Line data    Source code

       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 "GSI.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/MSF/StreamReader.h"
      30             : #include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
      31             : #include "llvm/DebugInfo/PDB/Raw/PublicsStream.h"
      32             : #include "llvm/DebugInfo/PDB/Raw/RawError.h"
      33             : #include "llvm/DebugInfo/PDB/Raw/SymbolStream.h"
      34             : #include "llvm/Support/Endian.h"
      35             : #include "llvm/Support/Error.h"
      36             : #include <algorithm>
      37             : #include <cstdint>
      38             : 
      39             : using namespace llvm;
      40             : using namespace llvm::msf;
      41             : using namespace llvm::support;
      42             : using namespace llvm::pdb;
      43             : 
      44             : // This is PSGSIHDR struct defined in
      45             : // https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.h
      46             : struct PublicsStream::HeaderInfo {
      47             :   ulittle32_t SymHash;
      48             :   ulittle32_t AddrMap;
      49             :   ulittle32_t NumThunks;
      50             :   ulittle32_t SizeOfThunk;
      51             :   ulittle16_t ISectThunkTable;
      52             :   char Padding[2];
      53             :   ulittle32_t OffThunkTable;
      54             :   ulittle32_t NumSections;
      55             : };
      56             : 
      57           2 : PublicsStream::PublicsStream(PDBFile &File,
      58           2 :                              std::unique_ptr<MappedBlockStream> Stream)
      59          16 :     : Pdb(File), Stream(std::move(Stream)) {}
      60             : 
      61             : PublicsStream::~PublicsStream() = default;
      62             : 
      63           4 : uint32_t PublicsStream::getSymHash() const { return Header->SymHash; }
      64           4 : uint32_t PublicsStream::getAddrMap() const { return Header->AddrMap; }
      65             : 
      66             : // Publics stream contains fixed-size headers and a serialized hash table.
      67             : // This implementation is not complete yet. It reads till the end of the
      68             : // stream so that we verify the stream is at least not corrupted. However,
      69             : // we skip over the hash table which we believe contains information about
      70             : // public symbols.
      71           2 : Error PublicsStream::reload() {
      72           4 :   StreamReader Reader(*Stream);
      73             : 
      74             :   // Check stream size.
      75           2 :   if (Reader.bytesRemaining() < sizeof(HeaderInfo) + sizeof(GSIHashHeader))
      76             :     return make_error<RawError>(raw_error_code::corrupt_file,
      77           0 :                                 "Publics Stream does not contain a header.");
      78             : 
      79             :   // Read PSGSIHDR and GSIHashHdr structs.
      80           6 :   if (Reader.readObject(Header))
      81             :     return make_error<RawError>(raw_error_code::corrupt_file,
      82           0 :                                 "Publics Stream does not contain a header.");
      83             : 
      84           6 :   if (auto EC = readGSIHashHeader(HashHdr, Reader))
      85           0 :     return EC;
      86             : 
      87           6 :   if (auto EC = readGSIHashRecords(HashRecords, HashHdr, Reader))
      88           0 :     return EC;
      89             : 
      90           6 :   if (auto EC = readGSIHashBuckets(HashBuckets, HashHdr, Reader))
      91           0 :     return EC;
      92           4 :   NumBuckets = HashBuckets.size();
      93             : 
      94             :   // Something called "address map" follows.
      95           4 :   uint32_t NumAddressMapEntries = Header->AddrMap / sizeof(uint32_t);
      96           6 :   if (auto EC = Reader.readArray(AddressMap, NumAddressMapEntries))
      97           0 :     return joinErrors(std::move(EC),
      98           0 :                       make_error<RawError>(raw_error_code::corrupt_file,
      99           0 :                                            "Could not read an address map."));
     100             : 
     101             :   // Something called "thunk map" follows.
     102           8 :   if (auto EC = Reader.readArray(ThunkMap, Header->NumThunks))
     103           0 :     return joinErrors(std::move(EC),
     104           0 :                       make_error<RawError>(raw_error_code::corrupt_file,
     105           0 :                                            "Could not read a thunk map."));
     106             : 
     107             :   // Something called "section map" follows.
     108           8 :   if (auto EC = Reader.readArray(SectionOffsets, Header->NumSections))
     109           0 :     return joinErrors(std::move(EC),
     110           0 :                       make_error<RawError>(raw_error_code::corrupt_file,
     111           0 :                                            "Could not read a section map."));
     112             : 
     113           2 :   if (Reader.bytesRemaining() > 0)
     114             :     return make_error<RawError>(raw_error_code::corrupt_file,
     115           0 :                                 "Corrupted publics stream.");
     116           6 :   return Error::success();
     117             : }
     118             : 
     119             : iterator_range<codeview::CVSymbolArray::Iterator>
     120           2 : PublicsStream::getSymbols(bool *HadError) const {
     121           4 :   auto SymbolS = Pdb.getPDBSymbolStream();
     122           6 :   if (SymbolS.takeError()) {
     123           0 :     codeview::CVSymbolArray::Iterator Iter;
     124           0 :     return make_range(Iter, Iter);
     125             :   }
     126           2 :   SymbolStream &SS = SymbolS.get();
     127             : 
     128           2 :   return SS.getSymbols(HadError);
     129             : }
     130             : 
     131           0 : Error PublicsStream::commit() { return Error::success(); }