Store.h revision 243830
1132718Skan//== Store.h - Interface for maps from Locations to Values ------*- C++ -*--==// 2132718Skan// 3132718Skan// The LLVM Compiler Infrastructure 4132718Skan// 5132718Skan// This file is distributed under the University of Illinois Open Source 6132718Skan// License. See LICENSE.TXT for details. 7132718Skan// 8132718Skan//===----------------------------------------------------------------------===// 9132718Skan// 10132718Skan// This file defined the types Store and StoreManager. 11132718Skan// 12132718Skan//===----------------------------------------------------------------------===// 13132718Skan 14132718Skan#ifndef LLVM_CLANG_GR_STORE_H 15132718Skan#define LLVM_CLANG_GR_STORE_H 16132718Skan 17132718Skan#include "clang/StaticAnalyzer/Core/PathSensitive/StoreRef.h" 18132718Skan#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" 19169689Skan#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h" 20169689Skan#include "llvm/ADT/DenseSet.h" 21132718Skan#include "llvm/ADT/Optional.h" 22132718Skan 23132718Skannamespace clang { 24132718Skan 25class Stmt; 26class Expr; 27class ObjCIvarDecl; 28class CXXBasePath; 29class StackFrameContext; 30 31namespace ento { 32 33class CallEvent; 34class ProgramState; 35class ProgramStateManager; 36class ScanReachableSymbols; 37 38class StoreManager { 39protected: 40 SValBuilder &svalBuilder; 41 ProgramStateManager &StateMgr; 42 43 /// MRMgr - Manages region objects associated with this StoreManager. 44 MemRegionManager &MRMgr; 45 ASTContext &Ctx; 46 47 StoreManager(ProgramStateManager &stateMgr); 48 49public: 50 virtual ~StoreManager() {} 51 52 /// Return the value bound to specified location in a given state. 53 /// \param[in] store The analysis state. 54 /// \param[in] loc The symbolic memory location. 55 /// \param[in] T An optional type that provides a hint indicating the 56 /// expected type of the returned value. This is used if the value is 57 /// lazily computed. 58 /// \return The value bound to the location \c loc. 59 virtual SVal getBinding(Store store, Loc loc, QualType T = QualType()) = 0; 60 61 /// Return a state with the specified value bound to the given location. 62 /// \param[in] store The analysis state. 63 /// \param[in] loc The symbolic memory location. 64 /// \param[in] val The value to bind to location \c loc. 65 /// \return A pointer to a ProgramState object that contains the same 66 /// bindings as \c state with the addition of having the value specified 67 /// by \c val bound to the location given for \c loc. 68 virtual StoreRef Bind(Store store, Loc loc, SVal val) = 0; 69 70 virtual StoreRef BindDefault(Store store, const MemRegion *R, SVal V); 71 72 /// \brief Create a new store with the specified binding removed. 73 /// \param ST the original store, that is the basis for the new store. 74 /// \param L the location whose binding should be removed. 75 virtual StoreRef killBinding(Store ST, Loc L) = 0; 76 77 /// \brief Create a new store that binds a value to a compound literal. 78 /// 79 /// \param ST The original store whose bindings are the basis for the new 80 /// store. 81 /// 82 /// \param CL The compound literal to bind (the binding key). 83 /// 84 /// \param LC The LocationContext for the binding. 85 /// 86 /// \param V The value to bind to the compound literal. 87 virtual StoreRef bindCompoundLiteral(Store ST, 88 const CompoundLiteralExpr *CL, 89 const LocationContext *LC, 90 SVal V) = 0; 91 92 /// getInitialStore - Returns the initial "empty" store representing the 93 /// value bindings upon entry to an analyzed function. 94 virtual StoreRef getInitialStore(const LocationContext *InitLoc) = 0; 95 96 /// getRegionManager - Returns the internal RegionManager object that is 97 /// used to query and manipulate MemRegion objects. 