llvm-project/llvm/lib/Support/BinaryStreamRef.cpp
Nico Weber 646299d183 [Support] Convert BinaryStream class zoo to 64-bit offsets
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
2021-09-16 19:14:52 -04:00

130 lines
4.8 KiB
C++

//===- BinaryStreamRef.cpp - ----------------------------------------------===//
//
// 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/BinaryStreamRef.h"
#include "llvm/Support/BinaryByteStream.h"
using namespace llvm;
using namespace llvm::support;
namespace {
class ArrayRefImpl : public BinaryStream {
public:
ArrayRefImpl(ArrayRef<uint8_t> Data, endianness Endian) : BBS(Data, Endian) {}
llvm::support::endianness getEndian() const override {
return BBS.getEndian();
}
Error readBytes(uint64_t Offset, uint64_t Size,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readBytes(Offset, Size, Buffer);
}
Error readLongestContiguousChunk(uint64_t Offset,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readLongestContiguousChunk(Offset, Buffer);
}
uint64_t getLength() override { return BBS.getLength(); }
private:
BinaryByteStream BBS;
};
class MutableArrayRefImpl : public WritableBinaryStream {
public:
MutableArrayRefImpl(MutableArrayRef<uint8_t> Data, endianness Endian)
: BBS(Data, Endian) {}
// Inherited via WritableBinaryStream
llvm::support::endianness getEndian() const override {
return BBS.getEndian();
}
Error readBytes(uint64_t Offset, uint64_t Size,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readBytes(Offset, Size, Buffer);
}
Error readLongestContiguousChunk(uint64_t Offset,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readLongestContiguousChunk(Offset, Buffer);
}
uint64_t getLength() override { return BBS.getLength(); }
Error writeBytes(uint64_t Offset, ArrayRef<uint8_t> Data) override {
return BBS.writeBytes(Offset, Data);
}
Error commit() override { return BBS.commit(); }
private:
MutableBinaryByteStream BBS;
};
} // namespace
BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream)
: BinaryStreamRefBase(Stream) {}
BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream, uint64_t Offset,
Optional<uint64_t> Length)
: BinaryStreamRefBase(Stream, Offset, Length) {}
BinaryStreamRef::BinaryStreamRef(ArrayRef<uint8_t> Data, endianness Endian)
: BinaryStreamRefBase(std::make_shared<ArrayRefImpl>(Data, Endian), 0,
Data.size()) {}
BinaryStreamRef::BinaryStreamRef(StringRef Data, endianness Endian)
: BinaryStreamRef(makeArrayRef(Data.bytes_begin(), Data.bytes_end()),
Endian) {}
Error BinaryStreamRef::readBytes(uint64_t Offset, uint64_t Size,
ArrayRef<uint8_t> &Buffer) const {
if (auto EC = checkOffsetForRead(Offset, Size))
return EC;
return BorrowedImpl->readBytes(ViewOffset + Offset, Size, Buffer);
}
Error BinaryStreamRef::readLongestContiguousChunk(
uint64_t Offset, ArrayRef<uint8_t> &Buffer) const {
if (auto EC = checkOffsetForRead(Offset, 1))
return EC;
if (auto EC =
BorrowedImpl->readLongestContiguousChunk(ViewOffset + Offset, Buffer))
return EC;
// This StreamRef might refer to a smaller window over a larger stream. In
// that case we will have read out more bytes than we should return, because
// we should not read past the end of the current view.
uint64_t MaxLength = getLength() - Offset;
if (Buffer.size() > MaxLength)
Buffer = Buffer.slice(0, MaxLength);
return Error::success();
}
WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream)
: BinaryStreamRefBase(Stream) {}
WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream,
uint64_t Offset,
Optional<uint64_t> Length)
: BinaryStreamRefBase(Stream, Offset, Length) {}
WritableBinaryStreamRef::WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,
endianness Endian)
: BinaryStreamRefBase(std::make_shared<MutableArrayRefImpl>(Data, Endian),
0, Data.size()) {}
Error WritableBinaryStreamRef::writeBytes(uint64_t Offset,
ArrayRef<uint8_t> Data) const {
if (auto EC = checkOffsetForWrite(Offset, Data.size()))
return EC;
return BorrowedImpl->writeBytes(ViewOffset + Offset, Data);
}
WritableBinaryStreamRef::operator BinaryStreamRef() const {
return BinaryStreamRef(*BorrowedImpl, ViewOffset, Length);
}
/// For buffered streams, commits changes to the backing store.
Error WritableBinaryStreamRef::commit() { return BorrowedImpl->commit(); }