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 /// 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] ConstValues The values to invalidate; these are known to be 168 /// const, so only regions accesible from them should be invalidated. 169 /// \param[in] E The current statement being evaluated. Used to conjure 170 /// symbols to mark the values of invalidated regions. 171 /// \param[in] Count The current block count. Used to conjure 172 /// symbols to mark the values of invalidated regions. 173 /// \param[in] Call The call expression which will be used to determine which 174 /// globals should get invalidated. 175 /// \param[in,out] IS A set to fill with any symbols that are no longer 176 /// accessible. Pass \c NULL if this information will not be used. 177 /// \param[in,out] ConstIS A set to fill with any symbols corresponding to 178 /// the ConstValues. 179 /// \param[in,out] InvalidatedTopLevel A vector to fill with regions 180 //// explicitely being invalidated. Pass \c NULL if this 181 /// information will not be used. 182 /// \param[in,out] InvalidatedTopLevelConst A vector to fill with const 183 //// regions explicitely being invalidated. Pass \c NULL if this 184 /// information will not be used. 185 /// \param[in,out] Invalidated A vector to fill with any regions being 186 /// invalidated. This should include any regions explicitly invalidated 187 /// even if they do not currently have bindings. Pass \c NULL if this 188 /// information will not be used. 189 virtual StoreRef invalidateRegions(Store store, 190 ArrayRef<SVal> Values, 191 ArrayRef<SVal> ConstValues, 192 const Expr *E, unsigned Count, 193 const LocationContext *LCtx, 194 const CallEvent *Call, 195 InvalidatedSymbols &IS, 196 InvalidatedSymbols &ConstIS, 197 InvalidatedRegions *InvalidatedTopLevel, 198 InvalidatedRegions *InvalidatedTopLevelConst, 199 InvalidatedRegions *Invalidated) = 0; 200 201 /// enterStackFrame - Let the StoreManager to do something when execution 202 /// engine is about to execute into a callee. 203 StoreRef enterStackFrame(Store store, 204 const CallEvent &Call, 205 const StackFrameContext *CalleeCtx); 206 207 /// Finds the transitive closure of symbols within the given region. 208 /// 209 /// Returns false if the visitor aborted the scan. 210 virtual bool scanReachableSymbols(Store S, const MemRegion *R, 211 ScanReachableSymbols &Visitor) = 0; 212 213 virtual void print(Store store, raw_ostream &Out, 214 const char* nl, const char *sep) = 0; 215 216 class BindingsHandler { 217 public: 218 virtual ~BindingsHandler(); 219 virtual bool HandleBinding(StoreManager& SMgr, Store store, 220 const MemRegion *region, SVal val) = 0; 221 }; 222 223 class FindUniqueBinding : 224 public BindingsHandler { 225 SymbolRef Sym; 226 const MemRegion* Binding; 227 bool First; 228 229 public: 230 FindUniqueBinding(SymbolRef sym) : Sym(sym), Binding(0), First(true) {} 231 232 bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R, 233 SVal val); 234 LLVM_EXPLICIT operator bool() { return First && Binding; } 235 const MemRegion *getRegion() { return Binding; } 236 }; 237 238 /// iterBindings - Iterate over the bindings in the Store. 239 virtual void iterBindings(Store store, BindingsHandler& f) = 0; 240 241 protected: 242 const MemRegion *MakeElementRegion(const MemRegion *baseRegion, 243 QualType pointeeTy, uint64_t index = 0); 244 245 /// CastRetrievedVal - Used by subclasses of StoreManager to implement 246 /// implicit casts that arise from loads from regions that are reinterpreted 247 /// as another region. 248 SVal CastRetrievedVal(SVal val, const TypedValueRegion *region, 249 QualType castTy, bool performTestOnly = true); 250 251 private: 252 SVal getLValueFieldOrIvar(const Decl *decl, SVal base); 253 }; 254 255 256 inline StoreRef::StoreRef(Store store, StoreManager & smgr) 257 : store(store), mgr(smgr) { 258 if (store) 259 mgr.incrementReferenceCount(store); 260 } 261 262 inline StoreRef::StoreRef(const StoreRef &sr) 263 : store(sr.store), mgr(sr.mgr) 264 { 265 if (store) 266 mgr.incrementReferenceCount(store); 267 } 268 269 inline StoreRef::~StoreRef() { 270 if (store) 271 mgr.decrementReferenceCount(store); 272 } 273 274 inline StoreRef &StoreRef::operator=(StoreRef const &newStore) { 275 assert(&newStore.mgr == &mgr); 276 if (store != newStore.store) { 277 mgr.incrementReferenceCount(newStore.store); 278 mgr.decrementReferenceCount(store); 279 store = newStore.getStore(); 280 } 281 return *this; 282 } 283 284 // FIXME: Do we need to pass ProgramStateManager anymore? 285 StoreManager *CreateRegionStoreManager(ProgramStateManager& StMgr); 286 StoreManager *CreateFieldsOnlyRegionStoreManager(ProgramStateManager& StMgr); 287 288 } // end GR namespace 289 290 } // end clang namespace 291 292 #endif 293