llvm/clang-tools-extra/clang-tidy/ClangTidyCheck.h

//===--- ClangTidyCheck.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_CLANGTIDYCHECK_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANGTIDYCHECK_H

#include "ClangTidyDiagnosticConsumer.h"
#include "ClangTidyOptions.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Basic/Diagnostic.h"
#include <optional>
#include <type_traits>
#include <utility>
#include <vector>

namespace clang {

class SourceManager;

namespace tidy {

/// This class should be specialized by any enum type that needs to be converted
/// to and from an \ref llvm::StringRef.
template <class T> struct OptionEnumMapping { … };

/// Base class for all clang-tidy checks.
///
/// To implement a ``ClangTidyCheck``, write a subclass and override some of the
/// base class's methods. E.g. to implement a check that validates namespace
/// declarations, override ``registerMatchers``:
///
/// ~~~{.cpp}
/// void registerMatchers(ast_matchers::MatchFinder *Finder) override {
///   Finder->addMatcher(namespaceDecl().bind("namespace"), this);
/// }
/// ~~~
///
/// and then override ``check(const MatchResult &Result)`` to do the actual
/// check for each match.
///
/// A new ``ClangTidyCheck`` instance is created per translation unit.
///
/// FIXME: Figure out whether carrying information from one TU to another is
/// useful/necessary.
class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback { … };

/// Read a named option from the ``Context`` and parse it as a bool.
///
/// Reads the option with the check-local name \p LocalName from the
/// ``CheckOptions``. If the corresponding key is not present, return
/// ``std::nullopt``.
///
/// If the corresponding key can't be parsed as a bool, emit a
/// diagnostic and return ``std::nullopt``.
template <>
std::optional<bool>
ClangTidyCheck::OptionsView::get<bool>(StringRef LocalName) const;

/// Read a named option from the ``Context`` and parse it as a bool.
///
/// Reads the option with the check-local name \p LocalName from the
/// ``CheckOptions``. If the corresponding key is not present, return
/// \p Default.
///
/// If the corresponding key can't be parsed as a bool, emit a
/// diagnostic and return \p Default.
template <>
std::optional<bool>
ClangTidyCheck::OptionsView::getLocalOrGlobal<bool>(StringRef LocalName) const;

/// Stores an option with the check-local name \p LocalName with
/// bool value \p Value to \p Options.
template <>
void ClangTidyCheck::OptionsView::store<bool>(
    ClangTidyOptions::OptionMap &Options, StringRef LocalName,
    bool Value) const;


} // namespace tidy
} // namespace clang

#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANGTIDYCHECK_H