3 @c Notes to self regarding line handling:
5 @c Empty lines are often significant before @end directives; avoid them.
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
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:
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.
24 @comment TBD: Document the finer details of statement anchoring?
26 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
27 @comment %**start of header (This is for running Texinfo on a region)
28 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
30 @comment No overfull hbox marks in the dvi file.
33 @setfilename ../info/ccmode
34 @settitle CC Mode Manual
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 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
43 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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>
50 @comment Barry A. Warsaw
51 @comment Martin Stjernholm
53 @comment Maintained by Martin Stjernholm <bug-cc-mode@gnu.org>
55 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
57 @comment Define an index for syntactic symbols.
62 @comment Combine key, syntactic symbol and concept indices into one.
67 This manual is for CC Mode in Emacs.
69 Copyright @copyright{} 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
70 2003 Free Software Foundation, Inc.
73 Permission is granted to copy, distribute and/or modify this document
74 under the terms of the GNU Free Documentation License, Version 1.1 or
75 any later version published by the Free Software Foundation; with the
76 Invariant Sections being ``The GNU Manifesto'', ``Distribution'' and
77 ``GNU GENERAL PUBLIC LICENSE'', with the Front-Cover texts being ``A GNU
78 Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
79 license is included in the section entitled ``GNU Free Documentation
80 License'' in the Emacs manual.
82 (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
83 this GNU Manual, like GNU software. Copies published by the Free
84 Software Foundation raise funds for GNU development.''
86 This document is part of a collection distributed under the GNU Free
87 Documentation License. If you want to distribute this document
88 separately from the collection, you can do so by adding a copy of the
89 license to the document, as described in section 6 of the license.
93 @comment Info directory entry for use by install-info. The indentation
94 @comment here is by request from the FSF folks.
97 * CC Mode: (ccmode). Emacs mode for editing C, C++, Objective-C,
98 Java, Pike, AWK, and CORBA IDL code.
101 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
102 @comment TeX title page
103 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
108 @center @titlefont{CC Mode 5.30}
110 @center @subtitlefont{A GNU Emacs mode for editing C and C-like languages}
112 @center Barry A. Warsaw, Martin Stjernholm, Alan Mackenzie (AWK support)
115 @vskip 0pt plus 1filll
119 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
120 @comment The Top node contains the master menu for the Info file.
121 @comment This appears only in the Info file, not the printed manual.
122 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
124 @node Top, Introduction, (dir), (dir)
125 @comment node-name, next, previous, up
134 @ccmode{} is a GNU Emacs mode for editing files containing C, C++,
135 Objective-C, Java, CORBA IDL (and the variants PSDL and CIDL), Pike
136 code and to a certain extent, AWK code @xref{AWK Mode}. It provides
137 syntax-based indentation, font locking, and has several handy commands
138 and some minor modes to make the editing easier. It does not provide
139 tools to look up and navigate between functions, classes etc - there are
140 other packages for that.
143 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
144 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
148 * Getting Connected::
149 * Indentation Engine::
151 * Text Filling and Line Breaking::
155 * Customizing Indentation::
156 * Syntactic Symbols::
157 * Indentation Functions::
160 * Performance Issues::
161 * Limitations and Known Bugs::
162 * Frequently Asked Questions::
163 * Getting the Latest CC Mode Release::
164 * Mailing Lists and Submitting Bug Reports::
165 * Sample .emacs File::
169 * Command and Function Index::
174 --- The Detailed Node Listing ---
178 * Syntactic Analysis::
179 * Indentation Calculation::
183 * Auto-newline Insertion::
184 * Hungry-deletion of Whitespace::
188 * Font Locking Preliminaries::
190 * Documentation Comments::
192 Auto-newline Insertion
196 * Hanging Semicolons and Commas::
197 * Other Electric Commands::
202 * Indentation Commands::
203 * Movement Commands::
206 Customizing Indentation
208 * Interactive Customization::
209 * Permanent Customization::
212 * Advanced Customizations::
221 Advanced Customizations
223 * Custom Indentation Functions::
224 * Custom Brace and Colon Hanging::
225 * Customizing Semicolons and Commas::
226 * Other Special Indentations::
230 * Initialising AWK Mode::
231 * AWK Mode Font Locking::
237 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
238 @node Introduction, Getting Connected, Top, Top
239 @comment node-name, next, previous, up
240 @chapter Introduction
241 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
245 Welcome to @ccmode{}, a GNU Emacs mode for editing files containing C,
246 C++, Objective-C, Java, CORBA IDL (and the variants CORBA PSDL and
247 CIDL), Pike and to a certain extent, AWK code (@pxref{AWK Mode}). This
248 incarnation of the mode is descended from @file{c-mode.el} (also called
249 ``Boring Old C Mode'' or BOCM @t{:-)}, and @file{c++-mode.el} version 2,
250 which Barry has been maintaining since 1992. Late in 1997, Martin
251 joined the @ccmode{} Maintainers Team, and implemented the Pike support.
252 As of 2000 Martin has taken over as the sole maintainer. @ccmode{} did
253 not originally contain the font lock support for its languages --- that
254 was added in version 5.30. AWK support was also added in 5.30 by Alan
257 This manual describes @ccmode{}
258 @comment The following line must appear on its own, so that the automated
260 @comment Release.py script can update the version number automatically
262 @ccmode{} supports the editing of K&R and ANSI C, C++, Objective-C,
263 Java, CORBA's Interface Definition Language, Pike@footnote{A C-like
264 scripting language with its roots in the LPC language used in some MUD
265 engines. See @uref{http://pike.ida.liu.se/}.} and AWK files. In this
266 way, you can easily set up consistent font locking and coding styles for
267 use in editing all of these languages, although AWK is not yet as
268 uniformly integrated as the other languages.
277 Note that the name of this package is ``@ccmode{},'' but there is no top
278 level @code{cc-mode} entry point. All of the variables, commands, and
279 functions in @ccmode{} are prefixed with @code{c-@var{thing}}, and
280 @code{c-mode}, @code{c++-mode}, @code{objc-mode}, @code{java-mode},
281 @code{idl-mode}, @code{pike-mode}, and @code{awk-mode} entry points are
282 provided. This package is intended to be a replacement for
283 @file{c-mode.el}, @file{c++-mode.el} and @file{awk-mode.el}.
285 @c @cindex @file{cc-compat.el} file
286 @c This distribution also contains a file
287 @c called @file{cc-compat.el} which should ease your transition from BOCM
288 @c to @ccmode{}. If you have a BOCM configuration you are really happy
289 @c with, and want to postpone learning how to configure @ccmode{}, take a
290 @c look at that file. It maps BOCM configuration variables to @ccmode{}'s
291 @c indentation model. It is not actively supported so for the long run,
292 @c you should learn how to customize @ccmode{} to support your coding
295 A special word of thanks goes to Krishna Padmasola for his work in
296 converting the original @file{README} file to Texinfo format. I'd also
297 like to thank all the @ccmode{} victims who help enormously during the
298 early beta stages of @ccmode{}'s development.
301 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
302 @node Getting Connected, Indentation Engine, Introduction, Top
303 @comment node-name, next, previous, up
304 @chapter Getting Connected
305 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
307 If you got this version of @ccmode{} with Emacs or XEmacs, it should
308 work just fine right out of the box. Note however that you may not have
309 the latest @ccmode{} release and may want to upgrade your copy.
311 If you are upgrading an existing @ccmode{} installation, please see the
312 @file{README} file for installation details. @ccmode{} may not work
313 with older versions of Emacs or XEmacs. See the @ccmode{} release notes
314 at @uref{http://cc-mode.sourceforge.net} for the latest information on
315 Emacs version and package compatibility (@pxref{Getting the Latest CC
318 @deffn Command c-version
320 You can find out what version of @ccmode{} you are using by visiting a C
321 file and entering @kbd{M-x c-version RET}. You should see this message in
325 Using CC Mode version 5.XX
329 where @samp{XX} is the minor release number.
333 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
334 @node Indentation Engine, Minor Modes, Getting Connected, Top
335 @comment node-name, next, previous, up
336 @chapter Indentation Engine
337 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
339 @ccmode{} has an indentation engine that provides a flexible and general
340 mechanism for customizing indentation. It separates indentation
341 calculation into two steps: first, @ccmode{} analyzes the line of code
342 being indented to determine the kind of language construct it's looking
343 at, then it applies user defined offsets to the current line based on
346 This section will briefly cover how indentation is calculated in
347 @ccmode{}. It is important to understand the indentation model being
348 used so that you will know how to customize @ccmode{} for your personal
349 coding style. All the details are in @ref{Customizing Indentation}, and
352 @defopt c-syntactic-indentation
353 @vindex syntactic-indentation (c-)
354 Syntactic analysis for indentation is done when this is non-@code{nil}
355 (which is the default). When it's @code{nil} every line is just
356 indented to the same level as the previous one, and @kbd{TAB}
357 (@code{c-indent-command}) adjusts the indentation in steps of
358 @code{c-basic-offset}. The indentation style has no effect, nor any of
359 the indentation associated variables, e.g., @code{c-special-indent-hook}.
363 * Syntactic Analysis::
364 * Indentation Calculation::
368 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
369 @node Syntactic Analysis, Indentation Calculation, , Indentation Engine
370 @comment node-name, next, previous, up
371 @section Syntactic Analysis
372 @cindex syntactic analysis
373 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
375 @cindex relative buffer position
376 @cindex syntactic symbols
377 @cindex syntactic component
378 @cindex syntactic component list
379 The first thing @ccmode{} does when indenting a line of code, is to
380 analyze the line, determining the @dfn{syntactic component list} of the
381 construct on that line. A syntactic component consists of a pair of
382 elements (in lisp parlance, a @emph{cons cell}), the first being
383 a @dfn{syntactic symbol}, the second being a @dfn{relative
384 buffer position}. Syntactic symbols describe elements of C code
385 @footnote{Unless otherwise noted, the term ``C code'' refers to all
386 the C-like languages.}, e.g., @code{statement}, @code{substatement},
387 @code{class-open}, @code{class-close}, etc. @xref{Syntactic Symbols},
388 for a complete list of currently recognized syntactic symbols and their
389 semantics. The style variable @code{c-offsets-alist} also contains the
390 list of currently supported syntactic symbols.
392 Conceptually, a line of C code is always indented relative to the
393 indentation of some line higher up in the buffer. This is represented
394 by the relative buffer position in the syntactic component.
396 Here is an example. Suppose we had the following code as the only thing
397 in a C++ buffer @footnote{The line numbers in this and future examples
398 don't actually appear in the buffer, of course!}:
401 1: void swap( int& a, int& b )
410 @findex c-show-syntactic-information
411 @findex show-syntactic-information (c-)
412 We can use the command @kbd{C-c C-s} (bound to
413 @code{c-show-syntactic-information}) to simply report what the
414 syntactic analysis is for the current line. Running this command on
415 line 4 of this example, we'd see in the echo area@footnote{With a
416 universal argument (i.e., @kbd{C-u C-c C-s}) the analysis is inserted
417 into the buffer as a comment on the current line.}:
423 This tells us that the line is a statement and it is indented relative
424 to buffer position 35, which happens to be the @samp{i} in @code{int} on
425 line 3. If you were to move point to line 3 and hit @kbd{C-c C-s}, you
429 ((defun-block-intro 29))
432 This indicates that the @samp{int} line is the first statement in a top
433 level function block, and is indented relative to buffer position 29,
434 which is the brace just after the function header.
436 Here's another example:
439 1: int add( int val, int incr, int doit )
443 5: return( val + incr );
450 Hitting @kbd{C-c C-s} on line 4 gives us:
453 ((substatement-open 46))
457 @cindex substatement block
459 which tells us that this is a brace that @emph{opens} a substatement
460 block. @footnote{A @dfn{substatement} is the line after a
461 conditional statement, such as @code{if}, @code{else}, @code{while},
462 @code{do}, @code{switch}, etc. A @dfn{substatement
463 block} is a brace block following one of these conditional statements.}
465 @cindex comment-only line
466 Syntactic component lists can contain more than one component, and
467 individual syntactic components need not have relative buffer positions.
468 The most common example of this is a line that contains a @dfn{comment
472 1: void draw_list( List<Drawables>& drawables )
474 3: // call the virtual draw() method on each element in list
475 4: for( int i=0; i < drawables.count(), ++i )
477 6: drawables[i].draw();
483 Hitting @kbd{C-c C-s} on line 3 of this example gives:
486 ((comment-intro) (defun-block-intro 46))
490 and you can see that the syntactic component list contains two syntactic
491 components. Also notice that the first component,
492 @samp{(comment-intro)} has no relative buffer position.
495 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
496 @node Indentation Calculation, , Syntactic Analysis, Indentation Engine
497 @comment node-name, next, previous, up
498 @section Indentation Calculation
500 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
502 Indentation for a line is calculated using the syntactic
503 component list derived in step 1 above (@pxref{Syntactic Analysis}).
504 Each component contributes to the final total indentation of the line in
507 First, the syntactic symbols are looked up in the @code{c-offsets-alist}
508 style variable, which is an association list of syntactic symbols and
509 the offsets to apply for those symbols. These offsets are added to a
512 Second, if the component has a relative buffer position, @ccmode{}
513 adds the column number of that position to the running total. By adding
514 up the offsets and columns for every syntactic component on the list,
515 the final total indentation for the current line is computed.
517 Let's use our two code examples above to see how this works. Here is
518 our first example again:
521 1: void swap( int& a, int& b )
529 Let's say point is on line 3 and we hit the @kbd{TAB} key to reindent
530 the line. Remember that the syntactic component list for that
534 ((defun-block-intro 29))
538 @ccmode{} looks up @code{defun-block-intro} in the
539 @code{c-offsets-alist} style variable. Let's say it finds the value
540 @samp{4}; it adds this to the running total (initialized to zero),
541 yielding a running total indentation of 4 spaces.
543 Next @ccmode{} goes to buffer position 29 and asks for the current
544 column. This brace is in column zero, so @ccmode{}
545 adds @samp{0} to the running total. Since there is only one syntactic
546 component on the list for this line, indentation calculation is
547 complete, and the total indentation for the line
550 Here's another example:
553 1: int add( int val, int incr, int doit )
557 5: return( val + incr );
563 If we were to hit @kbd{TAB} on line 4 in the above example, the same
564 basic process is performed, despite the differences in the syntactic
565 component list. Remember that the list for this line is:
568 ((substatement-open 46))
571 Here, @ccmode{} first looks up the @code{substatement-open} symbol
572 in @code{c-offsets-alist}. Let's say it finds the value @samp{4}. This
573 yields a running total of 4. @ccmode{} then goes to
574 buffer position 46, which is the @samp{i} in @code{if} on line 3. This
575 character is in the fourth column on that line so adding this to the
576 running total yields an indentation for the line of 8 spaces.
580 Actually, the mode usually just does The Right Thing without you having
581 to think about it in this much detail. But when customizing
582 indentation, it's helpful to understand the general indentation model
585 As you configure @ccmode{}, you might want to set the variable
586 @code{c-echo-syntactic-information-p} to non-@code{nil} so that the
587 syntactic component list and calculated offset will always be echoed in
588 the minibuffer when you hit @kbd{TAB}.
591 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
592 @node Minor Modes, Text Filling and Line Breaking, Indentation Engine, Top
593 @comment node-name, next, previous, up
595 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
597 @ccmode{} contains two minor-mode-like features that you should
598 find useful while entering new C code. The first is called
599 @dfn{auto-newline} mode, and the second is called @dfn{hungry-delete}
600 mode. These minor modes can be toggled on and off independently, and
601 @ccmode{} can be configured so that it starts up with any
602 combination of these minor modes. By default, both of these minor modes
605 The state of the minor modes is always reflected in the minor mode list
606 on the modeline of the @ccmode{} buffer. When auto-newline mode is
607 enabled, you will see @samp{C/a} on the mode line@footnote{The @samp{C}
608 would be replaced with the name of the language in question for the
609 other languages @ccmode{} supports.}. When hungry delete mode is
610 enabled you will see @samp{C/h} and if both modes were enabled, you'd
616 @findex c-toggle-hungry-state
617 @findex c-toggle-auto-state
618 @findex c-toggle-auto-hungry-state
619 @findex toggle-hungry-state (c-)
620 @findex toggle-auto-state (c-)
621 @findex toggle-auto-hungry-state (c-)
622 @ccmode{} provides key bindings which allow you to toggle the minor
623 modes on the fly while editing code. To toggle just the auto-newline
624 state, hit @kbd{C-c C-a} (bound to @code{c-toggle-auto-state}). When
625 you do this, you should see the @samp{a} indicator either appear or
626 disappear on the modeline. Similarly, to toggle just the
627 hungry-delete state, use @kbd{C-c C-d} (@code{c-toggle-hungry-state}),
628 and to toggle both states, use @kbd{C-c C-t}
629 (@code{c-toggle-auto-hungry-state}).
631 To set up the auto-newline and hungry-delete states to your preferred
632 values, you would need to add some lisp to your @file{.emacs} file that
633 called one of the @code{c-toggle-*-state} functions directly. When
634 called programmatically, each function takes a numeric value, where
635 a positive number enables the minor mode, a negative number disables the
636 mode, and zero toggles the current state of the mode.
638 So for example, if you wanted to enable both auto-newline and
639 hungry-delete for all your C file editing, you could add the following
640 to your @file{.emacs} file:
643 (add-hook 'c-mode-common-hook
644 (lambda () (c-toggle-auto-hungry-state 1)))
648 * Auto-newline Insertion::
649 * Hungry-deletion of Whitespace::
653 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
654 @node Auto-newline Insertion, Hungry-deletion of Whitespace, , Minor Modes
655 @comment node-name, next, previous, up
656 @section Auto-newline Insertion
658 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
660 @cindex electric characters
661 Auto-newline minor mode works by enabling certain @dfn{electric
662 characters}. Special characters such as the left and right braces,
663 colons, semicolons, etc., have been made electric to perform some
664 magic formatting in addition to inserting the typed character. As a
665 general rule, electric characters are only electric when the following
670 Auto-newline minor mode is enabled, as evidenced by a @samp{C/a} or
671 @samp{C/ah} indicator on the modeline.
675 @cindex syntactic whitespace
676 The character was not typed inside of a literal @footnote{A
677 @dfn{literal} is defined as any comment, string, or preprocessor macro
678 definition. These constructs are also known as @dfn{syntactic
679 whitespace} since they are usually ignored when scanning C code.}.
682 No numeric argument was supplied to the command (i.e., it was typed as
683 normal, with no @kbd{C-u} prefix).
689 * Hanging Semicolons and Commas::
690 * Other Electric Commands::
695 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
696 @node Hanging Braces, Hanging Colons, , Auto-newline Insertion
697 @comment node-name, next, previous, up
698 @subsection Hanging Braces
699 @cindex hanging braces
700 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
702 @findex c-electric-brace
703 @findex electric-brace (c-)
707 When you type either an open or close brace (i.e., @kbd{@{} or @kbd{@}}),
708 the electric command @code{c-electric-brace} gets run. This command has
709 two electric formatting behaviors. First, it will perform some
710 reindentation of the line the brace was typed on, and second, it will
711 add various newlines before and/or after the typed brace.
712 Reindentation occurs automatically whenever the electric behavior is
713 enabled. If the brace ends up on a line other than the one it was typed
714 on, then that line is also reindented.
716 The default in auto-newline mode is to insert newlines both before and
717 after a brace, but that can be controlled by the
718 @code{c-hanging-braces-alist} style variable.
720 @defopt c-hanging-braces-alist
721 @vindex hanging-braces-alist (c-)
723 This variable contains a mapping between syntactic symbols related to
724 braces, and a list of places to insert a newline. The syntactic symbols
725 that are useful for this list are @code{brace-list-intro},
726 @code{statement-cont}, @code{inexpr-class-open},
727 @code{inexpr-class-close}, and all the @code{*-open} and @code{*-close}
728 symbols. @xref{Syntactic Symbols}, for a more detailed description of
729 these syntactic symbols, except for @code{inexpr-class-open} and
730 @code{inexpr-class-close}, which aren't actual syntactic symbols.
732 The braces of anonymous inner classes in Java are given the special
733 symbols @code{inexpr-class-open} and @code{inexpr-class-close}, so that
734 they can be distinguished from the braces of normal classes@footnote{The
735 braces of anonymous classes produce a combination of
736 @code{inexpr-class}, and @code{class-open} or @code{class-close} in
737 normal indentation analysis.}.
739 Note that the aggregate constructs in Pike mode, @samp{(@{}, @samp{@})},
740 @samp{([}, @samp{])}, and @samp{(<}, @samp{>)}, do not count as brace
741 lists in this regard, even though they do for normal indentation
742 purposes. It's currently not possible to set automatic newlines on
745 The value associated with each syntactic symbol in this association list
746 is called an @var{action}, which can be either a function or a list.
747 @xref{Custom Brace and Colon Hanging}, for a more detailed discussion of
748 using a function as a brace hanging @var{action}.
750 When the @var{action} is a list, it can contain any combination of the
751 symbols @code{before} and @code{after}, directing @ccmode{} where to
752 put newlines in relationship to the brace being inserted. Thus, if the
753 list contains only the symbol @code{after}, then the brace is said to
754 @dfn{hang} on the right side of the line, as in:
757 // here, open braces always `hang'
758 void spam( int i ) @{
765 When the list contains both @code{after} and @code{before}, the braces
766 will appear on a line by themselves, as shown by the close braces in the
767 above example. The list can also be empty, in which case no newlines
768 are added either before or after the brace.
770 If a syntactic symbol is missing entirely from
771 @code{c-hanging-braces-alist}, it's treated in the same way as an
772 @var{action} with a list containing @code{before} and @code{after}, so
773 that braces by default end up on their own line.
775 For example, the default value of @code{c-hanging-braces-alist} is:
781 (substatement-open after)
782 (block-close . c-snug-do-while)
783 (extern-lang-open after)
784 (inexpr-class-open after)
785 (inexpr-class-close before))
788 @noindent which says that @code{brace-list-open},
789 @code{brace-entry-open} and @code{statement-cont}@footnote{Brace lists
790 inside statements, such as initializers for static array variables
791 inside functions in C, are recognized as @code{statement-cont}. All
792 normal substatement blocks are recognized with other symbols.} braces
793 should both hang on the right side and allow subsequent text to follow
794 on the same line as the brace. Also, @code{substatement-open},
795 @code{extern-lang-open}, and @code{inexpr-class-open} braces should hang
796 on the right side, but subsequent text should follow on the next line.
797 The opposite holds for @code{inexpr-class-close} braces; they won't
798 hang, but the following text continues on the same line. Here, in the
799 @code{block-close} entry, you also see an example of using a function as
800 an @var{action}. In all other cases, braces are put on a line by
805 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
806 @node Hanging Colons, Hanging Semicolons and Commas, Hanging Braces, Auto-newline Insertion
807 @comment node-name, next, previous, up
808 @subsection Hanging Colons
809 @cindex hanging colons
810 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
812 Using a mechanism similar to brace hanging (@pxref{Hanging Braces}),
813 colons can also be made to hang using the style variable
814 @code{c-hanging-colons-alist}.
