lisp/progmodes/asm-mode.el

   1 ;;; asm-mode.el --- mode for editing assembler code
   2
   3 ;; Copyright (C) 1991, 2001-2016 Free Software Foundation, Inc.
   4
   5 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
   6 ;; Maintainer: emacs-devel@gnu.org
   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 3 of the License, or
  14 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This mode was written by Eric S. Raymond <esr@snark.thyrsus.com>,
  27 ;; inspired by an earlier asm-mode by Martin Neitzel.
  28
  29 ;; This minor mode is based on text mode.  It defines a private abbrev table
  30 ;; that can be used to save abbrevs for assembler mnemonics.  It binds just
  31 ;; five keys:
  32 ;;
  33 ;;      TAB             tab to next tab stop
  34 ;;      :               outdent preceding label, tab to tab stop
  35 ;;      comment char    place or move comment
  36 ;;                      asm-comment-char specifies which character this is;
  37 ;;                      you can use a different character in different
  38 ;;                      Asm mode buffers.
  39 ;;      C-j, C-m        newline and tab to tab stop
  40 ;;
  41 ;; Code is indented to the first tab stop level.
  42
  43 ;; This mode runs two hooks:
  44 ;;   1) An asm-mode-set-comment-hook before the part of the initialization
  45 ;; depending on asm-comment-char, and
  46 ;;   2) an asm-mode-hook at the end of initialization.
  47
  48 ;;; Code:
  49
  50 (defgroup asm nil
  51   "Mode for editing assembler code."
  52   :link '(custom-group-link :tag "Font Lock Faces group" font-lock-faces)
  53   :group 'languages)
  54
  55 (defcustom asm-comment-char ?\;
  56   "The comment-start character assumed by Asm mode."
  57   :type 'character
  58   :group 'asm)
  59
  60 (defvar asm-mode-syntax-table
  61   (let ((st (make-syntax-table)))
  62     (modify-syntax-entry ?\n "> b" st)
  63     (modify-syntax-entry ?/  ". 124b" st)
  64     (modify-syntax-entry ?*  ". 23" st)
  65     st)
  66   "Syntax table used while in Asm mode.")
  67
  68 (defvar asm-mode-abbrev-table nil
  69   "Abbrev table used while in Asm mode.")
  70 (define-abbrev-table 'asm-mode-abbrev-table ())
  71
  72 (defvar asm-mode-map
  73   (let ((map (make-sparse-keymap)))
  74     ;; Note that the comment character isn't set up until asm-mode is called.
  75     (define-key map ":"         'asm-colon)
  76     (define-key map "\C-c;"     'comment-region)
  77     (define-key map "\C-j"      'newline-and-indent)
  78     (define-key map "\C-m"      'newline-and-indent)
  79     (define-key map [menu-bar asm-mode] (cons "Asm" (make-sparse-keymap)))
  80     (define-key map [menu-bar asm-mode comment-region]
  81       '(menu-item "Comment Region" comment-region
  82                   :help "Comment or uncomment each line in the region"))
  83     (define-key map [menu-bar asm-mode newline-and-indent]
  84       '(menu-item "Insert Newline and Indent" newline-and-indent
  85                   :help "Insert a newline, then indent according to major mode"))
  86     (define-key map [menu-bar asm-mode asm-colon]
  87       '(menu-item "Insert Colon" asm-colon
  88                   :help "Insert a colon; if it follows a label, delete the label's indentation"))
  89     map)
  90   "Keymap for Asm mode.")
  91
  92 (defconst asm-font-lock-keywords
  93   (append
  94    '(("^\\(\\(\\sw\\|\\s_\\)+\\)\\>:?[ \t]*\\(\\sw+\\(\\.\\sw+\\)*\\)?"
  95       (1 font-lock-function-name-face) (3 font-lock-keyword-face nil t))
  96      ;; label started from ".".
  97      ("^\\(\\.\\(\\sw\\|\\s_\\)+\\)\\>:"
  98       1 font-lock-function-name-face)
  99      ("^\\((\\sw+)\\)?\\s +\\(\\(\\.?\\sw\\|\\s_\\)+\\(\\.\\sw+\\)*\\)"
 100       2 font-lock-keyword-face)
 101      ;; directive started from ".".
 102      ("^\\(\\.\\(\\sw\\|\\s_\\)+\\)\\>[^:]?"
 103       1 font-lock-keyword-face)
 104      ;; %register
 105      ("%\\sw+" . font-lock-variable-name-face))
 106    cpp-font-lock-keywords)
 107   "Additional expressions to highlight in Assembler mode.")
 108
 109 ;;;###autoload
 110 (define-derived-mode asm-mode prog-mode "Assembler"
 111   "Major mode for editing typical assembler code.
 112 Features a private abbrev table and the following bindings:
 113
 114 \\[asm-colon]\toutdent a preceding label, tab to next tab stop.
 115 \\[tab-to-tab-stop]\ttab to next tab stop.
 116 \\[asm-newline]\tnewline, then tab to next tab stop.
 117 \\[asm-comment]\tsmart placement of assembler comments.
 118
 119 The character used for making comments is set by the variable
 120 `asm-comment-char' (which defaults to `?\\;').
 121
 122 Alternatively, you may set this variable in `asm-mode-set-comment-hook',
 123 which is called near the beginning of mode initialization.
