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_STATICANALYZER_CORE_PATHSENSITIVE_STORE_H 15#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_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 22namespace clang { 23 24class Stmt; 25class Expr; 26class ObjCIvarDecl; 27class CXXBasePath; 28class StackFrameContext; 29 30namespace ento { 31 32class CallEvent; 33class ProgramState; 34class ProgramStateManager; 35class ScanReachableSymbols; 36 37typedef llvm::DenseSet<SymbolRef> InvalidatedSymbols; 38 39class StoreManager { 40protected: 41 SValBuilder &svalBuilder; 42 ProgramStateManager &StateMgr; 43 44 /// MRMgr - Manages region objects associated with this StoreManager. 45 MemRegionManager &MRMgr; 46 ASTContext &Ctx; 47 48 StoreManager(ProgramStateManager &stateMgr); 49 50public: 51 virtual ~StoreManager() {} 52 53 /// Return the value bound to specified location in a given state. 54 /// \param[in] store The store in which to make the lookup. 55 /// \param[in] loc The symbolic memory location. 56 /// \param[in] T An optional type that provides a hint indicating the 57 /// expected type of the returned value. This is used if the value is 58 /// lazily computed. 59 /// \return The value bound to the location \c loc. 60 virtual SVal getBinding(Store store, Loc loc, QualType T = QualType()) = 0; 61 62 /// Return the default value bound to a region in a given store. The default 63 /// binding is the value of sub-regions that were not initialized separately 64 /// from their base region. For example, if the structure is zero-initialized 65 /// upon construction, this method retrieves the concrete zero value, even if 66 /// some or all fields were later overwritten manually. Default binding may be 67 /// an unknown, undefined, concrete, or symbolic value. 68 /// \param[in] store The store in which to make the lookup. 69 /// \param[in] R The region to find the default binding for. 70 /// \return The default value bound to the region in the store, if a default 71 /// binding exists. 72 virtual Optional<SVal> getDefaultBinding(Store store, const MemRegion *R) = 0; 73 74 /// Return the default value bound to a LazyCompoundVal. The default binding 75 /// is used to represent the value of any fields or elements within the 76 /// structure represented by the LazyCompoundVal which were not initialized 77 /// explicitly separately from the whole structure. Default binding may be an 78 /// unknown, undefined, concrete, or symbolic value. 79 /// \param[in] lcv The lazy compound value. 80 /// \return The default value bound to the LazyCompoundVal \c lcv, if a 81 /// default binding exists. 82 Optional<SVal> getDefaultBinding(nonloc::LazyCompoundVal lcv) { 83 return getDefaultBinding(lcv.getStore(), lcv.getRegion()); 84 } 85 86 /// Return a store with the specified value bound to the given location. 87 /// \param[in] store The store in which to make the binding. 88 /// \param[in] loc The symbolic memory location. 89 /// \param[in] val The value to bind to location \c loc. 90 /// \return A StoreRef object that contains the same 91 /// bindings as \c store with the addition of having the value specified 92 /// by \c val bound to the location given for \c loc. 93 virtual StoreRef Bind(Store store, Loc loc, SVal val) = 0; 94 95 virtual StoreRef BindDefault(Store store, const MemRegion *R, SVal V); 96 97 /// \brief Create a new store with the specified binding removed. 98 /// \param ST the original store, that is the basis for the new store. 99 /// \param L the location whose binding should be removed. 100 virtual StoreRef killBinding(Store ST, Loc L) = 0; 101 102 /// getInitialStore - Returns the initial "empty" store representing the 103 /// value bindings upon entry to an analyzed function. 104 virtual StoreRef getInitialStore(const LocationContext *InitLoc) = 0; 105 106 /// getRegionManager - Returns the internal RegionManager object that is 107 /// used to query and manipulate MemRegion objects. 