lisp/progmodes/asm-mode.el

   1 ;;; asm-mode.el --- mode for editing assembler code
   2
   3 ;; Copyright (C) 1991, 2001, 2002, 2003, 2004, 2005
   4 ;; Free Software Foundation, Inc.
   5
   6 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
   7 ;; Maintainer: FSF
   8 ;; Keywords: tools, languages
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; This mode was written by Eric S. Raymond <esr@snark.thyrsus.com>,
  30 ;; inspired by an earlier asm-mode by Martin Neitzel.
  31
  32 ;; This minor mode is based on text mode.  It defines a private abbrev table
  33 ;; that can be used to save abbrevs for assembler mnemonics.  It binds just
  34 ;; five keys:
  35 ;;
  36 ;;      TAB             tab to next tab stop
  37 ;;      :               outdent preceding label, tab to tab stop
  38 ;;      comment char    place or move comment
  39 ;;                      asm-comment-char specifies which character this is;
  40 ;;                      you can use a different character in different
  41 ;;                      Asm mode buffers.
  42 ;;      C-j, C-m        newline and tab to tab stop
  43 ;;
  44 ;; Code is indented to the first tab stop level.
  45
  46 ;; This mode runs two hooks:
  47 ;;   1) An asm-mode-set-comment-hook before the part of the initialization
  48 ;; depending on asm-comment-char, and
  49 ;;   2) an asm-mode-hook at the end of initialization.
  50
  51 ;;; Code:
  52
  53 (defgroup asm nil
  54   "Mode for editing assembler code."
  55   :link '(custom-group-link :tag "Font Lock Faces group" font-lock-faces)
  56   :group 'languages)
  57
  58 (defcustom asm-comment-char ?\;
  59   "*The comment-start character assumed by Asm mode."
  60   :type 'character
  61   :group 'asm)
  62
  63 (defvar asm-mode-syntax-table
  64   (let ((st (make-syntax-table)))
  65     (modify-syntax-entry ?\n ">" st)
  66     (modify-syntax-entry ?/  ". 14b" st)
  67     (modify-syntax-entry ?*  ". 23b" st)
  68     st)
  69   "Syntax table used while in Asm mode.")
  70
  71 (defvar asm-mode-abbrev-table nil
  72   "Abbrev table used while in Asm mode.")
  73 (define-abbrev-table 'asm-mode-abbrev-table ())
  74
  75 (defvar asm-mode-map
  76   (let ((map (make-sparse-keymap)))
  77     ;; Note that the comment character isn't set up until asm-mode is called.
  78     (define-key map ":"         'asm-colon)
  79     (define-key map "\C-c;"     'comment-region)
  80     (define-key map "\C-j"      'newline-and-indent)
  81     (define-key map "\C-m"      'newline-and-indent)
  82     map)
  83   "Keymap for Asm mode.")
  84
  85 (defconst asm-font-lock-keywords
  86  '(("^\\(\\(\\sw\\|\\s_\\)+\\)\\>:?[ \t]*\\(\\sw+\\(\\.\\sw+\\)*\\)?"
  87     (1 font-lock-function-name-face) (3 font-lock-keyword-face nil t))
  88    ;; label started from ".".
  89    ("^\\(\\.\\(\\sw\\|\\s_\\)+\\)\\>:"
  90     1 font-lock-function-name-face)
  91    ("^\\((\\sw+)\\)?\\s +\\(\\(\\.?\\sw\\|\\s_\\)+\\(\\.\\sw+\\)*\\)"
  92     2 font-lock-keyword-face)
  93    ;; directive started from ".".
  94    ("^\\(\\.\\(\\sw\\|\\s_\\)+\\)\\>[^:]?"
  95     1 font-lock-keyword-face)
  96    ;; %register
  97    ("%\\sw+" . font-lock-variable-name-face))
  98  "Additional expressions to highlight in Assembler mode.")
  99
 100 ;;;###autoload
 101 (defun asm-mode ()
 102   "Major mode for editing typical assembler code.
 103 Features a private abbrev table and the following bindings:
 104
 105 \\[asm-colon]\toutdent a preceding label, tab to next tab stop.
 106 \\[tab-to-tab-stop]\ttab to next tab stop.
 107 \\[asm-newline]\tnewline, then tab to next tab stop.
 108 \\[asm-comment]\tsmart placement of assembler comments.
 109
 110 The character used for making comments is set by the variable
 111 `asm-comment-char' (which defaults to `?\\;').
 112
 113 Alternatively, you may set this variable in `asm-mode-set-comment-hook',
 114 which is called near the beginning of mode initialization.
 115
 116 Turning on Asm mode runs the hook `asm-mode-hook' at the end of initialization.
 117
 118 Special commands:
 119 \\{asm-mode-map}"
 120   (interactive)
 121   (kill-all-local-variables)
 122   (setq mode-name "Assembler")
 123   (setq major-mode 'asm-mode)
 124   (setq local-abbrev-table asm-mode-abbrev-table)
 125   (make-local-variable 'font-lock-defaults)
 126   (setq font-lock-defaults '(asm-font-lock-keywords))
 127   (set (make-local-variable 'indent-line-function) 'asm-indent-line)
 128   ;; Stay closer to the old TAB behavior (was tab-to-tab-stop).
