Store.h revision 8bef8238181a30e52dea380789a7e2d760eac532 
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/StoreRef.h"
18#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
19#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
20#include "llvm/ADT/DenseSet.h"
21#include "llvm/ADT/Optional.h"
22
23namespace clang {
24
25class Stmt;
26class Expr;
27class ObjCIvarDecl;
28class StackFrameContext;
29
30namespace ento {
31
32class CallOrObjCMessage;
33class ProgramState;
34class ProgramStateManager;
35class SubRegionMap;
36
37class StoreManager {
38protected:
39  SValBuilder &svalBuilder;
40  ProgramStateManager &StateMgr;
41
42  /// MRMgr - Manages region objects associated with this StoreManager.
43  MemRegionManager &MRMgr;
44  ASTContext &Ctx;
45
46  StoreManager(ProgramStateManager &stateMgr);
47
48public:
49  virtual ~StoreManager() {}
50
51  /// Return the value bound to specified location in a given state.
52  /// \param[in] state The analysis state.
53  /// \param[in] loc The symbolic memory location.
54  /// \param[in] T An optional type that provides a hint indicating the
55  ///   expected type of the returned value.  This is used if the value is
56  ///   lazily computed.
57  /// \return The value bound to the location \c loc.
58  virtual SVal getBinding(Store store, Loc loc, QualType T = QualType()) = 0;
59
60  /// Return a state with the specified value bound to the given location.
61  /// \param[in] state The analysis state.
62  /// \param[in] loc The symbolic memory location.
63  /// \param[in] val The value to bind to location \c loc.
64  /// \return A pointer to a ProgramState object that contains the same bindings as
65  ///   \c state with the addition of having the value specified by \c val bound
66  ///   to the location given for \c loc.
67  virtual StoreRef Bind(Store store, Loc loc, SVal val) = 0;
68
69  virtual StoreRef BindDefault(Store store, const MemRegion *R, SVal V);
70  virtual StoreRef Remove(Store St, Loc L) = 0;
71
72  /// BindCompoundLiteral - Return the store that has the bindings currently
73  ///  in 'store' plus the bindings for the CompoundLiteral.  'R' is the region
74  ///  for the compound literal and 'BegInit' and 'EndInit' represent an
75  ///  array of initializer values.
76  virtual StoreRef BindCompoundLiteral(Store store,
77                                       const CompoundLiteralExpr *cl,
78                                       const LocationContext *LC, SVal v) = 0;
79
80  /// getInitialStore - Returns the initial "empty" store representing the
81  ///  value bindings upon entry to an analyzed function.
82  virtual StoreRef getInitialStore(const LocationContext *InitLoc) = 0;
83
84  /// getRegionManager - Returns the internal RegionManager object that is
85  ///  used to query and manipulate MemRegion objects.
86  MemRegionManager& getRegionManager() { return MRMgr; }
87
88  /// getSubRegionMap - Returns an opaque map object that clients can query
89  ///  to get the subregions of a given MemRegion object.  It is the
90  //   caller's responsibility to 'delete' the returned map.
91  virtual SubRegionMap *getSubRegionMap(Store store) = 0;
92
93  virtual Loc getLValueVar(const VarDecl *VD, const LocationContext *LC) {
94    return svalBuilder.makeLoc(MRMgr.getVarRegion(VD, LC));
95  }
96
97  virtual Loc getLValueString(const StringLiteral* S) {
98    return svalBuilder.makeLoc(MRMgr.getStringRegion(S));
99  }
100
101  Loc getLValueCompoundLiteral(const CompoundLiteralExpr *CL,
102                               const LocationContext *LC) {
103    return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC));
104  }
105
106  virtual SVal getLValueIvar(const ObjCIvarDecl *decl, SVal base) {
107    return getLValueFieldOrIvar(decl, base);
108  }
109
110  virtual SVal getLValueField(const FieldDecl *D, SVal Base) {
111    return getLValueFieldOrIvar(D, Base);
112  }
113
114  virtual SVal getLValueElement(QualType elementType, NonLoc offset, SVal Base);
115
116  // FIXME: This should soon be eliminated altogether; clients should deal with
117  // region extents directly.
118  virtual DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state,
119                                                 const MemRegion *region,
120                                                 QualType EleTy) {
121    return UnknownVal();
122  }
123
124  /// ArrayToPointer - Used by ExprEngine::VistCast to handle implicit
125  ///  conversions between arrays and pointers.
126  virtual SVal ArrayToPointer(Loc Array) = 0;
127
128  /// Evaluates DerivedToBase casts.
129  virtual SVal evalDerivedToBase(SVal derived, QualType basePtrType) {
130    return UnknownVal();
131  }
132
133  class CastResult {
134    ProgramStateRef state;
135    const MemRegion *region;
136  public:
137    ProgramStateRef getState() const { return state; }
138    const MemRegion* getRegion() const { return region; }
139    CastResult(ProgramStateRef s, const MemRegion* r = 0) : state(s), region(r){}
140  };
141
142  const ElementRegion *GetElementZeroRegion(const MemRegion *R, QualType T);
143
144  /// castRegion - Used by ExprEngine::VisitCast to handle casts from
145  ///  a MemRegion* to a specific location type.  'R' is the region being
146  ///  casted and 'CastToTy' the result type of the cast.