816 @defopt c-hanging-colons-alist
817 @vindex hanging-colons-alist (c-)
819 The syntactic symbols appropriate for this association list are:
820 @code{case-label}, @code{label}, @code{access-label},
821 @code{member-init-intro}, and @code{inher-intro}. Note however that for
822 @code{c-hanging-colons-alist}, @var{action}s as functions are not
823 supported. See also @ref{Custom Brace and Colon Hanging} for details.
825 In C++, double-colons are used as a scope operator but because these
826 colons always appear right next to each other, newlines before and after
827 them are controlled by a different mechanism, called @dfn{clean-ups} in
828 @ccmode{}. @xref{Clean-ups}, for details.
832 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
833 @node Hanging Semicolons and Commas, Other Electric Commands, Hanging Colons, Auto-newline Insertion
834 @comment node-name, next, previous, up
835 @subsection Hanging Semicolons and Commas
836 @cindex hanging semicolons
837 @cindex hanging commas
838 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
840 Semicolons and commas are also electric in @ccmode{}, but since
841 these characters do not correspond directly to syntactic symbols, a
842 different mechanism is used to determine whether newlines should be
843 automatically inserted after these characters. @xref{Customizing
844 Semicolons and Commas}, for details.
847 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
848 @node Other Electric Commands, Clean-ups, Hanging Semicolons and Commas, Auto-newline Insertion
849 @comment node-name, next, previous, up
850 @subsection Other Electric Commands
851 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
853 A few other keys also provide electric behavior, often only to reindent
854 the line. Common to all of them is that they only reindent if used in
855 normal code (as opposed to in a string literal or comment), and
856 @code{c-syntactic-indentation} isn't @code{nil}. They are:
861 @findex c-electric-pound
862 @findex electric-pound (c-)
863 @vindex c-electric-pound-behavior
864 @vindex electric-pound-behavior (c-)
865 Pound (bound to @code{c-electric-pound}) is electric when typed as the
866 first non-whitespace character on a line and not within a macro
867 definition. In this case, the variable @code{c-electric-pound-behavior}
868 is consulted for the electric behavior. This variable takes a list
869 value, although the only element currently defined is @code{alignleft},
870 which tells this command to force the @samp{#} character into column
871 zero. This is useful for entering preprocessor macro definitions.
873 Pound is not electric in AWK buffers, where @samp{#} starts a comment,
874 and is bound to @code{self-insert-command} like any typical printable
881 @findex c-electric-star
882 @findex electric-star (c-)
883 @findex c-electric-slash
884 @findex electric-slash (c-)
885 Stars and slashes (bound to @code{c-electric-star} and
886 @code{c-electric-slash} respectively) are also electric under certain
887 circumstances. If a @samp{*} is inserted as the second character of a C
888 style block comment on a comment-only line, then the comment delimiter
889 is indented as defined by @code{c-offsets-alist}. A comment-only line
890 is defined as a line which contains only a comment, as in:
896 // this is a comment-only line...
897 if( i == 7 ) // but this is not
905 Likewise, if a @samp{/} is inserted as the second slash in a C++ style
906 line comment (also only on a comment-only line), then the line is
907 indented as defined by @code{c-offsets-alist}.
909 In AWK mode, @samp{*} and @samp{/} do not delimit comments and are
910 bound to @code{self-insert-command}.
916 @findex c-electric-lt-gt
917 @findex electric-lt-gt (c-)
918 Less-than and greater-than signs (bound to @code{c-electric-lt-gt}) are
919 electric, but only in C++ mode. Hitting the second of two @kbd{<} or
920 @kbd{>} keys reindents the line if it is a C++ style stream operator.
926 @findex c-electric-paren
927 @findex electric-paren (c-)
928 The normal parenthesis characters @samp{(} and @samp{)} reindent the
929 current line. This is useful for getting the closing parenthesis of an
930 argument list aligned automatically.
933 @deffn Command c-electric-continued-statement
934 @findex electric-continued-statement (c-)
936 Certain keywords, depending on language, are electric to cause
937 reindentation when they are preceded only by whitespace on the line.
938 The keywords are those that continue an earlier statement instead of
939 starting a new one: @code{else}, @code{while}, @code{catch} (only in C++
940 and Java) and @code{finally} (only in Java).
946 for (i = 0; i < 17; i++)
953 Here, the @code{else} should be indented like the preceding @code{if},
954 since it continues that statement. @ccmode{} will automatically reindent
955 it after the @code{else} has been typed in full, since it's not until
956 then it's possible to decide whether it's a new statement or a
957 continuation of the preceding @code{if}.
962 @ccmode{} uses Abbrev mode (@pxref{Abbrevs,,, emacs, The Emacs Editor})
963 to accomplish this. It's therefore turned on by default in all language
964 modes except IDL mode, since CORBA IDL doesn't have any statements.
968 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
969 @node Clean-ups, , Other Electric Commands, Auto-newline Insertion
970 @comment node-name, next, previous, up
971 @subsection Clean-ups
973 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
975 @dfn{Clean-ups} are mechanisms complementary to colon and brace hanging.
976 On the surface, it would seem that clean-ups overlap the functionality
977 provided by the @code{c-hanging-*-alist} variables. Clean-ups are
978 however used to adjust code ``after-the-fact,'' i.e., to adjust the
979 whitespace in constructs after they are typed.
981 Most of the clean-ups are only applicable to counteract automatically
982 inserted newlines, and will therefore only have any effect if the
983 auto-newline minor mode is turned on. Others will work all the time.
985 @defopt c-cleanup-list
986 @vindex cleanup-list (c-)
989 You can configure @ccmode{}'s clean-ups by setting the style variable
990 @code{c-cleanup-list}, which is a list of clean-up symbols. By default,
991 @ccmode{} cleans up only the @code{scope-operator} construct, which is
992 necessary for proper C++ support. Note that clean-ups are only
993 performed when the construct does not occur within a literal
994 (@pxref{Auto-newline Insertion}), and when there is nothing but
995 whitespace appearing between the individual components of the construct.
998 These are the clean-ups that are only active in the auto-newline minor
1001 @c TBD: Would like to use some sort of @deffoo here; @table indents a
1002 @c bit too much in dvi output.
1004 @item brace-else-brace
1005 Clean up @samp{@} else @{} constructs by placing the entire construct on
1006 a single line. Clean-up occurs when the open brace after the
1007 @samp{else} is typed. So for example, this:
1022 appears like this after the last open brace is typed:
1034 @item brace-elseif-brace
1035 Similar to the @code{brace-else-brace} clean-up, but this cleans up
1036 @samp{@} else if (...) @{} constructs. For example:
1051 appears like this after the last open parenthesis is typed:
1065 and like this after the last open brace is typed:
1073 @} else if( i==3 ) @{
1077 @item brace-catch-brace
1078 Analogous to @code{brace-elseif-brace}, but cleans up @samp{@} catch
1079 (...) @{} in C++ and Java mode.
1081 @item empty-defun-braces
1082 Clean up braces following a top-level function or class definition that
1083 contains no body. Clean up occurs when the closing brace is typed.
1095 is transformed into this when the close brace is typed:
1104 @item defun-close-semi
1105 Clean up the terminating semicolon on top-level function or class
1106 definitions when they follow a close brace. Clean up occurs when the
1107 semicolon is typed. So for example, the following:
1119 is transformed into this when the semicolon is typed:
1129 @item list-close-comma
1130 Clean up commas following braces in array and aggregate initializers.
1131 Clean up occurs when the comma is typed.
1133 @item scope-operator
1134 Clean up double colons which may designate a C++ scope operator split
1135 across multiple lines@footnote{Certain C++ constructs introduce
1136 ambiguous situations, so @code{scope-operator} clean-ups may not always
1137 be correct. This usually only occurs when scoped identifiers appear in
1138 switch label tags.}. Clean up occurs when the second colon is typed.
1139 You will always want @code{scope-operator} in the @code{c-cleanup-list}
1140 when you are editing C++ code.
1143 The following clean-ups are always active when they occur on
1144 @code{c-cleanup-list}, and are thus not affected by the auto-newline
1148 @item space-before-funcall
1149 Insert a space between the function name and the opening parenthesis of
1150 a function call. This produces function calls in the style mandated by
1151 the GNU coding standards, e.g., @samp{signal (SIGINT, SIG_IGN)} and
1152 @samp{abort ()}. Clean up occurs when the opening parenthesis is typed.
1154 @item compact-empty-funcall
1155 Clean up any space between the function name and the opening parenthesis
1156 of a function call that has no arguments. This is typically used
1157 together with @code{space-before-funcall} if you prefer the GNU function
1158 call style for functions with arguments but think it looks ugly when
1159 it's only an empty parenthesis pair. I.e., you will get @samp{signal
1160 (SIGINT, SIG_IGN)}, but @samp{abort()}. Clean up occurs when the
1161 closing parenthesis is typed.
1165 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1166 @node Hungry-deletion of Whitespace, , Auto-newline Insertion, Minor Modes
1167 @comment node-name, next, previous, up
1168 @section Hungry-deletion of Whitespace
1169 @cindex hungry-deletion
1170 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1172 Hungry deletion of whitespace, or as it more commonly called,
1173 @dfn{hungry-delete mode}, is a simple feature that some people find
1174 extremely useful. In fact, you might find yourself wanting
1175 hungry-delete in @strong{all} your editing modes!
1180 In a nutshell, when hungry-delete mode is enabled, hitting the @kbd{DEL}
1181 or @kbd{C-d} keys will consume all preceding or following whitespace,
1182 including newlines and tabs. This can really cut down on the number of
1183 times you have to hit these keys if, for example, you made a mistake on
1186 @deffn Command c-electric-backspace
1187 @findex electric-backspace (c-)
1188 This command is run by default when you hit the @kbd{DEL} key. It
1189 deletes any amount of whitespace in the backwards direction if
1190 hungry-delete mode is enabled. When it's disabled, or when used with
1191 a prefix argument or in a literal (@pxref{Auto-newline Insertion}),
1192 the function contained in the @code{c-backspace-function} variable is
1193 called with the prefix argument.
1196 @defvar c-backspace-function
1197 @vindex backspace-function (c-)
1198 @findex backward-delete-char-untabify
1199 Hook that gets called by @code{c-electric-backspace} when it doesn't
1200 do an ``electric'' deletion of the preceding whitespace. The default
1201 value is @code{backward-delete-char-untabify}.
1204 @deffn Command c-electric-delete-forward
1205 @findex electric-delete-forward (c-)
1206 This function, which is bound to @kbd{C-d} by default, works just like
1207 @code{c-electric-backspace} but in the forward direction. When it
1208 doesn't do an ``electric'' deletion of the following whitespace, it
1209 calls the function in @code{c-delete-function} with its prefix
1213 @defvar c-delete-function
1214 @vindex delete-function (c-)
1216 Hook that gets called by @code{c-electric-delete-forward} when it
1217 doesn't do an ``electric'' deletion of the following whitespace. The
1218 default value is @code{delete-char}.
1221 Above we have only talked about the @kbd{DEL} and @kbd{C-d} key events,
1222 without connecting them to the physical keys commonly known as
1223 @key{Backspace} and @key{Delete}. The default behavior of those two
1224 depends on the flavor of (X)Emacs you are using.
1226 @findex c-electric-delete
1227 @findex electric-delete (c-)
1228 @vindex delete-key-deletes-forward
1230 In XEmacs 20.3 and beyond, the @key{Backspace} key is bound to
1231 @code{c-electric-backspace} and the @key{Delete} key is bound to
1232 @code{c-electric-delete}. You control the direction it deletes in by
1233 setting the variable @code{delete-key-deletes-forward}, a standard
1234 XEmacs variable. When this variable is non-@code{nil},
1235 @code{c-electric-delete} will do forward deletion with
1236 @code{c-electric-delete-forward}, otherwise it does backward deletion
1237 with @code{c-electric-backspace}.
1239 In other Emacs versions, @ccmode{} doesn't bind either @key{Backspace}
1240 or @key{Delete}. In XEmacs 19 and Emacs prior to 21 that means that
1241 it's up to you to fix them. Emacs 21 automatically binds them as
1242 appropriate to @kbd{DEL} and @kbd{C-d}.
1244 Another way to use hungry deletion is to bind
1245 @code{c-hungry-backspace} and @code{c-hungry-delete-forward} directly
1246 to keys, and not use the mode toggling. For example @kbd{C-c C-d} and
1247 @kbd{C-c DEL} to match plain @kbd{C-d} and @kbd{DEL},
1253 (define-key c-mode-base-map
1254 [?\C-c ?\d] 'c-hungry-backspace)
1255 (define-key c-mode-base-map
1256 [?\C-c ?\C-d] 'c-hungry-delete-forward)))
1259 @deffn Command c-hungry-backspace
1260 @findex hungry-backspace (c-)
1261 Delete any amount of whitespace in the backwards direction (regardless
1262 whether hungry-delete mode is enabled or not).
1265 @deffn Command c-hungry-delete-forward
1266 @findex hungry-delete-forward (c-)
1267 Delete any amount of whitespace in the forward direction (regardless
1268 whether hungry-delete mode is enabled or not).
1272 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1273 @node Text Filling and Line Breaking, Macro Handling, Minor Modes, Top
1274 @comment node-name, next, previous, up
1275 @chapter Text Filling and Line Breaking
1276 @cindex text filling
1277 @cindex line breaking
1278 @cindex comment handling
1279 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1281 Since there's a lot of normal text in comments and string literals,
1282 @ccmode{} provides features to edit these like in text mode. The goal
1283 is to do it as seamlessly as possible, i.e., you can use auto fill mode,
1284 sentence and paragraph movement, paragraph filling, adaptive filling etc
1285 wherever there's a piece of normal text without having to think much
1286 about it. @ccmode{} should keep the indentation, fix the comment line
1287 decorations, and so on, for you. It does that by hooking in on the
1288 different line breaking functions and tuning relevant variables as
1291 @vindex c-comment-prefix-regexp
1292 @vindex comment-prefix-regexp (c-)
1293 @cindex comment line prefix
1294 @vindex comment-start
1296 @vindex comment-start-skip
1297 @vindex paragraph-start
1298 @vindex paragraph-separate
1299 @vindex paragraph-ignore-fill-prefix
1300 @vindex adaptive-fill-mode
1301 @vindex adaptive-fill-regexp
1302 @vindex adaptive-fill-first-line-regexp
1303 To make Emacs recognize comments and treat text in them as normal
1304 paragraphs, @ccmode{} makes several standard
1305 variables@footnote{@code{comment-start}, @code{comment-end},
1306 @code{comment-start-skip}, @code{paragraph-start},
1307 @code{paragraph-separate}, @code{paragraph-ignore-fill-prefix},
1308 @code{adaptive-fill-mode}, @code{adaptive-fill-regexp}, and
1309 @code{adaptive-fill-first-line-regexp}.} buffer local and modifies them
1310 according to the language syntax and the comment line prefix.
1312 @defopt c-comment-prefix-regexp
1313 @vindex comment-prefix-regexp (c-)
1314 This style variable contains the regexp used to recognize the
1315 @dfn{comment line prefix}, which is the line decoration that starts
1316 every line in a comment. The default is @samp{//+\\|\\**}, which
1317 matches C++ style line comments like
1324 with two or more slashes in front of them, and C style block comments
1336 with zero or more stars at the beginning of every line. If you change
1337 this variable, please make sure it still matches the comment starter
1338 (i.e., @code{//}) of line comments @emph{and} the line prefix inside
1341 @findex c-setup-paragraph-variables
1342 @findex setup-paragraph-variables (c-)
1343 Also note that since @ccmode{} uses the value of
1344 @code{c-comment-prefix-regexp} to set up several other variables at mode
1345 initialization, there won't be any effect if you just change it inside a
1346 @ccmode{} buffer. You need to call the command
1347 @code{c-setup-paragraph-variables} too, to update those other variables with
1348 the new value. That's also the case if you modify this variable in a
1349 mode hook, since @ccmode{} sets up all variables before calling them.
1352 @findex auto-fill-mode
1353 @cindex Auto Fill mode
1354 @cindex paragraph filling
1355 Line breaks are by default handled (almost) the same regardless whether
1356 they are made by auto fill mode (@pxref{Auto Fill,,, emacs, The Emacs
1357 Editor}), paragraph filling (e.g., with @kbd{M-q}), or explicitly with
1358 @kbd{M-j} or similar methods. In string literals, the new line gets the
1359 same indentation as the previous nonempty line (may be changed with the
1360 @code{string} syntactic symbol). In comments, @ccmode{} uses
1361 @code{c-comment-prefix-regexp} to adapt the line prefix from the other
1362 lines in the comment.
1364 @vindex adaptive-fill-mode
1365 @cindex Adaptive Fill mode
1366 @ccmode{} uses adaptive fill mode (@pxref{Adaptive Fill,,, emacs, The
1367 Emacs Editor}) to make Emacs correctly keep the line prefix when filling
1368 paragraphs. That also makes Emacs preserve the text indentation
1369 @emph{inside} the comment line prefix. e.g., in the following comment,
1370 both paragraphs will be filled with the left margins of the texts kept
1375 /* Make a balanced b-tree of the nodes in the incoming
1376 * stream. But, to quote the famous words of Donald E.
1379 * Beware of bugs in the above code; I have only
1380 * proved it correct, not tried it.
1385 @findex c-setup-filladapt
1386 @findex setup-filladapt (c-)
1387 @findex filladapt-mode
1388 @vindex filladapt-mode
1389 @cindex Filladapt mode
1390 It's also possible to use other adaptive filling packages, notably Kyle
1391 E. Jones' Filladapt package@footnote{It's available from
1392 @uref{http://www.wonderworks.com/}. As of version 2.12, it does however
1393 lack a feature that makes it work suboptimally when
1394 @code{c-comment-prefix-regexp} matches the empty string (which it does
1395 by default). A patch for that is available from
1396 @uref{http://cc-mode.sourceforge.net/,, the CC Mode web site}.},
1397 which handles things like bulleted lists nicely. There's a convenience
1398 function @code{c-setup-filladapt} that tunes the relevant variables in
1399 Filladapt for use in @ccmode{}. Call it from a mode hook, e.g., with
1400 something like this in your @file{.emacs}:
1403 (defun my-c-mode-common-hook ()
1406 (add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
1409 @defopt c-block-comment-prefix
1410 @vindex block-comment-prefix (c-)
1411 @vindex c-comment-continuation-stars
1412 @vindex comment-continuation-stars (c-)
1413 Normally the comment line prefix inserted for a new line inside a
1414 comment is deduced from other lines in it. However there's one
1415 situation when there's no hint about what the prefix should look like,
1416 namely when a block comment is broken for the first time. This style
1417 variable@footnote{In versions before 5.26, this variable was called
1418 @code{c-comment-continuation-stars}. As a compatibility measure,
1419 @ccmode{} still uses the value on that variable if it's set.} is used
1420 then as the comment prefix. It defaults to @samp{*
1421 }@footnote{Actually, this default setting of
1422 @code{c-block-comment-prefix} typically gets overriden by the default
1423 style @code{gnu}, which sets it to blank. You can see the line
1424 splitting effect described here by setting a different style,
1425 e.g. @code{k&r} @xref{Choosing a Style}.}, which makes a comment
1428 /* Got O(n^2) here, which is a Bad Thing. */
1437 * which is a Bad Thing. */
1441 Note that it won't work to adjust the indentation by putting leading
1442 spaces in @code{c-block-comment-prefix}, since @ccmode{} still uses the
1443 normal indentation engine to indent the line. Thus, the right way to
1444 fix the indentation is by customizing the @code{c} syntactic symbol. It
1445 defaults to @code{c-lineup-C-comments}, which handles the indentation of
1446 most common comment styles, see @ref{Indentation Functions}.
1449 @defopt c-ignore-auto-fill
1450 @vindex ignore-auto-fill (c-)
1451 When auto fill mode is enabled, @ccmode{} can selectively ignore it
1452 depending on the context the line break would occur in, e.g., to never
1453 break a line automatically inside a string literal. This variable
1454 takes a list of symbols for the different contexts where auto-filling
1459 Inside a string or character literal.
1461 Inside a C style block comment.
1463 Inside a C++ style line comment.
1465 Inside a preprocessor directive.
1467 Anywhere else, i.e., in normal code.
1470 By default, @code{c-ignore-auto-fill} is set to @code{'(string cpp
1471 code)}, which means that auto-filling only occurs in comments when
1472 auto-fill mode is activated. In literals, it's often desirable to have
1473 explicit control over newlines. In preprocessor directives, the
1474 necessary @samp{\} escape character before the newline is not
1475 automatically inserted, so an automatic line break would produce invalid
1476 code. In normal code, line breaks are normally dictated by some logical
1477 structure in the code rather than the last whitespace character, so
1478 automatic line breaks there will produce poor results in the current
1482 The commands that do the actual work follow.
1485 @item @kbd{M-q} (@code{c-fill-paragraph})
1487 @findex c-fill-paragraph
1488 @findex fill-paragraph (c-)
1489 @cindex Javadoc markup
1490 @cindex Pike autodoc markup
1491 This is the replacement for @code{fill-paragraph} in @ccmode{}
1492 buffers. It's used to fill multiline string literals and both block and
1493 line style comments. In Java buffers, the Javadoc markup words are
1494 recognized as paragraph starters. The line oriented Pike autodoc markup
1495 words are recognized in the same way in Pike mode.
1497 The function keeps the comment starters and enders of block comments as
1498 they were before the filling. This means that a comment ender on the
1499 same line as the paragraph being filled will be filled with the
1500 paragraph, and one on a line by itself will stay as it is. The comment
1501 starter is handled similarly@footnote{This means that the variables
1502 @code{c-hanging-comment-starter-p} and @code{c-hanging-comment-ender-p},
1503 which controlled this behavior in earlier versions of @ccmode{}, are now
1506 @item @kbd{M-j} (@code{c-indent-new-comment-line})
1508 @findex c-indent-new-comment-line
1509 @findex indent-new-comment-line (c-)
1510 This is the replacement for @code{indent-new-comment-line}. It breaks
1511 the line at point and indents the new line like the current one.
1513 @vindex comment-multi-line
1514 If inside a comment and @code{comment-multi-line} is non-@code{nil}, the
1515 indentation and line prefix are preserved. If inside a comment and
1516 @code{comment-multi-line} is @code{nil}, a new comment of the same type
1517 is started on the next line and indented as appropriate for comments.
1519 Note that @ccmode{} sets @code{comment-multi-line} to @code{t} at
1520 startup. The reason is that @kbd{M-j} could otherwise produce sequences
1521 of single line block comments for texts that should logically be treated
1522 as one comment, and the rest of the paragraph handling code
1523 (e.g., @kbd{M-q} and @kbd{M-a}) can't cope with that, which would lead to
1524 inconsistent behavior.
