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 22 using namespace clang; 23 using namespace ento; 24 using namespace iterator; 25 26 namespace { 27 28 class 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; 39 public: 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 52 InvalidatedIteratorChecker::InvalidatedIteratorChecker() { 53 InvalidatedBugType.reset( 54 new BugType(this, "Iterator invalidated", "Misuse of STL APIs")); 55 } 56 57 void 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 75 void 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 89 void 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 } 99 100 void 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 } 106 107 void 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 } 116 117 void 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 } 128 129 void 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 } 137 138 void ento::registerInvalidatedIteratorChecker(CheckerManager &mgr) { 139 mgr.registerChecker<InvalidatedIteratorChecker>(); 140 } 141 142 bool ento::shouldRegisterInvalidatedIteratorChecker(const CheckerManager &mgr) { 143 return true; 144 } 145