MemRegion.cpp revision 3d7c44e01d568e5d5c0fac9c6ccb3f080157ba19 
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/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
18#include "clang/Analysis/AnalysisContext.h"
19#include "clang/Analysis/Support/BumpVector.h"
20#include "clang/AST/CharUnits.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/RecordLayout.h"
23#include "clang/Basic/SourceManager.h"
24#include "llvm/Support/raw_ostream.h"
25
26using namespace clang;
27using namespace ento;
28
29//===----------------------------------------------------------------------===//
30// MemRegion Construction.
31//===----------------------------------------------------------------------===//
32
33template<typename RegionTy> struct MemRegionManagerTrait;
34
35template <typename RegionTy, typename A1>
36RegionTy* MemRegionManager::getRegion(const A1 a1) {
37
38  const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
39  MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1);
40
41  llvm::FoldingSetNodeID ID;
42  RegionTy::ProfileRegion(ID, a1, superRegion);
43  void *InsertPos;
44  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
45                                                                   InsertPos));
46
47  if (!R) {
48    R = (RegionTy*) A.Allocate<RegionTy>();
49    new (R) RegionTy(a1, superRegion);
50    Regions.InsertNode(R, InsertPos);
51  }
52
53  return R;
54}
55
56template <typename RegionTy, typename A1>
57RegionTy* MemRegionManager::getSubRegion(const A1 a1,
58                                         const MemRegion *superRegion) {
59  llvm::FoldingSetNodeID ID;
60  RegionTy::ProfileRegion(ID, a1, superRegion);
61  void *InsertPos;
62  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
63                                                                   InsertPos));
64
65  if (!R) {
66    R = (RegionTy*) A.Allocate<RegionTy>();
67    new (R) RegionTy(a1, superRegion);
68    Regions.InsertNode(R, InsertPos);
69  }
70
71  return R;
72}
73
74template <typename RegionTy, typename A1, typename A2>
75RegionTy* MemRegionManager::getRegion(const A1 a1, const A2 a2) {
76
77  const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
78  MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1, a2);
79
80  llvm::FoldingSetNodeID ID;
81  RegionTy::ProfileRegion(ID, a1, a2, superRegion);
82  void *InsertPos;
83  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
84                                                                   InsertPos));
85
86  if (!R) {
87    R = (RegionTy*) A.Allocate<RegionTy>();
88    new (R) RegionTy(a1, a2, superRegion);
89    Regions.InsertNode(R, InsertPos);
90  }
91
92  return R;
93}
94
95template <typename RegionTy, typename A1, typename A2>
96RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2,
97                                         const MemRegion *superRegion) {
98
99  llvm::FoldingSetNodeID ID;
100  RegionTy::ProfileRegion(ID, a1, a2, superRegion);
101  void *InsertPos;
102  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
103                                                                   InsertPos));
104
105  if (!R) {
106    R = (RegionTy*) A.Allocate<RegionTy>();
107    new (R) RegionTy(a1, a2, superRegion);
108    Regions.InsertNode(R, InsertPos);
109  }
110
111  return R;
112}
113
114template <typename RegionTy, typename A1, typename A2, typename A3>
115RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2, const A3 a3,
116                                         const MemRegion *superRegion) {
117
118  llvm::FoldingSetNodeID ID;
119  RegionTy::ProfileRegion(ID, a1, a2, a3, superRegion);
120  void *InsertPos;
121  RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
122                                                                   InsertPos));
123
124  if (!R) {
125    R = (RegionTy*) A.Allocate<RegionTy>();
126    new (R) RegionTy(a1, a2, a3, superRegion);
127    Regions.InsertNode(R, InsertPos);
128  }
129
130  return R;
131}
132
133//===----------------------------------------------------------------------===//
134// Object destruction.
135//===----------------------------------------------------------------------===//
136
137MemRegion::~MemRegion() {}
138
139MemRegionManager::~MemRegionManager() {
140  // All regions and their data are BumpPtrAllocated.  No need to call
141  // their destructors.
142}
143
144//===----------------------------------------------------------------------===//
145// Basic methods.
146//===----------------------------------------------------------------------===//
147
148bool SubRegion::isSubRegionOf(const MemRegion* R) const {
149  const MemRegion* r = getSuperRegion();
150  while (r != 0) {
151    if (r == R)
152      return true;
153    if (const SubRegion* sr = dyn_cast<SubRegion>(r))
154      r = sr->getSuperRegion();
155    else
156      break;
157  }
158  return false;
159}
160
161MemRegionManager* SubRegion::getMemRegionManager() const {
162  const SubRegion* r = this;
163  do {
164    const MemRegion *superRegion = r->getSuperRegion();
165    if (const SubRegion *sr = dyn_cast<SubRegion>(superRegion)) {
166      r = sr;
167      continue;
168    }
169    return superRegion->getMemRegionManager();
170  } while (1);
171}
172
173const StackFrameContext *VarRegion::getStackFrame() const {
174  const StackSpaceRegion *SSR = dyn_cast<StackSpaceRegion>(getMemorySpace());
175  return SSR ? SSR->getStackFrame() : NULL;
176}
177
178//===----------------------------------------------------------------------===//
179// Region extents.
