Store.h revision 221345 
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 GRState;
33class GRStateManager;
34class SubRegionMap;
35
36class StoreManager {
37protected:
38  SValBuilder &svalBuilder;
39  GRStateManager &StateMgr;
40
41  /// MRMgr - Manages region objects associated with this StoreManager.
42  MemRegionManager &MRMgr;
43  ASTContext &Ctx;
44
45  StoreManager(GRStateManager &stateMgr);
46
47public:
48  virtual ~StoreManager() {}
49
50  /// Return the value bound to specified location in a given state.
51  /// \param[in] state The analysis state.
52  /// \param[in] loc The symbolic memory location.
53  /// \param[in] T An optional type that provides a hint indicating the
54  ///   expected type of the returned value.  This is used if the value is
55  ///   lazily computed.
56  /// \return The value bound to the location \c loc.
57  virtual SVal Retrieve(Store store, Loc loc, QualType T = QualType()) = 0;
58
59  /// Return a state with the specified value bound to the given location.
60  /// \param[in] state The analysis state.
61  /// \param[in] loc The symbolic memory location.
62  /// \param[in] val The value to bind to location \c loc.
63  /// \return A pointer to a GRState object that contains the same bindings as
64  ///   \c state with the addition of having the value specified by \c val bound
65  ///   to the location given for \c loc.
66  virtual StoreRef Bind(Store store, Loc loc, SVal val) = 0;
67
68  virtual StoreRef BindDefault(Store store, const MemRegion *R, SVal V);
69  virtual StoreRef Remove(Store St, Loc L) = 0;
70
71  /// BindCompoundLiteral - Return the store that has the bindings currently
72  ///  in 'store' plus the bindings for the CompoundLiteral.  'R' is the region
73  ///  for the compound literal and 'BegInit' and 'EndInit' represent an
74  ///  array of initializer values.
75  virtual StoreRef BindCompoundLiteral(Store store,
76                                       const CompoundLiteralExpr* cl,
77                                       const LocationContext *LC, SVal v) = 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  /// getSubRegionMap - Returns an opaque map object that clients can query
88  ///  to get the subregions of a given MemRegion object.  It is the
89  //   caller's responsibility to 'delete' the returned map.
90  virtual SubRegionMap *getSubRegionMap(Store store) = 0;
91
92  virtual Loc getLValueVar(const VarDecl *VD, const LocationContext *LC) {
93    return svalBuilder.makeLoc(MRMgr.getVarRegion(VD, LC));
94  }
95
96  virtual Loc getLValueString(const StringLiteral* S) {
97    return svalBuilder.makeLoc(MRMgr.getStringRegion(S));
98  }
99
100  Loc getLValueCompoundLiteral(const CompoundLiteralExpr* CL,
101                               const LocationContext *LC) {
102    return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC));
103  }
104
105  virtual SVal getLValueIvar(const ObjCIvarDecl* decl, SVal base) {
106    return getLValueFieldOrIvar(decl, base);
107  }
108
109  virtual SVal getLValueField(const FieldDecl* D, SVal Base) {
110    return getLValueFieldOrIvar(D, Base);
111  }
112
113  virtual SVal getLValueElement(QualType elementType, NonLoc offset, SVal Base);
114
115  // FIXME: This should soon be eliminated altogether; clients should deal with
116  // region extents directly.
117  virtual DefinedOrUnknownSVal getSizeInElements(const GRState *state,
118                                                 const MemRegion *region,
119                                                 QualType EleTy) {
120    return UnknownVal();
121  }
122
123  /// ArrayToPointer - Used by ExprEngine::VistCast to handle implicit
124  ///  conversions between arrays and pointers.
125  virtual SVal ArrayToPointer(Loc Array) = 0;
126
127  /// Evaluates DerivedToBase casts.
128  virtual SVal evalDerivedToBase(SVal derived, QualType basePtrType) {
129    return UnknownVal();
130  }
131
132  class CastResult {
133    const GRState *state;
134    const MemRegion *region;
135  public:
136    const GRState *getState() const { return state; }
137    const MemRegion* getRegion() const { return region; }
138    CastResult(const GRState *s, const MemRegion* r = 0) : state(s), region(r){}
139  };
140
141  const ElementRegion *GetElementZeroRegion(const MemRegion *R, QualType T);
142
143  /// castRegion - Used by ExprEngine::VisitCast to handle casts from
144  ///  a MemRegion* to a specific location type.  'R' is the region being
145  ///  casted and 'CastToTy' the result type of the cast.
146  const MemRegion *castRegion(const MemRegion *region, QualType CastToTy);
147
148  virtual StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
149                                      SymbolReaper& SymReaper,
150                      llvm::SmallVectorImpl<const MemRegion*>& RegionRoots) = 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  /// If the StoreManager supports it, increment the reference count of
157  /// the specified Store object.
158  virtual void incrementReferenceCount(Store store) {}
159
160  /// If the StoreManager supports it, decrement the reference count of
161  /// the specified Store object.  If the reference count hits 0, the memory
162  /// associated with the object is recycled.
