1//== MemRegion.cpp - Abstract memory regions for static analysis --*- 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 MemRegion and its subclasses.  MemRegion defines a
11//  partially-typed abstraction of memory useful for path-sensitive dataflow
12//  analyses.
13//
14//===----------------------------------------------------------------------===//
15
16#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
17#include "clang/AST/Attr.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/RecordLayout.h"
21#include "clang/Analysis/AnalysisContext.h"
22#include "clang/Analysis/Support/BumpVector.h"
23#include "clang/Basic/SourceManager.h"
24#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
25#include "llvm/Support/raw_ostream.h"
26
27using namespace clang;
28using namespace ento;
29
30//===----------------------------------------------------------------------===//
31// MemRegion Construction.
32//===----------------------------------------------------------------------===//
33
34template<typename RegionTy> struct MemRegionManagerTrait;
35
36template <typename RegionTy, typename A1>
37RegionTy* MemRegionManager::getRegion(const A1 a1) {
38
39  const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
40  MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1);
41
42  llvm::FoldingSetNodeID ID;
43  RegionTy::ProfileRegion(ID, a1, superRegion);
44  void *InsertPos;
45  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
46                                                                   InsertPos));
47
48  if (!R) {
49    R = (RegionTy*) A.Allocate<RegionTy>();
50    new (R) RegionTy(a1, superRegion);
51    Regions.InsertNode(R, InsertPos);
52  }
53
54  return R;
55}
56
57template <typename RegionTy, typename A1>
58RegionTy* MemRegionManager::getSubRegion(const A1 a1,
59                                         const MemRegion *superRegion) {
60  llvm::FoldingSetNodeID ID;
61  RegionTy::ProfileRegion(ID, a1, superRegion);
62  void *InsertPos;
63  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
64                                                                   InsertPos));
65
66  if (!R) {
67    R = (RegionTy*) A.Allocate<RegionTy>();
68    new (R) RegionTy(a1, superRegion);
69    Regions.InsertNode(R, InsertPos);
70  }
71
72  return R;
73}
74
75template <typename RegionTy, typename A1, typename A2>
76RegionTy* MemRegionManager::getRegion(const A1 a1, const A2 a2) {
77
78  const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
79  MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1, a2);
80
81  llvm::FoldingSetNodeID ID;
82  RegionTy::ProfileRegion(ID, a1, a2, superRegion);
83  void *InsertPos;
84  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
85                                                                   InsertPos));
86
87  if (!R) {
88    R = (RegionTy*) A.Allocate<RegionTy>();
89    new (R) RegionTy(a1, a2, superRegion);
90    Regions.InsertNode(R, InsertPos);
91  }
92
93  return R;
94}
95
96template <typename RegionTy, typename A1, typename A2>
97RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2,
98                                         const MemRegion *superRegion) {
99
100  llvm::FoldingSetNodeID ID;
101  RegionTy::ProfileRegion(ID, a1, a2, superRegion);
102  void *InsertPos;
103  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
104                                                                   InsertPos));
105
106  if (!R) {
107    R = (RegionTy*) A.Allocate<RegionTy>();
108    new (R) RegionTy(a1, a2, superRegion);
109    Regions.InsertNode(R, InsertPos);
110  }
111
112  return R;
113}
114
115template <typename RegionTy, typename A1, typename A2, typename A3>
116RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2, const A3 a3,
117                                         const MemRegion *superRegion) {
118
119  llvm::FoldingSetNodeID ID;
120  RegionTy::ProfileRegion(ID, a1, a2, a3, superRegion);
121  void *InsertPos;
122  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
123                                                                   InsertPos));
124
125  if (!R) {
126    R = (RegionTy*) A.Allocate<RegionTy>();
127    new (R) RegionTy(a1, a2, a3, superRegion);
128    Regions.InsertNode(R, InsertPos);
129  }
130
131  return R;
132}
133
134//===----------------------------------------------------------------------===//
135// Object destruction.
136//===----------------------------------------------------------------------===//
137
138MemRegion::~MemRegion() {}
139
140MemRegionManager::~MemRegionManager() {
141  // All regions and their data are BumpPtrAllocated.  No need to call
142  // their destructors.
143}
144
145//===----------------------------------------------------------------------===//
146// Basic methods.
147//===----------------------------------------------------------------------===//
148
149bool SubRegion::isSubRegionOf(const MemRegion* R) const {
150  const MemRegion* r = getSuperRegion();
151  while (r != nullptr) {
152    if (r == R)
153      return true;
154    if (const SubRegion* sr = dyn_cast<SubRegion>(r))
155      r = sr->getSuperRegion();
156    else
157      break;
158  }
159  return false;
160}
161
162MemRegionManager* SubRegion::getMemRegionManager() const {
163  const SubRegion* r = this;
164  do {
165    const MemRegion *superRegion = r->getSuperRegion();
166    if (const SubRegion *sr = dyn_cast<SubRegion>(superRegion)) {
167      r = sr;
168      continue;
169    }
170    return superRegion->getMemRegionManager();
171  } while (1);
172}
173
174const StackFrameContext *VarRegion::getStackFrame() const {
175  const StackSpaceRegion *SSR = dyn_cast<StackSpaceRegion>(getMemorySpace());
176  return SSR ? SSR->getStackFrame() : nullptr;
177}
178
179//===----------------------------------------------------------------------===//
180// Region extents.
181//===----------------------------------------------------------------------===//
182
183DefinedOrUnknownSVal TypedValueRegion::getExtent(SValBuilder &svalBuilder) const {
184  ASTContext &Ctx = svalBuilder.getContext();
185  QualType T = getDesugaredValueType(Ctx);
186
187  if (isa<VariableArrayType>(T))
188    return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
189  if (T->isIncompleteType())
190    return UnknownVal();
191
192  CharUnits size = Ctx.getTypeSizeInChars(T);
193  QualType sizeTy = svalBuilder.getArrayIndexType();
194  return svalBuilder.makeIntVal(size.getQuantity(), sizeTy);
195}
196
197DefinedOrUnknownSVal FieldRegion::getExtent(SValBuilder &svalBuilder) const {
198  // Force callers to deal with bitfields explicitly.
199  if (getDecl()->isBitField())
200    return UnknownVal();
201
202  DefinedOrUnknownSVal Extent = DeclRegion::getExtent(svalBuilder);
203
204  // A zero-length array at the end of a struct often stands for dynamically-
205  // allocated extra memory.