180//===----------------------------------------------------------------------===//
181
182DefinedOrUnknownSVal DeclRegion::getExtent(SValBuilder &svalBuilder) const {
183  ASTContext &Ctx = svalBuilder.getContext();
184  QualType T = getDesugaredValueType(Ctx);
185
186  if (isa<VariableArrayType>(T))
187    return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
188  if (isa<IncompleteArrayType>(T))
189    return UnknownVal();
190
191  CharUnits size = Ctx.getTypeSizeInChars(T);
192  QualType sizeTy = svalBuilder.getArrayIndexType();
193  return svalBuilder.makeIntVal(size.getQuantity(), sizeTy);
194}
195
196DefinedOrUnknownSVal FieldRegion::getExtent(SValBuilder &svalBuilder) const {
197  DefinedOrUnknownSVal Extent = DeclRegion::getExtent(svalBuilder);
198
199  // A zero-length array at the end of a struct often stands for dynamically-
200  // allocated extra memory.
201  if (Extent.isZeroConstant()) {
202    QualType T = getDesugaredValueType(svalBuilder.getContext());
203
204    if (isa<ConstantArrayType>(T))
205      return UnknownVal();
206  }
207
208  return Extent;
209}
210
211DefinedOrUnknownSVal AllocaRegion::getExtent(SValBuilder &svalBuilder) const {
212  return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
213}
214
215DefinedOrUnknownSVal SymbolicRegion::getExtent(SValBuilder &svalBuilder) const {
216  return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
217}
218
219DefinedOrUnknownSVal StringRegion::getExtent(SValBuilder &svalBuilder) const {
220  return svalBuilder.makeIntVal(getStringLiteral()->getByteLength()+1,
221                                svalBuilder.getArrayIndexType());
222}
223
224ObjCIvarRegion::ObjCIvarRegion(const ObjCIvarDecl *ivd, const MemRegion* sReg)
225  : DeclRegion(ivd, sReg, ObjCIvarRegionKind) {}
226
227const ObjCIvarDecl *ObjCIvarRegion::getDecl() const {
228  return cast<ObjCIvarDecl>(D);
229}
230
231QualType ObjCIvarRegion::getValueType() const {
232  return getDecl()->getType();
233}
234
235QualType CXXBaseObjectRegion::getValueType() const {
236  return QualType(decl->getTypeForDecl(), 0);
237}
238
239//===----------------------------------------------------------------------===//
240// FoldingSet profiling.
241//===----------------------------------------------------------------------===//
242
243void MemSpaceRegion::Profile(llvm::FoldingSetNodeID& ID) const {
244  ID.AddInteger((unsigned)getKind());
245}
246
247void StackSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
248  ID.AddInteger((unsigned)getKind());
249  ID.AddPointer(getStackFrame());
250}
251
252void StaticGlobalSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
253  ID.AddInteger((unsigned)getKind());
254  ID.AddPointer(getCodeRegion());
255}
256
257void StringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
258                                 const StringLiteral* Str,
259                                 const MemRegion* superRegion) {
260  ID.AddInteger((unsigned) StringRegionKind);
261  ID.AddPointer(Str);
262  ID.AddPointer(superRegion);
263}
264
265void ObjCStringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
266                                     const ObjCStringLiteral* Str,
267                                     const MemRegion* superRegion) {
268  ID.AddInteger((unsigned) ObjCStringRegionKind);
269  ID.AddPointer(Str);
270  ID.AddPointer(superRegion);
271}
272
273void AllocaRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
274                                 const Expr *Ex, unsigned cnt,
275                                 const MemRegion *) {
276  ID.AddInteger((unsigned) AllocaRegionKind);
277  ID.AddPointer(Ex);
278  ID.AddInteger(cnt);
279}
280
281void AllocaRegion::Profile(llvm::FoldingSetNodeID& ID) const {
282  ProfileRegion(ID, Ex, Cnt, superRegion);
283}
284
285void CompoundLiteralRegion::Profile(llvm::FoldingSetNodeID& ID) const {
286  CompoundLiteralRegion::ProfileRegion(ID, CL, superRegion);
287}
288
289void CompoundLiteralRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
290                                          const CompoundLiteralExpr *CL,
291                                          const MemRegion* superRegion) {
292  ID.AddInteger((unsigned) CompoundLiteralRegionKind);
293  ID.AddPointer(CL);
294  ID.AddPointer(superRegion);
295}
296
297void CXXThisRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
298                                  const PointerType *PT,
