C++ ArchiveMember::getData方法代码示例

// Write one member out to the file.
bool
Archive::writeMember(
  const ArchiveMember& member,
  raw_fd_ostream& ARFile,
  std::string* ErrMsg
) {

  uint64_t filepos = ARFile.tell();
  filepos -= 8;

  // Get the data and its size either from the
  // member's in-memory data or directly from the file.
  size_t fSize = member.getSize();
  const char *data = (const char*)member.getData();
  MemoryBuffer *mFile = 0;
  if (!data) {
    ErrorOr<std::unique_ptr<MemoryBuffer> > FileOrErr =
        MemoryBuffer::getFile(member.getPath());
    if (!FileOrErr) {
      if (ErrMsg)
        *ErrMsg = FileOrErr.getError().message();
      return true;
    }
    mFile = FileOrErr.get().release();
    data = mFile->getBufferStart();
    fSize = mFile->getBufferSize();
  }

  int hdrSize = fSize;

  // Compute the fields of the header
  ArchiveMemberHeader Hdr;
  bool writeLongName = fillHeader(member,Hdr,hdrSize);

  // Write header to archive file
  ARFile.write((char*)&Hdr, sizeof(Hdr));

  // Write the long filename if its long
  if (writeLongName) {
    StringRef Name = sys::path::filename(member.getPath());
    ARFile.write(Name.data(), Name.size());
  }

  // Write the (possibly compressed) member's content to the file.
  ARFile.write(data,fSize);

  // Make sure the member is an even length
  if ((ARFile.tell() & 1) == 1)
    ARFile << ARFILE_PAD;

  // Close the mapped file if it was opened
  delete mFile;
  return false;
}

// Look up one symbol in the symbol table and return the module that defines
// that symbol.
Module*
Archive::findModuleDefiningSymbol(const std::string& symbol, 
                                  std::string* ErrMsg) {
  SymTabType::iterator SI = symTab.find(symbol);
  if (SI == symTab.end())
    return 0;

  // The symbol table was previously constructed assuming that the members were
  // written without the symbol table header. Because VBR encoding is used, the
  // values could not be adjusted to account for the offset of the symbol table
  // because that could affect the size of the symbol table due to VBR encoding.
  // We now have to account for this by adjusting the offset by the size of the
  // symbol table and its header.
  unsigned fileOffset =
    SI->second +                // offset in symbol-table-less file
    firstFileOffset;            // add offset to first "real" file in archive

  // See if the module is already loaded
  ModuleMap::iterator MI = modules.find(fileOffset);
  if (MI != modules.end())
    return MI->second.first;

  // Module hasn't been loaded yet, we need to load it
  const char* modptr = base + fileOffset;
  ArchiveMember* mbr = parseMemberHeader(modptr, mapfile->getBufferEnd(),
                                         ErrMsg);
  if (!mbr)
    return 0;

  // Now, load the bitcode module to get the Module.
  std::string FullMemberName = archPath.str() + "(" +
    mbr->getPath().str() + ")";
  MemoryBuffer *Buffer =
    MemoryBuffer::getMemBufferCopy(StringRef(mbr->getData(), mbr->getSize()),
                                   FullMemberName.c_str());
  
  Module *m = getLazyBitcodeModule(Buffer, Context, ErrMsg);
  if (!m)
    return 0;

  modules.insert(std::make_pair(fileOffset, std::make_pair(m, mbr)));

  return m;
}

// Load just the symbol table from the archive file
bool
Archive::loadSymbolTable(std::string* ErrorMsg) {

  // Set up parsing
  members.clear();
  const char *At = base;
  const char *End = mapfile->getBufferEnd();

  // Make sure we're dealing with an archive
  if (!checkSignature(ErrorMsg))
    return false;

  At += 8; // Skip signature

  // Parse the first file member header
  const char* FirstFile = At;
  ArchiveMember* mbr = parseMemberHeader(At, End, ErrorMsg);
  if (!mbr)
    return false;

  if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
    // Skip the foreign symbol table, we don't do anything with it
    At += mbr->getSize();
    if ((intptr_t(At) & 1) == 1)
      At++;
    delete mbr;

    // Read the next one
    FirstFile = At;
    mbr = parseMemberHeader(At, End, ErrorMsg);
    if (!mbr) {
      delete mbr;
      return false;
    }
  }

  if (mbr->isStringTable()) {
    // Process the string table entry
    strtab.assign((const char*)mbr->getData(), mbr->getSize());
    At += mbr->getSize();
    if ((intptr_t(At) & 1) == 1)
      At++;
    delete mbr;
    // Get the next one
    FirstFile = At;
    mbr = parseMemberHeader(At, End, ErrorMsg);
    if (!mbr) {
      delete mbr;
      return false;
    }
  }

