lib/StaticAnalyzer/EntoSA/MemRegion.cpp

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