Re: font-lock in machine mode of gdba

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

Stefan Monnier writes:
 > > Now font-lock-mode is turn-on in gdb-assembler-mode when
 > > global-font-lock-mode is  true. gdb-assembler-mode-hook is also
 > > provided. See the comments at the tail of font-core.el.
 > 
 > This is still wrong (well, maybe not "wrong", but...).  Your patch should
 > only set font-lock-defaults and nothing more.  It should be all
 > that's needed.  If it's not enough, then there's a bug elsewhere (typically
 > an omission to call `kill-all-local-variables).

Currently these modes can't run kill-all-local-variables. See the FIXME in
gdb-get-create-buffer (which I think you put there a long while ago):

	  ;; FIXME: This should be set after calling the function, since the
	  ;; function should run kill-all-local-variables.

In gdb-get-create-buffer, gdb-buffer-type must currently be set *before*
the mode function because it (the mode function) runs a trigger (like
gdb-invalidate-assembler). This trigger needs to be moved out of the
mode function and into gdb-get-create-buffer. To do this gdb-get-create-buffer
needs to know the name of the trigger. How about something like this:

(defun gdb-get-create-buffer (key)
  "Create a new gdb  buffer of the type specified by KEY.
The key should be one of the cars in `gdb-buffer-rules-assoc'."
  (or (gdb-get-buffer key)
      (let* ((rules (assoc key gdb-buffer-rules-assoc))
	     (name (funcall (gdb-rules-name-maker rules)))
	     (new (get-buffer-create name)))
	(with-current-buffer new
	  (let ((trigger))	  
	    (if (cdr (cdr rules))
		(setq trigger (funcall (car (cdr (cdr rules))))))
	    (set (make-local-variable 'gdb-buffer-type) key)
	    (set (make-local-variable 'gud-minor-mode)
		 (with-current-buffer gud-comint-buffer gud-minor-mode))
	    (set (make-local-variable 'tool-bar-map) gud-tool-bar-map)
	    (if trigger (funcall trigger)))
	  new))))

So that gdb-assembler-mode would look like:

(defun gdb-assembler-mode ()
  "Major mode for viewing code assembler.

\\{gdb-assembler-mode-map}"
  (kill-all-local-variables)
  (setq major-mode 'gdb-assembler-mode)
  (setq mode-name "Machine")
  (setq gdb-overlay-arrow-position nil)
  (add-to-list 'overlay-arrow-variable-list 'gdb-overlay-arrow-position)
  (put 'gdb-overlay-arrow-position 'overlay-arrow-string "=>")
  (setq fringes-outside-margins t)
  (setq buffer-read-only t)
  (use-local-map gdb-assembler-mode-map)
  (gdb-invalidate-assembler)
  (set (make-local-variable 'font-lock-defaults)
       '(gdb-assembler-font-lock-keywords))
  (run-mode-hooks 'gdb-assembler-mode-hook)
  'gdb-invalidate-assembler)

and similarly for the other mode functions. This appears to work and so
does font-lock in the assembler buffer. I'm not looking for points for style,
just confirmation that I'm making sense and that run-mode-hooks doesn't
have to be the last item in the mode function.

Nick