1//== Store.h - Interface for maps from Locations to Values ------*- C++ -*--==// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defined the types Store and StoreManager. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_CLANG_GR_STORE_H 15#define LLVM_CLANG_GR_STORE_H 16 17#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" 18#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h" 19#include "clang/StaticAnalyzer/Core/PathSensitive/StoreRef.h" 20#include "llvm/ADT/DenseSet.h" 21#include "llvm/ADT/Optional.h" 22 23namespace clang { 24 25class Stmt; 26class Expr; 27class ObjCIvarDecl; 28class CXXBasePath; 29class StackFrameContext; 30 31namespace ento { 32 33class CallEvent; 34class ProgramState; 35class ProgramStateManager; 36class ScanReachableSymbols; 37 38typedef llvm::DenseSet<SymbolRef> InvalidatedSymbols; 39 40class StoreManager { 41protected: 42 SValBuilder &svalBuilder; 43 ProgramStateManager &StateMgr; 44 45 /// MRMgr - Manages region objects associated with this StoreManager. 46 MemRegionManager &MRMgr; 47 ASTContext &Ctx; 48 49 StoreManager(ProgramStateManager &stateMgr); 50 51public: 52 virtual ~StoreManager() {} 53 54 /// Return the value bound to specified location in a given state. 55 /// \param[in] store The analysis state. 56 /// \param[in] loc The symbolic memory location. 57 /// \param[in] T An optional type that provides a hint indicating the 58 /// expected type of the returned value. This is used if the value is 59 /// lazily computed. 60 /// \return The value bound to the location \c loc. 61 virtual SVal getBinding(Store store, Loc loc, QualType T = QualType()) = 0; 62 63 /// Return a state with the specified value bound to the given location. 64 /// \param[in] store The analysis state. 65 /// \param[in] loc The symbolic memory location. 66 /// \param[in] val The value to bind to location \c loc. 67 /// \return A pointer to a ProgramState object that contains the same 68 /// bindings as \c state with the addition of having the value specified 69 /// by \c val bound to the location given for \c loc. 70 virtual StoreRef Bind(Store store, Loc loc, SVal val) = 0; 71 72 virtual StoreRef BindDefault(Store store, const MemRegion *R, SVal V); 73 74 /// \brief Create a new store with the specified binding removed. 75 /// \param ST the original store, that is the basis for the new store. 76 /// \param L the location whose binding should be removed. 77 virtual StoreRef killBinding(Store ST, Loc L) = 0; 78 79 /// getInitialStore - Returns the initial "empty" store representing the 80 /// value bindings upon entry to an analyzed function. 81 virtual StoreRef getInitialStore(const LocationContext *InitLoc) = 0; 82 83 /// getRegionManager - Returns the internal RegionManager object that is 84 /// used to query and manipulate MemRegion objects. 85 MemRegionManager& getRegionManager() { return MRMgr; } 86 87 virtual Loc getLValueVar(const VarDecl *VD, const LocationContext *LC) { 88 return svalBuilder.makeLoc(MRMgr.getVarRegion(VD, LC)); 89 } 90 91 Loc getLValueCompoundLiteral(const CompoundLiteralExpr *CL, 92 const LocationContext *LC) { 93 return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)); 94 } 95 96 virtual SVal getLValueIvar(const ObjCIvarDecl *decl, SVal base); 97 98 virtual SVal getLValueField(const FieldDecl *D, SVal Base) { 99 return getLValueFieldOrIvar(D, Base); 100 } 101 102 virtual SVal getLValueElement(QualType elementType, NonLoc offset, SVal Base); 103 104 // FIXME: This should soon be eliminated altogether; clients should deal with 105 // region extents directly. 106 virtual DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state, 107 const MemRegion *region, 108 QualType EleTy) { 109 return UnknownVal(); 110 } 111 112 /// ArrayToPointer - Used by ExprEngine::VistCast to handle implicit 113 /// conversions between arrays and pointers. 114 virtual SVal ArrayToPointer(Loc Array, QualType ElementTy) = 0; 115 116 /// Evaluates a chain of derived-to-base casts through the path specified in 117 /// \p Cast. 118 SVal evalDerivedToBase(SVal Derived, const CastExpr *Cast); 119 120 /// Evaluates a chain of derived-to-base casts through the specified path. 121 SVal evalDerivedToBase(SVal Derived, const CXXBasePath &CastPath); 122 123 /// Evaluates a derived-to-base cast through a single level of derivation. 124 SVal evalDerivedToBase(SVal Derived, QualType DerivedPtrType, 125 bool IsVirtual); 126 127 /// \brief Evaluates C++ dynamic_cast cast. 128 /// The callback may result in the following 3 scenarios: 129 /// - Successful cast (ex: derived is subclass of base). 130 /// - Failed cast (ex: derived is definitely not a subclass of base). 131 /// - We don't know (base is a symbolic region and we don't have 132 /// enough info to determine if the cast will succeed at run time). 133 /// The function returns an SVal representing the derived class; it's 134 /// valid only if Failed flag is set to false. 135 SVal evalDynamicCast(SVal Base, QualType DerivedPtrType, bool &Failed); 136 137 const ElementRegion *GetElementZeroRegion(const MemRegion *R, QualType T); 138 139 /// castRegion - Used by ExprEngine::VisitCast to handle casts from 140 /// a MemRegion* to a specific location type. 