In /src/hotspot/share/services/diagnosticFramework.hpp:

CmdLine::is_executable() looks wrong, surely an empty line is not executable. I think it should be:

  70 bool is_executable() const { return !is_empty() && _cmd[0] != '#'; }
  
  
This does not cause a big issue as create_local_DCmd() checks for a null command, but does mean in DCmd::parse_and_execute() we will needlessly enter the code block that would execute the command.

is_executable() is not used outside of this area.