ProgramState.cpp revision 7affe151f5689b2d3547b8947c4099532c78a021
1//= ProgramState.cpp - Path-Sensitive "State" for tracking values --*- 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 implements ProgramState and ProgramStateManager. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 15#include "clang/Analysis/CFG.h" 16#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 17#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 18#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h" 19#include "clang/StaticAnalyzer/Core/PathSensitive/TaintManager.h" 20#include "llvm/Support/raw_ostream.h" 21 22using namespace clang; 23using namespace ento; 24 25namespace clang { namespace ento { 26/// Increments the number of times this state is referenced. 27 28void ProgramStateRetain(const ProgramState *state) { 29 ++const_cast<ProgramState*>(state)->refCount; 30} 31 32/// Decrement the number of times this state is referenced. 33void ProgramStateRelease(const ProgramState *state) { 34 assert(state->refCount > 0); 35 ProgramState *s = const_cast<ProgramState*>(state); 36 if (--s->refCount == 0) { 37 ProgramStateManager &Mgr = s->getStateManager(); 38 Mgr.StateSet.RemoveNode(s); 39 s->~ProgramState(); 40 Mgr.freeStates.push_back(s); 41 } 42} 43}} 44 45ProgramState::ProgramState(ProgramStateManager *mgr, const Environment& env, 46 StoreRef st, GenericDataMap gdm) 47 : stateMgr(mgr), 48 Env(env), 49 store(st.getStore()), 50 GDM(gdm), 51 refCount(0) { 52 stateMgr->getStoreManager().incrementReferenceCount(store); 53} 54 55ProgramState::ProgramState(const ProgramState &RHS) 56 : llvm::FoldingSetNode(), 57 stateMgr(RHS.stateMgr), 58 Env(RHS.Env), 59 store(RHS.store), 60 GDM(RHS.GDM), 61 refCount(0) { 62 stateMgr->getStoreManager().incrementReferenceCount(store); 63} 64 65ProgramState::~ProgramState() { 66 if (store) 67 stateMgr->getStoreManager().decrementReferenceCount(store); 68} 69 70ProgramStateManager::ProgramStateManager(ASTContext &Ctx, 71 StoreManagerCreator CreateSMgr, 72 ConstraintManagerCreator CreateCMgr, 73 llvm::BumpPtrAllocator &alloc, 74 SubEngine *SubEng) 75 : Eng(SubEng), EnvMgr(alloc), GDMFactory(alloc), 76 svalBuilder(createSimpleSValBuilder(alloc, Ctx, *this)), 77 CallEventMgr(new CallEventManager(alloc)), Alloc(alloc) { 78 StoreMgr.reset((*CreateSMgr)(*this)); 79 ConstraintMgr.reset((*CreateCMgr)(*this, SubEng)); 80} 81 82 83ProgramStateManager::~ProgramStateManager() { 84 for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end(); 85 I!=E; ++I) 86 I->second.second(I->second.first); 87} 88 89ProgramStateRef 90ProgramStateManager::removeDeadBindings(ProgramStateRef state, 91 const StackFrameContext *LCtx, 92 SymbolReaper& SymReaper) { 93 94 // This code essentially performs a "mark-and-sweep" of the VariableBindings. 95 // The roots are any Block-level exprs and Decls that our liveness algorithm 96 // tells us are live. We then see what Decls they may reference, and keep 97 // those around. This code more than likely can be made faster, and the 98 // frequency of which this method is called should be experimented with 99 // for optimum performance. 100 ProgramState NewState = *state; 101 102 NewState.Env = EnvMgr.removeDeadBindings(NewState.Env, SymReaper, state); 103 104 // Clean up the store. 