147  const MemRegion *castRegion(const MemRegion *region, QualType CastToTy);
148
149  virtual StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
150                                      SymbolReaper& SymReaper) = 0;
151
152  virtual StoreRef BindDecl(Store store, const VarRegion *VR, SVal initVal) = 0;
153
154  virtual StoreRef BindDeclWithNoInit(Store store, const VarRegion *VR) = 0;
155
156  virtual bool includedInBindings(Store store,
157                                  const MemRegion *region) const = 0;
158
159  /// If the StoreManager supports it, increment the reference count of
160  /// the specified Store object.
161  virtual void incrementReferenceCount(Store store) {}
162
163  /// If the StoreManager supports it, decrement the reference count of
164  /// the specified Store object.  If the reference count hits 0, the memory
165  /// associated with the object is recycled.
166  virtual void decrementReferenceCount(Store store) {}
167
168  typedef llvm::DenseSet<SymbolRef> InvalidatedSymbols;
169  typedef SmallVector<const MemRegion *, 8> InvalidatedRegions;
170
171  /// invalidateRegions - Clears out the specified regions from the store,
172  ///  marking their values as unknown. Depending on the store, this may also
173  ///  invalidate additional regions that may have changed based on accessing
174  ///  the given regions. Optionally, invalidates non-static globals as well.
175  /// \param[in] store The initial store
176  /// \param[in] Begin A pointer to the first region to invalidate.
177  /// \param[in] End A pointer just past the last region to invalidate.
178  /// \param[in] E The current statement being evaluated. Used to conjure
179  ///   symbols to mark the values of invalidated regions.
180  /// \param[in] Count The current block count. Used to conjure
181  ///   symbols to mark the values of invalidated regions.
182  /// \param[in,out] IS A set to fill with any symbols that are no longer
183  ///   accessible. Pass \c NULL if this information will not be used.
184  /// \param[in] Call The call expression which will be used to determine which
185  ///   globals should get invalidated.
186  /// \param[in,out] Regions A vector to fill with any regions being
187  ///   invalidated. This should include any regions explicitly invalidated
188  ///   even if they do not currently have bindings. Pass \c NULL if this
189  ///   information will not be used.
190  virtual StoreRef invalidateRegions(Store store,
191                                     ArrayRef<const MemRegion *> Regions,
192                                     const Expr *E, unsigned Count,
193                                     InvalidatedSymbols &IS,
194                                     const CallOrObjCMessage *Call,
195                                     InvalidatedRegions *Invalidated) = 0;
196
197  /// enterStackFrame - Let the StoreManager to do something when execution
198  /// engine is about to execute into a callee.
199  virtual StoreRef enterStackFrame(ProgramStateRef state,
200                                   const LocationContext *callerCtx,
201                                   const StackFrameContext *calleeCtx);
202
203  virtual void print(Store store, raw_ostream &Out,
204                     const char* nl, const char *sep) = 0;
205
206  class BindingsHandler {
207  public:
208    virtual ~BindingsHandler();
209    virtual bool HandleBinding(StoreManager& SMgr, Store store,
210                               const MemRegion *region, SVal val) = 0;
211  };
212
213  /// iterBindings - Iterate over the bindings in the Store.
214  virtual void iterBindings(Store store, BindingsHandler& f) = 0;
215
216protected:
217  const MemRegion *MakeElementRegion(const MemRegion *baseRegion,
218                                     QualType pointeeTy, uint64_t index = 0);
219
220  /// CastRetrievedVal - Used by subclasses of StoreManager to implement
221  ///  implicit casts that arise from loads from regions that are reinterpreted
222  ///  as another region.
223  SVal CastRetrievedVal(SVal val, const TypedValueRegion *region,
224                        QualType castTy, bool performTestOnly = true);
225
226private:
227  SVal getLValueFieldOrIvar(const Decl *decl, SVal base);
228};
229
230
231inline StoreRef::StoreRef(Store store, StoreManager & smgr)
232  : store(store), mgr(smgr) {
233  if (store)
234    mgr.incrementReferenceCount(store);
235}
236
237inline StoreRef::StoreRef(const StoreRef &sr)
238  : store(sr.store), mgr(sr.mgr)
239{
240  if (store)
241    mgr.incrementReferenceCount(store);
242}
243
244inline StoreRef::~StoreRef() {
245  if (store)
246    mgr.decrementReferenceCount(store);
247}
248
249inline StoreRef &StoreRef::operator=(StoreRef const &newStore) {
250  assert(&newStore.mgr == &mgr);
251  if (store != newStore.store) {
252    mgr.incrementReferenceCount(newStore.store);
253    mgr.decrementReferenceCount(store);
254    store = newStore.getStore();
255  }
256  return *this;
257}
258
259// FIXME: Do we still need this?
260/// SubRegionMap - An abstract interface that represents a queryable map
261///  between MemRegion objects and their subregions.
262class SubRegionMap {
263  virtual void anchor();
264public:
265  virtual ~SubRegionMap() {}
266
267  class Visitor {
268    virtual void anchor();
269  public:
270    virtual ~Visitor() {}
271    virtual bool Visit(const MemRegion* Parent, const MemRegion* SubRegion) = 0;
272  };
273
274  virtual bool iterSubRegions(const MemRegion *region, Visitor& V) const = 0;
275};
276
277// FIXME: Do we need to pass ProgramStateManager anymore?
278StoreManager *CreateRegionStoreManager(ProgramStateManager& StMgr);
279StoreManager *CreateFieldsOnlyRegionStoreManager(ProgramStateManager& StMgr);
280
281} // end GR namespace
282
283} // end clang namespace
284
285#endif
286