1526 @item @kbd{M-x c-context-line-break}
1527 @findex c-context-line-break
1528 @findex context-line-break (c-)
1529 This is a function that works like @code{indent-new-comment-line} in
1530 comments and @code{newline-and-indent} elsewhere, thus combining those
1531 two in a way that uses each one in the context it's best suited for.
1532 I.e., in comments the comment line prefix and indentation is kept for
1533 the new line, and in normal code it's indented according to context by
1534 the indentation engine.
1536 In macros it acts like @code{newline-and-indent} but additionally
1537 inserts and optionally aligns the line ending backslash so that the
1538 macro remains unbroken. @xref{Macro Handling}, for details about the
1539 backslash alignment.
1541 It's not bound to a key by default, but it's intended to be used on the
1542 @kbd{RET} key. If you like the behavior of @code{newline-and-indent} on
1543 @kbd{RET}, you should consider switching to this function.
1545 @item @kbd{M-x c-context-open-line}
1546 @findex c-context-open-line
1547 @findex context-open-line (c-)
1548 This is to @kbd{C-o} (@kbd{M-x open-line}) as
1549 @code{c-context-line-break} is to @kbd{RET}. I.e., it works just like
1550 @code{c-context-line-break} but leaves the point before the inserted
1555 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1556 @node Macro Handling, Font Locking, Text Filling and Line Breaking, Top
1557 @comment node-name, next, previous, up
1558 @chapter Macro Handling
1560 @cindex preprocessor directives
1561 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1563 Preprocessor directives are handled as syntactic whitespace from other
1564 code, i.e., they can be interspersed anywhere without affecting the
1565 syntactic analysis, just like comments.
1567 The code inside macro definitions is still analyzed syntactically so
1568 that you get relative indentation there just as you'd get if the same
1569 code was outside a macro. However, since there is no hint about the
1570 syntactic context, i.e., whether the macro expands to an expression, to some
1571 statements, or perhaps to whole functions, the syntactic recognition can be
1572 wrong. @ccmode{} manages to figure it out correctly most of the time,
1573 though. @xref{Syntactic Symbols}, for details about the indentation.
1575 @defopt c-syntactic-indentation-in-macros
1576 @vindex syntactic-indentation-in-macros (c-)
1577 Enable syntactic analysis inside macros, which is the default. If this
1578 is @code{nil}, all lines inside macro definitions are analyzed as
1579 @code{cpp-macro-cont}.
1582 @ccmode{} provides some tools to help keep the line continuation
1583 backslashes in macros neat and tidy:
1586 @item @kbd{C-c C-\} (@code{c-backslash-region})
1588 @findex c-backslash-region
1589 @findex backslash-region (c-)
1590 This function inserts and aligns or deletes the end-of-line backslashes
1591 in the current region.
1593 With no prefix argument, it inserts any missing backslashes and aligns
1594 them according to the @code{c-backslash-column} and
1595 @code{c-backslash-max-column} variables. With a prefix argument, it
1596 deletes any backslashes.
1598 The function does not modify blank lines at the start of the region. If
1599 the region ends at the start of a line, it always deletes the backslash
1600 (if any) at the end of the previous line.
1603 @defopt c-backslash-column
1604 @vindex backslash-column (c-)
1605 @defoptx c-backslash-max-column
1606 @vindex backslash-max-column (c-)
1607 These variables control the alignment columns for line continuation
1608 backslashes in multiline macros. They are used by the functions that
1609 automatically insert or align such backslashes,
1610 e.g., @code{c-backslash-region} and @code{c-context-line-break}.
1612 @code{c-backslash-column} specifies the minimum column for the
1613 backslashes. If any line in the macro exceeds it then the next tab
1614 stop from that line is used as the alignment column for all the
1615 backslashes, so that they remain in a single column. However, if some
1616 lines exceed @code{c-backslash-max-column} then the backslashes in the
1617 rest of the macro will be kept at that column, so that the
1618 lines which are too long ``stick out'' instead.
1621 @defopt c-auto-align-backslashes
1622 @vindex auto-align-backslashes (c-)
1623 Align automatically inserted line continuation backslashes if
1624 non-@code{nil}. When line continuation backslashes are inserted
1625 automatically for line breaks in multiline macros, e.g., by
1626 @code{c-context-line-break}, they are aligned with the other backslashes
1627 in the same macro if this flag is set. Otherwise the inserted
1628 backslashes are preceded by a single space.
1631 The recommended line breaking function, @code{c-context-line-break}
1632 (@pxref{Text Filling and Line Breaking}), is especially nice if you edit
1633 multiline macros frequently. When used inside a macro, it automatically
1634 inserts and adjusts the mandatory backslash at the end of the line to
1635 keep the macro together, and it leaves the point at the right
1636 indentation column for the code. Thus you can write code inside macros
1637 almost exactly as you can elsewhere, without having to bother with the
1638 trailing backslashes.
1641 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1642 @node Font Locking, Commands, Macro Handling, Top
1643 @comment node-name, next, previous, up
1644 @chapter Font Locking
1645 @cindex font locking
1646 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1648 @strong{Please note:} The font locking in AWK mode is currently not integrated
1649 with the rest of @ccmode{}, so this section does not apply there.
1650 @xref{AWK Mode Font Locking}, instead.
1652 @cindex Font Lock mode
1654 @ccmode{} provides font locking for its supported languages by supplying
1655 patterns for use with Font Lock mode. This means that you get distinct
1656 faces on the various syntactic parts such as comments, strings, keywords
1657 and types, which is very helpful in telling them apart at a glance and
1658 discovering syntactic errors. @xref{Font Lock,,, emacs, The Emacs
1659 Editor}, for ways to enable font locking in @ccmode{} buffers.
1662 * Font Locking Preliminaries::
1664 * Documentation Comments::
1668 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1669 @node Font Locking Preliminaries, Faces, , Font Locking
1670 @comment node-name, next, previous, up
1671 @section Font Locking Preliminaries
1672 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1674 The font locking for most of the @ccmode{} languages were provided
1675 directly by the Font Lock package prior to version 5.30 of @ccmode{}.
1676 In the transition to @ccmode{} the patterns have been reworked
1677 completely and are applied uniformly across all the languages except AWK
1678 mode, just like the indentation rules (although each language still has
1679 some pecularities of its own, of course). Since the languages
1680 previously had completely separate font locking patterns, this means
1681 that it's a bit different in most languages now.
1683 The main goal for the font locking in @ccmode{} is accuracy, to provide
1684 a dependable aid in recognizing the various constructs. Some, like
1685 strings and comments, are easy to recognize while others like
1686 declarations and types can be very tricky. @ccmode{} can go to great
1687 lengths to recognize declarations and casts correctly, especially when
1688 the types aren't recognized by standard patterns. This is a fairly
1689 demanding analysis which can be slow on older hardware, and it can
1690 therefore be disabled by choosing a lower decoration level with the
1691 variable @code{font-lock-maximum-decoration}.
1693 @vindex font-lock-maximum-decoration
1695 The decoration levels are used as follows:
1700 Minimal font locking: Fontify only comments, strings and preprocessor
1701 directives (in the languages that use cpp).
1705 Fast normal font locking: In addition to level 1, fontify keywords,
1706 simple types and declarations that are easy to recognize. The variables
1707 @code{*-font-lock-extra-types} (where @samp{*} is the name of the
1708 language) are used to recognize types (see below). Documentation
1709 comments like Javadoc are fontified according to
1710 @code{c-doc-comment-style} (@pxref{Documentation Comments}).
1712 Use this if you think the font locking is too slow. It's the closest
1713 corresponding level to level 3 in the old font lock patterns.
1717 Accurate normal font locking: Like level 2 but uses a different approach
1718 that can recognize types and declarations much more accurately. The
1719 @code{*-font-lock-extra-types} variables are still used, but user
1720 defined types are recognized correctly anyway in most cases. Therefore
1721 those variables should be fairly restrictive and not contain patterns
1724 @cindex Lazy Lock mode
1725 @cindex Just-in-time Lock mode
1727 This level is designed for fairly modern hardware and a font lock
1728 support mode like Lazy Lock or Just-in-time Lock mode that only
1729 fontifies the parts that are actually shown.
1732 @cindex user defined types
1733 @cindex types, user defined
1735 Since user defined types are hard to recognize you can provide
1736 additional regexps to match those you use:
1738 @defopt c-font-lock-extra-types
1739 @defoptx c++-font-lock-extra-types
1740 @defoptx objc-font-lock-extra-types
1741 @defoptx java-font-lock-extra-types
1742 @defoptx idl-font-lock-extra-types
1743 @defoptx pike-font-lock-extra-types
1744 For each language there's a variable @code{*-font-lock-extra-types},
1745 where @samp{*} stands for the language in question. It contains a list
1746 of regexps that matches identifiers that should be recognized as types,
1747 e.g., @samp{\\sw+_t} to recognize all identifiers ending with @samp{_t}
1748 as is customary in C code. Each regexp should not match more than a
1751 The default values contain regexps for many types in standard runtime
1752 libraries that are otherwise difficult to recognize, and patterns for
1753 standard type naming conventions like the @samp{_t} suffix in C and C++.
1754 Java, Objective-C and Pike have as a convention to start class names
1755 with capitals, so there are patterns for that in those languages.
1757 Despite the names of these variables, they are not only used for
1758 fontification but in other places as well where @ccmode{} needs to
1763 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1764 @node Faces, Documentation Comments, Font Locking Preliminaries, Font Locking
1765 @comment node-name, next, previous, up
1768 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1770 @ccmode{} attempts to use the standard faces for programming languages
1771 in accordance with their intended purposes as far as possible. No extra
1772 faces are currently provided, with the exception of a replacement face
1773 @code{c-invalid-face} for emacsen that don't provide
1774 @code{font-lock-warning-face}.
1778 @vindex font-lock-comment-face
1779 Normal comments are fontified in @code{font-lock-comment-face}.
1782 @vindex font-lock-doc-face
1783 @vindex font-lock-doc-string-face
1784 @vindex font-lock-comment-face
1785 Comments that are recognized as documentation (@pxref{Documentation
1786 Comments}) get @code{font-lock-doc-face} (Emacs) or
1787 @code{font-lock-doc-string-face} (XEmacs) if those faces exist. If they
1788 don't then @code{font-lock-comment-face} is used.
1791 @vindex font-lock-string-face
1792 String and character literals are fontified in
1793 @code{font-lock-string-face}.
1796 @vindex font-lock-keyword-face
1797 Keywords are fontified with @code{font-lock-keyword-face}.
1800 @vindex font-lock-function-name-face
1801 @code{font-lock-function-name-face} is used for function names in
1802 declarations and definitions, and classes in those contexts. It's also
1803 used for preprocessor defines with arguments.
1806 @vindex font-lock-variable-name-face
1807 Variables in declarations and definitions, and other identifiers in such
1808 variable contexts, get @code{font-lock-variable-name-face}. It's also
1809 used for preprocessor defines without arguments.
1812 @vindex font-lock-constant-face
1813 @vindex font-lock-reference-face
1814 Builtin constants are fontified in @code{font-lock-constant-face} if it
1815 exists, @code{font-lock-reference-face} otherwise. As opposed to the
1816 preceding two faces, this is used on the names in expressions, and it's
1817 not used in declarations, even if there happen to be a @samp{const} in
1821 @vindex font-lock-type-face
1822 @code{font-lock-type-face} is put on types (both predefined and user
1823 defined) and classes in type contexts.
1826 @vindex font-lock-constant-face
1827 @vindex font-lock-reference-face
1828 Label identifiers get @code{font-lock-constant-face} if it exists,
1829 @code{font-lock-reference-face} otherwise.
1832 Name qualifiers and identifiers for scope constructs are fontified like
1836 Special markup inside documentation comments are also fontified like
1840 @vindex font-lock-preprocessor-face
1841 @vindex font-lock-builtin-face
1842 @vindex font-lock-reference-face
1843 Preprocessor directives get @code{font-lock-preprocessor-face} if it
1844 exists (i.e., XEmacs). In Emacs they get @code{font-lock-builtin-face}
1845 or @code{font-lock-reference-face}, for lack of a closer equivalent.
1848 @vindex font-lock-warning-face
1849 @vindex c-invalid-face
1850 @vindex invalid-face (c-)
1851 Some kinds of syntactic errors are fontified with
1852 @code{font-lock-warning-face} in Emacs. In older XEmacs versions
1853 there's no corresponding standard face, so there a special
1854 @code{c-invalid-face} is used, which is defined to stand out sharply by
1857 Note that it's not used for @samp{#error} or @samp{#warning} directives,
1858 since those aren't syntactic errors in themselves.
1862 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1863 @node Documentation Comments, , Faces, Font Locking
1864 @comment node-name, next, previous, up
1865 @section Documentation Comments
1866 @cindex documentation comments
1867 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1869 There are various tools to supply documentation in the source as
1870 specially structured comments, e.g., the standard Javadoc tool in Java.
1871 @ccmode{} provides an extensible mechanism to fontify such comments and
1872 the special markup inside them.
1874 @defopt c-doc-comment-style
1875 @vindex doc-comment-style (c-)
1876 This is a style variable that specifies which documentation comment
1877 style to recognize, e.g., @code{javadoc} for Javadoc comments.
1879 The value may also be a list of styles, in which case all of them are
1880 recognized simultaneously (presumably with markup cues that don't
1883 The value may also be an association list to specify different comment
1884 styles for different languages. The symbol for the major mode is then
1885 looked up in the alist, and the value of that element is interpreted as
1886 above if found. If it isn't found then the symbol `other' is looked up
1887 and its value is used instead.
1889 Note that @ccmode{} uses this variable to set other variables that
1890 handle fontification etc. That's done at mode initialization or when
1891 you switch to a style which sets this variable. Thus, if you change it
1892 in some other way, e.g., interactively in a CC Mode buffer, you will need
1893 to do @kbd{M-x java-mode} (or whatever mode you're currently using) to
1896 @findex c-setup-doc-comment-style
1897 @findex setup-doc-comment-style (c-)
1898 Note also that when @ccmode{} starts up, the other variables are
1899 modified before the mode hooks are run. If you change this variable in
1900 a mode hook, you have to call @code{c-setup-doc-comment-style}
1901 afterwards to redo that work.
1904 @ccmode{} currently provides handing of the following doc comment
1909 @cindex Javadoc markup
1910 Javadoc comments, the standard tool in Java.
1913 @cindex Pike autodoc markup
1914 For Pike autodoc markup, the standard in Pike.
1917 The above is by no means complete. If you'd like to see support for
1918 other doc comment styles, please let us know (@pxref{Mailing Lists and
1919 Submitting Bug Reports}).
1921 You can also write your own doc comment fontification support to use
1922 with @code{c-doc-comment-style}: Supply a variable or function
1923 @code{*-font-lock-keywords} where @samp{*} is the name you want to use
1924 in @code{c-doc-comment-style}. If it's a variable, it's prepended to
1925 @code{font-lock-keywords}. If it's a function, it's called at mode
1926 initialization and the result is prepended. For an example, see
1927 @code{javadoc-font-lock-keywords} in @file{cc-fonts.el}.
1929 If you add support for another doc comment style, please consider
1930 contributing it --- send a note to @email{bug-cc-mode@@gnu.org}.
1933 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1934 @node Commands, Customizing Indentation, Font Locking, Top
1935 @comment node-name, next, previous, up
1937 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1940 * Indentation Commands::
1941 * Movement Commands::
1945 See also @ref{Text Filling and Line Breaking} and @ref{Macro Handling},
1946 for commands concerning those bits.
1949 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1950 @node Indentation Commands, Movement Commands, , Commands
1951 @comment node-name, next, previous,up
1952 @section Indentation Commands
1953 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1955 The following list of commands reindent C constructs. Note that when
1956 you change your coding style, either interactively or through some other
1957 means, your file does @emph{not} automatically get reindented. You
1958 will need to execute one of the following commands to see the effects of
1961 @cindex GNU indent program
1962 Also, variables like @code{c-hanging-*} and @code{c-cleanup-list}
1963 only affect how on-the-fly code is formatted. Changing the
1964 ``hanginess'' of a brace and then reindenting, will not move the brace
1965 to a different line. For this, you're better off getting an external
1966 program like GNU @code{indent}, which will rearrange brace location,
1969 Reindenting large sections of code can take a long time. When
1970 @ccmode{} reindents a region of code, it is essentially equivalent to
1971 hitting @kbd{TAB} on every line of the region.
1973 These commands are useful when indenting code:
1976 @item @kbd{TAB} (@code{c-indent-command})
1978 @findex c-indent-command
1979 @findex indent-command (c-)
1980 Indents the current line. The actual behavior is controlled by several
1981 variables, described below. See @code{c-tab-always-indent},
1982 @code{c-insert-tab-function}, and @code{indent-tabs-mode}. With a
1983 numeric argument, this command rigidly indents the region, preserving
1984 the relative indentation among the lines.
1986 @item @kbd{C-M-q} (@code{c-indent-exp})
1988 @findex c-indent-exp
1989 @findex indent-exp (c-)
1990 Indent an entire balanced brace or parenthesis expression. Note that
1991 point must be on the opening brace or parenthesis of the expression you
1994 @item @kbd{C-c C-q} (@code{c-indent-defun})
1996 @findex c-indent-defun
1997 @findex indent-defun (c-)
1998 Indents the entire top-level function, class or macro definition
1999 encompassing point. It leaves point unchanged. This function can't be
2000 used to reindent a nested brace construct, such as a nested class or
2001 function, or a Java method. The top-level construct being reindented
2002 must be complete, i.e., it must have both a beginning brace and an ending
2005 @item @kbd{C-M-\} (@code{indent-region})
2007 @findex indent-region
2008 Indents an arbitrary region of code. This is a standard Emacs command,
2009 tailored for C code in a @ccmode{} buffer. Note, of course, that point
2010 and mark must delineate the region you want to indent.
2012 @item @kbd{M-;} (@code{indent-for-comment})
2014 @findex indent-for-comment
2015 Insert a comment at the end of the current line, if none is there already.
2016 Then reindent the comment according to the variables
2017 @code{c-indent-comment-alist}, @code{c-indent-comments-syntactically-p}
2018 and @code{comment-column}. Then position the point after the comment
2019 starter. This is a standard Emacs command, but @ccmode{} enhances it a
2020 bit with two variables:
2022 @defopt c-indent-comment-alist
2023 @vindex indent-comment-alist (c-)
2024 @vindex comment-column
2025 This style variable allows you to control which column @kbd{M-;}
2026 indents the comment to, depending on the preceding code and the
2027 indentation of a similar comment on the preceding line, if there is
2028 any. It is an association list that maps different types of lines to
2029 actions describing how they should be handled. If a certain line type
2030 isn't present on the list then the line is indented to the column
2031 specified by @code{comment-column}. See the documentation string for
2032 @code{c-indent-comment-alist} for a full description of the available
2033 line types and actions (use @kbd{C-h v c-indent-comment-alist}).
2036 @defopt c-indent-comments-syntactically-p
2037 @vindex indent-comments-syntactically-p (c-)
2038 Normally, when this variable is @code{nil}, @kbd{M-;} will indent
2039 comment-only lines according to @code{c-indent-comment-alist}, just as
2040 it does with lines where other code precede the comments. However, if
2041 you want it to act just like @kbd{TAB} for comment-only lines you can
2042 get that by setting @code{c-indent-comments-syntactically-p} to
2045 If @code{c-indent-comments-syntactically-p} is non-@code{nil} then
2046 @code{c-indent-comment-alist} won't be consulted at all for comment-only
2050 @item @kbd{C-M-h} (@code{c-mark-function})
2052 @findex c-mark-function
2053 @findex mark-function (c-)
2054 While not strictly an indentation command, this is useful for marking
2055 the current top-level function or class definition as the current
2056 region. As with @code{c-indent-defun}, this command operates on
2057 top-level constructs, and can't be used to mark say, a Java method.
2060 These variables are also useful when indenting code:
2062 @defopt c-tab-always-indent
2063 @vindex tab-always-indent (c-)
2066 This variable controls how @kbd{TAB} (@code{c-indent-command})
2067 operates. When it is @code{t}, @kbd{TAB} always indents the current
2068 line. When it is @code{nil}, the line is indented only if point is at
2069 the left margin, or on or before the first non-whitespace character on
2070 the line, otherwise some whitespace is inserted. If this variable is
2071 some other value (not @code{nil} or @code{t}), then some whitespace is
2072 inserted only within strings and comments (literals), but the line is
2076 @defopt c-insert-tab-function
2077 @vindex insert-tab-function (c-)
2078 @findex tab-to-tab-stop
2079 When ``some whitespace'' is inserted as described above, what actually
2080 happens is that the function stored in @code{c-insert-tab-function} is
2081 called. Normally, this just inserts a real tab character, or the
2082 equivalent number of spaces, depending on @code{indent-tabs-mode}.
2083 Some people, however, set @code{c-insert-tab-function} to
2084 @code{tab-to-tab-stop} so as to get hard tab stops when indenting.
2087 @defopt indent-tabs-mode
2088 This is a standard Emacs variable that controls how line indentation
2089 is composed. When it's non-@code{nil}, tabs can be used in a line's
2090 indentation, otherwise only spaces can be used.
2093 @defopt c-progress-interval
2094 @vindex progress-interval (c-)
2095 When indenting large regions of code, this variable controls how often a
2096 progress message is displayed. Set this variable to @code{nil} to
2097 inhibit the progress messages, or set it to an integer which is how
2098 often (in seconds) progress messages are to be displayed.
2102 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2103 @node Movement Commands, Other Commands, Indentation Commands, Commands
2104 @comment node-name, next, previous, up
2105 @section Movement Commands
2107 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2109 @ccmode{} contains some useful commands for moving around in C
2113 @item @kbd{M-x c-beginning-of-defun}
2114 @findex c-beginning-of-defun
2115 @findex beginning-of-defun (c-)
2116 @findex beginning-of-defun
2117 Move point back to the least-enclosing brace. This function is
2118 analogous to the Emacs built-in command @code{beginning-of-defun},
2119 except it eliminates the constraint that the top-level opening brace
2120 must be in column zero. See @code{beginning-of-defun} for more
2123 Depending on the coding style being used, you might prefer
2124 @code{c-beginning-of-defun} to @code{beginning-of-defun}. If so,
2125 consider binding @kbd{C-M-a} to the former instead. For backwards
2126 compatibility reasons, the default binding remains in effect.
2128 In AWK mode, a defun doesn't necessarily have braces at all. AWK Mode
2129 therefore has its own version of this function which is bound by
2130 default to @kbd{C-M-a}. You can thus chose freely which function to
2131 bind to @kbd{C-M-a} for the other modes without worrying about AWK
2132 buffers. @xref{AWK Mode Defuns}.
