| //== RegionStore.cpp - Field-sensitive store model --------------*- C++ -*--==// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines a basic region store model. In this model, we do have field |
| // sensitivity. But we assume nothing about the heap shape. So recursive data |
| // structures are largely ignored. Basically we do 1-limiting analysis. |
| // Parameter pointers are assumed with no aliasing. Pointee objects of |
| // parameters are created lazily. |
| // |
| //===----------------------------------------------------------------------===// |
| #include "clang/Analysis/PathSensitive/MemRegion.h" |
| #include "clang/Analysis/PathSensitive/AnalysisContext.h" |
| #include "clang/Analysis/PathSensitive/GRState.h" |
| #include "clang/Analysis/PathSensitive/GRStateTrait.h" |
| #include "clang/Analysis/Analyses/LiveVariables.h" |
| #include "clang/Analysis/Support/Optional.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/AST/CharUnits.h" |
| |
| #include "llvm/ADT/ImmutableMap.h" |
| #include "llvm/ADT/ImmutableList.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| using namespace clang; |
| |
| #define USE_EXPLICIT_COMPOUND 0 |
| |
| //===----------------------------------------------------------------------===// |
| // Representation of value bindings. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class BindingVal { |
| public: |
| enum BindingKind { Direct, Default }; |
| private: |
| SVal Value; |
| BindingKind Kind; |
| |
| public: |
| BindingVal(SVal V, BindingKind K) : Value(V), Kind(K) {} |
| |
| bool isDefault() const { return Kind == Default; } |
| |
| const SVal *getValue() const { return &Value; } |
| |
| const SVal *getDirectValue() const { return isDefault() ? 0 : &Value; } |
| |
| const SVal *getDefaultValue() const { return isDefault() ? &Value : 0; } |
| |
| void Profile(llvm::FoldingSetNodeID& ID) const { |
| Value.Profile(ID); |
| ID.AddInteger(Kind); |
| } |
| |
| inline bool operator==(const BindingVal& R) const { |
| return Value == R.Value && Kind == R.Kind; |
| } |
| |
| inline bool operator!=(const BindingVal& R) const { |
| return !(*this == R); |
| } |
| }; |
| } |
| |
| namespace llvm { |
| static inline |
| llvm::raw_ostream& operator<<(llvm::raw_ostream& os, BindingVal V) { |
| if (V.isDefault()) |
| os << "(default) "; |
| else |
| os << "(direct) "; |
| os << *V.getValue(); |
| return os; |
| } |
| } // end llvm namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Representation of binding keys. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class BindingKey : public std::pair<const MemRegion*, uint64_t> { |
| public: |
| explicit BindingKey(const MemRegion *r, uint64_t offset) |
| : std::pair<const MemRegion*,uint64_t>(r, offset) { assert(r); } |
| |
| const MemRegion *getRegion() const { return first; } |
| uint64_t getOffset() const { return second; } |
| |
| void Profile(llvm::FoldingSetNodeID& ID) const { |
| ID.AddPointer(getRegion()); |
| ID.AddInteger(getOffset()); |
| } |
| |
| static BindingKey Make(const MemRegion *R); |
| }; |
| } // end anonymous namespace |
| |
| namespace llvm { |
| static inline |
| llvm::raw_ostream& operator<<(llvm::raw_ostream& os, BindingKey K) { |
| os << '(' << K.getRegion() << ',' << K.getOffset() << ')'; |
| return os; |
| } |
| } // end llvm namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Actual Store type. |
| //===----------------------------------------------------------------------===// |
| |
| typedef llvm::ImmutableMap<BindingKey, BindingVal> RegionBindings; |
| |
| //===----------------------------------------------------------------------===// |
| // Fine-grained control of RegionStoreManager. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| struct minimal_features_tag {}; |
| struct maximal_features_tag {}; |
| |
| class RegionStoreFeatures { |
| bool SupportsFields; |
| bool SupportsRemaining; |
| |
| public: |
| RegionStoreFeatures(minimal_features_tag) : |
| SupportsFields(false), SupportsRemaining(false) {} |
| |
| RegionStoreFeatures(maximal_features_tag) : |
| SupportsFields(true), SupportsRemaining(false) {} |
| |
| void enableFields(bool t) { SupportsFields = t; } |
| |
| bool supportsFields() const { return SupportsFields; } |
| bool supportsRemaining() const { return SupportsRemaining; } |
| }; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Region "Extents" |
| //===----------------------------------------------------------------------===// |
| // |
| // MemRegions represent chunks of memory with a size (their "extent"). This |
| // GDM entry tracks the extents for regions. Extents are in bytes. |
| // |
| namespace { class RegionExtents {}; } |
| static int RegionExtentsIndex = 0; |
| namespace clang { |
| template<> struct GRStateTrait<RegionExtents> |
| : public GRStatePartialTrait<llvm::ImmutableMap<const MemRegion*, SVal> > { |
| static void* GDMIndex() { return &RegionExtentsIndex; } |
| }; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Utility functions. |
| //===----------------------------------------------------------------------===// |
| |
| static bool IsAnyPointerOrIntptr(QualType ty, ASTContext &Ctx) { |
| if (ty->isAnyPointerType()) |
| return true; |
| |
| return ty->isIntegerType() && ty->isScalarType() && |
| Ctx.getTypeSize(ty) == Ctx.getTypeSize(Ctx.VoidPtrTy); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Main RegionStore logic. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| |
| class RegionStoreSubRegionMap : public SubRegionMap { |
| typedef llvm::ImmutableSet<const MemRegion*> SetTy; |
| typedef llvm::DenseMap<const MemRegion*, SetTy> Map; |
| SetTy::Factory F; |
| Map M; |
| public: |
| bool add(const MemRegion* Parent, const MemRegion* SubRegion) { |
| Map::iterator I = M.find(Parent); |
| |
| if (I == M.end()) { |
| M.insert(std::make_pair(Parent, F.Add(F.GetEmptySet(), SubRegion))); |
| return true; |
| } |
| |
| I->second = F.Add(I->second, SubRegion); |
| return false; |
| } |
| |
| void process(llvm::SmallVectorImpl<const SubRegion*> &WL, const SubRegion *R); |
| |
| ~RegionStoreSubRegionMap() {} |
| |
| bool iterSubRegions(const MemRegion* Parent, Visitor& V) const { |
| Map::const_iterator I = M.find(Parent); |
| |
| if (I == M.end()) |
| return true; |
| |
| llvm::ImmutableSet<const MemRegion*> S = I->second; |
| for (llvm::ImmutableSet<const MemRegion*>::iterator SI=S.begin(),SE=S.end(); |
| SI != SE; ++SI) { |
| if (!V.Visit(Parent, *SI)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| typedef SetTy::iterator iterator; |
| |
| std::pair<iterator, iterator> begin_end(const MemRegion *R) { |
| Map::iterator I = M.find(R); |
| SetTy S = I == M.end() ? F.GetEmptySet() : I->second; |
| return std::make_pair(S.begin(), S.end()); |
| } |
| }; |
| |
| class RegionStoreManager : public StoreManager { |
| const RegionStoreFeatures Features; |
| RegionBindings::Factory RBFactory; |
| |
| typedef llvm::DenseMap<const GRState *, RegionStoreSubRegionMap*> SMCache; |
| SMCache SC; |
| |
| public: |
| RegionStoreManager(GRStateManager& mgr, const RegionStoreFeatures &f) |
| : StoreManager(mgr), |
| Features(f), |
| RBFactory(mgr.getAllocator()) {} |
| |
| virtual ~RegionStoreManager() { |
| for (SMCache::iterator I = SC.begin(), E = SC.end(); I != E; ++I) |
| delete (*I).second; |
| } |
| |
| SubRegionMap *getSubRegionMap(const GRState *state); |
| |
| RegionStoreSubRegionMap *getRegionStoreSubRegionMap(Store store); |
| |
| Optional<SVal> getBinding(RegionBindings B, const MemRegion *R); |
| Optional<SVal> getDirectBinding(RegionBindings B, const MemRegion *R); |
| /// getDefaultBinding - Returns an SVal* representing an optional default |
| /// binding associated with a region and its subregions. |
| Optional<SVal> getDefaultBinding(RegionBindings B, const MemRegion *R); |
| |
| /// setImplicitDefaultValue - Set the default binding for the provided |
| /// MemRegion to the value implicitly defined for compound literals when |
| /// the value is not specified. |
| const GRState *setImplicitDefaultValue(const GRState *state, |
| const MemRegion *R, |
| QualType T); |
| |
| /// getLValueString - Returns an SVal representing the lvalue of a |
| /// StringLiteral. Within RegionStore a StringLiteral has an |
| /// associated StringRegion, and the lvalue of a StringLiteral is |
| /// the lvalue of that region. |
| SVal getLValueString(const StringLiteral* S); |
| |
| /// getLValueCompoundLiteral - Returns an SVal representing the |
| /// lvalue of a compound literal. Within RegionStore a compound |
| /// literal has an associated region, and the lvalue of the |
