clang-tools 10.0.0

UnusedAliasDeclsCheck.cpp
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1 //===--- UnusedAliasDeclsCheck.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 "UnusedAliasDeclsCheck.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 misc {
19
20 void UnusedAliasDeclsCheck::registerMatchers(MatchFinder *Finder) {
21 // Only register the matchers for C++11; the functionality currently does not
22 // provide any benefit to other languages, despite being benign.
23 if (!getLangOpts().CPlusPlus11)
24 return;
25
26 // We cannot do anything about headers (yet), as the alias declarations
27 // used in one header could be used by some other translation unit.
28 Finder->addMatcher(namespaceAliasDecl(isExpansionInMainFile()).bind("alias"),
29 this);
30 Finder->addMatcher(nestedNameSpecifier().bind("nns"), this);
31 }
32
33 void UnusedAliasDeclsCheck::check(const MatchFinder::MatchResult &Result) {
34 if (const auto *AliasDecl = Result.Nodes.getNodeAs<NamedDecl>("alias")) {
35 FoundDecls[AliasDecl] = CharSourceRange::getCharRange(
36 AliasDecl->getBeginLoc(),
37 Lexer::findLocationAfterToken(
38 AliasDecl->getEndLoc(), tok::semi, *Result.SourceManager,
39 getLangOpts(),
40 /*SkipTrailingWhitespaceAndNewLine=*/true));
41 return;
42 }
43
44 if (const auto *NestedName =
45 Result.Nodes.getNodeAs<NestedNameSpecifier>("nns")) {
46 if (const auto *AliasDecl = NestedName->getAsNamespaceAlias()) {
47 FoundDecls[AliasDecl] = CharSourceRange();
48 }
49 }
50 }
51
52 void UnusedAliasDeclsCheck::onEndOfTranslationUnit() {
53 for (const auto &FoundDecl : FoundDecls) {
54 if (!FoundDecl.second.isValid())
55 continue;
56 diag(FoundDecl.first->getLocation(), "namespace alias decl %0 is unused")
57 << FoundDecl.first << FixItHint::CreateRemoval(FoundDecl.second);
58 }
59 }
60
61 } // namespace misc
62 } // namespace tidy
63 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
UnusedAliasDeclsCheck.h
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27