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/DebugInfo/MSF/MappedBlockStream.h" 26 #include "llvm/DebugInfo/PDB/Native/RawError.h" 27 #include "llvm/DebugInfo/PDB/Native/RawTypes.h" 28 #include "llvm/Support/BinaryStreamReader.h" 29 #include "llvm/Support/Endian.h" 30 #include "llvm/Support/Error.h" 31 #include <cstdint> 32 33 using namespace llvm; 34 using namespace llvm::msf; 35 using namespace llvm::support; 36 using namespace llvm::pdb; 37 38 PublicsStream::PublicsStream(std::unique_ptr<MappedBlockStream> Stream) 39 : Stream(std::move(Stream)) {} 40 41 PublicsStream::~PublicsStream() = default; 42 43 uint32_t PublicsStream::getSymHash() const { return Header->SymHash; } 44 uint16_t PublicsStream::getThunkTableSection() const { 45 return Header->ISectThunkTable; 46 } 47 uint32_t PublicsStream::getThunkTableOffset() const { 48 return Header->OffThunkTable; 49 } 50 51 // Publics stream contains fixed-size headers and a serialized hash table. 52 // This implementation is not complete yet. It reads till the end of the 53 // stream so that we verify the stream is at least not corrupted. However, 54 // we skip over the hash table which we believe contains information about 55 // public symbols. 56 Error PublicsStream::reload() { 57 BinaryStreamReader Reader(*Stream); 58 59 // Check stream size. 60 if (Reader.bytesRemaining() < 61 sizeof(PublicsStreamHeader) + sizeof(GSIHashHeader)) 62 return make_error<RawError>(raw_error_code::corrupt_file, 63 "Publics Stream does not contain a header."); 64 65 // Read PSGSIHDR struct. 66 if (Reader.readObject(Header)) 67 return make_error<RawError>(raw_error_code::corrupt_file, 68 "Publics Stream does not contain a header."); 69 70 // Read the hash table. 71 if (auto E = PublicsTable.read(Reader)) 72 return E; 73 74 // Something called "address map" follows. 75 uint32_t NumAddressMapEntries = Header->AddrMap / sizeof(uint32_t); 76 if (auto EC = Reader.readArray(AddressMap, NumAddressMapEntries)) 77 return joinErrors(std::move(EC), 78 make_error<RawError>(raw_error_code::corrupt_file, 79 "Could not read an address map.")); 80 81 // Something called "thunk map" follows. 82 if (auto EC = Reader.readArray(ThunkMap, Header->NumThunks)) 83 return joinErrors(std::move(EC), 84 make_error<RawError>(raw_error_code::corrupt_file, 85 "Could not read a thunk map.")); 86 87 // Something called "section map" follows. 88 if (Reader.bytesRemaining() > 0) { 89 if (auto EC = Reader.readArray(SectionOffsets, Header->NumSections)) 90 return joinErrors(std::move(EC), 91 make_error<RawError>(raw_error_code::corrupt_file, 92 "Could not read a section map.")); 93 } 94 95 if (Reader.bytesRemaining() > 0) 96 return make_error<RawError>(raw_error_code::corrupt_file, 97 "Corrupted publics stream."); 98 return Error::success(); 99 } 100