MemRegion.cpp revision 4e4d08403ca5cfd4d558fa2936215d3a4e5a528d 
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
537//===----------------------------------------------------------------------===//
538// MemRegionManager methods.
539//===----------------------------------------------------------------------===//
540
541template <typename REG>
542const REG *MemRegionManager::LazyAllocate(REG*& region) {
543  if (!region) {
544    region = (REG*) A.Allocate<REG>();
545    new (region) REG(this);
546  }
547
548  return region;
549}
550
551template <typename REG, typename ARG>
552const REG *MemRegionManager::LazyAllocate(REG*& region, ARG a) {
553  if (!region) {
554    region = (REG*) A.Allocate<REG>();
555    new (region) REG(this, a);
556  }
557
558  return region;
559}
560
561const StackLocalsSpaceRegion*
562MemRegionManager::getStackLocalsRegion(const StackFrameContext *STC) {
563  assert(STC);
564  StackLocalsSpaceRegion *&R = StackLocalsSpaceRegions[STC];
565
566  if (R)
567    return R;
568
569  R = A.Allocate<StackLocalsSpaceRegion>();
570  new (R) StackLocalsSpaceRegion(this, STC);
571  return R;
572}
573
574const StackArgumentsSpaceRegion *
575MemRegionManager::getStackArgumentsRegion(const StackFrameContext *STC) {
576  assert(STC);
577  StackArgumentsSpaceRegion *&R = StackArgumentsSpaceRegions[STC];
578
579  if (R)
580    return R;
581
582  R = A.Allocate<StackArgumentsSpaceRegion>();
583  new (R) StackArgumentsSpaceRegion(this, STC);
584  return R;
585}
586
587const GlobalsSpaceRegion
588*MemRegionManager::getGlobalsRegion(MemRegion::Kind K,
589                                    const CodeTextRegion *CR) {
590  if (!CR) {
591    if (K == MemRegion::GlobalSystemSpaceRegionKind)
592      return LazyAllocate(SystemGlobals);
593    if (K == MemRegion::GlobalImmutableSpaceRegionKind)
594      return LazyAllocate(ImmutableGlobals);
595    assert(K == MemRegion::GlobalInternalSpaceRegionKind);
596    return LazyAllocate(InternalGlobals);
597  }
598
599  assert(K == MemRegion::StaticGlobalSpaceRegionKind);
600  StaticGlobalSpaceRegion *&R = StaticsGlobalSpaceRegions[CR];
601  if (R)
602    return R;
603
604  R = A.Allocate<StaticGlobalSpaceRegion>();
605  new (R) StaticGlobalSpaceRegion(this, CR);
606  return R;
607}
608
609const HeapSpaceRegion *MemRegionManager::getHeapRegion() {
610  return LazyAllocate(heap);
611}
612
613const MemSpaceRegion *MemRegionManager::getUnknownRegion() {
614  return LazyAllocate(unknown);
615}
616
617const MemSpaceRegion *MemRegionManager::getCodeRegion() {
618  return LazyAllocate(code);
619}
620
621//===----------------------------------------------------------------------===//
622// Constructing regions.
623//===----------------------------------------------------------------------===//
624const StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str){
625  return getSubRegion<StringRegion>(Str, getGlobalsRegion());
626}
627
628const ObjCStringRegion *
629MemRegionManager::getObjCStringRegion(const ObjCStringLiteral* Str){
630  return getSubRegion<ObjCStringRegion>(Str, getGlobalsRegion());
631}
632
633const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
634                                                const LocationContext *LC) {
635  const MemRegion *sReg = 0;
636
637  if (D->hasGlobalStorage() && !D->isStaticLocal()) {
638
639    // First handle the globals defined in system headers.
640    if (C.getSourceManager().isInSystemHeader(D->getLocation())) {
641      // Whitelist the system globals which often DO GET modified, assume the
642      // rest are immutable.
643      if (D->getName().find("errno") != StringRef::npos)
644        sReg = getGlobalsRegion(MemRegion::GlobalSystemSpaceRegionKind);
645      else
646        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
647
648    // Treat other globals as GlobalInternal unless they are constants.
649    } else {
650      QualType GQT = D->getType();
651      const Type *GT = GQT.getTypePtrOrNull();
652      // TODO: We could walk the complex types here and see if everything is
653      // constified.
654      if (GT && GQT.isConstQualified() && GT->isArithmeticType())
655        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
656      else
657        sReg = getGlobalsRegion();
658    }
659
660  // Finally handle static locals.
661  } else {
662    // FIXME: Once we implement scope handling, we will need to properly lookup
663    // 'D' to the proper LocationContext.