206  if (Extent.isZeroConstant()) {
207    QualType T = getDesugaredValueType(svalBuilder.getContext());
208
209    if (isa<ConstantArrayType>(T))
210      return UnknownVal();
211  }
212
213  return Extent;
214}
215
216DefinedOrUnknownSVal AllocaRegion::getExtent(SValBuilder &svalBuilder) const {
217  return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
218}
219
220DefinedOrUnknownSVal SymbolicRegion::getExtent(SValBuilder &svalBuilder) const {
221  return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
222}
223
224DefinedOrUnknownSVal StringRegion::getExtent(SValBuilder &svalBuilder) const {
225  return svalBuilder.makeIntVal(getStringLiteral()->getByteLength()+1,
226                                svalBuilder.getArrayIndexType());
227}
228
229ObjCIvarRegion::ObjCIvarRegion(const ObjCIvarDecl *ivd, const MemRegion* sReg)
230  : DeclRegion(ivd, sReg, ObjCIvarRegionKind) {}
231
232const ObjCIvarDecl *ObjCIvarRegion::getDecl() const {
233  return cast<ObjCIvarDecl>(D);
234}
235
236QualType ObjCIvarRegion::getValueType() const {
237  return getDecl()->getType();
238}
239
240QualType CXXBaseObjectRegion::getValueType() const {
241  return QualType(getDecl()->getTypeForDecl(), 0);
242}
243
244//===----------------------------------------------------------------------===//
245// FoldingSet profiling.
246//===----------------------------------------------------------------------===//
247
248void MemSpaceRegion::Profile(llvm::FoldingSetNodeID& ID) const {
249  ID.AddInteger((unsigned)getKind());
250}
251
252void StackSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
253  ID.AddInteger((unsigned)getKind());
254  ID.AddPointer(getStackFrame());
255}
256
257void StaticGlobalSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
258  ID.AddInteger((unsigned)getKind());
259  ID.AddPointer(getCodeRegion());
260}
261
262void StringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
263                                 const StringLiteral* Str,
264                                 const MemRegion* superRegion) {
265  ID.AddInteger((unsigned) StringRegionKind);
266  ID.AddPointer(Str);
267  ID.AddPointer(superRegion);
268}
269
270void ObjCStringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
271                                     const ObjCStringLiteral* Str,
272                                     const MemRegion* superRegion) {
273  ID.AddInteger((unsigned) ObjCStringRegionKind);
274  ID.AddPointer(Str);
275  ID.AddPointer(superRegion);
276}
277
278void AllocaRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
279                                 const Expr *Ex, unsigned cnt,
280                                 const MemRegion *superRegion) {
281  ID.AddInteger((unsigned) AllocaRegionKind);
282  ID.AddPointer(Ex);
283  ID.AddInteger(cnt);
284  ID.AddPointer(superRegion);
285}
286
287void AllocaRegion::Profile(llvm::FoldingSetNodeID& ID) const {
288  ProfileRegion(ID, Ex, Cnt, superRegion);
289}
290
291void CompoundLiteralRegion::Profile(llvm::FoldingSetNodeID& ID) const {
292  CompoundLiteralRegion::ProfileRegion(ID, CL, superRegion);
293}
294
295void CompoundLiteralRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
296                                          const CompoundLiteralExpr *CL,
297                                          const MemRegion* superRegion) {
298  ID.AddInteger((unsigned) CompoundLiteralRegionKind);
299  ID.AddPointer(CL);
300  ID.AddPointer(superRegion);
301}
302
303void CXXThisRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
304                                  const PointerType *PT,
305                                  const MemRegion *sRegion) {
306  ID.AddInteger((unsigned) CXXThisRegionKind);
307  ID.AddPointer(PT);
308  ID.AddPointer(sRegion);
309}
310
311void CXXThisRegion::Profile(llvm::FoldingSetNodeID &ID) const {
312  CXXThisRegion::ProfileRegion(ID, ThisPointerTy, superRegion);
313}
314
315void ObjCIvarRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
316                                   const ObjCIvarDecl *ivd,
317                                   const MemRegion* superRegion) {
318  DeclRegion::ProfileRegion(ID, ivd, superRegion, ObjCIvarRegionKind);
319}
320
321void DeclRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, const Decl *D,
322                               const MemRegion* superRegion, Kind k) {
323  ID.AddInteger((unsigned) k);
324  ID.AddPointer(D);
325  ID.AddPointer(superRegion);
326}
327
328void DeclRegion::Profile(llvm::FoldingSetNodeID& ID) const {
329  DeclRegion::ProfileRegion(ID, D, superRegion, getKind());
330}
331
332void VarRegion::Profile(llvm::FoldingSetNodeID &ID) const {
333  VarRegion::ProfileRegion(ID, getDecl(), superRegion);
334}
335
336void SymbolicRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SymbolRef sym,
337                                   const MemRegion *sreg) {
338  ID.AddInteger((unsigned) MemRegion::SymbolicRegionKind);
339  ID.Add(sym);
340  ID.AddPointer(sreg);
341}
342
343void SymbolicRegion::Profile(llvm::FoldingSetNodeID& ID) const {
344  SymbolicRegion::ProfileRegion(ID, sym, getSuperRegion());
345}
346
347void ElementRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
348                                  QualType ElementType, SVal Idx,
349                                  const MemRegion* superRegion) {
350  ID.AddInteger(MemRegion::ElementRegionKind);
351  ID.Add(ElementType);
352  ID.AddPointer(superRegion);
353  Idx.Profile(ID);
354}
355
356void ElementRegion::Profile(llvm::FoldingSetNodeID& ID) const {
357  ElementRegion::ProfileRegion(ID, ElementType, Index, superRegion);
358}
359
360void FunctionTextRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
361                                       const NamedDecl *FD,
362                                       const MemRegion*) {
363  ID.AddInteger(MemRegion::FunctionTextRegionKind);
364  ID.AddPointer(FD);
365}
366
367void FunctionTextRegion::Profile(llvm::FoldingSetNodeID& ID) const {
368  FunctionTextRegion::ProfileRegion(ID, FD, superRegion);
369}
370
371void BlockTextRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
372                                    const BlockDecl *BD, CanQualType,
373                                    const AnalysisDeclContext *AC,
374                                    const MemRegion*) {
375  ID.AddInteger(MemRegion::BlockTextRegionKind);
376  ID.AddPointer(BD);
377}
378
379void BlockTextRegion::Profile(llvm::FoldingSetNodeID& ID) const {
380  BlockTextRegion::ProfileRegion(ID, BD, locTy, AC, superRegion);
381}
382
383void BlockDataRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
384                                    const BlockTextRegion *BC,
385                                    const LocationContext *LC,
386                                    unsigned BlkCount,
387                                    const MemRegion *sReg) {
388  ID.AddInteger(MemRegion::BlockDataRegionKind);
389  ID.AddPointer(BC);
390  ID.AddPointer(LC);
391  ID.AddInteger(BlkCount);
392  ID.AddPointer(sReg);
393}
394
395void BlockDataRegion::Profile(llvm::FoldingSetNodeID& ID) const {
396  BlockDataRegion::ProfileRegion(ID, BC, LC, BlockCount, getSuperRegion());
397}
398
399void CXXTempObjectRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
400                                        Expr const *Ex,
401                                        const MemRegion *sReg) {
402  ID.AddPointer(Ex);
403  ID.AddPointer(sReg);
404}
405
406void CXXTempObjectRegion::Profile(llvm::FoldingSetNodeID &ID) const {
407  ProfileRegion(ID, Ex, getSuperRegion());
408}
409
410void CXXBaseObjectRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
411                                        const CXXRecordDecl *RD,
412                                        bool IsVirtual,
413                                        const MemRegion *SReg) {
414  ID.AddPointer(RD);
415  ID.AddBoolean(IsVirtual);
416  ID.AddPointer(SReg);
417}
418
419void CXXBaseObjectRegion::Profile(llvm::FoldingSetNodeID &ID) const {
420  ProfileRegion(ID, getDecl(), isVirtual(), superRegion);
421}
422
423//===----------------------------------------------------------------------===//
424// Region anchors.