98 MemRegionManager& getRegionManager() { return MRMgr; } 99 100 virtual Loc getLValueVar(const VarDecl *VD, const LocationContext *LC) { 101 return svalBuilder.makeLoc(MRMgr.getVarRegion(VD, LC)); 102 } 103 104 Loc getLValueCompoundLiteral(const CompoundLiteralExpr *CL, 105 const LocationContext *LC) { 106 return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)); 107 } 108 109 virtual SVal getLValueIvar(const ObjCIvarDecl *decl, SVal base); 110 111 virtual SVal getLValueField(const FieldDecl *D, SVal Base) { 112 return getLValueFieldOrIvar(D, Base); 113 } 114 115 virtual SVal getLValueElement(QualType elementType, NonLoc offset, SVal Base); 116 117 // FIXME: This should soon be eliminated altogether; clients should deal with 118 // region extents directly. 119 virtual DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state, 120 const MemRegion *region, 121 QualType EleTy) { 122 return UnknownVal(); 123 } 124 125 /// ArrayToPointer - Used by ExprEngine::VistCast to handle implicit 126 /// conversions between arrays and pointers. 127 virtual SVal ArrayToPointer(Loc Array) = 0; 128 129 /// Evaluates a chain of derived-to-base casts through the path specified in 130 /// \p Cast. 131 SVal evalDerivedToBase(SVal Derived, const CastExpr *Cast); 132 133 /// Evaluates a chain of derived-to-base casts through the specified path. 134 SVal evalDerivedToBase(SVal Derived, const CXXBasePath &CastPath); 135 136 /// Evaluates a derived-to-base cast through a single level of derivation. 137 SVal evalDerivedToBase(SVal Derived, QualType DerivedPtrType); 138 139 /// \brief Evaluates C++ dynamic_cast cast. 140 /// The callback may result in the following 3 scenarios: 141 /// - Successful cast (ex: derived is subclass of base). 142 /// - Failed cast (ex: derived is definitely not a subclass of base). 143 /// - We don't know (base is a symbolic region and we don't have 144 /// enough info to determine if the cast will succeed at run time). 145 /// The function returns an SVal representing the derived class; it's 146 /// valid only if Failed flag is set to false. 147 SVal evalDynamicCast(SVal Base, QualType DerivedPtrType, bool &Failed); 148 149 const ElementRegion *GetElementZeroRegion(const MemRegion *R, QualType T); 150 151 /// castRegion - Used by ExprEngine::VisitCast to handle casts from 152 /// a MemRegion* to a specific location type. 'R' is the region being 153 /// casted and 'CastToTy' the result type of the cast. 154 const MemRegion *castRegion(const MemRegion *region, QualType CastToTy); 155 156 virtual StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx, 157 SymbolReaper& SymReaper) = 0; 158 159 virtual bool includedInBindings(Store store, 160 const MemRegion *region) const = 0; 161 162 /// If the StoreManager supports it, increment the reference count of 163 /// the specified Store object. 164 virtual void incrementReferenceCount(Store store) {} 165 166 /// If the StoreManager supports it, decrement the reference count of 167 /// the specified Store object. If the reference count hits 0, the memory 168 /// associated with the object is recycled. 169 virtual void decrementReferenceCount(Store store) {} 170 171 typedef llvm::DenseSet<SymbolRef> InvalidatedSymbols; 172 typedef SmallVector<const MemRegion *, 8> InvalidatedRegions; 173 174 /// invalidateRegions - Clears out the specified regions from the store, 175 /// marking their values as unknown. Depending on the store, this may also 176 /// invalidate additional regions that may have changed based on accessing 177 /// the given regions. Optionally, invalidates non-static globals as well. 178 /// \param[in] store The initial store 179 /// \param[in] Regions The regions to invalidate. 180 /// \param[in] E The current statement being evaluated. Used to conjure 181 /// symbols to mark the values of invalidated regions. 