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 22 using namespace clang; 23 using namespace ento; 24 25 namespace clang { namespace ento { 26 /// Increments the number of times this state is referenced. 27 28 void ProgramStateRetain(const ProgramState *state) { 29 ++const_cast<ProgramState*>(state)->refCount; 30 } 31 32 /// Decrement the number of times this state is referenced. 33 void 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 45 ProgramState::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 55 ProgramState::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 65 ProgramState::~ProgramState() { 66 if (store) 67 stateMgr->getStoreManager().decrementReferenceCount(store); 68 } 69 70 ProgramStateManager::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 83 ProgramStateManager::~ProgramStateManager() { 84 for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end(); 85 I!=E; ++I) 86 I->second.second(I->second.first); 87 } 88 89 ProgramStateRef 90 ProgramStateManager::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 } 113 114 ProgramStateRef 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 } 121 122 ProgramStateRef 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 } 132 133 ProgramStateRef ProgramState::bindDefault(SVal loc, SVal V) const { 134 ProgramStateManager &Mgr = getStateManager(); 135 const MemRegion *R = loc.castAs<loc::MemRegionVal>().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 } 142 143 ProgramStateRef 144 ProgramState::invalidateRegions(ArrayRef<const MemRegion *> Regions, 145 const Expr *E, unsigned Count, 146 const LocationContext *LCtx, 147 bool CausedByPointerEscape, 148 InvalidatedSymbols *IS, 149 const CallEvent *Call) const { 150 if (!IS) { 151 InvalidatedSymbols invalidated; 152 return invalidateRegionsImpl(Regions, E, Count, LCtx, 153 CausedByPointerEscape, 154 invalidated, Call); 155 } 156 return invalidateRegionsImpl(Regions, E, Count, LCtx, CausedByPointerEscape, 157 *IS, Call); 158 } 159 160 ProgramStateRef 161 ProgramState::invalidateRegionsImpl(ArrayRef<const MemRegion *> Regions, 162 const Expr *E, unsigned Count, 163 const LocationContext *LCtx, 164 bool CausedByPointerEscape, 165 InvalidatedSymbols &IS, 166 const CallEvent *Call) const { 167 ProgramStateManager &Mgr = getStateManager(); 168 SubEngine* Eng = Mgr.getOwningEngine(); 169 170 if (Eng) { 171 StoreManager::InvalidatedRegions Invalidated; 172 const StoreRef &newStore 173 = Mgr.StoreMgr->invalidateRegions(getStore(), Regions, E, Count, LCtx, IS, 174 Call, &Invalidated); 175 176 ProgramStateRef newState = makeWithStore(newStore); 177 178 if (CausedByPointerEscape) 179 newState = Eng->processPointerEscapedOnInvalidateRegions(newState, 180 &IS, Regions, Invalidated, Call); 181 182 return Eng->processRegionChanges(newState, &IS, Regions, Invalidated, Call); 183 } 184 185 const StoreRef &newStore = 186 Mgr.StoreMgr->invalidateRegions(getStore(), Regions, E, Count, LCtx, IS, 187 Call, NULL); 188 return makeWithStore(newStore); 189 } 190 191 ProgramStateRef ProgramState::killBinding(Loc LV) const { 192 assert(!LV.getAs<loc::MemRegionVal>() && "Use invalidateRegion instead."); 193 194 Store OldStore = getStore(); 195 const StoreRef &newStore = 196 getStateManager().StoreMgr->killBinding(OldStore, LV); 197 198 if (newStore.getStore() == OldStore) 199 return this; 200 201 return makeWithStore(newStore); 202 } 203 204 ProgramStateRef 205 ProgramState::enterStackFrame(const CallEvent &Call, 206 const StackFrameContext *CalleeCtx) const { 207 const StoreRef &NewStore = 208 getStateManager().StoreMgr->enterStackFrame(getStore(), Call, CalleeCtx); 209 return makeWithStore(NewStore); 210 } 211 212 SVal ProgramState::getSValAsScalarOrLoc(const MemRegion *R) const { 213 // We only want to do fetches from regions that we can actually bind 214 // values. For example, SymbolicRegions of type 'id<...