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1 //== MemRegion.cpp - Abstract memory regions for static analysis --*- C++ -*--//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file defines MemRegion and its subclasses.  MemRegion defines a
11 //  partially-typed abstraction of memory useful for path-sensitive dataflow
12 //  analyses.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
17 #include "clang/AST/Attr.h"
18 #include "clang/AST/CharUnits.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/RecordLayout.h"
21 #include "clang/Analysis/AnalysisContext.h"
22 #include "clang/Analysis/Support/BumpVector.h"
23 #include "clang/Basic/SourceManager.h"
24 #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
25 #include "llvm/Support/raw_ostream.h"
26 
27 using namespace clang;
28 using namespace ento;
29 
30 //===----------------------------------------------------------------------===//
31 // MemRegion Construction.
32 //===----------------------------------------------------------------------===//
33 
34 template<typename RegionTy> struct MemRegionManagerTrait;
35 
36 template <typename RegionTy, typename A1>
getRegion(const A1 a1)37 RegionTy* MemRegionManager::getRegion(const A1 a1) {
38 
39   const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
40   MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1);
41 
42   llvm::FoldingSetNodeID ID;
43   RegionTy::ProfileRegion(ID, a1, superRegion);
44   void *InsertPos;
45   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
46                                                                    InsertPos));
47 
48   if (!R) {
49     R = (RegionTy*) A.Allocate<RegionTy>();
50     new (R) RegionTy(a1, superRegion);
51     Regions.InsertNode(R, InsertPos);
52   }
53 
54   return R;
55 }
56 
57 template <typename RegionTy, typename A1>
getSubRegion(const A1 a1,const MemRegion * superRegion)58 RegionTy* MemRegionManager::getSubRegion(const A1 a1,
59                                          const MemRegion *superRegion) {
60   llvm::FoldingSetNodeID ID;
61   RegionTy::ProfileRegion(ID, a1, superRegion);
62   void *InsertPos;
63   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
64                                                                    InsertPos));
65 
66   if (!R) {
67     R = (RegionTy*) A.Allocate<RegionTy>();
68     new (R) RegionTy(a1, superRegion);
69     Regions.InsertNode(R, InsertPos);
70   }
71 
72   return R;
73 }
74 
75 template <typename RegionTy, typename A1, typename A2>
getRegion(const A1 a1,const A2 a2)76 RegionTy* MemRegionManager::getRegion(const A1 a1, const A2 a2) {
77 
78   const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
79   MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1, a2);
80 
81   llvm::FoldingSetNodeID ID;
82   RegionTy::ProfileRegion(ID, a1, a2, superRegion);
83   void *InsertPos;
84   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
85                                                                    InsertPos));
86 
87   if (!R) {
88     R = (RegionTy*) A.Allocate<RegionTy>();
89     new (R) RegionTy(a1, a2, superRegion);
90     Regions.InsertNode(R, InsertPos);
91   }
92 
93   return R;
94 }
95 
96 template <typename RegionTy, typename A1, typename A2>
getSubRegion(const A1 a1,const A2 a2,const MemRegion * superRegion)97 RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2,
98                                          const MemRegion *superRegion) {
99 
100   llvm::FoldingSetNodeID ID;
101   RegionTy::ProfileRegion(ID, a1, a2, superRegion);
102   void *InsertPos;
103   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
104                                                                    InsertPos));
105 
106   if (!R) {
107     R = (RegionTy*) A.Allocate<RegionTy>();
108     new (R) RegionTy(a1, a2, superRegion);
109     Regions.InsertNode(R, InsertPos);
110   }
111 
112   return R;
113 }
114 
115 template <typename RegionTy, typename A1, typename A2, typename A3>
getSubRegion(const A1 a1,const A2 a2,const A3 a3,const MemRegion * superRegion)116 RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2, const A3 a3,
117                                          const MemRegion *superRegion) {
118 
119   llvm::FoldingSetNodeID ID;
120   RegionTy::ProfileRegion(ID, a1, a2, a3, superRegion);
121   void *InsertPos;
122   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
123                                                                    InsertPos));
124 
125   if (!R) {
126     R = (RegionTy*) A.Allocate<RegionTy>();
127     new (R) RegionTy(a1, a2, a3, superRegion);
128     Regions.InsertNode(R, InsertPos);
129   }
130 
131   return R;
132 }
133 
134 //===----------------------------------------------------------------------===//
135 // Object destruction.
136 //===----------------------------------------------------------------------===//
137 
~MemRegion()138 MemRegion::~MemRegion() {}
139 
~MemRegionManager()140 MemRegionManager::~MemRegionManager() {
141   // All regions and their data are BumpPtrAllocated.  No need to call
142   // their destructors.
143 }
144 
145 //===----------------------------------------------------------------------===//
146 // Basic methods.
147 //===----------------------------------------------------------------------===//
148 
isSubRegionOf(const MemRegion * R) const149 bool SubRegion::isSubRegionOf(const MemRegion* R) const {
150   const MemRegion* r = getSuperRegion();
151   while (r != 0) {
152     if (r == R)
153       return true;
154     if (const SubRegion* sr = dyn_cast<SubRegion>(r))
155       r = sr->getSuperRegion();
156     else
157       break;
158   }
159   return false;
160 }
161 
getMemRegionManager() const162 MemRegionManager* SubRegion::getMemRegionManager() const {
163   const SubRegion* r = this;
164   do {
165     const MemRegion *superRegion = r->getSuperRegion();
166     if (const SubRegion *sr = dyn_cast<SubRegion>(superRegion)) {
167       r = sr;
168       continue;
169     }
170     return superRegion->getMemRegionManager();
171   } while (1);
172 }
173 
getStackFrame() const174 const StackFrameContext *VarRegion::getStackFrame() const {
175   const StackSpaceRegion *SSR = dyn_cast<StackSpaceRegion>(getMemorySpace());
176   return SSR ? SSR->getStackFrame() : NULL;
177 }
178 
179 //===----------------------------------------------------------------------===//
180 // Region extents.
181 //===----------------------------------------------------------------------===//
182 
getExtent(SValBuilder & svalBuilder) const183 DefinedOrUnknownSVal TypedValueRegion::getExtent(SValBuilder &svalBuilder) const {
184   ASTContext &Ctx = svalBuilder.getContext();
185   QualType T = getDesugaredValueType(Ctx);
186 
187   if (isa<VariableArrayType>(T))
188     return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
189   if (T->isIncompleteType())
190     return UnknownVal();
191 
192   CharUnits size = Ctx.getTypeSizeInChars(T);
193   QualType sizeTy = svalBuilder.getArrayIndexType();
194   return svalBuilder.makeIntVal(size.getQuantity(), sizeTy);
195 }
196 
getExtent(SValBuilder & svalBuilder) const197 DefinedOrUnknownSVal FieldRegion::getExtent(SValBuilder &svalBuilder) const {
198   // Force callers to deal with bitfields explicitly.
199   if (getDecl()->isBitField())
200     return UnknownVal();
201 
202   DefinedOrUnknownSVal Extent = DeclRegion::getExtent(svalBuilder);
203 
204   // A zero-length array at the end of a struct often stands for dynamically-
205   // allocated extra memory.
