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