1//===-- InvalidatedIteratorChecker.cpp ----------------------------*- 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// Defines a checker for access of invalidated iterators. 10// 11//===----------------------------------------------------------------------===// 12 13#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" 14#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 15#include "clang/StaticAnalyzer/Core/Checker.h" 16#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 17#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 18 19 20#include "Iterator.h" 21 22using namespace clang; 23using namespace ento; 24using namespace iterator; 25 26namespace { 27 28class InvalidatedIteratorChecker 29 : public Checker<check::PreCall, check::PreStmt<UnaryOperator>, 30 check::PreStmt<BinaryOperator>, 31 check::PreStmt<ArraySubscriptExpr>, 32 check::PreStmt<MemberExpr>> { 33 34 std::unique_ptr<BugType> InvalidatedBugType; 35 36 void verifyAccess(CheckerContext &C, const SVal &Val) const; 37 void reportBug(const StringRef &Message, const SVal &Val, 38 CheckerContext &C, ExplodedNode *ErrNode) const; 39public: 40 InvalidatedIteratorChecker(); 41 42 void checkPreCall(const CallEvent &Call, CheckerContext &C) const; 43 void checkPreStmt(const UnaryOperator *UO, CheckerContext &C) const; 44 void checkPreStmt(const BinaryOperator *BO, CheckerContext &C) const; 45 void checkPreStmt(const ArraySubscriptExpr *ASE, CheckerContext &C) const; 46 void checkPreStmt(const MemberExpr *ME, CheckerContext &C) const; 47 48}; 49 50} //namespace 51 52InvalidatedIteratorChecker::InvalidatedIteratorChecker() { 53 InvalidatedBugType.reset( 54 new BugType(this, "Iterator invalidated", "Misuse of STL APIs")); 55} 56 57void InvalidatedIteratorChecker::checkPreCall(const CallEvent &Call, 58 CheckerContext &C) const { 59 // Check for access of invalidated position 60 const auto *Func = dyn_cast_or_null<FunctionDecl>(Call.getDecl()); 61 if (!Func) 62 return; 63 64 if (Func->isOverloadedOperator() && 65 isAccessOperator(Func->getOverloadedOperator())) { 66 // Check for any kind of access of invalidated iterator positions 67 if (const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call)) { 68 verifyAccess(C, InstCall->getCXXThisVal()); 69 } else { 70 verifyAccess(C, Call.getArgSVal(0)); 71 } 72 } 73} 74 75void InvalidatedIteratorChecker::checkPreStmt(const UnaryOperator *UO, 76 CheckerContext &C) const { 77 if (isa<CXXThisExpr>(UO->getSubExpr())) 78 return; 79 80 ProgramStateRef State = C.getState(); 81 UnaryOperatorKind OK = UO->getOpcode(); 82 SVal SubVal = State->getSVal(UO->getSubExpr(), C.getLocationContext()); 83 84 if (isAccessOperator(OK)) { 85 verifyAccess(C, SubVal); 86 } 87} 88 89void InvalidatedIteratorChecker::checkPreStmt(const BinaryOperator *BO, 90 CheckerContext &C) const { 91 ProgramStateRef State = C.getState(); 92 BinaryOperatorKind OK = BO->getOpcode(); 93 SVal LVal = State->getSVal(BO->getLHS(), C.getLocationContext()); 94 95 if (isAccessOperator(OK)) { 96 verifyAccess(C, LVal); 97 } 98} 99 100void InvalidatedIteratorChecker::checkPreStmt(const ArraySubscriptExpr *ASE, 101 CheckerContext &C) const { 102 ProgramStateRef State = C.getState(); 103 SVal LVal = State->getSVal(ASE->getLHS(), C.getLocationContext()); 104 verifyAccess(C, LVal); 105} 106 107void InvalidatedIteratorChecker::checkPreStmt(const MemberExpr *ME, 108 CheckerContext &C) const { 109 if (!ME->isArrow() || ME->isImplicitAccess()) 110 return; 111 112 ProgramStateRef State = C.getState(); 113 SVal BaseVal = State->getSVal(ME->getBase(), C.getLocationContext()); 114 verifyAccess(C, BaseVal); 115} 116 117void InvalidatedIteratorChecker::verifyAccess(CheckerContext &C, const SVal &Val) const { 118 auto State = C.getState(); 119 const auto *Pos = getIteratorPosition(State, Val); 120 if (Pos && !Pos->isValid()) { 121 auto *N = C.generateErrorNode(State); 122 if (!N) { 123 return; 124 } 125 reportBug("Invalidated iterator accessed.", Val, C, N); 126 } 127} 128 129void InvalidatedIteratorChecker::reportBug(const StringRef &Message, 130 const SVal &Val, CheckerContext &C, 131 ExplodedNode *ErrNode) const { 132 auto R = std::make_unique<PathSensitiveBugReport>(*InvalidatedBugType, 133 Message, ErrNode); 134 R->markInteresting(Val); 135 C.emitReport(std::move(R)); 136} 137 138void ento::registerInvalidatedIteratorChecker(CheckerManager &mgr) { 139 mgr.registerChecker<InvalidatedIteratorChecker>(); 140} 141 142bool ento::shouldRegisterInvalidatedIteratorChecker(const CheckerManager &mgr) { 143 return true; 144} 145