206   if (Extent.isZeroConstant()) {
207     QualType T = getDesugaredValueType(svalBuilder.getContext());
208 
209     if (isa<ConstantArrayType>(T))
210       return UnknownVal();
211   }
212 
213   return Extent;
214 }
215 
getExtent(SValBuilder & svalBuilder) const216 DefinedOrUnknownSVal AllocaRegion::getExtent(SValBuilder &svalBuilder) const {
217   return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
218 }
219 
getExtent(SValBuilder & svalBuilder) const220 DefinedOrUnknownSVal SymbolicRegion::getExtent(SValBuilder &svalBuilder) const {
221   return nonloc::SymbolVal(svalBuilder.getSymbolManager().getExtentSymbol(this));
222 }
223 
getExtent(SValBuilder & svalBuilder) const224 DefinedOrUnknownSVal StringRegion::getExtent(SValBuilder &svalBuilder) const {
225   return svalBuilder.makeIntVal(getStringLiteral()->getByteLength()+1,
226                                 svalBuilder.getArrayIndexType());
227 }
228 
ObjCIvarRegion(const ObjCIvarDecl * ivd,const MemRegion * sReg)229 ObjCIvarRegion::ObjCIvarRegion(const ObjCIvarDecl *ivd, const MemRegion* sReg)
230   : DeclRegion(ivd, sReg, ObjCIvarRegionKind) {}
231 
getDecl() const232 const ObjCIvarDecl *ObjCIvarRegion::getDecl() const {
233   return cast<ObjCIvarDecl>(D);
234 }
235 
getValueType() const236 QualType ObjCIvarRegion::getValueType() const {
237   return getDecl()->getType();
238 }
239 
getValueType() const240 QualType CXXBaseObjectRegion::getValueType() const {
241   return QualType(getDecl()->getTypeForDecl(), 0);
242 }
243 
244 //===----------------------------------------------------------------------===//
245 // FoldingSet profiling.
246 //===----------------------------------------------------------------------===//
247 
Profile(llvm::FoldingSetNodeID & ID) const248 void MemSpaceRegion::Profile(llvm::FoldingSetNodeID& ID) const {
249   ID.AddInteger((unsigned)getKind());
250 }
251 
Profile(llvm::FoldingSetNodeID & ID) const252 void StackSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
253   ID.AddInteger((unsigned)getKind());
254   ID.AddPointer(getStackFrame());
255 }
256 
Profile(llvm::FoldingSetNodeID & ID) const257 void StaticGlobalSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
258   ID.AddInteger((unsigned)getKind());
259   ID.AddPointer(getCodeRegion());
260 }
261 
ProfileRegion(llvm::FoldingSetNodeID & ID,const StringLiteral * Str,const MemRegion * superRegion)262 void StringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
263                                  const StringLiteral* Str,
264                                  const MemRegion* superRegion) {
265   ID.AddInteger((unsigned) StringRegionKind);
266   ID.AddPointer(Str);
267   ID.AddPointer(superRegion);
268 }
269 
ProfileRegion(llvm::FoldingSetNodeID & ID,const ObjCStringLiteral * Str,const MemRegion * superRegion)270 void ObjCStringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
271                                      const ObjCStringLiteral* Str,
272                                      const MemRegion* superRegion) {
273   ID.AddInteger((unsigned) ObjCStringRegionKind);
274   ID.AddPointer(Str);
275   ID.AddPointer(superRegion);
276 }
277 
ProfileRegion(llvm::FoldingSetNodeID & ID,const Expr * Ex,unsigned cnt,const MemRegion * superRegion)278 void AllocaRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
279                                  const Expr *Ex, unsigned cnt,
280                                  const MemRegion *superRegion) {
281   ID.AddInteger((unsigned) AllocaRegionKind);
282   ID.AddPointer(Ex);
283   ID.AddInteger(cnt);
284   ID.AddPointer(superRegion);
285 }
286 
Profile(llvm::FoldingSetNodeID & ID) const287 void AllocaRegion::Profile(llvm::FoldingSetNodeID& ID) const {
288   ProfileRegion(ID, Ex, Cnt, superRegion);
289 }
290 
Profile(llvm::FoldingSetNodeID & ID) const291 void CompoundLiteralRegion::Profile(llvm::FoldingSetNodeID& ID) const {
292   CompoundLiteralRegion::ProfileRegion(ID, CL, superRegion);
293 }
294 
ProfileRegion(llvm::FoldingSetNodeID & ID,const CompoundLiteralExpr * CL,const MemRegion * superRegion)295 void CompoundLiteralRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
296                                           const CompoundLiteralExpr *CL,
297                                           const MemRegion* superRegion) {
298   ID.AddInteger((unsigned) CompoundLiteralRegionKind);
299   ID.AddPointer(CL);
300   ID.AddPointer(superRegion);
301 }
302 
ProfileRegion(llvm::FoldingSetNodeID & ID,const PointerType * PT,const MemRegion * sRegion)303 void CXXThisRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
304                                   const PointerType *PT,
305                                   const MemRegion *sRegion) {
306   ID.AddInteger((unsigned) CXXThisRegionKind);
307   ID.AddPointer(PT);
308   ID.AddPointer(sRegion);
309 }
310 
Profile(llvm::FoldingSetNodeID & ID) const311 void CXXThisRegion::Profile(llvm::FoldingSetNodeID &ID) const {
312   CXXThisRegion::ProfileRegion(ID, ThisPointerTy, superRegion);
313 }
314 
ProfileRegion(llvm::FoldingSetNodeID & ID,const ObjCIvarDecl * ivd,const MemRegion * superRegion)315 void ObjCIvarRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
316                                    const ObjCIvarDecl *ivd,
317                                    const MemRegion* superRegion) {
318   DeclRegion::ProfileRegion(ID, ivd, superRegion, ObjCIvarRegionKind);
319 }
320 
ProfileRegion(llvm::FoldingSetNodeID & ID,const Decl * D,const MemRegion * superRegion,Kind k)321 void DeclRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, const Decl *D,
322                                const MemRegion* superRegion, Kind k) {
323   ID.AddInteger((unsigned) k);
324   ID.AddPointer(D);
325   ID.AddPointer(superRegion);
326 }
327 
Profile(llvm::FoldingSetNodeID & ID) const328 void DeclRegion::Profile(llvm::FoldingSetNodeID& ID) const {
329   DeclRegion::ProfileRegion(ID, D, superRegion, getKind());
330 }
331 
Profile(llvm::FoldingSetNodeID & ID) const332 void VarRegion::Profile(llvm::FoldingSetNodeID &ID) const {
333   VarRegion::ProfileRegion(ID, getDecl(), superRegion);
334 }
335 
ProfileRegion(llvm::FoldingSetNodeID & ID,SymbolRef sym,const MemRegion * sreg)336 void SymbolicRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SymbolRef sym,
337                                    const MemRegion *sreg) {
338   ID.AddInteger((unsigned) MemRegion::SymbolicRegionKind);
339   ID.Add(sym);
340   ID.AddPointer(sreg);
341 }
342 
Profile(llvm::FoldingSetNodeID & ID) const343 void SymbolicRegion::Profile(llvm::FoldingSetNodeID& ID) const {
344   SymbolicRegion::ProfileRegion(ID, sym, getSuperRegion());
345 }
346 
ProfileRegion(llvm::FoldingSetNodeID & ID,QualType ElementType,SVal Idx,const MemRegion * superRegion)347 void ElementRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
348                                   QualType ElementType, SVal Idx,
349                                   const MemRegion* superRegion) {
350   ID.AddInteger(MemRegion::ElementRegionKind);
351   ID.Add(ElementType);