299                                  const MemRegion *sRegion) {
300  ID.AddInteger((unsigned) CXXThisRegionKind);
301  ID.AddPointer(PT);
302  ID.AddPointer(sRegion);
303}
304
305void CXXThisRegion::Profile(llvm::FoldingSetNodeID &ID) const {
306  CXXThisRegion::ProfileRegion(ID, ThisPointerTy, superRegion);
307}
308
309void ObjCIvarRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
310                                   const ObjCIvarDecl *ivd,
311                                   const MemRegion* superRegion) {
312  DeclRegion::ProfileRegion(ID, ivd, superRegion, ObjCIvarRegionKind);
313}
314
315void DeclRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, const Decl *D,
316                               const MemRegion* superRegion, Kind k) {
317  ID.AddInteger((unsigned) k);
318  ID.AddPointer(D);
319  ID.AddPointer(superRegion);
320}
321
322void DeclRegion::Profile(llvm::FoldingSetNodeID& ID) const {
323  DeclRegion::ProfileRegion(ID, D, superRegion, getKind());
324}
325
326void VarRegion::Profile(llvm::FoldingSetNodeID &ID) const {
327  VarRegion::ProfileRegion(ID, getDecl(), superRegion);
328}
329
330void SymbolicRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SymbolRef sym,
331                                   const MemRegion *sreg) {
332  ID.AddInteger((unsigned) MemRegion::SymbolicRegionKind);
333  ID.Add(sym);
334  ID.AddPointer(sreg);
335}
336
337void SymbolicRegion::Profile(llvm::FoldingSetNodeID& ID) const {
338  SymbolicRegion::ProfileRegion(ID, sym, getSuperRegion());
339}
340
341void ElementRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
342                                  QualType ElementType, SVal Idx,
343                                  const MemRegion* superRegion) {
344  ID.AddInteger(MemRegion::ElementRegionKind);
345  ID.Add(ElementType);
346  ID.AddPointer(superRegion);
347  Idx.Profile(ID);
348}
349
350void ElementRegion::Profile(llvm::FoldingSetNodeID& ID) const {
351  ElementRegion::ProfileRegion(ID, ElementType, Index, superRegion);
352}
353
354void FunctionTextRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
355                                       const FunctionDecl *FD,
356                                       const MemRegion*) {
357  ID.AddInteger(MemRegion::FunctionTextRegionKind);
358  ID.AddPointer(FD);
359}
360
361void FunctionTextRegion::Profile(llvm::FoldingSetNodeID& ID) const {
362  FunctionTextRegion::ProfileRegion(ID, FD, superRegion);
363}
364
365void BlockTextRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
366                                    const BlockDecl *BD, CanQualType,
367                                    const AnalysisDeclContext *AC,
368                                    const MemRegion*) {
369  ID.AddInteger(MemRegion::BlockTextRegionKind);
370  ID.AddPointer(BD);
371}
372
373void BlockTextRegion::Profile(llvm::FoldingSetNodeID& ID) const {
374  BlockTextRegion::ProfileRegion(ID, BD, locTy, AC, superRegion);
375}
376
377void BlockDataRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
378                                    const BlockTextRegion *BC,
379                                    const LocationContext *LC,
380                                    const MemRegion *sReg) {
381  ID.AddInteger(MemRegion::BlockDataRegionKind);
382  ID.AddPointer(BC);
383  ID.AddPointer(LC);
384  ID.AddPointer(sReg);
385}
386
387void BlockDataRegion::Profile(llvm::FoldingSetNodeID& ID) const {
388  BlockDataRegion::ProfileRegion(ID, BC, LC, getSuperRegion());
389}
390
391void CXXTempObjectRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
392                                        Expr const *Ex,
393                                        const MemRegion *sReg) {
394  ID.AddPointer(Ex);
395  ID.AddPointer(sReg);
396}
397
398void CXXTempObjectRegion::Profile(llvm::FoldingSetNodeID &ID) const {
399  ProfileRegion(ID, Ex, getSuperRegion());
400}
401
402void CXXBaseObjectRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
403                                        const CXXRecordDecl *decl,
404                                        const MemRegion *sReg) {
405  ID.AddPointer(decl);
406  ID.AddPointer(sReg);
407}
408
409void CXXBaseObjectRegion::Profile(llvm::FoldingSetNodeID &ID) const {
410  ProfileRegion(ID, decl, superRegion);
411}
412
413//===----------------------------------------------------------------------===//
414// Region anchors.
