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path: root/contrib/libs/llvm12/lib/Support/BinaryStreamWriter.cpp
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//===- BinaryStreamWriter.cpp - Writes objects to a BinaryStream ----------===// 
// 
// 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 
// 
//===----------------------------------------------------------------------===// 
 
#include "llvm/Support/BinaryStreamWriter.h" 
 
#include "llvm/Support/BinaryStreamError.h" 
#include "llvm/Support/BinaryStreamReader.h" 
#include "llvm/Support/BinaryStreamRef.h" 
#include "llvm/Support/LEB128.h" 
 
using namespace llvm; 
 
BinaryStreamWriter::BinaryStreamWriter(WritableBinaryStreamRef Ref) 
    : Stream(Ref) {} 
 
BinaryStreamWriter::BinaryStreamWriter(WritableBinaryStream &Stream) 
    : Stream(Stream) {} 
 
BinaryStreamWriter::BinaryStreamWriter(MutableArrayRef<uint8_t> Data, 
                                       llvm::support::endianness Endian) 
    : Stream(Data, Endian) {} 
 
Error BinaryStreamWriter::writeBytes(ArrayRef<uint8_t> Buffer) { 
  if (auto EC = Stream.writeBytes(Offset, Buffer)) 
    return EC; 
  Offset += Buffer.size(); 
  return Error::success(); 
} 
 
Error BinaryStreamWriter::writeULEB128(uint64_t Value) { 
  uint8_t EncodedBytes[10] = {0}; 
  unsigned Size = encodeULEB128(Value, &EncodedBytes[0]); 
  return writeBytes({EncodedBytes, Size}); 
} 
 
Error BinaryStreamWriter::writeSLEB128(int64_t Value) { 
  uint8_t EncodedBytes[10] = {0}; 
  unsigned Size = encodeSLEB128(Value, &EncodedBytes[0]); 
  return writeBytes({EncodedBytes, Size}); 
} 
 
Error BinaryStreamWriter::writeCString(StringRef Str) { 
  if (auto EC = writeFixedString(Str)) 
    return EC; 
  if (auto EC = writeObject('\0')) 
    return EC; 
 
  return Error::success(); 
} 
 
Error BinaryStreamWriter::writeFixedString(StringRef Str) { 
 
  return writeBytes(arrayRefFromStringRef(Str)); 
} 
 
Error BinaryStreamWriter::writeStreamRef(BinaryStreamRef Ref) { 
  return writeStreamRef(Ref, Ref.getLength()); 
} 
 
Error BinaryStreamWriter::writeStreamRef(BinaryStreamRef Ref, uint32_t Length) { 
  BinaryStreamReader SrcReader(Ref.slice(0, Length)); 
  // This is a bit tricky.  If we just call readBytes, we are requiring that it 
  // return us the entire stream as a contiguous buffer.  There is no guarantee 
  // this can be satisfied by returning a reference straight from the buffer, as 
  // an implementation may not store all data in a single contiguous buffer.  So 
  // we iterate over each contiguous chunk, writing each one in succession. 
  while (SrcReader.bytesRemaining() > 0) { 
    ArrayRef<uint8_t> Chunk; 
    if (auto EC = SrcReader.readLongestContiguousChunk(Chunk)) 
      return EC; 
    if (auto EC = writeBytes(Chunk)) 
      return EC; 
  } 
  return Error::success(); 
} 
 
std::pair<BinaryStreamWriter, BinaryStreamWriter> 
BinaryStreamWriter::split(uint32_t Off) const { 
  assert(getLength() >= Off); 
 
  WritableBinaryStreamRef First = Stream.drop_front(Offset); 
 
  WritableBinaryStreamRef Second = First.drop_front(Off); 
  First = First.keep_front(Off); 
  BinaryStreamWriter W1{First}; 
  BinaryStreamWriter W2{Second}; 
  return std::make_pair(W1, W2); 
} 
 
Error BinaryStreamWriter::padToAlignment(uint32_t Align) { 
  uint32_t NewOffset = alignTo(Offset, Align); 
  if (NewOffset > getLength()) 
    return make_error<BinaryStreamError>(stream_error_code::stream_too_short); 
  while (Offset < NewOffset) 
    if (auto EC = writeInteger('\0')) 
      return EC; 
  return Error::success(); 
}