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File: ccmode.info, Node: Top, Next: Introduction, Prev: (dir), Up: (dir)
CC Mode
*******
CC Mode is a GNU Emacs mode for editing files containing C, C++,
Objective-C, Java, CORBA IDL (and the variants PSDL and CIDL), Pike and
AWK code. It provides syntax-based indentation, font locking, and has
several handy commands and some minor modes to make the editing easier.
It does not provide tools to look up and navigate between functions,
classes, etc.; there are other packages for that.
This manual is for CC Mode in Emacs.
Copyright (C) 1995-2013 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License,
Version 1.3 or any later version published by the Free Software
Foundation; with no Invariant Sections, with the Front-Cover texts
being "A GNU Manual", and with the Back-Cover Texts as in (a)
below. A copy of the license is included in the section entitled
"GNU Free Documentation License".
(a) The FSF's Back-Cover Text is: "You have the freedom to copy and
modify this GNU manual."
* Menu:
* Introduction::
* Overview::
* Getting Started::
* Commands::
* Font Locking::
* Config Basics::
* Custom Filling and Breaking::
* Custom Auto-newlines::
* Clean-ups::
* Indentation Engine Basics::
* Customizing Indentation::
* Custom Macros::
* Odds and Ends::
* Sample .emacs File::
* Performance Issues::
* Limitations and Known Bugs::
* FAQ::
* Updating CC Mode::
* Mailing Lists and Bug Reports::
* GNU Free Documentation License::
* Command and Function Index::
* Variable Index::
* Concept and Key Index::
-- The Detailed Node Listing --
Commands
* Indentation Commands::
* Comment Commands::
* Movement Commands::
* Filling and Breaking::
* Minor Modes::
* Electric Keys::
* Auto-newlines::
* Hungry WS Deletion::
* Subword Movement::
* Other Commands::
Font Locking
* Font Locking Preliminaries::
* Faces::
* Doc Comments::
* AWK Mode Font Locking::
Configuration Basics
* CC Hooks::
* Style Variables::
* Styles::
Styles
* Built-in Styles::
* Choosing a Style::
* Adding Styles::
* Guessing the Style::
* File Styles::
Customizing Auto-newlines
* Hanging Braces::
* Hanging Colons::
* Hanging Semicolons and Commas::
Hanging Braces
* Custom Braces::
Indentation Engine Basics
* Syntactic Analysis::
* Syntactic Symbols::
* Indentation Calculation::
Syntactic Symbols
* Function Symbols::
* Class Symbols::
* Conditional Construct Symbols::
* Switch Statement Symbols::
* Brace List Symbols::
* External Scope Symbols::
* Paren List Symbols::
* Literal Symbols::
* Multiline Macro Symbols::
* Objective-C Method Symbols::
* Java Symbols::
* Statement Block Symbols::
* K&R Symbols::
Customizing Indentation
* c-offsets-alist::
* Interactive Customization::
* Line-Up Functions::
* Custom Line-Up::
* Other Indentation::
Line-Up Functions
* Brace/Paren Line-Up::
* List Line-Up::
* Operator Line-Up::
* Comment Line-Up::
* Misc Line-Up::
Customizing Macros
* Macro Backslashes::
* Macros with ;::
File: ccmode.info, Node: Introduction, Next: Overview, Prev: Top, Up: Top
1 Introduction
**************
Welcome to CC Mode, a GNU Emacs mode for editing files containing C,
C++, Objective-C, Java, CORBA IDL (and the variants CORBA PSDL and
CIDL), Pike and AWK code. This incarnation of the mode is descended
from 'c-mode.el' (also called "Boring Old C Mode" or BOCM :-),
'c++-mode.el' version 2, which Barry Warsaw had been maintaining since
1992, and 'awk-mode.el', a long neglected mode in the (X)Emacs base.
Late in 1997, Martin Stjernholm joined Barry on the CC Mode
Maintainers Team, and implemented the Pike support. In 2000 Martin took
over as the sole maintainer. In 2001 Alan Mackenzie joined the team,
implementing AWK support in version 5.30. CC Mode did not originally
contain the font lock support for its languages; that was added in
version 5.30.
This manual describes CC Mode version 5.32.
CC Mode supports the editing of K&R and ANSI C, C++, Objective-C,
Java, CORBA's Interface Definition Language, Pike(1) and AWK files. In
this way, you can easily set up consistent font locking and coding
styles for use in editing all of these languages, although AWK is not
yet as uniformly integrated as the other languages.
Note that the name of this package is "CC Mode", but there is no top
level 'cc-mode' entry point. All of the variables, commands, and
functions in CC Mode are prefixed with 'c-THING', and 'c-mode',
'c++-mode', 'objc-mode', 'java-mode', 'idl-mode', 'pike-mode', and
'awk-mode' entry points are provided. This package is intended to be a
replacement for 'c-mode.el', 'c++-mode.el' and 'awk-mode.el'.
A special word of thanks goes to Krishna Padmasola for his work in
converting the original 'README' file to Texinfo format. I'd also like
to thank all the CC Mode victims who help enormously during the early
beta stages of CC Mode's development.
---------- Footnotes ----------
(1) A C-like scripting language with its roots in the LPC language
used in some MUD engines. See <http://pike.ida.liu.se/>.
File: ccmode.info, Node: Overview, Next: Getting Started, Prev: Introduction, Up: Top
2 Overview of the Manual
************************
The manual starts with several introductory chapters (including this
one).
The next chunk of the manual describes the day to day _use_ of CC Mode
(as contrasted with how to customize it).
* The chapter "Commands" describes in detail how to use (nearly) all
of CC Mode's features. There are extensive cross-references from
here to the corresponding sections later in the manual which tell
you how to customize these features.
* "Font Locking" describes how "syntax highlighting" is applied to
your buffers. It is mainly background information and can be
skipped over at a first reading.
The next chunk of the manual describes how to _customize_ CC Mode.
Typically, an overview of a topic is given at the chapter level, then
the sections and subsections describe the material in increasing detail.
* The chapter "Configuration Basics" tells you _how_ to write
customizations: whether in hooks, in styles, in both, or in
neither, depending on your needs. It describes the CC Mode style
system and lists the standard styles that CC Mode supplies.
* The next few chapters describe in detail how to customize the
various features of CC Mode.
* Finally, there is a sample '.emacs' fragment, which might help you
in creating your own customization.
The manual ends with "this and that", things that don't fit cleanly into
any of the previous chunks.
* Two chapters discuss the performance of CC Mode and known
bugs/limitations.
* The FAQ contains a list of common problems and questions.
* The next two chapters tell you how to get in touch with the CC Mode
project: whether for updating CC Mode or submitting bug reports.
Finally, there are the customary indices.
File: ccmode.info, Node: Getting Started, Next: Commands, Prev: Overview, Up: Top
3 Getting Started
*****************
If you got this version of CC Mode with Emacs or XEmacs, it should work
just fine right out of the box. Note however that you might not have
the latest CC Mode release and might want to upgrade your copy (see
below).
You should probably start by skimming through the entire Commands
chapter (*note Commands::) to get an overview of CC Mode's capabilities.
After trying out some commands, you may dislike some aspects of CC
Mode's default configuration. Here is an outline of how to change some
of the settings that newcomers to CC Mode most often want to change:
c-basic-offset
This Lisp variable holds an integer, the number of columns CC Mode
indents nested code. To set this value to 6, customize
'c-basic-offset' or put this into your '.emacs':
(setq c-basic-offset 6)
The (indentation) style
The basic "shape" of indentation created by CC Mode--by default,
this is 'gnu' style (except for Java and AWK buffers). A list of
the available styles and their descriptions can be found in *note
Built-in Styles::. A complete specification of the CC Mode style
system, including how to create your own style, can be found in the
chapter *note Styles::. To set your style to 'linux', either
customize 'c-default-style' or put this into your '.emacs':
(setq c-default-style '((java-mode . "java")
(awk-mode . "awk")
(other . "linux")))
Electric Indentation
Normally, when you type "punctuation" characters such as ';' or
'{', CC Mode instantly reindents the current line. This can be
disconcerting until you get used to it. To disable "electric
indentation" in the current buffer, type 'C-c C-l'. Type the same
thing to enable it again. To have electric indentation disabled by
default, put the following into your '.emacs' file(1):
(setq-default c-electric-flag nil)
Details of this and other similar "Minor Modes" appear in the
section *note Minor Modes::.
Making the <RET> key indent the new line
The standard Emacs binding for <RET> just adds a new line. If you
want it to reindent the new line as well, rebind the key. Note
that the action of rebinding would fail if the pertinent keymap
didn't yet exist--we thus need to delay the action until after CC
Mode has been loaded. Put the following code into your '.emacs':
(defun my-make-CR-do-indent ()
(define-key c-mode-base-map "\C-m" 'c-context-line-break))
(add-hook 'c-initialization-hook 'my-make-CR-do-indent)
This example demonstrates the use of a very powerful CC Mode (and
Emacs) facility, the hook. The use of CC Mode's hooks is described
in *note CC Hooks::.
All these settings should occur in your '.emacs' _before_ any CC Mode
buffers get loaded--in particular, before any call of 'desktop-read'.
As you get to know the mode better, you may want to make more
ambitious changes to your configuration. For this, you should start
reading the chapter *note Config Basics::.
If you are upgrading an existing CC Mode installation, please see the
'README' file for installation details. In particular, if you are going
to be editing AWK files, 'README' describes how to configure your
(X)Emacs so that CC Mode will supersede the obsolete 'awk-mode.el' which
might have been supplied with your (X)Emacs. CC Mode might not work
with older versions of Emacs or XEmacs. See the CC Mode release notes
at <http://cc-mode.sourceforge.net> for the latest information on Emacs
version and package compatibility (*note Updating CC Mode::).
-- Command: c-version
You can find out what version of CC Mode you are using by visiting
a C file and entering 'M-x c-version RET'. You should see this
message in the echo area:
Using CC Mode version 5.XX
where 'XX' is the minor release number.
---------- Footnotes ----------
(1) There is no "easy customization" facility for making this change.
File: ccmode.info, Node: Commands, Next: Font Locking, Prev: Getting Started, Up: Top
4 Commands
**********
This chapter specifies all of CC Mode's commands, and thus contains
nearly everything you need to know to _use_ CC Mode (as contrasted with
configuring it). "Commands" here means both control key sequences and
"electric keys", these being characters such as ';' which, as well as
inserting themselves into the buffer, also do other things.
You might well want to review *note (emacs)Moving by Parens::, which
describes commands for moving around brace and parenthesis structures.
* Menu:
* Indentation Commands::
* Comment Commands::
* Movement Commands::
* Filling and Breaking::
* Minor Modes::
* Electric Keys::
* Auto-newlines::
* Hungry WS Deletion::
* Subword Movement::
* Other Commands::
File: ccmode.info, Node: Indentation Commands, Next: Comment Commands, Prev: Commands, Up: Commands
4.1 Indentation Commands
========================
The following commands reindent C constructs. Note that when you change
your coding style, either interactively or through some other means,
your file does _not_ automatically get reindented. You will need to
execute one of the following commands to see the effects of your
changes.
Also, variables like 'c-hanging-*' and 'c-cleanup-list' (*note Custom
Auto-newlines::) only affect how on-the-fly code is formatted. Changing
the "hanginess" of a brace and then reindenting, will not move the brace
to a different line. For this, you're better off getting an external
program like GNU 'indent', which will rearrange brace location, amongst
other things.
Preprocessor directives are handled as syntactic whitespace from
other code, i.e., they can be interspersed anywhere without affecting
the indentation of the surrounding code, just like comments.
The code inside macro definitions is, by default, still analyzed
syntactically so that you get relative indentation there just as you'd
get if the same code was outside a macro. However, since there is no
hint about the syntactic context, i.e., whether the macro expands to an
expression, to some statements, or perhaps to whole functions, the
syntactic recognition can be wrong. CC Mode manages to figure it out
correctly most of the time, though.
Some macros, when invoked, "have their own semicolon". To get the
next line indented correctly, rather than as a continuation line, *Note
Macros with ;::.
Reindenting large sections of code can take a long time. When CC
Mode reindents a region of code, it is essentially equivalent to hitting
<TAB> on every line of the region.
These commands indent code:
'<TAB>' ('c-indent-command')
This command indents the current line. That is all you need to
know about it for normal use.
'c-indent-command' does different things, depending on the setting
of 'c-syntactic-indentation' (*note Indentation Engine Basics::):
* When it's non-'nil' (which it normally is), the command
indents the line according to its syntactic context. With a
prefix argument ('C-u <TAB>'), it will re-indent the entire
expression(1) that begins at the line's left margin.
* When it's 'nil', the command indents the line by an extra
'c-basic-offset' columns. A prefix argument acts as a
multiplier. A bare prefix ('C-u <TAB>') is equivalent to -1,
removing 'c-basic-offset' columns from the indentation.
The precise behavior is modified by several variables: With
'c-tab-always-indent', you can make <TAB> insert whitespace in some
circumstances--'c-insert-tab-function' then defines precisely what
sort of "whitespace" this will be. Set the standard Emacs variable
'indent-tabs-mode' to 't' if you want real 'tab' characters to be
used in the indentation, to 'nil' if you want only spaces. *Note
(emacs)Just Spaces::.
-- User Option: c-tab-always-indent
This variable modifies how <TAB> operates.
* When it is 't' (the default), <TAB> simply indents the
current line.
* When it is 'nil', <TAB> (re)indents the line only if
point is to the left of the first non-whitespace
character on the line. Otherwise it inserts some
whitespace (a tab or an equivalent number of spaces; see
below) at point.
* With some other value, the line is reindented.
Additionally, if point is within a string or comment,
some whitespace is inserted.
-- User Option: c-insert-tab-function
When "some whitespace" is inserted as described above, what
actually happens is that the function stored in
'c-insert-tab-function' is called. Normally, this is
'insert-tab', which inserts a real tab character or the
equivalent number of spaces (depending on 'indent-tabs-mode').
Some people, however, set 'c-insert-tab-function' to
'tab-to-tab-stop' so as to get hard tab stops when indenting.
The kind of indentation the next five commands do depends on the setting
of 'c-syntactic-indentation' (*note Indentation Engine Basics::):
* when it is non-'nil' (the default), the commands indent lines
according to their syntactic context;
* when it is 'nil', they just indent each line the same amount as the
previous non-blank line. The commands that indent a region aren't
very useful in this case.
'C-j' ('newline-and-indent')
Inserts a newline and indents the new blank line, ready to start
typing. This is a standard (X)Emacs command.
'C-M-q' ('c-indent-exp')
Indents an entire balanced brace or parenthesis expression. Note
that point must be on the opening brace or parenthesis of the
expression you want to indent.
'C-c C-q' ('c-indent-defun')
Indents the entire top-level function, class or macro definition
encompassing point. It leaves point unchanged. This function
can't be used to reindent a nested brace construct, such as a
nested class or function, or a Java method. The top-level
construct being reindented must be complete, i.e., it must have
both a beginning brace and an ending brace.
'C-M-\' ('indent-region')
Indents an arbitrary region of code. This is a standard Emacs
command, tailored for C code in a CC Mode buffer. Note, of course,
that point and mark must delineate the region you want to indent.
'C-M-h' ('c-mark-function')
While not strictly an indentation command, this is useful for
marking the current top-level function or class definition as the
current region. As with 'c-indent-defun', this command operates on
top-level constructs, and can't be used to mark say, a Java method.
These variables are also useful when indenting code:
-- User Option: indent-tabs-mode
This is a standard Emacs variable that controls how line
indentation is composed. When it's non-'nil', tabs can be used in
a line's indentation, otherwise only spaces are used.
-- User Option: c-progress-interval
When indenting large regions of code, this variable controls how
often a progress message is displayed. Set this variable to 'nil'
to inhibit the progress messages, or set it to an integer which is
how often (in seconds) progress messages are to be displayed.
---------- Footnotes ----------
(1) this is only useful for a line starting with a comment opener or
an opening brace, parenthesis, or string quote.
File: ccmode.info, Node: Comment Commands, Next: Movement Commands, Prev: Indentation Commands, Up: Commands
4.2 Comment Commands
====================
'C-c C-c' ('comment-region')
This command comments out the lines that start in the region. With
a negative argument, it does the opposite: it deletes the comment
delimiters from these lines. *Note (emacs)Multi-Line Comments::,
for fuller details. 'comment-region' isn't actually part of CC
Mode; it is given a CC Mode binding for convenience.
'M-;' ('comment-dwim' or 'indent-for-comment' (1))
Insert a comment at the end of the current line, if none is there
already. Then reindent the comment according to 'comment-column'
(*note (emacs)Options for Comments::) and the variables below.
Finally, position the point after the comment starter. 'C-u M-;'
kills any comment on the current line, together with any whitespace
before it. This is a standard Emacs command, but CC Mode enhances
it a bit with two variables:
-- User Option: c-indent-comment-alist
This style variable allows you to vary the column that 'M-;'
puts the comment at, depending on what sort of code is on the
line, and possibly the indentation of any similar comment on
the preceding line. It is an association list that maps
different types of lines to actions describing how they should
be handled. If a certain line type isn't present on the list
then the line is indented to the column specified by
'comment-column'.
See the documentation string for a full description of this
variable (use 'C-h v c-indent-comment-alist').
-- User Option: c-indent-comments-syntactically-p
Normally, when this style variable is 'nil', 'M-;' will indent
comment-only lines according to 'c-indent-comment-alist', just
as it does with lines where other code precede the comments.
However, if you want it to act just like <TAB> for
comment-only lines you can get that by setting
'c-indent-comments-syntactically-p' to non-'nil'.
If 'c-indent-comments-syntactically-p' is non-'nil' then
'c-indent-comment-alist' won't be consulted at all for
comment-only lines.
---------- Footnotes ----------
(1) The name of this command varies between (X)Emacs versions.
File: ccmode.info, Node: Movement Commands, Next: Filling and Breaking, Prev: Comment Commands, Up: Commands
4.3 Movement Commands
=====================
CC Mode contains some useful commands for moving around in C code.
'C-M-a' ('c-beginning-of-defun')
'C-M-e' ('c-end-of-defun')
Move to the beginning or end of the current or next function.
Other constructs (such as a structs or classes) which have a brace
block also count as "functions" here. To move over several
functions, you can give these commands a repeat count.
The start of a function is at its header. The end of the function
is after its closing brace, or after the semicolon of a construct
(such as a 'struct') which doesn't end at the brace. These two
commands try to leave point at the beginning of a line near the
actual start or end of the function. This occasionally causes
point not to move at all.
By default, these commands will recognize functions contained
within a "declaration scope" such as a C++ 'class' or 'namespace'
construct, should the point start inside it. If CC Mode fails to
find function beginnings or ends inside the current declaration
scope, it will search the enclosing scopes. If you want CC Mode to
recognize functions only at the top level(1), set 'c-defun-tactic'
to 't'.
These functions are analogous to the Emacs built-in commands
'beginning-of-defun' and 'end-of-defun', except they eliminate the
constraint that the top-level opening brace of the defun must be in
column zero. See *note (emacs)Defuns::, for more information.
'C-M-a' (AWK Mode) ('c-awk-beginning-of-defun')
'C-M-e' (AWK Mode) ('c-awk-end-of-defun')
Move to the beginning or end of the current or next AWK defun.
These commands can take prefix-arguments, their functionality being
entirely equivalent to 'beginning-of-defun' and 'end-of-defun'.
AWK Mode "defuns" are either pattern/action pairs (either of which
might be implicit) or user defined functions. Having the '{' and
'}' (if there are any) in column zero, as is suggested for some
modes, is neither necessary nor helpful in AWK mode.
'M-a' ('c-beginning-of-statement')
'M-e' ('c-end-of-statement')
Move to the beginning or end of the innermost C statement. If
point is already there, move to the next beginning or end of a
statement, even if that means moving into a block. (Use 'C-M-b' or
'C-M-f' to move over a balanced block.) A prefix argument N means
move over N statements.
If point is within or next to a comment or a string which spans
more than one line, these commands move by sentences instead of
statements.
When called from a program, these functions take three optional
arguments: the repetition count, a buffer position limit which is
the farthest back to search for the syntactic context, and a flag
saying whether to do sentence motion in or near comments and
multiline strings.
'C-c C-u' ('c-up-conditional')
Move back to the containing preprocessor conditional, leaving the
mark behind. A prefix argument acts as a repeat count. With a
negative argument, move forward to the end of the containing
preprocessor conditional.
'#elif' is treated like '#else' followed by '#if', so the function
stops at them when going backward, but not when going forward.
This key sequence is not bound in AWK Mode, which doesn't have
preprocessor statements.
'M-x c-up-conditional-with-else'
A variety of 'c-up-conditional' that also stops at '#else' lines.
Normally those lines are ignored.
'M-x c-down-conditional'
Move forward into the next nested preprocessor conditional, leaving
the mark behind. A prefix argument acts as a repeat count. With a
negative argument, move backward into the previous nested
preprocessor conditional.
'#elif' is treated like '#else' followed by '#if', so the function
stops at them when going forward, but not when going backward.
'M-x c-down-conditional-with-else'
A variety of 'c-down-conditional' that also stops at '#else' lines.
Normally those lines are ignored.
'C-c C-p' ('c-backward-conditional')
'C-c C-n' ('c-forward-conditional')
Move backward or forward across a preprocessor conditional, leaving
the mark behind. A prefix argument acts as a repeat count. With a
negative argument, move in the opposite direction.
These key sequences are not bound in AWK Mode, which doesn't have
preprocessor statements.
'M-x c-backward-into-nomenclature'
'M-x c-forward-into-nomenclature'
A popular programming style, especially for object-oriented
languages such as C++ is to write symbols in a mixed case format,
where the first letter of each word is capitalized, and not
separated by underscores. E.g.,
'SymbolsWithMixedCaseAndNoUnderlines'.
These commands move backward or forward to the beginning of the
next capitalized word. With prefix argument N, move N times. If N
is negative, move in the opposite direction.
Note that these two commands have been superseded by
'subword-mode', which you should use instead. *Note Subword
Movement::. They might be removed from a future release of CC
Mode.
---------- Footnotes ----------
(1) this was CC Mode's behavior prior to version 5.32.
File: ccmode.info, Node: Filling and Breaking, Next: Minor Modes, Prev: Movement Commands, Up: Commands
4.4 Filling and Line Breaking Commands
======================================
Since there's a lot of normal text in comments and string literals, CC
Mode provides features to edit these like in text mode. The goal is to
do it seamlessly, i.e., you can use auto fill mode, sentence and
paragraph movement, paragraph filling, adaptive filling etc. wherever
there's a piece of normal text without having to think much about it.
CC Mode keeps the indentation, fixes suitable comment line prefixes, and
so on.
You can configure the exact way comments get filled and broken, and
where Emacs does auto-filling (see *note Custom Filling and Breaking::).
Typically, the style system (*note Styles::) will have set this up for
you, so you probably won't have to bother.
Line breaks are by default handled (almost) the same regardless of
whether they are made by auto fill mode (*note (emacs)Auto Fill::), by
paragraph filling (e.g., with 'M-q'), or explicitly with 'M-j' or
similar methods. In string literals, the new line gets the same
indentation as the previous nonempty line.(1).
'M-q' ('c-fill-paragraph')
This command fills multiline string literals and both block and
line style comments. In Java buffers, the Javadoc markup words are
recognized as paragraph starters. The line oriented Pike autodoc
markup words are recognized in the same way in Pike mode.
The formatting of the starters ('/*') and enders ('*/') of block
comments are kept as they were before the filling. I.e., if either
the starter or ender were on a line of its own, then it stays on
its own line; conversely, if the delimiter has comment text on its
line, it keeps at least one word of that text with it on the line.
This command is the replacement for 'fill-paragraph' in CC Mode
buffers.
'M-j' ('c-indent-new-comment-line')
This breaks the current line at point and indents the new line. If
point was in a comment, the new line gets the proper comment line
prefix. If point was inside a macro, a backslash is inserted
before the line break. It is the replacement for
'indent-new-comment-line'.
'M-x c-context-line-break'
Insert a line break suitable to the context: If the point is inside
a comment, the new line gets the suitable indentation and comment
line prefix like 'c-indent-new-comment-line'. In normal code it's
indented like 'newline-and-indent' would do. In macros it acts
like 'newline-and-indent' but additionally inserts and optionally
aligns the line ending backslash so that the macro remains
unbroken. *Note Custom Macros::, for details about the backslash
alignment. In a string, a backslash is inserted only if the string
is within a macro(2).
This function is not bound to a key by default, but it's intended
to be used on the 'RET' key. If you like the behavior of
'newline-and-indent' on 'RET', you should consider switching to
this function. *Note Sample .emacs File::.
'M-x c-context-open-line'
This is to 'C-o' ('M-x open-line') as 'c-context-line-break' is to
'RET'. I.e., it works just like 'c-context-line-break' but leaves
the point before the inserted line break.
---------- Footnotes ----------
(1) You can change this default by setting the 'string' syntactic
symbol (*note Syntactic Symbols:: and *note Customizing Indentation::)
(2) In GCC, unescaped line breaks within strings are valid.
File: ccmode.info, Node: Minor Modes, Next: Electric Keys, Prev: Filling and Breaking, Up: Commands
4.5 Minor Modes
===============
CC Mode contains several minor-mode-like features that you might find
useful while writing new code or editing old code:
electric mode
When this is enabled, certain visible characters cause reformatting
as they are typed. This is normally helpful, but can be a nuisance
when editing chaotically formatted code. It can also be
disconcerting, especially for users who are new to CC Mode.
auto-newline mode
This automatically inserts newlines where you'd probably want to
type them yourself, e.g., after typing '}'s. Its action is
suppressed when electric mode is disabled.
hungry-delete mode
This lets you delete a contiguous block of whitespace with a single
key: for example, the newline and indentation just inserted by
auto-newline when you want to back up and write a comment after the
last statement.
subword mode
This mode makes basic word movement commands like 'M-f'
('forward-word') and 'M-b' ('backward-word') treat the parts of
sillycapsed symbols as different words. E.g., 'NSGraphicsContext'
is treated as three words 'NS', 'Graphics', and 'Context'.
syntactic-indentation mode
When this is enabled (which it normally is), indentation commands
such as 'C-j' indent lines of code according to their syntactic
structure. Otherwise, a line is simply indented to the same level
as the previous one and '<TAB>' adjusts the indentation in steps of
'c-basic-offset'.
Full details on how these minor modes work are at *note Electric
Keys::, *note Auto-newlines::, *note Hungry WS Deletion::, *note Subword
Movement::, and *note Indentation Engine Basics::.
You can toggle each of these minor modes on and off, and you can
configure CC Mode so that it starts up with your favorite combination of
them (*note Sample .emacs File::). By default, when you initialize a
buffer, electric mode and syntactic-indentation mode are enabled but the
other two modes are disabled.
CC Mode displays the current state of the first four of these minor
modes on the modeline by appending letters to the major mode's name, one
letter for each enabled minor mode: 'l' for electric mode, 'a' for
auto-newline mode, 'h' for hungry delete mode, and 'w' for subword mode.
If all these modes were enabled, you'd see 'C/lahw'(1).
Here are the commands to toggle these modes:
'C-c C-l' ('c-toggle-electric-state')
Toggle electric minor mode. When the command turns the mode off,
it also suppresses auto-newline mode.
'C-c C-a' ('c-toggle-auto-newline')
Toggle auto-newline minor mode. When the command turns the mode
on, it also enables electric minor mode.
'M-x c-toggle-hungry-state'(2)
Toggle hungry-delete minor mode.
'M-x c-toggle-auto-hungry-state'(3)
Toggle both auto-newline and hungry delete minor modes.
'C-c C-w' ('M-x subword-mode')
Toggle subword mode.
'M-x c-toggle-syntactic-indentation'
Toggle syntactic-indentation mode.
Common to all the toggle functions above is that if they are called
programmatically, they take an optional numerical argument. A positive
value will turn on the minor mode (or both of them in the case of
'c-toggle-auto-hungry-state') and a negative value will turn it (or
them) off.
---------- Footnotes ----------
(1) The 'C' would be replaced with the name of the language in
question for the other languages CC Mode supports.
(2) Prior to CC Mode 5.31, this command was bound to 'C-c C-d'.
(3) Prior to CC Mode 5.31, this command was bound to 'C-c C-t'.
File: ccmode.info, Node: Electric Keys, Next: Auto-newlines, Prev: Minor Modes, Up: Commands
4.6 Electric Keys and Keywords
==============================
Most punctuation keys provide "electric" behavior: as well as inserting
themselves they perform some other action, such as reindenting the line.
This reindentation saves you from having to reindent a line manually
after typing, say, a '}'. A few keywords, such as 'else', also trigger
electric action.
You can inhibit the electric behavior described here by disabling
electric minor mode (*note Minor Modes::).