 129   (set (make-local-variable 'tab-always-indent) nil)
 130
 131   (run-hooks 'asm-mode-set-comment-hook)
 132   ;; Make our own local child of asm-mode-map
 133   ;; so we can define our own comment character.
 134   (use-local-map (nconc (make-sparse-keymap) asm-mode-map))
 135   (local-set-key (vector asm-comment-char) 'asm-comment)
 136   (set-syntax-table (make-syntax-table asm-mode-syntax-table))
 137   (modify-syntax-entry  asm-comment-char "<")
 138
 139   (make-local-variable 'comment-start)
 140   (setq comment-start (string asm-comment-char))
 141   (make-local-variable 'comment-add)
 142   (setq comment-add 1)
 143   (make-local-variable 'comment-start-skip)
 144   (setq comment-start-skip "\\(?:\\s<+\\|/\\*+\\)[ \t]*")
 145   (make-local-variable 'comment-end-skip)
 146   (setq comment-end-skip "[ \t]*\\(\\s>\\|\\*+/\\)")
 147   (make-local-variable 'comment-end)
 148   (setq comment-end "")
 149   (setq fill-prefix "\t")
 150   (run-mode-hooks 'asm-mode-hook))
 151
 152 (defun asm-indent-line ()
 153   "Auto-indent the current line."
 154   (interactive)
 155   (let* ((savep (point))
 156          (indent (condition-case nil
 157                      (save-excursion
 158                        (forward-line 0)
 159                        (skip-chars-forward " \t")
 160                        (if (>= (point) savep) (setq savep nil))
 161                        (max (asm-calculate-indentation) 0))
 162                    (error 0))))
 163     (if savep
 164         (save-excursion (indent-line-to indent))
 165       (indent-line-to indent))))
 166
 167 (defun asm-calculate-indentation ()
 168   (or
 169    ;; Flush labels to the left margin.
 170    (and (looking-at "\\(\\sw\\|\\s_\\)+:") 0)
 171    ;; Same thing for `;;;' comments.
 172    (and (looking-at "\\s<\\s<\\s<") 0)
 173    ;; Simple `;' comments go to the comment-column.
 174    (and (looking-at "\\s<\\(\\S<\\|\\'\\)") comment-column)
 175    ;; The rest goes at the first tab stop.
 176    (or (car tab-stop-list) tab-width)))
 177
 178 (defun asm-colon ()
 179   "Insert a colon; if it follows a label, delete the label's indentation."
 180   (interactive)
 181   (let ((labelp nil))
 182     (save-excursion
 183       (skip-syntax-backward "w_")
 184       (skip-syntax-backward " ")
 185       (if (setq labelp (bolp)) (delete-horizontal-space)))
 186     (call-interactively 'self-insert-command)
 187     (when labelp
 188       (delete-horizontal-space)
 189       (tab-to-tab-stop))))
 190
 191 ;; Obsolete since Emacs-22.1.
 192 (defalias 'asm-newline 'newline-and-indent)
 193
 194 (defun asm-comment ()
 195   "Convert an empty comment to a `larger' kind, or start a new one.
 196 These are the known comment classes:
 197
 198    1 -- comment to the right of the code (at the comment-column)
 199    2 -- comment on its own line, indented like code
 200    3 -- comment on its own line, beginning at the left-most column.
 201
 202 Suggested usage:  while writing your code, trigger asm-comment
 203 repeatedly until you are satisfied with the kind of comment."
 204   (interactive)
 205   (comment-normalize-vars)
 206   (let (comempty comment)
 207     (save-excursion
 208       (beginning-of-line)
 209       (with-no-warnings
 210         (setq comment (comment-search-forward (line-end-position) t)))
 211       (setq comempty (looking-at "[ \t]*$")))
 212
 213   (cond
 214
 215    ;; Blank line?  Then start comment at code indent level.
 216    ;; Just like `comment-dwim'.  -stef
 217    ((save-excursion (beginning-of-line) (looking-at "^[ \t]*$"))
 218     (indent-according-to-mode)
 219     (insert asm-comment-char asm-comment-char ?\ ))
 220
 221    ;; Nonblank line w/o comment => start a comment at comment-column.
 222    ;; Also: point before the comment => jump inside.
 223    ((or (null comment) (< (point) comment))
 224     (indent-for-comment))
 225
 226    ;; Flush-left or non-empty comment present => just insert character.
 227    ((or (not comempty) (save-excursion (goto-char comment) (bolp)))
 228     (insert asm-comment-char))
 229
 230    ;; Empty code-level comment => upgrade to next comment level.
 231    ((save-excursion (goto-char comment) (skip-chars-backward " \t") (bolp))
 232     (goto-char comment)
 233     (insert asm-comment-char)
 234     (indent-for-comment))
 235
 236    ;; Empty comment ends non-empty code line => new comment above.
 237    (t
 238     (goto-char comment)
 239     (skip-chars-backward " \t")
 240     (delete-region (point) (line-end-position))
 241     (beginning-of-line) (insert "\n") (backward-char)
 242     (asm-comment)))))
 243
 244 (provide 'asm-mode)
 245
 246 ;;; arch-tag: 210e695f-f338-4376-8913-a4c5c72ac848
 247 ;;; asm-mode.el ends here