425//===----------------------------------------------------------------------===//
426
427void GlobalsSpaceRegion::anchor() { }
428void HeapSpaceRegion::anchor() { }
429void UnknownSpaceRegion::anchor() { }
430void StackLocalsSpaceRegion::anchor() { }
431void StackArgumentsSpaceRegion::anchor() { }
432void TypedRegion::anchor() { }
433void TypedValueRegion::anchor() { }
434void CodeTextRegion::anchor() { }
435void SubRegion::anchor() { }
436
437//===----------------------------------------------------------------------===//
438// Region pretty-printing.
439//===----------------------------------------------------------------------===//
440
441void MemRegion::dump() const {
442  dumpToStream(llvm::errs());
443}
444
445std::string MemRegion::getString() const {
446  std::string s;
447  llvm::raw_string_ostream os(s);
448  dumpToStream(os);
449  return os.str();
450}
451
452void MemRegion::dumpToStream(raw_ostream &os) const {
453  os << "<Unknown Region>";
454}
455
456void AllocaRegion::dumpToStream(raw_ostream &os) const {
457  os << "alloca{" << (const void*) Ex << ',' << Cnt << '}';
458}
459
460void FunctionTextRegion::dumpToStream(raw_ostream &os) const {
461  os << "code{" << getDecl()->getDeclName().getAsString() << '}';
462}
463
464void BlockTextRegion::dumpToStream(raw_ostream &os) const {
465  os << "block_code{" << (const void*) this << '}';
466}
467
468void BlockDataRegion::dumpToStream(raw_ostream &os) const {
469  os << "block_data{" << BC;
470  os << "; ";
471  for (BlockDataRegion::referenced_vars_iterator
472         I = referenced_vars_begin(),
473         E = referenced_vars_end(); I != E; ++I)
474    os << "(" << I.getCapturedRegion() << "," <<
475                 I.getOriginalRegion() << ") ";
476  os << '}';
477}
478
479void CompoundLiteralRegion::dumpToStream(raw_ostream &os) const {
480  // FIXME: More elaborate pretty-printing.
481  os << "{ " << (const void*) CL <<  " }";
482}
483
484void CXXTempObjectRegion::dumpToStream(raw_ostream &os) const {
485  os << "temp_object{" << getValueType().getAsString() << ','
486     << (const void*) Ex << '}';
487}
488
489void CXXBaseObjectRegion::dumpToStream(raw_ostream &os) const {
490  os << "base{" << superRegion << ',' << getDecl()->getName() << '}';
491}
492
493void CXXThisRegion::dumpToStream(raw_ostream &os) const {
494  os << "this";
495}
496
497void ElementRegion::dumpToStream(raw_ostream &os) const {
498  os << "element{" << superRegion << ','
499     << Index << ',' << getElementType().getAsString() << '}';
500}
501
502void FieldRegion::dumpToStream(raw_ostream &os) const {
503  os << superRegion << "->" << *getDecl();
504}
505
506void ObjCIvarRegion::dumpToStream(raw_ostream &os) const {
507  os << "ivar{" << superRegion << ',' << *getDecl() << '}';
508}
509
510void StringRegion::dumpToStream(raw_ostream &os) const {
511  assert(Str != nullptr && "Expecting non-null StringLiteral");
512  Str->printPretty(os, nullptr, PrintingPolicy(getContext().getLangOpts()));
513}
514
515void ObjCStringRegion::dumpToStream(raw_ostream &os) const {
516  assert(Str != nullptr && "Expecting non-null ObjCStringLiteral");
517  Str->printPretty(os, nullptr, PrintingPolicy(getContext().getLangOpts()));
518}
519
520void SymbolicRegion::dumpToStream(raw_ostream &os) const {
521  os << "SymRegion{" << sym << '}';
522}
523
524void VarRegion::dumpToStream(raw_ostream &os) const {
525  os << *cast<VarDecl>(D);
526}
527
528void RegionRawOffset::dump() const {
529  dumpToStream(llvm::errs());
530}
531
532void RegionRawOffset::dumpToStream(raw_ostream &os) const {
533  os << "raw_offset{" << getRegion() << ',' << getOffset().getQuantity() << '}';
534}
535
536void StaticGlobalSpaceRegion::dumpToStream(raw_ostream &os) const {
537  os << "StaticGlobalsMemSpace{" << CR << '}';
538}
539
540void GlobalInternalSpaceRegion::dumpToStream(raw_ostream &os) const {
541  os << "GlobalInternalSpaceRegion";
542}
543
544void GlobalSystemSpaceRegion::dumpToStream(raw_ostream &os) const {
545  os << "GlobalSystemSpaceRegion";
546}
547
548void GlobalImmutableSpaceRegion::dumpToStream(raw_ostream &os) const {
549  os << "GlobalImmutableSpaceRegion";
550}
551
552void HeapSpaceRegion::dumpToStream(raw_ostream &os) const {
553  os << "HeapSpaceRegion";
554}
555
556void UnknownSpaceRegion::dumpToStream(raw_ostream &os) const {
557  os << "UnknownSpaceRegion";
558}
559
560void StackArgumentsSpaceRegion::dumpToStream(raw_ostream &os) const {
561  os << "StackArgumentsSpaceRegion";
562}
563
564void StackLocalsSpaceRegion::dumpToStream(raw_ostream &os) const {
565  os << "StackLocalsSpaceRegion";
566}
567
568bool MemRegion::canPrintPretty() const {
569  return canPrintPrettyAsExpr();
570}
571
572bool MemRegion::canPrintPrettyAsExpr() const {
573  return false;
574}
575
576void MemRegion::printPretty(raw_ostream &os) const {
577  assert(canPrintPretty() && "This region cannot be printed pretty.");
578  os << "'";
579  printPrettyAsExpr(os);
580  os << "'";
581  return;
582}
583
584void MemRegion::printPrettyAsExpr(raw_ostream &os) const {
585  llvm_unreachable("This region cannot be printed pretty.");
586  return;
587}
588
589bool VarRegion::canPrintPrettyAsExpr() const {
590  return true;
591}
592
593void VarRegion::printPrettyAsExpr(raw_ostream &os) const {
594  os << getDecl()->getName();
595}
596
597bool ObjCIvarRegion::canPrintPrettyAsExpr() const {
598  return true;
599}
600
601void ObjCIvarRegion::printPrettyAsExpr(raw_ostream &os) const {
602  os << getDecl()->getName();
603}
604
605bool FieldRegion::canPrintPretty() const {
606  return true;
607}
608
609bool FieldRegion::canPrintPrettyAsExpr() const {
610  return superRegion->canPrintPrettyAsExpr();
611}
612
613void FieldRegion::printPrettyAsExpr(raw_ostream &os) const {
614  assert(canPrintPrettyAsExpr());
615  superRegion->printPrettyAsExpr(os);
616  os << "." << getDecl()->getName();
617}
618
619void FieldRegion::printPretty(raw_ostream &os) const {
620  if (canPrintPrettyAsExpr()) {
621    os << "\'";
622    printPrettyAsExpr(os);
623    os << "'";
624  } else {
625    os << "field " << "\'" << getDecl()->getName() << "'";
626  }
627  return;
628}
629
630bool CXXBaseObjectRegion::canPrintPrettyAsExpr() const {
631  return superRegion->canPrintPrettyAsExpr();
632}
633
634void CXXBaseObjectRegion::printPrettyAsExpr(raw_ostream &os) const {
635  superRegion->printPrettyAsExpr(os);
636}
637
638//===----------------------------------------------------------------------===//
639// MemRegionManager methods.
