 typedef BumpVector<BindingKey> RegionCluster;
462 typedef llvm::DenseMap<const MemRegion *, RegionCluster *> ClusterMap;
463 llvm::DenseMap<const RegionCluster*, unsigned> Visited;
464 typedef llvm::SmallVector<std::pair<const MemRegion *, RegionCluster*>, 10>
467 BumpVectorContext BVC;
471 RegionStoreManager &RM;
473 SValBuilder &svalBuilder;
477 const bool includeGlobals;
480 ClusterAnalysis(RegionStoreManager &rm, GRStateManager &StateMgr,
481 RegionBindings b, const bool includeGlobals)
482 : RM(rm), Ctx(StateMgr.getContext()),
483 svalBuilder(StateMgr.getSValBuilder()),
484 B(b), includeGlobals(includeGlobals) {}
486 RegionBindings getRegionBindings() const { return B; }
488 RegionCluster &AddToCluster(BindingKey K) {
489 const MemRegion *R = K.getRegion();
490 const MemRegion *baseR = R->getBaseRegion();
491 RegionCluster &C = getCluster(baseR);
493 static_cast<DERIVED*>(this)->VisitAddedToCluster(baseR, C);
497 bool isVisited(const MemRegion *R) {
498 return (bool) Visited[&getCluster(R->getBaseRegion())];
501 RegionCluster& getCluster(const MemRegion *R) {
502 RegionCluster *&CRef = ClusterM[R];
504 void *Mem = BVC.getAllocator().template Allocate<RegionCluster>();
505 CRef = new (Mem) RegionCluster(BVC, 10);
510 void GenerateClusters() {
511 // Scan the entire set of bindings and make the region clusters.
512 for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
513 RegionCluster &C = AddToCluster(RI.getKey());
514 if (const MemRegion *R = RI.getData().getAsRegion()) {
515 // Generate a cluster, but don't add the region to the cluster
516 // if there aren't any bindings.
517 getCluster(R->getBaseRegion());
519 if (includeGlobals) {
520 const MemRegion *R = RI.getKey().getRegion();
521 if (isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace()))
527 bool AddToWorkList(const MemRegion *R, RegionCluster &C) {
528 if (unsigned &visited = Visited[&C])
533 WL.push_back(std::make_pair(R, &C));
537 bool AddToWorkList(BindingKey K) {
538 return AddToWorkList(K.getRegion());
541 bool AddToWorkList(const MemRegion *R) {
542 const MemRegion *baseR = R->getBaseRegion();
543 return AddToWorkList(baseR, getCluster(baseR));
547 while (!WL.empty()) {
548 const MemRegion *baseR;
550 llvm::tie(baseR, C) = WL.back();
553 // First visit the cluster.
554 static_cast<DERIVED*>(this)->VisitCluster(baseR, C->begin(), C->end());
556 // Next, visit the base region.
557 static_cast<DERIVED*>(this)->VisitBaseRegion(baseR);
562 void VisitAddedToCluster(const MemRegion *baseR, RegionCluster &C) {}
563 void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E) {}
564 void VisitBaseRegion(const MemRegion *baseR) {}
568 //===----------------------------------------------------------------------===//
569 // Binding invalidation.
570 //===----------------------------------------------------------------------===//
572 void RegionStoreManager::RemoveSubRegionBindings(RegionBindings &B,
574 RegionStoreSubRegionMap &M) {
576 if (const RegionStoreSubRegionMap::Set *S = M.getSubRegions(R))
577 for (RegionStoreSubRegionMap::Set::iterator I = S->begin(), E = S->end();
579 RemoveSubRegionBindings(B, *I, M);
581 B = removeBinding(B, R);
585 class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
589 StoreManager::InvalidatedSymbols &IS;
590 StoreManager::InvalidatedRegions *Regions;
592 invalidateRegionsWorker(RegionStoreManager &rm,
593 GRStateManager &stateMgr,
595 const Expr *ex, unsigned count,
596 StoreManager::InvalidatedSymbols &is,
597 StoreManager::InvalidatedRegions *r,
599 : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b, includeGlobals),
600 Ex(ex), Count(count), IS(is), Regions(r) {}
602 void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E);
603 void VisitBaseRegion(const MemRegion *baseR);
606 void VisitBinding(SVal V);
610 void invalidateRegionsWorker::VisitBinding(SVal V) {
611 // A symbol? Mark it touched by the invalidation.
612 if (SymbolRef Sym = V.getAsSymbol())
615 if (const MemRegion *R = V.getAsRegion()) {
620 // Is it a LazyCompoundVal? All references get invalidated as well.
621 if (const nonloc::LazyCompoundVal *LCS =
622 dyn_cast<nonloc::LazyCompoundVal>(&V)) {
624 const MemRegion *LazyR = LCS->getRegion();
625 RegionBindings B = RegionStoreManager::GetRegionBindings(LCS->getStore());
627 for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
628 const SubRegion *baseR = dyn_cast<SubRegion>(RI.getKey().getRegion());
629 if (baseR && baseR->isSubRegionOf(LazyR))
630 VisitBinding(RI.getData());
637 void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
638 BindingKey *I, BindingKey *E) {
639 for ( ; I != E; ++I) {
640 // Get the old binding. Is it a region? If so, add it to the worklist.
641 const BindingKey &K = *I;
642 if (const SVal *V = RM.lookup(B, K))
645 B = RM.removeBinding(B, K);
649 void invalidateRegionsWorker::VisitBaseRegion(const MemRegion *baseR) {
650 // Symbolic region? Mark that symbol touched by the invalidation.
