Change release version from 21.4 to 22.1 throughout.
[bpt/emacs.git] / man / cc-mode.texi
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1\input texinfo
2
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3@c Notes to self regarding line handling:
4@c
5@c Empty lines are often significant before @end directives; avoid them.
6@c
7@c Empty lines before and after @example directives are significant in
8@c info output but not in TeX. Empty lines inside @example directives
9@c are significant.
10
11@c Conventions for formatting examples:
12@c o If the example contains empty lines then put the surrounding empty
13@c lines inside the @example directives. Put them outside otherwise.
14@c o Use @group inside the example only if it shows indentation where
15@c the relation between lines inside is relevant.
16@c o Format line number columns like this:
17@c 1: foo
18@c 2: bar
19@c ^ one space
20@c ^^ two columns, right alignment
21@c o Check line lengths in TeX output; they can typically be no longer
22@c than 70 chars, 60 if the paragraph is indented.
23
24@comment TBD: Document the finer details of statement anchoring?
25
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26@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
27@comment %**start of header (This is for running Texinfo on a region)
28@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
29
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30@comment No overfull hbox marks in the dvi file.
31@finalout
6bf7aab6 32
94cae5a8 33@setfilename ../info/ccmode
cb7f2e96 34@settitle CC Mode Manual
d7bd46ed 35@footnotestyle end
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36
37@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
38@comment @setchapternewpage odd !! we don't want blank pages !!
39@comment %**end of header (This is for running Texinfo on a region)
40@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
41
42
43@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
bf247b6e 44@comment
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45@comment Texinfo manual for CC Mode
46@comment Generated from the original README file by Krishna Padmasola
47@comment <krishna@earth-gw.njit.edu>
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48@comment
49@comment Authors:
50@comment Barry A. Warsaw
51@comment Martin Stjernholm
52@comment
f214c025 53@comment Maintained by Martin Stjernholm <bug-cc-mode@gnu.org>
bf247b6e 54@comment
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55@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
56
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57@comment Define an index for syntactic symbols.
58@defindex ss
59
60@comment Combine key, syntactic symbol and concept indices into one.
61@syncodeindex ss cp
62@syncodeindex ky cp
63
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64@copying
65This manual is for CC Mode in Emacs.
cb7f2e96 66
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67Copyright @copyright{} 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
682003 Free Software Foundation, Inc.
94cae5a8 69
18f952d5 70@quotation
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71Permission is granted to copy, distribute and/or modify this document
72under the terms of the GNU Free Documentation License, Version 1.1 or
73any later version published by the Free Software Foundation; with the
74Invariant Sections being ``The GNU Manifesto'', ``Distribution'' and
75``GNU GENERAL PUBLIC LICENSE'', with the Front-Cover texts being ``A GNU
76Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
77license is included in the section entitled ``GNU Free Documentation
78License'' in the Emacs manual.
79
80(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
81this GNU Manual, like GNU software. Copies published by the Free
82Software Foundation raise funds for GNU development.''
83
84This document is part of a collection distributed under the GNU Free
85Documentation License. If you want to distribute this document
86separately from the collection, you can do so by adding a copy of the
87license to the document, as described in section 6 of the license.
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88@end quotation
89@end copying
90
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91@comment Info directory entry for use by install-info. The indentation
92@comment here is by request from the FSF folks.
93@dircategory Emacs
94@direntry
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95* CC Mode: (ccmode). Emacs mode for editing C, C++, Objective-C,
96 Java, Pike, AWK, and CORBA IDL code.
18f952d5 97@end direntry
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98
99@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
cb7f2e96 100@comment TeX title page
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101@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
102
103@titlepage
104@sp 10
105
3a731e1f 106@center @titlefont{CC Mode 5.30}
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107@sp 2
108@center @subtitlefont{A GNU Emacs mode for editing C and C-like languages}
109@sp 2
3a731e1f 110@center Barry A. Warsaw, Martin Stjernholm, Alan Mackenzie (AWK support)
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111
112@page
113@vskip 0pt plus 1filll
18f952d5 114@insertcopying
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115@end titlepage
116
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117@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
118@comment The Top node contains the master menu for the Info file.
119@comment This appears only in the Info file, not the printed manual.
120@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
121
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122@node Top, Introduction, (dir), (dir)
123@comment node-name, next, previous, up
124
125@macro ccmode
126CC Mode
127@end macro
128
129@ifinfo
130@top @ccmode{}
6bf7aab6 131
d7bd46ed 132@ccmode{} is a GNU Emacs mode for editing files containing C, C++,
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133Objective-C, Java, CORBA IDL (and the variants PSDL and CIDL), Pike
134code and to a certain extent, AWK code @xref{AWK Mode}. It provides
135syntax-based indentation, font locking, and has several handy commands
136and some minor modes to make the editing easier. It does not provide
137tools to look up and navigate between functions, classes etc - there are
138other packages for that.
d7bd46ed 139@end ifinfo
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140
141@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
142@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
143
144@menu
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145* Introduction::
146* Getting Connected::
3a731e1f 147* Indentation Engine::
6bf7aab6 148* Minor Modes::
d7bd46ed 149* Text Filling and Line Breaking::
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150* Macro Handling::
151* Font Locking::
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152* Commands::
153* Customizing Indentation::
154* Syntactic Symbols::
d7bd46ed 155* Indentation Functions::
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156* AWK Mode::
157* Odds and Ends::
6bf7aab6 158* Performance Issues::
cb7f2e96 159* Limitations and Known Bugs::
6bf7aab6 160* Frequently Asked Questions::
d7bd46ed 161* Getting the Latest CC Mode Release::
d7bd46ed 162* Mailing Lists and Submitting Bug Reports::
cb7f2e96 163* Sample .emacs File::
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164
165 --- Indices ---
166
3a731e1f 167* Command and Function Index::
d7bd46ed 168* Variable Index::
3a731e1f 169* Concept Index::
d7bd46ed 170
3a731e1f 171@detailmenu
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172 --- The Detailed Node Listing ---
173
3a731e1f 174Indentation Engine
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175
176* Syntactic Analysis::
177* Indentation Calculation::
178
179Minor Modes
180
181* Auto-newline Insertion::
182* Hungry-deletion of Whitespace::
183
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184Font Locking
185
186* Font Locking Preliminaries::
187* Faces::
188* Documentation Comments::
189
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190Auto-newline Insertion
191
192* Hanging Braces::
193* Hanging Colons::
3a731e1f 194* Hanging Semicolons and Commas::
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195* Other Electric Commands::
196* Clean-ups::
197
198Commands
199
200* Indentation Commands::
201* Movement Commands::
202* Other Commands::
203
204Customizing Indentation
205
206* Interactive Customization::
207* Permanent Customization::
208* Hooks::
209* Styles::
210* Advanced Customizations::
211
212Styles
213
214* Built-in Styles::
3a731e1f 215* Choosing a Style::
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216* Adding Styles::
217* File Styles::
218
219Advanced Customizations
220
221* Custom Indentation Functions::
222* Custom Brace and Colon Hanging::
3a731e1f 223* Customizing Semicolons and Commas::
d7bd46ed 224* Other Special Indentations::
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225
226AWK Mode
227
228* Initialising AWK Mode::
229* AWK Mode Font Locking::
230* AWK Mode Defuns::
231@end detailmenu
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232@end menu
233
d7bd46ed 234
6bf7aab6 235@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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236@node Introduction, Getting Connected, Top, Top
237@comment node-name, next, previous, up
3a731e1f 238@chapter Introduction
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239@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
240
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241@cindex BOCM
242
d7bd46ed 243Welcome to @ccmode{}, a GNU Emacs mode for editing files containing C,
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244C++, Objective-C, Java, CORBA IDL (and the variants CORBA PSDL and
245CIDL), Pike and to a certain extent, AWK code (@pxref{AWK Mode}). This
246incarnation of the mode is descended from @file{c-mode.el} (also called
247``Boring Old C Mode'' or BOCM @t{:-)}, and @file{c++-mode.el} version 2,
248which Barry has been maintaining since 1992. Late in 1997, Martin
d7bd46ed 249joined the @ccmode{} Maintainers Team, and implemented the Pike support.
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250As of 2000 Martin has taken over as the sole maintainer. @ccmode{} did
251not originally contain the font lock support for its languages --- that
252was added in version 5.30. AWK support was also added in 5.30 by Alan
253Mackenzie.
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254
255This manual describes @ccmode{}
256@comment The following line must appear on its own, so that the automated
3a731e1f 257version 5.30.
d7bd46ed 258@comment Release.py script can update the version number automatically
6bf7aab6 259
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260@ccmode{} supports the editing of K&R and ANSI C, C++, Objective-C,
261Java, CORBA's Interface Definition Language, Pike@footnote{A C-like
262scripting language with its roots in the LPC language used in some MUD
263engines. See @uref{http://pike.ida.liu.se/}.} and AWK files. In this
264way, you can easily set up consistent font locking and coding styles for
265use in editing all of these languages, although AWK is not yet as
266uniformly integrated as the other languages.
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267
268@findex c-mode
269@findex c++-mode
270@findex objc-mode
271@findex java-mode
272@findex idl-mode
d7bd46ed 273@findex pike-mode
3a731e1f 274@findex awk-mode
94cae5a8 275Note that the name of this package is ``@ccmode{},'' but there is no top
6bf7aab6 276level @code{cc-mode} entry point. All of the variables, commands, and
3a731e1f 277functions in @ccmode{} are prefixed with @code{c-@var{thing}}, and
d7bd46ed 278@code{c-mode}, @code{c++-mode}, @code{objc-mode}, @code{java-mode},
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279@code{idl-mode}, @code{pike-mode}, and @code{awk-mode} entry points are
280provided. This package is intended to be a replacement for
281@file{c-mode.el}, @file{c++-mode.el} and @file{awk-mode.el}.
282
283@c @cindex @file{cc-compat.el} file
284@c This distribution also contains a file
285@c called @file{cc-compat.el} which should ease your transition from BOCM
286@c to @ccmode{}. If you have a BOCM configuration you are really happy
287@c with, and want to postpone learning how to configure @ccmode{}, take a
288@c look at that file. It maps BOCM configuration variables to @ccmode{}'s
289@c indentation model. It is not actively supported so for the long run,
290@c you should learn how to customize @ccmode{} to support your coding
291@c style.
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292
293A special word of thanks goes to Krishna Padmasola for his work in
294converting the original @file{README} file to Texinfo format. I'd also
295like to thank all the @ccmode{} victims who help enormously during the
296early beta stages of @ccmode{}'s development.
297
298
299@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 300@node Getting Connected, Indentation Engine, Introduction, Top
d7bd46ed 301@comment node-name, next, previous, up
3a731e1f 302@chapter Getting Connected
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303@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
304
305If you got this version of @ccmode{} with Emacs or XEmacs, it should
306work just fine right out of the box. Note however that you may not have
307the latest @ccmode{} release and may want to upgrade your copy.
308
309If you are upgrading an existing @ccmode{} installation, please see the
310@file{README} file for installation details. @ccmode{} may not work
311with older versions of Emacs or XEmacs. See the @ccmode{} release notes
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312at @uref{http://cc-mode.sourceforge.net} for the latest information on
313Emacs version and package compatibility (@pxref{Getting the Latest CC
314Mode Release}).
6bf7aab6 315
3a731e1f 316@deffn Command c-version
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317@findex version (c-)
318You can find out what version of @ccmode{} you are using by visiting a C
319file and entering @kbd{M-x c-version RET}. You should see this message in
320the echo area:
6bf7aab6 321
3a731e1f 322@example
6bf7aab6 323Using CC Mode version 5.XX
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324@end example
325
326@noindent
327where @samp{XX} is the minor release number.
3a731e1f 328@end deffn
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329
330
331@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 332@node Indentation Engine, Minor Modes, Getting Connected, Top
d7bd46ed 333@comment node-name, next, previous, up
3a731e1f 334@chapter Indentation Engine
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335@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
336
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337@ccmode{} has an indentation engine that provides a flexible and general
338mechanism for customizing indentation. It separates indentation
339calculation into two steps: first, @ccmode{} analyzes the line of code
340being indented to determine the kind of language construct it's looking
341at, then it applies user defined offsets to the current line based on
342this analysis.
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343
344This section will briefly cover how indentation is calculated in
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345@ccmode{}. It is important to understand the indentation model being
346used so that you will know how to customize @ccmode{} for your personal
347coding style. All the details are in @ref{Customizing Indentation}, and
348later chapters.
349
350@defopt c-syntactic-indentation
351@vindex syntactic-indentation (c-)
352Syntactic analysis for indentation is done when this is non-@code{nil}
353(which is the default). When it's @code{nil} every line is just
354indented to the same level as the previous one, and @kbd{TAB}
355(@code{c-indent-command}) adjusts the indentation in steps of
356@code{c-basic-offset}. The indentation style has no effect, nor any of
c3a2e2d5 357the indentation associated variables, e.g., @code{c-special-indent-hook}.
3a731e1f 358@end defopt
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359
360@menu
361* Syntactic Analysis::
362* Indentation Calculation::
363@end menu
364
365
366@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 367@node Syntactic Analysis, Indentation Calculation, , Indentation Engine
d7bd46ed 368@comment node-name, next, previous, up
3a731e1f 369@section Syntactic Analysis
d7bd46ed 370@cindex syntactic analysis
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371@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
372
6bf7aab6 373@cindex relative buffer position
3a731e1f 374@cindex syntactic symbols
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375@cindex syntactic component
376@cindex syntactic component list
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377The first thing @ccmode{} does when indenting a line of code, is to
378analyze the line, determining the @dfn{syntactic component list} of the
d7bd46ed 379construct on that line. A syntactic component consists of a pair of
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380elements (in lisp parlance, a @emph{cons cell}), the first being
381a @dfn{syntactic symbol}, the second being a @dfn{relative
6bf7aab6 382buffer position}. Syntactic symbols describe elements of C code
3a731e1f 383@footnote{Unless otherwise noted, the term ``C code'' refers to all
c3a2e2d5 384the C-like languages.}, e.g., @code{statement}, @code{substatement},
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385@code{class-open}, @code{class-close}, etc. @xref{Syntactic Symbols},
386for a complete list of currently recognized syntactic symbols and their
387semantics. The style variable @code{c-offsets-alist} also contains the
388list of currently supported syntactic symbols.
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389
390Conceptually, a line of C code is always indented relative to the
391indentation of some line higher up in the buffer. This is represented
392by the relative buffer position in the syntactic component.
393
394Here is an example. Suppose we had the following code as the only thing
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395in a C++ buffer @footnote{The line numbers in this and future examples
396don't actually appear in the buffer, of course!}:
6bf7aab6 397
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398@example
399 1: void swap( int& a, int& b )
400 2: @{
401 3: int tmp = a;
402 4: a = b;
403 5: b = tmp;
404 6: @}
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405@end example
406
407@kindex C-c C-s
408@findex c-show-syntactic-information
409@findex show-syntactic-information (c-)
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410We can use the command @kbd{C-c C-s} (bound to
411@code{c-show-syntactic-information}) to simply report what the
6bf7aab6 412syntactic analysis is for the current line. Running this command on
3a731e1f 413line 4 of this example, we'd see in the echo area@footnote{With a
c3a2e2d5 414universal argument (i.e., @kbd{C-u C-c C-s}) the analysis is inserted
3a731e1f 415into the buffer as a comment on the current line.}:
6bf7aab6 416
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417@example
418((statement 35))
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419@end example
420
421This tells us that the line is a statement and it is indented relative
422to buffer position 35, which happens to be the @samp{i} in @code{int} on
423line 3. If you were to move point to line 3 and hit @kbd{C-c C-s}, you
424would see:
6bf7aab6 425
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426@example
427((defun-block-intro 29))
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428@end example
429
430This indicates that the @samp{int} line is the first statement in a top
431level function block, and is indented relative to buffer position 29,
432which is the brace just after the function header.
433
434Here's another example:
6bf7aab6 435
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436@example
437 1: int add( int val, int incr, int doit )
438 2: @{
439 3: if( doit )
440 4: @{
441 5: return( val + incr );
442 6: @}
443 7: return( val );
444 8: @}
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445@end example
446
447@noindent
448Hitting @kbd{C-c C-s} on line 4 gives us:
6bf7aab6 449
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450@example
451((substatement-open 46))
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452@end example
453
454@cindex substatement
d7bd46ed 455@cindex substatement block
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456@noindent
457which tells us that this is a brace that @emph{opens} a substatement
458block. @footnote{A @dfn{substatement} is the line after a
459conditional statement, such as @code{if}, @code{else}, @code{while},
460@code{do}, @code{switch}, etc. A @dfn{substatement
461block} is a brace block following one of these conditional statements.}
462
463@cindex comment-only line
464Syntactic component lists can contain more than one component, and
465individual syntactic components need not have relative buffer positions.
466The most common example of this is a line that contains a @dfn{comment
467only line}.
6bf7aab6 468
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469@example
470 1: void draw_list( List<Drawables>& drawables )
471 2: @{
472 3: // call the virtual draw() method on each element in list
473 4: for( int i=0; i < drawables.count(), ++i )
474 5: @{
475 6: drawables[i].draw();
476 7: @}
477 8: @}
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478@end example
479
480@noindent
481Hitting @kbd{C-c C-s} on line 3 of this example gives:
6bf7aab6 482
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483@example
484((comment-intro) (defun-block-intro 46))
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485@end example
486
487@noindent
488and you can see that the syntactic component list contains two syntactic
489components. Also notice that the first component,
490@samp{(comment-intro)} has no relative buffer position.
491
492
493@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 494@node Indentation Calculation, , Syntactic Analysis, Indentation Engine
d7bd46ed 495@comment node-name, next, previous, up
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496@section Indentation Calculation
497@cindex indentation
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498@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
499
6bf7aab6 500Indentation for a line is calculated using the syntactic
d7bd46ed 501component list derived in step 1 above (@pxref{Syntactic Analysis}).
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502Each component contributes to the final total indentation of the line in
503two ways.
504
505First, the syntactic symbols are looked up in the @code{c-offsets-alist}
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506style variable, which is an association list of syntactic symbols and
507the offsets to apply for those symbols. These offsets are added to a
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508running total.
509
510Second, if the component has a relative buffer position, @ccmode{}
511adds the column number of that position to the running total. By adding
512up the offsets and columns for every syntactic component on the list,
513the final total indentation for the current line is computed.
514
515Let's use our two code examples above to see how this works. Here is
516our first example again:
6bf7aab6 517
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518@example
519 1: void swap( int& a, int& b )
520 2: @{
521 3: int tmp = a;
522 4: a = b;
523 5: b = tmp;
524 6: @}
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525@end example
526
3a731e1f 527Let's say point is on line 3 and we hit the @kbd{TAB} key to reindent
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528the line. Remember that the syntactic component list for that
529line is:
6bf7aab6 530
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531@example
532((defun-block-intro 29))
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533@end example
534
535@noindent
536@ccmode{} looks up @code{defun-block-intro} in the
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537@code{c-offsets-alist} style variable. Let's say it finds the value
538@samp{4}; it adds this to the running total (initialized to zero),
539yielding a running total indentation of 4 spaces.
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540
541Next @ccmode{} goes to buffer position 29 and asks for the current
542column. This brace is in column zero, so @ccmode{}
543adds @samp{0} to the running total. Since there is only one syntactic
544component on the list for this line, indentation calculation is
545complete, and the total indentation for the line
546is 4 spaces.
547
548Here's another example:
6bf7aab6 549
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550@example
551 1: int add( int val, int incr, int doit )
552 2: @{
553 3: if( doit )
554 4: @{
555 5: return( val + incr );
556 6: @}
557 7: return( val );
558 8: @}
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559@end example
560
561If we were to hit @kbd{TAB} on line 4 in the above example, the same
562basic process is performed, despite the differences in the syntactic
563component list. Remember that the list for this line is:
6bf7aab6 564
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565@example
566((substatement-open 46))
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567@end example
568
569Here, @ccmode{} first looks up the @code{substatement-open} symbol
570in @code{c-offsets-alist}. Let's say it finds the value @samp{4}. This
571yields a running total of 4. @ccmode{} then goes to
572buffer position 46, which is the @samp{i} in @code{if} on line 3. This
573character is in the fourth column on that line so adding this to the
574running total yields an indentation for the line of 8 spaces.
575
576Simple, huh?
577
578Actually, the mode usually just does The Right Thing without you having
579to think about it in this much detail. But when customizing
580indentation, it's helpful to understand the general indentation model
581being used.
582
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DL
583As you configure @ccmode{}, you might want to set the variable
584@code{c-echo-syntactic-information-p} to non-@code{nil} so that the
585syntactic component list and calculated offset will always be echoed in
586the minibuffer when you hit @kbd{TAB}.
587
588
589@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 590@node Minor Modes, Text Filling and Line Breaking, Indentation Engine, Top
d7bd46ed 591@comment node-name, next, previous, up
3a731e1f 592@chapter Minor Modes
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593@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
594
595@ccmode{} contains two minor-mode-like features that you should
3a731e1f 596find useful while entering new C code. The first is called
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597@dfn{auto-newline} mode, and the second is called @dfn{hungry-delete}
598mode. These minor modes can be toggled on and off independently, and
599@ccmode{} can be configured so that it starts up with any
600combination of these minor modes. By default, both of these minor modes
601are turned off.
602
603The state of the minor modes is always reflected in the minor mode list
604on the modeline of the @ccmode{} buffer. When auto-newline mode is
3a731e1f
MS
605enabled, you will see @samp{C/a} on the mode line@footnote{The @samp{C}
606would be replaced with the name of the language in question for the
607other languages @ccmode{} supports.}. When hungry delete mode is
608enabled you will see @samp{C/h} and if both modes were enabled, you'd
609see @samp{C/ah}.
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610
611@kindex C-c C-a
612@kindex C-c C-d
613@kindex C-c C-t
614@findex c-toggle-hungry-state
615@findex c-toggle-auto-state
616@findex c-toggle-auto-hungry-state
617@findex toggle-hungry-state (c-)
618@findex toggle-auto-state (c-)
619@findex toggle-auto-hungry-state (c-)
47d7776c 620@ccmode{} provides key bindings which allow you to toggle the minor
6bf7aab6 621modes on the fly while editing code. To toggle just the auto-newline
3a731e1f
MS
622state, hit @kbd{C-c C-a} (bound to @code{c-toggle-auto-state}). When
623you do this, you should see the @samp{a} indicator either appear or
624disappear on the modeline. Similarly, to toggle just the
625hungry-delete state, use @kbd{C-c C-d} (@code{c-toggle-hungry-state}),
626and to toggle both states, use @kbd{C-c C-t}
627(@code{c-toggle-auto-hungry-state}).
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628
629To set up the auto-newline and hungry-delete states to your preferred
630values, you would need to add some lisp to your @file{.emacs} file that
631called one of the @code{c-toggle-*-state} functions directly. When
632called programmatically, each function takes a numeric value, where
633a positive number enables the minor mode, a negative number disables the
634mode, and zero toggles the current state of the mode.
635
636So for example, if you wanted to enable both auto-newline and
637hungry-delete for all your C file editing, you could add the following
638to your @file{.emacs} file:
6bf7aab6 639
3a731e1f 640@example
6bf7aab6 641(add-hook 'c-mode-common-hook
3a731e1f 642 (lambda () (c-toggle-auto-hungry-state 1)))
6bf7aab6
DL
643@end example
644
6bf7aab6 645@menu
d7bd46ed
GM
646* Auto-newline Insertion::
647* Hungry-deletion of Whitespace::
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DL
648@end menu
649
6bf7aab6 650
d7bd46ed
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651@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
652@node Auto-newline Insertion, Hungry-deletion of Whitespace, , Minor Modes
653@comment node-name, next, previous, up
3a731e1f
MS
654@section Auto-newline Insertion
655@cindex auto-newline
6bf7aab6
DL
656@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
657
3a731e1f 658@cindex electric characters
6bf7aab6 659Auto-newline minor mode works by enabling certain @dfn{electric
3a731e1f
MS
660characters}. Special characters such as the left and right braces,
661colons, semicolons, etc., have been made electric to perform some
662magic formatting in addition to inserting the typed character. As a
663general rule, electric characters are only electric when the following
664conditions apply:
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665
666@itemize @bullet
667@item
668Auto-newline minor mode is enabled, as evidenced by a @samp{C/a} or
669@samp{C/ah} indicator on the modeline.
670
3a731e1f 671@item
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DL
672@cindex literal
673@cindex syntactic whitespace
6bf7aab6 674The character was not typed inside of a literal @footnote{A
3a731e1f 675@dfn{literal} is defined as any comment, string, or preprocessor macro
6bf7aab6
DL
676definition. These constructs are also known as @dfn{syntactic
677whitespace} since they are usually ignored when scanning C code.}.
678
679@item
c3a2e2d5 680No numeric argument was supplied to the command (i.e., it was typed as
6bf7aab6 681normal, with no @kbd{C-u} prefix).
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682@end itemize
683
684@menu
685* Hanging Braces::
686* Hanging Colons::
3a731e1f 687* Hanging Semicolons and Commas::
d7bd46ed 688* Other Electric Commands::
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689* Clean-ups::
690@end menu
691
6bf7aab6 692
d7bd46ed
GM
693@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
694@node Hanging Braces, Hanging Colons, , Auto-newline Insertion
695@comment node-name, next, previous, up
696@subsection Hanging Braces
697@cindex hanging braces
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698@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
699
700@findex c-electric-brace
701@findex electric-brace (c-)
3a731e1f
MS
702@kindex @{
703@kindex @}
704
c3a2e2d5 705When you type either an open or close brace (i.e., @kbd{@{} or @kbd{@}}),
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706the electric command @code{c-electric-brace} gets run. This command has
707two electric formatting behaviors. First, it will perform some
3a731e1f 708reindentation of the line the brace was typed on, and second, it will
6bf7aab6 709add various newlines before and/or after the typed brace.
3a731e1f 710Reindentation occurs automatically whenever the electric behavior is
6bf7aab6 711enabled. If the brace ends up on a line other than the one it was typed
3a731e1f 712on, then that line is also reindented.
d7bd46ed
GM
713
714The default in auto-newline mode is to insert newlines both before and
715after a brace, but that can be controlled by the
3a731e1f
MS
716@code{c-hanging-braces-alist} style variable.
717
718@defopt c-hanging-braces-alist
719@vindex hanging-braces-alist (c-)
720
721This variable contains a mapping between syntactic symbols related to
722braces, and a list of places to insert a newline. The syntactic symbols
723that are useful for this list are @code{brace-list-intro},
724@code{statement-cont}, @code{inexpr-class-open},
725@code{inexpr-class-close}, and all the @code{*-open} and @code{*-close}
726symbols. @xref{Syntactic Symbols}, for a more detailed description of
727these syntactic symbols, except for @code{inexpr-class-open} and
728@code{inexpr-class-close}, which aren't actual syntactic symbols.
d7bd46ed
GM
729
730The braces of anonymous inner classes in Java are given the special
731symbols @code{inexpr-class-open} and @code{inexpr-class-close}, so that
732they can be distinguished from the braces of normal classes@footnote{The
3a731e1f 733braces of anonymous classes produce a combination of
d7bd46ed
GM
734@code{inexpr-class}, and @code{class-open} or @code{class-close} in
735normal indentation analysis.}.
736
3a731e1f
MS
737Note that the aggregate constructs in Pike mode, @samp{(@{}, @samp{@})},
738@samp{([}, @samp{])}, and @samp{(<}, @samp{>)}, do not count as brace
739lists in this regard, even though they do for normal indentation
740purposes. It's currently not possible to set automatic newlines on
741these constructs.
742
6bf7aab6 743The value associated with each syntactic symbol in this association list
3a731e1f 744is called an @var{action}, which can be either a function or a list.
393759c7 745@xref{Custom Brace and Colon Hanging}, for a more detailed discussion of
3a731e1f 746using a function as a brace hanging @var{action}.
6bf7aab6 747
3a731e1f 748When the @var{action} is a list, it can contain any combination of the
6bf7aab6
DL
749symbols @code{before} and @code{after}, directing @ccmode{} where to
750put newlines in relationship to the brace being inserted. Thus, if the
751list contains only the symbol @code{after}, then the brace is said to
752@dfn{hang} on the right side of the line, as in:
6bf7aab6 753
3a731e1f 754@example
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DL
755// here, open braces always `hang'
756void spam( int i ) @{
757 if( i == 7 ) @{
758 dosomething(i);
759 @}
760@}
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DL
761@end example
762
763When the list contains both @code{after} and @code{before}, the braces
764will appear on a line by themselves, as shown by the close braces in the
765above example. The list can also be empty, in which case no newlines
766are added either before or after the brace.
767
d7bd46ed
GM
768If a syntactic symbol is missing entirely from
769@code{c-hanging-braces-alist}, it's treated in the same way as an
3a731e1f 770@var{action} with a list containing @code{before} and @code{after}, so
d7bd46ed
GM
771that braces by default end up on their own line.
772
6bf7aab6 773For example, the default value of @code{c-hanging-braces-alist} is:
6bf7aab6 774
3a731e1f
MS
775@example
776((brace-list-open)
777 (brace-entry-open)
778 (statement-cont)
779 (substatement-open after)
780 (block-close . c-snug-do-while)
781 (extern-lang-open after)
782 (inexpr-class-open after)
783 (inexpr-class-close before))
6bf7aab6
DL
784@end example
785
3a731e1f
MS
786@noindent which says that @code{brace-list-open},
787@code{brace-entry-open} and @code{statement-cont}@footnote{Brace lists
788inside statements, such as initializers for static array variables
789inside functions in C, are recognized as @code{statement-cont}. All
790normal substatement blocks are recognized with other symbols.} braces
791should both hang on the right side and allow subsequent text to follow
792on the same line as the brace. Also, @code{substatement-open},
793@code{extern-lang-open}, and @code{inexpr-class-open} braces should hang
794on the right side, but subsequent text should follow on the next line.
795The opposite holds for @code{inexpr-class-close} braces; they won't
796hang, but the following text continues on the same line. Here, in the
797@code{block-close} entry, you also see an example of using a function as
798an @var{action}. In all other cases, braces are put on a line by
799themselves.
