code.delx.au - gnu-emacs-elpa/blob - packages/dts-mode/dts-mode.el

   1 ;;; dts-mode.el --- Major mode for Device Tree source files
   2
   3 ;; Copyright (C) 2014-2015  Free Software Foundation, Inc.
   4
   5 ;; Version: 0.1.0
   6 ;; Author: Ben Gamari <ben@smart-cactus.org>
   7 ;; Keywords: languages
   8
   9 ;; This program is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; This program is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;;
  25
  26 ;;; Code:
  27
  28 (defconst dts-re-ident "\\([[:alpha:]_][[:alnum:]_,-]*\\)")
  29
  30 (defvar dts-mode-font-lock-keywords
  31   `(
  32     ;; Names like `name: hi {`
  33     (,(concat dts-re-ident ":") 1 font-lock-variable-name-face)
  34     ;; Nodes
  35     (,(concat dts-re-ident "\\(@[[:xdigit:]]+\\)?[[:space:]]*{")
  36      (1 font-lock-type-face))
  37     ;; Assignments
  38     (,(concat dts-re-ident "[[:space:]]*=") 1 font-lock-variable-name-face)
  39     (,(concat dts-re-ident "[[:space:]]*;") 1 font-lock-variable-name-face)
  40     ;; References
  41     (,(concat "&" dts-re-ident) 1 font-lock-variable-name-face)
  42     )
  43   )
  44
  45 (defvar dts-mode-syntax-table
  46   (let ((table (make-syntax-table)))
  47     (modify-syntax-entry ?<  "(>" table)
  48     (modify-syntax-entry ?>  ")<" table)
  49
  50     (modify-syntax-entry ?&  "." table)
  51     (modify-syntax-entry ?|  "." table)
  52     (modify-syntax-entry ?~  "." table)
  53
  54     ;; _ and , are both symbol constituents.
  55     (modify-syntax-entry ?,  "_" table)
  56     (modify-syntax-entry ?_  "_" table)
  57
  58     ;; Strings
  59     (modify-syntax-entry ?\" "\"" table)
  60     (modify-syntax-entry ?\\ "\\" table)
  61
  62     ;; Comments
  63     (modify-syntax-entry ?/  ". 124b" table)
  64     (modify-syntax-entry ?*  ". 23"   table)
  65     (modify-syntax-entry ?\n "> b"    table)
  66     (modify-syntax-entry ?\^m "> b"   table)
  67
  68     table))
  69
  70 ;;;; Original manual indentation code.
  71
  72 (defun dts--calculate-indentation ()
  73   (interactive)
  74   (save-excursion
  75     (let ((end (point-at-eol))
  76           (cnt 0)
  77           (initial-point (point)))
  78       (goto-char 0)
  79       (while (re-search-forward "\\([{}]\\)" end t)
  80         (if (string= (match-string-no-properties 0) "{")
  81             (setq cnt (1+ cnt))
  82           (setq cnt (1- cnt))))
  83       ;; subtract one if the current line has an opening brace since we
  84       ;; shouldn't add the indentation level until the following line
  85       (goto-char initial-point)
  86       (beginning-of-line)
  87       (when (re-search-forward "{" (point-at-eol) t)
  88         (setq cnt (1- cnt)))
  89       cnt)))
  90
  91 (defun dts-indent-line ()
  92   (interactive)
  93   (let ((indent (dts--calculate-indentation)))
  94     (indent-line-to (* indent tab-width))))
  95
  96 ;;;; New SMIE-based indentation code.
  97
  98 ;; Compatibility macro.
  99 (defmacro dts--using-macro (name exp)
 100   (declare (indent 1) (debug (symbolp form)))
 101   (if (fboundp name)            ;If macro exists at compiler-time, just use it.
 102       exp
 103     `(when (fboundp ',name)            ;Else, check if it exists at run-time.
 104        (eval ',exp))))                 ;If it does, then run the code.
 105
 106 (require 'smie nil t)
 107
 108 (defvar dts-use-smie (and (fboundp 'smie-prec2->grammar) (fboundp 'pcase)))
 109
 110 (defconst dts-grammar
 111   ;; FIXME: The syntax-table gives symbol-constituent syntax to the comma,
 112   ;; but the comma is also used as a separator!
 113   (when (fboundp 'smie-prec2->grammar)
 114     (smie-prec2->grammar
 115      (smie-bnf->prec2
 116       '((id) (val ("<" val ">"))
 117         (exp ("{" exps "}")
 118              ;; The "foo,bar = toto" can be handled either by considering
 119              ;; "foo,bar" as a single token or as 3 tokens.
 120              ;; Currently I consider it as 3 tokens, so the LHS of "=" can't be
 121              ;; just `id' but has to be `vals'.
 122              (vals "=" vals))
 123         (exps (exp) (exps ";" exps))
 124         (vals  (val "," val)))
 125       '((assoc ";")) '((assoc ","))))))
 126
 127 (defun dts-indent-rules (kind token)
 128   (dts--using-macro pcase
 129     (pcase (cons kind token)
 130       (`(:elem . basic) tab-width)
 131       ;; (`(:elem . args) 0)
 132       (`(:list-intro . "")                ;FIXME: Not sure why we get "" here!
 133        ;; After < we either have a plain list of data, as in: "operating-points
 134        ;;  = <1008000 1400000 ...>" or we have sometimes "refs with args" as in
 135        ;;  "clocks = <&apb1_gates 6>;".
 136        (and (eq (char-before) ?<) (not (looking-at "&"))))
 137       (`(:before . "{") (smie-rule-parent))
 138       (`(:before . "<") (if (smie-rule-hanging-p) (smie-rule-parent)))
 139       (`(:after . "=") (dts-indent-rules :elem 'basic))
 140       )))
 141
 142 ;;;; The major mode itself.
 143
 144 (defalias 'dts-parent-mode
 145   (if (fboundp 'prog-mode) 'prog-mode 'fundamental-mode))
 146
 147 ;;;###autoload
 148 (define-derived-mode dts-mode dts-parent-mode "Devicetree";DTS would be shorter!
 149   "Major mode for editing Device Tree source files."
 150
 151   ;; Fonts
 152   (set (make-local-variable 'font-lock-defaults)
 153        '(dts-mode-font-lock-keywords nil nil nil nil))
 154   (set (make-local-variable 'comment-start) "/* ")
 155   (set (make-local-variable 'comment-end)   " */")
 156   (set (make-local-variable 'comment-multi-line) t)
 157
 158   ;; This is not specific to the DTS format, really, but DTS is mostly
 159   ;; used in the context of the Linux kernel (and U-boot loader) where
 160   ;; there's a strong preference to indent with TABs.
 161   (set (make-local-variable 'indent-tabs-mode) t)
 162
 163   (dts--using-macro syntax-propertize-rules
 164     (set (make-local-variable 'syntax-propertize-function)
 165          (syntax-propertize-rules
 166           ("#include[ \t]+\\(<\\).*\\(>\\)" (1 "|") (2 "|"))
 167           ;; Treat things like /delete-property/ as a single identifier.
 168           ("\\(/\\)[a-z]+\\(/\\)" (1 "_") (2 "_")))))
 169   (if dts-use-smie
 170       (smie-setup dts-grammar #'dts-indent-rules)
 171     (set (make-local-variable 'indent-line-function) #'dts-indent-line)))
 172
 173 ;;;###autoload
 174 (add-to-list 'auto-mode-alist '("\\.dtsi?\\'" . dts-mode))
 175
 176 (provide 'dts-mode)
 177 ;;; dts-mode.el ends here