 124
 125 Turning on Asm mode runs the hook `asm-mode-hook' at the end of initialization.
 126
 127 Special commands:
 128 \\{asm-mode-map}"
 129   (setq local-abbrev-table asm-mode-abbrev-table)
 130   (set (make-local-variable 'font-lock-defaults) '(asm-font-lock-keywords))
 131   (set (make-local-variable 'indent-line-function) 'asm-indent-line)
 132   ;; Stay closer to the old TAB behavior (was tab-to-tab-stop).
 133   (set (make-local-variable 'tab-always-indent) nil)
 134
 135   (run-hooks 'asm-mode-set-comment-hook)
 136   ;; Make our own local child of asm-mode-map
 137   ;; so we can define our own comment character.
 138   (use-local-map (nconc (make-sparse-keymap) asm-mode-map))
 139   (local-set-key (vector asm-comment-char) 'asm-comment)
 140   (set-syntax-table (make-syntax-table asm-mode-syntax-table))
 141   (modify-syntax-entry  asm-comment-char "< b")
 142
 143   (set (make-local-variable 'comment-start) (string asm-comment-char))
 144   (set (make-local-variable 'comment-add) 1)
 145   (set (make-local-variable 'comment-start-skip)
 146        "\\(?:\\s<+\\|/[/*]+\\)[ \t]*")
 147   (set (make-local-variable 'comment-end-skip) "[ \t]*\\(\\s>\\|\\*+/\\)")
 148   (set (make-local-variable 'comment-end) "")
 149   (setq fill-prefix "\t"))
 150
 151 (defun asm-indent-line ()
 152   "Auto-indent the current line."
 153   (interactive)
 154   (let* ((savep (point))
 155          (indent (condition-case nil
 156                      (save-excursion
 157                        (forward-line 0)
 158                        (skip-chars-forward " \t")
 159                        (if (>= (point) savep) (setq savep nil))
 160                        (max (asm-calculate-indentation) 0))
 161                    (error 0))))
 162     (if savep
 163         (save-excursion (indent-line-to indent))
 164       (indent-line-to indent))))
 165
 166 (defun asm-calculate-indentation ()
 167   (or
 168    ;; Flush labels to the left margin.
 169    (and (looking-at "\\(\\sw\\|\\s_\\)+:") 0)
 170    ;; Same thing for `;;;' comments.
 171    (and (looking-at "\\s<\\s<\\s<") 0)
 172    ;; Simple `;' comments go to the comment-column.
 173    (and (looking-at "\\s<\\(\\S<\\|\\'\\)") comment-column)
 174    ;; The rest goes at the first tab stop.
 175    (or (indent-next-tab-stop 0))))
 176
 177 (defun asm-colon ()
 178   "Insert a colon; if it follows a label, delete the label's indentation."
 179   (interactive)
 180   (let ((labelp nil))
 181     (save-excursion
 182       (skip-syntax-backward "w_")
 183       (skip-syntax-backward " ")
 184       (if (setq labelp (bolp)) (delete-horizontal-space)))
 185     (call-interactively 'self-insert-command)
 186     (when labelp
 187       (delete-horizontal-space)
 188       (tab-to-tab-stop))))
 189
 190 ;; Obsolete since Emacs-22.1.
 191 (defalias 'asm-newline 'newline-and-indent)
 192
 193 (defun asm-comment ()
 194   "Convert an empty comment to a `larger' kind, or start a new one.
 195 These are the known comment classes:
 196
 197    1 -- comment to the right of the code (at the comment-column)
 198    2 -- comment on its own line, indented like code
 199    3 -- comment on its own line, beginning at the left-most column.
 200
 201 Suggested usage:  while writing your code, trigger asm-comment
 202 repeatedly until you are satisfied with the kind of comment."
 203   (interactive)
 204   (comment-normalize-vars)
 205   (let (comempty comment)
 206     (save-excursion
 207       (beginning-of-line)
 208       (with-no-warnings
 209         (setq comment (comment-search-forward (line-end-position) t)))
 210       (setq comempty (looking-at "[ \t]*$")))
 211
 212   (cond
 213
 214    ;; Blank line?  Then start comment at code indent level.
 215    ;; Just like `comment-dwim'.  -stef
 216    ((save-excursion (beginning-of-line) (looking-at "^[ \t]*$"))
 217     (indent-according-to-mode)
 218     (insert asm-comment-char asm-comment-char ?\ ))
 219
 220    ;; Nonblank line w/o comment => start a comment at comment-column.
 221    ;; Also: point before the comment => jump inside.
 222    ((or (null comment) (< (point) comment))
 223     (indent-for-comment))
 224
 225    ;; Flush-left or non-empty comment present => just insert character.
 226    ((or (not comempty) (save-excursion (goto-char comment) (bolp)))
 227     (insert asm-comment-char))
 228
 229    ;; Empty code-level comment => upgrade to next comment level.
 230    ((save-excursion (goto-char comment) (skip-chars-backward " \t") (bolp))
 231     (goto-char comment)
 232     (insert asm-comment-char)
 233     (indent-for-comment))
 234
 235    ;; Empty comment ends non-empty code line => new comment above.
 236    (t
 237     (goto-char comment)
 238     (skip-chars-backward " \t")
 239     (delete-region (point) (line-end-position))
 240     (beginning-of-line) (insert "\n") (backward-char)
 241     (asm-comment)))))
 242
 243 (provide 'asm-mode)
 244
 245 ;;; asm-mode.el ends here