800@end defopt
6bf7aab6
DL
801
802
803@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 804@node Hanging Colons, Hanging Semicolons and Commas, Hanging Braces, Auto-newline Insertion
d7bd46ed
GM
805@comment node-name, next, previous, up
806@subsection Hanging Colons
807@cindex hanging colons
6bf7aab6
DL
808@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
809
d7bd46ed
GM
810Using a mechanism similar to brace hanging (@pxref{Hanging Braces}),
811colons can also be made to hang using the style variable
3a731e1f
MS
812@code{c-hanging-colons-alist}.
813
814@defopt c-hanging-colons-alist
815@vindex hanging-colons-alist (c-)
816
817The syntactic symbols appropriate for this association list are:
818@code{case-label}, @code{label}, @code{access-label},
819@code{member-init-intro}, and @code{inher-intro}. Note however that for
820@code{c-hanging-colons-alist}, @var{action}s as functions are not
821supported. See also @ref{Custom Brace and Colon Hanging} for details.
6bf7aab6 822
6bf7aab6
DL
823In C++, double-colons are used as a scope operator but because these
824colons always appear right next to each other, newlines before and after
825them are controlled by a different mechanism, called @dfn{clean-ups} in
393759c7 826@ccmode{}. @xref{Clean-ups}, for details.
3a731e1f 827@end defopt
6bf7aab6
DL
828
829
830@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 831@node Hanging Semicolons and Commas, Other Electric Commands, Hanging Colons, Auto-newline Insertion
d7bd46ed 832@comment node-name, next, previous, up
3a731e1f
MS
833@subsection Hanging Semicolons and Commas
834@cindex hanging semicolons
d7bd46ed 835@cindex hanging commas
6bf7aab6
DL
836@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
837
838Semicolons and commas are also electric in @ccmode{}, but since
839these characters do not correspond directly to syntactic symbols, a
840different mechanism is used to determine whether newlines should be
841automatically inserted after these characters. @xref{Customizing
3a731e1f 842Semicolons and Commas}, for details.
6bf7aab6
DL
843
844
845@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 846@node Other Electric Commands, Clean-ups, Hanging Semicolons and Commas, Auto-newline Insertion
d7bd46ed
GM
847@comment node-name, next, previous, up
848@subsection Other Electric Commands
6bf7aab6
DL
849@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
850
3a731e1f
MS
851A few other keys also provide electric behavior, often only to reindent
852the line. Common to all of them is that they only reindent if used in
853normal code (as opposed to in a string literal or comment), and
854@code{c-syntactic-indentation} isn't @code{nil}. They are:
855
856@table @kbd
857@item #
6bf7aab6
DL
858@kindex #
859@findex c-electric-pound
6bf7aab6 860@findex electric-pound (c-)
3a731e1f 861@vindex c-electric-pound-behavior
6bf7aab6 862@vindex electric-pound-behavior (c-)
3a731e1f
MS
863Pound (bound to @code{c-electric-pound}) is electric when typed as the
864first non-whitespace character on a line and not within a macro
865definition. In this case, the variable @code{c-electric-pound-behavior}
866is consulted for the electric behavior. This variable takes a list
867value, although the only element currently defined is @code{alignleft},
868which tells this command to force the @samp{#} character into column
869zero. This is useful for entering preprocessor macro definitions.
870
871Pound is not electric in AWK buffers, where @samp{#} starts a comment,
872and is bound to @code{self-insert-command} like any typical printable
873character.
6bf7aab6 874
3a731e1f
MS
875@item *
876@kindex *
877@itemx /
878@kindex /
6bf7aab6 879@findex c-electric-star
6bf7aab6 880@findex electric-star (c-)
3a731e1f 881@findex c-electric-slash
6bf7aab6 882@findex electric-slash (c-)
3a731e1f
MS
883Stars and slashes (bound to @code{c-electric-star} and
884@code{c-electric-slash} respectively) are also electric under certain
885circumstances. If a @samp{*} is inserted as the second character of a C
886style block comment on a comment-only line, then the comment delimiter
887is indented as defined by @code{c-offsets-alist}. A comment-only line
888is defined as a line which contains only a comment, as in:
889
6bf7aab6
DL
890@example
891@group
177c0ea7 892void spam( int i )
6bf7aab6 893@{
3a731e1f
MS
894 // this is a comment-only line...
895 if( i == 7 ) // but this is not
6bf7aab6
DL
896 @{
897 dosomething(i);
898 @}
899@}
6bf7aab6
DL
900@end group
901@end example
902
3a731e1f
MS
903Likewise, if a @samp{/} is inserted as the second slash in a C++ style
904line comment (also only on a comment-only line), then the line is
905indented as defined by @code{c-offsets-alist}.
6bf7aab6 906
3a731e1f
MS
907In AWK mode, @samp{*} and @samp{/} do not delimit comments and are
908bound to @code{self-insert-command}.
909
910@item <
6bf7aab6 911@kindex <
3a731e1f 912@itemx >
6bf7aab6 913@kindex >
3a731e1f
MS
914@findex c-electric-lt-gt
915@findex electric-lt-gt (c-)
916Less-than and greater-than signs (bound to @code{c-electric-lt-gt}) are
6bf7aab6 917electric, but only in C++ mode. Hitting the second of two @kbd{<} or
3a731e1f 918@kbd{>} keys reindents the line if it is a C++ style stream operator.
6bf7aab6 919
3a731e1f 920@item (
d7bd46ed 921@kindex (
3a731e1f 922@itemx )
d7bd46ed 923@kindex )
3a731e1f
MS
924@findex c-electric-paren
925@findex electric-paren (c-)
926The normal parenthesis characters @samp{(} and @samp{)} reindent the
927current line. This is useful for getting the closing parenthesis of an
928argument list aligned automatically.
929@end table
930
931@deffn Command c-electric-continued-statement
932@findex electric-continued-statement (c-)
933
934Certain keywords, depending on language, are electric to cause
935reindentation when they are preceded only by whitespace on the line.
936The keywords are those that continue an earlier statement instead of
937starting a new one: @code{else}, @code{while}, @code{catch} (only in C++
938and Java) and @code{finally} (only in Java).
939
940An example:
941
942@example
943@group
944for (i = 0; i < 17; i++)
945 if (a[i])
946 res += a[i]->offset;
947else
948@end group
949@end example
950
951Here, the @code{else} should be indented like the preceding @code{if},
952since it continues that statement. @ccmode{} will automatically reindent
953it after the @code{else} has been typed in full, since it's not until
954then it's possible to decide whether it's a new statement or a
955continuation of the preceding @code{if}.
956
957@vindex abbrev-mode
958@findex abbrev-mode
959@cindex Abbrev mode
960@ccmode{} uses Abbrev mode (@pxref{Abbrevs,,, emacs, The Emacs Editor})
961to accomplish this. It's therefore turned on by default in all language
962modes except IDL mode, since CORBA IDL doesn't have any statements.
963@end deffn
6bf7aab6 964
6bf7aab6 965
d7bd46ed
GM
966@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
967@node Clean-ups, , Other Electric Commands, Auto-newline Insertion
968@comment node-name, next, previous, up
969@subsection Clean-ups
970@cindex clean-ups
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DL
971@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
972
cb7f2e96
GM
973@dfn{Clean-ups} are mechanisms complementary to colon and brace hanging.
974On the surface, it would seem that clean-ups overlap the functionality
975provided by the @code{c-hanging-*-alist} variables. Clean-ups are
c3a2e2d5 976however used to adjust code ``after-the-fact,'' i.e., to adjust the
cb7f2e96
GM
977whitespace in constructs after they are typed.
978
979Most of the clean-ups are only applicable to counteract automatically
980inserted newlines, and will therefore only have any effect if the
981auto-newline minor mode is turned on. Others will work all the time.
6bf7aab6 982
3a731e1f 983@defopt c-cleanup-list
d7bd46ed 984@vindex cleanup-list (c-)
6bf7aab6 985@cindex literal
3a731e1f 986
d7bd46ed 987You can configure @ccmode{}'s clean-ups by setting the style variable
6bf7aab6 988@code{c-cleanup-list}, which is a list of clean-up symbols. By default,
d7bd46ed
GM
989@ccmode{} cleans up only the @code{scope-operator} construct, which is
990necessary for proper C++ support. Note that clean-ups are only
991performed when the construct does not occur within a literal
992(@pxref{Auto-newline Insertion}), and when there is nothing but
993whitespace appearing between the individual components of the construct.
3a731e1f 994@end defopt
6bf7aab6 995
3a731e1f 996These are the clean-ups that are only active in the auto-newline minor
cb7f2e96 997mode:
6bf7aab6 998
3a731e1f
MS
999@c TBD: Would like to use some sort of @deffoo here; @table indents a
1000@c bit too much in dvi output.
1001@table @code
1002@item brace-else-brace
1003Clean up @samp{@} else @{} constructs by placing the entire construct on
1004a single line. Clean-up occurs when the open brace after the
1005@samp{else} is typed. So for example, this:
1006
6bf7aab6
DL
1007@example
1008@group
6bf7aab6
DL
1009void spam(int i)
1010@{
3a731e1f 1011 if( i==7 ) @{
6bf7aab6
DL
1012 dosomething();
1013 @}
1014 else
1015 @{
6bf7aab6
DL
1016@end group
1017@end example
3a731e1f 1018
6bf7aab6 1019@noindent
3a731e1f
MS
1020appears like this after the last open brace is typed:
1021
6bf7aab6
DL
1022@example
1023@group
6bf7aab6
DL
1024void spam(int i)
1025@{
1026 if( i==7 ) @{
1027 dosomething();
1028 @} else @{
6bf7aab6
DL
1029@end group
1030@end example
1031
3a731e1f
MS
1032@item brace-elseif-brace
1033Similar to the @code{brace-else-brace} clean-up, but this cleans up
1034@samp{@} else if (...) @{} constructs. For example:
1035
6bf7aab6
DL
1036@example
1037@group
6bf7aab6
DL
1038void spam(int i)
1039@{
3a731e1f 1040 if( i==7 ) @{
6bf7aab6
DL
1041 dosomething();
1042 @}
d7bd46ed
GM
1043 else if( i==3 )
1044 @{
6bf7aab6
DL
1045@end group
1046@end example
3a731e1f 1047
6bf7aab6 1048@noindent
3a731e1f
MS
1049appears like this after the last open parenthesis is typed:
1050
d7bd46ed
GM
1051@example
1052@group
d7bd46ed
GM
1053void spam(int i)
1054@{
1055 if( i==7 ) @{
1056 dosomething();
1057 @} else if( i==3 )
1058 @{
d7bd46ed
GM
1059@end group
1060@end example
3a731e1f 1061
d7bd46ed 1062@noindent
3a731e1f
MS
1063and like this after the last open brace is typed:
1064
6bf7aab6
DL
1065@example
1066@group
6bf7aab6
DL
1067void spam(int i)
1068@{
1069 if( i==7 ) @{
1070 dosomething();
1071 @} else if( i==3 ) @{
6bf7aab6
DL
1072@end group
1073@end example
1074
3a731e1f
MS
1075@item brace-catch-brace
1076Analogous to @code{brace-elseif-brace}, but cleans up @samp{@} catch
1077(...) @{} in C++ and Java mode.
1078
1079@item empty-defun-braces
1080Clean up braces following a top-level function or class definition that
1081contains no body. Clean up occurs when the closing brace is typed.
1082Thus the following:
d7bd46ed 1083
6bf7aab6
DL
1084@example
1085@group
6bf7aab6
DL
1086class Spam
1087@{
1088@}
6bf7aab6
DL
1089@end group
1090@end example
3a731e1f 1091
6bf7aab6
DL
1092@noindent
1093is transformed into this when the close brace is typed:
3a731e1f 1094
6bf7aab6
DL
1095@example
1096@group
6bf7aab6
DL
1097class Spam
1098@{@}
6bf7aab6
DL
1099@end group
1100@end example
1101
3a731e1f
MS
1102@item defun-close-semi
1103Clean up the terminating semicolon on top-level function or class
1104definitions when they follow a close brace. Clean up occurs when the
1105semicolon is typed. So for example, the following:
1106
6bf7aab6
DL
1107@example
1108@group
6bf7aab6
DL
1109class Spam
1110@{
1111@}
1112;
6bf7aab6
DL
1113@end group
1114@end example
3a731e1f 1115
6bf7aab6 1116@noindent
3a731e1f 1117is transformed into this when the semicolon is typed:
6bf7aab6
DL
1118
1119@example
1120@group
6bf7aab6
DL
1121class Spam
1122@{
1123@};
6bf7aab6
DL
1124@end group
1125@end example
1126
3a731e1f
MS
1127@item list-close-comma
1128Clean up commas following braces in array and aggregate initializers.
1129Clean up occurs when the comma is typed.
1130
1131@item scope-operator
1132Clean up double colons which may designate a C++ scope operator split
1133across multiple lines@footnote{Certain C++ constructs introduce
1134ambiguous situations, so @code{scope-operator} clean-ups may not always
1135be correct. This usually only occurs when scoped identifiers appear in
1136switch label tags.}. Clean up occurs when the second colon is typed.
1137You will always want @code{scope-operator} in the @code{c-cleanup-list}
1138when you are editing C++ code.
1139@end table
6bf7aab6 1140
cb7f2e96
GM
1141The following clean-ups are always active when they occur on
1142@code{c-cleanup-list}, and are thus not affected by the auto-newline
1143minor mode:
1144
3a731e1f
MS
1145@table @code
1146@item space-before-funcall
1147Insert a space between the function name and the opening parenthesis of
1148a function call. This produces function calls in the style mandated by
c3a2e2d5 1149the GNU coding standards, e.g., @samp{signal (SIGINT, SIG_IGN)} and
3a731e1f
MS
1150@samp{abort ()}. Clean up occurs when the opening parenthesis is typed.
1151
1152@item compact-empty-funcall
1153Clean up any space between the function name and the opening parenthesis
1154of a function call that has no arguments. This is typically used
1155together with @code{space-before-funcall} if you prefer the GNU function
1156call style for functions with arguments but think it looks ugly when
c3a2e2d5 1157it's only an empty parenthesis pair. I.e., you will get @samp{signal
3a731e1f
MS
1158(SIGINT, SIG_IGN)}, but @samp{abort()}. Clean up occurs when the
1159closing parenthesis is typed.
1160@end table
cb7f2e96 1161
6bf7aab6
DL
1162
1163@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
d7bd46ed
GM
1164@node Hungry-deletion of Whitespace, , Auto-newline Insertion, Minor Modes
1165@comment node-name, next, previous, up
3a731e1f
MS
1166@section Hungry-deletion of Whitespace
1167@cindex hungry-deletion
6bf7aab6
DL
1168@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1169
1170Hungry deletion of whitespace, or as it more commonly called,
1171@dfn{hungry-delete mode}, is a simple feature that some people find
1172extremely useful. In fact, you might find yourself wanting
1173hungry-delete in @strong{all} your editing modes!
1174
1175@kindex DEL
3a731e1f
MS
1176@kindex C-d
1177
1178In a nutshell, when hungry-delete mode is enabled, hitting the @kbd{DEL}
1179or @kbd{C-d} keys will consume all preceding or following whitespace,
1180including newlines and tabs. This can really cut down on the number of
1181times you have to hit these keys if, for example, you made a mistake on
6bf7aab6
DL
1182the preceding line.
1183
3a731e1f 1184@deffn Command c-electric-backspace
6bf7aab6 1185@findex electric-backspace (c-)
3a731e1f
MS
1186This command is run by default when you hit the @kbd{DEL} key. It
1187deletes any amount of whitespace in the backwards direction if
1188hungry-delete mode is enabled. When it's disabled, or when used with
1189a prefix argument or in a literal (@pxref{Auto-newline Insertion}),
1190the function contained in the @code{c-backspace-function} variable is
1191called with the prefix argument.
1192@end deffn
1193
1194@defvar c-backspace-function
6bf7aab6 1195@vindex backspace-function (c-)
3a731e1f
MS
1196@findex backward-delete-char-untabify
1197Hook that gets called by @code{c-electric-backspace} when it doesn't
1198do an ``electric'' deletion of the preceding whitespace. The default
1199value is @code{backward-delete-char-untabify}.
1200@end defvar
1201
1202@deffn Command c-electric-delete-forward
1203@findex electric-delete-forward (c-)
1204This function, which is bound to @kbd{C-d} by default, works just like
1205@code{c-electric-backspace} but in the forward direction. When it
1206doesn't do an ``electric'' deletion of the following whitespace, it
1207calls the function in @code{c-delete-function} with its prefix
1208argument.
1209@end deffn
1210
1211@defvar c-delete-function
1212@vindex delete-function (c-)
1213@findex delete-char
1214Hook that gets called by @code{c-electric-delete-forward} when it
1215doesn't do an ``electric'' deletion of the following whitespace. The
1216default value is @code{delete-char}.
1217@end defvar
1218
1219Above we have only talked about the @kbd{DEL} and @kbd{C-d} key events,
1220without connecting them to the physical keys commonly known as
1221@key{Backspace} and @key{Delete}. The default behavior of those two
1222depends on the flavor of (X)Emacs you are using.
6bf7aab6
DL
1223
1224@findex c-electric-delete
1225@findex electric-delete (c-)
3a731e1f 1226@vindex delete-key-deletes-forward
6bf7aab6 1227
3a731e1f
MS
1228In XEmacs 20.3 and beyond, the @key{Backspace} key is bound to
1229@code{c-electric-backspace} and the @key{Delete} key is bound to
1230@code{c-electric-delete}. You control the direction it deletes in by
1231setting the variable @code{delete-key-deletes-forward}, a standard
1232XEmacs variable. When this variable is non-@code{nil},
1233@code{c-electric-delete} will do forward deletion with
1234@code{c-electric-delete-forward}, otherwise it does backward deletion
1235with @code{c-electric-backspace}.
1236
1237In other Emacs versions, @ccmode{} doesn't bind either @key{Backspace}
1238or @key{Delete}. In XEmacs 19 and Emacs prior to 21 that means that
1239it's up to you to fix them. Emacs 21 automatically binds them as
1240appropriate to @kbd{DEL} and @kbd{C-d}.
1241
1242Another way to use hungry deletion is to bind
1243@code{c-hungry-backspace} and @code{c-hungry-delete-forward} directly
1244to keys, and not use the mode toggling. For example @kbd{C-c C-d} and
1245@kbd{C-c DEL} to match plain @kbd{C-d} and @kbd{DEL},
6bf7aab6 1246
3a731e1f
MS
1247@example
1248(add-hook
1249 'c-mode-common-hook
1250 (lambda ()
1251 (define-key c-mode-base-map
1252 [?\C-c ?\d] 'c-hungry-backspace)
1253 (define-key c-mode-base-map
1254 [?\C-c ?\C-d] 'c-hungry-delete-forward)))
1255@end example
6bf7aab6 1256
3a731e1f
MS
1257@deffn Command c-hungry-backspace
1258@findex hungry-backspace (c-)
1259Delete any amount of whitespace in the backwards direction (regardless
1260whether hungry-delete mode is enabled or not).
1261@end deffn
6bf7aab6 1262
3a731e1f
MS
1263@deffn Command c-hungry-delete-forward
1264@findex hungry-delete-forward (c-)
1265Delete any amount of whitespace in the forward direction (regardless
1266whether hungry-delete mode is enabled or not).
1267@end deffn
6bf7aab6
DL
1268
1269
1270@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 1271@node Text Filling and Line Breaking, Macro Handling, Minor Modes, Top
d7bd46ed 1272@comment node-name, next, previous, up
3a731e1f
MS
1273@chapter Text Filling and Line Breaking
1274@cindex text filling
1275@cindex line breaking
1276@cindex comment handling
6bf7aab6
DL
1277@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1278
d7bd46ed
GM
1279Since there's a lot of normal text in comments and string literals,
1280@ccmode{} provides features to edit these like in text mode. The goal
c3a2e2d5 1281is to do it as seamlessly as possible, i.e., you can use auto fill mode,
d7bd46ed
GM
1282sentence and paragraph movement, paragraph filling, adaptive filling etc
1283wherever there's a piece of normal text without having to think much
1284about it. @ccmode{} should keep the indentation, fix the comment line
1285decorations, and so on, for you. It does that by hooking in on the
1286different line breaking functions and tuning relevant variables as
1287necessary.
1288
1289@vindex c-comment-prefix-regexp
1290@vindex comment-prefix-regexp (c-)
1291@cindex comment line prefix
1292@vindex comment-start
1293@vindex comment-end
1294@vindex comment-start-skip
1295@vindex paragraph-start
1296@vindex paragraph-separate
1297@vindex paragraph-ignore-fill-prefix
1298@vindex adaptive-fill-mode
1299@vindex adaptive-fill-regexp
1300@vindex adaptive-fill-first-line-regexp
1301To make Emacs recognize comments and treat text in them as normal
1302paragraphs, @ccmode{} makes several standard
1303variables@footnote{@code{comment-start}, @code{comment-end},
1304@code{comment-start-skip}, @code{paragraph-start},
1305@code{paragraph-separate}, @code{paragraph-ignore-fill-prefix},
1306@code{adaptive-fill-mode}, @code{adaptive-fill-regexp}, and
1307@code{adaptive-fill-first-line-regexp}.} buffer local and modifies them
3a731e1f
MS
1308according to the language syntax and the comment line prefix.
1309
1310@defopt c-comment-prefix-regexp
1311@vindex comment-prefix-regexp (c-)
1312This style variable contains the regexp used to recognize the
1313@dfn{comment line prefix}, which is the line decoration that starts
1314every line in a comment. The default is @samp{//+\\|\\**}, which
d7bd46ed 1315matches C++ style line comments like
d7bd46ed 1316
3a731e1f 1317@example
d7bd46ed 1318// blah blah
d7bd46ed
GM
1319@end example
1320
1321@noindent
1322with two or more slashes in front of them, and C style block comments
1323like
3a731e1f 1324
d7bd46ed
GM
1325@example
1326@group
d7bd46ed
GM
1327/*
1328 * blah blah
1329 */
d7bd46ed
GM
1330@end group
1331@end example
1332
1333@noindent
1334with zero or more stars at the beginning of every line. If you change
3a731e1f 1335this variable, please make sure it still matches the comment starter
c3a2e2d5 1336(i.e., @code{//}) of line comments @emph{and} the line prefix inside
3a731e1f
MS
1337block comments.
1338
1339@findex c-setup-paragraph-variables
1340@findex setup-paragraph-variables (c-)
1341Also note that since @ccmode{} uses the value of
d7bd46ed 1342@code{c-comment-prefix-regexp} to set up several other variables at mode
2a15eb73 1343initialization, there won't be any effect if you just change it inside a
3a731e1f 1344@ccmode{} buffer. You need to call the command
2a15eb73 1345@code{c-setup-paragraph-variables} too, to update those other variables with
3a731e1f
MS
1346the new value. That's also the case if you modify this variable in a
1347mode hook, since @ccmode{} sets up all variables before calling them.
1348@end defopt
d7bd46ed
GM
1349
1350@findex auto-fill-mode
3a731e1f
MS
1351@cindex Auto Fill mode
1352@cindex paragraph filling
d7bd46ed
GM
1353Line breaks are by default handled (almost) the same regardless whether
1354they are made by auto fill mode (@pxref{Auto Fill,,, emacs, The Emacs
c3a2e2d5 1355Editor}), paragraph filling (e.g., with @kbd{M-q}), or explicitly with
d7bd46ed
GM
1356@kbd{M-j} or similar methods. In string literals, the new line gets the
1357same indentation as the previous nonempty line (may be changed with the
1358@code{string} syntactic symbol). In comments, @ccmode{} uses
1359@code{c-comment-prefix-regexp} to adapt the line prefix from the other
1360lines in the comment.
1361
1362@vindex adaptive-fill-mode
3a731e1f 1363@cindex Adaptive Fill mode
d7bd46ed
GM
1364@ccmode{} uses adaptive fill mode (@pxref{Adaptive Fill,,, emacs, The
1365Emacs Editor}) to make Emacs correctly keep the line prefix when filling
1366paragraphs. That also makes Emacs preserve the text indentation
c3a2e2d5 1367@emph{inside} the comment line prefix. e.g., in the following comment,
3a731e1f
MS
1368both paragraphs will be filled with the left margins of the texts kept
1369intact:
1370
d7bd46ed
GM
1371@example
1372@group
d7bd46ed
GM
1373/* Make a balanced b-tree of the nodes in the incoming
1374 * stream. But, to quote the famous words of Donald E.
1375 * Knuth,
1376 *
1377 * Beware of bugs in the above code; I have only
1378 * proved it correct, not tried it.
1379 */
d7bd46ed
GM
1380@end group
1381@end example
1382
1383@findex c-setup-filladapt
1384@findex setup-filladapt (c-)
1385@findex filladapt-mode
1386@vindex filladapt-mode
1387@cindex Filladapt mode
1388It's also possible to use other adaptive filling packages, notably Kyle
1389E. Jones' Filladapt package@footnote{It's available from
1390@uref{http://www.wonderworks.com/}. As of version 2.12, it does however
1391lack a feature that makes it work suboptimally when
1392@code{c-comment-prefix-regexp} matches the empty string (which it does
1393by default). A patch for that is available from
3a731e1f 1394@uref{http://cc-mode.sourceforge.net/,, the CC Mode web site}.},
d7bd46ed
GM
1395which handles things like bulleted lists nicely. There's a convenience
1396function @code{c-setup-filladapt} that tunes the relevant variables in
c3a2e2d5 1397Filladapt for use in @ccmode{}. Call it from a mode hook, e.g., with
d7bd46ed 1398something like this in your @file{.emacs}:
d7bd46ed 1399
3a731e1f 1400@example
d7bd46ed
GM
1401(defun my-c-mode-common-hook ()
1402 (c-setup-filladapt)
1403 (filladapt-mode 1))
1404(add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
d7bd46ed 1405@end example
6bf7aab6 1406
3a731e1f 1407@defopt c-block-comment-prefix
d7bd46ed 1408@vindex block-comment-prefix (c-)
6bf7aab6
DL
1409@vindex c-comment-continuation-stars
1410@vindex comment-continuation-stars (c-)
d7bd46ed
GM
1411Normally the comment line prefix inserted for a new line inside a
1412comment is deduced from other lines in it. However there's one
3a731e1f
MS
1413situation when there's no hint about what the prefix should look like,
1414namely when a block comment is broken for the first time. This style
1415variable@footnote{In versions before 5.26, this variable was called
1416@code{c-comment-continuation-stars}. As a compatibility measure,
1417@ccmode{} still uses the value on that variable if it's set.} is used
2a15eb73
MS
1418then as the comment prefix. It defaults to @samp{*
1419}@footnote{Actually, this default setting of
1420@code{c-block-comment-prefix} typically gets overriden by the default
1421style @code{gnu}, which sets it to blank. You can see the line
1422splitting effect described here by setting a different style,
c1386334 1423e.g. @code{k&r} @xref{Choosing a Style}.}, which makes a comment
6bf7aab6 1424
3a731e1f 1425@example
d7bd46ed 1426/* Got O(n^2) here, which is a Bad Thing. */
d7bd46ed 1427@end example
6bf7aab6 1428
d7bd46ed
GM
1429@noindent
1430break into
3a731e1f 1431
d7bd46ed
GM
1432@example
1433@group
d7bd46ed
GM
1434/* Got O(n^2) here,
1435 * which is a Bad Thing. */
d7bd46ed
GM
1436@end group
1437@end example
1438
3a731e1f
MS
1439Note that it won't work to adjust the indentation by putting leading
1440spaces in @code{c-block-comment-prefix}, since @ccmode{} still uses the
1441normal indentation engine to indent the line. Thus, the right way to
1442fix the indentation is by customizing the @code{c} syntactic symbol. It
1443defaults to @code{c-lineup-C-comments}, which handles the indentation of
1444most common comment styles, see @ref{Indentation Functions}.
1445@end defopt
d7bd46ed 1446
3a731e1f 1447@defopt c-ignore-auto-fill
d7bd46ed
GM
1448@vindex ignore-auto-fill (c-)
1449When auto fill mode is enabled, @ccmode{} can selectively ignore it
c3a2e2d5 1450depending on the context the line break would occur in, e.g., to never
3a731e1f
MS
1451break a line automatically inside a string literal. This variable
1452takes a list of symbols for the different contexts where auto-filling
1453never should occur:
d7bd46ed 1454
3a731e1f
MS
1455@table @code
1456@item string
1457Inside a string or character literal.
1458@item c
1459Inside a C style block comment.
1460@item c++
1461Inside a C++ style line comment.
1462@item cpp
1463Inside a preprocessor directive.
1464@item code
c3a2e2d5 1465Anywhere else, i.e., in normal code.
3a731e1f 1466@end table
d7bd46ed
GM
1467
1468By default, @code{c-ignore-auto-fill} is set to @code{'(string cpp
1469code)}, which means that auto-filling only occurs in comments when
1470auto-fill mode is activated. In literals, it's often desirable to have
1471explicit control over newlines. In preprocessor directives, the
1472necessary @samp{\} escape character before the newline is not
1473automatically inserted, so an automatic line break would produce invalid
1474code. In normal code, line breaks are normally dictated by some logical
1475structure in the code rather than the last whitespace character, so
1476automatic line breaks there will produce poor results in the current
1477implementation.
3a731e1f 1478@end defopt
d7bd46ed 1479
3a731e1f 1480The commands that do the actual work follow.
d7bd46ed
GM
1481
1482@table @asis
3a731e1f 1483@item @kbd{M-q} (@code{c-fill-paragraph})
d7bd46ed
GM
1484@kindex M-q
1485@findex c-fill-paragraph
1486@findex fill-paragraph (c-)
1487@cindex Javadoc markup
cb7f2e96 1488@cindex Pike autodoc markup
d7bd46ed
GM
1489This is the replacement for @code{fill-paragraph} in @ccmode{}
1490buffers. It's used to fill multiline string literals and both block and
1491line style comments. In Java buffers, the Javadoc markup words are
cb7f2e96
GM
1492recognized as paragraph starters. The line oriented Pike autodoc markup
1493words are recognized in the same way in Pike mode.
d7bd46ed
GM
1494
1495The function keeps the comment starters and enders of block comments as
1496they were before the filling. This means that a comment ender on the
1497same line as the paragraph being filled will be filled with the
1498paragraph, and one on a line by itself will stay as it is. The comment
1499starter is handled similarly@footnote{This means that the variables
1500@code{c-hanging-comment-starter-p} and @code{c-hanging-comment-ender-p},
1501which controlled this behavior in earlier versions of @ccmode{}, are now
1502obsolete.}.
