GlobalNamesInHeadersCheck.cpp

Go to the documentation of this file.

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "GlobalNamesInHeadersCheck.h"
#include "../utils/FileExtensionsUtils.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/ASTMatchers/ASTMatchers.h"
#include "clang/Lex/Lexer.h"
 
using namespace clang::ast_matchers;
 
namespace clang::tidy::google::readability {
 
GlobalNamesInHeadersCheck::GlobalNamesInHeadersCheck(StringRef Name,
                                                     ClangTidyContext *Context)
    : ClangTidyCheck(Name, Context) {}
 
void GlobalNamesInHeadersCheck::registerMatchers(
    ast_matchers::MatchFinder *Finder) {
  Finder->addMatcher(decl(anyOf(usingDecl(), usingDirectiveDecl()),
                          hasDeclContext(translationUnitDecl()))
                         .bind("using_decl"),
                     this);
}
 
void GlobalNamesInHeadersCheck::check(const MatchFinder::MatchResult &Result) {
  const auto *D = Result.Nodes.getNodeAs<Decl>("using_decl");
  // If it comes from a macro, we'll assume it is fine.
  if (D->getBeginLoc().isMacroID())
    return;
 
  // Ignore if it comes from the "main" file unless that file is a header.
  if (Result.SourceManager->isInMainFile(
          Result.SourceManager->getExpansionLoc(D->getBeginLoc())) &&
      !utils::isSpellingLocInHeaderFile(D->getBeginLoc(), *Result.SourceManager,
                                        getHeaderFileExtensions()))
    return;
 
  if (const auto *UsingDirective = dyn_cast<UsingDirectiveDecl>(D);
      UsingDirective &&
      UsingDirective->getNominatedNamespace()->isAnonymousNamespace()) {
    // Anonymous namespaces inject a using directive into the AST to import
    // the names into the containing namespace.
    // We should not have them in headers, but there is another warning for
    // that.
    return;
  }
 
  diag(D->getBeginLoc(),
       "using declarations in the global namespace in headers are prohibited");
}
 
} // namespace clang::tidy::google::readability