HeaderGuard.h

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//===--- HeaderGuard.h - clang-tidy -----------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_HEADERGUARD_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_HEADERGUARD_H
 
#include "../ClangTidyCheck.h"
#include "../utils/FileExtensionsUtils.h"
 
namespace clang::tidy::utils {
 
/// Finds and fixes header guards.
/// The check supports these options:
///   - `HeaderFileExtensions`: a semicolon-separated list of filename
///     extensions of header files (The filename extension should not contain
///     "." prefix). ";h;hh;hpp;hxx" by default.
///
///     For extension-less header files, using an empty string or leaving an
///     empty string between ";" if there are other filename extensions.
class HeaderGuardCheck : public ClangTidyCheck {
public:
  HeaderGuardCheck(StringRef Name, ClangTidyContext *Context)
      : ClangTidyCheck(Name, Context) {
    std::optional<StringRef> HeaderFileExtensionsOption =
        Options.get("HeaderFileExtensions");
    RawStringHeaderFileExtensions = HeaderFileExtensionsOption.value_or(
        utils::defaultHeaderFileExtensions());
    if (HeaderFileExtensionsOption) {
      if (!utils::parseFileExtensions(
              RawStringHeaderFileExtensions, HeaderFileExtensions,
              utils::defaultFileExtensionDelimiters())) {
        this->configurationDiag("Invalid header file extension: '%0'")
            << RawStringHeaderFileExtensions;
      }
    } else
      HeaderFileExtensions = Context->getHeaderFileExtensions();
  }
  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
  void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
                           Preprocessor *ModuleExpanderPP) override;
 
  /// Ensure that the provided header guard is a non-reserved identifier.
  std::string sanitizeHeaderGuard(StringRef Guard);
 
  /// Returns ``true`` if the check should suggest inserting a trailing comment
  /// on the ``#endif`` of the header guard. It will use the same name as
  /// returned by ``HeaderGuardCheck::getHeaderGuard``.
  virtual bool shouldSuggestEndifComment(StringRef Filename);
  /// Returns ``true`` if the check should suggest changing an existing header
  /// guard to the string returned by ``HeaderGuardCheck::getHeaderGuard``.
  virtual bool shouldFixHeaderGuard(StringRef Filename);
  /// Returns ``true`` if the check should add a header guard to the file
  /// if it has none.
  virtual bool shouldSuggestToAddHeaderGuard(StringRef Filename);
  /// Returns a replacement for the ``#endif`` line with a comment mentioning
  /// \p HeaderGuard. The replacement should start with ``endif``.
  virtual std::string formatEndIf(StringRef HeaderGuard);
  /// Gets the canonical header guard for a file.
  virtual std::string getHeaderGuard(StringRef Filename,
                                     StringRef OldGuard = StringRef()) = 0;
 
private:
  std::string RawStringHeaderFileExtensions;
  FileExtensionsSet HeaderFileExtensions;
};
 
} // namespace clang::tidy::utils
 
#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_HEADERGUARD_H