163  virtual void decrementReferenceCount(Store store) {}
164
165  typedef llvm::DenseSet<SymbolRef> InvalidatedSymbols;
166  typedef llvm::SmallVector<const MemRegion *, 8> InvalidatedRegions;
167
168  /// invalidateRegions - Clears out the specified regions from the store,
169  ///  marking their values as unknown. Depending on the store, this may also
170  ///  invalidate additional regions that may have changed based on accessing
171  ///  the given regions. Optionally, invalidates non-static globals as well.
172  /// \param[in] store The initial store
173  /// \param[in] Begin A pointer to the first region to invalidate.
174  /// \param[in] End A pointer just past the last region to invalidate.
175  /// \param[in] E The current statement being evaluated. Used to conjure
176  ///   symbols to mark the values of invalidated regions.
177  /// \param[in] Count The current block count. Used to conjure
178  ///   symbols to mark the values of invalidated regions.
179  /// \param[in,out] IS A set to fill with any symbols that are no longer
180  ///   accessible. Pass \c NULL if this information will not be used.
181  /// \param[in] invalidateGlobals If \c true, any non-static global regions
182  ///   are invalidated as well.
183  /// \param[in,out] Regions A vector to fill with any regions being
184  ///   invalidated. This should include any regions explicitly invalidated
185  ///   even if they do not currently have bindings. Pass \c NULL if this
186  ///   information will not be used.
187  virtual StoreRef invalidateRegions(Store store,
188                                     const MemRegion * const *Begin,
189                                     const MemRegion * const *End,
190                                     const Expr *E, unsigned Count,
191                                     InvalidatedSymbols *IS,
192                                     bool invalidateGlobals,
193                                     InvalidatedRegions *Regions) = 0;
194
195  /// enterStackFrame - Let the StoreManager to do something when execution
196  /// engine is about to execute into a callee.
197  virtual StoreRef enterStackFrame(const GRState *state,
198                                   const StackFrameContext *frame);
199
200  virtual void print(Store store, llvm::raw_ostream& Out,
201                     const char* nl, const char *sep) = 0;
202
203  class BindingsHandler {
204  public:
205    virtual ~BindingsHandler();
206    virtual bool HandleBinding(StoreManager& SMgr, Store store,
207                               const MemRegion *region, SVal val) = 0;
208  };
209
210  /// iterBindings - Iterate over the bindings in the Store.
211  virtual void iterBindings(Store store, BindingsHandler& f) = 0;
212
213protected:
214  const MemRegion *MakeElementRegion(const MemRegion *baseRegion,
215                                     QualType pointeeTy, uint64_t index = 0);
216
217  /// CastRetrievedVal - Used by subclasses of StoreManager to implement
218  ///  implicit casts that arise from loads from regions that are reinterpreted
219  ///  as another region.
220  SVal CastRetrievedVal(SVal val, const TypedRegion *region, QualType castTy,
221                        bool performTestOnly = true);
222
223private:
224  SVal getLValueFieldOrIvar(const Decl* decl, SVal base);
225};
226
227
228inline StoreRef::StoreRef(Store store, StoreManager & smgr)
229  : store(store), mgr(smgr) {
230  if (store)
231    mgr.incrementReferenceCount(store);
232}
233
234inline StoreRef::StoreRef(const StoreRef &sr)
235  : store(sr.store), mgr(sr.mgr)
236{
237  if (store)
238    mgr.incrementReferenceCount(store);
239}
240
241inline StoreRef::~StoreRef() {
242  if (store)
243    mgr.decrementReferenceCount(store);
244}
245
246inline StoreRef &StoreRef::operator=(StoreRef const &newStore) {
247  assert(&newStore.mgr == &mgr);
248  if (store != newStore.store) {
249    mgr.incrementReferenceCount(newStore.store);
250    mgr.decrementReferenceCount(store);
251    store = newStore.getStore();
252  }
253  return *this;
254}
255
256// FIXME: Do we still need this?
257/// SubRegionMap - An abstract interface that represents a queryable map
258///  between MemRegion objects and their subregions.
259class SubRegionMap {
260public:
261  virtual ~SubRegionMap() {}
262
263  class Visitor {
264  public:
265    virtual ~Visitor() {}
266    virtual bool Visit(const MemRegion* Parent, const MemRegion* SubRegion) = 0;
267  };
268
269  virtual bool iterSubRegions(const MemRegion *region, Visitor& V) const = 0;
270};
271
272// FIXME: Do we need to pass GRStateManager anymore?
273StoreManager *CreateBasicStoreManager(GRStateManager& StMgr);
274StoreManager *CreateRegionStoreManager(GRStateManager& StMgr);
275StoreManager *CreateFieldsOnlyRegionStoreManager(GRStateManager& StMgr);
276StoreManager *CreateFlatStoreManager(GRStateManager &StMgr);
277
278} // end GR namespace
279
280} // end clang namespace
281
282#endif
283