| /// compound literal is the lvalue of that region. |
| SVal getLValueCompoundLiteral(const CompoundLiteralExpr*); |
| |
| /// getLValueVar - Returns an SVal that represents the lvalue of a |
| /// variable. Within RegionStore a variable has an associated |
| /// VarRegion, and the lvalue of the variable is the lvalue of that region. |
| SVal getLValueVar(const VarDecl *VD, const LocationContext *LC); |
| |
| SVal getLValueIvar(const ObjCIvarDecl* D, SVal Base); |
| |
| SVal getLValueField(const FieldDecl* D, SVal Base); |
| |
| SVal getLValueFieldOrIvar(const Decl* D, SVal Base); |
| |
| SVal getLValueElement(QualType elementType, SVal Offset, SVal Base); |
| |
| |
| /// ArrayToPointer - Emulates the "decay" of an array to a pointer |
| /// type. 'Array' represents the lvalue of the array being decayed |
| /// to a pointer, and the returned SVal represents the decayed |
| /// version of that lvalue (i.e., a pointer to the first element of |
| /// the array). This is called by GRExprEngine when evaluating |
| /// casts from arrays to pointers. |
| SVal ArrayToPointer(Loc Array); |
| |
| SVal EvalBinOp(const GRState *state, BinaryOperator::Opcode Op,Loc L, |
| NonLoc R, QualType resultTy); |
| |
| Store getInitialStore(const LocationContext *InitLoc) { |
| return RBFactory.GetEmptyMap().getRoot(); |
| } |
| |
| //===-------------------------------------------------------------------===// |
| // Binding values to regions. |
| //===-------------------------------------------------------------------===// |
| |
| const GRState *InvalidateRegion(const GRState *state, const MemRegion *R, |
| const Expr *E, unsigned Count, |
| InvalidatedSymbols *IS) { |
| return RegionStoreManager::InvalidateRegions(state, &R, &R+1, E, Count, IS); |
| } |
| |
| const GRState *InvalidateRegions(const GRState *state, |
| const MemRegion * const *Begin, |
| const MemRegion * const *End, |
| const Expr *E, unsigned Count, |
| InvalidatedSymbols *IS); |
| |
| private: |
| void RemoveSubRegionBindings(RegionBindings &B, const MemRegion *R, |
| RegionStoreSubRegionMap &M); |
| |
| RegionBindings Add(RegionBindings B, BindingKey K, BindingVal V); |
| RegionBindings Add(RegionBindings B, const MemRegion *R, BindingVal V); |
| |
| const BindingVal *Lookup(RegionBindings B, BindingKey K); |
| const BindingVal *Lookup(RegionBindings B, const MemRegion *R); |
| |
| RegionBindings Remove(RegionBindings B, BindingKey K); |
| RegionBindings Remove(RegionBindings B, const MemRegion *R); |
| Store Remove(Store store, BindingKey K); |
| |
| public: |
| const GRState *Bind(const GRState *state, Loc LV, SVal V); |
| |
| const GRState *BindCompoundLiteral(const GRState *state, |
| const CompoundLiteralExpr* CL, |
| const LocationContext *LC, |
| SVal V); |
| |
| const GRState *BindDecl(const GRState *ST, const VarRegion *VR, |
| SVal InitVal); |
| |
| const GRState *BindDeclWithNoInit(const GRState *state, |
| const VarRegion *) { |
| return state; |
| } |
| |
| /// BindStruct - Bind a compound value to a structure. |
| const GRState *BindStruct(const GRState *, const TypedRegion* R, SVal V); |
| |
| const GRState *BindArray(const GRState *state, const TypedRegion* R, SVal V); |
| |
| /// KillStruct - Set the entire struct to unknown. |
| Store KillStruct(Store store, const TypedRegion* R); |
| |
| Store Remove(Store store, Loc LV); |
| |
| |
| //===------------------------------------------------------------------===// |
| // Loading values from regions. |
| //===------------------------------------------------------------------===// |
| |
| /// The high level logic for this method is this: |
| /// Retrieve (L) |
| /// if L has binding |
| /// return L's binding |
| /// else if L is in killset |
| /// return unknown |
| /// else |
| /// if L is on stack or heap |
| /// return undefined |
| /// else |
| /// return symbolic |
| SValuator::CastResult Retrieve(const GRState *state, Loc L, |
| QualType T = QualType()); |
| |
| SVal RetrieveElement(const GRState *state, const ElementRegion *R); |
| |
| SVal RetrieveField(const GRState *state, const FieldRegion *R); |
| |
| SVal RetrieveObjCIvar(const GRState *state, const ObjCIvarRegion *R); |
| |
| SVal RetrieveVar(const GRState *state, const VarRegion *R); |
| |
| SVal RetrieveLazySymbol(const GRState *state, const TypedRegion *R); |
| |
| SVal RetrieveFieldOrElementCommon(const GRState *state, const TypedRegion *R, |
| QualType Ty, const MemRegion *superR); |
| |
| /// Retrieve the values in a struct and return a CompoundVal, used when doing |
| /// struct copy: |
| /// struct s x, y; |
| /// x = y; |
| /// y's value is retrieved by this method. |
| SVal RetrieveStruct(const GRState *St, const TypedRegion* R); |
| |
| SVal RetrieveArray(const GRState *St, const TypedRegion* R); |
| |
| /// Get the state and region whose binding this region R corresponds to. |
| std::pair<const GRState*, const MemRegion*> |
| GetLazyBinding(RegionBindings B, const MemRegion *R); |
| |
| const GRState* CopyLazyBindings(nonloc::LazyCompoundVal V, |
| const GRState *state, |
| const TypedRegion *R); |
| |
| const ElementRegion *GetElementZeroRegion(const SymbolicRegion *SR, |
| QualType T); |
| |
| //===------------------------------------------------------------------===// |
| // State pruning. |
| //===------------------------------------------------------------------===// |
| |
| /// RemoveDeadBindings - Scans the RegionStore of 'state' for dead values. |
| /// It returns a new Store with these values removed. |
| void RemoveDeadBindings(GRState &state, Stmt* Loc, SymbolReaper& SymReaper, |
| llvm::SmallVectorImpl<const MemRegion*>& RegionRoots); |
| |
| const GRState *EnterStackFrame(const GRState *state, |
| const StackFrameContext *frame); |
| |
| //===------------------------------------------------------------------===// |
| // Region "extents". |
| //===------------------------------------------------------------------===// |
| |
| const GRState *setExtent(const GRState *state,const MemRegion* R,SVal Extent); |
| DefinedOrUnknownSVal getSizeInElements(const GRState *state, |
| const MemRegion* R, QualType EleTy); |
| |
| //===------------------------------------------------------------------===// |
| // Utility methods. |
| //===------------------------------------------------------------------===// |
| |
| static inline RegionBindings GetRegionBindings(Store store) { |
| return RegionBindings(static_cast<const RegionBindings::TreeTy*>(store)); |
| } |
| |
| void print(Store store, llvm::raw_ostream& Out, const char* nl, |
| const char *sep); |
| |
| void iterBindings(Store store, BindingsHandler& f) { |
| // FIXME: Implement. |
| } |
| |
| // FIXME: Remove. |
| BasicValueFactory& getBasicVals() { |
| return StateMgr.getBasicVals(); |
| } |
| |
| // FIXME: Remove. |
| ASTContext& getContext() { return StateMgr.getContext(); } |
| }; |
| |
| } // end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // RegionStore creation. |
| //===----------------------------------------------------------------------===// |
| |
| StoreManager *clang::CreateRegionStoreManager(GRStateManager& StMgr) { |
| RegionStoreFeatures F = maximal_features_tag(); |
| return new RegionStoreManager(StMgr, F); |
| } |
| |
| StoreManager *clang::CreateFieldsOnlyRegionStoreManager(GRStateManager &StMgr) { |
| RegionStoreFeatures F = minimal_features_tag(); |
| F.enableFields(true); |
| return new RegionStoreManager(StMgr, F); |
| } |
| |
| void |
| RegionStoreSubRegionMap::process(llvm::SmallVectorImpl<const SubRegion*> &WL, |
| const SubRegion *R) { |
| const MemRegion *superR = R->getSuperRegion(); |
| if (add(superR, R)) |
| if (const SubRegion *sr = dyn_cast<SubRegion>(superR)) |
| WL.push_back(sr); |
| } |
| |
| RegionStoreSubRegionMap* |
| RegionStoreManager::getRegionStoreSubRegionMap(Store store) { |
| RegionBindings B = GetRegionBindings(store); |
| RegionStoreSubRegionMap *M = new RegionStoreSubRegionMap(); |
| |
| llvm::SmallVector<const SubRegion*, 10> WL; |
| |
| for (RegionBindings::iterator I=B.begin(), E=B.end(); I!=E; ++I) |
| if (const SubRegion *R = dyn_cast<SubRegion>(I.getKey().getRegion())) |
| M->process(WL, R); |
| |
| // We also need to record in the subregion map "intermediate" regions that |
| // don't have direct bindings but are super regions of those that do. |
| while (!WL.empty()) { |
| const SubRegion *R = WL.back(); |
| WL.pop_back(); |
| M->process(WL, R); |
| } |
| |
| return M; |
| } |
| |
| SubRegionMap *RegionStoreManager::getSubRegionMap(const GRState *state) { |
| return getRegionStoreSubRegionMap(state->getStore()); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Binding invalidation. |
