| //= ProgramState.cpp - Path-Sensitive "State" for tracking values --*- C++ -*--= |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements ProgramState and ProgramStateManager. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" |
| #include "clang/Analysis/CFG.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/TaintManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeMap.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| using namespace clang; |
| using namespace ento; |
| |
| namespace clang { namespace ento { |
| /// Increments the number of times this state is referenced. |
| |
| void ProgramStateRetain(const ProgramState *state) { |
| ++const_cast<ProgramState*>(state)->refCount; |
| } |
| |
| /// Decrement the number of times this state is referenced. |
| void ProgramStateRelease(const ProgramState *state) { |
| assert(state->refCount > 0); |
| ProgramState *s = const_cast<ProgramState*>(state); |
| if (--s->refCount == 0) { |
| ProgramStateManager &Mgr = s->getStateManager(); |
| Mgr.StateSet.RemoveNode(s); |
| s->~ProgramState(); |
| Mgr.freeStates.push_back(s); |
| } |
| } |
| }} |
| |
| ProgramState::ProgramState(ProgramStateManager *mgr, const Environment& env, |
| StoreRef st, GenericDataMap gdm) |
| : stateMgr(mgr), |
| Env(env), |
| store(st.getStore()), |
| GDM(gdm), |
| refCount(0) { |
| stateMgr->getStoreManager().incrementReferenceCount(store); |
| } |
| |
| ProgramState::ProgramState(const ProgramState &RHS) |
| : llvm::FoldingSetNode(), |
| stateMgr(RHS.stateMgr), |
| Env(RHS.Env), |
| store(RHS.store), |
| GDM(RHS.GDM), |
| refCount(0) { |
| stateMgr->getStoreManager().incrementReferenceCount(store); |
| } |
| |
| ProgramState::~ProgramState() { |
| if (store) |
| stateMgr->getStoreManager().decrementReferenceCount(store); |
| } |
| |
| ProgramStateManager::ProgramStateManager(ASTContext &Ctx, |
| StoreManagerCreator CreateSMgr, |
| ConstraintManagerCreator CreateCMgr, |
| llvm::BumpPtrAllocator &alloc, |
| SubEngine *SubEng) |
| : Eng(SubEng), EnvMgr(alloc), GDMFactory(alloc), |
| svalBuilder(createSimpleSValBuilder(alloc, Ctx, *this)), |
| CallEventMgr(new CallEventManager(alloc)), Alloc(alloc) { |
| StoreMgr = (*CreateSMgr)(*this); |
| ConstraintMgr = (*CreateCMgr)(*this, SubEng); |
| } |
| |
| |
| ProgramStateManager::~ProgramStateManager() { |
| for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end(); |
| I!=E; ++I) |
| I->second.second(I->second.first); |
| } |
| |
| ProgramStateRef |
| ProgramStateManager::removeDeadBindings(ProgramStateRef state, |
| const StackFrameContext *LCtx, |
| SymbolReaper& SymReaper) { |
| |
| // This code essentially performs a "mark-and-sweep" of the VariableBindings. |
| // The roots are any Block-level exprs and Decls that our liveness algorithm |
| // tells us are live. We then see what Decls they may reference, and keep |
| // those around. This code more than likely can be made faster, and the |
| // frequency of which this method is called should be experimented with |
| // for optimum performance. |
| ProgramState NewState = *state; |
| |
| NewState.Env = EnvMgr.removeDeadBindings(NewState.Env, SymReaper, state); |
| |
| // Clean up the store. |
| StoreRef newStore = StoreMgr->removeDeadBindings(NewState.getStore(), LCtx, |
| SymReaper); |
| NewState.setStore(newStore); |
| SymReaper.setReapedStore(newStore); |
| |
