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 23 namespace clang { 24 25 class Stmt; 26 class Expr; 27 class ObjCIvarDecl; 28 class CXXBasePath; 29 class StackFrameContext; 30 31 namespace ento { 32 33 class CallEvent; 34 class ProgramState; 35 class ProgramStateManager; 36 class ScanReachableSymbols; 37 38 typedef llvm::DenseSet<SymbolRef> InvalidatedSymbols; 39 40 class StoreManager { 41 protected: 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 51 public: 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 /// \brief Create a new store that binds a value to a compound literal. 80 /// 81 /// \param ST The original store whose bindings are the basis for the new 82 /// store. 83 /// 84 /// \param CL The compound literal to bind (the binding key). 85 /// 86 /// \param LC The LocationContext for the binding. 87 /// 88 /// \param V The value to bind to the compound literal. 89 virtual StoreRef bindCompoundLiteral(Store ST, 90 const CompoundLiteralExpr *CL, 91 const LocationContext *LC, 92 SVal V) = 0; 93 94 /// getInitialStore - Returns the initial "empty" store representing the 95 /// value bindings upon entry to an analyzed function. 96 virtual StoreRef getInitialStore(const LocationContext *InitLoc) = 0; 97 98 /// getRegionManager - Returns the internal RegionManager object that is 99 /// used to query and manipulate MemRegion objects. 100 MemRegionManager& getRegionManager() { return MRMgr; } 101 102 virtual Loc getLValueVar(const VarDecl *VD, const LocationContext *LC) { 103 return svalBuilder.makeLoc(MRMgr.getVarRegion(VD, LC)); 104 } 105 106 Loc getLValueCompoundLiteral(const CompoundLiteralExpr *CL, 107 const LocationContext *LC) { 108 return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)); 109 } 110 111 virtual SVal getLValueIvar(const ObjCIvarDecl *decl, SVal base); 112 113 virtual SVal getLValueField(const FieldDecl *D, SVal Base) { 114 return getLValueFieldOrIvar(D, Base); 115 } 116 117 virtual SVal getLValueElement(QualType elementType, NonLoc offset, SVal Base); 118 119 // FIXME: This should soon be eliminated altogether; clients should deal with 120 // region extents directly. 121 virtual DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state, 122 const MemRegion *region, 123 QualType EleTy) { 124 return UnknownVal(); 125 } 126 127 /// ArrayToPointer - Used by ExprEngine::VistCast to handle implicit 128 /// conversions between arrays and pointers. 129 virtual SVal ArrayToPointer(Loc Array) = 0; 130 131 /// Evaluates a chain of derived-to-base casts through the path specified in 132 /// \p Cast. 133 SVal evalDerivedToBase(SVal Derived, const CastExpr *Cast); 134 135 /// Evaluates a chain of derived-to-base casts through the specified path. 136 SVal evalDerivedToBase(SVal Derived, const CXXBasePath &CastPath); 137 138 /// Evaluates a derived-to-base cast through a single level of derivation. 139 SVal evalDerivedToBase(SVal Derived, QualType DerivedPtrType, 140 bool IsVirtual); 141 142 /// \brief Evaluates C++ dynamic_cast cast. 143 /// The callback may result in the following 3 scenarios: 144 /// - Successful cast (ex: derived is subclass of base). 145 /// - Failed cast (ex: derived is definitely not a subclass of base). 146 /// - We don't know (base is a symbolic region and we don't have 147 /// enough info to determine if the cast will succeed at run time). 148 /// The function returns an SVal representing the derived class; it's 149 /// valid only if Failed flag is set to false. 150 SVal evalDynamicCast(SVal Base, QualType DerivedPtrType, bool &Failed); 151 152 const ElementRegion *GetElementZeroRegion(const MemRegion *R, QualType T); 153 154 /// castRegion - Used by ExprEngine::VisitCast to handle casts from 155 /// a MemRegion* to a specific location type. 'R' is the region being 156 /// casted and 'CastToTy' the result type of the cast. 157 const MemRegion *castRegion(const MemRegion *region, QualType CastToTy); 158 159 virtual StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx, 160 SymbolReaper& SymReaper) = 0; 161 162 virtual bool includedInBindings(Store store, 163 const MemRegion *region) const = 0; 164 165 /// If the StoreManager supports it, increment the reference count of 166 /// the specified Store object. 167 virtual void incrementReferenceCount(Store store) {} 168 169 /// If the StoreManager supports it, decrement the reference count of 170 /// the specified Store object. If the reference count hits 0, the memory 171 /// associated with the object is recycled. 