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/PDBFile.h" 30 #include "llvm/DebugInfo/PDB/Native/RawError.h" 31 #include "llvm/DebugInfo/PDB/Native/SymbolStream.h" 32 #include "llvm/Support/BinaryStreamReader.h" 33 #include "llvm/Support/Endian.h" 34 #include "llvm/Support/Error.h" 35 #include <algorithm> 36 #include <cstdint> 37 38 using namespace llvm; 39 using namespace llvm::msf; 40 using namespace llvm::support; 41 using namespace llvm::pdb; 42 43 PublicsStream::PublicsStream(std::unique_ptr<MappedBlockStream> Stream) 44 : Stream(std::move(Stream)) {} 45 46 PublicsStream::~PublicsStream() = default; 47 48 uint32_t PublicsStream::getSymHash() const { return Header->SymHash; } 49 uint16_t PublicsStream::getThunkTableSection() const { 50 return Header->ISectThunkTable; 51 } 52 uint32_t PublicsStream::getThunkTableOffset() const { 53 return Header->OffThunkTable; 54 } 55 56 // Publics stream contains fixed-size headers and a serialized hash table. 57 // This implementation is not complete yet. It reads till the end of the 58 // stream so that we verify the stream is at least not corrupted. However, 59 // we skip over the hash table which we believe contains information about 60 // public symbols. 61 Error PublicsStream::reload() { 62 BinaryStreamReader Reader(*Stream); 63 64 // Check stream size. 65 if (Reader.bytesRemaining() < 66 sizeof(PublicsStreamHeader) + sizeof(GSIHashHeader)) 67 return make_error<RawError>(raw_error_code::corrupt_file, 68 "Publics Stream does not contain a header."); 69 70 // Read PSGSIHDR struct. 71 if (Reader.readObject(Header)) 72 return make_error<RawError>(raw_error_code::corrupt_file, 73 "Publics Stream does not contain a header."); 74 75 // Read the hash table. 76 if (auto E = PublicsTable.read(Reader)) 77 return E; 78 79 // Something called "address map" follows. 80 uint32_t NumAddressMapEntries = Header->AddrMap / sizeof(uint32_t); 81 if (auto EC = Reader.readArray(AddressMap, NumAddressMapEntries)) 82 return joinErrors(std::move(EC), 83 make_error<RawError>(raw_error_code::corrupt_file, 84 "Could not read an address map.")); 85 86 // Something called "thunk map" follows. 87 if (auto EC = Reader.readArray(ThunkMap, Header->NumThunks)) 88 return joinErrors(std::move(EC), 89 make_error<RawError>(raw_error_code::corrupt_file, 90 "Could not read a thunk map.")); 91 92 // Something called "section map" follows. 93 if (Reader.bytesRemaining() > 0) { 94 if (auto EC = Reader.readArray(SectionOffsets, Header->NumSections)) 95 return joinErrors(std::move(EC), 96 make_error<RawError>(raw_error_code::corrupt_file, 97 "Could not read a section map.")); 98 } 99 100 if (Reader.bytesRemaining() > 0) 101 return make_error<RawError>(raw_error_code::corrupt_file, 102 "Corrupted publics stream."); 103 return Error::success(); 104 } 105