llvm/lib/Support/BinaryStreamWriter.cpp
Zachary Turner bbf9606175 [pdb] Write the module info and symbol record streams.
Previously we did not have support for writing detailed
module information for each module, as well as the symbol
records.  This patch adds support for this, and in doing
so enables the ability to construct minimal PDBs from
just a few lines of YAML.  A test is added to illustrate
this functionality.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297900 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-15 22:18:53 +00:00

69 lines
2.3 KiB
C++

//===- BinaryStreamWriter.cpp - Writes objects to a BinaryStream ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/BinaryStreamWriter.h"
#include "llvm/Support/BinaryStreamError.h"
#include "llvm/Support/BinaryStreamReader.h"
#include "llvm/Support/BinaryStreamRef.h"
using namespace llvm;
BinaryStreamWriter::BinaryStreamWriter(WritableBinaryStreamRef S)
: Stream(S), Offset(0) {}
Error BinaryStreamWriter::writeBytes(ArrayRef<uint8_t> Buffer) {
if (auto EC = Stream.writeBytes(Offset, Buffer))
return EC;
Offset += Buffer.size();
return Error::success();
}
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(ArrayRef<uint8_t>(Str.bytes_begin(), Str.bytes_end()));
}
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();
}
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);
Offset = NewOffset;
return Error::success();
}