ProgramState.cpp revision da8d37ce42d2db4e1e76ee6f7f38f10f6b0ef0f8
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//= ProgramState.cpp - Path-Sensitive "State" for tracking values --*- C++ -*--= 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The LLVM Compiler Infrastructure 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 5868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)// This file is distributed under the University of Illinois Open Source 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// License. See LICENSE.TXT for details. 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This file implements ProgramState and ProgramStateManager. 11eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch// 129ab5563a3196760eb381d102cbb2bc0f7abc6a50Ben Murdoch//===----------------------------------------------------------------------===// 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1458e6fbe4ee35d65e14b626c557d37565bf8ad179Ben Murdoch#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 15868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)#include "clang/Analysis/CFG.h" 16868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 18eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h" 19868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)#include "clang/StaticAnalyzer/Core/PathSensitive/TaintManager.h" 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/Support/raw_ostream.h" 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace clang; 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace ento; 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace clang { namespace ento { 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// Increments the number of times this state is referenced. 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void ProgramStateRetain(const ProgramState *state) { 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ++const_cast<ProgramState*>(state)->refCount; 30eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch} 31eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch 32eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch/// Decrement the number of times this state is referenced. 33eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdochvoid ProgramStateRelease(const ProgramState *state) { 34eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch assert(state->refCount > 0); 35eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch ProgramState *s = const_cast<ProgramState*>(state); 362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (--s->refCount == 0) { 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ProgramStateManager &Mgr = s->getStateManager(); 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Mgr.StateSet.RemoveNode(s); 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) s->~ProgramState(); 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Mgr.freeStates.push_back(s); 41eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch } 42eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch} 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}} 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramState::ProgramState(ProgramStateManager *mgr, const Environment& env, 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) StoreRef st, GenericDataMap gdm) 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : stateMgr(mgr), 48c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) Env(env), 492a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) store(st.getStore()), 502a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) GDM(gdm), 5190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) refCount(0) { 522a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) stateMgr->getStoreManager().incrementReferenceCount(store); 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramState::ProgramState(const ProgramState &RHS) 56eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch : llvm::FoldingSetNode(), 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) stateMgr(RHS.stateMgr), 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Env(RHS.Env), 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) store(RHS.store), 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) GDM(RHS.GDM), 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) refCount(0) { 