352   ID.AddPointer(superRegion);
353   Idx.Profile(ID);
354 }
355 
Profile(llvm::FoldingSetNodeID & ID) const356 void ElementRegion::Profile(llvm::FoldingSetNodeID& ID) const {
357   ElementRegion::ProfileRegion(ID, ElementType, Index, superRegion);
358 }
359 
ProfileRegion(llvm::FoldingSetNodeID & ID,const NamedDecl * FD,const MemRegion *)360 void FunctionTextRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
361                                        const NamedDecl *FD,
362                                        const MemRegion*) {
363   ID.AddInteger(MemRegion::FunctionTextRegionKind);
364   ID.AddPointer(FD);
365 }
366 
Profile(llvm::FoldingSetNodeID & ID) const367 void FunctionTextRegion::Profile(llvm::FoldingSetNodeID& ID) const {
368   FunctionTextRegion::ProfileRegion(ID, FD, superRegion);
369 }
370 
ProfileRegion(llvm::FoldingSetNodeID & ID,const BlockDecl * BD,CanQualType,const AnalysisDeclContext * AC,const MemRegion *)371 void BlockTextRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
372                                     const BlockDecl *BD, CanQualType,
373                                     const AnalysisDeclContext *AC,
374                                     const MemRegion*) {
375   ID.AddInteger(MemRegion::BlockTextRegionKind);
376   ID.AddPointer(BD);
377 }
378 
Profile(llvm::FoldingSetNodeID & ID) const379 void BlockTextRegion::Profile(llvm::FoldingSetNodeID& ID) const {
380   BlockTextRegion::ProfileRegion(ID, BD, locTy, AC, superRegion);
381 }
382 
ProfileRegion(llvm::FoldingSetNodeID & ID,const BlockTextRegion * BC,const LocationContext * LC,const MemRegion * sReg)383 void BlockDataRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
384                                     const BlockTextRegion *BC,
385                                     const LocationContext *LC,
386                                     const MemRegion *sReg) {
387   ID.AddInteger(MemRegion::BlockDataRegionKind);
388   ID.AddPointer(BC);
389   ID.AddPointer(LC);
390   ID.AddPointer(sReg);
391 }
392 
Profile(llvm::FoldingSetNodeID & ID) const393 void BlockDataRegion::Profile(llvm::FoldingSetNodeID& ID) const {
394   BlockDataRegion::ProfileRegion(ID, BC, LC, getSuperRegion());
395 }
396 
ProfileRegion(llvm::FoldingSetNodeID & ID,Expr const * Ex,const MemRegion * sReg)397 void CXXTempObjectRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
398                                         Expr const *Ex,
399                                         const MemRegion *sReg) {
400   ID.AddPointer(Ex);
401   ID.AddPointer(sReg);
402 }
403 
Profile(llvm::FoldingSetNodeID & ID) const404 void CXXTempObjectRegion::Profile(llvm::FoldingSetNodeID &ID) const {
405   ProfileRegion(ID, Ex, getSuperRegion());
406 }
407 
ProfileRegion(llvm::FoldingSetNodeID & ID,const CXXRecordDecl * RD,bool IsVirtual,const MemRegion * SReg)408 void CXXBaseObjectRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
409                                         const CXXRecordDecl *RD,
410                                         bool IsVirtual,
411                                         const MemRegion *SReg) {
412   ID.AddPointer(RD);
413   ID.AddBoolean(IsVirtual);
414   ID.AddPointer(SReg);
415 }
416 
Profile(llvm::FoldingSetNodeID & ID) const417 void CXXBaseObjectRegion::Profile(llvm::FoldingSetNodeID &ID) const {
418   ProfileRegion(ID, getDecl(), isVirtual(), superRegion);
419 }
420 
421 //===----------------------------------------------------------------------===//
422 // Region anchors.
423 //===----------------------------------------------------------------------===//
424 
anchor()425 void GlobalsSpaceRegion::anchor() { }
anchor()426 void HeapSpaceRegion::anchor() { }
anchor()427 void UnknownSpaceRegion::anchor() { }
anchor()428 void StackLocalsSpaceRegion::anchor() { }
anchor()429 void StackArgumentsSpaceRegion::anchor() { }
anchor()430 void TypedRegion::anchor() { }
anchor()431 void TypedValueRegion::anchor() { }
anchor()432 void CodeTextRegion::anchor() { }
anchor()433 void SubRegion::anchor() { }
434 
435 //===----------------------------------------------------------------------===//
436 // Region pretty-printing.
437 //===----------------------------------------------------------------------===//
438 
dump() const439 void MemRegion::dump() const {
440   dumpToStream(llvm::errs());
441 }
442 
getString() const443 std::string MemRegion::getString() const {
444   std::string s;
445   llvm::raw_string_ostream os(s);
446   dumpToStream(os);
447   return os.str();
448 }
449 
dumpToStream(raw_ostream & os) const450 void MemRegion::dumpToStream(raw_ostream &os) const {
451   os << "<Unknown Region>";
452 }
453 
dumpToStream(raw_ostream & os) const454 void AllocaRegion::dumpToStream(raw_ostream &os) const {
455   os << "alloca{" << (const void*) Ex << ',' << Cnt << '}';
456 }
457 
dumpToStream(raw_ostream & os) const458 void FunctionTextRegion::dumpToStream(raw_ostream &os) const {
459   os << "code{" << getDecl()->getDeclName().getAsString() << '}';
460 }
461 
dumpToStream(raw_ostream & os) const462 void BlockTextRegion::dumpToStream(raw_ostream &os) const {
463   os << "block_code{" << (const void*) this << '}';
464 }
465 
dumpToStream(raw_ostream & os) const466 void BlockDataRegion::dumpToStream(raw_ostream &os) const {
467   os << "block_data{" << BC << '}';
468 }
469 
dumpToStream(raw_ostream & os) const470 void CompoundLiteralRegion::dumpToStream(raw_ostream &os) const {
471   // FIXME: More elaborate pretty-printing.
472   os << "{ " << (const void*) CL <<  " }";
473 }
474 
dumpToStream(raw_ostream & os) const475 void CXXTempObjectRegion::dumpToStream(raw_ostream &os) const {
476   os << "temp_object{" << getValueType().getAsString() << ','
477      << (const void*) Ex << '}';
478 }
479 
dumpToStream(raw_ostream & os) const480 void CXXBaseObjectRegion::dumpToStream(raw_ostream &os) const {
481   os << "base{" << superRegion << ',' << getDecl()->getName() << '}';
482 }
483 
dumpToStream(raw_ostream & os) const484 void CXXThisRegion::dumpToStream(raw_ostream &os) const {
485   os << "this";
486 }
487 
dumpToStream(raw_ostream & os) const488 void ElementRegion::dumpToStream(raw_ostream &os) const {
489   os << "element{" << superRegion << ','
490      << Index << ',' << getElementType().getAsString() << '}';
491 }
492 
dumpToStream(raw_ostream & os) const493 void FieldRegion::dumpToStream(raw_ostream &os) const {
494   os << superRegion << "->" << *getDecl();
495 }
496 
dumpToStream(raw_ostream & os) const497 void ObjCIvarRegion::dumpToStream(raw_ostream &os) const {
498   os << "ivar{" << superRegion << ',' << *getDecl() << '}';
499 }
500 
dumpToStream(raw_ostream & os) const501 void StringRegion::dumpToStream(raw_ostream &os) const {
502   Str->printPretty(os, 0, PrintingPolicy(getContext().getLangOpts()));
503 }
504 
dumpToStream(raw_ostream & os) const505 void ObjCStringRegion::dumpToStream(raw_ostream &os) const {
506   Str->printPretty(os, 0, PrintingPolicy(getContext().getLangOpts()));
507 }
508 
