23 using namespace clang;
29 class IteratorRangeChecker
30 :
public Checker<check::PreCall> {
32 std::unique_ptr<BugType> OutOfRangeBugType;
34 void verifyDereference(CheckerContext &C,
const SVal &Val)
const;
35 void verifyIncrement(CheckerContext &C,
const SVal &Iter)
const;
36 void verifyDecrement(CheckerContext &C,
const SVal &Iter)
const;
38 const SVal &LHS,
const SVal &RHS)
const;
39 void reportBug(
const StringRef &Message,
const SVal &Val,
40 CheckerContext &C, ExplodedNode *ErrNode)
const;
42 IteratorRangeChecker();
44 void checkPreCall(
const CallEvent &Call, CheckerContext &C)
const;
55 IteratorRangeChecker::IteratorRangeChecker() {
56 OutOfRangeBugType.reset(
57 new BugType(
this,
"Iterator out of range",
"Misuse of STL APIs"));
60 void IteratorRangeChecker::checkPreCall(
const CallEvent &Call,
61 CheckerContext &C)
const {
63 const auto *Func = dyn_cast_or_null<FunctionDecl>(Call.getDecl());
67 if (Func->isOverloadedOperator()) {
70 if (
const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call)) {
71 verifyIncrement(C, InstCall->getCXXThisVal());
73 if (Call.getNumArgs() >= 1) {
74 verifyIncrement(C, Call.getArgSVal(0));
79 if (
const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call)) {
80 verifyDecrement(C, InstCall->getCXXThisVal());
82 if (Call.getNumArgs() >= 1) {
83 verifyDecrement(C, Call.getArgSVal(0));
87 if (
const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call)) {
89 if (Call.getNumArgs() >= 1 &&
90 Call.getArgExpr(0)->getType()->isIntegralOrEnumerationType()) {
91 verifyRandomIncrOrDecr(C, Func->getOverloadedOperator(),
92 InstCall->getCXXThisVal(),
96 if (Call.getNumArgs() >= 2 &&
97 Call.getArgExpr(1)->getType()->isIntegralOrEnumerationType()) {
98 verifyRandomIncrOrDecr(C, Func->getOverloadedOperator(),
99 Call.getArgSVal(0), Call.getArgSVal(1));
104 if (
const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call)) {
105 verifyDereference(C, InstCall->getCXXThisVal());
107 verifyDereference(C, Call.getArgSVal(0));
113 void IteratorRangeChecker::verifyDereference(CheckerContext &C,
114 const SVal &Val)
const {
115 auto State = C.getState();
117 if (Pos && isPastTheEnd(
State, *Pos)) {
118 auto *N = C.generateErrorNode(
State);
121 reportBug(
"Past-the-end iterator dereferenced.", Val, C, N);
126 void IteratorRangeChecker::verifyIncrement(CheckerContext &C,
127 const SVal &Iter)
const {
128 auto &BVF = C.getSValBuilder().getBasicValueFactory();
129 verifyRandomIncrOrDecr(C, OO_Plus, Iter,
130 nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(1))));
133 void IteratorRangeChecker::verifyDecrement(CheckerContext &C,
134 const SVal &Iter)
const {
135 auto &BVF = C.getSValBuilder().getBasicValueFactory();
136 verifyRandomIncrOrDecr(C, OO_Minus, Iter,
137 nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(1))));
140 void IteratorRangeChecker::verifyRandomIncrOrDecr(CheckerContext &C,
143 const SVal &RHS)
const {
144 auto State = C.getState();
147 if (
auto ValAsLoc = RHS.getAs<Loc>()) {
151 if (
Value.isUnknown())
166 "Iterator should have position after successful advancement");
167 if (isAheadOfRange(
State, *PosAfter)) {
168 auto *N = C.generateErrorNode(
State);
171 reportBug(
"Iterator decremented ahead of its valid range.", LHS,
174 if (isBehindPastTheEnd(
State, *PosAfter)) {
175 auto *N = C.generateErrorNode(
State);
178 reportBug(
"Iterator incremented behind the past-the-end " 179 "iterator.", LHS, C, N);
183 void IteratorRangeChecker::reportBug(
const StringRef &Message,
184 const SVal &Val, CheckerContext &C,
185 ExplodedNode *ErrNode)
const {
186 auto R = std::make_unique<PathSensitiveBugReport>(*OutOfRangeBugType, Message,
188 R->markInteresting(Val);
189 C.emitReport(std::move(R));
199 auto &BVF = State->getBasicVals();
201 nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(0))),
205 bool isPastTheEnd(
ProgramStateRef State,
const IteratorPosition &Pos) {
206 const auto *Cont = Pos.getContainer();
211 const auto End = CData->getEnd();
213 if (isEqual(State, Pos.getOffset(),
End)) {
221 bool isAheadOfRange(
ProgramStateRef State,
const IteratorPosition &Pos) {
222 const auto *Cont = Pos.getContainer();
227 const auto Beg = CData->getBegin();
229 if (isLess(State, Pos.getOffset(), Beg)) {
237 bool isBehindPastTheEnd(
ProgramStateRef State,
const IteratorPosition &Pos) {
238 const auto *Cont = Pos.getContainer();
243 const auto End = CData->getEnd();
245 if (isGreater(State, Pos.getOffset(),
End)) {
254 return compare(State, Sym1, Sym2, BO_LT);
258 return compare(State, Sym1, Sym2, BO_GT);
262 return compare(State, Sym1, Sym2, BO_EQ);
267 void ento::registerIteratorRangeChecker(CheckerManager &mgr) {
268 mgr.registerChecker<IteratorRangeChecker>();
271 bool ento::shouldRegisterIteratorRangeChecker(
const LangOptions &LO) {
bool isDecrementOperator(OverloadedOperatorKind OK)
IntrusiveRefCntPtr< const ProgramState > ProgramStateRef
const SymExpr * SymbolRef
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
bool isIncrementOperator(OverloadedOperatorKind OK)
const IteratorPosition * getIteratorPosition(ProgramStateRef State, const SVal &Val)
const ContainerData * getContainerData(ProgramStateRef State, const MemRegion *Cont)
bool isDereferenceOperator(OverloadedOperatorKind OK)
Dataflow Directional Tag Classes.
OverloadedOperatorKind
Enumeration specifying the different kinds of C++ overloaded operators.
bool isRandomIncrOrDecrOperator(OverloadedOperatorKind OK)
ProgramStateRef advancePosition(ProgramStateRef State, const SVal &Iter, OverloadedOperatorKind Op, const SVal &Distance)
bool compare(ProgramStateRef State, SymbolRef Sym1, SymbolRef Sym2, BinaryOperator::Opcode Opc)