https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120787
--- Comment #3 from James K. Lowden <jklowden at gcc dot gnu.org> --- This takes me back. According to the MF documentation, EXHIBIT appeared around the time of Comet Kohoutek. "These features are extensions to ANS X3.23-1974 that appear in IBM OS/VS COBOL." Exciting times. We will add Exhibit in all its oddball glory. I don't see how it can be done except in the parser. There is no way for a user to DISPLAY the name of a variable under program control (although the awk idea is interesting). The CHANGED option requires runtime support. And EXHIBIT, unlike DISPLAY, places a space between its arguments. If CHANGED is not important, we can emit a not-implemented warning and always print, changed or not.
