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Diffstat (limited to 'contrib/llvm/lib/Support/BinaryStreamReader.cpp')
| -rw-r--r-- | contrib/llvm/lib/Support/BinaryStreamReader.cpp | 149 | 
1 files changed, 149 insertions, 0 deletions
| diff --git a/contrib/llvm/lib/Support/BinaryStreamReader.cpp b/contrib/llvm/lib/Support/BinaryStreamReader.cpp new file mode 100644 index 000000000000..e00527f2519e --- /dev/null +++ b/contrib/llvm/lib/Support/BinaryStreamReader.cpp @@ -0,0 +1,149 @@ +//===- BinaryStreamReader.cpp - Reads objects from a binary stream --------===// +// +//                     The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/BinaryStreamReader.h" + +#include "llvm/Support/BinaryStreamError.h" +#include "llvm/Support/BinaryStreamRef.h" + +using namespace llvm; +using endianness = llvm::support::endianness; + +BinaryStreamReader::BinaryStreamReader(BinaryStreamRef Ref) : Stream(Ref) {} + +BinaryStreamReader::BinaryStreamReader(BinaryStream &Stream) : Stream(Stream) {} + +BinaryStreamReader::BinaryStreamReader(ArrayRef<uint8_t> Data, +                                       endianness Endian) +    : Stream(Data, Endian) {} + +BinaryStreamReader::BinaryStreamReader(StringRef Data, endianness Endian) +    : Stream(Data, Endian) {} + +Error BinaryStreamReader::readLongestContiguousChunk( +    ArrayRef<uint8_t> &Buffer) { +  if (auto EC = Stream.readLongestContiguousChunk(Offset, Buffer)) +    return EC; +  Offset += Buffer.size(); +  return Error::success(); +} + +Error BinaryStreamReader::readBytes(ArrayRef<uint8_t> &Buffer, uint32_t Size) { +  if (auto EC = Stream.readBytes(Offset, Size, Buffer)) +    return EC; +  Offset += Size; +  return Error::success(); +} + +Error BinaryStreamReader::readCString(StringRef &Dest) { +  uint32_t OriginalOffset = getOffset(); +  uint32_t FoundOffset = 0; +  while (true) { +    uint32_t ThisOffset = getOffset(); +    ArrayRef<uint8_t> Buffer; +    if (auto EC = readLongestContiguousChunk(Buffer)) +      return EC; +    StringRef S(reinterpret_cast<const char *>(Buffer.begin()), Buffer.size()); +    size_t Pos = S.find_first_of('\0'); +    if (LLVM_LIKELY(Pos != StringRef::npos)) { +      FoundOffset = Pos + ThisOffset; +      break; +    } +  } +  assert(FoundOffset >= OriginalOffset); + +  setOffset(OriginalOffset); +  size_t Length = FoundOffset - OriginalOffset; + +  if (auto EC = readFixedString(Dest, Length)) +    return EC; + +  // Now set the offset back to after the null terminator. +  setOffset(FoundOffset + 1); +  return Error::success(); +} + +Error BinaryStreamReader::readWideString(ArrayRef<UTF16> &Dest) { +  uint32_t Length = 0; +  uint32_t OriginalOffset = getOffset(); +  const UTF16 *C; +  while (true) { +    if (auto EC = readObject(C)) +      return EC; +    if (*C == 0x0000) +      break; +    ++Length; +  } +  uint32_t NewOffset = getOffset(); +  setOffset(OriginalOffset); + +  if (auto EC = readArray(Dest, Length)) +    return EC; +  setOffset(NewOffset); +  return Error::success(); +} + +Error BinaryStreamReader::readFixedString(StringRef &Dest, uint32_t Length) { +  ArrayRef<uint8_t> Bytes; +  if (auto EC = readBytes(Bytes, Length)) +    return EC; +  Dest = StringRef(reinterpret_cast<const char *>(Bytes.begin()), Bytes.size()); +  return Error::success(); +} + +Error BinaryStreamReader::readStreamRef(BinaryStreamRef &Ref) { +  return readStreamRef(Ref, bytesRemaining()); +} + +Error BinaryStreamReader::readStreamRef(BinaryStreamRef &Ref, uint32_t Length) { +  if (bytesRemaining() < Length) +    return make_error<BinaryStreamError>(stream_error_code::stream_too_short); +  Ref = Stream.slice(Offset, Length); +  Offset += Length; +  return Error::success(); +} + +Error BinaryStreamReader::readSubstream(BinarySubstreamRef &Stream, +                                        uint32_t Size) { +  Stream.Offset = getOffset(); +  return readStreamRef(Stream.StreamData, Size); +} + +Error BinaryStreamReader::skip(uint32_t Amount) { +  if (Amount > bytesRemaining()) +    return make_error<BinaryStreamError>(stream_error_code::stream_too_short); +  Offset += Amount; +  return Error::success(); +} + +Error BinaryStreamReader::padToAlignment(uint32_t Align) { +  uint32_t NewOffset = alignTo(Offset, Align); +  return skip(NewOffset - Offset); +} + +uint8_t BinaryStreamReader::peek() const { +  ArrayRef<uint8_t> Buffer; +  auto EC = Stream.readBytes(Offset, 1, Buffer); +  assert(!EC && "Cannot peek an empty buffer!"); +  llvm::consumeError(std::move(EC)); +  return Buffer[0]; +} + +std::pair<BinaryStreamReader, BinaryStreamReader> +BinaryStreamReader::split(uint32_t Off) const { +  assert(getLength() >= Off); + +  BinaryStreamRef First = Stream.drop_front(Offset); + +  BinaryStreamRef Second = First.drop_front(Off); +  First = First.keep_front(Off); +  BinaryStreamReader W1{First}; +  BinaryStreamReader W2{Second}; +  return std::make_pair(W1, W2); +}
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