dumpToStream(raw_ostream & os) const509 void SymbolicRegion::dumpToStream(raw_ostream &os) const {
510   os << "SymRegion{" << sym << '}';
511 }
512 
dumpToStream(raw_ostream & os) const513 void VarRegion::dumpToStream(raw_ostream &os) const {
514   os << *cast<VarDecl>(D);
515 }
516 
dump() const517 void RegionRawOffset::dump() const {
518   dumpToStream(llvm::errs());
519 }
520 
dumpToStream(raw_ostream & os) const521 void RegionRawOffset::dumpToStream(raw_ostream &os) const {
522   os << "raw_offset{" << getRegion() << ',' << getOffset().getQuantity() << '}';
523 }
524 
dumpToStream(raw_ostream & os) const525 void StaticGlobalSpaceRegion::dumpToStream(raw_ostream &os) const {
526   os << "StaticGlobalsMemSpace{" << CR << '}';
527 }
528 
dumpToStream(raw_ostream & os) const529 void GlobalInternalSpaceRegion::dumpToStream(raw_ostream &os) const {
530   os << "GlobalInternalSpaceRegion";
531 }
532 
dumpToStream(raw_ostream & os) const533 void GlobalSystemSpaceRegion::dumpToStream(raw_ostream &os) const {
534   os << "GlobalSystemSpaceRegion";
535 }
536 
dumpToStream(raw_ostream & os) const537 void GlobalImmutableSpaceRegion::dumpToStream(raw_ostream &os) const {
538   os << "GlobalImmutableSpaceRegion";
539 }
540 
dumpToStream(raw_ostream & os) const541 void HeapSpaceRegion::dumpToStream(raw_ostream &os) const {
542   os << "HeapSpaceRegion";
543 }
544 
dumpToStream(raw_ostream & os) const545 void UnknownSpaceRegion::dumpToStream(raw_ostream &os) const {
546   os << "UnknownSpaceRegion";
547 }
548 
dumpToStream(raw_ostream & os) const549 void StackArgumentsSpaceRegion::dumpToStream(raw_ostream &os) const {
550   os << "StackArgumentsSpaceRegion";
551 }
552 
dumpToStream(raw_ostream & os) const553 void StackLocalsSpaceRegion::dumpToStream(raw_ostream &os) const {
554   os << "StackLocalsSpaceRegion";
555 }
556 
canPrintPretty() const557 bool MemRegion::canPrintPretty() const {
558   return canPrintPrettyAsExpr();
559 }
560 
canPrintPrettyAsExpr() const561 bool MemRegion::canPrintPrettyAsExpr() const {
562   return false;
563 }
564 
printPretty(raw_ostream & os) const565 void MemRegion::printPretty(raw_ostream &os) const {
566   assert(canPrintPretty() && "This region cannot be printed pretty.");
567   os << "'";
568   printPrettyAsExpr(os);
569   os << "'";
570   return;
571 }
572 
printPrettyAsExpr(raw_ostream & os) const573 void MemRegion::printPrettyAsExpr(raw_ostream &os) const {
574   llvm_unreachable("This region cannot be printed pretty.");
575   return;
576 }
577 
canPrintPrettyAsExpr() const578 bool VarRegion::canPrintPrettyAsExpr() const {
579   return true;
580 }
581 
printPrettyAsExpr(raw_ostream & os) const582 void VarRegion::printPrettyAsExpr(raw_ostream &os) const {
583   os << getDecl()->getName();
584 }
585 
canPrintPrettyAsExpr() const586 bool ObjCIvarRegion::canPrintPrettyAsExpr() const {
587   return true;
588 }
589 
printPrettyAsExpr(raw_ostream & os) const590 void ObjCIvarRegion::printPrettyAsExpr(raw_ostream &os) const {
591   os << getDecl()->getName();
592 }
593 
canPrintPretty() const594 bool FieldRegion::canPrintPretty() const {
595   return true;
596 }
597 
canPrintPrettyAsExpr() const598 bool FieldRegion::canPrintPrettyAsExpr() const {
599   return superRegion->canPrintPrettyAsExpr();
600 }
601 
printPrettyAsExpr(raw_ostream & os) const602 void FieldRegion::printPrettyAsExpr(raw_ostream &os) const {
603   assert(canPrintPrettyAsExpr());
604   superRegion->printPrettyAsExpr(os);
605   os << "." << getDecl()->getName();
606 }
607 
printPretty(raw_ostream & os) const608 void FieldRegion::printPretty(raw_ostream &os) const {
609   if (canPrintPrettyAsExpr()) {
610     os << "\'";
611     printPrettyAsExpr(os);
612     os << "'";
613   } else {
614     os << "field " << "\'" << getDecl()->getName() << "'";
615   }
616   return;
617 }
618 
canPrintPrettyAsExpr() const619 bool CXXBaseObjectRegion::canPrintPrettyAsExpr() const {
620   return superRegion->canPrintPrettyAsExpr();
621 }
622 
printPrettyAsExpr(raw_ostream & os) const623 void CXXBaseObjectRegion::printPrettyAsExpr(raw_ostream &os) const {
624   superRegion->printPrettyAsExpr(os);
625 }
626 
627 //===----------------------------------------------------------------------===//
628 // MemRegionManager methods.
629 //===----------------------------------------------------------------------===//
630 
631 template <typename REG>
LazyAllocate(REG * & region)632 const REG *MemRegionManager::LazyAllocate(REG*& region) {
633   if (!region) {
634     region = (REG*) A.Allocate<REG>();
635     new (region) REG(this);
636   }
637 
638   return region;
639 }
640 
641 template <typename REG, typename ARG>
LazyAllocate(REG * & region,ARG a)642 const REG *MemRegionManager::LazyAllocate(REG*& region, ARG a) {
643   if (!region) {
644     region = (REG*) A.Allocate<REG>();
645     new (region) REG(this, a);
646   }
647 
648   return region;
649 }
650 
651 const StackLocalsSpaceRegion*
getStackLocalsRegion(const StackFrameContext * STC)652 MemRegionManager::getStackLocalsRegion(const StackFrameContext *STC) {
653   assert(STC);
654   StackLocalsSpaceRegion *&R = StackLocalsSpaceRegions[STC];
655 
656   if (R)
657     return R;
658 
659   R = A.Allocate<StackLocalsSpaceRegion>();
660   new (R) StackLocalsSpaceRegion(this, STC);
661   return R;
662 }
663 
664 const StackArgumentsSpaceRegion *
getStackArgumentsRegion(const StackFrameContext * STC)665 MemRegionManager::getStackArgumentsRegion(const StackFrameContext *STC) {
666   assert(STC);
667   StackArgumentsSpaceRegion *&R = StackArgumentsSpaceRegions[STC];
668 
669   if (R)
670     return R;
671 
672   R = A.Allocate<StackArgumentsSpaceRegion>();
673   new (R) StackArgumentsSpaceRegion(this, STC);
674   return R;
675 }
676 
677 const GlobalsSpaceRegion
getGlobalsRegion(MemRegion::Kind K,const CodeTextRegion * CR)678 *MemRegionManager::getGlobalsRegion(MemRegion::Kind K,
679                                     const CodeTextRegion *CR) {
680   if (!CR) {
681     if (K == MemRegion::GlobalSystemSpaceRegionKind)
682       return LazyAllocate(SystemGlobals);
683     if (K == MemRegion::GlobalImmutableSpaceRegionKind)
684       return LazyAllocate(ImmutableGlobals);
685     assert(K == MemRegion::GlobalInternalSpaceRegionKind);
686     return LazyAllocate(InternalGlobals);
687   }
688 
689   assert(K == MemRegion::StaticGlobalSpaceRegionKind);
690   StaticGlobalSpaceRegion *&R = StaticsGlobalSpaceRegions[CR];
691   if (R)
692     return R;
693 
694   R = A.Allocate<StaticGlobalSpaceRegion>();
695   new (R) StaticGlobalSpaceRegion(this, CR);
696   return R;
697 }
698 
getHeapRegion()699 const HeapSpaceRegion *MemRegionManager::getHeapRegion() {
700   return LazyAllocate(heap);
701 }
702 
getUnknownRegion()703 const MemSpaceRegion *MemRegionManager::getUnknownRegion() {
704   return LazyAllocate(unknown);
705 }
706 
getCodeRegion()707 const MemSpaceRegion *MemRegionManager::getCodeRegion() {
708   return LazyAllocate(code);
709 }
710 
711 //===----------------------------------------------------------------------===//
712 // Constructing regions.
