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
|
//===--- PreferIsaOrDynCastInConditionalsCheck.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 "PreferIsaOrDynCastInConditionalsCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace ast_matchers {
AST_MATCHER(Expr, isMacroID) { return Node.getExprLoc().isMacroID(); }
} // namespace ast_matchers
namespace tidy {
namespace llvm_check {
void PreferIsaOrDynCastInConditionalsCheck::registerMatchers(
MatchFinder *Finder) {
auto Condition = hasCondition(implicitCastExpr(has(
callExpr(
allOf(unless(isMacroID()), unless(cxxMemberCallExpr()),
anyOf(callee(namedDecl(hasName("cast"))),
callee(namedDecl(hasName("dyn_cast")).bind("dyn_cast")))))
.bind("call"))));
auto Any = anyOf(
has(declStmt(containsDeclaration(
0,
varDecl(hasInitializer(
callExpr(allOf(unless(isMacroID()), unless(cxxMemberCallExpr()),
callee(namedDecl(hasName("cast")))))
.bind("assign")))))),
Condition);
auto CallExpression =
callExpr(
allOf(
unless(isMacroID()), unless(cxxMemberCallExpr()),
allOf(callee(namedDecl(hasAnyName("isa", "cast", "cast_or_null",
"dyn_cast", "dyn_cast_or_null"))
.bind("func")),
hasArgument(
0,
mapAnyOf(declRefExpr, cxxMemberCallExpr).bind("arg")))))
.bind("rhs");
Finder->addMatcher(
traverse(TK_AsIs,
stmt(anyOf(
ifStmt(Any), whileStmt(Any), doStmt(Condition),
binaryOperator(
allOf(unless(isExpansionInFileMatching(
"llvm/include/llvm/Support/Casting.h")),
hasOperatorName("&&"),
hasLHS(implicitCastExpr().bind("lhs")),
hasRHS(anyOf(implicitCastExpr(has(CallExpression)),
CallExpression))))
.bind("and")))),
this);
}
void PreferIsaOrDynCastInConditionalsCheck::check(
const MatchFinder::MatchResult &Result) {
if (const auto *MatchedDecl = Result.Nodes.getNodeAs<CallExpr>("assign")) {
SourceLocation StartLoc = MatchedDecl->getCallee()->getExprLoc();
SourceLocation EndLoc =
StartLoc.getLocWithOffset(StringRef("cast").size() - 1);
diag(MatchedDecl->getBeginLoc(),
"cast<> in conditional will assert rather than return a null pointer")
<< FixItHint::CreateReplacement(SourceRange(StartLoc, EndLoc),
"dyn_cast");
} else if (const auto *MatchedDecl =
Result.Nodes.getNodeAs<CallExpr>("call")) {
SourceLocation StartLoc = MatchedDecl->getCallee()->getExprLoc();
SourceLocation EndLoc =
StartLoc.getLocWithOffset(StringRef("cast").size() - 1);
StringRef Message =
"cast<> in conditional will assert rather than return a null pointer";
if (Result.Nodes.getNodeAs<NamedDecl>("dyn_cast"))
Message = "return value from dyn_cast<> not used";
diag(MatchedDecl->getBeginLoc(), Message)
<< FixItHint::CreateReplacement(SourceRange(StartLoc, EndLoc), "isa");
} else if (const auto *MatchedDecl =
Result.Nodes.getNodeAs<BinaryOperator>("and")) {
const auto *LHS = Result.Nodes.getNodeAs<ImplicitCastExpr>("lhs");
const auto *RHS = Result.Nodes.getNodeAs<CallExpr>("rhs");
const auto *Arg = Result.Nodes.getNodeAs<Expr>("arg");
const auto *Func = Result.Nodes.getNodeAs<NamedDecl>("func");
assert(LHS && "LHS is null");
assert(RHS && "RHS is null");
assert(Arg && "Arg is null");
assert(Func && "Func is null");
StringRef LHSString(Lexer::getSourceText(
CharSourceRange::getTokenRange(LHS->getSourceRange()),
*Result.SourceManager, getLangOpts()));
StringRef ArgString(Lexer::getSourceText(
CharSourceRange::getTokenRange(Arg->getSourceRange()),
*Result.SourceManager, getLangOpts()));
if (ArgString != LHSString)
return;
StringRef RHSString(Lexer::getSourceText(
CharSourceRange::getTokenRange(RHS->getSourceRange()),
*Result.SourceManager, getLangOpts()));
std::string Replacement("isa_and_nonnull");
Replacement += RHSString.substr(Func->getName().size());
diag(MatchedDecl->getBeginLoc(),
"isa_and_nonnull<> is preferred over an explicit test for null "
"followed by calling isa<>")
<< FixItHint::CreateReplacement(SourceRange(MatchedDecl->getBeginLoc(),
MatchedDecl->getEndLoc()),
Replacement);
}
}
} // namespace llvm_check
} // namespace tidy
} // namespace clang
|
