//===-- RemarkSerializer.h - Remark serialization interface -----*- 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 provides an interface for serializing remarks to different formats.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_REMARKS_REMARKSERIALIZER_H
#define LLVM_REMARKS_REMARKSERIALIZER_H

#include "llvm/Remarks/RemarkFormat.h"
#include "llvm/Remarks/RemarkStringTable.h"
#include <optional>

namespace llvm {

class raw_ostream;

namespace remarks {

struct Remark;

enum class SerializerMode {
  Separate,  // A mode where the metadata is serialized separately from the
             // remarks. Typically, this is used when the remarks need to be
             // streamed to a side file and the metadata is embedded into the
             // final result of the compilation.
  Standalone // A mode where everything can be retrieved in the same
             // file/buffer. Typically, this is used for storing remarks for
             // later use.
};

struct MetaSerializer;

/// This is the base class for a remark serializer.
/// It includes support for using a string table while emitting.
struct RemarkSerializer {
  /// The format of the serializer.
  Format SerializerFormat;
  /// The open raw_ostream that the remark diagnostics are emitted to.
  raw_ostream &OS;
  /// The serialization mode.
  SerializerMode Mode;
  /// The string table containing all the unique strings used in the output.
  /// The table can be serialized to be consumed after the compilation.
  std::optional<StringTable> StrTab;

  RemarkSerializer(Format SerializerFormat, raw_ostream &OS,
                   SerializerMode Mode)
      : SerializerFormat(SerializerFormat), OS(OS), Mode(Mode) {}

  /// This is just an interface.
  virtual ~RemarkSerializer() = default;
  /// Emit a remark to the stream.
  virtual void emit(const Remark &Remark) = 0;
  /// Return the corresponding metadata serializer.
  virtual std::unique_ptr<MetaSerializer>
  metaSerializer(raw_ostream &OS,
                 std::optional<StringRef> ExternalFilename = std::nullopt) = 0;
};

/// This is the base class for a remark metadata serializer.
struct MetaSerializer {
  /// The open raw_ostream that the metadata is emitted to.
  raw_ostream &OS;

  MetaSerializer(raw_ostream &OS) : OS(OS) {}

  /// This is just an interface.
  virtual ~MetaSerializer() = default;
  virtual void emit() = 0;
};

/// Create a remark serializer.
Expected<std::unique_ptr<RemarkSerializer>>
createRemarkSerializer(Format RemarksFormat, SerializerMode Mode,
                       raw_ostream &OS);

/// Create a remark serializer that uses a pre-filled string table.
Expected<std::unique_ptr<RemarkSerializer>>
createRemarkSerializer(Format RemarksFormat, SerializerMode Mode,
                       raw_ostream &OS, remarks::StringTable StrTab);

} // end namespace remarks
} // end namespace llvm

#endif // LLVM_REMARKS_REMARKSERIALIZER_H