'R' is the region being 141 /// casted and 'CastToTy' the result type of the cast. 142 const MemRegion *castRegion(const MemRegion *region, QualType CastToTy); 143 144 virtual StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx, 145 SymbolReaper& SymReaper) = 0; 146 147 virtual bool includedInBindings(Store store, 148 const MemRegion *region) const = 0; 149 150 /// If the StoreManager supports it, increment the reference count of 151 /// the specified Store object. 152 virtual void incrementReferenceCount(Store store) {} 153 154 /// If the StoreManager supports it, decrement the reference count of 155 /// the specified Store object. If the reference count hits 0, the memory 156 /// associated with the object is recycled. 157 virtual void decrementReferenceCount(Store store) {} 158 159 typedef SmallVector<const MemRegion *, 8> InvalidatedRegions; 160 161 /// invalidateRegions - Clears out the specified regions from the store, 162 /// marking their values as unknown. Depending on the store, this may also 163 /// invalidate additional regions that may have changed based on accessing 164 /// the given regions. Optionally, invalidates non-static globals as well. 165 /// \param[in] store The initial store 166 /// \param[in] Values The values to invalidate. 167 /// \param[in] E The current statement being evaluated. Used to conjure 168 /// symbols to mark the values of invalidated regions. 169 /// \param[in] Count The current block count. Used to conjure 170 /// symbols to mark the values of invalidated regions. 171 /// \param[in] Call The call expression which will be used to determine which 172 /// globals should get invalidated. 173 /// \param[in,out] IS A set to fill with any symbols that are no longer 174 /// accessible. Pass \c NULL if this information will not be used. 175 /// \param[in] ITraits Information about invalidation for a particular 176 /// region/symbol. 177 /// \param[in,out] InvalidatedTopLevel A vector to fill with regions 178 //// explicitly being invalidated. Pass \c NULL if this 179 /// information will not be used. 180 /// \param[in,out] Invalidated A vector to fill with any regions being 181 /// invalidated. This should include any regions explicitly invalidated 182 /// even if they do not currently have bindings. Pass \c NULL if this 183 /// information will not be used. 184 virtual StoreRef invalidateRegions(Store store, 185 ArrayRef<SVal> Values, 186 const Expr *E, unsigned Count, 187 const LocationContext *LCtx, 188 const CallEvent *Call, 189 InvalidatedSymbols &IS, 190 RegionAndSymbolInvalidationTraits &ITraits, 191 InvalidatedRegions *InvalidatedTopLevel, 192 InvalidatedRegions *Invalidated) = 0; 193 194 /// enterStackFrame - Let the StoreManager to do something when execution 195 /// engine is about to execute into a callee. 196 StoreRef enterStackFrame(Store store, 197 const CallEvent &Call, 198 const StackFrameContext *CalleeCtx); 199 200 /// Finds the transitive closure of symbols within the given region. 201 /// 202 /// Returns false if the visitor aborted the scan. 203 virtual bool scanReachableSymbols(Store S, const MemRegion *R, 204 ScanReachableSymbols &Visitor) = 0; 205 206 virtual void print(Store store, raw_ostream &Out, 207 const char* nl, const char *sep) = 0; 208 209 class BindingsHandler { 210 public: 211 virtual ~BindingsHandler(); 212 virtual bool HandleBinding(StoreManager& SMgr, Store store, 213 const MemRegion *region, SVal val) = 0; 214 }; 215 216 class FindUniqueBinding : 217 public BindingsHandler { 218 SymbolRef Sym; 219 const MemRegion* Binding; 220 bool First; 221 222 public: 223 FindUniqueBinding(SymbolRef sym) 224 : Sym(sym), Binding(nullptr), First(true) {} 225 226 bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R, 227 SVal val) override; 228 LLVM_EXPLICIT operator bool() { return First && Binding; } 229 const MemRegion *getRegion() { return Binding; } 230 }; 231 232 /// iterBindings - Iterate over the bindings in the Store. 233 virtual void iterBindings(Store store, BindingsHandler& f) = 0; 234 235protected: 236 const MemRegion *MakeElementRegion(const MemRegion *baseRegion, 237 QualType pointeeTy, uint64_t index = 0); 238 239 /// CastRetrievedVal - Used by subclasses of StoreManager to implement 240 /// implicit casts that arise from loads from regions that are reinterpreted 241 /// as another region. 242 SVal CastRetrievedVal(SVal val, const TypedValueRegion *region, 243 QualType castTy, bool performTestOnly = true); 244 245private: 246 SVal getLValueFieldOrIvar(const Decl *decl, SVal base); 247}; 248 249 250inline StoreRef::StoreRef(Store store, StoreManager & smgr) 251 : store(store), mgr(smgr) { 252 if (store) 253 mgr.incrementReferenceCount(store); 254} 255 256inline StoreRef::StoreRef(const StoreRef &sr) 257 : store(sr.store), mgr(sr.mgr) 258{ 259 if (store) 260 mgr.incrementReferenceCount(store); 261} 262 263inline StoreRef::~StoreRef() { 264 if (store) 265 mgr.decrementReferenceCount(store); 266} 267 268inline StoreRef &StoreRef::operator=(StoreRef const &newStore) { 269 assert(&newStore.mgr == &mgr); 270 if (store != newStore.store) { 271 mgr.incrementReferenceCount(newStore.store); 272 mgr.decrementReferenceCount(store); 273 store = newStore.getStore(); 274 } 275 return *this; 276} 277 278// FIXME: Do we need to pass ProgramStateManager anymore? 279StoreManager *CreateRegionStoreManager(ProgramStateManager& StMgr); 280StoreManager *CreateFieldsOnlyRegionStoreManager(ProgramStateManager& StMgr); 281 282} // end GR namespace 283 284} // end clang namespace 285 286#endif 287