2134 @item @kbd{M-x c-end-of-defun}
2135 @findex c-end-of-defun
2136 @findex end-of-defun (c-)
2137 @findex end-of-defun
2138 Moves point to the end of the current top-level definition. This
2139 function is analogous to the Emacs built-in command @code{end-of-defun},
2140 except it eliminates the constraint that the top-level opening brace of
2141 the defun must be in column zero. See @code{end-of-defun} for more
2144 Depending on the coding style being used, you might prefer
2145 @code{c-end-of-defun} to @code{end-of-defun}. If so,
2146 consider binding @kbd{C-M-e} to the former instead. For backwards
2147 compatibility reasons, the default binding remains in effect.
2149 In AWK Mode, a defun doesn't necessarily have braces at all. AWK Mode
2150 therefore has its own version of this function which is bound by
2151 default to @kbd{C-M-e}. You can thus chose freely which function to
2152 bind to @kbd{C-M-e} for the other modes without worrying about AWK
2153 buffers. @ref{AWK Mode Defuns}.
2155 @item @kbd{C-c C-u} (@code{c-up-conditional})
2157 @findex c-up-conditional
2158 @findex up-conditional (c-)
2159 Move point back to the containing preprocessor conditional, leaving the
2160 mark behind. A prefix argument acts as a repeat count. With a negative
2161 argument, move point forward to the end of the containing
2162 preprocessor conditional.
2164 @samp{#elif} is treated like @samp{#else} followed by @samp{#if}, so the
2165 function stops at them when going backward, but not when going forward.
2167 @item @kbd{M-x c-up-conditional-with-else}
2168 @findex c-up-conditional-with-else
2169 @findex up-conditional-with-else (c-)
2170 A variety of @code{c-up-conditional} that also stops at @samp{#else}
2171 lines. Normally those lines are ignored.
2173 @item @kbd{M-x c-down-conditional}
2174 @findex c-down-conditional
2175 @findex down-conditional (c-)
2176 Move point forward into the next nested preprocessor conditional,
2177 leaving the mark behind. A prefix argument acts as a repeat count.
2178 With a negative argument, move point backward into the previous
2179 nested preprocessor conditional.
2181 @samp{#elif} is treated like @samp{#else} followed by @samp{#if}, so the
2182 function stops at them when going forward, but not when going backward.
2184 @item @kbd{M-x c-down-conditional-with-else}
2185 @findex c-down-conditional-with-else
2186 @findex down-conditional-with-else (c-)
2187 A variety of @code{c-down-conditional} that also stops at @samp{#else}
2188 lines. Normally those lines are ignored.
2190 @item @kbd{C-c C-p} (@code{c-backward-conditional})
2192 @findex c-backward-conditional
2193 @findex backward-conditional (c-)
2194 Move point back over a preprocessor conditional, leaving the mark
2195 behind. A prefix argument acts as a repeat count. With a negative
2196 argument, move forward.
2198 @item @kbd{C-c C-n} (@code{c-forward-conditional})
2200 @findex c-forward-conditional
2201 @findex forward-conditional (c-)
2202 Move point forward across a preprocessor conditional, leaving the mark
2203 behind. A prefix argument acts as a repeat count. With a negative
2204 argument, move backward.
2206 @item @kbd{M-a} (@code{c-beginning-of-statement})
2208 @findex c-beginning-of-statement
2209 @findex beginning-of-statement (c-)
2210 Move point to the beginning of the innermost C statement. If point is
2211 already at the beginning of a statement, move to the beginning of the
2212 closest preceding statement, even if that means moving into a block (you
2213 can use @kbd{C-M-b} to move over a balanced block). With prefix
2214 argument @var{n}, move back @var{n} @minus{} 1 statements.
2216 If point is within or next to a comment or a string which spans more
2217 than one line, this command moves by sentences instead of statements.
2219 When called from a program, this function takes three optional
2220 arguments: the repetition count, a buffer position limit which is the
2221 farthest back to search for the syntactic context, and a flag saying
2222 whether to do sentence motion in or near comments and multiline strings.
2224 @item @kbd{M-e} (@code{c-end-of-statement})
2226 @findex c-end-of-statement
2227 @findex end-of-statement (c-)
2228 Move point to the end of the innermost C statement. If point is at the
2229 end of a statement, move to the end of the next statement, even if it's
2230 inside a nested block (use @kbd{C-M-f} to move to the other side of the
2231 block). With prefix argument @var{n}, move forward @var{n} @minus{} 1
2234 If point is within or next to a comment or a string which spans more
2235 than one line, this command moves by sentences instead of statements.
2237 When called from a program, this function takes three optional
2238 arguments: the repetition count, a buffer position limit which is the
2239 farthest back to search for the syntactic context, and a flag saying
2240 whether to do sentence motion in or near comments and multiline strings.
2242 @item @kbd{M-x c-forward-into-nomenclature}
2243 @findex c-forward-into-nomenclature
2244 @findex forward-into-nomenclature (c-)
2245 A popular programming style, especially for object-oriented languages
2246 such as C++ is to write symbols in a mixed case format, where the first
2247 letter of each word is capitalized, and not separated by underscores.
2248 e.g., @samp{SymbolsWithMixedCaseAndNoUnderlines}.
2250 This command moves point forward to next capitalized word. With prefix
2251 argument @var{n}, move @var{n} times.
2253 @item @kbd{M-x c-backward-into-nomenclature}
2254 @findex c-backward-into-nomenclature
2255 @findex backward-into-nomenclature (c-)
2256 Move point backward to beginning of the next capitalized
2257 word. With prefix argument @var{n}, move @var{n} times. If
2258 @var{n} is negative, move forward.
2262 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2263 @node Other Commands, , Movement Commands, Commands
2264 @comment node-name, next, previous, up
2265 @section Other Commands
2266 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2268 Here are the various other commands that didn't fit anywhere else:
2271 @item @kbd{C-c :} (@code{c-scope-operator})
2273 @findex c-scope-operator
2274 @findex scope-operator (c-)
2275 In C++, it is also sometimes desirable to insert the double-colon scope
2276 operator without performing the electric behavior of colon insertion.
2277 @kbd{C-c :} does just this.
2280 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2281 @node Customizing Indentation, Syntactic Symbols, Commands, Top
2282 @comment node-name, next, previous, up
2283 @chapter Customizing Indentation
2284 @cindex customization, indentation
2286 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2288 The context sensitive indentation is mainly controlled by the variable
2289 @code{c-offsets-alist}:
2291 @defopt c-offsets-alist
2292 @vindex offsets-alist (c-)
2293 This special style variable contains the mappings between syntactic
2294 symbols and the offsets to apply for those symbols. It's set at mode
2295 initialization from a @emph{style} you may specify. Styles are
2296 groupings of syntactic symbol offsets and other style variable values.
2297 Most likely, you'll find that one of the predefined styles will suit
2298 your needs. @xref{Styles}, for an explanation of how to set up named
2301 Only syntactic symbols not already bound on @code{c-offsets-alist} will
2302 be set from styles. This means that any association you set on it, be
2303 it before or after mode initialization, will not be changed. The
2304 @code{c-offsets-alist} variable may therefore be used from e.g., the
2305 Customization interface@footnote{Available in Emacs 20 and later, and
2306 XEmacs 19.15 and later.} to easily change indentation offsets without
2307 having to bother about styles. Initially @code{c-offsets-alist} is
2308 empty, so that all syntactic symbols are set by the style system.
2310 The offset associated with any particular syntactic symbol can be an
2311 integer, a function or lambda expression, a variable name, a vector, a
2312 list, or one of the following special symbols: @code{+}, @code{-},
2313 @code{++}, @code{--}, @code{*}, or @code{/}. The meaning of these
2314 values are described in detail below.
2317 The special symbols describe an offset in multiples of the value of
2318 @code{c-basic-offset}:
2320 @defopt c-basic-offset
2321 @vindex basic-offset (c-)
2322 Style variable that holds the basic offset between indentation levels.
2325 By defining a style's indentation in terms of @code{c-basic-offset},
2326 you can change the amount of whitespace given to an indentation level
2327 while maintaining the same basic shape of your code. Here are the
2328 values that the special symbols correspond to:
2332 @code{c-basic-offset} times 1
2334 @code{c-basic-offset} times -1
2336 @code{c-basic-offset} times 2
2338 @code{c-basic-offset} times -2
2340 @code{c-basic-offset} times 0.5
2342 @code{c-basic-offset} times -0.5
2345 @cindex indentation functions
2347 When a function is used as offset, it's called an @dfn{indentation
2348 function}. Such functions are useful when more context than just the
2349 syntactic symbol is needed to get the desired indentation.
2350 @xref{Indentation Functions}, and @ref{Custom Indentation Functions},
2351 for details about them.
2353 If the offset is a vector, its first element sets the absolute
2354 indentation column, which will override any previous relative
2355 indentation. It won't override additional relative indentation for
2356 nested constructs, though.
2358 @vindex c-strict-syntax-p
2359 @vindex strict-syntax-p (c-)
2360 The offset can also be a list, in which case it is evaluated recursively
2361 using the semantics described above. The first element of the list that
2362 returns a non-@code{nil} value succeeds and the evaluation stops. If
2363 none of the list elements return a non-@code{nil} value, then an offset
2364 of 0 (zero) is used@footnote{There is however a variable
2365 @code{c-strict-syntax-p} that, when set to non-@code{nil}, will cause an
2366 error to be signaled in that case. It's now considered obsolete since
2367 it doesn't work well with some of the alignment functions that now
2368 returns @code{nil} instead of zero to be more usable in lists. You
2369 should therefore leave @code{c-strict-syntax-p} set to @code{nil}.}.
2371 So, for example, because most of the default offsets are defined in
2372 terms of @code{+}, @code{-}, and @code{0}, if you like the general
2373 indentation style, but you use 4 spaces instead of 2 spaces per level,
2374 you can probably achieve your style just by changing
2375 @code{c-basic-offset} like so@footnote{You can try this interactively in
2376 a C buffer by typing the text that appears in italics.}:
2379 @emph{M-x set-variable RET}
2380 Set variable: @emph{c-basic-offset RET}
2381 Set c-basic-offset to value: @emph{4 RET}
2389 int add( int val, int incr, int doit )
2393 return( val + incr );
2405 int add( int val, int incr, int doit )
2409 return( val + incr );
2416 To change indentation styles more radically, you will want to change the
2417 offsets associated with other syntactic symbols. First, I'll show you
2418 how to do that interactively, then I'll describe how to make changes to
2419 your @file{.emacs} file so that your changes are more permanent.
2422 * Interactive Customization::
2423 * Permanent Customization::
2426 * Advanced Customizations::
2430 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2431 @node Interactive Customization, Permanent Customization, , Customizing Indentation
2432 @comment node-name, next, previous, up
2433 @section Interactive Customization
2434 @cindex customization, interactive
2435 @cindex interactive customization
2436 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2438 As an example of how to customize indentation, let's change the
2439 style of this example@footnote{In this and subsequent examples, the
2440 original code is formatted using the @samp{gnu} style unless otherwise
2441 indicated. @xref{Styles}.}:
2445 1: int add( int val, int incr, int doit )
2449 5: return( val + incr );
2461 1: int add( int val, int incr, int doit )
2465 5: return( val + incr );
2472 In other words, we want to change the indentation of braces that open a
2473 block following a condition so that the braces line up under the
2474 conditional, instead of being indented. Notice that the construct we
2475 want to change starts on line 4. To change the indentation of a line,
2476 we need to see which syntactic components affect the offset calculations
2477 for that line. Hitting @kbd{C-c C-s} on line 4 yields:
2480 ((substatement-open 44))
2484 so we know that to change the offset of the open brace, we need to
2485 change the indentation for the @code{substatement-open} syntactic
2488 To do this interactively, just hit @kbd{C-c C-o}. This prompts
2489 you for the syntactic symbol to change, providing a reasonable default.
2490 In this case, the default is @code{substatement-open}, which is just the
2491 syntactic symbol we want to change!
2493 After you hit return, @ccmode{} will then prompt you for the new
2494 offset value, with the old value as the default. The default in this
2495 case is @samp{+}, but we want no extra indentation so enter
2496 @samp{0} and @kbd{RET}. This will associate the offset 0 with the
2497 syntactic symbol @code{substatement-open}.
2499 To check your changes quickly, just hit @kbd{C-c C-q}
2500 (@code{c-indent-defun}) to reindent the entire function. The example
2501 should now look like:
2505 1: int add( int val, int incr, int doit )
2509 5: return( val + incr );
2516 Notice how just changing the open brace offset on line 4 is all we
2517 needed to do. Since the other affected lines are indented relative to
2518 line 4, they are automatically indented the way you'd expect. For more
2519 complicated examples, this may not always work. The general approach to
2520 take is to always start adjusting offsets for lines higher up in the
2521 file, then reindent and see if any following lines need further
2524 @deffn Command c-set-offset symbol offset
2525 @findex set-offset (c-)
2527 This is the command bound to @kbd{C-c C-o}. It provides a convenient
2528 way to set offsets on @code{c-offsets-alist} both interactively (see
2529 the example above) and from your mode hook.
2531 It takes two arguments when used programmatically: @var{symbol} is the
2532 syntactic element symbol to change and @var{offset} is the new offset
2533 for that syntactic element.
2537 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2538 @node Permanent Customization, Hooks, Interactive Customization, Customizing Indentation
2539 @comment node-name, next, previous, up
2540 @section Permanent Customization
2541 @cindex customization, permanent
2542 @cindex permanent customization
2543 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2545 To make your changes permanent, you need to add some lisp code to your
2546 @file{.emacs} file. @ccmode{} supports many different ways to be
2547 configured, from the straightforward way by setting variables globally
2548 in @file{.emacs} or in the Customization interface, to the complex and
2549 precisely controlled way by using styles and hook functions.
2551 The simplest way of customizing @ccmode{} permanently is to set the
2552 variables in your @file{.emacs} with @code{setq} and similar commands.
2553 So to make a permanent setting of @code{substatement-open} to 0, add
2554 this to the @file{.emacs} file:
2558 (setq c-offsets-alist
2559 '((substatement-open . 0)))
2563 When @ccmode{} initializes a buffer, it will fill out
2564 @code{c-offsets-alist} with the remaining syntactic symbols according to
2567 You can also use the more user friendly Customization interface, but
2568 this manual does not cover how that works.
2570 Variables set like this at the top level in @file{.emacs} take effect in
2571 all @ccmode{} buffers, regardless of language. The indentation style
2572 related variables, e.g., @code{c-offsets-alist}, that you don't set this
2573 way get their value from the style system (@pxref{Styles}), and they
2574 therefore depend on the setting of @code{c-default-style}. Note that if
2575 you use Customize, this means that the greyed-out default values
2576 presented there might not be the ones you actually get, since the actual
2577 values depend on the style, which may very well be different for
2578 different languages.
2580 If you want to make more advanced configurations, e.g., language-specific
2581 customization, setting global variables isn't enough. For that you can
2582 use the language hooks, see @ref{Hooks}, and/or the style system, see
2585 @defopt c-style-variables-are-local-p
2586 @vindex style-variables-are-local-p (c-)
2587 By default, all style variables are buffer local, so that different
2588 buffers can have different style settings. If you only use one style
2589 in all the files you edit you might want to share them between buffers
2590 so that a change take effect in all buffers. That's done by setting
2591 this variable to @code{nil}. The value takes effect when @ccmode{} is
2592 activated in a buffer for the first time in the Emacs session, so you
2593 typically set it in your @file{.emacs} file and then restart Emacs.
2597 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2598 @node Hooks, Styles, Permanent Customization, Customizing Indentation
2599 @comment node-name, next, previous, up
2602 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2604 @ccmode{} provides several hooks that you can use to customize the mode
2605 according to your coding style. Each language mode has its own hook,
2606 adhering to standard Emacs major mode conventions. There is also one
2607 general hook and one package initialization hook:
2609 @defvar c-initialization-hook
2610 @vindex initialization-hook (c-)
2611 Hook run only once per Emacs session, when @ccmode{} is initialized.
2614 @defvar c-mode-common-hook
2615 @vindex mode-common-hook (c-)
2616 Common hook across all languages. It's run immediately before the
2617 language specific hook.
2621 @defvarx c++-mode-hook
2622 @defvarx objc-mode-hook
2623 @defvarx java-mode-hook
2624 @defvarx idl-mode-hook
2625 @defvarx pike-mode-hook
2626 @defvarx awk-mode-hook
2627 The language specific mode hooks. The appropriate one is run as the
2628 last thing when you enter that language mode.
2631 Note that all the language-specific mode setup that CC Mode does is done
2632 prior to both @code{c-mode-common-hook} and the language specific hook.
2633 That includes installing the indentation style, which can be mode
2634 specific (and also is by default for Java mode). Thus, any style
2635 settings done in @code{c-mode-common-hook} will override whatever
2636 language-specific style is chosen by @code{c-default-style}.
2638 Here's a simplified example of what you can add to your @file{.emacs}
2639 file to do things whenever any @ccmode{} language is edited. See the
2640 Emacs manuals for more information on customizing Emacs via hooks.
2641 @xref{Sample .emacs File}, for a more complete sample @file{.emacs}
2645 (defun my-c-mode-common-hook ()
2646 ;; my customizations for all of c-mode and related modes
2647 (no-case-fold-search)
2649 (add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
2653 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2654 @node Styles, Advanced Customizations, Hooks, Customizing Indentation
2655 @comment node-name, next, previous, up
2658 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2660 Most people only need to edit code formatted in just a few well-defined
2661 and consistent styles. For example, their organization might impose a
2662 ``blessed'' style that all its programmers must conform to. Similarly,
2663 people who work on GNU software will have to use the GNU coding style.
2664 Some shops are more lenient, allowing a variety of coding styles, and as
2665 programmers come and go, there could be a number of styles in use. For
2666 this reason, @ccmode{} makes it convenient for you to set up logical
2667 groupings of customizations called @dfn{styles}, associate a single name
2668 for any particular style, and pretty easily start editing new or
2669 existing code using these styles.
2671 @cindex style variables
2672 The variables that the style system affect are called @dfn{style
2673 variables}. They are handled specially in several ways:
2677 Style variables are by default buffer local variables. However, they
2678 can instead be made global by setting
2679 @code{c-style-variables-are-local-p} to @code{nil} before @ccmode{} is
2683 @vindex c-old-style-variable-behavior
2684 @vindex old-style-variable-behavior (c-)
2685 The default value of any style variable (with two exceptions --- see
2686 below) is the special symbol @code{set-from-style}. Variables that are
2687 still set to that symbol when a @ccmode{} buffer is initialized will be
2688 set according to the current style, otherwise they will keep their
2689 current value@footnote{This is a big change from versions of @ccmode{}
2690 earlier than 5.26, where such settings would get overridden by the style
2691 system unless special precautions were taken. That was changed since it
2692 was counterintuitive and confusing, especially to novice users. If your
2693 configuration depends on the old overriding behavior, you can set the
2694 variable @code{c-old-style-variable-behavior} to non-@code{nil}.}.
2696 Note that when we talk about the ``default value'' for a style variable,
2697 we don't mean the @code{set-from-style} symbol that all style variables
2698 are set to initially, but instead the value it will get at mode
2699 initialization when neither a style nor a global setting has set its
2702 The style variable @code{c-offsets-alist} is handled a little
2703 differently from the other style variables. It's an association list,
2704 and is thus by default set to the empty list, @code{nil}. When the
2705 style system is initialized, any syntactic symbols already on it are
2706 kept --- only the missing ones are filled in from the chosen style.
2708 The style variable @code{c-special-indent-hook} is also handled in a
2709 special way. Styles may only add more functions on this hook, so the
2710 global settings on it are always preserved@footnote{This did not change
2714 The global settings of style variables get captured in the special
2715 @code{user} style, which is used as the base for all the other styles.
2716 @xref{Built-in Styles}, for details.
2719 The style variables are:
2720 @code{c-basic-offset},
2721 @code{c-comment-only-line-offset},
2722 @code{c-block-comment-prefix},
2723 @code{c-comment-prefix-regexp},
2724 @code{c-cleanup-list},
2725 @code{c-hanging-braces-alist},
2726 @code{c-hanging-colons-alist},
2727 @code{c-hanging-semi&comma-criteria},
2728 @code{c-backslash-column},
2729 @code{c-backslash-max-column},
2730 @code{c-special-indent-hook},
2731 @code{c-label-minimum-indentation}, and
2732 @code{c-offsets-alist}.
2736 * Choosing a Style::
2742 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2743 @node Built-in Styles, Choosing a Style, , Styles
2744 @comment node-name, next, previous, up
2745 @subsection Built-in Styles
2746 @cindex styles, built-in
2747 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2749 If you're lucky, one of @ccmode{}'s built-in styles might be just
2750 what you're looking for. These include:
2755 Coding style blessed by the Free Software Foundation
2756 for C code in GNU programs.
2760 The classic Kernighan and Ritchie style for C code.
2764 Also known as ``Allman style'' after Eric Allman.
2767 @cindex Whitesmith style
2768 Popularized by the examples that came with Whitesmiths C, an early
2769 commercial C compiler.
2772 @cindex Stroustrup style
2773 The classic Stroustrup style for C++ code.
2776 @cindex Ellemtel style
2777 Popular C++ coding standards as defined by ``Programming in C++, Rules
2778 and Recommendations,'' Erik Nyquist and Mats Henricson,
2779 Ellemtel@footnote{This document is available at
2780 @uref{http://www.doc.ic.ac.uk/lab/cplus/c++.rules/} among other
2785 C coding standard for Linux (the kernel).
2788 @cindex Python style
2789 C coding standard for Python extension modules@footnote{Python is a
2790 high level scripting language with a C/C++ foreign function interface.
2791 For more information, see @uref{http://www.python.org/}.}.
2795 The style for editing Java code. Note that the default
2796 value for @code{c-default-style} installs this style when you enter
2801 This is a special style for several reasons. First, the
2802 @ccmode{} customizations you do by using either the Customization
2803 interface, or by writing @code{setq}'s at the top level of your
2804 @file{.emacs} file, will be captured in the @code{user} style. Also,
2805 all other styles implicitly inherit their settings from @code{user}
2806 style. This means that for any styles you add via @code{c-add-style}
2807 (@pxref{Adding Styles}) you need only define the differences between
2808 your new style and @code{user} style.
2812 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2813 @node Choosing a Style, Adding Styles, Built-in Styles, Styles
2814 @comment node-name, next, previous, up
2815 @subsection Choosing a Style
2816 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2818 Use @kbd{C-c .} to choose a style interactively:
2820 @deffn Command c-set-style style-name
2821 @findex set-style (c-)
2823 Switch to the specified style in the current buffer. Use
2824 interactively like this:
2827 @kbd{C-c . @var{style-name} RET}
2830 Note that all style names are case insensitive, even the ones you
2833 Setting a style in this way does @emph{not} automatically reindent your
2834 file. For commands that you can use to view the effect of your changes,
2838 The default style in all newly created buffers is @code{gnu}, except
2839 in Java mode where it's @code{java}. Although the @code{user} style
2840 is not the default style, any style variable settings you do with the
2841 Customization interface or on the top level in your @file{.emacs} file
2842 will by default override the style system, so you don't need to set
2843 @code{c-default-style} to @code{user} to see the effect of such
2846 @defopt c-default-style
2847 @vindex default-style (c-)
2848 This variable specifies which style to install by default in new
2849 buffers. It takes either a style name string, or an association list
2850 of major mode symbols to style names:
2854 When @code{c-default-style} is a string, it must be an existing style
2855 name. This style is then used for all modes.
