lisp/progmodes/asm-mode.el

   1 ;;; asm-mode.el --- mode for editing assembler code
   2
   3 ;; Copyright (C) 1991 Free Software Foundation, Inc.
   4
   5 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
   6 ;; Maintainer: FSF
   7 ;; Keywords: tools, languages
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; This mode was written by Eric S. Raymond <esr@snark.thyrsus.com>,
  29 ;; inspired by an earlier asm-mode by Martin Neitzel.
  30
  31 ;; This minor mode is based on text mode.  It defines a private abbrev table
  32 ;; that can be used to save abbrevs for assembler mnemonics.  It binds just
  33 ;; five keys:
  34 ;;
  35 ;;      TAB             tab to next tab stop
  36 ;;      :               outdent preceding label, tab to tab stop
  37 ;;      comment char    place or move comment
  38 ;;                      asm-comment-char specifies which character this is;
  39 ;;                      you can use a different character in different
  40 ;;                      Asm mode buffers.
  41 ;;      C-j, C-m        newline and tab to tab stop
  42 ;;
  43 ;; Code is indented to the first tab stop level.
  44
  45 ;; This mode runs two hooks:
  46 ;;   1) An asm-mode-set-comment-hook before the part of the initialization
  47 ;; depending on asm-comment-char, and
  48 ;;   2) an asm-mode-hook at the end of initialization.
  49
  50 ;;; Code:
  51
  52 (defgroup asm nil
  53   "Mode for editing assembler code."
  54   :group 'languages)
  55
  56 (defcustom asm-comment-char ?;
  57   "*The comment-start character assumed by Asm mode."
  58   :type 'character
  59   :group 'asm)
  60
  61 (defvar asm-mode-syntax-table nil
  62   "Syntax table used while in Asm mode.")
  63
  64 (defvar asm-mode-abbrev-table nil
  65   "Abbrev table used while in Asm mode.")
  66 (define-abbrev-table 'asm-mode-abbrev-table ())
  67
  68 (defvar asm-mode-map nil
  69   "Keymap for Asm mode.")
  70
  71 (if asm-mode-map
  72     nil
  73   (setq asm-mode-map (make-sparse-keymap))
  74   ;; Note that the comment character isn't set up until asm-mode is called.
  75   (define-key asm-mode-map ":"          'asm-colon)
  76   (define-key asm-mode-map "\C-c;"      'comment-region)
  77   (define-key asm-mode-map "\C-i"       'tab-to-tab-stop)
  78   (define-key asm-mode-map "\C-j"       'asm-newline)
  79   (define-key asm-mode-map "\C-m"       'asm-newline)
  80   )
  81
  82 (defconst asm-font-lock-keywords
  83  '(("^\\(\\(\\sw\\|\\s_\\)+\\)\\>:?[ \t]*\\(\\sw+\\)?"
  84     (1 font-lock-function-name-face) (3 font-lock-keyword-face nil t))
  85    ("^\\s +\\(\\(\\sw\\|\\s_\\)+\\)" 1 font-lock-keyword-face))
  86  "Additional expressions to highlight in Assembler mode.")
  87
  88 (defvar asm-code-level-empty-comment-pattern nil)
  89 (defvar asm-flush-left-empty-comment-pattern nil)
  90 (defvar asm-inline-empty-comment-pattern nil)
  91
  92 ;;;###autoload
  93 (defun asm-mode ()
  94   "Major mode for editing typical assembler code.
  95 Features a private abbrev table and the following bindings:
  96
  97 \\[asm-colon]\toutdent a preceding label, tab to next tab stop.
  98 \\[tab-to-tab-stop]\ttab to next tab stop.
  99 \\[asm-newline]\tnewline, then tab to next tab stop.
 100 \\[asm-comment]\tsmart placement of assembler comments.
 101
 102 The character used for making comments is set by the variable
 103 `asm-comment-char' (which defaults to `?;').
 104
 105 Alternatively, you may set this variable in `asm-mode-set-comment-hook',
 106 which is called near the beginning of mode initialization.
 107
 108 Turning on Asm mode runs the hook `asm-mode-hook' at the end of initialization.
 109
 110 Special commands:
 111 \\{asm-mode-map}
 112 "
 113   (interactive)
 114   (kill-all-local-variables)
 115   (setq mode-name "Assembler")
 116   (setq major-mode 'asm-mode)
 117   (setq local-abbrev-table asm-mode-abbrev-table)
 118   (make-local-variable 'font-lock-defaults)
 119   (setq font-lock-defaults '(asm-font-lock-keywords))
 120   (make-local-variable 'asm-mode-syntax-table)
 121   (setq asm-mode-syntax-table (make-syntax-table))
 122   (set-syntax-table asm-mode-syntax-table)
 123
 124   (run-hooks 'asm-mode-set-comment-hook)
 125   ;; Make our own local child of asm-mode-map
 126   ;; so we can define our own comment character.
