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comparison lisp/cc-mode/cc-lobotomy.el @ 165:5a88923fcbfe r20-3b9

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date Mon, 13 Aug 2007 09:44:42 +0200
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1 ;;; cc-lobotomy.el --- excise portions of cc-mode's brain... for speed
2
3 ;; Copyright (C) 1985,87,92,93,94,95,96,97 Free Software Foundation, Inc.
4
5 ;; Author: 1995 Barry A. Warsaw
6 ;; Maintainer: Unmaintained
7 ;; Created: March 1995, split from cc-mode.el
8 ;; Version: 5.11
9 ;; Keywords: c languages oop
10
11 ;; This file is not part of GNU Emacs.
12
13 ;; This program is free software; you can redistribute it and/or modify
14 ;; it under the terms of the GNU General Public License as published by
15 ;; the Free Software Foundation; either version 2 of the License, or
16 ;; (at your option) any later version.
17
18 ;; This program is distributed in the hope that it will be useful,
19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ;; GNU General Public License for more details.
22
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs; see the file COPYING. If not, write to the
25 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
26 ;; Boston, MA 02111-1307, USA.
27
28 ;;; Commentary:
29 ;;
30 ;; Every effort has been made to improve the performance of
31 ;; cc-mode. However, due to the nature of the C, C++, and Objective-C
32 ;; language definitions, a trade-off is often required between
33 ;; accuracy of construct recognition and speed. I believe it is always
34 ;; best to be correct, and that the mode is currently fast enough for
35 ;; most normal usage. Others disagree. I have no intention of
36 ;; including these hacks in the main distribution. When cc-mode
37 ;; version 5 comes out, it will include a rewritten indentation engine
38 ;; so that performance will be greatly improved automatically. This
39 ;; was not included in this release of version 4 so that Emacs 18
40 ;; could still be supported. Note that this implies that cc-mode
41 ;; version 5 will *not* work on Emacs 18!
42 ;;
43 ;; To use, see the variable cc-lobotomy-pith-list and the function
44 ;; cc-lobotomize. The variable contains a good explanation of the
45 ;; speed/accuracy trade-offs for each option. Set it to what you'd
46 ;; like, and call cc-lobotomy in your c-mode-hook.
47 ;;
48 ;; This will redefine certain cc-mode functions and affect all cc-mode
49 ;; buffers globally.
50 ;;
51 ;; This file is completely unsupported! I have no idea whether this
52 ;; will work with such things as cc-mode-18.el.
53
54
55 ;;; Code:
56 (require 'cc-mode)
57
58 (defvar cc-lobotomy-pith-list ()
59 "*List of things to dumb-ify to speed up cc-mode. Note that each
60 incurs a penalty in correct identification of certain code constructs.
61 Possible values to put on this list:
62
63 'literal -- `c-in-literal' is lobotomized. This will significantly
64 speed up parsing over large lists of cpp macros, as seen
65 for instance in header files. The penalty is that you
66 cannot put the `#' character as the first non-whitespace
67 character on a line inside other multi-line literals
68 (i.e. comments or strings)
69
70 'class -- `c-narrow-out-enclosing-class' and `c-search-uplist for
71 classkey' are lobotomized. This speeds up some
72 indenting inside and around class and struct
73 definitions. The penalty is that elements inside of
74 classes and structs may not indent correctly.
75
76 'lists -- `c-inside-bracelist-p' is lobotomized. This speeds up
77 indenting inside and around brace lists (e.g. aggregate
78 initializers, enum lists, etc.). The penalty is that
79 elements inside these lists may not indent correctly.")
80
81 (defun cc-lobotomize ()
82 "Perform lobotomies on cc-mode as described in `cc-lobotomy-pith-list'."