640//===----------------------------------------------------------------------===//
641
642template <typename REG>
643const REG *MemRegionManager::LazyAllocate(REG*& region) {
644  if (!region) {
645    region = (REG*) A.Allocate<REG>();
646    new (region) REG(this);
647  }
648
649  return region;
650}
651
652template <typename REG, typename ARG>
653const REG *MemRegionManager::LazyAllocate(REG*& region, ARG a) {
654  if (!region) {
655    region = (REG*) A.Allocate<REG>();
656    new (region) REG(this, a);
657  }
658
659  return region;
660}
661
662const StackLocalsSpaceRegion*
663MemRegionManager::getStackLocalsRegion(const StackFrameContext *STC) {
664  assert(STC);
665  StackLocalsSpaceRegion *&R = StackLocalsSpaceRegions[STC];
666
667  if (R)
668    return R;
669
670  R = A.Allocate<StackLocalsSpaceRegion>();
671  new (R) StackLocalsSpaceRegion(this, STC);
672  return R;
673}
674
675const StackArgumentsSpaceRegion *
676MemRegionManager::getStackArgumentsRegion(const StackFrameContext *STC) {
677  assert(STC);
678  StackArgumentsSpaceRegion *&R = StackArgumentsSpaceRegions[STC];
679
680  if (R)
681    return R;
682
683  R = A.Allocate<StackArgumentsSpaceRegion>();
684  new (R) StackArgumentsSpaceRegion(this, STC);
685  return R;
686}
687
688const GlobalsSpaceRegion
689*MemRegionManager::getGlobalsRegion(MemRegion::Kind K,
690                                    const CodeTextRegion *CR) {
691  if (!CR) {
692    if (K == MemRegion::GlobalSystemSpaceRegionKind)
693      return LazyAllocate(SystemGlobals);
694    if (K == MemRegion::GlobalImmutableSpaceRegionKind)
695      return LazyAllocate(ImmutableGlobals);
696    assert(K == MemRegion::GlobalInternalSpaceRegionKind);
697    return LazyAllocate(InternalGlobals);
698  }
699
700  assert(K == MemRegion::StaticGlobalSpaceRegionKind);
701  StaticGlobalSpaceRegion *&R = StaticsGlobalSpaceRegions[CR];
702  if (R)
703    return R;
704
705  R = A.Allocate<StaticGlobalSpaceRegion>();
706  new (R) StaticGlobalSpaceRegion(this, CR);
707  return R;
708}
709
710const HeapSpaceRegion *MemRegionManager::getHeapRegion() {
711  return LazyAllocate(heap);
712}
713
714const MemSpaceRegion *MemRegionManager::getUnknownRegion() {
715  return LazyAllocate(unknown);
716}
717
718const MemSpaceRegion *MemRegionManager::getCodeRegion() {
719  return LazyAllocate(code);
720}
721
722//===----------------------------------------------------------------------===//
723// Constructing regions.
724//===----------------------------------------------------------------------===//
725const StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str){
726  return getSubRegion<StringRegion>(Str, getGlobalsRegion());
727}
728
729const ObjCStringRegion *
730MemRegionManager::getObjCStringRegion(const ObjCStringLiteral* Str){
731  return getSubRegion<ObjCStringRegion>(Str, getGlobalsRegion());
732}
733
734/// Look through a chain of LocationContexts to either find the
735/// StackFrameContext that matches a DeclContext, or find a VarRegion
736/// for a variable captured by a block.
737static llvm::PointerUnion<const StackFrameContext *, const VarRegion *>
738getStackOrCaptureRegionForDeclContext(const LocationContext *LC,
739                                      const DeclContext *DC,
740                                      const VarDecl *VD) {
741  while (LC) {
742    if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC)) {
743      if (cast<DeclContext>(SFC->getDecl()) == DC)
744        return SFC;
745    }
746    if (const BlockInvocationContext *BC =
747        dyn_cast<BlockInvocationContext>(LC)) {
748      const BlockDataRegion *BR =
749        static_cast<const BlockDataRegion*>(BC->getContextData());
750      // FIXME: This can be made more efficient.
751      for (BlockDataRegion::referenced_vars_iterator
752           I = BR->referenced_vars_begin(),
753           E = BR->referenced_vars_end(); I != E; ++I) {
754        if (const VarRegion *VR = dyn_cast<VarRegion>(I.getOriginalRegion()))
755          if (VR->getDecl() == VD)
756            return cast<VarRegion>(I.getCapturedRegion());
757      }
758    }
759
760    LC = LC->getParent();
761  }
762  return (const StackFrameContext *)nullptr;
763}
764
765const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
766                                                const LocationContext *LC) {
767  const MemRegion *sReg = nullptr;
768
769  if (D->hasGlobalStorage() && !D->isStaticLocal()) {
770
771    // First handle the globals defined in system headers.
772    if (C.getSourceManager().isInSystemHeader(D->getLocation())) {
773      // Whitelist the system globals which often DO GET modified, assume the
774      // rest are immutable.