Common to all these keys is that they only behave electrically when
used in normal code (as contrasted with getting typed in a string
literal or comment). Those which cause re-indentation do so only when
'c-syntactic-indentation' has a non-'nil' value (which it does by
default).
These keys and keywords are:
'#'
Pound (bound to 'c-electric-pound') is electric when typed as the
first non-whitespace character on a line and not within a macro
definition. In this case, the variable 'c-electric-pound-behavior'
is consulted for the electric behavior. This variable takes a list
value, although the only element currently defined is 'alignleft',
which tells this command to force the '#' character into column
zero. This is useful for entering preprocessor macro definitions.
Pound is not electric in AWK buffers, where '#' starts a comment,
and is bound to 'self-insert-command' like any typical printable
character.
'*'
'/'
A star (bound to 'c-electric-star') or a slash ('c-electric-slash')
causes reindentation when you type it as the second component of a
C style block comment opener ('/*') or a C++ line comment opener
('//') respectively, but only if the comment opener is the first
thing on the line (i.e., there's only whitespace before it).
Additionally, you can configure CC Mode so that typing a slash at
the start of a line within a block comment will terminate the
comment. You don't need to have electric minor mode enabled to get
this behavior. *Note Clean-ups::.
In AWK mode, '*' and '/' do not delimit comments and are not
electric.
'<'
'>'
A less-than or greater-than sign (bound to 'c-electric-lt-gt') is
electric in two circumstances: when it is an angle bracket in a C++
'template' declaration (and similar constructs in other languages)
and when it is the second of two '<' or '>' characters in a C++
style stream operator. In either case, the line is reindented.
Angle brackets in C '#include' directives are not electric.
'('
')'
The normal parenthesis characters '(' and ')' (bound to
'c-electric-paren') reindent the current line. This is useful for
getting the closing parenthesis of an argument list aligned
automatically.
You can also configure CC Mode to insert a space automatically
between a function name and the '(' you've just typed, and to
remove it automatically after typing ')', should the argument list
be empty. You don't need to have electric minor mode enabled to
get these actions. *Note Clean-ups::.
'{'
'}'
Typing a brace (bound to 'c-electric-brace') reindents the current
line. Also, one or more newlines might be inserted if auto-newline
minor mode is enabled. *Note Auto-newlines::. Additionally, you
can configure CC Mode to compact excess whitespace inserted by
auto-newline mode in certain circumstances. *Note Clean-ups::.
':'
Typing a colon (bound to 'c-electric-colon') reindents the current
line. Additionally, one or more newlines might be inserted if
auto-newline minor mode is enabled. *Note Auto-newlines::. If you
type a second colon immediately after such an auto-newline, by
default the whitespace between the two colons is removed, leaving a
C++ scope operator. *Note Clean-ups::.
If you prefer, you can insert '::' in a single operation, avoiding
all these spurious reindentations, newlines, and clean-ups. *Note
Other Commands::.
';'
','
Typing a semicolon or comma (bound to 'c-electric-semi&comma')
reindents the current line. Also, a newline might be inserted if
auto-newline minor mode is enabled. *Note Auto-newlines::.
Additionally, you can configure CC Mode so that when auto-newline
has inserted whitespace after a '}', it will be removed again when
you type a semicolon or comma just after it. *Note Clean-ups::.
-- Command: c-electric-continued-statement
Certain keywords are electric, causing reindentation when they are
preceded only by whitespace on the line. The keywords are those
that continue an earlier statement instead of starting a new one:
'else', 'while', 'catch' (only in C++ and Java) and 'finally' (only
in Java).
An example:
for (i = 0; i < 17; i++)
if (a[i])
res += a[i]->offset;
else
Here, the 'else' should be indented like the preceding 'if', since
it continues that statement. CC Mode will automatically reindent
it after the 'else' has been typed in full, since only then is it
possible to decide whether it's a new statement or a continuation
of the preceding 'if'.
CC Mode uses Abbrev mode (*note (emacs)Abbrevs::) to accomplish
this. It's therefore turned on by default in all language modes
except IDL mode, since CORBA IDL doesn't have any statements.
File: ccmode.info, Node: Auto-newlines, Next: Hungry WS Deletion, Prev: Electric Keys, Up: Commands
4.7 Auto-newline Insertion
==========================
When you have "Auto-newline minor mode" enabled (*note Minor Modes::),
CC Mode inserts newlines for you automatically (in certain syntactic
contexts) when you type a left or right brace, a colon, a semicolon, or
a comma. Sometimes a newline appears before the character you type,
sometimes after it, sometimes both.
Auto-newline only triggers when the following conditions hold:
* Auto-newline minor mode is enabled, as evidenced by the indicator
'a' after the mode name on the modeline (e.g., 'C/a' or 'C/la').
* The character was typed at the end of a line, or with only
whitespace after it, and possibly a '\' escaping the newline.
* The character is not on its own line already. (This applies only
to insertion of a newline _before_ the character.)
* The character was not typed inside of a literal (1).
* No numeric argument was supplied to the command (i.e., it was typed
as normal, with no 'C-u' prefix).
You can configure the precise circumstances in which newlines get
inserted (see *note Custom Auto-newlines::). Typically, the style
system (*note Styles::) will have set this up for you, so you probably
won't have to bother.
Sometimes CC Mode inserts an auto-newline where you don't want one,
such as after a '}' when you're about to type a ';'. Hungry deletion
can help here (*note Hungry WS Deletion::), or you can activate an
appropriate "clean-up", which will remove the excess whitespace after
you've typed the ';'. See *note Clean-ups:: for a full description.
See also *note Electric Keys:: for a summary of clean-ups listed by key.
---------- Footnotes ----------
(1) A "literal" is defined as any comment, string, or preprocessor
macro definition. These constructs are also known as "syntactic
whitespace" since they are usually ignored when scanning C code.
File: ccmode.info, Node: Hungry WS Deletion, Next: Subword Movement, Prev: Auto-newlines, Up: Commands
4.8 Hungry Deletion of Whitespace
=================================
If you want to delete an entire block of whitespace at point, you can
use "hungry deletion". This deletes all the contiguous whitespace
either before point or after point in a single operation. "Whitespace"
here includes tabs and newlines, but not comments or preprocessor
commands. Hungry deletion can markedly cut down on the number of times
you have to hit deletion keys when, for example, you've made a mistake
on the preceding line and have already pressed 'C-j'.
Hungry deletion is a simple feature that some people find extremely
useful. In fact, you might find yourself wanting it in *all* your
editing modes!
Loosely speaking, in what follows, "<DEL>" means "the backspace key"
and "<DELETE>" means "the forward delete key". This is discussed in
more detail below.
There are two different ways you can use hungry deletion:
Using "Hungry Delete Mode" with '<DEL>' and 'C-d'
Here you toggle Hungry Delete minor mode with 'M-x
c-toggle-hungry-state'(1) (*note Minor Modes::.) This makes
'<DEL>' and 'C-d' do backwards and forward hungry deletion.
'<DEL>' ('c-electric-backspace')
This command is run by default when you hit the 'DEL' key.
When hungry delete mode is enabled, it deletes any amount of
whitespace in the backwards direction. Otherwise, or when
used with a prefix argument or in a literal (*note
Auto-newlines::), the command just deletes backwards in the
usual way. (More precisely, it calls the function contained
in the variable 'c-backspace-function', passing it the prefix
argument, if any.)
'c-backspace-function'
Hook that gets called by 'c-electric-backspace' when it
doesn't do an "electric" deletion of the preceding whitespace.
The default value is 'backward-delete-char-untabify' (*note
(elisp)Deletion::, the function which deletes a single
character.
'C-d' ('c-electric-delete-forward')
This function, which is bound to 'C-d' by default, works just
like 'c-electric-backspace' but in the forward direction.
When it doesn't do an "electric" deletion of the following
whitespace, it just does 'delete-char', more or less.
(Strictly speaking, it calls the function in
'c-delete-function' with the prefix argument.)
'c-delete-function'
Hook that gets called by 'c-electric-delete-forward' when it
doesn't do an "electric" deletion of the following whitespace.
The default value is 'delete-char'.
Using Distinct Bindings
The other (newer and recommended) way to use hungry deletion is to
perform 'c-hungry-delete-backwards' and 'c-hungry-delete-forward'
directly through their key sequences rather than using the minor
mode toggling.
'C-c C-<DEL>', or 'C-c <DEL>' ('c-hungry-delete-backwards')(2)
Delete any amount of whitespace in the backwards direction
(regardless whether hungry-delete mode is enabled or not).
This command is bound to both 'C-c C-<DEL>' and 'C-c <DEL>',
since the more natural one, 'C-c C-<DEL>', is sometimes
difficult to type at a character terminal.
'C-c C-d', 'C-c C-<DELETE>', or 'C-c <DELETE>' ('c-hungry-delete-forward')
Delete any amount of whitespace in the forward direction
(regardless whether hungry-delete mode is enabled or not).
This command is bound to both 'C-c C-<DELETE>' and 'C-c
<DELETE>' for the same reason as for <DEL> above.
When we talk about '<DEL>', and '<DELETE>' above, we actually do so
without connecting them to the physical keys commonly known as
<Backspace> and <Delete>. The default bindings to those two keys
depends on the flavor of (X)Emacs you are using.
In XEmacs 20.3 and beyond, the <Backspace> key is bound to
'c-electric-backspace' and the <Delete> key is bound to
'c-electric-delete'. You control the direction it deletes in by setting
the variable 'delete-key-deletes-forward', a standard XEmacs variable.
When this variable is non-'nil', 'c-electric-delete' will do forward
deletion with 'c-electric-delete-forward', otherwise it does backward
deletion with 'c-electric-backspace'. Similarly, 'C-c <Delete>' and
'C-c C-<Delete>' are bound to 'c-hungry-delete' which is controlled in
the same way by 'delete-key-deletes-forward'.
Emacs 21 and later automatically binds <Backspace> and <Delete> to
'DEL' and 'C-d' according to your environment, and CC Mode extends those
bindings to 'C-c C-<Backspace>' etc. If you need to change the bindings
through 'normal-erase-is-backspace-mode' then CC Mode will also adapt
its extended bindings accordingly.
In earlier (X)Emacs versions, CC Mode doesn't bind either <Backspace>
or <Delete> directly. Only the key codes 'DEL' and 'C-d' are bound, and
it's up to the default bindings to map the physical keys to them. You
might need to modify this yourself if the defaults are unsuitable.
Getting your <Backspace> and <Delete> keys properly set up can
sometimes be tricky. The information in *note (emacs)DEL Does Not
Delete::, might be helpful if you're having trouble with this in GNU
Emacs.
---------- Footnotes ----------
(1) Prior to CC Mode 5.31, this command was bound to 'C-c C-d'. 'C-c
C-d' is now the default binding for 'c-hungry-delete-forward'.
(2) This command was formerly known as 'c-hungry-backspace'.
File: ccmode.info, Node: Subword Movement, Next: Other Commands, Prev: Hungry WS Deletion, Up: Commands
4.9 Subword Movement and Editing
================================
In spite of the GNU Coding Standards, it is popular to name a symbol by
mixing uppercase and lowercase letters, e.g., 'GtkWidget',
'EmacsFrameClass', or 'NSGraphicsContext'. Here we call these mixed
case symbols "nomenclatures". Also, each capitalized (or completely
uppercase) part of a nomenclature is called a "subword". Here are some
examples:
Nomenclature Subwords
--------------------------------------
'GtkWindow' 'Gtk' and 'Window'
'EmacsFrameClass' 'Emacs', 'Frame', and 'Class'
'NSGraphicsContext' 'NS', 'Graphics', and 'Context'
The subword minor mode replaces the basic word oriented movement and
editing commands with variants that recognize subwords in a nomenclature
and treat them as separate words:
Key Word oriented command Subword oriented command
---------------------------------------------------
'M-f' 'forward-word' 'c-forward-subword'
'M-b' 'backward-word' 'c-backward-subword'
'M-@' 'mark-word' 'c-mark-subword'
'M-d' 'kill-word' 'c-kill-subword'
'M-DEL' 'backward-kill-word' 'c-backward-kill-subword'
'M-t' 'transpose-words' 'c-transpose-subwords'
'M-c' 'capitalize-word' 'c-capitalize-subword'
'M-u' 'upcase-word' 'c-upcase-subword'
'M-l' 'downcase-word' 'c-downcase-subword'
Note that if you have changed the key bindings for the word oriented
commands in your '.emacs' or a similar place, the keys you have
configured are also used for the corresponding subword oriented
commands.
Type 'C-c C-w' to toggle subword mode on and off. To make the mode
turn on automatically, put the following code in your '.emacs':
(add-hook 'c-mode-common-hook
(lambda () (subword-mode 1)))
As a bonus, you can also use 'subword-mode' in non-CC Mode buffers by
typing 'M-x subword-mode'.
File: ccmode.info, Node: Other Commands, Prev: Subword Movement, Up: Commands
4.10 Other Commands
===================
Here are the various other commands that didn't fit anywhere else:
'C-c .' ('c-set-style')
Switch to the specified style in the current buffer. Use like
this:
C-c . STYLE-NAME <RET>
You can use the <TAB> in the normal way to do completion on the
style name. Note that all style names are case insensitive, even
the ones you define yourself.
Setting a style in this way does _not_ automatically reindent your
file. For commands that you can use to view the effect of your
changes, see *note Indentation Commands:: and *note Filling and
Breaking::.
For details of the CC Mode style system, see *note Styles::.
'C-c :' ('c-scope-operator')
In C++, it is also sometimes desirable to insert the double-colon
scope operator without performing the electric behavior of colon
insertion. 'C-c :' does just this.
'C-c C-\' ('c-backslash-region')
This function inserts and aligns or deletes end-of-line backslashes
in the current region. These are typically used in multi-line
macros.
With no prefix argument, it inserts any missing backslashes and
aligns them according to the 'c-backslash-column' and
'c-backslash-max-column' variables. With a prefix argument, it
deletes any backslashes.
The function does not modify blank lines at the start of the
region. If the region ends at the start of a line, it always
deletes the backslash (if any) at the end of the previous line.
To customize the precise workings of this command, *note Custom
Macros::.
The recommended line breaking function, 'c-context-line-break' (*note
Filling and Breaking::), is especially nice if you edit multiline macros
frequently. When used inside a macro, it automatically inserts and
adjusts the mandatory backslash at the end of the line to keep the macro
together, and it leaves the point at the right indentation column for
the code. Thus you can write code inside macros almost exactly as you
can elsewhere, without having to bother with the trailing backslashes.
'C-c C-e' ('c-macro-expand')
This command expands C, C++, Objective C or Pike macros in the
region, using an appropriate external preprocessor program.
Normally it displays its output in a temporary buffer, but if you
give it a prefix arg (with 'C-u C-c C-e') it will overwrite the
original region with the expansion.
The command does not work in any of the other modes, and the key
sequence is not bound in these other modes.
'c-macro-expand' isn't actually part of CC Mode, even though it is
bound to a CC Mode key sequence. If you need help setting it up or
have other problems with it, you can either read its source code or
ask for help in the standard (X)Emacs forums.
File: ccmode.info, Node: Font Locking, Next: Config Basics, Prev: Commands, Up: Top
5 Font Locking
**************
CC Mode provides font locking for its supported languages by supplying
patterns for use with Font Lock mode. This means that you get distinct
faces on the various syntactic parts such as comments, strings, keywords
and types, which is very helpful in telling them apart at a glance and
discovering syntactic errors. *Note (emacs)Font Lock::, for ways to
enable font locking in CC Mode buffers.
*Please note:* The font locking in AWK mode is currently not
integrated with the rest of CC Mode. Only the last section of this
chapter, *note AWK Mode Font Locking::, applies to AWK. The other
sections apply to the other languages.
* Menu:
* Font Locking Preliminaries::
* Faces::
* Doc Comments::
* AWK Mode Font Locking::
File: ccmode.info, Node: Font Locking Preliminaries, Next: Faces, Prev: Font Locking, Up: Font Locking
5.1 Font Locking Preliminaries
==============================
The font locking for most of the CC Mode languages were provided
directly by the Font Lock package prior to version 5.30 of CC Mode. In
the transition to CC Mode the patterns have been reworked completely and
are applied uniformly across all the languages except AWK mode, just
like the indentation rules (although each language still has some
peculiarities of its own, of course). Since the languages previously
had completely separate font locking patterns, this means that it's a
bit different in most languages now.
The main goal for the font locking in CC Mode is accuracy, to provide
a dependable aid in recognizing the various constructs. Some, like
strings and comments, are easy to recognize while others, like
declarations and types, can be very tricky. CC Mode can go to great
lengths to recognize declarations and casts correctly, especially when
the types aren't recognized by standard patterns. This is a fairly
demanding analysis which can be slow on older hardware, and it can
therefore be disabled by choosing a lower decoration level with the
variable 'font-lock-maximum-decoration' (*note (emacs)Font Lock::).
The decoration levels are used as follows:
1. Minimal font locking: Fontify only comments, strings and
preprocessor directives (in the languages that use cpp).
2. Fast font locking: In addition to level 1, fontify keywords, simple
types and declarations that are easy to recognize. The variables
'*-font-lock-extra-types' (where '*' is the name of the language)
are used to recognize types (see below). Documentation comments
like Javadoc are fontified according to 'c-doc-comment-style'
(*note Doc Comments::).
Use this if you think the font locking is too slow. It's the
closest corresponding level to level 3 in the old font lock
patterns.
3. Accurate font locking: Like level 2 but uses a different approach
that can recognize types and declarations much more accurately.
The '*-font-lock-extra-types' variables are still used, but user
defined types are recognized correctly anyway in most cases.
Therefore those variables should be fairly restrictive and not
contain patterns that are uncertain.
This level is designed for fairly modern hardware and a font lock
support mode like Lazy Lock or Just-in-time Lock mode that only
fontifies the parts that are actually shown. Fontifying the whole
buffer at once can easily get bothersomely slow even on
contemporary hardware. *Note (emacs)Font Lock::.
Since user defined types are hard to recognize you can provide
additional regexps to match those you use:
-- User Option: c-font-lock-extra-types
-- User Option: c++-font-lock-extra-types
-- User Option: objc-font-lock-extra-types
-- User Option: java-font-lock-extra-types
-- User Option: idl-font-lock-extra-types
-- User Option: pike-font-lock-extra-types
For each language there's a variable '*-font-lock-extra-types',
where '*' stands for the language in question. It contains a list
of regexps that matches identifiers that should be recognized as
types, e.g., '\\sw+_t' to recognize all identifiers ending with
'_t' as is customary in C code. Each regexp should not match more
than a single identifier.
The default values contain regexps for many types in standard
runtime libraries that are otherwise difficult to recognize, and
patterns for standard type naming conventions like the '_t' suffix
in C and C++. Java, Objective-C and Pike have as a convention to
start class names with capitals, so there are patterns for that in
those languages.
Despite the names of these variables, they are not only used for
fontification but in other places as well where CC Mode needs to
recognize types.
File: ccmode.info, Node: Faces, Next: Doc Comments, Prev: Font Locking Preliminaries, Up: Font Locking
5.2 Faces
=========
CC Mode attempts to use the standard faces for programming languages in
accordance with their intended purposes as far as possible. No extra
faces are currently provided, with the exception of a replacement face
'c-invalid-face' for emacsen that don't provide
'font-lock-warning-face'.
* Normal comments are fontified in 'font-lock-comment-face'.
* Comments that are recognized as documentation (*note Doc
Comments::) get 'font-lock-doc-face' (Emacs) or
'font-lock-doc-string-face' (XEmacs) if those faces exist. If they
don't then 'font-lock-comment-face' is used.
* String and character literals are fontified in
'font-lock-string-face'.
* Keywords are fontified with 'font-lock-keyword-face'.
* 'font-lock-function-name-face' is used for function names in
declarations and definitions, and classes in those contexts. It's
also used for preprocessor defines with arguments.
* Variables in declarations and definitions, and other identifiers in
such variable contexts, get 'font-lock-variable-name-face'. It's
also used for preprocessor defines without arguments.
* Builtin constants are fontified in 'font-lock-constant-face' if it
exists, 'font-lock-reference-face' otherwise. As opposed to the
preceding two faces, this is used on the names in expressions, and
it's not used in declarations, even if there happen to be a 'const'
in them somewhere.
* 'font-lock-type-face' is put on types (both predefined and user
defined) and classes in type contexts.
* Label identifiers get 'font-lock-constant-face' if it exists,
'font-lock-reference-face' otherwise.
* Name qualifiers and identifiers for scope constructs are fontified
like labels.
* Special markup inside documentation comments are also fontified
like labels.
* Preprocessor directives get 'font-lock-preprocessor-face' if it
exists (i.e., XEmacs). In Emacs they get 'font-lock-builtin-face'
or 'font-lock-reference-face', for lack of a closer equivalent.
* Some kinds of syntactic errors are fontified with
'font-lock-warning-face' in Emacs. In older XEmacs versions
there's no corresponding standard face, so there a special
'c-invalid-face' is used, which is defined to stand out sharply by
default.
Note that it's not used for '#error' or '#warning' directives,
since those aren't syntactic errors in themselves.
File: ccmode.info, Node: Doc Comments, Next: AWK Mode Font Locking, Prev: Faces, Up: Font Locking
5.3 Documentation Comments
==========================
There are various tools to supply documentation in the source as
specially structured comments, e.g., the standard Javadoc tool in Java.
CC Mode provides an extensible mechanism to fontify such comments and
the special markup inside them.
-- User Option: c-doc-comment-style
This is a style variable that specifies which documentation comment
style to recognize, e.g., 'javadoc' for Javadoc comments.
The value may also be a list of styles, in which case all of them
are recognized simultaneously (presumably with markup cues that
don't conflict).
The value may also be an association list to specify different
comment styles for different languages. The symbol for the major
mode is then looked up in the alist, and the value of that element
is interpreted as above if found. If it isn't found then the
symbol 'other' is looked up and its value is used instead.
The default value for 'c-doc-comment-style' is
'((java-mode . javadoc) (pike-mode . autodoc) (c-mode . gtkdoc))'.
Note that CC Mode uses this variable to set other variables that
handle fontification etc. That's done at mode initialization or
when you switch to a style which sets this variable. Thus, if you
change it in some other way, e.g., interactively in a CC Mode
buffer, you will need to do 'M-x java-mode' (or whatever mode
you're currently using) to reinitialize.
Note also that when CC Mode starts up, the other variables are
modified before the mode hooks are run. If you change this
variable in a mode hook, you'll have to call
'c-setup-doc-comment-style' afterwards to redo that work.
CC Mode currently provides handing of the following doc comment
styles:
'javadoc'
Javadoc comments, the standard tool in Java.
'autodoc'
For Pike autodoc markup, the standard in Pike.
'gtkdoc'
For GtkDoc markup, widely used in the Gnome community.
The above is by no means complete. If you'd like to see support for
other doc comment styles, please let us know (*note Mailing Lists and
Bug Reports::).
You can also write your own doc comment fontification support to use
with 'c-doc-comment-style': Supply a variable or function
'*-font-lock-keywords' where '*' is the name you want to use in
'c-doc-comment-style'. If it's a variable, it's prepended to
'font-lock-keywords'. If it's a function, it's called at mode
initialization and the result is prepended. For an example, see
'javadoc-font-lock-keywords' in 'cc-fonts.el'.
If you add support for another doc comment style, please consider
contributing it: send a note to <bug-cc-mode AT gnu.org>.
File: ccmode.info, Node: AWK Mode Font Locking, Prev: Doc Comments, Up: Font Locking
5.4 AWK Mode Font Locking
=========================
The general appearance of font-locking in AWK mode is much like in any
other programming mode. *Note (elisp)Faces For Font Lock::.
The following faces are, however, used in a non-standard fashion in
AWK mode:
'font-lock-variable-name-face'
This face was intended for variable declarations. Since variables
are not declared in AWK, this face is used instead for AWK system
variables (such as 'NF') and "Special File Names" (such as
'"/dev/stderr"').
'font-lock-builtin-face' (Emacs)/'font-lock-preprocessor-face' (XEmacs)
This face is normally used for preprocessor directives in CC Mode.
There are no such things in AWK, so this face is used instead for
standard functions (such as 'match').
'font-lock-string-face'
As well as being used for strings, including localizable strings,
(delimited by '"' and '_"'), this face is also used for AWK regular
expressions (delimited by '/').
'font-lock-warning-face' (Emacs)/'c-invalid-face' (XEmacs)
This face highlights the following syntactically invalid AWK
constructs:
* An unterminated string or regular expression. Here the
opening delimiter ('"' or '/' or '_"') is displayed in
'font-lock-warning-face'. This is most noticeable when typing
in a new string/regular expression into a buffer, when the
warning-face serves as a continual reminder to terminate the
construct.
AWK mode fontifies unterminated strings/regular expressions
differently from other modes: Only the text up to the end of
the line is fontified as a string (escaped newlines being
handled correctly), rather than the text up to the next string
quote.
* A space between the function name and opening parenthesis when
calling a user function. The last character of the function
name and the opening parenthesis are highlighted. This
font-locking rule will spuriously highlight a valid
concatenation expression where an identifier precedes a
parenthesized expression. Unfortunately.
* Whitespace following the '\' in what otherwise looks like an
escaped newline. The '\' is highlighted.
File: ccmode.info, Node: Config Basics, Next: Custom Filling and Breaking, Prev: Font Locking, Up: Top
6 Configuration Basics
**********************
You configure CC Mode by setting Lisp variables and calling (and perhaps
writing) Lisp functions(1), which is usually done by adding code to an
Emacs initialization file. This file might be 'site-start.el' or
'.emacs' or 'init.el' or 'default.el' or perhaps some other file. *Note
(emacs)Init File::. For the sake of conciseness, we just call this file
"your '.emacs'" throughout the rest of the manual.
Several of these variables (currently 16), are known collectively as
"style variables". CC Mode provides a special mechanism, known as
"styles" to make it easier to set these variables as a group, to
"inherit" settings from one style into another, and so on. Style
variables remain ordinary Lisp variables, whose values can be read and
changed independently of the style system. *Note Style Variables::.
There are several ways you can write the code, depending on the
precise effect you want--they are described further down on this page.
If you are new to CC Mode, we suggest you begin with the simplest
method, "Top-level commands or the customization interface".
If you make conflicting settings in several of these ways, the way
that takes precedence is the one that appears latest in this list:
Style
File Style(2)
Top-level command or "customization interface"
Hook
File Local Variable setting
Here is a summary of the different ways of writing your configuration
settings:
Top-level commands or the "customization interface"
Most simply, you can write 'setq' and similar commands at the top
level of your '.emacs' file. When you load a CC Mode buffer, it
initializes its configuration from these global values (at least,
for those settings you have given values to), so it makes sense to
have these 'setq' commands run _before_ CC Mode is first
initialized--in particular, before any call to 'desktop-read'
(*note (emacs)Saving Emacs Sessions::). For example, you might set
c-basic-offset thus:
(setq c-basic-offset 4)
You can use the more user friendly Customization interface instead,
but this manual does not cover in detail how that works. To do
this, start by typing 'M-x customize-group <RET> c <RET>'. *Note
(emacs)Easy Customization::. Emacs normally writes the
customizations at the end of your '.emacs' file. If you use
'desktop-read', you should edit your '.emacs' to place the call to
'desktop-read' _after_ the customizations.
The first initialization of CC Mode puts a snapshot of the
configuration settings into the special style 'user'. *Note
Built-in Styles::.
For basic use of Emacs, either of these ways of configuring is
adequate. However, the settings are then the same in all CC Mode
buffers and it can be clumsy to communicate them between
programmers. For more flexibility, you'll want to use one (or
both) of CC Mode's more sophisticated facilities, hooks and styles.
Hooks
An Emacs "hook" is a place to put Lisp functions that you want
Emacs to execute later in specific circumstances. *Note
(elisp)Hooks::. CC Mode supplies a main hook and a
language-specific hook for each language it supports; any functions
you put onto these hooks get executed as the last part of a
buffer's initialization. Typically you put most of your
customization within the main hook, and use the language-specific
hooks to vary the customization settings between language modes.
For example, if you wanted different (non-standard) values of
'c-basic-offset' in C Mode and Java Mode buffers, you could do it
like this:
(defun my-c-mode-hook ()
(setq c-basic-offset 3))
(add-hook 'c-mode-hook 'my-c-mode-hook)
(defun my-java-mode-hook ()
(setq c-basic-offset 6))
(add-hook 'java-mode-hook 'my-java-mode-hook)
See *note CC Hooks:: for more details on the use of CC Mode hooks.
Styles
A CC Mode "style" is a coherent collection of customizations with a
name. At any time, exactly one style is active in each CC Mode
buffer, either the one you have selected or a default. CC Mode is
delivered with several existing styles. Additionally, you can
create your own styles, possibly based on these existing styles.