| //===----------------------------------------------------------------------===// |
| |
| void RegionStoreManager::RemoveSubRegionBindings(RegionBindings &B, |
| const MemRegion *R, |
| RegionStoreSubRegionMap &M) { |
| RegionStoreSubRegionMap::iterator I, E; |
| |
| for (llvm::tie(I, E) = M.begin_end(R); I != E; ++I) |
| RemoveSubRegionBindings(B, *I, M); |
| |
| B = Remove(B, R); |
| } |
| |
| const GRState *RegionStoreManager::InvalidateRegions(const GRState *state, |
| const MemRegion * const *I, |
| const MemRegion * const *E, |
| const Expr *Ex, |
| unsigned Count, |
| InvalidatedSymbols *IS) { |
| ASTContext& Ctx = StateMgr.getContext(); |
| |
| // Get the mapping of regions -> subregions. |
| llvm::OwningPtr<RegionStoreSubRegionMap> |
| SubRegions(getRegionStoreSubRegionMap(state->getStore())); |
| |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| |
| llvm::DenseMap<const MemRegion *, unsigned> Visited; |
| llvm::SmallVector<const MemRegion *, 10> WorkList; |
| |
| for ( ; I != E; ++I) { |
| // Strip away casts. |
| WorkList.push_back((*I)->StripCasts()); |
| } |
| |
| while (!WorkList.empty()) { |
| const MemRegion *R = WorkList.back(); |
| WorkList.pop_back(); |
| |
| // Have we visited this region before? |
| unsigned &visited = Visited[R]; |
| if (visited) |
| continue; |
| visited = 1; |
| |
| // Add subregions to work list. |
| RegionStoreSubRegionMap::iterator I, E; |
| for (llvm::tie(I, E) = SubRegions->begin_end(R); I!=E; ++I) |
| WorkList.push_back(*I); |
| |
| // Get the old binding. Is it a region? If so, add it to the worklist. |
| if (Optional<SVal> V = getDirectBinding(B, R)) { |
| if (const MemRegion *RV = V->getAsRegion()) |
| WorkList.push_back(RV); |
| |
| // A symbol? Mark it touched by the invalidation. |
| if (IS) { |
| if (SymbolRef Sym = V->getAsSymbol()) |
| IS->insert(Sym); |
| } |
| } |
| |
| // Symbolic region? Mark that symbol touched by the invalidation. |
| if (IS) { |
| if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) |
| IS->insert(SR->getSymbol()); |
| } |
| |
| // BlockDataRegion? If so, invalidate captured variables that are passed |
| // by reference. |
| if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) { |
| for (BlockDataRegion::referenced_vars_iterator |
| I = BR->referenced_vars_begin(), E = BR->referenced_vars_end() ; |
| I != E; ++I) { |
| const VarRegion *VR = *I; |
| if (VR->getDecl()->getAttr<BlocksAttr>()) |
| WorkList.push_back(VR); |
| } |
| continue; |
| } |
| |
| // Handle the region itself. |
| if (isa<AllocaRegion>(R) || isa<SymbolicRegion>(R)) { |
| // Invalidate the region by setting its default value to |
| // conjured symbol. The type of the symbol is irrelavant. |
| DefinedOrUnknownSVal V = ValMgr.getConjuredSymbolVal(R, Ex, Ctx.IntTy, |
| Count); |
| B = Add(B, R, BindingVal(V, BindingVal::Default)); |
| continue; |
| } |
| |
| if (!R->isBoundable()) |
| continue; |
| |
| const TypedRegion *TR = cast<TypedRegion>(R); |
| QualType T = TR->getValueType(Ctx); |
| |
| if (const RecordType *RT = T->getAsStructureType()) { |
| const RecordDecl *RD = RT->getDecl()->getDefinition(Ctx); |
| |
| // No record definition. There is nothing we can do. |
| if (!RD) |
| continue; |
| |
| // Invalidate the region by setting its default value to |
| // conjured symbol. The type of the symbol is irrelavant. |
| DefinedOrUnknownSVal V = ValMgr.getConjuredSymbolVal(R, Ex, Ctx.IntTy, |
| Count); |
| B = Add(B, R, BindingVal(V, BindingVal::Default)); |
| continue; |
| } |
| |
| if (const ArrayType *AT = Ctx.getAsArrayType(T)) { |
| // Set the default value of the array to conjured symbol. |
| DefinedOrUnknownSVal V = |
| ValMgr.getConjuredSymbolVal(R, Ex, AT->getElementType(), Count); |
| B = Add(B, R, BindingVal(V, BindingVal::Default)); |
| continue; |
| } |
| |
| if ((isa<FieldRegion>(R)||isa<ElementRegion>(R)||isa<ObjCIvarRegion>(R)) |
| && Visited[cast<SubRegion>(R)->getSuperRegion()]) { |
| // For fields and elements whose super region has also been invalidated, |
| // only remove the old binding. The super region will get set with a |
| // default value from which we can lazily derive a new symbolic value. |
| B = Remove(B, R); |
| continue; |
| } |
| |
| // Invalidate the binding. |
| DefinedOrUnknownSVal V = ValMgr.getConjuredSymbolVal(R, Ex, T, Count); |
| assert(SymbolManager::canSymbolicate(T) || V.isUnknown()); |
| B = Add(B, R, BindingVal(V, BindingVal::Direct)); |
| } |
| |
| // Create a new state with the updated bindings. |
| return state->makeWithStore(B.getRoot()); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // getLValueXXX methods. |
| //===----------------------------------------------------------------------===// |
| |
| /// getLValueString - Returns an SVal representing the lvalue of a |
| /// StringLiteral. Within RegionStore a StringLiteral has an |
| /// associated StringRegion, and the lvalue of a StringLiteral is the |
| /// lvalue of that region. |
| SVal RegionStoreManager::getLValueString(const StringLiteral* S) { |
| return loc::MemRegionVal(MRMgr.getStringRegion(S)); |
| } |
| |
| /// getLValueVar - Returns an SVal that represents the lvalue of a |
| /// variable. Within RegionStore a variable has an associated |
| /// VarRegion, and the lvalue of the variable is the lvalue of that region. |
| SVal RegionStoreManager::getLValueVar(const VarDecl *VD, |
| const LocationContext *LC) { |
| return loc::MemRegionVal(MRMgr.getVarRegion(VD, LC)); |
| } |
| |
| SVal RegionStoreManager::getLValueIvar(const ObjCIvarDecl* D, SVal Base) { |
| return getLValueFieldOrIvar(D, Base); |
| } |
| |
| SVal RegionStoreManager::getLValueField(const FieldDecl* D, SVal Base) { |
| return getLValueFieldOrIvar(D, Base); |
| } |
| |
| SVal RegionStoreManager::getLValueFieldOrIvar(const Decl* D, SVal Base) { |
| if (Base.isUnknownOrUndef()) |
| return Base; |
| |
| Loc BaseL = cast<Loc>(Base); |
| const MemRegion* BaseR = 0; |
| |
| switch (BaseL.getSubKind()) { |
| case loc::MemRegionKind: |
| BaseR = cast<loc::MemRegionVal>(BaseL).getRegion(); |
| break; |
| |
| case loc::GotoLabelKind: |
| // These are anormal cases. Flag an undefined value. |
| return UndefinedVal(); |
| |
| case loc::ConcreteIntKind: |
| // While these seem funny, this can happen through casts. |
| // FIXME: What we should return is the field offset. For example, |
| // add the field offset to the integer value. That way funny things |
| // like this work properly: &(((struct foo *) 0xa)->f) |
| return Base; |
| |
| default: |
| assert(0 && "Unhandled Base."); |
| return Base; |
| } |
| |
| // NOTE: We must have this check first because ObjCIvarDecl is a subclass |
| // of FieldDecl. |
| if (const ObjCIvarDecl *ID = dyn_cast<ObjCIvarDecl>(D)) |
| return loc::MemRegionVal(MRMgr.getObjCIvarRegion(ID, BaseR)); |
| |
| return loc::MemRegionVal(MRMgr.getFieldRegion(cast<FieldDecl>(D), BaseR)); |
| } |
| |
| SVal RegionStoreManager::getLValueElement(QualType elementType, SVal Offset, |
| SVal Base) { |
| |
| // If the base is an unknown or undefined value, just return it back. |
| // FIXME: For absolute pointer addresses, we just return that value back as |
| // well, although in reality we should return the offset added to that |
| // value. |
| if (Base.isUnknownOrUndef() || isa<loc::ConcreteInt>(Base)) |
| return Base; |
| |
| // Only handle integer offsets... for now. |
| if (!isa<nonloc::ConcreteInt>(Offset)) |
| return UnknownVal(); |
| |
| const MemRegion* BaseRegion = cast<loc::MemRegionVal>(Base).getRegion(); |
| |
| // Pointer of any type can be cast and used as array base. |
| const ElementRegion *ElemR = dyn_cast<ElementRegion>(BaseRegion); |
| |
| // Convert the offset to the appropriate size and signedness. |
| Offset = ValMgr.convertToArrayIndex(Offset); |
| |
| if (!ElemR) { |
| // |
| // If the base region is not an ElementRegion, create one. |
| // This can happen in the following example: |
| // |
| // char *p = __builtin_alloc(10); |
| // p[1] = 8; |
| // |
| // Observe that 'p' binds to an AllocaRegion. |
| // |
| return loc::MemRegionVal(MRMgr.getElementRegion(elementType, Offset, |
| BaseRegion, getContext())); |
| } |
| |
| SVal BaseIdx = ElemR->getIndex(); |
| |
| if (!isa<nonloc::ConcreteInt>(BaseIdx)) |
| return UnknownVal(); |
| |
| const llvm::APSInt& BaseIdxI = cast<nonloc::ConcreteInt>(BaseIdx).getValue(); |
| const llvm::APSInt& OffI = cast<nonloc::ConcreteInt>(Offset).getValue(); |
| assert(BaseIdxI.isSigned()); |
| |
| // Compute the new index. |
| SVal NewIdx = nonloc::ConcreteInt(getBasicVals().getValue(BaseIdxI + OffI)); |
| |
| // Construct the new ElementRegion. |