775      if (D->getName().find("errno") != StringRef::npos)
776        sReg = getGlobalsRegion(MemRegion::GlobalSystemSpaceRegionKind);
777      else
778        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
779
780    // Treat other globals as GlobalInternal unless they are constants.
781    } else {
782      QualType GQT = D->getType();
783      const Type *GT = GQT.getTypePtrOrNull();
784      // TODO: We could walk the complex types here and see if everything is
785      // constified.
786      if (GT && GQT.isConstQualified() && GT->isArithmeticType())
787        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
788      else
789        sReg = getGlobalsRegion();
790    }
791
792  // Finally handle static locals.
793  } else {
794    // FIXME: Once we implement scope handling, we will need to properly lookup
795    // 'D' to the proper LocationContext.
796    const DeclContext *DC = D->getDeclContext();
797    llvm::PointerUnion<const StackFrameContext *, const VarRegion *> V =
798      getStackOrCaptureRegionForDeclContext(LC, DC, D);
799
800    if (V.is<const VarRegion*>())
801      return V.get<const VarRegion*>();
802
803    const StackFrameContext *STC = V.get<const StackFrameContext*>();
804
805    if (!STC)
806      sReg = getUnknownRegion();
807    else {
808      if (D->hasLocalStorage()) {
809        sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
810               ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
811               : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
812      }
813      else {
814        assert(D->isStaticLocal());
815        const Decl *STCD = STC->getDecl();
816        if (isa<FunctionDecl>(STCD) || isa<ObjCMethodDecl>(STCD))
817          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
818                                  getFunctionTextRegion(cast<NamedDecl>(STCD)));
819        else if (const BlockDecl *BD = dyn_cast<BlockDecl>(STCD)) {
820          // FIXME: The fallback type here is totally bogus -- though it should
821          // never be queried, it will prevent uniquing with the real
822          // BlockTextRegion. Ideally we'd fix the AST so that we always had a
823          // signature.
824          QualType T;
825          if (const TypeSourceInfo *TSI = BD->getSignatureAsWritten())
826            T = TSI->getType();
827          else
828            T = getContext().getFunctionNoProtoType(getContext().VoidTy);
829
830          const BlockTextRegion *BTR =
831            getBlockTextRegion(BD, C.getCanonicalType(T),
832                               STC->getAnalysisDeclContext());
833          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
834                                  BTR);
835        }
836        else {
837          sReg = getGlobalsRegion();
838        }
839      }
840    }
841  }
842
843  return getSubRegion<VarRegion>(D, sReg);
844}
845
846const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
847                                                const MemRegion *superR) {
848  return getSubRegion<VarRegion>(D, superR);
849}
850
851const BlockDataRegion *
852MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
853                                     const LocationContext *LC,
854                                     unsigned blockCount) {
855  const MemRegion *sReg = nullptr;
856  const BlockDecl *BD = BC->getDecl();
857  if (!BD->hasCaptures()) {
858    // This handles 'static' blocks.
859    sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
860  }
861  else {
862    if (LC) {
863      // FIXME: Once we implement scope handling, we want the parent region
864      // to be the scope.
865      const StackFrameContext *STC = LC->getCurrentStackFrame();
866      assert(STC);
867      sReg = getStackLocalsRegion(STC);
868    }
869    else {
870      // We allow 'LC' to be NULL for cases where want BlockDataRegions
871      // without context-sensitivity.
872      sReg = getUnknownRegion();
873    }
874  }
875
876  return getSubRegion<BlockDataRegion>(BC, LC, blockCount, sReg);
877}
878
879const CXXTempObjectRegion *
880MemRegionManager::getCXXStaticTempObjectRegion(const Expr *Ex) {
881  return getSubRegion<CXXTempObjectRegion>(
882      Ex, getGlobalsRegion(MemRegion::GlobalInternalSpaceRegionKind, nullptr));
883}
884
885const CompoundLiteralRegion*
886MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr *CL,
887                                           const LocationContext *LC) {
888
889  const MemRegion *sReg = nullptr;
890
891  if (CL->isFileScope())
892    sReg = getGlobalsRegion();
893  else {
894    const StackFrameContext *STC = LC->getCurrentStackFrame();
895    assert(STC);
896    sReg = getStackLocalsRegion(STC);
897  }
898
899  return getSubRegion<CompoundLiteralRegion>(CL, sReg);
900}
901
902const ElementRegion*
903MemRegionManager::getElementRegion(QualType elementType, NonLoc Idx,
904                                   const MemRegion* superRegion,
905                                   ASTContext &Ctx){
906
907  QualType T = Ctx.getCanonicalType(elementType).getUnqualifiedType();
908
909  llvm::FoldingSetNodeID ID;
910  ElementRegion::ProfileRegion(ID, T, Idx, superRegion);
911
912  void *InsertPos;
913  MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
914  ElementRegion* R = cast_or_null<ElementRegion>(data);
915
916  if (!R) {
917    R = (ElementRegion*) A.Allocate<ElementRegion>();
918    new (R) ElementRegion(T, Idx, superRegion);
919    Regions.InsertNode(R, InsertPos);
920  }
921
922  return R;
923}
924
925const FunctionTextRegion *
926MemRegionManager::getFunctionTextRegion(const NamedDecl *FD) {
927  return getSubRegion<FunctionTextRegion>(FD, getCodeRegion());
928}
929
930const BlockTextRegion *
931MemRegionManager::getBlockTextRegion(const BlockDecl *BD, CanQualType locTy,
932                                     AnalysisDeclContext *AC) {
933  return getSubRegion<BlockTextRegion>(BD, locTy, AC, getCodeRegion());
934}
935
936
937/// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
938const SymbolicRegion *MemRegionManager::getSymbolicRegion(SymbolRef sym) {
939  return getSubRegion<SymbolicRegion>(sym, getUnknownRegion());
940}
941
942const SymbolicRegion *MemRegionManager::getSymbolicHeapRegion(SymbolRef Sym) {
943  return getSubRegion<SymbolicRegion>(Sym, getHeapRegion());
944}
945
946const FieldRegion*
947MemRegionManager::getFieldRegion(const FieldDecl *d,
948                                 const MemRegion* superRegion){
949  return getSubRegion<FieldRegion>(d, superRegion);
950}
951
952const ObjCIvarRegion*
953MemRegionManager::getObjCIvarRegion(const ObjCIvarDecl *d,
954                                    const MemRegion* superRegion) {
955  return getSubRegion<ObjCIvarRegion>(d, superRegion);
956}
957
958const CXXTempObjectRegion*
959MemRegionManager::getCXXTempObjectRegion(Expr const *E,
960                                         LocationContext const *LC) {
961  const StackFrameContext *SFC = LC->getCurrentStackFrame();
962  assert(SFC);
963  return getSubRegion<CXXTempObjectRegion>(E, getStackLocalsRegion(SFC));
964}
965
966/// Checks whether \p BaseClass is a valid virtual or direct non-virtual base
967/// class of the type of \p Super.
