clang  14.0.0git
DebugIteratorModeling.cpp
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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 
18 
19 #include "Iterator.h"
20 
21 using namespace clang;
22 using namespace ento;
23 using namespace iterator;
24 
25 namespace {
26 
27 class DebugIteratorModeling
28  : public Checker<eval::Call> {
29 
30  std::unique_ptr<BugType> DebugMsgBugType;
31 
32  template <typename Getter>
33  void analyzerIteratorDataField(const CallExpr *CE, CheckerContext &C,
34  Getter get, SVal Default) const;
35  void analyzerIteratorPosition(const CallExpr *CE, CheckerContext &C) const;
36  void analyzerIteratorContainer(const CallExpr *CE, CheckerContext &C) const;
37  void analyzerIteratorValidity(const CallExpr *CE, CheckerContext &C) const;
38  ExplodedNode *reportDebugMsg(llvm::StringRef Msg, CheckerContext &C) const;
39 
40  typedef void (DebugIteratorModeling::*FnCheck)(const CallExpr *,
41  CheckerContext &) const;
42 
43  CallDescriptionMap<FnCheck> Callbacks = {
44  {{0, "clang_analyzer_iterator_position", 1},
45  &DebugIteratorModeling::analyzerIteratorPosition},
46  {{0, "clang_analyzer_iterator_container", 1},
47  &DebugIteratorModeling::analyzerIteratorContainer},
48  {{0, "clang_analyzer_iterator_validity", 1},
49  &DebugIteratorModeling::analyzerIteratorValidity},
50  };
51 
52 public:
53  DebugIteratorModeling();
54 
55  bool evalCall(const CallEvent &Call, CheckerContext &C) const;
56 };
57 
58 } //namespace
59 
60 DebugIteratorModeling::DebugIteratorModeling() {
61  DebugMsgBugType.reset(
62  new BugType(this, "Checking analyzer assumptions", "debug",
63  /*SuppressOnSink=*/true));
64 }
65 
66 bool DebugIteratorModeling::evalCall(const CallEvent &Call,
67  CheckerContext &C) const {
68  const auto *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
69  if (!CE)
70  return false;
71 
72  const FnCheck *Handler = Callbacks.lookup(Call);
73  if (!Handler)
74  return false;
75 
76  (this->**Handler)(CE, C);
77  return true;
78 }
79 
80 template <typename Getter>
81 void DebugIteratorModeling::analyzerIteratorDataField(const CallExpr *CE,
82  CheckerContext &C,
83  Getter get,
84  SVal Default) const {
85  if (CE->getNumArgs() == 0) {
86  reportDebugMsg("Missing iterator argument", C);
87  return;
88  }
89 
90  auto State = C.getState();
91  SVal V = C.getSVal(CE->getArg(0));
92  const auto *Pos = getIteratorPosition(State, V);
93  if (Pos) {
94  State = State->BindExpr(CE, C.getLocationContext(), get(Pos));
95  } else {
96  State = State->BindExpr(CE, C.getLocationContext(), Default);
97  }
98  C.addTransition(State);
99 }
100 
101 void DebugIteratorModeling::analyzerIteratorPosition(const CallExpr *CE,
102  CheckerContext &C) const {
103  auto &BVF = C.getSValBuilder().getBasicValueFactory();
104  analyzerIteratorDataField(CE, C, [](const IteratorPosition *P) {
105  return nonloc::SymbolVal(P->getOffset());
106  }, nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(0))));
107 }
108 
109 void DebugIteratorModeling::analyzerIteratorContainer(const CallExpr *CE,
110  CheckerContext &C) const {
111  auto &BVF = C.getSValBuilder().getBasicValueFactory();
112  analyzerIteratorDataField(CE, C, [](const IteratorPosition *P) {
113  return loc::MemRegionVal(P->getContainer());
114  }, loc::ConcreteInt(BVF.getValue(llvm::APSInt::get(0))));
115 }
116 
117 void DebugIteratorModeling::analyzerIteratorValidity(const CallExpr *CE,
118  CheckerContext &C) const {
119  auto &BVF = C.getSValBuilder().getBasicValueFactory();
120  analyzerIteratorDataField(CE, C, [&BVF](const IteratorPosition *P) {
121  return
122  nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get((P->isValid()))));
123  }, nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(0))));
124 }
125 
126 ExplodedNode *DebugIteratorModeling::reportDebugMsg(llvm::StringRef Msg,
127  CheckerContext &C) const {
128  ExplodedNode *N = C.generateNonFatalErrorNode();
129  if (!N)
130  return nullptr;
131 
132  auto &BR = C.getBugReporter();
133  BR.emitReport(std::make_unique<PathSensitiveBugReport>(*DebugMsgBugType,
134  Msg, N));
135  return N;
136 }
137 
138 void ento::registerDebugIteratorModeling(CheckerManager &mgr) {
139  mgr.registerChecker<DebugIteratorModeling>();
140 }
141 
142 bool ento::shouldRegisterDebugIteratorModeling(const CheckerManager &mgr) {
143  return true;
144 }
AttributeLangSupport::C
@ C
Definition: SemaDeclAttr.cpp:54
clang::index::SymbolRole::Call
@ Call
CallEvent.h
V
#define V(N, I)
Definition: ASTContext.h:3121
BuiltinCheckerRegistration.h
clang::CallExpr::getArg
Expr * getArg(unsigned Arg)
getArg - Return the specified argument.
Definition: Expr.h:2986
clang::ento::iterator::getIteratorPosition
const IteratorPosition * getIteratorPosition(ProgramStateRef State, const SVal &Val)
Definition: Iterator.cpp:184
P
StringRef P
Definition: ASTMatchersInternal.cpp:563
BugType.h
clang::CallExpr::getNumArgs
unsigned getNumArgs() const
getNumArgs - Return the number of actual arguments to this call.
Definition: Expr.h:2973
Iterator.h
State
LineState State
Definition: UnwrappedLineFormatter.cpp:986
CheckerContext.h
Checker.h
clang
Definition: CalledOnceCheck.h:17
clang::CallExpr
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2795