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
InvalidatedIteratorChecker()52 InvalidatedIteratorChecker::InvalidatedIteratorChecker() {
53 InvalidatedBugType.reset(
54 new BugType(this, "Iterator invalidated", "Misuse of STL APIs"));
55 }
56
checkPreCall(const CallEvent & Call,CheckerContext & C) const57 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
checkPreStmt(const UnaryOperator * UO,CheckerContext & C) const75 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
checkPreStmt(const BinaryOperator * BO,CheckerContext & C) const89 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
checkPreStmt(const ArraySubscriptExpr * ASE,CheckerContext & C) const100 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
checkPreStmt(const MemberExpr * ME,CheckerContext & C) const107 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
verifyAccess(CheckerContext & C,const SVal & Val) const117 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
reportBug(const StringRef & Message,const SVal & Val,CheckerContext & C,ExplodedNode * ErrNode) const129 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
registerInvalidatedIteratorChecker(CheckerManager & mgr)138 void ento::registerInvalidatedIteratorChecker(CheckerManager &mgr) {
139 mgr.registerChecker<InvalidatedIteratorChecker>();
140 }
141
shouldRegisterInvalidatedIteratorChecker(const CheckerManager & mgr)142 bool ento::shouldRegisterInvalidatedIteratorChecker(const CheckerManager &mgr) {
143 return true;
144 }
145