>' cannot 215 // have direct bindings (but their can be bindings on their subregions). 216 if (!R->isBoundable()) 217 return UnknownVal(); 218 219 if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) { 220 QualType T = TR->getValueType(); 221 if (Loc::isLocType(T) || T->isIntegerType()) 222 return getSVal(R); 223 } 224 225 return UnknownVal(); 226 } 227 228 SVal ProgramState::getSVal(Loc location, QualType T) const { 229 SVal V = getRawSVal(cast<Loc>(location), T); 230 231 // If 'V' is a symbolic value that is *perfectly* constrained to 232 // be a constant value, use that value instead to lessen the burden 233 // on later analysis stages (so we have less symbolic values to reason 234 // about). 235 if (!T.isNull()) { 236 if (SymbolRef sym = V.getAsSymbol()) { 237 if (const llvm::APSInt *Int = getStateManager() 238 .getConstraintManager() 239 .getSymVal(this, sym)) { 240 // FIXME: Because we don't correctly model (yet) sign-extension 241 // and truncation of symbolic values, we need to convert 242 // the integer value to the correct signedness and bitwidth. 243 // 244 // This shows up in the following: 245 // 246 // char foo(); 247 // unsigned x = foo(); 248 // if (x == 54) 249 // ... 250 // 251 // The symbolic value stored to 'x' is actually the conjured 252 // symbol for the call to foo(); the type of that symbol is 'char', 253 // not unsigned. 254 const llvm::APSInt &NewV = getBasicVals().Convert(T, *Int); 255 256 if (V.getAs<Loc>()) 257 return loc::ConcreteInt(NewV); 258 else 259 return nonloc::ConcreteInt(NewV); 260 } 261 } 262 } 263 264 return V; 265 } 266 267 ProgramStateRef ProgramState::BindExpr(const Stmt *S, 268 const LocationContext *LCtx, 269 SVal V, bool Invalidate) const{ 270 Environment NewEnv = 271 getStateManager().EnvMgr.bindExpr(Env, EnvironmentEntry(S, LCtx), V, 272 Invalidate); 273 if (NewEnv == Env) 274 return this; 275 276 ProgramState NewSt = *this; 277 NewSt.Env = NewEnv; 278 return getStateManager().getPersistentState(NewSt); 279 } 280 281 ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx, 282 DefinedOrUnknownSVal UpperBound, 283 bool Assumption, 284 QualType indexTy) const { 285 if (Idx.isUnknown() || UpperBound.isUnknown()) 286 return this; 287 288 // Build an expression for 0 <= Idx < UpperBound. 289 // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed. 290 // FIXME: This should probably be part of SValBuilder. 291 ProgramStateManager &SM = getStateManager(); 292 SValBuilder &svalBuilder = SM.getSValBuilder(); 293 ASTContext &Ctx = svalBuilder.getContext(); 294 295 // Get the offset: the minimum value of the array index type. 296 BasicValueFactory &BVF = svalBuilder.getBasicValueFactory(); 297 // FIXME: This should be using ValueManager::ArrayindexTy...somehow. 298 if (indexTy.isNull()) 299 indexTy = Ctx.IntTy; 300 nonloc::ConcreteInt Min(BVF.getMinValue(indexTy)); 301 302 // Adjust the index. 303 SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add, 304 Idx.castAs<NonLoc>(), Min, indexTy); 305 if (newIdx.isUnknownOrUndef()) 306 return this; 307 308 // Adjust the upper bound. 