172 virtual void decrementReferenceCount(Store store) {} 173 174 typedef SmallVector<const MemRegion *, 8> InvalidatedRegions; 175 176 /// invalidateRegions - Clears out the specified regions from the store, 177 /// marking their values as unknown. Depending on the store, this may also 178 /// invalidate additional regions that may have changed based on accessing 179 /// the given regions. Optionally, invalidates non-static globals as well. 180 /// \param[in] store The initial store 181 /// \param[in] Regions The regions to invalidate. 182 /// \param[in] E The current statement being evaluated. Used to conjure 183 /// symbols to mark the values of invalidated regions. 184 /// \param[in] Count The current block count. Used to conjure 185 /// symbols to mark the values of invalidated regions. 186 /// \param[in,out] IS A set to fill with any symbols that are no longer 187 /// accessible. Pass \c NULL if this information will not be used. 188 /// \param[in] Call The call expression which will be used to determine which 189 /// globals should get invalidated. 190 /// \param[in,out] Invalidated A vector to fill with any regions being 191 /// invalidated. This should include any regions explicitly invalidated 192 /// even if they do not currently have bindings. Pass \c NULL if this 193 /// information will not be used. 194 virtual StoreRef invalidateRegions(Store store, 195 ArrayRef<const MemRegion *> Regions, 196 const Expr *E, unsigned Count, 197 const LocationContext *LCtx, 198 InvalidatedSymbols &IS, 199 const CallEvent *Call, 200 InvalidatedRegions *Invalidated) = 0; 201 202 /// enterStackFrame - Let the StoreManager to do something when execution 203 /// engine is about to execute into a callee. 204 StoreRef enterStackFrame(Store store, 205 const CallEvent &Call, 206 const StackFrameContext *CalleeCtx); 207 208 /// Finds the transitive closure of symbols within the given region. 209 /// 210 /// Returns false if the visitor aborted the scan. 211 virtual bool scanReachableSymbols(Store S, const MemRegion *R, 212 ScanReachableSymbols &Visitor) = 0; 213 214 virtual void print(Store store, raw_ostream &Out, 215 const char* nl, const char *sep) = 0; 216 217 class BindingsHandler { 218 public: 219 virtual ~BindingsHandler(); 220 virtual bool HandleBinding(StoreManager& SMgr, Store store, 221 const MemRegion *region, SVal val) = 0; 222 }; 223 224 class FindUniqueBinding : 225 public BindingsHandler { 226 SymbolRef Sym; 227 const MemRegion* Binding; 228 bool First; 229 230 public: 231 FindUniqueBinding(SymbolRef sym) : Sym(sym), Binding(0), First(true) {} 232 233 bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R, 234 SVal val); 235 operator bool() { return First && Binding; } 236 const MemRegion *getRegion() { return Binding; } 237 }; 238 239 /// iterBindings - Iterate over the bindings in the Store. 240 virtual void iterBindings(Store store, BindingsHandler& f) = 0; 241 242 protected: 243 const MemRegion *MakeElementRegion(const MemRegion *baseRegion, 244 QualType pointeeTy, uint64_t index = 0); 245 246 /// CastRetrievedVal - Used by subclasses of StoreManager to implement 247 /// implicit casts that arise from loads from regions that are reinterpreted 248 /// as another region. 249 SVal CastRetrievedVal(SVal val, const TypedValueRegion *region, 250 QualType castTy, bool performTestOnly = true); 251 252 private: 253 SVal getLValueFieldOrIvar(const Decl *decl, SVal base); 254 }; 255 256 257 inline StoreRef::StoreRef(Store store, StoreManager & smgr) 258 : store(store), mgr(smgr) { 259 if (store) 260 mgr.incrementReferenceCount(store); 261 } 262 263 inline StoreRef::StoreRef(const StoreRef &sr) 264 : store(sr.store), mgr(sr.mgr) 265 { 266 if (store) 267 mgr.incrementReferenceCount(store); 268 } 269 270 inline StoreRef::~StoreRef() { 271 if (store) 272 mgr.decrementReferenceCount(store); 273 } 274 275 inline StoreRef &StoreRef::operator=(StoreRef const &newStore) { 276 assert(&newStore.mgr == &mgr); 277 if (store != newStore.store) { 278 mgr.incrementReferenceCount(newStore.store); 279 mgr.decrementReferenceCount(store); 280 store = newStore.getStore(); 281 } 282 return *this; 283 } 284 285 // FIXME: Do we need to pass ProgramStateManager anymore? 286 StoreManager *CreateRegionStoreManager(ProgramStateManager& StMgr); 287 StoreManager *CreateFieldsOnlyRegionStoreManager(ProgramStateManager& StMgr); 288 289 } // end GR namespace 290 291 } // end clang namespace 292 293 #endif 294