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
|
//===--- UniqueptrResetReleaseCheck.cpp - clang-tidy ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "UniqueptrResetReleaseCheck.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace misc {
void UniqueptrResetReleaseCheck::registerMatchers(MatchFinder *Finder) {
// Only register the matchers for C++11; the functionality currently does not
// provide any benefit to other languages, despite being benign.
if (!getLangOpts().CPlusPlus11)
return;
Finder->addMatcher(
cxxMemberCallExpr(
on(expr().bind("left")), callee(memberExpr().bind("reset_member")),
callee(
cxxMethodDecl(hasName("reset"),
ofClass(cxxRecordDecl(hasName("::std::unique_ptr"),
decl().bind("left_class"))))),
has(ignoringParenImpCasts(cxxMemberCallExpr(
on(expr().bind("right")),
callee(memberExpr().bind("release_member")),
callee(cxxMethodDecl(
hasName("release"),
ofClass(cxxRecordDecl(hasName("::std::unique_ptr"),
decl().bind("right_class")))))))))
.bind("reset_call"),
this);
}
namespace {
const Type *getDeleterForUniquePtr(const MatchFinder::MatchResult &Result,
StringRef ID) {
const auto *Class =
Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>(ID);
if (!Class)
return nullptr;
auto DeleterArgument = Class->getTemplateArgs()[1];
if (DeleterArgument.getKind() != TemplateArgument::Type)
return nullptr;
return DeleterArgument.getAsType().getTypePtr();
}
bool areDeletersCompatible(const MatchFinder::MatchResult &Result) {
const Type *LeftDeleterType = getDeleterForUniquePtr(Result, "left_class");
const Type *RightDeleterType = getDeleterForUniquePtr(Result, "right_class");
if (LeftDeleterType->getUnqualifiedDesugaredType() ==
RightDeleterType->getUnqualifiedDesugaredType()) {
// Same type. We assume they are compatible.
// This check handles the case where the deleters are function pointers.
return true;
}
const CXXRecordDecl *LeftDeleter = LeftDeleterType->getAsCXXRecordDecl();
const CXXRecordDecl *RightDeleter = RightDeleterType->getAsCXXRecordDecl();
if (!LeftDeleter || !RightDeleter)
return false;
if (LeftDeleter->getCanonicalDecl() == RightDeleter->getCanonicalDecl()) {
// Same class. We assume they are compatible.
return true;
}
const auto *LeftAsTemplate =
dyn_cast<ClassTemplateSpecializationDecl>(LeftDeleter);
const auto *RightAsTemplate =
dyn_cast<ClassTemplateSpecializationDecl>(RightDeleter);
if (LeftAsTemplate && RightAsTemplate &&
LeftAsTemplate->getSpecializedTemplate() ==
RightAsTemplate->getSpecializedTemplate()) {
// They are different instantiations of the same template. We assume they
// are compatible.
// This handles things like std::default_delete<Base> vs.
// std::default_delete<Derived>.
return true;
}
return false;
}
} // namespace
void UniqueptrResetReleaseCheck::check(const MatchFinder::MatchResult &Result) {
if (!areDeletersCompatible(Result))
return;
const auto *ResetMember = Result.Nodes.getNodeAs<MemberExpr>("reset_member");
const auto *ReleaseMember =
Result.Nodes.getNodeAs<MemberExpr>("release_member");
const auto *Right = Result.Nodes.getNodeAs<Expr>("right");
const auto *Left = Result.Nodes.getNodeAs<Expr>("left");
const auto *ResetCall =
Result.Nodes.getNodeAs<CXXMemberCallExpr>("reset_call");
std::string LeftText = clang::Lexer::getSourceText(
CharSourceRange::getTokenRange(Left->getSourceRange()),
*Result.SourceManager, getLangOpts());
std::string RightText = clang::Lexer::getSourceText(
CharSourceRange::getTokenRange(Right->getSourceRange()),
*Result.SourceManager, getLangOpts());
if (ResetMember->isArrow())
LeftText = "*" + LeftText;
if (ReleaseMember->isArrow())
RightText = "*" + RightText;
std::string DiagText;
// Even if x was rvalue, *x is not rvalue anymore.
if (!Right->isRValue() || ReleaseMember->isArrow()) {
RightText = "std::move(" + RightText + ")";
DiagText = "prefer ptr1 = std::move(ptr2) over ptr1.reset(ptr2.release())";
} else {
DiagText =
"prefer ptr = ReturnUnique() over ptr.reset(ReturnUnique().release())";
}
std::string NewText = LeftText + " = " + RightText;
diag(ResetMember->getExprLoc(), DiagText) << FixItHint::CreateReplacement(
CharSourceRange::getTokenRange(ResetCall->getSourceRange()), NewText);
}
} // namespace misc
} // namespace tidy
} // namespace clang
|
