MemRegion.cpp revision e0d24eb1060a213ec9820dc02c45f26b2d5b348b 
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 TypedValueRegion::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{" << superRegion << ',' << 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 GlobalInternalSpaceRegion::dumpToStream(raw_ostream &os) const {
522  os << "GlobalInternalSpaceRegion";
523}
524
525void GlobalSystemSpaceRegion::dumpToStream(raw_ostream &os) const {
526  os << "GlobalSystemSpaceRegion";
527}
528
529void GlobalImmutableSpaceRegion::dumpToStream(raw_ostream &os) const {
530  os << "GlobalImmutableSpaceRegion";
531}
532
533void HeapSpaceRegion::dumpToStream(raw_ostream &os) const {
534  os << "HeapSpaceRegion";
535}
536
537void UnknownSpaceRegion::dumpToStream(raw_ostream &os) const {
538  os << "UnknownSpaceRegion";
539}
540
541void StackArgumentsSpaceRegion::dumpToStream(raw_ostream &os) const {
542  os << "StackArgumentsSpaceRegion";
543}
544
545void StackLocalsSpaceRegion::dumpToStream(raw_ostream &os) const {
546  os << "StackLocalsSpaceRegion";
547}
548
549void MemRegion::dumpPretty(raw_ostream &os) const {
550  return;
551}
552
553void VarRegion::dumpPretty(raw_ostream &os) const {
554  os << getDecl()->getName();
555}
556
557void FieldRegion::dumpPretty(raw_ostream &os) const {
558  superRegion->dumpPretty(os);
559  os << "->" << getDecl();
560}
561
562//===----------------------------------------------------------------------===//
563// MemRegionManager methods.
564//===----------------------------------------------------------------------===//
565
566template <typename REG>
567const REG *MemRegionManager::LazyAllocate(REG*& region) {
568  if (!region) {
569    region = (REG*) A.Allocate<REG>();
570    new (region) REG(this);
571  }
572
573  return region;
574}
575
576template <typename REG, typename ARG>
577const REG *MemRegionManager::LazyAllocate(REG*& region, ARG a) {
578  if (!region) {
579    region = (REG*) A.Allocate<REG>();
580    new (region) REG(this, a);
581  }
582
583  return region;
584}
585
586const StackLocalsSpaceRegion*
587MemRegionManager::getStackLocalsRegion(const StackFrameContext *STC) {
588  assert(STC);
589  StackLocalsSpaceRegion *&R = StackLocalsSpaceRegions[STC];
590
591  if (R)
592    return R;
593
594  R = A.Allocate<StackLocalsSpaceRegion>();
595  new (R) StackLocalsSpaceRegion(this, STC);
596  return R;
597}
598
599const StackArgumentsSpaceRegion *
600MemRegionManager::getStackArgumentsRegion(const StackFrameContext *STC) {
601  assert(STC);
602  StackArgumentsSpaceRegion *&R = StackArgumentsSpaceRegions[STC];
603
604  if (R)
605    return R;
606
607  R = A.Allocate<StackArgumentsSpaceRegion>();
608  new (R) StackArgumentsSpaceRegion(this, STC);
609  return R;
610}
611
612const GlobalsSpaceRegion
613*MemRegionManager::getGlobalsRegion(MemRegion::Kind K,
614                                    const CodeTextRegion *CR) {
615  if (!CR) {
616    if (K == MemRegion::GlobalSystemSpaceRegionKind)
617      return LazyAllocate(SystemGlobals);
618    if (K == MemRegion::GlobalImmutableSpaceRegionKind)
619      return LazyAllocate(ImmutableGlobals);
620    assert(K == MemRegion::GlobalInternalSpaceRegionKind);
621    return LazyAllocate(InternalGlobals);
622  }
623
624  assert(K == MemRegion::StaticGlobalSpaceRegionKind);
625  StaticGlobalSpaceRegion *&R = StaticsGlobalSpaceRegions[CR];
626  if (R)
627    return R;
628
629  R = A.Allocate<StaticGlobalSpaceRegion>();
630  new (R) StaticGlobalSpaceRegion(this, CR);
631  return R;
632}
633
634const HeapSpaceRegion *MemRegionManager::getHeapRegion() {
635  return LazyAllocate(heap);
636}
637
638const MemSpaceRegion *MemRegionManager::getUnknownRegion() {
639  return LazyAllocate(unknown);
640}
641
642const MemSpaceRegion *MemRegionManager::getCodeRegion() {
643  return LazyAllocate(code);
644}
645
646//===----------------------------------------------------------------------===//
647// Constructing regions.