415//===----------------------------------------------------------------------===//
416
417void GlobalsSpaceRegion::anchor() { }
418void HeapSpaceRegion::anchor() { }
419void UnknownSpaceRegion::anchor() { }
420void StackLocalsSpaceRegion::anchor() { }
421void StackArgumentsSpaceRegion::anchor() { }
422void TypedRegion::anchor() { }
423void TypedValueRegion::anchor() { }
424void CodeTextRegion::anchor() { }
425void SubRegion::anchor() { }
426
427//===----------------------------------------------------------------------===//
428// Region pretty-printing.
429//===----------------------------------------------------------------------===//
430
431void MemRegion::dump() const {
432  dumpToStream(llvm::errs());
433}
434
435std::string MemRegion::getString() const {
436  std::string s;
437  llvm::raw_string_ostream os(s);
438  dumpToStream(os);
439  return os.str();
440}
441
442void MemRegion::dumpToStream(raw_ostream &os) const {
443  os << "<Unknown Region>";
444}
445
446void AllocaRegion::dumpToStream(raw_ostream &os) const {
447  os << "alloca{" << (void*) Ex << ',' << Cnt << '}';
448}
449
450void FunctionTextRegion::dumpToStream(raw_ostream &os) const {
451  os << "code{" << getDecl()->getDeclName().getAsString() << '}';
452}
453
454void BlockTextRegion::dumpToStream(raw_ostream &os) const {
455  os << "block_code{" << (void*) this << '}';
456}
457
458void BlockDataRegion::dumpToStream(raw_ostream &os) const {
459  os << "block_data{" << BC << '}';
460}
461
462void CompoundLiteralRegion::dumpToStream(raw_ostream &os) const {
463  // FIXME: More elaborate pretty-printing.
464  os << "{ " << (void*) CL <<  " }";
465}
466
467void CXXTempObjectRegion::dumpToStream(raw_ostream &os) const {
468  os << "temp_object{" << getValueType().getAsString() << ','
469     << (void*) Ex << '}';
470}
471
472void CXXBaseObjectRegion::dumpToStream(raw_ostream &os) const {
473  os << "base " << decl->getName();
474}
475
476void CXXThisRegion::dumpToStream(raw_ostream &os) const {
477  os << "this";
478}
479
480void ElementRegion::dumpToStream(raw_ostream &os) const {
481  os << "element{" << superRegion << ','
482     << Index << ',' << getElementType().getAsString() << '}';
483}
484
485void FieldRegion::dumpToStream(raw_ostream &os) const {
486  os << superRegion << "->" << *getDecl();
487}
488
489void ObjCIvarRegion::dumpToStream(raw_ostream &os) const {
490  os << "ivar{" << superRegion << ',' << *getDecl() << '}';
491}
492
493void StringRegion::dumpToStream(raw_ostream &os) const {
494  Str->printPretty(os, 0, PrintingPolicy(getContext().getLangOpts()));
495}
496
497void ObjCStringRegion::dumpToStream(raw_ostream &os) const {
498  Str->printPretty(os, 0, PrintingPolicy(getContext().getLangOpts()));
499}
500
501void SymbolicRegion::dumpToStream(raw_ostream &os) const {
502  os << "SymRegion{" << sym << '}';
503}
504
505void VarRegion::dumpToStream(raw_ostream &os) const {
506  os << *cast<VarDecl>(D);
507}
508
509void RegionRawOffset::dump() const {
510  dumpToStream(llvm::errs());
511}
512
513void RegionRawOffset::dumpToStream(raw_ostream &os) const {
514  os << "raw_offset{" << getRegion() << ',' << getOffset().getQuantity() << '}';
515}
516
517void StaticGlobalSpaceRegion::dumpToStream(raw_ostream &os) const {
518  os << "StaticGlobalsMemSpace{" << CR << '}';
519}
520
521void NonStaticGlobalSpaceRegion::dumpToStream(raw_ostream &os) const {
522  os << "NonStaticGlobalSpaceRegion";
523}
524
525void GlobalInternalSpaceRegion::dumpToStream(raw_ostream &os) const {
526  os << "GlobalInternalSpaceRegion";
527}
528
529void GlobalSystemSpaceRegion::dumpToStream(raw_ostream &os) const {
530  os << "GlobalSystemSpaceRegion";
531}
532
533void GlobalImmutableSpaceRegion::dumpToStream(raw_ostream &os) const {
534  os << "GlobalImmutableSpaceRegion";
535}
536
537void MemRegion::dumpPretty(raw_ostream &os) const {
538  return;
539}
540
541void VarRegion::dumpPretty(raw_ostream &os) const {
542  os << getDecl()->getName();
543}
544
545void FieldRegion::dumpPretty(raw_ostream &os) const {
546  superRegion->dumpPretty(os);
547  os << "->" << getDecl();
548}
549
550//===----------------------------------------------------------------------===//
551// MemRegionManager methods.
