1 //===- PublicsStream.cpp - PDB Public Symbol Stream -----------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // The data structures defined in this file are based on the reference 11 // implementation which is available at 12 // https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.h 13 // 14 // When you are reading the reference source code, you'd find the 15 // information below useful. 16 // 17 // - ppdb1->m_fMinimalDbgInfo seems to be always true. 18 // - SMALLBUCKETS macro is defined. 19 // 20 // The reference doesn't compile, so I learned just by reading code. 21 // It's not guaranteed to be correct. 22 // 23 //===----------------------------------------------------------------------===// 24 25 #include "llvm/DebugInfo/PDB/Native/PublicsStream.h" 26 #include "llvm/ADT/iterator_range.h" 27 #include "llvm/DebugInfo/CodeView/SymbolRecord.h" 28 #include "llvm/DebugInfo/MSF/MappedBlockStream.h" 29 #include "llvm/DebugInfo/PDB/Native/RawError.h" 30 #include "llvm/Support/BinaryStreamReader.h" 31 #include "llvm/Support/Endian.h" 32 #include "llvm/Support/Error.h" 33 #include <algorithm> 34 #include <cstdint> 35 36 using namespace llvm; 37 using namespace llvm::msf; 38 using namespace llvm::support; 39 using namespace llvm::pdb; 40 41 PublicsStream::PublicsStream(std::unique_ptr<MappedBlockStream> Stream) 42 : Stream(std::move(Stream)) {} 43 44 PublicsStream::~PublicsStream() = default; 45 46 uint32_t PublicsStream::getSymHash() const { return Header->SymHash; } 47 uint16_t PublicsStream::getThunkTableSection() const { 48 return Header->ISectThunkTable; 49 } 50 uint32_t PublicsStream::getThunkTableOffset() const { 51 return Header->OffThunkTable; 52 } 53 54 // Publics stream contains fixed-size headers and a serialized hash table. 55 // This implementation is not complete yet. It reads till the end of the 56 // stream so that we verify the stream is at least not corrupted. However, 57 // we skip over the hash table which we believe contains information about 58 // public symbols. 59 Error PublicsStream::reload() { 60 BinaryStreamReader Reader(*Stream); 61 62 // Check stream size. 63 if (Reader.bytesRemaining() < 64 sizeof(PublicsStreamHeader) + sizeof(GSIHashHeader)) 65 return make_error<RawError>(raw_error_code::corrupt_file, 66 "Publics Stream does not contain a header."); 67 68 // Read PSGSIHDR struct. 69 if (Reader.readObject(Header)) 70 return make_error<RawError>(raw_error_code::corrupt_file, 71 "Publics Stream does not contain a header."); 72 73 // Read the hash table. 74 if (auto E = PublicsTable.read(Reader)) 75 return E; 76 77 // Something called "address map" follows. 78 uint32_t NumAddressMapEntries = Header->AddrMap / sizeof(uint32_t); 79 if (auto EC = Reader.readArray(AddressMap, NumAddressMapEntries)) 80 return joinErrors(std::move(EC), 81 make_error<RawError>(raw_error_code::corrupt_file, 82 "Could not read an address map.")); 83 84 // Something called "thunk map" follows. 85 if (auto EC = Reader.readArray(ThunkMap, Header->NumThunks)) 86 return joinErrors(std::move(EC), 87 make_error<RawError>(raw_error_code::corrupt_file, 88 "Could not read a thunk map.")); 89 90 // Something called "section map" follows. 91 if (Reader.bytesRemaining() > 0) { 92 if (auto EC = Reader.readArray(SectionOffsets, Header->NumSections)) 93 return joinErrors(std::move(EC), 94 make_error<RawError>(raw_error_code::corrupt_file, 95 "Could not read a section map.")); 96 } 97 98 if (Reader.bytesRemaining() > 0) 99 return make_error<RawError>(raw_error_code::corrupt_file, 100 "Corrupted publics stream."); 101 return Error::success(); 102 } 103