648//===----------------------------------------------------------------------===//
649const StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str){
650  return getSubRegion<StringRegion>(Str, getGlobalsRegion());
651}
652
653const ObjCStringRegion *
654MemRegionManager::getObjCStringRegion(const ObjCStringLiteral* Str){
655  return getSubRegion<ObjCStringRegion>(Str, getGlobalsRegion());
656}
657
658/// Look through a chain of LocationContexts to either find the
659/// StackFrameContext that matches a DeclContext, or find a VarRegion
660/// for a variable captured by a block.
661static llvm::PointerUnion<const StackFrameContext *, const VarRegion *>
662getStackOrCaptureRegionForDeclContext(const LocationContext *LC,
663                                      const DeclContext *DC,
664                                      const VarDecl *VD) {
665  while (LC) {
666    if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC)) {
667      if (cast<DeclContext>(SFC->getDecl()) == DC)
668        return SFC;
669    }
670    if (const BlockInvocationContext *BC =
671        dyn_cast<BlockInvocationContext>(LC)) {
672      const BlockDataRegion *BR =
673        static_cast<const BlockDataRegion*>(BC->getContextData());
674      // FIXME: This can be made more efficient.
675      for (BlockDataRegion::referenced_vars_iterator
676           I = BR->referenced_vars_begin(),
677           E = BR->referenced_vars_end(); I != E; ++I) {
678        if (const VarRegion *VR = dyn_cast<VarRegion>(I.getOriginalRegion()))
679          if (VR->getDecl() == VD)
680            return cast<VarRegion>(I.getCapturedRegion());
681      }
682    }
683
684    LC = LC->getParent();
685  }
686  return (const StackFrameContext*)0;
687}
688
689const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
690                                                const LocationContext *LC) {
691  const MemRegion *sReg = 0;
692
693  if (D->hasGlobalStorage() && !D->isStaticLocal()) {
694
695    // First handle the globals defined in system headers.
696    if (C.getSourceManager().isInSystemHeader(D->getLocation())) {
697      // Whitelist the system globals which often DO GET modified, assume the
698      // rest are immutable.
699      if (D->getName().find("errno") != StringRef::npos)
700        sReg = getGlobalsRegion(MemRegion::GlobalSystemSpaceRegionKind);
701      else
702        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
703
704    // Treat other globals as GlobalInternal unless they are constants.
705    } else {
706      QualType GQT = D->getType();
707      const Type *GT = GQT.getTypePtrOrNull();
708      // TODO: We could walk the complex types here and see if everything is
709      // constified.
710      if (GT && GQT.isConstQualified() && GT->isArithmeticType())
711        sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
712      else
713        sReg = getGlobalsRegion();
714    }
715
716  // Finally handle static locals.
717  } else {
718    // FIXME: Once we implement scope handling, we will need to properly lookup
719    // 'D' to the proper LocationContext.
720    const DeclContext *DC = D->getDeclContext();
721    llvm::PointerUnion<const StackFrameContext *, const VarRegion *> V =
722      getStackOrCaptureRegionForDeclContext(LC, DC, D);
723
724    if (V.is<const VarRegion*>())
725      return V.get<const VarRegion*>();
726
727    const StackFrameContext *STC = V.get<const StackFrameContext*>();
728
729    if (!STC)
730      sReg = getUnknownRegion();
731    else {
732      if (D->hasLocalStorage()) {
733        sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
734               ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
735               : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
736      }
737      else {
738        assert(D->isStaticLocal());
739        const Decl *D = STC->getDecl();
740        if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
741          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
742                                  getFunctionTextRegion(FD));
743        else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
744          const BlockTextRegion *BTR =
745            getBlockTextRegion(BD,
746                     C.getCanonicalType(BD->getSignatureAsWritten()->getType()),
747                     STC->getAnalysisDeclContext());
748          sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
749                                  BTR);
750        }
751        else {
752          // FIXME: For ObjC-methods, we need a new CodeTextRegion.  For now
753          // just use the main global memspace.