664    const DeclContext *DC = D->getDeclContext();
665    const StackFrameContext *STC = LC->getStackFrameForDeclContext(DC);
666
667    if (!STC)
668      sReg = getUnknownRegion();
669    else {
670      if (D->hasLocalStorage()) {
671        sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
672               ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
673               : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
674      }
675      else {
676        assert(D->isStaticLocal());
677        const Decl *D = STC->getDecl();
678        if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
679          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
680                                  getFunctionTextRegion(FD));
681        else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
682          const BlockTextRegion *BTR =
683            getBlockTextRegion(BD,
684                     C.getCanonicalType(BD->getSignatureAsWritten()->getType()),
685                     STC->getAnalysisDeclContext());
686          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
687                                  BTR);
688        }
689        else {
690          // FIXME: For ObjC-methods, we need a new CodeTextRegion.  For now
691          // just use the main global memspace.
692          sReg = getGlobalsRegion();
693        }
694      }
695    }
696  }
697
698  return getSubRegion<VarRegion>(D, sReg);
699}
700
701const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
702                                                const MemRegion *superR) {
703  return getSubRegion<VarRegion>(D, superR);
704}
705
706const BlockDataRegion *
707MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
708                                     const LocationContext *LC) {
709  const MemRegion *sReg = 0;
710  const BlockDecl *BD = BC->getDecl();
711  if (!BD->hasCaptures()) {
712    // This handles 'static' blocks.
713    sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
714  }
715  else {
716    if (LC) {
717      // FIXME: Once we implement scope handling, we want the parent region
718      // to be the scope.
719      const StackFrameContext *STC = LC->getCurrentStackFrame();
720      assert(STC);
721      sReg = getStackLocalsRegion(STC);
722    }
723    else {
724      // We allow 'LC' to be NULL for cases where want BlockDataRegions
725      // without context-sensitivity.
726      sReg = getUnknownRegion();
727    }
728  }
729
730  return getSubRegion<BlockDataRegion>(BC, LC, sReg);
731}
732
733const CompoundLiteralRegion*
734MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr *CL,
735                                           const LocationContext *LC) {
736
737  const MemRegion *sReg = 0;
738
739  if (CL->isFileScope())
740    sReg = getGlobalsRegion();
741  else {
742    const StackFrameContext *STC = LC->getCurrentStackFrame();
743    assert(STC);
744    sReg = getStackLocalsRegion(STC);
745  }
746
747  return getSubRegion<CompoundLiteralRegion>(CL, sReg);
748}
749
750const ElementRegion*
751MemRegionManager::getElementRegion(QualType elementType, NonLoc Idx,
752                                   const MemRegion* superRegion,
753                                   ASTContext &Ctx){
754
755  QualType T = Ctx.getCanonicalType(elementType).getUnqualifiedType();
756
757  llvm::FoldingSetNodeID ID;
758  ElementRegion::ProfileRegion(ID, T, Idx, superRegion);
759
760  void *InsertPos;
761  MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
762  ElementRegion* R = cast_or_null<ElementRegion>(data);
763
764  if (!R) {
765    R = (ElementRegion*) A.Allocate<ElementRegion>();
766    new (R) ElementRegion(T, Idx, superRegion);
767    Regions.InsertNode(R, InsertPos);
768  }
769
770  return R;
771}
772
773const FunctionTextRegion *
774MemRegionManager::getFunctionTextRegion(const FunctionDecl *FD) {
775  return getSubRegion<FunctionTextRegion>(FD, getCodeRegion());
776}
777
778const BlockTextRegion *
779MemRegionManager::getBlockTextRegion(const BlockDecl *BD, CanQualType locTy,
780                                     AnalysisDeclContext *AC) {
781  return getSubRegion<BlockTextRegion>(BD, locTy, AC, getCodeRegion());
782}
783
784
785/// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
786const SymbolicRegion *MemRegionManager::getSymbolicRegion(SymbolRef sym) {
787  return getSubRegion<SymbolicRegion>(sym, getUnknownRegion());
788}
789
790const FieldRegion*
791MemRegionManager::getFieldRegion(const FieldDecl *d,
792                                 const MemRegion* superRegion){
793  return getSubRegion<FieldRegion>(d, superRegion);
794}
795
796const ObjCIvarRegion*
797MemRegionManager::getObjCIvarRegion(const ObjCIvarDecl *d,
798                                    const MemRegion* superRegion) {
799  return getSubRegion<ObjCIvarRegion>(d, superRegion);
800}
801
802const CXXTempObjectRegion*