552//===----------------------------------------------------------------------===//
553
554template <typename REG>
555const REG *MemRegionManager::LazyAllocate(REG*& region) {
556  if (!region) {
557    region = (REG*) A.Allocate<REG>();
558    new (region) REG(this);
559  }
560
561  return region;
562}
563
564template <typename REG, typename ARG>
565const REG *MemRegionManager::LazyAllocate(REG*& region, ARG a) {
566  if (!region) {
567    region = (REG*) A.Allocate<REG>();
568    new (region) REG(this, a);
569  }
570
571  return region;
572}
573
574const StackLocalsSpaceRegion*
575MemRegionManager::getStackLocalsRegion(const StackFrameContext *STC) {
576  assert(STC);
577  StackLocalsSpaceRegion *&R = StackLocalsSpaceRegions[STC];
578
579  if (R)
580    return R;
581
582  R = A.Allocate<StackLocalsSpaceRegion>();
583  new (R) StackLocalsSpaceRegion(this, STC);
584  return R;
585}
586
587const StackArgumentsSpaceRegion *
588MemRegionManager::getStackArgumentsRegion(const StackFrameContext *STC) {
589  assert(STC);
590  StackArgumentsSpaceRegion *&R = StackArgumentsSpaceRegions[STC];
591
592  if (R)
593    return R;
594
595  R = A.Allocate<StackArgumentsSpaceRegion>();
596  new (R) StackArgumentsSpaceRegion(this, STC);
597  return R;
598}
599
600const GlobalsSpaceRegion
601*MemRegionManager::getGlobalsRegion(MemRegion::Kind K,
602                                    const CodeTextRegion *CR) {
603  if (!CR) {
604    if (K == MemRegion::GlobalSystemSpaceRegionKind)
605      return LazyAllocate(SystemGlobals);
606    if (K == MemRegion::GlobalImmutableSpaceRegionKind)
607      return LazyAllocate(ImmutableGlobals);
608    assert(K == MemRegion::GlobalInternalSpaceRegionKind);
609    return LazyAllocate(InternalGlobals);
610  }
611
612  assert(K == MemRegion::StaticGlobalSpaceRegionKind);
613  StaticGlobalSpaceRegion *&R = StaticsGlobalSpaceRegions[CR];
614  if (R)
615    return R;
616
617  R = A.Allocate<StaticGlobalSpaceRegion>();
618  new (R) StaticGlobalSpaceRegion(this, CR);
619  return R;
620}
621
622const HeapSpaceRegion *MemRegionManager::getHeapRegion() {
623  return LazyAllocate(heap);
624}
625
626const MemSpaceRegion *MemRegionManager::getUnknownRegion() {
627  return LazyAllocate(unknown);
628}
629
630const MemSpaceRegion *MemRegionManager::getCodeRegion() {
631  return LazyAllocate(code);
632}
633
634//===----------------------------------------------------------------------===//
635// Constructing regions.
636//===----------------------------------------------------------------------===//
637const StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str){
638  return getSubRegion<StringRegion>(Str, getGlobalsRegion());
639}
640
641const ObjCStringRegion *
642MemRegionManager::getObjCStringRegion(const ObjCStringLiteral* Str){
643  return getSubRegion<ObjCStringRegion>(Str, getGlobalsRegion());
644}
645
646const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
647                                                const LocationContext *LC) {
648  const MemRegion *sReg = 0;
649
650  if (D->hasGlobalStorage() && !D->isStaticLocal()) {
651
652    // First handle the globals defined in system headers.
653    if (C.getSourceManager().isInSystemHeader(D->getLocation())) {
654      // Whitelist the system globals which often DO GET modified, assume the
655      // rest are immutable.
656      if (D->getName().find("errno") != StringRef::npos)
657        sReg = getGlobalsRegion(MemRegion::GlobalSystemSpaceRegionKind);
658      else
659        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
660
661    // Treat other globals as GlobalInternal unless they are constants.
662    } else {
663      QualType GQT = D->getType();
664      const Type *GT = GQT.getTypePtrOrNull();
665      // TODO: We could walk the complex types here and see if everything is
666      // constified.
667      if (GT && GQT.isConstQualified() && GT->isArithmeticType())
668        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
669      else
670        sReg = getGlobalsRegion();
671    }
672
673  // Finally handle static locals.
674  } else {
675    // FIXME: Once we implement scope handling, we will need to properly lookup
676    // 'D' to the proper LocationContext.
