Decompressor.h

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//===-- Decompressor.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
//
//===----------------------------------------------------------------------===/
 
#ifndef LLVM_OBJECT_DECOMPRESSOR_H
#define LLVM_OBJECT_DECOMPRESSOR_H
 
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/Error.h"
 
namespace llvm {
namespace object {
 
/// Decompressor helps to handle decompression of compressed sections.
class Decompressor {
public:
  /// Create decompressor object.
  /// @param Name        Section name.
  /// @param Data        Section content.
  /// @param IsLE        Flag determines if Data is in little endian form.
  /// @param Is64Bit     Flag determines if object is 64 bit.
  LLVM_ABI static Expected<Decompressor> create(StringRef Name, StringRef Data,
                                                bool IsLE, bool Is64Bit);
 
  /// Resize the buffer and uncompress section data into it.
  /// @param Out         Destination buffer.
  template <class T> Error resizeAndDecompress(T &Out) {
    Out.resize(DecompressedSize);
    return decompress({(uint8_t *)Out.data(), (size_t)DecompressedSize});
  }
 
  /// Uncompress section data to raw buffer provided.
  LLVM_ABI Error decompress(MutableArrayRef<uint8_t> Output);
 
  /// Return memory buffer size required for decompression.
  uint64_t getDecompressedSize() { return DecompressedSize; }
 
private:
  Decompressor(StringRef Data);
 
  Error consumeCompressedHeader(bool Is64Bit, bool IsLittleEndian);
 
  StringRef SectionData;
  uint64_t DecompressedSize;
  DebugCompressionType CompressionType = DebugCompressionType::None;
};
 
} // end namespace object
} // end namespace llvm
 
#endif // LLVM_OBJECT_DECOMPRESSOR_H