xref: /llvm-project/clang-tools-extra/clang-tidy/modernize/UseEqualsDeleteCheck.cpp (revision 096977abbf448455519c38b0be3d11f58abb0b5c)
1 //===--- UseEqualsDeleteCheck.cpp - clang-tidy-----------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "UseEqualsDeleteCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Lex/Lexer.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 namespace modernize {
20 
21 static const char SpecialFunction[] = "SpecialFunction";
22 static const char DeletedNotPublic[] = "DeletedNotPublic";
23 
24 void UseEqualsDeleteCheck::registerMatchers(MatchFinder *Finder) {
25   if (!getLangOpts().CPlusPlus)
26     return;
27 
28   auto PrivateSpecialFn = cxxMethodDecl(
29       isPrivate(),
30       anyOf(cxxConstructorDecl(anyOf(isDefaultConstructor(),
31                                      isCopyConstructor(), isMoveConstructor())),
32             cxxMethodDecl(
33                 anyOf(isCopyAssignmentOperator(), isMoveAssignmentOperator())),
34             cxxDestructorDecl()));
35 
36   Finder->addMatcher(
37       cxxMethodDecl(
38           PrivateSpecialFn,
39           unless(anyOf(hasBody(stmt()), isDefaulted(), isDeleted(),
40                        ast_matchers::isTemplateInstantiation(),
41                        // Ensure that all methods except private special member
42                        // functions are defined.
43                        hasParent(cxxRecordDecl(hasMethod(unless(
44                            anyOf(PrivateSpecialFn, hasBody(stmt()), isPure(),
45                                  isDefaulted(), isDeleted()))))))))
46           .bind(SpecialFunction),
47       this);
48 
49   Finder->addMatcher(
50       cxxMethodDecl(isDeleted(), unless(isPublic())).bind(DeletedNotPublic),
51       this);
52 }
53 
54 void UseEqualsDeleteCheck::check(const MatchFinder::MatchResult &Result) {
55   if (const auto *Func =
56           Result.Nodes.getNodeAs<CXXMethodDecl>(SpecialFunction)) {
57     SourceLocation EndLoc = Lexer::getLocForEndOfToken(
58         Func->getLocEnd(), 0, *Result.SourceManager, getLangOpts());
59 
60     // FIXME: Improve FixItHint to make the method public.
61     diag(Func->getLocation(),
62          "use '= delete' to prohibit calling of a special member function")
63         << FixItHint::CreateInsertion(EndLoc, " = delete");
64   } else if (const auto *Func =
65                  Result.Nodes.getNodeAs<CXXMethodDecl>(DeletedNotPublic)) {
66     // Ignore this warning in macros, since it's extremely noisy in code using
67     // DISALLOW_COPY_AND_ASSIGN-style macros and there's no easy way to
68     // automatically fix the warning when macros are in play.
69     if (Func->getLocation().isMacroID())
70       return;
71     // FIXME: Add FixItHint to make the method public.
72     diag(Func->getLocation(), "deleted member function should be public");
73   }
74 }
75 
76 } // namespace modernize
77 } // namespace tidy
78 } // namespace clang
79