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) stateMgr->getStoreManager().incrementReferenceCount(store); 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 6490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramState::~ProgramState() { 66c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) if (store) 67c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) stateMgr->getStoreManager().decrementReferenceCount(store); 68c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)} 69c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramStateManager::ProgramStateManager(ASTContext &Ctx, 71eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch StoreManagerCreator CreateSMgr, 720529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch ConstraintManagerCreator CreateCMgr, 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) llvm::BumpPtrAllocator &alloc, 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SubEngine *SubEng) 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : Eng(SubEng), EnvMgr(alloc), GDMFactory(alloc), 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) svalBuilder(createSimpleSValBuilder(alloc, Ctx, *this)), 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CallEventMgr(new CallEventManager(alloc)), Alloc(alloc) { 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) StoreMgr.reset((*CreateSMgr)(*this)); 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ConstraintMgr.reset((*CreateCMgr)(*this, SubEng)); 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramStateManager::~ProgramStateManager() { 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end(); 85c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) I!=E; ++I) 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) I->second.second(I->second.first); 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramStateRef 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramStateManager::removeDeadBindings(ProgramStateRef state, 91c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) const StackFrameContext *LCtx, 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SymbolReaper& SymReaper) { 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This code essentially performs a "mark-and-sweep" of the VariableBindings. 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The roots are any Block-level exprs and Decls that our liveness algorithm 96c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) // tells us are live. We then see what Decls they may reference, and keep 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // those around. This code more than likely can be made faster, and the 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // frequency of which this method is called should be experimented with 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // for optimum performance. 10090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ProgramState NewState = *state; 101eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch 10290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) NewState.Env = EnvMgr.removeDeadBindings(NewState.Env, SymReaper, state); 10390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Clean up the store. 105eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch StoreRef newStore = StoreMgr->removeDeadBindings(NewState.getStore(), LCtx, 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SymReaper); 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) NewState.setStore(newStore); 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SymReaper.setReapedStore(newStore); 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ProgramStateRef Result = getPersistentState(NewState); 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return ConstraintMgr->removeDeadBindings(Result, SymReaper); 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramStateRef ProgramState::bindLoc(Loc LV, SVal V, bool notifyChanges) const { 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ProgramStateManager &Mgr = getStateManager(); 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ProgramStateRef newState = makeWithStore(Mgr.StoreMgr->Bind(getStore(), 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) LV, V)); 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const MemRegion *MR = LV.getAsRegion(); 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (MR && Mgr.getOwningEngine() && notifyChanges) 