/** Enter a set of generated class files. */
    private List<ClassSymbol> enterClassFiles(Map<String, JavaFileObject> classFiles) {
      ClassReader reader = ClassReader.instance(context);
      Names names = Names.instance(context);
      List<ClassSymbol> list = List.nil();

      for (Map.Entry<String, JavaFileObject> entry : classFiles.entrySet()) {
        Name name = names.fromString(entry.getKey());
        JavaFileObject file = entry.getValue();
        if (file.getKind() != JavaFileObject.Kind.CLASS) throw new AssertionError(file);
        ClassSymbol cs;
        if (isPkgInfo(file, JavaFileObject.Kind.CLASS)) {
          Name packageName = Convert.packagePart(name);
          PackageSymbol p = reader.enterPackage(packageName);
          if (p.package_info == null)
            p.package_info = reader.enterClass(Convert.shortName(name), p);
          cs = p.package_info;
          if (cs.classfile == null) cs.classfile = file;
        } else cs = reader.enterClass(name, file);
        list = list.prepend(cs);
      }
      return list.reverse();
    }
 private boolean isPkgInfo(ClassSymbol sym) {
   return isPkgInfo(sym.classfile, JavaFileObject.Kind.CLASS)
       && (sym.packge().package_info == sym);
 }