968static bool isValidBaseClass(const CXXRecordDecl *BaseClass,
969                             const TypedValueRegion *Super,
970                             bool IsVirtual) {
971  BaseClass = BaseClass->getCanonicalDecl();
972
973  const CXXRecordDecl *Class = Super->getValueType()->getAsCXXRecordDecl();
974  if (!Class)
975    return true;
976
977  if (IsVirtual)
978    return Class->isVirtuallyDerivedFrom(BaseClass);
979
980  for (const auto &I : Class->bases()) {
981    if (I.getType()->getAsCXXRecordDecl()->getCanonicalDecl() == BaseClass)
982      return true;
983  }
984
985  return false;
986}
987
988const CXXBaseObjectRegion *
989MemRegionManager::getCXXBaseObjectRegion(const CXXRecordDecl *RD,
990                                         const MemRegion *Super,
991                                         bool IsVirtual) {
992  if (isa<TypedValueRegion>(Super)) {
993    assert(isValidBaseClass(RD, dyn_cast<TypedValueRegion>(Super), IsVirtual));
994    (void)&isValidBaseClass;
995
996    if (IsVirtual) {
997      // Virtual base regions should not be layered, since the layout rules
998      // are different.
999      while (const CXXBaseObjectRegion *Base =
1000               dyn_cast<CXXBaseObjectRegion>(Super)) {
1001        Super = Base->getSuperRegion();
1002      }
1003      assert(Super && !isa<MemSpaceRegion>(Super));
1004    }
1005  }
1006
1007  return getSubRegion<CXXBaseObjectRegion>(RD, IsVirtual, Super);
1008}
1009
1010const CXXThisRegion*
1011MemRegionManager::getCXXThisRegion(QualType thisPointerTy,
1012                                   const LocationContext *LC) {
1013  const StackFrameContext *STC = LC->getCurrentStackFrame();
1014  assert(STC);
1015  const PointerType *PT = thisPointerTy->getAs<PointerType>();
1016  assert(PT);
1017  return getSubRegion<CXXThisRegion>(PT, getStackArgumentsRegion(STC));
1018}
1019
1020const AllocaRegion*
1021MemRegionManager::getAllocaRegion(const Expr *E, unsigned cnt,
1022                                  const LocationContext *LC) {
1023  const StackFrameContext *STC = LC->getCurrentStackFrame();
1024  assert(STC);
1025  return getSubRegion<AllocaRegion>(E, cnt, getStackLocalsRegion(STC));
1026}
1027
1028const MemSpaceRegion *MemRegion::getMemorySpace() const {
1029  const MemRegion *R = this;
1030  const SubRegion* SR = dyn_cast<SubRegion>(this);
1031
1032  while (SR) {
1033    R = SR->getSuperRegion();
1034    SR = dyn_cast<SubRegion>(R);
1035  }
1036
1037  return dyn_cast<MemSpaceRegion>(R);
1038}
1039
1040bool MemRegion::hasStackStorage() const {
1041  return isa<StackSpaceRegion>(getMemorySpace());
1042}
1043
1044bool MemRegion::hasStackNonParametersStorage() const {
1045  return isa<StackLocalsSpaceRegion>(getMemorySpace());
1046}
1047
1048bool MemRegion::hasStackParametersStorage() const {
1049  return isa<StackArgumentsSpaceRegion>(getMemorySpace());
1050}
1051
1052bool MemRegion::hasGlobalsOrParametersStorage() const {
1053  const MemSpaceRegion *MS = getMemorySpace();
1054  return isa<StackArgumentsSpaceRegion>(MS) ||
1055         isa<GlobalsSpaceRegion>(MS);
1056}
1057
1058// getBaseRegion strips away all elements and fields, and get the base region
1059// of them.
1060const MemRegion *MemRegion::getBaseRegion() const {
1061  const MemRegion *R = this;
1062  while (true) {
1063    switch (R->getKind()) {
1064      case MemRegion::ElementRegionKind:
1065      case MemRegion::FieldRegionKind:
1066      case MemRegion::ObjCIvarRegionKind:
1067      case MemRegion::CXXBaseObjectRegionKind:
1068        R = cast<SubRegion>(R)->getSuperRegion();
1069        continue;
1070      default:
1071        break;
1072    }
1073    break;
1074  }
1075  return R;
1076}
1077
1078bool MemRegion::isSubRegionOf(const MemRegion *R) const {
1079  return false;
1080}
1081
1082//===----------------------------------------------------------------------===//
1083// View handling.
1084//===----------------------------------------------------------------------===//
1085
1086const MemRegion *MemRegion::StripCasts(bool StripBaseCasts) const {
1087  const MemRegion *R = this;
1088  while (true) {
1089    switch (R->getKind()) {
1090    case ElementRegionKind: {
1091      const ElementRegion *ER = cast<ElementRegion>(R);
1092      if (!ER->getIndex().isZeroConstant())
1093        return R;
1094      R = ER->getSuperRegion();
1095      break;
1096    }
1097    case CXXBaseObjectRegionKind:
1098      if (!StripBaseCasts)
1099        return R;
1100      R = cast<CXXBaseObjectRegion>(R)->getSuperRegion();
1101      break;
1102    default:
1103      return R;
1104    }
1105  }
1106}
1107
1108const SymbolicRegion *MemRegion::getSymbolicBase() const {
1109  const SubRegion *SubR = dyn_cast<SubRegion>(this);
1110
1111  while (SubR) {
1112    if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(SubR))
1113      return SymR;
1114    SubR = dyn_cast<SubRegion>(SubR->getSuperRegion());
1115  }
1116  return nullptr;
1117}
1118
1119// FIXME: Merge with the implementation of the same method in Store.cpp
1120static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
1121  if (const RecordType *RT = Ty->getAs<RecordType>()) {
1122    const RecordDecl *D = RT->getDecl();
1123    if (!D->getDefinition())
1124      return false;
1125  }
1126
1127  return true;
1128}
1129
1130RegionRawOffset ElementRegion::getAsArrayOffset() const {
1131  CharUnits offset = CharUnits::Zero();
1132  const ElementRegion *ER = this;
1133  const MemRegion *superR = nullptr;
1134  ASTContext &C = getContext();
1135
1136  // FIXME: Handle multi-dimensional arrays.
1137
1138  while (ER) {
1139    superR = ER->getSuperRegion();
1140
1141    // FIXME: generalize to symbolic offsets.
1142    SVal index = ER->getIndex();
1143    if (Optional<nonloc::ConcreteInt> CI = index.getAs<nonloc::ConcreteInt>()) {
1144      // Update the offset.
1145      int64_t i = CI->getValue().getSExtValue();
1146
1147      if (i != 0) {
1148        QualType elemType = ER->getElementType();
1149
1150        // If we are pointing to an incomplete type, go no further.