83 (let (pithedp)
84 (if (memq 'literal cc-lobotomy-pith-list)
85 (progn
86 (fset 'c-in-literal 'cc-in-literal-lobotomized)
87 (setq pithedp t)))
88 (if (memq 'class cc-lobotomy-pith-list)
89 (progn
90 (fset 'c-narrow-out-enclosing-class
91 'cc-narrow-out-enclosing-class-lobotomized)
92 (fset 'c-search-uplist-for-classkey
93 'cc-search-uplist-for-classkey-lobotomized)
94 (setq pithedp t)))
95 (if (memq 'lists cc-lobotomy-pith-list)
96 (progn
97 (fset 'c-inside-bracelist-p 'cc-inside-bracelist-p-lobotomized)
98 (setq pithedp t)))
99 (if pithedp
100 (fset 'c-submit-bug-report 'cc-submit-bug-report-lobotomized))
101 ))
102
103
104 ;; This is a faster version of c-in-literal. It trades speed for one
105 ;; approximation, namely that within other literals, the `#' character
106 ;; cannot be the first non-whitespace on a line.
107 (defun cc-in-literal-lobotomized (&optional lim)
108 ;; first check the cache
109 (if (and (boundp 'c-in-literal-cache)
110 c-in-literal-cache
111 (= (point) (aref c-in-literal-cache 0)))
112 (aref c-in-literal-cache 1)
113 ;; quickly check for cpp macro. this breaks if the `#' character
114 ;; appears as the first non-whitespace on a line inside another
115 ;; literal.
116 (let* (state
117 (char-at-boi (char-after (c-point 'boi)))
118 (rtn (cond
119 ((and char-at-boi (= char-at-boi ?#))
120 'pound)
121 ((nth 3 (setq state (save-excursion
122 (parse-partial-sexp
123 (or lim (c-point 'bod))
124 (point)))))
125 'string)
126 ((nth 4 state) (if (nth 7 state) 'c++ 'c))
127 (t nil))))
128 ;; cache this result if the cache is enabled
129 (and (boundp 'c-in-literal-cache)
130 (setq c-in-literal-cache (vector (point) rtn)))
131 rtn)))
132
133 (defun cc-narrow-out-enclosing-class-lobotomized (dummy1 dummy2) nil)
134
135 (defun cc-search-uplist-for-classkey-lobotomized (dummy) nil)
136
137 (defun cc-inside-bracelist-p-lobotomized (dummy1 dummy2) nil)
138
139 (defun cc-submit-bug-report-lobotomized ()
140 "Submit via mail a bug report on cc-mode."
141 (interactive)
142 ;; load in reporter
143 (let ((reporter-prompt-for-summary-p t)
144 (reporter-dont-compact-list '(c-offsets-alist)))
145 (and
146 (y-or-n-p "Do you want to submit a report on cc-mode? ")
147 (require 'reporter)
148 (reporter-submit-bug-report
149 c-mode-help-address
150 (concat "cc-mode " c-version " ("
151 (cond ((eq major-mode 'c++-mode) "C++")
152 ((eq major-mode 'c-mode) "C")
153 ((eq major-mode 'objc-mode) "ObjC"))
154 ")")
155 (let ((vars (list
156 ;; report only the vars that affect indentation
157 'c-basic-offset
158 'c-offsets-alist
159 'c-block-comments-indent-p
160 'c-cleanup-list
161 'c-comment-only-line-offset
162 'c-backslash-column
163 'c-delete-function
164 'c-electric-pound-behavior
165 'c-hanging-braces-alist
166 'c-hanging-colons-alist
167 'c-hanging-comment-ender-p
168 'c-tab-always-indent
169 'c-recognize-knr-p
170 'defun-prompt-regexp
171 'tab-width
172 )))
173 (if (not (boundp 'defun-prompt-regexp))
174 (delq 'defun-prompt-regexp vars)
175 vars))
176 (function
177 (lambda ()
178 (insert
179 (if c-special-indent-hook
180 (concat "\n@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n"
181 "c-special-indent-hook is set to '"
182 (format "%s" c-special-indent-hook)
183 ".\nPerhaps this is your problem?\n"
184 "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n\n")
185 "\n")
186 (format "c-emacs-features: %s\n" c-emacs-features)
187 )))
188 (function
189 (lambda ()
190 (insert
191 "You are using cc-lobotomy.el. You realize that by doing\n"
192 "so you have already made the decision to trade off accuracy\n"
193 "for speed? Don't set your hopes too high that your problem\n"
194 "will be fixed.\n\n"
195 )))
196 "Dear Barry,"
197 ))))
198
199 (provide 'cc-lobotomy)
200 ;;; cc-lobotomy.el ends here