MemRegion.cpp revision 581deb3da481053c4993c7600f97acf7768caac5 
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
646/// Look through a chain of LocationContexts to either find the
647/// StackFrameContext that matches a DeclContext, or find a VarRegion
648/// for a variable captured by a block.
649static llvm::PointerUnion<const StackFrameContext *, const VarRegion *>
650getStackOrCaptureRegionForDeclContext(const LocationContext *LC,
651                                      const DeclContext *DC,
652                                      const VarDecl *VD) {
653  while (LC) {
654    if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC)) {
655      if (cast<DeclContext>(SFC->getDecl()) == DC)
656        return SFC;
657    }
658    if (const BlockInvocationContext *BC =
659        dyn_cast<BlockInvocationContext>(LC)) {
660      const BlockDataRegion *BR =
661        static_cast<const BlockDataRegion*>(BC->getContextData());
662      // FIXME: This can be made more efficient.
663      for (BlockDataRegion::referenced_vars_iterator
664           I = BR->referenced_vars_begin(),
665           E = BR->referenced_vars_end(); I != E; ++I) {
666        if (const VarRegion *VR = dyn_cast<VarRegion>(I.getOriginalRegion()))
667          if (VR->getDecl() == VD)
668            return cast<VarRegion>(I.getCapturedRegion());
669      }
670    }
671
672    LC = LC->getParent();
673  }
674  return (const StackFrameContext*)0;
675}
676
677const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
678                                                const LocationContext *LC) {
679  const MemRegion *sReg = 0;
680
681  if (D->hasGlobalStorage() && !D->isStaticLocal()) {
682
683    // First handle the globals defined in system headers.
684    if (C.getSourceManager().isInSystemHeader(D->getLocation())) {
685      // Whitelist the system globals which often DO GET modified, assume the
686      // rest are immutable.
687      if (D->getName().find("errno") != StringRef::npos)
688        sReg = getGlobalsRegion(MemRegion::GlobalSystemSpaceRegionKind);
689      else
690        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
691
692    // Treat other globals as GlobalInternal unless they are constants.
693    } else {
694      QualType GQT = D->getType();
695      const Type *GT = GQT.getTypePtrOrNull();
696      // TODO: We could walk the complex types here and see if everything is
697      // constified.
698      if (GT && GQT.isConstQualified() && GT->isArithmeticType())
699        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
700      else
701        sReg = getGlobalsRegion();
702    }
703
704  // Finally handle static locals.
705  } else {
706    // FIXME: Once we implement scope handling, we will need to properly lookup
707    // 'D' to the proper LocationContext.
708    const DeclContext *DC = D->getDeclContext();
709    llvm::PointerUnion<const StackFrameContext *, const VarRegion *> V =
710      getStackOrCaptureRegionForDeclContext(LC, DC, D);
711
712    if (V.is<const VarRegion*>())
713      return V.get<const VarRegion*>();
714
715    const StackFrameContext *STC = V.get<const StackFrameContext*>();
716
717    if (!STC)
718      sReg = getUnknownRegion();
719    else {
720      if (D->hasLocalStorage()) {
721        sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
722               ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
723               : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
724      }
725      else {
726        assert(D->isStaticLocal());
727        const Decl *D = STC->getDecl();
728        if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
729          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
730                                  getFunctionTextRegion(FD));
731        else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
732          const BlockTextRegion *BTR =
733            getBlockTextRegion(BD,
734                     C.getCanonicalType(BD->getSignatureAsWritten()->getType()),
735                     STC->getAnalysisDeclContext());
736          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
737                                  BTR);
738        }
739        else {
740          // FIXME: For ObjC-methods, we need a new CodeTextRegion.  For now
741          // just use the main global memspace.
742          sReg = getGlobalsRegion();
743        }
744      }
745    }
746  }
747
748  return getSubRegion<VarRegion>(D, sReg);
749}
750
751const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
752                                                const MemRegion *superR) {
753  return getSubRegion<VarRegion>(D, superR);
754}
755
756const BlockDataRegion *
757MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
758                                     const LocationContext *LC) {
759  const MemRegion *sReg = 0;
760  const BlockDecl *BD = BC->getDecl();
761  if (!BD->hasCaptures()) {
762    // This handles 'static' blocks.
763    sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
764  }
765  else {
766    if (LC) {
767      // FIXME: Once we implement scope handling, we want the parent region
768      // to be the scope.
769      const StackFrameContext *STC = LC->getCurrentStackFrame();
770      assert(STC);
771      sReg = getStackLocalsRegion(STC);
772    }
773    else {
774      // We allow 'LC' to be NULL for cases where want BlockDataRegions
775      // without context-sensitivity.
