1 //= ProgramState.cpp - Path-Sensitive "State" for tracking values --*- C++ -*--= 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements ProgramState and ProgramStateManager. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 14 #include "clang/Analysis/CFG.h" 15 #include "clang/Basic/JsonSupport.h" 16 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" 17 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 18 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicType.h" 19 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 20 #include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h" 21 #include "llvm/Support/raw_ostream.h" 22 23 using namespace clang; 24 using namespace ento; 25 26 namespace clang { namespace ento { 27 /// Increments the number of times this state is referenced. 28 29 void ProgramStateRetain(const ProgramState *state) { 30 ++const_cast<ProgramState*>(state)->refCount; 31 } 32 33 /// Decrement the number of times this state is referenced. 34 void ProgramStateRelease(const ProgramState *state) { 35 assert(state->refCount > 0); 36 ProgramState *s = const_cast<ProgramState*>(state); 37 if (--s->refCount == 0) { 38 ProgramStateManager &Mgr = s->getStateManager(); 39 Mgr.StateSet.RemoveNode(s); 40 s->~ProgramState(); 41 Mgr.freeStates.push_back(s); 42 } 43 } 44 }} 45 46 ProgramState::ProgramState(ProgramStateManager *mgr, const Environment& env, 47 StoreRef st, GenericDataMap gdm) 48 : stateMgr(mgr), 49 Env(env), 50 store(st.getStore()), 51 GDM(gdm), 52 refCount(0) { 53 stateMgr->getStoreManager().incrementReferenceCount(store); 54 } 55 56 ProgramState::ProgramState(const ProgramState &RHS) 57 : llvm::FoldingSetNode(), 58 stateMgr(RHS.stateMgr), 59 Env(RHS.Env), 60 store(RHS.store), 61 GDM(RHS.GDM), 62 refCount(0) { 63 stateMgr->getStoreManager().incrementReferenceCount(store); 64 } 65 66 ProgramState::~ProgramState() { 67 if (store) 68 stateMgr->getStoreManager().decrementReferenceCount(store); 69 } 70 71 int64_t ProgramState::getID() const { 72 return getStateManager().Alloc.identifyKnownAlignedObject<ProgramState>(this); 73 } 74 75 ProgramStateManager::ProgramStateManager(ASTContext &Ctx, 76 StoreManagerCreator CreateSMgr, 77 ConstraintManagerCreator CreateCMgr, 78 llvm::BumpPtrAllocator &alloc, 79 SubEngine *SubEng) 80 : Eng(SubEng), EnvMgr(alloc), GDMFactory(alloc), 81 svalBuilder(createSimpleSValBuilder(alloc, Ctx, *this)), 82 CallEventMgr(new CallEventManager(alloc)), Alloc(alloc) { 83 StoreMgr = (*CreateSMgr)(*this); 84 ConstraintMgr = (*CreateCMgr)(*this, SubEng); 85 } 86 87 88 ProgramStateManager::~ProgramStateManager() { 89 for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end(); 90 I!=E; ++I) 91 I->second.second(I->second.first); 92 } 93 94 ProgramStateRef 95 ProgramStateManager::removeDeadBindings(ProgramStateRef state, 96 const StackFrameContext *LCtx, 97 SymbolReaper& SymReaper) { 98 99 // This code essentially performs a "mark-and-sweep" of the VariableBindings. 100 // The roots are any Block-level exprs and Decls that our liveness algorithm 101 // tells us are live. We then see what Decls they may reference, and keep 102 // those around. This code more than likely can be made faster, and the 103 // frequency of which this method is called should be experimented with 104 // for optimum performance. 105 ProgramState NewState = *state; 106 107 NewState.Env = EnvMgr.removeDeadBindings(NewState.Env, SymReaper, state); 108 109 // Clean up the store. 