  // There's no symbol table in the file. We have to rebuild it from scratch
  // because the intent of this method is to get the symbol table loaded so
  // it can be searched efficiently.
  // Add the member to the members list
  members.push_back(mbr);

  firstFileOffset = FirstFile - base;
  return true;
}

// Write one member out to the file.
bool
Archive::writeMember(
  const ArchiveMember& member,
  std::ofstream& ARFile,
  bool CreateSymbolTable,
  bool TruncateNames,
  bool ShouldCompress,
  std::string* ErrMsg
) {

  unsigned filepos = ARFile.tellp();
  filepos -= 8;

  // Get the data and its size either from the
  // member's in-memory data or directly from the file.
  size_t fSize = member.getSize();
  const char *data = (const char*)member.getData();
  MemoryBuffer *mFile = 0;
  if (!data) {
    mFile = MemoryBuffer::getFile(member.getPath().c_str(), ErrMsg);
    if (mFile == 0)
      return true;
    data = mFile->getBufferStart();
    fSize = mFile->getBufferSize();
  }

  // Now that we have the data in memory, update the
  // symbol table if its a bitcode file.
  if (CreateSymbolTable && member.isBitcode()) {
    std::vector<std::string> symbols;
    std::string FullMemberName = archPath.str() + "(" + member.getPath().str()
      + ")";
    Module* M = 
      GetBitcodeSymbols((const unsigned char*)data,fSize,
                        FullMemberName, Context, symbols, ErrMsg);

    // If the bitcode parsed successfully
    if ( M ) {
      for (std::vector<std::string>::iterator SI = symbols.begin(),
           SE = symbols.end(); SI != SE; ++SI) {

        std::pair<SymTabType::iterator,bool> Res =
          symTab.insert(std::make_pair(*SI,filepos));

        if (Res.second) {
          symTabSize += SI->length() +
                        numVbrBytes(SI->length()) +
                        numVbrBytes(filepos);
        }
      }
      // We don't need this module any more.
      delete M;
    } else {
      delete mFile;
      if (ErrMsg)
        *ErrMsg = "Can't parse bitcode member: " + member.getPath().str()
          + ": " + *ErrMsg;
      return true;
    }
  }

  int hdrSize = fSize;

  // Compute the fields of the header
  ArchiveMemberHeader Hdr;
  bool writeLongName = fillHeader(member,Hdr,hdrSize,TruncateNames);

  // Write header to archive file
  ARFile.write((char*)&Hdr, sizeof(Hdr));

  // Write the long filename if its long
  if (writeLongName) {
    ARFile.write(member.getPath().str().data(),
                 member.getPath().str().length());
  }

  // Write the (possibly compressed) member's content to the file.
  ARFile.write(data,fSize);

  // Make sure the member is an even length
  if ((ARFile.tellp() & 1) == 1)
    ARFile << ARFILE_PAD;

  // Close the mapped file if it was opened
  delete mFile;
  return false;
}

// This function loads the entire archive and fully populates its ilist with
// the members of the archive file. This is typically used in preparation for
// editing the contents of the archive.
bool
Archive::loadArchive(std::string* error) {

  // Set up parsing
  members.clear();
  symTab.clear();
  const char *At = base;
  const char *End = mapfile->getBufferEnd();

  if (!checkSignature(error))
    return false;

  At += 8;  // Skip the magic string.

  bool seenSymbolTable = false;
  bool foundFirstFile = false;
  while (At < End) {
    // parse the member header
    const char* Save = At;
    ArchiveMember* mbr = parseMemberHeader(At, End, error);
    if (!mbr)
      return false;

    // check if this is the foreign symbol table
    if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
      // We just save this but don't do anything special
      // with it. It doesn't count as the "first file".
      if (foreignST) {
        // What? Multiple foreign symbol tables? Just chuck it
        // and retain the last one found.
        delete foreignST;
      }
      foreignST = mbr;
      At += mbr->getSize();
      if ((intptr_t(At) & 1) == 1)
        At++;
    } else if (mbr->isStringTable()) {
      // Simply suck the entire string table into a string
      // variable. This will be used to get the names of the
      // members that use the "/ddd" format for their names
      // (SVR4 style long names).
      strtab.assign(At, mbr->getSize());
      At += mbr->getSize();
      if ((intptr_t(At) & 1) == 1)
        At++;
      delete mbr;
    } else if (mbr->isLLVMSymbolTable()) {
      // This is the LLVM symbol table for the archive. If we've seen it
      // already, its an error. Otherwise, parse the symbol table and move on.
      if (seenSymbolTable) {
        if (error)
          *error = "invalid archive: multiple symbol tables";
        return false;
      }
      if (!parseSymbolTable(mbr->getData(), mbr->getSize(), error))
        return false;
      seenSymbolTable = true;
      At += mbr->getSize();
      if ((intptr_t(At) & 1) == 1)
        At++;
      delete mbr; // We don't need this member in the list of members.
    } else {
      // This is just a regular file. If its the first one, save its offset.
      // Otherwise just push it on the list and move on to the next file.
      if (!foundFirstFile) {
        firstFileOffset = Save - base;
        foundFirstFile = true;
      }
      members.push_back(mbr);
      At += mbr->getSize();
      if ((intptr_t(At) & 1) == 1)
        At++;
    }
  }
  return true;
}