1205d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) return Mgr.getOwningEngine()->processRegionChange(newState, MR); 1215d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return newState; 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramStateRef ProgramState::bindDefault(SVal loc, SVal V) const { 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ProgramStateManager &Mgr = getStateManager(); 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion(); 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const StoreRef &newStore = Mgr.StoreMgr->BindDefault(getStore(), R, V); 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ProgramStateRef new_state = makeWithStore(newStore); 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return Mgr.getOwningEngine() ? 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Mgr.getOwningEngine()->processRegionChange(new_state, R) : 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) new_state; 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef ArrayRef<const MemRegion *> RegionList; 1362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef ArrayRef<SVal> ValueList; 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramStateRef 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProgramState::invalidateRegions(RegionList Regions, 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Expr *E, unsigned Count, 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const LocationContext *LCtx, 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool CausedByPointerEscape, 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InvalidatedSymbols *IS, 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const CallEvent *Call, 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) RegionAndSymbolInvalidationTraits *ITraits) const { 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SmallVector<SVal, 8> Values; 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (RegionList::const_iterator I = Regions.begin(), 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) End = Regions.end(); I != End; ++I) 149 Values.push_back(loc::MemRegionVal(*I)); 150 151 return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape, 152 IS, ITraits, Call); 153} 154 155ProgramStateRef 156ProgramState::invalidateRegions(ValueList Values, 157 const Expr *E, unsigned Count, 158 const LocationContext *LCtx, 159 bool CausedByPointerEscape, 160 InvalidatedSymbols *IS, 161 const CallEvent *Call, 162 RegionAndSymbolInvalidationTraits *ITraits) const { 163 164 return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape, 165 IS, ITraits, Call); 166} 167 168ProgramStateRef 169ProgramState::invalidateRegionsImpl(ValueList Values, 170 const Expr *E, unsigned Count, 171 const LocationContext *LCtx, 172 bool CausedByPointerEscape, 173 InvalidatedSymbols *IS, 174 RegionAndSymbolInvalidationTraits *ITraits, 175 const CallEvent *Call) const { 176 ProgramStateManager &Mgr = getStateManager(); 177 SubEngine* Eng = Mgr.getOwningEngine(); 178 InvalidatedSymbols ConstIS; 179 180 InvalidatedSymbols Invalidated; 181 if (!IS) 182 IS = &Invalidated; 183 184 RegionAndSymbolInvalidationTraits ITraitsLocal; 185 if (!ITraits) 186 ITraits = &ITraitsLocal; 187 188 if (Eng) { 189 StoreManager::InvalidatedRegions TopLevelInvalidated; 190 StoreManager::InvalidatedRegions Invalidated; 191 const StoreRef &newStore 192 = Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call, 193 *IS, *ITraits, &TopLevelInvalidated, 194 &Invalidated); 195 196 ProgramStateRef newState = makeWithStore(newStore); 197 198 if (CausedByPointerEscape) { 199 newState = Eng->notifyCheckersOfPointerEscape(newState, IS, 200 TopLevelInvalidated, 201 Invalidated, Call, 202 *ITraits); 203 } 204 205 return Eng->processRegionChanges(newState, IS, TopLevelInvalidated, 206 Invalidated, Call); 207 } 208 209 const StoreRef &newStore = 210 Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call, 211 *IS, *ITraits, NULL, NULL); 212 return makeWithStore(newStore); 213} 214 215ProgramStateRef ProgramState::killBinding(Loc LV) const { 216 assert(!LV.getAs<loc::MemRegionVal>() && "Use invalidateRegion instead."); 217 218 Store OldStore = getStore(); 219 const StoreRef &newStore = 220 getStateManager().StoreMgr->killBinding(OldStore, LV); 221 222 if (newStore.getStore() == OldStore) 223 return this; 224 225 return makeWithStore(newStore); 226} 227 228ProgramStateRef 229ProgramState::enterStackFrame(const CallEvent &Call, 230 const StackFrameContext *CalleeCtx) const { 231 const StoreRef &NewStore = 232 getStateManager().StoreMgr->enterStackFrame(getStore(), Call, CalleeCtx); 233 return makeWithStore(NewStore); 234} 235 236SVal ProgramState::getSValAsScalarOrLoc(const MemRegion *R) const { 237 // We only want to do fetches from regions that we can actually bind 238 // values. For example, SymbolicRegions of type 'id<...