1503
3a731e1f 1504@item @kbd{M-j} (@code{c-indent-new-comment-line})
d7bd46ed
GM
1505@kindex M-j
1506@findex c-indent-new-comment-line
1507@findex indent-new-comment-line (c-)
d7bd46ed
GM
1508This is the replacement for @code{indent-new-comment-line}. It breaks
1509the line at point and indents the new line like the current one.
1510
1511@vindex comment-multi-line
1512If inside a comment and @code{comment-multi-line} is non-@code{nil}, the
1513indentation and line prefix are preserved. If inside a comment and
1514@code{comment-multi-line} is @code{nil}, a new comment of the same type
1515is started on the next line and indented as appropriate for comments.
1516
3a731e1f
MS
1517Note that @ccmode{} sets @code{comment-multi-line} to @code{t} at
1518startup. The reason is that @kbd{M-j} could otherwise produce sequences
1519of single line block comments for texts that should logically be treated
1520as one comment, and the rest of the paragraph handling code
c3a2e2d5 1521(e.g., @kbd{M-q} and @kbd{M-a}) can't cope with that, which would lead to
3a731e1f
MS
1522inconsistent behavior.
1523
1524@item @kbd{M-x c-context-line-break}
d7bd46ed
GM
1525@findex c-context-line-break
1526@findex context-line-break (c-)
d7bd46ed
GM
1527This is a function that works like @code{indent-new-comment-line} in
1528comments and @code{newline-and-indent} elsewhere, thus combining those
1529two in a way that uses each one in the context it's best suited for.
c3a2e2d5 1530I.e., in comments the comment line prefix and indentation is kept for
3a731e1f
MS
1531the new line, and in normal code it's indented according to context by
1532the indentation engine.
1533
1534In macros it acts like @code{newline-and-indent} but additionally
1535inserts and optionally aligns the line ending backslash so that the
1536macro remains unbroken. @xref{Macro Handling}, for details about the
1537backslash alignment.
d7bd46ed
GM
1538
1539It's not bound to a key by default, but it's intended to be used on the
1540@kbd{RET} key. If you like the behavior of @code{newline-and-indent} on
3a731e1f
MS
1541@kbd{RET}, you should consider switching to this function.
1542
1543@item @kbd{M-x c-context-open-line}
1544@findex c-context-open-line
1545@findex context-open-line (c-)
1546This is to @kbd{C-o} (@kbd{M-x open-line}) as
c3a2e2d5 1547@code{c-context-line-break} is to @kbd{RET}. I.e., it works just like
3a731e1f
MS
1548@code{c-context-line-break} but leaves the point before the inserted
1549line break.
d7bd46ed 1550@end table
6bf7aab6 1551
d7bd46ed
GM
1552
1553@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 1554@node Macro Handling, Font Locking, Text Filling and Line Breaking, Top
d7bd46ed 1555@comment node-name, next, previous, up
3a731e1f
MS
1556@chapter Macro Handling
1557@cindex macros
1558@cindex preprocessor directives
6bf7aab6
DL
1559@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1560
3a731e1f 1561Preprocessor directives are handled as syntactic whitespace from other
c3a2e2d5 1562code, i.e., they can be interspersed anywhere without affecting the
3a731e1f 1563syntactic analysis, just like comments.
6bf7aab6 1564
3a731e1f
MS
1565The code inside macro definitions is still analyzed syntactically so
1566that you get relative indentation there just as you'd get if the same
1567code was outside a macro. However, since there is no hint about the
c3a2e2d5 1568syntactic context, i.e., whether the macro expands to an expression, to some
3a731e1f
MS
1569statements, or perhaps to whole functions, the syntactic recognition can be
1570wrong. @ccmode{} manages to figure it out correctly most of the time,
1571though. @xref{Syntactic Symbols}, for details about the indentation.
6bf7aab6 1572
3a731e1f
MS
1573@defopt c-syntactic-indentation-in-macros
1574@vindex syntactic-indentation-in-macros (c-)
1575Enable syntactic analysis inside macros, which is the default. If this
1576is @code{nil}, all lines inside macro definitions are analyzed as
1577@code{cpp-macro-cont}.
1578@end defopt
6bf7aab6 1579
3a731e1f
MS
1580@ccmode{} provides some tools to help keep the line continuation
1581backslashes in macros neat and tidy:
1582
1583@table @asis
1584@item @kbd{C-c C-\} (@code{c-backslash-region})
1585@kindex C-c C-\
1586@findex c-backslash-region
1587@findex backslash-region (c-)
1588This function inserts and aligns or deletes the end-of-line backslashes
1589in the current region.
1590
1591With no prefix argument, it inserts any missing backslashes and aligns
1592them according to the @code{c-backslash-column} and
1593@code{c-backslash-max-column} variables. With a prefix argument, it
1594deletes any backslashes.
1595
1596The function does not modify blank lines at the start of the region. If
1597the region ends at the start of a line, it always deletes the backslash
1598(if any) at the end of the previous line.
1599@end table
1600
1601@defopt c-backslash-column
1602@vindex backslash-column (c-)
1603@defoptx c-backslash-max-column
1604@vindex backslash-max-column (c-)
1605These variables control the alignment columns for line continuation
1606backslashes in multiline macros. They are used by the functions that
1607automatically insert or align such backslashes,
c3a2e2d5 1608e.g., @code{c-backslash-region} and @code{c-context-line-break}.
3a731e1f
MS
1609
1610@code{c-backslash-column} specifies the minimum column for the
1611backslashes. If any line in the macro exceeds it then the next tab
1612stop from that line is used as the alignment column for all the
1613backslashes, so that they remain in a single column. However, if some
1614lines exceed @code{c-backslash-max-column} then the backslashes in the
1615rest of the macro will be kept at that column, so that the
1616lines which are too long ``stick out'' instead.
1617@end defopt
1618
1619@defopt c-auto-align-backslashes
1620@vindex auto-align-backslashes (c-)
1621Align automatically inserted line continuation backslashes if
1622non-@code{nil}. When line continuation backslashes are inserted
c3a2e2d5 1623automatically for line breaks in multiline macros, e.g., by
3a731e1f
MS
1624@code{c-context-line-break}, they are aligned with the other backslashes
1625in the same macro if this flag is set. Otherwise the inserted
1626backslashes are preceded by a single space.
1627@end defopt
1628
1629The recommended line breaking function, @code{c-context-line-break}
1630(@pxref{Text Filling and Line Breaking}), is especially nice if you edit
1631multiline macros frequently. When used inside a macro, it automatically
1632inserts and adjusts the mandatory backslash at the end of the line to
1633keep the macro together, and it leaves the point at the right
1634indentation column for the code. Thus you can write code inside macros
1635almost exactly as you can elsewhere, without having to bother with the
1636trailing backslashes.
1637
1638
1639@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1640@node Font Locking, Commands, Macro Handling, Top
1641@comment node-name, next, previous, up
1642@chapter Font Locking
1643@cindex font locking
1644@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1645
c1386334 1646@strong{Please note:} The font locking in AWK mode is currently not integrated
3a731e1f
MS
1647with the rest of @ccmode{}, so this section does not apply there.
1648@xref{AWK Mode Font Locking}, instead.
1649
1650@cindex Font Lock mode
1651
1652@ccmode{} provides font locking for its supported languages by supplying
1653patterns for use with Font Lock mode. This means that you get distinct
1654faces on the various syntactic parts such as comments, strings, keywords
1655and types, which is very helpful in telling them apart at a glance and
1656discovering syntactic errors. @xref{Font Lock,,, emacs, The Emacs
1657Editor}, for ways to enable font locking in @ccmode{} buffers.
1658
1659@menu
1660* Font Locking Preliminaries::
1661* Faces::
1662* Documentation Comments::
1663@end menu
1664
1665
1666@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1667@node Font Locking Preliminaries, Faces, , Font Locking
1668@comment node-name, next, previous, up
1669@section Font Locking Preliminaries
1670@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1671
1672The font locking for most of the @ccmode{} languages were provided
1673directly by the Font Lock package prior to version 5.30 of @ccmode{}.
1674In the transition to @ccmode{} the patterns have been reworked
1675completely and are applied uniformly across all the languages except AWK
1676mode, just like the indentation rules (although each language still has
1677some pecularities of its own, of course). Since the languages
1678previously had completely separate font locking patterns, this means
1679that it's a bit different in most languages now.
1680
1681The main goal for the font locking in @ccmode{} is accuracy, to provide
1682a dependable aid in recognizing the various constructs. Some, like
1683strings and comments, are easy to recognize while others like
1684declarations and types can be very tricky. @ccmode{} can go to great
1685lengths to recognize declarations and casts correctly, especially when
1686the types aren't recognized by standard patterns. This is a fairly
1687demanding analysis which can be slow on older hardware, and it can
1688therefore be disabled by choosing a lower decoration level with the
1689variable @code{font-lock-maximum-decoration}.
1690
1691@vindex font-lock-maximum-decoration
1692
1693The decoration levels are used as follows:
1694
1695@enumerate
1696@comment 1
1697@item
1698Minimal font locking: Fontify only comments, strings and preprocessor
1699directives (in the languages that use cpp).
1700
1701@comment 2
1702@item
1703Fast normal font locking: In addition to level 1, fontify keywords,
1704simple types and declarations that are easy to recognize. The variables
1705@code{*-font-lock-extra-types} (where @samp{*} is the name of the
1706language) are used to recognize types (see below). Documentation
1707comments like Javadoc are fontified according to
1708@code{c-doc-comment-style} (@pxref{Documentation Comments}).
1709
1710Use this if you think the font locking is too slow. It's the closest
1711corresponding level to level 3 in the old font lock patterns.
1712
1713@comment 3
1714@item
1715Accurate normal font locking: Like level 2 but uses a different approach
1716that can recognize types and declarations much more accurately. The
1717@code{*-font-lock-extra-types} variables are still used, but user
1718defined types are recognized correctly anyway in most cases. Therefore
1719those variables should be fairly restrictive and not contain patterns
1720that are uncertain.
1721
1722@cindex Lazy Lock mode
1723@cindex Just-in-time Lock mode
1724
1725This level is designed for fairly modern hardware and a font lock
1726support mode like Lazy Lock or Just-in-time Lock mode that only
1727fontifies the parts that are actually shown.
1728@end enumerate
1729
1730@cindex user defined types
1731@cindex types, user defined
1732
1733Since user defined types are hard to recognize you can provide
1734additional regexps to match those you use:
1735
1736@defopt c-font-lock-extra-types
1737@defoptx c++-font-lock-extra-types
1738@defoptx objc-font-lock-extra-types
1739@defoptx java-font-lock-extra-types
1740@defoptx idl-font-lock-extra-types
1741@defoptx pike-font-lock-extra-types
1742For each language there's a variable @code{*-font-lock-extra-types},
1743where @samp{*} stands for the language in question. It contains a list
1744of regexps that matches identifiers that should be recognized as types,
c3a2e2d5 1745e.g., @samp{\\sw+_t} to recognize all identifiers ending with @samp{_t}
3a731e1f
MS
1746as is customary in C code. Each regexp should not match more than a
1747single identifier.
1748
1749The default values contain regexps for many types in standard runtime
1750libraries that are otherwise difficult to recognize, and patterns for
1751standard type naming conventions like the @samp{_t} suffix in C and C++.
1752Java, Objective-C and Pike have as a convention to start class names
1753with capitals, so there are patterns for that in those languages.
1754
1755Despite the names of these variables, they are not only used for
1756fontification but in other places as well where @ccmode{} needs to
1757recognize types.
1758@end defopt
1759
1760
1761@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1762@node Faces, Documentation Comments, Font Locking Preliminaries, Font Locking
1763@comment node-name, next, previous, up
1764@section Faces
1765@cindex faces
1766@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1767
1768@ccmode{} attempts to use the standard faces for programming languages
1769in accordance with their intended purposes as far as possible. No extra
1770faces are currently provided, with the exception of a replacement face
1771@code{c-invalid-face} for emacsen that don't provide
1772@code{font-lock-warning-face}.
1773
1774@itemize @bullet
1775@item
1776@vindex font-lock-comment-face
1777Normal comments are fontified in @code{font-lock-comment-face}.
1778
1779@item
1780@vindex font-lock-doc-face
1781@vindex font-lock-doc-string-face
1782@vindex font-lock-comment-face
1783Comments that are recognized as documentation (@pxref{Documentation
1784Comments}) get @code{font-lock-doc-face} (Emacs) or
1785@code{font-lock-doc-string-face} (XEmacs) if those faces exist. If they
1786don't then @code{font-lock-comment-face} is used.
1787
1788@item
1789@vindex font-lock-string-face
1790String and character literals are fontified in
1791@code{font-lock-string-face}.
1792
1793@item
1794@vindex font-lock-keyword-face
1795Keywords are fontified with @code{font-lock-keyword-face}.
1796
1797@item
1798@vindex font-lock-function-name-face
1799@code{font-lock-function-name-face} is used for function names in
1800declarations and definitions, and classes in those contexts. It's also
1801used for preprocessor defines with arguments.
1802
1803@item
1804@vindex font-lock-variable-name-face
1805Variables in declarations and definitions, and other identifiers in such
1806variable contexts, get @code{font-lock-variable-name-face}. It's also
1807used for preprocessor defines without arguments.
1808
1809@item
1810@vindex font-lock-constant-face
1811@vindex font-lock-reference-face
1812Builtin constants are fontified in @code{font-lock-constant-face} if it
1813exists, @code{font-lock-reference-face} otherwise. As opposed to the
1814preceding two faces, this is used on the names in expressions, and it's
1815not used in declarations, even if there happen to be a @samp{const} in
1816them somewhere.
1817
1818@item
1819@vindex font-lock-type-face
1820@code{font-lock-type-face} is put on types (both predefined and user
1821defined) and classes in type contexts.
1822
1823@item
1824@vindex font-lock-constant-face
1825@vindex font-lock-reference-face
1826Label identifiers get @code{font-lock-constant-face} if it exists,
1827@code{font-lock-reference-face} otherwise.
1828
1829@item
1830Name qualifiers and identifiers for scope constructs are fontified like
1831labels.
1832
1833@item
1834Special markup inside documentation comments are also fontified like
1835labels.
1836
1837@item
1838@vindex font-lock-preprocessor-face
1839@vindex font-lock-builtin-face
1840@vindex font-lock-reference-face
1841Preprocessor directives get @code{font-lock-preprocessor-face} if it
c3a2e2d5 1842exists (i.e., XEmacs). In Emacs they get @code{font-lock-builtin-face}
3a731e1f
MS
1843or @code{font-lock-reference-face}, for lack of a closer equivalent.
1844
1845@item
1846@vindex font-lock-warning-face
1847@vindex c-invalid-face
1848@vindex invalid-face (c-)
1849Some kinds of syntactic errors are fontified with
1850@code{font-lock-warning-face} in Emacs. In older XEmacs versions
1851there's no corresponding standard face, so there a special
1852@code{c-invalid-face} is used, which is defined to stand out sharply by
1853default.
1854
1855Note that it's not used for @samp{#error} or @samp{#warning} directives,
1856since those aren't syntactic errors in themselves.
1857@end itemize
1858
1859
1860@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1861@node Documentation Comments, , Faces, Font Locking
1862@comment node-name, next, previous, up
1863@section Documentation Comments
1864@cindex documentation comments
1865@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1866
1867There are various tools to supply documentation in the source as
c3a2e2d5 1868specially structured comments, e.g., the standard Javadoc tool in Java.
3a731e1f
MS
1869@ccmode{} provides an extensible mechanism to fontify such comments and
1870the special markup inside them.
1871
1872@defopt c-doc-comment-style
1873@vindex doc-comment-style (c-)
1874This is a style variable that specifies which documentation comment
c3a2e2d5 1875style to recognize, e.g., @code{javadoc} for Javadoc comments.
3a731e1f
MS
1876
1877The value may also be a list of styles, in which case all of them are
1878recognized simultaneously (presumably with markup cues that don't
1879conflict).
1880
1881The value may also be an association list to specify different comment
1882styles for different languages. The symbol for the major mode is then
1883looked up in the alist, and the value of that element is interpreted as
1884above if found. If it isn't found then the symbol `other' is looked up
1885and its value is used instead.
1886
1887Note that @ccmode{} uses this variable to set other variables that
1888handle fontification etc. That's done at mode initialization or when
1889you switch to a style which sets this variable. Thus, if you change it
c3a2e2d5 1890in some other way, e.g., interactively in a CC Mode buffer, you will need
3a731e1f
MS
1891to do @kbd{M-x java-mode} (or whatever mode you're currently using) to
1892reinitialize.
1893
1894@findex c-setup-doc-comment-style
1895@findex setup-doc-comment-style (c-)
1896Note also that when @ccmode{} starts up, the other variables are
1897modified before the mode hooks are run. If you change this variable in
1898a mode hook, you have to call @code{c-setup-doc-comment-style}
1899afterwards to redo that work.
1900@end defopt
1901
1902@ccmode{} currently provides handing of the following doc comment
1903styles:
1904
1905@table @code
1906@item javadoc
1907@cindex Javadoc markup
1908Javadoc comments, the standard tool in Java.
1909
1910@item autodoc
1911@cindex Pike autodoc markup
1912For Pike autodoc markup, the standard in Pike.
1913@end table
1914
1915The above is by no means complete. If you'd like to see support for
1916other doc comment styles, please let us know (@pxref{Mailing Lists and
1917Submitting Bug Reports}).
1918
1919You can also write your own doc comment fontification support to use
1920with @code{c-doc-comment-style}: Supply a variable or function
1921@code{*-font-lock-keywords} where @samp{*} is the name you want to use
1922in @code{c-doc-comment-style}. If it's a variable, it's prepended to
1923@code{font-lock-keywords}. If it's a function, it's called at mode
1924initialization and the result is prepended. For an example, see
1925@code{javadoc-font-lock-keywords} in @file{cc-fonts.el}.
1926
1927If you add support for another doc comment style, please consider
1928contributing it --- send a note to @email{bug-cc-mode@@gnu.org}.
1929
1930
1931@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1932@node Commands, Customizing Indentation, Font Locking, Top
1933@comment node-name, next, previous, up
1934@chapter Commands
1935@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1936
1937@menu
1938* Indentation Commands::
1939* Movement Commands::
1940* Other Commands::
1941@end menu
1942
1943See also @ref{Text Filling and Line Breaking} and @ref{Macro Handling},
1944for commands concerning those bits.
1945
1946
1947@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
d7bd46ed
GM
1948@node Indentation Commands, Movement Commands, , Commands
1949@comment node-name, next, previous,up
3a731e1f 1950@section Indentation Commands
d7bd46ed 1951@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
6bf7aab6 1952
3a731e1f 1953The following list of commands reindent C constructs. Note that when
bf247b6e 1954you change your coding style, either interactively or through some other
3a731e1f 1955means, your file does @emph{not} automatically get reindented. You
bf247b6e 1956will need to execute one of the following commands to see the effects of
d7bd46ed
GM
1957your changes.
1958
1959@cindex GNU indent program
1960Also, variables like @code{c-hanging-*} and @code{c-cleanup-list}
1961only affect how on-the-fly code is formatted. Changing the
3a731e1f 1962``hanginess'' of a brace and then reindenting, will not move the brace
d7bd46ed 1963to a different line. For this, you're better off getting an external
3a731e1f 1964program like GNU @code{indent}, which will rearrange brace location,
d7bd46ed
GM
1965among other things.
1966
3a731e1f 1967Reindenting large sections of code can take a long time. When
d7bd46ed 1968@ccmode{} reindents a region of code, it is essentially equivalent to
3a731e1f 1969hitting @kbd{TAB} on every line of the region.
d7bd46ed
GM
1970
1971These commands are useful when indenting code:
6bf7aab6 1972
d7bd46ed 1973@table @asis
3a731e1f 1974@item @kbd{TAB} (@code{c-indent-command})
d7bd46ed 1975@kindex TAB
6bf7aab6
DL
1976@findex c-indent-command
1977@findex indent-command (c-)
d7bd46ed
GM
1978Indents the current line. The actual behavior is controlled by several
1979variables, described below. See @code{c-tab-always-indent},
1980@code{c-insert-tab-function}, and @code{indent-tabs-mode}. With a
1981numeric argument, this command rigidly indents the region, preserving
1982the relative indentation among the lines.
6bf7aab6 1983
3a731e1f 1984@item @kbd{C-M-q} (@code{c-indent-exp})
718fb8a1 1985@kindex C-M-q
6bf7aab6
DL
1986@findex c-indent-exp
1987@findex indent-exp (c-)
d7bd46ed
GM
1988Indent an entire balanced brace or parenthesis expression. Note that
1989point must be on the opening brace or parenthesis of the expression you
1990want to indent.
6bf7aab6 1991
3a731e1f 1992@item @kbd{C-c C-q} (@code{c-indent-defun})
6bf7aab6
DL
1993@kindex C-c C-q
1994@findex c-indent-defun
1995@findex indent-defun (c-)
3a731e1f
MS
1996Indents the entire top-level function, class or macro definition
1997encompassing point. It leaves point unchanged. This function can't be
1998used to reindent a nested brace construct, such as a nested class or
1999function, or a Java method. The top-level construct being reindented
c3a2e2d5 2000must be complete, i.e., it must have both a beginning brace and an ending
3a731e1f 2001brace.
6bf7aab6 2002
3a731e1f 2003@item @kbd{C-M-\} (@code{indent-region})
718fb8a1 2004@kindex C-M-\
6bf7aab6 2005@findex indent-region
d7bd46ed 2006Indents an arbitrary region of code. This is a standard Emacs command,
3a731e1f 2007tailored for C code in a @ccmode{} buffer. Note, of course, that point
d7bd46ed 2008and mark must delineate the region you want to indent.
6bf7aab6 2009
3a731e1f
MS
2010@item @kbd{M-;} (@code{indent-for-comment})
2011@kindex M-;
2012@findex indent-for-comment
2013Insert a comment at the end of the current line, if none is there already.
2014Then reindent the comment according to the variables
2015@code{c-indent-comment-alist}, @code{c-indent-comments-syntactically-p}
2016and @code{comment-column}. Then position the point after the comment
2017starter. This is a standard Emacs command, but @ccmode{} enhances it a
2018bit with two variables:
2019
2020@defopt c-indent-comment-alist
2021@vindex indent-comment-alist (c-)
2022@vindex comment-column
2023This style variable allows you to control which column @kbd{M-;}
2024indents the comment to, depending on the preceding code and the
2025indentation of a similar comment on the preceding line, if there is
2026any. It is an association list that maps different types of lines to
2027actions describing how they should be handled. If a certain line type
2028isn't present on the list then the line is indented to the column
2029specified by @code{comment-column}. See the documentation string for
2030@code{c-indent-comment-alist} for a full description of the available
2031line types and actions (use @kbd{C-h v c-indent-comment-alist}).
2032@end defopt
2033
2034@defopt c-indent-comments-syntactically-p
2035@vindex indent-comments-syntactically-p (c-)
2036Normally, when this variable is @code{nil}, @kbd{M-;} will indent
2037comment-only lines according to @code{c-indent-comment-alist}, just as
2038it does with lines where other code precede the comments. However, if
2039you want it to act just like @kbd{TAB} for comment-only lines you can
2040get that by setting @code{c-indent-comments-syntactically-p} to
2041non-@code{nil}.
2042
2043If @code{c-indent-comments-syntactically-p} is non-@code{nil} then
2044@code{c-indent-comment-alist} won't be consulted at all for comment-only
2045lines.
2046@end defopt
2047
2048@item @kbd{C-M-h} (@code{c-mark-function})
718fb8a1 2049@kindex C-M-h
6bf7aab6
DL
2050@findex c-mark-function
2051@findex mark-function (c-)
d7bd46ed
GM
2052While not strictly an indentation command, this is useful for marking
2053the current top-level function or class definition as the current
2054region. As with @code{c-indent-defun}, this command operates on
2055top-level constructs, and can't be used to mark say, a Java method.
d7bd46ed
GM
2056@end table
2057
2058These variables are also useful when indenting code:
2059
3a731e1f 2060@defopt c-tab-always-indent
d7bd46ed
GM
2061@vindex tab-always-indent (c-)
2062@kindex TAB
2063@cindex literal
2a15eb73
MS
2064This variable controls how @kbd{TAB} (@code{c-indent-command})
2065operates. When it is @code{t}, @kbd{TAB} always indents the current
2066line. When it is @code{nil}, the line is indented only if point is at
2067the left margin, or on or before the first non-whitespace character on
2068the line, otherwise some whitespace is inserted. If this variable is
2069some other value (not @code{nil} or @code{t}), then some whitespace is
2070inserted only within strings and comments (literals), but the line is
3a731e1f
MS
2071always reindented.
2072@end defopt
2073
2074@defopt c-insert-tab-function
d7bd46ed
GM
2075@vindex insert-tab-function (c-)
2076@findex tab-to-tab-stop
d7bd46ed
GM
2077When ``some whitespace'' is inserted as described above, what actually
2078happens is that the function stored in @code{c-insert-tab-function} is
2079called. Normally, this just inserts a real tab character, or the
2080equivalent number of spaces, depending on @code{indent-tabs-mode}.
2081Some people, however, set @code{c-insert-tab-function} to
2082@code{tab-to-tab-stop} so as to get hard tab stops when indenting.
3a731e1f 2083@end defopt
d7bd46ed 2084
3a731e1f
MS
2085@defopt indent-tabs-mode
2086This is a standard Emacs variable that controls how line indentation
2087is composed. When it's non-@code{nil}, tabs can be used in a line's
2088indentation, otherwise only spaces can be used.
2089@end defopt
d7bd46ed 2090
3a731e1f 2091@defopt c-progress-interval
d7bd46ed 2092@vindex progress-interval (c-)
177c0ea7 2093When indenting large regions of code, this variable controls how often a
d7bd46ed 2094progress message is displayed. Set this variable to @code{nil} to
3a731e1f
MS
2095inhibit the progress messages, or set it to an integer which is how
2096often (in seconds) progress messages are to be displayed.
2097@end defopt
d7bd46ed
GM
2098
2099
2100@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2101@node Movement Commands, Other Commands, Indentation Commands, Commands
2102@comment node-name, next, previous, up
3a731e1f
MS
2103@section Movement Commands
2104@cindex movement
6bf7aab6
DL
2105@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2106
3a731e1f 2107@ccmode{} contains some useful commands for moving around in C
6bf7aab6
DL
2108code.
2109
d7bd46ed 2110@table @asis
3a731e1f 2111@item @kbd{M-x c-beginning-of-defun}
6bf7aab6
DL
2112@findex c-beginning-of-defun
2113@findex beginning-of-defun (c-)
2114@findex beginning-of-defun
3a731e1f 2115Move point back to the least-enclosing brace. This function is
6bf7aab6
DL
2116analogous to the Emacs built-in command @code{beginning-of-defun},
2117except it eliminates the constraint that the top-level opening brace
2118must be in column zero. See @code{beginning-of-defun} for more
2119information.
2120
2121Depending on the coding style being used, you might prefer
2122@code{c-beginning-of-defun} to @code{beginning-of-defun}. If so,
2123consider binding @kbd{C-M-a} to the former instead. For backwards
2124compatibility reasons, the default binding remains in effect.
2125
3a731e1f
MS
2126In AWK mode, a defun doesn't necessarily have braces at all. AWK Mode
2127therefore has its own version of this function which is bound by
2128default to @kbd{C-M-a}. You can thus chose freely which function to
2129bind to @kbd{C-M-a} for the other modes without worrying about AWK
2130buffers. @xref{AWK Mode Defuns}.
2131
2132@item @kbd{M-x c-end-of-defun}
6bf7aab6
DL
2133@findex c-end-of-defun
2134@findex end-of-defun (c-)
2135@findex end-of-defun
6bf7aab6
DL
2136Moves point to the end of the current top-level definition. This
2137function is analogous to the Emacs built-in command @code{end-of-defun},
2138except it eliminates the constraint that the top-level opening brace of
3a731e1f 2139the defun must be in column zero. See @code{end-of-defun} for more
6bf7aab6
DL
2140information.
2141
2142Depending on the coding style being used, you might prefer
2143@code{c-end-of-defun} to @code{end-of-defun}. If so,
2144consider binding @kbd{C-M-e} to the former instead. For backwards
2145compatibility reasons, the default binding remains in effect.
2146
3a731e1f
MS
2147In AWK Mode, a defun doesn't necessarily have braces at all. AWK Mode
2148therefore has its own version of this function which is bound by
2149default to @kbd{C-M-e}. You can thus chose freely which function to
2150bind to @kbd{C-M-e} for the other modes without worrying about AWK
2151buffers. @ref{AWK Mode Defuns}.
2152
2153@item @kbd{C-c C-u} (@code{c-up-conditional})
6bf7aab6
DL
2154@kindex C-c C-u
2155@findex c-up-conditional
2156@findex up-conditional (c-)
6bf7aab6
DL
2157Move point back to the containing preprocessor conditional, leaving the
2158mark behind. A prefix argument acts as a repeat count. With a negative
2159argument, move point forward to the end of the containing
d7bd46ed
GM
2160preprocessor conditional.
2161
2162@samp{#elif} is treated like @samp{#else} followed by @samp{#if}, so the
2163function stops at them when going backward, but not when going forward.
2164
3a731e1f 2165@item @kbd{M-x c-up-conditional-with-else}
d7bd46ed
GM
2166@findex c-up-conditional-with-else
2167@findex up-conditional-with-else (c-)
d7bd46ed
GM
2168A variety of @code{c-up-conditional} that also stops at @samp{#else}
2169lines. Normally those lines are ignored.
2170
3a731e1f 2171@item @kbd{M-x c-down-conditional}
d7bd46ed
GM
2172@findex c-down-conditional
2173@findex down-conditional (c-)
d7bd46ed
GM
2174Move point forward into the next nested preprocessor conditional,
2175leaving the mark behind. A prefix argument acts as a repeat count.
2176With a negative argument, move point backward into the previous
2177nested preprocessor conditional.
2178
2179@samp{#elif} is treated like @samp{#else} followed by @samp{#if}, so the
2180function stops at them when going forward, but not when going backward.
2181
3a731e1f 2182@item @kbd{M-x c-down-conditional-with-else}
d7bd46ed
GM
2183@findex c-down-conditional-with-else
2184@findex down-conditional-with-else (c-)
d7bd46ed
GM
2185A variety of @code{c-down-conditional} that also stops at @samp{#else}
2186lines. Normally those lines are ignored.
