code: private void writeSource(final Writer writer, final String basePath, final File groupMember) throws IOException {
      writer.write("# Begin Source File\r\n\r\nSOURCE=");
      String relativePath = CUtil.getRelativePath(basePath, groupMember);
      //
      // if relative path is just a name (hello.c) then
      // make it .\hello.c
      if (!relativePath.startsWith(".") && !relativePath.contains(":") && !relativePath.startsWith("\\")) {
        relativePath = ".\\" + relativePath;
      }
      writer.write(CUtil.toWindowsPath(relativePath));
      writer.write("\r\n# End Source File\r\n");
    }
docs: Writes the entry for one source file in the project.
  
  @param writer
  Writer writer
  @param basePath
  String base path for project
  @param groupMember
  File project source file
  @throws IOException
  if error writing project file