803MemRegionManager::getCXXTempObjectRegion(Expr const *E,
804                                         LocationContext const *LC) {
805  const StackFrameContext *SFC = LC->getCurrentStackFrame();
806  assert(SFC);
807  return getSubRegion<CXXTempObjectRegion>(E, getStackLocalsRegion(SFC));
808}
809
810const CXXBaseObjectRegion *
811MemRegionManager::getCXXBaseObjectRegion(const CXXRecordDecl *decl,
812                                         const MemRegion *superRegion) {
813  return getSubRegion<CXXBaseObjectRegion>(decl, superRegion);
814}
815
816const CXXThisRegion*
817MemRegionManager::getCXXThisRegion(QualType thisPointerTy,
818                                   const LocationContext *LC) {
819  const StackFrameContext *STC = LC->getCurrentStackFrame();
820  assert(STC);
821  const PointerType *PT = thisPointerTy->getAs<PointerType>();
822  assert(PT);
823  return getSubRegion<CXXThisRegion>(PT, getStackArgumentsRegion(STC));
824}
825
826const AllocaRegion*
827MemRegionManager::getAllocaRegion(const Expr *E, unsigned cnt,
828                                  const LocationContext *LC) {
829  const StackFrameContext *STC = LC->getCurrentStackFrame();
830  assert(STC);
831  return getSubRegion<AllocaRegion>(E, cnt, getStackLocalsRegion(STC));
832}
833
834const MemSpaceRegion *MemRegion::getMemorySpace() const {
835  const MemRegion *R = this;
836  const SubRegion* SR = dyn_cast<SubRegion>(this);
837
838  while (SR) {
839    R = SR->getSuperRegion();
840    SR = dyn_cast<SubRegion>(R);
841  }
842
843  return dyn_cast<MemSpaceRegion>(R);
844}
845
846bool MemRegion::hasStackStorage() const {
847  return isa<StackSpaceRegion>(getMemorySpace());
848}
849
850bool MemRegion::hasStackNonParametersStorage() const {
851  return isa<StackLocalsSpaceRegion>(getMemorySpace());
852}
853
854bool MemRegion::hasStackParametersStorage() const {
855  return isa<StackArgumentsSpaceRegion>(getMemorySpace());
856}
857
858bool MemRegion::hasGlobalsOrParametersStorage() const {
859  const MemSpaceRegion *MS = getMemorySpace();
860  return isa<StackArgumentsSpaceRegion>(MS) ||
861         isa<GlobalsSpaceRegion>(MS);
862}
863
864// getBaseRegion strips away all elements and fields, and get the base region
865// of them.
866const MemRegion *MemRegion::getBaseRegion() const {
867  const MemRegion *R = this;
868  while (true) {
869    switch (R->getKind()) {
870      case MemRegion::ElementRegionKind:
871      case MemRegion::FieldRegionKind:
872      case MemRegion::ObjCIvarRegionKind:
873      case MemRegion::CXXBaseObjectRegionKind:
874        R = cast<SubRegion>(R)->getSuperRegion();
875        continue;
876      default:
877        break;
878    }
879    break;
880  }
881  return R;
882}
883
884//===----------------------------------------------------------------------===//
885// View handling.
886//===----------------------------------------------------------------------===//
887
888const MemRegion *MemRegion::StripCasts() const {
889  const MemRegion *R = this;
890  while (true) {
891    if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
892      // FIXME: generalize.  Essentially we want to strip away ElementRegions
893      // that were layered on a symbolic region because of casts.  We only
894      // want to strip away ElementRegions, however, where the index is 0.
895      SVal index = ER->getIndex();
896      if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&index)) {
897        if (CI->getValue().getSExtValue() == 0) {
898          R = ER->getSuperRegion();
899          continue;
900        }
901      }
902    }
903    break;
904  }
905  return R;
906}
907
908// FIXME: Merge with the implementation of the same method in Store.cpp
909static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
910  if (const RecordType *RT = Ty->getAs<RecordType>()) {
911    const RecordDecl *D = RT->getDecl();
912    if (!D->getDefinition())
913      return false;
914  }
915
916  return true;
917}
918
919RegionRawOffset ElementRegion::getAsArrayOffset() const {
920  CharUnits offset = CharUnits::Zero();
921  const ElementRegion *ER = this;
922  const MemRegion *superR = NULL;
923  ASTContext &C = getContext();
924
925  // FIXME: Handle multi-dimensional arrays.
926
927  while (ER) {
928    superR = ER->getSuperRegion();
929
930    // FIXME: generalize to symbolic offsets.
931    SVal index = ER->getIndex();
932    if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&index)) {
933      // Update the offset.
934      int64_t i = CI->getValue().getSExtValue();
935
936      if (i != 0) {
937        QualType elemType = ER->getElementType();
938
939        // If we are pointing to an incomplete type, go no further.
940        if (!IsCompleteType(C, elemType)) {
941          superR = ER;
942          break;
943        }
944
945        CharUnits size = C.getTypeSizeInChars(elemType);
946        offset += (i * size);
947      }
948
949      // Go to the next ElementRegion (if any).
