Store.h revision 226633 
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 ProgramState;
33class ProgramStateManager;
34class SubRegionMap;
35
36class StoreManager {
37protected:
38  SValBuilder &svalBuilder;
39  ProgramStateManager &StateMgr;
40
41  /// MRMgr - Manages region objects associated with this StoreManager.
42  MemRegionManager &MRMgr;
43  ASTContext &Ctx;
44
45  StoreManager(ProgramStateManager &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 ProgramState 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 ProgramState *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 ProgramState *state;
134    const MemRegion *region;
135  public:
136    const ProgramState *getState() const { return state; }
137    const MemRegion* getRegion() const { return region; }
138    CastResult(const ProgramState *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) = 0;
150
151  virtual StoreRef BindDecl(Store store, const VarRegion *VR, SVal initVal) = 0;
152
153  virtual StoreRef BindDeclWithNoInit(Store store, const VarRegion *VR) = 0;
154
155  virtual bool includedInBindings(Store store,
156                                  const MemRegion *region) const = 0;
157
158  /// If the StoreManager supports it, increment the reference count of
159  /// the specified Store object.
160  virtual void incrementReferenceCount(Store store) {}
161
162  /// If the StoreManager supports it, decrement the reference count of
163  /// the specified Store object.  If the reference count hits 0, the memory
164  /// associated with the object is recycled.
165  virtual void decrementReferenceCount(Store store) {}
166
167  typedef llvm::DenseSet<SymbolRef> InvalidatedSymbols;
168  typedef SmallVector<const MemRegion *, 8> InvalidatedRegions;
169
170  /// invalidateRegions - Clears out the specified regions from the store,
171  ///  marking their values as unknown. Depending on the store, this may also
172  ///  invalidate additional regions that may have changed based on accessing
173  ///  the given regions. Optionally, invalidates non-static globals as well.
174  /// \param[in] store The initial store
175  /// \param[in] Begin A pointer to the first region to invalidate.
176  /// \param[in] End A pointer just past the last region to invalidate.
177  /// \param[in] E The current statement being evaluated. Used to conjure
178  ///   symbols to mark the values of invalidated regions.
179  /// \param[in] Count The current block count. Used to conjure
180  ///   symbols to mark the values of invalidated regions.
181  /// \param[in,out] IS A set to fill with any symbols that are no longer
182  ///   accessible. Pass \c NULL if this information will not be used.
183  /// \param[in] invalidateGlobals If \c true, any non-static global regions
184  ///   are invalidated as well.
185  /// \param[in,out] Regions 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<const MemRegion *> Regions,
191                                     const Expr *E, unsigned Count,
192                                     InvalidatedSymbols &IS,
193                                     bool invalidateGlobals,
194                                     InvalidatedRegions *Invalidated) = 0;
195
196  /// enterStackFrame - Let the StoreManager to do something when execution
197  /// engine is about to execute into a callee.
198  virtual StoreRef enterStackFrame(const ProgramState *state,
199                                   const StackFrameContext *frame);
200
201  virtual void print(Store store, raw_ostream &Out,
202                     const char* nl, const char *sep) = 0;
203
204  class BindingsHandler {
205  public:
206    virtual ~BindingsHandler();
207    virtual bool HandleBinding(StoreManager& SMgr, Store store,
208                               const MemRegion *region, SVal val) = 0;
209  };
210
211  /// iterBindings - Iterate over the bindings in the Store.
212  virtual void iterBindings(Store store, BindingsHandler& f) = 0;
213
214protected:
215  const MemRegion *MakeElementRegion(const MemRegion *baseRegion,
216                                     QualType pointeeTy, uint64_t index = 0);
217
218  /// CastRetrievedVal - Used by subclasses of StoreManager to implement
219  ///  implicit casts that arise from loads from regions that are reinterpreted
220  ///  as another region.
221  SVal CastRetrievedVal(SVal val, const TypedValueRegion *region,
222                        QualType castTy, bool performTestOnly = true);
223
224private:
225  SVal getLValueFieldOrIvar(const Decl *decl, SVal base);
226};
227
228
229inline StoreRef::StoreRef(Store store, StoreManager & smgr)
230  : store(store), mgr(smgr) {
231  if (store)
232    mgr.incrementReferenceCount(store);
233}
234
235inline StoreRef::StoreRef(const StoreRef &sr)
236  : store(sr.store), mgr(sr.mgr)
237{
238  if (store)
239    mgr.incrementReferenceCount(store);
240}
241
242inline StoreRef::~StoreRef() {
243  if (store)
244    mgr.decrementReferenceCount(store);
245}
246
247inline StoreRef &StoreRef::operator=(StoreRef const &newStore) {
248  assert(&newStore.mgr == &mgr);
249  if (store != newStore.store) {
250    mgr.incrementReferenceCount(newStore.store);
251    mgr.decrementReferenceCount(store);
252    store = newStore.getStore();
253  }
254  return *this;
255}
256
257// FIXME: Do we still need this?
258/// SubRegionMap - An abstract interface that represents a queryable map
259///  between MemRegion objects and their subregions.
260class SubRegionMap {
261public:
262  virtual ~SubRegionMap() {}
263
264  class Visitor {
265  public:
266    virtual ~Visitor() {}
267    virtual bool Visit(const MemRegion* Parent, const MemRegion* SubRegion) = 0;
268  };
269
270  virtual bool iterSubRegions(const MemRegion *region, Visitor& V) const = 0;
271};
272
273// FIXME: Do we need to pass ProgramStateManager anymore?
274StoreManager *CreateRegionStoreManager(ProgramStateManager& StMgr);
275StoreManager *CreateFieldsOnlyRegionStoreManager(ProgramStateManager& StMgr);
276
277} // end GR namespace
278
279} // end clang namespace
280
281#endif
282