xref: /freebsd/share/man/man9/intro.9 (revision 0957b409)
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28.\" $FreeBSD$
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30.Dd December 13, 1995
31.Dt INTRO 9
32.Os
33.Sh NAME
34.Nm intro
35.Nd "introduction to system kernel interfaces"
36.Sh DESCRIPTION
37This section contains information about the interfaces and
38subroutines in the kernel.
39.Sh PROTOTYPES ANSI-C AND ALL THAT
40Yes please.
41.Pp
42We would like all code to be fully prototyped.
43.Pp
44If your code compiles cleanly with
45.Nm cc
46.Ar -Wall
47we would feel happy about it.
48It is important to understand that this is not a question of just shutting up
49.Nm cc ,
50it is a question about avoiding the things it complains about.
51To put it bluntly, do not hide the problem by casting and other
52obfuscating practices, solve the problem.
53.Sh INDENTATION AND STYLE
54Believe it or not, there actually exists a guide for indentation and style.
55It is not generally applied though.
56.Pp
57We would appreciate if people would pay attention to it, and at least not
58violate it blatantly.
59.Pp
60We do not mind it too badly if you have your own style, but please make
61sure we can read it too.
62.Pp
63Please take time to read
64.Xr style 9
65for more information.
66.Sh NAMING THINGS
67Some general rules exist:
68.Bl -enum
69.It
70If a function is meant as a debugging aid in DDB, it should be enclosed
71in
72.Bd -literal -offset indent
73#ifdef DDB
74
75#endif /* DDB */
76.Ed
77.Pp
78And the name of the procedure should start with the prefix
79.Li DDB_
80to clearly identify the procedure as a debugger routine.
81.El
82.Sh SCOPE OF SYMBOLS
83It is important to carefully consider the scope of symbols in the kernel.
84The default is to make everything static, unless some reason requires
85the opposite.
86.Pp
87There are several reasons for this policy,
88the main one is that the kernel is one monolithic name-space,
89and pollution is not a good idea here either.
90.Pp
91For device drivers and other modules that do not add new internal interfaces
92to the kernel, the entire source should be in one file if possible.
93That way all symbols can be made static.
94.Pp
95If for some reason a module is split over multiple source files, then try
96to split the module along some major fault-line and consider using the
97number of global symbols as your guide.
98The fewer the better.
99.Sh SEE ALSO
100.Xr style 9
101.Sh HISTORY
102The
103.Nm
104section manual page appeared in
105.Fx 2.2 .
106