651 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
652 IS.insert(SR->getSymbol());
654 // BlockDataRegion? If so, invalidate captured variables that are passed
656 if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
657 for (BlockDataRegion::referenced_vars_iterator
658 BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
660 const VarRegion *VR = *BI;
661 const VarDecl *VD = VR->getDecl();
662 if (VD->getAttr<BlocksAttr>() || !VD->hasLocalStorage())
668 // Otherwise, we have a normal data region. Record that we touched the region.
670 Regions->push_back(baseR);
672 if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
673 // Invalidate the region by setting its default value to
674 // conjured symbol. The type of the symbol is irrelavant.
675 DefinedOrUnknownSVal V =
676 svalBuilder.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy, Count);
677 B = RM.addBinding(B, baseR, BindingKey::Default, V);
681 if (!baseR->isBoundable())
684 const TypedRegion *TR = cast<TypedRegion>(baseR);
685 QualType T = TR->getValueType();
687 // Invalidate the binding.
688 if (T->isStructureOrClassType()) {
689 // Invalidate the region by setting its default value to
690 // conjured symbol. The type of the symbol is irrelavant.
691 DefinedOrUnknownSVal V =
692 svalBuilder.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy, Count);
693 B = RM.addBinding(B, baseR, BindingKey::Default, V);
697 if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
698 // Set the default value of the array to conjured symbol.
699 DefinedOrUnknownSVal V =
700 svalBuilder.getConjuredSymbolVal(baseR, Ex, AT->getElementType(), Count);
701 B = RM.addBinding(B, baseR, BindingKey::Default, V);
705 if (includeGlobals &&
706 isa<NonStaticGlobalSpaceRegion>(baseR->getMemorySpace())) {
707 // If the region is a global and we are invalidating all globals,
708 // just erase the entry. This causes all globals to be lazily
709 // symbolicated from the same base symbol.
710 B = RM.removeBinding(B, baseR);
715 DefinedOrUnknownSVal V = svalBuilder.getConjuredSymbolVal(baseR, Ex, T, Count);
716 assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
717 B = RM.addBinding(B, baseR, BindingKey::Direct, V);
720 StoreRef RegionStoreManager::invalidateRegions(Store store,
721 const MemRegion * const *I,
722 const MemRegion * const *E,
723 const Expr *Ex, unsigned Count,
724 InvalidatedSymbols &IS,
725 bool invalidateGlobals,
726 InvalidatedRegions *Regions) {
727 invalidateRegionsWorker W(*this, StateMgr,
728 RegionStoreManager::GetRegionBindings(store),
729 Ex, Count, IS, Regions, invalidateGlobals);
731 // Scan the bindings and generate the clusters.
732 W.GenerateClusters();
734 // Add I .. E to the worklist.
740 // Return the new bindings.
741 RegionBindings B = W.getRegionBindings();
743 if (invalidateGlobals) {
744 // Bind the non-static globals memory space to a new symbol that we will
745 // use to derive the bindings for all non-static globals.
746 const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion();
748 svalBuilder.getConjuredSymbolVal(/* SymbolTag = */ (void*) GS, Ex,
749 /* symbol type, doesn't matter */ Ctx.IntTy,
751 B = addBinding(B, BindingKey::Make(GS, BindingKey::Default), V);
753 // Even if there are no bindings in the global scope, we still need to
754 // record that we touched it.
756 Regions->push_back(GS);
759 return StoreRef(B.getRootWithoutRetain(), *this);
762 //===----------------------------------------------------------------------===//
763 // Extents for regions.
764 //===----------------------------------------------------------------------===//
766 DefinedOrUnknownSVal RegionStoreManager::getSizeInElements(const GRState *state,
769 SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
770 const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
774 CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());
776 if (Ctx.getAsVariableArrayType(EleTy)) {
777 // FIXME: We need to track extra state to properly record the size
778 // of VLAs. Returning UnknownVal here, however, is a stop-gap so that
779 // we don't have a divide-by-zero below.
783 CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);
785 // If a variable is reinterpreted as a type that doesn't fit into a larger
786 // type evenly, round it down.
787 // This is a signed value, since it's used in arithmetic with signed indices.
788 return svalBuilder.makeIntVal(RegionSize / EleSize, false);
791 //===----------------------------------------------------------------------===//
792 // Location and region casting.
793 //===----------------------------------------------------------------------===//
795 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
796 /// type. 'Array' represents the lvalue of the array being decayed
797 /// to a pointer, and the returned SVal represents the decayed
798 /// version of that lvalue (i.e., a pointer to the first element of
799 /// the array). This is called by ExprEngine when evaluating casts
800 /// from arrays to pointers.
801 SVal RegionStoreManager::ArrayToPointer(Loc Array) {
802 if (!isa<loc::MemRegionVal>(Array))
805 const MemRegion* R = cast<loc::MemRegionVal>(&Array)->getRegion();
806 const TypedRegion* ArrayR = dyn_cast<TypedRegion>(R);
811 // Strip off typedefs from the ArrayRegion's ValueType.
812 QualType T = ArrayR->getValueType().getDesugaredType(Ctx);
813 const ArrayType *AT = cast<ArrayType>(T);
814 T = AT->getElementType();
816 NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
817 return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, ArrayR, Ctx));
820 SVal RegionStoreManager::evalDerivedToBase(SVal derived, QualType baseType) {
821 const CXXRecordDecl *baseDecl;
822 if (baseType->isPointerType())
823 baseDecl = baseType->getCXXRecordDeclForPointerType();
825 baseDecl = baseType->getAsCXXRecordDecl();
827 assert(baseDecl && "not a CXXRecordDecl?");
829 loc::MemRegionVal *derivedRegVal = dyn_cast<loc::MemRegionVal>(&derived);
833 const MemRegion *baseReg =
834 MRMgr.getCXXBaseObjectRegion(baseDecl, derivedRegVal->getRegion());
836 return loc::MemRegionVal(baseReg);
839 //===----------------------------------------------------------------------===//
840 // Loading values from regions.