105 StoreRef newStore = StoreMgr->removeDeadBindings(NewState.getStore(), LCtx, 106 SymReaper); 107 NewState.setStore(newStore); 108 SymReaper.setReapedStore(newStore); 109 110 ProgramStateRef Result = getPersistentState(NewState); 111 return ConstraintMgr->removeDeadBindings(Result, SymReaper); 112} 113 114ProgramStateRef ProgramState::bindCompoundLiteral(const CompoundLiteralExpr *CL, 115 const LocationContext *LC, 116 SVal V) const { 117 const StoreRef &newStore = 118 getStateManager().StoreMgr->bindCompoundLiteral(getStore(), CL, LC, V); 119 return makeWithStore(newStore); 120} 121 122ProgramStateRef ProgramState::bindLoc(Loc LV, SVal V, bool notifyChanges) const { 123 ProgramStateManager &Mgr = getStateManager(); 124 ProgramStateRef newState = makeWithStore(Mgr.StoreMgr->Bind(getStore(), 125 LV, V)); 126 const MemRegion *MR = LV.getAsRegion(); 127 if (MR && Mgr.getOwningEngine() && notifyChanges) 128 return Mgr.getOwningEngine()->processRegionChange(newState, MR); 129 130 return newState; 131} 132 133ProgramStateRef ProgramState::bindDefault(SVal loc, SVal V) const { 134 ProgramStateManager &Mgr = getStateManager(); 135 const MemRegion *R = cast<loc::MemRegionVal>(loc).getRegion(); 136 const StoreRef &newStore = Mgr.StoreMgr->BindDefault(getStore(), R, V); 137 ProgramStateRef new_state = makeWithStore(newStore); 138 return Mgr.getOwningEngine() ? 139 Mgr.getOwningEngine()->processRegionChange(new_state, R) : 140 new_state; 141} 142 143ProgramStateRef 144ProgramState::invalidateRegions(ArrayRef<const MemRegion *> Regions, 145 const Expr *E, unsigned Count, 146 const LocationContext *LCtx, 147 StoreManager::InvalidatedSymbols *IS, 148 const CallEvent *Call) const { 149 if (!IS) { 150 StoreManager::InvalidatedSymbols invalidated; 151 return invalidateRegionsImpl(Regions, E, Count, LCtx, 152 invalidated, Call); 153 } 154 return invalidateRegionsImpl(Regions, E, Count, LCtx, *IS, Call); 155} 156 157ProgramStateRef 158ProgramState::invalidateRegionsImpl(ArrayRef<const MemRegion *> Regions, 159 const Expr *E, unsigned Count, 160 const LocationContext *LCtx, 161 StoreManager::InvalidatedSymbols &IS, 162 const CallEvent *Call) const { 163 ProgramStateManager &Mgr = getStateManager(); 164 SubEngine* Eng = Mgr.getOwningEngine(); 165 166 if (Eng && Eng->wantsRegionChangeUpdate(this)) { 167 StoreManager::InvalidatedRegions Invalidated; 168 const StoreRef &newStore 169 = Mgr.StoreMgr->invalidateRegions(getStore(), Regions, E, Count, LCtx, IS, 170 Call, &Invalidated); 171 ProgramStateRef newState = makeWithStore(newStore); 172 return Eng->processRegionChanges(newState, &IS, Regions, Invalidated, Call); 173 } 174 175 const StoreRef &newStore = 176 Mgr.StoreMgr->invalidateRegions(getStore(), Regions, E, Count, LCtx, IS, 177 Call, NULL); 178 return makeWithStore(newStore); 179} 180 181ProgramStateRef ProgramState::killBinding(Loc LV) const { 182 assert(!isa<loc::MemRegionVal>(LV) && "Use invalidateRegion instead."); 183 184 Store OldStore = getStore(); 185 const StoreRef &newStore = 186 getStateManager().StoreMgr->killBinding(OldStore, LV); 187 188 if (newStore.getStore() == OldStore) 189 return this; 190 191 return makeWithStore(newStore); 192} 193 194ProgramStateRef 195ProgramState::enterStackFrame(const CallEvent &Call, 196 const StackFrameContext *CalleeCtx) const { 197 const StoreRef &NewStore = 198 getStateManager().StoreMgr->enterStackFrame(getStore(), Call, CalleeCtx); 199 return makeWithStore(NewStore); 200} 201 202SVal ProgramState::getSValAsScalarOrLoc(const MemRegion *R) const { 203 // We only want to do fetches from regions that we can actually bind 204 // values. For example, SymbolicRegions of type 'id<...