110 StoreRef newStore = StoreMgr->removeDeadBindings(NewState.getStore(), LCtx, 111 SymReaper); 112 NewState.setStore(newStore); 113 SymReaper.setReapedStore(newStore); 114 115 ProgramStateRef Result = getPersistentState(NewState); 116 return ConstraintMgr->removeDeadBindings(Result, SymReaper); 117 } 118 119 ProgramStateRef ProgramState::bindLoc(Loc LV, 120 SVal V, 121 const LocationContext *LCtx, 122 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 && notifyChanges) 128 return Mgr.getOwningEngine().processRegionChange(newState, MR, LCtx); 129 130 return newState; 131 } 132 133 ProgramStateRef 134 ProgramState::bindDefaultInitial(SVal loc, SVal V, 135 const LocationContext *LCtx) const { 136 ProgramStateManager &Mgr = getStateManager(); 137 const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion(); 138 const StoreRef &newStore = Mgr.StoreMgr->BindDefaultInitial(getStore(), R, V); 139 ProgramStateRef new_state = makeWithStore(newStore); 140 return Mgr.getOwningEngine().processRegionChange(new_state, R, LCtx); 141 } 142 143 ProgramStateRef 144 ProgramState::bindDefaultZero(SVal loc, const LocationContext *LCtx) const { 145 ProgramStateManager &Mgr = getStateManager(); 146 const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion(); 147 const StoreRef &newStore = Mgr.StoreMgr->BindDefaultZero(getStore(), R); 148 ProgramStateRef new_state = makeWithStore(newStore); 149 return Mgr.getOwningEngine().processRegionChange(new_state, R, LCtx); 150 } 151 152 typedef ArrayRef<const MemRegion *> RegionList; 153 typedef ArrayRef<SVal> ValueList; 154 155 ProgramStateRef 156 ProgramState::invalidateRegions(RegionList Regions, 157 const Expr *E, unsigned Count, 158 const LocationContext *LCtx, 159 bool CausedByPointerEscape, 160 InvalidatedSymbols *IS, 161 const CallEvent *Call, 162 RegionAndSymbolInvalidationTraits *ITraits) const { 163 SmallVector<SVal, 8> Values; 164 for (RegionList::const_iterator I = Regions.begin(), 165 End = Regions.end(); I != End; ++I) 166 Values.push_back(loc::MemRegionVal(*I)); 167 168 return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape, 169 IS, ITraits, Call); 170 } 171 172 ProgramStateRef 173 ProgramState::invalidateRegions(ValueList Values, 174 const Expr *E, unsigned Count, 175 const LocationContext *LCtx, 176 bool CausedByPointerEscape, 177 InvalidatedSymbols *IS, 178 const CallEvent *Call, 179 RegionAndSymbolInvalidationTraits *ITraits) const { 180 181 return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape, 182 IS, ITraits, Call); 183 } 184 185 ProgramStateRef 186 ProgramState::invalidateRegionsImpl(ValueList Values, 187 const Expr *E, unsigned Count, 188 const LocationContext *LCtx, 189 bool CausedByPointerEscape, 190 InvalidatedSymbols *IS, 191 RegionAndSymbolInvalidationTraits *ITraits, 192 const CallEvent *Call) const { 193 ProgramStateManager &Mgr = getStateManager(); 194 SubEngine &Eng = Mgr.getOwningEngine(); 195 196 InvalidatedSymbols InvalidatedSyms; 197 if (!IS) 198 IS = &InvalidatedSyms; 199 200 RegionAndSymbolInvalidationTraits ITraitsLocal; 201 if (!ITraits) 202 ITraits = &ITraitsLocal; 203 204 StoreManager::InvalidatedRegions TopLevelInvalidated; 205 StoreManager::InvalidatedRegions Invalidated; 206 const StoreRef &newStore 207 = Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call, 208 *IS, *ITraits, &TopLevelInvalidated, 209 &Invalidated); 210 211 