841 //===----------------------------------------------------------------------===//
843 Optional<SVal> RegionStoreManager::getDirectBinding(RegionBindings B,
844 const MemRegion *R) {
846 if (const SVal *V = lookup(B, R, BindingKey::Direct))
849 return Optional<SVal>();
852 Optional<SVal> RegionStoreManager::getDefaultBinding(RegionBindings B,
853 const MemRegion *R) {
854 if (R->isBoundable())
855 if (const TypedRegion *TR = dyn_cast<TypedRegion>(R))
856 if (TR->getValueType()->isUnionType())
859 if (const SVal *V = lookup(B, R, BindingKey::Default))
862 return Optional<SVal>();
865 SVal RegionStoreManager::Retrieve(Store store, Loc L, QualType T) {
866 assert(!isa<UnknownVal>(L) && "location unknown");
867 assert(!isa<UndefinedVal>(L) && "location undefined");
869 // For access to concrete addresses, return UnknownVal. Checks
870 // for null dereferences (and similar errors) are done by checkers, not
872 // FIXME: We can consider lazily symbolicating such memory, but we really
873 // should defer this when we can reason easily about symbolicating arrays
875 if (isa<loc::ConcreteInt>(L)) {
878 if (!isa<loc::MemRegionVal>(L)) {
882 const MemRegion *MR = cast<loc::MemRegionVal>(L).getRegion();
884 if (isa<AllocaRegion>(MR) || isa<SymbolicRegion>(MR)) {
886 const SymbolicRegion *SR = cast<SymbolicRegion>(MR);
887 T = SR->getSymbol()->getType(Ctx);
889 MR = GetElementZeroRegion(MR, T);
892 if (isa<CodeTextRegion>(MR)) {
893 assert(0 && "Why load from a code text region?");
897 // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
898 // instead of 'Loc', and have the other Loc cases handled at a higher level.
899 const TypedRegion *R = cast<TypedRegion>(MR);
900 QualType RTy = R->getValueType();
902 // FIXME: We should eventually handle funny addressing. e.g.:
906 // char *q = (char*) p;
907 // char c = *q; // returns the first byte of 'x'.
909 // Such funny addressing will occur due to layering of regions.
911 if (RTy->isStructureOrClassType())
912 return RetrieveStruct(store, R);
914 // FIXME: Handle unions.
915 if (RTy->isUnionType())
918 if (RTy->isArrayType())
919 return RetrieveArray(store, R);
921 // FIXME: handle Vector types.
922 if (RTy->isVectorType())
925 if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
926 return CastRetrievedVal(RetrieveField(store, FR), FR, T, false);
928 if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
929 // FIXME: Here we actually perform an implicit conversion from the loaded
930 // value to the element type. Eventually we want to compose these values
931 // more intelligently. For example, an 'element' can encompass multiple
932 // bound regions (e.g., several bound bytes), or could be a subset of
934 return CastRetrievedVal(RetrieveElement(store, ER), ER, T, false);
937 if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
938 // FIXME: Here we actually perform an implicit conversion from the loaded
939 // value to the ivar type. What we should model is stores to ivars
940 // that blow past the extent of the ivar. If the address of the ivar is
941 // reinterpretted, it is possible we stored a different value that could
942 // fit within the ivar. Either we need to cast these when storing them
943 // or reinterpret them lazily (as we do here).
944 return CastRetrievedVal(RetrieveObjCIvar(store, IVR), IVR, T, false);
947 if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
948 // FIXME: Here we actually perform an implicit conversion from the loaded
949 // value to the variable type. What we should model is stores to variables
950 // that blow past the extent of the variable. If the address of the
951 // variable is reinterpretted, it is possible we stored a different value
952 // that could fit within the variable. Either we need to cast these when
953 // storing them or reinterpret them lazily (as we do here).
954 return CastRetrievedVal(RetrieveVar(store, VR), VR, T, false);
957 RegionBindings B = GetRegionBindings(store);
958 const SVal *V = lookup(B, R, BindingKey::Direct);
960 // Check if the region has a binding.
964 // The location does not have a bound value. This means that it has
965 // the value it had upon its creation and/or entry to the analyzed
966 // function/method. These are either symbolic values or 'undefined'.
967 if (R->hasStackNonParametersStorage()) {
968 // All stack variables are considered to have undefined values
969 // upon creation. All heap allocated blocks are considered to
970 // have undefined values as well unless they are explicitly bound
971 // to specific values.
972 return UndefinedVal();
975 // All other values are symbolic.
976 return svalBuilder.getRegionValueSymbolVal(R);
979 std::pair<Store, const MemRegion *>
980 RegionStoreManager::GetLazyBinding(RegionBindings B, const MemRegion *R,
981 const MemRegion *originalRegion) {
983 if (originalRegion != R) {
984 if (Optional<SVal> OV = getDefaultBinding(B, R)) {
985 if (const nonloc::LazyCompoundVal *V =
986 dyn_cast<nonloc::LazyCompoundVal>(OV.getPointer()))
987 return std::make_pair(V->getStore(), V->getRegion());
991 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
992 const std::pair<Store, const MemRegion *> &X =
993 GetLazyBinding(B, ER->getSuperRegion(), originalRegion);
996 return std::make_pair(X.first,
997 MRMgr.getElementRegionWithSuper(ER, X.second));
999 else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
1000 const std::pair<Store, const MemRegion *> &X =
1001 GetLazyBinding(B, FR->getSuperRegion(), originalRegion);
1004 return std::make_pair(X.first,
1005 MRMgr.getFieldRegionWithSuper(FR, X.second));
1007 // C++ base object region is another kind of region that we should blast
1008 // through to look for lazy compound value. It is like a field region.
