lisp/progmodes/cc-compat.el

   1 ;;; cc-compat.el --- cc-mode compatibility with c-mode.el confusion
   2
   3 ;; Copyright (C) 1985, 1987, 1992-2013 Free Software Foundation, Inc.
   4
   5 ;; Authors:    1998- Martin Stjernholm
   6 ;;             1994-1999 Barry A. Warsaw
   7 ;; Maintainer: bug-cc-mode@gnu.org
   8 ;; Created:    August 1994, split from cc-mode.el
   9 ;; Keywords:   c languages
  10 ;; Package:    cc-mode
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software: you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation, either version 3 of the License, or
  17 ;; (at your option) any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  26
  27 ;;; Commentary:
  28 ;;
  29 ;; Boring old c-mode.el (BOCM) is confusion and brain melt. cc-mode.el
  30 ;; is clarity of thought and purity of chi. If you are still unwilling
  31 ;; to accept enlightenment, this might help, or it may prolong your
  32 ;; agony.
  33 ;;
  34 ;; To use, add the following to your c-mode-hook:
  35 ;;
  36 ;; (require 'cc-compat)
  37 ;; (c-set-style "BOCM")
  38 ;;
  39 ;; This file is completely unsupported!  Although it has been patched
  40 ;; superficially to keep pace with the rest of CC Mode, it hasn't been
  41 ;; tested for a long time.
  42
  43 ;;; Code:
  44
  45 (eval-when-compile
  46   (let ((load-path
  47          (if (and (boundp 'byte-compile-dest-file)
  48                   (stringp byte-compile-dest-file))
  49              (cons (file-name-directory byte-compile-dest-file) load-path)
  50            load-path)))
  51     (load "cc-bytecomp" nil t)))
  52
  53 (cc-require 'cc-defs)
  54 (cc-require 'cc-vars)
  55 (cc-require 'cc-styles)
  56 (cc-require 'cc-engine)
  57
  58 \f
  59 ;; In case c-mode.el isn't loaded
  60 (defvar c-indent-level 2
  61   "*Indentation of C statements with respect to containing block.")
  62 ;;;###autoload(put 'c-indent-level 'safe-local-variable 'integerp)
  63
  64 (defvar c-brace-imaginary-offset 0
  65   "*Imagined indentation of a C open brace that actually follows a statement.")
  66 (defvar c-brace-offset 0
  67   "*Extra indentation for braces, compared with other text in same context.")
  68 (defvar c-argdecl-indent 5
  69   "*Indentation level of declarations of C function arguments.")
  70 (defvar c-label-offset -2
  71   "*Offset of C label lines and case statements relative to usual indentation.")
  72 (defvar c-continued-statement-offset 2
  73   "*Extra indent for lines not starting new statements.")
  74 (defvar c-continued-brace-offset 0
  75   "*Extra indent for substatements that start with open-braces.
  76 This is in addition to c-continued-statement-offset.")
  77
  78
  79 \f
  80 ;; these offsets are taken by brute force testing c-mode.el, since
  81 ;; there's no logic to what it does.
  82 (let* ((offsets '(c-offsets-alist .
  83                     ((defun-block-intro     . cc-block-intro-offset)
  84                      (statement-block-intro . cc-block-intro-offset)
  85                      (defun-open            . 0)
  86                      (class-open            . 0)
  87                      (inline-open           . c-brace-offset)
  88                      (block-open            . c-brace-offset)
  89                      (block-close           . cc-block-close-offset)
  90                      (brace-list-open       . c-brace-offset)
  91                      (substatement-open     . cc-substatement-open-offset)
  92                      (substatement          . c-continued-statement-offset)
  93                      (knr-argdecl-intro     . c-argdecl-indent)
  94                      (case-label            . c-label-offset)
  95                      (access-label          . c-label-offset)
  96                      (label                 . c-label-offset)
  97                      ))))
  98   (c-add-style "BOCM" offsets))
  99
 100
 101 (defun cc-block-intro-offset (langelem)
 102   ;; taken directly from calculate-c-indent confusion
 103   (save-excursion
 104     (c-backward-syntactic-ws)
 105     (if (eq (char-before) ?{)
 106         (forward-char -1)
 107       (goto-char (cdr langelem)))
 108     (let* ((curcol (save-excursion
 109                      (goto-char (cdr langelem))
 110                      (current-column)))
 111           (bocm-lossage
 112            ;; If no previous statement, indent it relative to line
 113            ;; brace is on.  For open brace in column zero, don't let
 114            ;; statement start there too.  If c-indent-level is zero,
 115            ;; use c-brace-offset + c-continued-statement-offset
 116            ;; instead.  For open-braces not the first thing in a line,
 117            ;; add in c-brace-imaginary-offset.
 118            (+ (if (and (bolp) (zerop c-indent-level))
 119                   (+ c-brace-offset c-continued-statement-offset)
 120                 c-indent-level)
 121               ;; Move back over whitespace before the openbrace.  If
 122               ;; openbrace is not first nonwhite thing on the line,
 123               ;; add the c-brace-imaginary-offset.
 124               (progn (skip-chars-backward " \t")
 125                      (if (bolp) 0 c-brace-imaginary-offset))
 126               ;; If the openbrace is preceded by a parenthesized exp,
 127               ;; move to the beginning of that; possibly a different
 128               ;; line
 129               (progn
 130                 (if (eq (char-before) ?\))
 131                     (c-forward-sexp -1))
 132                 ;; Get initial indentation of the line we are on.
 133                 (current-indentation)))))
 134       (- bocm-lossage curcol))))
 135
 136
 137 (defun cc-block-close-offset (langelem)
 138   (save-excursion
 139     (let* ((here (point))
 140            bracep
 141            (curcol (progn
 142                      (goto-char (cdr langelem))
 143                      (current-column)))
 144            (bocm-lossage (progn
 145                            (goto-char (cdr langelem))
 146                            (if (eq (char-after) ?{)
 147                                (setq bracep t)
 148                              (goto-char here)
 149                              (beginning-of-line)
 150                              (backward-up-list 1)
 151                              (forward-char 1)
 152                              (c-forward-syntactic-ws))
 153                            (current-column))))
 154       (- bocm-lossage curcol
 155          (if bracep 0 c-indent-level)))))
 156
 157
 158 (defun cc-substatement-open-offset (langelem)
 159   (+ c-continued-statement-offset c-continued-brace-offset))
 160
 161 \f
 162 (cc-provide 'cc-compat)
 163
 164 ;;; cc-compat.el ends here