| const MemRegion *ArrayR = ElemR->getSuperRegion(); |
| return loc::MemRegionVal(MRMgr.getElementRegion(elementType, NewIdx, ArrayR, |
| getContext())); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Extents for regions. |
| //===----------------------------------------------------------------------===// |
| |
| DefinedOrUnknownSVal RegionStoreManager::getSizeInElements(const GRState *state, |
| const MemRegion *R, |
| QualType EleTy) { |
| |
| switch (R->getKind()) { |
| case MemRegion::CXXThisRegionKind: |
| assert(0 && "Cannot get size of 'this' region"); |
| case MemRegion::GenericMemSpaceRegionKind: |
| case MemRegion::StackLocalsSpaceRegionKind: |
| case MemRegion::StackArgumentsSpaceRegionKind: |
| case MemRegion::HeapSpaceRegionKind: |
| case MemRegion::GlobalsSpaceRegionKind: |
| case MemRegion::UnknownSpaceRegionKind: |
| assert(0 && "Cannot index into a MemSpace"); |
| return UnknownVal(); |
| |
| case MemRegion::FunctionTextRegionKind: |
| case MemRegion::BlockTextRegionKind: |
| case MemRegion::BlockDataRegionKind: |
| // Technically this can happen if people do funny things with casts. |
| return UnknownVal(); |
| |
| // Not yet handled. |
| case MemRegion::AllocaRegionKind: |
| case MemRegion::CompoundLiteralRegionKind: |
| case MemRegion::ElementRegionKind: |
| case MemRegion::FieldRegionKind: |
| case MemRegion::ObjCIvarRegionKind: |
| case MemRegion::CXXObjectRegionKind: |
| return UnknownVal(); |
| |
| case MemRegion::SymbolicRegionKind: { |
| const SVal *Size = state->get<RegionExtents>(R); |
| if (!Size) |
| return UnknownVal(); |
| const nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(Size); |
| if (!CI) |
| return UnknownVal(); |
| |
| CharUnits RegionSize = |
| CharUnits::fromQuantity(CI->getValue().getSExtValue()); |
| CharUnits EleSize = getContext().getTypeSizeInChars(EleTy); |
| assert(RegionSize % EleSize == 0); |
| |
| return ValMgr.makeIntVal(RegionSize / EleSize, false); |
| } |
| |
| case MemRegion::StringRegionKind: { |
| const StringLiteral* Str = cast<StringRegion>(R)->getStringLiteral(); |
| // We intentionally made the size value signed because it participates in |
| // operations with signed indices. |
| return ValMgr.makeIntVal(Str->getByteLength()+1, false); |
| } |
| |
| case MemRegion::VarRegionKind: { |
| const VarRegion* VR = cast<VarRegion>(R); |
| // Get the type of the variable. |
| QualType T = VR->getDesugaredValueType(getContext()); |
| |
| // FIXME: Handle variable-length arrays. |
| if (isa<VariableArrayType>(T)) |
| return UnknownVal(); |
| |
| if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(T)) { |
| // return the size as signed integer. |
| return ValMgr.makeIntVal(CAT->getSize(), false); |
| } |
| |
| // Clients can use ordinary variables as if they were arrays. These |
| // essentially are arrays of size 1. |
| return ValMgr.makeIntVal(1, false); |
| } |
| } |
| |
| assert(0 && "Unreachable"); |
| return UnknownVal(); |
| } |
| |
| const GRState *RegionStoreManager::setExtent(const GRState *state, |
| const MemRegion *region, |
| SVal extent) { |
| return state->set<RegionExtents>(region, extent); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Location and region casting. |
| //===----------------------------------------------------------------------===// |
| |
| /// ArrayToPointer - Emulates the "decay" of an array to a pointer |
| /// type. 'Array' represents the lvalue of the array being decayed |
| /// to a pointer, and the returned SVal represents the decayed |
| /// version of that lvalue (i.e., a pointer to the first element of |
| /// the array). This is called by GRExprEngine when evaluating casts |
| /// from arrays to pointers. |
| SVal RegionStoreManager::ArrayToPointer(Loc Array) { |
| if (!isa<loc::MemRegionVal>(Array)) |
| return UnknownVal(); |
| |
| const MemRegion* R = cast<loc::MemRegionVal>(&Array)->getRegion(); |
| const TypedRegion* ArrayR = dyn_cast<TypedRegion>(R); |
| |
| if (!ArrayR) |
| return UnknownVal(); |
| |
| // Strip off typedefs from the ArrayRegion's ValueType. |
| QualType T = ArrayR->getValueType(getContext()).getDesugaredType(); |
| ArrayType *AT = cast<ArrayType>(T); |
| T = AT->getElementType(); |
| |
| SVal ZeroIdx = ValMgr.makeZeroArrayIndex(); |
| return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, ArrayR, |
| getContext())); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Pointer arithmetic. |
| //===----------------------------------------------------------------------===// |
| |
| SVal RegionStoreManager::EvalBinOp(const GRState *state, |
| BinaryOperator::Opcode Op, Loc L, NonLoc R, |
| QualType resultTy) { |
| // Assume the base location is MemRegionVal. |
| if (!isa<loc::MemRegionVal>(L)) |
| return UnknownVal(); |
| |
| const MemRegion* MR = cast<loc::MemRegionVal>(L).getRegion(); |
| const ElementRegion *ER = 0; |
| |
| switch (MR->getKind()) { |
| case MemRegion::SymbolicRegionKind: { |
| const SymbolicRegion *SR = cast<SymbolicRegion>(MR); |
| SymbolRef Sym = SR->getSymbol(); |
| QualType T = Sym->getType(getContext()); |
| QualType EleTy; |
| |
| if (const PointerType *PT = T->getAs<PointerType>()) |
| EleTy = PT->getPointeeType(); |
| else |
| EleTy = T->getAs<ObjCObjectPointerType>()->getPointeeType(); |
| |
| SVal ZeroIdx = ValMgr.makeZeroArrayIndex(); |
| ER = MRMgr.getElementRegion(EleTy, ZeroIdx, SR, getContext()); |
| break; |
| } |
| case MemRegion::AllocaRegionKind: { |
| const AllocaRegion *AR = cast<AllocaRegion>(MR); |
| QualType T = getContext().CharTy; // Create an ElementRegion of bytes. |
| QualType EleTy = T->getAs<PointerType>()->getPointeeType(); |
| SVal ZeroIdx = ValMgr.makeZeroArrayIndex(); |
| ER = MRMgr.getElementRegion(EleTy, ZeroIdx, AR, getContext()); |
| break; |
| } |
| |
| case MemRegion::ElementRegionKind: { |
| ER = cast<ElementRegion>(MR); |
| break; |
| } |
| |
| // Not yet handled. |
| case MemRegion::VarRegionKind: |
| case MemRegion::StringRegionKind: { |
| |
| } |
| // Fall-through. |
| case MemRegion::CompoundLiteralRegionKind: |
| case MemRegion::FieldRegionKind: |
| case MemRegion::ObjCIvarRegionKind: |
| case MemRegion::CXXObjectRegionKind: |
| return UnknownVal(); |
| |
| case MemRegion::FunctionTextRegionKind: |
| case MemRegion::BlockTextRegionKind: |
| case MemRegion::BlockDataRegionKind: |
| // Technically this can happen if people do funny things with casts. |
| return UnknownVal(); |
| |
| case MemRegion::CXXThisRegionKind: |
| assert(0 && |
| "Cannot perform pointer arithmetic on implicit argument 'this'"); |
| case MemRegion::GenericMemSpaceRegionKind: |
| case MemRegion::StackLocalsSpaceRegionKind: |
| case MemRegion::StackArgumentsSpaceRegionKind: |
| case MemRegion::HeapSpaceRegionKind: |
| case MemRegion::GlobalsSpaceRegionKind: |
| case MemRegion::UnknownSpaceRegionKind: |
| assert(0 && "Cannot perform pointer arithmetic on a MemSpace"); |
| return UnknownVal(); |
| } |
| |
| SVal Idx = ER->getIndex(); |
| nonloc::ConcreteInt* Base = dyn_cast<nonloc::ConcreteInt>(&Idx); |
| |
| // For now, only support: |
| // (a) concrete integer indices that can easily be resolved |
| // (b) 0 + symbolic index |
| if (Base) { |
| if (nonloc::ConcreteInt *Offset = dyn_cast<nonloc::ConcreteInt>(&R)) { |
| // FIXME: Should use SValuator here. |
| SVal NewIdx = |
| Base->evalBinOp(ValMgr, Op, |
| cast<nonloc::ConcreteInt>(ValMgr.convertToArrayIndex(*Offset))); |
| const MemRegion* NewER = |
| MRMgr.getElementRegion(ER->getElementType(), NewIdx, |
| ER->getSuperRegion(), getContext()); |
| return ValMgr.makeLoc(NewER); |
| } |
| if (0 == Base->getValue()) { |
| const MemRegion* NewER = |
| MRMgr.getElementRegion(ER->getElementType(), R, |
| ER->getSuperRegion(), getContext()); |
| return ValMgr.makeLoc(NewER); |
| } |
| } |
| |
| return UnknownVal(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Loading values from regions. |
| //===----------------------------------------------------------------------===// |
| |
| Optional<SVal> RegionStoreManager::getDirectBinding(RegionBindings B, |
| const MemRegion *R) { |
| if (const BindingVal *BV = Lookup(B, R)) |
| return Optional<SVal>::create(BV->getDirectValue()); |
| |
| return Optional<SVal>(); |
| } |
| |
| Optional<SVal> RegionStoreManager::getDefaultBinding(RegionBindings B, |
| const MemRegion *R) { |
| |
| if (R->isBoundable()) |
| if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) |
| if (TR->getValueType(getContext())->isUnionType()) |
| return UnknownVal(); |
| |
| if (const BindingVal *V = Lookup(B, R)) |
| return Optional<SVal>::create(V->getDefaultValue()); |
| |
| return Optional<SVal>(); |
| } |