677    const DeclContext *DC = D->getDeclContext();
678    const StackFrameContext *STC = LC->getStackFrameForDeclContext(DC);
679
680    if (!STC)
681      sReg = getUnknownRegion();
682    else {
683      if (D->hasLocalStorage()) {
684        sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
685               ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
686               : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
687      }
688      else {
689        assert(D->isStaticLocal());
690        const Decl *D = STC->getDecl();
691        if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
692          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
693                                  getFunctionTextRegion(FD));
694        else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
695          const BlockTextRegion *BTR =
696            getBlockTextRegion(BD,
697                     C.getCanonicalType(BD->getSignatureAsWritten()->getType()),
698                     STC->getAnalysisDeclContext());
699          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
700                                  BTR);
701        }
702        else {
703          // FIXME: For ObjC-methods, we need a new CodeTextRegion.  For now
704          // just use the main global memspace.
705          sReg = getGlobalsRegion();
706        }
707      }
708    }
709  }
710
711  return getSubRegion<VarRegion>(D, sReg);
712}
713
714const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
715                                                const MemRegion *superR) {
716  return getSubRegion<VarRegion>(D, superR);
717}
718
719const BlockDataRegion *
720MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
721                                     const LocationContext *LC) {
722  const MemRegion *sReg = 0;
723  const BlockDecl *BD = BC->getDecl();
724  if (!BD->hasCaptures()) {
725    // This handles 'static' blocks.
726    sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
727  }
728  else {
729    if (LC) {
730      // FIXME: Once we implement scope handling, we want the parent region
731      // to be the scope.
732      const StackFrameContext *STC = LC->getCurrentStackFrame();
733      assert(STC);
734      sReg = getStackLocalsRegion(STC);
735    }
736    else {
737      // We allow 'LC' to be NULL for cases where want BlockDataRegions
738      // without context-sensitivity.
739      sReg = getUnknownRegion();
740    }
741  }
742
743  return getSubRegion<BlockDataRegion>(BC, LC, sReg);
744}
745
746const CompoundLiteralRegion*
747MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr *CL,
748                                           const LocationContext *LC) {
749
750  const MemRegion *sReg = 0;
751
752  if (CL->isFileScope())
753    sReg = getGlobalsRegion();
754  else {
755    const StackFrameContext *STC = LC->getCurrentStackFrame();
756    assert(STC);
757    sReg = getStackLocalsRegion(STC);
758  }
759
760  return getSubRegion<CompoundLiteralRegion>(CL, sReg);
761}
762
763const ElementRegion*
764MemRegionManager::getElementRegion(QualType elementType, NonLoc Idx,
765                                   const MemRegion* superRegion,
766                                   ASTContext &Ctx){
767
768  QualType T = Ctx.getCanonicalType(elementType).getUnqualifiedType();
769
770  llvm::FoldingSetNodeID ID;
771  ElementRegion::ProfileRegion(ID, T, Idx, superRegion);
772
773  void *InsertPos;
774  MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
775  ElementRegion* R = cast_or_null<ElementRegion>(data);
776
777  if (!R) {
778    R = (ElementRegion*) A.Allocate<ElementRegion>();
779    new (R) ElementRegion(T, Idx, superRegion);
780    Regions.InsertNode(R, InsertPos);
781  }
782
783  return R;
784}
785
786const FunctionTextRegion *
787MemRegionManager::getFunctionTextRegion(const FunctionDecl *FD) {
788  return getSubRegion<FunctionTextRegion>(FD, getCodeRegion());
789}
790
791const BlockTextRegion *
792MemRegionManager::getBlockTextRegion(const BlockDecl *BD, CanQualType locTy,
793                                     AnalysisDeclContext *AC) {
794  return getSubRegion<BlockTextRegion>(BD, locTy, AC, getCodeRegion());
795}
796
797
798/// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
799const SymbolicRegion *MemRegionManager::getSymbolicRegion(SymbolRef sym) {
800  return getSubRegion<SymbolicRegion>(sym, getUnknownRegion());
801}
802
803const FieldRegion*
804MemRegionManager::getFieldRegion(const FieldDecl *d,
805                                 const MemRegion* superRegion){
806  return getSubRegion<FieldRegion>(d, superRegion);
807}
808
809const ObjCIvarRegion*
810MemRegionManager::getObjCIvarRegion(const ObjCIvarDecl *d,
811                                    const MemRegion* superRegion) {
812  return getSubRegion<ObjCIvarRegion>(d, superRegion);
813}
814
815const CXXTempObjectRegion*