| ProgramStateRef Result = getPersistentState(NewState); |
| return ConstraintMgr->removeDeadBindings(Result, SymReaper); |
| } |
| |
| ProgramStateRef ProgramState::bindLoc(Loc LV, |
| SVal V, |
| const LocationContext *LCtx, |
| bool notifyChanges) const { |
| ProgramStateManager &Mgr = getStateManager(); |
| ProgramStateRef newState = makeWithStore(Mgr.StoreMgr->Bind(getStore(), |
| LV, V)); |
| const MemRegion *MR = LV.getAsRegion(); |
| if (MR && Mgr.getOwningEngine() && notifyChanges) |
| return Mgr.getOwningEngine()->processRegionChange(newState, MR, LCtx); |
| |
| return newState; |
| } |
| |
| ProgramStateRef |
| ProgramState::bindDefaultInitial(SVal loc, SVal V, |
| const LocationContext *LCtx) const { |
| ProgramStateManager &Mgr = getStateManager(); |
| const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion(); |
| const StoreRef &newStore = Mgr.StoreMgr->BindDefaultInitial(getStore(), R, V); |
| ProgramStateRef new_state = makeWithStore(newStore); |
| return Mgr.getOwningEngine() |
| ? Mgr.getOwningEngine()->processRegionChange(new_state, R, LCtx) |
| : new_state; |
| } |
| |
| ProgramStateRef |
| ProgramState::bindDefaultZero(SVal loc, const LocationContext *LCtx) const { |
| ProgramStateManager &Mgr = getStateManager(); |
| const MemRegion *R = loc.castAs<loc::MemRegionVal>().getRegion(); |
| const StoreRef &newStore = Mgr.StoreMgr->BindDefaultZero(getStore(), R); |
| ProgramStateRef new_state = makeWithStore(newStore); |
| return Mgr.getOwningEngine() |
| ? Mgr.getOwningEngine()->processRegionChange(new_state, R, LCtx) |
| : new_state; |
| } |
| |
| typedef ArrayRef<const MemRegion *> RegionList; |
| typedef ArrayRef<SVal> ValueList; |
| |
| ProgramStateRef |
| ProgramState::invalidateRegions(RegionList Regions, |
| const Expr *E, unsigned Count, |
| const LocationContext *LCtx, |
| bool CausedByPointerEscape, |
| InvalidatedSymbols *IS, |
| const CallEvent *Call, |
| RegionAndSymbolInvalidationTraits *ITraits) const { |
| SmallVector<SVal, 8> Values; |
| for (RegionList::const_iterator I = Regions.begin(), |
| End = Regions.end(); I != End; ++I) |
| Values.push_back(loc::MemRegionVal(*I)); |
| |
| return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape, |
| IS, ITraits, Call); |
| } |
| |
| ProgramStateRef |
| ProgramState::invalidateRegions(ValueList Values, |
| const Expr *E, unsigned Count, |
| const LocationContext *LCtx, |
| bool CausedByPointerEscape, |
| InvalidatedSymbols *IS, |
| const CallEvent *Call, |
| RegionAndSymbolInvalidationTraits *ITraits) const { |
| |
| return invalidateRegionsImpl(Values, E, Count, LCtx, CausedByPointerEscape, |
| IS, ITraits, Call); |
| } |
| |
| ProgramStateRef |
| ProgramState::invalidateRegionsImpl(ValueList Values, |
| const Expr *E, unsigned Count, |
| const LocationContext *LCtx, |
| bool CausedByPointerEscape, |
| InvalidatedSymbols *IS, |
| RegionAndSymbolInvalidationTraits *ITraits, |
| const CallEvent *Call) const { |
| ProgramStateManager &Mgr = getStateManager(); |
| SubEngine* Eng = Mgr.getOwningEngine(); |
| |
| InvalidatedSymbols Invalidated; |
| if (!IS) |
| IS = &Invalidated; |
| |
| RegionAndSymbolInvalidationTraits ITraitsLocal; |
| if (!ITraits) |
| ITraits = &ITraitsLocal; |
| |
| if (Eng) { |
| StoreManager::InvalidatedRegions TopLevelInvalidated; |
| StoreManager::InvalidatedRegions Invalidated; |
| const StoreRef &newStore |
| = Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call, |
| *IS, *ITraits, &TopLevelInvalidated, |
| &Invalidated); |
| |
| ProgramStateRef newState = makeWithStore(newStore); |
| |
| if (CausedByPointerEscape) { |
| newState = Eng->notifyCheckersOfPointerEscape(newState, IS, |
| TopLevelInvalidated, |
| Invalidated, Call, |
| *ITraits); |
| } |
| |
| return Eng->processRegionChanges(newState, IS, TopLevelInvalidated, |
| Invalidated, LCtx, Call); |
| } |
| |
| const StoreRef &newStore = |
| Mgr.StoreMgr->invalidateRegions(getStore(), Values, E, Count, LCtx, Call, |
| *IS, *ITraits, nullptr, nullptr); |
| return makeWithStore(newStore); |
| } |
| |
| ProgramStateRef ProgramState::killBinding(Loc LV) const { |
| assert(!LV.getAs<loc::MemRegionVal>() && "Use invalidateRegion instead."); |
| |
| Store OldStore = getStore(); |
| const StoreRef &newStore = |
| getStateManager().StoreMgr->killBinding(OldStore, LV); |
| |
| if (newStore.getStore() == OldStore) |
| return this; |
| |
| return makeWithStore(newStore); |
| } |
| |
| ProgramStateRef |
| ProgramState::enterStackFrame(const CallEvent &Call, |
| const StackFrameContext *CalleeCtx) const { |
| const StoreRef &NewStore = |
| getStateManager().StoreMgr->enterStackFrame(getStore(), Call, CalleeCtx); |
| return makeWithStore(NewStore); |
| } |
| |
| SVal ProgramState::getSValAsScalarOrLoc(const MemRegion *R) const { |
| // We only want to do fetches from regions that we can actually bind |
| // values. For example, SymbolicRegions of type 'id<...>' cannot |
| // have direct bindings (but their can be bindings on their subregions). |
| if (!R->isBoundable()) |
| return UnknownVal(); |
| |
| if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) { |
| QualType T = TR->getValueType(); |
| if (Loc::isLocType(T) || T->isIntegralOrEnumerationType()) |
| return getSVal(R); |
| } |
| |
| return UnknownVal(); |
| } |
| |
| SVal ProgramState::getSVal(Loc location, QualType T) const { |
| SVal V = getRawSVal(location, T); |
| |
| // If 'V' is a symbolic value that is *perfectly* constrained to |
| // be a constant value, use that value instead to lessen the burden |
| // on later analysis stages (so we have less symbolic values to reason |
| // about). |
| // We only go into this branch if we can convert the APSInt value we have |
| // to the type of T, which is not always the case (e.g. for void). |
| if (!T.isNull() && (T->isIntegralOrEnumerationType() || Loc::isLocType(T))) { |
| if (SymbolRef sym = V.getAsSymbol()) { |
| if (const llvm::APSInt *Int = getStateManager() |
| .getConstraintManager() |
| .getSymVal(this, sym)) { |
| // FIXME: Because we don't correctly model (yet) sign-extension |
| // and truncation of symbolic values, we need to convert |
| // the integer value to the correct signedness and bitwidth. |
| // |
| // This shows up in the following: |
| // |
| // char foo(); |
| // unsigned x = foo(); |
| // if (x == 54) |
| // ... |
| // |
| // The symbolic value stored to 'x' is actually the conjured |
| // symbol for the call to foo(); the type of that symbol is 'char', |
| // not unsigned. |
| const llvm::APSInt &NewV = getBasicVals().Convert(T, *Int); |
| |
| if (V.getAs<Loc>()) |
| return loc::ConcreteInt(NewV); |
| else |
| return nonloc::ConcreteInt(NewV); |
| } |
| } |
| } |
| |
| return V; |
| } |
| |
| ProgramStateRef ProgramState::BindExpr(const Stmt *S, |