6bf7aab6 2187
3a731e1f 2188@item @kbd{C-c C-p} (@code{c-backward-conditional})
6bf7aab6
DL
2189@kindex C-c C-p
2190@findex c-backward-conditional
2191@findex backward-conditional (c-)
6bf7aab6
DL
2192Move point back over a preprocessor conditional, leaving the mark
2193behind. A prefix argument acts as a repeat count. With a negative
2194argument, move forward.
2195
3a731e1f 2196@item @kbd{C-c C-n} (@code{c-forward-conditional})
6bf7aab6
DL
2197@kindex C-c C-n
2198@findex c-forward-conditional
2199@findex forward-conditional (c-)
6bf7aab6
DL
2200Move point forward across a preprocessor conditional, leaving the mark
2201behind. A prefix argument acts as a repeat count. With a negative
2202argument, move backward.
2203
3a731e1f 2204@item @kbd{M-a} (@code{c-beginning-of-statement})
d7bd46ed 2205@kindex M-a
6bf7aab6
DL
2206@findex c-beginning-of-statement
2207@findex beginning-of-statement (c-)
6bf7aab6 2208Move point to the beginning of the innermost C statement. If point is
cb7f2e96
GM
2209already at the beginning of a statement, move to the beginning of the
2210closest preceding statement, even if that means moving into a block (you
718fb8a1 2211can use @kbd{C-M-b} to move over a balanced block). With prefix
6bf7aab6
DL
2212argument @var{n}, move back @var{n} @minus{} 1 statements.
2213
cb7f2e96
GM
2214If point is within or next to a comment or a string which spans more
2215than one line, this command moves by sentences instead of statements.
6bf7aab6
DL
2216
2217When called from a program, this function takes three optional
cb7f2e96
GM
2218arguments: the repetition count, a buffer position limit which is the
2219farthest back to search for the syntactic context, and a flag saying
2220whether to do sentence motion in or near comments and multiline strings.
6bf7aab6 2221
3a731e1f 2222@item @kbd{M-e} (@code{c-end-of-statement})
d7bd46ed 2223@kindex M-e
6bf7aab6
DL
2224@findex c-end-of-statement
2225@findex end-of-statement (c-)
6bf7aab6
DL
2226Move point to the end of the innermost C statement. If point is at the
2227end of a statement, move to the end of the next statement, even if it's
718fb8a1 2228inside a nested block (use @kbd{C-M-f} to move to the other side of the
6bf7aab6
DL
2229block). With prefix argument @var{n}, move forward @var{n} @minus{} 1
2230statements.
2231
cb7f2e96
GM
2232If point is within or next to a comment or a string which spans more
2233than one line, this command moves by sentences instead of statements.
6bf7aab6
DL
2234
2235When called from a program, this function takes three optional
cb7f2e96
GM
2236arguments: the repetition count, a buffer position limit which is the
2237farthest back to search for the syntactic context, and a flag saying
2238whether to do sentence motion in or near comments and multiline strings.
6bf7aab6 2239
3a731e1f 2240@item @kbd{M-x c-forward-into-nomenclature}
6bf7aab6
DL
2241@findex c-forward-into-nomenclature
2242@findex forward-into-nomenclature (c-)
6bf7aab6
DL
2243A popular programming style, especially for object-oriented languages
2244such as C++ is to write symbols in a mixed case format, where the first
2245letter of each word is capitalized, and not separated by underscores.
c3a2e2d5 2246e.g., @samp{SymbolsWithMixedCaseAndNoUnderlines}.
6bf7aab6
DL
2247
2248This command moves point forward to next capitalized word. With prefix
2249argument @var{n}, move @var{n} times.
2250
3a731e1f 2251@item @kbd{M-x c-backward-into-nomenclature}
6bf7aab6
DL
2252@findex c-backward-into-nomenclature
2253@findex backward-into-nomenclature (c-)
6bf7aab6
DL
2254Move point backward to beginning of the next capitalized
2255word. With prefix argument @var{n}, move @var{n} times. If
2256@var{n} is negative, move forward.
d7bd46ed
GM
2257@end table
2258
2259
2260@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2261@node Other Commands, , Movement Commands, Commands
2262@comment node-name, next, previous, up
3a731e1f 2263@section Other Commands
d7bd46ed
GM
2264@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2265
3a731e1f 2266Here are the various other commands that didn't fit anywhere else:
d7bd46ed
GM
2267
2268@table @asis
3a731e1f 2269@item @kbd{C-c :} (@code{c-scope-operator})
6bf7aab6
DL
2270@kindex C-c :
2271@findex c-scope-operator
2272@findex scope-operator (c-)
6bf7aab6
DL
2273In C++, it is also sometimes desirable to insert the double-colon scope
2274operator without performing the electric behavior of colon insertion.
2275@kbd{C-c :} does just this.
6bf7aab6
DL
2276@end table
2277
d7bd46ed
GM
2278@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2279@node Customizing Indentation, Syntactic Symbols, Commands, Top
2280@comment node-name, next, previous, up
3a731e1f
MS
2281@chapter Customizing Indentation
2282@cindex customization, indentation
2283@cindex indentation
6bf7aab6
DL
2284@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2285
3a731e1f
MS
2286The context sensitive indentation is mainly controlled by the variable
2287@code{c-offsets-alist}:
2288
2289@defopt c-offsets-alist
6bf7aab6 2290@vindex offsets-alist (c-)
3a731e1f
MS
2291This special style variable contains the mappings between syntactic
2292symbols and the offsets to apply for those symbols. It's set at mode
2293initialization from a @emph{style} you may specify. Styles are
d7bd46ed 2294groupings of syntactic symbol offsets and other style variable values.
3a731e1f 2295Most likely, you'll find that one of the predefined styles will suit
d7bd46ed
GM
2296your needs. @xref{Styles}, for an explanation of how to set up named
2297styles.
2298
2299Only syntactic symbols not already bound on @code{c-offsets-alist} will
2300be set from styles. This means that any association you set on it, be
2301it before or after mode initialization, will not be changed. The
c3a2e2d5 2302@code{c-offsets-alist} variable may therefore be used from e.g., the
d7bd46ed
GM
2303Customization interface@footnote{Available in Emacs 20 and later, and
2304XEmacs 19.15 and later.} to easily change indentation offsets without
2305having to bother about styles. Initially @code{c-offsets-alist} is
2306empty, so that all syntactic symbols are set by the style system.
2307
3a731e1f
MS
2308The offset associated with any particular syntactic symbol can be an
2309integer, a function or lambda expression, a variable name, a vector, a
2310list, or one of the following special symbols: @code{+}, @code{-},
2311@code{++}, @code{--}, @code{*}, or @code{/}. The meaning of these
2312values are described in detail below.
2313@end defopt
d7bd46ed 2314
3a731e1f
MS
2315The special symbols describe an offset in multiples of the value of
2316@code{c-basic-offset}:
2317
2318@defopt c-basic-offset
d7bd46ed 2319@vindex basic-offset (c-)
3a731e1f
MS
2320Style variable that holds the basic offset between indentation levels.
2321@end defopt
6bf7aab6 2322
3a731e1f
MS
2323By defining a style's indentation in terms of @code{c-basic-offset},
2324you can change the amount of whitespace given to an indentation level
2325while maintaining the same basic shape of your code. Here are the
2326values that the special symbols correspond to:
6bf7aab6 2327
3a731e1f 2328@table @code
6bf7aab6
DL
2329@item +
2330@code{c-basic-offset} times 1
2331@item -
2332@code{c-basic-offset} times -1
2333@item ++
2334@code{c-basic-offset} times 2
2335@item --
2336@code{c-basic-offset} times -2
2337@item *
2338@code{c-basic-offset} times 0.5
2339@item /
2340@code{c-basic-offset} times -0.5
6bf7aab6
DL
2341@end table
2342
d7bd46ed
GM
2343@cindex indentation functions
2344
2345When a function is used as offset, it's called an @dfn{indentation
2346function}. Such functions are useful when more context than just the
2347syntactic symbol is needed to get the desired indentation.
2348@xref{Indentation Functions}, and @ref{Custom Indentation Functions},
2349for details about them.
2350
cb7f2e96 2351If the offset is a vector, its first element sets the absolute
3a731e1f
MS
2352indentation column, which will override any previous relative
2353indentation. It won't override additional relative indentation for
2354nested constructs, though.
cb7f2e96 2355
d7bd46ed
GM
2356@vindex c-strict-syntax-p
2357@vindex strict-syntax-p (c-)
2358The offset can also be a list, in which case it is evaluated recursively
2359using the semantics described above. The first element of the list that
2360returns a non-@code{nil} value succeeds and the evaluation stops. If
2361none of the list elements return a non-@code{nil} value, then an offset
2362of 0 (zero) is used@footnote{There is however a variable
2363@code{c-strict-syntax-p} that, when set to non-@code{nil}, will cause an
3a731e1f 2364error to be signalled in that case. It's now considered obsolete since
d7bd46ed
GM
2365it doesn't work well with some of the alignment functions that now
2366returns @code{nil} instead of zero to be more usable in lists. You
2367should therefore leave @code{c-strict-syntax-p} set to @code{nil}.}.
2368
6bf7aab6
DL
2369So, for example, because most of the default offsets are defined in
2370terms of @code{+}, @code{-}, and @code{0}, if you like the general
2371indentation style, but you use 4 spaces instead of 2 spaces per level,
2372you can probably achieve your style just by changing
d7bd46ed
GM
2373@code{c-basic-offset} like so@footnote{You can try this interactively in
2374a C buffer by typing the text that appears in italics.}:
6bf7aab6 2375
3a731e1f 2376@example
d7bd46ed
GM
2377@emph{M-x set-variable RET}
2378Set variable: @emph{c-basic-offset RET}
2379Set c-basic-offset to value: @emph{4 RET}
6bf7aab6
DL
2380@end example
2381
2382@noindent
2383This would change
3a731e1f 2384
6bf7aab6
DL
2385@example
2386@group
6bf7aab6
DL
2387int add( int val, int incr, int doit )
2388@{
2389 if( doit )
2390 @{
2391 return( val + incr );
2392 @}
2393 return( val );
2394@}
6bf7aab6
DL
2395@end group
2396@end example
3a731e1f 2397
6bf7aab6
DL
2398@noindent
2399to
3a731e1f 2400
6bf7aab6
DL
2401@example
2402@group
6bf7aab6
DL
2403int add( int val, int incr, int doit )
2404@{
2405 if( doit )
2406 @{
2407 return( val + incr );
2408 @}
2409 return( val );
2410@}
6bf7aab6
DL
2411@end group
2412@end example
2413
6bf7aab6 2414To change indentation styles more radically, you will want to change the
d7bd46ed
GM
2415offsets associated with other syntactic symbols. First, I'll show you
2416how to do that interactively, then I'll describe how to make changes to
2417your @file{.emacs} file so that your changes are more permanent.
6bf7aab6
DL
2418
2419@menu
2420* Interactive Customization::
2421* Permanent Customization::
d7bd46ed 2422* Hooks::
6bf7aab6
DL
2423* Styles::
2424* Advanced Customizations::
2425@end menu
2426
6bf7aab6 2427
d7bd46ed
GM
2428@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2429@node Interactive Customization, Permanent Customization, , Customizing Indentation
2430@comment node-name, next, previous, up
3a731e1f
MS
2431@section Interactive Customization
2432@cindex customization, interactive
d7bd46ed 2433@cindex interactive customization
6bf7aab6
DL
2434@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2435
2436As an example of how to customize indentation, let's change the
3a731e1f 2437style of this example@footnote{In this and subsequent examples, the
6bf7aab6 2438original code is formatted using the @samp{gnu} style unless otherwise
d7bd46ed 2439indicated. @xref{Styles}.}:
3a731e1f 2440
6bf7aab6
DL
2441@example
2442@group
3a731e1f
MS
2443 1: int add( int val, int incr, int doit )
2444 2: @{
2445 3: if( doit )
2446 4: @{
2447 5: return( val + incr );
2448 6: @}
2449 7: return( val );
2450 8: @}
6bf7aab6
DL
2451@end group
2452@end example
3a731e1f 2453
6bf7aab6
DL
2454@noindent
2455to:
3a731e1f 2456
6bf7aab6
DL
2457@example
2458@group
3a731e1f
MS
2459 1: int add( int val, int incr, int doit )
2460 2: @{
2461 3: if( doit )
2462 4: @{
2463 5: return( val + incr );
2464 6: @}
2465 7: return( val );
2466 8: @}
6bf7aab6
DL
2467@end group
2468@end example
2469
2470In other words, we want to change the indentation of braces that open a
2471block following a condition so that the braces line up under the
2472conditional, instead of being indented. Notice that the construct we
2473want to change starts on line 4. To change the indentation of a line,
2474we need to see which syntactic components affect the offset calculations
2475for that line. Hitting @kbd{C-c C-s} on line 4 yields:
6bf7aab6 2476
3a731e1f
MS
2477@example
2478((substatement-open 44))
6bf7aab6
DL
2479@end example
2480
6bf7aab6
DL
2481@noindent
2482so we know that to change the offset of the open brace, we need to
2483change the indentation for the @code{substatement-open} syntactic
3a731e1f
MS
2484symbol.
2485
2486To do this interactively, just hit @kbd{C-c C-o}. This prompts
d7bd46ed
GM
2487you for the syntactic symbol to change, providing a reasonable default.
2488In this case, the default is @code{substatement-open}, which is just the
2489syntactic symbol we want to change!
6bf7aab6
DL
2490
2491After you hit return, @ccmode{} will then prompt you for the new
2492offset value, with the old value as the default. The default in this
2493case is @samp{+}, but we want no extra indentation so enter
2494@samp{0} and @kbd{RET}. This will associate the offset 0 with the
d7bd46ed 2495syntactic symbol @code{substatement-open}.
6bf7aab6 2496
6bf7aab6
DL
2497To check your changes quickly, just hit @kbd{C-c C-q}
2498(@code{c-indent-defun}) to reindent the entire function. The example
2499should now look like:
3a731e1f 2500
6bf7aab6
DL
2501@example
2502@group
3a731e1f
MS
2503 1: int add( int val, int incr, int doit )
2504 2: @{
2505 3: if( doit )
2506 4: @{
2507 5: return( val + incr );
2508 6: @}
2509 7: return( val );
2510 8: @}
6bf7aab6
DL
2511@end group
2512@end example
2513
2514Notice how just changing the open brace offset on line 4 is all we
2515needed to do. Since the other affected lines are indented relative to
2516line 4, they are automatically indented the way you'd expect. For more
2517complicated examples, this may not always work. The general approach to
2518take is to always start adjusting offsets for lines higher up in the
3a731e1f 2519file, then reindent and see if any following lines need further
6bf7aab6
DL
2520adjustments.
2521
3a731e1f
MS
2522@deffn Command c-set-offset symbol offset
2523@findex set-offset (c-)
2524@kindex C-c C-o
2525This is the command bound to @kbd{C-c C-o}. It provides a convenient
2526way to set offsets on @code{c-offsets-alist} both interactively (see
2527the example above) and from your mode hook.
2528
2529It takes two arguments when used programmatically: @var{symbol} is the
2530syntactic element symbol to change and @var{offset} is the new offset
2531for that syntactic element.
2532@end deffn
2533
d7bd46ed
GM
2534
2535@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2536@node Permanent Customization, Hooks, Interactive Customization, Customizing Indentation
2537@comment node-name, next, previous, up
3a731e1f
MS
2538@section Permanent Customization
2539@cindex customization, permanent
d7bd46ed 2540@cindex permanent customization
6bf7aab6 2541@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
6bf7aab6 2542
d7bd46ed
GM
2543To make your changes permanent, you need to add some lisp code to your
2544@file{.emacs} file. @ccmode{} supports many different ways to be
2545configured, from the straightforward way by setting variables globally
2546in @file{.emacs} or in the Customization interface, to the complex and
2547precisely controlled way by using styles and hook functions.
2548
2549The simplest way of customizing @ccmode{} permanently is to set the
2550variables in your @file{.emacs} with @code{setq} and similar commands.
3a731e1f
MS
2551So to make a permanent setting of @code{substatement-open} to 0, add
2552this to the @file{.emacs} file:
2553
d7bd46ed
GM
2554@example
2555@group
3a731e1f
MS
2556(setq c-offsets-alist
2557 '((substatement-open . 0)))
d7bd46ed
GM
2558@end group
2559@end example
2560
3a731e1f
MS
2561When @ccmode{} initializes a buffer, it will fill out
2562@code{c-offsets-alist} with the remaining syntactic symbols according to
2563the style system.
d7bd46ed
GM
2564
2565You can also use the more user friendly Customization interface, but
2566this manual does not cover how that works.
2567
2568Variables set like this at the top level in @file{.emacs} take effect in
2569all @ccmode{} buffers, regardless of language. The indentation style
c3a2e2d5 2570related variables, e.g., @code{c-offsets-alist}, that you don't set this
f214c025
GM
2571way get their value from the style system (@pxref{Styles}), and they
2572therefore depend on the setting of @code{c-default-style}. Note that if
2573you use Customize, this means that the greyed-out default values
2574presented there might not be the ones you actually get, since the actual
2575values depend on the style, which may very well be different for
2576different languages.
d7bd46ed 2577
c3a2e2d5 2578If you want to make more advanced configurations, e.g., language-specific
3a731e1f 2579customization, setting global variables isn't enough. For that you can
d7bd46ed
GM
2580use the language hooks, see @ref{Hooks}, and/or the style system, see
2581@ref{Styles}.
2582
3a731e1f 2583@defopt c-style-variables-are-local-p
d7bd46ed 2584@vindex style-variables-are-local-p (c-)
3a731e1f
MS
2585By default, all style variables are buffer local, so that different
2586buffers can have different style settings. If you only use one style
2587in all the files you edit you might want to share them between buffers
2588so that a change take effect in all buffers. That's done by setting
2589this variable to @code{nil}. The value takes effect when @ccmode{} is
2590activated in a buffer for the first time in the Emacs session, so you
2591typically set it in your @file{.emacs} file and then restart Emacs.
2592@end defopt
d7bd46ed
GM
2593
2594
2595@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2596@node Hooks, Styles, Permanent Customization, Customizing Indentation
2597@comment node-name, next, previous, up
3a731e1f
MS
2598@section Hooks
2599@cindex mode hooks
6bf7aab6
DL
2600@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2601
d7bd46ed
GM
2602@ccmode{} provides several hooks that you can use to customize the mode
2603according to your coding style. Each language mode has its own hook,
2604adhering to standard Emacs major mode conventions. There is also one
2605general hook and one package initialization hook:
6bf7aab6 2606
3a731e1f
MS
2607@defvar c-initialization-hook
2608@vindex initialization-hook (c-)
2609Hook run only once per Emacs session, when @ccmode{} is initialized.
2610@end defvar
6bf7aab6 2611
3a731e1f
MS
2612@defvar c-mode-common-hook
2613@vindex mode-common-hook (c-)
2614Common hook across all languages. It's run immediately before the
2615language specific hook.
2616@end defvar
2617
2618@defvar c-mode-hook
2619@defvarx c++-mode-hook
2620@defvarx objc-mode-hook
2621@defvarx java-mode-hook
2622@defvarx idl-mode-hook
2623@defvarx pike-mode-hook
2624@defvarx awk-mode-hook
2625The language specific mode hooks. The appropriate one is run as the
2626last thing when you enter that language mode.
2627@end defvar
cb7f2e96
GM
2628
2629Note that all the language-specific mode setup that CC Mode does is done
2630prior to both @code{c-mode-common-hook} and the language specific hook.
2631That includes installing the indentation style, which can be mode
2632specific (and also is by default for Java mode). Thus, any style
2633settings done in @code{c-mode-common-hook} will override whatever
2634language-specific style is chosen by @code{c-default-style}.
6bf7aab6
DL
2635
2636Here's a simplified example of what you can add to your @file{.emacs}
d7bd46ed
GM
2637file to do things whenever any @ccmode{} language is edited. See the
2638Emacs manuals for more information on customizing Emacs via hooks.
2639@xref{Sample .emacs File}, for a more complete sample @file{.emacs}
2640file.
6bf7aab6 2641
3a731e1f 2642@example
6bf7aab6
DL
2643(defun my-c-mode-common-hook ()
2644 ;; my customizations for all of c-mode and related modes
d7bd46ed 2645 (no-case-fold-search)
6bf7aab6
DL
2646 )
2647(add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
6bf7aab6
DL
2648@end example
2649
6bf7aab6
DL
2650
2651@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
d7bd46ed
GM
2652@node Styles, Advanced Customizations, Hooks, Customizing Indentation
2653@comment node-name, next, previous, up
3a731e1f 2654@section Styles
d7bd46ed 2655@cindex styles
6bf7aab6
DL
2656@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2657
2658Most people only need to edit code formatted in just a few well-defined
2659and consistent styles. For example, their organization might impose a
2660``blessed'' style that all its programmers must conform to. Similarly,
d7bd46ed
GM
2661people who work on GNU software will have to use the GNU coding style.
2662Some shops are more lenient, allowing a variety of coding styles, and as
2663programmers come and go, there could be a number of styles in use. For
2664this reason, @ccmode{} makes it convenient for you to set up logical
2665groupings of customizations called @dfn{styles}, associate a single name
2666for any particular style, and pretty easily start editing new or
2667existing code using these styles.
2668
2669@cindex style variables
2670The variables that the style system affect are called @dfn{style
2671variables}. They are handled specially in several ways:
2672
2673@itemize @bullet
2674@item
3a731e1f
MS
2675Style variables are by default buffer local variables. However, they
2676can instead be made global by setting
2677@code{c-style-variables-are-local-p} to @code{nil} before @ccmode{} is
2678initialized.
d7bd46ed 2679
3a731e1f 2680@item
d7bd46ed
GM
2681@vindex c-old-style-variable-behavior
2682@vindex old-style-variable-behavior (c-)
d7bd46ed
GM
2683The default value of any style variable (with two exceptions --- see
2684below) is the special symbol @code{set-from-style}. Variables that are
2685still set to that symbol when a @ccmode{} buffer is initialized will be
2686set according to the current style, otherwise they will keep their
2687current value@footnote{This is a big change from versions of @ccmode{}
2688earlier than 5.26, where such settings would get overridden by the style
2689system unless special precautions were taken. That was changed since it
2690was counterintuitive and confusing, especially to novice users. If your
2691configuration depends on the old overriding behavior, you can set the
2692variable @code{c-old-style-variable-behavior} to non-@code{nil}.}.
2693
2694Note that when we talk about the ``default value'' for a style variable,
2695we don't mean the @code{set-from-style} symbol that all style variables
2696are set to initially, but instead the value it will get at mode
2697initialization when neither a style nor a global setting has set its
2698value.
2699
2700The style variable @code{c-offsets-alist} is handled a little
2701differently from the other style variables. It's an association list,
2702and is thus by default set to the empty list, @code{nil}. When the
2703style system is initialized, any syntactic symbols already on it are
2704kept --- only the missing ones are filled in from the chosen style.
2705
2706The style variable @code{c-special-indent-hook} is also handled in a
2707special way. Styles may only add more functions on this hook, so the
2708global settings on it are always preserved@footnote{This did not change
2709in version 5.26.}.
2710
2711@item
2712The global settings of style variables get captured in the special
2713@code{user} style, which is used as the base for all the other styles.
2714@xref{Built-in Styles}, for details.
d7bd46ed
GM
2715@end itemize
2716
2717The style variables are:
2718@code{c-basic-offset},
2719@code{c-comment-only-line-offset},
2720@code{c-block-comment-prefix},
2721@code{c-comment-prefix-regexp},
2722@code{c-cleanup-list},
2723@code{c-hanging-braces-alist},
2724@code{c-hanging-colons-alist},
2725@code{c-hanging-semi&comma-criteria},
2726@code{c-backslash-column},
3a731e1f 2727@code{c-backslash-max-column},
d7bd46ed
GM
2728@code{c-special-indent-hook},
2729@code{c-label-minimum-indentation}, and
2730@code{c-offsets-alist}.
6bf7aab6
DL
2731
2732@menu
2733* Built-in Styles::
3a731e1f 2734* Choosing a Style::
6bf7aab6
DL
2735* Adding Styles::
2736* File Styles::
2737@end menu
2738
2739
2740@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 2741@node Built-in Styles, Choosing a Style, , Styles
d7bd46ed
GM
2742@comment node-name, next, previous, up
2743@subsection Built-in Styles
3a731e1f 2744@cindex styles, built-in
6bf7aab6
DL
2745@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2746
2747If you're lucky, one of @ccmode{}'s built-in styles might be just
2748what you're looking for. These include:
2749
3a731e1f
MS
2750@table @code
2751@item gnu
6bf7aab6 2752@cindex GNU style
3a731e1f 2753Coding style blessed by the Free Software Foundation
d7bd46ed 2754for C code in GNU programs.
6bf7aab6 2755
3a731e1f 2756@item k&r
6bf7aab6 2757@cindex K&R style
3a731e1f 2758The classic Kernighan and Ritchie style for C code.
6bf7aab6 2759
3a731e1f 2760@item bsd
6bf7aab6 2761@cindex BSD style
3a731e1f 2762Also known as ``Allman style'' after Eric Allman.
6bf7aab6 2763
3a731e1f
MS
2764@item whitesmith
2765@cindex Whitesmith style
2766Popularized by the examples that came with Whitesmiths C, an early
2767commercial C compiler.
6bf7aab6 2768
3a731e1f 2769@item stroustrup
6bf7aab6 2770@cindex Stroustrup style
3a731e1f 2771The classic Stroustrup style for C++ code.
6bf7aab6 2772
3a731e1f 2773@item ellemtel
6bf7aab6 2774@cindex Ellemtel style
3a731e1f
MS
2775Popular C++ coding standards as defined by ``Programming in C++, Rules
2776and Recommendations,'' Erik Nyquist and Mats Henricson,
2777Ellemtel@footnote{This document is available at
d7bd46ed
GM
2778@uref{http://www.doc.ic.ac.uk/lab/cplus/c++.rules/} among other
2779places.}.
6bf7aab6 2780
3a731e1f 2781@item linux
6bf7aab6 2782@cindex Linux style
3a731e1f 2783C coding standard for Linux (the kernel).
6bf7aab6 2784
3a731e1f 2785@item python
6bf7aab6 2786@cindex Python style
3a731e1f
MS
2787C coding standard for Python extension modules@footnote{Python is a
2788high level scripting language with a C/C++ foreign function interface.
2789For more information, see @uref{http://www.python.org/}.}.
6bf7aab6 2790
3a731e1f 2791@item java
6bf7aab6 2792@cindex Java style
3a731e1f 2793The style for editing Java code. Note that the default
cb7f2e96
GM
2794value for @code{c-default-style} installs this style when you enter
2795@code{java-mode}.
6bf7aab6 2796
3a731e1f 2797@item user
6bf7aab6 2798@cindex User style
3a731e1f 2799This is a special style for several reasons. First, the
d7bd46ed
GM
2800@ccmode{} customizations you do by using either the Customization
2801interface, or by writing @code{setq}'s at the top level of your
2802@file{.emacs} file, will be captured in the @code{user} style. Also,
2803all other styles implicitly inherit their settings from @code{user}
2804style. This means that for any styles you add via @code{c-add-style}
2805(@pxref{Adding Styles}) you need only define the differences between
2806your new style and @code{user} style.
3a731e1f 2807@end table
d7bd46ed 2808
d7bd46ed 2809
3a731e1f
MS
2810@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2811@node Choosing a Style, Adding Styles, Built-in Styles, Styles
2812@comment node-name, next, previous, up
2813@subsection Choosing a Style
2814@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2815
2816Use @kbd{C-c .} to choose a style interactively:
2817
2818@deffn Command c-set-style style-name
2819@findex set-style (c-)
2820@kindex C-c .
2821Switch to the specified style in the current buffer. Use
2822interactively like this:
2823
2824@example
2825@kbd{C-c . @var{style-name} RET}
2826@end example
2827
2828Note that all style names are case insensitive, even the ones you
2829define.
2830
2831Setting a style in this way does @emph{not} automatically reindent your
2832file. For commands that you can use to view the effect of your changes,
2833see @ref{Commands}.
2834@end deffn
2835
2836The default style in all newly created buffers is @code{gnu}, except
2837in Java mode where it's @code{java}. Although the @code{user} style
2838is not the default style, any style variable settings you do with the
2839Customization interface or on the top level in your @file{.emacs} file
2840will by default override the style system, so you don't need to set
2841@code{c-default-style} to @code{user} to see the effect of such
2842settings.
2843
2844@defopt c-default-style
2845@vindex default-style (c-)
2846This variable specifies which style to install by default in new
2847buffers. It takes either a style name string, or an association list
2848of major mode symbols to style names:
2849
2850@enumerate
2851@item
2852When @code{c-default-style} is a string, it must be an existing style
2853name. This style is then used for all modes.
6bf7aab6 2854
d7bd46ed 2855@item
3a731e1f
MS
2856When @code{c-default-style} is an association list, the mode language
2857is looked up to find a style name string.
d7bd46ed
GM
2858
2859@item
3a731e1f
MS
2860If @code{c-default-style} is an association list where the mode
2861language mode isn't found then the special symbol @samp{other} is
2862looked up. If it's found then the associated style is used.
d7bd46ed
GM
2863
2864@item
3a731e1f 2865If @samp{other} is not found then the @samp{gnu} style is used.
d7bd46ed
GM
2866
2867@item
bf247b6e 2868In all cases, the style described in @code{c-default-style} is installed
d7bd46ed 2869@emph{before} the language hooks are run, so you can always override
bf247b6e 2870this setting by including an explicit call to @code{c-set-style} in your
d7bd46ed 2871language mode hook, or in @code{c-mode-common-hook}.
d7bd46ed 2872@end enumerate
3a731e1f 2873@end defopt
6bf7aab6 2874
3a731e1f 2875@defvar c-indentation-style
6bf7aab6 2876@vindex indentation-style (c-)
3a731e1f
MS
2877This variable always contains the buffer's current style name, as a
2878string.