1009 else if (const CXXBaseObjectRegion *baseReg =
1010 dyn_cast<CXXBaseObjectRegion>(R)) {
1011 const std::pair<Store, const MemRegion *> &X =
1012 GetLazyBinding(B, baseReg->getSuperRegion(), originalRegion);
1015 return std::make_pair(X.first,
1016 MRMgr.getCXXBaseObjectRegionWithSuper(baseReg, X.second));
1019 // The NULL MemRegion indicates an non-existent lazy binding. A NULL Store is
1020 // possible for a valid lazy binding.
1021 return std::make_pair((Store) 0, (const MemRegion *) 0);
1024 SVal RegionStoreManager::RetrieveElement(Store store,
1025 const ElementRegion* R) {
1026 // Check if the region has a binding.
1027 RegionBindings B = GetRegionBindings(store);
1028 if (const Optional<SVal> &V = getDirectBinding(B, R))
1031 const MemRegion* superR = R->getSuperRegion();
1033 // Check if the region is an element region of a string literal.
1034 if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
1035 // FIXME: Handle loads from strings where the literal is treated as
1036 // an integer, e.g., *((unsigned int*)"hello")
1037 QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
1038 if (T != Ctx.getCanonicalType(R->getElementType()))
1039 return UnknownVal();
1041 const StringLiteral *Str = StrR->getStringLiteral();
1042 SVal Idx = R->getIndex();
1043 if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&Idx)) {
1044 int64_t i = CI->getValue().getSExtValue();
1045 int64_t byteLength = Str->getByteLength();
1046 // Technically, only i == byteLength is guaranteed to be null.
1047 // However, such overflows should be caught before reaching this point;
1048 // the only time such an access would be made is if a string literal was
1049 // used to initialize a larger array.
1050 char c = (i >= byteLength) ? '\0' : Str->getString()[i];
1051 return svalBuilder.makeIntVal(c, T);
1055 // Check for loads from a code text region. For such loads, just give up.
1056 if (isa<CodeTextRegion>(superR))
1057 return UnknownVal();
1059 // Handle the case where we are indexing into a larger scalar object.
1060 // For example, this handles:
1064 // FIXME: This is a hack, and doesn't do anything really intelligent yet.
1065 const RegionRawOffset &O = R->getAsArrayOffset();
1067 // If we cannot reason about the offset, return an unknown value.
1069 return UnknownVal();
1071 if (const TypedRegion *baseR = dyn_cast_or_null<TypedRegion>(O.getRegion())) {
1072 QualType baseT = baseR->getValueType();
1073 if (baseT->isScalarType()) {
1074 QualType elemT = R->getElementType();
1075 if (elemT->isScalarType()) {
1076 if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
1077 if (const Optional<SVal> &V = getDirectBinding(B, superR)) {
1078 if (SymbolRef parentSym = V->getAsSymbol())
1079 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1081 if (V->isUnknownOrUndef())
1083 // Other cases: give up. We are indexing into a larger object
1084 // that has some value, but we don't know how to handle that yet.
1085 return UnknownVal();
1091 return RetrieveFieldOrElementCommon(store, R, R->getElementType(), superR);
1094 SVal RegionStoreManager::RetrieveField(Store store,
1095 const FieldRegion* R) {
1097 // Check if the region has a binding.
1098 RegionBindings B = GetRegionBindings(store);
1099 if (const Optional<SVal> &V = getDirectBinding(B, R))
1102 QualType Ty = R->getValueType();
1103 return RetrieveFieldOrElementCommon(store, R, Ty, R->getSuperRegion());
1107 RegionStoreManager::RetrieveDerivedDefaultValue(RegionBindings B,
1108 const MemRegion *superR,
1109 const TypedRegion *R,
1112 if (const Optional<SVal> &D = getDefaultBinding(B, superR)) {
1113 const SVal &val = D.getValue();
1114 if (SymbolRef parentSym = val.getAsSymbol())
1115 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1117 if (val.isZeroConstant())
1118 return svalBuilder.makeZeroVal(Ty);
1120 if (val.isUnknownOrUndef())
1123 // Lazy bindings are handled later.
1124 if (isa<nonloc::LazyCompoundVal>(val))
1125 return Optional<SVal>();
1127 assert(0 && "Unknown default value");
1130 return Optional<SVal>();
1133 SVal RegionStoreManager::RetrieveLazyBinding(const MemRegion *lazyBindingRegion,
1134 Store lazyBindingStore) {
1135 if (const ElementRegion *ER = dyn_cast<ElementRegion>(lazyBindingRegion))
1136 return RetrieveElement(lazyBindingStore, ER);
1138 return RetrieveField(lazyBindingStore,
1139 cast<FieldRegion>(lazyBindingRegion));
1142 SVal RegionStoreManager::RetrieveFieldOrElementCommon(Store store,
1143 const TypedRegion *R,
1145 const MemRegion *superR) {
1147 // At this point we have already checked in either RetrieveElement or
1148 // RetrieveField if 'R' has a direct binding.
1150 RegionBindings B = GetRegionBindings(store);
1153 if (const Optional<SVal> &D =
1154 RetrieveDerivedDefaultValue(B, superR, R, Ty))
1157 // If our super region is a field or element itself, walk up the region
1158 // hierarchy to see if there is a default value installed in an ancestor.
1159 if (const SubRegion *SR = dyn_cast<SubRegion>(superR)) {
1160 superR = SR->getSuperRegion();
1167 Store lazyBindingStore = NULL;
1168 const MemRegion *lazyBindingRegion = NULL;
1169 llvm::tie(lazyBindingStore, lazyBindingRegion) = GetLazyBinding(B, R, R);
1171 if (lazyBindingRegion)
1172 return RetrieveLazyBinding(lazyBindingRegion, lazyBindingStore);
1174 if (R->hasStackNonParametersStorage()) {
1175 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1176 // Currently we don't reason specially about Clang-style vectors. Check
1177 // if superR is a vector and if so return Unknown.
