646299d183
Most PDB fields on disk are 32-bit but describe the file in terms of MSF blocks, which are 4 kiB by default. So PDB files can be a bit larger than 4 GiB, and much larger if you create them with a block size > 4 kiB. This is a first (necessary, but by far not not sufficient) step towards supporting such PDB files. Now we don't truncate in-memory file offsets (which are in terms of bytes, not in terms of blocks). No effective behavior change. lld-link will still error out if it were to produce PDBs > 4 GiB. Differential Revision: https://reviews.llvm.org/D109923
102 lines
3.7 KiB
C++
102 lines
3.7 KiB
C++
//===- BinaryStream.h - Base interface for a stream of data -----*- 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_SUPPORT_BINARYSTREAM_H
|
|
#define LLVM_SUPPORT_BINARYSTREAM_H
|
|
|
|
#include "llvm/ADT/ArrayRef.h"
|
|
#include "llvm/ADT/BitmaskEnum.h"
|
|
#include "llvm/Support/BinaryStreamError.h"
|
|
#include "llvm/Support/Endian.h"
|
|
#include "llvm/Support/Error.h"
|
|
#include <cstdint>
|
|
|
|
namespace llvm {
|
|
|
|
enum BinaryStreamFlags {
|
|
BSF_None = 0,
|
|
BSF_Write = 1, // Stream supports writing.
|
|
BSF_Append = 2, // Writing can occur at offset == length.
|
|
LLVM_MARK_AS_BITMASK_ENUM(/* LargestValue = */ BSF_Append)
|
|
};
|
|
|
|
/// An interface for accessing data in a stream-like format, but which
|
|
/// discourages copying. Instead of specifying a buffer in which to copy
|
|
/// data on a read, the API returns an ArrayRef to data owned by the stream's
|
|
/// implementation. Since implementations may not necessarily store data in a
|
|
/// single contiguous buffer (or even in memory at all), in such cases a it may
|
|
/// be necessary for an implementation to cache such a buffer so that it can
|
|
/// return it.
|
|
class BinaryStream {
|
|
public:
|
|
virtual ~BinaryStream() = default;
|
|
|
|
virtual llvm::support::endianness getEndian() const = 0;
|
|
|
|
/// Given an offset into the stream and a number of bytes, attempt to
|
|
/// read the bytes and set the output ArrayRef to point to data owned by the
|
|
/// stream.
|
|
virtual Error readBytes(uint64_t Offset, uint64_t Size,
|
|
ArrayRef<uint8_t> &Buffer) = 0;
|
|
|
|
/// Given an offset into the stream, read as much as possible without
|
|
/// copying any data.
|
|
virtual Error readLongestContiguousChunk(uint64_t Offset,
|
|
ArrayRef<uint8_t> &Buffer) = 0;
|
|
|
|
/// Return the number of bytes of data in this stream.
|
|
virtual uint64_t getLength() = 0;
|
|
|
|
/// Return the properties of this stream.
|
|
virtual BinaryStreamFlags getFlags() const { return BSF_None; }
|
|
|
|
protected:
|
|
Error checkOffsetForRead(uint64_t Offset, uint64_t DataSize) {
|
|
if (Offset > getLength())
|
|
return make_error<BinaryStreamError>(stream_error_code::invalid_offset);
|
|
if (getLength() < DataSize + Offset)
|
|
return make_error<BinaryStreamError>(stream_error_code::stream_too_short);
|
|
return Error::success();
|
|
}
|
|
};
|
|
|
|
/// A BinaryStream which can be read from as well as written to. Note
|
|
/// that writing to a BinaryStream always necessitates copying from the input
|
|
/// buffer to the stream's backing store. Streams are assumed to be buffered
|
|
/// so that to be portable it is necessary to call commit() on the stream when
|
|
/// all data has been written.
|
|
class WritableBinaryStream : public BinaryStream {
|
|
public:
|
|
~WritableBinaryStream() override = default;
|
|
|
|
/// Attempt to write the given bytes into the stream at the desired
|
|
/// offset. This will always necessitate a copy. Cannot shrink or grow the
|
|
/// stream, only writes into existing allocated space.
|
|
virtual Error writeBytes(uint64_t Offset, ArrayRef<uint8_t> Data) = 0;
|
|
|
|
/// For buffered streams, commits changes to the backing store.
|
|
virtual Error commit() = 0;
|
|
|
|
/// Return the properties of this stream.
|
|
BinaryStreamFlags getFlags() const override { return BSF_Write; }
|
|
|
|
protected:
|
|
Error checkOffsetForWrite(uint64_t Offset, uint64_t DataSize) {
|
|
if (!(getFlags() & BSF_Append))
|
|
return checkOffsetForRead(Offset, DataSize);
|
|
|
|
if (Offset > getLength())
|
|
return make_error<BinaryStreamError>(stream_error_code::invalid_offset);
|
|
return Error::success();
|
|
}
|
|
};
|
|
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_SUPPORT_BINARYSTREAM_H
|