2879@end defvar
6bf7aab6
DL
2880
2881
2882@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 2883@node Adding Styles, File Styles, Choosing a Style, Styles
d7bd46ed 2884@comment node-name, next, previous, up
2a15eb73 2885@subsection Adding and Amending Styles
6bf7aab6
DL
2886@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2887
6bf7aab6 2888If none of the built-in styles is appropriate, you'll probably want to
2a15eb73
MS
2889create a new @dfn{style definition}, possibly based on an existing
2890style. To do this, put the new style's settings into a list with the
2891following format - the list can then be passed as an argument to the
2892function @code{c-add-style}:
2893
2894@cindex style definition
2895@defvr {List} style definition
2896([@var{base-style}] [(@var{variable} . @var{value}) @dots{}])
2897
2898Optional @var{base-style}, if present, must be a string which is the
2899name of the @dfn{base style} from which this style inherits. At most
2900one @var{base-style} is allowed in a style definition. If
2901@var{base-style} is not specified, the style inherits from a table of
2902default values@footnote{This table is stored internally in the
2903variable c-fallback-style. It is computed during the initialisation
2904of @ccmode{} from the factory defaults of the style variables and any
2905global values they may have been given since starting Emacs.} instead.
2906All styles eventually inherit from this internal table. Style loops
2907generate errors. The list of pre-existing styles can be seen in
2908@ref{Built-in Styles}.
2909
2910The dotted pairs (@var{variable} . @var{value}) each consist of a
2911variable and the value it is to be set to when the style is later
2912activated.@footnote{In certain circumstances, this value can get
2913overridden by another value.} The variable can be either a @ccmode{}
2914style variable or an arbitrary Emacs variable. In the latter case, it
2915is @emph{not} made buffer local by the @ccmode{} style system.
2916@end defvr
2917
2918Two variables are treated specially in the dotted pair list:
2919
2920@table @code
2921@item c-offsets-alist
2922The value is in turn a dotted list on the form
2923
2924(@var{syntactic-symbol} . @var{offset})
2925
2926as described in @ref{Customizing Indentation}. These are passed to
2927@code{c-set-offset} so there is no need to set every syntactic symbol in
2928your style, only those that are different from the inherited style.
2929
2930@item c-special-indent-hook
2931The value is added to @code{c-special-indent-hook} using
2932@code{add-hook}, so any functions already on it are kept. If the value
2933is a list, each element of the list is added with @code{add-hook}.
2934@end table
2935
2936Styles are kept in the @code{c-style-alist} variable, but you
2937should never modify this variable directly. Instead, @ccmode{}
2938provides the function @code{c-add-style} for this purpose.
3a731e1f
MS
2939
2940@defun c-add-style stylename description &optional set-p
2941@findex add-style (c-)
2a15eb73
MS
2942Add or update a style called @var{stylename}, a string.
2943@var{description} is the new style definition in the form described
2944above. If @var{stylename} already exists in @code{c-style-alist} then
2945it is replaced by @var{description}. (Note, this replacement is
2946total. The old style is @emph{not} merged into the new one.)
2947Otherwise, a new style is added. If the optional @var{set-p} is
2948non-@code{nil} then the new style is applied to the current buffer as
2949well.
6bf7aab6
DL
2950
2951The sample @file{.emacs} file provides a concrete example of how a new
2952style can be added and automatically set. @xref{Sample .emacs File}.
3a731e1f
MS
2953@end defun
2954
2955@defvar c-style-alist
2956@vindex style-alist (c-)
2957This is the variable that holds the definitions for the styles. It
2958should not be changed directly; use @code{c-add-style} instead.
2959@end defvar
6bf7aab6 2960
6bf7aab6 2961
d7bd46ed
GM
2962@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2963@node File Styles, , Adding Styles, Styles
2964@comment node-name, next, previous, up
2965@subsection File Styles
3a731e1f 2966@cindex styles, file local
6bf7aab6
DL
2967@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2968
3a731e1f 2969@cindex file local variables
6bf7aab6 2970
3a731e1f
MS
2971The Emacs manual describes how you can customize certain variables on
2972a per-file basis by including a @dfn{file local variable} block at the
2973end of the file. So far, you've only seen a functional interface to
2974@ccmode{} customization, which can't be used there. @ccmode{}
2975provides two variables allow customization of the indentation style on
2976a per-file basis:
6bf7aab6 2977
3a731e1f 2978@defvar c-file-style
6bf7aab6 2979@vindex file-style (c-)
3a731e1f
MS
2980This variable can be set to a style name string. When the file is
2981visited, @ccmode{} will automatically set the file's style to this
2982one using @code{c-set-style}.
2983@end defvar
6bf7aab6 2984
3a731e1f
MS
2985@defvar c-file-offsets
2986@vindex file-offsets (c-)
2987This variable takes an association list similar to what is allowed in
2988@code{c-offsets-alist}. When the file is visited, @ccmode{} will
2989automatically institute these offsets using @code{c-set-offset}.
2990@end defvar
6bf7aab6 2991
c3a2e2d5
RS
2992Note that file style settings (i.e., @code{c-file-style}) are applied
2993before file offset settings (i.e., @code{c-file-offsets}). Also, if
6bf7aab6
DL
2994either of these are set in a file's local variable section, all the
2995style variable values are made local to that buffer.
2996
2997
2998@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
d7bd46ed
GM
2999@node Advanced Customizations, , Styles, Customizing Indentation
3000@comment node-name, next, previous, up
3a731e1f 3001@section Advanced Customizations
6bf7aab6
DL
3002@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3003
3a731e1f
MS
3004For most users, @ccmode{} will support their coding styles with very
3005little need for more advanced customizations. Usually, one of the
3006standard styles (@pxref{Built-in Styles}) will do the trick. At most,
3007perhaps one of the syntactic symbol offsets will need to be tweaked
3008slightly, or maybe @code{c-basic-offset} will need to be changed.
3009However, some styles require a more flexible framework for
3010customization, and one of the real strengths of @ccmode{} is that the
3011syntactic analysis model provides just such a framework. This allows
6bf7aab6
DL
3012you to implement custom indentation calculations for situations not
3013handled by the mode directly.
3014
6bf7aab6
DL
3015@menu
3016* Custom Indentation Functions::
3017* Custom Brace and Colon Hanging::
3a731e1f 3018* Customizing Semicolons and Commas::
6bf7aab6
DL
3019* Other Special Indentations::
3020@end menu
3021
3022@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
d7bd46ed
GM
3023@node Custom Indentation Functions, Custom Brace and Colon Hanging, , Advanced Customizations
3024@comment node-name, next, previous, up
3025@subsection Custom Indentation Functions
3a731e1f 3026@cindex customization, indentation functions
6bf7aab6
DL
3027@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3028
d7bd46ed
GM
3029The most flexible way to customize @ccmode{} is by writing custom
3030indentation functions, and associating them with specific syntactic
3031symbols (@pxref{Syntactic Symbols}). @ccmode{} itself uses indentation
3032functions to provide more sophisticated indentation, for example when
3033lining up C++ stream operator blocks:
3a731e1f 3034
6bf7aab6
DL
3035@example
3036@group
3a731e1f
MS
3037 1: void main(int argc, char**)
3038 2: @{
3039 3: cout << "There were "
3040 4: << argc
3041 5: << "arguments passed to the program"
3042 6: << endl;
3043 7: @}
6bf7aab6
DL
3044@end group
3045@end example
3046
3047In this example, lines 4 through 6 are assigned the @code{stream-op}
3048syntactic symbol. Here, @code{stream-op} has an offset of @code{+}, and
3049with a @code{c-basic-offset} of 2, you can see that lines 4 through 6
3050are simply indented two spaces to the right of line 3. But perhaps we'd
3051like @ccmode{} to be a little more intelligent so that it aligns
3052all the @samp{<<} symbols in lines 3 through 6. To do this, we have
3a731e1f 3053to write a custom indentation function which finds the column of the first
bf247b6e 3054stream operator on the first line of the statement. Here is sample
6bf7aab6 3055lisp code implementing this:
6bf7aab6 3056
3a731e1f 3057@example
6bf7aab6 3058(defun c-lineup-streamop (langelem)
6bf7aab6 3059 (save-excursion
3a731e1f
MS
3060 (goto-char (cdr langelem))
3061 (re-search-forward "<<\\|>>" (c-point 'eol) 'move)
3062 (goto-char (match-beginning 0))
3063 (vector (current-column))))
6bf7aab6 3064@end example
3a731e1f 3065
d7bd46ed 3066Indentation functions take a single argument, which is a syntactic
3a731e1f
MS
3067component cons cell (@pxref{Syntactic Analysis}). The function can
3068return an integer which is added to the running total indentation for
3069the line, or a vector containing an integer which is an absolute
3070column to align to. Usually an absolute column is wanted when
3071aligning to existing text, as in this example.
d7bd46ed
GM
3072
3073The function should return @code{nil} if it's used in a situation where
3a731e1f 3074it doesn't want to make any decision. If the function is used in a list
d7bd46ed
GM
3075expression (@pxref{Customizing Indentation}), that will cause @ccmode{}
3076to go on and check the next entry in the list.
6bf7aab6 3077
6bf7aab6
DL
3078Now, to associate the function @code{c-lineup-streamop} with the
3079@code{stream-op} syntactic symbol, we can add something like the
3080following to our @code{c++-mode-hook}@footnote{It probably makes more
3081sense to add this to @code{c++-mode-hook} than @code{c-mode-common-hook}
d7bd46ed 3082since stream operators are only relevant for C++.}:
6bf7aab6 3083
3a731e1f 3084@example
6bf7aab6 3085(c-set-offset 'stream-op 'c-lineup-streamop)
6bf7aab6
DL
3086@end example
3087
3a731e1f 3088Now the function looks like this after reindenting (using @kbd{C-c
6bf7aab6 3089C-q}):
3a731e1f 3090
6bf7aab6
DL
3091@example
3092@group
3a731e1f
MS
3093 1: void main(int argc, char**)
3094 2: @{
3095 3: cout << "There were "
3096 4: << argc
3097 5: << " arguments passed to the program"
3098 6: << endl;
3099 7: @}
6bf7aab6
DL
3100@end group
3101@end example
3102
6bf7aab6
DL
3103Custom indentation functions can be as simple or as complex as you like,
3104and any syntactic symbol that appears in @code{c-offsets-alist} can have
d7bd46ed 3105a custom indentation function associated with it.
6bf7aab6 3106
d7bd46ed
GM
3107@ccmode{} comes with an extensive set of predefined indentation
3108functions, not all of which are used by the default styles. So there's
3109a good chance the function you want already exists. @xref{Indentation
3110Functions}, for a list of them. If you have written an indentation
3111function that you think is generally useful, you're very welcome to
3112contribute it; please contact @email{bug-cc-mode@@gnu.org}.
6bf7aab6 3113
6bf7aab6
DL
3114
3115@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 3116@node Custom Brace and Colon Hanging, Customizing Semicolons and Commas, Custom Indentation Functions, Advanced Customizations
d7bd46ed
GM
3117@comment node-name, next, previous, up
3118@subsection Custom Brace and Colon Hanging
6bf7aab6
DL
3119@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3120
3121@vindex c-hanging-braces-alist
3122@vindex hanging-braces-alist (c-)
3123Syntactic symbols aren't the only place where you can customize
3124@ccmode{} with the lisp equivalent of callback functions. Brace
3125``hanginess'' can also be determined by custom functions associated with
d7bd46ed 3126syntactic symbols on the @code{c-hanging-braces-alist} style variable.
3a731e1f 3127Remember that @var{action}'s are typically a list containing some
d7bd46ed 3128combination of the symbols @code{before} and @code{after}
3a731e1f 3129(@pxref{Hanging Braces}). However, an @var{action} can also be a
d7bd46ed
GM
3130function which gets called when a brace matching that syntactic symbol
3131is entered.
6bf7aab6 3132
3a731e1f
MS
3133@cindex customization, brace hanging
3134These @var{action} functions are called with two arguments: the
6bf7aab6 3135syntactic symbol for the brace, and the buffer position at which the
3a731e1f 3136brace was inserted. The @var{action} function is expected to return a
d7bd46ed 3137list containing some combination of @code{before} and @code{after},
c3a2e2d5 3138including neither of them (i.e., @code{nil}). This return value has the
d7bd46ed 3139normal brace hanging semantics.
6bf7aab6
DL
3140
3141As an example, @ccmode{} itself uses this feature to dynamically
3142determine the hanginess of braces which close ``do-while''
3143constructs:
6bf7aab6 3144
3a731e1f 3145@example
6bf7aab6
DL
3146void do_list( int count, char** atleast_one_string )
3147@{
3148 int i=0;
3149 do @{
3150 handle_string( atleast_one_string[i] );
3151 i++;
3152 @} while( i < count );
3153@}
6bf7aab6
DL
3154@end example
3155
6bf7aab6
DL
3156@ccmode{} assigns the @code{block-close} syntactic symbol to the
3157brace that closes the @code{do} construct, and normally we'd like the
3158line that follows a @code{block-close} brace to begin on a separate
3159line. However, with ``do-while'' constructs, we want the
3160@code{while} clause to follow the closing brace. To do this, we
3a731e1f 3161associate the @code{block-close} symbol with the @var{action} function
6bf7aab6 3162@code{c-snug-do-while}:
6bf7aab6 3163
3a731e1f 3164@example
6bf7aab6 3165(defun c-snug-do-while (syntax pos)
3a731e1f 3166 "Dynamically calculate brace hanginess for do-while statements."
6bf7aab6
DL
3167 (save-excursion
3168 (let (langelem)
3169 (if (and (eq syntax 'block-close)
3170 (setq langelem (assq 'block-close c-syntactic-context))
3171 (progn (goto-char (cdr langelem))
3172 (if (= (following-char) ?@{)
3173 (forward-sexp -1))
3174 (looking-at "\\<do\\>[^_]")))
3175 '(before)
3176 '(before after)))))
6bf7aab6
DL
3177@end example
3178
3a731e1f
MS
3179@findex c-snug-do-while
3180@findex snug-do-while (c-)
6bf7aab6
DL
3181This function simply looks to see if the brace closes a ``do-while''
3182clause and if so, returns the list @samp{(before)} indicating
3183that a newline should be inserted before the brace, but not after it.
3184In all other cases, it returns the list @samp{(before after)} so
3185that the brace appears on a line by itself.
3186
3a731e1f 3187@defvar c-syntactic-context
6bf7aab6 3188@vindex syntactic-context (c-)
3a731e1f
MS
3189During the call to the indentation or brace hanging @var{action}
3190function, this variable is bound to the full syntactic analysis list.
3191@end defvar
6bf7aab6 3192
3a731e1f
MS
3193@cindex customization, colon hanging
3194@vindex c-hanging-colons-alist
3195@vindex hanging-colons-alist (c-)
6bf7aab6 3196Note that for symmetry, colon hanginess should be customizable by
3a731e1f
MS
3197allowing function symbols as @var{action}s on the
3198@code{c-hanging-colons-alist} style variable. Since no use has actually
d7bd46ed 3199been found for this feature, it isn't currently implemented!
6bf7aab6 3200
6bf7aab6 3201
d7bd46ed 3202@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 3203@node Customizing Semicolons and Commas, Other Special Indentations, Custom Brace and Colon Hanging, Advanced Customizations
d7bd46ed 3204@comment node-name, next, previous, up
3a731e1f
MS
3205@subsection Customizing Semicolons and Commas
3206@cindex customization, semicolon newlines
3207@cindex customization, comma newlines
6bf7aab6
DL
3208@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3209
3a731e1f
MS
3210You can also customize the insertion of newlines after semicolons and
3211commas when the auto-newline minor mode is enabled (@pxref{Minor
3212Modes}).
6bf7aab6 3213
3a731e1f
MS
3214@defopt c-hanging-semi&comma-criteria
3215@vindex hanging-semi&comma-criteria (c-)
3216This style variable takes a list of hooks that get called when a
3217semicolon or comma is inserted. The hooks are called in order without
3218arguments, and are expected to return one of the following values:
6bf7aab6 3219
3a731e1f
MS
3220@table @code
3221@item t
3222A newline is inserted, and no more functions from the list are called.
3223@item stop
3224No more functions from the list are called, but no newline is
3225inserted.
3226@item nil
3227No determination is made, and the next function in the list is called.
3228@end table
6bf7aab6
DL
3229
3230If every function in the list is called without a determination being
3231made, then no newline is added. The default value for this variable is a
3232list containing a single function which inserts newlines only after
c3a2e2d5 3233semicolons which do not appear inside parenthesis lists (i.e., those
6bf7aab6 3234that separate @code{for}-clause statements).
3a731e1f 3235@end defopt
6bf7aab6 3236
3a731e1f 3237@defun c-semi&comma-no-newlines-before-nonblanks
6bf7aab6 3238@findex semi&comma-no-newlines-before-nonblanks (c-)
3a731e1f
MS
3239This is an example of a criteria function, provided by @ccmode{}. It
3240prevents newlines from being inserted after semicolons when there is a
3241non-blank following line. Otherwise, it makes no determination. To
3242use, add this function to the front of the
3243@code{c-hanging-semi&comma-criteria} list.
6bf7aab6
DL
3244
3245@example
6bf7aab6
DL
3246(defun c-semi&comma-no-newlines-before-nonblanks ()
3247 (save-excursion
3248 (if (and (eq last-command-char ?\;)
3249 (zerop (forward-line 1))
3250 (not (looking-at "^[ \t]*$")))
3251 'stop
3252 nil)))
6bf7aab6 3253@end example
3a731e1f 3254@end defun
6bf7aab6 3255
3a731e1f 3256@defun c-semi&comma-inside-parenlist
6bf7aab6 3257@findex semi&comma-inside-parenlist (c-)
3a731e1f 3258@defunx c-semi&comma-no-newlines-for-oneline-inliners
6bf7aab6 3259@findex semi&comma-no-newlines-for-oneline-inliners (c-)
d7bd46ed
GM
3260The function @code{c-semi&comma-inside-parenlist} is what prevents
3261newlines from being inserted inside the parenthesis list of @code{for}
3262statements. In addition to
6bf7aab6
DL
3263@code{c-semi&comma-no-newlines-before-nonblanks} described above,
3264@ccmode{} also comes with the criteria function
3265@code{c-semi&comma-no-newlines-for-oneline-inliners}, which suppresses
3266newlines after semicolons inside one-line inline method definitions
c3a2e2d5 3267(e.g., in C++ or Java).
3a731e1f 3268@end defun
6bf7aab6 3269
6bf7aab6 3270
d7bd46ed 3271@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 3272@node Other Special Indentations, , Customizing Semicolons and Commas, Advanced Customizations
d7bd46ed
GM
3273@comment node-name, next, previous, up
3274@subsection Other Special Indentations
6bf7aab6
DL
3275@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3276
3a731e1f
MS
3277Here are the remaining odds and ends regarding indentation:
3278
3279@defopt c-label-minimum-indentation
6bf7aab6 3280@vindex label-minimum-indentation (c-)
d7bd46ed 3281In @samp{gnu} style (@pxref{Built-in Styles}), a minimum indentation
6bf7aab6 3282is imposed on lines inside top-level constructs. This minimum
3a731e1f 3283indentation is controlled by this style variable. The default value
6bf7aab6 3284is 1.
3a731e1f 3285@end defopt
6bf7aab6 3286
3a731e1f 3287@defopt c-special-indent-hook
6bf7aab6 3288@vindex special-indent-hook (c-)
3a731e1f
MS
3289This style variable is a standard hook variable that is called after
3290every line is indented by @ccmode{}. You can use it to do any special
3291indentation or line adjustments your style dictates, such as adding
3292extra indentation to constructors or destructor declarations in a
3293class definition, etc. Note that you should not change point or mark
c3a2e2d5 3294inside your @code{c-special-indent-hook} functions, i.e., you'll
3a731e1f
MS
3295probably want to wrap your function in a @code{save-excursion}.
3296
3297Setting @code{c-special-indent-hook} in your style definition is
3298handled slightly differently than other variables. In your style
3299definition, you should set the value for @code{c-special-indent-hook}
3300to a function or list of functions, which will be appended to
3301@code{c-special-indent-hook} using @code{add-hook}. That way, the
3302current setting for the buffer local value of
6bf7aab6 3303@code{c-special-indent-hook} won't be overridden.
3a731e1f 3304@end defopt
d7bd46ed 3305
6bf7aab6 3306
d7bd46ed
GM
3307@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3308@node Syntactic Symbols, Indentation Functions, Customizing Indentation, Top
3309@comment node-name, next, previous, up
3a731e1f 3310@chapter Syntactic Symbols
6bf7aab6
DL
3311@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3312
3a731e1f 3313@cindex syntactic symbols, brief list
6bf7aab6
DL
3314@vindex c-offsets-alist
3315@vindex offsets-alist (c-)
6bf7aab6 3316Here is a complete list of the recognized syntactic symbols as described
d7bd46ed
GM
3317in the @code{c-offsets-alist} style variable, along with a brief
3318description. More detailed descriptions follow.
6bf7aab6 3319
d7bd46ed
GM
3320@table @code
3321@item string
3a731e1f 3322Inside a multiline string.
d7bd46ed 3323@item c
3a731e1f 3324Inside a multiline C style block comment.
d7bd46ed
GM
3325@item defun-open
3326Brace that opens a top-level function definition.
3327@item defun-close
3328Brace that closes a top-level function definition.
3329@item defun-block-intro
3330The first line in a top-level defun.
3331@item class-open
3332Brace that opens a class definition.
3333@item class-close
3334Brace that closes a class definition.
3335@item inline-open
3336Brace that opens an in-class inline method.
3337@item inline-close
3338Brace that closes an in-class inline method.
3339@item func-decl-cont
3340The region between a function definition's argument list and the
3341function opening brace (excluding K&R argument declarations). In C, you
3342cannot put anything but whitespace and comments in this region, however
3343in C++ and Java, @code{throws} declarations and other things can appear
3344here.
3345@item knr-argdecl-intro
3346First line of a K&R C argument declaration.
3347@item knr-argdecl
3348Subsequent lines in a K&R C argument declaration.
3349@item topmost-intro
3350The first line in a ``topmost'' definition.
3351@item topmost-intro-cont
3a731e1f
MS
3352Topmost definition continuation lines. This is only used in the parts
3353that aren't covered by other symbols such as @code{func-decl-cont} and
3354@code{knr-argdecl}.
d7bd46ed
GM
3355@item member-init-intro
3356First line in a member initialization list.
3357@item member-init-cont
3358Subsequent member initialization list lines.
3359@item inher-intro
3360First line of a multiple inheritance list.
3361@item inher-cont
3362Subsequent multiple inheritance lines.
3363@item block-open
3364Statement block open brace.
3365@item block-close
3366Statement block close brace.
3367@item brace-list-open
3368Open brace of an enum or static array list.
3369@item brace-list-close
3370Close brace of an enum or static array list.
3371@item brace-list-intro
3372First line in an enum or static array list.
3373@item brace-list-entry
3374Subsequent lines in an enum or static array list.
3375@item brace-entry-open
3376Subsequent lines in an enum or static array list where the line begins
3377with an open brace.
3378@item statement
3379A statement.
3380@item statement-cont
3381A continuation of a statement.
3382@item statement-block-intro
3383The first line in a new statement block.
3384@item statement-case-intro
3385The first line in a case block.
3386@item statement-case-open
3387The first line in a case block that starts with a brace.
3388@item substatement
3389The first line after a conditional or loop construct.
3390@item substatement-open
3391The brace that opens a substatement block.
3a731e1f
MS
3392@item substatement-label
3393The first line after a conditional or loop construct if it's a label.
d7bd46ed 3394@item case-label
3a731e1f 3395A label in a @code{switch} block.
d7bd46ed
GM
3396@item access-label
3397C++ access control label.
3398@item label
3a731e1f 3399Any other label.
d7bd46ed
GM
3400@item do-while-closure
3401The @code{while} line that ends a @code{do}-@code{while} construct.
3402@item else-clause
3403The @code{else} line of an @code{if}-@code{else} construct.
3404@item catch-clause
3405The @code{catch} or @code{finally} (in Java) line of a
3406@code{try}-@code{catch} construct.
3407@item comment-intro
3408A line containing only a comment introduction.
3409@item arglist-intro
3410The first line in an argument list.
3411@item arglist-cont
3412Subsequent argument list lines when no arguments follow on the same line
6b1f5814 3413as the arglist opening paren.
d7bd46ed
GM
3414@item arglist-cont-nonempty
3415Subsequent argument list lines when at least one argument follows on the
3416same line as the arglist opening paren.
3417@item arglist-close
3418The solo close paren of an argument list.
3419@item stream-op
3420Lines continuing a stream operator (C++ only).
3421@item inclass
3422The line is nested inside a class definition.
3423@item cpp-macro
3a731e1f
MS
3424The start of a preprocessor macro definition.
3425@item cpp-define-intro
3426The first line inside a multiline preproprocessor macro if
3427@code{c-syntactic-indentation-in-macros} is set.
d7bd46ed 3428@item cpp-macro-cont
3a731e1f
MS
3429All lines inside multiline preprocessor macros if
3430@code{c-syntactic-indentation-in-macros} is @code{nil}.
d7bd46ed
GM
3431@item friend
3432A C++ friend declaration.
3433@item objc-method-intro
3a731e1f 3434The first line of an Objective-C method definition.
d7bd46ed 3435@item objc-method-args-cont
3a731e1f 3436Lines continuing an Objective-C method definition.
d7bd46ed
GM
3437@item objc-method-call-cont
3438Lines continuing an Objective-C method call.
3439@item extern-lang-open
c3a2e2d5 3440Brace that opens an @code{extern} block (e.g., @code{extern "C" @{...@}}).
d7bd46ed 3441@item extern-lang-close
3a731e1f 3442Brace that closes an @code{extern} block.
d7bd46ed 3443@item inextern-lang
3a731e1f
MS
3444Analogous to @code{inclass} syntactic symbol, but used inside
3445@code{extern} blocks.
d7bd46ed 3446@item namespace-open
3a731e1f
MS
3447@itemx namespace-close
3448@itemx innamespace
3449These are analogous to the three @code{extern-lang} symbols above, but
3450are returned for C++ namespace blocks.
3451@item module-open
3452@itemx module-close
3453@itemx inmodule
3454Analogous to the above, but for CORBA IDL @code{module} blocks.
3455@item composition-open
3456@itemx composition-close
3457@itemx incomposition
3458Analogous to the above, but for CORBA CIDL @code{composition} blocks.
d7bd46ed
GM
3459@item template-args-cont
3460C++ template argument list continuations.
3461@item inlambda
3462Analogous to @code{inclass} syntactic symbol, but used inside lambda
c3a2e2d5 3463(i.e., anonymous) functions. Only used in Pike mode.
d7bd46ed 3464@item lambda-intro-cont
c3a2e2d5 3465Lines continuing the header of a lambda function, i.e., between the
d7bd46ed
GM
3466@code{lambda} keyword and the function body. Only used in Pike mode.
3467@item inexpr-statement
2a15eb73
MS
3468A statement block inside an expression. The gcc C and C++ extension for
3469this is recognized. It's also used for the special functions that take
3470a statement block as an argument in Pike.
d7bd46ed
GM
3471@item inexpr-class
3472A class definition inside an expression. This is used for anonymous
3473classes in Java. It's also used for anonymous array initializers in
3474Java.
3475@end table
6bf7aab6 3476
3a731e1f
MS
3477@ssindex -open symbols
3478@ssindex -close symbols
6bf7aab6
DL
3479Most syntactic symbol names follow a general naming convention. When a
3480line begins with an open or close brace, the syntactic symbol will
3481contain the suffix @code{-open} or @code{-close} respectively.
3482
3a731e1f
MS
3483@ssindex -intro symbols
3484@ssindex -cont symbols
3485@ssindex -block-intro symbols
6bf7aab6
DL
3486Usually, a distinction is made between the first line that introduces a
3487construct and lines that continue a construct, and the syntactic symbols
3488that represent these lines will contain the suffix @code{-intro} or
3489@code{-cont} respectively. As a sub-classification of this scheme, a
3490line which is the first of a particular brace block construct will
3491contain the suffix @code{-block-intro}.
3492
6bf7aab6
DL
3493Let's look at some examples to understand how this works. Remember that
3494you can check the syntax of any line by using @kbd{C-c C-s}.
6bf7aab6 3495
3a731e1f
MS
3496@example
3497 1: void
3498 2: swap( int& a, int& b )
3499 3: @{
3500 4: int tmp = a;
3501 5: a = b;
3502 6: b = tmp;
3503 7: int ignored =
3504 8: a + b;
3505 9: @}
6bf7aab6
DL
3506@end example
3507
3a731e1f
MS
3508@ssindex topmost-intro
3509@ssindex topmost-intro-cont
3510@ssindex defun-open
3511@ssindex defun-close
3512@ssindex defun-block-intro
6bf7aab6
DL
3513Line 1 shows a @code{topmost-intro} since it is the first line that
3514introduces a top-level construct. Line 2 is a continuation of the
3515top-level construct introduction so it has the syntax
3516@code{topmost-intro-cont}. Line 3 shows a @code{defun-open} since it is
d7bd46ed
GM
3517the brace that opens a top-level function definition. Line 9 is the
3518corresponding
6bf7aab6 3519@code{defun-close} since it contains the brace that closes the top-level
c3a2e2d5 3520function definition. Line 4 is a @code{defun-block-intro}, i.e., it is
6bf7aab6
DL
3521the first line of a brace-block, enclosed in a
3522top-level function definition.
3523
3a731e1f
MS
3524@ssindex statement
3525@ssindex statement-cont
6bf7aab6
DL
3526Lines 5, 6, and 7 are all given @code{statement} syntax since there
3527isn't much special about them. Note however that line 8 is given
3528@code{statement-cont} syntax since it continues the statement begun
3529on the previous line.
3530
3531Here's another example, which illustrates some C++ class syntactic
3532symbols:
6bf7aab6 3533
3a731e1f
MS
3534@example
3535 1: class Bass
3536 2: : public Guitar,
3537 3: public Amplifiable
3538 4: @{
3539 5: public:
3540 6: Bass()
3541 7: : eString( new BassString( 0.105 )),
3542 8: aString( new BassString( 0.085 )),
3543 9: dString( new BassString( 0.065 )),
354410: gString( new BassString( 0.045 ))
354511: @{
354612: eString.tune( 'E' );
354713: aString.tune( 'A' );
354814: dString.tune( 'D' );
354915: gString.tune( 'G' );
355016: @}
355117: friend class Luthier;
355218: @};
6bf7aab6
DL
3553@end example
3554
3a731e1f
MS
3555@ssindex class-open
3556@ssindex class-close
6bf7aab6
DL
3557As in the previous example, line 1 has the @code{topmost-intro} syntax.
