De-commenting mode

-d

Intended to help count non-commented source lines via something like:

pmccabe -d *.c | grep -v '^[<blank><tab>]*$' | wc -l

Comments are removed, cpp directives are replaced by cpp, string literals are replaced by STRINGLITERAL, character constants are replaced by CHARLITERAL. The resulting source code is much easier to parse. This is the first step performed by pmccabe so that its parser can be simpler.

Only -X and -x work sensibly with -d.

-X

instructs pmccabe to use a better approximation of the C preprocessor (courtesy of Matt Hargett) than the original one. WARNING! if you have archived results using the old algorithm, they may break because -X is now the default.

-x

pmccabe uses the original rudimentary approximation of the C preprocessor (described below). WARNING! This is no longer the default algorithm as of version 2.8 and may be removed after version 2.8.

Line-counting mode

-n

Counts non-commented source lines. The output format is identical to that of the anac program except that column headers and totals must be requested if desired. If you want column headers add -v. If you want totals add -t. If all you want is totals add -T.

Complexity mode (default)

-C

Custom output format - don't use it.

-c

Report non-commented, non-blank lines per function (and file) instead of the raw number of lines. Note that pre-processor directives are NOT counted.

-b

Output format compatible with compiler error browsing tools which understand "classic" compiler errors. Numerical sorting on this format is possible using:

sort -n +1 -t%

-t

Print column totals. Note the total number of lines is *NOT* the number of non-commented source lines - it's the same as would be reported by "wc -l".

-T

Print column totals *ONLY*.

-f

Include per-file totals along with the per-function totals.

-F

Print per-file totals but NOT per-function totals.

Parsing

pmccabe ignores all cpp 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 getchar(3) expand into macros which increase complexity.

Output Format

A line is written to standard output for each function found of the form:

Modified McCabe Cyclomatic Complexity
|   Traditional McCabe Cyclomatic Complexity
|       |    # Statements in function
|       |        |   First line of function
|       |        |       |   # lines in function
|       |        |       |       |  filename(definition line number):function
|       |        |       |       |           |
5       6       11      34      27      gettoken.c(35): matchparen

Column 1 contains cyclomatic complexity calculated by adding 1 (for the function) to the occurrences of for, if, while, switch, &&, ||, and ?. 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 case rather than the switch and may be more useful than column 1 for judging testing effort.

Column 3 contains a statement count. It is calculated by adding each occurrence of for, if, while, switch, ?, and semicolon within the function. One possible surprise is that for statements have a minimum statement count of 3. This is realistic since for(A; B; C){...} is really shorthand for A; while (B) { ... C;}. The number of statements within a file is the sum of the number of statements for each function implemented within that file, plus one for each of those functions (because functions are statements too), plus one for each other file-scoped statement (usually declarations).

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.