1 //===--- UseEqualsDeleteCheck.cpp - clang-tidy-----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "UseEqualsDeleteCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Lex/Lexer.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace modernize {
19 
20 static const char SpecialFunction[] = "SpecialFunction";
21 static const char DeletedNotPublic[] = "DeletedNotPublic";
22 
storeOptions(ClangTidyOptions::OptionMap & Opts)23 void UseEqualsDeleteCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
24   Options.store(Opts, "IgnoreMacros", IgnoreMacros);
25 }
26 
registerMatchers(MatchFinder * Finder)27 void UseEqualsDeleteCheck::registerMatchers(MatchFinder *Finder) {
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(hasAnyBody(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, hasAnyBody(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 
check(const MatchFinder::MatchResult & Result)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->getEndLoc(), 0, *Result.SourceManager, getLangOpts());
59 
60     if (Func->getLocation().isMacroID() && IgnoreMacros)
61       return;
62     // FIXME: Improve FixItHint to make the method public.
63     diag(Func->getLocation(),
64          "use '= delete' to prohibit calling of a special member function")
65         << FixItHint::CreateInsertion(EndLoc, " = delete");
66   } else if (const auto *Func =
67                  Result.Nodes.getNodeAs<CXXMethodDecl>(DeletedNotPublic)) {
68     // Ignore this warning in macros, since it's extremely noisy in code using
69     // DISALLOW_COPY_AND_ASSIGN-style macros and there's no easy way to
70     // automatically fix the warning when macros are in play.
71     if (Func->getLocation().isMacroID() && IgnoreMacros)
72       return;
73     // FIXME: Add FixItHint to make the method public.
74     diag(Func->getLocation(), "deleted member function should be public");
75   }
76 }
77 
78 } // namespace modernize
79 } // namespace tidy
80 } // namespace clang
81