1//===--- UnusedUsingDeclsCheck.h - clang-tidy--------------------*- C++ -*-===//
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#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_USING_DECLS_H
10#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_USING_DECLS_H
11
12#include "../ClangTidyCheck.h"
13#include "../utils/FileExtensionsUtils.h"
14#include "llvm/ADT/SmallPtrSet.h"
15#include <vector>
16
17namespace clang::tidy::misc {
18
19/// Finds unused using declarations.
20///
21/// For the user-facing documentation see:
22/// http://clang.llvm.org/extra/clang-tidy/checks/misc/unused-using-decls.html
23class UnusedUsingDeclsCheck : public ClangTidyCheck {
24public:
25 UnusedUsingDeclsCheck(StringRef Name, ClangTidyContext *Context);
26 void registerMatchers(ast_matchers::MatchFinder *Finder) override;
27 void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
28 void onEndOfTranslationUnit() override;
29 bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
30 return LangOpts.CPlusPlus;
31 }
32
33private:
34 void removeFromFoundDecls(const Decl *D);
35
36 struct UsingDeclContext {
37 explicit UsingDeclContext(const UsingDecl *FoundUsingDecl)
38 : FoundUsingDecl(FoundUsingDecl) {}
39 // A set saves all UsingShadowDecls introduced by a UsingDecl. A UsingDecl
40 // can introduce multiple UsingShadowDecls in some cases (such as
41 // overloaded functions).
42 llvm::SmallPtrSet<const Decl *, 4> UsingTargetDecls;
43 // The original UsingDecl.
44 const UsingDecl *FoundUsingDecl;
45 // The source range of the UsingDecl.
46 CharSourceRange UsingDeclRange;
47 // Whether the UsingDecl is used.
48 bool IsUsed = false;
49 };
50
51 std::vector<UsingDeclContext> Contexts;
52 llvm::SmallPtrSet<const Decl *, 32> UsingTargetDeclsCache;
53
54 StringRef RawStringHeaderFileExtensions;
55 FileExtensionsSet HeaderFileExtensions;
56};
57
58} // namespace clang::tidy::misc
59
60#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_USING_DECLS_H
61

source code of clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.h