[Ann] Emacs major mode for editing GNAT project files

[rolf.ebert_nospam_@gmx.net (Rolf Ebert)]

Please see below an Emacs mode for editing GNAT project files ending
in .gpr.  It reuses almost all from the standard Ada-mode with the
following differences:

 -  add font-locking for "project" and "external"
 -  correctly indent after a "project Foo is"

It would have been shorter (in number of bytes) to integrate gpr
support into ada-mode.el as a variant, but is was easier to write a
new file.

HTH
    Rolf
------------------------------------------
;;; ada-gpr.el --- major-mode for editing GNAT project files

;; Copyright (C) 2004  Rolf Ebert

;; Author: Rolf Ebert      <rolf.ebert_nospam_@gmx.net>
;; Keywords: languages ada

;; This file is not part of GNU Emacs.

;; ada-gpr is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published
by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; ada-gpr is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

(require 'ada-mode)

;; ---------------------------------------------------
;;    support for font-lock.el
;; ----------------------------------------------------

(defvar ada-gpr-font-lock-keywords
  (progn ;; eval-when-compile
    (list
     ;;
     ;; keyword plus name.
     (list (concat
            "\\<\\("
            "package\\|"
            "project\\|"
            "for"
            "\\)\\>[ \t]*"
            "\\(\\sw+\\(\\.\\sw*\\)*\\)?")
           '(1 font-lock-keyword-face) '(2
font-lock-function-name-face nil t))
     ;;
     ;; Main keywords
     (list (concat "\\<"
		   (regexp-opt
		    '("case" "external" "is" "others" "renames" "type"
		      "use" "when" "with") t)
		   "\\>")
	   '(1 font-lock-keyword-face))
     ;;
     ;; Anything following end and not already fontified is a body
name.
     '("\\<\\(end\\)\\>\\([ \t]+\\)?\\(\\(\\sw\\|[_.]\\)+\\)?"
       (1 font-lock-keyword-face) (3 font-lock-function-name-face nil
t))
     ;;
     ))
  "Default expressions to highlight in GNAT project file (gpr) mode.")



;;;
(defun ada-gpr-mode ()
  "Ada gpr mode is the major mode for editing GNAT project files."

  (interactive)
  (kill-all-local-variables)

  (set (make-local-variable 'require-final-newline) t)

  ;;  Set the paragraph delimiters so that one can select a whole
block
  ;;  simply with M-h
  (set (make-local-variable 'paragraph-start) "[ \t\n\f]*$")
  (set (make-local-variable 'paragraph-separate) "[ \t\n\f]*$")

  ;; comment end must be set because it may hold a wrong value if
  ;; this buffer had been in another mode before. RE
  (set (make-local-variable 'comment-end) "")

  ;; used by autofill and indent-new-comment-line
  (set (make-local-variable 'comment-start-skip) "---*[ \t]*")

  ;; used by autofill to break a comment line and continue it on
another line.
  ;; The reason we need this one is that the default behavior does not
work
  ;; correctly with the definition of paragraph-start above when the
comment
  ;; is right after a multi-line subprogram declaration (the comments
are
  ;; aligned under the latest parameter, not under the declaration
start).
  (set (make-local-variable 'comment-line-break-function)
       (lambda (&optional soft) (let ((fill-prefix nil))
                                  (indent-new-comment-line soft))))

  ;; use indenting from Ada, just add "project"
  (set (make-local-variable 'ada-subprog-start-re)
       (concat "\\<" (regexp-opt '("project" "package") t) "\\>"))

  (set (make-local-variable 'indent-line-function)
       'ada-indent-current-function)

  (set (make-local-variable 'comment-column) 40)

  (set 'case-fold-search t)

  (set (make-local-variable 'fill-paragraph-function)
       'ada-fill-comment-paragraph)

  ;;  font-lock support :
  ;;  We need to set some properties for XEmacs, and define some
variables
  ;;  for Emacs

  (if ada-xemacs
      ;;  XEmacs
      (put 'ada-mode 'font-lock-defaults
           '(ada-gpr-font-lock-keywords
             nil t ((?\_ . "w") (?# . ".")) beginning-of-line))
    ;;  Emacs
    (set (make-local-variable 'font-lock-defaults)
         '(ada-gpr-font-lock-keywords
           nil t
           ((?\_ . "w") (?# . "."))
           beginning-of-line
           (font-lock-syntactic-keywords .
ada-font-lock-syntactic-keywords)))
    )

  ;;  Support for ispell : Check only comments
  (set (make-local-variable 'ispell-check-comments) 'exclusive)

  ;;  Support for indent-new-comment-line (Especially for XEmacs)
  (setq comment-multi-line nil)

  (setq major-mode 'ada-gpr-mode
	mode-name "GNAT Project")

  ;;  use the keybindings from Ada mode
  (use-local-map ada-mode-map)

  ;; (easy-menu-add ada-mode-menu ada-mode-map)

  ;;  use Ada syntax table
  (set-syntax-table ada-mode-syntax-table)

  (if ada-clean-buffer-before-saving
      (progn
        ;; remove all spaces at the end of lines in the whole buffer.
        (add-hook 'local-write-file-hooks 'delete-trailing-whitespace)
        ;; convert all tabs to the correct number of spaces.
        (add-hook 'local-write-file-hooks
                  (lambda () (untabify (point-min) (point-max))))))

  (run-hooks 'ada-gpr-mode-hook)

  ;;  To be run after the hook, in case the user modified
  ;;  ada-fill-comment-prefix
  (make-local-variable 'comment-start)
  (if ada-fill-comment-prefix
      (set 'comment-start ada-fill-comment-prefix)
    (set 'comment-start "-- "))
  
  ;;  Run this after the hook to give the users a chance to activate
  ;;  font-lock-mode

  (unless ada-xemacs
    (progn
      (ada-initialize-properties)
      (make-local-hook 'font-lock-mode-hook)
      (add-hook 'font-lock-mode-hook 'ada-deactivate-properties nil
t)))

  (if ada-auto-case
      (ada-activate-keys-for-case)))



;;; set file extension
(setq auto-mode-alist
      (cons '("\\.gpr\\'" . ada-gpr-mode) auto-mode-alist))

;;; provide ourselves
(provide 'ada-gpr-mode)

;;; ada-gpr.el ends here