//===- SerializedDiagnosticReader.h - Reads diagnostics ---------*- 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_FRONTEND_SERIALIZEDDIAGNOSTICREADER_H

#define LLVM_CLANG_FRONTEND_SERIALIZEDDIAGNOSTICREADER_H

#include "clang/Basic/LLVM.h"

#include "llvm/Bitstream/BitstreamReader.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/ErrorOr.h"

#include <system_error>

namespace clang {

namespace serialized_diags {

enum class SDError {

  CouldNotLoad = 1,

  InvalidSignature,

  InvalidDiagnostics,

  MalformedTopLevelBlock,

  MalformedSubBlock,

  MalformedBlockInfoBlock,

  MalformedMetadataBlock,

  MalformedDiagnosticBlock,

  MalformedDiagnosticRecord,

  MissingVersion,

  VersionMismatch,

  UnsupportedConstruct,

  /// A generic error for subclass handlers that don't want or need to define

  /// their own error_category.

  HandlerFailed

};

const std::error_category &SDErrorCategory();

inline std::error_code make_error_code(SDError E) {

  return std::error_code(static_cast<int>(E), SDErrorCategory());

}

/// A location that is represented in the serialized diagnostics.

struct Location {

  unsigned FileID;

  unsigned Line;

  unsigned Col;

  unsigned Offset;

  Location(unsigned FileID, unsigned Line, unsigned Col, unsigned Offset)

      : FileID(FileID), Line(Line), Col(Col), Offset(Offset) {}

};

/// A base class that handles reading serialized diagnostics from a file.

///

/// Subclasses should override the visit* methods with their logic for handling

/// the various constructs that are found in serialized diagnostics.

class SerializedDiagnosticReader {

public:

  SerializedDiagnosticReader() = default;

  virtual ~SerializedDiagnosticReader() = default;

  /// Read the diagnostics in \c File

  std::error_code readDiagnostics(StringRef File);

private:

  enum class Cursor;

  /// Read to the next record or block to process.

  llvm::ErrorOr<Cursor> skipUntilRecordOrBlock(llvm::BitstreamCursor &Stream,

                                               unsigned &BlockOrRecordId);

  /// Read a metadata block from \c Stream.

  std::error_code readMetaBlock(llvm::BitstreamCursor &Stream);

  /// Read a diagnostic block from \c Stream.

  std::error_code readDiagnosticBlock(llvm::BitstreamCursor &Stream);

protected:

  /// Visit the start of a diagnostic block.

  virtual std::error_code visitStartOfDiagnostic() { return {}; }

  /// Visit the end of a diagnostic block.

  virtual std::error_code visitEndOfDiagnostic() { return {}; }

  /// Visit a category. This associates the category \c ID to a \c Name.

  virtual std::error_code visitCategoryRecord(unsigned ID, StringRef Name) {

    return {};

  }

  /// Visit a flag. This associates the flag's \c ID to a \c Name.

  virtual std::error_code visitDiagFlagRecord(unsigned ID, StringRef Name) {

    return {};

  }

  /// Visit a diagnostic.

  virtual std::error_code

  visitDiagnosticRecord(unsigned Severity, const Location &Location,

                        unsigned Category, unsigned Flag, StringRef Message) {

    return {};

  }

  /// Visit a filename. This associates the file's \c ID to a \c Name.

  virtual std::error_code visitFilenameRecord(unsigned ID, unsigned Size,

                                              unsigned Timestamp,

                                              StringRef Name) {

    return {};

  }

  /// Visit a fixit hint.

  virtual std::error_code

  visitFixitRecord(const Location &Start, const Location &End, StringRef Text) {

    return {};

  }

  /// Visit a source range.

  virtual std::error_code visitSourceRangeRecord(const Location &Start,

                                                 const Location &End) {

    return {};

  }

  /// Visit the version of the set of diagnostics.

  virtual std::error_code visitVersionRecord(unsigned Version) { return {}; }

};

} // namespace serialized_diags

} // namespace clang

namespace std {

template <>

struct is_error_code_enum<clang::serialized_diags::SDError> : std::true_type {};

} // namespace std

#endif // LLVM_CLANG_FRONTEND_SERIALIZEDDIAGNOSTICREADER_H