Difference between revisions of "Coding style"
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__NOTOC__ |
__NOTOC__ |
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| − | The C language '''Coding style''' described here is based on the BSD coding style, with some additional elements from the GNU coding standards and the SunOS coding standards. |
+ | The C language '''Coding style''' described here is based on the BSD coding style (Kernel Normal Form - KNF), with some additional elements from the GNU coding standards and the SunOS coding standards. |
* [[Coding style/Formatting|Formatting]] |
* [[Coding style/Formatting|Formatting]] |
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* [[Coding style/Practices|Practices]] |
* [[Coding style/Practices|Practices]] |
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| + | * [[Coding style/Style checker|Style checker]] |
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| + | * [[Coding style/Version control practices|Version control practices]] |
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| + | * [[Coding style/Transition_strategies|Transition strategies]] |
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| + | * [[Coding style/Reindenting|Reindenting]] |
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== External links == |
== External links == |
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* [http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/share/misc/style?rev=HEAD NetBSD <code>/usr/share/misc/style</code>] [http://cvsweb.netbsd.org/bsdweb.cgi/src/share/misc/style (log)] |
* [http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/share/misc/style?rev=HEAD NetBSD <code>/usr/share/misc/style</code>] [http://cvsweb.netbsd.org/bsdweb.cgi/src/share/misc/style (log)] |
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* [http://www.gnu.org/prep/standards/ GNU coding standards] |
* [http://www.gnu.org/prep/standards/ GNU coding standards] |
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| − | * [http://opensolaris.org/os/community/ |
+ | * [http://opensolaris.org/os/community/on/cstyle.ms.pdf C Style and Coding Standards for SunOS] |
| − | |||
| − | == Old version == |
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| − | |||
| − | Old content to be moved elsewhere is below. |
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| − | |||
| − | ---- |
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| − | |||
| − | == WRITING C CODE == |
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| − | |||
| − | The code in the krb5 source tree largely follows BSD KNF |
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| − | (/usr/share/misc/style on NetBSD) except that it uses a four column |
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| − | basic offset. The style described here is a synthesis of BSD KNF and |
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| − | the GNU coding standards for the C language. The formatting described |
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| − | in the "Formatting Your Source Code" section of the GNU coding |
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| − | standards is mostly what we want, except we use BSD brace style and |
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| − | BSD-ish conventions for the spacing around operators. |
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| − | |||
| − | === Coding practices for C === |
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| + | == General information == |
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=== Aspects of C style in GNU coding std but not here === |
=== Aspects of C style in GNU coding std but not here === |
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=== Emacs cc-mode style === |
=== Emacs cc-mode style === |
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| − | Putting the following code in your .emacs file will result in mostly |
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| + | Load the elisp file {{trunkref|src/util/krb5-c-style.el}} to get mostly |
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| − | the right thing happening with respect to formatting style. Note that |
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| + | the right thing to happen with respect to formatting style. <code>krb5-c-style.el</code> uses a heuristic to detect whether a file should have the "krb5" C coding style applied. Currently, it uses the combined presence of <code>c-basic-offset: 4</code> and <code>indent-tabs-mode: nil</code> as a signal to use the "krb5" style. See [[Coding_style/Transition strategies]] for some details. Also, if you are newly adding the file-local variable settings line to a file, use <code>M-x normal-mode</code> to reinitialize cc-mode with the new settings. |
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| ⚫ | |||
| ⚫ | |||
| − | the version of cc-mode that comes with emacs 20.3. |
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| − | (defconst krb5-c-style |
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| ⚫ | |||
| − | '("bsd" |
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| ⚫ | |||
| − | (c-cleanup-list |
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| + | old versions of cc-mode (Emacs 20.3 or so). |
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| − | brace-elseif-brace brace-else-brace defun-close-semi) |
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| − | (c-comment-continuation-stars . "* ") |
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| − | (c-electric-pound-behavior alignleft) |
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| − | (c-hanging-braces-alist |
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| − | (brace-list-open) |
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| − | (class-open after) |
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| − | (substatement-open after) |
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| − | (block-close . c-snug-do-while) |
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| − | (extern-lang-open after)) |
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| − | (c-hanging-colons-alist |
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| − | (case-label after) |
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| − | (label after)) |
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| − | (c-hanging-comment-starter-p) |