If you worked in a programming team called the "Free Group", which
had its own coding standards, you might well have this in your
'.emacs' file:
(setq c-default-style '((java-mode . "java")
(awk-mode . "awk")
(other . "free-group-style")))
See *note Styles:: for fuller details on using CC Mode styles and
how to create them.
File Local Variable setting
A "file local variable setting" is a setting which applies to an
individual source file. You put this in a "local variables list",
a special block at the end of the source file (*note
(emacs)Specifying File Variables::).
File Styles
A "file style" is a rarely used variant of the "style" mechanism
described above, which applies to an individual source file. *Note
File Styles::. You use this by setting certain special variables
in a local variables list (*note (emacs)Specifying File
Variables::).
Hooks with Styles
For ultimate flexibility, you can use hooks and styles together.
For example, if your team were developing a product which required
a Linux driver, you'd probably want to use the "linux" style for
the driver, and your own team's style for the rest of the code.
You could achieve this with code like this in your '.emacs':
(defun my-c-mode-hook ()
(c-set-style
(if (and (buffer-file-name)
(string-match "/usr/src/linux" (buffer-file-name)))
"linux"
"free-group-style")))
(add-hook 'c-mode-hook 'my-c-mode-hook)
In a programming team, a hook is a also a good place for each
member to put his own personal preferences. For example, you might
be the only person in your team who likes Auto-newline minor mode.
You could have it enabled by default by placing the following in
your '.emacs':
(defun my-turn-on-auto-newline ()
(c-toggle-auto-newline 1))
(add-hook 'c-mode-common-hook 'my-turn-on-auto-newline)
* Menu:
* CC Hooks::
* Style Variables::
* Styles::
---------- Footnotes ----------
(1) DON'T PANIC!!! This isn't difficult.
(2) In earlier versions of CC Mode, a File Style setting took
precedence over any other setting apart from a File Local Variable
setting.
File: ccmode.info, Node: CC Hooks, Next: Style Variables, Prev: Config Basics, Up: Config Basics
6.1 Hooks
=========
CC Mode provides several hooks that you can use to customize the mode
for your coding style. The main hook is 'c-mode-common-hook';
typically, you'll put the bulk of your customizations here. In
addition, each language mode has its own hook, allowing you to fine tune
your settings individually for the different CC Mode languages, and
there is a package initialization hook. Finally, there is
'c-special-indent-hook', which enables you to solve anomalous
indentation problems. It is described in *note Other Indentation::, not
here. All these hooks adhere to the standard Emacs conventions.
When you open a buffer, CC Mode first initializes it with the
currently active style (*note Styles::). Then it calls
'c-mode-common-hook', and finally it calls the language-specific hook.
Thus, any style settings done in these hooks will override those set by
'c-default-style'.
-- Variable: c-initialization-hook
Hook run only once per Emacs session, when CC Mode is initialized.
This is a good place to change key bindings (or add new ones) in
any of the CC Mode key maps. *Note Sample .emacs File::.
-- Variable: c-mode-common-hook
Common hook across all languages. It's run immediately before the
language specific hook.
-- Variable: c-mode-hook
-- Variable: c++-mode-hook
-- Variable: objc-mode-hook
-- Variable: java-mode-hook
-- Variable: idl-mode-hook
-- Variable: pike-mode-hook
-- Variable: awk-mode-hook
The language specific mode hooks. The appropriate one is run as
the last thing when you enter that language mode.
Although these hooks are variables defined in CC Mode, you can give
them values before CC Mode's code is loaded--indeed, this is the only
way to use 'c-initialization-hook'. Their values aren't overwritten
when CC Mode gets loaded.
Here's a simplified example of what you can add to your '.emacs' file
to do things whenever any CC Mode language is edited. See the Emacs
manuals for more information on customizing Emacs via hooks. *Note
Sample .emacs File::, for a more complete sample '.emacs' file.
(defun my-c-mode-common-hook ()
;; my customizations for all of c-mode and related modes
(no-case-fold-search)
)
(add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
File: ccmode.info, Node: Style Variables, Next: Styles, Prev: CC Hooks, Up: Config Basics
6.2 Style Variables
===================
The variables that CC Mode's style system control are called "style
variables". Note that style variables are ordinary Lisp variables,
which the style system initializes; you can change their values at any
time (e.g., in a hook function). The style system can also set other
variables, to some extent. *Note Styles::.
"Style variables" are handled specially in several ways:
* Style variables are by default buffer-local variables. However,
they can instead be made global by setting
'c-style-variables-are-local-p' to 'nil' before CC Mode is
initialized.
* The default global binding of any style variable (with two
exceptions - see below) is the special symbol 'set-from-style'.
When the style system initializes a buffer-local copy of a style
variable for a CC Mode buffer, if its global binding is still that
symbol then it will be set from the current style. Otherwise it
will retain its global default(1). This "otherwise" happens, for
example, when you've set the variable with 'setq' at the top level
of your '.emacs' (*note Config Basics::).
* The style variable 'c-offsets-alist' (*note c-offsets-alist::) is
an association list with an element for each syntactic symbol.
It's handled a little differently from the other style variables.
It's default global binding is the empty list 'nil', rather than
'set-from-style'. Before the style system is initialized, you can
add individual elements to 'c-offsets-alist' by calling
'c-set-offset'(*note c-offsets-alist::) just like you would set
other style variables with 'setq'. Those elements will then
prevail when the style system later initializes a buffer-local copy
of 'c-offsets-alist'.
* The style variable 'c-special-indent-hook' is also handled in a
special way. Styles can only add functions to this hook, not
remove them, so any global settings you put on it are always
preserved(2). The value you give this variable in a style
definition can be either a function or a list of functions.
* The global bindings of the style variables get captured in the
special 'user' style when the style system is first initialized.
*Note Built-in Styles::, for details.
The style variables are:
'c-indent-comment-alist', 'c-indent-comments-syntactically-p' (*note
Indentation Commands::);
'c-doc-comment-style' (*note Doc Comments::);
'c-block-comment-prefix', 'c-comment-prefix-regexp' (*note Custom
Filling and Breaking::);
'c-hanging-braces-alist' (*note Hanging Braces::);
'c-hanging-colons-alist' (*note Hanging Colons::);
'c-hanging-semi&comma-criteria' (*note Hanging Semicolons and Commas::);
'c-cleanup-list' (*note Clean-ups::);
'c-basic-offset' (*note Customizing Indentation::);
'c-offsets-alist' (*note c-offsets-alist::);
'c-comment-only-line-offset' (*note Comment Line-Up::);
'c-special-indent-hook', 'c-label-minimum-indentation' (*note Other
Indentation::);
'c-backslash-column', 'c-backslash-max-column' (*note Custom Macros::).
---------- Footnotes ----------
(1) This is a big change from versions of CC Mode earlier than 5.26,
where such settings would get overridden by the style system unless
special precautions were taken. That was changed since it was
counterintuitive and confusing, especially to novice users. If your
configuration depends on the old overriding behavior, you can set the
variable 'c-old-style-variable-behavior' to non-'nil'.
(2) This did not change in version 5.26.
File: ccmode.info, Node: Styles, Prev: Style Variables, Up: Config Basics
6.3 Styles
==========
By "style" we mean the layout of the code--things like how many columns
to indent a block of code, whether an opening brace gets indented to the
level of the code it encloses, or of the construct that introduces it,
or "hangs" at the end of a line.
Most people only need to edit code formatted in just a few
well-defined and consistent styles. For example, their organization
might impose a "blessed" style that all its programmers must conform to.
Similarly, people who work on GNU software will have to use the GNU
coding style. Some shops are more lenient, allowing a variety of coding
styles, and as programmers come and go, there could be a number of
styles in use. For this reason, CC Mode makes it convenient for you to
set up logical groupings of customizations called "styles", associate a
single name for any particular style, and pretty easily start editing
new or existing code using these styles.
As an alternative to writing a style definition yourself, you can
have CC Mode "guess" (at least part of) your style by looking at an
already formatted piece of your code, *note Guessing the Style::.
* Menu:
* Built-in Styles::
* Choosing a Style::
* Adding Styles::
* Guessing the Style::
* File Styles::
File: ccmode.info, Node: Built-in Styles, Next: Choosing a Style, Prev: Styles, Up: Styles
6.3.1 Built-in Styles
---------------------
If you're lucky, one of CC Mode's built-in styles might be just what
you're looking for. These are:
'gnu'
Coding style blessed by the Free Software Foundation for C code in
GNU programs.
'k&r'
The classic Kernighan and Ritchie style for C code.
'bsd'
Also known as "Allman style" after Eric Allman.
'whitesmith'
Popularized by the examples that came with Whitesmiths C, an early
commercial C compiler.
'stroustrup'
The classic Stroustrup style for C++ code.
'ellemtel'
Popular C++ coding standards as defined by "Programming in C++,
Rules and Recommendations," Erik Nyquist and Mats Henricson,
Ellemtel(1).
'linux'
C coding standard for Linux (the kernel).
'python'
C coding standard for Python extension modules(2).
'java'
The style for editing Java code. Note that the default value for
'c-default-style' installs this style when you enter 'java-mode'.
'awk'
The style for editing AWK code. Note that the default value for
'c-default-style' installs this style when you enter 'awk-mode'.
'user'
This is a special style created by you. It consists of the factory
defaults for all the style variables as modified by the
customizations you do either with the Customization interface or by
writing 'setq's and 'c-set-offset's at the top level of your
'.emacs' file (*note Config Basics::). The style system creates
this style as part of its initialization and doesn't modify it
afterwards.
---------- Footnotes ----------
(1) This document is available at
<http://www.doc.ic.ac.uk/lab/cplus/c++.rules/> among other places.
(2) Python is a high level scripting language with a C/C++ foreign
function interface. For more information, see <http://www.python.org/>.
File: ccmode.info, Node: Choosing a Style, Next: Adding Styles, Prev: Built-in Styles, Up: Styles
6.3.2 Choosing a Style
----------------------
When you create a new buffer, its style will be set from
'c-default-style'. The factory default is the style 'gnu', except in
Java and AWK modes where it's 'java' and 'awk'.
Remember that if you set a style variable with the Customization
interface or at the top level of your '.emacs' file before the style
system is initialized (*note Config Basics::), this setting will
override the one that the style system would have given the variable.
To set a buffer's style interactively, use the command 'C-c .' (*note
Other Commands::). To set it from a file's local variable list, *note
File Styles::.
-- User Option: c-default-style
This variable specifies which style to install by default in new
buffers. It takes either a style name string, or an association
list of major mode symbols to style names:
1. When 'c-default-style' is a string, it must be an existing
style name. This style is then used for all modes.
2. When 'c-default-style' is an association list, the mode
language is looked up to find a style name string.
3. If 'c-default-style' is an association list where the mode
language mode isn't found then the special symbol 'other' is
looked up. If it's found then the associated style is used.
4. If 'other' is not found then the 'gnu' style is used.
In all cases, the style described in 'c-default-style' is installed
_before_ the language hooks are run, so you can always override
this setting by including an explicit call to 'c-set-style' in your
language mode hook, or in 'c-mode-common-hook'.
The standard value of 'c-default-style' is
'((java-mode . "java") (awk-mode . "awk") (other . "gnu"))'.
-- Variable: c-indentation-style
This variable always contains the buffer's current style name, as a
string.
File: ccmode.info, Node: Adding Styles, Next: Guessing the Style, Prev: Choosing a Style, Up: Styles
6.3.3 Adding and Amending Styles
--------------------------------
If none of the built-in styles is appropriate, you'll probably want to
create a new "style definition", possibly based on an existing style.
To do this, put the new style's settings into a list with the following
format; the list can then be passed as an argument to the function
'c-add-style'. You can see an example of a style definition in *note
Sample .emacs File::.
Structure of a Style Definition List
([BASE-STYLE] [(VARIABLE . VALUE) ...])
Optional BASE-STYLE, if present, must be a string which is the name
of the "base style" from which this style inherits. At most one
BASE-STYLE is allowed in a style definition. If BASE-STYLE is not
specified, the style inherits from the table of factory default
values(1) instead. All styles eventually inherit from this
internal table. Style loops generate errors. The list of
pre-existing styles can be seen in *note Built-in Styles::.
The dotted pairs (VARIABLE . VALUE) each consist of a variable and
the value it is to be set to when the style is later activated.(2)
The variable can be either a CC Mode style variable or an arbitrary
Emacs variable. In the latter case, it is _not_ made buffer-local
by the CC Mode style system.
Two variables are treated specially in the dotted pair list:
'c-offsets-alist'
The value is in turn a list of dotted pairs of the form
(SYNTACTIC-SYMBOL . OFFSET)
as described in *note c-offsets-alist::. These are passed to
'c-set-offset' so there is no need to set every syntactic
symbol in your style, only those that are different from the
inherited style.
'c-special-indent-hook'
The value is added to 'c-special-indent-hook' using
'add-hook', so any functions already on it are kept. If the
value is a list, each element of the list is added with
'add-hook'.
Styles are kept in the 'c-style-alist' variable, but you should never
modify this variable directly. Instead, CC Mode provides the function
'c-add-style' for this purpose.
-- Function: c-add-style stylename description &optional set-p
Add or update a style called STYLENAME, a string. DESCRIPTION is
the new style definition in the form described above. If STYLENAME
already exists in 'c-style-alist' then it is replaced by
DESCRIPTION. (Note, this replacement is total. The old style is
_not_ merged into the new one.) Otherwise, a new style is added.
If the optional SET-P is non-'nil' then the new style is applied to
the current buffer as well. The use of this facility is deprecated
and it might be removed from CC Mode in a future release. You
should use 'c-set-style' instead.
The sample '.emacs' file provides a concrete example of how a new
style can be added and automatically set. *Note Sample .emacs
File::.
-- Variable: c-style-alist
This is the variable that holds the definitions for the styles. It
should not be changed directly; use 'c-add-style' instead.
---------- Footnotes ----------
(1) This table is stored internally in the variable c-fallback-style.
(2) Note that if the variable has been given a value by the
Customization interface or a 'setq' at the top level of your '.emacs',
this value will override the one the style system tries to give it.
*Note Config Basics::.
File: ccmode.info, Node: Guessing the Style, Next: File Styles, Prev: Adding Styles, Up: Styles
6.3.4 Guessing the Style
------------------------
Instead of specifying a style, you can get CC Mode to "guess" your style
by examining an already formatted code buffer. CC Mode then determines
the "most frequent" offset (*note c-offsets-alist::) for each of the
syntactic symbols (*note Indentation Engine Basics::) encountered in the
buffer, and the "most frequent" value of c-basic-offset (*note
Customizing Indentation::), then merges the current style with these
"guesses" to form a new style. This combined style is known as the
"guessed style".
To do this, call 'c-guess' (or one of the other 5 guessing commands)
on your sample buffer. The analysis of your code may take some time.
You can then set the guessed style in any CC Mode buffer with
'c-guess-install'. You can display the style with 'c-guess-view', and
preserve it by copying it into your '.emacs' for future use, preferably
after editing it.
'M-x c-guess-no-install'
'M-x c-guess-buffer-no-install'
'M-x c-guess-region-no-install'
These commands analyze a part of the current buffer and guess the
style from it.
The part of the buffer examined is either the region
('c-guess-region-no-install'), the entire buffer
('c-guess-buffer-no-install'), or the first 'c-guess-region-max'
bytes ('c-guess-no-install').
Each of these commands can be given an optional prefix argument.
This instructs CC Mode to combine the new guesses with the current
guesses before forming the guessed style.
'M-x c-guess'
'M-x c-guess-buffer'
'M-x c-guess-region'
These commands analyze a part of the current buffer, guess the
style from it, then install the guessed style on the buffer. The
guessed style is given a name based on the buffer's absolute file
name, and you can then set this style on any CC Mode buffer with
'C-c .'.
The part of the buffer examined is either the region
('c-guess-region'), the entire buffer ('c-guess-buffer'), or the
first 'c-guess-region-max' bytes ('c-guess').
Each of these commands can be given an optional prefix argument.
This instructs CC Mode to combine the new guesses with the current
guesses before forming the guessed style.
-- User Option: c-guess-region-max
This variable, default 50000, is the size in bytes of the buffer
portion examined by c-guess and c-guess-no-install. If set to
'nil', the entire buffer is examined.
-- User Option: c-guess-offset-threshold
This variable, default 10, is the maximum offset, either outwards
or inwards, which will be taken into account by the analysis
process. Any offset bigger than this will be ignored. For no
limit, set this variable to a large number.
'M-x c-guess-install'
Set the current buffer's style to the guessed style. This prompts
you to enter an optional new style name to give to the guessed
style. By default, this name is based on the buffer's absolute
file name. You can then use this style like any other.
'M-x c-guess-view'
Display the most recently guessed style in a temporary buffer.
This display is in the form of a 'c-add-style' form (*note Adding
Styles::) which can be easily copied to your '.emacs'. You will
probably want to edit it first.
The display of the guessed style contains these elements:
Placeholder Name
You should replace this with a style name of your own.
Parent Style
The style current when the guessing began, from which the
guessed style inherits (*note Config Basics::) the settings
which weren't guessed.
Guessed Offsets
These are the core result of the guessing process. Each of
them is marked by a comment.
Inherited Offsets
These are syntactic offsets which have been taken over from
the parent style. To avoid possible future conflicts, you
should remove either these offsets or the parent style name.
File: ccmode.info, Node: File Styles, Prev: Guessing the Style, Up: Styles
6.3.5 File Styles
-----------------
The Emacs manual describes how you can customize certain variables on a
per-file basis by including a "file local variable" block at the end of
the file (*note Local Variables in Files: (emacs)File Variables.).
So far, you've only seen a functional interface for setting styles in
CC Mode, and this can't be used here. CC Mode fills the gap by
providing two variables for use in a file's local variable list. Don't
use them anywhere else! These allow you to customize the style on a
per-file basis:
-- Variable: c-file-style
Set this variable to a style name string in the Local Variables
list. From now on, when you visit the file, CC Mode will
automatically set the file's style to this one using 'c-set-style'.
-- Variable: c-file-offsets
Set this variable (in the Local Variables list) to an association
list of the same format as 'c-offsets-alist'. From now on, when
you visit the file, CC Mode will automatically institute these
offsets using 'c-set-offset'.
Note that file style settings (i.e., 'c-file-style') are applied
before file offset settings (i.e., 'c-file-offsets')(1).
If you set any variable by the file local variables mechanism, that
setting takes priority over all other settings, even those in your mode
hooks (*note CC Hooks::). Any individual setting of a variable will
override one made through 'c-file-style' or 'c-file-offsets'.
---------- Footnotes ----------
(1) Also, if either of these are set in a file's local variable
section, all the style variable values are made local to that buffer,
even if 'c-style-variables-are-local-p' is 'nil'. Since this variable
is virtually always non-'nil' anyhow, you're unlikely to notice this
effect.
File: ccmode.info, Node: Custom Filling and Breaking, Next: Custom Auto-newlines, Prev: Config Basics, Up: Top
7 Customizing Filling and Line Breaking
***************************************
Since there's a lot of normal text in comments and string literals, CC
Mode provides features to edit these like in text mode. It does this by
hooking in on the different line breaking functions and tuning relevant
variables as necessary.
To make Emacs recognize comments and treat text in them as normal
paragraphs, CC Mode makes several standard variables(1) buffer-local and
modifies them according to the language syntax and the comment line
prefix.
-- User Option: c-comment-prefix-regexp
This style variable contains the regexp used to recognize the
"comment line prefix", which is the line decoration that starts
every line in a comment. The variable is either the comment line
prefix itself, or (more usually) an association list with different
values for different languages. The symbol for the major mode is
looked up in the alist to get the regexp for the language, and if
it isn't found then the special symbol 'other' is looked up
instead.
When a comment line gets divided by 'M-j' or the like, CC Mode
inserts the comment line prefix from a neighboring line at the
start of the new line. The default value of
c-comment-prefix-regexp is '//+\\|\\**', which matches C++ style
line comments like
// blah blah
with two or more slashes in front of them, and the second and
subsequent lines of C style block comments like
/*
* blah blah
*/
with zero or more stars at the beginning of every line. If you
change this variable, please make sure it still matches the comment
starter (i.e., '//') of line comments _and_ the line prefix inside
block comments.
Also note that since CC Mode uses the value of
'c-comment-prefix-regexp' to set up several other variables at mode
initialization, there won't be any effect if you just change it
inside a CC Mode buffer. You need to call the command
'c-setup-paragraph-variables' too, to update those other variables.
That's also the case if you modify 'c-comment-prefix-regexp' in a
mode hook, since CC Mode will already have set up these variables
before calling the hook.
In comments, CC Mode uses 'c-comment-prefix-regexp' to adapt the line
prefix from the other lines in the comment.
CC Mode uses adaptive fill mode (*note (emacs)Adaptive Fill::) to
make Emacs correctly keep the line prefix when filling paragraphs. That
also makes Emacs preserve the text indentation _inside_ the comment line
prefix. E.g., in the following comment, both paragraphs will be filled
with the left margins of the texts kept intact:
/* Make a balanced b-tree of the nodes in the incoming
* stream. But, to quote the famous words of Donald E.
* Knuth,
*
* Beware of bugs in the above code; I have only
* proved it correct, not tried it.
*/
It's also possible to use other adaptive filling packages, notably
Kyle E. Jones' Filladapt package(2), which handles things like bulleted
lists nicely. There's a convenience function 'c-setup-filladapt' that
tunes the relevant variables in Filladapt for use in CC Mode. Call it
from a mode hook, e.g., with something like this in your '.emacs':
(defun my-c-mode-common-hook ()
(c-setup-filladapt)
(filladapt-mode 1))
(add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
-- User Option: c-block-comment-prefix
Normally the comment line prefix inserted for a new line inside a
comment is deduced from other lines in it. However there's one
situation when there's no hint about what the prefix should look
like, namely when a block comment is broken for the first time.
This style variable(3) is used then as the comment prefix. It
defaults to '* '(4), which makes a comment
/* Got O(n^2) here, which is a Bad Thing. */
break into
/* Got O(n^2) here, which
* is a Bad Thing. */
Note that it won't work to adjust the indentation by putting
leading spaces in 'c-block-comment-prefix', since CC Mode still
uses the normal indentation engine to indent the line. Thus, the
right way to fix the indentation is by customizing the 'c'
syntactic symbol. It defaults to 'c-lineup-C-comments', which
handles the indentation of most common comment styles, see *note
Line-Up Functions::.
-- User Option: c-ignore-auto-fill
When auto fill mode is enabled, CC Mode can selectively ignore it
depending on the context the line break would occur in, e.g., to
never break a line automatically inside a string literal. This
variable takes a list of symbols for the different contexts where
auto-filling never should occur:
'string'
Inside a string or character literal.
'c'
Inside a C style block comment.
'c++'
Inside a C++ style line comment.
'cpp'
Inside a preprocessor directive.
'code'
Anywhere else, i.e., in normal code.
By default, 'c-ignore-auto-fill' is set to '(string cpp code)',
which means that when auto-fill mode is activated, auto-filling
only occurs in comments. In literals, it's often desirable to have
explicit control over newlines. In preprocessor directives, the
necessary '\' escape character before the newline is not
automatically inserted, so an automatic line break would produce
invalid code. In normal code, line breaks are normally dictated by
some logical structure in the code rather than the last whitespace
character, so automatic line breaks there will produce poor results
in the current implementation.
If inside a comment and 'comment-multi-line' (*note (emacs)Auto
Fill:: is non-'nil', the indentation and line prefix are preserved. If
inside a comment and 'comment-multi-line' is 'nil', a new comment of the
same type is started on the next line and indented as appropriate for
comments.
Note that CC Mode sets 'comment-multi-line' to 't' at startup. The
reason is that 'M-j' could otherwise produce sequences of single line
block comments for texts that should logically be treated as one
comment, and the rest of the paragraph handling code (e.g., 'M-q' and
'M-a') can't cope with that, which would lead to inconsistent behavior.
---------- Footnotes ----------
(1) 'comment-start', 'comment-end', 'comment-start-skip',
'paragraph-start', 'paragraph-separate', 'paragraph-ignore-fill-prefix',
'adaptive-fill-mode', 'adaptive-fill-regexp', and
'adaptive-fill-first-line-regexp'.
(2) It's available from <http://www.wonderworks.com/>. As of version
2.12, it does however lack a feature that makes it work suboptimally
when 'c-comment-prefix-regexp' matches the empty string (which it does
by default). A patch for that is available from the CC Mode web site.
(3) In versions before 5.26, this variable was called
'c-comment-continuation-stars'. As a compatibility measure, CC Mode
still uses the value on that variable if it's set.
(4) Actually, this default setting of 'c-block-comment-prefix'
typically gets overridden by the default style 'gnu', which sets it to
blank. You can see the line splitting effect described here by setting
a different style, e.g., 'k&r' *Note Choosing a Style::.
File: ccmode.info, Node: Custom Auto-newlines, Next: Clean-ups, Prev: Custom Filling and Breaking, Up: Top
8 Customizing Auto-newlines
***************************
CC Mode determines whether to insert auto-newlines in two basically
different ways, depending on the character just typed:
Braces and Colons
CC Mode first determines the syntactic context of the brace or
colon (*note Syntactic Symbols::), then looks for a corresponding
element in an alist. This element specifies where to put newlines:
this is any combination of before and after the brace or colon. If
no alist element is found, newlines are inserted both before and
after a brace, but none are inserted around a colon. See *note
Hanging Braces:: and *note Hanging Colons::.
Semicolons and Commas
The variable 'c-hanging-semi&comma-criteria' contains a list of
functions which determine whether to insert a newline after a newly
typed semicolon or comma. *Note Hanging Semicolons and Commas::.
The names of these configuration variables contain 'hanging' because
they let you "hang" the pertinent characters. A character which
introduces a C construct is said to "hang on the right" when it appears
at the end of a line after other code, being separated by a line break
from the construct it introduces, like the opening brace in:
while (i < MAX) {
total += entry[i];
entry [i++] = 0;
}
A character "hangs on the left" when it appears at the start of the line
after the construct it closes off, like the above closing brace.
The next chapter, "Clean-ups", describes how to configure CC Mode to
remove these automatically added newlines in certain specific
circumstances. *Note Clean-ups::.
* Menu:
* Hanging Braces::
* Hanging Colons::
* Hanging Semicolons and Commas::
File: ccmode.info, Node: Hanging Braces, Next: Hanging Colons, Prev: Custom Auto-newlines, Up: Custom Auto-newlines
8.1 Hanging Braces
==================
To specify which kinds of braces you want auto-newlines put around, you
set the style variable 'c-hanging-braces-alist'. Its structure and
semantics are described in this section. Details of how to set it up,
and its relationship to CC Mode's style system are given in *note Style
Variables::.
Say you wanted an auto-newline after (but not before) the following
'{':
if (foo < 17) {
First you need to find the "syntactic context" of the brace--type a
<RET> before the brace to get it on a line of its own(1), then type 'C-c
C-s'. That will tell you something like:
((substatement-open 1061))
So here you need to put the entry '(substatement-open . (after))' into
'c-hanging-braces-alist'.
If you don't want any auto-newlines for a particular syntactic
symbol, put this into 'c-hanging-braces-alist':
(brace-entry-open)
If some brace syntactic symbol is not in 'c-hanging-brace-alist', its
entry is taken by default as '(before after)'--insert a newline both
before and after the brace. In place of a "before/after" list you can
specify a function in this alist--this is useful when the auto newlines
depend on the code around the brace.
-- User Option: c-hanging-braces-alist
This variable is an association list which maps syntactic symbols
to lists of places to insert a newline. *Note (elisp)Association
Lists::. The key of each element is the syntactic symbol, the
associated value is either 'nil', a list, or a function.
The Key: the syntactic symbol
The syntactic symbols that are useful as keys in this list are
'brace-list-intro', 'statement-cont', 'inexpr-class-open',
'inexpr-class-close', and all the '*-open' and '*-close'
symbols. *Note Syntactic Symbols::, for a more detailed
description of these syntactic symbols, except for
'inexpr-class-open' and 'inexpr-class-close', which aren't
actual syntactic symbols. Elements with any other value as a
key get ignored.
The braces of anonymous inner classes in Java are given the
special symbols 'inexpr-class-open' and 'inexpr-class-close',
so that they can be distinguished from the braces of normal
classes(2).
Note that the aggregate constructs in Pike mode, '({', '})',
'([', '])', and '(<', '>)', do not count as brace lists in
this regard, even though they do for normal indentation
purposes. It's currently not possible to set automatic
newlines on these constructs.
The associated value: the "ACTION" list or function
The value associated with each syntactic symbol in this
association list is called an ACTION, which can be either a
list or a function which returns a list. *Note Custom
Braces::, for how to use a function as a brace hanging ACTION.