>' cannot 239 // have direct bindings (but their can be bindings on their subregions). 240 if (!R->isBoundable()) 241 return UnknownVal(); 242 243 if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) { 244 QualType T = TR->getValueType(); 245 if (Loc::isLocType(T) || T->isIntegralOrEnumerationType()) 246 return getSVal(R); 247 } 248 249 return UnknownVal(); 250} 251 252SVal ProgramState::getSVal(Loc location, QualType T) const { 253 SVal V = getRawSVal(cast<Loc>(location), T); 254 255 // If 'V' is a symbolic value that is *perfectly* constrained to 256 // be a constant value, use that value instead to lessen the burden 257 // on later analysis stages (so we have less symbolic values to reason 258 // about). 259 if (!T.isNull()) { 260 if (SymbolRef sym = V.getAsSymbol()) { 261 if (const llvm::APSInt *Int = getStateManager() 262 .getConstraintManager() 263 .getSymVal(this, sym)) { 264 // FIXME: Because we don't correctly model (yet) sign-extension 265 // and truncation of symbolic values, we need to convert 266 // the integer value to the correct signedness and bitwidth. 267 // 268 // This shows up in the following: 269 // 270 // char foo(); 271 // unsigned x = foo(); 272 // if (x == 54) 273 // ... 274 // 275 // The symbolic value stored to 'x' is actually the conjured 276 // symbol for the call to foo(); the type of that symbol is 'char', 277 // not unsigned. 278 const llvm::APSInt &NewV = getBasicVals().Convert(T, *Int); 279 280 if (V.getAs<Loc>()) 281 return loc::ConcreteInt(NewV); 282 else 283 return nonloc::ConcreteInt(NewV); 284 } 285 } 286 } 287 288 return V; 289} 290 291ProgramStateRef ProgramState::BindExpr(const Stmt *S, 292 const LocationContext *LCtx, 293 SVal V, bool Invalidate) const{ 294 Environment NewEnv = 295 getStateManager().EnvMgr.bindExpr(Env, EnvironmentEntry(S, LCtx), V, 296 Invalidate); 297 if (NewEnv == Env) 298 return this; 299 300 ProgramState NewSt = *this; 301 NewSt.Env = NewEnv; 302 return getStateManager().getPersistentState(NewSt); 303} 304 305ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx, 306 DefinedOrUnknownSVal UpperBound, 307 bool Assumption, 308 QualType indexTy) const { 309 if (Idx.isUnknown() || UpperBound.isUnknown()) 310 return this; 311 312 // Build an expression for 0 <= Idx < UpperBound. 313 // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed. 314 // FIXME: This should probably be part of SValBuilder. 315 ProgramStateManager &SM = getStateManager(); 316 SValBuilder &svalBuilder = SM.getSValBuilder(); 317 ASTContext &Ctx = svalBuilder.getContext(); 318 319 // Get the offset: the minimum value of the array index type. 320 BasicValueFactory &BVF = svalBuilder.getBasicValueFactory(); 321 // FIXME: This should be using ValueManager::ArrayindexTy...somehow. 322 if (indexTy.isNull()) 323 indexTy = Ctx.IntTy; 324 nonloc::ConcreteInt Min(BVF.getMinValue(indexTy)); 325 326 // Adjust the index. 327 SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add, 328 Idx.castAs<NonLoc>(), Min, indexTy); 329 if (newIdx.isUnknownOrUndef()) 330 return this; 331 332 // Adjust the upper bound. 333 SVal newBound = 334 svalBuilder.evalBinOpNN(this, BO_Add, UpperBound.castAs<NonLoc>(), 335 Min, indexTy); 336 337 if (newBound.isUnknownOrUndef()) 338 return this; 339 340 // Build the actual comparison. 