1178 if (const TypedRegion *typedSuperR = dyn_cast<TypedRegion>(superR)) {
1179 if (typedSuperR->getValueType()->isVectorType())
1180 return UnknownVal();
1183 // FIXME: We also need to take ElementRegions with symbolic indexes into
1185 if (!ER->getIndex().isConstant())
1186 return UnknownVal();
1189 return UndefinedVal();
1192 // All other values are symbolic.
1193 return svalBuilder.getRegionValueSymbolVal(R);
1196 SVal RegionStoreManager::RetrieveObjCIvar(Store store, const ObjCIvarRegion* R){
1198 // Check if the region has a binding.
1199 RegionBindings B = GetRegionBindings(store);
1201 if (const Optional<SVal> &V = getDirectBinding(B, R))
1204 const MemRegion *superR = R->getSuperRegion();
1206 // Check if the super region has a default binding.
1207 if (const Optional<SVal> &V = getDefaultBinding(B, superR)) {
1208 if (SymbolRef parentSym = V->getAsSymbol())
1209 return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1211 // Other cases: give up.
1212 return UnknownVal();
1215 return RetrieveLazySymbol(R);
1218 SVal RegionStoreManager::RetrieveVar(Store store, const VarRegion *R) {
1220 // Check if the region has a binding.
1221 RegionBindings B = GetRegionBindings(store);
1223 if (const Optional<SVal> &V = getDirectBinding(B, R))
1226 // Lazily derive a value for the VarRegion.
1227 const VarDecl *VD = R->getDecl();
1228 QualType T = VD->getType();
1229 const MemSpaceRegion *MS = R->getMemorySpace();
1231 if (isa<UnknownSpaceRegion>(MS) ||
1232 isa<StackArgumentsSpaceRegion>(MS))
1233 return svalBuilder.getRegionValueSymbolVal(R);
1235 if (isa<GlobalsSpaceRegion>(MS)) {
1236 if (isa<NonStaticGlobalSpaceRegion>(MS)) {
1237 // Is 'VD' declared constant? If so, retrieve the constant value.
1238 QualType CT = Ctx.getCanonicalType(T);
1239 if (CT.isConstQualified()) {
1240 const Expr *Init = VD->getInit();
1241 // Do the null check first, as we want to call 'IgnoreParenCasts'.
1243 if (const IntegerLiteral *IL =
1244 dyn_cast<IntegerLiteral>(Init->IgnoreParenCasts())) {
1245 const nonloc::ConcreteInt &V = svalBuilder.makeIntVal(IL);
1246 return svalBuilder.evalCast(V, Init->getType(), IL->getType());
1250 if (const Optional<SVal> &V = RetrieveDerivedDefaultValue(B, MS, R, CT))
1251 return V.getValue();
1253 return svalBuilder.getRegionValueSymbolVal(R);
1256 if (T->isIntegerType())
1257 return svalBuilder.makeIntVal(0, T);
1258 if (T->isPointerType())
1259 return svalBuilder.makeNull();
1261 return UnknownVal();
1264 return UndefinedVal();
1267 SVal RegionStoreManager::RetrieveLazySymbol(const TypedRegion *R) {
1268 // All other values are symbolic.
1269 return svalBuilder.getRegionValueSymbolVal(R);
1272 SVal RegionStoreManager::RetrieveStruct(Store store, const TypedRegion* R) {
1273 QualType T = R->getValueType();
1274 assert(T->isStructureOrClassType());
1275 return svalBuilder.makeLazyCompoundVal(StoreRef(store, *this), R);
1278 SVal RegionStoreManager::RetrieveArray(Store store, const TypedRegion * R) {
1279 assert(Ctx.getAsConstantArrayType(R->getValueType()));
1280 return svalBuilder.makeLazyCompoundVal(StoreRef(store, *this), R);
1283 //===----------------------------------------------------------------------===//
1284 // Binding values to regions.
1285 //===----------------------------------------------------------------------===//
1287 StoreRef RegionStoreManager::Remove(Store store, Loc L) {
1288 if (isa<loc::MemRegionVal>(L))
1289 if (const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion())
1290 return StoreRef(removeBinding(GetRegionBindings(store),
1291 R).getRootWithoutRetain(),
1294 return StoreRef(store, *this);
1297 StoreRef RegionStoreManager::Bind(Store store, Loc L, SVal V) {
1298 if (isa<loc::ConcreteInt>(L))
1299 return StoreRef(store, *this);
1301 // If we get here, the location should be a region.
1302 const MemRegion *R = cast<loc::MemRegionVal>(L).getRegion();
1304 // Check if the region is a struct region.
1305 if (const TypedRegion* TR = dyn_cast<TypedRegion>(R))
1306 if (TR->getValueType()->isStructureOrClassType())
1307 return BindStruct(store, TR, V);
1309 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1310 if (ER->getIndex().isZeroConstant()) {
1311 if (const TypedRegion *superR =
1312 dyn_cast<TypedRegion>(ER->getSuperRegion())) {
1313 QualType superTy = superR->getValueType();
1314 // For now, just invalidate the fields of the struct/union/class.
1315 // This is for test rdar_test_7185607 in misc-ps-region-store.m.
1316 // FIXME: Precisely handle the fields of the record.
1317 if (superTy->isStructureOrClassType())
1318 return KillStruct(store, superR, UnknownVal());
1322 else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
1323 // Binding directly to a symbolic region should be treated as binding
1325 QualType T = SR->getSymbol()->getType(Ctx);
1327 // FIXME: Is this the right way to handle symbols that are references?
1328 if (const PointerType *PT = T->getAs<PointerType>())
1329 T = PT->getPointeeType();
1331 T = T->getAs<ReferenceType>()->getPointeeType();
1333 R = GetElementZeroRegion(SR, T);
1336 // Perform the binding.
