clang-tools  14.0.0git
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 
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  // We cannot do anything about headers (yet), as the alias declarations
22  // used in one header could be used by some other translation unit.
23  Finder->addMatcher(namespaceAliasDecl(isExpansionInMainFile()).bind("alias"),
24  this);
25  Finder->addMatcher(nestedNameSpecifier().bind("nns"), this);
26 }
27 
28 void UnusedAliasDeclsCheck::check(const MatchFinder::MatchResult &Result) {
29  if (const auto *AliasDecl = Result.Nodes.getNodeAs<NamedDecl>("alias")) {
30  FoundDecls[AliasDecl] = CharSourceRange::getCharRange(
31  AliasDecl->getBeginLoc(),
32  Lexer::findLocationAfterToken(
33  AliasDecl->getEndLoc(), tok::semi, *Result.SourceManager,
34  getLangOpts(),
35  /*SkipTrailingWhitespaceAndNewLine=*/true));
36  return;
37  }
38 
39  if (const auto *NestedName =
40  Result.Nodes.getNodeAs<NestedNameSpecifier>("nns")) {
41  if (const auto *AliasDecl = NestedName->getAsNamespaceAlias()) {
42  FoundDecls[AliasDecl] = CharSourceRange();
43  }
44  }
45 }
46 
47 void UnusedAliasDeclsCheck::onEndOfTranslationUnit() {
48  for (const auto &FoundDecl : FoundDecls) {
49  if (!FoundDecl.second.isValid())
50  continue;
51  diag(FoundDecl.first->getLocation(), "namespace alias decl %0 is unused")
52  << FoundDecl.first << FixItHint::CreateRemoval(FoundDecl.second);
53  }
54 }
55 
56 } // namespace misc
57 } // namespace tidy
58 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang::clangd::check
bool check(llvm::StringRef File, llvm::function_ref< bool(const Position &)> ShouldCheckLine, const ThreadsafeFS &TFS, const ClangdLSPServer::Options &Opts, bool EnableCodeCompletion)
Definition: Check.cpp:259
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
UnusedAliasDeclsCheck.h