2858 When @code{c-default-style} is an association list, the mode language
2859 is looked up to find a style name string.
2862 If @code{c-default-style} is an association list where the mode
2863 language mode isn't found then the special symbol @samp{other} is
2864 looked up. If it's found then the associated style is used.
2867 If @samp{other} is not found then the @samp{gnu} style is used.
2870 In all cases, the style described in @code{c-default-style} is installed
2871 @emph{before} the language hooks are run, so you can always override
2872 this setting by including an explicit call to @code{c-set-style} in your
2873 language mode hook, or in @code{c-mode-common-hook}.
2877 @defvar c-indentation-style
2878 @vindex indentation-style (c-)
2879 This variable always contains the buffer's current style name, as a
2884 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2885 @node Adding Styles, File Styles, Choosing a Style, Styles
2886 @comment node-name, next, previous, up
2887 @subsection Adding and Amending Styles
2888 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2890 If none of the built-in styles is appropriate, you'll probably want to
2891 create a new @dfn{style definition}, possibly based on an existing
2892 style. To do this, put the new style's settings into a list with the
2893 following format - the list can then be passed as an argument to the
2894 function @code{c-add-style}:
2896 @cindex style definition
2897 @defvr {List} style definition
2898 ([@var{base-style}] [(@var{variable} . @var{value}) @dots{}])
2900 Optional @var{base-style}, if present, must be a string which is the
2901 name of the @dfn{base style} from which this style inherits. At most
2902 one @var{base-style} is allowed in a style definition. If
2903 @var{base-style} is not specified, the style inherits from a table of
2904 default values@footnote{This table is stored internally in the
2905 variable c-fallback-style. It is computed during the initialisation
2906 of @ccmode{} from the factory defaults of the style variables and any
2907 global values they may have been given since starting Emacs.} instead.
2908 All styles eventually inherit from this internal table. Style loops
2909 generate errors. The list of pre-existing styles can be seen in
2910 @ref{Built-in Styles}.
2912 The dotted pairs (@var{variable} . @var{value}) each consist of a
2913 variable and the value it is to be set to when the style is later
2914 activated.@footnote{In certain circumstances, this value can get
2915 overridden by another value.} The variable can be either a @ccmode{}
2916 style variable or an arbitrary Emacs variable. In the latter case, it
2917 is @emph{not} made buffer local by the @ccmode{} style system.
2920 Two variables are treated specially in the dotted pair list:
2923 @item c-offsets-alist
2924 The value is in turn a dotted list on the form
2926 (@var{syntactic-symbol} . @var{offset})
2928 as described in @ref{Customizing Indentation}. These are passed to
2929 @code{c-set-offset} so there is no need to set every syntactic symbol in
2930 your style, only those that are different from the inherited style.
2932 @item c-special-indent-hook
2933 The value is added to @code{c-special-indent-hook} using
2934 @code{add-hook}, so any functions already on it are kept. If the value
2935 is a list, each element of the list is added with @code{add-hook}.
2938 Styles are kept in the @code{c-style-alist} variable, but you
2939 should never modify this variable directly. Instead, @ccmode{}
2940 provides the function @code{c-add-style} for this purpose.
2942 @defun c-add-style stylename description &optional set-p
2943 @findex add-style (c-)
2944 Add or update a style called @var{stylename}, a string.
2945 @var{description} is the new style definition in the form described
2946 above. If @var{stylename} already exists in @code{c-style-alist} then
2947 it is replaced by @var{description}. (Note, this replacement is
2948 total. The old style is @emph{not} merged into the new one.)
2949 Otherwise, a new style is added. If the optional @var{set-p} is
2950 non-@code{nil} then the new style is applied to the current buffer as
2953 The sample @file{.emacs} file provides a concrete example of how a new
2954 style can be added and automatically set. @xref{Sample .emacs File}.
2957 @defvar c-style-alist
2958 @vindex style-alist (c-)
2959 This is the variable that holds the definitions for the styles. It
2960 should not be changed directly; use @code{c-add-style} instead.
2964 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2965 @node File Styles, , Adding Styles, Styles
2966 @comment node-name, next, previous, up
2967 @subsection File Styles
2968 @cindex styles, file local
2969 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2971 @cindex file local variables
2973 The Emacs manual describes how you can customize certain variables on
2974 a per-file basis by including a @dfn{file local variable} block at the
2975 end of the file. So far, you've only seen a functional interface to
2976 @ccmode{} customization, which can't be used there. @ccmode{}
2977 provides two variables allow customization of the indentation style on
2980 @defvar c-file-style
2981 @vindex file-style (c-)
2982 This variable can be set to a style name string. When the file is
2983 visited, @ccmode{} will automatically set the file's style to this
2984 one using @code{c-set-style}.
2987 @defvar c-file-offsets
2988 @vindex file-offsets (c-)
2989 This variable takes an association list similar to what is allowed in
2990 @code{c-offsets-alist}. When the file is visited, @ccmode{} will
2991 automatically institute these offsets using @code{c-set-offset}.
2994 Note that file style settings (i.e., @code{c-file-style}) are applied
2995 before file offset settings (i.e., @code{c-file-offsets}). Also, if
2996 either of these are set in a file's local variable section, all the
2997 style variable values are made local to that buffer.
3000 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3001 @node Advanced Customizations, , Styles, Customizing Indentation
3002 @comment node-name, next, previous, up
3003 @section Advanced Customizations
3004 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3006 For most users, @ccmode{} will support their coding styles with very
3007 little need for more advanced customizations. Usually, one of the
3008 standard styles (@pxref{Built-in Styles}) will do the trick. At most,
3009 perhaps one of the syntactic symbol offsets will need to be tweaked
3010 slightly, or maybe @code{c-basic-offset} will need to be changed.
3011 However, some styles require a more flexible framework for
3012 customization, and one of the real strengths of @ccmode{} is that the
3013 syntactic analysis model provides just such a framework. This allows
3014 you to implement custom indentation calculations for situations not
3015 handled by the mode directly.
3018 * Custom Indentation Functions::
3019 * Custom Brace and Colon Hanging::
3020 * Customizing Semicolons and Commas::
3021 * Other Special Indentations::
3024 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3025 @node Custom Indentation Functions, Custom Brace and Colon Hanging, , Advanced Customizations
3026 @comment node-name, next, previous, up
3027 @subsection Custom Indentation Functions
3028 @cindex customization, indentation functions
3029 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3031 The most flexible way to customize @ccmode{} is by writing custom
3032 indentation functions, and associating them with specific syntactic
3033 symbols (@pxref{Syntactic Symbols}). @ccmode{} itself uses indentation
3034 functions to provide more sophisticated indentation, for example when
3035 lining up C++ stream operator blocks:
3039 1: void main(int argc, char**)
3041 3: cout << "There were "
3043 5: << "arguments passed to the program"
3049 In this example, lines 4 through 6 are assigned the @code{stream-op}
3050 syntactic symbol. Here, @code{stream-op} has an offset of @code{+}, and
3051 with a @code{c-basic-offset} of 2, you can see that lines 4 through 6
3052 are simply indented two spaces to the right of line 3. But perhaps we'd
3053 like @ccmode{} to be a little more intelligent so that it aligns
3054 all the @samp{<<} symbols in lines 3 through 6. To do this, we have
3055 to write a custom indentation function which finds the column of the first
3056 stream operator on the first line of the statement. Here is sample
3057 lisp code implementing this:
3060 (defun c-lineup-streamop (langelem)
3062 (goto-char (cdr langelem))
3063 (re-search-forward "<<\\|>>" (c-point 'eol) 'move)
3064 (goto-char (match-beginning 0))
3065 (vector (current-column))))
3068 Indentation functions take a single argument, which is a syntactic
3069 component cons cell (@pxref{Syntactic Analysis}). The function can
3070 return an integer which is added to the running total indentation for
3071 the line, or a vector containing an integer which is an absolute
3072 column to align to. Usually an absolute column is wanted when
3073 aligning to existing text, as in this example.
3075 The function should return @code{nil} if it's used in a situation where
3076 it doesn't want to make any decision. If the function is used in a list
3077 expression (@pxref{Customizing Indentation}), that will cause @ccmode{}
3078 to go on and check the next entry in the list.
3080 Now, to associate the function @code{c-lineup-streamop} with the
3081 @code{stream-op} syntactic symbol, we can add something like the
3082 following to our @code{c++-mode-hook}@footnote{It probably makes more
3083 sense to add this to @code{c++-mode-hook} than @code{c-mode-common-hook}
3084 since stream operators are only relevant for C++.}:
3087 (c-set-offset 'stream-op 'c-lineup-streamop)
3090 Now the function looks like this after reindenting (using @kbd{C-c
3095 1: void main(int argc, char**)
3097 3: cout << "There were "
3099 5: << " arguments passed to the program"
3105 Custom indentation functions can be as simple or as complex as you like,
3106 and any syntactic symbol that appears in @code{c-offsets-alist} can have
3107 a custom indentation function associated with it.
3109 @ccmode{} comes with an extensive set of predefined indentation
3110 functions, not all of which are used by the default styles. So there's
3111 a good chance the function you want already exists. @xref{Indentation
3112 Functions}, for a list of them. If you have written an indentation
3113 function that you think is generally useful, you're very welcome to
3114 contribute it; please contact @email{bug-cc-mode@@gnu.org}.
3117 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3118 @node Custom Brace and Colon Hanging, Customizing Semicolons and Commas, Custom Indentation Functions, Advanced Customizations
3119 @comment node-name, next, previous, up
3120 @subsection Custom Brace and Colon Hanging
3121 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3123 @vindex c-hanging-braces-alist
3124 @vindex hanging-braces-alist (c-)
3125 Syntactic symbols aren't the only place where you can customize
3126 @ccmode{} with the lisp equivalent of callback functions. Brace
3127 ``hanginess'' can also be determined by custom functions associated with
3128 syntactic symbols on the @code{c-hanging-braces-alist} style variable.
3129 Remember that @var{action}'s are typically a list containing some
3130 combination of the symbols @code{before} and @code{after}
3131 (@pxref{Hanging Braces}). However, an @var{action} can also be a
3132 function which gets called when a brace matching that syntactic symbol
3135 @cindex customization, brace hanging
3136 These @var{action} functions are called with two arguments: the
3137 syntactic symbol for the brace, and the buffer position at which the
3138 brace was inserted. The @var{action} function is expected to return a
3139 list containing some combination of @code{before} and @code{after},
3140 including neither of them (i.e., @code{nil}). This return value has the
3141 normal brace hanging semantics.
3143 As an example, @ccmode{} itself uses this feature to dynamically
3144 determine the hanginess of braces which close ``do-while''
3148 void do_list( int count, char** atleast_one_string )
3152 handle_string( atleast_one_string[i] );
3154 @} while( i < count );
3158 @ccmode{} assigns the @code{block-close} syntactic symbol to the
3159 brace that closes the @code{do} construct, and normally we'd like the
3160 line that follows a @code{block-close} brace to begin on a separate
3161 line. However, with ``do-while'' constructs, we want the
3162 @code{while} clause to follow the closing brace. To do this, we
3163 associate the @code{block-close} symbol with the @var{action} function
3164 @code{c-snug-do-while}:
3167 (defun c-snug-do-while (syntax pos)
3168 "Dynamically calculate brace hanginess for do-while statements."
3171 (if (and (eq syntax 'block-close)
3172 (setq langelem (assq 'block-close c-syntactic-context))
3173 (progn (goto-char (cdr langelem))
3174 (if (= (following-char) ?@{)
3176 (looking-at "\\<do\\>[^_]")))
3181 @findex c-snug-do-while
3182 @findex snug-do-while (c-)
3183 This function simply looks to see if the brace closes a ``do-while''
3184 clause and if so, returns the list @samp{(before)} indicating
3185 that a newline should be inserted before the brace, but not after it.
3186 In all other cases, it returns the list @samp{(before after)} so
3187 that the brace appears on a line by itself.
3189 @defvar c-syntactic-context
3190 @vindex syntactic-context (c-)
3191 During the call to the indentation or brace hanging @var{action}
3192 function, this variable is bound to the full syntactic analysis list.
3195 @cindex customization, colon hanging
3196 @vindex c-hanging-colons-alist
3197 @vindex hanging-colons-alist (c-)
3198 Note that for symmetry, colon hanginess should be customizable by
3199 allowing function symbols as @var{action}s on the
3200 @code{c-hanging-colons-alist} style variable. Since no use has actually
3201 been found for this feature, it isn't currently implemented!
3204 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3205 @node Customizing Semicolons and Commas, Other Special Indentations, Custom Brace and Colon Hanging, Advanced Customizations
3206 @comment node-name, next, previous, up
3207 @subsection Customizing Semicolons and Commas
3208 @cindex customization, semicolon newlines
3209 @cindex customization, comma newlines
3210 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3212 You can also customize the insertion of newlines after semicolons and
3213 commas when the auto-newline minor mode is enabled (@pxref{Minor
3216 @defopt c-hanging-semi&comma-criteria
3217 @vindex hanging-semi&comma-criteria (c-)
3218 This style variable takes a list of hooks that get called when a
3219 semicolon or comma is inserted. The hooks are called in order without
3220 arguments, and are expected to return one of the following values:
3224 A newline is inserted, and no more functions from the list are called.
3226 No more functions from the list are called, but no newline is
3229 No determination is made, and the next function in the list is called.
3232 If every function in the list is called without a determination being
3233 made, then no newline is added. The default value for this variable is a
3234 list containing a single function which inserts newlines only after
3235 semicolons which do not appear inside parenthesis lists (i.e., those
3236 that separate @code{for}-clause statements).
3239 @defun c-semi&comma-no-newlines-before-nonblanks
3240 @findex semi&comma-no-newlines-before-nonblanks (c-)
3241 This is an example of a criteria function, provided by @ccmode{}. It
3242 prevents newlines from being inserted after semicolons when there is a
3243 non-blank following line. Otherwise, it makes no determination. To
3244 use, add this function to the front of the
3245 @code{c-hanging-semi&comma-criteria} list.
3248 (defun c-semi&comma-no-newlines-before-nonblanks ()
3250 (if (and (eq last-command-char ?\;)
3251 (zerop (forward-line 1))
3252 (not (looking-at "^[ \t]*$")))
3258 @defun c-semi&comma-inside-parenlist
3259 @findex semi&comma-inside-parenlist (c-)
3260 @defunx c-semi&comma-no-newlines-for-oneline-inliners
3261 @findex semi&comma-no-newlines-for-oneline-inliners (c-)
3262 The function @code{c-semi&comma-inside-parenlist} is what prevents
3263 newlines from being inserted inside the parenthesis list of @code{for}
3264 statements. In addition to
3265 @code{c-semi&comma-no-newlines-before-nonblanks} described above,
3266 @ccmode{} also comes with the criteria function
3267 @code{c-semi&comma-no-newlines-for-oneline-inliners}, which suppresses
3268 newlines after semicolons inside one-line inline method definitions
3269 (e.g., in C++ or Java).
3273 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3274 @node Other Special Indentations, , Customizing Semicolons and Commas, Advanced Customizations
3275 @comment node-name, next, previous, up
3276 @subsection Other Special Indentations
3277 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3279 Here are the remaining odds and ends regarding indentation:
3281 @defopt c-label-minimum-indentation
3282 @vindex label-minimum-indentation (c-)
3283 In @samp{gnu} style (@pxref{Built-in Styles}), a minimum indentation
3284 is imposed on lines inside top-level constructs. This minimum
3285 indentation is controlled by this style variable. The default value
3289 @defopt c-special-indent-hook
3290 @vindex special-indent-hook (c-)
3291 This style variable is a standard hook variable that is called after
3292 every line is indented by @ccmode{}. You can use it to do any special
3293 indentation or line adjustments your style dictates, such as adding
3294 extra indentation to constructors or destructor declarations in a
3295 class definition, etc. Note that you should not change point or mark
3296 inside your @code{c-special-indent-hook} functions, i.e., you'll
3297 probably want to wrap your function in a @code{save-excursion}.
3299 Setting @code{c-special-indent-hook} in your style definition is
3300 handled slightly differently than other variables. In your style
3301 definition, you should set the value for @code{c-special-indent-hook}
3302 to a function or list of functions, which will be appended to
3303 @code{c-special-indent-hook} using @code{add-hook}. That way, the
3304 current setting for the buffer local value of
3305 @code{c-special-indent-hook} won't be overridden.
3309 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3310 @node Syntactic Symbols, Indentation Functions, Customizing Indentation, Top
3311 @comment node-name, next, previous, up
3312 @chapter Syntactic Symbols
3313 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
3315 @cindex syntactic symbols, brief list
3316 @vindex c-offsets-alist
3317 @vindex offsets-alist (c-)
3318 Here is a complete list of the recognized syntactic symbols as described
3319 in the @code{c-offsets-alist} style variable, along with a brief
3320 description. More detailed descriptions follow.
3324 Inside a multiline string.
3326 Inside a multiline C style block comment.
3328 Brace that opens a top-level function definition.
3330 Brace that closes a top-level function definition.
3331 @item defun-block-intro
3332 The first line in a top-level defun.
3334 Brace that opens a class definition.
3336 Brace that closes a class definition.
3338 Brace that opens an in-class inline method.
3340 Brace that closes an in-class inline method.
3341 @item func-decl-cont
3342 The region between a function definition's argument list and the
3343 function opening brace (excluding K&R argument declarations). In C, you
3344 cannot put anything but whitespace and comments in this region, however
3345 in C++ and Java, @code{throws} declarations and other things can appear
3347 @item knr-argdecl-intro
3348 First line of a K&R C argument declaration.
3350 Subsequent lines in a K&R C argument declaration.
3352 The first line in a ``topmost'' definition.
3353 @item topmost-intro-cont
3354 Topmost definition continuation lines. This is only used in the parts
3355 that aren't covered by other symbols such as @code{func-decl-cont} and
3357 @item member-init-intro
3358 First line in a member initialization list.
3359 @item member-init-cont
3360 Subsequent member initialization list lines.
3362 First line of a multiple inheritance list.
3364 Subsequent multiple inheritance lines.
3366 Statement block open brace.
3368 Statement block close brace.
3369 @item brace-list-open
3370 Open brace of an enum or static array list.
3371 @item brace-list-close
3372 Close brace of an enum or static array list.
3373 @item brace-list-intro
3374 First line in an enum or static array list.
3375 @item brace-list-entry
3376 Subsequent lines in an enum or static array list.
3377 @item brace-entry-open
3378 Subsequent lines in an enum or static array list where the line begins
3382 @item statement-cont
3383 A continuation of a statement.
3384 @item statement-block-intro
3385 The first line in a new statement block.
3386 @item statement-case-intro
3387 The first line in a case block.
3388 @item statement-case-open
3389 The first line in a case block that starts with a brace.
3391 The first line after a conditional or loop construct.
3392 @item substatement-open
3393 The brace that opens a substatement block.
3394 @item substatement-label
3395 The first line after a conditional or loop construct if it's a label.
3397 A label in a @code{switch} block.
3399 C++ access control label.
3402 @item do-while-closure
3403 The @code{while} line that ends a @code{do}-@code{while} construct.
3405 The @code{else} line of an @code{if}-@code{else} construct.
3407 The @code{catch} or @code{finally} (in Java) line of a
3408 @code{try}-@code{catch} construct.
3410 A line containing only a comment introduction.
3412 The first line in an argument list.
3414 Subsequent argument list lines when no arguments follow on the same line
3415 as the arglist opening paren.
3416 @item arglist-cont-nonempty
3417 Subsequent argument list lines when at least one argument follows on the
3418 same line as the arglist opening paren.
3420 The solo close paren of an argument list.
3422 Lines continuing a stream operator (C++ only).
3424 The line is nested inside a class definition.
3426 The start of a preprocessor macro definition.
3427 @item cpp-define-intro
3428 The first line inside a multiline preproprocessor macro if
3429 @code{c-syntactic-indentation-in-macros} is set.
3430 @item cpp-macro-cont
3431 All lines inside multiline preprocessor macros if
3432 @code{c-syntactic-indentation-in-macros} is @code{nil}.
3434 A C++ friend declaration.
3435 @item objc-method-intro
3436 The first line of an Objective-C method definition.
3437 @item objc-method-args-cont
3438 Lines continuing an Objective-C method definition.
3439 @item objc-method-call-cont
3440 Lines continuing an Objective-C method call.
3441 @item extern-lang-open
3442 Brace that opens an @code{extern} block (e.g., @code{extern "C" @{...@}}).
3443 @item extern-lang-close
3444 Brace that closes an @code{extern} block.
3446 Analogous to @code{inclass} syntactic symbol, but used inside
3447 @code{extern} blocks.
3448 @item namespace-open
3449 @itemx namespace-close
3451 These are analogous to the three @code{extern-lang} symbols above, but
3452 are returned for C++ namespace blocks.
3456 Analogous to the above, but for CORBA IDL @code{module} blocks.
3457 @item composition-open
3458 @itemx composition-close
3459 @itemx incomposition
3460 Analogous to the above, but for CORBA CIDL @code{composition} blocks.
3461 @item template-args-cont
3462 C++ template argument list continuations.
3464 Analogous to @code{inclass} syntactic symbol, but used inside lambda
3465 (i.e., anonymous) functions. Only used in Pike mode.
3466 @item lambda-intro-cont
3467 Lines continuing the header of a lambda function, i.e., between the
3468 @code{lambda} keyword and the function body. Only used in Pike mode.
3469 @item inexpr-statement
3470 A statement block inside an expression. The gcc C and C++ extension for
3471 this is recognized. It's also used for the special functions that take
3472 a statement block as an argument in Pike.
3474 A class definition inside an expression. This is used for anonymous
3475 classes in Java. It's also used for anonymous array initializers in
3479 @ssindex -open symbols
3480 @ssindex -close symbols
3481 Most syntactic symbol names follow a general naming convention. When a
3482 line begins with an open or close brace, the syntactic symbol will
3483 contain the suffix @code{-open} or @code{-close} respectively.
3485 @ssindex -intro symbols
3486 @ssindex -cont symbols
3487 @ssindex -block-intro symbols
3488 Usually, a distinction is made between the first line that introduces a
3489 construct and lines that continue a construct, and the syntactic symbols
3490 that represent these lines will contain the suffix @code{-intro} or
3491 @code{-cont} respectively. As a sub-classification of this scheme, a
3492 line which is the first of a particular brace block construct will
3493 contain the suffix @code{-block-intro}.
3495 Let's look at some examples to understand how this works. Remember that
3496 you can check the syntax of any line by using @kbd{C-c C-s}.
