cflow(1p) - phpMan

CFLOW(P) CFLOW(P)

NAME
cflow - generate a C-language flowgraph (DEVELOPMENT)

SYNOPSIS
cflow [-r][-d num][-D name[=def]] ... [-i incl][-I dir] ...
[-U dir] ... file ...

DESCRIPTION
The cflow utility shall analyze a collection of object files or assembler, C-lan-
guage, lex, or yacc source files, and attempt to build a graph, written to standard
output, charting the external references.

OPTIONS
The cflow utility shall conform to the Base Definitions volume of
IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines, except that the
order of the -D, -I, and -U options (which are identical to their interpretation by
c99) is significant.

The following options shall be supported:

-d num
Indicate the depth at which the flowgraph is cut off. The application shall
ensure that the argument num is a decimal integer. By default this is a very
large number (typically greater than 32000). Attempts to set the cut-off
depth to a non-positive integer shall be ignored.

-i incl
Increase the number of included symbols. The incl option-argument is one of
the following characters:

x
Include external and static data symbols. The default shall be to include
only functions in the flowgraph.

_
(Underscore) Include names that begin with an underscore. The default shall
be to exclude these functions (and data if -i x is used).

-r Reverse the caller:callee relationship, producing an inverted listing show-
ing the callers of each function. The listing shall also be sorted in lexi-
cographical order by callee.

OPERANDS
The following operand is supported:

file The pathname of a file for which a graph is to be generated. Filenames suf-
fixed by .l shall shall be taken to be lex input, .y as yacc input, .c as
c99 input, and .i as the output of c99 -E. Such files shall be processed as
appropriate, determined by their suffix.

Files suffixed by .s (conventionally assembler source) may have more limited infor-
mation extracted from them.

STDIN
Not used.

INPUT FILES
The input files shall be object files or assembler, C-language, lex, or yacc source
files.

ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of cflow:

LANG Provide a default value for the internationalization variables that are
unset or null. (See the Base Definitions volume of IEEE Std 1003.1-2001,
Section 8.2, Internationalization Variables for the precedence of interna-
tionalization variables used to determine the values of locale categories.)

LC_ALL If set to a non-empty string value, override the values of all the other
internationalization variables.

LC_COLLATE

Determine the locale for the ordering of the output when the -r option is
used.

LC_CTYPE
Determine the locale for the interpretation of sequences of bytes of text
data as characters (for example, single-byte as opposed to multi-byte char-
acters in arguments and input files).

LC_MESSAGES
Determine the locale that should be used to affect the format and contents
of diagnostic messages written to standard error.

NLSPATH
Determine the location of message catalogs for the processing of LC_MESSAGES
.

ASYNCHRONOUS EVENTS
Default.

STDOUT
The flowgraph written to standard output shall be formatted as follows:

"%d %s:%s\n", <reference number>, <global>, <definition>

Each line of output begins with a reference (that is, line) number, followed by
indentation of at least one column position per level. This is followed by the name
of the global, a colon, and its definition. Normally globals are only functions not
defined as an external or beginning with an underscore; see the OPTIONS section for
the -i inclusion option. For information extracted from C-language source, the def-
inition consists of an abstract type declaration (for example, char *) and, delim-
ited by angle brackets, the name of the source file and the line number where the
definition was found. Definitions extracted from object files indicate the filename
and location counter under which the symbol appeared (for example, text).

Once a definition of a name has been written, subsequent references to that name
contain only the reference number of the line where the definition can be found.
For undefined references, only "<>" shall be written.

STDERR
The standard error shall be used only for diagnostic messages.

OUTPUT FILES
None.

EXTENDED DESCRIPTION
None.

EXIT STATUS
The following exit values shall be returned:

0 Successful completion.

>0 An error occurred.

CONSEQUENCES OF ERRORS
Default.

The following sections are informative.

APPLICATION USAGE
Files produced by lex and yacc cause the reordering of line number declarations,
and this can confuse cflow. To obtain proper results, the input of yacc or lex
must be directed to cflow.

EXAMPLES
Given the following in file.c:

int i;
int f();
int g();
int h();
int
main()
{
f();
g();
f();
}
int
f()
{
i = h();
}

The command:

cflow -i x file.c

produces the output:

1 main: int(), <file.c 6>
2 f: int(), <file.c 13>
3 h: <>
4 i: int, <file.c 1>
5 g: <>

RATIONALE
None.

FUTURE DIRECTIONS
None.