The list ACTION (or the list returned by ACTION when it's a
function) contains some combination of the symbols 'before'
and 'after', directing CC Mode where to put newlines in
relationship to the brace being inserted. Thus, if the list
contains only the symbol 'after', then the brace hangs on the
right side of the line, as in:
// here, open braces always `hang'
void spam( int i ) {
if( i == 7 ) {
dosomething(i);
}
}
When the list contains both 'after' and 'before', the braces
will appear on a line by themselves, as shown by the close
braces in the above example. The list can also be empty, in
which case newlines are added neither before nor after the
brace.
If a syntactic symbol is missing entirely from
'c-hanging-braces-alist', it's treated in the same way as an ACTION
with a list containing 'before' and 'after', so that braces by
default end up on their own line.
For example, the default value of 'c-hanging-braces-alist' is:
((brace-list-open)
(brace-entry-open)
(statement-cont)
(substatement-open after)
(block-close . c-snug-do-while)
(extern-lang-open after)
(namespace-open after)
(module-open after)
(composition-open after)
(inexpr-class-open after)
(inexpr-class-close before))
which says that 'brace-list-open', 'brace-entry-open' and
'statement-cont'(3) braces should both hang on the right side and
allow subsequent text to follow on the same line as the brace.
Also, 'substatement-open', 'extern-lang-open', and
'inexpr-class-open' braces should hang on the right side, but
subsequent text should follow on the next line. The opposite holds
for 'inexpr-class-close' braces; they won't hang, but the following
text continues on the same line. Here, in the 'block-close' entry,
you also see an example of using a function as an ACTION. In all
other cases, braces are put on a line by themselves.
* Menu:
* Custom Braces::
---------- Footnotes ----------
(1) Also insert a '\' at the end of the previous line if you're in
AWK Mode.
(2) The braces of anonymous classes produce a combination of
'inexpr-class', and 'class-open' or 'class-close' in normal indentation
analysis.
(3) Brace lists inside statements, such as initializers for static
array variables inside functions in C, are recognized as
'statement-cont'. All normal substatement blocks are recognized with
other symbols.
File: ccmode.info, Node: Custom Braces, Prev: Hanging Braces, Up: Hanging Braces
8.1.1 Custom Brace Hanging
--------------------------
Syntactic symbols aren't the only place where you can customize CC Mode
with the lisp equivalent of callback functions. Remember that ACTIONs
are usually a list containing some combination of the symbols 'before'
and 'after' (*note Hanging Braces::). For more flexibility, you can
instead specify brace "hanginess" by giving a syntactic symbol an
"action function" in 'c-hanging-braces-alist'; this function determines
the "hanginess" of a brace, usually by looking at the code near it.
An action function is called with two arguments: the syntactic symbol
for the brace (e.g., 'substatement-open'), and the buffer position where
the brace has been inserted. Point is undefined on entry to an action
function, but the function must preserve it (e.g., by using
'save-excursion'). The return value should be a list containing some
combination of 'before' and 'after', including neither of them (i.e.,
'nil').
-- Variable: c-syntactic-context
During the call to the indentation or brace hanging ACTION
function, this variable is bound to the full syntactic analysis
list. This might be, for example, '((block-close 73))'. Don't
ever give 'c-syntactic-context' a value yourself--this would
disrupt the proper functioning of CC Mode.
This variable is also bound in three other circumstances: (i) when
calling a c-hanging-semi&comma-criteria function (*note Hanging
Semicolons and Commas::); (ii) when calling a line-up function
(*note Custom Line-Up::); (iii) when calling a
c-special-indent-hook function (*note Other Indentation::).
As an example, CC Mode itself uses this feature to dynamically
determine the hanginess of braces which close "do-while" constructs:
void do_list( int count, char** atleast_one_string )
{
int i=0;
do {
handle_string( atleast_one_string[i] );
i++;
} while( i < count );
}
CC Mode assigns the 'block-close' syntactic symbol to the brace that
closes the 'do' construct, and normally we'd like the line that follows
a 'block-close' brace to begin on a separate line. However, with
"do-while" constructs, we want the 'while' clause to follow the closing
brace. To do this, we associate the 'block-close' symbol with the
ACTION function 'c-snug-do-while':
(defun c-snug-do-while (syntax pos)
"Dynamically calculate brace hanginess for do-while statements."
(save-excursion
(let (langelem)
(if (and (eq syntax 'block-close)
(setq langelem (assq 'block-close c-syntactic-context))
(progn (goto-char (cdr langelem))
(if (= (following-char) ?{)
(forward-sexp -1))
(looking-at "\\<do\\>[^_]")))
'(before)
'(before after)))))
This function simply looks to see if the brace closes a "do-while"
clause and if so, returns the list '(before)' indicating that a newline
should be inserted before the brace, but not after it. In all other
cases, it returns the list '(before after)' so that the brace appears on
a line by itself.
File: ccmode.info, Node: Hanging Colons, Next: Hanging Semicolons and Commas, Prev: Hanging Braces, Up: Custom Auto-newlines
8.2 Hanging Colons
==================
Using a mechanism similar to brace hanging (*note Hanging Braces::),
colons can also be made to hang using the style variable
'c-hanging-colons-alist': when a colon is typed, CC Mode determines its
syntactic context, looks this up in the alist 'c-changing-colons-alist'
and inserts up to two newlines accordingly. Here, however, If CC Mode
fails to find an entry for a syntactic symbol in the alist, no newlines
are inserted around the newly typed colon.
-- User Option: c-hanging-colons-alist
The Key: the syntactic symbol
The syntactic symbols appropriate as keys in this association
list are: 'case-label', 'label', 'access-label',
'member-init-intro', and 'inher-intro'. *Note Syntactic
Symbols::. Elements with any other value as a key get
ignored.
The associated value: the "ACTION" list
The ACTION here is simply a list containing a combination of
the symbols 'before' and 'after'. Unlike in
'c-hanging-braces-alist', functions as ACTIONS are not
supported; there doesn't seem to be any need for them.
In C++, double-colons are used as a scope operator but because these
colons always appear right next to each other, newlines before and after
them are controlled by a different mechanism, called "clean-ups" in CC
Mode. *Note Clean-ups::, for details.
File: ccmode.info, Node: Hanging Semicolons and Commas, Prev: Hanging Colons, Up: Custom Auto-newlines
8.3 Hanging Semicolons and Commas
=================================
-- User Option: c-hanging-semi&comma-criteria
This style variable takes a list of functions; these get called
when you type a semicolon or comma. The functions are called in
order without arguments. When these functions are entered, point
is just after the newly inserted ';' or ',' and they must preserve
point (e.g., by using 'save-excursion'). During the call, the
variable 'c-syntactic-context' is bound to the syntactic context of
the current line(1) *note Custom Braces::. These functions don't
insert newlines themselves, rather they direct CC Mode whether or
not to do so. They should return one of the following values:
't'
A newline is to be inserted after the ';' or ',', and no more
functions from the list are to be called.
'stop'
No more functions from the list are to be called, and no
newline is to be inserted.
'nil'
No determination has been made, and the next function in the
list is to be called.
Note that auto-newlines are never inserted _before_ a semicolon or
comma. If every function in the list is called without a
determination being made, then no newline is added.
In AWK mode, this variable is set by default to 'nil'. In the
other modes, the default value is a list containing a single
function, 'c-semi&comma-inside-parenlist'. This inserts newlines
after all semicolons, apart from those separating 'for'-clause
statements.
-- Function: c-semi&comma-no-newlines-before-nonblanks
This is an example of a criteria function, provided by CC Mode. It
prevents newlines from being inserted after semicolons when there
is a non-blank following line. Otherwise, it makes no
determination. To use, add this function to the front of the
'c-hanging-semi&comma-criteria' list.
(defun c-semi&comma-no-newlines-before-nonblanks ()
(save-excursion
(if (and (eq last-command-char ?\;)
(zerop (forward-line 1))
(not (looking-at "^[ \t]*$")))
'stop
nil)))
-- Function: c-semi&comma-inside-parenlist
-- Function: c-semi&comma-no-newlines-for-oneline-inliners
The function 'c-semi&comma-inside-parenlist' is what prevents
newlines from being inserted inside the parenthesis list of 'for'
statements. In addition to
'c-semi&comma-no-newlines-before-nonblanks' described above, CC
Mode also comes with the criteria function
'c-semi&comma-no-newlines-for-oneline-inliners', which suppresses
newlines after semicolons inside one-line inline method definitions
(e.g., in C++ or Java).
---------- Footnotes ----------
(1) This was first introduced in CC Mode 5.31.
File: ccmode.info, Node: Clean-ups, Next: Indentation Engine Basics, Prev: Custom Auto-newlines, Up: Top
9 Clean-ups
***********
"Clean-ups" are mechanisms which remove (or exceptionally, add)
whitespace in specific circumstances and are complementary to colon and
brace hanging. You enable a clean-up by adding its symbol into
'c-cleanup-list', e.g., like this:
(add-to-list 'c-cleanup-list 'space-before-funcall)
On the surface, it would seem that clean-ups overlap the
functionality provided by the 'c-hanging-*-alist' variables. Clean-ups,
however, are used to adjust code "after-the-fact", i.e., to adjust the
whitespace in constructs later than when they were typed.
Most of the clean-ups remove automatically inserted newlines, and are
only active when auto-newline minor mode is turned on. Others will work
all the time. Note that clean-ups are only performed when there is
nothing but whitespace appearing between the individual components of
the construct, and (apart from 'comment-close-slash') when the construct
does not occur within a literal (*note Auto-newlines::).
-- User Option: c-cleanup-list
You configure CC Mode's clean-ups by setting the style variable
'c-cleanup-list', which is a list of clean-up symbols. By default,
CC Mode cleans up only the 'scope-operator' construct, which is
necessary for proper C++ support.
These are the clean-ups that are only active when electric and
auto-newline minor modes are enabled:
'brace-else-brace'
Clean up '} else {' constructs by placing the entire construct on a
single line. Clean up occurs when the open brace after the 'else'
is typed. So for example, this:
void spam(int i)
{
if( i==7 ) {
dosomething();
}
else
{
appears like this after the last open brace is typed:
void spam(int i)
{
if( i==7 ) {
dosomething();
} else {
'brace-elseif-brace'
Similar to the 'brace-else-brace' clean-up, but this cleans up '}
else if (...) {' constructs. For example:
void spam(int i)
{
if( i==7 ) {
dosomething();
}
else if( i==3 )
{
appears like this after the last open parenthesis is typed:
void spam(int i)
{
if( i==7 ) {
dosomething();
} else if(
and like this after the last open brace is typed:
void spam(int i)
{
if( i==7 ) {
dosomething();
} else if( i==3 ) {
'brace-catch-brace'
Analogous to 'brace-elseif-brace', but cleans up '} catch (...) {'
in C++ and Java mode.
'empty-defun-braces'
Clean up braces following a top-level function or class definition
that contains no body. Clean up occurs when the closing brace is
typed. Thus the following:
class Spam
{
}
is transformed into this when the close brace is typed:
class Spam
{}
'defun-close-semi'
Clean up the terminating semicolon on top-level function or class
definitions when they follow a close brace. Clean up occurs when
the semicolon is typed. So for example, the following:
class Spam
{
...
}
;
is transformed into this when the semicolon is typed:
class Spam
{
...
};
'list-close-comma'
Clean up commas following braces in array and aggregate
initializers. Clean up occurs when the comma is typed. The space
before the comma is zapped just like the space before the semicolon
in 'defun-close-semi'.
'scope-operator'
Clean up double colons which might designate a C++ scope operator
split across multiple lines(1). Clean up occurs when the second
colon is typed. You will always want 'scope-operator' in the
'c-cleanup-list' when you are editing C++ code.
'one-liner-defun'
Clean up a single line of code enclosed by defun braces by removing
the whitespace before and after the code. The clean-up happens
when the closing brace is typed. If the variable
'c-max-one-liner-length' is set, the cleanup is only done if the
resulting line would be no longer than the value of that variable.
For example, consider this AWK code:
BEGIN {
FS = "\t" # use <TAB> as a field separator
}
It gets compacted to the following when the closing brace is typed:
BEGIN {FS = "\t"} # use <TAB> as a field separator
-- User Option: c-max-one-liner-length
The maximum length of the resulting line for which the
clean-up 'one-liner-defun' will be triggered. This length is
that of the entire line, including any leading whitespace and
any trailing comment. Its default value is 80. If the value
is zero or 'nil', no limit applies.
The following clean-ups are always active when they occur on
'c-cleanup-list', regardless of whether Electric minor mode or
Auto-newline minor mode are enabled:
'space-before-funcall'
Insert a space between the function name and the opening
parenthesis of a function call. This produces function calls in
the style mandated by the GNU coding standards, e.g.,
'signal (SIGINT, SIG_IGN)' and 'abort ()'. Clean up occurs when
the opening parenthesis is typed. This clean-up should never be
active in AWK Mode, since such a space is syntactically invalid for
user defined functions.
'compact-empty-funcall'
Clean up any space between the function name and the opening
parenthesis of a function call that has no arguments. This is
typically used together with 'space-before-funcall' if you prefer
the GNU function call style for functions with arguments but think
it looks ugly when it's only an empty parenthesis pair. I.e., you
will get 'signal (SIGINT, SIG_IGN)', but 'abort()'. Clean up
occurs when the closing parenthesis is typed.
'comment-close-slash'
When inside a block comment, terminate the comment when you type a
slash at the beginning of a line (i.e., immediately after the
comment prefix). This clean-up removes whitespace preceding the
slash and if needed, inserts a star to complete the token '*/'.
Type 'C-q /' in this situation if you just want a literal '/'
inserted.
---------- Footnotes ----------
(1) Certain C++ constructs introduce ambiguous situations, so
'scope-operator' clean-ups might not always be correct. This usually
only occurs when scoped identifiers appear in switch label tags.
File: ccmode.info, Node: Indentation Engine Basics, Next: Customizing Indentation, Prev: Clean-ups, Up: Top
10 Indentation Engine Basics
****************************
This chapter will briefly cover how CC Mode indents lines of code. It
is helpful to understand the indentation model being used so that you
will know how to customize CC Mode for your personal coding style. All
the details are in *note Customizing Indentation::.
CC Mode has an indentation engine that provides a flexible and
general mechanism for customizing indentation. When CC Mode indents a
line of code, it separates its calculations into two steps:
1. It analyzes the line to determine its "syntactic symbol(s)" (the
kind of language construct it's looking at) and its "anchor
position" (the position earlier in the file that CC Mode will
indent the line relative to). The anchor position might be the
location of an opening brace in the previous line, for example.
*Note Syntactic Analysis::.
2. It looks up the syntactic symbol(s) in the configuration to get the
corresponding "offset(s)". The symbol '+', which means "indent
this line one more level" is a typical offset. CC Mode then
applies these offset(s) to the anchor position, giving the
indentation for the line. The different sorts of offsets are
described in *note c-offsets-alist::.
In exceptional circumstances, the syntax directed indentation
described here may be a nuisance rather than a help. You can disable it
by setting 'c-syntactic-indentation' to 'nil'. (To set the variable
interactively, *note Minor Modes::).
-- User Option: c-syntactic-indentation
When this is non-'nil' (which it is by default), the indentation of
code is done according to its syntactic structure. When it's
'nil', every line is just indented to the same level as the
previous one, and 'TAB' ('c-indent-command') adjusts the
indentation in steps of 'c-basic-offset'. The current style (*note
Config Basics::) then has no effect on indentation, nor do any of
the variables associated with indentation, not even
'c-special-indent-hook'.
* Menu:
* Syntactic Analysis::
* Syntactic Symbols::
* Indentation Calculation::
File: ccmode.info, Node: Syntactic Analysis, Next: Syntactic Symbols, Prev: Indentation Engine Basics, Up: Indentation Engine Basics
10.1 Syntactic Analysis
=======================
The first thing CC Mode does when indenting a line of code, is to
analyze the line, determining the "syntactic context" of the (first)
construct on that line. It's a list of "syntactic elements", where each
syntactic element in turn is a list(1) Here is a brief and typical
example:
((defun-block-intro 1959))
The first thing inside each syntactic element is always a "syntactic
symbol". It describes the kind of construct that was recognized, e.g.,
'statement', 'substatement', 'class-open', 'class-close', etc. *Note
Syntactic Symbols::, for a complete list of currently recognized
syntactic symbols and their semantics. The remaining entries are
various data associated with the recognized construct; there might be
zero or more.
Conceptually, a line of code is always indented relative to some
position higher up in the buffer (typically the indentation of the
previous line). That position is the "anchor position" in the syntactic
element. If there is an entry after the syntactic symbol in the
syntactic element list then it's either nil or that anchor position.
Here is an example. Suppose we had the following code as the only
thing in a C++ buffer (2):
1: void swap( int& a, int& b )
2: {
3: int tmp = a;
4: a = b;
5: b = tmp;
6: }
We can use 'C-c C-s' ('c-show-syntactic-information') to report what the
syntactic analysis is for the current line:
'C-c C-s' ('c-show-syntactic-information')
This command calculates the syntactic analysis of the current line
and displays it in the minibuffer. The command also highlights the
anchor position(s).
Running this command on line 4 of this example, we'd see in the echo
area(3):
((statement 35))
and the 'i' of 'int' on line 3 would be highlighted. This tells us that
the line is a statement and it is indented relative to buffer position
35, the highlighted position. If you were to move point to line 3 and
hit 'C-c C-s', you would see:
((defun-block-intro 29))
This indicates that the 'int' line is the first statement in a top level
function block, and is indented relative to buffer position 29, which is
the brace just after the function header.
Here's another example:
1: int add( int val, int incr, int doit )
2: {
3: if( doit )
4: {
5: return( val + incr );
6: }
7: return( val );
8: }
Hitting 'C-c C-s' on line 4 gives us:
((substatement-open 46))
which tells us that this is a brace that _opens_ a substatement block.
(4)
Syntactic contexts can contain more than one element, and syntactic
elements need not have anchor positions. The most common example of
this is a "comment-only line":
1: void draw_list( List<Drawables>& drawables )
2: {
3: // call the virtual draw() method on each element in list
4: for( int i=0; i < drawables.count(), ++i )
5: {
6: drawables[i].draw();
7: }
8: }
Hitting 'C-c C-s' on line 3 of this example gives:
((comment-intro) (defun-block-intro 46))
and you can see that the syntactic context contains two syntactic
elements. Notice that the first element, '(comment-intro)', has no
anchor position.
---------- Footnotes ----------
(1) In CC Mode 5.28 and earlier, a syntactic element was a dotted
pair; the cons was the syntactic symbol and the cdr was the anchor
position. For compatibility's sake, the parameter passed to a line-up
function still has this dotted pair form (*note Custom Line-Up::).
(2) The line numbers in this and future examples don't actually
appear in the buffer, of course!
(3) With a universal argument (i.e., 'C-u C-c C-s') the analysis is
inserted into the buffer as a comment on the current line.
(4) A "substatement" is the line after a conditional statement, such
as 'if', 'else', 'while', 'do', 'switch', etc. A "substatement block"
is a brace block following one of these conditional statements.
File: ccmode.info, Node: Syntactic Symbols, Next: Indentation Calculation, Prev: Syntactic Analysis, Up: Indentation Engine Basics
10.2 Syntactic Symbols
======================
This section is a complete list of the syntactic symbols which appear in
the 'c-offsets-alist' style variable, along with brief descriptions.
The previous section (*note Syntactic Analysis::) states what syntactic
symbols are and how the indentation engine uses them.
More detailed descriptions of these symbols, together with snippets
of source code to which they apply, appear in the examples in the
subsections below. Note that, in the interests of brevity, the anchor
position associated with most syntactic symbols is _not_ specified. In
cases of doubt, type 'C-c C-s' on a pertinent line--this highlights the
anchor position.
The syntactic symbols which indicate brace constructs follow a
general naming convention. When a line begins with an open or close
brace, its syntactic symbol will contain the suffix '-open' or '-close'
respectively. The first line within the brace block construct will
contain the suffix '-block-intro'.
In constructs which can span several lines, a distinction is usually
made between the first line that introduces the construct and the lines
that continue it. The syntactic symbols that indicate these lines will
contain the suffixes '-intro' or '-cont' respectively.
The best way to understand how all this works is by looking at some
examples. Remember that you can see the syntax of any source code line
by using 'C-c C-s'.
'string'
Inside a multiline string. *note Literal Symbols::.
'c'
Inside a multiline C style block comment. *note Literal Symbols::.
'defun-open'
Brace that opens a top-level function definition. *note Function
Symbols::.
'defun-close'
Brace that closes a top-level function definition. *note Function
Symbols::.
'defun-block-intro'
The first line in a top-level defun. *note Function Symbols::.
'class-open'
Brace that opens a class definition. *note Class Symbols::.
'class-close'
Brace that closes a class definition. *note Class Symbols::.
'inline-open'
Brace that opens an in-class inline method. *note Class Symbols::.
'inline-close'
Brace that closes an in-class inline method. *note Class
Symbols::.
'func-decl-cont'
The region between a function definition's argument list and the
function opening brace (excluding K&R argument declarations). In
C, you cannot put anything but whitespace and comments in this
region, however in C++ and Java, 'throws' declarations and other
things can appear here. *note Literal Symbols::.
'knr-argdecl-intro'
First line of a K&R C argument declaration. *note K&R Symbols::.
'knr-argdecl'
Subsequent lines in a K&R C argument declaration. *note K&R
Symbols::.
'topmost-intro'
The first line in a "topmost" definition. *note Function
Symbols::.
'topmost-intro-cont'
Topmost definition continuation lines. This is only used in the
parts that aren't covered by other symbols such as 'func-decl-cont'
and 'knr-argdecl'. *note Function Symbols::.
'annotation-top-cont'
Topmost definition continuation lines where all previous items are
annotations. *note Java Symbols::.
'member-init-intro'
First line in a member initialization list. *note Class Symbols::.
'member-init-cont'
Subsequent member initialization list lines. *note Class
Symbols::.
'inher-intro'
First line of a multiple inheritance list. *note Class Symbols::.
'inher-cont'
Subsequent multiple inheritance lines. *note Class Symbols::.
'block-open'
Statement block open brace. *note Literal Symbols::.
'block-close'
Statement block close brace. *note Conditional Construct
Symbols::.
'brace-list-open'
Open brace of an enum or static array list. *note Brace List
Symbols::.
'brace-list-close'
Close brace of an enum or static array list. *note Brace List
Symbols::.
'brace-list-intro'
First line in an enum or static array list. *note Brace List
Symbols::.
'brace-list-entry'
Subsequent lines in an enum or static array list. *note Brace List
Symbols::.
'brace-entry-open'
Subsequent lines in an enum or static array list where the line
begins with an open brace. *note Brace List Symbols::.
'statement'
A statement. *note Function Symbols::.
'statement-cont'
A continuation of a statement. *note Function Symbols::.
'annotation-var-cont'
A continuation of a statement where all previous items are
annotations. *note Java Symbols::.
'statement-block-intro'
The first line in a new statement block. *note Conditional
Construct Symbols::.
'statement-case-intro'
The first line in a case block. *note Switch Statement Symbols::.
'statement-case-open'
The first line in a case block that starts with a brace. *note
Switch Statement Symbols::.
'substatement'
The first line after a conditional or loop construct. *note
Conditional Construct Symbols::.
'substatement-open'
The brace that opens a substatement block. *note Conditional
Construct Symbols::.
'substatement-label'
The first line after a conditional or loop construct if it's a
label. *note Conditional Construct Symbols::.
'case-label'
A label in a 'switch' block. *note Switch Statement Symbols::.
'access-label'
C++ access control label. *note Class Symbols::.
'label'
Any other label. *note Literal Symbols::.
'do-while-closure'
The 'while' line that ends a 'do'-'while' construct. *note
Conditional Construct Symbols::.
'else-clause'
The 'else' line of an 'if'-'else' construct. *note Conditional
Construct Symbols::.
'catch-clause'
The 'catch' or 'finally' (in Java) line of a 'try'-'catch'
construct. *note Conditional Construct Symbols::.
'comment-intro'
A line containing only a comment introduction. *note Literal
Symbols::.
'arglist-intro'
The first line in an argument list. *note Paren List Symbols::.
'arglist-cont'
Subsequent argument list lines when no arguments follow on the same
line as the arglist opening paren. *note Paren List Symbols::.
'arglist-cont-nonempty'
Subsequent argument list lines when at least one argument follows
on the same line as the arglist opening paren. *note Paren List
Symbols::.
'arglist-close'
The solo close paren of an argument list. *note Paren List
Symbols::.
'stream-op'
Lines continuing a stream operator (C++ only). *note Literal
Symbols::.
'inclass'
The line is nested inside a class definition. *note Class
Symbols::.
'cpp-macro'
The start of a preprocessor macro definition. *note Literal
Symbols::.
'cpp-define-intro'
The first line inside a multiline preprocessor macro if
'c-syntactic-indentation-in-macros' is set. *note Multiline Macro
Symbols::.
'cpp-macro-cont'
All lines inside multiline preprocessor macros if
'c-syntactic-indentation-in-macros' is 'nil'. *note Multiline
Macro Symbols::.
'friend'
A C++ friend declaration. *note Class Symbols::.
'objc-method-intro'
The first line of an Objective-C method definition. *note
Objective-C Method Symbols::.
'objc-method-args-cont'
Lines continuing an Objective-C method definition. *note
Objective-C Method Symbols::.
'objc-method-call-cont'
Lines continuing an Objective-C method call. *note Objective-C
Method Symbols::.
'extern-lang-open'
Brace that opens an 'extern' block (e.g., 'extern "C" {...}').
*note External Scope Symbols::.
'extern-lang-close'
Brace that closes an 'extern' block. *note External Scope
Symbols::.
'inextern-lang'
Analogous to 'inclass' syntactic symbol, but used inside 'extern'
blocks. *note External Scope Symbols::.
'namespace-open'
'namespace-close'
'innamespace'
These are analogous to the three 'extern-lang' symbols above, but
are returned for C++ namespace blocks. *note External Scope
Symbols::.
'module-open'
'module-close'
'inmodule'
Analogous to the above, but for CORBA IDL 'module' blocks. *note
External Scope Symbols::.
'composition-open'
'composition-close'
'incomposition'
Analogous to the above, but for CORBA CIDL 'composition' blocks.
*note External Scope Symbols::.
'template-args-cont'
C++ template argument list continuations. *note Class Symbols::.
'inlambda'
Analogous to 'inclass' syntactic symbol, but used inside lambda
(i.e., anonymous) functions. Only used in Pike mode. *note
Statement Block Symbols::.
'lambda-intro-cont'
Lines continuing the header of a lambda function, i.e., between the
'lambda' keyword and the function body. Only used in Pike mode.
*note Statement Block Symbols::.
'inexpr-statement'
A statement block inside an expression. The gcc C and C++
extension for this is recognized. It's also used for the special
functions that take a statement block as an argument in Pike.
*note Statement Block Symbols::.
'inexpr-class'
A class definition inside an expression. This is used for
anonymous classes in Java. It's also used for anonymous array
initializers in Java. *note Java Symbols::.
* Menu:
* Function Symbols::
* Class Symbols::
* Conditional Construct Symbols::
* Switch Statement Symbols::
* Brace List Symbols::
* External Scope Symbols::
* Paren List Symbols::
* Literal Symbols::
* Multiline Macro Symbols::
* Objective-C Method Symbols::
* Java Symbols::
* Statement Block Symbols::
* K&R Symbols::
File: ccmode.info, Node: Function Symbols, Next: Class Symbols, Prev: Syntactic Symbols, Up: Syntactic Symbols
10.2.1 Function Symbols
-----------------------
This example shows a typical function declaration.
1: void
2: swap( int& a, int& b )
3: {
4: int tmp = a;
5: a = b;
6: b = tmp;
7: int ignored =
8: a + b;
9: }
Line 1 shows a 'topmost-intro' since it is the first line that
introduces a top-level construct. Line 2 is a continuation of the
top-level construct introduction so it has the syntax
'topmost-intro-cont'. Line 3 shows a 'defun-open' since it is the brace
that opens a top-level function definition. Line 9 is the corresponding
'defun-close' since it contains the brace that closes the top-level
function definition. Line 4 is a 'defun-block-intro', i.e., it is the
first line of a brace-block, enclosed in a top-level function
definition.
Lines 5, 6, and 7 are all given 'statement' syntax since there isn't
much special about them. Note however that line 8 is given
'statement-cont' syntax since it continues the statement begun on the
previous line.