309 SVal newBound = 310 svalBuilder.evalBinOpNN(this, BO_Add, UpperBound.castAs<NonLoc>(), 311 Min, indexTy); 312 313 if (newBound.isUnknownOrUndef()) 314 return this; 315 316 // Build the actual comparison. 317 SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, newIdx.castAs<NonLoc>(), 318 newBound.castAs<NonLoc>(), Ctx.IntTy); 319 if (inBound.isUnknownOrUndef()) 320 return this; 321 322 // Finally, let the constraint manager take care of it. 323 ConstraintManager &CM = SM.getConstraintManager(); 324 return CM.assume(this, inBound.castAs<DefinedSVal>(), Assumption); 325 } 326 327 ConditionTruthVal ProgramState::isNull(SVal V) const { 328 if (V.isZeroConstant()) 329 return true; 330 331 SymbolRef Sym = V.getAsSymbol(); 332 if (!Sym) 333 return false; 334 return getStateManager().ConstraintMgr->isNull(this, Sym); 335 } 336 337 ProgramStateRef ProgramStateManager::getInitialState(const LocationContext *InitLoc) { 338 ProgramState State(this, 339 EnvMgr.getInitialEnvironment(), 340 StoreMgr->getInitialStore(InitLoc), 341 GDMFactory.getEmptyMap()); 342 343 return getPersistentState(State); 344 } 345 346 ProgramStateRef ProgramStateManager::getPersistentStateWithGDM( 347 ProgramStateRef FromState, 348 ProgramStateRef GDMState) { 349 ProgramState NewState(*FromState); 350 NewState.GDM = GDMState->GDM; 351 return getPersistentState(NewState); 352 } 353 354 ProgramStateRef ProgramStateManager::getPersistentState(ProgramState &State) { 355 356 llvm::FoldingSetNodeID ID; 357 State.Profile(ID); 358 void *InsertPos; 359 360 if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos)) 361 return I; 362 363 ProgramState *newState = 0; 364 if (!freeStates.empty()) { 365 newState = freeStates.back(); 366 freeStates.pop_back(); 367 } 368 else { 369 newState = (ProgramState*) Alloc.Allocate<ProgramState>(); 370 } 371 new (newState) ProgramState(State); 372 StateSet.InsertNode(newState, InsertPos); 373 return newState; 374 } 375 376 ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const { 377 ProgramState NewSt(*this); 378 NewSt.setStore(store); 379 return getStateManager().getPersistentState(NewSt); 380 } 381 382 void ProgramState::setStore(const StoreRef &newStore) { 383 Store newStoreStore = newStore.getStore(); 384 if (newStoreStore) 385 stateMgr->getStoreManager().incrementReferenceCount(newStoreStore); 386 if (store) 387 stateMgr->getStoreManager().decrementReferenceCount(store); 388 store = newStoreStore; 389 } 390 391 //===----------------------------------------------------------------------===// 392 // State pretty-printing. 393 //===----------------------------------------------------------------------===// 394 395 void ProgramState::print(raw_ostream &Out, 396 const char *NL, const char *Sep) const { 397 // Print the store. 398 ProgramStateManager &Mgr = getStateManager(); 399 Mgr.getStoreManager().print(getStore(), Out, NL, Sep); 400 401 // Print out the environment. 402 Env.print(Out, NL, Sep); 403 404 // Print out the constraints. 