clang  3.8.0
RegionStore.cpp
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1 //== RegionStore.cpp - Field-sensitive store model --------------*- 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 defines a basic region store model. In this model, we do have field
11 // sensitivity. But we assume nothing about the heap shape. So recursive data
12 // structures are largely ignored. Basically we do 1-limiting analysis.
13 // Parameter pointers are assumed with no aliasing. Pointee objects of
14 // parameters are created lazily.
15 //
16 //===----------------------------------------------------------------------===//
17 #include "clang/AST/Attr.h"
18 #include "clang/AST/CharUnits.h"
21 #include "clang/Basic/TargetInfo.h"
28 #include "llvm/ADT/ImmutableList.h"
29 #include "llvm/ADT/ImmutableMap.h"
30 #include "llvm/ADT/Optional.h"
31 #include "llvm/Support/raw_ostream.h"
32 
33 using namespace clang;
34 using namespace ento;
35 
36 //===----------------------------------------------------------------------===//
37 // Representation of binding keys.
38 //===----------------------------------------------------------------------===//
39 
40 namespace {
41 class BindingKey {
42 public:
43  enum Kind { Default = 0x0, Direct = 0x1 };
44 private:
45  enum { Symbolic = 0x2 };
46 
47  llvm::PointerIntPair<const MemRegion *, 2> P;
48  uint64_t Data;
49 
50  /// Create a key for a binding to region \p r, which has a symbolic offset
51  /// from region \p Base.
52  explicit BindingKey(const SubRegion *r, const SubRegion *Base, Kind k)
53  : P(r, k | Symbolic), Data(reinterpret_cast<uintptr_t>(Base)) {
54  assert(r && Base && "Must have known regions.");
55  assert(getConcreteOffsetRegion() == Base && "Failed to store base region");
56  }
57 
58  /// Create a key for a binding at \p offset from base region \p r.
59  explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
60  : P(r, k), Data(offset) {
61  assert(r && "Must have known regions.");
62  assert(getOffset() == offset && "Failed to store offset");
63  assert((r == r->getBaseRegion() || isa<ObjCIvarRegion>(r)) && "Not a base");
64  }
65 public:
66 
67  bool isDirect() const { return P.getInt() & Direct; }
68  bool hasSymbolicOffset() const { return P.getInt() & Symbolic; }
69 
70  const MemRegion *getRegion() const { return P.getPointer(); }
71  uint64_t getOffset() const {
72  assert(!hasSymbolicOffset());
73  return Data;
74  }
75 
76  const SubRegion *getConcreteOffsetRegion() const {
77  assert(hasSymbolicOffset());
78  return reinterpret_cast<const SubRegion *>(static_cast<uintptr_t>(Data));
79  }
80 
81  const MemRegion *getBaseRegion() const {
82  if (hasSymbolicOffset())
83  return getConcreteOffsetRegion()->getBaseRegion();
84  return getRegion()->getBaseRegion();
85  }
86 
87  void Profile(llvm::FoldingSetNodeID& ID) const {
88  ID.AddPointer(P.getOpaqueValue());
89  ID.AddInteger(Data);
90  }
91 
92  static BindingKey Make(const MemRegion *R, Kind k);
93 
94  bool operator<(const BindingKey &X) const {
95  if (P.getOpaqueValue() < X.P.getOpaqueValue())
96  return true;
97  if (P.getOpaqueValue() > X.P.getOpaqueValue())
98  return false;
99  return Data < X.Data;
100  }
101 
102  bool operator==(const BindingKey &X) const {
103  return P.getOpaqueValue() == X.P.getOpaqueValue() &&
104  Data == X.Data;
105  }
106 
107  void dump() const;
108 };
109 } // end anonymous namespace
110 
111 BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
112  const RegionOffset &RO = R->getAsOffset();
113  if (RO.hasSymbolicOffset())
114  return BindingKey(cast<SubRegion>(R), cast<SubRegion>(RO.getRegion()), k);
115 
116  return BindingKey(RO.getRegion(), RO.getOffset(), k);
117 }
118 
119 namespace llvm {
120  static inline
121  raw_ostream &operator<<(raw_ostream &os, BindingKey K) {
122  os << '(' << K.getRegion();
123  if (!K.hasSymbolicOffset())
124  os << ',' << K.getOffset();
125  os << ',' << (K.isDirect() ? "direct" : "default")
126  << ')';
127  return os;
128  }
129 
130  template <typename T> struct isPodLike;
131  template <> struct isPodLike<BindingKey> {
132  static const bool value = true;
133  };
134 } // end llvm namespace
135 
136 LLVM_DUMP_METHOD void BindingKey::dump() const { llvm::errs() << *this; }
137 
138 //===----------------------------------------------------------------------===//
139 // Actual Store type.
140 //===----------------------------------------------------------------------===//
141 
143 typedef llvm::ImmutableMapRef<BindingKey, SVal> ClusterBindingsRef;
144 typedef std::pair<BindingKey, SVal> BindingPair;
145 
148 
149 namespace {
150 class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
151  ClusterBindings> {
152  ClusterBindings::Factory *CBFactory;
153 
154 public:
155  typedef llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>
156  ParentTy;
157 
158  RegionBindingsRef(ClusterBindings::Factory &CBFactory,
159  const RegionBindings::TreeTy *T,
160  RegionBindings::TreeTy::Factory *F)
161  : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(T, F),
162  CBFactory(&CBFactory) {}
163 
164  RegionBindingsRef(const ParentTy &P, ClusterBindings::Factory &CBFactory)
165  : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(P),
166  CBFactory(&CBFactory) {}
167 
168  RegionBindingsRef add(key_type_ref K, data_type_ref D) const {
169  return RegionBindingsRef(static_cast<const ParentTy *>(this)->add(K, D),
170  *CBFactory);
171  }
172 
173  RegionBindingsRef remove(key_type_ref K) const {
174  return RegionBindingsRef(static_cast<const ParentTy *>(this)->remove(K),
175  *CBFactory);
176  }
177 
178  RegionBindingsRef addBinding(BindingKey K, SVal V) const;
179 
180  RegionBindingsRef addBinding(const MemRegion *R,
181  BindingKey::Kind k, SVal V) const;
182 
183  const SVal *lookup(BindingKey K) const;
184  const SVal *lookup(const MemRegion *R, BindingKey::Kind k) const;
185  using llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>::lookup;
186 
187  RegionBindingsRef removeBinding(BindingKey K);
188 
189  RegionBindingsRef removeBinding(const MemRegion *R,
190  BindingKey::Kind k);
191 
192  RegionBindingsRef removeBinding(const MemRegion *R) {
193  return removeBinding(R, BindingKey::Direct).
194  removeBinding(R, BindingKey::Default);
195  }
196 
197  Optional<SVal> getDirectBinding(const MemRegion *R) const;
198 
199  /// getDefaultBinding - Returns an SVal* representing an optional default
200  /// binding associated with a region and its subregions.
201  Optional<SVal> getDefaultBinding(const MemRegion *R) const;
202 
203  /// Return the internal tree as a Store.
204  Store asStore() const {
205  return asImmutableMap().getRootWithoutRetain();
206  }
207 
208  void dump(raw_ostream &OS, const char *nl) const {
209  for (iterator I = begin(), E = end(); I != E; ++I) {
210  const ClusterBindings &Cluster = I.getData();
211  for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
212  CI != CE; ++CI) {
213  OS << ' ' << CI.getKey() << " : " << CI.getData() << nl;
214  }
215  OS << nl;
216  }
217  }
218 
219  LLVM_DUMP_METHOD void dump() const { dump(llvm::errs(), "\n"); }
220 };
221 } // end anonymous namespace
222 
223 typedef const RegionBindingsRef& RegionBindingsConstRef;
224 
225 Optional<SVal> RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
226  return Optional<SVal>::create(lookup(R, BindingKey::Direct));
227 }
228 
229 Optional<SVal> RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
230  if (R->isBoundable())
231  if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R))
232  if (TR->getValueType()->isUnionType())
233  return UnknownVal();
234 
235  return Optional<SVal>::create(lookup(R, BindingKey::Default));
236 }
237 
238 RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
239  const MemRegion *Base = K.getBaseRegion();
240 
241  const ClusterBindings *ExistingCluster = lookup(Base);
242  ClusterBindings Cluster =
243  (ExistingCluster ? *ExistingCluster : CBFactory->getEmptyMap());
244 
245  ClusterBindings NewCluster = CBFactory->add(Cluster, K, V);
246  return add(Base, NewCluster);
247 }
248 
249 
250 RegionBindingsRef RegionBindingsRef::addBinding(const MemRegion *R,
251  BindingKey::Kind k,
252  SVal V) const {
253  return addBinding(BindingKey::Make(R, k), V);
254 }
255 
256 const SVal *RegionBindingsRef::lookup(BindingKey K) const {
257  const ClusterBindings *Cluster = lookup(K.getBaseRegion());
258  if (!Cluster)
259  return nullptr;
260  return Cluster->lookup(K);
261 }
262 
263 const SVal *RegionBindingsRef::lookup(const MemRegion *R,
264  BindingKey::Kind k) const {
265  return lookup(BindingKey::Make(R, k));
266 }
267 
268 RegionBindingsRef RegionBindingsRef::removeBinding(BindingKey K) {
269  const MemRegion *Base = K.getBaseRegion();
270  const ClusterBindings *Cluster = lookup(Base);
271  if (!Cluster)
272  return *this;
273 
274  ClusterBindings NewCluster = CBFactory->remove(*Cluster, K);
275  if (NewCluster.isEmpty())
276  return remove(Base);
277  return add(Base, NewCluster);
278 }
279 
280 RegionBindingsRef RegionBindingsRef::removeBinding(const MemRegion *R,
281  BindingKey::Kind k){
282  return removeBinding(BindingKey::Make(R, k));
283 }
284 
285 //===----------------------------------------------------------------------===//
286 // Fine-grained control of RegionStoreManager.
287 //===----------------------------------------------------------------------===//
288 
289 namespace {
290 struct minimal_features_tag {};
291 struct maximal_features_tag {};
292 
293 class RegionStoreFeatures {
294  bool SupportsFields;
295 public:
296  RegionStoreFeatures(minimal_features_tag) :
297  SupportsFields(false) {}
298 
299  RegionStoreFeatures(maximal_features_tag) :
300  SupportsFields(true) {}
301 
302  void enableFields(bool t) { SupportsFields = t; }
303 
304  bool supportsFields() const { return SupportsFields; }
305 };
306 }
307 
308 //===----------------------------------------------------------------------===//
309 // Main RegionStore logic.
310 //===----------------------------------------------------------------------===//
311 
312 namespace {
313 class invalidateRegionsWorker;
314 
315 class RegionStoreManager : public StoreManager {
316 public:
317  const RegionStoreFeatures Features;
318 
319  RegionBindings::Factory RBFactory;
320  mutable ClusterBindings::Factory CBFactory;
321 
322  typedef std::vector<SVal> SValListTy;
323 private:
324  typedef llvm::DenseMap<const LazyCompoundValData *,
325  SValListTy> LazyBindingsMapTy;
326  LazyBindingsMapTy LazyBindingsMap;
327 
328  /// The largest number of fields a struct can have and still be
329  /// considered "small".
330  ///
331  /// This is currently used to decide whether or not it is worth "forcing" a
332  /// LazyCompoundVal on bind.
333  ///
334  /// This is controlled by 'region-store-small-struct-limit' option.
335  /// To disable all small-struct-dependent behavior, set the option to "0".
336  unsigned SmallStructLimit;
337 
338  /// \brief A helper used to populate the work list with the given set of
339  /// regions.