1337 RegionBindings B = GetRegionBindings(store);
1338 return StoreRef(addBinding(B, R, BindingKey::Direct,
1339 V).getRootWithoutRetain(), *this);
1342 StoreRef RegionStoreManager::BindDecl(Store store, const VarRegion *VR,
1345 QualType T = VR->getDecl()->getType();
1347 if (T->isArrayType())
1348 return BindArray(store, VR, InitVal);
1349 if (T->isStructureOrClassType())
1350 return BindStruct(store, VR, InitVal);
1352 return Bind(store, svalBuilder.makeLoc(VR), InitVal);
1355 // FIXME: this method should be merged into Bind().
1356 StoreRef RegionStoreManager::BindCompoundLiteral(Store store,
1357 const CompoundLiteralExpr *CL,
1358 const LocationContext *LC,
1360 return Bind(store, loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)),
1364 StoreRef RegionStoreManager::setImplicitDefaultValue(Store store,
1367 RegionBindings B = GetRegionBindings(store);
1370 if (Loc::isLocType(T))
1371 V = svalBuilder.makeNull();
1372 else if (T->isIntegerType())
1373 V = svalBuilder.makeZeroVal(T);
1374 else if (T->isStructureOrClassType() || T->isArrayType()) {
1375 // Set the default value to a zero constant when it is a structure
1376 // or array. The type doesn't really matter.
1377 V = svalBuilder.makeZeroVal(Ctx.IntTy);
1380 // We can't represent values of this type, but we still need to set a value
1381 // to record that the region has been initialized.
1382 // If this assertion ever fires, a new case should be added above -- we
1383 // should know how to default-initialize any value we can symbolicate.
1384 assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
1388 return StoreRef(addBinding(B, R, BindingKey::Default,
1389 V).getRootWithoutRetain(), *this);
1392 StoreRef RegionStoreManager::BindArray(Store store, const TypedRegion* R,
1395 const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
1396 QualType ElementTy = AT->getElementType();
1397 Optional<uint64_t> Size;
1399 if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
1400 Size = CAT->getSize().getZExtValue();
1402 // Check if the init expr is a string literal.
1403 if (loc::MemRegionVal *MRV = dyn_cast<loc::MemRegionVal>(&Init)) {
1404 const StringRegion *S = cast<StringRegion>(MRV->getRegion());
1406 // Treat the string as a lazy compound value.
1407 nonloc::LazyCompoundVal LCV =
1408 cast<nonloc::LazyCompoundVal>(svalBuilder.
1409 makeLazyCompoundVal(StoreRef(store, *this), S));
1410 return CopyLazyBindings(LCV, store, R);
1413 // Handle lazy compound values.
1414 if (nonloc::LazyCompoundVal *LCV = dyn_cast<nonloc::LazyCompoundVal>(&Init))
1415 return CopyLazyBindings(*LCV, store, R);
1417 // Remaining case: explicit compound values.
1419 if (Init.isUnknown())
1420 return setImplicitDefaultValue(store, R, ElementTy);
1422 nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(Init);
1423 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
1426 StoreRef newStore(store, *this);
1427 for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
1428 // The init list might be shorter than the array length.
1432 const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
1433 const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
1435 if (ElementTy->isStructureOrClassType())
1436 newStore = BindStruct(newStore.getStore(), ER, *VI);
1437 else if (ElementTy->isArrayType())
1438 newStore = BindArray(newStore.getStore(), ER, *VI);
1440 newStore = Bind(newStore.getStore(), svalBuilder.makeLoc(ER), *VI);
1443 // If the init list is shorter than the array length, set the
1444 // array default value.
1445 if (Size.hasValue() && i < Size.getValue())
1446 newStore = setImplicitDefaultValue(newStore.getStore(), R, ElementTy);
1451 StoreRef RegionStoreManager::BindStruct(Store store, const TypedRegion* R,
1454 if (!Features.supportsFields())
1455 return StoreRef(store, *this);
1457 QualType T = R->getValueType();
1458 assert(T->isStructureOrClassType());
1460 const RecordType* RT = T->getAs<RecordType>();
1461 RecordDecl* RD = RT->getDecl();
1463 if (!RD->isDefinition())
1464 return StoreRef(store, *this);
1466 // Handle lazy compound values.
1467 if (const nonloc::LazyCompoundVal *LCV=dyn_cast<nonloc::LazyCompoundVal>(&V))
1468 return CopyLazyBindings(*LCV, store, R);
1470 // We may get non-CompoundVal accidentally due to imprecise cast logic or
1471 // that we are binding symbolic struct value. Kill the field values, and if
1472 // the value is symbolic go and bind it as a "default" binding.
1473 if (V.isUnknown() || !isa<nonloc::CompoundVal>(V)) {
1474 SVal SV = isa<nonloc::SymbolVal>(V) ? V : UnknownVal();
1475 return KillStruct(store, R, SV);
1478 nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(V);
1479 nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
1481 RecordDecl::field_iterator FI, FE;
1482 StoreRef newStore(store, *this);
1484 for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI, ++VI) {
1489 QualType FTy = (*FI)->getType();
1490 const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
1492 if (FTy->isArrayType())
1493 newStore = BindArray(newStore.getStore(), FR, *VI);
1494 else if (FTy->isStructureOrClassType())
1495 newStore = BindStruct(newStore.getStore(), FR, *VI);
1497 newStore = Bind(newStore.getStore(), svalBuilder.makeLoc(FR), *VI);
1500 // There may be fewer values in the initialize list than the fields of struct.