>' cannot 205 // have direct bindings (but their can be bindings on their subregions). 206 if (!R->isBoundable()) 207 return UnknownVal(); 208 209 if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) { 210 QualType T = TR->getValueType(); 211 if (Loc::isLocType(T) || T->isIntegerType()) 212 return getSVal(R); 213 } 214 215 return UnknownVal(); 216} 217 218SVal ProgramState::getSVal(Loc location, QualType T) const { 219 SVal V = getRawSVal(cast<Loc>(location), T); 220 221 // If 'V' is a symbolic value that is *perfectly* constrained to 222 // be a constant value, use that value instead to lessen the burden 223 // on later analysis stages (so we have less symbolic values to reason 224 // about). 225 if (!T.isNull()) { 226 if (SymbolRef sym = V.getAsSymbol()) { 227 if (const llvm::APSInt *Int = getStateManager() 228 .getConstraintManager() 229 .getSymVal(this, sym)) { 230 // FIXME: Because we don't correctly model (yet) sign-extension 231 // and truncation of symbolic values, we need to convert 232 // the integer value to the correct signedness and bitwidth. 233 // 234 // This shows up in the following: 235 // 236 // char foo(); 237 // unsigned x = foo(); 238 // if (x == 54) 239 // ... 240 // 241 // The symbolic value stored to 'x' is actually the conjured 242 // symbol for the call to foo(); the type of that symbol is 'char', 243 // not unsigned. 244 const llvm::APSInt &NewV = getBasicVals().Convert(T, *Int); 245 246 if (isa<Loc>(V)) 247 return loc::ConcreteInt(NewV); 248 else 249 return nonloc::ConcreteInt(NewV); 250 } 251 } 252 } 253 254 return V; 255} 256 257ProgramStateRef ProgramState::BindExpr(const Stmt *S, 258 const LocationContext *LCtx, 259 SVal V, bool Invalidate) const{ 260 Environment NewEnv = 261 getStateManager().EnvMgr.bindExpr(Env, EnvironmentEntry(S, LCtx), V, 262 Invalidate); 263 if (NewEnv == Env) 264 return this; 265 266 ProgramState NewSt = *this; 267 NewSt.Env = NewEnv; 268 return getStateManager().getPersistentState(NewSt); 269} 270 271ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx, 272 DefinedOrUnknownSVal UpperBound, 273 bool Assumption, 274 QualType indexTy) const { 275 if (Idx.isUnknown() || UpperBound.isUnknown()) 276 return this; 277 278 // Build an expression for 0 <= Idx < UpperBound. 279 // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed. 280 // FIXME: This should probably be part of SValBuilder. 281 ProgramStateManager &SM = getStateManager(); 282 SValBuilder &svalBuilder = SM.getSValBuilder(); 283 ASTContext &Ctx = svalBuilder.getContext(); 284 285 // Get the offset: the minimum value of the array index type. 286 BasicValueFactory &BVF = svalBuilder.getBasicValueFactory(); 287 // FIXME: This should be using ValueManager::ArrayindexTy...somehow. 288 if (indexTy.isNull()) 289 indexTy = Ctx.IntTy; 290 nonloc::ConcreteInt Min(BVF.getMinValue(indexTy)); 291 292 // Adjust the index. 