340  void populateWorkList(invalidateRegionsWorker &W,
341  ArrayRef<SVal> Values,
342  InvalidatedRegions *TopLevelRegions);
343 
344 public:
345  RegionStoreManager(ProgramStateManager& mgr, const RegionStoreFeatures &f)
346  : StoreManager(mgr), Features(f),
347  RBFactory(mgr.getAllocator()), CBFactory(mgr.getAllocator()),
348  SmallStructLimit(0) {
349  if (SubEngine *Eng = StateMgr.getOwningEngine()) {
350  AnalyzerOptions &Options = Eng->getAnalysisManager().options;
351  SmallStructLimit =
352  Options.getOptionAsInteger("region-store-small-struct-limit", 2);
353  }
354  }
355 
356 
357  /// setImplicitDefaultValue - Set the default binding for the provided
358  /// MemRegion to the value implicitly defined for compound literals when
359  /// the value is not specified.
360  RegionBindingsRef setImplicitDefaultValue(RegionBindingsConstRef B,
361  const MemRegion *R, QualType T);
362 
363  /// ArrayToPointer - Emulates the "decay" of an array to a pointer
364  /// type. 'Array' represents the lvalue of the array being decayed
365  /// to a pointer, and the returned SVal represents the decayed
366  /// version of that lvalue (i.e., a pointer to the first element of
367  /// the array). This is called by ExprEngine when evaluating
368  /// casts from arrays to pointers.
369  SVal ArrayToPointer(Loc Array, QualType ElementTy) override;
370 
371  StoreRef getInitialStore(const LocationContext *InitLoc) override {
372  return StoreRef(RBFactory.getEmptyMap().getRootWithoutRetain(), *this);
373  }
374 
375  //===-------------------------------------------------------------------===//
376  // Binding values to regions.
377  //===-------------------------------------------------------------------===//
378  RegionBindingsRef invalidateGlobalRegion(MemRegion::Kind K,
379  const Expr *Ex,
380  unsigned Count,
381  const LocationContext *LCtx,
382  RegionBindingsRef B,
383  InvalidatedRegions *Invalidated);
384 
385  StoreRef invalidateRegions(Store store,
386  ArrayRef<SVal> Values,
387  const Expr *E, unsigned Count,
388  const LocationContext *LCtx,
389  const CallEvent *Call,
390  InvalidatedSymbols &IS,
392  InvalidatedRegions *Invalidated,
393  InvalidatedRegions *InvalidatedTopLevel) override;
394 
395  bool scanReachableSymbols(Store S, const MemRegion *R,
396  ScanReachableSymbols &Callbacks) override;
397 
398  RegionBindingsRef removeSubRegionBindings(RegionBindingsConstRef B,
399  const SubRegion *R);
400 
401 public: // Part of public interface to class.
402 
403  StoreRef Bind(Store store, Loc LV, SVal V) override {
404  return StoreRef(bind(getRegionBindings(store), LV, V).asStore(), *this);
405  }
406 
407  RegionBindingsRef bind(RegionBindingsConstRef B, Loc LV, SVal V);
408 
409  // BindDefault is only used to initialize a region with a default value.
410  StoreRef BindDefault(Store store, const MemRegion *R, SVal V) override {
411  RegionBindingsRef B = getRegionBindings(store);
412  assert(!B.lookup(R, BindingKey::Direct));
413 
414  BindingKey Key = BindingKey::Make(R, BindingKey::Default);
415  if (B.lookup(Key)) {
416  const SubRegion *SR = cast<SubRegion>(R);
417  assert(SR->getAsOffset().getOffset() ==
418  SR->getSuperRegion()->getAsOffset().getOffset() &&
419  "A default value must come from a super-region");
420  B = removeSubRegionBindings(B, SR);
421  } else {
422  B = B.addBinding(Key, V);
423  }
424 
425  return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
426  }
427 
428  /// Attempt to extract the fields of \p LCV and bind them to the struct region
429  /// \p R.
430  ///
431  /// This path is used when it seems advantageous to "force" loading the values
432  /// within a LazyCompoundVal to bind memberwise to the struct region, rather
433  /// than using a Default binding at the base of the entire region. This is a
434  /// heuristic attempting to avoid building long chains of LazyCompoundVals.
435  ///
436  /// \returns The updated store bindings, or \c None if binding non-lazily
437  /// would be too expensive.
439  const TypedValueRegion *R,
440  const RecordDecl *RD,
442 
443  /// BindStruct - Bind a compound value to a structure.
444  RegionBindingsRef bindStruct(RegionBindingsConstRef B,
445  const TypedValueRegion* R, SVal V);
446 
447  /// BindVector - Bind a compound value to a vector.
448  RegionBindingsRef bindVector(RegionBindingsConstRef B,
449  const TypedValueRegion* R, SVal V);
450 
451  RegionBindingsRef bindArray(RegionBindingsConstRef B,
452  const TypedValueRegion* R,
453  SVal V);
454 
455  /// Clears out all bindings in the given region and assigns a new value
456  /// as a Default binding.
457  RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
458  const TypedRegion *R,
459  SVal DefaultVal);
460 
461  /// \brief Create a new store with the specified binding removed.
462  /// \param ST the original store, that is the basis for the new store.
463  /// \param L the location whose binding should be removed.
464  StoreRef killBinding(Store ST, Loc L) override;
465 
466  void incrementReferenceCount(Store store) override {
467  getRegionBindings(store).manualRetain();
468  }
469 
470  /// If the StoreManager supports it, decrement the reference count of
471  /// the specified Store object. If the reference count hits 0, the memory
472  /// associated with the object is recycled.
473  void decrementReferenceCount(Store store) override {
474  getRegionBindings(store).manualRelease();
475  }
476 
477  bool includedInBindings(Store store, const MemRegion *region) const override;
478 
479  /// \brief Return the value bound to specified location in a given state.
480  ///
481  /// The high level logic for this method is this:
482  /// getBinding (L)
483  /// if L has binding
484  /// return L's binding
485  /// else if L is in killset
486  /// return unknown
487  /// else
488  /// if L is on stack or heap
489  /// return undefined
490  /// else
491  /// return symbolic
492  SVal getBinding(Store S, Loc L, QualType T) override {
493  return getBinding(getRegionBindings(S), L, T);
494  }
495 
496  SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());
497 
498  SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);
499 
500  SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);
501 
502  SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);
503 
504  SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);
505 
506  SVal getBindingForLazySymbol(const TypedValueRegion *R);
507 
508  SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
509  const TypedValueRegion *R,
510  QualType Ty);
511 
512  SVal getLazyBinding(const SubRegion *LazyBindingRegion,
513  RegionBindingsRef LazyBinding);
514 
515  /// Get bindings for the values in a struct and return a CompoundVal, used
516  /// when doing struct copy:
517  /// struct s x, y;
518  /// x = y;
519  /// y's value is retrieved by this method.
520  SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
521  SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
522  NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);
523 
524  /// Used to lazily generate derived symbols for bindings that are defined
525  /// implicitly by default bindings in a super region.
526  ///
527  /// Note that callers may need to specially handle LazyCompoundVals, which
528  /// are returned as is in case the caller needs to treat them differently.
529  Optional<SVal> getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
530  const MemRegion *superR,
531  const TypedValueRegion *R,
532  QualType Ty);
533 
534  /// Get the state and region whose binding this region \p R corresponds to.
535  ///
536  /// If there is no lazy binding for \p R, the returned value will have a null
537  /// \c second. Note that a null pointer can represents a valid Store.
538  std::pair<Store, const SubRegion *>
539  findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
540  const SubRegion *originalRegion);
541 
542  /// Returns the cached set of interesting SVals contained within a lazy
543  /// binding.
544  ///
545  /// The precise value of "interesting" is determined for the purposes of
546  /// RegionStore's internal analysis. It must always contain all regions and
547  /// symbols, but may omit constants and other kinds of SVal.
548  const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);
549 
550  //===------------------------------------------------------------------===//
551  // State pruning.
552  //===------------------------------------------------------------------===//
553 
554  /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
555  /// It returns a new Store with these values removed.
556  StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
557  SymbolReaper& SymReaper) override;
558 
559  //===------------------------------------------------------------------===//
560  // Region "extents".
561  //===------------------------------------------------------------------===//
562 
563  // FIXME: This method will soon be eliminated; see the note in Store.h.
564  DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state,
565  const MemRegion* R,
566  QualType EleTy) override;
567 
568  //===------------------------------------------------------------------===//
569  // Utility methods.
570  //===------------------------------------------------------------------===//
571 
572  RegionBindingsRef getRegionBindings(Store store) const {
573  return RegionBindingsRef(CBFactory,
574  static_cast<const RegionBindings::TreeTy*>(store),
575  RBFactory.getTreeFactory());
576  }
577 
578  void print(Store store, raw_ostream &Out, const char* nl,
579  const char *sep) override;
580 
581  void iterBindings(Store store, BindingsHandler& f) override {
582  RegionBindingsRef B = getRegionBindings(store);
583  for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
584  const ClusterBindings &Cluster = I.getData();
585  for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
586  CI != CE; ++CI) {
587  const BindingKey &K = CI.getKey();
588  if (!K.isDirect())
589  continue;
590  if (const SubRegion *R = dyn_cast<SubRegion>(K.getRegion())) {
591  // FIXME: Possibly incorporate the offset?
592  if (!f.HandleBinding(*this, store, R, CI.getData()))
593  return;
594  }
595  }
596  }
597  }
598 };
599 
600 } // end anonymous namespace
601 
602 //===----------------------------------------------------------------------===//
603 // RegionStore creation.
604 //===----------------------------------------------------------------------===//
605 
606 std::unique_ptr<StoreManager>
608  RegionStoreFeatures F = maximal_features_tag();
609  return llvm::make_unique<RegionStoreManager>(StMgr, F);
610 }
611 
612 std::unique_ptr<StoreManager>
614  RegionStoreFeatures F = minimal_features_tag();
615  F.enableFields(true);
616  return llvm::make_unique<RegionStoreManager>(StMgr, F);
617 }
618 
619 
620 //===----------------------------------------------------------------------===//
621 // Region Cluster analysis.
622 //===----------------------------------------------------------------------===//
623 
624 namespace {
625 /// Used to determine which global regions are automatically included in the
626 /// initial worklist of a ClusterAnalysis.
628  /// Don't include any global regions.
629  GFK_None,
630  /// Only include system globals.
631  GFK_SystemOnly,
632  /// Include all global regions.
633  GFK_All
634 };
635 
636 template <typename DERIVED>
637 class ClusterAnalysis {
638 protected:
639  typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
640  typedef const MemRegion * WorkListElement;
642 
643  llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
644 
645  WorkList WL;
646 
647  RegionStoreManager &RM;
648  ASTContext &Ctx;
649  SValBuilder &svalBuilder;
650 
651  RegionBindingsRef B;
652 
653 
654 protected:
655  const ClusterBindings *getCluster(const MemRegion *R) {
656  return B.lookup(R);
657  }
658 
659  /// Returns true if all clusters in the given memspace should be initially
660  /// included in the cluster analysis. Subclasses may provide their
661  /// own implementation.
662  bool includeEntireMemorySpace(const MemRegion *Base) {
663  return false;
664  }
665 
666 public:
667  ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
668  RegionBindingsRef b )
669  : RM(rm), Ctx(StateMgr.getContext()),
670  svalBuilder(StateMgr.getSValBuilder()),
671  B(b) {}
672 
673  RegionBindingsRef getRegionBindings() const { return B; }
674 
675  bool isVisited(const MemRegion *R) {
676  return Visited.count(getCluster(R));
677  }
678 
679  void GenerateClusters() {
680  // Scan the entire set of bindings and record the region clusters.
681  for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
682  RI != RE; ++RI){
683  const MemRegion *Base = RI.getKey();
684 
685  const ClusterBindings &Cluster = RI.getData();
686  assert(!Cluster.isEmpty() && "Empty clusters should be removed");
687  static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);
688 
689  // If the base's memspace should be entirely invalidated, add the cluster
690  // to the workspace up front.
