//== Yaml.h ---------------------------------------------------- -*- 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

//

//===----------------------------------------------------------------------===//

//

// This file defines convenience functions for handling YAML configuration files

// for checkers/packages.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_LIB_STATICANALYZER_CHECKER_YAML_H

#define LLVM_CLANG_LIB_STATICANALYZER_CHECKER_YAML_H

#include "clang/StaticAnalyzer/Core/CheckerManager.h"

#include "llvm/Support/VirtualFileSystem.h"

#include "llvm/Support/YAMLTraits.h"

#include <optional>

namespace clang {

namespace ento {

/// Read the given file from the filesystem and parse it as a yaml file. The

/// template parameter must have a yaml MappingTraits.

/// Emit diagnostic error in case of any failure.

template <class T, class Checker>

std::optional<T> getConfiguration(CheckerManager &Mgr, Checker *Chk,

                                  StringRef Option, StringRef ConfigFile) {

  if (ConfigFile.trim().empty())

    return std::nullopt;

  llvm::vfs::FileSystem *FS = llvm::vfs::getRealFileSystem().get();

  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buffer =

      FS->getBufferForFile(ConfigFile.str());

  if (Buffer.getError()) {

    Mgr.reportInvalidCheckerOptionValue(Chk, Option,

                                        "a valid filename instead of '" +

                                            std::string(ConfigFile) + "'");

    return std::nullopt;

  }

  llvm::yaml::Input Input(Buffer.get()->getBuffer());

  T Config;

  Input >> Config;

  if (std::error_code ec = Input.error()) {

    Mgr.reportInvalidCheckerOptionValue(Chk, Option,

                                        "a valid yaml file: " + ec.message());

    return std::nullopt;

  }

  return Config;

}

} // namespace ento

} // namespace clang

#endif // LLVM_CLANG_LIB_STATICANALYZER_CHECKER_YAML_H