| |
| Optional<SVal> RegionStoreManager::getBinding(RegionBindings B, |
| const MemRegion *R) { |
| if (const BindingVal *BV = Lookup(B, R)) |
| return Optional<SVal>::create(BV->getValue()); |
| |
| return Optional<SVal>(); |
| } |
| |
| static bool IsReinterpreted(QualType RTy, QualType UsedTy, ASTContext &Ctx) { |
| RTy = Ctx.getCanonicalType(RTy); |
| UsedTy = Ctx.getCanonicalType(UsedTy); |
| |
| if (RTy == UsedTy) |
| return false; |
| |
| |
| // Recursively check the types. We basically want to see if a pointer value |
| // is ever reinterpreted as a non-pointer, e.g. void** and intptr_t* |
| // represents a reinterpretation. |
| if (Loc::IsLocType(RTy) && Loc::IsLocType(UsedTy)) { |
| const PointerType *PRTy = RTy->getAs<PointerType>(); |
| const PointerType *PUsedTy = UsedTy->getAs<PointerType>(); |
| |
| return PUsedTy && PRTy && |
| IsReinterpreted(PRTy->getPointeeType(), |
| PUsedTy->getPointeeType(), Ctx); |
| } |
| |
| return true; |
| } |
| |
| const ElementRegion * |
| RegionStoreManager::GetElementZeroRegion(const SymbolicRegion *SR, QualType T) { |
| ASTContext &Ctx = getContext(); |
| SVal idx = ValMgr.makeZeroArrayIndex(); |
| assert(!T.isNull()); |
| return MRMgr.getElementRegion(T, idx, SR, Ctx); |
| } |
| |
| |
| |
| SValuator::CastResult |
| RegionStoreManager::Retrieve(const GRState *state, Loc L, QualType T) { |
| |
| assert(!isa<UnknownVal>(L) && "location unknown"); |
| assert(!isa<UndefinedVal>(L) && "location undefined"); |
| |
| // FIXME: Is this even possible? Shouldn't this be treated as a null |
| // dereference at a higher level? |
| if (isa<loc::ConcreteInt>(L)) |
| return SValuator::CastResult(state, UndefinedVal()); |
| |
| const MemRegion *MR = cast<loc::MemRegionVal>(L).getRegion(); |
| |
| // FIXME: return symbolic value for these cases. |
| // Example: |
| // void f(int* p) { int x = *p; } |
| // char* p = alloca(); |
| // read(p); |
| // c = *p; |
| if (isa<AllocaRegion>(MR)) |
| return SValuator::CastResult(state, UnknownVal()); |
| |
| if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR)) |
| MR = GetElementZeroRegion(SR, T); |
| |
| if (isa<CodeTextRegion>(MR)) |
| return SValuator::CastResult(state, UnknownVal()); |
| |
| // FIXME: Perhaps this method should just take a 'const MemRegion*' argument |
| // instead of 'Loc', and have the other Loc cases handled at a higher level. |
| const TypedRegion *R = cast<TypedRegion>(MR); |
| QualType RTy = R->getValueType(getContext()); |
| |
| // FIXME: We should eventually handle funny addressing. e.g.: |
| // |
| // int x = ...; |
| // int *p = &x; |
| // char *q = (char*) p; |
| // char c = *q; // returns the first byte of 'x'. |
| // |
| // Such funny addressing will occur due to layering of regions. |
| |
| #if 0 |
| ASTContext &Ctx = getContext(); |
| if (!T.isNull() && IsReinterpreted(RTy, T, Ctx)) { |
| SVal ZeroIdx = ValMgr.makeZeroArrayIndex(); |
| R = MRMgr.getElementRegion(T, ZeroIdx, R, Ctx); |
| RTy = T; |
| assert(Ctx.getCanonicalType(RTy) == |
| Ctx.getCanonicalType(R->getValueType(Ctx))); |
| } |
| #endif |
| |
| if (RTy->isStructureType()) |
| return SValuator::CastResult(state, RetrieveStruct(state, R)); |
| |
| // FIXME: Handle unions. |
| if (RTy->isUnionType()) |
| return SValuator::CastResult(state, UnknownVal()); |
| |
| if (RTy->isArrayType()) |
| return SValuator::CastResult(state, RetrieveArray(state, R)); |
| |
| // FIXME: handle Vector types. |
| if (RTy->isVectorType()) |
| return SValuator::CastResult(state, UnknownVal()); |
| |
| if (const FieldRegion* FR = dyn_cast<FieldRegion>(R)) |
| return SValuator::CastResult(state, |
| CastRetrievedVal(RetrieveField(state, FR), FR, |
| T, false)); |
| |
| if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) { |
| // FIXME: Here we actually perform an implicit conversion from the loaded |
| // value to the element type. Eventually we want to compose these values |
| // more intelligently. For example, an 'element' can encompass multiple |
| // bound regions (e.g., several bound bytes), or could be a subset of |
| // a larger value. |
| return SValuator::CastResult(state, |
| CastRetrievedVal(RetrieveElement(state, ER), |
| ER, T, false)); |
| } |
| |
| if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) { |
| // FIXME: Here we actually perform an implicit conversion from the loaded |
| // value to the ivar type. What we should model is stores to ivars |
| // that blow past the extent of the ivar. If the address of the ivar is |
| // reinterpretted, it is possible we stored a different value that could |
| // fit within the ivar. Either we need to cast these when storing them |
| // or reinterpret them lazily (as we do here). |
| return SValuator::CastResult(state, |
| CastRetrievedVal(RetrieveObjCIvar(state, IVR), |
| IVR, T, false)); |
| } |
| |
| if (const VarRegion *VR = dyn_cast<VarRegion>(R)) { |
| // FIXME: Here we actually perform an implicit conversion from the loaded |
| // value to the variable type. What we should model is stores to variables |
| // that blow past the extent of the variable. If the address of the |
| // variable is reinterpretted, it is possible we stored a different value |
| // that could fit within the variable. Either we need to cast these when |
| // storing them or reinterpret them lazily (as we do here). |
| return SValuator::CastResult(state, |
| CastRetrievedVal(RetrieveVar(state, VR), VR, T, |
| false)); |
| } |
| |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| const BindingVal *V = Lookup(B, R); |
| |
| // Check if the region has a binding. |
| if (V) |
| if (SVal const *SV = V->getValue()) |
| return SValuator::CastResult(state, *SV); |
| |
| // The location does not have a bound value. This means that it has |
| // the value it had upon its creation and/or entry to the analyzed |
| // function/method. These are either symbolic values or 'undefined'. |
| if (R->hasStackNonParametersStorage()) { |
| // All stack variables are considered to have undefined values |
| // upon creation. All heap allocated blocks are considered to |
| // have undefined values as well unless they are explicitly bound |
| // to specific values. |
| return SValuator::CastResult(state, UndefinedVal()); |
| } |
| |
| // All other values are symbolic. |
| return SValuator::CastResult(state, ValMgr.getRegionValueSymbolVal(R, RTy)); |
| } |
| |
| std::pair<const GRState*, const MemRegion*> |
| RegionStoreManager::GetLazyBinding(RegionBindings B, const MemRegion *R) { |
| if (Optional<SVal> OV = getDirectBinding(B, R)) |
| if (const nonloc::LazyCompoundVal *V = |
| dyn_cast<nonloc::LazyCompoundVal>(OV.getPointer())) |
| return std::make_pair(V->getState(), V->getRegion()); |
| |
| if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) { |
| const std::pair<const GRState *, const MemRegion *> &X = |
| GetLazyBinding(B, ER->getSuperRegion()); |
| |
| if (X.first) |
| return std::make_pair(X.first, |
| MRMgr.getElementRegionWithSuper(ER, X.second)); |
| } |
| else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) { |
| const std::pair<const GRState *, const MemRegion *> &X = |
| GetLazyBinding(B, FR->getSuperRegion()); |
| |
| if (X.first) |
| return std::make_pair(X.first, |
| MRMgr.getFieldRegionWithSuper(FR, X.second)); |
| } |
| |
| return std::make_pair((const GRState*) 0, (const MemRegion *) 0); |
| } |
| |
| SVal RegionStoreManager::RetrieveElement(const GRState* state, |
| const ElementRegion* R) { |
| // Check if the region has a binding. |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| if (Optional<SVal> V = getDirectBinding(B, R)) |
| return *V; |
| |
| const MemRegion* superR = R->getSuperRegion(); |
| |
| // Check if the region is an element region of a string literal. |
| if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) { |
| // FIXME: Handle loads from strings where the literal is treated as |
| // an integer, e.g., *((unsigned int*)"hello") |
| ASTContext &Ctx = getContext(); |
| QualType T = Ctx.getAsArrayType(StrR->getValueType(Ctx))->getElementType(); |
| if (T != Ctx.getCanonicalType(R->getElementType())) |
| return UnknownVal(); |
| |
| const StringLiteral *Str = StrR->getStringLiteral(); |
| SVal Idx = R->getIndex(); |
| if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&Idx)) { |
| int64_t i = CI->getValue().getSExtValue(); |
| int64_t byteLength = Str->getByteLength(); |
| if (i > byteLength) { |
| // Buffer overflow checking in GRExprEngine should handle this case, |
| // but we shouldn't rely on it to not overflow here if that checking |
| // is disabled. |
| return UnknownVal(); |
| } |
| char c = (i == byteLength) ? '\0' : Str->getStrData()[i]; |
