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::tidy::modernize {
17
18 namespace {
AST_MATCHER(FunctionDecl,hasAnyDefinition)19 AST_MATCHER(FunctionDecl, hasAnyDefinition) {
20 if (Node.hasBody() || Node.isPureVirtual() || Node.isDefaulted() ||
21 Node.isDeleted())
22 return true;
23
24 if (const FunctionDecl *Definition = Node.getDefinition())
25 if (Definition->hasBody() || Definition->isPureVirtual() ||
26 Definition->isDefaulted() || Definition->isDeleted())
27 return true;
28
29 return false;
30 }
31
AST_MATCHER(Decl,isUsed)32 AST_MATCHER(Decl, isUsed) { return Node.isUsed(); }
33
AST_MATCHER(CXXMethodDecl,isSpecialFunction)34 AST_MATCHER(CXXMethodDecl, isSpecialFunction) {
35 if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(&Node))
36 return Constructor->isDefaultConstructor() ||
37 Constructor->isCopyOrMoveConstructor();
38
39 return isa<CXXDestructorDecl>(Node) || Node.isCopyAssignmentOperator() ||
40 Node.isMoveAssignmentOperator();
41 }
42 } // namespace
43
44 static const char SpecialFunction[] = "SpecialFunction";
45 static const char DeletedNotPublic[] = "DeletedNotPublic";
46
UseEqualsDeleteCheck(StringRef Name,ClangTidyContext * Context)47 UseEqualsDeleteCheck::UseEqualsDeleteCheck(StringRef Name,
48 ClangTidyContext *Context)
49 : ClangTidyCheck(Name, Context),
50 IgnoreMacros(Options.getLocalOrGlobal("IgnoreMacros", true)) {}
51
storeOptions(ClangTidyOptions::OptionMap & Opts)52 void UseEqualsDeleteCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
53 Options.store(Opts, "IgnoreMacros", IgnoreMacros);
54 }
55
registerMatchers(MatchFinder * Finder)56 void UseEqualsDeleteCheck::registerMatchers(MatchFinder *Finder) {
57 auto PrivateSpecialFn = cxxMethodDecl(isPrivate(), isSpecialFunction());
58
59 Finder->addMatcher(
60 cxxMethodDecl(
61 PrivateSpecialFn, unless(hasAnyDefinition()), unless(isUsed()),
62 // Ensure that all methods except private special member functions are
63 // defined.
64 unless(ofClass(hasMethod(cxxMethodDecl(unless(PrivateSpecialFn),
65 unless(hasAnyDefinition()))))))
66 .bind(SpecialFunction),
67 this);
68
69 Finder->addMatcher(
70 cxxMethodDecl(isDeleted(), unless(isPublic())).bind(DeletedNotPublic),
71 this);
72 }
73
check(const MatchFinder::MatchResult & Result)74 void UseEqualsDeleteCheck::check(const MatchFinder::MatchResult &Result) {
75 if (const auto *Func =
76 Result.Nodes.getNodeAs<CXXMethodDecl>(SpecialFunction)) {
77 SourceLocation EndLoc = Lexer::getLocForEndOfToken(
78 Func->getEndLoc(), 0, *Result.SourceManager, getLangOpts());
79
80 if (IgnoreMacros && Func->getLocation().isMacroID())
81 return;
82 // FIXME: Improve FixItHint to make the method public.
83 diag(Func->getLocation(),
84 "use '= delete' to prohibit calling of a special member function")
85 << FixItHint::CreateInsertion(EndLoc, " = delete");
86 } else if (const auto *Func =
87 Result.Nodes.getNodeAs<CXXMethodDecl>(DeletedNotPublic)) {
88 // Ignore this warning in macros, since it's extremely noisy in code using
89 // DISALLOW_COPY_AND_ASSIGN-style macros and there's no easy way to
90 // automatically fix the warning when macros are in play.
91 if (IgnoreMacros && Func->getLocation().isMacroID())
92 return;
93 // FIXME: Add FixItHint to make the method public.
94 diag(Func->getLocation(), "deleted member function should be public");
95 }
96 }
97
98 } // namespace clang::tidy::modernize
99