293 SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add, 294 cast<NonLoc>(Idx), Min, indexTy); 295 if (newIdx.isUnknownOrUndef()) 296 return this; 297 298 // Adjust the upper bound. 299 SVal newBound = 300 svalBuilder.evalBinOpNN(this, BO_Add, cast<NonLoc>(UpperBound), 301 Min, indexTy); 302 303 if (newBound.isUnknownOrUndef()) 304 return this; 305 306 // Build the actual comparison. 307 SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, 308 cast<NonLoc>(newIdx), cast<NonLoc>(newBound), 309 Ctx.IntTy); 310 if (inBound.isUnknownOrUndef()) 311 return this; 312 313 // Finally, let the constraint manager take care of it. 314 ConstraintManager &CM = SM.getConstraintManager(); 315 return CM.assume(this, cast<DefinedSVal>(inBound), Assumption); 316} 317 318ProgramStateRef ProgramStateManager::getInitialState(const LocationContext *InitLoc) { 319 ProgramState State(this, 320 EnvMgr.getInitialEnvironment(), 321 StoreMgr->getInitialStore(InitLoc), 322 GDMFactory.getEmptyMap()); 323 324 return getPersistentState(State); 325} 326 327ProgramStateRef ProgramStateManager::getPersistentStateWithGDM( 328 ProgramStateRef FromState, 329 ProgramStateRef GDMState) { 330 ProgramState NewState(*FromState); 331 NewState.GDM = GDMState->GDM; 332 return getPersistentState(NewState); 333} 334 335ProgramStateRef ProgramStateManager::getPersistentState(ProgramState &State) { 336 337 llvm::FoldingSetNodeID ID; 338 State.Profile(ID); 339 void *InsertPos; 340 341 if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos)) 342 return I; 343 344 ProgramState *newState = 0; 345 if (!freeStates.empty()) { 346 newState = freeStates.back(); 347 freeStates.pop_back(); 348 } 349 else { 350 newState = (ProgramState*) Alloc.Allocate<ProgramState>(); 351 } 352 new (newState) ProgramState(State); 353 StateSet.InsertNode(newState, InsertPos); 354 return newState; 355} 356 357ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const { 358 ProgramState NewSt(*this); 359 NewSt.setStore(store); 360 return getStateManager().getPersistentState(NewSt); 361} 362 363void ProgramState::setStore(const StoreRef &newStore) { 364 Store newStoreStore = newStore.getStore(); 365 if (newStoreStore) 366 stateMgr->getStoreManager().incrementReferenceCount(newStoreStore); 367 if (store) 368 stateMgr->getStoreManager().decrementReferenceCount(store); 369 store = newStoreStore; 370} 371 372//===----------------------------------------------------------------------===// 373// State pretty-printing. 374//===----------------------------------------------------------------------===// 375 376void ProgramState::print(raw_ostream &Out, 377 const char *NL, const char *Sep) const { 378 // Print the store. 379 ProgramStateManager &Mgr = getStateManager(); 380 Mgr.getStoreManager().print(getStore(), Out, NL, Sep); 381 382 // Print out the environment. 383 Env.print(Out, NL, Sep); 384 385 // Print out the constraints. 