Re: gdb-ui.el assumes images support

[Nick Roberts <nickrob@snap.net.nz>]

 >     Yes, but the problem is, tooltip.el requires gdb-ui.el at compile
 >     time,
 > 
 > Can't we get rid of that dependency?
 > What is the reason for it anyway?

Yes. I don't think its needed, but gdb-ui is designed to work on text-only
terminals and presumably it won't currently when configured without X?

Anyway, tooltip.el has:

(eval-when-compile
  (require 'cl)
  (require 'comint)
  (require 'gud)
  (require 'gdb-ui))

I added the last require after Gerd Moellmann included the others. My
understanding now is that a file only requires another, at compilation,
if it uses a macro defined in that other file.

If this is the case, tooltip does not need the last three requires,
and requiring cl just seems to redefine push for compilation, so
perhaps thats not needed either.

It's sometimes hard to see why files are required at compilation, so it may
be good practice to add a comment as in vc.el:

(eval-when-compile
  (require 'cl)
  (require 'compile)
  (require 'dired)      ; for dired-map-over-marks macro
  (require 'dired-aux))	; for dired-kill-{line,tree}

I see that dired is required, but dired-kill-line, dired-kill-tree are not
macros so is dired-aux required? I think not, but if the answer is yes that
would explain the need for the requires in tooltip.

Nick