1//===- PublicsStream.cpp - PDB Public Symbol Stream -----------------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// The data structures defined in this file are based on the reference 10// implementation which is available at 11// https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.h 12// 13// When you are reading the reference source code, you'd find the 14// information below useful. 15// 16// - ppdb1->m_fMinimalDbgInfo seems to be always true. 17// - SMALLBUCKETS macro is defined. 18// 19// The reference doesn't compile, so I learned just by reading code. 20// It's not guaranteed to be correct. 21// 22//===----------------------------------------------------------------------===// 23 24#include "llvm/DebugInfo/PDB/Native/PublicsStream.h" 25#include "llvm/ADT/iterator_range.h" 26#include "llvm/DebugInfo/CodeView/SymbolRecord.h" 27#include "llvm/DebugInfo/MSF/MappedBlockStream.h" 28#include "llvm/DebugInfo/PDB/Native/RawError.h" 29#include "llvm/Support/BinaryStreamReader.h" 30#include "llvm/Support/Endian.h" 31#include "llvm/Support/Error.h" 32#include <algorithm> 33#include <cstdint> 34 35using namespace llvm; 36using namespace llvm::msf; 37using namespace llvm::support; 38using namespace llvm::pdb; 39 40PublicsStream::PublicsStream(std::unique_ptr<MappedBlockStream> Stream) 41 : Stream(std::move(Stream)) {} 42 43PublicsStream::~PublicsStream() = default; 44 45uint32_t PublicsStream::getSymHash() const { return Header->SymHash; } 46uint16_t PublicsStream::getThunkTableSection() const { 47 return Header->ISectThunkTable; 48} 49uint32_t PublicsStream::getThunkTableOffset() const { 50 return Header->OffThunkTable; 51} 52 53// Publics stream contains fixed-size headers and a serialized hash table. 54// This implementation is not complete yet. It reads till the end of the 55// stream so that we verify the stream is at least not corrupted. However, 56// we skip over the hash table which we believe contains information about 57// public symbols. 58Error PublicsStream::reload() { 59 BinaryStreamReader Reader(*Stream); 60 61 // Check stream size. 62 if (Reader.bytesRemaining() < 63 sizeof(PublicsStreamHeader) + sizeof(GSIHashHeader)) 64 return make_error<RawError>(raw_error_code::corrupt_file, 65 "Publics Stream does not contain a header."); 66 67 // Read PSGSIHDR struct. 68 if (Reader.readObject(Header)) 69 return make_error<RawError>(raw_error_code::corrupt_file, 70 "Publics Stream does not contain a header."); 71 72 // Read the hash table. 73 if (auto E = PublicsTable.read(Reader)) 74 return E; 75 76 // Something called "address map" follows. 77 uint32_t NumAddressMapEntries = Header->AddrMap / sizeof(uint32_t); 78 if (auto EC = Reader.readArray(AddressMap, NumAddressMapEntries)) 79 return joinErrors(std::move(EC), 80 make_error<RawError>(raw_error_code::corrupt_file, 81 "Could not read an address map.")); 82 83 // Something called "thunk map" follows. 84 if (auto EC = Reader.readArray(ThunkMap, Header->NumThunks)) 85 return joinErrors(std::move(EC), 86 make_error<RawError>(raw_error_code::corrupt_file, 87 "Could not read a thunk map.")); 88 89 // Something called "section map" follows. 90 if (Reader.bytesRemaining() > 0) { 91 if (auto EC = Reader.readArray(SectionOffsets, Header->NumSections)) 92 return joinErrors(std::move(EC), 93 make_error<RawError>(raw_error_code::corrupt_file, 94 "Could not read a section map.")); 95 } 96 97 if (Reader.bytesRemaining() > 0) 98 return make_error<RawError>(raw_error_code::corrupt_file, 99 "Corrupted publics stream."); 100 return Error::success(); 101} 102