386 Mgr.getConstraintManager().print(this, Out, NL, Sep); 387 388 // Print checker-specific data. 389 Mgr.getOwningEngine()->printState(Out, this, NL, Sep); 390} 391 392void ProgramState::printDOT(raw_ostream &Out) const { 393 print(Out, "\\l", "\\|"); 394} 395 396void ProgramState::dump() const { 397 print(llvm::errs()); 398} 399 400void ProgramState::printTaint(raw_ostream &Out, 401 const char *NL, const char *Sep) const { 402 TaintMapImpl TM = get<TaintMap>(); 403 404 if (!TM.isEmpty()) 405 Out <<"Tainted Symbols:" << NL; 406 407 for (TaintMapImpl::iterator I = TM.begin(), E = TM.end(); I != E; ++I) { 408 Out << I->first << " : " << I->second << NL; 409 } 410} 411 412void ProgramState::dumpTaint() const { 413 printTaint(llvm::errs()); 414} 415 416//===----------------------------------------------------------------------===// 417// Generic Data Map. 418//===----------------------------------------------------------------------===// 419 420void *const* ProgramState::FindGDM(void *K) const { 421 return GDM.lookup(K); 422} 423 424void* 425ProgramStateManager::FindGDMContext(void *K, 426 void *(*CreateContext)(llvm::BumpPtrAllocator&), 427 void (*DeleteContext)(void*)) { 428 429 std::pair<void*, void (*)(void*)>& p = GDMContexts[K]; 430 if (!p.first) { 431 p.first = CreateContext(Alloc); 432 p.second = DeleteContext; 433 } 434 435 return p.first; 436} 437 438ProgramStateRef ProgramStateManager::addGDM(ProgramStateRef St, void *Key, void *Data){ 439 ProgramState::GenericDataMap M1 = St->getGDM(); 440 ProgramState::GenericDataMap M2 = GDMFactory.add(M1, Key, Data); 441 442 if (M1 == M2) 443 return St; 444 445 ProgramState NewSt = *St; 446 NewSt.GDM = M2; 447 return getPersistentState(NewSt); 448} 449 450ProgramStateRef ProgramStateManager::removeGDM(ProgramStateRef state, void *Key) { 451 ProgramState::GenericDataMap OldM = state->getGDM(); 452 ProgramState::GenericDataMap NewM = GDMFactory.remove(OldM, Key); 453 454 if (NewM == OldM) 455 return state; 456 457 ProgramState NewState = *state; 458 NewState.GDM = NewM; 459 return getPersistentState(NewState); 460} 461 462bool ScanReachableSymbols::scan(nonloc::CompoundVal val) { 463 for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I) 464 if (!scan(*I)) 465 return false; 466 467 return true; 468} 469 470bool ScanReachableSymbols::scan(const SymExpr *sym) { 471 unsigned &isVisited = visited[sym]; 472 if (isVisited) 473 return true; 474 isVisited = 1; 475 476 if (!visitor.VisitSymbol(sym)) 477 return false; 478 479 // TODO: should be rewritten using SymExpr::symbol_iterator. 480 switch (sym->getKind()) { 481 case SymExpr::RegionValueKind: 482 case SymExpr::ConjuredKind: 483 case SymExpr::DerivedKind: 484 case SymExpr::ExtentKind: 485 case SymExpr::MetadataKind: 486 break; 487 case SymExpr::CastSymbolKind: 488 return scan(cast<SymbolCast>(sym)->getOperand()); 489 case SymExpr::SymIntKind: 490 return scan(cast<SymIntExpr>(sym)->getLHS()); 491 case SymExpr::IntSymKind: 492 return scan(cast<IntSymExpr>(sym)->getRHS()); 493 case SymExpr::SymSymKind: { 494 const SymSymExpr *x = cast<SymSymExpr>(sym); 495 return scan(x->getLHS()) && scan(x->getRHS()); 496 } 497 } 498 return true; 499} 500 501bool ScanReachableSymbols::scan(SVal val) { 502 if (loc::MemRegionVal *X = dyn_cast<loc::MemRegionVal>(&val)) 503 return scan(X->getRegion()); 504 505 if (nonloc::LazyCompoundVal *X = dyn_cast<nonloc::LazyCompoundVal>(&val)) 506 return scan(X->getRegion()); 507 508 if (nonloc::LocAsInteger *X = dyn_cast<nonloc::LocAsInteger>(&val)) 509 return scan(X->getLoc()); 510 511 if (SymbolRef Sym = val.getAsSymbol()) 512 return scan(Sym); 513 514 if (const SymExpr *Sym = val.getAsSymbolicExpression()) 515 return scan(Sym); 516 517 if (nonloc::CompoundVal *X = dyn_cast<nonloc::CompoundVal>(&val)) 518 return scan(*X); 519 520 return true; 521} 522 523bool ScanReachableSymbols::scan(const MemRegion *R) { 524 if (isa<MemSpaceRegion>(R)) 525 return true; 526 527 unsigned &isVisited = visited[R]; 528 if (isVisited) 529 return true; 530 isVisited = 1; 531 532 533 if (!visitor.VisitMemRegion(R)) 534 return false; 535 536 // If this is a symbolic region, visit the symbol for the region. 