| const LocationContext *LCtx, |
| SVal V, bool Invalidate) const{ |
| Environment NewEnv = |
| getStateManager().EnvMgr.bindExpr(Env, EnvironmentEntry(S, LCtx), V, |
| Invalidate); |
| if (NewEnv == Env) |
| return this; |
| |
| ProgramState NewSt = *this; |
| NewSt.Env = NewEnv; |
| return getStateManager().getPersistentState(NewSt); |
| } |
| |
| ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx, |
| DefinedOrUnknownSVal UpperBound, |
| bool Assumption, |
| QualType indexTy) const { |
| if (Idx.isUnknown() || UpperBound.isUnknown()) |
| return this; |
| |
| // Build an expression for 0 <= Idx < UpperBound. |
| // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed. |
| // FIXME: This should probably be part of SValBuilder. |
| ProgramStateManager &SM = getStateManager(); |
| SValBuilder &svalBuilder = SM.getSValBuilder(); |
| ASTContext &Ctx = svalBuilder.getContext(); |
| |
| // Get the offset: the minimum value of the array index type. |
| BasicValueFactory &BVF = svalBuilder.getBasicValueFactory(); |
| if (indexTy.isNull()) |
| indexTy = svalBuilder.getArrayIndexType(); |
| nonloc::ConcreteInt Min(BVF.getMinValue(indexTy)); |
| |
| // Adjust the index. |
| SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add, |
| Idx.castAs<NonLoc>(), Min, indexTy); |
| if (newIdx.isUnknownOrUndef()) |
| return this; |
| |
| // Adjust the upper bound. |
| SVal newBound = |
| svalBuilder.evalBinOpNN(this, BO_Add, UpperBound.castAs<NonLoc>(), |
| Min, indexTy); |
| |
| if (newBound.isUnknownOrUndef()) |
| return this; |
| |
| // Build the actual comparison. |
| SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, newIdx.castAs<NonLoc>(), |
| newBound.castAs<NonLoc>(), Ctx.IntTy); |
| if (inBound.isUnknownOrUndef()) |
| return this; |
| |
| // Finally, let the constraint manager take care of it. |
| ConstraintManager &CM = SM.getConstraintManager(); |
| return CM.assume(this, inBound.castAs<DefinedSVal>(), Assumption); |
| } |
| |
| ConditionTruthVal ProgramState::isNonNull(SVal V) const { |
| ConditionTruthVal IsNull = isNull(V); |
| if (IsNull.isUnderconstrained()) |
| return IsNull; |
| return ConditionTruthVal(!IsNull.getValue()); |
| } |
| |
| ConditionTruthVal ProgramState::areEqual(SVal Lhs, SVal Rhs) const { |
| return stateMgr->getSValBuilder().areEqual(this, Lhs, Rhs); |
| } |
| |
| ConditionTruthVal ProgramState::isNull(SVal V) const { |
| if (V.isZeroConstant()) |
| return true; |
| |
| if (V.isConstant()) |
| return false; |
| |
| SymbolRef Sym = V.getAsSymbol(/* IncludeBaseRegion */ true); |
| if (!Sym) |
| return ConditionTruthVal(); |
| |
| return getStateManager().ConstraintMgr->isNull(this, Sym); |
| } |
| |
| ProgramStateRef ProgramStateManager::getInitialState(const LocationContext *InitLoc) { |
| ProgramState State(this, |
| EnvMgr.getInitialEnvironment(), |
| StoreMgr->getInitialStore(InitLoc), |
| GDMFactory.getEmptyMap()); |
| |
| return getPersistentState(State); |
| } |
| |
| ProgramStateRef ProgramStateManager::getPersistentStateWithGDM( |
| ProgramStateRef FromState, |
| ProgramStateRef GDMState) { |
| ProgramState NewState(*FromState); |
| NewState.GDM = GDMState->GDM; |
| return getPersistentState(NewState); |
| } |
| |
| ProgramStateRef ProgramStateManager::getPersistentState(ProgramState &State) { |
| |
| llvm::FoldingSetNodeID ID; |
| State.Profile(ID); |
