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
|
//===--- ChainedComparisonCheck.cpp - clang-tidy --------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "ChainedComparisonCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include <algorithm>
using namespace clang::ast_matchers;
namespace clang::tidy::bugprone {
static bool isExprAComparisonOperator(const Expr *E) {
if (const auto *Op = dyn_cast_or_null<BinaryOperator>(E->IgnoreImplicit()))
return Op->isComparisonOp();
if (const auto *Op =
dyn_cast_or_null<CXXOperatorCallExpr>(E->IgnoreImplicit()))
return Op->isComparisonOp();
return false;
}
namespace {
AST_MATCHER(BinaryOperator,
hasBinaryOperatorAChildComparisonOperatorWithoutParen) {
return isExprAComparisonOperator(Node.getLHS()) ||
isExprAComparisonOperator(Node.getRHS());
}
AST_MATCHER(CXXOperatorCallExpr,
hasCppOperatorAChildComparisonOperatorWithoutParen) {
return llvm::any_of(Node.arguments(), isExprAComparisonOperator);
}
struct ChainedComparisonData {
llvm::SmallString<256U> Name;
llvm::SmallVector<const Expr *, 32U> Operands;
explicit ChainedComparisonData(const Expr *Op) { extract(Op); }
private:
void add(const Expr *Operand);
void add(llvm::StringRef Opcode);
void extract(const Expr *Op);
void extract(const BinaryOperator *Op);
void extract(const CXXOperatorCallExpr *Op);
};
void ChainedComparisonData::add(const Expr *Operand) {
if (!Name.empty())
Name += ' ';
Name += 'v';
Name += std::to_string(Operands.size());
Operands.push_back(Operand);
}
void ChainedComparisonData::add(llvm::StringRef Opcode) {
Name += ' ';
Name += Opcode;
}
void ChainedComparisonData::extract(const BinaryOperator *Op) {
const Expr *LHS = Op->getLHS()->IgnoreImplicit();
if (isExprAComparisonOperator(LHS))
extract(LHS);
else
add(LHS);
add(Op->getOpcodeStr());
const Expr *RHS = Op->getRHS()->IgnoreImplicit();
if (isExprAComparisonOperator(RHS))
extract(RHS);
else
add(RHS);
}
void ChainedComparisonData::extract(const CXXOperatorCallExpr *Op) {
const Expr *FirstArg = Op->getArg(0U)->IgnoreImplicit();
if (isExprAComparisonOperator(FirstArg))
extract(FirstArg);
else
add(FirstArg);
add(getOperatorSpelling(Op->getOperator()));
const Expr *SecondArg = Op->getArg(1U)->IgnoreImplicit();
if (isExprAComparisonOperator(SecondArg))
extract(SecondArg);
else
add(SecondArg);
}
void ChainedComparisonData::extract(const Expr *Op) {
if (!Op)
return;
if (const auto *BinaryOp = dyn_cast<BinaryOperator>(Op)) {
extract(BinaryOp);
return;
}
if (const auto *OverloadedOp = dyn_cast<CXXOperatorCallExpr>(Op)) {
if (OverloadedOp->getNumArgs() == 2U)
extract(OverloadedOp);
}
}
} // namespace
void ChainedComparisonCheck::registerMatchers(MatchFinder *Finder) {
const auto OperatorMatcher = expr(anyOf(
binaryOperator(isComparisonOperator(),
hasBinaryOperatorAChildComparisonOperatorWithoutParen()),
cxxOperatorCallExpr(
isComparisonOperator(),
hasCppOperatorAChildComparisonOperatorWithoutParen())));
Finder->addMatcher(
expr(OperatorMatcher, unless(hasParent(OperatorMatcher))).bind("op"),
this);
}
void ChainedComparisonCheck::check(const MatchFinder::MatchResult &Result) {
const auto *MatchedOperator = Result.Nodes.getNodeAs<Expr>("op");
ChainedComparisonData Data(MatchedOperator);
if (Data.Operands.empty())
return;
diag(MatchedOperator->getBeginLoc(),
"chained comparison '%0' may generate unintended results, use "
"parentheses to specify order of evaluation or a logical operator to "
"separate comparison expressions")
<< llvm::StringRef(Data.Name).trim() << MatchedOperator->getSourceRange();
for (std::size_t Index = 0U; Index < Data.Operands.size(); ++Index) {
diag(Data.Operands[Index]->getBeginLoc(), "operand 'v%0' is here",
DiagnosticIDs::Note)
<< Index << Data.Operands[Index]->getSourceRange();
}
}
} // namespace clang::tidy::bugprone
|
