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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
//===--- VirtualClassDestructorCheck.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 "VirtualClassDestructorCheck.h"
#include "../utils/LexerUtils.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
#include <string>
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace cppcoreguidelines {
AST_MATCHER(CXXRecordDecl, hasPublicVirtualOrProtectedNonVirtualDestructor) {
// We need to call Node.getDestructor() instead of matching a
// CXXDestructorDecl. Otherwise, tests will fail for class templates, since
// the primary template (not the specialization) always gets a non-virtual
// CXXDestructorDecl in the AST. https://bugs.llvm.org/show_bug.cgi?id=51912
const CXXDestructorDecl *Destructor = Node.getDestructor();
if (!Destructor)
return false;
return (((Destructor->getAccess() == AccessSpecifier::AS_public) &&
Destructor->isVirtual()) ||
((Destructor->getAccess() == AccessSpecifier::AS_protected) &&
!Destructor->isVirtual()));
}
void VirtualClassDestructorCheck::registerMatchers(MatchFinder *Finder) {
ast_matchers::internal::Matcher<CXXRecordDecl> InheritsVirtualMethod =
hasAnyBase(hasType(cxxRecordDecl(has(cxxMethodDecl(isVirtual())))));
Finder->addMatcher(
cxxRecordDecl(
anyOf(has(cxxMethodDecl(isVirtual())), InheritsVirtualMethod),
unless(hasPublicVirtualOrProtectedNonVirtualDestructor()))
.bind("ProblematicClassOrStruct"),
this);
}
static Optional<CharSourceRange>
getVirtualKeywordRange(const CXXDestructorDecl &Destructor,
const SourceManager &SM, const LangOptions &LangOpts) {
if (Destructor.getLocation().isMacroID())
return None;
SourceLocation VirtualBeginLoc = Destructor.getBeginLoc();
SourceLocation VirtualEndLoc = VirtualBeginLoc.getLocWithOffset(
Lexer::MeasureTokenLength(VirtualBeginLoc, SM, LangOpts));
/// Range ends with \c StartOfNextToken so that any whitespace after \c
/// virtual is included.
SourceLocation StartOfNextToken =
Lexer::findNextToken(VirtualEndLoc, SM, LangOpts)
.getValue()
.getLocation();
return CharSourceRange::getCharRange(VirtualBeginLoc, StartOfNextToken);
}
static const AccessSpecDecl *
getPublicASDecl(const CXXRecordDecl &StructOrClass) {
for (DeclContext::specific_decl_iterator<AccessSpecDecl>
AS{StructOrClass.decls_begin()},
ASEnd{StructOrClass.decls_end()};
AS != ASEnd; ++AS) {
AccessSpecDecl *ASDecl = *AS;
if (ASDecl->getAccess() == AccessSpecifier::AS_public)
return ASDecl;
}
return nullptr;
}
static FixItHint
generateUserDeclaredDestructor(const CXXRecordDecl &StructOrClass,
const SourceManager &SourceManager) {
std::string DestructorString;
SourceLocation Loc;
bool AppendLineBreak = false;
const AccessSpecDecl *AccessSpecDecl = getPublicASDecl(StructOrClass);
if (!AccessSpecDecl) {
if (StructOrClass.isClass()) {
Loc = StructOrClass.getEndLoc();
DestructorString = "public:";
AppendLineBreak = true;
} else {
Loc = StructOrClass.getBraceRange().getBegin().getLocWithOffset(1);
}
} else {
Loc = AccessSpecDecl->getEndLoc().getLocWithOffset(1);
}
DestructorString = (llvm::Twine(DestructorString) + "\nvirtual ~" +
StructOrClass.getName().str() + "() = default;" +
(AppendLineBreak ? "\n" : ""))
.str();
return FixItHint::CreateInsertion(Loc, DestructorString);
}
static std::string getSourceText(const CXXDestructorDecl &Destructor) {
std::string SourceText;
llvm::raw_string_ostream DestructorStream(SourceText);
Destructor.print(DestructorStream);
return SourceText;
}
static std::string eraseKeyword(std::string &DestructorString,
const std::string &Keyword) {
size_t KeywordIndex = DestructorString.find(Keyword);
if (KeywordIndex != std::string::npos)
DestructorString.erase(KeywordIndex, Keyword.length());
return DestructorString;
}
static FixItHint changePrivateDestructorVisibilityTo(
const std::string &Visibility, const CXXDestructorDecl &Destructor,
const SourceManager &SM, const LangOptions &LangOpts) {
std::string DestructorString =
(llvm::Twine() + Visibility + ":\n" +
(Visibility == "public" && !Destructor.isVirtual() ? "virtual " : ""))
.str();
std::string OriginalDestructor = getSourceText(Destructor);
if (Visibility == "protected" && Destructor.isVirtualAsWritten())
OriginalDestructor = eraseKeyword(OriginalDestructor, "virtual ");
DestructorString =
(llvm::Twine(DestructorString) + OriginalDestructor +
(Destructor.isExplicitlyDefaulted() ? ";\n" : "") + "private:")
.str();
/// Semicolons ending an explicitly defaulted destructor have to be deleted.