| void *InsertPos; |
| |
| if (ProgramState *I = StateSet.FindNodeOrInsertPos(ID, InsertPos)) |
| return I; |
| |
| ProgramState *newState = nullptr; |
| if (!freeStates.empty()) { |
| newState = freeStates.back(); |
| freeStates.pop_back(); |
| } |
| else { |
| newState = (ProgramState*) Alloc.Allocate<ProgramState>(); |
| } |
| new (newState) ProgramState(State); |
| StateSet.InsertNode(newState, InsertPos); |
| return newState; |
| } |
| |
| ProgramStateRef ProgramState::makeWithStore(const StoreRef &store) const { |
| ProgramState NewSt(*this); |
| NewSt.setStore(store); |
| return getStateManager().getPersistentState(NewSt); |
| } |
| |
| void ProgramState::setStore(const StoreRef &newStore) { |
| Store newStoreStore = newStore.getStore(); |
| if (newStoreStore) |
| stateMgr->getStoreManager().incrementReferenceCount(newStoreStore); |
| if (store) |
| stateMgr->getStoreManager().decrementReferenceCount(store); |
| store = newStoreStore; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // State pretty-printing. |
| //===----------------------------------------------------------------------===// |
| |
| void ProgramState::print(raw_ostream &Out, const char *NL, const char *Sep, |
| const LocationContext *LC) const { |
| // Print the store. |
| ProgramStateManager &Mgr = getStateManager(); |
| Mgr.getStoreManager().print(getStore(), Out, NL, Sep); |
| |
| // Print out the environment. |
| Env.print(Out, NL, Sep, LC); |
| |
| // Print out the constraints. |
| Mgr.getConstraintManager().print(this, Out, NL, Sep); |
| |
| // Print out the tracked dynamic types. |
| printDynamicTypeInfo(this, Out, NL, Sep); |
| |
| // Print out tainted symbols. |
| printTaint(Out, NL, Sep); |
| |
| // Print checker-specific data. |
| Mgr.getOwningEngine()->printState(Out, this, NL, Sep, LC); |
| } |
| |
| void ProgramState::printDOT(raw_ostream &Out, const LocationContext *LC) const { |
| print(Out, "\\l", "\\|", LC); |
| } |
| |
| LLVM_DUMP_METHOD void ProgramState::dump() const { |
| print(llvm::errs()); |
| } |
| |
| void ProgramState::printTaint(raw_ostream &Out, |
| const char *NL, const char *Sep) const { |
| TaintMapImpl TM = get<TaintMap>(); |
| |
| if (!TM.isEmpty()) |
| Out <<"Tainted symbols:" << NL; |
| |
| for (TaintMapImpl::iterator I = TM.begin(), E = TM.end(); I != E; ++I) { |
| Out << I->first << " : " << I->second << NL; |
| } |
| } |
| |
| void ProgramState::dumpTaint() const { |
| printTaint(llvm::errs()); |
| } |
| |
| AnalysisManager& ProgramState::getAnalysisManager() const { |
| return stateMgr->getOwningEngine()->getAnalysisManager(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Generic Data Map. |
| //===----------------------------------------------------------------------===// |
| |
| void *const* ProgramState::FindGDM(void *K) const { |
| return GDM.lookup(K); |
| } |
| |
| void* |
| ProgramStateManager::FindGDMContext(void *K, |
| void *(*CreateContext)(llvm::BumpPtrAllocator&), |
| void (*DeleteContext)(void*)) { |
| |
| std::pair<void*, void (*)(void*)>& p = GDMContexts[K]; |
| if (!p.first) { |
| p.first = CreateContext(Alloc); |
| p.second = DeleteContext; |
| } |
| |
| return p.first; |
| } |
| |
| ProgramStateRef ProgramStateManager::addGDM(ProgramStateRef St, void *Key, void *Data){ |
| ProgramState::GenericDataMap M1 = St->getGDM(); |
| ProgramState::GenericDataMap M2 = GDMFactory.add(M1, Key, Data); |