713 //===----------------------------------------------------------------------===//
getStringRegion(const StringLiteral * Str)714 const StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str){
715   return getSubRegion<StringRegion>(Str, getGlobalsRegion());
716 }
717 
718 const ObjCStringRegion *
getObjCStringRegion(const ObjCStringLiteral * Str)719 MemRegionManager::getObjCStringRegion(const ObjCStringLiteral* Str){
720   return getSubRegion<ObjCStringRegion>(Str, getGlobalsRegion());
721 }
722 
723 /// Look through a chain of LocationContexts to either find the
724 /// StackFrameContext that matches a DeclContext, or find a VarRegion
725 /// for a variable captured by a block.
726 static llvm::PointerUnion<const StackFrameContext *, const VarRegion *>
getStackOrCaptureRegionForDeclContext(const LocationContext * LC,const DeclContext * DC,const VarDecl * VD)727 getStackOrCaptureRegionForDeclContext(const LocationContext *LC,
728                                       const DeclContext *DC,
729                                       const VarDecl *VD) {
730   while (LC) {
731     if (const StackFrameContext *SFC = dyn_cast<StackFrameContext>(LC)) {
732       if (cast<DeclContext>(SFC->getDecl()) == DC)
733         return SFC;
734     }
735     if (const BlockInvocationContext *BC =
736         dyn_cast<BlockInvocationContext>(LC)) {
737       const BlockDataRegion *BR =
738         static_cast<const BlockDataRegion*>(BC->getContextData());
739       // FIXME: This can be made more efficient.
740       for (BlockDataRegion::referenced_vars_iterator
741            I = BR->referenced_vars_begin(),
742            E = BR->referenced_vars_end(); I != E; ++I) {
743         if (const VarRegion *VR = dyn_cast<VarRegion>(I.getOriginalRegion()))
744           if (VR->getDecl() == VD)
745             return cast<VarRegion>(I.getCapturedRegion());
746       }
747     }
748 
749     LC = LC->getParent();
750   }
751   return (const StackFrameContext*)0;
752 }
753 
getVarRegion(const VarDecl * D,const LocationContext * LC)754 const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
755                                                 const LocationContext *LC) {
756   const MemRegion *sReg = 0;
757 
758   if (D->hasGlobalStorage() && !D->isStaticLocal()) {
759 
760     // First handle the globals defined in system headers.
761     if (C.getSourceManager().isInSystemHeader(D->getLocation())) {
762       // Whitelist the system globals which often DO GET modified, assume the
763       // rest are immutable.
764       if (D->getName().find("errno") != StringRef::npos)
765         sReg = getGlobalsRegion(MemRegion::GlobalSystemSpaceRegionKind);
766       else
767         sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
768 
769     // Treat other globals as GlobalInternal unless they are constants.
770     } else {
771       QualType GQT = D->getType();
772       const Type *GT = GQT.getTypePtrOrNull();
773       // TODO: We could walk the complex types here and see if everything is
774       // constified.
775       if (GT && GQT.isConstQualified() && GT->isArithmeticType())
776         sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
777       else
778         sReg = getGlobalsRegion();
779     }
780 
781   // Finally handle static locals.
782   } else {
783     // FIXME: Once we implement scope handling, we will need to properly lookup
784     // 'D' to the proper LocationContext.
785     const DeclContext *DC = D->getDeclContext();
786     llvm::PointerUnion<const StackFrameContext *, const VarRegion *> V =
787       getStackOrCaptureRegionForDeclContext(LC, DC, D);
788 
789     if (V.is<const VarRegion*>())
790       return V.get<const VarRegion*>();
791 
792     const StackFrameContext *STC = V.get<const StackFrameContext*>();
793 
794     if (!STC)
795       sReg = getUnknownRegion();
796     else {
797       if (D->hasLocalStorage()) {
798         sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
799                ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
800                : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
801       }
802       else {
803         assert(D->isStaticLocal());
804         const Decl *STCD = STC->getDecl();
805         if (isa<FunctionDecl>(STCD) || isa<ObjCMethodDecl>(STCD))
806           sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
807                                   getFunctionTextRegion(cast<NamedDecl>(STCD)));
808         else if (const BlockDecl *BD = dyn_cast<BlockDecl>(STCD)) {
809           // FIXME: The fallback type here is totally bogus -- though it should
810           // never be queried, it will prevent uniquing with the real
811           // BlockTextRegion. Ideally we'd fix the AST so that we always had a
812           // signature.
813           QualType T;
814           if (const TypeSourceInfo *TSI = BD->getSignatureAsWritten())
815             T = TSI->getType();
816           else
817             T = getContext().getFunctionNoProtoType(getContext().VoidTy);
818 
819           const BlockTextRegion *BTR =
820             getBlockTextRegion(BD, C.getCanonicalType(T),
821                                STC->getAnalysisDeclContext());
822           sReg = getGlobalsRegion(MemRegion::StaticGlobalSpaceRegionKind,
823                                   BTR);
824         }
825         else {
826           sReg = getGlobalsRegion();
827         }
828       }
829     }
830   }
831 
832   return getSubRegion<VarRegion>(D, sReg);
833 }
834 
getVarRegion(const VarDecl * D,const MemRegion * superR)835 const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
836                                                 const MemRegion *superR) {
837   return getSubRegion<VarRegion>(D, superR);
838 }
839 
840 const BlockDataRegion *
getBlockDataRegion(const BlockTextRegion * BC,const LocationContext * LC)841 MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
842                                      const LocationContext *LC) {
843   const MemRegion *sReg = 0;
844   const BlockDecl *BD = BC->getDecl();
845   if (!BD->hasCaptures()) {
846     // This handles 'static' blocks.
847     sReg = getGlobalsRegion(MemRegion::GlobalImmutableSpaceRegionKind);
848   }
849   else {
850     if (LC) {
851       // FIXME: Once we implement scope handling, we want the parent region
852       // to be the scope.
853       const StackFrameContext *STC = LC->getCurrentStackFrame();
854       assert(STC);
855       sReg = getStackLocalsRegion(STC);
856     }
857     else {
858       // We allow 'LC' to be NULL for cases where want BlockDataRegions
859       // without context-sensitivity.