1151        if (!IsCompleteType(C, elemType)) {
1152          superR = ER;
1153          break;
1154        }
1155
1156        CharUnits size = C.getTypeSizeInChars(elemType);
1157        offset += (i * size);
1158      }
1159
1160      // Go to the next ElementRegion (if any).
1161      ER = dyn_cast<ElementRegion>(superR);
1162      continue;
1163    }
1164
1165    return nullptr;
1166  }
1167
1168  assert(superR && "super region cannot be NULL");
1169  return RegionRawOffset(superR, offset);
1170}
1171
1172
1173/// Returns true if \p Base is an immediate base class of \p Child
1174static bool isImmediateBase(const CXXRecordDecl *Child,
1175                            const CXXRecordDecl *Base) {
1176  // Note that we do NOT canonicalize the base class here, because
1177  // ASTRecordLayout doesn't either. If that leads us down the wrong path,
1178  // so be it; at least we won't crash.
1179  for (const auto &I : Child->bases()) {
1180    if (I.getType()->getAsCXXRecordDecl() == Base)
1181      return true;
1182  }
1183
1184  return false;
1185}
1186
1187RegionOffset MemRegion::getAsOffset() const {
1188  const MemRegion *R = this;
1189  const MemRegion *SymbolicOffsetBase = nullptr;
1190  int64_t Offset = 0;
1191
1192  while (1) {
1193    switch (R->getKind()) {
1194    case GenericMemSpaceRegionKind:
1195    case StackLocalsSpaceRegionKind:
1196    case StackArgumentsSpaceRegionKind:
1197    case HeapSpaceRegionKind:
1198    case UnknownSpaceRegionKind:
1199    case StaticGlobalSpaceRegionKind:
1200    case GlobalInternalSpaceRegionKind:
1201    case GlobalSystemSpaceRegionKind:
1202    case GlobalImmutableSpaceRegionKind:
1203      // Stores can bind directly to a region space to set a default value.
1204      assert(Offset == 0 && !SymbolicOffsetBase);
1205      goto Finish;
1206
1207    case FunctionTextRegionKind:
1208    case BlockTextRegionKind:
1209    case BlockDataRegionKind:
1210      // These will never have bindings, but may end up having values requested
1211      // if the user does some strange casting.
1212      if (Offset != 0)
1213        SymbolicOffsetBase = R;
1214      goto Finish;
1215
1216    case SymbolicRegionKind:
1217    case AllocaRegionKind:
1218    case CompoundLiteralRegionKind:
1219    case CXXThisRegionKind:
1220    case StringRegionKind:
1221    case ObjCStringRegionKind:
1222    case VarRegionKind:
1223    case CXXTempObjectRegionKind:
1224      // Usual base regions.
1225      goto Finish;
1226
1227    case ObjCIvarRegionKind:
1228      // This is a little strange, but it's a compromise between
1229      // ObjCIvarRegions having unknown compile-time offsets (when using the
1230      // non-fragile runtime) and yet still being distinct, non-overlapping
1231      // regions. Thus we treat them as "like" base regions for the purposes
1232      // of computing offsets.
1233      goto Finish;
1234
1235    case CXXBaseObjectRegionKind: {
1236      const CXXBaseObjectRegion *BOR = cast<CXXBaseObjectRegion>(R);
1237      R = BOR->getSuperRegion();
1238
1239      QualType Ty;
1240      bool RootIsSymbolic = false;
1241      if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R)) {
1242        Ty = TVR->getDesugaredValueType(getContext());
1243      } else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
1244        // If our base region is symbolic, we don't know what type it really is.
1245        // Pretend the type of the symbol is the true dynamic type.
1246        // (This will at least be self-consistent for the life of the symbol.)
1247        Ty = SR->getSymbol()->getType()->getPointeeType();
1248        RootIsSymbolic = true;
1249      }
1250
1251      const CXXRecordDecl *Child = Ty->getAsCXXRecordDecl();
1252      if (!Child) {
1253        // We cannot compute the offset of the base class.
1254        SymbolicOffsetBase = R;
1255      }
1256
1257      if (RootIsSymbolic) {
1258        // Base layers on symbolic regions may not be type-correct.
1259        // Double-check the inheritance here, and revert to a symbolic offset
1260        // if it's invalid (e.g. due to a reinterpret_cast).
1261        if (BOR->isVirtual()) {
1262          if (!Child->isVirtuallyDerivedFrom(BOR->getDecl()))
1263            SymbolicOffsetBase = R;
1264        } else {
1265          if (!isImmediateBase(Child, BOR->getDecl()))
1266            SymbolicOffsetBase = R;
1267        }
1268      }
1269
1270      // Don't bother calculating precise offsets if we already have a
1271      // symbolic offset somewhere in the chain.
1272      if (SymbolicOffsetBase)
1273        continue;
1274
1275      CharUnits BaseOffset;
1276      const ASTRecordLayout &Layout = getContext().getASTRecordLayout(Child);
1277      if (BOR->isVirtual())
1278        BaseOffset = Layout.getVBaseClassOffset(BOR->getDecl());
1279      else
1280        BaseOffset = Layout.getBaseClassOffset(BOR->getDecl());
1281
1282      // The base offset is in chars, not in bits.
1283      Offset += BaseOffset.getQuantity() * getContext().getCharWidth();
1284      break;
1285    }
1286    case ElementRegionKind: {
1287      const ElementRegion *ER = cast<ElementRegion>(R);
1288      R = ER->getSuperRegion();
1289
1290      QualType EleTy = ER->getValueType();
1291      if (!IsCompleteType(getContext(), EleTy)) {
1292        // We cannot compute the offset of the base class.
1293        SymbolicOffsetBase = R;
1294        continue;
1295      }
1296
1297      SVal Index = ER->getIndex();
1298      if (Optional<nonloc::ConcreteInt> CI =
1299              Index.getAs<nonloc::ConcreteInt>()) {
1300        // Don't bother calculating precise offsets if we already have a
1301        // symbolic offset somewhere in the chain.
1302        if (SymbolicOffsetBase)
1303          continue;
1304
1305        int64_t i = CI->getValue().getSExtValue();
1306        // This type size is in bits.
1307        Offset += i * getContext().getTypeSize(EleTy);
1308      } else {
1309        // We cannot compute offset for non-concrete index.
1310        SymbolicOffsetBase = R;
1311      }
1312      break;
1313    }
1314    case FieldRegionKind: {
1315      const FieldRegion *FR = cast<FieldRegion>(R);
1316      R = FR->getSuperRegion();
1317
1318      const RecordDecl *RD = FR->getDecl()->getParent();
1319      if (RD->isUnion() || !RD->isCompleteDefinition()) {
1320        // We cannot compute offset for incomplete type.