ProgramStateRef newState = makeWithStore(newStore); 212 213 if (CausedByPointerEscape) { 214 newState = Eng.notifyCheckersOfPointerEscape(newState, IS, 215 TopLevelInvalidated, 216 Call, 217 *ITraits); 218 } 219 220 return Eng.processRegionChanges(newState, IS, TopLevelInvalidated, 221 Invalidated, LCtx, Call); 222 } 223 224 ProgramStateRef ProgramState::killBinding(Loc LV) const { 225 assert(!LV.getAs<loc::MemRegionVal>() && "Use invalidateRegion instead."); 226 227 Store OldStore = getStore(); 228 const StoreRef &newStore = 229 getStateManager().StoreMgr->killBinding(OldStore, LV); 230 231 if (newStore.getStore() == OldStore) 232 return this; 233 234 return makeWithStore(newStore); 235 } 236 237 ProgramStateRef 238 ProgramState::enterStackFrame(const CallEvent &Call, 239 const StackFrameContext *CalleeCtx) const { 240 const StoreRef &NewStore = 241 getStateManager().StoreMgr->enterStackFrame(getStore(), Call, CalleeCtx); 242 return makeWithStore(NewStore); 243 } 244 245 SVal ProgramState::getSValAsScalarOrLoc(const MemRegion *R) const { 246 // We only want to do fetches from regions that we can actually bind 247 // values. For example, SymbolicRegions of type 'id<...>' cannot 248 // have direct bindings (but their can be bindings on their subregions). 249 if (!R->isBoundable()) 250 return UnknownVal(); 251 252 if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) { 253 QualType T = TR->getValueType(); 254 if (Loc::isLocType(T) || T->isIntegralOrEnumerationType()) 255 return getSVal(R); 256 } 257 258 return UnknownVal(); 259 } 260 261 SVal ProgramState::getSVal(Loc location, QualType T) const { 262 SVal V = getRawSVal(location, T); 263 264 // If 'V' is a symbolic value that is *perfectly* constrained to 265 // be a constant value, use that value instead to lessen the burden 266 // on later analysis stages (so we have less symbolic values to reason 267 // about). 268 // We only go into this branch if we can convert the APSInt value we have 269 // to the type of T, which is not always the case (e.g. for void). 270 if (!T.isNull() && (T->isIntegralOrEnumerationType() || Loc::isLocType(T))) { 271 if (SymbolRef sym = V.getAsSymbol()) { 272 if (const llvm::APSInt *Int = getStateManager() 273 .getConstraintManager() 274 .getSymVal(this, sym)) { 275 // FIXME: Because we don't correctly model (yet) sign-extension 276 // and truncation of symbolic values, we need to convert 277 // the integer value to the correct signedness and bitwidth. 278 // 279 // This shows up in the following: 280 // 281 // char foo(); 282 // unsigned x = foo(); 283 // if (x == 54) 284 // ... 285 // 286 // The symbolic value stored to 'x' is actually the conjured 287 // symbol for the call to foo(); the type of that symbol is 'char', 288 // not unsigned. 289 const llvm::APSInt &NewV = getBasicVals().Convert(T, *Int); 290 291 if (V.getAs<Loc>()) 292 return loc::ConcreteInt(NewV); 293 else 294 return nonloc::ConcreteInt(NewV); 295 } 296 } 297 } 298 299 return V; 300 } 301 302 ProgramStateRef ProgramState::BindExpr(const Stmt *S, 303 const LocationContext *LCtx, 304 SVal V, bool Invalidate) const{ 305 Environment NewEnv = 306 getStateManager().EnvMgr.bindExpr(Env, EnvironmentEntry(S, LCtx), V, 307 Invalidate); 308 if (NewEnv == Env) 309 return this; 310 311 ProgramState NewSt = *this; 312 NewSt.Env = NewEnv; 313 return getStateManager().getPersistentState(NewSt); 314 } 315 316 ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx, 317 DefinedOrUnknownSVal UpperBound, 318 bool Assumption, 319 QualType indexTy) const { 320 if (Idx.isUnknown() || UpperBound.isUnknown()) 321 return this; 322 323 // Build an expression for 0 <= Idx < UpperBound. 