| return ValMgr.makeIntVal(c, T); |
| } |
| } |
| |
| // Check if the immediate super region has a direct binding. |
| if (Optional<SVal> V = getDirectBinding(B, superR)) { |
| if (SymbolRef parentSym = V->getAsSymbol()) |
| return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R); |
| |
| if (V->isUnknownOrUndef()) |
| return *V; |
| |
| // Handle LazyCompoundVals for the immediate super region. Other cases |
| // are handled in 'RetrieveFieldOrElementCommon'. |
| if (const nonloc::LazyCompoundVal *LCV = |
| dyn_cast<nonloc::LazyCompoundVal>(V)) { |
| |
| R = MRMgr.getElementRegionWithSuper(R, LCV->getRegion()); |
| return RetrieveElement(LCV->getState(), R); |
| } |
| |
| // Other cases: give up. |
| return UnknownVal(); |
| } |
| |
| return RetrieveFieldOrElementCommon(state, R, R->getElementType(), superR); |
| } |
| |
| SVal RegionStoreManager::RetrieveField(const GRState* state, |
| const FieldRegion* R) { |
| |
| // Check if the region has a binding. |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| if (Optional<SVal> V = getDirectBinding(B, R)) |
| return *V; |
| |
| QualType Ty = R->getValueType(getContext()); |
| return RetrieveFieldOrElementCommon(state, R, Ty, R->getSuperRegion()); |
| } |
| |
| SVal RegionStoreManager::RetrieveFieldOrElementCommon(const GRState *state, |
| const TypedRegion *R, |
| QualType Ty, |
| const MemRegion *superR) { |
| |
| // At this point we have already checked in either RetrieveElement or |
| // RetrieveField if 'R' has a direct binding. |
| |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| |
| while (superR) { |
| if (const Optional<SVal> &D = getDefaultBinding(B, superR)) { |
| if (SymbolRef parentSym = D->getAsSymbol()) |
| return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R); |
| |
| if (D->isZeroConstant()) |
| return ValMgr.makeZeroVal(Ty); |
| |
| if (D->isUnknown()) |
| return *D; |
| |
| assert(0 && "Unknown default value"); |
| } |
| |
| // If our super region is a field or element itself, walk up the region |
| // hierarchy to see if there is a default value installed in an ancestor. |
| if (isa<FieldRegion>(superR) || isa<ElementRegion>(superR)) { |
| superR = cast<SubRegion>(superR)->getSuperRegion(); |
| continue; |
| } |
| |
| break; |
| } |
| |
| // Lazy binding? |
| const GRState *lazyBindingState = NULL; |
| const MemRegion *lazyBindingRegion = NULL; |
| llvm::tie(lazyBindingState, lazyBindingRegion) = GetLazyBinding(B, R); |
| |
| if (lazyBindingState) { |
| assert(lazyBindingRegion && "Lazy-binding region not set"); |
| |
| if (isa<ElementRegion>(R)) |
| return RetrieveElement(lazyBindingState, |
| cast<ElementRegion>(lazyBindingRegion)); |
| |
| return RetrieveField(lazyBindingState, |
| cast<FieldRegion>(lazyBindingRegion)); |
| } |
| |
| if (R->hasStackNonParametersStorage()) { |
| if (isa<ElementRegion>(R)) { |
| // Currently we don't reason specially about Clang-style vectors. Check |
| // if superR is a vector and if so return Unknown. |
| if (const TypedRegion *typedSuperR = dyn_cast<TypedRegion>(superR)) { |
| if (typedSuperR->getValueType(getContext())->isVectorType()) |
| return UnknownVal(); |
| } |
| } |
| |
| return UndefinedVal(); |
| } |
| |
| // All other values are symbolic. |
| return ValMgr.getRegionValueSymbolVal(R, Ty); |
| } |
| |
| SVal RegionStoreManager::RetrieveObjCIvar(const GRState* state, |
| const ObjCIvarRegion* R) { |
| |
| // Check if the region has a binding. |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| |
| if (Optional<SVal> V = getDirectBinding(B, R)) |
| return *V; |
| |
| const MemRegion *superR = R->getSuperRegion(); |
| |
| // Check if the super region has a default binding. |
| if (Optional<SVal> V = getDefaultBinding(B, superR)) { |
| if (SymbolRef parentSym = V->getAsSymbol()) |
| return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R); |
| |
| // Other cases: give up. |
| return UnknownVal(); |
| } |
| |
| return RetrieveLazySymbol(state, R); |
| } |
| |
| SVal RegionStoreManager::RetrieveVar(const GRState *state, |
| const VarRegion *R) { |
| |
| // Check if the region has a binding. |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| |
| if (Optional<SVal> V = getDirectBinding(B, R)) |
| return *V; |
| |
| // Lazily derive a value for the VarRegion. |
| const VarDecl *VD = R->getDecl(); |
| |
| if (R->hasGlobalsOrParametersStorage() || |
| isa<UnknownSpaceRegion>(R->getMemorySpace())) |
| return ValMgr.getRegionValueSymbolVal(R, VD->getType()); |
| |
| return UndefinedVal(); |
| } |
| |
| SVal RegionStoreManager::RetrieveLazySymbol(const GRState *state, |
| const TypedRegion *R) { |
| |
| QualType valTy = R->getValueType(getContext()); |
| |
| // All other values are symbolic. |
| return ValMgr.getRegionValueSymbolVal(R, valTy); |
| } |
| |
| SVal RegionStoreManager::RetrieveStruct(const GRState *state, |
| const TypedRegion* R) { |
| QualType T = R->getValueType(getContext()); |
| assert(T->isStructureType()); |
| |
| const RecordType* RT = T->getAsStructureType(); |
| RecordDecl* RD = RT->getDecl(); |
| assert(RD->isDefinition()); |
| (void)RD; |
| #if USE_EXPLICIT_COMPOUND |
| llvm::ImmutableList<SVal> StructVal = getBasicVals().getEmptySValList(); |
| |
| // FIXME: We shouldn't use a std::vector. If RecordDecl doesn't have a |
| // reverse iterator, we should implement one. |
| std::vector<FieldDecl *> Fields(RD->field_begin(), RD->field_end()); |
| |
| for (std::vector<FieldDecl *>::reverse_iterator Field = Fields.rbegin(), |
| FieldEnd = Fields.rend(); |
| Field != FieldEnd; ++Field) { |
| FieldRegion* FR = MRMgr.getFieldRegion(*Field, R); |
| QualType FTy = (*Field)->getType(); |
| SVal FieldValue = Retrieve(state, loc::MemRegionVal(FR), FTy).getSVal(); |
| StructVal = getBasicVals().consVals(FieldValue, StructVal); |
| } |
| |
| return ValMgr.makeCompoundVal(T, StructVal); |
| #else |
| return ValMgr.makeLazyCompoundVal(state, R); |
| #endif |
| } |
| |
| SVal RegionStoreManager::RetrieveArray(const GRState *state, |
| const TypedRegion * R) { |
| #if USE_EXPLICIT_COMPOUND |
| QualType T = R->getValueType(getContext()); |
| ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr()); |
| |
| llvm::ImmutableList<SVal> ArrayVal = getBasicVals().getEmptySValList(); |
| uint64_t size = CAT->getSize().getZExtValue(); |
| for (uint64_t i = 0; i < size; ++i) { |
| SVal Idx = ValMgr.makeArrayIndex(i); |
| ElementRegion* ER = MRMgr.getElementRegion(CAT->getElementType(), Idx, R, |
| getContext()); |
| QualType ETy = ER->getElementType(); |
| SVal ElementVal = Retrieve(state, loc::MemRegionVal(ER), ETy).getSVal(); |
| ArrayVal = getBasicVals().consVals(ElementVal, ArrayVal); |
| } |
| |
| return ValMgr.makeCompoundVal(T, ArrayVal); |
| #else |
| assert(isa<ConstantArrayType>(R->getValueType(getContext()))); |
| return ValMgr.makeLazyCompoundVal(state, R); |
| #endif |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Binding values to regions. |
| //===----------------------------------------------------------------------===// |
| |
| Store RegionStoreManager::Remove(Store store, Loc L) { |
| if (isa<loc::MemRegionVal>(L)) |
| if (const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion()) |
| return Remove(store, BindingKey::Make(R)); |
| |
| return store; |
| } |
| |
| const GRState *RegionStoreManager::Bind(const GRState *state, Loc L, SVal V) { |
| if (isa<loc::ConcreteInt>(L)) |
| return state; |
| |
| // If we get here, the location should be a region. |
| const MemRegion *R = cast<loc::MemRegionVal>(L).getRegion(); |
| |
| // Check if the region is a struct region. |
| if (const TypedRegion* TR = dyn_cast<TypedRegion>(R)) |
| if (TR->getValueType(getContext())->isStructureType()) |
| return BindStruct(state, TR, V); |
| |
| // Special case: the current region represents a cast and it and the super |
| // region both have pointer types or intptr_t types. If so, perform the |
| // bind to the super region. |
| // This is needed to support OSAtomicCompareAndSwap and friends or other |
| // loads that treat integers as pointers and vis versa. |
| if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) { |
| if (ER->getIndex().isZeroConstant()) { |
| if (const TypedRegion *superR = |
| dyn_cast<TypedRegion>(ER->getSuperRegion())) { |
| ASTContext &Ctx = getContext(); |
| QualType superTy = superR->getValueType(Ctx); |
| QualType erTy = ER->getValueType(Ctx); |
| |
| if (IsAnyPointerOrIntptr(superTy, Ctx) && |
| IsAnyPointerOrIntptr(erTy, Ctx)) { |
| SValuator::CastResult cr = |
| ValMgr.getSValuator().EvalCast(V, state, superTy, erTy); |