405 Mgr.getConstraintManager().print(this, Out, NL, Sep); 406 407 // Print checker-specific data. 408 Mgr.getOwningEngine()->printState(Out, this, NL, Sep); 409 } 410 411 void ProgramState::printDOT(raw_ostream &Out) const { 412 print(Out, "\\l", "\\|"); 413 } 414 415 void ProgramState::dump() const { 416 print(llvm::errs()); 417 } 418 419 void ProgramState::printTaint(raw_ostream &Out, 420 const char *NL, const char *Sep) const { 421 TaintMapImpl TM = get<TaintMap>(); 422 423 if (!TM.isEmpty()) 424 Out <<"Tainted Symbols:" << NL; 425 426 for (TaintMapImpl::iterator I = TM.begin(), E = TM.end(); I != E; ++I) { 427 Out << I->first << " : " << I->second << NL; 428 } 429 } 430 431 void ProgramState::dumpTaint() const { 432 printTaint(llvm::errs()); 433 } 434 435 //===----------------------------------------------------------------------===// 436 // Generic Data Map. 437 //===----------------------------------------------------------------------===// 438 439 void *const* ProgramState::FindGDM(void *K) const { 440 return GDM.lookup(K); 441 } 442 443 void* 444 ProgramStateManager::FindGDMContext(void *K, 445 void *(*CreateContext)(llvm::BumpPtrAllocator&), 446 void (*DeleteContext)(void*)) { 447 448 std::pair<void*, void (*)(void*)>& p = GDMContexts[K]; 449 if (!p.first) { 450 p.first = CreateContext(Alloc); 451 p.second = DeleteContext; 452 } 453 454 return p.first; 455 } 456 457 ProgramStateRef ProgramStateManager::addGDM(ProgramStateRef St, void *Key, void *Data){ 458 ProgramState::GenericDataMap M1 = St->getGDM(); 459 ProgramState::GenericDataMap M2 = GDMFactory.add(M1, Key, Data); 460 461 if (M1 == M2) 462 return St; 463 464 ProgramState NewSt = *St; 465 NewSt.GDM = M2; 466 return getPersistentState(NewSt); 467 } 468 469 ProgramStateRef ProgramStateManager::removeGDM(ProgramStateRef state, void *Key) { 470 ProgramState::GenericDataMap OldM = state->getGDM(); 471 ProgramState::GenericDataMap NewM = GDMFactory.remove(OldM, Key); 472 473 if (NewM == OldM) 474 return state; 475 476 ProgramState NewState = *state; 477 NewState.GDM = NewM; 478 return getPersistentState(NewState); 479 } 480 481 bool ScanReachableSymbols::scan(nonloc::CompoundVal val) { 482 for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I) 483 if (!scan(*I)) 484 return false; 485 486 return true; 487 } 488 489 bool ScanReachableSymbols::scan(const SymExpr *sym) { 490 unsigned &isVisited = visited[sym]; 491 if (isVisited) 492 return true; 493 isVisited = 1; 494 495 if (!visitor.VisitSymbol(sym)) 496 return false; 497 498 // TODO: should be rewritten using SymExpr::symbol_iterator. 499 switch (sym->getKind()) { 500 case SymExpr::RegionValueKind: 501 case SymExpr::ConjuredKind: 502 case SymExpr::DerivedKind: 503 case SymExpr::ExtentKind: 504 case SymExpr::MetadataKind: 505 break; 506 case SymExpr::CastSymbolKind: 507 return scan(cast<SymbolCast>(sym)->getOperand()); 508 case SymExpr::SymIntKind: 509 return scan(cast<SymIntExpr>(sym)->getLHS()); 510 case SymExpr::IntSymKind: 511 return scan(cast<IntSymExpr>(sym)->getRHS()); 512 case SymExpr::SymSymKind: { 513 const SymSymExpr *x = cast<SymSymExpr>(sym); 514 return scan(x->getLHS()) && scan(x->getRHS()); 515 } 516 } 517 return true; 518 } 519 520 bool ScanReachableSymbols::scan(SVal val) { 521 if (Optional<loc::MemRegionVal> X = val.getAs<loc::MemRegionVal>()) 522 return scan(X->getRegion()); 523 524 if (Optional<nonloc::LazyCompoundVal> X = 525 val.getAs<nonloc::LazyCompoundVal>()) { 526 StoreManager &StoreMgr = state->getStateManager().getStoreManager(); 527 // FIXME: We don't really want to use getBaseRegion() here because pointer 528 // arithmetic doesn't apply, but scanReachableSymbols only accepts base 529 // regions right now. 530 if (!StoreMgr.scanReachableSymbols(X->getStore(), 531 X->getRegion()->getBaseRegion(), 532 *this)) 533 return false; 534 } 535 536 if (Optional<nonloc::LocAsInteger> X = val.getAs<nonloc::LocAsInteger>()) 537 return scan(X->getLoc()); 538 539 if (SymbolRef Sym = val.getAsSymbol()) 540 return scan(Sym); 541 542 if (const SymExpr *Sym = val.getAsSymbolicExpression()) 543 return scan(Sym); 544 545 if (Optional<nonloc::CompoundVal> X = val.getAs<nonloc::CompoundVal>()) 546 return scan(*X); 547 548 return true; 549 } 550 551 bool ScanReachableSymbols::scan(const MemRegion *R) { 552 if (isa<MemSpaceRegion>(R)) 553 return true; 554 555 unsigned &isVisited = visited[R]; 556 if (isVisited) 557 return true; 558 isVisited = 1; 559 560 561 if (!visitor.VisitMemRegion(R)) 562 return false; 563 564 // If this is a symbolic region, visit the symbol for the region. 565 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 566 if (!visitor.VisitSymbol(SR->getSymbol())) 567 return false; 568 569 // If this is a subregion, also visit the parent regions. 570 if (const SubRegion *SR = dyn_cast<SubRegion>(R)) { 571 const MemRegion *Super = SR->getSuperRegion(); 572 if (!scan(Super)) 573 return false; 574 575 // When we reach the topmost region, scan all symbols in it. 576 if (isa<MemSpaceRegion>(Super)) { 577 StoreManager &StoreMgr = state->getStateManager().getStoreManager(); 578 if (!StoreMgr.scanReachableSymbols(state->getStore(), SR, *this)) 579 return false; 580 } 581 } 582 583 // Regions captured by a block are also implicitly reachable. 584 if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) { 585 BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), 586 E = BDR->referenced_vars_end(); 587 for ( ; I != E; ++I) { 588 if (!scan(I.getCapturedRegion())) 589 return false; 590 } 591 } 592 593 return true; 594 } 595 596 bool ProgramState::scanReachableSymbols(SVal val, SymbolVisitor& visitor) const { 597 ScanReachableSymbols S(this, visitor); 598 return S.scan(val); 599 } 600 601 bool ProgramState::scanReachableSymbols(const SVal *I, const SVal *E, 602 SymbolVisitor &visitor) const { 603 ScanReachableSymbols S(this, visitor); 604 for ( ; I != E; ++I) { 605 if (!S.scan(*I)) 606 return false; 607 } 608 return true; 609 } 610 611 bool ProgramState::scanReachableSymbols(const MemRegion * const *I, 612 const MemRegion * const *E, 613 SymbolVisitor &visitor) const { 614 ScanReachableSymbols S(this, visitor); 615 for ( ; I != E; ++I) { 616 if (!S.scan(*I)) 617 return false; 618 } 619 return true; 620 } 621 622 ProgramStateRef ProgramState::addTaint(const Stmt *S, 623 const LocationContext *LCtx, 624 TaintTagType Kind) const { 625 if (const Expr *E = dyn_cast_or_null<Expr>(S)) 626 S = E->IgnoreParens(); 627 628 SymbolRef Sym = getSVal(S, LCtx).getAsSymbol(); 629 if (Sym) 630 return addTaint(Sym, Kind); 631 632 const MemRegion *R = getSVal(S, LCtx).getAsRegion(); 633 addTaint(R, Kind); 634 635 // Cannot add taint, so just return the state. 636 return this; 637 } 638 639 ProgramStateRef ProgramState::addTaint(const MemRegion *R, 640 TaintTagType Kind) const { 641 if (const SymbolicRegion *SR = dyn_cast_or_null<SymbolicRegion>(R)) 642 return addTaint(SR->getSymbol(), Kind); 643 return this; 644 } 645 646 ProgramStateRef ProgramState::addTaint(SymbolRef Sym, 647 TaintTagType Kind) const { 648 // If this is a symbol cast, remove the cast before adding the taint. Taint 649 // is cast agnostic. 