324 // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed. 325 // FIXME: This should probably be part of SValBuilder. 326 ProgramStateManager &SM = getStateManager(); 327 SValBuilder &svalBuilder = SM.getSValBuilder(); 328 ASTContext &Ctx = svalBuilder.getContext(); 329 330 // Get the offset: the minimum value of the array index type. 331 BasicValueFactory &BVF = svalBuilder.getBasicValueFactory(); 332 if (indexTy.isNull()) 333 indexTy = svalBuilder.getArrayIndexType(); 334 nonloc::ConcreteInt Min(BVF.getMinValue(indexTy)); 335 336 // Adjust the index. 337 SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add, 338 Idx.castAs<NonLoc>(), Min, indexTy); 339 if (newIdx.isUnknownOrUndef()) 340 return this; 341 342 // Adjust the upper bound. 343 SVal newBound = 344 svalBuilder.evalBinOpNN(this, BO_Add, UpperBound.castAs<NonLoc>(), 345 Min, indexTy); 346 347 if (newBound.isUnknownOrUndef()) 348 return this; 349 350 // Build the actual comparison. 351 SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, newIdx.castAs<NonLoc>(), 352 newBound.castAs<NonLoc>(), Ctx.IntTy); 353 if (inBound.isUnknownOrUndef()) 354 return this; 355 356 // Finally, let the constraint manager take care of it. 357 ConstraintManager &CM = SM.getConstraintManager(); 358 return CM.assume(this, inBound.castAs<DefinedSVal>(), Assumption); 359 } 360 361 ConditionTruthVal ProgramState::isNonNull(SVal V) const { 362 ConditionTruthVal IsNull = isNull(V); 363 if (IsNull.isUnderconstrained()) 364 return IsNull; 365 return ConditionTruthVal(!IsNull.getValue()); 366 } 367 368 ConditionTruthVal ProgramState::areEqual(SVal Lhs, SVal Rhs) const { 369 return stateMgr->getSValBuilder().areEqual(this, Lhs, Rhs); 370 } 371 372 ConditionTruthVal ProgramState::isNull(SVal V) const { 373 if (V.isZeroConstant()) 374 return true; 375 376 if (V.isConstant()) 377 return false; 378 379 SymbolRef Sym = V.getAsSymbol(/* IncludeBaseRegion */ true); 380 if (!Sym) 381 return ConditionTruthVal(); 382 383 return getStateManager().ConstraintMgr->isNull(this, Sym); 384 } 385 386 ProgramStateRef ProgramStateManager::getInitialState(const LocationContext *InitLoc) { 387 ProgramState State(this, 388 EnvMgr.getInitialEnvironment(), 389 StoreMgr->getInitialStore(InitLoc), 390 GDMFactory.getEmptyMap()); 391 392 return getPersistentState(State); 393 } 394 395 ProgramStateRef ProgramStateManager::getPersistentStateWithGDM( 396 ProgramStateRef FromState, 397 ProgramStateRef GDMState) { 398 ProgramState NewState(*FromState); 399 NewState.GDM = GDMState->GDM; 400 return getPersistentState(NewState); 401 } 402 403 ProgramStateRef ProgramStateManager::getPersistentState(ProgramState &State) { 404 405 llvm::FoldingSetNodeID ID; 406 State.Profile(ID); 407 void *InsertPos; 408 409 if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos)) 410 return I; 411 412 ProgramState *newState = nullptr; 413 if (!freeStates.empty()) { 414 newState = freeStates.back(); 415 freeStates.pop_back(); 416 } 417 else { 418 newState = (ProgramState*) Alloc.Allocate<ProgramState>(); 419 } 420 new (newState) ProgramState(State); 421 StateSet.InsertNode(newState, InsertPos); 422 return newState; 423 } 424 425 ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const { 426 ProgramState NewSt(*this); 427 NewSt.setStore(store); 428 return getStateManager().getPersistentState(NewSt); 429 } 430 431 void ProgramState::setStore(const StoreRef &newStore) { 432 Store newStoreStore = newStore.getStore(); 433 if (newStoreStore) 434 stateMgr->getStoreManager().incrementReferenceCount(newStoreStore); 435 if (store) 436 stateMgr->getStoreManager().decrementReferenceCount(store); 437 store = newStoreStore; 438 } 439 440 //===----------------------------------------------------------------------===// 441 // State pretty-printing. 442 //===----------------------------------------------------------------------===// 443 444 void ProgramState::printJson(raw_ostream &Out, const LocationContext *LCtx, 445 const char *NL, unsigned int Space, 446 bool IsDot) const { 447 Indent(Out, Space, IsDot) << "\"program_state\": {" << NL; 448 ++Space; 449 450 ProgramStateManager &Mgr = getStateManager(); 451 452 // Print the store. 453 Mgr.getStoreManager().printJson(Out, getStore(), NL, Space, IsDot); 454 455 // Print out the environment. 456 Env.printJson(Out, Mgr.getContext(), LCtx, NL, Space, IsDot); 457 458 // Print out the constraints. 459 Mgr.getConstraintManager().printJson(Out, this, NL, Space, IsDot); 460 461 // Print out the tracked dynamic types. 462 printDynamicTypeInfoJson(Out, this, NL, Space, IsDot); 463 464 // Print checker-specific data. 465 Mgr.getOwningEngine().printJson(Out, this, LCtx, NL, Space, IsDot); 466 467 --Space; 468 Indent(Out, Space, IsDot) << '}'; 469 } 470 471 void ProgramState::printDOT(raw_ostream &Out, const LocationContext *LCtx, 472 unsigned int Space) const { 473 printJson(Out, LCtx, /*NL=*/"\\l", Space, /*IsDot=*/true); 474 } 475 476 LLVM_DUMP_METHOD void ProgramState::dump() const { 477 printJson(llvm::errs()); 478 } 479 480 AnalysisManager& ProgramState::getAnalysisManager() const { 481 return stateMgr->getOwningEngine().getAnalysisManager(); 482 } 483 484 //===----------------------------------------------------------------------===// 485 // Generic Data Map. 486 //===----------------------------------------------------------------------===// 487 488 void *const* ProgramState::FindGDM(void *K) const { 489 return GDM.lookup(K); 490 } 491 492 void* 493 ProgramStateManager::FindGDMContext(void *K, 494 void *(*CreateContext)(llvm::BumpPtrAllocator&), 495 void (*DeleteContext)(void*)) { 496 497 std::pair<void*, void (*)(void*)>& p = GDMContexts[K]; 498 if (!p.first) { 499 p.first = CreateContext(Alloc); 500 p.second = DeleteContext; 501 } 502 503 return p.first; 504 } 505 506 ProgramStateRef ProgramStateManager::addGDM(ProgramStateRef St, void *Key, void *Data){ 507 ProgramState::GenericDataMap M1 = St->getGDM(); 508 ProgramState::GenericDataMap M2 = GDMFactory.add(M1, Key, Data); 509 510 if (M1 == M2) 511 return St; 512 513 ProgramState NewSt = *St; 514 NewSt.GDM = M2; 515 return getPersistentState(NewSt); 516 } 517 518 ProgramStateRef ProgramStateManager::removeGDM(ProgramStateRef state, void *Key) { 519 ProgramState::GenericDataMap OldM = state->getGDM(); 520 ProgramState::GenericDataMap NewM = GDMFactory.remove(OldM, Key); 521 522 if (NewM == OldM) 523 return state; 524 525 ProgramState NewState = *state; 526 NewState.GDM = NewM; 527 return getPersistentState(NewState); 528 } 529 530 bool ScanReachableSymbols::scan(nonloc::LazyCompoundVal val) { 531 bool wasVisited = !visited.insert(val.getCVData()).second; 532 if (wasVisited) 533 return true; 534 535 StoreManager &StoreMgr = state->getStateManager().getStoreManager(); 536 // FIXME: We don't really want to use getBaseRegion() here because pointer 537 // arithmetic doesn't apply, but scanReachableSymbols only accepts base 538 // regions right now. 539 const MemRegion *R = val.getRegion()->getBaseRegion(); 540 return StoreMgr.scanReachableSymbols(val.getStore(), R, *this); 541 } 542 543 bool ScanReachableSymbols::scan(nonloc::CompoundVal val) { 544 for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I) 545 if (!scan(*I)) 546 return false; 547 548 return true; 549 } 550 551 bool ScanReachableSymbols::scan(const SymExpr *sym) { 552 for (SymExpr::symbol_iterator SI = sym->symbol_begin(), 553 SE = sym->symbol_end(); 554 SI != SE; ++SI) { 555 bool wasVisited = !visited.insert(*SI).second; 556 if (wasVisited) 557 continue; 558 559 if (!visitor.VisitSymbol(*SI)) 560 return false; 561 } 562 563 return true; 564 } 565 566 bool ScanReachableSymbols::scan(SVal val) { 567 if (Optional<loc::MemRegionVal> X = val.getAs<loc::MemRegionVal>()) 568 return scan(X->getRegion()); 569 570 if (Optional<nonloc::LazyCompoundVal> X = 571 val.getAs<nonloc::LazyCompoundVal>()) 572 return scan(*X); 573 574 if (Optional<nonloc::LocAsInteger> X = val.getAs<nonloc::LocAsInteger>()) 575 return scan(X->getLoc()); 576 577 if (SymbolRef Sym = val.getAsSymbol()) 578 return scan(Sym); 579 580 if (const SymExpr *Sym = val.getAsSymbolicExpression()) 581 return scan(Sym); 582 583 if (Optional<nonloc::CompoundVal> X = val.getAs<nonloc::CompoundVal>()) 584 return scan(*X); 585 586 return true; 587 } 588 589 bool ScanReachableSymbols::scan(const MemRegion *R) { 590 if (isa<MemSpaceRegion>(R)) 591 return true; 592 593 bool wasVisited = !visited.insert(R).second; 594 if (wasVisited) 595 return true; 596 597 if (!visitor.VisitMemRegion(R)) 598 return false; 599 600 // If this is a symbolic region, visit the symbol for the region. 601 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 602 if (!visitor.VisitSymbol(SR->getSymbol())) 603 return false; 604 605 // If this is a subregion, also visit the parent regions. 606 if (const SubRegion *SR = dyn_cast<SubRegion>(R)) { 607 const MemRegion *Super = SR->getSuperRegion(); 608 if (!scan(Super)) 609 return false; 610 611 // When we reach the topmost region, scan all symbols in it. 612 if (isa<MemSpaceRegion>(Super)) { 613 StoreManager &StoreMgr = state->getStateManager().getStoreManager(); 614 if (!StoreMgr.scanReachableSymbols(state->getStore(), SR, *this)) 615 return false; 616 } 617 } 618 619 // Regions captured by a block are also implicitly reachable. 620 if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) { 621 BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), 622 E = BDR->referenced_vars_end(); 623 for ( ; I != E; ++I) { 624 if (!scan(I.getCapturedRegion())) 625 return false; 626 } 627 } 628 629 return true; 630 } 631 632 bool ProgramState::scanReachableSymbols(SVal val, SymbolVisitor& visitor) const { 633 ScanReachableSymbols S(this, visitor); 634 return S.scan(val); 635 } 636 637 bool ProgramState::scanReachableSymbols( 638 llvm::iterator_range<region_iterator> Reachable, 639 SymbolVisitor &visitor) const { 640 ScanReachableSymbols S(this, visitor); 641 for (const MemRegion *R : Reachable) { 642 if (!S.scan(R)) 643 return false; 644 } 645 return true; 646 } 647