691  if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
692  AddToWorkList(WorkListElement(Base), &Cluster);
693  }
694  }
695 
696  bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
697  if (C && !Visited.insert(C).second)
698  return false;
699  WL.push_back(E);
700  return true;
701  }
702 
703  bool AddToWorkList(const MemRegion *R) {
704  return static_cast<DERIVED*>(this)->AddToWorkList(R);
705  }
706 
707  void RunWorkList() {
708  while (!WL.empty()) {
709  WorkListElement E = WL.pop_back_val();
710  const MemRegion *BaseR = E;
711 
712  static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
713  }
714  }
715 
716  void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
717  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}
718 
719  void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
720  bool Flag) {
721  static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
722  }
723 };
724 }
725 
726 //===----------------------------------------------------------------------===//
727 // Binding invalidation.
728 //===----------------------------------------------------------------------===//
729 
730 bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
731  ScanReachableSymbols &Callbacks) {
732  assert(R == R->getBaseRegion() && "Should only be called for base regions");
733  RegionBindingsRef B = getRegionBindings(S);
734  const ClusterBindings *Cluster = B.lookup(R);
735 
736  if (!Cluster)
737  return true;
738 
739  for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
740  RI != RE; ++RI) {
741  if (!Callbacks.scan(RI.getData()))
742  return false;
743  }
744 
745  return true;
746 }
747 
748 static inline bool isUnionField(const FieldRegion *FR) {
749  return FR->getDecl()->getParent()->isUnion();
750 }
751 
753 
754 static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
755  assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
756 
757  const MemRegion *Base = K.getConcreteOffsetRegion();
758  const MemRegion *R = K.getRegion();
759 
760  while (R != Base) {
761  if (const FieldRegion *FR = dyn_cast<FieldRegion>(R))
762  if (!isUnionField(FR))
763  Fields.push_back(FR->getDecl());
764 
765  R = cast<SubRegion>(R)->getSuperRegion();
766  }
767 }
768 
769 static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
770  assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
771 
772  if (Fields.empty())
773  return true;
774 
775  FieldVector FieldsInBindingKey;
776  getSymbolicOffsetFields(K, FieldsInBindingKey);
777 
778  ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
779  if (Delta >= 0)
780  return std::equal(FieldsInBindingKey.begin() + Delta,
781  FieldsInBindingKey.end(),
782  Fields.begin());
783  else
784  return std::equal(FieldsInBindingKey.begin(), FieldsInBindingKey.end(),
785  Fields.begin() - Delta);
786 }
787 
788 /// Collects all bindings in \p Cluster that may refer to bindings within
789 /// \p Top.
790 ///
791 /// Each binding is a pair whose \c first is the key (a BindingKey) and whose
792 /// \c second is the value (an SVal).
793 ///
794 /// The \p IncludeAllDefaultBindings parameter specifies whether to include
795 /// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
796 /// an aggregate within a larger aggregate with a default binding.
797 static void
799  SValBuilder &SVB, const ClusterBindings &Cluster,
800  const SubRegion *Top, BindingKey TopKey,
801  bool IncludeAllDefaultBindings) {
802  FieldVector FieldsInSymbolicSubregions;
803  if (TopKey.hasSymbolicOffset()) {
804  getSymbolicOffsetFields(TopKey, FieldsInSymbolicSubregions);
805  Top = cast<SubRegion>(TopKey.getConcreteOffsetRegion());
806  TopKey = BindingKey::Make(Top, BindingKey::Default);
807  }
808 
809  // Find the length (in bits) of the region being invalidated.
810  uint64_t Length = UINT64_MAX;
811  SVal Extent = Top->getExtent(SVB);
812  if (Optional<nonloc::ConcreteInt> ExtentCI =
813  Extent.getAs<nonloc::ConcreteInt>()) {
814  const llvm::APSInt &ExtentInt = ExtentCI->getValue();
815  assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
816  // Extents are in bytes but region offsets are in bits. Be careful!
817  Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
818  } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Top)) {
819  if (FR->getDecl()->isBitField())
820  Length = FR->getDecl()->getBitWidthValue(SVB.getContext());
821  }
822 
823  for (ClusterBindings::iterator I = Cluster.begin(), E = Cluster.end();
824  I != E; ++I) {
825  BindingKey NextKey = I.getKey();
826  if (NextKey.getRegion() == TopKey.getRegion()) {
827  // FIXME: This doesn't catch the case where we're really invalidating a
828  // region with a symbolic offset. Example:
829  // R: points[i].y
830  // Next: points[0].x
831 
832  if (NextKey.getOffset() > TopKey.getOffset() &&
833  NextKey.getOffset() - TopKey.getOffset() < Length) {
834  // Case 1: The next binding is inside the region we're invalidating.
835  // Include it.
836  Bindings.push_back(*I);
837 
838  } else if (NextKey.getOffset() == TopKey.getOffset()) {
839  // Case 2: The next binding is at the same offset as the region we're
840  // invalidating. In this case, we need to leave default bindings alone,
841  // since they may be providing a default value for a regions beyond what
842  // we're invalidating.
843  // FIXME: This is probably incorrect; consider invalidating an outer
844  // struct whose first field is bound to a LazyCompoundVal.
845  if (IncludeAllDefaultBindings || NextKey.isDirect())
846  Bindings.push_back(*I);
847  }
848 
849  } else if (NextKey.hasSymbolicOffset()) {
850  const MemRegion *Base = NextKey.getConcreteOffsetRegion();
851  if (Top->isSubRegionOf(Base)) {
852  // Case 3: The next key is symbolic and we just changed something within
853  // its concrete region. We don't know if the binding is still valid, so
854  // we'll be conservative and include it.
855  if (IncludeAllDefaultBindings || NextKey.isDirect())
856  if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
857  Bindings.push_back(*I);
858  } else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Base)) {
859  // Case 4: The next key is symbolic, but we changed a known
860  // super-region. In this case the binding is certainly included.
861  if (Top == Base || BaseSR->isSubRegionOf(Top))
862  if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
863  Bindings.push_back(*I);
864  }
865  }
866  }
867 }
868 
869 static void
871  SValBuilder &SVB, const ClusterBindings &Cluster,
872  const SubRegion *Top, bool IncludeAllDefaultBindings) {
873  collectSubRegionBindings(Bindings, SVB, Cluster, Top,
874  BindingKey::Make(Top, BindingKey::Default),
875  IncludeAllDefaultBindings);
876 }
877 
878 RegionBindingsRef
879 RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
880  const SubRegion *Top) {
881  BindingKey TopKey = BindingKey::Make(Top, BindingKey::Default);
882  const MemRegion *ClusterHead = TopKey.getBaseRegion();
883 
884  if (Top == ClusterHead) {
885  // We can remove an entire cluster's bindings all in one go.
886  return B.remove(Top);
887  }
888 
889  const ClusterBindings *Cluster = B.lookup(ClusterHead);
890  if (!Cluster) {
891  // If we're invalidating a region with a symbolic offset, we need to make
892  // sure we don't treat the base region as uninitialized anymore.
893  if (TopKey.hasSymbolicOffset()) {
894  const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
895  return B.addBinding(Concrete, BindingKey::Default, UnknownVal());
896  }
897  return B;
898  }
899 
901  collectSubRegionBindings(Bindings, svalBuilder, *Cluster, Top, TopKey,
902  /*IncludeAllDefaultBindings=*/false);
903 
904  ClusterBindingsRef Result(*Cluster, CBFactory);
905  for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
906  E = Bindings.end();
907  I != E; ++I)
908  Result = Result.remove(I->first);
909 
910  // If we're invalidating a region with a symbolic offset, we need to make sure
911  // we don't treat the base region as uninitialized anymore.
912  // FIXME: This isn't very precise; see the example in
913  // collectSubRegionBindings.
914  if (TopKey.hasSymbolicOffset()) {
915  const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
916  Result = Result.add(BindingKey::Make(Concrete, BindingKey::Default),
917  UnknownVal());
918  }
919 
920  if (Result.isEmpty())
921  return B.remove(ClusterHead);
922  return B.add(ClusterHead, Result.asImmutableMap());
923 }
924 
925 namespace {
926 class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
927 {
928  const Expr *Ex;
929  unsigned Count;
930  const LocationContext *LCtx;
931  InvalidatedSymbols &IS;
934  GlobalsFilterKind GlobalsFilter;
935 public:
936  invalidateRegionsWorker(RegionStoreManager &rm,
937  ProgramStateManager &stateMgr,
938  RegionBindingsRef b,
939  const Expr *ex, unsigned count,
940  const LocationContext *lctx,
941  InvalidatedSymbols &is,
944  GlobalsFilterKind GFK)
945  : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b),
946  Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
947  GlobalsFilter(GFK) {}
948 
949  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
950  void VisitBinding(SVal V);
951 
952  using ClusterAnalysis::AddToWorkList;
953 
954  bool AddToWorkList(const MemRegion *R);
955 
956  /// Returns true if all clusters in the memory space for \p Base should be
957  /// be invalidated.
958  bool includeEntireMemorySpace(const MemRegion *Base);
959 
960  /// Returns true if the memory space of the given region is one of the global
961  /// regions specially included at the start of invalidation.
962  bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
963 };
964 }
965 
966 bool invalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
967  bool doNotInvalidateSuperRegion = ITraits.hasTrait(
969  const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
970  return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
971 }
972 
973 void invalidateRegionsWorker::VisitBinding(SVal V) {
974  // A symbol? Mark it touched by the invalidation.
975  if (SymbolRef Sym = V.getAsSymbol())
976  IS.insert(Sym);
977 
978  if (const MemRegion *R = V.getAsRegion()) {
979  AddToWorkList(R);
980  return;
981  }
982 
983  // Is it a LazyCompoundVal? All references get invalidated as well.
986 
987  const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
988 
989  for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
990  E = Vals.end();
991  I != E; ++I)
992  VisitBinding(*I);
993 
994  return;
995  }
996 }
997 
998 void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
999  const ClusterBindings *C) {
1000 
1001  bool PreserveRegionsContents =
1002  ITraits.hasTrait(baseR,
1004 
1005  if (C) {
1006  for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
1007  VisitBinding(I.getData());
1008 
1009  // Invalidate regions contents.
1010  if (!PreserveRegionsContents)
1011  B = B.remove(baseR);
1012  }
1013 
1014  // BlockDataRegion? If so, invalidate captured variables that are passed
1015  // by reference.
1016  if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
1018  BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
1019  BI != BE; ++BI) {
1020  const VarRegion *VR = BI.getCapturedRegion();
1021  const VarDecl *VD = VR->getDecl();
1022  if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
1023  AddToWorkList(VR);
1024  }
1025  else if (Loc::isLocType(VR->getValueType())) {
1026  // Map the current bindings to a Store to retrieve the value
1027  // of the binding. If that binding itself is a region, we should
1028  // invalidate that region. This is because a block may capture
1029  // a pointer value, but the thing pointed by that pointer may
1030  // get invalidated.
1031  SVal V = RM.getBinding(B, loc::MemRegionVal(VR));
1032  if (Optional<Loc> L = V.getAs<Loc>()) {
1033  if (const MemRegion *LR = L->getAsRegion())
1034  AddToWorkList(LR);
1035  }
1036  }
1037  }
1038  return;
1039  }
1040 
1041  // Symbolic region?
1042  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
1043  IS.insert(SR->getSymbol());
1044 
1045  // Nothing else should be done in the case when we preserve regions context.
1046  if (PreserveRegionsContents)
1047  return;
1048 
1049  // Otherwise, we have a normal data region. Record that we touched the region.
1050  if (Regions)
1051  Regions->push_back(baseR);
1052 
1053  if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
1054  // Invalidate the region by setting its default value to
1055  // conjured symbol. The type of the symbol is irrelevant.
1057  svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
1058  B = B.addBinding(baseR, BindingKey::Default, V);
1059  return;
1060  }
1061 
1062  if (!baseR->isBoundable())
1063  return;
1064 
1065  const TypedValueRegion *TR = cast<TypedValueRegion>(baseR);
1066  QualType T = TR->getValueType();
1067 
1068  if (isInitiallyIncludedGlobalRegion(baseR)) {
1069  // If the region is a global and we are invalidating all globals,
1070  // erasing the entry is good enough. This causes all globals to be lazily
1071  // symbolicated from the same base symbol.