650 while (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) 651 Sym = SC->getOperand(); 652 653 ProgramStateRef NewState = set<TaintMap>(Sym, Kind); 654 assert(NewState); 655 return NewState; 656 } 657 658 bool ProgramState::isTainted(const Stmt *S, const LocationContext *LCtx, 659 TaintTagType Kind) const { 660 if (const Expr *E = dyn_cast_or_null<Expr>(S)) 661 S = E->IgnoreParens(); 662 663 SVal val = getSVal(S, LCtx); 664 return isTainted(val, Kind); 665 } 666 667 bool ProgramState::isTainted(SVal V, TaintTagType Kind) const { 668 if (const SymExpr *Sym = V.getAsSymExpr()) 669 return isTainted(Sym, Kind); 670 if (const MemRegion *Reg = V.getAsRegion()) 671 return isTainted(Reg, Kind); 672 return false; 673 } 674 675 bool ProgramState::isTainted(const MemRegion *Reg, TaintTagType K) const { 676 if (!Reg) 677 return false; 678 679 // Element region (array element) is tainted if either the base or the offset 680 // are tainted. 681 if (const ElementRegion *ER = dyn_cast<ElementRegion>(Reg)) 682 return isTainted(ER->getSuperRegion(), K) || isTainted(ER->getIndex(), K); 683 684 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) 685 return isTainted(SR->getSymbol(), K); 686 687 if (const SubRegion *ER = dyn_cast<SubRegion>(Reg)) 688 return isTainted(ER->getSuperRegion(), K); 689 690 return false; 691 } 692 693 bool ProgramState::isTainted(SymbolRef Sym, TaintTagType Kind) const { 694 if (!Sym) 695 return false; 696 697 // Traverse all the symbols this symbol depends on to see if any are tainted. 698 bool Tainted = false; 699 for (SymExpr::symbol_iterator SI = Sym->symbol_begin(), SE =Sym->symbol_end(); 700 SI != SE; ++SI) { 701 if (!isa<SymbolData>(*SI)) 702 continue; 703 704 const TaintTagType *Tag = get<TaintMap>(*SI); 705 Tainted = (Tag && *Tag == Kind); 706 707 // If this is a SymbolDerived with a tainted parent, it's also tainted. 708 if (const SymbolDerived *SD = dyn_cast<SymbolDerived>(*SI)) 709 Tainted = Tainted || isTainted(SD->getParentSymbol(), Kind); 710 711 // If memory region is tainted, data is also tainted. 712 if (const SymbolRegionValue *SRV = dyn_cast<SymbolRegionValue>(*SI)) 713 Tainted = Tainted || isTainted(SRV->getRegion(), Kind); 714 715 // If If this is a SymbolCast from a tainted value, it's also tainted. 716 if (const SymbolCast *SC = dyn_cast<SymbolCast>(*SI)) 717 Tainted = Tainted || isTainted(SC->getOperand(), Kind); 718 719 if (Tainted) 720 return true; 721 } 722 723 return Tainted; 724 } 725 726 /// The GDM component containing the dynamic type info. This is a map from a 727 /// symbol to its most likely type. 728 REGISTER_TRAIT_WITH_PROGRAMSTATE(DynamicTypeMap, 729 CLANG_ENTO_PROGRAMSTATE_MAP(const MemRegion *, 730 DynamicTypeInfo)) 731 732 DynamicTypeInfo ProgramState::getDynamicTypeInfo(const MemRegion *Reg) const { 733 Reg = Reg->StripCasts(); 734 735 // Look up the dynamic type in the GDM. 736 const DynamicTypeInfo *GDMType = get<DynamicTypeMap>(Reg); 737 if (GDMType) 738 return *GDMType; 739 740 // Otherwise, fall back to what we know about the region. 741 if (const TypedRegion *TR = dyn_cast<TypedRegion>(Reg)) 742 return DynamicTypeInfo(TR->getLocationType(), /*CanBeSubclass=*/false); 743 744 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) { 745 SymbolRef Sym = SR->getSymbol(); 746 return DynamicTypeInfo(Sym->getType()); 747 } 748 749 return DynamicTypeInfo(); 750 } 751 752 ProgramStateRef ProgramState::setDynamicTypeInfo(const MemRegion *Reg, 753 DynamicTypeInfo NewTy) const { 754 Reg = Reg->StripCasts(); 755 ProgramStateRef NewState = set<DynamicTypeMap>(Reg, NewTy); 756 assert(NewState); 757 return NewState; 758 } 759