182 /// \param[in] Count The current block count. Used to conjure 183 /// symbols to mark the values of invalidated regions. 184 /// \param[in,out] IS A set to fill with any symbols that are no longer 185 /// accessible. Pass \c NULL if this information will not be used. 186 /// \param[in] Call The call expression which will be used to determine which 187 /// globals should get invalidated. 188 /// \param[in,out] Invalidated A vector to fill with any regions being 189 /// invalidated. This should include any regions explicitly invalidated 190 /// even if they do not currently have bindings. Pass \c NULL if this 191 /// information will not be used. 192 virtual StoreRef invalidateRegions(Store store, 193 ArrayRef<const MemRegion *> Regions, 194 const Expr *E, unsigned Count, 195 const LocationContext *LCtx, 196 InvalidatedSymbols &IS, 197 const CallEvent *Call, 198 InvalidatedRegions *Invalidated) = 0; 199 200 /// enterStackFrame - Let the StoreManager to do something when execution 201 /// engine is about to execute into a callee. 202 StoreRef enterStackFrame(Store store, 203 const CallEvent &Call, 204 const StackFrameContext *CalleeCtx); 205 206 /// Finds the transitive closure of symbols within the given region. 207 /// 208 /// Returns false if the visitor aborted the scan. 209 virtual bool scanReachableSymbols(Store S, const MemRegion *R, 210 ScanReachableSymbols &Visitor) = 0; 211 212 virtual void print(Store store, raw_ostream &Out, 213 const char* nl, const char *sep) = 0; 214 215 class BindingsHandler { 216 public: 217 virtual ~BindingsHandler(); 218 virtual bool HandleBinding(StoreManager& SMgr, Store store, 219 const MemRegion *region, SVal val) = 0; 220 }; 221 222 class FindUniqueBinding : 223 public BindingsHandler { 224 SymbolRef Sym; 225 const MemRegion* Binding; 226 bool First; 227 228 public: 229 FindUniqueBinding(SymbolRef sym) : Sym(sym), Binding(0), First(true) {} 230 231 bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R, 232 SVal val); 233 operator bool() { return First && Binding; } 234 const MemRegion *getRegion() { return Binding; } 235 }; 236 237 /// iterBindings - Iterate over the bindings in the Store. 238 virtual void iterBindings(Store store, BindingsHandler& f) = 0; 239 240protected: 241 const MemRegion *MakeElementRegion(const MemRegion *baseRegion, 242 QualType pointeeTy, uint64_t index = 0); 243 244 /// CastRetrievedVal - Used by subclasses of StoreManager to implement 245 /// implicit casts that arise from loads from regions that are reinterpreted 246 /// as another region. 247 SVal CastRetrievedVal(SVal val, const TypedValueRegion *region, 248 QualType castTy, bool performTestOnly = true); 249 250private: 251 SVal getLValueFieldOrIvar(const Decl *decl, SVal base); 252}; 253 254 255inline StoreRef::StoreRef(Store store, StoreManager & smgr) 256 : store(store), mgr(smgr) { 257 if (store) 258 mgr.incrementReferenceCount(store); 259} 260 261inline StoreRef::StoreRef(const StoreRef &sr) 262 : store(sr.store), mgr(sr.mgr) 263{ 264 if (store) 265 mgr.incrementReferenceCount(store); 266} 267 268inline StoreRef::~StoreRef() { 269 if (store) 270 mgr.decrementReferenceCount(store); 271} 272 273inline StoreRef &StoreRef::operator=(StoreRef const &newStore) { 274 assert(&newStore.mgr == &mgr); 275 if (store != newStore.store) { 276 mgr.incrementReferenceCount(newStore.store); 277 mgr.decrementReferenceCount(store); 278 store = newStore.getStore(); 279 } 280 return *this; 281} 282 283// FIXME: Do we need to pass ProgramStateManager anymore? 284StoreManager *CreateRegionStoreManager(ProgramStateManager& StMgr); 285StoreManager *CreateFieldsOnlyRegionStoreManager(ProgramStateManager& StMgr); 286 287} // end GR namespace 288 289} // end clang namespace 290 291#endif 292