pdp11v/usr/man/u_man/man1/lint.1

.TH LINT 1 
.SH NAME
lint \- a C program checker
.SH SYNOPSIS
.B lint
[
.B \-abhlnpuvx
]
file ...
.SH DESCRIPTION
.I Lint\^
attempts to detect features of the C program
.I files\^
which are
likely to be bugs, non-portable, or wasteful.
It also checks type usage more strictly
than the compilers.
Among the things which are currently detected are
unreachable statements,
loops not entered at the top,
automatic variables declared and not used,
and logical expressions whose value is constant.
Moreover, the usage of functions is checked to find
functions which return values in some places and not in others,
functions called with varying numbers of arguments,
and functions whose values are not used.
.PP
It is assumed that all the
.I files\^
are to be loaded together; they are checked for
mutual compatibility.
By default,
.I lint\^
uses function definitions from the standard lint library
.BR llib-lc.ln ;
function definitions from the portable lint library
.B llib-port.ln
are used when
.I lint\^
is invoked with the
.B \-p
option.
.PP
Any number of
.I lint\^
options may be used, in any order.
The following options are used to suppress certain kinds of complaints:
.TP
.B \-a
Suppress complaints about assignments of long values to variables that are not
long.
.TP
.B \-b
Suppress complaints about
.B break
statements that cannot be reached.
(Programs produced by 
.I lex\^
or
.I yacc\^
will often result in a large number of such complaints.)
.TP
.B \-h
Do not apply heuristic tests that attempt to intuit bugs, improve
style, and reduce waste.
.TP
.B \-u
Suppress complaints about functions and external variables used and not defined,
or defined and not used.
(This option is suitable for running
.I lint\^
on a subset of files of a larger program.)
.TP
.B \-v
Suppress complaints about unused arguments in functions.
.TP
.B \-x
Do not report variables referred to by external declarations but never used.
.PP
The following arguments alter
.I lint's\^
behavior:
.TP
.BI \-l x\^
Include additional lint library
.BI llib-l x .ln .
You can include a lint version of the math library
.B llib-lm.ln
by inserting
.B \-lm
on the command line. This argument does not suppress the default use of
.BR llib-lc.ln .
This option can be used to keep local lint libraries and is useful in the
development of multi-file projects.
.TP
.B \-n
Do not check compatibility against either the standard or the portable
lint library.
.TP
.B \-p
Attempt to check portability to other dialects
(\s-1IBM\s0 and \s-1GCOS\s0) of C.
.PP
The
.BR \-D ,
.BR \-U ,
and
.B \-I
options of
.IR cc (1)
are also recognized as separate arguments.
.PP
Certain conventional comments in the C source
will change the behavior of
.IR lint :
.RS
.TP
/\(**\s-1NOTREACHED\s0\(**/
at appropriate points
stops comments about unreachable code.
.TP
.RI /\(**\s-1VARARGS\s+1 n \(**/
suppresses
the usual checking for variable numbers of arguments
in the following function declaration.
The data types of the first
.I n\^
arguments are checked;
a missing
.I n\^
is taken to be 0.
.TP
/\(**\s-1ARGSUSED\s0\(**/
turns on the
.B \-v
option for the next function.
.TP
/\(**\s-1LINTLIBRARY\s0\(**/
at the beginning of a file shuts off complaints about
unused functions in this file.
.RE
.PP
.I Lint\^
produces its first output on a per source file basis.
Complaints regarding included files are collected and printed
after all source files have been processed.
Finally,
information gathered from all input files is collected and checked for
consistency.
At this point,
if it is not clear whether a complaint stems from a given source file or from
one of its included files,
the source file name will be printed followed by a question mark.
.PP
.SH FILES
.PD 0
.TP "\w'/usr/lib/llib-port.ln  'u"
/usr/lib/lint[12]
programs
.TP
/usr/lib/llib-lc.ln
declarations for standard functions 
(binary format; source is in
.BR /usr/lib/llib-lc )
.TP
/usr/lib/llib-port.ln
declarations for portable functions 
(binary format; source is in
.BR /usr/lib/llib-port )
.TP
/usr/lib/llib-lm.ln
declarations for standard math functions 
(binary format; source is in
.BR /usr/lib/llib-lm )
.TP
/usr/tmp/\(**lint\(**
temporaries
.PD
.SH SEE ALSO
cc(1). 
.SH BUGS
.IR Exit (2)
and other functions which do not return
are not understood; this causes various lies.
.\"	@(#)lint.1	5.2 of 5/18/82