776      sReg = getUnknownRegion();
777    }
778  }
779
780  return getSubRegion<BlockDataRegion>(BC, LC, sReg);
781}
782
783const CompoundLiteralRegion*
784MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr *CL,
785                                           const LocationContext *LC) {
786
787  const MemRegion *sReg = 0;
788
789  if (CL->isFileScope())
790    sReg = getGlobalsRegion();
791  else {
792    const StackFrameContext *STC = LC->getCurrentStackFrame();
793    assert(STC);
794    sReg = getStackLocalsRegion(STC);
795  }
796
797  return getSubRegion<CompoundLiteralRegion>(CL, sReg);
798}
799
800const ElementRegion*
801MemRegionManager::getElementRegion(QualType elementType, NonLoc Idx,
802                                   const MemRegion* superRegion,
803                                   ASTContext &Ctx){
804
805  QualType T = Ctx.getCanonicalType(elementType).getUnqualifiedType();
806
807  llvm::FoldingSetNodeID ID;
808  ElementRegion::ProfileRegion(ID, T, Idx, superRegion);
809
810  void *InsertPos;
811  MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
812  ElementRegion* R = cast_or_null<ElementRegion>(data);
813
814  if (!R) {
815    R = (ElementRegion*) A.Allocate<ElementRegion>();
816    new (R) ElementRegion(T, Idx, superRegion);
817    Regions.InsertNode(R, InsertPos);
818  }
819
820  return R;
821}
822
823const FunctionTextRegion *
824MemRegionManager::getFunctionTextRegion(const FunctionDecl *FD) {
825  return getSubRegion<FunctionTextRegion>(FD, getCodeRegion());
826}
827
828const BlockTextRegion *
829MemRegionManager::getBlockTextRegion(const BlockDecl *BD, CanQualType locTy,
830                                     AnalysisDeclContext *AC) {
831  return getSubRegion<BlockTextRegion>(BD, locTy, AC, getCodeRegion());
832}
833
834
835/// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
836const SymbolicRegion *MemRegionManager::getSymbolicRegion(SymbolRef sym) {
837  return getSubRegion<SymbolicRegion>(sym, getUnknownRegion());
838}
839
840const FieldRegion*
841MemRegionManager::getFieldRegion(const FieldDecl *d,
842                                 const MemRegion* superRegion){
843  return getSubRegion<FieldRegion>(d, superRegion);
844}
845
846const ObjCIvarRegion*
847MemRegionManager::getObjCIvarRegion(const ObjCIvarDecl *d,
848                                    const MemRegion* superRegion) {
849  return getSubRegion<ObjCIvarRegion>(d, superRegion);
850}
851
852const CXXTempObjectRegion*
853MemRegionManager::getCXXTempObjectRegion(Expr const *E,
854                                         LocationContext const *LC) {
855  const StackFrameContext *SFC = LC->getCurrentStackFrame();
856  assert(SFC);
857  return getSubRegion<CXXTempObjectRegion>(E, getStackLocalsRegion(SFC));
858}
859
860const CXXBaseObjectRegion *
861MemRegionManager::getCXXBaseObjectRegion(const CXXRecordDecl *decl,
862                                         const MemRegion *superRegion) {
863  return getSubRegion<CXXBaseObjectRegion>(decl, superRegion);
864}
865
866const CXXThisRegion*
867MemRegionManager::getCXXThisRegion(QualType thisPointerTy,
868                                   const LocationContext *LC) {
869  const StackFrameContext *STC = LC->getCurrentStackFrame();
870  assert(STC);
871  const PointerType *PT = thisPointerTy->getAs<PointerType>();
872  assert(PT);
873  return getSubRegion<CXXThisRegion>(PT, getStackArgumentsRegion(STC));
874}
875
876const AllocaRegion*
877MemRegionManager::getAllocaRegion(const Expr *E, unsigned cnt,
878                                  const LocationContext *LC) {
879  const StackFrameContext *STC = LC->getCurrentStackFrame();
880  assert(STC);
881  return getSubRegion<AllocaRegion>(E, cnt, getStackLocalsRegion(STC));
882}
883
884const MemSpaceRegion *MemRegion::getMemorySpace() const {
885  const MemRegion *R = this;
886  const SubRegion* SR = dyn_cast<SubRegion>(this);
887
888  while (SR) {
889    R = SR->getSuperRegion();
890    SR = dyn_cast<SubRegion>(R);
891  }
892
893  return dyn_cast<MemSpaceRegion>(R);
894}
895
896bool MemRegion::hasStackStorage() const {
897  return isa<StackSpaceRegion>(getMemorySpace());
898}
899
900bool MemRegion::hasStackNonParametersStorage() const {
901  return isa<StackLocalsSpaceRegion>(getMemorySpace());
902}
903
904bool MemRegion::hasStackParametersStorage() const {
905  return isa<StackArgumentsSpaceRegion>(getMemorySpace());
906}
907
908bool MemRegion::hasGlobalsOrParametersStorage() const {
909  const MemSpaceRegion *MS = getMemorySpace();
910  return isa<StackArgumentsSpaceRegion>(MS) ||
911         isa<GlobalsSpaceRegion>(MS);
912}
913
914// getBaseRegion strips away all elements and fields, and get the base region
915// of them.
