clang 18.0.0git
DebugIteratorModeling.cpp
Go to the documentation of this file.
1//===-- DebugIteratorModeling.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 debugging iterator modeling.
10//
11//===----------------------------------------------------------------------===//
12
19
20#include "Iterator.h"
21
22using namespace clang;
23using namespace ento;
24using namespace iterator;
25
26namespace {
27
28class DebugIteratorModeling
29 : public Checker<eval::Call> {
30
31 std::unique_ptr<BugType> DebugMsgBugType;
32
33 template <typename Getter>
34 void analyzerIteratorDataField(const CallExpr *CE, CheckerContext &C,
35 Getter get, SVal Default) const;
36 void analyzerIteratorPosition(const CallExpr *CE, CheckerContext &C) const;
37 void analyzerIteratorContainer(const CallExpr *CE, CheckerContext &C) const;
38 void analyzerIteratorValidity(const CallExpr *CE, CheckerContext &C) const;
39 ExplodedNode *reportDebugMsg(llvm::StringRef Msg, CheckerContext &C) const;
40
41 typedef void (DebugIteratorModeling::*FnCheck)(const CallExpr *,
42 CheckerContext &) const;
43
44 CallDescriptionMap<FnCheck> Callbacks = {
45 {{{"clang_analyzer_iterator_position"}, 1},
46 &DebugIteratorModeling::analyzerIteratorPosition},
47 {{{"clang_analyzer_iterator_container"}, 1},
48 &DebugIteratorModeling::analyzerIteratorContainer},
49 {{{"clang_analyzer_iterator_validity"}, 1},
50 &DebugIteratorModeling::analyzerIteratorValidity},
51 };
52
53public:
54 DebugIteratorModeling();
55
56 bool evalCall(const CallEvent &Call, CheckerContext &C) const;
57};
58
59} //namespace
60
61DebugIteratorModeling::DebugIteratorModeling() {
62 DebugMsgBugType.reset(
63 new BugType(this, "Checking analyzer assumptions", "debug",
64 /*SuppressOnSink=*/true));
65}
66
67bool DebugIteratorModeling::evalCall(const CallEvent &Call,
68 CheckerContext &C) const {
69 const auto *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
70 if (!CE)
71 return false;
72
73 const FnCheck *Handler = Callbacks.lookup(Call);
74 if (!Handler)
75 return false;
76
77 (this->**Handler)(CE, C);
78 return true;
79}
80
81template <typename Getter>
82void DebugIteratorModeling::analyzerIteratorDataField(const CallExpr *CE,
84 Getter get,
85 SVal Default) const {
86 if (CE->getNumArgs() == 0) {
87 reportDebugMsg("Missing iterator argument", C);
88 return;
89 }
90
91 auto State = C.getState();
92 SVal V = C.getSVal(CE->getArg(0));
93 const auto *Pos = getIteratorPosition(State, V);
94 if (Pos) {
95 State = State->BindExpr(CE, C.getLocationContext(), get(Pos));
96 } else {
97 State = State->BindExpr(CE, C.getLocationContext(), Default);
98 }
99 C.addTransition(State);
100}
101
102void DebugIteratorModeling::analyzerIteratorPosition(const CallExpr *CE,
103 CheckerContext &C) const {
104 auto &BVF = C.getSValBuilder().getBasicValueFactory();
105 analyzerIteratorDataField(CE, C, [](const IteratorPosition *P) {
106 return nonloc::SymbolVal(P->getOffset());
107 }, nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(0))));
108}
109
110void DebugIteratorModeling::analyzerIteratorContainer(const CallExpr *CE,
111 CheckerContext &C) const {
112 auto &BVF = C.getSValBuilder().getBasicValueFactory();
113 analyzerIteratorDataField(CE, C, [](const IteratorPosition *P) {
114 return loc::MemRegionVal(P->getContainer());
115 }, loc::ConcreteInt(BVF.getValue(llvm::APSInt::get(0))));
116}
117
118void DebugIteratorModeling::analyzerIteratorValidity(const CallExpr *CE,
119 CheckerContext &C) const {
120 auto &BVF = C.getSValBuilder().getBasicValueFactory();
121 analyzerIteratorDataField(CE, C, [&BVF](const IteratorPosition *P) {
122 return
123 nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get((P->isValid()))));
124 }, nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(0))));
125}
126
127ExplodedNode *DebugIteratorModeling::reportDebugMsg(llvm::StringRef Msg,
128 CheckerContext &C) const {
129 ExplodedNode *N = C.generateNonFatalErrorNode();
130 if (!N)
131 return nullptr;
132
133 auto &BR = C.getBugReporter();
134 BR.emitReport(std::make_unique<PathSensitiveBugReport>(*DebugMsgBugType,
135 Msg, N));
136 return N;
137}
138
139void ento::registerDebugIteratorModeling(CheckerManager &mgr) {
140 mgr.registerChecker<DebugIteratorModeling>();
141}
142
143bool ento::shouldRegisterDebugIteratorModeling(const CheckerManager &mgr) {
144 return true;
145}
#define V(N, I)
Definition: ASTContext.h:3241
StringRef P
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2847
Expr * getArg(unsigned Arg)
getArg - Return the specified argument.
Definition: Expr.h:3038
unsigned getNumArgs() const
getNumArgs - Return the number of actual arguments to this call.
Definition: Expr.h:3025
An immutable map from CallDescriptions to arbitrary data.
Represents an abstract call to a function or method along a particular path.
Definition: CallEvent.h:152
CHECKER * registerChecker(AT &&... Args)
Used to register checkers.
SVal - This represents a symbolic expression, which can be either an L-value or an R-value.
Definition: SVals.h:55
Value representing integer constant.
Definition: SVals.h:305
Represents symbolic expression that isn't a location.
Definition: SVals.h:284
const IteratorPosition * getIteratorPosition(ProgramStateRef State, const SVal &Val)
Definition: Iterator.cpp:184