1072  return;
1073  }
1074 
1075  if (T->isStructureOrClassType()) {
1076  // Invalidate the region by setting its default value to
1077  // conjured symbol. The type of the symbol is irrelevant.
1078  DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1079  Ctx.IntTy, Count);
1080  B = B.addBinding(baseR, BindingKey::Default, V);
1081  return;
1082  }
1083 
1084  if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
1085  bool doNotInvalidateSuperRegion = ITraits.hasTrait(
1086  baseR,
1088 
1089  if (doNotInvalidateSuperRegion) {
1090  // We are not doing blank invalidation of the whole array region so we
1091  // have to manually invalidate each elements.
1092  Optional<uint64_t> NumElements;
1093 
1094  // Compute lower and upper offsets for region within array.
1095  if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
1096  NumElements = CAT->getSize().getZExtValue();
1097  if (!NumElements) // We are not dealing with a constant size array
1098  goto conjure_default;
1099  QualType ElementTy = AT->getElementType();
1100  uint64_t ElemSize = Ctx.getTypeSize(ElementTy);
1101  const RegionOffset &RO = baseR->getAsOffset();
1102  const MemRegion *SuperR = baseR->getBaseRegion();
1103  if (RO.hasSymbolicOffset()) {
1104  // If base region has a symbolic offset,
1105  // we revert to invalidating the super region.
1106  if (SuperR)
1107  AddToWorkList(SuperR);
1108  goto conjure_default;
1109  }
1110 
1111  uint64_t LowerOffset = RO.getOffset();
1112  uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
1113  bool UpperOverflow = UpperOffset < LowerOffset;
1114 
1115  // Invalidate regions which are within array boundaries,
1116  // or have a symbolic offset.
1117  if (!SuperR)
1118  goto conjure_default;
1119 
1120  const ClusterBindings *C = B.lookup(SuperR);
1121  if (!C)
1122  goto conjure_default;
1123 
1124  for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E;
1125  ++I) {
1126  const BindingKey &BK = I.getKey();
1127  Optional<uint64_t> ROffset =
1128  BK.hasSymbolicOffset() ? Optional<uint64_t>() : BK.getOffset();
1129 
1130  // Check offset is not symbolic and within array's boundaries.
1131  // Handles arrays of 0 elements and of 0-sized elements as well.
1132  if (!ROffset ||
1133  (ROffset &&
1134  ((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
1135  (UpperOverflow &&
1136  (*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
1137  (LowerOffset == UpperOffset && *ROffset == LowerOffset)))) {
1138  B = B.removeBinding(I.getKey());
1139  // Bound symbolic regions need to be invalidated for dead symbol
1140  // detection.
1141  SVal V = I.getData();
1142  const MemRegion *R = V.getAsRegion();
1143  if (R && isa<SymbolicRegion>(R))
1144  VisitBinding(V);
1145  }
1146  }
1147  }
1148  conjure_default:
1149  // Set the default value of the array to conjured symbol.
1151  svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1152  AT->getElementType(), Count);
1153  B = B.addBinding(baseR, BindingKey::Default, V);
1154  return;
1155  }
1156 
1157  DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
1158  T,Count);
1159  assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
1160  B = B.addBinding(baseR, BindingKey::Direct, V);
1161 }
1162 
1163 bool invalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
1164  const MemRegion *R) {
1165  switch (GlobalsFilter) {
1166  case GFK_None:
1167  return false;
1168  case GFK_SystemOnly:
1169  return isa<GlobalSystemSpaceRegion>(R->getMemorySpace());
1170  case GFK_All:
1171  return isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace());
1172  }
1173 
1174  llvm_unreachable("unknown globals filter");
1175 }
1176 
1177 bool invalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
1178  if (isInitiallyIncludedGlobalRegion(Base))
1179  return true;
1180 
1181  const MemSpaceRegion *MemSpace = Base->getMemorySpace();
1182  return ITraits.hasTrait(MemSpace,
1184 }
1185 
1186 RegionBindingsRef
1187 RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
1188  const Expr *Ex,
1189  unsigned Count,
1190  const LocationContext *LCtx,
1191  RegionBindingsRef B,
1192  InvalidatedRegions *Invalidated) {
1193  // Bind the globals memory space to a new symbol that we will use to derive
1194  // the bindings for all globals.
1195  const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
1196  SVal V = svalBuilder.conjureSymbolVal(/* SymbolTag = */ (const void*) GS, Ex, LCtx,
1197  /* type does not matter */ Ctx.IntTy,
1198  Count);
1199 
1200  B = B.removeBinding(GS)
1201  .addBinding(BindingKey::Make(GS, BindingKey::Default), V);
1202 
1203  // Even if there are no bindings in the global scope, we still need to
1204  // record that we touched it.
1205  if (Invalidated)
1206  Invalidated->push_back(GS);
1207 
1208  return B;
1209 }
1210 
1211 void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
1212  ArrayRef<SVal> Values,
1213  InvalidatedRegions *TopLevelRegions) {
1214  for (ArrayRef<SVal>::iterator I = Values.begin(),
1215  E = Values.end(); I != E; ++I) {
1216  SVal V = *I;
1219 
1220  const SValListTy &Vals = getInterestingValues(*LCS);
1221 
1222  for (SValListTy::const_iterator I = Vals.begin(),
1223  E = Vals.end(); I != E; ++I) {
1224  // Note: the last argument is false here because these are
1225  // non-top-level regions.
1226  if (const MemRegion *R = (*I).getAsRegion())
1227  W.AddToWorkList(R);
1228  }
1229  continue;
1230  }
1231 
1232  if (const MemRegion *R = V.getAsRegion()) {
1233  if (TopLevelRegions)
1234  TopLevelRegions->push_back(R);
1235  W.AddToWorkList(R);
1236  continue;
1237  }
1238  }
1239 }
1240 
1241 StoreRef
1242 RegionStoreManager::invalidateRegions(Store store,
1243  ArrayRef<SVal> Values,
1244  const Expr *Ex, unsigned Count,
1245  const LocationContext *LCtx,
1246  const CallEvent *Call,
1247  InvalidatedSymbols &IS,
1249  InvalidatedRegions *TopLevelRegions,
1250  InvalidatedRegions *Invalidated) {
1251  GlobalsFilterKind GlobalsFilter;
1252  if (Call) {
1253  if (Call->isInSystemHeader())
1254  GlobalsFilter = GFK_SystemOnly;
1255  else
1256  GlobalsFilter = GFK_All;
1257  } else {
1258  GlobalsFilter = GFK_None;
1259  }
1260 
1261  RegionBindingsRef B = getRegionBindings(store);
1262  invalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
1263  Invalidated, GlobalsFilter);
1264 
1265  // Scan the bindings and generate the clusters.
1266  W.GenerateClusters();
1267 
1268  // Add the regions to the worklist.
1269  populateWorkList(W, Values, TopLevelRegions);
1270 
1271  W.RunWorkList();
1272 
1273  // Return the new bindings.
1274  B = W.getRegionBindings();
1275 
1276  // For calls, determine which global regions should be invalidated and
1277  // invalidate them. (Note that function-static and immutable globals are never
1278  // invalidated by this.)
1279  // TODO: This could possibly be more precise with modules.
1280  switch (GlobalsFilter) {
1281  case GFK_All:
1282  B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
1283  Ex, Count, LCtx, B, Invalidated);
1284  // FALLTHROUGH
1285  case GFK_SystemOnly:
1286  B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
1287  Ex, Count, LCtx, B, Invalidated);
1288  // FALLTHROUGH
1289  case GFK_None:
1290  break;
1291  }
1292 
1293  return StoreRef(B.asStore(), *this);
1294 }
1295 
1296 //===----------------------------------------------------------------------===//
1297 // Extents for regions.
1298 //===----------------------------------------------------------------------===//
1299 
1301 RegionStoreManager::getSizeInElements(ProgramStateRef state,
1302  const MemRegion *R,
1303  QualType EleTy) {
1304  SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
1305  const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
1306  if (!SizeInt)
1307  return UnknownVal();
1308 
1309  CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());
1310 
1311  if (Ctx.getAsVariableArrayType(EleTy)) {
1312  // FIXME: We need to track extra state to properly record the size
1313  // of VLAs. Returning UnknownVal here, however, is a stop-gap so that
1314  // we don't have a divide-by-zero below.
1315  return UnknownVal();
1316  }
1317 
1318  CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);
1319 
1320  // If a variable is reinterpreted as a type that doesn't fit into a larger
1321  // type evenly, round it down.
1322  // This is a signed value, since it's used in arithmetic with signed indices.
1323  return svalBuilder.makeIntVal(RegionSize / EleSize, false);
1324 }
1325 
1326 //===----------------------------------------------------------------------===//
1327 // Location and region casting.
1328 //===----------------------------------------------------------------------===//
1329 
1330 /// ArrayToPointer - Emulates the "decay" of an array to a pointer
1331 /// type. 'Array' represents the lvalue of the array being decayed
1332 /// to a pointer, and the returned SVal represents the decayed
1333 /// version of that lvalue (i.e., a pointer to the first element of
1334 /// the array). This is called by ExprEngine when evaluating casts
1335 /// from arrays to pointers.
1336 SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
1337  if (!Array.getAs<loc::MemRegionVal>())
1338  return UnknownVal();
1339 
1340  const MemRegion* R = Array.castAs<loc::MemRegionVal>().getRegion();
1341  NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
1342  return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
1343 }
1344 
1345 //===----------------------------------------------------------------------===//
1346 // Loading values from regions.
1347 //===----------------------------------------------------------------------===//
1348 
1349 SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
1350  assert(!L.getAs<UnknownVal>() && "location unknown");
1351  assert(!L.getAs<UndefinedVal>() && "location undefined");
1352 
1353  // For access to concrete addresses, return UnknownVal. Checks
1354  // for null dereferences (and similar errors) are done by checkers, not
1355  // the Store.
1356  // FIXME: We can consider lazily symbolicating such memory, but we really
1357  // should defer this when we can reason easily about symbolicating arrays
1358  // of bytes.
1359  if (L.getAs<loc::ConcreteInt>()) {
1360  return UnknownVal();
1361  }
1362  if (!L.getAs<loc::MemRegionVal>()) {
1363  return UnknownVal();
1364  }
1365 
1366  const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();
1367 
1368  if (isa<BlockDataRegion>(MR)) {
1369  return UnknownVal();
1370  }
1371 
1372  if (isa<AllocaRegion>(MR) ||
1373  isa<SymbolicRegion>(MR) ||
1374  isa<CodeTextRegion>(MR)) {
1375  if (T.isNull()) {
1376  if (const TypedRegion *TR = dyn_cast<TypedRegion>(MR))
1377  T = TR->getLocationType();
1378  else {
1379  const SymbolicRegion *SR = cast<SymbolicRegion>(MR);
1380  T = SR->getSymbol()->getType();
1381  }
1382  }
1383  MR = GetElementZeroRegion(MR, T);
1384  }
1385 
1386  // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
1387  // instead of 'Loc', and have the other Loc cases handled at a higher level.
1388  const TypedValueRegion *R = cast<TypedValueRegion>(MR);
1389  QualType RTy = R->getValueType();
1390 
1391  // FIXME: we do not yet model the parts of a complex type, so treat the
1392  // whole thing as "unknown".
1393  if (RTy->isAnyComplexType())
1394  return UnknownVal();
1395 
1396  // FIXME: We should eventually handle funny addressing. e.g.:
1397  //
1398  // int x = ...;
1399  // int *p = &x;
1400  // char *q = (char*) p;
1401  // char c = *q; // returns the first byte of 'x'.
1402  //
1403  // Such funny addressing will occur due to layering of regions.
1404  if (RTy->isStructureOrClassType())
1405  return getBindingForStruct(B, R);
1406 
1407  // FIXME: Handle unions.
1408  if (RTy->isUnionType())
1409  return createLazyBinding(B, R);
1410 
1411  if (RTy->isArrayType()) {
1412  if (RTy->isConstantArrayType())
1413  return getBindingForArray(B, R);
1414  else
1415  return UnknownVal();
1416  }
1417 
1418  // FIXME: handle Vector types.
1419  if (RTy->isVectorType())
1420  return UnknownVal();
1421 
1422  if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
1423  return CastRetrievedVal(getBindingForField(B, FR), FR, T, false);
1424 
1425  if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
1426  // FIXME: Here we actually perform an implicit conversion from the loaded
1427  // value to the element type. Eventually we want to compose these values
1428  // more intelligently. For example, an 'element' can encompass multiple
1429  // bound regions (e.g., several bound bytes), or could be a subset of
1430  // a larger value.
1431  return CastRetrievedVal(getBindingForElement(B, ER), ER, T, false);
1432  }
1433 
1434  if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
1435  // FIXME: Here we actually perform an implicit conversion from the loaded
1436  // value to the ivar type. What we should model is stores to ivars
1437  // that blow past the extent of the ivar. If the address of the ivar is
1438  // reinterpretted, it is possible we stored a different value that could
1439  // fit within the ivar. Either we need to cast these when storing them
1440  // or reinterpret them lazily (as we do here).
1441  return CastRetrievedVal(getBindingForObjCIvar(B, IVR), IVR, T, false);
1442  }
1443 
1444  if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
1445  // FIXME: Here we actually perform an implicit conversion from the loaded
1446  // value to the variable type. What we should model is stores to variables
1447  // that blow past the extent of the variable. If the address of the
1448  // variable is reinterpretted, it is possible we stored a different value
1449  // that could fit within the variable. Either we need to cast these when
1450  // storing them or reinterpret them lazily (as we do here).
1451  return CastRetrievedVal(getBindingForVar(B, VR), VR, T, false);
1452  }
1453 
1454  const SVal *V = B.lookup(R, BindingKey::Direct);
1455 
1456  // Check if the region has a binding.
1457  if (V)
1458  return *V;
1459 
1460  // The location does not have a bound value. This means that it has
1461  // the value it had upon its creation and/or entry to the analyzed
1462  // function/method. These are either symbolic values or 'undefined'.
1463  if (R->hasStackNonParametersStorage()) {
1464  // All stack variables are considered to have undefined values
1465  // upon creation. All heap allocated blocks are considered to
1466  // have undefined values as well unless they are explicitly bound
1467  // to specific values.
1468  return UndefinedVal();
1469  }
1470 
1471  // All other values are symbolic.
1472  return svalBuilder.getRegionValueSymbolVal(R);
1473 }
1474 
1476  QualType RegionTy;
1477  if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
1478  RegionTy = TVR->getValueType();
1479 
1480  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
1481  RegionTy = SR->getSymbol()->getType();
1482 
1483  return RegionTy;
1484 }
1485 
1486 /// Checks to see if store \p B has a lazy binding for region \p R.
1487 ///
1488 /// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
1489 /// if there are additional bindings within \p R.
1490 ///
1491 /// Note that unlike RegionStoreManager::findLazyBinding, this will not search
1492 /// for lazy bindings for super-regions of \p R.
1495  const SubRegion *R, bool AllowSubregionBindings) {
1496  Optional<SVal> V = B.getDefaultBinding(R);
1497  if (!V)
1498  return None;
1499 
1501  if (!LCV)
1502  return None;
1503 
1504  // If the LCV is for a subregion, the types might not match, and we shouldn't
1505  // reuse the binding.
1506  QualType RegionTy = getUnderlyingType(R);
1507  if (!RegionTy.isNull() &&
1508  !RegionTy->isVoidPointerType()) {
1509  QualType SourceRegionTy = LCV->getRegion()->getValueType();
1510  if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
1511  return None;
1512  }
1513 
1514  if (!AllowSubregionBindings) {
1515  // If there are any other bindings within this region, we shouldn't reuse
1516  // the top-level binding.
1518  collectSubRegionBindings(Bindings, SVB, *B.lookup(R->getBaseRegion()), R,
1519  /*IncludeAllDefaultBindings=*/true);
1520  if (Bindings.size() > 1)
1521  return None;
1522  }
1523 
1524  return *LCV;
1525 }
1526 
1527 
1528 std::pair<Store, const SubRegion *>
1529 RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
1530  const SubRegion *R,
1531  const SubRegion *originalRegion) {
1532  if (originalRegion != R) {
1534  getExistingLazyBinding(svalBuilder, B, R, true))
1535  return std::make_pair(V->getStore(), V->getRegion());
1536  }
1537 
1538  typedef std::pair<Store, const SubRegion *> StoreRegionPair;
1539  StoreRegionPair Result = StoreRegionPair();
1540 
1541  if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
1542  Result = findLazyBinding(B, cast<SubRegion>(ER->getSuperRegion()),
1543  originalRegion);
1544 
1545  if (Result.second)
1546  Result.second = MRMgr.getElementRegionWithSuper(ER, Result.second);
1547 
1548  } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
1549  Result = findLazyBinding(B, cast<SubRegion>(FR->getSuperRegion()),
1550  originalRegion);
1551 
1552  if (Result.second)
1553  Result.second = MRMgr.getFieldRegionWithSuper(FR, Result.second);
1554 
1555  } else if (const CXXBaseObjectRegion *BaseReg =
1556  dyn_cast<CXXBaseObjectRegion>(R)) {
1557  // C++ base object region is another kind of region that we should blast
1558  // through to look for lazy compound value. It is like a field region.
1559  Result = findLazyBinding(B, cast<SubRegion>(BaseReg->getSuperRegion()),
1560  originalRegion);
1561 
1562  if (Result.second)
1563  Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(BaseReg,
1564  Result.second);
1565  }
1566 
1567  return Result;
1568 }
1569 
1570 SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
1571  const ElementRegion* R) {
1572  // We do not currently model bindings of the CompoundLiteralregion.
1573  if (isa<CompoundLiteralRegion>(R->getBaseRegion()))
1574  return UnknownVal();
1575 
1576  // Check if the region has a binding.
1577  if (const Optional<SVal> &V = B.getDirectBinding(R))
1578  return *V;
1579 
1580  const MemRegion* superR = R->getSuperRegion();
1581 
1582  // Check if the region is an element region of a string literal.
1583  if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
1584  // FIXME: Handle loads from strings where the literal is treated as
1585  // an integer, e.g., *((unsigned int*)"hello")
1586  QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
1587  if (!Ctx.hasSameUnqualifiedType(T, R->getElementType()))
1588  return UnknownVal();
1589 
1590  const StringLiteral *Str = StrR->getStringLiteral();
1591  SVal Idx = R->getIndex();
1593  int64_t i = CI->getValue().getSExtValue();
1594  // Abort on string underrun. This can be possible by arbitrary
1595  // clients of getBindingForElement().
1596  if (i < 0)
1597  return UndefinedVal();
1598  int64_t length = Str->getLength();
1599  // Technically, only i == length is guaranteed to be null.
1600  // However, such overflows should be caught before reaching this point;
1601  // the only time such an access would be made is if a string literal was
1602  // used to initialize a larger array.
1603  char c = (i >= length) ? '\0' : Str->getCodeUnit(i);
1604  return svalBuilder.makeIntVal(c, T);
1605  }
1606  }
1607 
1608  // Check for loads from a code text region. For such loads, just give up.
1609  if (isa<CodeTextRegion>(superR))
1610  return UnknownVal();
1611 
1612  // Handle the case where we are indexing into a larger scalar object.
1613  // For example, this handles:
1614  // int x = ...
1615  // char *y = &x;
1616  // return *y;
1617  // FIXME: This is a hack, and doesn't do anything really intelligent yet.
1618  const RegionRawOffset &O = R->getAsArrayOffset();
1619 
1620  // If we cannot reason about the offset, return an unknown value.
1621  if (!O.getRegion())
1622  return UnknownVal();
1623 
1624  if (const TypedValueRegion *baseR =
1625  dyn_cast_or_null<TypedValueRegion>(O.getRegion())) {
1626  QualType baseT = baseR->getValueType();
1627  if (baseT->isScalarType()) {
1628  QualType elemT = R->getElementType();
1629  if (elemT->isScalarType()) {
1630  if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
1631  if (const Optional<SVal> &V = B.getDirectBinding(superR)) {
1632  if (SymbolRef parentSym = V->getAsSymbol())
1633  return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1634 
1635  if (V->isUnknownOrUndef())
1636  return *V;
1637  // Other cases: give up. We are indexing into a larger object
1638  // that has some value, but we don't know how to handle that yet.
1639  return UnknownVal();
1640  }
1641  }
1642  }
1643  }
1644  }
1645  return getBindingForFieldOrElementCommon(B, R, R->getElementType());
1646 }
1647 
1648 SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
1649  const FieldRegion* R) {
1650 
1651  // Check if the region has a binding.
1652  if (const Optional<SVal> &V = B.getDirectBinding(R))
1653  return *V;
1654 
1655  QualType Ty = R->getValueType();
1656  return getBindingForFieldOrElementCommon(B, R, Ty);
1657 }
1658 
1660 RegionStoreManager::getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
1661  const MemRegion *superR,
1662  const TypedValueRegion *R,
1663  QualType Ty) {
1664 
1665  if (const Optional<SVal> &D = B.getDefaultBinding(superR)) {
1666  const SVal &val = D.getValue();
1667  if (SymbolRef parentSym = val.getAsSymbol())
1668  return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1669 
1670  if (val.isZeroConstant())
1671  return svalBuilder.makeZeroVal(Ty);
1672 
1673  if (val.isUnknownOrUndef())
1674  return val;
1675 
1676  // Lazy bindings are usually handled through getExistingLazyBinding().
1677  // We should unify these two code paths at some point.
1678  if (val.getAs<nonloc::LazyCompoundVal>())
1679  return val;
1680 
1681  llvm_unreachable("Unknown default value");
1682  }
1683 
1684  return None;
1685 }
1686 
1687 SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
1688  RegionBindingsRef LazyBinding) {
1689  SVal Result;
1690  if (const ElementRegion *ER = dyn_cast<ElementRegion>(LazyBindingRegion))
1691  Result = getBindingForElement(LazyBinding, ER);
1692  else
1693  Result = getBindingForField(LazyBinding,
1694  cast<FieldRegion>(LazyBindingRegion));
1695 
1696  // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1697  // default value for /part/ of an aggregate from a default value for the
1698  // /entire/ aggregate. The most common case of this is when struct Outer
1699  // has as its first member a struct Inner, which is copied in from a stack
1700  // variable. In this case, even if the Outer's default value is symbolic, 0,
1701  // or unknown, it gets overridden by the Inner's default value of undefined.
1702  //
1703  // This is a general problem -- if the Inner is zero-initialized, the Outer
1704  // will now look zero-initialized. The proper way to solve this is with a
1705  // new version of RegionStore that tracks the extent of a binding as well
1706  // as the offset.
1707  //
1708  // This hack only takes care of the undefined case because that can very
1709  // quickly result in a warning.
1710  if (Result.isUndef())
1711  Result = UnknownVal();
1712 
1713  return Result;
1714 }
1715 
1716 SVal
1717 RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
1718  const TypedValueRegion *R,
1719  QualType Ty) {
1720 
1721  // At this point we have already checked in either getBindingForElement or
1722  // getBindingForField if 'R' has a direct binding.
1723 
1724  // Lazy binding?
1725  Store lazyBindingStore = nullptr;
1726  const SubRegion *lazyBindingRegion = nullptr;
1727  std::tie(lazyBindingStore, lazyBindingRegion) = findLazyBinding(B, R, R);
1728  if (lazyBindingRegion)
1729  return getLazyBinding(lazyBindingRegion,
1730  getRegionBindings(lazyBindingStore));
1731 
1732  // Record whether or not we see a symbolic index. That can completely
1733  // be out of scope of our lookup.
1734  bool hasSymbolicIndex = false;
1735 
1736  // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
1737  // default value for /part/ of an aggregate from a default value for the
1738  // /entire/ aggregate. The most common case of this is when struct Outer
1739  // has as its first member a struct Inner, which is copied in from a stack
1740  // variable. In this case, even if the Outer's default value is symbolic, 0,
1741  // or unknown, it gets overridden by the Inner's default value of undefined.