537 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 538 if (!visitor.VisitSymbol(SR->getSymbol())) 539 return false; 540 541 // If this is a subregion, also visit the parent regions. 542 if (const SubRegion *SR = dyn_cast<SubRegion>(R)) { 543 const MemRegion *Super = SR->getSuperRegion(); 544 if (!scan(Super)) 545 return false; 546 547 // When we reach the topmost region, scan all symbols in it. 548 if (isa<MemSpaceRegion>(Super)) { 549 StoreManager &StoreMgr = state->getStateManager().getStoreManager(); 550 if (!StoreMgr.scanReachableSymbols(state->getStore(), SR, *this)) 551 return false; 552 } 553 } 554 555 // Regions captured by a block are also implicitly reachable. 556 if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) { 557 BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), 558 E = BDR->referenced_vars_end(); 559 for ( ; I != E; ++I) { 560 if (!scan(I.getCapturedRegion())) 561 return false; 562 } 563 } 564 565 return true; 566} 567 568bool ProgramState::scanReachableSymbols(SVal val, SymbolVisitor& visitor) const { 569 ScanReachableSymbols S(this, visitor); 570 return S.scan(val); 571} 572 573bool ProgramState::scanReachableSymbols(const SVal *I, const SVal *E, 574 SymbolVisitor &visitor) const { 575 ScanReachableSymbols S(this, visitor); 576 for ( ; I != E; ++I) { 577 if (!S.scan(*I)) 578 return false; 579 } 580 return true; 581} 582 583bool ProgramState::scanReachableSymbols(const MemRegion * const *I, 584 const MemRegion * const *E, 585 SymbolVisitor &visitor) const { 586 ScanReachableSymbols S(this, visitor); 587 for ( ; I != E; ++I) { 588 if (!S.scan(*I)) 589 return false; 590 } 591 return true; 592} 593 594ProgramStateRef ProgramState::addTaint(const Stmt *S, 595 const LocationContext *LCtx, 596 TaintTagType Kind) const { 597 if (const Expr *E = dyn_cast_or_null<Expr>(S)) 598 S = E->IgnoreParens(); 599 600 SymbolRef Sym = getSVal(S, LCtx).getAsSymbol(); 601 if (Sym) 602 return addTaint(Sym, Kind); 603 604 const MemRegion *R = getSVal(S, LCtx).getAsRegion(); 605 addTaint(R, Kind); 606 607 // Cannot add taint, so just return the state. 608 return this; 609} 610 611ProgramStateRef ProgramState::addTaint(const MemRegion *R, 612 TaintTagType Kind) const { 613 if (const SymbolicRegion *SR = dyn_cast_or_null<SymbolicRegion>(R)) 614 return addTaint(SR->getSymbol(), Kind); 615 return this; 616} 617 618ProgramStateRef ProgramState::addTaint(SymbolRef Sym, 619 TaintTagType Kind) const { 620 // If this is a symbol cast, remove the cast before adding the taint. Taint 621 // is cast agnostic. 