1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
//===-- STLAlgorithmModeling.cpp -----------------------------------*- C++ -*--//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Models STL algorithms.
//
//===----------------------------------------------------------------------===//
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "Iterator.h"
using namespace clang;
using namespace ento;
using namespace iterator;
namespace {
class STLAlgorithmModeling : public Checker<eval::Call> {
bool evalFind(CheckerContext &C, const CallExpr *CE) const;
void Find(CheckerContext &C, const CallExpr *CE, unsigned paramNum) const;
using FnCheck = bool (STLAlgorithmModeling::*)(CheckerContext &,
const CallExpr *) const;
const CallDescriptionMap<FnCheck> Callbacks = {
{{{"std", "find"}, 3}, &STLAlgorithmModeling::evalFind},
{{{"std", "find"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_if"}, 3}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_if"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_if_not"}, 3}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_if_not"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_first_of"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_first_of"}, 5}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_first_of"}, 6}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_end"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_end"}, 5}, &STLAlgorithmModeling::evalFind},
{{{"std", "find_end"}, 6}, &STLAlgorithmModeling::evalFind},
{{{"std", "lower_bound"}, 3}, &STLAlgorithmModeling::evalFind},
{{{"std", "lower_bound"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "upper_bound"}, 3}, &STLAlgorithmModeling::evalFind},
{{{"std", "upper_bound"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "search"}, 3}, &STLAlgorithmModeling::evalFind},
{{{"std", "search"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "search"}, 5}, &STLAlgorithmModeling::evalFind},
{{{"std", "search"}, 6}, &STLAlgorithmModeling::evalFind},
{{{"std", "search_n"}, 4}, &STLAlgorithmModeling::evalFind},
{{{"std", "search_n"}, 5}, &STLAlgorithmModeling::evalFind},
{{{"std", "search_n"}, 6}, &STLAlgorithmModeling::evalFind},
};
public:
STLAlgorithmModeling() = default;
bool AggressiveStdFindModeling;
bool evalCall(const CallEvent &Call, CheckerContext &C) const;
}; //
bool STLAlgorithmModeling::evalCall(const CallEvent &Call,
CheckerContext &C) const {
const auto *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
if (!CE)
return false;
const FnCheck *Handler = Callbacks.lookup(Call);
if (!Handler)
return false;
return (this->**Handler)(C, CE);
}
bool STLAlgorithmModeling::evalFind(CheckerContext &C,
const CallExpr *CE) const {
// std::find()-like functions either take their primary range in the first
// two parameters, or if the first parameter is "execution policy" then in
// the second and third. This means that the second parameter must always be
// an iterator.
if (!isIteratorType(CE->getArg(1)->getType()))
return false;
// If no "execution policy" parameter is used then the first argument is the
// beginning of the range.
if (isIteratorType(CE->getArg(0)->getType())) {
Find(C, CE, 0);
return true;
}
// If "execution policy" parameter is used then the second argument is the
// beginning of the range.
if (isIteratorType(CE->getArg(2)->getType())) {
Find(C, CE, 1);
return true;
}
return false;
}
void STLAlgorithmModeling::Find(CheckerContext &C, const CallExpr *CE,
unsigned paramNum) const {
auto State = C.getState();
auto &SVB = C.getSValBuilder();
const auto *LCtx = C.getLocationContext();
SVal RetVal = SVB.conjureSymbolVal(nullptr, CE, LCtx, C.blockCount());
SVal Param = State->getSVal(CE->getArg(paramNum), LCtx);
auto StateFound = State->BindExpr(CE, LCtx, RetVal);
// If we have an iterator position for the range-begin argument then we can
// assume that in case of successful search the position of the found element
// is not ahead of it.
// FIXME: Reverse iterators
const auto *Pos = getIteratorPosition(State, Param);
if (Pos) {
StateFound = createIteratorPosition(StateFound, RetVal, Pos->getContainer(),
CE, LCtx, C.blockCount());
const auto *NewPos = getIteratorPosition(StateFound, RetVal);
assert(NewPos && "Failed to create new iterator position.");
SVal GreaterOrEqual = SVB.evalBinOp(StateFound, BO_GE,
nonloc::SymbolVal(NewPos->getOffset()),
nonloc::SymbolVal(Pos->getOffset()),
SVB.getConditionType());
assert(GreaterOrEqual.getAs<DefinedSVal>() &&
"Symbol comparison must be a `DefinedSVal`");
StateFound = StateFound->assume(GreaterOrEqual.castAs<DefinedSVal>(), true);
}
Param = State->getSVal(CE->getArg(paramNum + 1), LCtx);
// If we have an iterator position for the range-end argument then we can
// assume that in case of successful search the position of the found element
// is ahead of it.
// FIXME: Reverse iterators
Pos = getIteratorPosition(State, Param);
if (Pos) {
StateFound = createIteratorPosition(StateFound, RetVal, Pos->getContainer(),
CE, LCtx, C.blockCount());
const auto *NewPos = getIteratorPosition(StateFound, RetVal);
assert(NewPos && "Failed to create new iterator position.");
SVal Less = SVB.evalBinOp(StateFound, BO_LT,
nonloc::SymbolVal(NewPos->getOffset()),
nonloc::SymbolVal(Pos->getOffset()),
SVB.getConditionType());
assert(Less.getAs<DefinedSVal>() &&
"Symbol comparison must be a `DefinedSVal`");
StateFound = StateFound->assume(Less.castAs<DefinedSVal>(), true);
}
C.addTransition(StateFound);
if (AggressiveStdFindModeling) {
auto StateNotFound = State->BindExpr(CE, LCtx, Param);
C.addTransition(StateNotFound);
}
}
} // namespace
void ento::registerSTLAlgorithmModeling(CheckerManager &Mgr) {
auto *Checker = Mgr.registerChecker<STLAlgorithmModeling>();
Checker->AggressiveStdFindModeling =
Mgr.getAnalyzerOptions().getCheckerBooleanOption(Checker,
"AggressiveStdFindModeling");
}
bool ento::shouldRegisterSTLAlgorithmModeling(const CheckerManager &mgr) {
return true;
}
|