3500 2: swap( int& a, int& b )
3510 @ssindex topmost-intro
3511 @ssindex topmost-intro-cont
3513 @ssindex defun-close
3514 @ssindex defun-block-intro
3515 Line 1 shows a @code{topmost-intro} since it is the first line that
3516 introduces a top-level construct. Line 2 is a continuation of the
3517 top-level construct introduction so it has the syntax
3518 @code{topmost-intro-cont}. Line 3 shows a @code{defun-open} since it is
3519 the brace that opens a top-level function definition. Line 9 is the
3521 @code{defun-close} since it contains the brace that closes the top-level
3522 function definition. Line 4 is a @code{defun-block-intro}, i.e., it is
3523 the first line of a brace-block, enclosed in a
3524 top-level function definition.
3527 @ssindex statement-cont
3528 Lines 5, 6, and 7 are all given @code{statement} syntax since there
3529 isn't much special about them. Note however that line 8 is given
3530 @code{statement-cont} syntax since it continues the statement begun
3531 on the previous line.
3533 Here's another example, which illustrates some C++ class syntactic
3539 3: public Amplifiable
3543 7: : eString( new BassString( 0.105 )),
3544 8: aString( new BassString( 0.085 )),
3545 9: dString( new BassString( 0.065 )),
3546 10: gString( new BassString( 0.045 ))
3548 12: eString.tune( 'E' );
3549 13: aString.tune( 'A' );
3550 14: dString.tune( 'D' );
3551 15: gString.tune( 'G' );
3553 17: friend class Luthier;
3558 @ssindex class-close
3559 As in the previous example, line 1 has the @code{topmost-intro} syntax.
3560 Here however, the brace that opens a C++ class definition on line 4 is
3561 assigned the @code{class-open} syntax. Note that in C++, classes,
3562 structs, and unions are essentially equivalent syntactically (and are
3563 very similar semantically), so replacing the @code{class} keyword in the
3564 example above with @code{struct} or @code{union} would still result in a
3565 syntax of @code{class-open} for line 4 @footnote{This is the case even
3566 for C and Objective-C. For consistency, structs in all supported
3567 languages are syntactically equivalent to classes. Note however that
3568 the keyword @code{class} is meaningless in C and Objective-C.}.
3569 Similarly, line 18 is assigned @code{class-close} syntax.
3571 @ssindex inher-intro
3573 Line 2 introduces the inheritance list for the class so it is assigned
3574 the @code{inher-intro} syntax, and line 3, which continues the
3575 inheritance list is given @code{inher-cont} syntax.
3577 @ssindex access-label
3579 Hitting @kbd{C-c C-s} on line 5 shows the following analysis:
3582 ((inclass 58) (access-label 58))
3586 The primary syntactic symbol for this line is @code{access-label} as
3587 this a label keyword that specifies access protection in C++. However,
3588 because this line is also a top-level construct inside a class
3589 definition, the analysis actually shows two syntactic symbols. The
3590 other syntactic symbol assigned to this line is @code{inclass}.
3591 Similarly, line 6 is given both @code{inclass} and @code{topmost-intro}
3595 ((inclass 58) (topmost-intro 60))
3598 @ssindex member-init-intro
3599 @ssindex member-init-cont
3600 Line 7 introduces a C++ member initialization list and as such is given
3601 @code{member-init-intro} syntax. Note that in this case it is
3602 @emph{not} assigned @code{inclass} since this is not considered a
3603 top-level construct. Lines 8 through 10 are all assigned
3604 @code{member-init-cont} since they continue the member initialization
3605 list started on line 7.
3607 @cindex in-class inline methods
3608 @ssindex inline-open
3609 @ssindex inline-close
3610 Line 11's analysis is a bit more complicated:
3613 ((inclass 58) (inline-open))
3616 This line is assigned a syntax of both @code{inline-open} and
3617 @code{inclass} because it opens an @dfn{in-class} C++ inline method
3618 definition. This is distinct from, but related to, the C++ notion of an
3619 inline function in that its definition occurs inside an enclosing class
3620 definition, which in C++ implies that the function should be inlined.
3621 However, if the definition of the @code{Bass} constructor appeared
3622 outside the class definition, the construct would be given the
3623 @code{defun-open} syntax, even if the keyword @code{inline} appeared
3624 before the method name, as in:
3629 3: public Amplifiable
3637 11: : eString( new BassString( 0.105 )),
3638 12: aString( new BassString( 0.085 )),
3639 13: dString( new BassString( 0.065 )),
3640 14: gString( new BassString( 0.045 ))
3642 16: eString.tune( 'E' );
3643 17: aString.tune( 'A' );
3644 18: dString.tune( 'D' );
3645 19: gString.tune( 'G' );
3650 Returning to the previous example, line 16 is given @code{inline-close}
3651 syntax, while line 12 is given @code{defun-block-open} syntax, and lines
3652 13 through 15 are all given @code{statement} syntax. Line 17 is
3653 interesting in that its syntactic analysis list contains three
3657 ((inclass 58) (topmost-intro 380) (friend))
3660 The @code{friend} syntactic symbol is a modifier that typically does not
3661 have a relative buffer position.
3663 Template definitions introduce yet another syntactic symbol:
3666 1: ThingManager <int,
3667 2: Framework::Callback *,
3668 3: Mutex> framework_callbacks;
3671 Here, line 1 is analyzed as a @code{topmost-intro}, but lines 2 and 3
3672 are both analyzed as @code{template-args-cont} lines.
3674 Here is another (totally contrived) example which illustrates how syntax
3675 is assigned to various conditional constructs:
3678 1: void spam( int index )
3680 3: for( int i=0; i<index; i++ )
3683 6: do_something_special();
3686 9: do_something( i );
3689 12: another_thing( i-- );
3695 Only the lines that illustrate new syntactic symbols will be discussed.
3697 @ssindex substatement-open
3698 @ssindex substatement-block-intro
3699 @ssindex block-close
3700 Line 4 has a brace which opens a conditional's substatement block. It
3701 is thus assigned @code{substatement-open} syntax, and since line 5 is
3702 the first line in the substatement block, it is assigned
3703 @code{substatement-block-intro} syntax. Line 10 contains the brace that
3704 closes the inner substatement block, and is therefore given the syntax
3705 @code{block-close}. Line 13 is treated the same way.
3707 @ssindex substatement
3708 Lines 6 and 9 are also substatements of conditionals, but since they
3709 don't start blocks they are given @code{substatement} syntax
3710 instead of @code{substatement-open}.
3712 @ssindex substatement-label
3713 Line 8 contains a label, which is normally given @code{label} syntax.
3714 This one is however a bit special since it's between a conditional and
3715 its substatement. It's analyzed as @code{substatement-label} to let you
3716 handle this rather odd case differently from normal labels.
3718 @ssindex else-clause
3719 @ssindex catch-clause
3720 Line 7 start with an @code{else} that matches the @code{if} statement on
3721 line 5. It is therefore given the @code{else-clause} syntax and is
3722 anchored on the matching @code{if}. The @code{try}-@code{catch}
3723 constructs in C++ and Java are treated this way too, except that
3724 @code{catch} and (in Java) @code{finally}, are marked with
3725 @code{catch-clause}.
3727 @ssindex do-while-closure
3728 The @code{while} construct on line 14 that closes a @code{do}
3729 conditional is given the special syntax @code{do-while-closure} if it
3730 appears on a line by itself. Note that if the @code{while} appeared on
3731 the same line as the preceding close brace, that line would still have
3732 @code{block-close} syntax.
3734 Switch statements have their own set of syntactic symbols. Here's an
3738 1: void spam( enum Ingredient i )
3745 8: drink_some_water();
3757 @ssindex statement-case-intro
3758 @ssindex statement-case-open
3759 Here, lines 4, 7, and 10 are all assigned @code{case-label} syntax,
3760 while lines 5 and 8 are assigned @code{statement-case-intro}. Line 11
3761 is treated slightly differently since it contains a brace that opens a
3762 block --- it is given @code{statement-case-open} syntax.
3765 There are a set of syntactic symbols that are used to recognize
3766 constructs inside of brace lists. A brace list is defined as an
3767 @code{enum} or aggregate initializer list, such as might statically
3768 initialize an array of structs. The three special aggregate constructs
3769 in Pike, @code{(@{ @})}, @code{([ ])} and @code{(< >)}, are treated as
3770 brace lists too. An example:
3773 1: static char* ingredients[] =
3781 @ssindex brace-list-open
3782 @ssindex brace-list-intro
3783 @ssindex brace-list-close
3784 @ssindex brace-list-entry
3785 Following convention, line 2 in this example is assigned
3786 @code{brace-list-open} syntax, and line 3 is assigned
3787 @code{brace-list-intro} syntax. Likewise, line 6 is assigned
3788 @code{brace-list-close} syntax. Lines 4 and 5 however, are assigned
3789 @code{brace-list-entry} syntax, as would all subsequent lines in this
3792 @ssindex brace-entry-open
3793 Your static initializer might be initializing nested structures, for
3797 1: struct intpairs[] =
3810 Here, you've already seen the analysis of lines 1, 2, 3, and 11. On
3811 line 4, things get interesting; this line is assigned
3812 @code{brace-entry-open} syntactic symbol because it's a bracelist entry
3813 line that starts with an open brace. Lines 5 and 6 (and line 9) are
3814 pretty standard, and line 7 is a @code{brace-list-close} as you'd
3815 expect. Once again, line 8 is assigned as @code{brace-entry-open} as is
3818 External language definition blocks also have their own syntactic
3819 symbols. In this example:
3824 3: int thing_one( int );
3825 4: int thing_two( double );
3829 @ssindex extern-lang-open
3830 @ssindex extern-lang-close
3831 @ssindex inextern-lang
3834 line 2 is given the @code{extern-lang-open} syntax, while line 5 is given
3835 the @code{extern-lang-close} syntax. The analysis for line 3 yields:
3838 ((inextern-lang) (topmost-intro 14))
3842 where @code{inextern-lang} is a modifier similar in purpose to
3845 There are various other top level blocks like @code{extern}, and they
3846 are all treated in the same way except that the symbols are named after
3847 the keyword that introduces the block. e.g., C++ namespace blocks get
3848 the three symbols @code{namespace-open}, @code{namespace-close} and
3849 @code{innamespace}. The currently recognized top level blocks are:
3852 @item @code{extern-lang-open}, @code{extern-lang-close}, @code{inextern-lang}
3853 @code{extern} blocks in C and C++.@footnote{These should logically be
3854 named @code{extern-open}, @code{extern-close} and @code{inextern}, but
3855 that isn't the case for historical reasons.}
3857 @item @code{namespace-open}, @code{namespace-close}, @code{innamespace}
3858 @ssindex namespace-open
3859 @ssindex namespace-close
3860 @ssindex innamespace
3861 @code{namespace} blocks in C++.
3863 @item @code{module-open}, @code{module-close}, @code{inmodule}
3864 @ssindex module-open
3865 @ssindex module-close
3867 @code{module} blocks in CORBA IDL.
3869 @item @code{composition-open}, @code{composition-close}, @code{incomposition}
3870 @ssindex composition-open
3871 @ssindex composition-close
3872 @ssindex incomposition
3873 @code{composition} blocks in CORBA CIDL.
3876 A number of syntactic symbols are associated with parenthesis lists,
3877 a.k.a argument lists, as found in function declarations and function
3878 calls. This example illustrates these:
3881 1: void a_function( int line1,
3884 4: void a_longer_function(
3889 9: void call_them( int line1, int line2 )
3896 16: a_longer_function( line1,
3901 @ssindex arglist-intro
3902 @ssindex arglist-close
3903 Lines 5 and 12 are assigned @code{arglist-intro} syntax since they are
3904 the first line following the open parenthesis, and lines 7 and 14 are
3905 assigned @code{arglist-close} syntax since they contain the parenthesis
3906 that closes the argument list.
3908 @ssindex arglist-cont-nonempty
3909 @ssindex arglist-cont
3910 Lines that continue argument lists can be assigned one of two syntactic
3911 symbols. For example, Lines 2 and 17
3912 are assigned @code{arglist-cont-nonempty} syntax. What this means
3913 is that they continue an argument list, but that the line containing the
3914 parenthesis that opens the list is @emph{not empty} following the open
3915 parenthesis. Contrast this against lines 6 and 13 which are assigned
3916 @code{arglist-cont} syntax. This is because the parenthesis that opens
3917 their argument lists is the last character on that line.
3919 Note that there is no @code{arglist-open} syntax. This is because any
3920 parenthesis that opens an argument list, appearing on a separate line,
3921 is assigned the @code{statement-cont} syntax instead.
3923 A few miscellaneous syntactic symbols that haven't been previously
3924 covered are illustrated by this C++ example:
3927 1: void Bass::play( int volume )
3930 4: /* this line starts a multiline
3931 5: * comment. This line should get `c' syntax */
3933 7: char* a_multiline_string = "This line starts a multiline \
3934 8: string. This line should get `string' syntax.";
3942 16: cout << "I played "
3948 The lines to note in this example include:
3952 @ssindex func-decl-cont
3953 Line 2 is assigned the @code{func-decl-cont} syntax.
3956 @ssindex comment-intro
3957 Line 4 is assigned both @code{defun-block-intro} @emph{and}
3958 @code{comment-intro} syntax.
3962 Line 5 is assigned @code{c} syntax.
3965 @cindex syntactic whitespace
3966 Line 6 which, even though it contains nothing but whitespace, is
3967 assigned @code{defun-block-intro}. Note that the appearance of the
3968 comment on lines 4 and 5 do not cause line 6 to be assigned
3969 @code{statement} syntax because comments are considered to be
3970 @dfn{syntactic whitespace}, which are ignored when analyzing
3975 Line 8 is assigned @code{string} syntax.
3979 Line 10 is assigned @code{label} syntax.
3983 Line 11 is assigned @code{block-open} syntax.
3987 Lines 12 and 14 are assigned @code{cpp-macro} syntax in addition to the
3988 normal syntactic symbols (@code{statement-block-intro} and
3989 @code{statement}, respectively). Normally @code{cpp-macro} is
3990 configured to cancel out the normal syntactic context to make all
3991 preprocessor directives stick to the first column, but that's easily
3992 changed if you want preprocessor directives to be indented like the rest
3997 Line 17 is assigned @code{stream-op} syntax.
4000 @cindex multiline macros
4001 @cindex syntactic whitespace
4002 @ssindex cpp-define-intro
4003 Multiline preprocessor macro definitions are normally handled just like
4004 other code, i.e., the lines inside them are indented according to the
4005 syntactic analysis of the preceding lines inside the macro. The first
4006 line inside a macro definition (i.e., the line after the starting line of
4007 the cpp directive itself) gets @code{cpp-define-intro}. In this example:
4010 1: #define LIST_LOOP(cons, listp) \
4011 2: for (cons = listp; !NILP (cons); cons = XCDR (cons)) \
4012 3: if (!CONSP (cons)) \
4013 4: signal_error ("Invalid list format", listp); \
4018 line 1 is given the syntactic symbol @code{cpp-macro}. The first line
4019 of a cpp directive is always given that symbol. Line 2 is given
4020 @code{cpp-define-intro}, so that you can give the macro body as a whole
4021 some extra indentation. Lines 3 through 5 are then analyzed as normal
4022 code, i.e., @code{substatement} on lines 3 and 4, and @code{else-clause}
4025 The syntactic analysis inside macros can be turned off with
4026 @code{c-syntactic-indentation-in-macros}. In that case, lines 2 through
4027 5 would all be given @code{cpp-macro-cont} with a relative buffer
4028 position pointing to the @code{#} which starts the cpp
4029 directive@footnote{This is how @ccmode{} 5.28 and earlier analyzed
4032 @xref{Macro Handling}, for more info about the treatment of macros.
4034 In Objective-C buffers, there are three additional syntactic symbols
4035 assigned to various message calling constructs. Here's an example
4039 1: - (void)setDelegate:anObject
4042 4: [delegate masterWillRebind:self
4043 5: toDelegate:anObject
4044 6: withExtraStuff:stuff];
4048 @ssindex objc-method-intro
4049 @ssindex objc-method-args-cont
4050 @ssindex objc-method-call-cont
4051 Here, line 1 is assigned @code{objc-method-intro} syntax, and line 2 is
4052 assigned @code{objc-method-args-cont} syntax. Lines 5 and 6 are both
4053 assigned @code{objc-method-call-cont} syntax.
4055 Java has a concept of anonymous classes, which may look something like
4059 1: public void watch(Observable o) @{
4060 2: o.addObserver(new Observer() @{
4061 3: public void update(Observable o, Object arg) @{
4062 4: history.addElement(arg);
4068 @ssindex inexpr-class
4069 The brace following the @code{new} operator opens the anonymous class.
4070 Lines 3 and 6 are assigned the @code{inexpr-class} syntax, besides the
4071 @code{inclass} symbol used in normal classes. Thus, the class will be
4072 indented just like a normal class, with the added indentation given to
4073 @code{inexpr-class}.
4075 There are a few occasions where a statement block may be used inside an
4076 expression. One is in C or C++ code using the gcc extension for this,
4081 2: int y = foo (); int z;
4082 3: if (y > 0) z = y; else z = - y;
4087 @ssindex inexpr-statement
4088 Lines 2 and 5 get the @code{inexpr-statement} syntax, besides the
4089 symbols they'd get in a normal block. Therefore, the indentation put on
4090 @code{inexpr-statement} is added to the normal statement block
4093 In Pike code, there are a few other situations where blocks occur inside
4094 statements, as illustrated here:
4099 3: string s = map (backtrace()[-2][3..],
4103 7: return sprintf ("%t", arg);
4104 8: @}) * ", " + "\n";
4106 10: write (s + "\n");
4112 @ssindex lambda-intro-cont
4113 Lines 4 through 8 contain a lambda function, which @ccmode{} recognizes
4114 by the @code{lambda} keyword. If the function argument list is put
4115 on a line of its own, as in line 5, it gets the @code{lambda-intro-cont}
4116 syntax. The function body is handled as an inline method body, with the
4117 addition of the @code{inlambda} syntactic symbol. This means that line
4118 6 gets @code{inlambda} and @code{inline-open}, and line 8 gets
4119 @code{inline-close}@footnote{You might wonder why it doesn't get
4120 @code{inlambda} too. It's because the closing brace is relative to the
4121 opening brace, which stands on its own line in this example. If the
4122 opening brace was hanging on the previous line, then the closing brace
4123 would get the @code{inlambda} syntax too to be indented correctly.}.
4125 @ssindex inexpr-statement
4126 On line 9, @code{catch} is a special function taking a statement block
4127 as its argument. The block is handled as an in-expression statement
4128 with the @code{inexpr-statement} syntax, just like the gcc extended C
4129 example above. The other similar special function, @code{gauge}, is
4130 handled like this too.
4132 @ssindex knr-argdecl-intro
4133 @ssindex knr-argdecl
4134 Two other syntactic symbols can appear in old style, non-prototyped C
4135 code @footnote{a.k.a. K&R C, or Kernighan & Ritchie C}:
4138 1: int add_three_integers(a, b, c)
4143 6: return a + b + c;
4147 Here, line 2 is the first line in an argument declaration list and so is
4148 given the @code{knr-argdecl-intro} syntactic symbol. Subsequent lines
4149 (i.e., lines 3 and 4 in this example), are given @code{knr-argdecl}
4153 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
4154 @node Indentation Functions, AWK Mode, Syntactic Symbols, Top
4155 @comment node-name, next, previous, up
4156 @chapter Indentation Functions
4157 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
4159 @cindex indentation function
4160 @cindex line-up function
4161 Often there are cases when a simple offset setting on a syntactic
4162 symbol isn't enough to get the desired indentation. Therefore, it's
4163 also possible to use an @dfn{indentation function} (a.k.a. @dfn{line-up
4164 function}) for a syntactic symbol.
4166 @ccmode{} comes with many predefined indentation functions for common
4167 situations. If none of these does what you want, you can write your
4168 own, see @ref{Custom Indentation Functions}. If you do, it's probably a
4169 good idea to start working from one of these predefined functions, they
4170 can be found in the file @file{cc-align.el}.
4172 For every function below there is a ``works with'' list that indicates
4173 which syntactic symbols the function is intended to be used with.
4176 @emph{Works with:@ }
4185 @macro sssTBasicOffset
4186 <--> @i{c-basic-offset}@c
4189 @macro sssTsssTBasicOffset
4190 <--><--> @i{c-basic-offset}@c
4197 @c The TeX backend seems to insert extra spaces around the argument. :P
4205 @comment ------------------------------------------------------------
4207 @defun c-indent-one-line-block
4208 @findex indent-one-line-block (c-)
4209 Indent a one line block @code{c-basic-offset} extra. E.g:
4214 @{m+=n; n=0;@} @hereFn{c-indent-one-line-block}
4225 @{ @hereFn{c-indent-one-line-block}
4231 The block may be surrounded by any kind of parenthesis characters.
4232 @code{nil} is returned if the line doesn't start with a one line block,
4233 which makes the function usable in list expressions.
4235 @workswith Almost all syntactic symbols, but most useful on the
4236 @code{-open} symbols.
4239 @comment ------------------------------------------------------------
4241 @defun c-indent-multi-line-block
4242 @findex indent-multi-line-block (c-)
4243 Indent a multiline block @code{c-basic-offset} extra. E.g:
4249 @{17@}, @hereFn{c-indent-multi-line-block}
4260 @{ @hereFn{c-indent-multi-line-block}
4267 The block may be surrounded by any kind of parenthesis characters.
4268 @code{nil} is returned if the line doesn't start with a multiline
4269 block, which makes the function usable in list expressions.
4271 @workswith Almost all syntactic symbols, but most useful on the
4272 @code{-open} symbols.
4275 @comment ------------------------------------------------------------
4277 @defun c-lineup-argcont
4278 @findex lineup-argcont (c-)
4279 Line up a continued argument. E.g:
4283 foo (xyz, aaa + bbb + ccc
4284 + ddd + eee + fff); @hereFn{c-lineup-argcont}
4288 Only continuation lines like this are touched, @code{nil} is returned on
4289 lines which are the start of an argument.
4291 Within a gcc @code{asm} block, @code{:} is recognised as an argument
4292 separator, but of course only between operand specifications, not in the
4293 expressions for the operands.
4295 @workswith @code{arglist-cont}, @code{arglist-cont-nonempty}.
4298 @comment ------------------------------------------------------------
4300 @defun c-lineup-arglist
4301 @findex lineup-arglist (c-)
4302 Line up the current argument line under the first argument.
4304 As a special case, if an argument on the same line as the open
4305 parenthesis starts with a brace block opener, the indentation is
4306 @code{c-basic-offset} only. This is intended as a ``DWIM'' measure in
4307 cases like macros that contains statement blocks, e.g:
4311 A_VERY_LONG_MACRO_NAME (@{
4312 some (code, with + long, lines * in[it]);
4318 This is motivated partly because it's more in line with how code
4319 blocks are handled, and partly since it approximates the behavior of
4320 earlier CC Mode versions, which due to inaccurate analysis tended to
4321 indent such cases this way.