File: ccmode.info, Node: Class Symbols, Next: Conditional Construct Symbols, Prev: Function Symbols, Up: Syntactic Symbols
10.2.2 Class related Symbols
----------------------------
Here's an example which illustrates some C++ class syntactic symbols:
1: class Bass
2: : public Guitar,
3: public Amplifiable
4: {
5: public:
6: Bass()
7: : eString( new BassString( 0.105 )),
8: aString( new BassString( 0.085 )),
9: dString( new BassString( 0.065 )),
10: gString( new BassString( 0.045 ))
11: {
12: eString.tune( 'E' );
13: aString.tune( 'A' );
14: dString.tune( 'D' );
15: gString.tune( 'G' );
16: }
17: friend class Luthier;
18: };
As in the previous example, line 1 has the 'topmost-intro' syntax.
Here however, the brace that opens a C++ class definition on line 4 is
assigned the 'class-open' syntax. Note that in C++, classes, structs,
and unions are essentially equivalent syntactically (and are very
similar semantically), so replacing the 'class' keyword in the example
above with 'struct' or 'union' would still result in a syntax of
'class-open' for line 4 (1). Similarly, line 18 is assigned
'class-close' syntax.
Line 2 introduces the inheritance list for the class so it is
assigned the 'inher-intro' syntax, and line 3, which continues the
inheritance list is given 'inher-cont' syntax.
Hitting 'C-c C-s' on line 5 shows the following analysis:
((inclass 58) (access-label 58))
The primary syntactic symbol for this line is 'access-label' as this is
a label keyword that specifies access protection in C++. However,
because this line is also a top-level construct inside a class
definition, the analysis actually shows two syntactic symbols. The
other syntactic symbol assigned to this line is 'inclass'. Similarly,
line 6 is given both 'inclass' and 'topmost-intro' syntax:
((inclass 58) (topmost-intro 60))
Line 7 introduces a C++ member initialization list and as such is
given 'member-init-intro' syntax. Note that in this case it is _not_
assigned 'inclass' since this is not considered a top-level construct.
Lines 8 through 10 are all assigned 'member-init-cont' since they
continue the member initialization list started on line 7.
Line 11's analysis is a bit more complicated:
((inclass 58) (inline-open))
This line is assigned a syntax of both 'inline-open' and 'inclass'
because it opens an "in-class" C++ inline method definition. This is
distinct from, but related to, the C++ notion of an inline function in
that its definition occurs inside an enclosing class definition, which
in C++ implies that the function should be inlined. However, if the
definition of the 'Bass' constructor appeared outside the class
definition, the construct would be given the 'defun-open' syntax, even
if the keyword 'inline' appeared before the method name, as in:
1: class Bass
2: : public Guitar,
3: public Amplifiable
4: {
5: public:
6: Bass();
7: };
8:
9: inline
10: Bass::Bass()
11: : eString( new BassString( 0.105 )),
12: aString( new BassString( 0.085 )),
13: dString( new BassString( 0.065 )),
14: gString( new BassString( 0.045 ))
15: {
16: eString.tune( 'E' );
17: aString.tune( 'A' );
18: dString.tune( 'D' );
19: gString.tune( 'G' );
20: }
Returning to the previous example, line 16 is given 'inline-close'
syntax, while line 12 is given 'defun-block-open' syntax, and lines 13
through 15 are all given 'statement' syntax. Line 17 is interesting in
that its syntactic analysis list contains three elements:
((inclass 58) (topmost-intro 380) (friend))
The 'friend' and 'inline-open' syntactic symbols are modifiers that
do not have anchor positions.
Template definitions introduce yet another syntactic symbol:
1: ThingManager <int,
2: Framework::Callback *,
3: Mutex> framework_callbacks;
Here, line 1 is analyzed as a 'topmost-intro', but lines 2 and 3 are
both analyzed as 'template-args-cont' lines.
---------- Footnotes ----------
(1) This is the case even for C and Objective-C. For consistency,
structs in all supported languages are syntactically equivalent to
classes. Note however that the keyword 'class' is meaningless in C and
Objective-C.
File: ccmode.info, Node: Conditional Construct Symbols, Next: Switch Statement Symbols, Prev: Class Symbols, Up: Syntactic Symbols
10.2.3 Conditional Construct Symbols
------------------------------------
Here is a (totally contrived) example which illustrates how syntax is
assigned to various conditional constructs:
1: void spam( int index )
2: {
3: for( int i=0; i<index; i++ )
4: {
5: if( i == 10 )
6: do_something_special();
7: else
8: silly_label:
9: do_something( i );
10: }
11: do {
12: another_thing( i-- );
13: }
14: while( i > 0 );
15: }
Only the lines that illustrate new syntactic symbols will be
discussed.
Line 4 has a brace which opens a conditional's substatement block.
It is thus assigned 'substatement-open' syntax, and since line 5 is the
first line in the substatement block, it is assigned
'statement-block-intro' syntax. Line 10 contains the brace that closes
the inner substatement block, and is therefore given the syntax
'block-close'(1). Line 13 is treated the same way.
Lines 6 and 9 are also substatements of conditionals, but since they
don't start blocks they are given 'substatement' syntax instead of
'substatement-open'.
Line 8 contains a label, which is normally given 'label' syntax.
This one is however a bit special since it's between a conditional and
its substatement. It's analyzed as 'substatement-label' to let you
handle this rather odd case differently from normal labels.
Line 7 start with an 'else' that matches the 'if' statement on line
5. It is therefore given the 'else-clause' syntax and is anchored on
the matching 'if'. The 'try'-'catch' constructs in C++ and Java are
treated this way too, except that 'catch' and (in Java) 'finally', are
marked with 'catch-clause'.
The 'while' construct on line 14 that closes a 'do' conditional is
given the special syntax 'do-while-closure' if it appears on a line by
itself. Note that if the 'while' appeared on the same line as the
preceding close brace, that line would still have 'block-close' syntax.
---------- Footnotes ----------
(1) 'block-open' is used only for "free-standing" blocks, and is
somewhat rare (*note Literal Symbols:: for an example.)
File: ccmode.info, Node: Switch Statement Symbols, Next: Brace List Symbols, Prev: Conditional Construct Symbols, Up: Syntactic Symbols
10.2.4 Switch Statement Symbols
-------------------------------
Switch statements have their own set of syntactic symbols. Here's an
example:
1: void spam( enum Ingredient i )
2: {
3: switch( i ) {
4: case Ham:
5: be_a_pig();
6: break;
7: case Salt:
8: drink_some_water();
9: break;
10: default:
11: {
12: what_is_it();
13: break;
14: }
15: }
14: }
Here, lines 4, 7, and 10 are all assigned 'case-label' syntax, while
lines 5 and 8 are assigned 'statement-case-intro'. Line 11 is treated
slightly differently since it contains a brace that opens a block; it is
given 'statement-case-open' syntax.
File: ccmode.info, Node: Brace List Symbols, Next: External Scope Symbols, Prev: Switch Statement Symbols, Up: Syntactic Symbols
10.2.5 Brace List Symbols
-------------------------
There are a set of syntactic symbols that are used to recognize
constructs inside of brace lists. A brace list is defined as an 'enum'
or aggregate initializer list, such as might statically initialize an
array of structs. The three special aggregate constructs in Pike, '({
})', '([ ])' and '(< >)', are treated as brace lists too. An example:
1: static char* ingredients[] =
2: {
3: "Ham",
4: "Salt",
5: NULL
6: };
Following convention, line 2 in this example is assigned
'brace-list-open' syntax, and line 3 is assigned 'brace-list-intro'
syntax. Likewise, line 6 is assigned 'brace-list-close' syntax. Lines
4 and 5 however, are assigned 'brace-list-entry' syntax, as would all
subsequent lines in this initializer list.
Your static initializer might be initializing nested structures, for
example:
1: struct intpairs[] =
2: {
3: { 1, 2 },
4: {
5: 3,
6: 4
7: }
8: { 1,
9: 2 },
10: { 3, 4 }
11: };
Here, you've already seen the analysis of lines 1, 2, 3, and 11. On
line 4, things get interesting; this line is assigned 'brace-entry-open'
syntactic symbol because it's a bracelist entry line that starts with an
open brace. Lines 5 and 6 (and line 9) are pretty standard, and line 7
is a 'brace-list-close' as you'd expect. Once again, line 8 is assigned
as 'brace-entry-open' as is line 10.
File: ccmode.info, Node: External Scope Symbols, Next: Paren List Symbols, Prev: Brace List Symbols, Up: Syntactic Symbols
10.2.6 External Scope Symbols
-----------------------------
External language definition blocks also have their own syntactic
symbols. In this example:
1: extern "C"
2: {
3: int thing_one( int );
4: int thing_two( double );
5: }
line 2 is given the 'extern-lang-open' syntax, while line 5 is given the
'extern-lang-close' syntax. The analysis for line 3 yields:
((inextern-lang) (topmost-intro 14))
where 'inextern-lang' is a modifier similar in purpose to 'inclass'.
There are various other top level blocks like 'extern', and they are
all treated in the same way except that the symbols are named after the
keyword that introduces the block. E.g., C++ namespace blocks get the
three symbols 'namespace-open', 'namespace-close' and 'innamespace'.
The currently recognized top level blocks are:
'extern-lang-open', 'extern-lang-close', 'inextern-lang'
'extern' blocks in C and C++.(1)
'namespace-open', 'namespace-close', 'innamespace'
'namespace' blocks in C++.
'module-open', 'module-close', 'inmodule'
'module' blocks in CORBA IDL.
'composition-open', 'composition-close', 'incomposition'
'composition' blocks in CORBA CIDL.
---------- Footnotes ----------
(1) These should logically be named 'extern-open', 'extern-close' and
'inextern', but that isn't the case for historical reasons.
File: ccmode.info, Node: Paren List Symbols, Next: Literal Symbols, Prev: External Scope Symbols, Up: Syntactic Symbols
10.2.7 Parenthesis (Argument) List Symbols
------------------------------------------
A number of syntactic symbols are associated with parenthesis lists,
a.k.a argument lists, as found in function declarations and function
calls. This example illustrates these:
1: void a_function( int line1,
2: int line2 );
3:
4: void a_longer_function(
5: int line1,
6: int line2
7: );
8:
9: void call_them( int line1, int line2 )
10: {
11: a_function(
12: line1,
13: line2
14: );
15:
16: a_longer_function( line1,
17: line2 );
18: }
Lines 5 and 12 are assigned 'arglist-intro' syntax since they are the
first line following the open parenthesis, and lines 7 and 14 are
assigned 'arglist-close' syntax since they contain the parenthesis that
closes the argument list.
Lines that continue argument lists can be assigned one of two
syntactic symbols. For example, Lines 2 and 17 are assigned
'arglist-cont-nonempty' syntax. What this means is that they continue
an argument list, but that the line containing the parenthesis that
opens the list is _not empty_ following the open parenthesis. Contrast
this against lines 6 and 13 which are assigned 'arglist-cont' syntax.
This is because the parenthesis that opens their argument lists is the
last character on that line.
Syntactic elements with 'arglist-intro', 'arglist-cont-nonempty', and
'arglist-close' contain two buffer positions: the anchor position (the
beginning of the declaration or statement) and the position of the open
parenthesis. The latter position can be used in a line-up function
(*note Line-Up Functions::).
Note that there is no 'arglist-open' syntax. This is because any
parenthesis that opens an argument list, appearing on a separate line,
is assigned the 'statement-cont' syntax instead.
File: ccmode.info, Node: Literal Symbols, Next: Multiline Macro Symbols, Prev: Paren List Symbols, Up: Syntactic Symbols
10.2.8 Comment String Label and Macro Symbols
---------------------------------------------
A few miscellaneous syntactic symbols that haven't been previously
covered are illustrated by this C++ example:
1: void Bass::play( int volume )
2: const
3: {
4: /* this line starts a multiline
5: * comment. This line should get `c' syntax */
6:
7: char* a_multiline_string = "This line starts a multiline \
8: string. This line should get `string' syntax.";
9:
10: note:
11: {
12: #ifdef LOCK
13: Lock acquire();
14: #endif // LOCK
15: slap_pop();
16: cout << "I played "
17: << "a note\n";
18: }
19: }
The lines to note in this example include:
* Line 2 is assigned the 'func-decl-cont' syntax.
* Line 4 is assigned both 'defun-block-intro' _and_ 'comment-intro'
syntax. A syntactic element with 'comment-intro' has no anchor
point. It is always accompanied by another syntactic element which
does have one.
* Line 5 is assigned 'c' syntax.
* Line 6 which, even though it contains nothing but whitespace, is
assigned 'defun-block-intro'. Note that the appearance of the
comment on lines 4 and 5 do not cause line 6 to be assigned
'statement' syntax because comments are considered to be "syntactic
whitespace", which are ignored when analyzing code.
* Line 8 is assigned 'string' syntax.
* Line 10 is assigned 'label' syntax.
* Line 11 is assigned 'block-open' as well as 'statement' syntax. A
'block-open' syntactic element doesn't have an anchor position,
since it always appears with another syntactic element which does
have one.
* Lines 12 and 14 are assigned 'cpp-macro' syntax in addition to the
normal syntactic symbols ('statement-block-intro' and 'statement',
respectively). Normally 'cpp-macro' is configured to cancel out
the normal syntactic context to make all preprocessor directives
stick to the first column, but that's easily changed if you want
preprocessor directives to be indented like the rest of the code.
Like 'comment-intro', a syntactic element with 'cpp-macro' doesn't
contain an anchor position.
* Line 17 is assigned 'stream-op' syntax.
File: ccmode.info, Node: Multiline Macro Symbols, Next: Objective-C Method Symbols, Prev: Literal Symbols, Up: Syntactic Symbols
10.2.9 Multiline Macro Symbols
------------------------------
Multiline preprocessor macro definitions are normally handled just like
other code, i.e., the lines inside them are indented according to the
syntactic analysis of the preceding lines inside the macro. The first
line inside a macro definition (i.e., the line after the starting line
of the cpp directive itself) gets 'cpp-define-intro'. In this example:
1: #define LIST_LOOP(cons, listp) \
2: for (cons = listp; !NILP (cons); cons = XCDR (cons)) \
3: if (!CONSP (cons)) \
4: signal_error ("Invalid list format", listp); \
5: else
line 1 is given the syntactic symbol 'cpp-macro'. The first line of a
cpp directive is always given that symbol. Line 2 is given
'cpp-define-intro', so that you can give the macro body as a whole some
extra indentation. Lines 3 through 5 are then analyzed as normal code,
i.e., 'substatement' on lines 3 and 4, and 'else-clause' on line 5.
The syntactic analysis inside macros can be turned off with
'c-syntactic-indentation-in-macros' (*note Custom Macros::). In that
case, lines 2 through 5 would all be given 'cpp-macro-cont' with an
anchor position pointing to the '#' which starts the cpp directive(1).
*Note Custom Macros::, for more info about the treatment of macros.
---------- Footnotes ----------
(1) This is how CC Mode 5.28 and earlier analyzed macros.
File: ccmode.info, Node: Objective-C Method Symbols, Next: Java Symbols, Prev: Multiline Macro Symbols, Up: Syntactic Symbols
10.2.10 Objective-C Method Symbols
----------------------------------
In Objective-C buffers, there are three additional syntactic symbols
assigned to various message calling constructs. Here's an example
illustrating these:
1: - (void)setDelegate:anObject
2: withStuff:stuff
3: {
4: [delegate masterWillRebind:self
5: toDelegate:anObject
6: withExtraStuff:stuff];
7: }
Here, line 1 is assigned 'objc-method-intro' syntax, and line 2 is
assigned 'objc-method-args-cont' syntax. Lines 5 and 6 are both
assigned 'objc-method-call-cont' syntax.
File: ccmode.info, Node: Java Symbols, Next: Statement Block Symbols, Prev: Objective-C Method Symbols, Up: Syntactic Symbols
10.2.11 Java Symbols
--------------------
Java has a concept of anonymous classes which can look something like
this:
1: @Test
2: public void watch(Observable o) {
3: @NonNull
4: Observer obs = new Observer() {
5: public void update(Observable o, Object arg) {
6: history.addElement(arg);
7: }
8: };
9: o.addObserver(obs);
10: }
The brace following the 'new' operator opens the anonymous class.
Lines 5 and 8 are assigned the 'inexpr-class' syntax, besides the
'inclass' symbol used in normal classes. Thus, the class will be
indented just like a normal class, with the added indentation given to
'inexpr-class'. An 'inexpr-class' syntactic element doesn't have an
anchor position.
Line 2 is assigned the 'annotation-top-cont' syntax, due to it being
a continuation of a topmost introduction with an annotation symbol
preceding the current line. Similarly, line 4 is assigned the
'annotation-var-cont' syntax due to it being a continuation of a
variable declaration where preceding the declaration is an annotation.
File: ccmode.info, Node: Statement Block Symbols, Next: K&R Symbols, Prev: Java Symbols, Up: Syntactic Symbols
10.2.12 Statement Block Symbols
-------------------------------
There are a few occasions where a statement block might be used inside
an expression. One is in C or C++ code using the gcc extension for
this, e.g.:
1: int res = ({
2: int y = foo (); int z;
3: if (y > 0) z = y; else z = - y;
4: z;
5: });
Lines 2 and 5 get the 'inexpr-statement' syntax, besides the symbols
they'd get in a normal block. Therefore, the indentation put on
'inexpr-statement' is added to the normal statement block indentation.
An 'inexpr-statement' syntactic element doesn't contain an anchor
position.
In Pike code, there are a few other situations where blocks occur
inside statements, as illustrated here:
1: array itgob()
2: {
3: string s = map (backtrace()[-2][3..],
4: lambda
5: (mixed arg)
6: {
7: return sprintf ("%t", arg);
8: }) * ", " + "\n";
9: return catch {
10: write (s + "\n");
11: };
12: }
Lines 4 through 8 contain a lambda function, which CC Mode recognizes
by the 'lambda' keyword. If the function argument list is put on a line
of its own, as in line 5, it gets the 'lambda-intro-cont' syntax. The
function body is handled as an inline method body, with the addition of
the 'inlambda' syntactic symbol. This means that line 6 gets 'inlambda'
and 'inline-open', and line 8 gets 'inline-close'(1).
On line 9, 'catch' is a special function taking a statement block as
its argument. The block is handled as an in-expression statement with
the 'inexpr-statement' syntax, just like the gcc extended C example
above. The other similar special function, 'gauge', is handled like
this too.
---------- Footnotes ----------
(1) You might wonder why it doesn't get 'inlambda' too. It's because
the closing brace is relative to the opening brace, which stands on its
own line in this example. If the opening brace was hanging on the
previous line, then the closing brace would get the 'inlambda' syntax
too to be indented correctly.
File: ccmode.info, Node: K&R Symbols, Prev: Statement Block Symbols, Up: Syntactic Symbols
10.2.13 K&R Symbols
-------------------
Two other syntactic symbols can appear in old style, non-prototyped C
code (1):
1: int add_three_integers(a, b, c)
2: int a;
3: int b;
4: int c;
5: {
6: return a + b + c;
7: }
Here, line 2 is the first line in an argument declaration list and so
is given the 'knr-argdecl-intro' syntactic symbol. Subsequent lines
(i.e., lines 3 and 4 in this example), are given 'knr-argdecl' syntax.
---------- Footnotes ----------
(1) a.k.a. K&R C, or Kernighan & Ritchie C
File: ccmode.info, Node: Indentation Calculation, Prev: Syntactic Symbols, Up: Indentation Engine Basics
10.3 Indentation Calculation
============================
Indentation for a line is calculated from the syntactic context (*note
Syntactic Analysis::).
First, a buffer position is found whose column will be the base for
the indentation calculation. It's the anchor position in the first
syntactic element that provides one that is used. If no syntactic
element has an anchor position then column zero is used.
Second, the syntactic symbols in each syntactic element are looked up
in the 'c-offsets-alist' style variable (*note c-offsets-alist::), which
is an association list of syntactic symbols and the offsets to apply for
those symbols. These offsets are added together with the base column to
produce the new indentation column.
Let's use our two code examples above to see how this works. Here is
our first example again:
1: void swap( int& a, int& b )
2: {
3: int tmp = a;
4: a = b;
5: b = tmp;
6: }
Let's say point is on line 3 and we hit the <TAB> key to reindent the
line. The syntactic context for that line is:
((defun-block-intro 29))
Since buffer position 29 is the first and only anchor position in the
list, CC Mode goes there and asks for the current column. This brace is
in column zero, so CC Mode uses '0' as the base column.
Next, CC Mode looks up 'defun-block-intro' in the 'c-offsets-alist'
style variable. Let's say it finds the value '4'; it adds this to the
base column '0', yielding a running total indentation of 4 spaces.
Since there is only one syntactic element on the list for this line,
indentation calculation is complete, and the total indentation for the
line is 4 spaces.
Here's another example:
1: int add( int val, int incr, int doit )
2: {
3: if( doit )
4: {
5: return( val + incr );
6: }
7: return( val );
8: }
If we were to hit 'TAB' on line 4 in the above example, the same
basic process is performed, despite the differences in the syntactic
context. The context for this line is:
((substatement-open 46))
Here, CC Mode goes to buffer position 46, which is the 'i' in 'if' on
line 3. This character is in the fourth column on that line so the base
column is '4'. Then CC Mode looks up the 'substatement-open' symbol in
'c-offsets-alist'. Let's say it finds the value '4'. It's added with
the base column and yields an indentation for the line of 8 spaces.
Simple, huh?
Actually, it's a bit more complicated than that since the entries on
'c-offsets-alist' can be much more than plain offsets. *Note
c-offsets-alist::, for the full story.
Anyway, the mode usually just does The Right Thing without you having
to think about it in this much detail. But when customizing
indentation, it's helpful to understand the general indentation model
being used.
As you configure CC Mode, you might want to set the variable
'c-echo-syntactic-information-p' to non-'nil' so that the syntactic
context and calculated offset always is echoed in the minibuffer when
you hit 'TAB'.
File: ccmode.info, Node: Customizing Indentation, Next: Custom Macros, Prev: Indentation Engine Basics, Up: Top
11 Customizing Indentation
**************************
The principal variable for customizing indentation is the style variable
'c-offsets-alist', which gives an "offset" (an indentation rule) for
each syntactic symbol. Its structure and semantics are completely
described in *note c-offsets-alist::. The various ways you can set the
variable, including the use of the CC Mode style system, are described
in *note Config Basics:: and its sections, in particular *note Style
Variables::.
The simplest and most used kind of "offset" setting in
'c-offsets-alist' is in terms of multiples of 'c-basic-offset':
-- User Option: c-basic-offset
This style variable holds the basic offset between indentation
levels. It's factory default is 4, but all the built-in styles set
it themselves, to some value between 2 (for 'gnu' style) and 8 (for
'bsd', 'linux', and 'python' styles).
The most flexible "offset" setting you can make in 'c-offsets-alist'
is a line-up function (or even a list of them), either one supplied by
CC Mode (*note Line-Up Functions::) or one you write yourself (*note
Custom Line-Up::).
Finally, in *note Other Indentation:: you'll find the tool of last
resort: a hook which is called after a line has been indented. You can
install functions here to make ad-hoc adjustments to any line's
indentation.
* Menu:
* c-offsets-alist::
* Interactive Customization::
* Line-Up Functions::
* Custom Line-Up::
* Other Indentation::
File: ccmode.info, Node: c-offsets-alist, Next: Interactive Customization, Prev: Customizing Indentation, Up: Customizing Indentation
11.1 c-offsets-alist
====================
This section explains the structure and semantics of the style variable
'c-offsets-alist', the principal variable for configuring indentation.
Details of how to set it up, and its relationship to CC Mode's style
system are given in *note Style Variables::.
-- User Option: c-offsets-alist
This is an alist which associates an offset with each syntactic
symbol. This "offset" is a rule specifying how to indent a line
whose syntactic context matches the symbol. *Note Syntactic
Analysis::.
Note that the buffer-local binding of this alist in a CC Mode
buffer contains an entry for _every_ syntactic symbol. Its global
binding and its settings within style specifications usually
contain only a few entries. *Note Style Variables::.
The offset specification associated with any particular syntactic
symbol can be an integer, a variable name, a vector, a function or
lambda expression, a list, or one of the following special symbols:
'+', '-', '++', '--', '*', or '/'. The meanings of these values
are described in detail below.
Here is an example fragment of a 'c-offsets-alist', showing some of
these kinds of offsets:
((statement . 0)
(substatement . +)
(cpp-macro . [0])
(topmost-intro-cont . c-lineup-topmost-intro-cont)
(statement-block-intro . (add c-lineup-whitesmith-in-block
c-indent-multi-line-block))
...
)
-- Command: c-set-offset ('C-c C-o')
This command changes the entry for a syntactic symbol in the
current binding of 'c-offsets-alist', or it inserts a new entry if
there isn't already one for that syntactic symbol.
You can use 'c-set-offsets' interactively within a CC Mode buffer
to make experimental changes to your indentation settings. 'C-c
C-o' prompts you for the syntactic symbol to change (defaulting to
that of the current line) and the new offset (defaulting to the
current offset).
'c-set-offsets' takes two arguments when used programmatically:
SYMBOL, the syntactic element symbol to change and OFFSET, the new
offset for that syntactic element. You can call the command in
your '.emacs' to change the global binding of 'c-offsets-alist'
(*note Style Variables::); you can use it in a hook function to
make changes from the current style. CC Mode itself uses this
function when initializing styles.
The "offset specifications" in 'c-offsets-alist' can be any of the
following:
An integer
The integer specifies a relative offset. All relative offsets(1)
will be added together and used to calculate the indentation
relative to an anchor position earlier in the buffer. *Note
Indentation Calculation::, for details. Most of the time, it's
probably better to use one of the special symbols like '+' than an
integer (apart from zero).
One of the symbols '+', '-', '++', '--', '*', or '/'
These special symbols describe a relative offset in multiples of
'c-basic-offset':
By defining a style's indentation in terms of 'c-basic-offset', you
can change the amount of whitespace given to an indentation level
while maintaining the same basic shape of your code. Here are the
values that the special symbols correspond to:
'+'
'c-basic-offset' times 1
'-'
'c-basic-offset' times -1
'++'
'c-basic-offset' times 2
'--'
'c-basic-offset' times -2
'*'
'c-basic-offset' times 0.5
'/'
'c-basic-offset' times -0.5
A vector
The first element of the vector, an integer, sets the absolute
indentation column. This will override any previously calculated
indentation, but won't override relative indentation calculated
from syntactic elements later on in the syntactic context of the
line being indented. *Note Indentation Calculation::. Any
elements in the vector beyond the first will be ignored.
A function or lambda expression
The function will be called and its return value will in turn be
evaluated as an offset specification. Functions are useful when
more context than just the syntactic symbol is needed to get the
desired indentation. *Note Line-Up Functions::, and *note Custom
Line-Up::, for details about them.
A symbol with a variable binding
If the symbol also has a function binding, the function takes
precedence over the variable. Otherwise the value of the variable
is used. It must be an integer (which is used as relative offset)
or a vector (an absolute offset).
A list
The offset can also be a list containing several offset
specifications; these are evaluated recursively and combined. A
list is typically only useful when some of the offsets are line-up
functions. A common strategy is calling a sequence of functions in
turn until one of them recognizes that it is appropriate for the
source line and returns a non-'nil' value.
'nil' values are always ignored when the offsets are combined. The
first element of the list specifies the method of combining the
non-'nil' offsets from the remaining elements:
'first'
Use the first offset that doesn't evaluate to 'nil'.
Subsequent elements of the list don't get evaluated.
'min'
Use the minimum of all the offsets. All must be either
relative or absolute; they can't be mixed.
'max'
Use the maximum of all the offsets. All must be either
relative or absolute; they can't be mixed.
'add'
Add all the evaluated offsets together. Exactly one of them
may be absolute, in which case the result is absolute. Any
relative offsets that preceded the absolute one in the list
will be ignored in that case.
As a compatibility measure, if the first element is none of the
above then it too will be taken as an offset specification and the
whole list will be combined according to the method 'first'.
If an offset specification evaluates to 'nil', then a relative offset
of 0 (zero) is used(2).
---------- Footnotes ----------
(1) The syntactic context
'((defun-block-intro 2724) (comment-intro))' would likely have two
relative offsets.
(2) There is however a variable 'c-strict-syntax-p' that when set to
non-'nil' will cause an error to be signaled in that case. It's now
considered obsolete since it doesn't work well with some of the
alignment functions that return 'nil' instead of zero. You should
therefore leave 'c-strict-syntax-p' set to 'nil'.
File: ccmode.info, Node: Interactive Customization, Next: Line-Up Functions, Prev: c-offsets-alist, Up: Customizing Indentation
11.2 Interactive Customization
==============================
As an example of how to customize indentation, let's change the style of
this example(1):
1: int add( int val, int incr, int doit )
2: {
3: if( doit )
4: {
5: return( val + incr );
6: }
7: return( val );
8: }
to:
1: int add( int val, int incr, int doit )
2: {
3: if( doit )
4: {
5: return( val + incr );
6: }
7: return( val );
8: }
In other words, we want to change the indentation of braces that open
a block following a condition so that the braces line up under the
conditional, instead of being indented. Notice that the construct we
want to change starts on line 4. To change the indentation of a line,
we need to see which syntactic symbols affect the offset calculations
for that line. Hitting 'C-c C-s' on line 4 yields:
((substatement-open 44))
so we know that to change the offset of the open brace, we need to
change the indentation for the 'substatement-open' syntactic symbol.