1742  //
1743  // This is a general problem -- if the Inner is zero-initialized, the Outer
1744  // will now look zero-initialized. The proper way to solve this is with a
1745  // new version of RegionStore that tracks the extent of a binding as well
1746  // as the offset.
1747  //
1748  // This hack only takes care of the undefined case because that can very
1749  // quickly result in a warning.
1750  bool hasPartialLazyBinding = false;
1751 
1752  const SubRegion *SR = dyn_cast<SubRegion>(R);
1753  while (SR) {
1754  const MemRegion *Base = SR->getSuperRegion();
1755  if (Optional<SVal> D = getBindingForDerivedDefaultValue(B, Base, R, Ty)) {
1756  if (D->getAs<nonloc::LazyCompoundVal>()) {
1757  hasPartialLazyBinding = true;
1758  break;
1759  }
1760 
1761  return *D;
1762  }
1763 
1764  if (const ElementRegion *ER = dyn_cast<ElementRegion>(Base)) {
1765  NonLoc index = ER->getIndex();
1766  if (!index.isConstant())
1767  hasSymbolicIndex = true;
1768  }
1769 
1770  // If our super region is a field or element itself, walk up the region
1771  // hierarchy to see if there is a default value installed in an ancestor.
1772  SR = dyn_cast<SubRegion>(Base);
1773  }
1774 
1775  if (R->hasStackNonParametersStorage()) {
1776  if (isa<ElementRegion>(R)) {
1777  // Currently we don't reason specially about Clang-style vectors. Check
1778  // if superR is a vector and if so return Unknown.
1779  if (const TypedValueRegion *typedSuperR =
1780  dyn_cast<TypedValueRegion>(R->getSuperRegion())) {
1781  if (typedSuperR->getValueType()->isVectorType())
1782  return UnknownVal();
1783  }
1784  }
1785 
1786  // FIXME: We also need to take ElementRegions with symbolic indexes into
1787  // account. This case handles both directly accessing an ElementRegion
1788  // with a symbolic offset, but also fields within an element with
1789  // a symbolic offset.
1790  if (hasSymbolicIndex)
1791  return UnknownVal();
1792 
1793  if (!hasPartialLazyBinding)
1794  return UndefinedVal();
1795  }
1796 
1797  // All other values are symbolic.
1798  return svalBuilder.getRegionValueSymbolVal(R);
1799 }
1800 
1801 SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
1802  const ObjCIvarRegion* R) {
1803  // Check if the region has a binding.
1804  if (const Optional<SVal> &V = B.getDirectBinding(R))
1805  return *V;
1806 
1807  const MemRegion *superR = R->getSuperRegion();
1808 
1809  // Check if the super region has a default binding.
1810  if (const Optional<SVal> &V = B.getDefaultBinding(superR)) {
1811  if (SymbolRef parentSym = V->getAsSymbol())
1812  return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
1813 
1814  // Other cases: give up.
1815  return UnknownVal();
1816  }
1817 
1818  return getBindingForLazySymbol(R);
1819 }
1820 
1821 SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
1822  const VarRegion *R) {
1823 
1824  // Check if the region has a binding.
1825  if (const Optional<SVal> &V = B.getDirectBinding(R))
1826  return *V;
1827 
1828  // Lazily derive a value for the VarRegion.
1829  const VarDecl *VD = R->getDecl();
1830  const MemSpaceRegion *MS = R->getMemorySpace();
1831 
1832  // Arguments are always symbolic.
1833  if (isa<StackArgumentsSpaceRegion>(MS))
1834  return svalBuilder.getRegionValueSymbolVal(R);
1835 
1836  // Is 'VD' declared constant? If so, retrieve the constant value.
1837  if (VD->getType().isConstQualified())
1838  if (const Expr *Init = VD->getInit())
1839  if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
1840  return *V;
1841 
1842  // This must come after the check for constants because closure-captured
1843  // constant variables may appear in UnknownSpaceRegion.
1844  if (isa<UnknownSpaceRegion>(MS))
1845  return svalBuilder.getRegionValueSymbolVal(R);
1846 
1847  if (isa<GlobalsSpaceRegion>(MS)) {
1848  QualType T = VD->getType();
1849 
1850  // Function-scoped static variables are default-initialized to 0; if they
1851  // have an initializer, it would have been processed by now.
1852  if (isa<StaticGlobalSpaceRegion>(MS))
1853  return svalBuilder.makeZeroVal(T);
1854 
1855  if (Optional<SVal> V = getBindingForDerivedDefaultValue(B, MS, R, T)) {
1856  assert(!V->getAs<nonloc::LazyCompoundVal>());
1857  return V.getValue();
1858  }
1859 
1860  return svalBuilder.getRegionValueSymbolVal(R);
1861  }
1862 
1863  return UndefinedVal();
1864 }
1865 
1866 SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
1867  // All other values are symbolic.
1868  return svalBuilder.getRegionValueSymbolVal(R);
1869 }
1870 
1871 const RegionStoreManager::SValListTy &
1872 RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
1873  // First, check the cache.
1874  LazyBindingsMapTy::iterator I = LazyBindingsMap.find(LCV.getCVData());
1875  if (I != LazyBindingsMap.end())
1876  return I->second;
1877 
1878  // If we don't have a list of values cached, start constructing it.
1879  SValListTy List;
1880 
1881  const SubRegion *LazyR = LCV.getRegion();
1882  RegionBindingsRef B = getRegionBindings(LCV.getStore());
1883 
1884  // If this region had /no/ bindings at the time, there are no interesting
1885  // values to return.
1886  const ClusterBindings *Cluster = B.lookup(LazyR->getBaseRegion());
1887  if (!Cluster)
1888  return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1889 
1891  collectSubRegionBindings(Bindings, svalBuilder, *Cluster, LazyR,
1892  /*IncludeAllDefaultBindings=*/true);
1893  for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
1894  E = Bindings.end();
1895  I != E; ++I) {
1896  SVal V = I->second;
1897  if (V.isUnknownOrUndef() || V.isConstant())
1898  continue;
1899 
1900  if (Optional<nonloc::LazyCompoundVal> InnerLCV =
1902  const SValListTy &InnerList = getInterestingValues(*InnerLCV);
1903  List.insert(List.end(), InnerList.begin(), InnerList.end());
1904  continue;
1905  }
1906 
1907  List.push_back(V);
1908  }
1909 
1910  return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
1911 }
1912 
1913 NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
1914  const TypedValueRegion *R) {
1916  getExistingLazyBinding(svalBuilder, B, R, false))
1917  return *V;
1918 
1919  return svalBuilder.makeLazyCompoundVal(StoreRef(B.asStore(), *this), R);
1920 }
1921 
1922 static bool isRecordEmpty(const RecordDecl *RD) {
1923  if (!RD->field_empty())
1924  return false;
1925  if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD))
1926  return CRD->getNumBases() == 0;
1927  return true;
1928 }
1929 
1930 SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
1931  const TypedValueRegion *R) {
1932  const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
1933  if (!RD->getDefinition() || isRecordEmpty(RD))
1934  return UnknownVal();
1935 
1936  return createLazyBinding(B, R);
1937 }
1938 
1939 SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
1940  const TypedValueRegion *R) {
1941  assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
1942  "Only constant array types can have compound bindings.");
1943 
1944  return createLazyBinding(B, R);
1945 }
1946 
1947 bool RegionStoreManager::includedInBindings(Store store,
1948  const MemRegion *region) const {
1949  RegionBindingsRef B = getRegionBindings(store);
1950  region = region->getBaseRegion();
1951 
1952  // Quick path: if the base is the head of a cluster, the region is live.
1953  if (B.lookup(region))
1954  return true;
1955 
1956  // Slow path: if the region is the VALUE of any binding, it is live.
1957  for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
1958  const ClusterBindings &Cluster = RI.getData();
1959  for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
1960  CI != CE; ++CI) {
1961  const SVal &D = CI.getData();
1962  if (const MemRegion *R = D.getAsRegion())
1963  if (R->getBaseRegion() == region)
1964  return true;
1965  }
1966  }
1967 
1968  return false;
1969 }
1970 
1971 //===----------------------------------------------------------------------===//
1972 // Binding values to regions.
1973 //===----------------------------------------------------------------------===//
1974 
1975 StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
1977  if (const MemRegion* R = LV->getRegion())
1978  return StoreRef(getRegionBindings(ST).removeBinding(R)
1979  .asImmutableMap()
1980  .getRootWithoutRetain(),
1981  *this);
1982 
1983  return StoreRef(ST, *this);
1984 }
1985 
1986 RegionBindingsRef
1987 RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
1988  if (L.getAs<loc::ConcreteInt>())
1989  return B;
1990 
1991  // If we get here, the location should be a region.
1992  const MemRegion *R = L.castAs<loc::MemRegionVal>().getRegion();
1993 
1994  // Check if the region is a struct region.
1995  if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(R)) {
1996  QualType Ty = TR->getValueType();
1997  if (Ty->isArrayType())
1998  return bindArray(B, TR, V);
1999  if (Ty->isStructureOrClassType())
2000  return bindStruct(B, TR, V);
2001  if (Ty->isVectorType())
2002  return bindVector(B, TR, V);
2003  if (Ty->isUnionType())
2004  return bindAggregate(B, TR, V);
2005  }
2006 
2007  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
2008  // Binding directly to a symbolic region should be treated as binding
2009  // to element 0.
2010  QualType T = SR->getSymbol()->getType();
2011  if (T->isAnyPointerType() || T->isReferenceType())
2012  T = T->getPointeeType();
2013 
2014  R = GetElementZeroRegion(SR, T);
2015  }
2016 
2017  // Clear out bindings that may overlap with this binding.
2018  RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
2019  return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
2020 }
2021 
2022 RegionBindingsRef
2023 RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
2024  const MemRegion *R,
2025  QualType T) {
2026  SVal V;
2027 
2028  if (Loc::isLocType(T))
2029  V = svalBuilder.makeNull();
2030  else if (T->isIntegralOrEnumerationType())
2031  V = svalBuilder.makeZeroVal(T);
2032  else if (T->isStructureOrClassType() || T->isArrayType()) {
2033  // Set the default value to a zero constant when it is a structure
2034  // or array. The type doesn't really matter.
2035  V = svalBuilder.makeZeroVal(Ctx.IntTy);
2036  }
2037  else {
2038  // We can't represent values of this type, but we still need to set a value
2039  // to record that the region has been initialized.
2040  // If this assertion ever fires, a new case should be added above -- we
2041  // should know how to default-initialize any value we can symbolicate.
2042  assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
2043  V = UnknownVal();
2044  }
2045 
2046  return B.addBinding(R, BindingKey::Default, V);
2047 }
2048 
2049 RegionBindingsRef
2050 RegionStoreManager::bindArray(RegionBindingsConstRef B,
2051  const TypedValueRegion* R,
2052  SVal Init) {
2053 
2054  const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
2055  QualType ElementTy = AT->getElementType();
2056  Optional<uint64_t> Size;
2057 
2058  if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
2059  Size = CAT->getSize().getZExtValue();
2060 
2061  // Check if the init expr is a string literal.
2063  const StringRegion *S = cast<StringRegion>(MRV->getRegion());
2064 
2065  // Treat the string as a lazy compound value.
2066  StoreRef store(B.asStore(), *this);
2067  nonloc::LazyCompoundVal LCV = svalBuilder.makeLazyCompoundVal(store, S)
2069  return bindAggregate(B, R, LCV);
2070  }
2071 
2072  // Handle lazy compound values.
2073  if (Init.getAs<nonloc::LazyCompoundVal>())
2074  return bindAggregate(B, R, Init);
2075 
2076  // Remaining case: explicit compound values.
2077 
2078  if (Init.isUnknown())
2079  return setImplicitDefaultValue(B, R, ElementTy);
2080 
2081  const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
2082  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2083  uint64_t i = 0;
2084 
2085  RegionBindingsRef NewB(B);
2086 
2087  for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
2088  // The init list might be shorter than the array length.