860       sReg = getUnknownRegion();
861     }
862   }
863 
864   return getSubRegion<BlockDataRegion>(BC, LC, sReg);
865 }
866 
867 const CXXTempObjectRegion *
getCXXStaticTempObjectRegion(const Expr * Ex)868 MemRegionManager::getCXXStaticTempObjectRegion(const Expr *Ex) {
869   return getSubRegion<CXXTempObjectRegion>(
870       Ex, getGlobalsRegion(MemRegion::GlobalInternalSpaceRegionKind, NULL));
871 }
872 
873 const CompoundLiteralRegion*
getCompoundLiteralRegion(const CompoundLiteralExpr * CL,const LocationContext * LC)874 MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr *CL,
875                                            const LocationContext *LC) {
876 
877   const MemRegion *sReg = 0;
878 
879   if (CL->isFileScope())
880     sReg = getGlobalsRegion();
881   else {
882     const StackFrameContext *STC = LC->getCurrentStackFrame();
883     assert(STC);
884     sReg = getStackLocalsRegion(STC);
885   }
886 
887   return getSubRegion<CompoundLiteralRegion>(CL, sReg);
888 }
889 
890 const ElementRegion*
getElementRegion(QualType elementType,NonLoc Idx,const MemRegion * superRegion,ASTContext & Ctx)891 MemRegionManager::getElementRegion(QualType elementType, NonLoc Idx,
892                                    const MemRegion* superRegion,
893                                    ASTContext &Ctx){
894 
895   QualType T = Ctx.getCanonicalType(elementType).getUnqualifiedType();
896 
897   llvm::FoldingSetNodeID ID;
898   ElementRegion::ProfileRegion(ID, T, Idx, superRegion);
899 
900   void *InsertPos;
901   MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
902   ElementRegion* R = cast_or_null<ElementRegion>(data);
903 
904   if (!R) {
905     R = (ElementRegion*) A.Allocate<ElementRegion>();
906     new (R) ElementRegion(T, Idx, superRegion);
907     Regions.InsertNode(R, InsertPos);
908   }
909 
910   return R;
911 }
912 
913 const FunctionTextRegion *
getFunctionTextRegion(const NamedDecl * FD)914 MemRegionManager::getFunctionTextRegion(const NamedDecl *FD) {
915   return getSubRegion<FunctionTextRegion>(FD, getCodeRegion());
916 }
917 
918 const BlockTextRegion *
getBlockTextRegion(const BlockDecl * BD,CanQualType locTy,AnalysisDeclContext * AC)919 MemRegionManager::getBlockTextRegion(const BlockDecl *BD, CanQualType locTy,
920                                      AnalysisDeclContext *AC) {
921   return getSubRegion<BlockTextRegion>(BD, locTy, AC, getCodeRegion());
922 }
923 
924 
925 /// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
getSymbolicRegion(SymbolRef sym)926 const SymbolicRegion *MemRegionManager::getSymbolicRegion(SymbolRef sym) {
927   return getSubRegion<SymbolicRegion>(sym, getUnknownRegion());
928 }
929 
getSymbolicHeapRegion(SymbolRef Sym)930 const SymbolicRegion *MemRegionManager::getSymbolicHeapRegion(SymbolRef Sym) {
931   return getSubRegion<SymbolicRegion>(Sym, getHeapRegion());
932 }
933 
934 const FieldRegion*
getFieldRegion(const FieldDecl * d,const MemRegion * superRegion)935 MemRegionManager::getFieldRegion(const FieldDecl *d,
936                                  const MemRegion* superRegion){
937   return getSubRegion<FieldRegion>(d, superRegion);
938 }
939 
940 const ObjCIvarRegion*
getObjCIvarRegion(const ObjCIvarDecl * d,const MemRegion * superRegion)941 MemRegionManager::getObjCIvarRegion(const ObjCIvarDecl *d,
942                                     const MemRegion* superRegion) {
943   return getSubRegion<ObjCIvarRegion>(d, superRegion);
944 }
945 
946 const CXXTempObjectRegion*
getCXXTempObjectRegion(Expr const * E,LocationContext const * LC)947 MemRegionManager::getCXXTempObjectRegion(Expr const *E,
948                                          LocationContext const *LC) {
949   const StackFrameContext *SFC = LC->getCurrentStackFrame();
950   assert(SFC);
951   return getSubRegion<CXXTempObjectRegion>(E, getStackLocalsRegion(SFC));
952 }
953 
954 /// Checks whether \p BaseClass is a valid virtual or direct non-virtual base
955 /// class of the type of \p Super.
isValidBaseClass(const CXXRecordDecl * BaseClass,const TypedValueRegion * Super,bool IsVirtual)956 static bool isValidBaseClass(const CXXRecordDecl *BaseClass,
957                              const TypedValueRegion *Super,
958                              bool IsVirtual) {
959   BaseClass = BaseClass->getCanonicalDecl();
960 
961   const CXXRecordDecl *Class = Super->getValueType()->getAsCXXRecordDecl();
962   if (!Class)
963     return true;
964 
965   if (IsVirtual)
966     return Class->isVirtuallyDerivedFrom(BaseClass);
967 
968   for (CXXRecordDecl::base_class_const_iterator I = Class->bases_begin(),
969                                                 E = Class->bases_end();
970        I != E; ++I) {
971     if (I->getType()->getAsCXXRecordDecl()->getCanonicalDecl() == BaseClass)
972       return true;
973   }
974 
975   return false;
976 }
977 
978 const CXXBaseObjectRegion *
getCXXBaseObjectRegion(const CXXRecordDecl * RD,const MemRegion * Super,bool IsVirtual)979 MemRegionManager::getCXXBaseObjectRegion(const CXXRecordDecl *RD,
980                                          const MemRegion *Super,
981                                          bool IsVirtual) {
982   if (isa<TypedValueRegion>(Super)) {
983     assert(isValidBaseClass(RD, dyn_cast<TypedValueRegion>(Super), IsVirtual));
984     (void)&isValidBaseClass;
985 
986     if (IsVirtual) {
987       // Virtual base regions should not be layered, since the layout rules
988       // are different.
989       while (const CXXBaseObjectRegion *Base =
990                dyn_cast<CXXBaseObjectRegion>(Super)) {
991         Super = Base->getSuperRegion();
992       }
993       assert(Super && !isa<MemSpaceRegion>(Super));
994     }
995   }
996 
997   return getSubRegion<CXXBaseObjectRegion>(RD, IsVirtual, Super);
998 }
999 
1000 const CXXThisRegion*
getCXXThisRegion(QualType thisPointerTy,const LocationContext * LC)1001 MemRegionManager::getCXXThisRegion(QualType thisPointerTy,
1002                                    const LocationContext *LC) {
1003   const StackFrameContext *STC = LC->getCurrentStackFrame();
1004   assert(STC);
1005   const PointerType *PT = thisPointerTy->getAs<PointerType>();
1006   assert(PT);
1007   return getSubRegion<CXXThisRegion>(PT, getStackArgumentsRegion(STC));
1008 }
1009 
1010 const AllocaRegion*
getAllocaRegion(const Expr * E,unsigned cnt,const LocationContext * LC)1011 MemRegionManager::getAllocaRegion(const Expr *E, unsigned cnt,
1012                                   const LocationContext *LC) {
1013   const StackFrameContext *STC = LC->getCurrentStackFrame();
1014   assert(STC);
1015   return getSubRegion<AllocaRegion>(E, cnt, getStackLocalsRegion(STC));
1016 }
1017 
getMemorySpace() const1018 const MemSpaceRegion *MemRegion::getMemorySpace() const {
1019   const MemRegion *R = this;
1020   const SubRegion* SR = dyn_cast<SubRegion>(this);
1021 
1022   while (SR) {
1023     R = SR->getSuperRegion();
1024     SR = dyn_cast<SubRegion>(R);
1025   }
1026 
1027   return dyn_cast<MemSpaceRegion>(R);
1028 }
1029 
hasStackStorage() const1030 bool MemRegion::hasStackStorage() const {
1031   return isa<StackSpaceRegion>(getMemorySpace());
1032 }
1033 
hasStackNonParametersStorage() const1034 bool MemRegion::hasStackNonParametersStorage() const {
1035   return isa<StackLocalsSpaceRegion>(getMemorySpace());
1036 }
1037 
hasStackParametersStorage() const1038 bool MemRegion::hasStackParametersStorage() const {
1039   return isa<StackArgumentsSpaceRegion>(getMemorySpace());
1040 }
1041 
hasGlobalsOrParametersStorage() const1042 bool MemRegion::hasGlobalsOrParametersStorage() const {
1043   const MemSpaceRegion *MS = getMemorySpace();
1044   return isa<StackArgumentsSpaceRegion>(MS) ||
1045          isa<GlobalsSpaceRegion>(MS);
1046 }
1047 
1048 // getBaseRegion strips away all elements and fields, and get the base region
1049 // of them.
getBaseRegion() const1050 const MemRegion *MemRegion::getBaseRegion() const {
1051   const MemRegion *R = this;
1052   while (true) {
1053     switch (R->getKind()) {
1054       case MemRegion::ElementRegionKind:
1055       case MemRegion::FieldRegionKind:
1056       case MemRegion::ObjCIvarRegionKind:
1057       case MemRegion::CXXBaseObjectRegionKind:
1058         R = cast<SubRegion>(R)->getSuperRegion();
1059         continue;
1060       default:
1061         break;
1062     }
1063     break;
1064   }
1065   return R;
1066 }
1067 
isSubRegionOf(const MemRegion * R) const1068 bool MemRegion::isSubRegionOf(const MemRegion *R) const {
1069   return false;
1070 }
1071 
1072 //===----------------------------------------------------------------------===//
1073 // View handling.