754          sReg = getGlobalsRegion();
755        }
756      }
757    }
758  }
759
760  return getSubRegion<VarRegion>(D, sReg);
761}
762
763const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
764                                                const MemRegion *superR) {
765  return getSubRegion<VarRegion>(D, superR);
766}
767
768const BlockDataRegion *
769MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
770                                     const LocationContext *LC) {
771  const MemRegion *sReg = 0;
772  const BlockDecl *BD = BC->getDecl();
773  if (!BD->hasCaptures()) {
774    // This handles 'static' blocks.
775    sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
776  }
777  else {
778    if (LC) {
779      // FIXME: Once we implement scope handling, we want the parent region
780      // to be the scope.
781      const StackFrameContext *STC = LC->getCurrentStackFrame();
782      assert(STC);
783      sReg = getStackLocalsRegion(STC);
784    }
785    else {
786      // We allow 'LC' to be NULL for cases where want BlockDataRegions
787      // without context-sensitivity.
788      sReg = getUnknownRegion();
789    }
790  }
791
792  return getSubRegion<BlockDataRegion>(BC, LC, sReg);
793}
794
795const CompoundLiteralRegion*
796MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr *CL,
797                                           const LocationContext *LC) {
798
799  const MemRegion *sReg = 0;
800
801  if (CL->isFileScope())
802    sReg = getGlobalsRegion();
803  else {
804    const StackFrameContext *STC = LC->getCurrentStackFrame();
805    assert(STC);
806    sReg = getStackLocalsRegion(STC);
807  }
808
809  return getSubRegion<CompoundLiteralRegion>(CL, sReg);
810}
811
812const ElementRegion*
813MemRegionManager::getElementRegion(QualType elementType, NonLoc Idx,
814                                   const MemRegion* superRegion,
815                                   ASTContext &Ctx){
816
817  QualType T = Ctx.getCanonicalType(elementType).getUnqualifiedType();
818
819  llvm::FoldingSetNodeID ID;
820  ElementRegion::ProfileRegion(ID, T, Idx, superRegion);
821
822  void *InsertPos;
823  MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
824  ElementRegion* R = cast_or_null<ElementRegion>(data);
825
826  if (!R) {
827    R = (ElementRegion*) A.Allocate<ElementRegion>();
828    new (R) ElementRegion(T, Idx, superRegion);
829    Regions.InsertNode(R, InsertPos);
830  }
831
832  return R;
833}
834
835const FunctionTextRegion *
836MemRegionManager::getFunctionTextRegion(const FunctionDecl *FD) {
837  return getSubRegion<FunctionTextRegion>(FD, getCodeRegion());
838}
839
840const BlockTextRegion *
841MemRegionManager::getBlockTextRegion(const BlockDecl *BD, CanQualType locTy,
842                                     AnalysisDeclContext *AC) {
843  return getSubRegion<BlockTextRegion>(BD, locTy, AC, getCodeRegion());
844}
845
846
847/// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
848const SymbolicRegion *MemRegionManager::getSymbolicRegion(SymbolRef sym) {
849  return getSubRegion<SymbolicRegion>(sym, getUnknownRegion());
850}
851
852const SymbolicRegion *MemRegionManager::getSymbolicHeapRegion(SymbolRef Sym) {
853  return getSubRegion<SymbolicRegion>(Sym, getHeapRegion());
854}
855
856const FieldRegion*
857MemRegionManager::getFieldRegion(const FieldDecl *d,
858                                 const MemRegion* superRegion){
859  return getSubRegion<FieldRegion>(d, superRegion);
860}
861
862const ObjCIvarRegion*
863MemRegionManager::getObjCIvarRegion(const ObjCIvarDecl *d,
864                                    const MemRegion* superRegion) {
865  return getSubRegion<ObjCIvarRegion>(d, superRegion);
866}
867
868const CXXTempObjectRegion*
869MemRegionManager::getCXXTempObjectRegion(Expr const *E,
870                                         LocationContext const *LC) {