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| − | (c-hanging-comment-ender-p) |
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| − | (c-indent-comments-syntactically-p . t) |
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| − | (c-label-minimum-indentation . 0) |
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| − | (c-special-indent-hook))) |
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| − | (defun krb5-c-hook () |
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| − | (c-add-style "krb5" krb5-c-style t)) |
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| − | (add-hook 'c-mode-common-hook 'krb5-c-hook) |
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You might also want to try (for Emacs 22 and later): |
You might also want to try (for Emacs 22 and later): |
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reasonable approximation to the C coding style described here, though |
reasonable approximation to the C coding style described here, though |
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some manual cleanup may be necessary. Note that the gindent installed |
some manual cleanup may be necessary. Note that the gindent installed |
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| − | in the gnu locker does not currently handle -psl correctly though. |
+ | in the gnu locker does not currently handle -nut or -psl correctly though. |
<pre> |
<pre> |
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| Line 120: | Line 102: | ||
-nbc |
-nbc |
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-ncdb |
-ncdb |
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| + | -ncs |
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-ndj |
-ndj |
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-nfc1 |
-nfc1 |
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-lp |
-lp |
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-npcs |
-npcs |
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| + | -nut |
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-psl |
-psl |
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-sc |
-sc |
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-sob |
-sob |
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| + | </pre> |
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| + | |||
| + | === vim/gvim editor settings === |
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| + | These settings allow the vim or gvim editor to conform to the MITKC code style: |
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| + | |||
| + | <pre> |
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| + | set shiftwidth=4 |
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| + | set tabstop=8 |
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| + | set softtabstop=4 |
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| + | set expandtab |
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| + | set nosmartindent |
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| + | set cindent |
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| + | set cinoptions=p0,t0,+4,(0,u4,U1,:0 |
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| + | set formatoptions=croq |
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| + | set comments=sr:/*,mb:*,ex:*/,:// |
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| + | set textwidth=79 |
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</pre> |
</pre> |
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Latest revision as of 12:59, 2 February 2016
The C language Coding style described here is based on the BSD coding style (Kernel Normal Form - KNF), with some additional elements from the GNU coding standards and the SunOS coding standards.
External links
General information
Aspects of C style in GNU coding std but not here
- redundant parens to force extra indent of operators of different precedences
- redundant parens to force general extra indent of expressions that are broken between lines
- use of ^L characters to break up source files into pages
- nitpicking about capitalization in comments of variable names when their values are meant
- commenting usages of static variables
- casts to void
- separation of word in names with underscores vs case change
- enum vs #define'd integer constants
- 14 char filename limits, MS-DOS filename limits
- portability
- system library function quirks
- internationalization
- mmap()
Aspects of C style in BSD KNF but not here
- sorting of header files
- sorting of struct members
- separating struct tag decl and struct typedef
- sorting of var decl
- lining up var names in decls
- newline after decls
- usage of __P
- usage of getopt
- not initializing vars in decls
- stdarg/varargs handling
Emacs cc-mode style
Load the elisp file src/util/krb5-c-style.el (raw | annotated | history) to get mostly
the right thing to happen with respect to formatting style. krb5-c-style.el uses a heuristic to detect whether a file should have the "krb5" C coding style applied. Currently, it uses the combined presence of c-basic-offset: 4 and indent-tabs-mode: nil as a signal to use the "krb5" style. See Coding_style/Transition strategies for some details. Also, if you are newly adding the file-local variable settings line to a file, use M-x normal-mode to reinitialize cc-mode with the new settings.
You may want to turn on auto-newline feature of cc-mode, though that seems to have some bugs with brace-elseif-brace handling at least in old versions of cc-mode (Emacs 20.3 or so).
You might also want to try (for Emacs 22 and later):
(add-hook 'before-save-hook 'copyright-update)
which will offer to update the year in the top-most copyright notice in a file when you save it, if it's not already current.
indent.pro settings
The following settings for the indent program should produce a reasonable approximation to the C coding style described here, though some manual cleanup may be necessary. Note that the gindent installed in the gnu locker does not currently handle -nut or -psl correctly though.
-bap -br -ce -ci4 -cli0 -d0 -di8 -i4 -ip4 -l79 -nbc -ncdb -ncs -ndj -nfc1 -lp -npcs -nut -psl -sc -sob
vim/gvim editor settings
These settings allow the vim or gvim editor to conform to the MITKC code style:
set shiftwidth=4 set tabstop=8 set softtabstop=4 set expandtab set nosmartindent set cindent set cinoptions=p0,t0,+4,(0,u4,U1,:0 set formatoptions=croq set comments=sr:/*,mb:*,ex:*/,:// set textwidth=79