| return Bind(cr.getState(), loc::MemRegionVal(superR), cr.getSVal()); |
| } |
| // For now, just invalidate the fields of the struct/union/class. |
| // FIXME: Precisely handle the fields of the record. |
| if (superTy->isRecordType()) |
| return InvalidateRegion(state, superR, NULL, 0, NULL); |
| } |
| } |
| } |
| else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) { |
| // Binding directly to a symbolic region should be treated as binding |
| // to element 0. |
| QualType T = SR->getSymbol()->getType(getContext()); |
| |
| // FIXME: Is this the right way to handle symbols that are references? |
| if (const PointerType *PT = T->getAs<PointerType>()) |
| T = PT->getPointeeType(); |
| else |
| T = T->getAs<ReferenceType>()->getPointeeType(); |
| |
| R = GetElementZeroRegion(SR, T); |
| } |
| |
| // Perform the binding. |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| return state->makeWithStore(Add(B, R, |
| BindingVal(V, BindingVal::Direct)).getRoot()); |
| } |
| |
| const GRState *RegionStoreManager::BindDecl(const GRState *ST, |
| const VarRegion *VR, |
| SVal InitVal) { |
| |
| QualType T = VR->getDecl()->getType(); |
| |
| if (T->isArrayType()) |
| return BindArray(ST, VR, InitVal); |
| if (T->isStructureType()) |
| return BindStruct(ST, VR, InitVal); |
| |
| return Bind(ST, ValMgr.makeLoc(VR), InitVal); |
| } |
| |
| // FIXME: this method should be merged into Bind(). |
| const GRState * |
| RegionStoreManager::BindCompoundLiteral(const GRState *state, |
| const CompoundLiteralExpr *CL, |
| const LocationContext *LC, |
| SVal V) { |
| return Bind(state, loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)), |
| V); |
| } |
| |
| const GRState *RegionStoreManager::setImplicitDefaultValue(const GRState *state, |
| const MemRegion *R, |
| QualType T) { |
| Store store = state->getStore(); |
| RegionBindings B = GetRegionBindings(store); |
| SVal V; |
| |
| if (Loc::IsLocType(T)) |
| V = ValMgr.makeNull(); |
| else if (T->isIntegerType()) |
| V = ValMgr.makeZeroVal(T); |
| else if (T->isStructureType() || T->isArrayType()) { |
| // Set the default value to a zero constant when it is a structure |
| // or array. The type doesn't really matter. |
| V = ValMgr.makeZeroVal(ValMgr.getContext().IntTy); |
| } |
| else { |
| return state; |
| } |
| |
| return state->makeWithStore(Add(B, R, |
| BindingVal(V, BindingVal::Default)).getRoot()); |
| } |
| |
| const GRState *RegionStoreManager::BindArray(const GRState *state, |
| const TypedRegion* R, |
| SVal Init) { |
| |
| QualType T = R->getValueType(getContext()); |
| ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr()); |
| QualType ElementTy = CAT->getElementType(); |
| |
| uint64_t size = CAT->getSize().getZExtValue(); |
| |
| // Check if the init expr is a StringLiteral. |
| if (isa<loc::MemRegionVal>(Init)) { |
| const MemRegion* InitR = cast<loc::MemRegionVal>(Init).getRegion(); |
| const StringLiteral* S = cast<StringRegion>(InitR)->getStringLiteral(); |
| const char* str = S->getStrData(); |
| unsigned len = S->getByteLength(); |
| unsigned j = 0; |
| |
| // Copy bytes from the string literal into the target array. Trailing bytes |
| // in the array that are not covered by the string literal are initialized |
| // to zero. |
| for (uint64_t i = 0; i < size; ++i, ++j) { |
| if (j >= len) |
| break; |
| |
| SVal Idx = ValMgr.makeArrayIndex(i); |
| const ElementRegion* ER = MRMgr.getElementRegion(ElementTy, Idx, R, |
| getContext()); |
| |
| SVal V = ValMgr.makeIntVal(str[j], sizeof(char)*8, true); |
| state = Bind(state, loc::MemRegionVal(ER), V); |
| } |
| |
| return state; |
| } |
| |
| // Handle lazy compound values. |
| if (nonloc::LazyCompoundVal *LCV = dyn_cast<nonloc::LazyCompoundVal>(&Init)) |
| return CopyLazyBindings(*LCV, state, R); |
| |
| // Remaining case: explicit compound values. |
| |
| if (Init.isUnknown()) |
| return setImplicitDefaultValue(state, R, ElementTy); |
| |
| nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(Init); |
| nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end(); |
| uint64_t i = 0; |
| |
| for (; i < size; ++i, ++VI) { |
| // The init list might be shorter than the array length. |
| if (VI == VE) |
| break; |
| |
| SVal Idx = ValMgr.makeArrayIndex(i); |
| const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, getContext()); |
| |
| if (CAT->getElementType()->isStructureType()) |
| state = BindStruct(state, ER, *VI); |
| else |
| // FIXME: Do we need special handling of nested arrays? |
| state = Bind(state, ValMgr.makeLoc(ER), *VI); |
| } |
| |
| // If the init list is shorter than the array length, set the |
| // array default value. |
| if (i < size) |
| state = setImplicitDefaultValue(state, R, ElementTy); |
| |
| return state; |
| } |
| |
| const GRState * |
| RegionStoreManager::BindStruct(const GRState *state, const TypedRegion* R, |
| SVal V) { |
| |
| if (!Features.supportsFields()) |
| return state; |
| |
| QualType T = R->getValueType(getContext()); |
| assert(T->isStructureType()); |
| |
| const RecordType* RT = T->getAs<RecordType>(); |
| RecordDecl* RD = RT->getDecl(); |
| |
| if (!RD->isDefinition()) |
| return state; |
| |
| // Handle lazy compound values. |
| if (const nonloc::LazyCompoundVal *LCV=dyn_cast<nonloc::LazyCompoundVal>(&V)) |
| return CopyLazyBindings(*LCV, state, R); |
| |
| // We may get non-CompoundVal accidentally due to imprecise cast logic. |
| // Ignore them and kill the field values. |
| if (V.isUnknown() || !isa<nonloc::CompoundVal>(V)) |
| return state->makeWithStore(KillStruct(state->getStore(), R)); |
| |
| nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(V); |
| nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end(); |
| |
| RecordDecl::field_iterator FI, FE; |
| |
| for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI, ++VI) { |
| |
| if (VI == VE) |
| break; |
| |
| QualType FTy = (*FI)->getType(); |
| const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R); |
| |
| if (FTy->isArrayType()) |
| state = BindArray(state, FR, *VI); |
| else if (FTy->isStructureType()) |
| state = BindStruct(state, FR, *VI); |
| else |
| state = Bind(state, ValMgr.makeLoc(FR), *VI); |
| } |
| |
| // There may be fewer values in the initialize list than the fields of struct. |
| if (FI != FE) { |
| Store store = state->getStore(); |
| RegionBindings B = GetRegionBindings(store); |
| B = Add(B, R, BindingVal(ValMgr.makeIntVal(0, false), BindingVal::Default)); |
| state = state->makeWithStore(B.getRoot()); |
| } |
| |
| return state; |
| } |
| |
| Store RegionStoreManager::KillStruct(Store store, const TypedRegion* R) { |
| RegionBindings B = GetRegionBindings(store); |
| llvm::OwningPtr<RegionStoreSubRegionMap> |
| SubRegions(getRegionStoreSubRegionMap(store)); |
| RemoveSubRegionBindings(B, R, *SubRegions); |
| |
| // Set the default value of the struct region to "unknown". |
| B = Add(B, R, BindingVal(UnknownVal(), BindingVal::Default)); |
| |
| return B.getRoot(); |
| } |
| |
| const GRState* |
| RegionStoreManager::CopyLazyBindings(nonloc::LazyCompoundVal V, |
| const GRState *state, |
| const TypedRegion *R) { |
| |
| // Nuke the old bindings stemming from R. |
| RegionBindings B = GetRegionBindings(state->getStore()); |
| |
| llvm::OwningPtr<RegionStoreSubRegionMap> |
| SubRegions(getRegionStoreSubRegionMap(state->getStore())); |
| |
| // B and DVM are updated after the call to RemoveSubRegionBindings. |
| RemoveSubRegionBindings(B, R, *SubRegions.get()); |
| |
| // Now copy the bindings. This amounts to just binding 'V' to 'R'. This |
| // results in a zero-copy algorithm. |
| return state->makeWithStore(Add(B, R, |
| BindingVal(V, BindingVal::Direct)).getRoot()); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // "Raw" retrievals and bindings. |
| //===----------------------------------------------------------------------===// |
| |
| BindingKey BindingKey::Make(const MemRegion *R) { |
| if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) { |
| const RegionRawOffset &O = ER->getAsRawOffset(); |
| |
| if (O.getRegion()) |
| return BindingKey(O.getRegion(), O.getByteOffset()); |
| |
| // FIXME: There are some ElementRegions for which we cannot compute |
| // raw offsets yet, including regions with symbolic offsets. |
| } |
| |
| return BindingKey(R, 0); |
| } |
| |
| RegionBindings RegionStoreManager::Add(RegionBindings B, BindingKey K, |
| BindingVal V) { |
| return RBFactory.Add(B, K, V); |
| } |
| |
| RegionBindings RegionStoreManager::Add(RegionBindings B, const MemRegion *R, |
| BindingVal V) { |
| return Add(B, BindingKey::Make(R), V); |
| } |
| |
| const BindingVal *RegionStoreManager::Lookup(RegionBindings B, BindingKey K) { |