1502 RegionBindings B = GetRegionBindings(newStore.getStore());
1503 B = addBinding(B, R, BindingKey::Default, svalBuilder.makeIntVal(0, false));
1504 newStore = StoreRef(B.getRootWithoutRetain(), *this);
1510 StoreRef RegionStoreManager::KillStruct(Store store, const TypedRegion* R,
1512 BindingKey key = BindingKey::Make(R, BindingKey::Default);
1514 // The BindingKey may be "invalid" if we cannot handle the region binding
1515 // explicitly. One example is something like array[index], where index
1516 // is a symbolic value. In such cases, we want to invalidate the entire
1517 // array, as the index assignment could have been to any element. In
1518 // the case of nested symbolic indices, we need to march up the region
1519 // hierarchy untile we reach a region whose binding we can reason about.
1520 const SubRegion *subReg = R;
1522 while (!key.isValid()) {
1523 if (const SubRegion *tmp = dyn_cast<SubRegion>(subReg->getSuperRegion())) {
1525 key = BindingKey::Make(tmp, BindingKey::Default);
1531 // Remove the old bindings, using 'subReg' as the root of all regions
1532 // we will invalidate.
1533 RegionBindings B = GetRegionBindings(store);
1534 llvm::OwningPtr<RegionStoreSubRegionMap>
1535 SubRegions(getRegionStoreSubRegionMap(store));
1536 RemoveSubRegionBindings(B, subReg, *SubRegions);
1538 // Set the default value of the struct region to "unknown".
1540 return StoreRef(B.getRootWithoutRetain(), *this);
1542 return StoreRef(addBinding(B, key, DefaultVal).getRootWithoutRetain(), *this);
1545 StoreRef RegionStoreManager::CopyLazyBindings(nonloc::LazyCompoundVal V,
1547 const TypedRegion *R) {
1549 // Nuke the old bindings stemming from R.
1550 RegionBindings B = GetRegionBindings(store);
1552 llvm::OwningPtr<RegionStoreSubRegionMap>
1553 SubRegions(getRegionStoreSubRegionMap(store));
1555 // B and DVM are updated after the call to RemoveSubRegionBindings.
1556 RemoveSubRegionBindings(B, R, *SubRegions.get());
1558 // Now copy the bindings. This amounts to just binding 'V' to 'R'. This
1559 // results in a zero-copy algorithm.
1560 return StoreRef(addBinding(B, R, BindingKey::Default,
1561 V).getRootWithoutRetain(), *this);
1564 //===----------------------------------------------------------------------===//
1565 // "Raw" retrievals and bindings.
1566 //===----------------------------------------------------------------------===//
1569 RegionBindings RegionStoreManager::addBinding(RegionBindings B, BindingKey K,
1573 return RBFactory.add(B, K, V);
1576 RegionBindings RegionStoreManager::addBinding(RegionBindings B,
1578 BindingKey::Kind k, SVal V) {
1579 return addBinding(B, BindingKey::Make(R, k), V);
1582 const SVal *RegionStoreManager::lookup(RegionBindings B, BindingKey K) {
1588 const SVal *RegionStoreManager::lookup(RegionBindings B,
1590 BindingKey::Kind k) {
1591 return lookup(B, BindingKey::Make(R, k));
1594 RegionBindings RegionStoreManager::removeBinding(RegionBindings B,
1598 return RBFactory.remove(B, K);
1601 RegionBindings RegionStoreManager::removeBinding(RegionBindings B,
1603 BindingKey::Kind k){
1604 return removeBinding(B, BindingKey::Make(R, k));
1607 //===----------------------------------------------------------------------===//
1609 //===----------------------------------------------------------------------===//
1612 class removeDeadBindingsWorker :
1613 public ClusterAnalysis<removeDeadBindingsWorker> {
1614 llvm::SmallVector<const SymbolicRegion*, 12> Postponed;
1615 SymbolReaper &SymReaper;
1616 const StackFrameContext *CurrentLCtx;
1619 removeDeadBindingsWorker(RegionStoreManager &rm, GRStateManager &stateMgr,
1620 RegionBindings b, SymbolReaper &symReaper,
1621 const StackFrameContext *LCtx)
1622 : ClusterAnalysis<removeDeadBindingsWorker>(rm, stateMgr, b,
1623 /* includeGlobals = */ false),
1624 SymReaper(symReaper), CurrentLCtx(LCtx) {}
1626 // Called by ClusterAnalysis.
1627 void VisitAddedToCluster(const MemRegion *baseR, RegionCluster &C);
1628 void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E);
1630 void VisitBindingKey(BindingKey K);
1631 bool UpdatePostponed();
1632 void VisitBinding(SVal V);
1636 void removeDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
1639 if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
1640 if (SymReaper.isLive(VR))
1641 AddToWorkList(baseR, C);
1646 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
1647 if (SymReaper.isLive(SR->getSymbol()))
1648 AddToWorkList(SR, C);
1650 Postponed.push_back(SR);
1655 if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
1656 AddToWorkList(baseR, C);
1660 // CXXThisRegion in the current or parent location context is live.
1661 if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
1662 const StackArgumentsSpaceRegion *StackReg =
1663 cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
1664 const StackFrameContext *RegCtx = StackReg->getStackFrame();
1665 if (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx))
1666 AddToWorkList(TR, C);
1670 void removeDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
1671 BindingKey *I, BindingKey *E) {
1672 for ( ; I != E; ++I)
1673 VisitBindingKey(*I);
1676 void removeDeadBindingsWorker::VisitBinding(SVal V) {
1677 // Is it a LazyCompoundVal? All referenced regions are live as well.
1678 if (const nonloc::LazyCompoundVal *LCS =
1679 dyn_cast<nonloc::LazyCompoundVal>(&V)) {
1681 const MemRegion *LazyR = LCS->getRegion();
1682 RegionBindings B = RegionStoreManager::GetRegionBindings(LCS->getStore());
1683 for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
1684 const SubRegion *baseR = dyn_cast<SubRegion>(RI.getKey().getRegion());
1685 if (baseR && baseR->isSubRegionOf(LazyR))
1686 VisitBinding(RI.getData());
1691 // If V is a region, then add it to the worklist.