 127   (use-local-map (nconc (make-sparse-keymap) asm-mode-map))
 128   (local-set-key (vector asm-comment-char) 'asm-comment)
 129
 130   (modify-syntax-entry  asm-comment-char
 131                         "<" asm-mode-syntax-table)
 132   (modify-syntax-entry  ?\n
 133                          ">" asm-mode-syntax-table)
 134   (let ((cs (regexp-quote (char-to-string asm-comment-char))))
 135     (make-local-variable 'comment-start)
 136     (setq comment-start (concat cs " "))
 137     (make-local-variable 'comment-start-skip)
 138     (setq comment-start-skip (concat cs "+[ \t]*"))
 139     (setq asm-inline-empty-comment-pattern (concat "^.+" cs "+ *$"))
 140     (setq asm-code-level-empty-comment-pattern (concat "^[\t ]+" cs cs " *$"))
 141     (setq asm-flush-left-empty-comment-pattern (concat "^" cs cs cs " *$"))
 142     )
 143   (make-local-variable 'comment-end)
 144   (setq comment-end "")
 145   (make-local-variable 'comment-column)
 146   (setq comment-column 32)
 147   (setq fill-prefix "\t")
 148   (run-hooks 'asm-mode-hook))
 149 \f
 150 (defun asm-colon ()
 151   "Insert a colon; if it follows a label, delete the label's indentation."
 152   (interactive)
 153   (save-excursion
 154     (beginning-of-line)
 155     (if (looking-at "[ \t]+\\(\\sw\\|\\s_\\)+$")
 156         (delete-horizontal-space)))
 157   (insert ":")
 158   (tab-to-tab-stop)
 159   )
 160
 161 (defun asm-newline ()
 162   "Insert LFD + fill-prefix, to bring us back to code-indent level."
 163   (interactive)
 164   (if (eolp) (delete-horizontal-space))
 165   (insert "\n")
 166   (tab-to-tab-stop)
 167   )
 168
 169 (defun asm-line-matches (pattern &optional withcomment)
 170   (save-excursion
 171     (beginning-of-line)
 172     (looking-at pattern)))
 173
 174 (defun asm-pop-comment-level ()
 175   ;; Delete an empty comment ending current line.  Then set up for a new one,
 176   ;; on the current line if it was all comment, otherwise above it
 177   (end-of-line)
 178   (delete-horizontal-space)
 179   (while (= (preceding-char) asm-comment-char)
 180     (delete-backward-char 1))
 181   (delete-horizontal-space)
 182   (if (bolp)
 183       nil
 184     (beginning-of-line)
 185     (open-line 1))
 186   )
 187
 188
 189 (defun asm-comment ()
 190   "Convert an empty comment to a `larger' kind, or start a new one.
 191 These are the known comment classes:
 192
 193    1 -- comment to the right of the code (at the comment-column)
 194    2 -- comment on its own line, indented like code
 195    3 -- comment on its own line, beginning at the left-most column.
 196
 197 Suggested usage:  while writing your code, trigger asm-comment
 198 repeatedly until you are satisfied with the kind of comment."
 199   (interactive)
 200   (cond
 201
 202    ;; Blank line?  Then start comment at code indent level.
 203    ((asm-line-matches "^[ \t]*$")
 204     (delete-horizontal-space)
 205     (tab-to-tab-stop)
 206     (insert asm-comment-char comment-start))
 207
 208    ;; Nonblank line with no comment chars in it?
 209    ;; Then start a comment at the current comment column
 210    ((asm-line-matches (format "^[^%c\n]+$" asm-comment-char))
 211     (indent-for-comment))
 212
 213    ;; Flush-left comment present?  Just insert character.
 214    ((asm-line-matches asm-flush-left-empty-comment-pattern)
 215     (insert asm-comment-char))
 216
 217    ;; Empty code-level comment already present?
 218    ;; Then start flush-left comment, on line above if this one is nonempty.
 219    ((asm-line-matches asm-code-level-empty-comment-pattern)
 220     (asm-pop-comment-level)
 221     (insert asm-comment-char asm-comment-char comment-start))
 222
 223    ;; Empty comment ends line?
 224    ;; Then make code-level comment, on line above if this one is nonempty.
 225    ((asm-line-matches asm-inline-empty-comment-pattern)
 226     (asm-pop-comment-level)
 227     (tab-to-tab-stop)
 228     (insert asm-comment-char comment-start))
 229
 230    ;; If all else fails, insert character
 231    (t
 232     (insert asm-comment-char))
 233
 234    )
 235   (end-of-line))
 236
 237 (provide 'asm-mode)
 238
 239 ;;; asm-mode.el ends here