The cflow utility shall analyze a collection of object files
or assembler, C-language, 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
showing the callers of each function. The listing shall
also be sorted in lexicographical order by callee.
OPERANDS
The following operand is supported:
file
The pathname of a file for which a graph is to be generated. Filenames
suffixed 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 information 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 internationalization 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 characters 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:
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 definition consists of an abstract type
declaration (for example, char *) and, delimited 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();
}
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