3558Here however, the brace that opens a C++ class definition on line 4 is
3559assigned the @code{class-open} syntax. Note that in C++, classes,
3560structs, and unions are essentially equivalent syntactically (and are
3561very similar semantically), so replacing the @code{class} keyword in the
3562example above with @code{struct} or @code{union} would still result in a
3563syntax of @code{class-open} for line 4 @footnote{This is the case even
3564for C and Objective-C. For consistency, structs in all supported
3565languages are syntactically equivalent to classes. Note however that
3566the keyword @code{class} is meaningless in C and Objective-C.}.
3567Similarly, line 18 is assigned @code{class-close} syntax.
3568
3a731e1f
MS
3569@ssindex inher-intro
3570@ssindex inher-cont
6bf7aab6
DL
3571Line 2 introduces the inheritance list for the class so it is assigned
3572the @code{inher-intro} syntax, and line 3, which continues the
3573inheritance list is given @code{inher-cont} syntax.
3574
3a731e1f
MS
3575@ssindex access-label
3576@ssindex inclass
6bf7aab6
DL
3577Hitting @kbd{C-c C-s} on line 5 shows the following analysis:
3578
3579@example
3a731e1f 3580((inclass 58) (access-label 58))
6bf7aab6
DL
3581@end example
3582
3583@noindent
3584The primary syntactic symbol for this line is @code{access-label} as
3585this a label keyword that specifies access protection in C++. However,
3586because this line is also a top-level construct inside a class
3587definition, the analysis actually shows two syntactic symbols. The
3588other syntactic symbol assigned to this line is @code{inclass}.
3589Similarly, line 6 is given both @code{inclass} and @code{topmost-intro}
3590syntax:
3591
3592@example
3a731e1f 3593((inclass 58) (topmost-intro 60))
6bf7aab6
DL
3594@end example
3595
3a731e1f
MS
3596@ssindex member-init-intro
3597@ssindex member-init-cont
6bf7aab6
DL
3598Line 7 introduces a C++ member initialization list and as such is given
3599@code{member-init-intro} syntax. Note that in this case it is
3600@emph{not} assigned @code{inclass} since this is not considered a
3601top-level construct. Lines 8 through 10 are all assigned
3602@code{member-init-cont} since they continue the member initialization
3603list started on line 7.
3604
3605@cindex in-class inline methods
3a731e1f
MS
3606@ssindex inline-open
3607@ssindex inline-close
6bf7aab6
DL
3608Line 11's analysis is a bit more complicated:
3609
3610@example
3a731e1f 3611((inclass 58) (inline-open))
6bf7aab6
DL
3612@end example
3613
3614This line is assigned a syntax of both @code{inline-open} and
3615@code{inclass} because it opens an @dfn{in-class} C++ inline method
3616definition. This is distinct from, but related to, the C++ notion of an
3617inline function in that its definition occurs inside an enclosing class
3618definition, which in C++ implies that the function should be inlined.
3a731e1f 3619However, if the definition of the @code{Bass} constructor appeared
6bf7aab6
DL
3620outside the class definition, the construct would be given the
3621@code{defun-open} syntax, even if the keyword @code{inline} appeared
3622before the method name, as in:
6bf7aab6 3623
3a731e1f
MS
3624@example
3625 1: class Bass
3626 2: : public Guitar,
3627 3: public Amplifiable
3628 4: @{
3629 5: public:
3630 6: Bass();
3631 7: @};
3632 8:
3633 9: inline
363410: Bass::Bass()
363511: : eString( new BassString( 0.105 )),
363612: aString( new BassString( 0.085 )),
363713: dString( new BassString( 0.065 )),
363814: gString( new BassString( 0.045 ))
363915: @{
364016: eString.tune( 'E' );
364117: aString.tune( 'A' );
364218: dString.tune( 'D' );
364319: gString.tune( 'G' );
364420: @}
6bf7aab6
DL
3645@end example
3646
3a731e1f 3647@ssindex friend
6bf7aab6
DL
3648Returning to the previous example, line 16 is given @code{inline-close}
3649syntax, while line 12 is given @code{defun-block-open} syntax, and lines
365013 through 15 are all given @code{statement} syntax. Line 17 is
3651interesting in that its syntactic analysis list contains three
3652elements:
3653
3654@example
3a731e1f 3655((inclass 58) (topmost-intro 380) (friend))
6bf7aab6
DL
3656@end example
3657
3658The @code{friend} syntactic symbol is a modifier that typically does not
3659have a relative buffer position.
3660
3661Template definitions introduce yet another syntactic symbol:
3662
3663@example
3a731e1f
MS
3664 1: ThingManager <int,
3665 2: Framework::Callback *,
3666 3: Mutex> framework_callbacks;
6bf7aab6
DL
3667@end example
3668
3669Here, line 1 is analyzed as a @code{topmost-intro}, but lines 2 and 3
3670are both analyzed as @code{template-args-cont} lines.
3671
3672Here is another (totally contrived) example which illustrates how syntax
3673is assigned to various conditional constructs:
6bf7aab6 3674
3a731e1f
MS
3675@example
3676 1: void spam( int index )
3677 2: @{
3678 3: for( int i=0; i<index; i++ )
3679 4: @{
3680 5: if( i == 10 )
3681 6: do_something_special();
3682 7: else
3683 8: silly_label:
3684 9: do_something( i );
368510: @}
368611: do @{
368712: another_thing( i-- );
368813: @}
368914: while( i > 0 );
369015: @}
6bf7aab6
DL
3691@end example
3692
6bf7aab6
DL
3693Only the lines that illustrate new syntactic symbols will be discussed.
3694
3a731e1f
MS
3695@ssindex substatement-open
3696@ssindex substatement-block-intro
3697@ssindex block-close
6bf7aab6
DL
3698Line 4 has a brace which opens a conditional's substatement block. It
3699is thus assigned @code{substatement-open} syntax, and since line 5 is
3700the first line in the substatement block, it is assigned
3a731e1f
MS
3701@code{substatement-block-intro} syntax. Line 10 contains the brace that
3702closes the inner substatement block, and is therefore given the syntax
3703@code{block-close}. Line 13 is treated the same way.
3704
3705@ssindex substatement
3706Lines 6 and 9 are also substatements of conditionals, but since they
3707don't start blocks they are given @code{substatement} syntax
3708instead of @code{substatement-open}.
3709
3710@ssindex substatement-label
3711Line 8 contains a label, which is normally given @code{label} syntax.
3712This one is however a bit special since it's between a conditional and
3713its substatement. It's analyzed as @code{substatement-label} to let you
3714handle this rather odd case differently from normal labels.
3715
3716@ssindex else-clause
3717@ssindex catch-clause
3718Line 7 start with an @code{else} that matches the @code{if} statement on
3719line 5. It is therefore given the @code{else-clause} syntax and is
3720anchored on the matching @code{if}. The @code{try}-@code{catch}
3721constructs in C++ and Java are treated this way too, except that
3722@code{catch} and (in Java) @code{finally}, are marked with
3723@code{catch-clause}.
3724
3725@ssindex do-while-closure
3726The @code{while} construct on line 14 that closes a @code{do}
3727conditional is given the special syntax @code{do-while-closure} if it
3728appears on a line by itself. Note that if the @code{while} appeared on
3729the same line as the preceding close brace, that line would still have
3730@code{block-close} syntax.
6bf7aab6
DL
3731
3732Switch statements have their own set of syntactic symbols. Here's an
3733example:
6bf7aab6 3734
3a731e1f
MS
3735@example
3736 1: void spam( enum Ingredient i )
3737 2: @{
3738 3: switch( i ) @{
3739 4: case Ham:
3740 5: be_a_pig();
3741 6: break;
3742 7: case Salt:
3743 8: drink_some_water();
3744 9: break;
374510: default:
374611: @{
374712: what_is_it();
374813: break;
374914: @}
375015: @}
375114: @}
6bf7aab6
DL
3752@end example
3753
3a731e1f
MS
3754@ssindex case-label
3755@ssindex statement-case-intro
3756@ssindex statement-case-open
6bf7aab6
DL
3757Here, lines 4, 7, and 10 are all assigned @code{case-label} syntax,
3758while lines 5 and 8 are assigned @code{statement-case-intro}. Line 11
3759is treated slightly differently since it contains a brace that opens a
3760block --- it is given @code{statement-case-open} syntax.
3761
3762@cindex brace lists
3763There are a set of syntactic symbols that are used to recognize
3764constructs inside of brace lists. A brace list is defined as an
3765@code{enum} or aggregate initializer list, such as might statically
d7bd46ed
GM
3766initialize an array of structs. The three special aggregate constructs
3767in Pike, @code{(@{ @})}, @code{([ ])} and @code{(< >)}, are treated as
3768brace lists too. An example:
6bf7aab6 3769
3a731e1f
MS
3770@example
3771 1: static char* ingredients[] =
3772 2: @{
3773 3: "Ham",
3774 4: "Salt",
3775 5: NULL
3776 6: @};
6bf7aab6
DL
3777@end example
3778
3a731e1f
MS
3779@ssindex brace-list-open
3780@ssindex brace-list-intro
3781@ssindex brace-list-close
3782@ssindex brace-list-entry
6bf7aab6
DL
3783Following convention, line 2 in this example is assigned
3784@code{brace-list-open} syntax, and line 3 is assigned
3785@code{brace-list-intro} syntax. Likewise, line 6 is assigned
3786@code{brace-list-close} syntax. Lines 4 and 5 however, are assigned
3787@code{brace-list-entry} syntax, as would all subsequent lines in this
3788initializer list.
3789
3a731e1f 3790@ssindex brace-entry-open
d7bd46ed
GM
3791Your static initializer might be initializing nested structures, for
3792example:
d7bd46ed 3793
3a731e1f
MS
3794@example
3795 1: struct intpairs[] =
3796 2: @{
3797 3: @{ 1, 2 @},
3798 4: @{
3799 5: 3,
3800 6: 4
3801 7: @}
3802 8: @{ 1,
3803 9: 2 @},
380410: @{ 3, 4 @}
380511: @};
d7bd46ed
GM
3806@end example
3807
3808Here, you've already seen the analysis of lines 1, 2, 3, and 11. On
3809line 4, things get interesting; this line is assigned
3810@code{brace-entry-open} syntactic symbol because it's a bracelist entry
3811line that starts with an open brace. Lines 5 and 6 (and line 9) are
3812pretty standard, and line 7 is a @code{brace-list-close} as you'd
3813expect. Once again, line 8 is assigned as @code{brace-entry-open} as is
3814line 10.
3815
6bf7aab6
DL
3816External language definition blocks also have their own syntactic
3817symbols. In this example:
6bf7aab6 3818
3a731e1f
MS
3819@example
3820 1: extern "C"
3821 2: @{
3822 3: int thing_one( int );
3823 4: int thing_two( double );
3824 5: @}
6bf7aab6
DL
3825@end example
3826
3a731e1f
MS
3827@ssindex extern-lang-open
3828@ssindex extern-lang-close
3829@ssindex inextern-lang
3830@ssindex inclass
6bf7aab6
DL
3831@noindent
3832line 2 is given the @code{extern-lang-open} syntax, while line 5 is given
3833the @code{extern-lang-close} syntax. The analysis for line 3 yields:
6bf7aab6 3834
6bf7aab6 3835@example
3a731e1f 3836((inextern-lang) (topmost-intro 14))
6bf7aab6
DL
3837@end example
3838
6bf7aab6 3839@noindent
3a731e1f
MS
3840where @code{inextern-lang} is a modifier similar in purpose to
3841@code{inclass}.
3842
3843There are various other top level blocks like @code{extern}, and they
3844are all treated in the same way except that the symbols are named after
c3a2e2d5 3845the keyword that introduces the block. e.g., C++ namespace blocks get
3a731e1f
MS
3846the three symbols @code{namespace-open}, @code{namespace-close} and
3847@code{innamespace}. The currently recognized top level blocks are:
3848
3849@table @asis
3850@item @code{extern-lang-open}, @code{extern-lang-close}, @code{inextern-lang}
3851@code{extern} blocks in C and C++.@footnote{These should logically be
3852named @code{extern-open}, @code{extern-close} and @code{inextern}, but
3853that isn't the case for historical reasons.}
3854
3855@item @code{namespace-open}, @code{namespace-close}, @code{innamespace}
3856@ssindex namespace-open
3857@ssindex namespace-close
3858@ssindex innamespace
3859@code{namespace} blocks in C++.
3860
3861@item @code{module-open}, @code{module-close}, @code{inmodule}
3862@ssindex module-open
3863@ssindex module-close
3864@ssindex inmodule
3865@code{module} blocks in CORBA IDL.
3866
3867@item @code{composition-open}, @code{composition-close}, @code{incomposition}
3868@ssindex composition-open
3869@ssindex composition-close
3870@ssindex incomposition
3871@code{composition} blocks in CORBA CIDL.
3872@end table
6bf7aab6
DL
3873
3874A number of syntactic symbols are associated with parenthesis lists,
3875a.k.a argument lists, as found in function declarations and function
3876calls. This example illustrates these:
6bf7aab6 3877
3a731e1f
MS
3878@example
3879 1: void a_function( int line1,
3880 2: int line2 );
bf247b6e 3881 3:
3a731e1f
MS
3882 4: void a_longer_function(
3883 5: int line1,
3884 6: int line2
3885 7: );
bf247b6e 3886 8:
3a731e1f
MS
3887 9: void call_them( int line1, int line2 )
388810: @{
388911: a_function(
389012: line1,
389113: line2
389214: );
bf247b6e 389315:
3a731e1f
MS
389416: a_longer_function( line1,
389517: line2 );
389618: @}
6bf7aab6
DL
3897@end example
3898
3a731e1f
MS
3899@ssindex arglist-intro
3900@ssindex arglist-close
6bf7aab6
DL
3901Lines 5 and 12 are assigned @code{arglist-intro} syntax since they are
3902the first line following the open parenthesis, and lines 7 and 14 are
3903assigned @code{arglist-close} syntax since they contain the parenthesis
3904that closes the argument list.
3905
3a731e1f
MS
3906@ssindex arglist-cont-nonempty
3907@ssindex arglist-cont
6bf7aab6
DL
3908Lines that continue argument lists can be assigned one of two syntactic
3909symbols. For example, Lines 2 and 17
3910are assigned @code{arglist-cont-nonempty} syntax. What this means
3911is that they continue an argument list, but that the line containing the
3912parenthesis that opens the list is @emph{not empty} following the open
3913parenthesis. Contrast this against lines 6 and 13 which are assigned
3914@code{arglist-cont} syntax. This is because the parenthesis that opens
3915their argument lists is the last character on that line.
3916
3917Note that there is no @code{arglist-open} syntax. This is because any
3918parenthesis that opens an argument list, appearing on a separate line,
3919is assigned the @code{statement-cont} syntax instead.
3920
3921A few miscellaneous syntactic symbols that haven't been previously
3922covered are illustrated by this C++ example:
6bf7aab6 3923
3a731e1f
MS
3924@example
3925 1: void Bass::play( int volume )
3926 2: const
3927 3: @{
3928 4: /* this line starts a multiline
3929 5: * comment. This line should get `c' syntax */
bf247b6e 3930 6:
3a731e1f
MS
3931 7: char* a_multiline_string = "This line starts a multiline \
3932 8: string. This line should get `string' syntax.";
bf247b6e 3933 9:
3a731e1f
MS
393410: note:
393511: @{
393612: #ifdef LOCK
393713: Lock acquire();
393814: #endif // LOCK
393915: slap_pop();
394016: cout << "I played "
394117: << "a note\n";
394218: @}
394319: @}
6bf7aab6
DL
3944@end example
3945
6bf7aab6
DL
3946The lines to note in this example include:
3947
3948@itemize @bullet
6bf7aab6 3949@item
3a731e1f 3950@ssindex func-decl-cont
f214c025 3951Line 2 is assigned the @code{func-decl-cont} syntax.
6bf7aab6 3952
6bf7aab6 3953@item
3a731e1f 3954@ssindex comment-intro
f214c025
GM
3955Line 4 is assigned both @code{defun-block-intro} @emph{and}
3956@code{comment-intro} syntax.
6bf7aab6 3957
6bf7aab6 3958@item
3a731e1f 3959@ssindex c
f214c025 3960Line 5 is assigned @code{c} syntax.
6bf7aab6
DL
3961
3962@item
3963@cindex syntactic whitespace
f214c025 3964Line 6 which, even though it contains nothing but whitespace, is
6bf7aab6
DL
3965assigned @code{defun-block-intro}. Note that the appearance of the
3966comment on lines 4 and 5 do not cause line 6 to be assigned
3967@code{statement} syntax because comments are considered to be
3968@dfn{syntactic whitespace}, which are ignored when analyzing
f214c025 3969code.
6bf7aab6 3970
6bf7aab6 3971@item
3a731e1f 3972@ssindex string
f214c025 3973Line 8 is assigned @code{string} syntax.
6bf7aab6 3974
6bf7aab6 3975@item
3a731e1f 3976@ssindex label
f214c025 3977Line 10 is assigned @code{label} syntax.
6bf7aab6 3978
6bf7aab6 3979@item
3a731e1f 3980@ssindex block-open
f214c025 3981Line 11 is assigned @code{block-open} syntax.
6bf7aab6 3982
6bf7aab6 3983@item
3a731e1f 3984@ssindex cpp-macro
f214c025
GM
3985Lines 12 and 14 are assigned @code{cpp-macro} syntax in addition to the
3986normal syntactic symbols (@code{statement-block-intro} and
3987@code{statement}, respectively). Normally @code{cpp-macro} is
3988configured to cancel out the normal syntactic context to make all
3989preprocessor directives stick to the first column, but that's easily
3990changed if you want preprocessor directives to be indented like the rest
3991of the code.
6bf7aab6 3992
6bf7aab6 3993@item
3a731e1f 3994@ssindex stream-op
f214c025 3995Line 17 is assigned @code{stream-op} syntax.
6bf7aab6
DL
3996@end itemize
3997
3a731e1f 3998@cindex multiline macros
6bf7aab6 3999@cindex syntactic whitespace
3a731e1f
MS
4000@ssindex cpp-define-intro
4001Multiline preprocessor macro definitions are normally handled just like
c3a2e2d5 4002other code, i.e., the lines inside them are indented according to the
3a731e1f 4003syntactic analysis of the preceding lines inside the macro. The first
c3a2e2d5 4004line inside a macro definition (i.e., the line after the starting line of
3a731e1f 4005the cpp directive itself) gets @code{cpp-define-intro}. In this example:
6bf7aab6 4006
3a731e1f
MS
4007@example
4008 1: #define LIST_LOOP(cons, listp) \
4009 2: for (cons = listp; !NILP (cons); cons = XCDR (cons)) \
4010 3: if (!CONSP (cons)) \
4011 4: signal_error ("Invalid list format", listp); \
4012 5: else
6bf7aab6 4013@end example
3a731e1f 4014
6bf7aab6 4015@noindent
3a731e1f
MS
4016line 1 is given the syntactic symbol @code{cpp-macro}. The first line
4017of a cpp directive is always given that symbol. Line 2 is given
4018@code{cpp-define-intro}, so that you can give the macro body as a whole
4019some extra indentation. Lines 3 through 5 are then analyzed as normal
c3a2e2d5 4020code, i.e., @code{substatement} on lines 3 and 4, and @code{else-clause}
3a731e1f
MS
4021on line 5.
4022
4023The syntactic analysis inside macros can be turned off with
4024@code{c-syntactic-indentation-in-macros}. In that case, lines 2 through
40255 would all be given @code{cpp-macro-cont} with a relative buffer
4026position pointing to the @code{#} which starts the cpp
4027directive@footnote{This is how @ccmode{} 5.28 and earlier analyzed
4028macros.}.
4029
4030@xref{Macro Handling}, for more info about the treatment of macros.
6bf7aab6
DL
4031
4032In Objective-C buffers, there are three additional syntactic symbols
4033assigned to various message calling constructs. Here's an example
4034illustrating these:
6bf7aab6 4035
3a731e1f
MS
4036@example
4037 1: - (void)setDelegate:anObject
4038 2: withStuff:stuff
4039 3: @{
4040 4: [delegate masterWillRebind:self
4041 5: toDelegate:anObject
4042 6: withExtraStuff:stuff];
4043 7: @}
6bf7aab6
DL
4044@end example
4045
3a731e1f
MS
4046@ssindex objc-method-intro
4047@ssindex objc-method-args-cont
4048@ssindex objc-method-call-cont
6bf7aab6
DL
4049Here, line 1 is assigned @code{objc-method-intro} syntax, and line 2 is
4050assigned @code{objc-method-args-cont} syntax. Lines 5 and 6 are both
4051assigned @code{objc-method-call-cont} syntax.
4052
d7bd46ed
GM
4053Java has a concept of anonymous classes, which may look something like
4054this:
d7bd46ed 4055
3a731e1f
MS
4056@example
4057 1: public void watch(Observable o) @{
4058 2: o.addObserver(new Observer() @{
4059 3: public void update(Observable o, Object arg) @{
4060 4: history.addElement(arg);
4061 5: @}
4062 6: @});
4063 7: @}
d7bd46ed
GM
4064@end example
4065
3a731e1f 4066@ssindex inexpr-class
d7bd46ed
GM
4067The brace following the @code{new} operator opens the anonymous class.
4068Lines 3 and 6 are assigned the @code{inexpr-class} syntax, besides the
4069@code{inclass} symbol used in normal classes. Thus, the class will be
4070indented just like a normal class, with the added indentation given to
4071@code{inexpr-class}.
4072
4073There are a few occasions where a statement block may be used inside an
2a15eb73
MS
4074expression. One is in C or C++ code using the gcc extension for this,
4075e.g:
d7bd46ed 4076
3a731e1f
MS
4077@example
4078 1: int res = (@{
4079 2: int y = foo (); int z;
4080 3: if (y > 0) z = y; else z = - y;
4081 4: z;
4082 5: @});
d7bd46ed
GM
4083@end example
4084
3a731e1f 4085@ssindex inexpr-statement
d7bd46ed
GM
4086Lines 2 and 5 get the @code{inexpr-statement} syntax, besides the
4087symbols they'd get in a normal block. Therefore, the indentation put on
4088@code{inexpr-statement} is added to the normal statement block
4089indentation.
4090
4091In Pike code, there are a few other situations where blocks occur inside
4092statements, as illustrated here:
d7bd46ed 4093
3a731e1f
MS
4094@example
4095 1: array itgob()
4096 2: @{
4097 3: string s = map (backtrace()[-2][3..],
4098 4: lambda
4099 5: (mixed arg)
4100 6: @{
4101 7: return sprintf ("%t", arg);
4102 8: @}) * ", " + "\n";
4103 9: return catch @{
410410: write (s + "\n");
410511: @};
410612: @}
d7bd46ed
GM
4107@end example
4108
3a731e1f
MS
4109@ssindex inlambda
4110@ssindex lambda-intro-cont
d7bd46ed
GM
4111Lines 4 through 8 contain a lambda function, which @ccmode{} recognizes
4112by the @code{lambda} keyword. If the function argument list is put
4113on a line of its own, as in line 5, it gets the @code{lambda-intro-cont}
4114syntax. The function body is handled as an inline method body, with the
4115addition of the @code{inlambda} syntactic symbol. This means that line
41166 gets @code{inlambda} and @code{inline-open}, and line 8 gets
4117@code{inline-close}@footnote{You might wonder why it doesn't get
4118@code{inlambda} too. It's because the closing brace is relative to the
4119opening brace, which stands on its own line in this example. If the
4120opening brace was hanging on the previous line, then the closing brace
4121would get the @code{inlambda} syntax too to be indented correctly.}.
4122
3a731e1f 4123@ssindex inexpr-statement
d7bd46ed
GM
4124On line 9, @code{catch} is a special function taking a statement block
4125as its argument. The block is handled as an in-expression statement
4126with the @code{inexpr-statement} syntax, just like the gcc extended C
4127example above. The other similar special function, @code{gauge}, is
4128handled like this too.
4129
3a731e1f
MS
4130@ssindex knr-argdecl-intro
4131@ssindex knr-argdecl
6bf7aab6
DL
4132Two other syntactic symbols can appear in old style, non-prototyped C
4133code @footnote{a.k.a. K&R C, or Kernighan & Ritchie C}:
6bf7aab6 4134
3a731e1f
MS
4135@example
4136 1: int add_three_integers(a, b, c)
4137 2: int a;
4138 3: int b;
4139 4: int c;
4140 5: @{
4141 6: return a + b + c;
4142 7: @}
6bf7aab6
DL
4143@end example
4144
4145Here, line 2 is the first line in an argument declaration list and so is
4146given the @code{knr-argdecl-intro} syntactic symbol. Subsequent lines
c3a2e2d5 4147(i.e., lines 3 and 4 in this example), are given @code{knr-argdecl}
6bf7aab6
DL
4148syntax.
4149
d7bd46ed 4150
6bf7aab6 4151@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 4152@node Indentation Functions, AWK Mode, Syntactic Symbols, Top
d7bd46ed 4153@comment node-name, next, previous, up
3a731e1f 4154@chapter Indentation Functions
d7bd46ed
GM
4155@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
4156
3a731e1f
MS
4157@cindex indentation function
4158@cindex line-up function
4159Often there are cases when a simple offset setting on a syntactic
4160symbol isn't enough to get the desired indentation. Therefore, it's
4161also possible to use an @dfn{indentation function} (a.k.a. @dfn{line-up
4162function}) for a syntactic symbol.
d7bd46ed
GM
4163
4164@ccmode{} comes with many predefined indentation functions for common
4165situations. If none of these does what you want, you can write your
4166own, see @ref{Custom Indentation Functions}. If you do, it's probably a
4167good idea to start working from one of these predefined functions, they
4168can be found in the file @file{cc-align.el}.
4169
4170For every function below there is a ``works with'' list that indicates
4171which syntactic symbols the function is intended to be used with.
4172
4173@macro workswith
cb7f2e96 4174@emph{Works with:@ }
d7bd46ed
GM
4175@end macro
4176@ifinfo
4177@unmacro workswith
4178@macro workswith
4179Works with:
4180@end macro
4181@end ifinfo
4182
3a731e1f
MS
4183@macro sssTBasicOffset
4184<--> @i{c-basic-offset}@c
4185@end macro
d7bd46ed 4186
3a731e1f
MS
4187@macro sssTsssTBasicOffset
4188<--><--> @i{c-basic-offset}@c
4189@end macro
d7bd46ed 4190
3a731e1f
MS
4191@macro hereFn{func}
4192<- @i{\func\}@c
4193@end macro
d7bd46ed 4194
3a731e1f
MS
4195@c The TeX backend seems to insert extra spaces around the argument. :P
4196@iftex
4197@unmacro hereFn
4198@macro hereFn{func}
4199<-@i{\func\}@c
4200@end macro
4201@end iftex
d7bd46ed 4202
3a731e1f 4203@comment ------------------------------------------------------------
d7bd46ed 4204
3a731e1f
MS
4205@defun c-indent-one-line-block
4206@findex indent-one-line-block (c-)
4207Indent a one line block @code{c-basic-offset} extra. E.g:
d7bd46ed 4208
d7bd46ed
GM
4209@example
4210@group
3a731e1f
MS
4211if (n > 0)
4212 @{m+=n; n=0;@} @hereFn{c-indent-one-line-block}
4213@sssTBasicOffset{}
d7bd46ed
GM
4214@end group
4215@end example
3a731e1f 4216
d7bd46ed
GM
4217@noindent
4218and
3a731e1f 4219
d7bd46ed
GM
4220@example
4221@group
3a731e1f
MS
4222if (n > 0)
4223@{ @hereFn{c-indent-one-line-block}
4224 m+=n; n=0;
4225@}
d7bd46ed
GM
4226@end group
4227@end example
4228
3a731e1f
MS
4229The block may be surrounded by any kind of parenthesis characters.
4230@code{nil} is returned if the line doesn't start with a one line block,
4231which makes the function usable in list expressions.
d7bd46ed 4232
3a731e1f
MS
4233@workswith Almost all syntactic symbols, but most useful on the
4234@code{-open} symbols.
4235@end defun
d7bd46ed 4236
3a731e1f
MS
4237@comment ------------------------------------------------------------
4238
4239@defun c-indent-multi-line-block
4240@findex indent-multi-line-block (c-)
4241Indent a multiline block @code{c-basic-offset} extra. E.g:
d7bd46ed 4242
f214c025
GM
4243@example
4244@group
3a731e1f 4245int *foo[] = @{
bf247b6e 4246 NULL,
3a731e1f 4247 @{17@}, @hereFn{c-indent-multi-line-block}
f214c025
GM
4248@end group
4249@end example
3a731e1f 4250
f214c025
GM
4251@noindent
4252and
3a731e1f 4253
f214c025
GM
4254@example
4255@group
3a731e1f
MS
4256int *foo[] = @{
4257 NULL,
4258 @{ @hereFn{c-indent-multi-line-block}
4259 17
4260 @},
4261 @sssTBasicOffset{}
4262@end group
4263@end example
f214c025 4264
3a731e1f
MS
4265The block may be surrounded by any kind of parenthesis characters.
4266@code{nil} is returned if the line doesn't start with a multiline
4267block, which makes the function usable in list expressions.
4268
4269@workswith Almost all syntactic symbols, but most useful on the
4270@code{-open} symbols.
4271@end defun
f214c025 4272
3a731e1f
MS
4273@comment ------------------------------------------------------------
4274
4275@defun c-lineup-argcont
4276@findex lineup-argcont (c-)
4277Line up a continued argument. E.g:
4278
4279@example
4280@group
4281foo (xyz, aaa + bbb + ccc
4282 + ddd + eee + fff); @hereFn{c-lineup-argcont}
f214c025
GM
4283@end group
4284@end example
3a731e1f
MS
4285
4286Only continuation lines like this are touched, @code{nil} is returned on
4287lines which are the start of an argument.
4288
4289Within a gcc @code{asm} block, @code{:} is recognised as an argument
4290separator, but of course only between operand specifications, not in the
4291expressions for the operands.
4292
4293@workswith @code{arglist-cont}, @code{arglist-cont-nonempty}.
4294@end defun
4295
4296@comment ------------------------------------------------------------
4297
4298@defun c-lineup-arglist
4299@findex lineup-arglist (c-)
4300Line up the current argument line under the first argument.