To do this interactively, just hit 'C-c C-o'. This prompts you for
the syntactic symbol to change, providing a reasonable default. In this
case, the default is 'substatement-open', which is just the syntactic
symbol we want to change!
After you hit return, CC Mode will then prompt you for the new offset
value, with the old value as the default. The default in this case is
'+', but we want no extra indentation so enter '0' and 'RET'. This will
associate the offset 0 with the syntactic symbol 'substatement-open'.
To check your changes quickly, just hit 'C-c C-q' ('c-indent-defun')
to reindent the entire function. The example should now look like:
1: int add( int val, int incr, int doit )
2: {
3: if( doit )
4: {
5: return( val + incr );
6: }
7: return( val );
8: }
Notice how just changing the open brace offset on line 4 is all we
needed to do. Since the other affected lines are indented relative to
line 4, they are automatically indented the way you'd expect. For more
complicated examples, this might not always work. The general approach
to take is to always start adjusting offsets for lines higher up in the
file, then reindent and see if any following lines need further
adjustments.
-- Command: c-set-offset symbol offset
This is the command bound to 'C-c C-o'. It provides a convenient
way to set offsets on 'c-offsets-alist' both interactively (see the
example above) and from your mode hook.
It takes two arguments when used programmatically: SYMBOL is the
syntactic element symbol to change and OFFSET is the new offset for
that syntactic element.
---------- Footnotes ----------
(1) In this and subsequent examples, the original code is formatted
using the 'gnu' style unless otherwise indicated. *Note Styles::.
File: ccmode.info, Node: Line-Up Functions, Next: Custom Line-Up, Prev: Interactive Customization, Up: Customizing Indentation
11.3 Line-Up Functions
======================
Often there are cases when a simple offset setting on a syntactic symbol
isn't enough to get the desired indentation--for example, you might want
to line up a closing parenthesis with the matching opening one rather
than indenting relative to its "anchor point". CC Mode provides this
flexibility with "line-up functions".
The way you associate a line-up function with a syntactic symbol is
described in *note c-offsets-alist::. CC Mode comes with many
predefined line-up functions for common situations. If none of these
does what you want, you can write your own. *Note Custom Line-Up::.
Sometimes, it is easier to tweak the standard indentation by adding a
function to 'c-special-indent-hook' (*note Other Indentation::).
The line-up functions haven't been adapted for AWK buffers or tested
with them. Some of them might work serendipitously. There shouldn't be
any problems writing custom line-up functions for AWK mode.
The calling convention for line-up functions is described fully in
*note Custom Line-Up::. Roughly speaking, the return value is either an
offset itself (such as '+' or '[0]') or it's 'nil', meaning "this
function is inappropriate in this case; try a different one". *Note
c-offsets-alist::.
The subsections below describe all the standard line-up functions,
categorized by the sort of token the lining-up centers around. For each
of these functions there is a "works with" list that indicates which
syntactic symbols the function is intended to be used with.
* Menu:
* Brace/Paren Line-Up::
* List Line-Up::
* Operator Line-Up::
* Comment Line-Up::
* Misc Line-Up::
File: ccmode.info, Node: Brace/Paren Line-Up, Next: List Line-Up, Prev: Line-Up Functions, Up: Line-Up Functions
11.3.1 Brace and Parenthesis Line-Up Functions
----------------------------------------------
The line-up functions here calculate the indentation for braces,
parentheses and statements within brace blocks.
-- Function: c-lineup-close-paren
Line up the closing paren under its corresponding open paren if the
open paren is followed by code. If the open paren ends its line,
no indentation is added. E.g.:
main (int,
char **
) <- c-lineup-close-paren
and
main (
int, char **
) <- c-lineup-close-paren
As a special case, if a brace block is opened at the same line as
the open parenthesis of the argument list, the indentation is
'c-basic-offset' instead of the open paren column. See
'c-lineup-arglist' for further discussion of this "DWIM" measure.
Works with: All '*-close' symbols.
-- Function: c-lineup-arglist-close-under-paren
Set your 'arglist-close' syntactic symbol to this line-up function
so that parentheses that close argument lists will line up under
the parenthesis that opened the argument list. It can also be used
with 'arglist-cont' and 'arglist-cont-nonempty' to line up all
lines inside a parenthesis under the open paren.
As a special case, if a brace block is opened at the same line as
the open parenthesis of the argument list, the indentation is
'c-basic-offset' only. See 'c-lineup-arglist' for further
discussion of this "DWIM" measure.
Works with: Almost all symbols, but are typically most useful on
'arglist-close', 'brace-list-close', 'arglist-cont' and
'arglist-cont-nonempty'.
-- Function: c-indent-one-line-block
Indent a one line block 'c-basic-offset' extra. E.g.:
if (n > 0)
{m+=n; n=0;} <- c-indent-one-line-block<--> c-basic-offset
and
if (n > 0)
{ <- c-indent-one-line-block m+=n; n=0;
}
The block may be surrounded by any kind of parenthesis characters.
'nil' is returned if the line doesn't start with a one line block,
which makes the function usable in list expressions.
Works with: Almost all syntactic symbols, but most useful on the
'-open' symbols.
-- Function: c-indent-multi-line-block
Indent a multiline block 'c-basic-offset' extra. E.g.:
int *foo[] = {
NULL,
{17}, <- c-indent-multi-line-block
and
int *foo[] = {
NULL,
{ <- c-indent-multi-line-block 17
},
<--> c-basic-offset
The block may be surrounded by any kind of parenthesis characters.
'nil' is returned if the line doesn't start with a multiline block,
which makes the function usable in list expressions.
Works with: Almost all syntactic symbols, but most useful on the
'-open' symbols.
-- Function: c-lineup-runin-statements
Line up statements for coding standards which place the first
statement in a block on the same line as the block opening
brace(1). E.g.:
int main()
{ puts ("Hello!");
return 0; <- c-lineup-runin-statements}
If there is no statement after the opening brace to align with,
'nil' is returned. This makes the function usable in list
expressions.
Works with: The 'statement' syntactic symbol.
-- Function: c-lineup-inexpr-block
This can be used with the in-expression block symbols to indent the
whole block to the column where the construct is started. E.g.,
for Java anonymous classes, this lines up the class under the 'new'
keyword, and in Pike it lines up the lambda function body under the
'lambda' keyword. Returns 'nil' if the block isn't part of such a
construct.
Works with: 'inlambda', 'inexpr-statement', 'inexpr-class'.
-- Function: c-lineup-after-whitesmith-blocks
Compensate for Whitesmith style indentation of blocks. Due to the
way CC Mode calculates anchor positions for normal lines inside
blocks, this function is necessary for those lines to get correct
Whitesmith style indentation. Consider the following examples:
int foo()
{
a;
x; <- c-lineup-after-whitesmith-blocks
int foo()
{
{
a;
}
x; <- c-lineup-after-whitesmith-blocks
The fact that the line with 'x' is preceded by a Whitesmith style
indented block in the latter case and not the first should not
affect its indentation. But since CC Mode in cases like this uses
the indentation of the preceding statement as anchor position, the
'x' would in the second case be indented too much if the offset for
'statement' was set simply to zero.
This lineup function corrects for this situation by detecting if
the anchor position is at an open paren character. In that case,
it instead indents relative to the surrounding block just like
'c-lineup-whitesmith-in-block'.
Works with: 'brace-list-entry', 'brace-entry-open', 'statement',
'arglist-cont'.
-- Function: c-lineup-whitesmith-in-block
Line up lines inside a block in Whitesmith style. It's done in a
way that works both when the opening brace hangs and when it
doesn't. E.g.:
something
{
foo; <- c-lineup-whitesmith-in-block }
and
something {
foo; <- c-lineup-whitesmith-in-block }
<--> c-basic-offset
In the first case the indentation is kept unchanged, in the second
'c-basic-offset' is added.
Works with: 'defun-close', 'defun-block-intro', 'inline-close',
'block-close', 'brace-list-close', 'brace-list-intro',
'statement-block-intro', 'arglist-intro', 'arglist-cont-nonempty',
'arglist-close', and all 'in*' symbols, e.g., 'inclass' and
'inextern-lang'.
---------- Footnotes ----------
(1) Run-in style doesn't really work too well. You might need to
write your own custom line-up functions to better support this style.
File: ccmode.info, Node: List Line-Up, Next: Operator Line-Up, Prev: Brace/Paren Line-Up, Up: Line-Up Functions
11.3.2 List Line-Up Functions
-----------------------------
The line-up functions here calculate the indentation for lines which
form lists of items, usually separated by commas.
The function *note c-lineup-arglist-close-under-paren::, which is
mainly for indenting a close parenthesis, is also useful for the lines
contained within parentheses.
-- Function: c-lineup-arglist
Line up the current argument line under the first argument.
As a special case, if an argument on the same line as the open
parenthesis starts with a brace block opener, the indentation is
'c-basic-offset' only. This is intended as a "DWIM" measure in
cases like macros that contain statement blocks, e.g.:
A_VERY_LONG_MACRO_NAME ({
some (code, with + long, lines * in[it]);
});
<--> c-basic-offset
This is motivated partly because it's more in line with how code
blocks are handled, and partly since it approximates the behavior
of earlier CC Mode versions, which due to inaccurate analysis
tended to indent such cases this way.
Works with: 'arglist-cont-nonempty', 'arglist-close'.
-- Function: c-lineup-arglist-intro-after-paren
Line up a line to just after the open paren of the surrounding
paren or brace block.
Works with: 'defun-block-intro', 'brace-list-intro',
'statement-block-intro', 'statement-case-intro', 'arglist-intro'.
-- Function: c-lineup-multi-inher
Line up the classes in C++ multiple inheritance clauses and member
initializers under each other. E.g.:
Foo::Foo (int a, int b):
Cyphr (a),
Bar (b) <- c-lineup-multi-inher
and
class Foo
: public Cyphr,
public Bar <- c-lineup-multi-inher
and
Foo::Foo (int a, int b)
: Cyphr (a)
, Bar (b) <- c-lineup-multi-inher
Works with: 'inher-cont', 'member-init-cont'.
-- Function: c-lineup-java-inher
Line up Java implements and extends declarations. If class names
follow on the same line as the 'implements'/'extends' keyword, they
are lined up under each other. Otherwise, they are indented by
adding 'c-basic-offset' to the column of the keyword. E.g.:
class Foo
extends
Bar <- c-lineup-java-inher <--> c-basic-offset
and
class Foo
extends Cyphr,
Bar <- c-lineup-java-inher
Works with: 'inher-cont'.
-- Function: c-lineup-java-throws
Line up Java throws declarations. If exception names follow on the
same line as the throws keyword, they are lined up under each
other. Otherwise, they are indented by adding 'c-basic-offset' to
the column of the 'throws' keyword. The 'throws' keyword itself is
also indented by 'c-basic-offset' from the function declaration
start if it doesn't hang. E.g.:
int foo()
throws <- c-lineup-java-throws Bar <- c-lineup-java-throws<--><--> c-basic-offset
and
int foo() throws Cyphr,
Bar, <- c-lineup-java-throws Vlod <- c-lineup-java-throws
Works with: 'func-decl-cont'.
-- Function: c-lineup-template-args
Line up the arguments of a template argument list under each other,
but only in the case where the first argument is on the same line
as the opening '<'.
To allow this function to be used in a list expression, 'nil' is
returned if there's no template argument on the first line.
Works with: 'template-args-cont'.
-- Function: c-lineup-ObjC-method-call
For Objective-C code, line up selector args as Emacs Lisp mode does
with function args: go to the position right after the message
receiver, and if you are at the end of the line, indent the current
line c-basic-offset columns from the opening bracket; otherwise you
are looking at the first character of the first method call
argument, so lineup the current line with it.
Works with: 'objc-method-call-cont'.
-- Function: c-lineup-ObjC-method-args
For Objective-C code, line up the colons that separate args. The
colon on the current line is aligned with the one on the first
line.
Works with: 'objc-method-args-cont'.
-- Function: c-lineup-ObjC-method-args-2
Similar to 'c-lineup-ObjC-method-args' but lines up the colon on
the current line with the colon on the previous line.
Works with: 'objc-method-args-cont'.
File: ccmode.info, Node: Operator Line-Up, Next: Comment Line-Up, Prev: List Line-Up, Up: Line-Up Functions
11.3.3 Operator Line-Up Functions
---------------------------------
The line-up functions here calculate the indentation for lines which
start with an operator, by lining it up with something on the previous
line.
-- Function: c-lineup-argcont
Line up a continued argument. E.g.:
foo (xyz, aaa + bbb + ccc
+ ddd + eee + fff); <- c-lineup-argcont
Only continuation lines like this are touched, 'nil' is returned on
lines which are the start of an argument.
Within a gcc 'asm' block, ':' is recognized as an argument
separator, but of course only between operand specifications, not
in the expressions for the operands.
Works with: 'arglist-cont', 'arglist-cont-nonempty'.
-- Function: c-lineup-arglist-operators
Line up lines starting with an infix operator under the open paren.
Return 'nil' on lines that don't start with an operator, to leave
those cases to other line-up functions. Example:
if ( x < 10
|| at_limit (x, <- c-lineup-arglist-operators list) <- c-lineup-arglist-operators returns nil )
Since this function doesn't do anything for lines without an infix
operator you typically want to use it together with some other
lineup settings, e.g., as follows (the 'arglist-close' setting is
just a suggestion to get a consistent style):
(c-set-offset 'arglist-cont
'(c-lineup-arglist-operators 0))
(c-set-offset 'arglist-cont-nonempty
'(c-lineup-arglist-operators c-lineup-arglist))
(c-set-offset 'arglist-close
'(c-lineup-arglist-close-under-paren))
Works with: 'arglist-cont', 'arglist-cont-nonempty'.
-- Function: c-lineup-assignments
Line up the current line after the assignment operator on the first
line in the statement. If there isn't any, return nil to allow
stacking with other line-up functions. If the current line
contains an assignment operator too, try to align it with the first
one.
Works with: 'topmost-intro-cont', 'statement-cont', 'arglist-cont',
'arglist-cont-nonempty'.
-- Function: c-lineup-math
Like 'c-lineup-assignments' but indent with 'c-basic-offset' if no
assignment operator was found on the first line. I.e., this
function is the same as specifying a list '(c-lineup-assignments
+)'. It's provided for compatibility with old configurations.
Works with: 'topmost-intro-cont', 'statement-cont', 'arglist-cont',
'arglist-cont-nonempty'.
-- Function: c-lineup-cascaded-calls
Line up "cascaded calls" under each other. If the line begins with
'->' or '.' and the preceding line ends with one or more function
calls preceded by the same token, then the arrow is lined up with
the first of those tokens. E.g.:
r = proc->add(17)->add(18)
->add(19) + <- c-lineup-cascaded-calls offset; <- c-lineup-cascaded-calls (inactive)
In any other situation 'nil' is returned to allow use in list
expressions.
Works with: 'topmost-intro-cont', 'statement-cont', 'arglist-cont',
'arglist-cont-nonempty'.
-- Function: c-lineup-streamop
Line up C++ stream operators (i.e., '<<' and '>>').
Works with: 'stream-op'.
-- Function: c-lineup-string-cont
Line up a continued string under the one it continues. A continued
string in this sense is where a string literal follows directly
after another one. E.g.:
result = prefix + "A message "
"string."; <- c-lineup-string-cont
'nil' is returned in other situations, to allow stacking with other
lineup functions.
Works with: 'topmost-intro-cont', 'statement-cont', 'arglist-cont',
'arglist-cont-nonempty'.
File: ccmode.info, Node: Comment Line-Up, Next: Misc Line-Up, Prev: Operator Line-Up, Up: Line-Up Functions
11.3.4 Comment Line-Up Functions
--------------------------------
The lineup functions here calculate the indentation for several types of
comment structure.
-- Function: c-lineup-C-comments
Line up C block comment continuation lines. Various heuristics are
used to handle most of the common comment styles. Some examples:
/* /** /*
* text * text text
*/ */ */
/* text /* /**
text ** text ** text
*/ */ */
/**************************************************
* text
*************************************************/
/**************************************************
Free form text comments:
In comments with a long delimiter line at the
start, the indentation is kept unchanged for lines
that start with an empty comment line prefix. The
delimiter line is whatever matches the
comment-start-skip regexp.
**************************************************/
The style variable 'c-comment-prefix-regexp' is used to recognize
the comment line prefix, e.g., the '*' that usually starts every
line inside a comment.
Works with: The 'c' syntactic symbol.
-- Function: c-lineup-comment
Line up a comment-only line according to the style variable
'c-comment-only-line-offset'. If the comment is lined up with a
comment starter on the previous line, that alignment is preserved.
-- User Option: c-comment-only-line-offset
This style variable specifies the extra offset for the line.
It can contain an integer or a cons cell of the form
(NON-ANCHORED-OFFSET . ANCHORED-OFFSET)
where NON-ANCHORED-OFFSET is the amount of offset given to
non-column-zero anchored lines, and ANCHORED-OFFSET is the
amount of offset to give column-zero anchored lines. Just an
integer as value is equivalent to '(VALUE . -1000)'.
Works with: 'comment-intro'.
-- Function: c-lineup-knr-region-comment
Line up a comment in the "K&R region" with the declaration. That
is the region between the function or class header and the
beginning of the block. E.g.:
int main()
/* Called at startup. */ <- c-lineup-knr-region-comment{
return 0;
}
Return 'nil' if called in any other situation, to be useful in list
expressions.
Works with: 'comment-intro'.
File: ccmode.info, Node: Misc Line-Up, Prev: Comment Line-Up, Up: Line-Up Functions
11.3.5 Miscellaneous Line-Up Functions
--------------------------------------
The line-up functions here are the odds and ends which didn't fit into
any earlier category.
-- Function: c-lineup-dont-change
This lineup function makes the line stay at whatever indentation it
already has; think of it as an identity function for lineups.
Works with: Any syntactic symbol.
-- Function: c-lineup-cpp-define
Line up macro continuation lines according to the indentation of
the construct preceding the macro. E.g.:
const char msg[] = <- The beginning of the preceding construct. \"Some text.\";
#define X(A, B) \
do { \ <- c-lineup-cpp-define printf (A, B); \
} while (0)
and:
int dribble() {
if (!running) <- The beginning of the preceding construct. error(\"Not running!\");
#define X(A, B) \
do { \ <- c-lineup-cpp-define printf (A, B); \
} while (0)
If 'c-syntactic-indentation-in-macros' is non-'nil', the function
returns the relative indentation to the macro start line to allow
accumulation with other offsets. E.g., in the following cases,
'cpp-define-intro' is combined with the 'statement-block-intro'
that comes from the 'do {' that hangs on the '#define' line:
const char msg[] =
\"Some text.\";
#define X(A, B) do { \
printf (A, B); \ <- c-lineup-cpp-define this->refs++; \
} while (0) <- c-lineup-cpp-define
and:
int dribble() {
if (!running)
error(\"Not running!\");
#define X(A, B) do { \
printf (A, B); \ <- c-lineup-cpp-define this->refs++; \
} while (0) <- c-lineup-cpp-define
The relative indentation returned by 'c-lineup-cpp-define' is zero
and two, respectively, on the two lines in each of these examples.
They are then added to the two column indentation that
'statement-block-intro' gives in both cases here.
If the relative indentation is zero, then 'nil' is returned
instead. That is useful in a list expression to specify the
default indentation on the top level.
If 'c-syntactic-indentation-in-macros' is 'nil' then this function
keeps the current indentation, except for empty lines (ignoring the
ending backslash) where it takes the indentation from the closest
preceding nonempty line in the macro. If there's no such line in
the macro then the indentation is taken from the construct
preceding it, as described above.
Works with: 'cpp-define-intro'.
-- Function: c-lineup-gcc-asm-reg
Line up a gcc asm register under one on a previous line.
asm ("foo %1, %0\n"
"bar %0, %1"
: "=r" (w),
"=r" (x)
: "0" (y),
"1" (z));
The 'x' line is aligned to the text after the ':' on the 'w' line,
and similarly 'z' under 'y'.
This is done only in an 'asm' or '__asm__' block, and only to those
lines mentioned. Anywhere else 'nil' is returned. The usual
arrangement is to have this routine as an extra feature at the
start of arglist lineups, e.g.:
(c-lineup-gcc-asm-reg c-lineup-arglist)
Works with: 'arglist-cont', 'arglist-cont-nonempty'.
-- Function: c-lineup-topmost-intro-cont
Line up declaration continuation lines zero or one indentation
step(1). For lines preceding a definition, zero is used. For
other lines, 'c-basic-offset' is added to the indentation. E.g.:
int
neg (int i) <- c-lineup-topmost-intro-cont{
return -i;
}
and
struct
larch <- c-lineup-topmost-intro-cont{
double height;
}
the_larch, <- c-lineup-topmost-intro-cont another_larch; <- c-lineup-topmost-intro-cont<--> c-basic-offset
and
struct larch
the_larch, <- c-lineup-topmost-intro-cont another_larch; <- c-lineup-topmost-intro-cont
Works with: 'topmost-intro-cont'.
---------- Footnotes ----------
(1) This function is mainly provided to mimic the behavior of CC Mode
5.28 and earlier where this case wasn't handled consistently so that
those lines could be analyzed as either topmost-intro-cont or
statement-cont. It's used for 'topmost-intro-cont' by default, but you
might consider using '+' instead.
File: ccmode.info, Node: Custom Line-Up, Next: Other Indentation, Prev: Line-Up Functions, Up: Customizing Indentation
11.4 Custom Line-Up Functions
=============================
The most flexible way to customize indentation is by writing custom
line-up functions, and associating them with specific syntactic symbols
(*note c-offsets-alist::). Depending on the effect you want, it might
be better to write a 'c-special-indent-hook' function rather than a
line-up function (*note Other Indentation::).
CC Mode comes with an extensive set of predefined line-up functions,
not all of which are used by the default styles. So there's a good
chance the function you want already exists. *Note Line-Up Functions::,
for a list of them. If you write your own line-up function, it's
probably a good idea to start working from one of these predefined
functions, which can be found in the file 'cc-align.el'. If you have
written a line-up function that you think is generally useful, you're
very welcome to contribute it; please contact <bug-cc-mode AT gnu.org>.
Line-up functions are passed a single argument, the syntactic element
(see below). The return value is a 'c-offsets-alist' offset
specification: for example, an integer, a symbol such as '+', a vector,
'nil'(1), or even another line-up function. Full details of these are
in *note c-offsets-alist::.
Line-up functions must not move point or change the content of the
buffer (except temporarily). They are however allowed to do "hidden
buffer changes", i.e., setting text properties for caching purposes etc.
Buffer undo recording is disabled while they run.
The syntactic element passed as the parameter to a line-up function
is a cons cell of the form
(SYNTACTIC-SYMBOL . ANCHOR-POSITION)
where SYNTACTIC-SYMBOL is the symbol that the function was called for,
and ANCHOR-POSITION is the anchor position (if any) for the construct
that triggered the syntactic symbol (*note Syntactic Analysis::). This
cons cell is how the syntactic element of a line used to be represented
in CC Mode 5.28 and earlier. Line-up functions are still passed this
cons cell, so as to preserve compatibility with older configurations.
In the future, we may decide to convert to using the full list
format--you can prepare your setup for this by using the access
functions ('c-langelem-sym', etc.) described below.
Some syntactic symbols, e.g., 'arglist-cont-nonempty', have more info
in the syntactic element: typically other positions that can be
interesting besides the anchor position. That info can't be accessed
through the passed argument, which is a cons cell. Instead, you can get
this information from the variable 'c-syntactic-element', which is
dynamically bound to the complete syntactic element. The variable
'c-syntactic-context' might also be useful: it gets dynamically bound to
the complete syntactic context. *Note Custom Braces::.
CC Mode provides a few functions to access parts of syntactic
elements in a more abstract way. Besides making the code easier to
read, they also hide the difference between the old cons cell form used
in the line-up function argument and the new list form used in
'c-syntactic-element' and everywhere else. The functions are:
-- Function: c-langelem-sym langelem
Return the syntactic symbol in LANGELEM.
-- Function: c-langelem-pos langelem
Return the anchor position in LANGELEM, or nil if there is none.
-- Function: c-langelem-col langelem &optional preserve-point
Return the column of the anchor position in LANGELEM. Also move
the point to that position unless PRESERVE-POINT is non-'nil'.
-- Function: c-langelem-2nd-pos langelem
Return the secondary position in LANGELEM, or 'nil' if there is
none.
Note that the return value of this function is always 'nil' if
LANGELEM is in the old cons cell form. Thus this function is only
meaningful when used on syntactic elements taken from
'c-syntactic-element' or 'c-syntactic-context'.
Custom line-up functions can be as simple or as complex as you like,
and any syntactic symbol that appears in 'c-offsets-alist' can have a
custom line-up function associated with it.
---------- Footnotes ----------
(1) Returning 'nil' is useful when the offset specification for a
syntactic element is a list containing the line-up function (*note
c-offsets-alist::).
File: ccmode.info, Node: Other Indentation, Prev: Custom Line-Up, Up: Customizing Indentation
11.5 Other Special Indentations
===============================
To configure macros which you invoke without a terminating ';', see
*Note Macros with ;::.
Here are the remaining odds and ends regarding indentation:
-- User Option: c-label-minimum-indentation
In 'gnu' style (*note Built-in Styles::), a minimum indentation is
imposed on lines inside code blocks. This minimum indentation is
controlled by this style variable. The default value is 1.
It's the function 'c-gnu-impose-minimum' that enforces this minimum
indentation. It must be present on 'c-special-indent-hook' to
work.
-- User Option: c-special-indent-hook
This style variable is a standard hook variable that is called
after every line is indented by CC Mode. It is called only if
'c-syntactic-indentation' is non-'nil' (which it is by default
(*note Indentation Engine Basics::)). You can put a function on
this hook to do any special indentation or ad hoc line adjustments
your style dictates, such as adding extra indentation to
constructors or destructor declarations in a class definition, etc.
Sometimes it is better to write a custom Line-up Function instead
(*note Custom Line-Up::).
When the indentation engine calls this hook, the variable
'c-syntactic-context' is bound to the current syntactic context
(i.e., what you would get by typing 'C-c C-s' on the source line.
*Note Custom Braces::.). Note that you should not change point or
mark inside a 'c-special-indent-hook' function, i.e., you'll
probably want to wrap your function in a 'save-excursion'(1).
Setting 'c-special-indent-hook' in style definitions is handled
slightly differently from other variables--A style can only add
functions to this hook, not remove them. *Note Style Variables::.
---------- Footnotes ----------
(1) The numerical value returned by 'point' will change if you change
the indentation of the line within a 'save-excursion' form, but point
itself will still be over the same piece of text.
File: ccmode.info, Node: Custom Macros, Next: Odds and Ends, Prev: Customizing Indentation, Up: Top
12 Customizing Macros
*********************
Preprocessor macros in C, C++, and Objective C (introduced by '#define')
have a syntax different from the main language--for example, a macro
declaration is not terminated by a semicolon, and if it is more than a
line long, line breaks in it must be escaped with backslashes. CC Mode
has some commands to manipulate these, see *note Macro Backslashes::.
Normally, the lines in a multi-line macro are indented relative to
each other as though they were code. You can suppress this behavior by
setting the following user option:
-- User Option: c-syntactic-indentation-in-macros
Enable syntactic analysis inside macros, which is the default. If
this is 'nil', all lines inside macro definitions are analyzed as
'cpp-macro-cont'.
Because a macro can expand into anything at all, near where one is
invoked CC Mode can only indent and fontify code heuristically.
Sometimes it gets it wrong. Usually you should try to design your
macros so that they "look like ordinary code" when you invoke them.
However, one situation is so common that CC Mode handles it specially:
that is when certain macros needn't (or mustn't) be followed by a ';'.
You need to configure CC Mode to handle these macros properly, see *note
Macros with ;::.
* Menu:
* Macro Backslashes::
* Macros with ;::
File: ccmode.info, Node: Macro Backslashes, Next: Macros with ;, Prev: Custom Macros, Up: Custom Macros
12.1 Customizing Macro Backslashes
==================================
CC Mode provides some tools to help keep the line continuation
backslashes in macros neat and tidy. Their precise action is customized
with these variables:
-- User Option: c-backslash-column
-- User Option: c-backslash-max-column
These variables control the alignment columns for line continuation
backslashes in multiline macros. They are used by the functions
that automatically insert or align such backslashes, e.g.,
'c-backslash-region' and 'c-context-line-break'.