341 SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, newIdx.castAs<NonLoc>(), 342 newBound.castAs<NonLoc>(), Ctx.IntTy); 343 if (inBound.isUnknownOrUndef()) 344 return this; 345 346 // Finally, let the constraint manager take care of it. 347 ConstraintManager &CM = SM.getConstraintManager(); 348 return CM.assume(this, inBound.castAs<DefinedSVal>(), Assumption); 349} 350 351ConditionTruthVal ProgramState::isNull(SVal V) const { 352 if (V.isZeroConstant()) 353 return true; 354 355 if (V.isConstant()) 356 return false; 357 358 SymbolRef Sym = V.getAsSymbol(/* IncludeBaseRegion */ true); 359 if (!Sym) 360 return ConditionTruthVal(); 361 362 return getStateManager().ConstraintMgr->isNull(this, Sym); 363} 364 365ProgramStateRef ProgramStateManager::getInitialState(const LocationContext *InitLoc) { 366 ProgramState State(this, 367 EnvMgr.getInitialEnvironment(), 368 StoreMgr->getInitialStore(InitLoc), 369 GDMFactory.getEmptyMap()); 370 371 return getPersistentState(State); 372} 373 374ProgramStateRef ProgramStateManager::getPersistentStateWithGDM( 375 ProgramStateRef FromState, 376 ProgramStateRef GDMState) { 377 ProgramState NewState(*FromState); 378 NewState.GDM = GDMState->GDM; 379 return getPersistentState(NewState); 380} 381 382ProgramStateRef ProgramStateManager::getPersistentState(ProgramState &State) { 383 384 llvm::FoldingSetNodeID ID; 385 State.Profile(ID); 386 void *InsertPos; 387 388 if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos)) 389 return I; 390 391 ProgramState *newState = 0; 392 if (!freeStates.empty()) { 393 newState = freeStates.back(); 394 freeStates.pop_back(); 395 } 396 else { 397 newState = (ProgramState*) Alloc.Allocate<ProgramState>(); 398 } 399 new (newState) ProgramState(State); 400 StateSet.InsertNode(newState, InsertPos); 401 return newState; 402} 403 404ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const { 405 ProgramState NewSt(*this); 406 NewSt.setStore(store); 407 return getStateManager().getPersistentState(NewSt); 408} 409 410void ProgramState::setStore(const StoreRef &newStore) { 411 Store newStoreStore = newStore.getStore(); 412 if (newStoreStore) 413 stateMgr->getStoreManager().incrementReferenceCount(newStoreStore); 414 if (store) 415 stateMgr->getStoreManager().decrementReferenceCount(store); 416 store = newStoreStore; 417} 418 419//===----------------------------------------------------------------------===// 420// State pretty-printing. 421//===----------------------------------------------------------------------===// 422 423void ProgramState::print(raw_ostream &Out, 424 const char *NL, const char *Sep) const { 425 // Print the store. 426 ProgramStateManager &Mgr = getStateManager(); 427 Mgr.getStoreManager().print(getStore(), Out, NL, Sep); 428 429 // Print out the environment. 430 Env.print(Out, NL, Sep); 431 432 // Print out the constraints. 433 Mgr.getConstraintManager().print(this, Out, NL, Sep); 434 435 // Print checker-specific data. 436 Mgr.getOwningEngine()->printState(Out, this, NL, Sep); 437} 438 439void ProgramState::printDOT(raw_ostream &Out) const { 440 print(Out, "\\l", "\\|"); 441} 442 443void ProgramState::dump() const { 444 print(llvm::errs()); 445} 446 447void ProgramState::printTaint(raw_ostream &Out, 448 const char *NL, const char *Sep) const { 449 TaintMapImpl TM = get<TaintMap>(); 450 451 if (!TM.isEmpty()) 452 Out <<"Tainted Symbols:" << NL; 453 454 for (TaintMapImpl::iterator I = TM.begin(), E = TM.end(); I != E; ++I) { 455 Out << I->first << " : " << I->second << NL; 456 } 457} 458 459void ProgramState::dumpTaint() const { 460 printTaint(llvm::errs()); 461} 462 463//===----------------------------------------------------------------------===// 464// Generic Data Map. 465//===----------------------------------------------------------------------===// 466 467void *const* ProgramState::FindGDM(void *K) const { 468 return GDM.lookup(K); 469} 470 471void* 472ProgramStateManager::FindGDMContext(void *K, 473 void *(*CreateContext)(llvm::BumpPtrAllocator&), 474 void (*DeleteContext)(void*)) { 475 476 std::pair<void*, void (*)(void*)>& p = GDMContexts[K]; 477 if (!p.first) { 478 p.first = CreateContext(Alloc); 479 p.second = DeleteContext; 480 } 481 482 return p.first; 483} 484 485ProgramStateRef ProgramStateManager::addGDM(ProgramStateRef St, void *Key, void *Data){ 486 ProgramState::GenericDataMap M1 = St->getGDM(); 487 ProgramState::GenericDataMap M2 = GDMFactory.add(M1, Key, Data); 488 489 if (M1 == M2) 490 return St; 491 492 ProgramState NewSt = *St; 493 NewSt.GDM = M2; 494 return getPersistentState(NewSt); 495} 496 497ProgramStateRef ProgramStateManager::removeGDM(ProgramStateRef state, void *Key) { 498 ProgramState::GenericDataMap OldM = state->getGDM(); 499 ProgramState::GenericDataMap NewM = GDMFactory.remove(OldM, Key); 500 501 if (NewM == OldM) 502 return state; 503 504 ProgramState NewState = *state; 505 NewState.GDM = NewM; 506 return getPersistentState(NewState); 507} 508 509bool ScanReachableSymbols::scan(nonloc::LazyCompoundVal