4301
4302As a special case, if an argument on the same line as the open
4303parenthesis starts with a brace block opener, the indentation is
4304@code{c-basic-offset} only. This is intended as a ``DWIM'' measure in
4305cases like macros that contains statement blocks, e.g:
4306
f214c025
GM
4307@example
4308@group
3a731e1f
MS
4309A_VERY_LONG_MACRO_NAME (@{
4310 some (code, with + long, lines * in[it]);
4311 @});
4312@sssTBasicOffset{}
4313@end group
4314@end example
f214c025 4315
3a731e1f
MS
4316This is motivated partly because it's more in line with how code
4317blocks are handled, and partly since it approximates the behavior of
4318earlier CC Mode versions, which due to inaccurate analysis tended to
4319indent such cases this way.
4320
4321@workswith @code{arglist-cont-nonempty}, @code{arglist-close}.
4322@end defun
4323
4324@comment ------------------------------------------------------------
4325
4326@defun c-lineup-arglist-intro-after-paren
4327@findex lineup-arglist-intro-after-paren (c-)
4328Line up a line to just after the open paren of the surrounding paren or
4329brace block.
4330
4331@workswith @code{defun-block-intro}, @code{brace-list-intro},
4332@code{statement-block-intro}, @code{statement-case-intro},
4333@code{arglist-intro}.
4334@end defun
4335
4336@comment ------------------------------------------------------------
4337
4338@defun c-lineup-arglist-close-under-paren
4339@findex lineup-arglist-close-under-paren (c-)
4340Set your @code{arglist-close} syntactic symbol to this line-up function
4341so that parentheses that close argument lists will line up under the
4342parenthesis that opened the argument list. It can also be used with
4343@code{arglist-cont} and @code{arglist-cont-nonempty} to line up all
4344lines inside a parenthesis under the open paren.
4345
4346As a special case, if a brace block is opened at the same line as the
4347open parenthesis of the argument list, the indentation is
4348@code{c-basic-offset} only. See @code{c-lineup-arglist} for further
4349discussion of this ``DWIM'' measure.
4350
4351@workswith Almost all symbols, but are typically most useful on
4352@code{arglist-close}, @code{brace-list-close}, @code{arglist-cont} and
4353@code{arglist-cont-nonempty}.
4354@end defun
4355
4356@comment ------------------------------------------------------------
4357
4358@defun c-lineup-arglist-operators
4359@findex lineup-arglist-operators (c-)
4360Line up lines starting with an infix operator under the open paren.
4361Return @code{nil} on lines that don't start with an operator, to leave
4362those cases to other lineup functions. Example:
f214c025 4363
3a731e1f
MS
4364@example
4365@group
4366if ( x < 10
4367 || at_limit (x, @hereFn{c-lineup-arglist-operators}
4368 list) @hereFn{c-lineup-arglist-operators@r{ returns nil}}
4369 )
f214c025
GM
4370@end group
4371@end example
4372
3a731e1f
MS
4373Since this function doesn't do anything for lines without an infix
4374operator you typically want to use it together with some other lineup
c3a2e2d5 4375settings, e.g., as follows (the @code{arglist-close} setting is just a
3a731e1f 4376suggestion to get a consistent style):
d7bd46ed 4377
d7bd46ed 4378@example
3a731e1f
MS
4379(c-set-offset 'arglist-cont
4380 '(c-lineup-arglist-operators 0))
4381(c-set-offset 'arglist-cont-nonempty
4382 '(c-lineup-arglist-operators c-lineup-arglist))
4383(c-set-offset 'arglist-close
4384 '(c-lineup-arglist-close-under-paren))
4385@end example
d7bd46ed 4386
3a731e1f
MS
4387@workswith @code{arglist-cont}, @code{arglist-cont-nonempty}.
4388@end defun
4389
4390@comment ------------------------------------------------------------
d7bd46ed 4391
3a731e1f
MS
4392@defun c-lineup-C-comments
4393@findex lineup-C-comments (c-)
4394Line up C block comment continuation lines. Various heuristics are used
4395to handle most of the common comment styles. Some examples:
d7bd46ed 4396
3a731e1f
MS
4397@example
4398@group
4399/* /** /*
4400 * text * text text
4401 */ */ */
d7bd46ed
GM
4402@end group
4403@end example
3a731e1f 4404
d7bd46ed
GM
4405@example
4406@group
3a731e1f
MS
4407/* text /* /**
4408 text ** text ** text
4409*/ */ */
4410@end group
4411@end example
d7bd46ed 4412
3a731e1f
MS
4413@example
4414@group
4415/**************************************************
4416 * text
4417 *************************************************/
4418@end group
4419@end example
d7bd46ed 4420
3a731e1f
MS
4421@vindex comment-start-skip
4422@example
4423@group
4424/**************************************************
4425 Free form text comments:
4426 In comments with a long delimiter line at the
4427 start, the indentation is kept unchanged for lines
4428 that start with an empty comment line prefix. The
4429 delimiter line is whatever matches the
4430 @code{comment-start-skip} regexp.
4431**************************************************/
d7bd46ed
GM
4432@end group
4433@end example
4434
3a731e1f 4435The style variable @code{c-comment-prefix-regexp} is used to recognize
c3a2e2d5 4436the comment line prefix, e.g., the @samp{*} that usually starts every
3a731e1f
MS
4437line inside a comment.
4438
4439@workswith The @code{c} syntactic symbol.
4440@end defun
4441
4442@comment ------------------------------------------------------------
4443
4444@defun c-lineup-cascaded-calls
4445@findex lineup-cascaded-calls (c-)
4446Line up ``cascaded calls'' under each other. If the line begins with
4447@code{->} or @code{.} and the preceding line ends with one or more
4448function calls preceded by the same token, then the arrow is lined up
4449with the first of those tokens. E.g:
d7bd46ed 4450
d7bd46ed
GM
4451@example
4452@group
3a731e1f
MS
4453r = proc->add(17)->add(18)
4454 ->add(19) + @hereFn{c-lineup-cascaded-calls}
4455 offset; @hereFn{c-lineup-cascaded-calls@r{ (inactive)}}
4456@end group
4457@end example
d7bd46ed 4458
3a731e1f
MS
4459In any other situation @code{nil} is returned to allow use in list
4460expressions.
4461
4462@workswith @code{topmost-intro-cont}, @code{statement-cont},
4463@code{arglist-cont}, @code{arglist-cont-nonempty}.
4464@end defun
d7bd46ed 4465
3a731e1f
MS
4466@comment ------------------------------------------------------------
4467
4468@defun c-lineup-close-paren
4469@findex lineup-close-paren (c-)
4470Line up the closing paren under its corresponding open paren if the
4471open paren is followed by code. If the open paren ends its line, no
4472indentation is added. E.g:
d7bd46ed 4473
3a731e1f
MS
4474@example
4475@group
4476main (int,
bf247b6e 4477 char **
3a731e1f 4478 ) @hereFn{c-lineup-close-paren}
d7bd46ed
GM
4479@end group
4480@end example
3a731e1f 4481
d7bd46ed
GM
4482@noindent
4483and
3a731e1f 4484
d7bd46ed
GM
4485@example
4486@group
3a731e1f
MS
4487main (
4488 int, char **
4489) @hereFn{c-lineup-close-paren}
4490@end group
4491@end example
d7bd46ed 4492
3a731e1f
MS
4493As a special case, if a brace block is opened at the same line as the
4494open parenthesis of the argument list, the indentation is
4495@code{c-basic-offset} instead of the open paren column. See
4496@code{c-lineup-arglist} for further discussion of this ``DWIM'' measure.
4497
4498@workswith All @code{*-close} symbols.
4499@end defun
4500
4501@comment ------------------------------------------------------------
4502
4503@defun c-lineup-comment
4504@findex lineup-comment (c-)
4505Line up a comment-only line according to the style variable
4506@code{c-comment-only-line-offset}. If the comment is lined up with a
4507comment starter on the previous line, that alignment is preserved.
4508
4509@defopt c-comment-only-line-offset
4510@vindex comment-only-line-offset (c-)
4511This style variable specifies the extra offset for the line. It can
4512contain an integer or a cons cell of the form
4513
4514@example
4515(@r{@var{non-anchored-offset}} . @r{@var{anchored-offset}})
4516@end example
4517
4518@noindent
4519where @var{non-anchored-offset} is the amount of offset given to
4520non-column-zero anchored lines, and @var{anchored-offset} is the amount
4521of offset to give column-zero anchored lines. Just an integer as value
4522is equivalent to @code{(@r{@var{value}} . -1000)}.
4523@end defopt
4524
4525@workswith @code{comment-intro}.
4526@end defun
4527
4528@comment ------------------------------------------------------------
4529
4530@defun c-lineup-cpp-define
4531@findex lineup-cpp-define (c-)
4532Line up macro continuation lines according to the indentation of the
4533construct preceding the macro. E.g:
d7bd46ed 4534
3a731e1f
MS
4535@example
4536@group
4537const char msg[] = @hereFn{@r{The beginning of the preceding construct.}}
4538 \"Some text.\";
4539
4540#define X(A, B) \
4541do @{ \ @hereFn{c-lineup-cpp-define}
4542 printf (A, B); \
4543@} while (0)
d7bd46ed
GM
4544@end group
4545@end example
4546
3a731e1f
MS
4547@noindent
4548and:
d7bd46ed 4549
d7bd46ed
GM
4550@example
4551@group
3a731e1f
MS
4552int dribble() @{
4553 if (!running) @hereFn{@r{The beginning of the preceding construct.}}
4554 error(\"Not running!\");
4555
4556#define X(A, B) \
4557 do @{ \ @hereFn{c-lineup-cpp-define}
4558 printf (A, B); \
4559 @} while (0)
4560@end group
4561@end example
d7bd46ed 4562
3a731e1f
MS
4563If @code{c-syntactic-indentation-in-macros} is non-@code{nil}, the
4564function returns the relative indentation to the macro start line to
c3a2e2d5 4565allow accumulation with other offsets. e.g., in the following cases,
3a731e1f
MS
4566@code{cpp-define-intro} is combined with the
4567@code{statement-block-intro} that comes from the @samp{do @{} that hangs
4568on the @samp{#define} line:
177c0ea7 4569
3a731e1f
MS
4570@example
4571@group
4572const char msg[] =
4573 \"Some text.\";
d7bd46ed 4574
3a731e1f
MS
4575#define X(A, B) do @{ \
4576 printf (A, B); \ @hereFn{c-lineup-cpp-define}
4577 this->refs++; \
4578@} while (0) @hereFn{c-lineup-cpp-define}
d7bd46ed
GM
4579@end group
4580@end example
3a731e1f 4581
d7bd46ed 4582@noindent
3a731e1f
MS
4583and:
4584
d7bd46ed
GM
4585@example
4586@group
3a731e1f
MS
4587int dribble() @{
4588 if (!running)
4589 error(\"Not running!\");
4590
4591#define X(A, B) do @{ \
4592 printf (A, B); \ @hereFn{c-lineup-cpp-define}
4593 this->refs++; \
4594 @} while (0) @hereFn{c-lineup-cpp-define}
4595@end group
4596@end example
d7bd46ed 4597
3a731e1f
MS
4598The relative indentation returned by @code{c-lineup-cpp-define} is zero
4599and two, respectively, on the two lines in each of these examples. They
4600are then added to the two column indentation that
4601@code{statement-block-intro} gives in both cases here.
4602
4603If the relative indentation is zero, then @code{nil} is returned
4604instead. That is useful in a list expression to specify the default
4605indentation on the top level.
4606
4607If @code{c-syntactic-indentation-in-macros} is @code{nil} then this
4608function keeps the current indentation, except for empty lines (ignoring
4609the ending backslash) where it takes the indentation from the closest
4610preceding nonempty line in the macro. If there's no such line in the
4611macro then the indentation is taken from the construct preceding it, as
4612described above.
4613
4614@workswith @code{cpp-define-intro}.
4615@end defun
4616
4617@comment ------------------------------------------------------------
4618
4619@defun c-lineup-dont-change
4620@findex lineup-dont-change (c-)
4621This lineup function makes the line stay at whatever indentation it
4622already has; think of it as an identity function for lineups.
4623
4624@workswith Any syntactic symbol.
4625@end defun
4626
4627@comment ------------------------------------------------------------
d7bd46ed 4628
3a731e1f
MS
4629@defun c-lineup-gcc-asm-reg
4630@findex lineup-gcc-asm-reg (c-)
4631Line up a gcc asm register under one on a previous line.
4632
4633@example
4634@group
4635 asm ("foo %1, %0\n"
4636 "bar %0, %1"
4637 : "=r" (w),
4638 "=r" (x)
4639 : "0" (y),
4640 "1" (z));
d7bd46ed
GM
4641@end group
4642@end example
4643
3a731e1f
MS
4644The @samp{x} line is aligned to the text after the @samp{:} on the
4645@samp{w} line, and similarly @samp{z} under @samp{y}.
d7bd46ed 4646
3a731e1f
MS
4647This is done only in an @samp{asm} or @samp{__asm__} block, and only to
4648those lines mentioned. Anywhere else @code{nil} is returned. The usual
4649arrangement is to have this routine as an extra feature at the start of
4650arglist lineups, e.g.
d7bd46ed 4651
d7bd46ed 4652@example
3a731e1f
MS
4653(c-lineup-gcc-asm-reg c-lineup-arglist)
4654@end example
d7bd46ed 4655
3a731e1f
MS
4656@workswith @code{arglist-cont}, @code{arglist-cont-nonempty}.
4657@end defun
4658
4659@comment ------------------------------------------------------------
4660
4661@defun c-lineup-inexpr-block
4662@findex lineup-inexpr-block (c-)
4663This can be used with the in-expression block symbols to indent the
c3a2e2d5 4664whole block to the column where the construct is started. e.g., for Java
3a731e1f
MS
4665anonymous classes, this lines up the class under the @samp{new} keyword,
4666and in Pike it lines up the lambda function body under the @samp{lambda}
4667keyword. Returns @code{nil} if the block isn't part of such a
4668construct.
4669
4670@workswith @code{inlambda}, @code{inexpr-statement},
4671@code{inexpr-class}.
4672@end defun
d7bd46ed 4673
3a731e1f
MS
4674@comment ------------------------------------------------------------
4675
4676@defun c-lineup-java-inher
4677@findex lineup-java-inher (c-)
4678Line up Java implements and extends declarations. If class names
4679follow on the same line as the @samp{implements}/@samp{extends}
4680keyword, they are lined up under each other. Otherwise, they are
4681indented by adding @code{c-basic-offset} to the column of the keyword.
4682E.g:
4683
4684@example
4685@group
4686class Foo
bf247b6e 4687 extends
3a731e1f
MS
4688 Bar @hereFn{c-lineup-java-inher}
4689 @sssTBasicOffset{}
d7bd46ed
GM
4690@end group
4691@end example
3a731e1f 4692
d7bd46ed
GM
4693@noindent
4694and
3a731e1f 4695
d7bd46ed
GM
4696@example
4697@group
3a731e1f
MS
4698class Foo
4699 extends Cyphr,
4700 Bar @hereFn{c-lineup-java-inher}
4701@end group
4702@end example
d7bd46ed 4703
3a731e1f
MS
4704@workswith @code{inher-cont}.
4705@end defun
4706
4707@comment ------------------------------------------------------------
d7bd46ed 4708
3a731e1f
MS
4709@defun c-lineup-java-throws
4710@findex lineup-java-throws (c-)
4711Line up Java throws declarations. If exception names follow on the
4712same line as the throws keyword, they are lined up under each other.
4713Otherwise, they are indented by adding @code{c-basic-offset} to the
4714column of the @samp{throws} keyword. The @samp{throws} keyword itself
4715is also indented by @code{c-basic-offset} from the function declaration
4716start if it doesn't hang. E.g:
d7bd46ed 4717
3a731e1f
MS
4718@example
4719@group
4720int foo()
4721 throws @hereFn{c-lineup-java-throws}
4722 Bar @hereFn{c-lineup-java-throws}
4723@sssTsssTBasicOffset{}
d7bd46ed
GM
4724@end group
4725@end example
4726
3a731e1f
MS
4727@noindent
4728and
d7bd46ed 4729
d7bd46ed 4730@example
d7bd46ed 4731@group
3a731e1f
MS
4732int foo() throws Cyphr,
4733 Bar, @hereFn{c-lineup-java-throws}
4734 Vlod @hereFn{c-lineup-java-throws}
d7bd46ed 4735@end group
3a731e1f
MS
4736@end example
4737
4738@workswith @code{func-decl-cont}.
4739@end defun
4740
4741@comment ------------------------------------------------------------
d7bd46ed 4742
3a731e1f
MS
4743@defun c-lineup-knr-region-comment
4744@findex lineup-knr-region-comment (c-)
4745Line up a comment in the ``K&R region'' with the declaration. That is
4746the region between the function or class header and the beginning of the
4747block. E.g:
4748
4749@example
d7bd46ed 4750@group
3a731e1f
MS
4751int main()
4752/* Called at startup. */ @hereFn{c-lineup-knr-region-comment}
4753@{
4754 return 0;
4755@}
d7bd46ed 4756@end group
3a731e1f 4757@end example
d7bd46ed 4758
3a731e1f
MS
4759Return @code{nil} if called in any other situation, to be useful in list
4760expressions.
4761
4762@workswith @code{comment-intro}.
4763@end defun
4764
4765@comment ------------------------------------------------------------
4766
4767@defun c-lineup-math
4768@findex lineup-math (c-)
4769Line up the current line to after the equal sign on the first line in the
4770statement. If there isn't any, indent with @code{c-basic-offset}. If
4771the current line contains an equal sign too, try to align it with the
4772first one.
4773
4774@workswith @code{topmost-intro-cont}, @code{statement-cont},
4775@code{arglist-cont}, @code{arglist-cont-nonempty}.
4776@end defun
4777
4778@comment ------------------------------------------------------------
4779
4780@defun c-lineup-multi-inher
4781@findex lineup-multi-inher (c-)
4782Line up the classes in C++ multiple inheritance clauses and member
4783initializers under each other. E.g:
4784
4785@example
d7bd46ed 4786@group
3a731e1f
MS
4787Foo::Foo (int a, int b):
4788 Cyphr (a),
4789 Bar (b) @hereFn{c-lineup-multi-inher}
d7bd46ed 4790@end group
3a731e1f 4791@end example
d7bd46ed 4792
3a731e1f
MS
4793@noindent
4794and
4795
4796@example
d7bd46ed 4797@group
3a731e1f
MS
4798class Foo
4799 : public Cyphr,
4800 public Bar @hereFn{c-lineup-multi-inher}
d7bd46ed 4801@end group
3a731e1f
MS
4802@end example
4803
4804@noindent
4805and
d7bd46ed 4806
3a731e1f
MS
4807@example
4808@group
4809Foo::Foo (int a, int b)
4810 : Cyphr (a)
4811 , Bar (b) @hereFn{c-lineup-multi-inher}
4812@end group
d7bd46ed
GM
4813@end example
4814
3a731e1f
MS
4815@workswith @code{inher-cont}, @code{member-init-cont}.
4816@end defun
d7bd46ed 4817
3a731e1f 4818@comment ------------------------------------------------------------
d7bd46ed 4819
3a731e1f
MS
4820@defun c-lineup-ObjC-method-call
4821@findex lineup-ObjC-method-call (c-)
4822For Objective-C code, line up selector args as Emacs Lisp mode does
4823with function args: go to the position right after the message receiver,
4824and if you are at the end of the line, indent the current line
4825c-basic-offset columns from the opening bracket; otherwise you are
4826looking at the first character of the first method call argument, so
4827lineup the current line with it.
d7bd46ed 4828
3a731e1f
MS
4829@workswith @code{objc-method-call-cont}.
4830@end defun
d7bd46ed 4831
3a731e1f 4832@comment ------------------------------------------------------------
d7bd46ed 4833
3a731e1f
MS
4834@defun c-lineup-ObjC-method-args
4835@findex lineup-ObjC-method-args (c-)
4836For Objective-C code, line up the colons that separate args. The colon
4837on the current line is aligned with the one on the first line.
d7bd46ed 4838
3a731e1f
MS
4839@workswith @code{objc-method-args-cont}.
4840@end defun
d7bd46ed 4841
3a731e1f
MS
4842@comment ------------------------------------------------------------
4843
4844@defun c-lineup-ObjC-method-args-2
4845@findex lineup-ObjC-method-args-2 (c-)
4846Similar to @code{c-lineup-ObjC-method-args} but lines up the colon on
4847the current line with the colon on the previous line.
4848
4849@workswith @code{objc-method-args-cont}.
4850@end defun
4851
4852@comment ------------------------------------------------------------
d7bd46ed 4853
3a731e1f 4854@defun c-lineup-runin-statements
d7bd46ed 4855@findex lineup-runin-statements (c-)
d7bd46ed
GM
4856Line up statements for coding standards which place the first statement
4857in a block on the same line as the block opening brace@footnote{Run-in
4858style doesn't really work too well. You might need to write your own
4859custom indentation functions to better support this style.}. E.g:
3a731e1f 4860
d7bd46ed
GM
4861@example
4862@group
d7bd46ed 4863int main()
3a731e1f
MS
4864@{ puts ("Hello!");
4865 return 0; @hereFn{c-lineup-runin-statements}
d7bd46ed 4866@}
d7bd46ed
GM
4867@end group
4868@end example
4869
4870If there is no statement after the opening brace to align with,
4871@code{nil} is returned. This makes the function usable in list
4872expressions.
4873
4874@workswith The @code{statement} syntactic symbol.
3a731e1f 4875@end defun
d7bd46ed 4876
3a731e1f
MS
4877@comment ------------------------------------------------------------
4878
4879@defun c-lineup-streamop
4880@findex lineup-streamop (c-)
c3a2e2d5 4881Line up C++ stream operators (i.e., @samp{<<} and @samp{>>}).
3a731e1f
MS
4882
4883@workswith @code{stream-op}.
4884@end defun
4885
4886@comment ------------------------------------------------------------
4887
4888@defun c-lineup-string-cont
4889@findex lineup-string-cont (c-)
4890Line up a continued string under the one it continues. A continued
4891string in this sense is where a string literal follows directly after
4892another one. E.g:
d7bd46ed 4893
3a731e1f
MS
4894@example
4895@group
4896result = prefix + "A message "
4897 "string."; @hereFn{c-lineup-string-cont}
4898@end group
4899@end example
d7bd46ed 4900
3a731e1f
MS
4901@code{nil} is returned in other situations, to allow stacking with other
4902lineup functions.
4903
4904@workswith @code{topmost-intro-cont}, @code{statement-cont},
4905@code{arglist-cont}, @code{arglist-cont-nonempty}.
4906@end defun
4907
4908@comment ------------------------------------------------------------
4909
4910@defun c-lineup-template-args
d7bd46ed 4911@findex lineup-template-args (c-)
d7bd46ed
GM
4912Line up the arguments of a template argument list under each other, but
4913only in the case where the first argument is on the same line as the
4914opening @samp{<}.
4915
4916To allow this function to be used in a list expression, @code{nil} is
4917returned if there's no template argument on the first line.
4918
4919@workswith @code{template-args-cont}.
3a731e1f 4920@end defun
d7bd46ed 4921
3a731e1f 4922@comment ------------------------------------------------------------
d7bd46ed 4923
3a731e1f
MS
4924@defun c-lineup-topmost-intro-cont
4925@findex lineup-topmost-intro-cont (c-)
4926Line up declaration continuation lines zero or one indentation
4927step@footnote{This function is mainly provided to mimic the behavior of
4928CC Mode 5.28 and earlier where this case wasn't handled consistently so
4929that those lines could be analyzed as either topmost-intro-cont or
4930statement-cont. It's used for @code{topmost-intro-cont} by default, but
4931you might consider using @code{+} instead.}. For lines preceding a
4932definition, zero is used. For other lines, @code{c-basic-offset} is
4933added to the indentation. E.g:
d7bd46ed 4934
3a731e1f
MS
4935@example
4936@group
4937int
4938neg (int i) @hereFn{c-lineup-topmost-intro-cont}
4939@{
4940 return -i;
4941@}
4942@end group
4943@end example
d7bd46ed 4944
3a731e1f
MS
4945@noindent
4946and
d7bd46ed 4947
3a731e1f
MS
4948@example
4949@group
4950struct
4951larch @hereFn{c-lineup-topmost-intro-cont}
4952@{
4953 double height;
4954@}
4955 the_larch, @hereFn{c-lineup-topmost-intro-cont}
4956 another_larch; @hereFn{c-lineup-topmost-intro-cont}
4957@sssTBasicOffset{}
4958@end group
4959@end example
d7bd46ed 4960
3a731e1f
MS
4961@noindent
4962and
d7bd46ed 4963
3a731e1f
MS
4964@example
4965@group
4966struct larch
4967the_larch, @hereFn{c-lineup-topmost-intro-cont}
4968 another_larch; @hereFn{c-lineup-topmost-intro-cont}
4969@end group
4970@end example
d7bd46ed 4971
3a731e1f
MS
4972@workswith @code{topmost-intro-cont}.
4973@end defun
4974
4975@comment ------------------------------------------------------------
d7bd46ed 4976
3a731e1f 4977@defun c-lineup-whitesmith-in-block
d7bd46ed 4978@findex lineup-whitesmith-in-block (c-)
3a731e1f 4979Line up lines inside a block in Whitesmith style. It's done in a way
d7bd46ed 4980that works both when the opening brace hangs and when it doesn't. E.g:
3a731e1f 4981
d7bd46ed
GM
4982@example
4983@group
d7bd46ed
GM
4984something
4985 @{
3a731e1f 4986 foo; @hereFn{c-lineup-whitesmith-in-block}
d7bd46ed 4987 @}
d7bd46ed
GM
4988@end group
4989@end example
3a731e1f 4990
d7bd46ed
GM
4991@noindent
4992and
3a731e1f 4993
d7bd46ed
GM
4994@example
4995@group
d7bd46ed 4996something @{
3a731e1f 4997 foo; @hereFn{c-lineup-whitesmith-in-block}
d7bd46ed 4998 @}
3a731e1f 4999@sssTBasicOffset{}
d7bd46ed
GM
5000@end group
5001@end example
5002
5003In the first case the indentation is kept unchanged, in the second
5004@code{c-basic-offset} is added.
5005
5006@workswith @code{defun-close}, @code{defun-block-intro},
5007@code{block-close}, @code{brace-list-close}, @code{brace-list-intro},
3a731e1f 5008@code{statement-block-intro} and all @code{in*} symbols,
c3a2e2d5 5009e.g., @code{inclass} and @code{inextern-lang}.
3a731e1f 5010@end defun
d7bd46ed 5011
d7bd46ed 5012
3a731e1f
MS
5013@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5014@node AWK Mode, Odds and Ends, Indentation Functions, Top
5015@comment node-name, next, previous, up
5016@chapter Status of AWK Mode
5017@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5018
5019@dfn{AWK mode} existed until recently in the file @file{awk-mode.el}
5020as a mode derived from c-mode. It had not been actively maintained to
5021keep pace with the newer @ccmode{}, and its indentation mechanism no
5022longer worked satisfactorally.
5023
5024The current AWK mode is based around the GNU implementation,
5025@emph{GAWK version 3.1.0}, though it should work pretty well with any
5026AWK. It has now been updated and integrated into @ccmode{} to a
5027substantial extent, though as yet not all the features of @ccmode{}
5028have been adapted to support it.
5029
5030If your (X)Emacs is set up to use the old file @file{awk-mode.elc}
5031(which will usually be the case if you have obtained this @ccmode{}
5032independently of (X)Emacs itself), or if you are not sure, insert the
5033following form into your @file{.emacs} or @file{init.el} so that the new
5034AWK mode will be used instead:
5035
5036@example
5037(autoload 'awk-mode "cc-mode" nil t)
5038@end example
5039
5040You can check which AWK mode you are running by displaying the mode
5041documentation string with @kbd{C-h m} from an AWK buffer. The newer
5042mode's doc string contains @code{To submit a problem report, enter
5043`C-c C-b'} near the top of the doc string where the older mode has
5044@code{This is much like C mode except ....}.
d7bd46ed 5045
3a731e1f
MS
5046Since this newer AWK mode makes essential use of a relatively new
5047Emacs Lisp feature@footnote{Specifically, the @code{syntax-table} text
5048property.}, you need either GNU Emacs 20.1 (or later) or XEmacs 21.4
5049(or later) to use it. If your Emacs version is earlier than one of
5050these, the older @file{awk-mode.el} will get loaded and run in place
5051of the AWK mode described here, even when you have put the above
5052@code{autoload} form into your @file{.emacs} or @file{init.el}.
5053Upgrading your (X)Emacs is strongly recommended if this is the case.
5054
5055Here is an overview of which @ccmode{} features currently work with
5056AWK mode and which don't:
5057
5058@table @asis
5059@item Indentation Engine
5060The @ccmode{} indentation engine fully supports AWK mode.
5061@xref{Indentation Engine}.
5062
5063AWK mode handles code formatted in the conventional AWK fashion:
5064@samp{@{}s which start actions, user-defined functions, or compound
5065statements are placed on the same line as the associated construct; the
5066matching @samp{@}}s are normally placed under the start of the
5067respective pattern, function definition, or structured statement.
5068@c Add in a bit about the @samp{@}} being on the same line when the
5069@c contents are short.
5070
5071The predefined indentation functions (@pxref{Indentation Functions})
5072haven't yet been adapted for AWK mode, though some of them may work
5073serendipitously. There shouldn't be any problems writing custom
5074indentation functions for AWK mode.
5075
5076The command @kbd{C-c C-q} (@code{c-indent-defun}) hasn't yet been
5077adapted for AWK, though in practice it works properly nearly all the
5078time. Should it fail, explicitly set the region around the function
5079(using @kbd{C-u C-SPC}: @kbd{C-M-h} probably won't work either) then do
5080@kbd{C-M-\} (@code{indent-region}).
5081
5082@item Font Locking
5083There is a single level of font locking in AWK mode, rather than the
5084three distinct levels the other modes have. There are several
5085idiosyncrasies in AWK mode's font-locking due to the peculiarities of
5086the AWK language itself. @xref{AWK Mode Font Locking}.
5087
5088@item Comment Commands
5089@kbd{M-;} (@code{indent-for-comment}) works fine. None of the other
5090@ccmode{} comment formatting commands have yet been adapted for AWK
5091mode. @xref{Text Filling and Line Breaking}.