108 MemRegionManager& getRegionManager() { return MRMgr; } 109 110 virtual Loc getLValueVar(const VarDecl *VD, const LocationContext *LC) { 111 return svalBuilder.makeLoc(MRMgr.getVarRegion(VD, LC)); 112 } 113 114 Loc getLValueCompoundLiteral(const CompoundLiteralExpr *CL, 115 const LocationContext *LC) { 116 return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)); 117 } 118 119 virtual SVal getLValueIvar(const ObjCIvarDecl *decl, SVal base); 120 121 virtual SVal getLValueField(const FieldDecl *D, SVal Base) { 122 return getLValueFieldOrIvar(D, Base); 123 } 124 125 virtual SVal getLValueElement(QualType elementType, NonLoc offset, SVal Base); 126 127 // FIXME: This should soon be eliminated altogether; clients should deal with 128 // region extents directly. 129 virtual DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state, 130 const MemRegion *region, 131 QualType EleTy) { 132 return UnknownVal(); 133 } 134 135 /// ArrayToPointer - Used by ExprEngine::VistCast to handle implicit 136 /// conversions between arrays and pointers. 137 virtual SVal ArrayToPointer(Loc Array, QualType ElementTy) = 0; 138 139 /// Evaluates a chain of derived-to-base casts through the path specified in 140 /// \p Cast. 141 SVal evalDerivedToBase(SVal Derived, const CastExpr *Cast); 142 143 /// Evaluates a chain of derived-to-base casts through the specified path. 144 SVal evalDerivedToBase(SVal Derived, const CXXBasePath &CastPath); 145 146 /// Evaluates a derived-to-base cast through a single level of derivation. 147 SVal evalDerivedToBase(SVal Derived, QualType DerivedPtrType, 148 bool IsVirtual); 149 150 /// \brief Attempts to do a down cast. Used to model BaseToDerived and C++ 151 /// dynamic_cast. 152 /// The callback may result in the following 3 scenarios: 153 /// - Successful cast (ex: derived is subclass of base). 154 /// - Failed cast (ex: derived is definitely not a subclass of base). 155 /// The distinction of this case from the next one is necessary to model 156 /// dynamic_cast. 157 /// - We don't know (base is a symbolic region and we don't have 158 /// enough info to determine if the cast will succeed at run time). 159 /// The function returns an SVal representing the derived class; it's 160 /// valid only if Failed flag is set to false. 161 SVal attemptDownCast(SVal Base, QualType DerivedPtrType, bool &Failed); 162 163 const ElementRegion *GetElementZeroRegion(const SubRegion *R, QualType T); 164 165 /// castRegion - Used by ExprEngine::VisitCast to handle casts from 166 /// a MemRegion* to a specific location type. 'R' is the region being 167 /// casted and 'CastToTy' the result type of the cast. 168 const MemRegion *castRegion(const MemRegion *region, QualType CastToTy); 169 170 virtual StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx, 171 SymbolReaper& SymReaper) = 0; 172 173 virtual bool includedInBindings(Store store, 174 const MemRegion *region) const = 0; 175 176 /// If the StoreManager supports it, increment the reference count of 177 /// the specified Store object. 178 virtual void incrementReferenceCount(Store store) {} 179 180 /// If the StoreManager supports it, decrement the reference count of 181 /// the specified Store object. If the reference count hits 0, the memory 182 /// associated with the object is recycled. 183 virtual void decrementReferenceCount(Store store) {} 184 185 typedef SmallVector<const MemRegion *, 8> InvalidatedRegions; 186 187 /// invalidateRegions - Clears out the specified regions from the store, 188 /// marking their values as unknown. Depending on the store, this may also 189 /// invalidate additional regions that may have changed based on accessing 190 /// the given regions. Optionally, invalidates non-static globals as well. 191 /// \param[in] store The initial store 192 /// \param[in] Values The values to invalidate. 193 /// \param[in] E The current statement being evaluated. Used to conjure 194 /// symbols to mark the values of invalidated regions. 195 /// \param[in] Count The current block count. Used to conjure 196 /// symbols to mark the values of invalidated regions. 