'c-backslash-column' specifies the minimum column for the
backslashes. If any line in the macro goes past this column, then
the next tab stop (i.e., next multiple of 'tab-width') in that line
is used as the alignment column for all the backslashes, so that
they remain in a single column. However, if any lines go past
'c-backslash-max-column' then the backslashes in the rest of the
macro will be kept at that column, so that the lines which are too
long "stick out" instead.
Don't ever set these variables to 'nil'. If you want to disable
the automatic alignment of backslashes, use
'c-auto-align-backslashes'.
-- User Option: c-auto-align-backslashes
Align automatically inserted line continuation backslashes if
non-'nil'. When line continuation backslashes are inserted
automatically for line breaks in multiline macros, e.g., by
'c-context-line-break', they are aligned with the other backslashes
in the same macro if this flag is set.
If 'c-auto-align-backslashes' is 'nil', automatically inserted
backslashes are preceded by a single space, and backslashes get
aligned only when you explicitly invoke the command
'c-backslash-region' ('C-c C-\').
File: ccmode.info, Node: Macros with ;, Prev: Macro Backslashes, Up: Custom Macros
12.2 Macros with semicolons
===========================
Macros which needn't (or mustn't) be followed by a semicolon when you
invoke them, "macros with semicolons", are very common. These can cause
CC Mode to parse the next line wrongly as a 'statement-cont' (*note
Function Symbols::) and thus mis-indent it.
You can prevent this by specifying which macros have semicolons. It
doesn't matter whether or not such a macro has a parameter list:
-- User Option: c-macro-names-with-semicolon
This buffer-local variable specifies which macros have semicolons.
After setting its value, you need to call
'c-make-macro-with-semi-re' for it to take effect. It should be
set to one of these values:
nil
There are no macros with semicolons.
a list of strings
Each string is the name of a macro with a semicolon. Only
valid '#define' names are allowed here. For example, to set
the default value, you could write the following into your
'.emacs':
(setq c-macro-names-with-semicolon
'("Q_OBJECT" "Q_PROPERTY" "Q_DECLARE" "Q_ENUMS"))
a regular expression
This matches each symbol which is a macro with a semicolon.
It must not match any string which isn't a valid '#define'
name. For example:
(setq c-macro-names-with-semicolon
"\\<\\(CLEAN_UP_AND_RETURN\\|Q_[[:upper:]]+\\)\\>")
-- Function: c-make-macro-with-semi-re
Call this (non-interactive) function, which sets internal
variables, each time you change the value of
'c-macro-names-with-semicolon'. It takes no arguments, and its
return value has no meaning. This function is called by CC Mode's
initialization code.
File: ccmode.info, Node: Odds and Ends, Next: Sample .emacs File, Prev: Custom Macros, Up: Top
13 Odds and Ends
****************
The stuff that didn't fit in anywhere else is documented here.
-- User Option: c-require-final-newline
Controls whether a final newline is enforced when the file is
saved. The value is an association list that for each language
mode specifies the value to give to 'require-final-newline' (*note
(elisp)Saving Buffers::) at mode initialization. If a language
isn't present on the association list, CC Mode won't touch
'require-final-newline' in buffers for that language.
The default is to set 'require-final-newline' to 't' in the
languages that mandate that source files should end with newlines.
These are C, C++ and Objective-C.
-- User Option: c-echo-syntactic-information-p
If non-'nil', the syntactic analysis for the current line is shown
in the echo area when it's indented (unless
'c-syntactic-indentation' is 'nil'). That's useful when finding
out which syntactic symbols to modify to get the indentation you
want.
-- User Option: c-report-syntactic-errors
If non-'nil', certain syntactic errors are reported with a ding and
a message, for example when an 'else' is indented for which there
is no corresponding 'if'.
Note however that CC Mode doesn't make any special effort to check
for syntactic errors; that's the job of the compiler. The reason
it can report cases like the one above is that it can't find the
correct anchoring position to indent the line in that case.
File: ccmode.info, Node: Sample .emacs File, Next: Performance Issues, Prev: Odds and Ends, Up: Top
Appendix A Sample .emacs File
*****************************
Here's a sample .emacs file fragment that might help you along the way.
Just copy this region and paste it into your .emacs file. You might
want to change some of the actual values.
;; Make a non-standard key binding. We can put this in
;; c-mode-base-map because c-mode-map, c++-mode-map, and so on,
;; inherit from it.
(defun my-c-initialization-hook ()
(define-key c-mode-base-map "\C-m" 'c-context-line-break))
(add-hook 'c-initialization-hook 'my-c-initialization-hook)
;; offset customizations not in my-c-style
;; This will take precedence over any setting of the syntactic symbol
;; made by a style.
(setq c-offsets-alist '((member-init-intro . ++)))
;; Create my personal style.
(defconst my-c-style
'((c-tab-always-indent . t)
(c-comment-only-line-offset . 4)
(c-hanging-braces-alist . ((substatement-open after)
(brace-list-open)))
(c-hanging-colons-alist . ((member-init-intro before)
(inher-intro)
(case-label after)
(label after)
(access-label after)))
(c-cleanup-list . (scope-operator
empty-defun-braces
defun-close-semi))
(c-offsets-alist . ((arglist-close . c-lineup-arglist)
(substatement-open . 0)
(case-label . 4)
(block-open . 0)
(knr-argdecl-intro . -)))
(c-echo-syntactic-information-p . t))
"My C Programming Style")
(c-add-style "PERSONAL" my-c-style)
;; Customizations for all modes in CC Mode.
(defun my-c-mode-common-hook ()
;; set my personal style for the current buffer
(c-set-style "PERSONAL")
;; other customizations
(setq tab-width 8
;; this will make sure spaces are used instead of tabs
indent-tabs-mode nil)
;; we like auto-newline, but not hungry-delete
(c-toggle-auto-newline 1))
(add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
File: ccmode.info, Node: Performance Issues, Next: Limitations and Known Bugs, Prev: Sample .emacs File, Up: Top
B Performance Issues
********************
C and its derivative languages are highly complex creatures. Often,
ambiguous code situations arise that require CC Mode to scan large
portions of the buffer to determine syntactic context. Such
pathological code can cause CC Mode to perform fairly badly. This
section gives some insight in how CC Mode operates, how that interacts
with some coding styles, and what you can use to improve performance.
The overall goal is that CC Mode shouldn't be overly slow (i.e., take
more than a fraction of a second) in any interactive operation. I.e.,
it's tuned to limit the maximum response time in single operations,
which is sometimes at the expense of batch-like operations like
reindenting whole blocks. If you find that CC Mode gradually gets
slower and slower in certain situations, perhaps as the file grows in
size or as the macro or comment you're editing gets bigger, then chances
are that something isn't working right. You should consider reporting
it, unless it's something that's mentioned in this section.
Because CC Mode has to scan the buffer backwards from the current
insertion point, and because C's syntax is fairly difficult to parse in
the backwards direction, CC Mode often tries to find the nearest
position higher up in the buffer from which to begin a forward scan
(it's typically an opening or closing parenthesis of some kind). The
farther this position is from the current insertion point, the slower it
gets.
In earlier versions of CC Mode, we used to recommend putting the
opening brace of a top-level construct(1) into the leftmost column.
Earlier still, this used to be a rigid Emacs constraint, as embodied in
the 'beginning-of-defun' function. CC Mode now caches syntactic
information much better, so that the delay caused by searching for such
a brace when it's not in column 0 is minimal, except perhaps when you've
just moved a long way inside the file.
A special note about 'defun-prompt-regexp' in Java mode: The common
style is to hang the opening braces of functions and classes on the
right side of the line, and that doesn't work well with the Emacs
approach. CC Mode comes with a constant 'c-Java-defun-prompt-regexp'
which tries to define a regular expression usable for this style, but
there are problems with it. In some cases it can cause
'beginning-of-defun' to hang(2). For this reason, it is not used by
default, but if you feel adventurous, you can set 'defun-prompt-regexp'
to it in your mode hook. In any event, setting and relying on
'defun-prompt-regexp' will definitely slow things down because (X)Emacs
will be doing regular expression searches a lot, so you'll probably be
taking a hit either way!
CC Mode maintains a cache of the opening parentheses of the blocks
surrounding the point, and it adapts that cache as the point is moved
around. That means that in bad cases it can take noticeable time to
indent a line in a new surrounding, but after that it gets fast as long
as the point isn't moved far off. The farther the point is moved, the
less useful is the cache. Since editing typically is done in "chunks"
rather than on single lines far apart from each other, the cache
typically gives good performance even when the code doesn't fit the
Emacs approach to finding the defun starts.
XEmacs users can set the variable
'c-enable-xemacs-performance-kludge-p' to non-'nil'. This tells CC Mode
to use XEmacs-specific built-in functions which, in some circumstances,
can locate the top-most opening brace much more quickly than
'beginning-of-defun'. Preliminary testing has shown that for styles
where these braces are hung (e.g., most JDK-derived Java styles), this
hack can improve performance of the core syntax parsing routines from 3
to 60 times. However, for styles which _do_ conform to Emacs's
recommended style of putting top-level braces in column zero, this hack
can degrade performance by about as much. Thus this variable is set to
'nil' by default, since the Emacs-friendly styles should be more common
(and encouraged!). Note that this variable has no effect in Emacs since
the necessary built-in functions don't exist (in Emacs 22.1 as of this
writing in February 2007).
Text properties are used to speed up skipping over syntactic
whitespace, i.e., comments and preprocessor directives. Indenting a
line after a huge macro definition can be slow the first time, but after
that the text properties are in place and it should be fast (even after
you've edited other parts of the file and then moved back).
Font locking can be a CPU hog, especially the font locking done on
decoration level 3 which tries to be very accurate. Note that that
level is designed to be used with a font lock support mode that only
fontifies the text that's actually shown, i.e., Lazy Lock or
Just-in-time Lock mode, so make sure you use one of them. Fontification
of a whole buffer with some thousand lines can often take over a minute.
That is a known weakness; the idea is that it never should happen.
The most effective way to speed up font locking is to reduce the
decoration level to 2 by setting 'font-lock-maximum-decoration'
appropriately. That level is designed to be as pretty as possible
without sacrificing performance. *Note Font Locking Preliminaries::,
for more info.
---------- Footnotes ----------
(1) E.g., a function in C, or outermost class definition in C++ or
Java.
(2) This has been observed in Emacs 19.34 and XEmacs 19.15.
File: ccmode.info, Node: Limitations and Known Bugs, Next: FAQ, Prev: Performance Issues, Up: Top
C Limitations and Known Bugs
****************************
* CC Mode doesn't support trigraphs. (These are character sequences
such as '??(', which represents '['. They date from a time when
some character sets didn't have all the characters that C needs,
and are now utterly obsolete.)
* There is no way to apply auto newline settings (*note
Auto-newlines::) on already typed lines. That's only a feature to
ease interactive editing.
To generalize this issue a bit: CC Mode is not intended to be used
as a reformatter for old code in some more or less batch-like way.
With the exception of some functions like 'c-indent-region', it's
only geared to be used interactively to edit new code. There's
currently no intention to change this goal.
If you want to reformat old code, you're probably better off using
some other tool instead, e.g., *note GNU indent: (indent)Top, which
has more powerful reformatting capabilities than CC Mode.
* The support for C++ templates (in angle brackets) is not yet
complete. When a non-nested template is used in a declaration, CC
Mode indents it and font-locks it OK. Templates used in
expressions, and nested templates do not fare so well. Sometimes a
workaround is to refontify the expression after typing the closing
'>'.
* In a "k&r region" (the part of an old-fashioned C function
declaration which specifies the types of its parameters, coming
between the parameter list and the opening brace), there should be
at most 20 top-level parenthesis and bracket pairs. This limit has
been imposed for performance reasons. If it is violated, the
source file might be incorrectly indented or fontified.
* On loading CC Mode, sometimes this error message appears:
File mode specification error: (void-variable c-font-lock-keywords-3)
This is due to a bug in the function 'eval-after-load' in some
versions of (X)Emacs. It can manifest itself when there is a
symbolic link in the path of the directory which contains (X)Emacs.
As a workaround, put the following into your '.emacs' file, fairly
early on:
(defun my-load-cc-fonts ()
(require "cc-fonts"))
(add-hook 'c-initialization-hook 'my-load-cc-fonts)
File: ccmode.info, Node: FAQ, Next: Updating CC Mode, Prev: Limitations and Known Bugs, Up: Top
Appendix D Frequently Asked Questions
*************************************
* _How can I change the indent level from 4 spaces to 2 spaces?_
Set the variable 'c-basic-offset'. *Note Getting Started::.
* _Why doesn't the 'RET' key indent the new line?_
Emacs's convention is that 'RET' just adds a newline, and that
'C-j' adds a newline and indents it. You can make 'RET' do this
too by adding this to your 'c-initialization-hook':
(define-key c-mode-base-map "\C-m" 'c-context-line-break)
*Note Getting Started::. This is a very common question. If you
want this to be the default behavior, don't lobby us, lobby RMS!
:-)
* _How do I stop my code jumping all over the place when I type?_
Deactivate "electric minor mode" with 'C-c C-l'. *Note Getting
Started::.
* _How do I reindent the whole file?_
Visit the file and hit 'C-x h' to mark the whole buffer. Then hit
'C-M-\'. *Note Indentation Commands::.
* _How do I reindent the current block?_
First move to the brace which opens the block with 'C-M-u', then
reindent that expression with 'C-M-q'. *Note Indentation
Commands::.
* _I put '(c-set-offset 'substatement-open 0)' in my '.emacs' file
but I get an error saying that 'c-set-offset''s function definition
is void. What's wrong?_
This means that CC Mode hasn't yet been loaded into your Emacs
session by the time the 'c-set-offset' call is reached, most likely
because CC Mode is being autoloaded. Instead of putting the
'c-set-offset' line in your top-level '.emacs' file, put it in your
'c-initialization-hook' (*note CC Hooks::), or simply modify
'c-offsets-alist' directly:
(setq c-offsets-alist '((substatement-open . 0)))
* _I have an open paren character at column zero inside a comment or
multiline string literal, and it causes the fontification and/or
indentation to go haywire. What gives?_
It's due to the ad-hoc rule in (X)Emacs that such open parens
always start defuns (which translates to functions, classes,
namespaces or any other top-level block constructs in the CC Mode
languages). *Note (emacs)Left Margin Paren::, for details (*Note
(emacs)Defuns::, in the Emacs 20 manual).
This heuristic is built into the core syntax analysis routines in
(X)Emacs, so it's not really a CC Mode issue. However, in Emacs
21.1 it became possible to turn it off(1) and CC Mode does so there
since it's got its own system to keep track of blocks.
---------- Footnotes ----------
(1) Using the variable 'open-paren-in-column-0-is-defun-start'.
File: ccmode.info, Node: Updating CC Mode, Next: Mailing Lists and Bug Reports, Prev: FAQ, Up: Top
Appendix E Getting the Latest CC Mode Release
*********************************************
CC Mode has been standard with all versions of Emacs since 19.34 and of
XEmacs since 19.16.
Due to release schedule skew, it is likely that all of these Emacsen
have old versions of CC Mode and so should be upgraded. Access to the
CC Mode source code, as well as more detailed information on Emacsen
compatibility, etc. are all available on the web site:
<http://cc-mode.sourceforge.net/>
File: ccmode.info, Node: Mailing Lists and Bug Reports, Next: GNU Free Documentation License, Prev: Updating CC Mode, Up: Top
Appendix F Mailing Lists and Submitting Bug Reports
***************************************************
To report bugs, use the 'C-c C-b' (bound to 'c-submit-bug-report')
command. This provides vital information we need to reproduce your
problem. Make sure you include a concise, but complete code example.
Please try to boil your example down to just the essential code needed
to reproduce the problem, and include an exact recipe of steps needed to
expose the bug. Be especially sure to include any code that appears
_before_ your bug example, if you think it might affect our ability to
reproduce it.
Please try to produce the problem in an Emacs instance without any
customizations loaded (i.e., start it with the '-q --no-site-file'
arguments). If it works correctly there, the problem might be caused by
faulty customizations in either your own or your site configuration. In
that case, we'd appreciate it if you isolate the Emacs Lisp code that
triggers the bug and include it in your report.
Bug reports should be sent to <bug-cc-mode AT gnu.org>. You can also
send other questions and suggestions (kudos? ;-) to that address. It's
a mailing list which you can join or browse an archive of; see the web
site at <http://cc-mode.sourceforge.net/> for further details.
If you want to get announcements of new CC Mode releases, send the
word _subscribe_ in the body of a message to
<cc-mode-announce-request AT lists.net>. It's possible to
subscribe from the web site too. Announcements will also be posted to
the Usenet newsgroups 'gnu.emacs.sources', 'comp.emacs',
'comp.emacs.xemacs', 'comp.lang.c', 'comp.lang.c++',
'comp.lang.objective-c', 'comp.lang.java.softwaretools',
'comp.lang.idl', and 'comp.lang.awk'.
File: ccmode.info, Node: GNU Free Documentation License, Next: Command and Function Index, Prev: Mailing Lists and Bug Reports, Up: Top
Appendix G GNU Free Documentation License
*****************************************
Version 1.3, 3 November 2008
Copyright (C) 2000, 2001, 2002, 2007, 2008, 2009 Free Software Foundation, Inc.
<http://fsf.org/>
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
0. PREAMBLE
The purpose of this License is to make a manual, textbook, or other
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This License is a kind of "copyleft", which means that derivative
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It complements the GNU General Public License, which is a copyleft
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We have designed this License in order to use it for manuals for
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File: ccmode.info, Node: Command and Function Index, Next: Variable Index, Prev: GNU Free Documentation License, Up: Top
Command and Function Index
**************************
Since most CC Mode commands are prepended with the string 'c-', each
appears under its 'c-THING' name and its 'THING (c-)' name.
[index]
* Menu:
* abbrev-mode: Electric Keys. (line 124)
* add-style (c-): Adding Styles. (line 53)
* auto-fill-mode: Filling and Breaking.
(line 19)
* awk-beginning-of-defun (c-): Movement Commands. (line 38)
* awk-end-of-defun (c-): Movement Commands. (line 38)
* awk-mode: Introduction. (line 28)
* backslash-region (c-): Other Commands. (line 30)
* backward-conditional (c-): Movement Commands. (line 96)
* backward-delete-char-untabify: Hungry WS Deletion. (line 40)
* backward-into-nomenclature (c-): Movement Commands. (line 105)
* backward-kill-subword (c-): Subword Movement. (line 23)
* backward-subword (c-): Subword Movement. (line 23)
* beginning-of-defun: Performance Issues. (line 31)
* beginning-of-statement (c-): Movement Commands. (line 49)
* c++-mode: Introduction. (line 28)
* c-add-style: Adding Styles. (line 52)
* c-awk-beginning-of-defun: Movement Commands. (line 38)
* c-awk-end-of-defun: Movement Commands. (line 38)
* c-backslash-region: Other Commands. (line 30)
* c-backward-conditional: Movement Commands. (line 96)
* c-backward-into-nomenclature: Movement Commands. (line 105)
* c-backward-kill-subword: Subword Movement. (line 23)
* c-backward-subword: Subword Movement. (line 23)
* c-beginning-of-defun: Movement Commands. (line 10)
* c-beginning-of-statement: Movement Commands. (line 49)
* c-capitalize-subword: Subword Movement. (line 23)
* c-context-line-break: Filling and Breaking.
(line 48)
* c-context-open-line: Filling and Breaking.
(line 64)
* c-down-conditional: Movement Commands. (line 82)
* c-down-conditional-with-else: Movement Commands. (line 91)
* c-downcase-subword: Subword Movement. (line 23)
* c-electric-backspace: Hungry WS Deletion. (line 30)
* c-electric-brace: Electric Keys. (line 76)
* c-electric-colon: Electric Keys. (line 83)
* c-electric-continued-statement: Electric Keys. (line 103)
* c-electric-delete: Hungry WS Deletion. (line 83)
* c-electric-delete-forward: Hungry WS Deletion. (line 47)
* c-electric-lt-gt: Electric Keys. (line 54)
* c-electric-paren: Electric Keys. (line 63)
* c-electric-pound: Electric Keys. (line 24)
* c-electric-semi&comma: Electric Keys. (line 96)
* c-electric-slash: Electric Keys. (line 38)
* c-electric-star: Electric Keys. (line 38)
* c-end-of-defun: Movement Commands. (line 10)
* c-end-of-statement: Movement Commands. (line 49)
* c-fill-paragraph: Filling and Breaking.
(line 26)
* c-forward-conditional: Movement Commands. (line 96)
* c-forward-into-nomenclature: Movement Commands. (line 105)
* c-forward-subword: Subword Movement. (line 23)
* c-gnu-impose-minimum: Other Indentation. (line 16)
* c-guess: Guessing the Style. (line 41)
* c-guess-buffer: Guessing the Style. (line 41)
* c-guess-buffer-no-install: Guessing the Style. (line 26)
* c-guess-install: Guessing the Style. (line 67)
* c-guess-no-install: Guessing the Style. (line 26)
* c-guess-region: Guessing the Style. (line 41)
* c-guess-region-no-install: Guessing the Style. (line 26)
* c-guess-view: Guessing the Style. (line 74)
* c-hungry-delete: Hungry WS Deletion. (line 83)
* c-hungry-delete-backwards: Hungry WS Deletion. (line 66)
* c-hungry-delete-forward: Hungry WS Deletion. (line 73)
* c-indent-command: Indentation Commands.
(line 42)
* c-indent-defun: Indentation Commands.
(line 106)
* c-indent-exp: Indentation Commands.
(line 101)
* c-indent-multi-line-block: Brace/Paren Line-Up. (line 66)
* c-indent-new-comment-line: Filling and Breaking.
(line 41)
* c-indent-one-line-block: Brace/Paren Line-Up. (line 47)
* c-kill-subword: Subword Movement. (line 23)
* c-langelem-2nd-pos: Custom Line-Up. (line 72)
* c-langelem-col: Custom Line-Up. (line 68)
* c-langelem-pos: Custom Line-Up. (line 65)
* c-langelem-sym: Custom Line-Up. (line 62)
* c-lineup-after-whitesmith-blocks: Brace/Paren Line-Up. (line 113)
* c-lineup-argcont: Operator Line-Up. (line 10)
* c-lineup-arglist: List Line-Up. (line 13)
* c-lineup-arglist-close-under-paren: Brace/Paren Line-Up. (line 31)
* c-lineup-arglist-intro-after-paren: List Line-Up. (line 33)
* c-lineup-arglist-operators: Operator Line-Up. (line 25)
* c-lineup-assignments: Operator Line-Up. (line 47)
* c-lineup-C-comments: Comment Line-Up. (line 9)
* c-lineup-cascaded-calls: Operator Line-Up. (line 66)
* c-lineup-close-paren: Brace/Paren Line-Up. (line 9)
* c-lineup-comment: Comment Line-Up. (line 40)
* c-lineup-cpp-define: Misc Line-Up. (line 15)
* c-lineup-dont-change: Misc Line-Up. (line 9)
* c-lineup-gcc-asm-reg: Misc Line-Up. (line 75)
* c-lineup-inexpr-block: Brace/Paren Line-Up. (line 103)
* c-lineup-java-inher: List Line-Up. (line 62)
* c-lineup-java-throws: List Line-Up. (line 80)
* c-lineup-knr-region-comment: Comment Line-Up. (line 58)
* c-lineup-math: Operator Line-Up. (line 57)
* c-lineup-multi-inher: List Line-Up. (line 40)
* c-lineup-ObjC-method-args: List Line-Up. (line 118)
* c-lineup-ObjC-method-args-2: List Line-Up. (line 125)
* c-lineup-ObjC-method-call: List Line-Up. (line 108)
* c-lineup-runin-statements: Brace/Paren Line-Up. (line 88)
* c-lineup-streamop: Operator Line-Up. (line 81)
* c-lineup-string-cont: Operator Line-Up. (line 86)
* c-lineup-template-args: List Line-Up. (line 98)
* c-lineup-topmost-intro-cont: Misc Line-Up. (line 97)
* c-lineup-whitesmith-in-block: Brace/Paren Line-Up. (line 146)
* c-macro-expand: Other Commands. (line 55)
* c-make-macro-with-semi-re: Macros with ;. (line 39)
* c-mark-function: Indentation Commands.
(line 119)
* c-mark-subword: Subword Movement. (line 23)
* c-mode: Introduction. (line 28)
* c-scope-operator: Other Commands. (line 25)
* c-semi&comma-inside-parenlist: Hanging Semicolons and Commas.
(line 52)
* c-semi&comma-no-newlines-before-nonblanks: Hanging Semicolons and Commas.
(line 37)
* c-semi&comma-no-newlines-for-oneline-inliners: Hanging Semicolons and Commas.
(line 53)
* c-set-offset: c-offsets-alist. (line 41)
* c-set-offset <1>: Interactive Customization.
(line 71)
* c-set-style: Other Commands. (line 9)
* c-setup-doc-comment-style: Doc Comments. (line 35)
* c-setup-filladapt: Custom Filling and Breaking.
(line 72)
* c-setup-paragraph-variables: Custom Filling and Breaking.
(line 46)
* c-show-syntactic-information: Syntactic Analysis. (line 42)
* c-snug-do-while: Custom Braces. (line 67)
* c-submit-bug-report: Mailing Lists and Bug Reports.
(line 6)
* c-toggle-auto-hungry-state: Minor Modes. (line 65)
* c-toggle-auto-newline: Minor Modes. (line 58)
* c-toggle-electric-state: Minor Modes. (line 54)
* c-toggle-hungry-state: Minor Modes. (line 62)
* c-toggle-syntactic-indentation: Minor Modes. (line 71)
* c-transpose-subwords: Subword Movement. (line 23)
* c-up-conditional: Movement Commands. (line 66)
* c-up-conditional-with-else: Movement Commands. (line 78)
* c-upcase-subword: Subword Movement. (line 23)
* c-version: Getting Started. (line 82)
* capitalize-subword (c-): Subword Movement. (line 23)
* comment-dwim: Comment Commands. (line 14)
* comment-region: Comment Commands. (line 7)
* context-line-break (c-): Filling and Breaking.
(line 48)
* context-open-line (c-): Filling and Breaking.
(line 64)
* defun-prompt-regexp: Performance Issues. (line 39)
* delete-char: Hungry WS Deletion. (line 55)
* down-conditional (c-): Movement Commands. (line 82)
* down-conditional-with-else (c-): Movement Commands. (line 91)
* downcase-subword (c-): Subword Movement. (line 23)
* electric-backspace (c-): Hungry WS Deletion. (line 30)
* electric-brace (c-): Electric Keys. (line 76)
* electric-colon (c-): Electric Keys. (line 83)
* electric-continued-statement (c-): Electric Keys. (line 104)
* electric-delete (c-): Hungry WS Deletion. (line 83)
* electric-delete-forward (c-): Hungry WS Deletion. (line 47)
* electric-lt-gt (c-): Electric Keys. (line 54)
* electric-paren (c-): Electric Keys. (line 63)
* electric-pound (c-): Electric Keys. (line 24)
* electric-semi&comma (c-): Electric Keys. (line 96)
* electric-slash (c-): Electric Keys. (line 38)
* electric-star (c-): Electric Keys. (line 38)
* end-of-statement (c-): Movement Commands. (line 49)
* fill-paragraph (c-): Filling and Breaking.
(line 26)
* filladapt-mode: Custom Filling and Breaking.
(line 72)
* forward-conditional (c-): Movement Commands. (line 96)
* forward-into-nomenclature (c-): Movement Commands. (line 105)
* forward-subword (c-): Subword Movement. (line 23)
* gnu-impose-minimum (c-): Other Indentation. (line 16)
* guess (c-): Guessing the Style. (line 41)
* guess-buffer (c-): Guessing the Style. (line 41)
* guess-buffer-no-install (c-): Guessing the Style. (line 26)
* guess-install (c-): Guessing the Style. (line 67)
* guess-no-install (c-): Guessing the Style. (line 26)
* guess-region (c-): Guessing the Style. (line 41)
* guess-region-no-install (c-): Guessing the Style. (line 26)
* guess-view (c-): Guessing the Style. (line 74)
* hungry-delete (c-): Hungry WS Deletion. (line 83)
* hungry-delete-backwards (c-): Hungry WS Deletion. (line 66)
* hungry-delete-forward (c-): Hungry WS Deletion. (line 73)
* idl-mode: Introduction. (line 28)
* indent-command (c-): Indentation Commands.
(line 42)
* indent-defun (c-): Indentation Commands.
(line 106)
* indent-exp (c-): Indentation Commands.