2089  if (VI == VE)
2090  break;
2091 
2092  const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
2093  const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
2094 
2095  if (ElementTy->isStructureOrClassType())
2096  NewB = bindStruct(NewB, ER, *VI);
2097  else if (ElementTy->isArrayType())
2098  NewB = bindArray(NewB, ER, *VI);
2099  else
2100  NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2101  }
2102 
2103  // If the init list is shorter than the array length, set the
2104  // array default value.
2105  if (Size.hasValue() && i < Size.getValue())
2106  NewB = setImplicitDefaultValue(NewB, R, ElementTy);
2107 
2108  return NewB;
2109 }
2110 
2111 RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
2112  const TypedValueRegion* R,
2113  SVal V) {
2114  QualType T = R->getValueType();
2115  assert(T->isVectorType());
2116  const VectorType *VT = T->getAs<VectorType>(); // Use getAs for typedefs.
2117 
2118  // Handle lazy compound values and symbolic values.
2120  return bindAggregate(B, R, V);
2121 
2122  // We may get non-CompoundVal accidentally due to imprecise cast logic or
2123  // that we are binding symbolic struct value. Kill the field values, and if
2124  // the value is symbolic go and bind it as a "default" binding.
2125  if (!V.getAs<nonloc::CompoundVal>()) {
2126  return bindAggregate(B, R, UnknownVal());
2127  }
2128 
2129  QualType ElemType = VT->getElementType();
2131  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2132  unsigned index = 0, numElements = VT->getNumElements();
2133  RegionBindingsRef NewB(B);
2134 
2135  for ( ; index != numElements ; ++index) {
2136  if (VI == VE)
2137  break;
2138 
2139  NonLoc Idx = svalBuilder.makeArrayIndex(index);
2140  const ElementRegion *ER = MRMgr.getElementRegion(ElemType, Idx, R, Ctx);
2141 
2142  if (ElemType->isArrayType())
2143  NewB = bindArray(NewB, ER, *VI);
2144  else if (ElemType->isStructureOrClassType())
2145  NewB = bindStruct(NewB, ER, *VI);
2146  else
2147  NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
2148  }
2149  return NewB;
2150 }
2151 
2153 RegionStoreManager::tryBindSmallStruct(RegionBindingsConstRef B,
2154  const TypedValueRegion *R,
2155  const RecordDecl *RD,
2157  FieldVector Fields;
2158 
2159  if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(RD))
2160  if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
2161  return None;
2162 
2163  for (const auto *FD : RD->fields()) {
2164  if (FD->isUnnamedBitfield())
2165  continue;
2166 
2167  // If there are too many fields, or if any of the fields are aggregates,
2168  // just use the LCV as a default binding.
2169  if (Fields.size() == SmallStructLimit)
2170  return None;
2171 
2172  QualType Ty = FD->getType();
2173  if (!(Ty->isScalarType() || Ty->isReferenceType()))
2174  return None;
2175 
2176  Fields.push_back(FD);
2177  }
2178 
2179  RegionBindingsRef NewB = B;
2180 
2181  for (FieldVector::iterator I = Fields.begin(), E = Fields.end(); I != E; ++I){
2182  const FieldRegion *SourceFR = MRMgr.getFieldRegion(*I, LCV.getRegion());
2183  SVal V = getBindingForField(getRegionBindings(LCV.getStore()), SourceFR);
2184 
2185  const FieldRegion *DestFR = MRMgr.getFieldRegion(*I, R);
2186  NewB = bind(NewB, loc::MemRegionVal(DestFR), V);
2187  }
2188 
2189  return NewB;
2190 }
2191 
2192 RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
2193  const TypedValueRegion* R,
2194  SVal V) {
2195  if (!Features.supportsFields())
2196  return B;
2197 
2198  QualType T = R->getValueType();
2199  assert(T->isStructureOrClassType());
2200 
2201  const RecordType* RT = T->getAs<RecordType>();
2202  const RecordDecl *RD = RT->getDecl();
2203 
2204  if (!RD->isCompleteDefinition())
2205  return B;
2206 
2207  // Handle lazy compound values and symbolic values.
2210  if (Optional<RegionBindingsRef> NewB = tryBindSmallStruct(B, R, RD, *LCV))
2211  return *NewB;
2212  return bindAggregate(B, R, V);
2213  }
2214  if (V.getAs<nonloc::SymbolVal>())
2215  return bindAggregate(B, R, V);
2216 
2217  // We may get non-CompoundVal accidentally due to imprecise cast logic or
2218  // that we are binding symbolic struct value. Kill the field values, and if
2219  // the value is symbolic go and bind it as a "default" binding.
2220  if (V.isUnknown() || !V.getAs<nonloc::CompoundVal>())
2221  return bindAggregate(B, R, UnknownVal());
2222 
2224  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
2225 
2227  RegionBindingsRef NewB(B);
2228 
2229  for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {
2230 
2231  if (VI == VE)
2232  break;
2233 
2234  // Skip any unnamed bitfields to stay in sync with the initializers.
2235  if (FI->isUnnamedBitfield())
2236  continue;
2237 
2238  QualType FTy = FI->getType();
2239  const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
2240 
2241  if (FTy->isArrayType())
2242  NewB = bindArray(NewB, FR, *VI);
2243  else if (FTy->isStructureOrClassType())
2244  NewB = bindStruct(NewB, FR, *VI);
2245  else
2246  NewB = bind(NewB, loc::MemRegionVal(FR), *VI);
2247  ++VI;
2248  }
2249 
2250  // There may be fewer values in the initialize list than the fields of struct.
2251  if (FI != FE) {
2252  NewB = NewB.addBinding(R, BindingKey::Default,
2253  svalBuilder.makeIntVal(0, false));
2254  }
2255 
2256  return NewB;
2257 }
2258 
2259 RegionBindingsRef
2260 RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
2261  const TypedRegion *R,
2262  SVal Val) {
2263  // Remove the old bindings, using 'R' as the root of all regions
2264  // we will invalidate. Then add the new binding.
2265  return removeSubRegionBindings(B, R).addBinding(R, BindingKey::Default, Val);
2266 }
2267 
2268 //===----------------------------------------------------------------------===//
2269 // State pruning.
2270 //===----------------------------------------------------------------------===//
2271 
2272 namespace {
2273 class removeDeadBindingsWorker :
2274  public ClusterAnalysis<removeDeadBindingsWorker> {
2276  SymbolReaper &SymReaper;
2277  const StackFrameContext *CurrentLCtx;
2278 
2279 public:
2280  removeDeadBindingsWorker(RegionStoreManager &rm,
2281  ProgramStateManager &stateMgr,
2282  RegionBindingsRef b, SymbolReaper &symReaper,
2283  const StackFrameContext *LCtx)
2284  : ClusterAnalysis<removeDeadBindingsWorker>(rm, stateMgr, b),
2285  SymReaper(symReaper), CurrentLCtx(LCtx) {}
2286 
2287  // Called by ClusterAnalysis.
2288  void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
2289  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
2290  using ClusterAnalysis<removeDeadBindingsWorker>::VisitCluster;
2291 
2292  using ClusterAnalysis::AddToWorkList;
2293 
2294  bool AddToWorkList(const MemRegion *R);
2295 
2296  bool UpdatePostponed();
2297  void VisitBinding(SVal V);
2298 };
2299 }
2300 
2301 bool removeDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
2302  const MemRegion *BaseR = R->getBaseRegion();
2303  return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
2304 }
2305 
2306 void removeDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
2307  const ClusterBindings &C) {
2308 
2309  if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
2310  if (SymReaper.isLive(VR))
2311  AddToWorkList(baseR, &C);
2312 
2313  return;
2314  }
2315 
2316  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
2317  if (SymReaper.isLive(SR->getSymbol()))
2318  AddToWorkList(SR, &C);
2319  else
2320  Postponed.push_back(SR);
2321 
2322  return;
2323  }
2324 
2325  if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
2326  AddToWorkList(baseR, &C);
2327  return;
2328  }
2329 
2330  // CXXThisRegion in the current or parent location context is live.
2331  if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
2332  const StackArgumentsSpaceRegion *StackReg =
2333  cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
2334  const StackFrameContext *RegCtx = StackReg->getStackFrame();
2335  if (CurrentLCtx &&
2336  (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx)))
2337  AddToWorkList(TR, &C);
2338  }
2339 }
2340 
2341 void removeDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
2342  const ClusterBindings *C) {
2343  if (!C)
2344  return;
2345 
2346  // Mark the symbol for any SymbolicRegion with live bindings as live itself.
2347  // This means we should continue to track that symbol.
2348  if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(baseR))
2349  SymReaper.markLive(SymR->getSymbol());
2350 
2351  for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I) {
2352  // Element index of a binding key is live.
2353  SymReaper.markElementIndicesLive(I.getKey().getRegion());
2354 
2355  VisitBinding(I.getData());
2356  }
2357 }
2358 
2359 void removeDeadBindingsWorker::VisitBinding(SVal V) {
2360  // Is it a LazyCompoundVal? All referenced regions are live as well.
2363 
2364  const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
2365 
2366  for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
2367  E = Vals.end();
2368  I != E; ++I)
2369  VisitBinding(*I);
2370 
2371  return;
2372  }
2373 
2374  // If V is a region, then add it to the worklist.
2375  if (const MemRegion *R = V.getAsRegion()) {
2376  AddToWorkList(R);
2377  SymReaper.markLive(R);
2378 
2379  // All regions captured by a block are also live.
2380  if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
2381  BlockDataRegion::referenced_vars_iterator I = BR->referenced_vars_begin(),
2382  E = BR->referenced_vars_end();
2383  for ( ; I != E; ++I)
2384  AddToWorkList(I.getCapturedRegion());
2385  }
2386  }
2387 
2388 
2389  // Update the set of live symbols.
2390  for (SymExpr::symbol_iterator SI = V.symbol_begin(), SE = V.symbol_end();
2391  SI!=SE; ++SI)
2392  SymReaper.markLive(*SI);
2393 }
2394 
2395 bool removeDeadBindingsWorker::UpdatePostponed() {
2396  // See if any postponed SymbolicRegions are actually live now, after
2397  // having done a scan.
2398  bool changed = false;
2399 
2401  I = Postponed.begin(), E = Postponed.end() ; I != E ; ++I) {
2402  if (const SymbolicRegion *SR = *I) {
2403  if (SymReaper.isLive(SR->getSymbol())) {
2404  changed |= AddToWorkList(SR);
2405  *I = nullptr;
2406  }
2407  }
2408  }
2409 
2410  return changed;
2411 }
2412 
2413 StoreRef RegionStoreManager::removeDeadBindings(Store store,
2414  const StackFrameContext *LCtx,
2415  SymbolReaper& SymReaper) {
2416  RegionBindingsRef B = getRegionBindings(store);
2417  removeDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
2418  W.GenerateClusters();
2419 
2420  // Enqueue the region roots onto the worklist.
2421  for (SymbolReaper::region_iterator I = SymReaper.region_begin(),
2422  E = SymReaper.region_end(); I != E; ++I) {
2423  W.AddToWorkList(*I);
2424  }
2425 
2426  do W.RunWorkList(); while (W.UpdatePostponed());
2427 
2428  // We have now scanned the store, marking reachable regions and symbols
2429  // as live. We now remove all the regions that are dead from the store
2430  // as well as update DSymbols with the set symbols that are now dead.
2431  for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
2432  const MemRegion *Base = I.getKey();
2433 
2434  // If the cluster has been visited, we know the region has been marked.
2435  if (W.isVisited(Base))
2436  continue;
2437 
2438  // Remove the dead entry.
2439  B = B.remove(Base);
2440 
2441  if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(Base))
2442  SymReaper.maybeDead(SymR->getSymbol());
2443 
2444  // Mark all non-live symbols that this binding references as dead.
