C++ ArchiveMember::isBitcode方法代码示例

// Look up multiple symbols in the symbol table and return a set of
// Modules that define those symbols.
bool
Archive::findModulesDefiningSymbols(std::set<std::string>& symbols,
                                    SmallVectorImpl<Module*>& result,
                                    std::string* error) {
  if (!mapfile || !base) {
    if (error)
      *error = "Empty archive invalid for finding modules defining symbols";
    return false;
  }

  if (symTab.empty()) {
    // We don't have a symbol table, so we must build it now but lets also
    // make sure that we populate the modules table as we do this to ensure
    // that we don't load them twice when findModuleDefiningSymbol is called
    // below.

    // Get a pointer to the first file
    const char* At  = base + firstFileOffset;
    const char* End = mapfile->getBufferEnd();

    while ( At < End) {
      // Compute the offset to be put in the symbol table
      unsigned offset = At - base - firstFileOffset;

      // Parse the file's header
      ArchiveMember* mbr = parseMemberHeader(At, End, error);
      if (!mbr)
        return false;

      // If it contains symbols
      if (mbr->isBitcode()) {
        // Get the symbols
        std::vector<std::string> symbols;
        std::string FullMemberName = archPath.str() + "(" +
          mbr->getPath().str() + ")";
        Module* M = 
          GetBitcodeSymbols(At, mbr->getSize(), FullMemberName, Context,
                            symbols, error);

        if (M) {
          // Insert the module's symbols into the symbol table
          for (std::vector<std::string>::iterator I = symbols.begin(),
               E=symbols.end(); I != E; ++I ) {
            symTab.insert(std::make_pair(*I, offset));
          }
          // Insert the Module and the ArchiveMember into the table of
          // modules.
          modules.insert(std::make_pair(offset, std::make_pair(M, mbr)));
        } else {
          if (error)
            *error = "Can't parse bitcode member: " + 
              mbr->getPath().str() + ": " + *error;
          delete mbr;
          return false;
        }
      }

      // Go to the next file location
      At += mbr->getSize();
      if ((intptr_t(At) & 1) == 1)
        At++;
    }
  }

  // At this point we have a valid symbol table (one way or another) so we
  // just use it to quickly find the symbols requested.

  SmallPtrSet<Module*, 16> Added;
  for (std::set<std::string>::iterator I=symbols.begin(),
         Next = I,
         E=symbols.end(); I != E; I = Next) {
    // Increment Next before we invalidate it.
    ++Next;

    // See if this symbol exists
    Module* m = findModuleDefiningSymbol(*I,error);
    if (!m)
      continue;
    bool NewMember = Added.insert(m);
    if (!NewMember)
      continue;

    // The symbol exists, insert the Module into our result.
    result.push_back(m);

    // Remove the symbol now that its been resolved.
    symbols.erase(I);
  }
  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;
}

// Look up multiple symbols in the symbol table and return a set of
// ModuleProviders that define those symbols.
bool
Archive::findModulesDefiningSymbols(std::set<std::string>& symbols,
                                    std::set<ModuleProvider*>& result,
                                    std::string* error) {
  if (!mapfile || !base) {
    if (error)
      *error = "Empty archive invalid for finding modules defining symbols";
    return false;
  }

  if (symTab.empty()) {
    // We don't have a symbol table, so we must build it now but lets also
    // make sure that we populate the modules table as we do this to ensure
    // that we don't load them twice when findModuleDefiningSymbol is called
    // below.

    // Get a pointer to the first file
    const char* At  = base + firstFileOffset;
    const char* End = mapfile->getBufferEnd();

    while ( At < End) {
      // Compute the offset to be put in the symbol table
      unsigned offset = At - base - firstFileOffset;

      // Parse the file's header
      ArchiveMember* mbr = parseMemberHeader(At, End, error);
      if (!mbr)
        return false;

      // If it contains symbols
      if (mbr->isBitcode()) {
        // Get the symbols
        std::vector<std::string> symbols;
        std::string FullMemberName = archPath.toString() + "(" +
          mbr->getPath().toString() + ")";
        ModuleProvider* MP = 
          GetBitcodeSymbols((const unsigned char*)At, mbr->getSize(),
                            FullMemberName, symbols, error);

        if (MP) {
          // Insert the module's symbols into the symbol table
          for (std::vector<std::string>::iterator I = symbols.begin(),
               E=symbols.end(); I != E; ++I ) {
            symTab.insert(std::make_pair(*I, offset));
          }
          // Insert the ModuleProvider and the ArchiveMember into the table of
          // modules.
          modules.insert(std::make_pair(offset, std::make_pair(MP, mbr)));
        } else {
          if (error)
            *error = "Can't parse bitcode member: " + 
              mbr->getPath().toString() + ": " + *error;
          delete mbr;
          return false;
        }
      }

      // Go to the next file location
      At += mbr->getSize();
      if ((intptr_t(At) & 1) == 1)
        At++;
    }
  }

  // At this point we have a valid symbol table (one way or another) so we
  // just use it to quickly find the symbols requested.

  for (std::set<std::string>::iterator I=symbols.begin(),
       E=symbols.end(); I != E;) {
    // See if this symbol exists
    ModuleProvider* mp = findModuleDefiningSymbol(*I,error);
    if (mp) {
      // The symbol exists, insert the ModuleProvider into our result,
      // duplicates wil be ignored
      result.insert(mp);

      // Remove the symbol now that its been resolved, being careful to
      // post-increment the iterator.
      symbols.erase(I++);
    } else {
      ++I;
    }
  }
  return true;
}