871  const StackFrameContext *SFC = LC->getCurrentStackFrame();
872  assert(SFC);
873  return getSubRegion<CXXTempObjectRegion>(E, getStackLocalsRegion(SFC));
874}
875
876const CXXBaseObjectRegion *
877MemRegionManager::getCXXBaseObjectRegion(const CXXRecordDecl *decl,
878                                         const MemRegion *superRegion) {
879  return getSubRegion<CXXBaseObjectRegion>(decl, superRegion);
880}
881
882const CXXThisRegion*
883MemRegionManager::getCXXThisRegion(QualType thisPointerTy,
884                                   const LocationContext *LC) {
885  const StackFrameContext *STC = LC->getCurrentStackFrame();
886  assert(STC);
887  const PointerType *PT = thisPointerTy->getAs<PointerType>();
888  assert(PT);
889  return getSubRegion<CXXThisRegion>(PT, getStackArgumentsRegion(STC));
890}
891
892const AllocaRegion*
893MemRegionManager::getAllocaRegion(const Expr *E, unsigned cnt,
894                                  const LocationContext *LC) {
895  const StackFrameContext *STC = LC->getCurrentStackFrame();
896  assert(STC);
897  return getSubRegion<AllocaRegion>(E, cnt, getStackLocalsRegion(STC));
898}
899
900const MemSpaceRegion *MemRegion::getMemorySpace() const {
901  const MemRegion *R = this;
902  const SubRegion* SR = dyn_cast<SubRegion>(this);
903
904  while (SR) {
905    R = SR->getSuperRegion();
906    SR = dyn_cast<SubRegion>(R);
907  }
908
909  return dyn_cast<MemSpaceRegion>(R);
910}
911
912bool MemRegion::hasStackStorage() const {
913  return isa<StackSpaceRegion>(getMemorySpace());
914}
915
916bool MemRegion::hasStackNonParametersStorage() const {
917  return isa<StackLocalsSpaceRegion>(getMemorySpace());
918}
919
920bool MemRegion::hasStackParametersStorage() const {
921  return isa<StackArgumentsSpaceRegion>(getMemorySpace());
922}
923
924bool MemRegion::hasGlobalsOrParametersStorage() const {
925  const MemSpaceRegion *MS = getMemorySpace();
926  return isa<StackArgumentsSpaceRegion>(MS) ||
927         isa<GlobalsSpaceRegion>(MS);
928}
929
930// getBaseRegion strips away all elements and fields, and get the base region
931// of them.
932const MemRegion *MemRegion::getBaseRegion() const {
933  const MemRegion *R = this;
934  while (true) {
935    switch (R->getKind()) {
936      case MemRegion::ElementRegionKind:
937      case MemRegion::FieldRegionKind:
938      case MemRegion::ObjCIvarRegionKind:
939      case MemRegion::CXXBaseObjectRegionKind:
940        R = cast<SubRegion>(R)->getSuperRegion();
941        continue;
942      default:
943        break;
944    }
945    break;
946  }
947  return R;
948}
949
950//===----------------------------------------------------------------------===//
951// View handling.
952//===----------------------------------------------------------------------===//
953
954const MemRegion *MemRegion::StripCasts() const {
955  const MemRegion *R = this;
956  while (true) {
957    switch (R->getKind()) {
958    case ElementRegionKind: {
959      const ElementRegion *ER = cast<ElementRegion>(R);
960      if (!ER->getIndex().isZeroConstant())
961        return R;
962      R = ER->getSuperRegion();
963      break;
964    }
965    case CXXBaseObjectRegionKind:
966      R = cast<CXXBaseObjectRegion>(R)->getSuperRegion();
967      break;
968    default:
969      return R;
970    }
971  }
972}
973
974// FIXME: Merge with the implementation of the same method in Store.cpp
975static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
976  if (const RecordType *RT = Ty->getAs<RecordType>()) {
977    const RecordDecl *D = RT->getDecl();
978    if (!D->getDefinition())
979      return false;
980  }
981
982  return true;
983}
984
985RegionRawOffset ElementRegion::getAsArrayOffset() const {
986  CharUnits offset = CharUnits::Zero();
987  const ElementRegion *ER = this;
988  const MemRegion *superR = NULL;
989  ASTContext &C = getContext();
990
991  // FIXME: Handle multi-dimensional arrays.