5092
5093@item Movement Commands
5094Most of the movement commands work in AWK mode. The most important
5095exceptions are @kbd{M-a} (@code{c-beginning-of-statement}) and
5096@kbd{M-e} (@code{c-end-of-statement}) which haven't yet been adapted.
5097
5098The notion of @dfn{defun} has been augmented to include pattern-action
5099pairs. See @ref{AWK Mode Defuns} for a description of commands which
5100work on AWK ``defuns''.
5101
5102Since there is no preprocessor in AWK, the commands which move to
c3a2e2d5 5103preprocessor directives (e.g., @code{c-up-conditional}) are meaningless
3a731e1f
MS
5104in AWK mode and are not bound in the AWK mode keymap.
5105
5106@item Auto-newline Insertion and Clean-ups
5107Auto-newline insertion hasn't yet been adapted for AWK. Some of the
5108clean-ups can actually convert good AWK code into syntactically
5109invalid code.
5110
5111If auto-newline or its associated clean-ups are enabled generally for
5112the modes in @ccmode{}, you are strongly recommended to disable them
5113in the AWK Mode hook. @xref{Initialising AWK Mode}.
5114
5115The clean-up @code{space-before-funcall}, which is independent of
5116auto-newline, should never be active in AWK mode (since inserting a
5117space between a user function's name and its opening @samp{(} makes
5118the call syntactically invalid). If necessary, this should be
5119disabled in the AWK Mode hook. @xref{Initialising AWK Mode}.
5120
5121@end table
5122
5123@menu
5124* Initialising AWK Mode::
5125* AWK Mode Font Locking::
5126* AWK Mode Defuns::
5127@end menu
5128
5129
5130@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5131@node Initialising AWK Mode, AWK Mode Font Locking, , AWK Mode
5132@comment node-name, next, previous, up
5133@section AWK mode - What to put in your @file{.emacs} or @file{init.el}
5134@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5135
5136Much of the AWK mode initialization can, of course, be done by the
5137@ccmode{} general initialization procedure. You may want to use certain
5138@ccmode{} features such as @code{auto-newline} and @code{clean-ups} in
5139the other modes, and you might thus have enabled them in a
5140@code{c-mode-common-hook} function, as described in @ref{Sample .emacs File}.
5141These features have not yet been amended for AWK mode, and far from
5142being useful, can be irritating in AWK mode or actually make AWK code
5143syntactically invalid. Adding the following code to your
5144@file{.emacs} or @file{init.el} file will disable them for AWK mode.
5145
5146@example
5147(defun my-awk-mode-hook ()
5148 "Disable certain @ccmode{} features which could impair AWK mode."
5149 (c-toggle-auto-state -1) ; disable automatic insertions of newlines
5150 (if (memq 'space-before-funcall c-cleanup-list)
5151 (setq c-cleanup-list ; don't automatically insert a space into "foo("
5152 (remove 'space-before-funcall c-cleanup-list))))
5153(add-hook 'awk-mode-hook 'my-awk-mode-hook)
5154@end example
5155
5156Naturally you can add your own AWK-specific customizations to this
5157function. @xref{Hooks}.
5158
5159
5160@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5161@node AWK Mode Font Locking, AWK Mode Defuns, Initialising AWK Mode, AWK Mode
5162@comment node-name, next, previous, up
5163@section AWK Mode Font Locking
5164@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5165
5166The general appearance of font-locking in AWK mode is much like in any
5167other programming mode. @xref{Faces For Font Lock,,,elisp}.
5168
5169The following faces are, however, used in a non-standard fashion in
5170AWK mode:
5171
5172@table @asis
5173@item @code{font-lock-variable-name-face}
5174This face was intended for variable declarations. Since variables are
5175not declared in AWK, this face is used instead for AWK system
5176variables (such as @code{NF}) and ``Special File Names'' (such as
5177@code{"/dev/stderr"}).
5178
5179@item @code{font-lock-builtin-face} (Emacs)/@code{font-lock-preprocessor-face} (XEmacs)
5180This face is normally used for preprocessor directives in @ccmode{}.
5181There are no such things in AWK, so this face is used instead for
5182standard functions (such as @code{match}).
5183
5184@item @code{font-lock-string-face}
5185As well as being used for strings, including localizable strings,
5186(delimited by @samp{"} and @samp{_"}), this face is also used for AWK
5187regular expressions (delimited by @samp{/}).
5188
5189@item @code{font-lock-warning-face} (Emacs)/@code{c-invalid-face} (XEmacs)
5190This face highlights the following syntactically invalid AWK
5191constructs:
5192
5193@itemize @bullet
5194@item
5195An unterminated string or regular expression. Here the opening
5196delimiter (@samp{"} or @samp{/} or @samp{_"}) is displayed in
5197@code{font-lock-warning-face}. This is most noticeable when typing in a
5198new string/regular expression into a buffer, when the warning-face
5199serves as a continual reminder to terminate the construct.
5200
5201AWK mode fontifies unterminated strings/regular expressions
5202differently from other modes: Only the text up to the end of the line
5203is fontified as a string (escaped newlines being handled correctly),
5204rather than the text up to the next string quote.
5205
5206@item
5207A space between the function name and opening parenthesis when calling
5208a user function. The last character of the function name and the
5209opening parenthesis are highlighted. This font-locking rule will
5210spuriously highlight a valid concatenation expression where an
5211identifier precedes a parenthesised expression. Unfortunately.
5212
5213@item
5214Whitespace following the @samp{\} in what otherwise looks like an
5215escaped newline. The @samp{\} is highlighted.
5216@end itemize
5217@end table
5218
5219
5220@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5221@node AWK Mode Defuns, , AWK Mode Font Locking, AWK Mode
5222@comment node-name, next, previous, up
5223@section AWK Mode Defuns
5224@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5225
5226In AWK mode, @dfn{defun} means either a user-defined function or a
5227pattern-action pair. Either the pattern or the action may be
5228implicit.
5229
5230The beginning of a defun is recognised heuristically as, more or less,
5231code which begins in column zero. Having the @samp{@{} in column zero,
5232as is suggested for some modes, is neither necessary nor helpful in AWK
5233mode.
5234
5235More precisely, the beginning of a defun is code which begins in
5236column zero, and which isn't a closing brace, a comment, or a
5237continuation of the previous line. Code is the @dfn{continuation of
5238the previous line} when that line is syntactically incomplete, for
5239example when it ends with @samp{@{} or an escaped newline.
5240
5241The end of a defun is the @samp{@}} which matches the @samp{@{} (if
5242any) at the beginning of the action or function body, or the EOL or
5243@samp{;} which marks an implicit action. Although this @samp{@}} is
5244usually placed in column zero, AWK mode doesn't need it to be placed
5245there.
5246
5247@table @asis
5248@item @kbd{C-M-a} @code{c-awk-beginning-of-defun}
5249@itemx @kbd{C-M-e} @code{c-awk-end-of-defun}
5250@findex c-awk-beginning-of-defun
5251@findex awk-beginning-of-defun (c-)
5252@findex c-awk-end-of-defun
5253@findex awk-end-of-defun (c-)
5254Move point back to the beginning or forward to the end of the current
5255AWK defun. These functions can take prefix-arguments, their
5256functionality being entirely equivalent to @code{beginning-of-defun}
5257and @code{end-of-defun}. @xref{Moving by Defuns,,,emacs}.
5258
5259@item @kbd{C-M-h} @code{c-mark-function}
5260This works fine with AWK defuns. @xref{Indentation Commands}.
d7bd46ed
GM
5261@end table
5262
6bf7aab6 5263
d7bd46ed 5264@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f
MS
5265@node Odds and Ends, Performance Issues, AWK Mode, Top
5266@comment node-name, next, previous, up
5267@chapter Odds and Ends
5268@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5269
5270The stuff that didn't fit in anywhere else is documented here.
5271
5272@defopt c-require-final-newline
5273@vindex require-final-newline (c-)
5274Controls whether a final newline is ensured when the file is saved. The
5275value is an association list that for each language mode specifies the
5276value to give to @code{require-final-newline} at mode initialization;
5277see that variable for details about the value. If a language isn't
2a15eb73 5278present on the association list, CC Mode won't touch
3a731e1f
MS
5279@code{require-final-newline} in buffers for that language.
5280
5281The default is to set @code{require-final-newline} to @code{t} in the
5282languages that mandates that source files should end with newlines,
c3a2e2d5 5283i.e., C, C++ and Objective-C.
3a731e1f
MS
5284@end defopt
5285
5286@defopt c-echo-syntactic-information-p
5287@vindex echo-syntactic-information-p (c-)
5288If non-@code{nil}, the syntactic analysis for the current line is shown
5289in the echo area when it's indented (unless
5290@code{c-syntactic-indentation} is @code{nil}). That's useful when
5291finding out which syntactic symbols to modify to get the indentation you
5292want.
5293@end defopt
5294
5295@defopt c-report-syntactic-errors
5296@vindex report-syntactic-errors (c-)
5297If non-@code{nil}, certain syntactic errors are reported with a ding and
5298a message, for example when an @code{else} is indented for which there
5299is no corresponding @code{if}.
5300
5301Note however that @ccmode{} doesn't make any special effort to check for
5302syntactic errors; that's the job of the compiler. The reason it can
5303report cases like the one above is that it can't find the correct
5304anchoring position to indent the line in that case.
5305@end defopt
5306
5307
5308@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5309@node Performance Issues, Limitations and Known Bugs, Odds and Ends, Top
d7bd46ed 5310@comment node-name, next, previous, up
3a731e1f
MS
5311@chapter Performance Issues
5312@cindex performance
6bf7aab6
DL
5313@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5314
3a731e1f
MS
5315@comment FIXME: (ACM, 2003/5/24). Check whether AWK needs mentioning here.
5316
6bf7aab6 5317C and its derivative languages are highly complex creatures. Often,
3a731e1f
MS
5318ambiguous code situations arise that require @ccmode{} to scan large
5319portions of the buffer to determine syntactic context. Such
5320pathological code can cause @ccmode{} to perform fairly badly. This
5321section gives some insight in how @ccmode{} operates, how that interacts
5322with some coding styles, and what you can use to improve performance.
5323
c3a2e2d5 5324The overall goal is that @ccmode{} shouldn't be overly slow (i.e., take
3a731e1f 5325more than a fraction of a second) in any interactive operation.
c3a2e2d5 5326i.e., it's tuned to limit the maximum response time in single operations,
3a731e1f
MS
5327which sometimes is at the expense of batch-like operations like
5328reindenting whole blocks. If you find that @ccmode{} gradually gets
5329slower and slower in certain situations, perhaps as the file grows in
5330size or as the macro or comment you're editing gets bigger, then chances
5331are that something isn't working right. You should consider reporting
5332it, unless it's something that's mentioned in this section.
6bf7aab6
DL
5333
5334Because @ccmode{} has to scan the buffer backwards from the current
5335insertion point, and because C's syntax is fairly difficult to parse in
5336the backwards direction, @ccmode{} often tries to find the nearest
3a731e1f
MS
5337position higher up in the buffer from which to begin a forward scan
5338(it's typically an opening or closing parethesis of some kind). The
5339farther this position is from the current insertion point, the slower it
5340gets.
6bf7aab6
DL
5341
5342@findex beginning-of-defun
5343@findex defun-prompt-regexp
5344One of the simplest things you can do to reduce scan time, is make sure
c3a2e2d5 5345any brace that opens a top-level construct@footnote{e.g., a function in
6bf7aab6
DL
5346C, or outermost class definition in C++ or Java.} always appears in the
5347leftmost column. This is actually an Emacs constraint, as embodied in
d7bd46ed 5348the @code{beginning-of-defun} function which @ccmode{} uses heavily. If
3a731e1f
MS
5349you hang top-level open braces on the right side of the line, then you
5350might want to set the variable @code{defun-prompt-regexp} to something
5351reasonable, however that ``something reasonable'' is difficult to
5352define, so @ccmode{} doesn't do it for you.
6bf7aab6
DL
5353
5354@vindex c-Java-defun-prompt-regexp
5355@vindex Java-defun-prompt-regexp (c-)
3a731e1f
MS
5356A special note about @code{defun-prompt-regexp} in Java mode: The common
5357style is to hang the opening braces of functions and classes on the
5358right side of the line, and that doesn't work well with the Emacs
5359approach. @ccmode{} comes with a variable
6bf7aab6
DL
5360@code{c-Java-defun-prompt-regexp} which tries to define a regular
5361expression usable for this style, but there are problems with it. In
5362some cases it can cause @code{beginning-of-defun} to hang@footnote{This
5363has been observed in Emacs 19.34 and XEmacs 19.15.}. For this reason,
5364it is not used by default, but if you feel adventurous, you can set
5365@code{defun-prompt-regexp} to it in your mode hook. In any event,
3a731e1f
MS
5366setting and relying on @code{defun-prompt-regexp} will definitely slow
5367things down because (X)Emacs will be doing regular expression searches a
5368lot, so you'll probably be taking a hit either way!
5369
5370@ccmode{} maintains a cache of the opening parentheses of the blocks
5371surrounding the point, and it adapts that cache as the point is moved
5372around. That means that in bad cases it can take noticeable time to
5373indent a line in a new surrounding, but after that it gets fast as long
5374as the point isn't moved far off. The farther the point is moved, the
5375less useful is the cache. Since editing typically is done in ``chunks''
5376rather than on single lines far apart from each other, the cache
5377typically gives good performance even when the code doesn't fit the
5378Emacs approach to finding the defun starts.
d7bd46ed
GM
5379
5380@vindex c-enable-xemacs-performance-kludge-p
5381@vindex enable-xemacs-performance-kludge-p (c-)
3a731e1f 5382XEmacs users can set the variable
d7bd46ed
GM
5383@code{c-enable-xemacs-performance-kludge-p} to non-@code{nil}. This
5384tells @ccmode{} to use XEmacs-specific built-in functions which, in some
3a731e1f 5385circumstances, can locate the top-most opening brace much more quickly than
d7bd46ed 5386@code{beginning-of-defun}. Preliminary testing has shown that for
c3a2e2d5 5387styles where these braces are hung (e.g., most JDK-derived Java styles),
d7bd46ed
GM
5388this hack can improve performance of the core syntax parsing routines
5389from 3 to 60 times. However, for styles which @emph{do} conform to
5390Emacs' recommended style of putting top-level braces in column zero,
5391this hack can degrade performance by about as much. Thus this variable
3a731e1f
MS
5392is set to @code{nil} by default, since the Emacs-friendly styles should
5393be more common (and encouraged!). Note that this variable has no effect
5394in Emacs since the necessary built-in functions don't exist (in Emacs
539521.3 as of this writing in May 2003).
5396
5397Text properties are used to speed up skipping over syntactic whitespace,
c3a2e2d5 5398i.e., comments and preprocessor directives. Indenting a line after a
3a731e1f
MS
5399huge macro definition can be slow the first time, but after that the
5400text properties are in place and it should be fast (even after you've
5401edited other parts of the file and then moved back).
5402
5403Font locking can be a CPU hog, especially the font locking done on
5404decoration level 3 which tries to be very accurate. Note that that
5405level is designed to be used with a font lock support mode that only
c3a2e2d5 5406fontifies the text that's actually shown, i.e., Lazy Lock or Just-in-time
3a731e1f
MS
5407Lock mode, so make sure you use one of them. Fontification of a whole
5408buffer with some thousand lines can often take over a minute. That is
5409a known weakness; the idea is that it never should happen.
5410
5411The most effective way to speed up font locking is to reduce the
5412decoration level to 2 by setting @code{font-lock-maximum-decoration}
5413appropriately. That level is designed to be as pretty as possible
5414without sacrificing performance. @xref{Font Locking Preliminaries}, for
5415more info.
6bf7aab6
DL
5416
5417
cb7f2e96
GM
5418@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5419@node Limitations and Known Bugs, Frequently Asked Questions, Performance Issues, Top
5420@comment node-name, next, previous, up
3a731e1f 5421@chapter Limitations and Known Bugs
cb7f2e96
GM
5422@cindex limitations
5423@cindex bugs
5424@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5425
5426@itemize @bullet
5427@item
3a731e1f
MS
5428There is no way to apply auto newline settings (@pxref{Auto-newline
5429Insertion}) on already typed lines. That's only a feature to ease
5430interactive editing.
cb7f2e96 5431
3a731e1f
MS
5432To generalize this issue a bit: @ccmode{} is not intended to be used as
5433a reformatter for old code in some more or less batch-like way. With
5434the exception of some functions like @code{c-indent-region}, it's only
5435geared to be used interactively to edit new code. There's currently no
5436intention to change this goal.
5437
5438If you want to reformat old code, you're probably better off using some
c3a2e2d5 5439other tool instead, e.g., @ref{Top, , GNU indent, indent, The `indent'
3a731e1f
MS
5440Manual}, which has more powerful reformatting capabilities than
5441@ccmode{}.
cb7f2e96 5442
cb7f2e96 5443@item
3a731e1f
MS
5444@vindex signal-error-on-buffer-boundary
5445XEmacs has a variable called @code{signal-error-on-buffer-boundary}.
5446It's used as a solution to user interface problems associated with
cb7f2e96 5447buffer movement and the @code{zmacs-region} deactivation on errors.
3a731e1f
MS
5448However, setting this variable to a non-default value in XEmacs 19 and
544920 had the deleterious side effect of breaking many built-in primitive
5450functions. @strong{Do not set this variable to @code{nil} in XEmacs
545119 and 20}; you will cause serious problems in @ccmode{} and probably
5452other XEmacs packages! In XEmacs 21 the effects of the variable is
5453limited to some functions that are only used interactively, so it's
5454not a problem there.
cb7f2e96
GM
5455@end itemize
5456
5457
6bf7aab6 5458@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
cb7f2e96 5459@node Frequently Asked Questions, Getting the Latest CC Mode Release, Limitations and Known Bugs, Top
d7bd46ed 5460@comment node-name, next, previous, up
cb7f2e96 5461@appendix Frequently Asked Questions
6bf7aab6
DL
5462@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5463
3a731e1f
MS
5464@itemize @bullet
5465@item
6bf7aab6 5466@kindex C-x h
d7bd46ed 5467@kindex C-M-\
3a731e1f 5468@emph{How do I reindent the whole file?}
6bf7aab6 5469
3a731e1f
MS
5470Visit the file and hit @kbd{C-x h} to mark the whole buffer. Then hit
5471@kbd{C-M-\}.
6bf7aab6 5472
3a731e1f
MS
5473@item
5474@kindex C-M-q
5475@kindex C-M-u
5476@emph{How do I reindent the current block?}
6bf7aab6 5477
3a731e1f
MS
5478First move to the brace which opens the block with @kbd{C-M-u}, then
5479reindent that expression with @kbd{C-M-q}.
6bf7aab6 5480
3a731e1f
MS
5481@item
5482@kindex RET
5483@kindex C-j
5484@emph{Why doesn't the @kbd{RET} key indent the new line?}
6bf7aab6 5485
3a731e1f
MS
5486Emacs' convention is that @kbd{RET} just adds a newline, and that
5487@kbd{C-j} adds a newline and indents it. You can make @kbd{RET} do this
5488too by adding this to your @code{c-mode-common-hook}:
6bf7aab6 5489
6bf7aab6 5490@example
d7bd46ed 5491(define-key c-mode-base-map "\C-m" 'c-context-line-break)
6bf7aab6
DL
5492@end example
5493
5494This is a very common question. If you want this to be the default
d7bd46ed 5495behavior, don't lobby me, lobby RMS! @t{:-)}
6bf7aab6 5496
3a731e1f
MS
5497@item
5498@emph{I put @code{(c-set-offset 'substatement-open 0)} in my
5499@file{.emacs} file but I get an error saying that @code{c-set-offset}'s
5500function definition is void. What's wrong?}
6bf7aab6 5501
3a731e1f
MS
5502This means that @ccmode{} wasn't loaded into your Emacs session by the
5503time the @code{c-set-offset} call was reached, most likely because
5504@ccmode{} is being autoloaded. Instead of putting the
5505@code{c-set-offset} line in your top-level @file{.emacs} file, put it in
5506your @code{c-mode-common-hook}, or simply modify @code{c-offsets-alist}
5507directly:
f214c025 5508
3a731e1f
MS
5509@example
5510(setq c-offsets-alist '((substatement-open . 0)))
6bf7aab6
DL
5511@end example
5512
3a731e1f
MS
5513@item
5514@kindex M-a
5515@kindex M-e
5516@emph{@kbd{M-a} and @kbd{M-e} used to move over entire balanced brace
5517lists, but now they move into blocks. How do I get the old behavior
5518back?}
5519
5520Use @kbd{C-M-f} and @kbd{C-M-b} to move over balanced brace blocks. Use
5521@kbd{M-a} and @kbd{M-e} to move by statements, which will also move into
5522blocks.
5523
5524@item
5525@emph{Whenever I try to indent a line or type an ``electric'' key such
5526as @kbd{;}, @kbd{@{}, or @kbd{@}}, I get an error that look like this:
5527@code{Invalid function: (macro . #[...}. What gives?}
5528
5529This is a common error when @ccmode{} hasn't been compiled correctly,
5530especially under Emacs 19.34@footnote{Technically, it's because some
5531macro wasn't defined during the compilation, so the byte compiler put
5532in function calls instead of the macro expansions. Later, when the
5533interpreter tries to call the macro as a function, it shows this
5534(somewhat cryptic) error message.}. If you are using the standalone
d7bd46ed
GM
5535@ccmode{} distribution, try recompiling it according to the instructions
5536in the @file{README} file.
2a15eb73
MS
5537
5538@item
5539@cindex open paren in column zero
5540@emph{I have an open paren character at column zero inside a comment or
5541multiline string literal, and it causes the fontification and/or
5542indentation to go haywire. What gives?}
5543
5544It's due to the ad-hoc rule in (X)Emacs that such open parens always
5545start defuns (which translates to functions, classes, namespaces or any
5546other top-level block constructs in the @ccmode{} languages).
5547@xref{Left Margin Paren,,, emacs, The Emacs Editor}, for details
5548(@xref{Defuns,,, emacs, The Emacs Editor}, in the Emacs 20 manual).
5549
5550This heuristic is built into the core syntax analysis routines in
bf247b6e 5551(X)Emacs, so it's not really a @ccmode{} issue. However, in Emacs 22.1
2a15eb73
MS
5552it has become possible to turn it off@footnote{Using the variable
5553@code{open-paren-in-column-0-is-defun-start}.} and @ccmode{} does so
5554there since it got its own system to keep track of blocks.
5555
3a731e1f 5556@end itemize
6bf7aab6
DL
5557
5558
5559@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
cb7f2e96 5560@node Getting the Latest CC Mode Release, Mailing Lists and Submitting Bug Reports, Frequently Asked Questions, Top
d7bd46ed 5561@comment node-name, next, previous, up
cb7f2e96 5562@appendix Getting the Latest CC Mode Release
6bf7aab6
DL
5563@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5564
3a731e1f
MS
5565@ccmode{} has been standard with all versions of Emacs since 19.34 and
5566of XEmacs since 19.16.
d7bd46ed 5567
3a731e1f 5568@cindex web site
d7bd46ed 5569Due to release schedule skew, it is likely that all of these Emacsen
177c0ea7 5570have old versions of @ccmode{} and so should be upgraded. Access to the
d7bd46ed 5571@ccmode{} source code, as well as more detailed information on Emacsen
3a731e1f 5572compatibility, etc. are all available on the web site:
6bf7aab6 5573
3a731e1f
MS
5574@quotation
5575@uref{http://cc-mode.sourceforge.net/}
5576@end quotation
6bf7aab6 5577
6bf7aab6 5578
cb7f2e96
GM
5579@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5580@node Mailing Lists and Submitting Bug Reports, Sample .emacs File, Getting the Latest CC Mode Release, Top
5581@comment node-name, next, previous, up
5582@appendix Mailing Lists and Submitting Bug Reports
cb7f2e96
GM
5583@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5584
5585@kindex C-c C-b
5586@findex c-submit-bug-report
5587@findex submit-bug-report (c-)
3a731e1f
MS
5588To report bugs, use the @kbd{C-c C-b} (bound to
5589@code{c-submit-bug-report}) command. This provides vital information
5590we need to reproduce your problem. Make sure you include a concise,
5591but complete code example. Please try to boil your example down to
5592just the essential code needed to reproduce the problem, and include
5593an exact recipe of steps needed to expose the bug. Be especially sure
5594to include any code that appears @emph{before} your bug example, if
5595you think it might affect our ability to reproduce it.
cb7f2e96
GM
5596
5597Please try to produce the problem in an Emacs instance without any
c3a2e2d5 5598customizations loaded (i.e., start it with the @samp{-q --no-site-file}
cb7f2e96
GM
5599arguments). If it works correctly there, the problem might be caused by
5600faulty customizations in either your own or your site configuration. In
5601that case, we'd appreciate if you isolate the Emacs Lisp code that trigs
5602the bug and include it in your report.
5603
5604@cindex bug report mailing list
3a731e1f
MS
5605Bug reports are sent to @email{bug-cc-mode@@gnu.org}. You can also send
5606other questions and suggestions (kudos? @t{;-)} to that address. It's a
5607mailing list which you can join or browse an archive of; see the web
5608site at @uref{http://cc-mode.sourceforge.net/} for further details.
cb7f2e96
GM
5609
5610@cindex announcement mailing list
5611If you want to get announcements of new @ccmode{} releases, send the
5612word @emph{subscribe} in the body of a message to
3a731e1f
MS
5613@email{cc-mode-announce-request@@lists.sourceforge.net}. It's possible
5614to subscribe from the web site too. Announcements will also be posted
5615to the Usenet newsgroups @code{gnu.emacs.sources}, @code{comp.emacs} and
5616@code{comp.emacs.xemacs}.
cb7f2e96
GM
5617
5618
6bf7aab6 5619@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 5620@node Sample .emacs File, Command and Function Index, Mailing Lists and Submitting Bug Reports, Top
d7bd46ed 5621@comment node-name, next, previous, up
cb7f2e96 5622@appendix Sample .emacs file
6bf7aab6
DL
5623@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5624
5625@example
3a731e1f
MS
5626;; Here's a sample .emacs file that might help you along the way.
5627;; Just copy this region and paste it into your .emacs file. You may
5628;; want to change some of the actual values.
6bf7aab6
DL
5629
5630(defconst my-c-style
5631 '((c-tab-always-indent . t)
5632 (c-comment-only-line-offset . 4)
5633 (c-hanging-braces-alist . ((substatement-open after)
5634 (brace-list-open)))
5635 (c-hanging-colons-alist . ((member-init-intro before)
5636 (inher-intro)
5637 (case-label after)
5638 (label after)
5639 (access-label after)))
5640 (c-cleanup-list . (scope-operator
5641 empty-defun-braces
5642 defun-close-semi))
5643 (c-offsets-alist . ((arglist-close . c-lineup-arglist)
5644 (substatement-open . 0)
5645 (case-label . 4)
5646 (block-open . 0)
5647 (knr-argdecl-intro . -)))
3a731e1f 5648 (c-echo-syntactic-information-p . t))
6bf7aab6
DL
5649 "My C Programming Style")
5650
d7bd46ed 5651;; offset customizations not in my-c-style
f214c025 5652(setq c-offsets-alist '((member-init-intro . ++)))
d7bd46ed
GM
5653
5654;; Customizations for all modes in CC Mode.
6bf7aab6
DL
5655(defun my-c-mode-common-hook ()
5656 ;; add my personal style and set it for the current buffer
5657 (c-add-style "PERSONAL" my-c-style t)
6bf7aab6
DL
5658 ;; other customizations
5659 (setq tab-width 8
5660 ;; this will make sure spaces are used instead of tabs
5661 indent-tabs-mode nil)
5662 ;; we like auto-newline and hungry-delete
5663 (c-toggle-auto-hungry-state 1)
47d7776c 5664 ;; key bindings for all supported languages. We can put these in
6bf7aab6 5665 ;; c-mode-base-map because c-mode-map, c++-mode-map, objc-mode-map,
d7bd46ed 5666 ;; java-mode-map, idl-mode-map, and pike-mode-map inherit from it.
3a731e1f 5667 (define-key c-mode-base-map "\C-m" 'c-context-line-break))
6bf7aab6
DL
5668
5669(add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
5670@end example
5671
d7bd46ed 5672
6bf7aab6 5673@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 5674@node Command and Function Index, Variable Index, Sample .emacs File, Top
d7bd46ed 5675@comment node-name, next, previous, up
3a731e1f 5676@unnumbered Command and Function Index
d7bd46ed 5677@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
6bf7aab6 5678
3a731e1f
MS
5679Since most @ccmode{} commands are prepended with the string
5680@samp{c-}, each appears under its @code{c-@var{thing}} name and its
5681@code{@var{thing} (c-)} name.
5682@iftex
5683@sp 2
5684@end iftex
5685@printindex fn
6bf7aab6
DL
5686
5687
d7bd46ed 5688@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 5689@node Variable Index, Concept Index, Command and Function Index, Top
d7bd46ed 5690@comment node-name, next, previous, up
3a731e1f 5691@unnumbered Variable Index
d7bd46ed 5692@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
6bf7aab6 5693
3a731e1f
MS
5694Since most @ccmode{} variables are prepended with the string
5695@samp{c-}, each appears under its @code{c-@var{thing}} name and its
5696@code{@var{thing} (c-)} name.
6bf7aab6
DL
5697@iftex
5698@sp 2
5699@end iftex
3a731e1f 5700@printindex vr
6bf7aab6
DL
5701
5702
d7bd46ed 5703@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 5704@node Concept Index, , Variable Index, Top
d7bd46ed 5705@comment node-name, next, previous, up
3a731e1f 5706@unnumbered Concept Index
d7bd46ed 5707@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
6bf7aab6 5708
3a731e1f 5709@printindex cp
6bf7aab6
DL
5710
5711
d7bd46ed 5712@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3a731e1f 5713@comment Epilogue.
d7bd46ed 5714@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
6bf7aab6 5715
cb7f2e96 5716@iftex
6bf7aab6
DL
5717@page
5718@summarycontents
5719@contents
cb7f2e96
GM
5720@end iftex
5721
6bf7aab6 5722@bye
ab5796a9
MB
5723
5724@ignore
5725 arch-tag: c4cab162-5e57-4366-bdce-4a9db2fc97f0
5726@end ignore