1321        // For unions, we could treat everything as offset 0, but we'd rather
1322        // treat each field as a symbolic offset so they aren't stored on top
1323        // of each other, since we depend on things in typed regions actually
1324        // matching their types.
1325        SymbolicOffsetBase = R;
1326      }
1327
1328      // Don't bother calculating precise offsets if we already have a
1329      // symbolic offset somewhere in the chain.
1330      if (SymbolicOffsetBase)
1331        continue;
1332
1333      // Get the field number.
1334      unsigned idx = 0;
1335      for (RecordDecl::field_iterator FI = RD->field_begin(),
1336             FE = RD->field_end(); FI != FE; ++FI, ++idx)
1337        if (FR->getDecl() == *FI)
1338          break;
1339
1340      const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1341      // This is offset in bits.
1342      Offset += Layout.getFieldOffset(idx);
1343      break;
1344    }
1345    }
1346  }
1347
1348 Finish:
1349  if (SymbolicOffsetBase)
1350    return RegionOffset(SymbolicOffsetBase, RegionOffset::Symbolic);
1351  return RegionOffset(R, Offset);
1352}
1353
1354//===----------------------------------------------------------------------===//
1355// BlockDataRegion
1356//===----------------------------------------------------------------------===//
1357
1358std::pair<const VarRegion *, const VarRegion *>
1359BlockDataRegion::getCaptureRegions(const VarDecl *VD) {
1360  MemRegionManager &MemMgr = *getMemRegionManager();
1361  const VarRegion *VR = nullptr;
1362  const VarRegion *OriginalVR = nullptr;
1363
1364  if (!VD->hasAttr<BlocksAttr>() && VD->hasLocalStorage()) {
1365    VR = MemMgr.getVarRegion(VD, this);
1366    OriginalVR = MemMgr.getVarRegion(VD, LC);
1367  }
1368  else {
1369    if (LC) {
1370      VR = MemMgr.getVarRegion(VD, LC);
1371      OriginalVR = VR;
1372    }
1373    else {
1374      VR = MemMgr.getVarRegion(VD, MemMgr.getUnknownRegion());
1375      OriginalVR = MemMgr.getVarRegion(VD, LC);
1376    }
1377  }
1378  return std::make_pair(VR, OriginalVR);
1379}
1380
1381void BlockDataRegion::LazyInitializeReferencedVars() {
1382  if (ReferencedVars)
1383    return;
1384
1385  AnalysisDeclContext *AC = getCodeRegion()->getAnalysisDeclContext();
1386  AnalysisDeclContext::referenced_decls_iterator I, E;
1387  std::tie(I, E) = AC->getReferencedBlockVars(BC->getDecl());
1388
1389  if (I == E) {
1390    ReferencedVars = (void*) 0x1;
1391    return;
1392  }
1393
1394  MemRegionManager &MemMgr = *getMemRegionManager();
1395  llvm::BumpPtrAllocator &A = MemMgr.getAllocator();
1396  BumpVectorContext BC(A);
1397
1398  typedef BumpVector<const MemRegion*> VarVec;
1399  VarVec *BV = (VarVec*) A.Allocate<VarVec>();
1400  new (BV) VarVec(BC, E - I);
1401  VarVec *BVOriginal = (VarVec*) A.Allocate<VarVec>();
1402  new (BVOriginal) VarVec(BC, E - I);
1403
1404  for ( ; I != E; ++I) {
1405    const VarRegion *VR = nullptr;
1406    const VarRegion *OriginalVR = nullptr;
1407    std::tie(VR, OriginalVR) = getCaptureRegions(*I);
1408    assert(VR);
1409    assert(OriginalVR);
1410    BV->push_back(VR, BC);
1411    BVOriginal->push_back(OriginalVR, BC);
1412  }
1413
1414  ReferencedVars = BV;
1415  OriginalVars = BVOriginal;
1416}
1417
1418BlockDataRegion::referenced_vars_iterator
1419BlockDataRegion::referenced_vars_begin() const {
1420  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1421
1422  BumpVector<const MemRegion*> *Vec =
1423    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1424
1425  if (Vec == (void*) 0x1)
1426    return BlockDataRegion::referenced_vars_iterator(nullptr, nullptr);
1427
1428  BumpVector<const MemRegion*> *VecOriginal =
1429    static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1430
1431  return BlockDataRegion::referenced_vars_iterator(Vec->begin(),
1432                                                   VecOriginal->begin());
1433}
1434
1435BlockDataRegion::referenced_vars_iterator
1436BlockDataRegion::referenced_vars_end() const {
1437  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1438
1439  BumpVector<const MemRegion*> *Vec =
1440    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1441
1442  if (Vec == (void*) 0x1)
1443    return BlockDataRegion::referenced_vars_iterator(nullptr, nullptr);
1444
1445  BumpVector<const MemRegion*> *VecOriginal =
1446    static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1447
1448  return BlockDataRegion::referenced_vars_iterator(Vec->end(),
1449                                                   VecOriginal->end());
1450}
1451
1452const VarRegion *BlockDataRegion::getOriginalRegion(const VarRegion *R) const {
1453  for (referenced_vars_iterator I = referenced_vars_begin(),
1454                                E = referenced_vars_end();
1455       I != E; ++I) {
1456    if (I.getCapturedRegion() == R)
1457      return I.getOriginalRegion();
1458  }
1459  return nullptr;
1460}
1461
1462//===----------------------------------------------------------------------===//
1463// RegionAndSymbolInvalidationTraits
1464//===----------------------------------------------------------------------===//
1465
1466void RegionAndSymbolInvalidationTraits::setTrait(SymbolRef Sym,
1467                                                 InvalidationKinds IK) {
1468  SymTraitsMap[Sym] |= IK;
1469}
1470
1471void RegionAndSymbolInvalidationTraits::setTrait(const MemRegion *MR,
1472                                                 InvalidationKinds IK) {
1473  assert(MR);
1474  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
1475    setTrait(SR->getSymbol(), IK);
1476  else
1477    MRTraitsMap[MR] |= IK;
1478}
1479
1480bool RegionAndSymbolInvalidationTraits::hasTrait(SymbolRef Sym,
1481                                                 InvalidationKinds IK) {
1482  const_symbol_iterator I = SymTraitsMap.find(Sym);
1483  if (I != SymTraitsMap.end())
1484    return I->second & IK;
1485
1486  return false;
1487}
1488
1489bool RegionAndSymbolInvalidationTraits::hasTrait(const MemRegion *MR,
1490                                                 InvalidationKinds IK) {
1491  if (!MR)
1492    return false;
1493
1494  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
1495    return hasTrait(SR->getSymbol(), IK);
1496
1497  const_region_iterator I = MRTraitsMap.find(MR);
1498  if (I != MRTraitsMap.end())
1499    return I->second & IK;
1500
1501  return false;
1502}
1503