| return B.lookup(K); |
| } |
| |
| const BindingVal *RegionStoreManager::Lookup(RegionBindings B, |
| const MemRegion *R) { |
| return Lookup(B, BindingKey::Make(R)); |
| } |
| |
| RegionBindings RegionStoreManager::Remove(RegionBindings B, BindingKey K) { |
| return RBFactory.Remove(B, K); |
| } |
| |
| RegionBindings RegionStoreManager::Remove(RegionBindings B, const MemRegion *R){ |
| return Remove(B, BindingKey::Make(R)); |
| } |
| |
| Store RegionStoreManager::Remove(Store store, BindingKey K) { |
| RegionBindings B = GetRegionBindings(store); |
| return Remove(B, K).getRoot(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // State pruning. |
| //===----------------------------------------------------------------------===// |
| |
| void RegionStoreManager::RemoveDeadBindings(GRState &state, Stmt* Loc, |
| SymbolReaper& SymReaper, |
| llvm::SmallVectorImpl<const MemRegion*>& RegionRoots) |
| { |
| typedef std::pair<const GRState*, const MemRegion *> RBDNode; |
| |
| Store store = state.getStore(); |
| RegionBindings B = GetRegionBindings(store); |
| |
| // The backmap from regions to subregions. |
| llvm::OwningPtr<RegionStoreSubRegionMap> |
| SubRegions(getRegionStoreSubRegionMap(store)); |
| |
| // Do a pass over the regions in the store. For VarRegions we check if |
| // the variable is still live and if so add it to the list of live roots. |
| // For other regions we populate our region backmap. |
| llvm::SmallVector<const MemRegion*, 10> IntermediateRoots; |
| |
| // Scan the direct bindings for "intermediate" roots. |
| for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| const MemRegion *R = I.getKey().getRegion(); |
| IntermediateRoots.push_back(R); |
| } |
| |
| // Process the "intermediate" roots to find if they are referenced by |
| // real roots. |
| llvm::SmallVector<RBDNode, 10> WorkList; |
| llvm::SmallVector<RBDNode, 10> Postponed; |
| |
| llvm::DenseSet<const MemRegion*> IntermediateVisited; |
| |
| while (!IntermediateRoots.empty()) { |
| const MemRegion* R = IntermediateRoots.back(); |
| IntermediateRoots.pop_back(); |
| |
| if (IntermediateVisited.count(R)) |
| continue; |
| IntermediateVisited.insert(R); |
| |
| if (const VarRegion* VR = dyn_cast<VarRegion>(R)) { |
| if (SymReaper.isLive(Loc, VR)) |
| WorkList.push_back(std::make_pair(&state, VR)); |
| continue; |
| } |
| |
| if (const SymbolicRegion* SR = dyn_cast<SymbolicRegion>(R)) { |
| llvm::SmallVectorImpl<RBDNode> &Q = |
| SymReaper.isLive(SR->getSymbol()) ? WorkList : Postponed; |
| |
| Q.push_back(std::make_pair(&state, SR)); |
| |
| continue; |
| } |
| |
| // Add the super region for R to the worklist if it is a subregion. |
| if (const SubRegion* superR = |
| dyn_cast<SubRegion>(cast<SubRegion>(R)->getSuperRegion())) |
| IntermediateRoots.push_back(superR); |
| } |
| |
| // Enqueue the RegionRoots onto WorkList. |
| for (llvm::SmallVectorImpl<const MemRegion*>::iterator I=RegionRoots.begin(), |
| E=RegionRoots.end(); I!=E; ++I) { |
| WorkList.push_back(std::make_pair(&state, *I)); |
| } |
| RegionRoots.clear(); |
| |
| llvm::DenseSet<RBDNode> Visited; |
| |
| tryAgain: |
| while (!WorkList.empty()) { |
| RBDNode N = WorkList.back(); |
| WorkList.pop_back(); |
| |
| // Have we visited this node before? |
| if (Visited.count(N)) |
| continue; |
| Visited.insert(N); |
| |
| const MemRegion *R = N.second; |
| const GRState *state_N = N.first; |
| |
| // Enqueue subregions. |
| RegionStoreSubRegionMap *M; |
| |
| if (&state == state_N) |
| M = SubRegions.get(); |
| else { |
| RegionStoreSubRegionMap *& SM = SC[state_N]; |
| if (!SM) |
| SM = getRegionStoreSubRegionMap(state_N->getStore()); |
| M = SM; |
| } |
| |
| RegionStoreSubRegionMap::iterator I, E; |
| for (llvm::tie(I, E) = M->begin_end(R); I != E; ++I) |
| WorkList.push_back(std::make_pair(state_N, *I)); |
| |
| // Enqueue the super region. |
| if (const SubRegion *SR = dyn_cast<SubRegion>(R)) { |
| const MemRegion *superR = SR->getSuperRegion(); |
| if (!isa<MemSpaceRegion>(superR)) { |
| // If 'R' is a field or an element, we want to keep the bindings |
| // for the other fields and elements around. The reason is that |
| // pointer arithmetic can get us to the other fields or elements. |
| assert(isa<FieldRegion>(R) || isa<ElementRegion>(R) |
| || isa<ObjCIvarRegion>(R)); |
| WorkList.push_back(std::make_pair(state_N, superR)); |
| } |
| } |
| |
| // Mark the symbol for any live SymbolicRegion as "live". This means we |
| // should continue to track that symbol. |
| if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(R)) |
| SymReaper.markLive(SymR->getSymbol()); |
| |
| // For BlockDataRegions, enqueue the VarRegions for variables marked |
| // with __block (passed-by-reference). |
| // via BlockDeclRefExprs. |
| if (const BlockDataRegion *BD = dyn_cast<BlockDataRegion>(R)) { |
| for (BlockDataRegion::referenced_vars_iterator |
| RI = BD->referenced_vars_begin(), RE = BD->referenced_vars_end(); |
| RI != RE; ++RI) { |
| if ((*RI)->getDecl()->getAttr<BlocksAttr>()) |
| WorkList.push_back(std::make_pair(state_N, *RI)); |
| } |
| // No possible data bindings on a BlockDataRegion. Continue to the |
| // next region in the worklist. |
| continue; |
| } |
| |
| Store store_N = state_N->getStore(); |
| RegionBindings B_N = GetRegionBindings(store_N); |
| |
| // Get the data binding for R (if any). |
| Optional<SVal> V = getBinding(B_N, R); |
| |
| if (V) { |
| // Check for lazy bindings. |
| if (const nonloc::LazyCompoundVal *LCV = |
| dyn_cast<nonloc::LazyCompoundVal>(V.getPointer())) { |
| |
| const LazyCompoundValData *D = LCV->getCVData(); |
| WorkList.push_back(std::make_pair(D->getState(), D->getRegion())); |
| } |
| else { |
| // Update the set of live symbols. |
| for (SVal::symbol_iterator SI=V->symbol_begin(), SE=V->symbol_end(); |
| SI!=SE;++SI) |
| SymReaper.markLive(*SI); |
| |
| // If V is a region, then add it to the worklist. |
| if (const MemRegion *RX = V->getAsRegion()) |
| WorkList.push_back(std::make_pair(state_N, RX)); |
| } |
| } |
| } |
| |
| // See if any postponed SymbolicRegions are actually live now, after |
| // having done a scan. |
| for (llvm::SmallVectorImpl<RBDNode>::iterator I = Postponed.begin(), |
| E = Postponed.end() ; I != E ; ++I) { |
| if (const SymbolicRegion *SR = cast_or_null<SymbolicRegion>(I->second)) { |
| if (SymReaper.isLive(SR->getSymbol())) { |
| WorkList.push_back(*I); |
| I->second = NULL; |
| } |
| } |
| } |
| |
| if (!WorkList.empty()) |
| goto tryAgain; |
| |
| // We have now scanned the store, marking reachable regions and symbols |
| // as live. We now remove all the regions that are dead from the store |
| // as well as update DSymbols with the set symbols that are now dead. |
| for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| const MemRegion* R = I.getKey().getRegion(); |
| // If this region live? Is so, none of its symbols are dead. |
| if (Visited.count(std::make_pair(&state, R))) |
| continue; |
| |
| // Remove this dead region from the store. |
| store = Remove(store, I.getKey()); |
| |
| // Mark all non-live symbols that this region references as dead. |
| if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(R)) |
| SymReaper.maybeDead(SymR->getSymbol()); |
| |
| SVal X = *I.getData().getValue(); |
| SVal::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end(); |
| for (; SI != SE; ++SI) |
| SymReaper.maybeDead(*SI); |
| } |
| |
| // Write the store back. |
| state.setStore(store); |
| } |
| |
| GRState const *RegionStoreManager::EnterStackFrame(GRState const *state, |
| StackFrameContext const *frame) { |
| FunctionDecl const *FD = cast<FunctionDecl>(frame->getDecl()); |
| CallExpr const *CE = cast<CallExpr>(frame->getCallSite()); |
| |
| FunctionDecl::param_const_iterator PI = FD->param_begin(); |
| |
| CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end(); |
| |
| // Copy the arg expression value to the arg variables. |
| for (; AI != AE; ++AI, ++PI) { |
| SVal ArgVal = state->getSVal(*AI); |
| state = Bind(state, ValMgr.makeLoc(MRMgr.getVarRegion(*PI, frame)), ArgVal); |
| } |
| |
| return state; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Utility methods. |
| //===----------------------------------------------------------------------===// |
| |
| void RegionStoreManager::print(Store store, llvm::raw_ostream& OS, |
| const char* nl, const char *sep) { |
| RegionBindings B = GetRegionBindings(store); |
| OS << "Store (direct and default bindings):" << nl; |
| |
| for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) |
| OS << ' ' << I.getKey() << " : " << I.getData() << nl; |
| } |