(line 101)
* indent-for-comment: Comment Commands. (line 14)
* indent-multi-line-block (c-): Brace/Paren Line-Up. (line 67)
* indent-new-comment-line (c-): Filling and Breaking.
(line 41)
* indent-one-line-block (c-): Brace/Paren Line-Up. (line 48)
* indent-region: Indentation Commands.
(line 114)
* java-mode: Introduction. (line 28)
* kill-subword (c-): Subword Movement. (line 23)
* langelem-2nd-pos (c-): Custom Line-Up. (line 73)
* langelem-col (c-): Custom Line-Up. (line 69)
* langelem-pos (c-): Custom Line-Up. (line 66)
* langelem-sym (c-): Custom Line-Up. (line 63)
* lineup-after-whitesmith-blocks (c-): Brace/Paren Line-Up. (line 114)
* lineup-argcont (c-): Operator Line-Up. (line 11)
* lineup-arglist (c-): List Line-Up. (line 14)
* lineup-arglist-close-under-paren (c-): Brace/Paren Line-Up. (line 32)
* lineup-arglist-intro-after-paren (c-): List Line-Up. (line 34)
* lineup-arglist-operators (c-): Operator Line-Up. (line 26)
* lineup-assignments (c-): Operator Line-Up. (line 48)
* lineup-C-comments (c-): Comment Line-Up. (line 10)
* lineup-cascaded-calls (c-): Operator Line-Up. (line 67)
* lineup-close-paren (c-): Brace/Paren Line-Up. (line 10)
* lineup-comment (c-): Comment Line-Up. (line 41)
* lineup-cpp-define (c-): Misc Line-Up. (line 16)
* lineup-dont-change (c-): Misc Line-Up. (line 10)
* lineup-gcc-asm-reg (c-): Misc Line-Up. (line 76)
* lineup-inexpr-block (c-): Brace/Paren Line-Up. (line 104)
* lineup-java-inher (c-): List Line-Up. (line 63)
* lineup-java-throws (c-): List Line-Up. (line 81)
* lineup-knr-region-comment (c-): Comment Line-Up. (line 59)
* lineup-math (c-): Operator Line-Up. (line 58)
* lineup-multi-inher (c-): List Line-Up. (line 41)
* lineup-ObjC-method-args (c-): List Line-Up. (line 119)
* lineup-ObjC-method-args-2 (c-): List Line-Up. (line 126)
* lineup-ObjC-method-call (c-): List Line-Up. (line 109)
* lineup-runin-statements (c-): Brace/Paren Line-Up. (line 89)
* lineup-streamop (c-): Operator Line-Up. (line 82)
* lineup-string-cont (c-): Operator Line-Up. (line 87)
* lineup-template-args (c-): List Line-Up. (line 99)
* lineup-topmost-intro-cont (c-): Misc Line-Up. (line 98)
* lineup-whitesmith-in-block (c-): Brace/Paren Line-Up. (line 147)
* macro-expand (c-): Other Commands. (line 55)
* make-macro-with-semi-re (c-): Macros with ;. (line 40)
* mark-function (c-): Indentation Commands.
(line 119)
* mark-subword (c-): Subword Movement. (line 23)
* newline-and-indent: Indentation Commands.
(line 97)
* normal-erase-is-backspace-mode: Hungry WS Deletion. (line 93)
* objc-mode: Introduction. (line 28)
* pike-mode: Introduction. (line 28)
* scope-operator (c-): Other Commands. (line 25)
* semi&comma-inside-parenlist (c-): Hanging Semicolons and Commas.
(line 53)
* semi&comma-no-newlines-before-nonblanks (c-): Hanging Semicolons and Commas.
(line 38)
* semi&comma-no-newlines-for-oneline-inliners (c-): Hanging Semicolons and Commas.
(line 54)
* set-offset (c-): c-offsets-alist. (line 42)
* set-offset (c-) <1>: Interactive Customization.
(line 72)
* set-style (c-): Other Commands. (line 9)
* setup-doc-comment-style (c-): Doc Comments. (line 35)
* setup-filladapt (c-): Custom Filling and Breaking.
(line 72)
* setup-paragraph-variables (c-): Custom Filling and Breaking.
(line 46)
* show-syntactic-information (c-): Syntactic Analysis. (line 42)
* snug-do-while (c-): Custom Braces. (line 67)
* submit-bug-report (c-): Mailing Lists and Bug Reports.
(line 6)
* subword-mode: Minor Modes. (line 68)
* tab-to-tab-stop: Indentation Commands.
(line 80)
* toggle-auto-hungry-state (c-): Minor Modes. (line 65)
* toggle-auto-newline (c-): Minor Modes. (line 58)
* toggle-electric-state (c-): Minor Modes. (line 54)
* toggle-hungry-state (c-): Minor Modes. (line 62)
* toggle-syntactic-indentation (c-): Minor Modes. (line 71)
* transpose-subwords (c-): Subword Movement. (line 23)
* up-conditional (c-): Movement Commands. (line 66)
* up-conditional-with-else (c-): Movement Commands. (line 78)
* upcase-subword (c-): Subword Movement. (line 23)
* version (c-): Getting Started. (line 83)
File: ccmode.info, Node: Variable Index, Next: Concept and Key Index, Prev: Command and Function Index, Up: Top
Variable Index
**************
Since most CC Mode variables are prepended with the string 'c-', each
appears under its 'c-THING' name and its 'THING (c-)' name.
[index]
* Menu:
* abbrev-mode: Electric Keys. (line 124)
* adaptive-fill-first-line-regexp: Custom Filling and Breaking.
(line 11)
* adaptive-fill-mode: Custom Filling and Breaking.
(line 11)
* adaptive-fill-mode <1>: Custom Filling and Breaking.
(line 58)
* adaptive-fill-regexp: Custom Filling and Breaking.
(line 11)
* auto-align-backslashes (c-): Macro Backslashes. (line 31)
* awk-mode-hook: CC Hooks. (line 37)
* backslash-column (c-): Macro Backslashes. (line 11)
* backslash-max-column (c-): Macro Backslashes. (line 12)
* backspace-function (c-): Hungry WS Deletion. (line 40)
* basic-offset (c-): Customizing Indentation.
(line 18)
* block-comment-prefix (c-): Custom Filling and Breaking.
(line 84)
* c++-font-lock-extra-types: Font Locking Preliminaries.
(line 58)
* c++-mode-hook: CC Hooks. (line 32)
* c-auto-align-backslashes: Macro Backslashes. (line 30)
* c-backslash-column: Macro Backslashes. (line 10)
* c-backslash-max-column: Macro Backslashes. (line 11)
* c-backspace-function: Hungry WS Deletion. (line 40)
* c-basic-offset: Customizing Indentation.
(line 17)
* c-block-comment-prefix: Custom Filling and Breaking.
(line 83)
* c-cleanup-list: Clean-ups. (line 25)
* c-comment-continuation-stars: Custom Filling and Breaking.
(line 84)
* c-comment-only-line-offset: Comment Line-Up. (line 45)
* c-comment-prefix-regexp: Custom Filling and Breaking.
(line 11)
* c-comment-prefix-regexp <1>: Custom Filling and Breaking.
(line 16)
* c-default-style: Choosing a Style. (line 19)
* c-defun-tactic: Movement Commands. (line 10)
* c-delete-function: Hungry WS Deletion. (line 55)
* c-doc-comment-style: Doc Comments. (line 11)
* c-echo-syntactic-information-p: Odds and Ends. (line 20)
* c-electric-pound-behavior: Electric Keys. (line 24)
* c-enable-xemacs-performance-kludge-p: Performance Issues. (line 62)
* c-file-offsets: File Styles. (line 21)
* c-file-style: File Styles. (line 16)
* c-font-lock-extra-types: Font Locking Preliminaries.
(line 57)
* c-guess-offset-threshold: Guessing the Style. (line 60)
* c-guess-region-max: Guessing the Style. (line 55)
* c-hanging-braces-alist: Hanging Braces. (line 37)
* c-hanging-braces-alist <1>: Custom Braces. (line 6)
* c-hanging-colons-alist: Hanging Colons. (line 6)
* c-hanging-colons-alist <1>: Hanging Colons. (line 14)
* c-hanging-semi&comma-criteria: Hanging Semicolons and Commas.
(line 6)
* c-ignore-auto-fill: Custom Filling and Breaking.
(line 106)
* c-indent-comment-alist: Comment Commands. (line 22)
* c-indent-comments-syntactically-p: Comment Commands. (line 35)
* c-indentation-style: Choosing a Style. (line 44)
* c-initialization-hook: CC Hooks. (line 22)
* c-insert-tab-function: Indentation Commands.
(line 79)
* c-invalid-face: Faces. (line 54)
* c-Java-defun-prompt-regexp: Performance Issues. (line 39)
* c-label-minimum-indentation: Other Indentation. (line 11)
* c-macro-names-with-semicolon: Macros with ;. (line 14)
* c-max-one-liner-length: Clean-ups. (line 149)
* c-mode-common-hook: CC Hooks. (line 27)
* c-mode-hook: CC Hooks. (line 31)
* c-offsets-alist: Syntactic Symbols. (line 6)
* c-offsets-alist <1>: c-offsets-alist. (line 11)
* c-old-style-variable-behavior: Style Variables. (line 19)
* c-progress-interval: Indentation Commands.
(line 131)
* c-report-syntactic-errors: Odds and Ends. (line 27)
* c-require-final-newline: Odds and Ends. (line 8)
* c-special-indent-hook: Other Indentation. (line 20)
* c-strict-syntax-p: c-offsets-alist. (line 145)
* c-style-alist: Adding Styles. (line 68)
* c-syntactic-context: Custom Braces. (line 22)
* c-syntactic-context <1>: Custom Line-Up. (line 47)
* c-syntactic-element: Custom Line-Up. (line 47)
* c-syntactic-indentation: Indentation Engine Basics.
(line 33)
* c-syntactic-indentation-in-macros: Custom Macros. (line 16)
* c-tab-always-indent: Indentation Commands.
(line 66)
* cleanup-list (c-): Clean-ups. (line 26)
* comment-column: Comment Commands. (line 23)
* comment-continuation-stars (c-): Custom Filling and Breaking.
(line 84)
* comment-end: Custom Filling and Breaking.
(line 11)
* comment-multi-line: Custom Filling and Breaking.
(line 135)
* comment-only-line-offset (c-): Comment Line-Up. (line 46)
* comment-prefix-regexp (c-): Custom Filling and Breaking.
(line 11)
* comment-prefix-regexp (c-) <1>: Custom Filling and Breaking.
(line 17)
* comment-start: Custom Filling and Breaking.
(line 11)
* comment-start-skip: Custom Filling and Breaking.
(line 11)
* comment-start-skip <1>: Comment Line-Up. (line 25)
* default-style (c-): Choosing a Style. (line 20)
* defun-tactic (c-): Movement Commands. (line 10)
* delete-function (c-): Hungry WS Deletion. (line 55)
* delete-key-deletes-forward: Hungry WS Deletion. (line 83)
* doc-comment-style (c-): Doc Comments. (line 12)
* echo-syntactic-information-p (c-): Odds and Ends. (line 21)
* electric-pound-behavior (c-): Electric Keys. (line 24)
* enable-xemacs-performance-kludge-p (c-): Performance Issues.
(line 62)
* file-offsets (c-): File Styles. (line 22)
* file-style (c-): File Styles. (line 17)
* filladapt-mode: Custom Filling and Breaking.
(line 72)
* font-lock-builtin-face: Faces. (line 50)
* font-lock-comment-face: Faces. (line 12)
* font-lock-comment-face <1>: Faces. (line 14)
* font-lock-constant-face: Faces. (line 32)
* font-lock-constant-face <1>: Faces. (line 41)
* font-lock-doc-face: Faces. (line 14)
* font-lock-doc-string-face: Faces. (line 14)
* font-lock-function-name-face: Faces. (line 24)
* font-lock-keyword-face: Faces. (line 22)
* font-lock-maximum-decoration: Font Locking Preliminaries.
(line 25)
* font-lock-preprocessor-face: Faces. (line 50)
* font-lock-reference-face: Faces. (line 32)
* font-lock-reference-face <1>: Faces. (line 41)
* font-lock-reference-face <2>: Faces. (line 50)
* font-lock-string-face: Faces. (line 19)
* font-lock-type-face: Faces. (line 38)
* font-lock-variable-name-face: Faces. (line 28)
* font-lock-warning-face: Faces. (line 54)
* guess-offset-threshold (c-): Guessing the Style. (line 61)
* guess-region-max (c-): Guessing the Style. (line 56)
* hanging-braces-alist (c-): Hanging Braces. (line 38)
* hanging-braces-alist (c-) <1>: Custom Braces. (line 6)
* hanging-colons-alist (c-): Hanging Colons. (line 6)
* hanging-colons-alist (c-) <1>: Hanging Colons. (line 15)
* hanging-semi&comma-criteria (c-): Hanging Semicolons and Commas.
(line 7)
* idl-font-lock-extra-types: Font Locking Preliminaries.
(line 61)
* idl-mode-hook: CC Hooks. (line 35)
* ignore-auto-fill (c-): Custom Filling and Breaking.
(line 107)
* indent-comment-alist (c-): Comment Commands. (line 23)
* indent-comments-syntactically-p (c-): Comment Commands. (line 36)
* indent-tabs-mode: Indentation Commands.
(line 126)
* indentation-style (c-): Choosing a Style. (line 45)
* initialization-hook (c-): CC Hooks. (line 23)
* insert-tab-function (c-): Indentation Commands.
(line 80)
* invalid-face (c-): Faces. (line 54)
* Java-defun-prompt-regexp (c-): Performance Issues. (line 39)
* java-font-lock-extra-types: Font Locking Preliminaries.
(line 60)
* java-mode-hook: CC Hooks. (line 34)
* label-minimum-indentation (c-): Other Indentation. (line 12)
* macro-names-with-semicolon (c-): Macros with ;. (line 15)
* max-one-liner-length (c-): Clean-ups. (line 150)
* mode-common-hook (c-): CC Hooks. (line 28)
* objc-font-lock-extra-types: Font Locking Preliminaries.
(line 59)
* objc-mode-hook: CC Hooks. (line 33)
* offsets-alist (c-): Syntactic Symbols. (line 6)
* offsets-alist (c-) <1>: c-offsets-alist. (line 12)
* old-style-variable-behavior (c-): Style Variables. (line 19)
* paragraph-ignore-fill-prefix: Custom Filling and Breaking.
(line 11)
* paragraph-separate: Custom Filling and Breaking.
(line 11)
* paragraph-start: Custom Filling and Breaking.
(line 11)
* pike-font-lock-extra-types: Font Locking Preliminaries.
(line 62)
* pike-mode-hook: CC Hooks. (line 36)
* progress-interval (c-): Indentation Commands.
(line 132)
* report-syntactic-errors (c-): Odds and Ends. (line 28)
* require-final-newline (c-): Odds and Ends. (line 9)
* special-indent-hook (c-): Other Indentation. (line 21)
* strict-syntax-p (c-): c-offsets-alist. (line 145)
* style-alist (c-): Adding Styles. (line 69)
* syntactic-context (c-): Custom Braces. (line 23)
* syntactic-context (c-) <1>: Custom Line-Up. (line 47)
* syntactic-element (c-): Custom Line-Up. (line 47)
* syntactic-indentation (c-): Indentation Engine Basics.
(line 34)
* syntactic-indentation-in-macros (c-): Custom Macros. (line 17)
* tab-always-indent (c-): Indentation Commands.
(line 67)
File: ccmode.info, Node: Concept and Key Index, Prev: Variable Index, Up: Top
Concept and Key Index
*********************
[index]
* Menu:
* #: Electric Keys. (line 24)
* '#define': Macro Backslashes. (line 6)
* (: Electric Keys. (line 62)
* ): Electric Keys. (line 63)
* *: Electric Keys. (line 37)
* ,: Electric Keys. (line 96)
* -block-intro symbols: Syntactic Symbols. (line 18)
* -close symbols: Syntactic Symbols. (line 18)
* -cont symbols: Syntactic Symbols. (line 24)
* -intro symbols: Syntactic Symbols. (line 24)
* -open symbols: Syntactic Symbols. (line 18)
* /: Electric Keys. (line 38)
* :: Electric Keys. (line 83)
* ;: Electric Keys. (line 95)
* <: Electric Keys. (line 53)
* <backspace>: Hungry WS Deletion. (line 78)
* <delete>: Hungry WS Deletion. (line 78)
* >: Electric Keys. (line 54)
* {: Electric Keys. (line 75)
* }: Electric Keys. (line 76)
* Abbrev mode: Electric Keys. (line 124)
* access-label: Class Symbols. (line 40)
* action functions: Custom Braces. (line 6)
* Adaptive Fill mode: Custom Filling and Breaking.
(line 58)
* anchor position: Indentation Engine Basics.
(line 15)
* anchor position <1>: Syntactic Analysis. (line 22)
* annotation-top-cont: Java Symbols. (line 27)
* annotation-var-cont: Java Symbols. (line 27)
* announcement mailing list: Mailing Lists and Bug Reports.
(line 27)
* arglist-close: Paren List Symbols. (line 29)
* arglist-cont: Paren List Symbols. (line 34)
* arglist-cont-nonempty: Paren List Symbols. (line 34)
* arglist-intro: Paren List Symbols. (line 29)
* Auto Fill mode: Filling and Breaking.
(line 19)
* auto-newline: Auto-newlines. (line 6)
* AWK style: Built-in Styles. (line 42)
* awk-mode.el: Introduction. (line 6)
* block-close: Conditional Construct Symbols.
(line 28)
* block-open: Literal Symbols. (line 50)
* BOCM: Introduction. (line 6)
* brace lists: Brace List Symbols. (line 6)
* brace-entry-open: Brace List Symbols. (line 25)
* brace-list-close: Brace List Symbols. (line 19)
* brace-list-entry: Brace List Symbols. (line 19)
* brace-list-intro: Brace List Symbols. (line 19)
* brace-list-open: Brace List Symbols. (line 19)
* BSD style: Built-in Styles. (line 17)
* bug report mailing list: Mailing Lists and Bug Reports.
(line 22)
* bugs: Limitations and Known Bugs.
(line 6)
* c: Literal Symbols. (line 38)
* c++-mode.el: Introduction. (line 6)
* C-c .: Other Commands. (line 9)
* C-c :: Other Commands. (line 25)
* C-c <backspace>: Hungry WS Deletion. (line 66)
* C-c <DELETE>: Hungry WS Deletion. (line 73)
* C-c C-<backspace>: Hungry WS Deletion. (line 66)
* C-c C-<DELETE>: Hungry WS Deletion. (line 73)
* C-c C-a: Minor Modes. (line 58)
* C-c C-b: Mailing Lists and Bug Reports.
(line 6)
* C-c C-c: Comment Commands. (line 7)
* C-c C-d: Hungry WS Deletion. (line 73)
* C-c C-DEL: Hungry WS Deletion. (line 66)
* C-c C-e: Other Commands. (line 55)
* C-c C-l: Minor Modes. (line 54)
* C-c C-n: Movement Commands. (line 96)
* C-c C-o: c-offsets-alist. (line 42)
* C-c C-o <1>: Interactive Customization.
(line 72)
* C-c C-p: Movement Commands. (line 96)
* C-c C-q: Indentation Commands.
(line 106)
* C-c C-s: Syntactic Analysis. (line 42)
* C-c C-u: Movement Commands. (line 66)
* C-c C-w: Minor Modes. (line 68)
* C-c C-\: Other Commands. (line 30)
* C-c DEL: Hungry WS Deletion. (line 66)
* C-d: Hungry WS Deletion. (line 47)
* C-j: Indentation Commands.
(line 97)
* C-j <1>: FAQ. (line 10)
* C-M-a (AWK Mode): Movement Commands. (line 38)
* C-M-e (AWK Mode): Movement Commands. (line 38)
* C-M-h: Indentation Commands.
(line 119)
* C-M-q: Indentation Commands.
(line 101)
* C-M-q <1>: FAQ. (line 32)
* C-M-u: FAQ. (line 32)
* C-M-\: Indentation Commands.
(line 114)
* C-M-\ <1>: FAQ. (line 27)
* c-mode.el: Introduction. (line 6)
* C-x h: FAQ. (line 27)
* case-label: Switch Statement Symbols.
(line 26)
* catch-clause: Conditional Construct Symbols.
(line 44)
* class-close: Class Symbols. (line 27)
* class-open: Class Symbols. (line 27)
* clean-ups: Clean-ups. (line 6)
* comment handling: Filling and Breaking.
(line 6)
* comment line prefix: Custom Filling and Breaking.
(line 11)
* comment-intro: Literal Symbols. (line 33)
* comment-only line: Syntactic Analysis. (line 80)
* comments (insertion of): Comment Commands. (line 6)
* composition-close: External Scope Symbols.
(line 38)
* composition-open: External Scope Symbols.
(line 38)
* Configuration: Config Basics. (line 6)
* cpp-define-intro: Multiline Macro Symbols.
(line 6)
* cpp-macro: Literal Symbols. (line 55)
* cpp-macro-cont: Multiline Macro Symbols.
(line 6)
* customization, brace hanging: Custom Braces. (line 14)
* customization, colon hanging: Hanging Colons. (line 6)
* customization, comma newlines: Hanging Semicolons and Commas.
(line 6)
* customization, indentation: Customizing Indentation.
(line 6)
* customization, indentation functions: Custom Line-Up. (line 6)
* customization, interactive: Interactive Customization.
(line 6)
* customization, semicolon newlines: Hanging Semicolons and Commas.
(line 6)
* defun-block-intro: Function Symbols. (line 18)
* defun-close: Function Symbols. (line 18)
* defun-open: Function Symbols. (line 18)
* DEL: Hungry WS Deletion. (line 30)
* do-while-closure: Conditional Construct Symbols.
(line 50)
* documentation comments: Doc Comments. (line 6)
* electric characters: Electric Keys. (line 6)
* Ellemtel style: Built-in Styles. (line 27)
* else-clause: Conditional Construct Symbols.
(line 44)
* Emacs Initialization File: Config Basics. (line 6)
* extern-lang-close: External Scope Symbols.
(line 15)
* extern-lang-open: External Scope Symbols.
(line 15)
* faces: Faces. (line 6)
* file local variables: File Styles. (line 6)
* Filladapt mode: Custom Filling and Breaking.
(line 72)
* Font Lock mode: Font Locking. (line 6)
* font locking: Font Locking. (line 6)
* friend: Class Symbols. (line 93)
* func-decl-cont: Literal Symbols. (line 31)
* GNU indent program: Indentation Commands.
(line 12)
* GNU style: Built-in Styles. (line 10)
* GtkDoc markup: Doc Comments. (line 50)
* hanging braces: Hanging Braces. (line 6)
* hanging colons: Hanging Colons. (line 6)
* hanging commas: Hanging Semicolons and Commas.
(line 6)
* hanging semicolons: Hanging Semicolons and Commas.
(line 6)
* history: Introduction. (line 6)
* hungry-deletion: Hungry WS Deletion. (line 6)
* in-class inline methods: Class Symbols. (line 59)
* inclass: Class Symbols. (line 40)
* inclass <1>: External Scope Symbols.
(line 15)
* incomposition: External Scope Symbols.
(line 38)
* indentation: Indentation Commands.
(line 6)
* indentation <1>: Indentation Calculation.
(line 6)
* indentation <2>: Customizing Indentation.
(line 6)
* indentation function: Line-Up Functions. (line 6)
* indentation offset specifications: Indentation Engine Basics.
(line 21)
* inexpr-class: Java Symbols. (line 20)
* inexpr-statement: Statement Block Symbols.
(line 16)
* inexpr-statement <1>: Statement Block Symbols.
(line 45)
* inextern-lang: External Scope Symbols.
(line 15)
* inher-cont: Class Symbols. (line 36)
* inher-intro: Class Symbols. (line 36)
* inlambda: Statement Block Symbols.
(line 38)
* inline-close: Class Symbols. (line 59)
* inline-open: Class Symbols. (line 59)
* inmodule: External Scope Symbols.
(line 35)
* innamespace: External Scope Symbols.
(line 32)
* interactive customization: Interactive Customization.
(line 6)
* Java style: Built-in Styles. (line 38)
* Javadoc markup: Filling and Breaking.
(line 26)
* Javadoc markup <1>: Doc Comments. (line 44)
* Just-in-time Lock mode: Font Locking Preliminaries.
(line 48)
* K&R style: Built-in Styles. (line 14)
* knr-argdecl: K&R Symbols. (line 6)
* knr-argdecl-intro: K&R Symbols. (line 6)
* label: Literal Symbols. (line 48)
* lambda-intro-cont: Statement Block Symbols.
(line 38)
* Lazy Lock mode: Font Locking Preliminaries.
(line 48)
* limitations: Limitations and Known Bugs.
(line 6)
* line breaking: Filling and Breaking.
(line 6)
* line-up function: Line-Up Functions. (line 6)
* Linux style: Built-in Styles. (line 32)
* literal: Indentation Commands.
(line 67)
* literal <1>: Auto-newlines. (line 23)
* literal <2>: Clean-ups. (line 26)
* M-;: Comment Commands. (line 14)
* M-a: Movement Commands. (line 49)
* M-e: Movement Commands. (line 49)
* M-j: Filling and Breaking.
(line 41)
* M-q: Filling and Breaking.
(line 26)
* macros: Custom Macros. (line 6)
* macros with semicolons: Macros with ;. (line 6)
* member-init-cont: Class Symbols. (line 53)
* member-init-intro: Class Symbols. (line 53)
* Minor Modes: Minor Modes. (line 6)
* mode hooks: CC Hooks. (line 6)
* module-close: External Scope Symbols.
(line 35)
* module-open: External Scope Symbols.
(line 35)
* movement: Movement Commands. (line 6)
* multiline macros: Multiline Macro Symbols.
(line 6)
* namespace-close: External Scope Symbols.
(line 32)
* namespace-open: External Scope Symbols.
(line 32)
* nomenclature: Subword Movement. (line 6)
* objc-method-args-cont: Objective-C Method Symbols.
(line 18)
* objc-method-call-cont: Objective-C Method Symbols.
(line 18)
* objc-method-intro: Objective-C Method Symbols.
(line 18)
* offset specification: c-offsets-alist. (line 60)
* offsets: Indentation Engine Basics.
(line 21)
* open paren in column zero: FAQ. (line 51)
* paragraph filling: Filling and Breaking.
(line 19)
* performance: Performance Issues. (line 6)
* Pike autodoc markup: Filling and Breaking.
(line 26)
* Pike autodoc markup <1>: Doc Comments. (line 47)
* preprocessor directives: Custom Macros. (line 6)
* Python style: Built-in Styles. (line 35)
* RET: FAQ. (line 10)
* statement: Function Symbols. (line 28)
* statement-block-intro: Conditional Construct Symbols.
(line 28)
* statement-case-intro: Switch Statement Symbols.
(line 26)
* statement-case-open: Switch Statement Symbols.
(line 26)
* statement-cont: Function Symbols. (line 28)
* stream-op: Literal Symbols. (line 64)
* string: Literal Symbols. (line 46)
* Stroustrup style: Built-in Styles. (line 24)
* style definition: Adding Styles. (line 13)
* style variables: Style Variables. (line 6)
* styles: Style Variables. (line 6)
* styles <1>: Styles. (line 6)
* styles, built-in: Built-in Styles. (line 6)
* styles, file local: File Styles. (line 6)
* substatement: Conditional Construct Symbols.
(line 35)
* substatement <1>: Syntactic Analysis. (line 77)
* substatement block: Syntactic Analysis. (line 77)
* substatement-label: Conditional Construct Symbols.
(line 39)
* substatement-open: Conditional Construct Symbols.
(line 28)
* subword: Subword Movement. (line 6)
* syntactic analysis: Syntactic Analysis. (line 6)
* syntactic context: Syntactic Analysis. (line 6)
* syntactic element: Syntactic Analysis. (line 6)
* syntactic symbol: Indentation Engine Basics.
(line 15)
* syntactic symbol <1>: Syntactic Analysis. (line 14)
* syntactic symbols, brief list: Syntactic Symbols. (line 6)
* syntactic whitespace: Auto-newlines. (line 23)
* syntactic whitespace <1>: Literal Symbols. (line 40)
* syntactic whitespace <2>: Multiline Macro Symbols.
(line 6)
* TAB: Indentation Commands.
(line 42)
* template-args-cont: Class Symbols. (line 103)
* text filling: Filling and Breaking.
(line 6)
* topmost-intro: Function Symbols. (line 18)
* topmost-intro-cont: Function Symbols. (line 18)
* types, user defined: Font Locking Preliminaries.
(line 54)
* user defined types: Font Locking Preliminaries.
(line 54)
* User style: Built-in Styles. (line 46)
* web site: Updating CC Mode. (line 9)
* Whitesmith style: Built-in Styles. (line 20)
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