/// Otherwise, the left-over semicolon trails the \c private: access
/// specifier.
SourceLocation EndLocation;
if (Destructor.isExplicitlyDefaulted())
EndLocation =
utils::lexer::findNextTerminator(Destructor.getEndLoc(), SM, LangOpts)
.getLocWithOffset(1);
else
EndLocation = Destructor.getEndLoc().getLocWithOffset(1);
auto OriginalDestructorRange =
CharSourceRange::getCharRange(Destructor.getBeginLoc(), EndLocation);
return FixItHint::CreateReplacement(OriginalDestructorRange,
DestructorString);
}
void VirtualClassDestructorCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *MatchedClassOrStruct =
Result.Nodes.getNodeAs<CXXRecordDecl>("ProblematicClassOrStruct");
const CXXDestructorDecl *Destructor = MatchedClassOrStruct->getDestructor();
if (!Destructor)
return;
if (Destructor->getAccess() == AccessSpecifier::AS_private) {
diag(MatchedClassOrStruct->getLocation(),
"destructor of %0 is private and prevents using the type")
<< MatchedClassOrStruct;
diag(MatchedClassOrStruct->getLocation(),
/*Description=*/"make it public and virtual", DiagnosticIDs::Note)
<< changePrivateDestructorVisibilityTo(
"public", *Destructor, *Result.SourceManager, getLangOpts());
diag(MatchedClassOrStruct->getLocation(),
/*Description=*/"make it protected", DiagnosticIDs::Note)
<< changePrivateDestructorVisibilityTo(
"protected", *Destructor, *Result.SourceManager, getLangOpts());
return;
}
// Implicit destructors are public and non-virtual for classes and structs.
bool ProtectedAndVirtual = false;
FixItHint Fix;
if (MatchedClassOrStruct->hasUserDeclaredDestructor()) {
if (Destructor->getAccess() == AccessSpecifier::AS_public) {
Fix = FixItHint::CreateInsertion(Destructor->getLocation(), "virtual ");
} else if (Destructor->getAccess() == AccessSpecifier::AS_protected) {
ProtectedAndVirtual = true;
if (const auto MaybeRange =
getVirtualKeywordRange(*Destructor, *Result.SourceManager,
Result.Context->getLangOpts()))
Fix = FixItHint::CreateRemoval(*MaybeRange);
}
} else {
Fix = generateUserDeclaredDestructor(*MatchedClassOrStruct,
*Result.SourceManager);
}
diag(MatchedClassOrStruct->getLocation(),
"destructor of %0 is %select{public and non-virtual|protected and "
"virtual}1")
<< MatchedClassOrStruct << ProtectedAndVirtual;
diag(MatchedClassOrStruct->getLocation(),
"make it %select{public and virtual|protected and non-virtual}0",
DiagnosticIDs::Note)
<< ProtectedAndVirtual << Fix;
}
} // namespace cppcoreguidelines
} // namespace tidy
} // namespace clang
|