916const MemRegion *MemRegion::getBaseRegion() const {
917  const MemRegion *R = this;
918  while (true) {
919    switch (R->getKind()) {
920      case MemRegion::ElementRegionKind:
921      case MemRegion::FieldRegionKind:
922      case MemRegion::ObjCIvarRegionKind:
923      case MemRegion::CXXBaseObjectRegionKind:
924        R = cast<SubRegion>(R)->getSuperRegion();
925        continue;
926      default:
927        break;
928    }
929    break;
930  }
931  return R;
932}
933
934//===----------------------------------------------------------------------===//
935// View handling.
936//===----------------------------------------------------------------------===//
937
938const MemRegion *MemRegion::StripCasts() const {
939  const MemRegion *R = this;
940  while (true) {
941    if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
942      // FIXME: generalize.  Essentially we want to strip away ElementRegions
943      // that were layered on a symbolic region because of casts.  We only
944      // want to strip away ElementRegions, however, where the index is 0.
945      SVal index = ER->getIndex();
946      if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&index)) {
947        if (CI->getValue().getSExtValue() == 0) {
948          R = ER->getSuperRegion();
949          continue;
950        }
951      }
952    }
953    break;
954  }
955  return R;
956}
957
958// FIXME: Merge with the implementation of the same method in Store.cpp
959static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
960  if (const RecordType *RT = Ty->getAs<RecordType>()) {
961    const RecordDecl *D = RT->getDecl();
962    if (!D->getDefinition())
963      return false;
964  }
965
966  return true;
967}
968
969RegionRawOffset ElementRegion::getAsArrayOffset() const {
970  CharUnits offset = CharUnits::Zero();
971  const ElementRegion *ER = this;
972  const MemRegion *superR = NULL;
973  ASTContext &C = getContext();
974
975  // FIXME: Handle multi-dimensional arrays.
976
977  while (ER) {
978    superR = ER->getSuperRegion();
979
980    // FIXME: generalize to symbolic offsets.
981    SVal index = ER->getIndex();
982    if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&index)) {
983      // Update the offset.
984      int64_t i = CI->getValue().getSExtValue();
985
986      if (i != 0) {
987        QualType elemType = ER->getElementType();
988
989        // If we are pointing to an incomplete type, go no further.
990        if (!IsCompleteType(C, elemType)) {
991          superR = ER;
992          break;
993        }
994
995        CharUnits size = C.getTypeSizeInChars(elemType);
996        offset += (i * size);
997      }
998
999      // Go to the next ElementRegion (if any).
1000      ER = dyn_cast<ElementRegion>(superR);
1001      continue;
1002    }
1003
1004    return NULL;
1005  }
1006
1007  assert(superR && "super region cannot be NULL");
1008  return RegionRawOffset(superR, offset);
1009}
1010
1011RegionOffset MemRegion::getAsOffset() const {
1012  const MemRegion *R = this;
1013  int64_t Offset = 0;
1014
1015  while (1) {
1016    switch (R->getKind()) {
1017    default:
1018      return RegionOffset(0);
1019    case SymbolicRegionKind:
1020    case AllocaRegionKind:
1021    case CompoundLiteralRegionKind:
1022    case CXXThisRegionKind:
1023    case StringRegionKind:
1024    case VarRegionKind:
1025    case CXXTempObjectRegionKind:
1026      goto Finish;
1027    case ElementRegionKind: {
1028      const ElementRegion *ER = cast<ElementRegion>(R);
1029      QualType EleTy = ER->getValueType();
1030
1031      if (!IsCompleteType(getContext(), EleTy))
1032        return RegionOffset(0);
1033
1034      SVal Index = ER->getIndex();
1035      if (const nonloc::ConcreteInt *CI=dyn_cast<nonloc::ConcreteInt>(&Index)) {
1036        int64_t i = CI->getValue().getSExtValue();
1037        CharUnits Size = getContext().getTypeSizeInChars(EleTy);
1038        Offset += i * Size.getQuantity() * 8;
1039      } else {
1040        // We cannot compute offset for non-concrete index.