2445  const ClusterBindings &Cluster = I.getData();
2446  for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
2447  CI != CE; ++CI) {
2448  SVal X = CI.getData();
2450  for (; SI != SE; ++SI)
2451  SymReaper.maybeDead(*SI);
2452  }
2453  }
2454 
2455  return StoreRef(B.asStore(), *this);
2456 }
2457 
2458 //===----------------------------------------------------------------------===//
2459 // Utility methods.
2460 //===----------------------------------------------------------------------===//
2461 
2462 void RegionStoreManager::print(Store store, raw_ostream &OS,
2463  const char* nl, const char *sep) {
2464  RegionBindingsRef B = getRegionBindings(store);
2465  OS << "Store (direct and default bindings), "
2466  << B.asStore()
2467  << " :" << nl;
2468  B.dump(OS, nl);
2469 }
TypedValueRegion - An abstract class representing regions having a typed value.
Definition: MemRegion.h:510
unsigned Length
A (possibly-)qualified type.
Definition: Type.h:575
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:78
virtual DefinedOrUnknownSVal getExtent(SValBuilder &svalBuilder) const
getExtent - Returns the size of the region in bytes.
Definition: MemRegion.h:438
bool isInSystemHeader() const
Returns true if the callee is known to be from a system header.
Definition: CallEvent.h:210
static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields)
bool operator==(CanQual< T > x, CanQual< U > y)
Information about invalidation for a particular region/symbol.
Definition: MemRegion.h:1332
bool maybeDead(SymbolRef sym)
If a symbol is known to be live, marks the symbol as live.
virtual QualType getValueType() const =0
virtual bool isBoundable() const
Definition: MemRegion.h:189
static bool isRecordEmpty(const RecordDecl *RD)
bool isVoidPointerType() const
Definition: Type.cpp:385
const void * Store
Store - This opaque type encapsulates an immutable mapping from locations to values.
Definition: StoreRef.h:26
Represents an array type, per C99 6.7.5.2 - Array Declarators.
Definition: Type.h:2424
const Expr * getInit() const
Definition: Decl.h:1070
MemSpaceRegion - A memory region that represents a "memory space"; for example, the set of global var...
Definition: MemRegion.h:194
static Optional< nonloc::LazyCompoundVal > getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B, const SubRegion *R, bool AllowSubregionBindings)
Checks to see if store B has a lazy binding for region R.
Value representing integer constant.
Definition: SVals.h:339
int Delta
A Utility class that allows to visit the reachable symbols using a custom SymbolVisitor.
Definition: ProgramState.h:832
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:699
QualType getElementType() const
Definition: MemRegion.h:1045
const MemRegion * getBaseRegion() const
Definition: MemRegion.cpp:1079
iterator begin() const
Definition: Type.h:4072
bool isZeroConstant() const
Definition: SVals.cpp:186
bool isUnionType() const
Definition: Type.cpp:391
std::unique_ptr< StoreManager > CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr)
Symbolic value.
Definition: SymbolManager.h:42
CXXThisRegion - Represents the region for the implicit 'this' parameter in a call to a C++ method...
Definition: MemRegion.h:912
RecordDecl - Represents a struct/union/class.
Definition: Decl.h:3166
llvm::ImmutableMap< BindingKey, SVal > ClusterBindings
const MemSpaceRegion * getMemorySpace() const
Definition: MemRegion.cpp:1047
bool isScalarType() const
Definition: Type.h:5581
SmallVector< const FieldDecl *, 8 > FieldVector
bool hasAttr() const
Definition: DeclBase.h:498
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:91
const ASTMatchFinder::BindKind Bind
bool isReferenceType() const
Definition: Type.h:5314
bool isStructureOrClassType() const
Definition: Type.cpp:378
bool isAnyPointerType() const
Definition: Type.h:5308
const MemRegion * getRegion() const
Definition: MemRegion.h:1013
static bool canSymbolicate(QualType T)
bool hasSameUnqualifiedType(QualType T1, QualType T2) const
Determine whether the given types are equivalent after cvr-qualifiers have been removed.
Definition: ASTContext.h:1987
const VarDecl * getDecl() const
Definition: MemRegion.h:889
RegionRawOffset getAsArrayOffset() const
Compute the offset within the array. The array might also be a subobject.
Definition: MemRegion.cpp:1138
static bool isLocType(QualType T)
Definition: SVals.h:291
uint32_t getCodeUnit(size_t i) const
Definition: Expr.h:1522
BlockDataRegion - A region that represents a block instance.
Definition: MemRegion.h:643
unsigned getLength() const
Definition: Expr.h:1533
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
static void dump(llvm::raw_ostream &OS, StringRef FunctionName, ArrayRef< CounterExpression > Expressions, ArrayRef< CounterMappingRegion > Regions)
field_range fields() const
Definition: Decl.h:3295
SymbolRef getSymbol() const
Definition: MemRegion.h:731
bool isUnknownOrUndef() const
Definition: SVals.h:125
llvm::ImmutableMap< const MemRegion *, ClusterBindings > RegionBindings
SymExpr::symbol_iterator symbol_begin() const
Definition: SVals.h:177
iterator end() const
QualType getValueType() const override
Definition: MemRegion.h:893
bool isConstant() const
Definition: SVals.cpp:174
detail::InMemoryDirectory::const_iterator I
Represent a region's offset within the top level base region.
Definition: MemRegion.h:46
QualType getType() const
Definition: Decl.h:530
virtual QualType getType() const =0
const MemRegion * getSuperRegion() const
Definition: MemRegion.h:433
AnnotatingParser & P
std::unique_ptr< StoreManager > CreateRegionStoreManager(ProgramStateManager &StMgr)
bool isUnion() const
Definition: Decl.h:2856
const StackFrameContext * getStackFrame() const
Definition: MemRegion.h:383
llvm::ImmutableList< SVal >::iterator iterator
Definition: SVals.h:420
static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields)
When applied to a MemSpaceRegion, indicates the entire memory space should be invalidated.
Definition: MemRegion.h:1353
ID
Defines the set of possible language-specific address spaces.
Definition: AddressSpaces.h:27
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:415
SymbolicRegion - A special, "non-concrete" region.
Definition: MemRegion.h:723
static void collectSubRegionBindings(SmallVectorImpl< BindingPair > &Bindings, SValBuilder &SVB, const ClusterBindings &Cluster, const SubRegion *Top, BindingKey TopKey, bool IncludeAllDefaultBindings)
Collects all bindings in Cluster that may refer to bindings within Top.
Expr - This represents one expression.
Definition: Expr.h:104
GlobalsFilterKind
Used to determine which global regions are automatically included in the initial worklist of a Cluste...
bool hasSymbolicOffset() const
Definition: MemRegion.h:63
Optional< T > getAs() const
Convert to the specified SVal type, returning None if this SVal is not of the desired type...
Definition: SVals.h:86
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
Represents a GCC generic vector type.
Definition: Type.h:2724
RegionSetTy::const_iterator region_iterator
The result type of a method or function.
RecordDecl * getDefinition() const
getDefinition - Returns the RecordDecl that actually defines this struct/union/class.
Definition: Decl.h:3285
const LazyCompoundValData * getCVData() const
Definition: SVals.h:442
llvm::ImmutableMapRef< BindingKey, SVal > ClusterBindingsRef
const MatchFinder::MatchFinderOptions & Options
bool scan(nonloc::LazyCompoundVal val)
#define false
Definition: stdbool.h:33
Kind
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:5596
const TemplateArgument * iterator
Definition: Type.h:4070
region_iterator region_begin() const
static QualType getUnderlyingType(const SubRegion *R)
const FieldDecl * getDecl() const
Definition: MemRegion.h:946
bool isSubRegionOf(const MemRegion *R) const override
Check if the region is a subregion of the given region.
Definition: MemRegion.cpp:149
ASTContext & getContext()
Definition: SValBuilder.h:125
SymExpr::symbol_iterator symbol_end() const
Definition: SVals.h:185
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:44
void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx)
Definition: Type.h:4095
A class responsible for cleaning up unused symbols.
bool isUndef() const
Definition: SVals.h:121
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:5706
QualType getLocationType() const override
Definition: MemRegion.h:519
bool isVectorType() const
Definition: Type.h:5371
bool operator<(DeclarationName LHS, DeclarationName RHS)
Ordering on two declaration names.
Tells that a region's contents is not changed.
Definition: MemRegion.h:1346
NonLoc getIndex() const
Definition: MemRegion.h:1039
RegionOffset getAsOffset() const
Compute the offset within the top level memory object.
Definition: MemRegion.cpp:1196
Represents a template argument.
Definition: TemplateBase.h:40
static const Type * getElementType(const Expr *BaseExpr)
raw_ostream & operator<<(raw_ostream &Out, const CheckerBase &Checker)
Dump checker name to stream.
Definition: Checker.cpp:34
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
Represents symbolic expression.
Definition: SVals.h:313
detail::InMemoryDirectory::const_iterator E
const MemRegion * getAsRegion() const
Definition: SVals.cpp:135
Represents an abstract call to a function or method along a particular path.
Definition: CallEvent.h:113
bool field_empty() const
Definition: Decl.h:3304
specific_decl_iterator - Iterates over a subrange of declarations stored in a DeclContext, providing only those that are of type SpecificDecl (or a class derived from it).
Definition: DeclBase.h:1459
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:3544
region_iterator region_end() const
const T * getAs() const
Member-template getAs<specific type>'.
Definition: Type.h:5675
SubRegion - A region that subsets another larger region.
Definition: MemRegion.h:426
bool isUnknown() const
Definition: SVals.h:117
int64_t getOffset() const
Definition: MemRegion.h:65
const TypedValueRegion * getRegion() const
Definition: SVals.cpp:154
uint64_t getCharWidth() const
Return the size of the character type, in bits.
Definition: ASTContext.h:1797
std::pair< BindingKey, SVal > BindingPair
__PTRDIFF_TYPE__ ptrdiff_t
Definition: stddef.h:51
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:11761
static bool isUnionField(const FieldRegion *FR)
Represents a C++ struct/union/class.
Definition: DeclCXX.h:285
SymbolRef getAsSymbol(bool IncludeBaseRegions=false) const
If this SVal wraps a symbol return that SymbolRef.
Definition: SVals.cpp:111
bool isArrayType() const
Definition: Type.h:5344
StringLiteral - This represents a string literal expression, e.g.
Definition: Expr.h:1452
Defines the clang::TargetInfo interface.
StringRegion - Region associated with a StringLiteral.
Definition: MemRegion.h:753
ElementRegin is used to represent both array elements and casts.
Definition: MemRegion.h:1020
QualType getValueType() const override
Definition: MemRegion.h:948
const MemRegion * getRegion() const
Definition: MemRegion.h:61
virtual bool isSubRegionOf(const MemRegion *R) const
Check if the region is a subregion of the given region.
Definition: MemRegion.cpp:1097
QualType getElementType() const
Definition: Type.h:2458
int getOptionAsInteger(StringRef Name, int DefaultVal, const ento::CheckerBase *C=nullptr, bool SearchInParents=false)
Interprets an option's string value as an integer value.
const RegionBindingsRef & RegionBindingsConstRef
iterator begin() const
Definition: SVals.cpp:162
#define true
Definition: stdbool.h:32
bool hasStackNonParametersStorage() const
Definition: MemRegion.cpp:1063
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:5148
bool isNull() const
Return true if this QualType doesn't point to a type yet.
Definition: Type.h:642
T castAs() const
Convert to the specified SVal type, asserting that this SVal is of the desired type.
Definition: SVals.h:75
Represents the canonical version of C arrays with a specified constant size.
Definition: Type.h:2480
TypedRegion - An abstract class representing regions that are typed.
Definition: MemRegion.h:488
bool hasLocalStorage() const
hasLocalStorage - Returns true if a variable with function scope is a non-static local variable...
Definition: Decl.h:891
const RecordDecl * getParent() const
getParent - Returns the parent of this field declaration, which is the struct in which this method is...
Definition: Decl.h:2371
Iterator over symbols that the current symbol depends on.
Definition: SymbolManager.h:84
const void * getStore() const
Definition: SVals.cpp:150