val) { 510 bool wasVisited = !visited.insert(val.getCVData()).second; 511 if (wasVisited) 512 return true; 513 514 StoreManager &StoreMgr = state->getStateManager().getStoreManager(); 515 // FIXME: We don't really want to use getBaseRegion() here because pointer 516 // arithmetic doesn't apply, but scanReachableSymbols only accepts base 517 // regions right now. 518 const MemRegion *R = val.getRegion()->getBaseRegion(); 519 return StoreMgr.scanReachableSymbols(val.getStore(), R, *this); 520} 521 522bool ScanReachableSymbols::scan(nonloc::CompoundVal val) { 523 for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I) 524 if (!scan(*I)) 525 return false; 526 527 return true; 528} 529 530bool ScanReachableSymbols::scan(const SymExpr *sym) { 531 bool wasVisited = !visited.insert(sym).second; 532 if (wasVisited) 533 return true; 534 535 if (!visitor.VisitSymbol(sym)) 536 return false; 537 538 // TODO: should be rewritten using SymExpr::symbol_iterator. 539 switch (sym->getKind()) { 540 case SymExpr::RegionValueKind: 541 case SymExpr::ConjuredKind: 542 case SymExpr::DerivedKind: 543 case SymExpr::ExtentKind: 544 case SymExpr::MetadataKind: 545 break; 546 case SymExpr::CastSymbolKind: 547 return scan(cast<SymbolCast>(sym)->getOperand()); 548 case SymExpr::SymIntKind: 549 return scan(cast<SymIntExpr>(sym)->getLHS()); 550 case SymExpr::IntSymKind: 551 return scan(cast<IntSymExpr>(sym)->getRHS()); 552 case SymExpr::SymSymKind: { 553 const SymSymExpr *x = cast<SymSymExpr>(sym); 554 return scan(x->getLHS()) && scan(x->getRHS()); 555 } 556 } 557 return true; 558} 559 560bool ScanReachableSymbols::scan(SVal val) { 561 if (Optional<loc::MemRegionVal> X = val.getAs<loc::MemRegionVal>()) 562 return scan(X->getRegion()); 563 564 if (Optional<nonloc::LazyCompoundVal> X = 565 val.getAs<nonloc::LazyCompoundVal>()) 566 return scan(*X); 567 568 if (Optional<nonloc::LocAsInteger> X = val.getAs<nonloc::LocAsInteger>()) 569 return scan(X->getLoc()); 570 571 if (SymbolRef Sym = val.getAsSymbol()) 572 return scan(Sym); 573 574 if (const SymExpr *Sym = val.getAsSymbolicExpression()) 575 return scan(Sym); 576 577 if (Optional<nonloc::CompoundVal> X = val.getAs<nonloc::CompoundVal>()) 578 return scan(*X); 579 580 return true; 581} 582 583bool ScanReachableSymbols::scan(const MemRegion *R) { 584 if (isa<MemSpaceRegion>(R)) 585 return true; 586 587 bool wasVisited = !visited.insert(R).second; 588 if (wasVisited) 589 return true; 590 591 if (!visitor.VisitMemRegion(R)) 592 return false; 593 594 // If this is a symbolic region, visit the symbol for the region. 595 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 596 if (!visitor.VisitSymbol(SR->getSymbol())) 597 return false; 598 599 // If this is a subregion, also visit the parent regions. 600 if (const SubRegion *SR = dyn_cast<SubRegion>(R)) { 601 const MemRegion *Super = SR->getSuperRegion(); 602 if (!scan(Super)) 603 return false; 604 605 // When we reach the topmost region, scan all symbols in it. 606 if (isa<MemSpaceRegion>(Super)) { 607 StoreManager &StoreMgr = state->getStateManager().getStoreManager(); 608 if (!StoreMgr.scanReachableSymbols(state->getStore(), SR, *this)) 609 return false; 610 } 611 } 612 613 // Regions captured by a block are also implicitly reachable. 614 if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) { 615 BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), 616 E = BDR->referenced_vars_end(); 617 for ( ; I != E; ++I) { 618 if (!scan(I.getCapturedRegion())) 619 return false; 620 } 621 } 622 623 return true; 624} 625 626bool ProgramState::scanReachableSymbols(SVal val, SymbolVisitor& visitor) const { 627 ScanReachableSymbols S(this, visitor); 628 return S.scan(val); 629} 630 631bool ProgramState::scanReachableSymbols(const SVal *I, const SVal *E, 632 SymbolVisitor &visitor) const { 633 ScanReachableSymbols S(this, visitor); 634 for ( ; I != E; ++I) { 635 if (!S.scan(*I)) 636 return false; 637 } 638 return true; 639} 640 641bool ProgramState::scanReachableSymbols(const MemRegion * const *I, 642 const MemRegion * const *E, 643 SymbolVisitor &visitor) const { 644 ScanReachableSymbols S(this, visitor); 645 for ( ; I != E; ++I) { 646 if (!S.scan(*I)) 647 return false; 648 } 649 return true; 650} 651 652ProgramStateRef ProgramState::addTaint(const Stmt *S, 653 const LocationContext *LCtx, 654 TaintTagType Kind) const { 655 if (const Expr *E = dyn_cast_or_null<Expr>(S)) 656 S = E->IgnoreParens(); 657 658 SymbolRef Sym = getSVal(S, LCtx).getAsSymbol(); 659 if (Sym) 660 return addTaint(Sym, Kind); 661 662 const MemRegion *R = getSVal(S, LCtx).getAsRegion(); 663 addTaint(R, Kind); 664 665 // Cannot add taint, so just return the state. 