4323 @workswith @code{arglist-cont-nonempty}, @code{arglist-close}.
4326 @comment ------------------------------------------------------------
4328 @defun c-lineup-arglist-intro-after-paren
4329 @findex lineup-arglist-intro-after-paren (c-)
4330 Line up a line to just after the open paren of the surrounding paren or
4333 @workswith @code{defun-block-intro}, @code{brace-list-intro},
4334 @code{statement-block-intro}, @code{statement-case-intro},
4335 @code{arglist-intro}.
4338 @comment ------------------------------------------------------------
4340 @defun c-lineup-arglist-close-under-paren
4341 @findex lineup-arglist-close-under-paren (c-)
4342 Set your @code{arglist-close} syntactic symbol to this line-up function
4343 so that parentheses that close argument lists will line up under the
4344 parenthesis that opened the argument list. It can also be used with
4345 @code{arglist-cont} and @code{arglist-cont-nonempty} to line up all
4346 lines inside a parenthesis under the open paren.
4348 As a special case, if a brace block is opened at the same line as the
4349 open parenthesis of the argument list, the indentation is
4350 @code{c-basic-offset} only. See @code{c-lineup-arglist} for further
4351 discussion of this ``DWIM'' measure.
4353 @workswith Almost all symbols, but are typically most useful on
4354 @code{arglist-close}, @code{brace-list-close}, @code{arglist-cont} and
4355 @code{arglist-cont-nonempty}.
4358 @comment ------------------------------------------------------------
4360 @defun c-lineup-arglist-operators
4361 @findex lineup-arglist-operators (c-)
4362 Line up lines starting with an infix operator under the open paren.
4363 Return @code{nil} on lines that don't start with an operator, to leave
4364 those cases to other lineup functions. Example:
4369 || at_limit (x, @hereFn{c-lineup-arglist-operators}
4370 list) @hereFn{c-lineup-arglist-operators@r{ returns nil}}
4375 Since this function doesn't do anything for lines without an infix
4376 operator you typically want to use it together with some other lineup
4377 settings, e.g., as follows (the @code{arglist-close} setting is just a
4378 suggestion to get a consistent style):
4381 (c-set-offset 'arglist-cont
4382 '(c-lineup-arglist-operators 0))
4383 (c-set-offset 'arglist-cont-nonempty
4384 '(c-lineup-arglist-operators c-lineup-arglist))
4385 (c-set-offset 'arglist-close
4386 '(c-lineup-arglist-close-under-paren))
4389 @workswith @code{arglist-cont}, @code{arglist-cont-nonempty}.
4392 @comment ------------------------------------------------------------
4394 @defun c-lineup-C-comments
4395 @findex lineup-C-comments (c-)
4396 Line up C block comment continuation lines. Various heuristics are used
4397 to handle most of the common comment styles. Some examples:
4410 text ** text ** text
4417 /**************************************************
4419 *************************************************/
4423 @vindex comment-start-skip
4426 /**************************************************
4427 Free form text comments:
4428 In comments with a long delimiter line at the
4429 start, the indentation is kept unchanged for lines
4430 that start with an empty comment line prefix. The
4431 delimiter line is whatever matches the
4432 @code{comment-start-skip} regexp.
4433 **************************************************/
4437 The style variable @code{c-comment-prefix-regexp} is used to recognize
4438 the comment line prefix, e.g., the @samp{*} that usually starts every
4439 line inside a comment.
4441 @workswith The @code{c} syntactic symbol.
4444 @comment ------------------------------------------------------------
4446 @defun c-lineup-cascaded-calls
4447 @findex lineup-cascaded-calls (c-)
4448 Line up ``cascaded calls'' under each other. If the line begins with
4449 @code{->} or @code{.} and the preceding line ends with one or more
4450 function calls preceded by the same token, then the arrow is lined up
4451 with the first of those tokens. E.g:
4455 r = proc->add(17)->add(18)
4456 ->add(19) + @hereFn{c-lineup-cascaded-calls}
4457 offset; @hereFn{c-lineup-cascaded-calls@r{ (inactive)}}
4461 In any other situation @code{nil} is returned to allow use in list
4464 @workswith @code{topmost-intro-cont}, @code{statement-cont},
4465 @code{arglist-cont}, @code{arglist-cont-nonempty}.
4468 @comment ------------------------------------------------------------
4470 @defun c-lineup-close-paren
4471 @findex lineup-close-paren (c-)
4472 Line up the closing paren under its corresponding open paren if the
4473 open paren is followed by code. If the open paren ends its line, no
4474 indentation is added. E.g:
4480 ) @hereFn{c-lineup-close-paren}
4491 ) @hereFn{c-lineup-close-paren}
4495 As a special case, if a brace block is opened at the same line as the
4496 open parenthesis of the argument list, the indentation is
4497 @code{c-basic-offset} instead of the open paren column. See
4498 @code{c-lineup-arglist} for further discussion of this ``DWIM'' measure.
4500 @workswith All @code{*-close} symbols.
4503 @comment ------------------------------------------------------------
4505 @defun c-lineup-comment
4506 @findex lineup-comment (c-)
4507 Line up a comment-only line according to the style variable
4508 @code{c-comment-only-line-offset}. If the comment is lined up with a
4509 comment starter on the previous line, that alignment is preserved.
4511 @defopt c-comment-only-line-offset
4512 @vindex comment-only-line-offset (c-)
4513 This style variable specifies the extra offset for the line. It can
4514 contain an integer or a cons cell of the form
4517 (@r{@var{non-anchored-offset}} . @r{@var{anchored-offset}})
4521 where @var{non-anchored-offset} is the amount of offset given to
4522 non-column-zero anchored lines, and @var{anchored-offset} is the amount
4523 of offset to give column-zero anchored lines. Just an integer as value
4524 is equivalent to @code{(@r{@var{value}} . -1000)}.
4527 @workswith @code{comment-intro}.
4530 @comment ------------------------------------------------------------
4532 @defun c-lineup-cpp-define
4533 @findex lineup-cpp-define (c-)
4534 Line up macro continuation lines according to the indentation of the
4535 construct preceding the macro. E.g:
4539 const char msg[] = @hereFn{@r{The beginning of the preceding construct.}}
4543 do @{ \ @hereFn{c-lineup-cpp-define}
4555 if (!running) @hereFn{@r{The beginning of the preceding construct.}}
4556 error(\"Not running!\");
4559 do @{ \ @hereFn{c-lineup-cpp-define}
4565 If @code{c-syntactic-indentation-in-macros} is non-@code{nil}, the
4566 function returns the relative indentation to the macro start line to
4567 allow accumulation with other offsets. e.g., in the following cases,
4568 @code{cpp-define-intro} is combined with the
4569 @code{statement-block-intro} that comes from the @samp{do @{} that hangs
4570 on the @samp{#define} line:
4577 #define X(A, B) do @{ \
4578 printf (A, B); \ @hereFn{c-lineup-cpp-define}
4580 @} while (0) @hereFn{c-lineup-cpp-define}
4591 error(\"Not running!\");
4593 #define X(A, B) do @{ \
4594 printf (A, B); \ @hereFn{c-lineup-cpp-define}
4596 @} while (0) @hereFn{c-lineup-cpp-define}
4600 The relative indentation returned by @code{c-lineup-cpp-define} is zero
4601 and two, respectively, on the two lines in each of these examples. They
4602 are then added to the two column indentation that
4603 @code{statement-block-intro} gives in both cases here.
4605 If the relative indentation is zero, then @code{nil} is returned
4606 instead. That is useful in a list expression to specify the default
4607 indentation on the top level.
4609 If @code{c-syntactic-indentation-in-macros} is @code{nil} then this
4610 function keeps the current indentation, except for empty lines (ignoring
4611 the ending backslash) where it takes the indentation from the closest
4612 preceding nonempty line in the macro. If there's no such line in the
4613 macro then the indentation is taken from the construct preceding it, as
4616 @workswith @code{cpp-define-intro}.
4619 @comment ------------------------------------------------------------
4621 @defun c-lineup-dont-change
4622 @findex lineup-dont-change (c-)
4623 This lineup function makes the line stay at whatever indentation it
4624 already has; think of it as an identity function for lineups.
4626 @workswith Any syntactic symbol.
4629 @comment ------------------------------------------------------------
4631 @defun c-lineup-gcc-asm-reg
4632 @findex lineup-gcc-asm-reg (c-)
4633 Line up a gcc asm register under one on a previous line.
4646 The @samp{x} line is aligned to the text after the @samp{:} on the
4647 @samp{w} line, and similarly @samp{z} under @samp{y}.
4649 This is done only in an @samp{asm} or @samp{__asm__} block, and only to
4650 those lines mentioned. Anywhere else @code{nil} is returned. The usual
4651 arrangement is to have this routine as an extra feature at the start of
4652 arglist lineups, e.g.
4655 (c-lineup-gcc-asm-reg c-lineup-arglist)
4658 @workswith @code{arglist-cont}, @code{arglist-cont-nonempty}.
4661 @comment ------------------------------------------------------------
4663 @defun c-lineup-inexpr-block
4664 @findex lineup-inexpr-block (c-)
4665 This can be used with the in-expression block symbols to indent the
4666 whole block to the column where the construct is started. e.g., for Java
4667 anonymous classes, this lines up the class under the @samp{new} keyword,
4668 and in Pike it lines up the lambda function body under the @samp{lambda}
4669 keyword. Returns @code{nil} if the block isn't part of such a
4672 @workswith @code{inlambda}, @code{inexpr-statement},
4673 @code{inexpr-class}.
4676 @comment ------------------------------------------------------------
4678 @defun c-lineup-java-inher
4679 @findex lineup-java-inher (c-)
4680 Line up Java implements and extends declarations. If class names
4681 follow on the same line as the @samp{implements}/@samp{extends}
4682 keyword, they are lined up under each other. Otherwise, they are
4683 indented by adding @code{c-basic-offset} to the column of the keyword.
4690 Bar @hereFn{c-lineup-java-inher}
4702 Bar @hereFn{c-lineup-java-inher}
4706 @workswith @code{inher-cont}.
4709 @comment ------------------------------------------------------------
4711 @defun c-lineup-java-throws
4712 @findex lineup-java-throws (c-)
4713 Line up Java throws declarations. If exception names follow on the
4714 same line as the throws keyword, they are lined up under each other.
4715 Otherwise, they are indented by adding @code{c-basic-offset} to the
4716 column of the @samp{throws} keyword. The @samp{throws} keyword itself
4717 is also indented by @code{c-basic-offset} from the function declaration
4718 start if it doesn't hang. E.g:
4723 throws @hereFn{c-lineup-java-throws}
4724 Bar @hereFn{c-lineup-java-throws}
4725 @sssTsssTBasicOffset{}
4734 int foo() throws Cyphr,
4735 Bar, @hereFn{c-lineup-java-throws}
4736 Vlod @hereFn{c-lineup-java-throws}
4740 @workswith @code{func-decl-cont}.
4743 @comment ------------------------------------------------------------
4745 @defun c-lineup-knr-region-comment
4746 @findex lineup-knr-region-comment (c-)
4747 Line up a comment in the ``K&R region'' with the declaration. That is
4748 the region between the function or class header and the beginning of the
4754 /* Called at startup. */ @hereFn{c-lineup-knr-region-comment}
4761 Return @code{nil} if called in any other situation, to be useful in list
4764 @workswith @code{comment-intro}.
4767 @comment ------------------------------------------------------------
4769 @defun c-lineup-math
4770 @findex lineup-math (c-)
4771 Line up the current line to after the equal sign on the first line in the
4772 statement. If there isn't any, indent with @code{c-basic-offset}. If
4773 the current line contains an equal sign too, try to align it with the
4776 @workswith @code{topmost-intro-cont}, @code{statement-cont},
4777 @code{arglist-cont}, @code{arglist-cont-nonempty}.
4780 @comment ------------------------------------------------------------
4782 @defun c-lineup-multi-inher
4783 @findex lineup-multi-inher (c-)
4784 Line up the classes in C++ multiple inheritance clauses and member
4785 initializers under each other. E.g:
4789 Foo::Foo (int a, int b):
4791 Bar (b) @hereFn{c-lineup-multi-inher}
4802 public Bar @hereFn{c-lineup-multi-inher}
4811 Foo::Foo (int a, int b)
4813 , Bar (b) @hereFn{c-lineup-multi-inher}
4817 @workswith @code{inher-cont}, @code{member-init-cont}.
4820 @comment ------------------------------------------------------------
4822 @defun c-lineup-ObjC-method-call
4823 @findex lineup-ObjC-method-call (c-)
4824 For Objective-C code, line up selector args as Emacs Lisp mode does
4825 with function args: go to the position right after the message receiver,
4826 and if you are at the end of the line, indent the current line
4827 c-basic-offset columns from the opening bracket; otherwise you are
4828 looking at the first character of the first method call argument, so
4829 lineup the current line with it.
4831 @workswith @code{objc-method-call-cont}.
4834 @comment ------------------------------------------------------------
4836 @defun c-lineup-ObjC-method-args
4837 @findex lineup-ObjC-method-args (c-)
4838 For Objective-C code, line up the colons that separate args. The colon
4839 on the current line is aligned with the one on the first line.
4841 @workswith @code{objc-method-args-cont}.
4844 @comment ------------------------------------------------------------
4846 @defun c-lineup-ObjC-method-args-2
4847 @findex lineup-ObjC-method-args-2 (c-)
4848 Similar to @code{c-lineup-ObjC-method-args} but lines up the colon on
4849 the current line with the colon on the previous line.
4851 @workswith @code{objc-method-args-cont}.
4854 @comment ------------------------------------------------------------
4856 @defun c-lineup-runin-statements
4857 @findex lineup-runin-statements (c-)
4858 Line up statements for coding standards which place the first statement
4859 in a block on the same line as the block opening brace@footnote{Run-in
4860 style doesn't really work too well. You might need to write your own
4861 custom indentation functions to better support this style.}. E.g:
4867 return 0; @hereFn{c-lineup-runin-statements}
4872 If there is no statement after the opening brace to align with,
4873 @code{nil} is returned. This makes the function usable in list
4876 @workswith The @code{statement} syntactic symbol.
4879 @comment ------------------------------------------------------------
4881 @defun c-lineup-streamop
4882 @findex lineup-streamop (c-)
4883 Line up C++ stream operators (i.e., @samp{<<} and @samp{>>}).
4885 @workswith @code{stream-op}.
4888 @comment ------------------------------------------------------------
4890 @defun c-lineup-string-cont
4891 @findex lineup-string-cont (c-)
4892 Line up a continued string under the one it continues. A continued
4893 string in this sense is where a string literal follows directly after
4898 result = prefix + "A message "
4899 "string."; @hereFn{c-lineup-string-cont}
4903 @code{nil} is returned in other situations, to allow stacking with other
4906 @workswith @code{topmost-intro-cont}, @code{statement-cont},
4907 @code{arglist-cont}, @code{arglist-cont-nonempty}.
4910 @comment ------------------------------------------------------------
4912 @defun c-lineup-template-args
4913 @findex lineup-template-args (c-)
4914 Line up the arguments of a template argument list under each other, but
4915 only in the case where the first argument is on the same line as the
4918 To allow this function to be used in a list expression, @code{nil} is
4919 returned if there's no template argument on the first line.
4921 @workswith @code{template-args-cont}.
4924 @comment ------------------------------------------------------------
4926 @defun c-lineup-topmost-intro-cont
4927 @findex lineup-topmost-intro-cont (c-)
4928 Line up declaration continuation lines zero or one indentation
4929 step@footnote{This function is mainly provided to mimic the behavior of
4930 CC Mode 5.28 and earlier where this case wasn't handled consistently so
4931 that those lines could be analyzed as either topmost-intro-cont or
4932 statement-cont. It's used for @code{topmost-intro-cont} by default, but
4933 you might consider using @code{+} instead.}. For lines preceding a
4934 definition, zero is used. For other lines, @code{c-basic-offset} is
4935 added to the indentation. E.g:
4940 neg (int i) @hereFn{c-lineup-topmost-intro-cont}
4953 larch @hereFn{c-lineup-topmost-intro-cont}
4957 the_larch, @hereFn{c-lineup-topmost-intro-cont}
4958 another_larch; @hereFn{c-lineup-topmost-intro-cont}
4969 the_larch, @hereFn{c-lineup-topmost-intro-cont}
4970 another_larch; @hereFn{c-lineup-topmost-intro-cont}
4974 @workswith @code{topmost-intro-cont}.
4977 @comment ------------------------------------------------------------
4979 @defun c-lineup-whitesmith-in-block
4980 @findex lineup-whitesmith-in-block (c-)
4981 Line up lines inside a block in Whitesmith style. It's done in a way
4982 that works both when the opening brace hangs and when it doesn't. E.g:
4988 foo; @hereFn{c-lineup-whitesmith-in-block}
4999 foo; @hereFn{c-lineup-whitesmith-in-block}
5005 In the first case the indentation is kept unchanged, in the second
5006 @code{c-basic-offset} is added.
5008 @workswith @code{defun-close}, @code{defun-block-intro},
5009 @code{block-close}, @code{brace-list-close}, @code{brace-list-intro},
5010 @code{statement-block-intro} and all @code{in*} symbols,
5011 e.g., @code{inclass} and @code{inextern-lang}.
5015 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5016 @node AWK Mode, Odds and Ends, Indentation Functions, Top
5017 @comment node-name, next, previous, up
5018 @chapter Status of AWK Mode
5019 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5021 @dfn{AWK mode} existed until recently in the file @file{awk-mode.el}
5022 as a mode derived from c-mode. It had not been actively maintained to
5023 keep pace with the newer @ccmode{}, and its indentation mechanism no
5024 longer worked satisfactorally.
5026 The current AWK mode is based around the GNU implementation,
5027 @emph{GAWK version 3.1.0}, though it should work pretty well with any
5028 AWK. It has now been updated and integrated into @ccmode{} to a
5029 substantial extent, though as yet not all the features of @ccmode{}
5030 have been adapted to support it.
5032 If your (X)Emacs is set up to use the old file @file{awk-mode.elc}
5033 (which will usually be the case if you have obtained this @ccmode{}
5034 independently of (X)Emacs itself), or if you are not sure, insert the
5035 following form into your @file{.emacs} or @file{init.el} so that the new
5036 AWK mode will be used instead:
5039 (autoload 'awk-mode "cc-mode" nil t)
5042 You can check which AWK mode you are running by displaying the mode
5043 documentation string with @kbd{C-h m} from an AWK buffer. The newer
5044 mode's doc string contains @code{To submit a problem report, enter
5045 `C-c C-b'} near the top of the doc string where the older mode has
5046 @code{This is much like C mode except ....}.
5048 Since this newer AWK mode makes essential use of a relatively new
5049 Emacs Lisp feature@footnote{Specifically, the @code{syntax-table} text
5050 property.}, you need either GNU Emacs 20.1 (or later) or XEmacs 21.4
5051 (or later) to use it. If your Emacs version is earlier than one of
5052 these, the older @file{awk-mode.el} will get loaded and run in place
5053 of the AWK mode described here, even when you have put the above
5054 @code{autoload} form into your @file{.emacs} or @file{init.el}.
5055 Upgrading your (X)Emacs is strongly recommended if this is the case.
5057 Here is an overview of which @ccmode{} features currently work with
5058 AWK mode and which don't:
5061 @item Indentation Engine
5062 The @ccmode{} indentation engine fully supports AWK mode.
5063 @xref{Indentation Engine}.
5065 AWK mode handles code formatted in the conventional AWK fashion:
5066 @samp{@{}s which start actions, user-defined functions, or compound
5067 statements are placed on the same line as the associated construct; the
5068 matching @samp{@}}s are normally placed under the start of the
5069 respective pattern, function definition, or structured statement.
5070 @c Add in a bit about the @samp{@}} being on the same line when the
5071 @c contents are short.
5073 The predefined indentation functions (@pxref{Indentation Functions})
5074 haven't yet been adapted for AWK mode, though some of them may work
5075 serendipitously. There shouldn't be any problems writing custom
5076 indentation functions for AWK mode.
5078 The command @kbd{C-c C-q} (@code{c-indent-defun}) hasn't yet been
5079 adapted for AWK, though in practice it works properly nearly all the
5080 time. Should it fail, explicitly set the region around the function
5081 (using @kbd{C-u C-SPC}: @kbd{C-M-h} probably won't work either) then do
5082 @kbd{C-M-\} (@code{indent-region}).
5085 There is a single level of font locking in AWK mode, rather than the
5086 three distinct levels the other modes have. There are several
5087 idiosyncrasies in AWK mode's font-locking due to the peculiarities of
5088 the AWK language itself. @xref{AWK Mode Font Locking}.
5090 @item Comment Commands
5091 @kbd{M-;} (@code{indent-for-comment}) works fine. None of the other
5092 @ccmode{} comment formatting commands have yet been adapted for AWK
5093 mode. @xref{Text Filling and Line Breaking}.
5095 @item Movement Commands
5096 Most of the movement commands work in AWK mode. The most important
5097 exceptions are @kbd{M-a} (@code{c-beginning-of-statement}) and
5098 @kbd{M-e} (@code{c-end-of-statement}) which haven't yet been adapted.
5100 The notion of @dfn{defun} has been augmented to include pattern-action
5101 pairs. See @ref{AWK Mode Defuns} for a description of commands which
5102 work on AWK ``defuns''.
5104 Since there is no preprocessor in AWK, the commands which move to
5105 preprocessor directives (e.g., @code{c-up-conditional}) are meaningless
5106 in AWK mode and are not bound in the AWK mode keymap.
5108 @item Auto-newline Insertion and Clean-ups
5109 Auto-newline insertion hasn't yet been adapted for AWK. Some of the
5110 clean-ups can actually convert good AWK code into syntactically
5113 If auto-newline or its associated clean-ups are enabled generally for
5114 the modes in @ccmode{}, you are strongly recommended to disable them
5115 in the AWK Mode hook. @xref{Initialising AWK Mode}.
5117 The clean-up @code{space-before-funcall}, which is independent of
5118 auto-newline, should never be active in AWK mode (since inserting a
5119 space between a user function's name and its opening @samp{(} makes
5120 the call syntactically invalid). If necessary, this should be
5121 disabled in the AWK Mode hook. @xref{Initialising AWK Mode}.
5126 * Initialising AWK Mode::
5127 * AWK Mode Font Locking::
5132 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5133 @node Initialising AWK Mode, AWK Mode Font Locking, , AWK Mode
5134 @comment node-name, next, previous, up
5135 @section AWK mode - What to put in your @file{.emacs} or @file{init.el}
5136 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5138 Much of the AWK mode initialization can, of course, be done by the
5139 @ccmode{} general initialization procedure. You may want to use certain
5140 @ccmode{} features such as @code{auto-newline} and @code{clean-ups} in
5141 the other modes, and you might thus have enabled them in a
5142 @code{c-mode-common-hook} function, as described in @ref{Sample .emacs File}.