622 while (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) 623 Sym = SC->getOperand(); 624 625 ProgramStateRef NewState = set<TaintMap>(Sym, Kind); 626 assert(NewState); 627 return NewState; 628} 629 630bool ProgramState::isTainted(const Stmt *S, const LocationContext *LCtx, 631 TaintTagType Kind) const { 632 if (const Expr *E = dyn_cast_or_null<Expr>(S)) 633 S = E->IgnoreParens(); 634 635 SVal val = getSVal(S, LCtx); 636 return isTainted(val, Kind); 637} 638 639bool ProgramState::isTainted(SVal V, TaintTagType Kind) const { 640 if (const SymExpr *Sym = V.getAsSymExpr()) 641 return isTainted(Sym, Kind); 642 if (const MemRegion *Reg = V.getAsRegion()) 643 return isTainted(Reg, Kind); 644 return false; 645} 646 647bool ProgramState::isTainted(const MemRegion *Reg, TaintTagType K) const { 648 if (!Reg) 649 return false; 650 651 // Element region (array element) is tainted if either the base or the offset 652 // are tainted. 653 if (const ElementRegion *ER = dyn_cast<ElementRegion>(Reg)) 654 return isTainted(ER->getSuperRegion(), K) || isTainted(ER->getIndex(), K); 655 656 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) 657 return isTainted(SR->getSymbol(), K); 658 659 if (const SubRegion *ER = dyn_cast<SubRegion>(Reg)) 660 return isTainted(ER->getSuperRegion(), K); 661 662 return false; 663} 664 665bool ProgramState::isTainted(SymbolRef Sym, TaintTagType Kind) const { 666 if (!Sym) 667 return false; 668 669 // Traverse all the symbols this symbol depends on to see if any are tainted. 670 bool Tainted = false; 671 for (SymExpr::symbol_iterator SI = Sym->symbol_begin(), SE =Sym->symbol_end(); 672 SI != SE; ++SI) { 673 if (!isa<SymbolData>(*SI)) 674 continue; 675 676 const TaintTagType *Tag = get<TaintMap>(*SI); 677 Tainted = (Tag && *Tag == Kind); 678 679 // If this is a SymbolDerived with a tainted parent, it's also tainted. 680 if (const SymbolDerived *SD = dyn_cast<SymbolDerived>(*SI)) 681 Tainted = Tainted || isTainted(SD->getParentSymbol(), Kind); 682 683 // If memory region is tainted, data is also tainted. 684 if (const SymbolRegionValue *SRV = dyn_cast<SymbolRegionValue>(*SI)) 685 Tainted = Tainted || isTainted(SRV->getRegion(), Kind); 686 687 // If If this is a SymbolCast from a tainted value, it's also tainted. 688 if (const SymbolCast *SC = dyn_cast<SymbolCast>(*SI)) 689 Tainted = Tainted || isTainted(SC->getOperand(), Kind); 690 691 if (Tainted) 692 return true; 693 } 694 695 return Tainted; 696} 697 698/// The GDM component containing the dynamic type info. This is a map from a 699/// symbol to its most likely type. 700REGISTER_TRAIT_WITH_PROGRAMSTATE(DynamicTypeMap, 701 CLANG_ENTO_PROGRAMSTATE_MAP(const MemRegion *, 702 DynamicTypeInfo)) 703 704DynamicTypeInfo ProgramState::getDynamicTypeInfo(const MemRegion *Reg) const { 705 Reg = Reg->StripCasts(); 706 707 // Look up the dynamic type in the GDM. 708 const DynamicTypeInfo *GDMType = get<DynamicTypeMap>(Reg); 709 if (GDMType) 710 return *GDMType; 711 712 // Otherwise, fall back to what we know about the region. 713 if (const TypedRegion *TR = dyn_cast<TypedRegion>(Reg)) 714 return DynamicTypeInfo(TR->getLocationType(), /*CanBeSubclass=*/false); 715 716 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) { 717 SymbolRef Sym = SR->getSymbol(); 718 return DynamicTypeInfo(Sym->getType()); 719 } 720 721 return DynamicTypeInfo(); 722} 723 724ProgramStateRef ProgramState::setDynamicTypeInfo(const MemRegion *Reg, 725 DynamicTypeInfo NewTy) const { 726 Reg = Reg->StripCasts(); 727 ProgramStateRef NewState = set<DynamicTypeMap>(Reg, NewTy); 728 assert(NewState); 729 return NewState; 730} 731