1074 //===----------------------------------------------------------------------===//
1075 
StripCasts(bool StripBaseCasts) const1076 const MemRegion *MemRegion::StripCasts(bool StripBaseCasts) const {
1077   const MemRegion *R = this;
1078   while (true) {
1079     switch (R->getKind()) {
1080     case ElementRegionKind: {
1081       const ElementRegion *ER = cast<ElementRegion>(R);
1082       if (!ER->getIndex().isZeroConstant())
1083         return R;
1084       R = ER->getSuperRegion();
1085       break;
1086     }
1087     case CXXBaseObjectRegionKind:
1088       if (!StripBaseCasts)
1089         return R;
1090       R = cast<CXXBaseObjectRegion>(R)->getSuperRegion();
1091       break;
1092     default:
1093       return R;
1094     }
1095   }
1096 }
1097 
getSymbolicBase() const1098 const SymbolicRegion *MemRegion::getSymbolicBase() const {
1099   const SubRegion *SubR = dyn_cast<SubRegion>(this);
1100 
1101   while (SubR) {
1102     if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(SubR))
1103       return SymR;
1104     SubR = dyn_cast<SubRegion>(SubR->getSuperRegion());
1105   }
1106   return 0;
1107 }
1108 
1109 // FIXME: Merge with the implementation of the same method in Store.cpp
IsCompleteType(ASTContext & Ctx,QualType Ty)1110 static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
1111   if (const RecordType *RT = Ty->getAs<RecordType>()) {
1112     const RecordDecl *D = RT->getDecl();
1113     if (!D->getDefinition())
1114       return false;
1115   }
1116 
1117   return true;
1118 }
1119 
getAsArrayOffset() const1120 RegionRawOffset ElementRegion::getAsArrayOffset() const {
1121   CharUnits offset = CharUnits::Zero();
1122   const ElementRegion *ER = this;
1123   const MemRegion *superR = NULL;
1124   ASTContext &C = getContext();
1125 
1126   // FIXME: Handle multi-dimensional arrays.
1127 
1128   while (ER) {
1129     superR = ER->getSuperRegion();
1130 
1131     // FIXME: generalize to symbolic offsets.
1132     SVal index = ER->getIndex();
1133     if (Optional<nonloc::ConcreteInt> CI = index.getAs<nonloc::ConcreteInt>()) {
1134       // Update the offset.
1135       int64_t i = CI->getValue().getSExtValue();
1136 
1137       if (i != 0) {
1138         QualType elemType = ER->getElementType();
1139 
1140         // If we are pointing to an incomplete type, go no further.
1141         if (!IsCompleteType(C, elemType)) {
1142           superR = ER;
1143           break;
1144         }
1145 
1146         CharUnits size = C.getTypeSizeInChars(elemType);
1147         offset += (i * size);
1148       }
1149 
1150       // Go to the next ElementRegion (if any).
1151       ER = dyn_cast<ElementRegion>(superR);
1152       continue;
1153     }
1154 
1155     return NULL;
1156   }
1157 
1158   assert(superR && "super region cannot be NULL");
1159   return RegionRawOffset(superR, offset);
1160 }
1161 
1162 
1163 /// Returns true if \p Base is an immediate base class of \p Child
isImmediateBase(const CXXRecordDecl * Child,const CXXRecordDecl * Base)1164 static bool isImmediateBase(const CXXRecordDecl *Child,
1165                             const CXXRecordDecl *Base) {
1166   // Note that we do NOT canonicalize the base class here, because
1167   // ASTRecordLayout doesn't either. If that leads us down the wrong path,
1168   // so be it; at least we won't crash.
1169   for (CXXRecordDecl::base_class_const_iterator I = Child->bases_begin(),
1170                                                 E = Child->bases_end();
1171        I != E; ++I) {
1172     if (I->getType()->getAsCXXRecordDecl() == Base)
1173       return true;
1174   }
1175 
1176   return false;
1177 }
1178 
getAsOffset() const1179 RegionOffset MemRegion::getAsOffset() const {
1180   const MemRegion *R = this;
1181   const MemRegion *SymbolicOffsetBase = 0;
1182   int64_t Offset = 0;
1183 
1184   while (1) {
1185     switch (R->getKind()) {
1186     case GenericMemSpaceRegionKind:
1187     case StackLocalsSpaceRegionKind:
1188     case StackArgumentsSpaceRegionKind:
1189     case HeapSpaceRegionKind:
1190     case UnknownSpaceRegionKind:
1191     case StaticGlobalSpaceRegionKind:
1192     case GlobalInternalSpaceRegionKind:
1193     case GlobalSystemSpaceRegionKind:
1194     case GlobalImmutableSpaceRegionKind:
1195       // Stores can bind directly to a region space to set a default value.
1196       assert(Offset == 0 && !SymbolicOffsetBase);
1197       goto Finish;
1198 
1199     case FunctionTextRegionKind:
1200     case BlockTextRegionKind:
1201     case BlockDataRegionKind:
1202       // These will never have bindings, but may end up having values requested
1203       // if the user does some strange casting.
1204       if (Offset != 0)
1205         SymbolicOffsetBase = R;
1206       goto Finish;
1207 
1208     case SymbolicRegionKind:
1209     case AllocaRegionKind:
1210     case CompoundLiteralRegionKind:
1211     case CXXThisRegionKind:
1212     case StringRegionKind:
1213     case ObjCStringRegionKind:
1214     case VarRegionKind:
1215     case CXXTempObjectRegionKind:
1216       // Usual base regions.
1217       goto Finish;
1218 
1219     case ObjCIvarRegionKind:
1220       // This is a little strange, but it's a compromise between
1221       // ObjCIvarRegions having unknown compile-time offsets (when using the
1222       // non-fragile runtime) and yet still being distinct, non-overlapping
1223       // regions. Thus we treat them as "like" base regions for the purposes
1224       // of computing offsets.
1225       goto Finish;
1226 
1227     case CXXBaseObjectRegionKind: {
1228       const CXXBaseObjectRegion *BOR = cast<CXXBaseObjectRegion>(R);
1229       R = BOR->getSuperRegion();
1230 
1231       QualType Ty;
1232       bool RootIsSymbolic = false;
1233       if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R)) {
1234         Ty = TVR->getDesugaredValueType(getContext());
1235       } else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
1236         // If our base region is symbolic, we don't know what type it really is.
1237         // Pretend the type of the symbol is the true dynamic type.
1238         // (This will at least be self-consistent for the life of the symbol.)
1239         Ty = SR->getSymbol()->getType()->getPointeeType();
1240         RootIsSymbolic = true;
1241       }
1242 
1243       const CXXRecordDecl *Child = Ty->getAsCXXRecordDecl();
1244       if (!Child) {
1245         // We cannot compute the offset of the base class.
1246         SymbolicOffsetBase = R;
1247       }
1248 
1249       if (RootIsSymbolic) {
1250         // Base layers on symbolic regions may not be type-correct.
1251         // Double-check the inheritance here, and revert to a symbolic offset
1252         // if it's invalid (e.g. due to a reinterpret_cast).
1253         if (BOR->isVirtual()) {
1254           if (!Child->isVirtuallyDerivedFrom(BOR->getDecl()))
1255             SymbolicOffsetBase = R;
1256         } else {
1257           if (!isImmediateBase(Child, BOR->getDecl()))
1258             SymbolicOffsetBase = R;
1259         }
1260       }
1261 
1262       // Don't bother calculating precise offsets if we already have a
1263       // symbolic offset somewhere in the chain.
