.TH LINT 1 88/2/22
.SH NAME
lint \- a C program checker
.SH SYNOPSIS
.B lint
[
.B \-abhuvx \-KR
]
[file | libname
.BR \-l xxx
] ...
.br
.B lint
.BR \-L libname
[file | libname2 ] ...
.br
.SH DESCRIPTION
.I Lint
does an extensive consistency and plausibility check on a set of C
program files.
When it detects a doubtful construction
(which need not be an error) it gives a warning.
.I Lint
does a full flow-of-control check, except that
.BR goto s
are not followed and non-termination of functions is not propagated.
If, however, no
.BR goto s
are used, each call to a non-terminating function is followed by
/*NOTREACHED*/ and each switch has a default clause (possibly consisting
of /*NOTREACHED*/), the initialization state of all local variables will
be checked correctly.
.PP
The second command is used to maintain lint libraries; these are ASCII files
that contain the output of the first pass.
A library name must start with
.B llib\-l
and cannot end in
.BR .c .
A lint user library can be created and updated by using the
.B \-L
option.  The
.I libname
must be a local file and can be passed to
.I lint
again as a normal argument.
.PP
Standard libraries are searched using the
.B \-l
option; their format is identical to that of the user library files.
Possibilities are
.BR \-lm ,
.B \-ltermcap
and 
.BR \-lcurses .
.B \-lc
is default; a single
.B \-l
tells
.I lint
not to use the standard C library.
.PP
The
.BR \-D ,
.B \-U
and
.B \-I
options are recognized as separate arguments.  The
.B \-KR
option tells
.I lint
to check strictly according to Kernighan & Ritchie; since
.I lint
is trying to be helpful rather than obnoxious, this is not the default.
.PP
.I Lint
understands the following additional options:
.TP
.B a
Warn about conversions that may cause a loss of precision.
.TP
.B b
Do not report not-reachable 
.I break
statements.
This flag may be useful when
.I lint
is run on a generated source file.
.TP
.B h
Signal "null effects", possible pointer alignment problems and unexpected
constructs.  Report definitions of variables that have a scope wider than
necessary: extern variables that are used in one file only, automatic
variables that could be more local.
.TP
.B u
Do not complain about unused and undefined functions and global variables.
.TP
.B v
Do not warn about unused arguments of functions.
.TP
.B x
Complain about unused external variables.
.PP
In some cases where the programmer knows that a construction is questionable
but nevertheless correct, a pseudo-comment can be used to silence
.IR lint ;
the comments recognized are:
.TP
/* VARARGS\fIn\fR */
The next function can be called with a variable number of
arguments.
Only check the types of the first \fIn\fR arguments.
The \fIn\fR must follow the word VARARGS immediately.
.TP
/* VARARGS */
Same as /* VARARGS0 */
.TP
/* ARGSUSED */
Do not warn about arguments not used in the next function
(see also the \-\fBv\fR option).
.TP
/* NOTREACHED */
This tells
.I lint
that the flow of control "cannot reach" this comment.
This is a way to tell
.I lint
that a statement never "returns".
.TP
/* LINTLIBRARY */
The following definitions are assumed to be part of a library.
It suppresses complaints about unused functions and variables
and is used in the creation of lint libraries.
.SH FILES
.IP ???/lnt 35
first pass
.IP ???/lpass2/lpass2
second pass
.IP ???/llib/llib\-l*
lint libraries
.SH SEE ALSO
cem(1)
.br
Frans Kunst,
.I Lint, a C Program Checker
.SH BUGS
Conflicting options in the command line are not detected.
.br
After a label, all automatic variables are assumed initialized.
.br
Initializations hidden inside for statements are sometimes overlooked.
.SH AUTHOR
Frans Kunst, Vrije Universiteit, Amsterdam.