666 return this; 667} 668 669ProgramStateRef ProgramState::addTaint(const MemRegion *R, 670 TaintTagType Kind) const { 671 if (const SymbolicRegion *SR = dyn_cast_or_null<SymbolicRegion>(R)) 672 return addTaint(SR->getSymbol(), Kind); 673 return this; 674} 675 676ProgramStateRef ProgramState::addTaint(SymbolRef Sym, 677 TaintTagType Kind) const { 678 // If this is a symbol cast, remove the cast before adding the taint. Taint 679 // is cast agnostic. 680 while (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) 681 Sym = SC->getOperand(); 682 683 ProgramStateRef NewState = set<TaintMap>(Sym, Kind); 684 assert(NewState); 685 return NewState; 686} 687 688bool ProgramState::isTainted(const Stmt *S, const LocationContext *LCtx, 689 TaintTagType Kind) const { 690 if (const Expr *E = dyn_cast_or_null<Expr>(S)) 691 S = E->IgnoreParens(); 692 693 SVal val = getSVal(S, LCtx); 694 return isTainted(val, Kind); 695} 696 697bool ProgramState::isTainted(SVal V, TaintTagType Kind) const { 698 if (const SymExpr *Sym = V.getAsSymExpr()) 699 return isTainted(Sym, Kind); 700 if (const MemRegion *Reg = V.getAsRegion()) 701 return isTainted(Reg, Kind); 702 return false; 703} 704 705bool ProgramState::isTainted(const MemRegion *Reg, TaintTagType K) const { 706 if (!Reg) 707 return false; 708 709 // Element region (array element) is tainted if either the base or the offset 710 // are tainted. 711 if (const ElementRegion *ER = dyn_cast<ElementRegion>(Reg)) 712 return isTainted(ER->getSuperRegion(), K) || isTainted(ER->getIndex(), K); 713 714 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) 715 return isTainted(SR->getSymbol(), K); 716 717 if (const SubRegion *ER = dyn_cast<SubRegion>(Reg)) 718 return isTainted(ER->getSuperRegion(), K); 719 720 return false; 721} 722 723bool ProgramState::isTainted(SymbolRef Sym, TaintTagType Kind) const { 724 if (!Sym) 725 return false; 726 727 // Traverse all the symbols this symbol depends on to see if any are tainted. 728 bool Tainted = false; 729 for (SymExpr::symbol_iterator SI = Sym->symbol_begin(), SE =Sym->symbol_end(); 730 SI != SE; ++SI) { 731 if (!isa<SymbolData>(*SI)) 732 continue; 733 734 const TaintTagType *Tag = get<TaintMap>(*SI); 735 Tainted = (Tag && *Tag == Kind); 736 737 // If this is a SymbolDerived with a tainted parent, it's also tainted. 738 if (const SymbolDerived *SD = dyn_cast<SymbolDerived>(*SI)) 739 Tainted = Tainted || isTainted(SD->getParentSymbol(), Kind); 740 741 // If memory region is tainted, data is also tainted. 742 if (const SymbolRegionValue *SRV = dyn_cast<SymbolRegionValue>(*SI)) 743 Tainted = Tainted || isTainted(SRV->getRegion(), Kind); 744 745 // If If this is a SymbolCast from a tainted value, it's also tainted. 746 if (const SymbolCast *SC = dyn_cast<SymbolCast>(*SI)) 747 Tainted = Tainted || isTainted(SC->getOperand(), Kind); 748 749 if (Tainted) 750 return true; 751 } 752 753 return Tainted; 754} 755 756/// The GDM component containing the dynamic type info. This is a map from a 757/// symbol to its most likely type. 758REGISTER_TRAIT_WITH_PROGRAMSTATE(DynamicTypeMap, 759 CLANG_ENTO_PROGRAMSTATE_MAP(const MemRegion *, 760 DynamicTypeInfo)) 761 762DynamicTypeInfo ProgramState::getDynamicTypeInfo(const MemRegion *Reg) const { 763 Reg = Reg->StripCasts(); 764 765 // Look up the dynamic type in the GDM. 766 const DynamicTypeInfo *GDMType = get<DynamicTypeMap>(Reg); 767 if (GDMType) 768 return *GDMType; 769 770 // Otherwise, fall back to what we know about the region. 771 if (const TypedRegion *TR = dyn_cast<TypedRegion>(Reg)) 772 return DynamicTypeInfo(TR->getLocationType(), /*CanBeSubclass=*/false); 773 774 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) { 775 SymbolRef Sym = SR->getSymbol(); 776 return DynamicTypeInfo(Sym->getType()); 777 } 778 779 return DynamicTypeInfo(); 780} 781 782ProgramStateRef ProgramState::setDynamicTypeInfo(const MemRegion *Reg, 783 DynamicTypeInfo NewTy) const { 784 Reg = Reg->StripCasts(); 785 ProgramStateRef NewState = set<DynamicTypeMap>(Reg, NewTy); 786 assert(NewState); 787 return NewState; 788} 789