1264       if (SymbolicOffsetBase)
1265         continue;
1266 
1267       CharUnits BaseOffset;
1268       const ASTRecordLayout &Layout = getContext().getASTRecordLayout(Child);
1269       if (BOR->isVirtual())
1270         BaseOffset = Layout.getVBaseClassOffset(BOR->getDecl());
1271       else
1272         BaseOffset = Layout.getBaseClassOffset(BOR->getDecl());
1273 
1274       // The base offset is in chars, not in bits.
1275       Offset += BaseOffset.getQuantity() * getContext().getCharWidth();
1276       break;
1277     }
1278     case ElementRegionKind: {
1279       const ElementRegion *ER = cast<ElementRegion>(R);
1280       R = ER->getSuperRegion();
1281 
1282       QualType EleTy = ER->getValueType();
1283       if (!IsCompleteType(getContext(), EleTy)) {
1284         // We cannot compute the offset of the base class.
1285         SymbolicOffsetBase = R;
1286         continue;
1287       }
1288 
1289       SVal Index = ER->getIndex();
1290       if (Optional<nonloc::ConcreteInt> CI =
1291               Index.getAs<nonloc::ConcreteInt>()) {
1292         // Don't bother calculating precise offsets if we already have a
1293         // symbolic offset somewhere in the chain.
1294         if (SymbolicOffsetBase)
1295           continue;
1296 
1297         int64_t i = CI->getValue().getSExtValue();
1298         // This type size is in bits.
1299         Offset += i * getContext().getTypeSize(EleTy);
1300       } else {
1301         // We cannot compute offset for non-concrete index.
1302         SymbolicOffsetBase = R;
1303       }
1304       break;
1305     }
1306     case FieldRegionKind: {
1307       const FieldRegion *FR = cast<FieldRegion>(R);
1308       R = FR->getSuperRegion();
1309 
1310       const RecordDecl *RD = FR->getDecl()->getParent();
1311       if (RD->isUnion() || !RD->isCompleteDefinition()) {
1312         // We cannot compute offset for incomplete type.
1313         // For unions, we could treat everything as offset 0, but we'd rather
1314         // treat each field as a symbolic offset so they aren't stored on top
1315         // of each other, since we depend on things in typed regions actually
1316         // matching their types.
1317         SymbolicOffsetBase = R;
1318       }
1319 
1320       // Don't bother calculating precise offsets if we already have a
1321       // symbolic offset somewhere in the chain.
1322       if (SymbolicOffsetBase)
1323         continue;
1324 
1325       // Get the field number.
1326       unsigned idx = 0;
1327       for (RecordDecl::field_iterator FI = RD->field_begin(),
1328              FE = RD->field_end(); FI != FE; ++FI, ++idx)
1329         if (FR->getDecl() == *FI)
1330           break;
1331 
1332       const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1333       // This is offset in bits.
1334       Offset += Layout.getFieldOffset(idx);
1335       break;
1336     }
1337     }
1338   }
1339 
1340  Finish:
1341   if (SymbolicOffsetBase)
1342     return RegionOffset(SymbolicOffsetBase, RegionOffset::Symbolic);
1343   return RegionOffset(R, Offset);
1344 }
1345 
1346 //===----------------------------------------------------------------------===//
1347 // BlockDataRegion
1348 //===----------------------------------------------------------------------===//
1349 
1350 std::pair<const VarRegion *, const VarRegion *>
getCaptureRegions(const VarDecl * VD)1351 BlockDataRegion::getCaptureRegions(const VarDecl *VD) {
1352   MemRegionManager &MemMgr = *getMemRegionManager();
1353   const VarRegion *VR = 0;
1354   const VarRegion *OriginalVR = 0;
1355 
1356   if (!VD->getAttr<BlocksAttr>() && VD->hasLocalStorage()) {
1357     VR = MemMgr.getVarRegion(VD, this);
1358     OriginalVR = MemMgr.getVarRegion(VD, LC);
1359   }
1360   else {
1361     if (LC) {
1362       VR = MemMgr.getVarRegion(VD, LC);
1363       OriginalVR = VR;
1364     }
1365     else {
1366       VR = MemMgr.getVarRegion(VD, MemMgr.getUnknownRegion());
1367       OriginalVR = MemMgr.getVarRegion(VD, LC);
1368     }
1369   }
1370   return std::make_pair(VR, OriginalVR);
1371 }
1372 
LazyInitializeReferencedVars()1373 void BlockDataRegion::LazyInitializeReferencedVars() {
1374   if (ReferencedVars)
1375     return;
1376 
1377   AnalysisDeclContext *AC = getCodeRegion()->getAnalysisDeclContext();
1378   AnalysisDeclContext::referenced_decls_iterator I, E;
1379   llvm::tie(I, E) = AC->getReferencedBlockVars(BC->getDecl());
1380 
1381   if (I == E) {
1382     ReferencedVars = (void*) 0x1;
1383     return;
1384   }
1385 
1386   MemRegionManager &MemMgr = *getMemRegionManager();
1387   llvm::BumpPtrAllocator &A = MemMgr.getAllocator();
1388   BumpVectorContext BC(A);
1389 
1390   typedef BumpVector<const MemRegion*> VarVec;
1391   VarVec *BV = (VarVec*) A.Allocate<VarVec>();
1392   new (BV) VarVec(BC, E - I);
1393   VarVec *BVOriginal = (VarVec*) A.Allocate<VarVec>();
1394   new (BVOriginal) VarVec(BC, E - I);
1395 
1396   for ( ; I != E; ++I) {
1397     const VarRegion *VR = 0;
1398     const VarRegion *OriginalVR = 0;
1399     llvm::tie(VR, OriginalVR) = getCaptureRegions(*I);
1400     assert(VR);
1401     assert(OriginalVR);
1402     BV->push_back(VR, BC);
1403     BVOriginal->push_back(OriginalVR, BC);
1404   }
1405 
1406   ReferencedVars = BV;
1407   OriginalVars = BVOriginal;
1408 }
1409 
1410 BlockDataRegion::referenced_vars_iterator
referenced_vars_begin() const1411 BlockDataRegion::referenced_vars_begin() const {
1412   const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1413 
1414   BumpVector<const MemRegion*> *Vec =
1415     static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1416 
1417   if (Vec == (void*) 0x1)
1418     return BlockDataRegion::referenced_vars_iterator(0, 0);
1419 
1420   BumpVector<const MemRegion*> *VecOriginal =
1421     static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1422 
1423   return BlockDataRegion::referenced_vars_iterator(Vec->begin(),
1424                                                    VecOriginal->begin());
1425 }
1426 
1427 BlockDataRegion::referenced_vars_iterator
referenced_vars_end() const1428 BlockDataRegion::referenced_vars_end() const {
1429   const_cast<BlockDataRegion*>(this)->LazyInitializeReferencedVars();
1430 
1431   BumpVector<const MemRegion*> *Vec =
1432     static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
1433 
1434   if (Vec == (void*) 0x1)
1435     return BlockDataRegion::referenced_vars_iterator(0, 0);
1436 
1437   BumpVector<const MemRegion*> *VecOriginal =
1438     static_cast<BumpVector<const MemRegion*>*>(OriginalVars);
1439 
1440   return BlockDataRegion::referenced_vars_iterator(Vec->end(),
1441                                                    VecOriginal->end());
1442 }
1443 
getOriginalRegion(const VarRegion * R) const1444 const VarRegion *BlockDataRegion::getOriginalRegion(const VarRegion *R) const {
1445   for (referenced_vars_iterator I = referenced_vars_begin(),
1446                                 E = referenced_vars_end();
1447        I != E; ++I) {
1448     if (I.getCapturedRegion() == R)
1449       return I.getOriginalRegion();
1450   }
1451   return 0;
1452 }
1453