950      ER = dyn_cast<ElementRegion>(superR);
951      continue;
952    }
953
954    return NULL;
955  }
956
957  assert(superR && "super region cannot be NULL");
958  return RegionRawOffset(superR, offset);
959}
960
961RegionOffset MemRegion::getAsOffset() const {
962  const MemRegion *R = this;
963  int64_t Offset = 0;
964
965  while (1) {
966    switch (R->getKind()) {
967    default:
968      return RegionOffset(0);
969    case SymbolicRegionKind:
970    case AllocaRegionKind:
971    case CompoundLiteralRegionKind:
972    case CXXThisRegionKind:
973    case StringRegionKind:
974    case VarRegionKind:
975    case CXXTempObjectRegionKind:
976      goto Finish;
977    case ElementRegionKind: {
978      const ElementRegion *ER = cast<ElementRegion>(R);
979      QualType EleTy = ER->getValueType();
980
981      if (!IsCompleteType(getContext(), EleTy))
982        return RegionOffset(0);
983
984      SVal Index = ER->getIndex();
985      if (const nonloc::ConcreteInt *CI=dyn_cast<nonloc::ConcreteInt>(&Index)) {
986        int64_t i = CI->getValue().getSExtValue();
987        CharUnits Size = getContext().getTypeSizeInChars(EleTy);
988        Offset += i * Size.getQuantity() * 8;
989      } else {
990        // We cannot compute offset for non-concrete index.
991        return RegionOffset(0);
992      }
993      R = ER->getSuperRegion();
994      break;
995    }
996    case FieldRegionKind: {
997      const FieldRegion *FR = cast<FieldRegion>(R);
998      const RecordDecl *RD = FR->getDecl()->getParent();
999      if (!RD->isCompleteDefinition())
1000        // We cannot compute offset for incomplete type.
1001        return RegionOffset(0);
1002      // Get the field number.
1003      unsigned idx = 0;
1004      for (RecordDecl::field_iterator FI = RD->field_begin(),
1005             FE = RD->field_end(); FI != FE; ++FI, ++idx)
1006        if (FR->getDecl() == *FI)
1007          break;
1008
1009      const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1010      // This is offset in bits.
1011      Offset += Layout.getFieldOffset(idx);
1012      R = FR->getSuperRegion();
1013      break;
1014    }
1015    }
1016  }
1017
1018 Finish:
1019  return RegionOffset(R, Offset);
1020}
1021
1022//===----------------------------------------------------------------------===//
1023// BlockDataRegion
1024//===----------------------------------------------------------------------===//
1025
1026void BlockDataRegion::LazyInitializeReferencedVars() {
1027  if (ReferencedVars)
1028    return;
1029
1030  AnalysisDeclContext *AC = getCodeRegion()->getAnalysisDeclContext();
1031  AnalysisDeclContext::referenced_decls_iterator I, E;
1032  llvm::tie(I, E) = AC->getReferencedBlockVars(BC->getDecl());
1033
1034  if (I == E) {
1035    ReferencedVars = (void*) 0x1;
1036    return;
1037  }
1038
1039  MemRegionManager &MemMgr = *getMemRegionManager();
1040  llvm::BumpPtrAllocator &A = MemMgr.getAllocator();
1041  BumpVectorContext BC(A);
1042
1043  typedef BumpVector<const MemRegion*> VarVec;
1044  VarVec *BV = (VarVec*) A.Allocate<VarVec>();
1045  new (BV) VarVec(BC, E - I);
1046
1047  for ( ; I != E; ++I) {
1048    const VarDecl *VD = *I;
1049    const VarRegion *VR = 0;
1050
1051    if (!VD->getAttr<BlocksAttr>() && VD->hasLocalStorage())
1052      VR = MemMgr.getVarRegion(VD, this);
1053    else {
1054      if (LC)
1055        VR = MemMgr.getVarRegion(VD, LC);
1056      else {
1057        VR = MemMgr.getVarRegion(VD, MemMgr.getUnknownRegion());
1058      }
1059    }
1060
1061    assert(VR);
1062    BV->push_back(VR, BC);
1063  }
1064
1065  ReferencedVars = BV;
1066}
1067
1068BlockDataRegion::referenced_vars_iterator
1069BlockDataRegion::referenced_vars_begin() const {
1070  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1071
1072  BumpVector<const MemRegion*> *Vec =
1073    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1074
1075  return BlockDataRegion::referenced_vars_iterator(Vec == (void*) 0x1 ?
1076                                                   NULL : Vec->begin());
1077}
1078
1079BlockDataRegion::referenced_vars_iterator
1080BlockDataRegion::referenced_vars_end() const {
1081  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1082
1083  BumpVector<const MemRegion*> *Vec =
1084    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1085
1086  return BlockDataRegion::referenced_vars_iterator(Vec == (void*) 0x1 ?
1087                                                   NULL : Vec->end());
1088}
1089