1041        return RegionOffset(0);
1042      }
1043      R = ER->getSuperRegion();
1044      break;
1045    }
1046    case FieldRegionKind: {
1047      const FieldRegion *FR = cast<FieldRegion>(R);
1048      const RecordDecl *RD = FR->getDecl()->getParent();
1049      if (!RD->isCompleteDefinition())
1050        // We cannot compute offset for incomplete type.
1051        return RegionOffset(0);
1052      // Get the field number.
1053      unsigned idx = 0;
1054      for (RecordDecl::field_iterator FI = RD->field_begin(),
1055             FE = RD->field_end(); FI != FE; ++FI, ++idx)
1056        if (FR->getDecl() == *FI)
1057          break;
1058
1059      const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1060      // This is offset in bits.
1061      Offset += Layout.getFieldOffset(idx);
1062      R = FR->getSuperRegion();
1063      break;
1064    }
1065    }
1066  }
1067
1068 Finish:
1069  return RegionOffset(R, Offset);
1070}
1071
1072//===----------------------------------------------------------------------===//
1073// BlockDataRegion
1074//===----------------------------------------------------------------------===//
1075
1076void BlockDataRegion::LazyInitializeReferencedVars() {
1077  if (ReferencedVars)
1078    return;
1079
1080  AnalysisDeclContext *AC = getCodeRegion()->getAnalysisDeclContext();
1081  AnalysisDeclContext::referenced_decls_iterator I, E;
1082  llvm::tie(I, E) = AC->getReferencedBlockVars(BC->getDecl());
1083
1084  if (I == E) {
1085    ReferencedVars = (void*) 0x1;
1086    return;
1087  }
1088
1089  MemRegionManager &MemMgr = *getMemRegionManager();
1090  llvm::BumpPtrAllocator &A = MemMgr.getAllocator();
1091  BumpVectorContext BC(A);
1092
1093  typedef BumpVector<const MemRegion*> VarVec;
1094  VarVec *BV = (VarVec*) A.Allocate<VarVec>();
1095  new (BV) VarVec(BC, E - I);
1096  VarVec *BVOriginal = (VarVec*) A.Allocate<VarVec>();
1097  new (BVOriginal) VarVec(BC, E - I);
1098
1099  for ( ; I != E; ++I) {
1100    const VarDecl *VD = *I;
1101    const VarRegion *VR = 0;
1102    const VarRegion *OriginalVR = 0;
1103
1104    if (!VD->getAttr<BlocksAttr>() && VD->hasLocalStorage()) {
1105      VR = MemMgr.getVarRegion(VD, this);
1106      OriginalVR = MemMgr.getVarRegion(VD, LC);
1107    }
1108    else {
1109      if (LC) {
1110        VR = MemMgr.getVarRegion(VD, LC);
1111        OriginalVR = VR;
1112      }
1113      else {
1114        VR = MemMgr.getVarRegion(VD, MemMgr.getUnknownRegion());
1115        OriginalVR = MemMgr.getVarRegion(VD, LC);
1116      }
1117    }
1118
1119    assert(VR);
1120    assert(OriginalVR);
1121    BV->push_back(VR, BC);
1122    BVOriginal->push_back(OriginalVR, BC);
1123  }
1124
1125  ReferencedVars = BV;
1126  OriginalVars = BVOriginal;
1127}
1128
1129BlockDataRegion::referenced_vars_iterator
1130BlockDataRegion::referenced_vars_begin() const {
1131  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1132
1133  BumpVector<const MemRegion*> *Vec =
1134    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1135
1136  if (Vec == (void*) 0x1)
1137    return BlockDataRegion::referenced_vars_iterator(0, 0);
1138
1139  BumpVector<const MemRegion*> *VecOriginal =
1140    static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1141
1142  return BlockDataRegion::referenced_vars_iterator(Vec->begin(),
1143                                                   VecOriginal->begin());
1144}
1145
1146BlockDataRegion::referenced_vars_iterator
1147BlockDataRegion::referenced_vars_end() const {
1148  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1149
1150  BumpVector<const MemRegion*> *Vec =
1151    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1152
1153  if (Vec == (void*) 0x1)
1154    return BlockDataRegion::referenced_vars_iterator(0, 0);
1155
1156  BumpVector<const MemRegion*> *VecOriginal =
1157    static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1158
1159  return BlockDataRegion::referenced_vars_iterator(Vec->end(),
1160                                                   VecOriginal->end());
1161}
1162