| |
| if (M1 == M2) |
| return St; |
| |
| ProgramState NewSt = *St; |
| NewSt.GDM = M2; |
| return getPersistentState(NewSt); |
| } |
| |
| ProgramStateRef ProgramStateManager::removeGDM(ProgramStateRef state, void *Key) { |
| ProgramState::GenericDataMap OldM = state->getGDM(); |
| ProgramState::GenericDataMap NewM = GDMFactory.remove(OldM, Key); |
| |
| if (NewM == OldM) |
| return state; |
| |
| ProgramState NewState = *state; |
| NewState.GDM = NewM; |
| return getPersistentState(NewState); |
| } |
| |
| bool ScanReachableSymbols::scan(nonloc::LazyCompoundVal val) { |
| bool wasVisited = !visited.insert(val.getCVData()).second; |
| if (wasVisited) |
| return true; |
| |
| StoreManager &StoreMgr = state->getStateManager().getStoreManager(); |
| // FIXME: We don't really want to use getBaseRegion() here because pointer |
| // arithmetic doesn't apply, but scanReachableSymbols only accepts base |
| // regions right now. |
| const MemRegion *R = val.getRegion()->getBaseRegion(); |
| return StoreMgr.scanReachableSymbols(val.getStore(), R, *this); |
| } |
| |
| bool ScanReachableSymbols::scan(nonloc::CompoundVal val) { |
| for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I) |
| if (!scan(*I)) |
| return false; |
| |
| return true; |
| } |
| |
| bool ScanReachableSymbols::scan(const SymExpr *sym) { |
| for (SymExpr::symbol_iterator SI = sym->symbol_begin(), |
| SE = sym->symbol_end(); |
| SI != SE; ++SI) { |
| bool wasVisited = !visited.insert(*SI).second; |
| if (wasVisited) |
| continue; |
| |
| if (!visitor.VisitSymbol(*SI)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool ScanReachableSymbols::scan(SVal val) { |
| if (Optional<loc::MemRegionVal> X = val.getAs<loc::MemRegionVal>()) |
| return scan(X->getRegion()); |
| |
| if (Optional<nonloc::LazyCompoundVal> X = |
| val.getAs<nonloc::LazyCompoundVal>()) |
| return scan(*X); |
| |
| if (Optional<nonloc::LocAsInteger> X = val.getAs<nonloc::LocAsInteger>()) |
| return scan(X->getLoc()); |
| |
| if (SymbolRef Sym = val.getAsSymbol()) |
| return scan(Sym); |
| |
| if (const SymExpr *Sym = val.getAsSymbolicExpression()) |
| return scan(Sym); |
| |
| if (Optional<nonloc::CompoundVal> X = val.getAs<nonloc::CompoundVal>()) |
| return scan(*X); |
| |
| return true; |
| } |
| |
| bool ScanReachableSymbols::scan(const MemRegion *R) { |
| if (isa<MemSpaceRegion>(R)) |
| return true; |
| |
| bool wasVisited = !visited.insert(R).second; |
| if (wasVisited) |
| return true; |
| |
| if (!visitor.VisitMemRegion(R)) |
| return false; |
| |
| // If this is a symbolic region, visit the symbol for the region. |
| if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) |
| if (!visitor.VisitSymbol(SR->getSymbol())) |
| return false; |
| |
| // If this is a subregion, also visit the parent regions. |
| if (const SubRegion *SR = dyn_cast<SubRegion>(R)) { |
| const MemRegion *Super = SR->getSuperRegion(); |
| if (!scan(Super)) |
| return false; |
| |
| // When we reach the topmost region, scan all symbols in it. |
| if (isa<MemSpaceRegion>(Super)) { |
| StoreManager &StoreMgr = state->getStateManager().getStoreManager(); |
| if (!StoreMgr.scanReachableSymbols(state->getStore(), SR, *this)) |
| return false; |
| } |
| } |
| |
| // Regions captured by a block are also implicitly reachable. |
| if (const BlockDataRegion *BDR = dyn_cast<BlockDataRegion>(R)) { |
| BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), |
| E = BDR->referenced_vars_end(); |
| for ( ; I != E; ++I) { |
| if (!scan(I.getCapturedRegion())) |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| bool ProgramState::scanReachableSymbols(SVal val, SymbolVisitor& visitor) const { |
| ScanReachableSymbols S(this, visitor); |
| return S.scan(val); |
| } |
| |
| bool ProgramState::scanReachableSymbols(const SVal *I, const SVal *E, |
| SymbolVisitor &visitor) const { |
| ScanReachableSymbols S(this, visitor); |
| for ( ; I != E; ++I) { |
| if (!S.scan(*I)) |
| return false; |
| } |
| return true; |
| } |
| |
| bool ProgramState::scanReachableSymbols(const MemRegion * const *I, |
| const MemRegion * const *E, |
| SymbolVisitor &visitor) const { |
| ScanReachableSymbols S(this, visitor); |
| for ( ; I != E; ++I) { |
| if (!S.scan(*I)) |
| return false; |
| } |
| return true; |
| } |
| |
| ProgramStateRef ProgramState::addTaint(const Stmt *S, |
| const LocationContext *LCtx, |
| TaintTagType Kind) const { |
| if (const Expr *E = dyn_cast_or_null<Expr>(S)) |
| S = E->IgnoreParens(); |
| |
| return addTaint(getSVal(S, LCtx), Kind); |
| } |
| |
| ProgramStateRef ProgramState::addTaint(SVal V, |
| TaintTagType Kind) const { |
| SymbolRef Sym = V.getAsSymbol(); |
| if (Sym) |
| return addTaint(Sym, Kind); |
| |
| // If the SVal represents a structure, try to mass-taint all values within the |
| // structure. For now it only works efficiently on lazy compound values that |
| // were conjured during a conservative evaluation of a function - either as |
| // return values of functions that return structures or arrays by value, or as |
| // values of structures or arrays passed into the function by reference, |
| // directly or through pointer aliasing. Such lazy compound values are |
| // characterized by having exactly one binding in their captured store within |
| // their parent region, which is a conjured symbol default-bound to the base |
| // region of the parent region. |
| if (auto LCV = V.getAs<nonloc::LazyCompoundVal>()) { |
| if (Optional<SVal> binding = getStateManager().StoreMgr->getDefaultBinding(*LCV)) { |
| if (SymbolRef Sym = binding->getAsSymbol()) |
| return addPartialTaint(Sym, LCV->getRegion(), Kind); |
| } |
| } |
| |
| const MemRegion *R = V.getAsRegion(); |
| return addTaint(R, Kind); |
| } |
| |
| ProgramStateRef ProgramState::addTaint(const MemRegion *R, |
| TaintTagType Kind) const { |
| if (const SymbolicRegion *SR = dyn_cast_or_null<SymbolicRegion>(R)) |
| return addTaint(SR->getSymbol(), Kind); |
| return this; |
| } |
| |
| ProgramStateRef ProgramState::addTaint(SymbolRef Sym, |
| TaintTagType Kind) const { |
| // If this is a symbol cast, remove the cast before adding the taint. Taint |
| // is cast agnostic. |
| while (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) |
| Sym = SC->getOperand(); |
| |
| ProgramStateRef NewState = set<TaintMap>(Sym, Kind); |
| assert(NewState); |
| return NewState; |
| } |
| |
| ProgramStateRef ProgramState::addPartialTaint(SymbolRef ParentSym, |
| const SubRegion *SubRegion, |
| TaintTagType Kind) const { |
| // Ignore partial taint if the entire parent symbol is already tainted. |
| if (contains<TaintMap>(ParentSym) && *get<TaintMap>(ParentSym) == Kind) |
| return this; |
| |
| // Partial taint applies if only a portion of the symbol is tainted. |
