LiteLoaderBDS-1.16.40/LLPreLoader/third-party/rawpdb/PDB_InfoStream.cpp
2023-03-03 10:18:21 -08:00

72 lines
2.9 KiB
C++

// Copyright 2011-2022, Molecular Matters GmbH <office@molecular-matters.com>
// See LICENSE.txt for licensing details (2-clause BSD License: https://opensource.org/licenses/BSD-2-Clause)
#include "PDB_PCH.h"
#include "PDB_InfoStream.h"
#include "PDB_RawFile.h"
namespace
{
// the PDB info stream always resides at index 1
static constexpr const uint32_t InfoStreamIndex = 1u;
}
// ------------------------------------------------------------------------------------------------
// ------------------------------------------------------------------------------------------------
PDB::InfoStream::InfoStream(void) PDB_NO_EXCEPT
: m_stream()
, m_header(nullptr)
, m_usesDebugFastlink(false)
{
}
// ------------------------------------------------------------------------------------------------
// ------------------------------------------------------------------------------------------------
PDB::InfoStream::InfoStream(const RawFile& file) PDB_NO_EXCEPT
: m_stream(file.CreateMSFStream<CoalescedMSFStream>(InfoStreamIndex))
, m_header(m_stream.GetDataAtOffset<const Header>(0u))
, m_usesDebugFastlink(false)
{
// the info stream starts with the header, followed by the named stream map, followed by the feature codes
// https://llvm.org/docs/PDB/PdbStream.html#named-stream-map
size_t streamOffset = sizeof(Header);
const NamedStreamMap* namedStreamMap = m_stream.GetDataAtOffset<const NamedStreamMap>(streamOffset);
streamOffset += sizeof(NamedStreamMap) + namedStreamMap->length;
const SerializedHashTable::Header* hashTableHeader = m_stream.GetDataAtOffset<const SerializedHashTable::Header>(streamOffset);
streamOffset += sizeof(SerializedHashTable::Header);
const SerializedHashTable::BitVector* presentBitVector = m_stream.GetDataAtOffset<const SerializedHashTable::BitVector>(streamOffset);
streamOffset += sizeof(SerializedHashTable::BitVector) + sizeof(uint32_t) * presentBitVector->wordCount;
const SerializedHashTable::BitVector* deletedBitVector = m_stream.GetDataAtOffset<const SerializedHashTable::BitVector>(streamOffset);
streamOffset += sizeof(SerializedHashTable::BitVector) + sizeof(uint32_t) * deletedBitVector->wordCount;
// the hash table entries can be used to identify the indices of certain common streams like:
// "/UDTSRCLINEUNDONE"
// "/src/headerblock"
// "/LinkInfo"
// "/TMCache"
// "/names"
// however, none of those streams are of interest to us, so we just skip the whole hash table
streamOffset += sizeof(NamedStreamMap::HashTableEntry) * hashTableHeader->size;
// read feature codes by consuming remaining bytes
// https://llvm.org/docs/PDB/PdbStream.html#pdb-feature-codes
const FeatureCode* featureCodes = m_stream.GetDataAtOffset<const FeatureCode>(streamOffset);
const size_t remainingBytes = m_stream.GetSize() - streamOffset;
const size_t count = remainingBytes / sizeof(FeatureCode);
for (size_t i=0u; i < count; ++i)
{
if (featureCodes[i] == PDB::FeatureCode::MinimalDebugInfo)
{
m_usesDebugFastlink = true;
}
}
}