1692 if (const MemRegion *R = V.getAsRegion())
1695 // Update the set of live symbols.
1696 for (SVal::symbol_iterator SI=V.symbol_begin(), SE=V.symbol_end();
1698 SymReaper.markLive(*SI);
1701 void removeDeadBindingsWorker::VisitBindingKey(BindingKey K) {
1702 const MemRegion *R = K.getRegion();
1704 // Mark this region "live" by adding it to the worklist. This will cause
1705 // use to visit all regions in the cluster (if we haven't visited them
1707 if (AddToWorkList(R)) {
1708 // Mark the symbol for any live SymbolicRegion as "live". This means we
1709 // should continue to track that symbol.
1710 if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(R))
1711 SymReaper.markLive(SymR->getSymbol());
1713 // For BlockDataRegions, enqueue the VarRegions for variables marked
1714 // with __block (passed-by-reference).
1715 // via BlockDeclRefExprs.
1716 if (const BlockDataRegion *BD = dyn_cast<BlockDataRegion>(R)) {
1717 for (BlockDataRegion::referenced_vars_iterator
1718 RI = BD->referenced_vars_begin(), RE = BD->referenced_vars_end();
1720 if ((*RI)->getDecl()->getAttr<BlocksAttr>())
1724 // No possible data bindings on a BlockDataRegion.
1729 // Visit the data binding for K.
1730 if (const SVal *V = RM.lookup(B, K))
1734 bool removeDeadBindingsWorker::UpdatePostponed() {
1735 // See if any postponed SymbolicRegions are actually live now, after
1736 // having done a scan.
1737 bool changed = false;
1739 for (llvm::SmallVectorImpl<const SymbolicRegion*>::iterator
1740 I = Postponed.begin(), E = Postponed.end() ; I != E ; ++I) {
1741 if (const SymbolicRegion *SR = cast_or_null<SymbolicRegion>(*I)) {
1742 if (SymReaper.isLive(SR->getSymbol())) {
1743 changed |= AddToWorkList(SR);
1752 StoreRef RegionStoreManager::removeDeadBindings(Store store,
1753 const StackFrameContext *LCtx,
1754 SymbolReaper& SymReaper,
1755 llvm::SmallVectorImpl<const MemRegion*>& RegionRoots)
1757 RegionBindings B = GetRegionBindings(store);
1758 removeDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
1759 W.GenerateClusters();
1761 // Enqueue the region roots onto the worklist.
1762 for (llvm::SmallVectorImpl<const MemRegion*>::iterator I=RegionRoots.begin(),
1763 E=RegionRoots.end(); I!=E; ++I)
1764 W.AddToWorkList(*I);
1766 do W.RunWorkList(); while (W.UpdatePostponed());
1768 // We have now scanned the store, marking reachable regions and symbols
1769 // as live. We now remove all the regions that are dead from the store
1770 // as well as update DSymbols with the set symbols that are now dead.
1771 for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
1772 const BindingKey &K = I.getKey();
1774 // If the cluster has been visited, we know the region has been marked.
1775 if (W.isVisited(K.getRegion()))
1778 // Remove the dead entry.
1779 B = removeBinding(B, K);
1781 // Mark all non-live symbols that this binding references as dead.
1782 if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(K.getRegion()))
1783 SymReaper.maybeDead(SymR->getSymbol());
1785 SVal X = I.getData();
1786 SVal::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
1787 for (; SI != SE; ++SI)
1788 SymReaper.maybeDead(*SI);
1791 return StoreRef(B.getRootWithoutRetain(), *this);
1795 StoreRef RegionStoreManager::enterStackFrame(const GRState *state,
1796 const StackFrameContext *frame) {
1797 FunctionDecl const *FD = cast<FunctionDecl>(frame->getDecl());
1798 FunctionDecl::param_const_iterator PI = FD->param_begin(),
1799 PE = FD->param_end();
1800 StoreRef store = StoreRef(state->getStore(), *this);
1802 if (CallExpr const *CE = dyn_cast<CallExpr>(frame->getCallSite())) {
1803 CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end();
1805 // Copy the arg expression value to the arg variables. We check that
1806 // PI != PE because the actual number of arguments may be different than
1807 // the function declaration.
1808 for (; AI != AE && PI != PE; ++AI, ++PI) {
1809 SVal ArgVal = state->getSVal(*AI);
1810 store = Bind(store.getStore(),
1811 svalBuilder.makeLoc(MRMgr.getVarRegion(*PI, frame)), ArgVal);
1813 } else if (const CXXConstructExpr *CE =
1814 dyn_cast<CXXConstructExpr>(frame->getCallSite())) {
1815 CXXConstructExpr::const_arg_iterator AI = CE->arg_begin(),
1818 // Copy the arg expression value to the arg variables.
1819 for (; AI != AE; ++AI, ++PI) {
1820 SVal ArgVal = state->getSVal(*AI);
1821 store = Bind(store.getStore(),
1822 svalBuilder.makeLoc(MRMgr.getVarRegion(*PI,frame)), ArgVal);
1825 assert(isa<CXXDestructorDecl>(frame->getDecl()));
1830 //===----------------------------------------------------------------------===//
1832 //===----------------------------------------------------------------------===//
1834 void RegionStoreManager::print(Store store, llvm::raw_ostream& OS,
1835 const char* nl, const char *sep) {
1836 RegionBindings B = GetRegionBindings(store);
1837 OS << "Store (direct and default bindings):" << nl;
1839 for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I)
1840 OS << ' ' << I.getKey() << " : " << I.getData() << nl;