| if (SubRegion == SubRegion->getBaseRegion()) |
| return addTaint(ParentSym, Kind); |
| |
| const TaintedSubRegions *SavedRegs = get<DerivedSymTaint>(ParentSym); |
| TaintedSubRegions Regs = |
| SavedRegs ? *SavedRegs : stateMgr->TSRFactory.getEmptyMap(); |
| |
| Regs = stateMgr->TSRFactory.add(Regs, SubRegion, Kind); |
| ProgramStateRef NewState = set<DerivedSymTaint>(ParentSym, Regs); |
| assert(NewState); |
| return NewState; |
| } |
| |
| bool ProgramState::isTainted(const Stmt *S, const LocationContext *LCtx, |
| TaintTagType Kind) const { |
| if (const Expr *E = dyn_cast_or_null<Expr>(S)) |
| S = E->IgnoreParens(); |
| |
| SVal val = getSVal(S, LCtx); |
| return isTainted(val, Kind); |
| } |
| |
| bool ProgramState::isTainted(SVal V, TaintTagType Kind) const { |
| if (const SymExpr *Sym = V.getAsSymExpr()) |
| return isTainted(Sym, Kind); |
| if (const MemRegion *Reg = V.getAsRegion()) |
| return isTainted(Reg, Kind); |
| return false; |
| } |
| |
| bool ProgramState::isTainted(const MemRegion *Reg, TaintTagType K) const { |
| if (!Reg) |
| return false; |
| |
| // Element region (array element) is tainted if either the base or the offset |
| // are tainted. |
| if (const ElementRegion *ER = dyn_cast<ElementRegion>(Reg)) |
| return isTainted(ER->getSuperRegion(), K) || isTainted(ER->getIndex(), K); |
| |
| if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) |
| return isTainted(SR->getSymbol(), K); |
| |
| if (const SubRegion *ER = dyn_cast<SubRegion>(Reg)) |
| return isTainted(ER->getSuperRegion(), K); |
| |
| return false; |
| } |
| |
| bool ProgramState::isTainted(SymbolRef Sym, TaintTagType Kind) const { |
| if (!Sym) |
| return false; |
| |
| // Traverse all the symbols this symbol depends on to see if any are tainted. |
| for (SymExpr::symbol_iterator SI = Sym->symbol_begin(), SE =Sym->symbol_end(); |
| SI != SE; ++SI) { |
| if (!isa<SymbolData>(*SI)) |
| continue; |
| |
| if (const TaintTagType *Tag = get<TaintMap>(*SI)) { |
| if (*Tag == Kind) |
| return true; |
| } |
| |
| if (const SymbolDerived *SD = dyn_cast<SymbolDerived>(*SI)) { |
| // If this is a SymbolDerived with a tainted parent, it's also tainted. |
| if (isTainted(SD->getParentSymbol(), Kind)) |
| return true; |
| |
| // If this is a SymbolDerived with the same parent symbol as another |
| // tainted SymbolDerived and a region that's a sub-region of that tainted |
| // symbol, it's also tainted. |
| if (const TaintedSubRegions *Regs = |
| get<DerivedSymTaint>(SD->getParentSymbol())) { |
| const TypedValueRegion *R = SD->getRegion(); |
| for (auto I : *Regs) { |
| // FIXME: The logic to identify tainted regions could be more |
| // complete. For example, this would not currently identify |
| // overlapping fields in a union as tainted. To identify this we can |
| // check for overlapping/nested byte offsets. |
| if (Kind == I.second && R->isSubRegionOf(I.first)) |
| return true; |
| } |
| } |
| } |
| |
| // If memory region is tainted, data is also tainted. |
| if (const SymbolRegionValue *SRV = dyn_cast<SymbolRegionValue>(*SI)) { |
| if (isTainted(SRV->getRegion(), Kind)) |
| return true; |
| } |
| |
| // If this is a SymbolCast from a tainted value, it's also tainted. |
| if (const SymbolCast *SC = dyn_cast<SymbolCast>(*SI)) { |
| if (isTainted(SC->getOperand(), Kind)) |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |