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<head>
<title>HP-UX 9.03 manual page entry for pmccabe</title>
</head>
<body>
<pre>
<b><a href="/cgi-bin/man?1+pmccabe">pmccabe(1)</a></b> <b><a href="/cgi-bin/man?1+pmccabe">pmccabe(1)</a></b>
<b>HP-GJD</b>
<b>NAME</b>
pmccabe - calculate McCabe cyclomatic complexity for C and C++
programs
<b>SYNOPSIS</b>
<b>pmccabe</b> <b>[-vdCbtT?]</b> <b>[file(s)]</b>
<b>DESCRIPTION</b>
<em>pmccabe</em> processes the named files, or standard input if none are
named, calculating statistics including McCabe cyclomatic complexity
for each function found. The files are expected to be either C (ANSI
or K&R) or C++.
<b>-?</b> Print an informative usage message.
<b>-v</b> Print column headers
<b>-d</b> Intended to help count non-commented source lines via something
like:
pmccabe -d *.c | grep -v '^[<blank><tab>]*$' | wc -l
Comments and cpp directives are removed, string literals are
replaced by <b>STRINGLITERAL</b>, character constants are replaced by
<b>CHARLITERAL</b>. The resulting source code is much easier to parse.
This is the first step performed by <em>pmccabe</em> so that its parser
can be simpler.
<b>-C</b> Custom output format - don't use it.
<b>-b</b> Output format compatible with <em>softbuild</em>. Numerical sorting on
this format is possible using:
sort -n +1 -t%
<b>-t</b> Print column totals. Note the total number of lines is *NOT* the
number of non-commented source lines - in fact it may not be very
useful at all.
<b>-T</b> Print column totals *ONLY*.
<b>Parsing</b>
<em>pmccabe</em> ignores all <em>cpp</em> preprocessor directives - calculating the
complexity of the appearance of the code rather than the complexity
after the preprocessor mangles the code. This is especially important
since simple things like <em>getchar</em>(3) expand into macros which increase
complexity.
- 1 - Formatted: June 29, 1998
<b><a href="/cgi-bin/man?1+pmccabe">pmccabe(1)</a></b> <b><a href="/cgi-bin/man?1+pmccabe">pmccabe(1)</a></b>
<b>HP-GJD</b>
<b>Output</b> <b>Format</b>
A line is written to standard output for each function found of the
form:
5 6 11 34 27 gettoken.c(35): matchparen
Column 1 contains cyclomatic complexity calculated by adding 1 (for
the function) to the occurences of <b>for</b>, <b>if</b>, <b>while</b>, <b>switch</b>, <b>&&</b>, <b>||</b>, and
<b>?</b>. Unlike "normal" McCabe cyclomatic complexity, each case in a
switch statement is not counted as additional complexity. This
treatment of switch statements and complexity may be more useful than
the "normal" measure for judging maintenance effort and code
difficulty.
Column 2 is the cyclomatic complexity calculated in the "usual" way
with regard to switch statements. Specifically it is calculated as in
column 1 but counting each <b>case</b> rather than the <b>switch</b> and may be more
useful than column 1 for judging testing effort.
Column 3 contains a statement count. It is calculated by adding each
occurence of <b>for</b>,<b>if</b>,<b>while</b>, <b>switch</b>, and semicolon within the function.
One possible surprise is that <b>for</b> statements have a minimum statement
count of 3. This is realistic since <b>for(A;</b> <b>B;</b> <b>C){...}</b> is really
shorthand for
A;
while (B)
{
...
C;
}
Column 4 contains the first line number in the function. This is not
necessarily the same line on which the function name appears.
Column 5 is the number of lines of the function, from the number in
column 4 through the line containing the closing curly brace.
The final column contains the file name, line number on which the
function name occurs, and the name of the function.
<b>APPLICATIONS</b>
The obvious application of <em>pmccabe</em> is illustrated by the following
which gives a list of the "top ten" most complex functions:
pmccabe *.c | sort -nr | head -10
Many files contain more than one C function and sometimes it would be
useful to extract each function separately. <b>matchparen()</b> (see example
- 2 - Formatted: June 29, 1998
<b><a href="/cgi-bin/man?1+pmccabe">pmccabe(1)</a></b> <b><a href="/cgi-bin/man?1+pmccabe">pmccabe(1)</a></b>
<b>HP-GJD</b>
output above) can be extracted from gettoken.c by extracting 27 lines
starting with line 34. This can form the basis of tools which operate
on functions instead of files (e.g., use as a front-end for <em><a href="/cgi-bin/man?1+diff">diff</em>(1)</a>).
<b>DIAGNOSTICS</b>
<em>pmccabe</em> returns a nonzero exit status if any errors occur during
parsing.
Error messages to standard error, usually explaining that the parser
is confused about something, mimic normal C compiler error messages.
<b>WARNINGS</b>
<em>pmccabe</em> is confused by unmatched curly braces or parentheses which
sometimes occur with hasty use of <em>cpp</em> directives. In these cases a
diagnostic is printed and the complexity results for the files named
may be unreliable. Most times the "#ifdef" directives may be modified
such that the curly braces match. Note that if <em>pmccabe</em> is confused by
a <em>cpp</em> directive, most pretty printers will be too. In some cases,
preprocessing with <em><a href="/cgi-bin/man?1+unifdef">unifdef</em>(1)</a> may be appropriate.
Treatment of <b>?</b> for statement counting could perhaps be improved.
Statement counting could arguably be improved by: counting occurences
of the comma operator, multiple assignments, assignments within
conditional tests, and logical conjunction.
Destructors implemented within class definitions have no '~' in their
name.
<b>AUTHOR</b>
Paul Bame
<b>SEE</b> <b>ALSO</b>
<em><a href="/cgi-bin/man?1+sort">sort</em>(1)</a>, <em><a href="/cgi-bin/man?1+diff">diff</em>(1)</a>, <em>softbuild</em>(1), <em><a href="/cgi-bin/man?1+wc">wc</em>(1)</a>, <em><a href="/cgi-bin/man?1+grep">grep</em>(1)</a>, <em><a href="/cgi-bin/man?1+unifdef">unifdef</em>(1)</a>, <em><a href="/cgi-bin/man?1+head">head</em>(1)</a>
- 3 - Formatted: June 29, 1998
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