816MemRegionManager::getCXXTempObjectRegion(Expr const *E,
817                                         LocationContext const *LC) {
818  const StackFrameContext *SFC = LC->getCurrentStackFrame();
819  assert(SFC);
820  return getSubRegion<CXXTempObjectRegion>(E, getStackLocalsRegion(SFC));
821}
822
823const CXXBaseObjectRegion *
824MemRegionManager::getCXXBaseObjectRegion(const CXXRecordDecl *decl,
825                                         const MemRegion *superRegion) {
826  return getSubRegion<CXXBaseObjectRegion>(decl, superRegion);
827}
828
829const CXXThisRegion*
830MemRegionManager::getCXXThisRegion(QualType thisPointerTy,
831                                   const LocationContext *LC) {
832  const StackFrameContext *STC = LC->getCurrentStackFrame();
833  assert(STC);
834  const PointerType *PT = thisPointerTy->getAs<PointerType>();
835  assert(PT);
836  return getSubRegion<CXXThisRegion>(PT, getStackArgumentsRegion(STC));
837}
838
839const AllocaRegion*
840MemRegionManager::getAllocaRegion(const Expr *E, unsigned cnt,
841                                  const LocationContext *LC) {
842  const StackFrameContext *STC = LC->getCurrentStackFrame();
843  assert(STC);
844  return getSubRegion<AllocaRegion>(E, cnt, getStackLocalsRegion(STC));
845}
846
847const MemSpaceRegion *MemRegion::getMemorySpace() const {
848  const MemRegion *R = this;
849  const SubRegion* SR = dyn_cast<SubRegion>(this);
850
851  while (SR) {
852    R = SR->getSuperRegion();
853    SR = dyn_cast<SubRegion>(R);
854  }
855
856  return dyn_cast<MemSpaceRegion>(R);
857}
858
859bool MemRegion::hasStackStorage() const {
860  return isa<StackSpaceRegion>(getMemorySpace());
861}
862
863bool MemRegion::hasStackNonParametersStorage() const {
864  return isa<StackLocalsSpaceRegion>(getMemorySpace());
865}
866
867bool MemRegion::hasStackParametersStorage() const {
868  return isa<StackArgumentsSpaceRegion>(getMemorySpace());
869}
870
871bool MemRegion::hasGlobalsOrParametersStorage() const {
872  const MemSpaceRegion *MS = getMemorySpace();
873  return isa<StackArgumentsSpaceRegion>(MS) ||
874         isa<GlobalsSpaceRegion>(MS);
875}
876
877// getBaseRegion strips away all elements and fields, and get the base region
878// of them.
879const MemRegion *MemRegion::getBaseRegion() const {
880  const MemRegion *R = this;
881  while (true) {
882    switch (R->getKind()) {
883      case MemRegion::ElementRegionKind:
884      case MemRegion::FieldRegionKind:
885      case MemRegion::ObjCIvarRegionKind:
886      case MemRegion::CXXBaseObjectRegionKind:
887        R = cast<SubRegion>(R)->getSuperRegion();
888        continue;
889      default:
890        break;
891    }
892    break;
893  }
894  return R;
895}
896
897//===----------------------------------------------------------------------===//
898// View handling.
899//===----------------------------------------------------------------------===//
900
901const MemRegion *MemRegion::StripCasts() const {
902  const MemRegion *R = this;
903  while (true) {
904    if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
905      // FIXME: generalize.  Essentially we want to strip away ElementRegions
906      // that were layered on a symbolic region because of casts.  We only
907      // want to strip away ElementRegions, however, where the index is 0.
908      SVal index = ER->getIndex();
909      if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&index)) {
910        if (CI->getValue().getSExtValue() == 0) {
911          R = ER->getSuperRegion();
912          continue;
913        }
914      }
915    }
916    break;
917  }
918  return R;
919}
920
921// FIXME: Merge with the implementation of the same method in Store.cpp
922static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
923  if (const RecordType *RT = Ty->getAs<RecordType>()) {
924    const RecordDecl *D = RT->getDecl();
925    if (!D->getDefinition())
926      return false;
927  }
928
929  return true;
930}
931
932RegionRawOffset ElementRegion::getAsArrayOffset() const {
933  CharUnits offset = CharUnits::Zero();
934  const ElementRegion *ER = this;
935  const MemRegion *superR = NULL;
936  ASTContext &C = getContext();
937
938  // FIXME: Handle multi-dimensional arrays.
939
940  while (ER) {
941    superR = ER->getSuperRegion();
942
943    // FIXME: generalize to symbolic offsets.
944    SVal index = ER->getIndex();
945    if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&index)) {
946      // Update the offset.
947      int64_t i = CI->getValue().getSExtValue();
948
949      if (i != 0) {
950        QualType elemType = ER->getElementType();
951
952        // If we are pointing to an incomplete type, go no further.
953        if (!IsCompleteType(C, elemType)) {
954          superR = ER;
955          break;
956        }
957
958        CharUnits size = C.getTypeSizeInChars(elemType);
959        offset += (i * size);
960      }
961
962      // Go to the next ElementRegion (if any).