197 /// \param[in] Call The call expression which will be used to determine which 198 /// globals should get invalidated. 199 /// \param[in,out] IS A set to fill with any symbols that are no longer 200 /// accessible. Pass \c NULL if this information will not be used. 201 /// \param[in] ITraits Information about invalidation for a particular 202 /// region/symbol. 203 /// \param[in,out] InvalidatedTopLevel A vector to fill with regions 204 //// explicitly being invalidated. Pass \c NULL if this 205 /// information will not be used. 206 /// \param[in,out] Invalidated A vector to fill with any regions being 207 /// invalidated. This should include any regions explicitly invalidated 208 /// even if they do not currently have bindings. Pass \c NULL if this 209 /// information will not be used. 210 virtual StoreRef invalidateRegions(Store store, 211 ArrayRef<SVal> Values, 212 const Expr *E, unsigned Count, 213 const LocationContext *LCtx, 214 const CallEvent *Call, 215 InvalidatedSymbols &IS, 216 RegionAndSymbolInvalidationTraits &ITraits, 217 InvalidatedRegions *InvalidatedTopLevel, 218 InvalidatedRegions *Invalidated) = 0; 219 220 /// enterStackFrame - Let the StoreManager to do something when execution 221 /// engine is about to execute into a callee. 222 StoreRef enterStackFrame(Store store, 223 const CallEvent &Call, 224 const StackFrameContext *CalleeCtx); 225 226 /// Finds the transitive closure of symbols within the given region. 227 /// 228 /// Returns false if the visitor aborted the scan. 229 virtual bool scanReachableSymbols(Store S, const MemRegion *R, 230 ScanReachableSymbols &Visitor) = 0; 231 232 virtual void print(Store store, raw_ostream &Out, 233 const char* nl, const char *sep) = 0; 234 235 class BindingsHandler { 236 public: 237 virtual ~BindingsHandler(); 238 virtual bool HandleBinding(StoreManager& SMgr, Store store, 239 const MemRegion *region, SVal val) = 0; 240 }; 241 242 class FindUniqueBinding : 243 public BindingsHandler { 244 SymbolRef Sym; 245 const MemRegion* Binding; 246 bool First; 247 248 public: 249 FindUniqueBinding(SymbolRef sym) 250 : Sym(sym), Binding(nullptr), First(true) {} 251 252 bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R, 253 SVal val) override; 254 explicit operator bool() { return First && Binding; } 255 const MemRegion *getRegion() { return Binding; } 256 }; 257 258 /// iterBindings - Iterate over the bindings in the Store. 259 virtual void iterBindings(Store store, BindingsHandler& f) = 0; 260 261protected: 262 const ElementRegion *MakeElementRegion(const SubRegion *baseRegion, 263 QualType pointeeTy, 264 uint64_t index = 0); 265 266 /// CastRetrievedVal - Used by subclasses of StoreManager to implement 267 /// implicit casts that arise from loads from regions that are reinterpreted 268 /// as another region. 269 SVal CastRetrievedVal(SVal val, const TypedValueRegion *region, 270 QualType castTy, bool performTestOnly = true); 271 272private: 273 SVal getLValueFieldOrIvar(const Decl *decl, SVal base); 274}; 275 276 277inline StoreRef::StoreRef(Store store, StoreManager & smgr) 278 : store(store), mgr(smgr) { 279 if (store) 280 mgr.incrementReferenceCount(store); 281} 282 283inline StoreRef::StoreRef(const StoreRef &sr) 284 : store(sr.store), mgr(sr.mgr) 285{ 286 if (store) 287 mgr.incrementReferenceCount(store); 288} 289 290inline StoreRef::~StoreRef() { 291 if (store) 292 mgr.decrementReferenceCount(store); 293} 294 295inline StoreRef &StoreRef::operator=(StoreRef const &newStore) { 296 assert(&newStore.mgr == &mgr); 297 if (store != newStore.store) { 298 mgr.incrementReferenceCount(newStore.store); 299 mgr.decrementReferenceCount(store); 300 store = newStore.getStore(); 301 } 302 return *this; 303} 304 305// FIXME: Do we need to pass ProgramStateManager anymore? 306std::unique_ptr<StoreManager> 307CreateRegionStoreManager(ProgramStateManager &StMgr); 308std::unique_ptr<StoreManager> 309CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr); 310 311} // end GR namespace 312 313} // end clang namespace 314 315#endif 316