992
993  while (ER) {
994    superR = ER->getSuperRegion();
995
996    // FIXME: generalize to symbolic offsets.
997    SVal index = ER->getIndex();
998    if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&index)) {
999      // Update the offset.
1000      int64_t i = CI->getValue().getSExtValue();
1001
1002      if (i != 0) {
1003        QualType elemType = ER->getElementType();
1004
1005        // If we are pointing to an incomplete type, go no further.
1006        if (!IsCompleteType(C, elemType)) {
1007          superR = ER;
1008          break;
1009        }
1010
1011        CharUnits size = C.getTypeSizeInChars(elemType);
1012        offset += (i * size);
1013      }
1014
1015      // Go to the next ElementRegion (if any).
1016      ER = dyn_cast<ElementRegion>(superR);
1017      continue;
1018    }
1019
1020    return NULL;
1021  }
1022
1023  assert(superR && "super region cannot be NULL");
1024  return RegionRawOffset(superR, offset);
1025}
1026
1027RegionOffset MemRegion::getAsOffset() const {
1028  const MemRegion *R = this;
1029  int64_t Offset = 0;
1030
1031  while (1) {
1032    switch (R->getKind()) {
1033    default:
1034      return RegionOffset();
1035    case SymbolicRegionKind:
1036    case AllocaRegionKind:
1037    case CompoundLiteralRegionKind:
1038    case CXXThisRegionKind:
1039    case StringRegionKind:
1040    case VarRegionKind:
1041    case ObjCIvarRegionKind:
1042    case CXXTempObjectRegionKind:
1043      goto Finish;
1044    case CXXBaseObjectRegionKind: {
1045      const CXXBaseObjectRegion *BOR = cast<CXXBaseObjectRegion>(R);
1046      R = BOR->getSuperRegion();
1047
1048      QualType Ty;
1049      if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R)) {
1050        Ty = TVR->getDesugaredValueType(getContext());
1051      } else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
1052        // If our base region is symbolic, we don't know what type it really is.
1053        // Pretend the type of the symbol is the true dynamic type.
1054        // (This will at least be self-consistent for the life of the symbol.)
1055        Ty = SR->getSymbol()->getType(getContext())->getPointeeType();
1056      }
1057
1058      const CXXRecordDecl *Child = Ty->getAsCXXRecordDecl();
1059      if (!Child) {
1060        // We cannot compute the offset of the base class.
1061        return RegionOffset();
1062      }
1063      const ASTRecordLayout &Layout = getContext().getASTRecordLayout(Child);
1064
1065      CharUnits BaseOffset;
1066      const CXXRecordDecl *Base = BOR->getDecl();
1067      if (Child->isVirtuallyDerivedFrom(Base))
1068        BaseOffset = Layout.getVBaseClassOffset(Base);
1069      else
1070        BaseOffset = Layout.getBaseClassOffset(Base);
1071
1072      // The base offset is in chars, not in bits.
1073      Offset += BaseOffset.getQuantity() * getContext().getCharWidth();
1074      break;
1075    }
1076    case ElementRegionKind: {
1077      const ElementRegion *ER = cast<ElementRegion>(R);
1078      QualType EleTy = ER->getValueType();
1079
1080      if (!IsCompleteType(getContext(), EleTy))
1081        return RegionOffset();
1082
1083      SVal Index = ER->getIndex();
1084      if (const nonloc::ConcreteInt *CI=dyn_cast<nonloc::ConcreteInt>(&Index)) {
1085        int64_t i = CI->getValue().getSExtValue();
1086        // This type size is in bits.
1087        Offset += i * getContext().getTypeSize(EleTy);
1088      } else {
1089        // We cannot compute offset for non-concrete index.
1090        return RegionOffset();
1091      }
1092      R = ER->getSuperRegion();
1093      break;
1094    }
1095    case FieldRegionKind: {
1096      const FieldRegion *FR = cast<FieldRegion>(R);
1097      const RecordDecl *RD = FR->getDecl()->getParent();
1098      if (!RD->isCompleteDefinition())
1099        // We cannot compute offset for incomplete type.