5143 These features have not yet been amended for AWK mode, and far from
5144 being useful, can be irritating in AWK mode or actually make AWK code
5145 syntactically invalid. Adding the following code to your
5146 @file{.emacs} or @file{init.el} file will disable them for AWK mode.
5149 (defun my-awk-mode-hook ()
5150 "Disable certain @ccmode{} features which could impair AWK mode."
5151 (c-toggle-auto-state -1) ; disable automatic insertions of newlines
5152 (if (memq 'space-before-funcall c-cleanup-list)
5153 (setq c-cleanup-list ; don't automatically insert a space into "foo("
5154 (remove 'space-before-funcall c-cleanup-list))))
5155 (add-hook 'awk-mode-hook 'my-awk-mode-hook)
5158 Naturally you can add your own AWK-specific customizations to this
5159 function. @xref{Hooks}.
5162 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5163 @node AWK Mode Font Locking, AWK Mode Defuns, Initialising AWK Mode, AWK Mode
5164 @comment node-name, next, previous, up
5165 @section AWK Mode Font Locking
5166 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5168 The general appearance of font-locking in AWK mode is much like in any
5169 other programming mode. @xref{Faces For Font Lock,,,elisp}.
5171 The following faces are, however, used in a non-standard fashion in
5175 @item @code{font-lock-variable-name-face}
5176 This face was intended for variable declarations. Since variables are
5177 not declared in AWK, this face is used instead for AWK system
5178 variables (such as @code{NF}) and ``Special File Names'' (such as
5179 @code{"/dev/stderr"}).
5181 @item @code{font-lock-builtin-face} (Emacs)/@code{font-lock-preprocessor-face} (XEmacs)
5182 This face is normally used for preprocessor directives in @ccmode{}.
5183 There are no such things in AWK, so this face is used instead for
5184 standard functions (such as @code{match}).
5186 @item @code{font-lock-string-face}
5187 As well as being used for strings, including localizable strings,
5188 (delimited by @samp{"} and @samp{_"}), this face is also used for AWK
5189 regular expressions (delimited by @samp{/}).
5191 @item @code{font-lock-warning-face} (Emacs)/@code{c-invalid-face} (XEmacs)
5192 This face highlights the following syntactically invalid AWK
5197 An unterminated string or regular expression. Here the opening
5198 delimiter (@samp{"} or @samp{/} or @samp{_"}) is displayed in
5199 @code{font-lock-warning-face}. This is most noticeable when typing in a
5200 new string/regular expression into a buffer, when the warning-face
5201 serves as a continual reminder to terminate the construct.
5203 AWK mode fontifies unterminated strings/regular expressions
5204 differently from other modes: Only the text up to the end of the line
5205 is fontified as a string (escaped newlines being handled correctly),
5206 rather than the text up to the next string quote.
5209 A space between the function name and opening parenthesis when calling
5210 a user function. The last character of the function name and the
5211 opening parenthesis are highlighted. This font-locking rule will
5212 spuriously highlight a valid concatenation expression where an
5213 identifier precedes a parenthesised expression. Unfortunately.
5216 Whitespace following the @samp{\} in what otherwise looks like an
5217 escaped newline. The @samp{\} is highlighted.
5222 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5223 @node AWK Mode Defuns, , AWK Mode Font Locking, AWK Mode
5224 @comment node-name, next, previous, up
5225 @section AWK Mode Defuns
5226 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5228 In AWK mode, @dfn{defun} means either a user-defined function or a
5229 pattern-action pair. Either the pattern or the action may be
5232 The beginning of a defun is recognised heuristically as, more or less,
5233 code which begins in column zero. Having the @samp{@{} in column zero,
5234 as is suggested for some modes, is neither necessary nor helpful in AWK
5237 More precisely, the beginning of a defun is code which begins in
5238 column zero, and which isn't a closing brace, a comment, or a
5239 continuation of the previous line. Code is the @dfn{continuation of
5240 the previous line} when that line is syntactically incomplete, for
5241 example when it ends with @samp{@{} or an escaped newline.
5243 The end of a defun is the @samp{@}} which matches the @samp{@{} (if
5244 any) at the beginning of the action or function body, or the EOL or
5245 @samp{;} which marks an implicit action. Although this @samp{@}} is
5246 usually placed in column zero, AWK mode doesn't need it to be placed
5250 @item @kbd{C-M-a} @code{c-awk-beginning-of-defun}
5251 @itemx @kbd{C-M-e} @code{c-awk-end-of-defun}
5252 @findex c-awk-beginning-of-defun
5253 @findex awk-beginning-of-defun (c-)
5254 @findex c-awk-end-of-defun
5255 @findex awk-end-of-defun (c-)
5256 Move point back to the beginning or forward to the end of the current
5257 AWK defun. These functions can take prefix-arguments, their
5258 functionality being entirely equivalent to @code{beginning-of-defun}
5259 and @code{end-of-defun}. @xref{Moving by Defuns,,,emacs}.
5261 @item @kbd{C-M-h} @code{c-mark-function}
5262 This works fine with AWK defuns. @xref{Indentation Commands}.
5266 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5267 @node Odds and Ends, Performance Issues, AWK Mode, Top
5268 @comment node-name, next, previous, up
5269 @chapter Odds and Ends
5270 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5272 The stuff that didn't fit in anywhere else is documented here.
5274 @defopt c-require-final-newline
5275 @vindex require-final-newline (c-)
5276 Controls whether a final newline is ensured when the file is saved. The
5277 value is an association list that for each language mode specifies the
5278 value to give to @code{require-final-newline} at mode initialization;
5279 see that variable for details about the value. If a language isn't
5280 present on the association list, CC Mode won't touch
5281 @code{require-final-newline} in buffers for that language.
5283 The default is to set @code{require-final-newline} to @code{t} in the
5284 languages that mandates that source files should end with newlines,
5285 i.e., C, C++ and Objective-C.
5288 @defopt c-echo-syntactic-information-p
5289 @vindex echo-syntactic-information-p (c-)
5290 If non-@code{nil}, the syntactic analysis for the current line is shown
5291 in the echo area when it's indented (unless
5292 @code{c-syntactic-indentation} is @code{nil}). That's useful when
5293 finding out which syntactic symbols to modify to get the indentation you
5297 @defopt c-report-syntactic-errors
5298 @vindex report-syntactic-errors (c-)
5299 If non-@code{nil}, certain syntactic errors are reported with a ding and
5300 a message, for example when an @code{else} is indented for which there
5301 is no corresponding @code{if}.
5303 Note however that @ccmode{} doesn't make any special effort to check for
5304 syntactic errors; that's the job of the compiler. The reason it can
5305 report cases like the one above is that it can't find the correct
5306 anchoring position to indent the line in that case.
5310 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5311 @node Performance Issues, Limitations and Known Bugs, Odds and Ends, Top
5312 @comment node-name, next, previous, up
5313 @chapter Performance Issues
5315 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5317 @comment FIXME: (ACM, 2003/5/24). Check whether AWK needs mentioning here.
5319 C and its derivative languages are highly complex creatures. Often,
5320 ambiguous code situations arise that require @ccmode{} to scan large
5321 portions of the buffer to determine syntactic context. Such
5322 pathological code can cause @ccmode{} to perform fairly badly. This
5323 section gives some insight in how @ccmode{} operates, how that interacts
5324 with some coding styles, and what you can use to improve performance.
5326 The overall goal is that @ccmode{} shouldn't be overly slow (i.e., take
5327 more than a fraction of a second) in any interactive operation.
5328 i.e., it's tuned to limit the maximum response time in single operations,
5329 which sometimes is at the expense of batch-like operations like
5330 reindenting whole blocks. If you find that @ccmode{} gradually gets
5331 slower and slower in certain situations, perhaps as the file grows in
5332 size or as the macro or comment you're editing gets bigger, then chances
5333 are that something isn't working right. You should consider reporting
5334 it, unless it's something that's mentioned in this section.
5336 Because @ccmode{} has to scan the buffer backwards from the current
5337 insertion point, and because C's syntax is fairly difficult to parse in
5338 the backwards direction, @ccmode{} often tries to find the nearest
5339 position higher up in the buffer from which to begin a forward scan
5340 (it's typically an opening or closing parethesis of some kind). The
5341 farther this position is from the current insertion point, the slower it
5344 @findex beginning-of-defun
5345 @findex defun-prompt-regexp
5346 One of the simplest things you can do to reduce scan time, is make sure
5347 any brace that opens a top-level construct@footnote{e.g., a function in
5348 C, or outermost class definition in C++ or Java.} always appears in the
5349 leftmost column. This is actually an Emacs constraint, as embodied in
5350 the @code{beginning-of-defun} function which @ccmode{} uses heavily. If
5351 you hang top-level open braces on the right side of the line, then you
5352 might want to set the variable @code{defun-prompt-regexp} to something
5353 reasonable, however that ``something reasonable'' is difficult to
5354 define, so @ccmode{} doesn't do it for you.
5356 @vindex c-Java-defun-prompt-regexp
5357 @vindex Java-defun-prompt-regexp (c-)
5358 A special note about @code{defun-prompt-regexp} in Java mode: The common
5359 style is to hang the opening braces of functions and classes on the
5360 right side of the line, and that doesn't work well with the Emacs
5361 approach. @ccmode{} comes with a variable
5362 @code{c-Java-defun-prompt-regexp} which tries to define a regular
5363 expression usable for this style, but there are problems with it. In
5364 some cases it can cause @code{beginning-of-defun} to hang@footnote{This
5365 has been observed in Emacs 19.34 and XEmacs 19.15.}. For this reason,
5366 it is not used by default, but if you feel adventurous, you can set
5367 @code{defun-prompt-regexp} to it in your mode hook. In any event,
5368 setting and relying on @code{defun-prompt-regexp} will definitely slow
5369 things down because (X)Emacs will be doing regular expression searches a
5370 lot, so you'll probably be taking a hit either way!
5372 @ccmode{} maintains a cache of the opening parentheses of the blocks
5373 surrounding the point, and it adapts that cache as the point is moved
5374 around. That means that in bad cases it can take noticeable time to
5375 indent a line in a new surrounding, but after that it gets fast as long
5376 as the point isn't moved far off. The farther the point is moved, the
5377 less useful is the cache. Since editing typically is done in ``chunks''
5378 rather than on single lines far apart from each other, the cache
5379 typically gives good performance even when the code doesn't fit the
5380 Emacs approach to finding the defun starts.
5382 @vindex c-enable-xemacs-performance-kludge-p
5383 @vindex enable-xemacs-performance-kludge-p (c-)
5384 XEmacs users can set the variable
5385 @code{c-enable-xemacs-performance-kludge-p} to non-@code{nil}. This
5386 tells @ccmode{} to use XEmacs-specific built-in functions which, in some
5387 circumstances, can locate the top-most opening brace much more quickly than
5388 @code{beginning-of-defun}. Preliminary testing has shown that for
5389 styles where these braces are hung (e.g., most JDK-derived Java styles),
5390 this hack can improve performance of the core syntax parsing routines
5391 from 3 to 60 times. However, for styles which @emph{do} conform to
5392 Emacs' recommended style of putting top-level braces in column zero,
5393 this hack can degrade performance by about as much. Thus this variable
5394 is set to @code{nil} by default, since the Emacs-friendly styles should
5395 be more common (and encouraged!). Note that this variable has no effect
5396 in Emacs since the necessary built-in functions don't exist (in Emacs
5397 21.3 as of this writing in May 2003).
5399 Text properties are used to speed up skipping over syntactic whitespace,
5400 i.e., comments and preprocessor directives. Indenting a line after a
5401 huge macro definition can be slow the first time, but after that the
5402 text properties are in place and it should be fast (even after you've
5403 edited other parts of the file and then moved back).
5405 Font locking can be a CPU hog, especially the font locking done on
5406 decoration level 3 which tries to be very accurate. Note that that
5407 level is designed to be used with a font lock support mode that only
5408 fontifies the text that's actually shown, i.e., Lazy Lock or Just-in-time
5409 Lock mode, so make sure you use one of them. Fontification of a whole
5410 buffer with some thousand lines can often take over a minute. That is
5411 a known weakness; the idea is that it never should happen.
5413 The most effective way to speed up font locking is to reduce the
5414 decoration level to 2 by setting @code{font-lock-maximum-decoration}
5415 appropriately. That level is designed to be as pretty as possible
5416 without sacrificing performance. @xref{Font Locking Preliminaries}, for
5420 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5421 @node Limitations and Known Bugs, Frequently Asked Questions, Performance Issues, Top
5422 @comment node-name, next, previous, up
5423 @chapter Limitations and Known Bugs
5426 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5430 There is no way to apply auto newline settings (@pxref{Auto-newline
5431 Insertion}) on already typed lines. That's only a feature to ease
5432 interactive editing.
5434 To generalize this issue a bit: @ccmode{} is not intended to be used as
5435 a reformatter for old code in some more or less batch-like way. With
5436 the exception of some functions like @code{c-indent-region}, it's only
5437 geared to be used interactively to edit new code. There's currently no
5438 intention to change this goal.
5440 If you want to reformat old code, you're probably better off using some
5441 other tool instead, e.g., @ref{Top, , GNU indent, indent, The `indent'
5442 Manual}, which has more powerful reformatting capabilities than
5446 @vindex signal-error-on-buffer-boundary
5447 XEmacs has a variable called @code{signal-error-on-buffer-boundary}.
5448 It's used as a solution to user interface problems associated with
5449 buffer movement and the @code{zmacs-region} deactivation on errors.
5450 However, setting this variable to a non-default value in XEmacs 19 and
5451 20 had the deleterious side effect of breaking many built-in primitive
5452 functions. @strong{Do not set this variable to @code{nil} in XEmacs
5453 19 and 20}; you will cause serious problems in @ccmode{} and probably
5454 other XEmacs packages! In XEmacs 21 the effects of the variable is
5455 limited to some functions that are only used interactively, so it's
5456 not a problem there.
5460 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5461 @node Frequently Asked Questions, Getting the Latest CC Mode Release, Limitations and Known Bugs, Top
5462 @comment node-name, next, previous, up
5463 @appendix Frequently Asked Questions
5464 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5470 @emph{How do I reindent the whole file?}
5472 Visit the file and hit @kbd{C-x h} to mark the whole buffer. Then hit
5478 @emph{How do I reindent the current block?}
5480 First move to the brace which opens the block with @kbd{C-M-u}, then
5481 reindent that expression with @kbd{C-M-q}.
5486 @emph{Why doesn't the @kbd{RET} key indent the new line?}
5488 Emacs' convention is that @kbd{RET} just adds a newline, and that
5489 @kbd{C-j} adds a newline and indents it. You can make @kbd{RET} do this
5490 too by adding this to your @code{c-mode-common-hook}:
5493 (define-key c-mode-base-map "\C-m" 'c-context-line-break)
5496 This is a very common question. If you want this to be the default
5497 behavior, don't lobby me, lobby RMS! @t{:-)}
5500 @emph{I put @code{(c-set-offset 'substatement-open 0)} in my
5501 @file{.emacs} file but I get an error saying that @code{c-set-offset}'s
5502 function definition is void. What's wrong?}
5504 This means that @ccmode{} wasn't loaded into your Emacs session by the
5505 time the @code{c-set-offset} call was reached, most likely because
5506 @ccmode{} is being autoloaded. Instead of putting the
5507 @code{c-set-offset} line in your top-level @file{.emacs} file, put it in
5508 your @code{c-mode-common-hook}, or simply modify @code{c-offsets-alist}
5512 (setq c-offsets-alist '((substatement-open . 0)))
5518 @emph{@kbd{M-a} and @kbd{M-e} used to move over entire balanced brace
5519 lists, but now they move into blocks. How do I get the old behavior
5522 Use @kbd{C-M-f} and @kbd{C-M-b} to move over balanced brace blocks. Use
5523 @kbd{M-a} and @kbd{M-e} to move by statements, which will also move into
5527 @emph{Whenever I try to indent a line or type an ``electric'' key such
5528 as @kbd{;}, @kbd{@{}, or @kbd{@}}, I get an error that look like this:
5529 @code{Invalid function: (macro . #[...}. What gives?}
5531 This is a common error when @ccmode{} hasn't been compiled correctly,
5532 especially under Emacs 19.34@footnote{Technically, it's because some
5533 macro wasn't defined during the compilation, so the byte compiler put
5534 in function calls instead of the macro expansions. Later, when the
5535 interpreter tries to call the macro as a function, it shows this
5536 (somewhat cryptic) error message.}. If you are using the standalone
5537 @ccmode{} distribution, try recompiling it according to the instructions
5538 in the @file{README} file.
5541 @cindex open paren in column zero
5542 @emph{I have an open paren character at column zero inside a comment or
5543 multiline string literal, and it causes the fontification and/or
5544 indentation to go haywire. What gives?}
5546 It's due to the ad-hoc rule in (X)Emacs that such open parens always
5547 start defuns (which translates to functions, classes, namespaces or any
5548 other top-level block constructs in the @ccmode{} languages).
5549 @xref{Left Margin Paren,,, emacs, The Emacs Editor}, for details
5550 (@xref{Defuns,,, emacs, The Emacs Editor}, in the Emacs 20 manual).
5552 This heuristic is built into the core syntax analysis routines in
5553 (X)Emacs, so it's not really a @ccmode{} issue. However, in Emacs 22.1
5554 it has become possible to turn it off@footnote{Using the variable
5555 @code{open-paren-in-column-0-is-defun-start}.} and @ccmode{} does so
5556 there since it got its own system to keep track of blocks.
5561 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5562 @node Getting the Latest CC Mode Release, Mailing Lists and Submitting Bug Reports, Frequently Asked Questions, Top
5563 @comment node-name, next, previous, up
5564 @appendix Getting the Latest CC Mode Release
5565 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5567 @ccmode{} has been standard with all versions of Emacs since 19.34 and
5568 of XEmacs since 19.16.
5571 Due to release schedule skew, it is likely that all of these Emacsen
5572 have old versions of @ccmode{} and so should be upgraded. Access to the
5573 @ccmode{} source code, as well as more detailed information on Emacsen
5574 compatibility, etc. are all available on the web site:
5577 @uref{http://cc-mode.sourceforge.net/}
5581 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5582 @node Mailing Lists and Submitting Bug Reports, Sample .emacs File, Getting the Latest CC Mode Release, Top
5583 @comment node-name, next, previous, up
5584 @appendix Mailing Lists and Submitting Bug Reports
5585 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5588 @findex c-submit-bug-report
5589 @findex submit-bug-report (c-)
5590 To report bugs, use the @kbd{C-c C-b} (bound to
5591 @code{c-submit-bug-report}) command. This provides vital information
5592 we need to reproduce your problem. Make sure you include a concise,
5593 but complete code example. Please try to boil your example down to
5594 just the essential code needed to reproduce the problem, and include
5595 an exact recipe of steps needed to expose the bug. Be especially sure
5596 to include any code that appears @emph{before} your bug example, if
5597 you think it might affect our ability to reproduce it.
5599 Please try to produce the problem in an Emacs instance without any
5600 customizations loaded (i.e., start it with the @samp{-q --no-site-file}
5601 arguments). If it works correctly there, the problem might be caused by
5602 faulty customizations in either your own or your site configuration. In
5603 that case, we'd appreciate if you isolate the Emacs Lisp code that trigs
5604 the bug and include it in your report.
5606 @cindex bug report mailing list
5607 Bug reports are sent to @email{bug-cc-mode@@gnu.org}. You can also send
5608 other questions and suggestions (kudos? @t{;-)} to that address. It's a
5609 mailing list which you can join or browse an archive of; see the web
5610 site at @uref{http://cc-mode.sourceforge.net/} for further details.
5612 @cindex announcement mailing list
5613 If you want to get announcements of new @ccmode{} releases, send the
5614 word @emph{subscribe} in the body of a message to
5615 @email{cc-mode-announce-request@@lists.sourceforge.net}. It's possible
5616 to subscribe from the web site too. Announcements will also be posted
5617 to the Usenet newsgroups @code{gnu.emacs.sources}, @code{comp.emacs} and
5618 @code{comp.emacs.xemacs}.
5621 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5622 @node Sample .emacs File, Command and Function Index, Mailing Lists and Submitting Bug Reports, Top
5623 @comment node-name, next, previous, up
5624 @appendix Sample .emacs file
5625 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5628 ;; Here's a sample .emacs file that might help you along the way.
5629 ;; Just copy this region and paste it into your .emacs file. You may
5630 ;; want to change some of the actual values.
5632 (defconst my-c-style
5633 '((c-tab-always-indent . t)
5634 (c-comment-only-line-offset . 4)
5635 (c-hanging-braces-alist . ((substatement-open after)
5637 (c-hanging-colons-alist . ((member-init-intro before)
5641 (access-label after)))
5642 (c-cleanup-list . (scope-operator
5645 (c-offsets-alist . ((arglist-close . c-lineup-arglist)
5646 (substatement-open . 0)
5649 (knr-argdecl-intro . -)))
5650 (c-echo-syntactic-information-p . t))
5651 "My C Programming Style")
5653 ;; offset customizations not in my-c-style
5654 (setq c-offsets-alist '((member-init-intro . ++)))
5656 ;; Customizations for all modes in CC Mode.
5657 (defun my-c-mode-common-hook ()
5658 ;; add my personal style and set it for the current buffer
5659 (c-add-style "PERSONAL" my-c-style t)
5660 ;; other customizations
5662 ;; this will make sure spaces are used instead of tabs
5663 indent-tabs-mode nil)
5664 ;; we like auto-newline and hungry-delete
5665 (c-toggle-auto-hungry-state 1)
5666 ;; key bindings for all supported languages. We can put these in
5667 ;; c-mode-base-map because c-mode-map, c++-mode-map, objc-mode-map,
5668 ;; java-mode-map, idl-mode-map, and pike-mode-map inherit from it.
5669 (define-key c-mode-base-map "\C-m" 'c-context-line-break))
5671 (add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
5675 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5676 @node Command and Function Index, Variable Index, Sample .emacs File, Top
5677 @comment node-name, next, previous, up
5678 @unnumbered Command and Function Index
5679 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5681 Since most @ccmode{} commands are prepended with the string
5682 @samp{c-}, each appears under its @code{c-@var{thing}} name and its
5683 @code{@var{thing} (c-)} name.
5690 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5691 @node Variable Index, Concept Index, Command and Function Index, Top
5692 @comment node-name, next, previous, up
5693 @unnumbered Variable Index
5694 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5696 Since most @ccmode{} variables are prepended with the string
5697 @samp{c-}, each appears under its @code{c-@var{thing}} name and its
5698 @code{@var{thing} (c-)} name.
5705 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5706 @node Concept Index, , Variable Index, Top
5707 @comment node-name, next, previous, up
5708 @unnumbered Concept Index
5709 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5714 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5716 @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
5727 arch-tag: c4cab162-5e57-4366-bdce-4a9db2fc97f0