963      ER = dyn_cast<ElementRegion>(superR);
964      continue;
965    }
966
967    return NULL;
968  }
969
970  assert(superR && "super region cannot be NULL");
971  return RegionRawOffset(superR, offset);
972}
973
974RegionOffset MemRegion::getAsOffset() const {
975  const MemRegion *R = this;
976  int64_t Offset = 0;
977
978  while (1) {
979    switch (R->getKind()) {
980    default:
981      return RegionOffset(0);
982    case SymbolicRegionKind:
983    case AllocaRegionKind:
984    case CompoundLiteralRegionKind:
985    case CXXThisRegionKind:
986    case StringRegionKind:
987    case VarRegionKind:
988    case CXXTempObjectRegionKind:
989      goto Finish;
990    case ElementRegionKind: {
991      const ElementRegion *ER = cast<ElementRegion>(R);
992      QualType EleTy = ER->getValueType();
993
994      if (!IsCompleteType(getContext(), EleTy))
995        return RegionOffset(0);
996
997      SVal Index = ER->getIndex();
998      if (const nonloc::ConcreteInt *CI=dyn_cast<nonloc::ConcreteInt>(&Index)) {
999        int64_t i = CI->getValue().getSExtValue();
1000        CharUnits Size = getContext().getTypeSizeInChars(EleTy);
1001        Offset += i * Size.getQuantity() * 8;
1002      } else {
1003        // We cannot compute offset for non-concrete index.
1004        return RegionOffset(0);
1005      }
1006      R = ER->getSuperRegion();
1007      break;
1008    }
1009    case FieldRegionKind: {
1010      const FieldRegion *FR = cast<FieldRegion>(R);
1011      const RecordDecl *RD = FR->getDecl()->getParent();
1012      if (!RD->isCompleteDefinition())
1013        // We cannot compute offset for incomplete type.
1014        return RegionOffset(0);
1015      // Get the field number.
1016      unsigned idx = 0;
1017      for (RecordDecl::field_iterator FI = RD->field_begin(),
1018             FE = RD->field_end(); FI != FE; ++FI, ++idx)
1019        if (FR->getDecl() == *FI)
1020          break;
1021
1022      const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1023      // This is offset in bits.
1024      Offset += Layout.getFieldOffset(idx);
1025      R = FR->getSuperRegion();
1026      break;
1027    }
1028    }
1029  }
1030
1031 Finish:
1032  return RegionOffset(R, Offset);
1033}
1034
1035//===----------------------------------------------------------------------===//
1036// BlockDataRegion
1037//===----------------------------------------------------------------------===//
1038
1039void BlockDataRegion::LazyInitializeReferencedVars() {
1040  if (ReferencedVars)
1041    return;
1042
1043  AnalysisDeclContext *AC = getCodeRegion()->getAnalysisDeclContext();
1044  AnalysisDeclContext::referenced_decls_iterator I, E;
1045  llvm::tie(I, E) = AC->getReferencedBlockVars(BC->getDecl());
1046
1047  if (I == E) {
1048    ReferencedVars = (void*) 0x1;
1049    return;
1050  }
1051
1052  MemRegionManager &MemMgr = *getMemRegionManager();
1053  llvm::BumpPtrAllocator &A = MemMgr.getAllocator();
1054  BumpVectorContext BC(A);
1055
1056  typedef BumpVector<const MemRegion*> VarVec;
1057  VarVec *BV = (VarVec*) A.Allocate<VarVec>();
1058  new (BV) VarVec(BC, E - I);
1059
1060  for ( ; I != E; ++I) {
1061    const VarDecl *VD = *I;
1062    const VarRegion *VR = 0;
1063
1064    if (!VD->getAttr<BlocksAttr>() && VD->hasLocalStorage())
1065      VR = MemMgr.getVarRegion(VD, this);
1066    else {
1067      if (LC)
1068        VR = MemMgr.getVarRegion(VD, LC);
1069      else {
1070        VR = MemMgr.getVarRegion(VD, MemMgr.getUnknownRegion());
1071      }
1072    }
1073
1074    assert(VR);
1075    BV->push_back(VR, BC);
1076  }
1077
1078  ReferencedVars = BV;
1079}
1080
1081BlockDataRegion::referenced_vars_iterator
1082BlockDataRegion::referenced_vars_begin() const {
1083  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1084
1085  BumpVector<const MemRegion*> *Vec =
1086    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1087
1088  return BlockDataRegion::referenced_vars_iterator(Vec == (void*) 0x1 ?
1089                                                   NULL : Vec->begin());
1090}
1091
1092BlockDataRegion::referenced_vars_iterator
1093BlockDataRegion::referenced_vars_end() const {
1094  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1095
1096  BumpVector<const MemRegion*> *Vec =
1097    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1098
1099  return BlockDataRegion::referenced_vars_iterator(Vec == (void*) 0x1 ?
1100                                                   NULL : Vec->end());
1101}
1102