1100        return RegionOffset();
1101      // Get the field number.
1102      unsigned idx = 0;
1103      for (RecordDecl::field_iterator FI = RD->field_begin(),
1104             FE = RD->field_end(); FI != FE; ++FI, ++idx)
1105        if (FR->getDecl() == *FI)
1106          break;
1107
1108      const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1109      // This is offset in bits.
1110      Offset += Layout.getFieldOffset(idx);
1111      R = FR->getSuperRegion();
1112      break;
1113    }
1114    }
1115  }
1116
1117 Finish:
1118  return RegionOffset(R, Offset);
1119}
1120
1121//===----------------------------------------------------------------------===//
1122// BlockDataRegion
1123//===----------------------------------------------------------------------===//
1124
1125void BlockDataRegion::LazyInitializeReferencedVars() {
1126  if (ReferencedVars)
1127    return;
1128
1129  AnalysisDeclContext *AC = getCodeRegion()->getAnalysisDeclContext();
1130  AnalysisDeclContext::referenced_decls_iterator I, E;
1131  llvm::tie(I, E) = AC->getReferencedBlockVars(BC->getDecl());
1132
1133  if (I == E) {
1134    ReferencedVars = (void*) 0x1;
1135    return;
1136  }
1137
1138  MemRegionManager &MemMgr = *getMemRegionManager();
1139  llvm::BumpPtrAllocator &A = MemMgr.getAllocator();
1140  BumpVectorContext BC(A);
1141
1142  typedef BumpVector<const MemRegion*> VarVec;
1143  VarVec *BV = (VarVec*) A.Allocate<VarVec>();
1144  new (BV) VarVec(BC, E - I);
1145  VarVec *BVOriginal = (VarVec*) A.Allocate<VarVec>();
1146  new (BVOriginal) VarVec(BC, E - I);
1147
1148  for ( ; I != E; ++I) {
1149    const VarDecl *VD = *I;
1150    const VarRegion *VR = 0;
1151    const VarRegion *OriginalVR = 0;
1152
1153    if (!VD->getAttr<BlocksAttr>() && VD->hasLocalStorage()) {
1154      VR = MemMgr.getVarRegion(VD, this);
1155      OriginalVR = MemMgr.getVarRegion(VD, LC);
1156    }
1157    else {
1158      if (LC) {
1159        VR = MemMgr.getVarRegion(VD, LC);
1160        OriginalVR = VR;
1161      }
1162      else {
1163        VR = MemMgr.getVarRegion(VD, MemMgr.getUnknownRegion());
1164        OriginalVR = MemMgr.getVarRegion(VD, LC);
1165      }
1166    }
1167
1168    assert(VR);
1169    assert(OriginalVR);
1170    BV->push_back(VR, BC);
1171    BVOriginal->push_back(OriginalVR, BC);
1172  }
1173
1174  ReferencedVars = BV;
1175  OriginalVars = BVOriginal;
1176}
1177
1178BlockDataRegion::referenced_vars_iterator
1179BlockDataRegion::referenced_vars_begin() const {
1180  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1181
1182  BumpVector<const MemRegion*> *Vec =
1183    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1184
1185  if (Vec == (void*) 0x1)
1186    return BlockDataRegion::referenced_vars_iterator(0, 0);
1187
1188  BumpVector<const MemRegion*> *VecOriginal =
1189    static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1190
1191  return BlockDataRegion::referenced_vars_iterator(Vec->begin(),
1192                                                   VecOriginal->begin());
1193}
1194
1195BlockDataRegion::referenced_vars_iterator
1196BlockDataRegion::referenced_vars_end() const {
1197  const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1198
1199  BumpVector<const MemRegion*> *Vec =
1200    static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1201
1202  if (Vec == (void*) 0x1)
1203    return BlockDataRegion::referenced_vars_iterator(0, 0);
1204
1205  BumpVector<const MemRegion*> *VecOriginal =
1206    static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1207
1208  return BlockDataRegion::referenced_vars_iterator(Vec->end(),
1209                                                   VecOriginal->end());
1210}
1211