NAME
fflow - generate a flowgraph for fortran files.
SYNOPSIS
fflow [-cefhinpqtuv] -Eext -Idir -ddepth -llevel -ofile
-sname -xname [files]
DESCRIPTION
fflow Generates a (partial) flowgraph of a collection of
fortran files. When fed with a couple of directories
and/or files, fflow creates a flowgraph indicating the
flow in your program. The output is written on stdout by
default but can be written to file. fflow is very usefull
for large programs where you only want to see the flow-
graph of a certain part of a program.
OPTIONS
-c Using this option instructs fflow to generate a
complete flowgraph for each subroutine or function
it encounters. By default, fflow will place a ==
Line XX == in the output for each subroutine or
function for which it has already generated a flow-
graph. Beware though that using this option can
significantly increase the size of the output file
and that it can take a little longer to generate
all flowgraphs.
-e Using this option will cause fflow to not include
functions without calls in the output. Helps to
decrease the size of the output file.
-f Include the full path of files in the output. The
default is to print the name of the file only.
Using this option increases the memory fflow uses
to store its data, so it might be unwise to use
this option on msdos systems with their 640kb mem-
ory limit.
-h, --help
gives a short description of every option you can
use.
-i Using this option causes fflow to not print unknown
function calls in the output. Usefull if you only
want to have a flowgraph of a part of a source
tree.
-n, -n-
Using this option will cause fflow to tell what
subroutines are never invoked. If you only want to
check your files for this and do not want to gener-
ate a flowgraph, use -n-
-p Starts the flowgraph at the PROGRAM definition.
When used with -u , fflow generates a flowgraph for
PROGRAM only.
Note: if you use the -u option, fflow will generate
a flowgraph for the first PROGRAM statement it
encounters.
-q Be really quiet (usefull if called from a script).
Only error messages will be shown.
-t Use tabs instead of | as level indicator.
-u Do not print unused functions in the output file.
Using this option will cause fflow to not print
functions and/or routines which are not referenced.
Use the -n or -n- option if you only want to print
unused subroutines.
-v Be verbose. Using this option shows a lot of use-
full information about the files being scanned.
--version
Show the version number of fflow
-Eext Extensions fflow must use to determine which files
it has to scan. Up to eight -E are allowed. The
default extension is .f
-Idir Using this option tells fflow which directories it
has to search for f77 files. Only the contents of
that directory are scanned. Subdirectories are
ignored. Up to 64 -I are allowed.
-ddepth
Sets the maximum recursion depth to depth. The
default value is 64. This recursion depth is the
maximum depth of function calls, and is mainly used
as a test for detecting recursion. If fflow manages
to get to the default value, this probably indi-
cates that somewhere in your program infinite
recursion might occur. If fflow aborts saying it
has reached the maximum recursion depth, it means
that this number has been hit. If you are abso-
lutely sure that recursion does not appear in your
program, you can increase this number to the maxi-
mum value of an unsigned integer on your system.
The default value of 64 should be enough for any
program.
-llevel
Using this option will cause fflow to generate a
flowgraph which is only level levels deep. This
option can be very usefull to get a general idea on
the flow in a very large program. It also will help
reduce the size of the generated flowgraph.
-ofile file to write flowgraph to. The default is stdout.
-sname This option causes fflow to start the output file
with the named function. When used with -u , fflow
generates a flowgraph for this function only.
-xname Tells fflow to exclude the named file when scanning
the files found with the -I -E options. Up to 64 -x
options can be given.
EXAMPLES
fflow -p -u fortran-files generates a flowgraph for your
program only.
fflow -sname -u fortran-files generates a flowgraph for
[name] only.
fflow -Idir1 -Idir2 -E.f -E.f,v generates a flowgraph from
files ending in .f and .f,v from the directories dir1 and
dir2.
DIAGNOSTICS
The following warning messages can occur:
WARNING: no program entry point found in file <file>
a call statement was encountered before a PROGRAM
statement was found. fflow will use the name of
the file where this warning occurs as a program
name and continue.
Write failed
This error can occur when fflow is writing a flow-
graph to file and a write error occurs. The most
likely reasons for this error to occur are disk
full or no space left on device
The flowgraph generated by fflow can be very huge.
We have seen a complete flowgraph of a single func-
tion which was in excess of 50MB, so it's easy to
fill up your disk. When you encounter such large
flowgraphs, you might want to use the -llevel
option in order to generate a useable flowgraph.
DISTRIBUTION POLICY
All utilities in this fortran utility suite are dis-
tributed under the GNU Public License.
COMPATIBILITY
fflow has run under HP-UX 9 and 10, SGI IRIX 5.2 & 5.3,
DEC OSF1, SunOs 4.1 and 4.3, Cray Unicos, IBM AIX 3.2 &
4.1, Linux and MSDOS 6.2. fflow also runs in a dos box
under Windows 3.1, 3.11 and Win95. An MS-Windows version,
Winfflow, is also available.
SHORTCOMINGS
The output of fflow contains a flowgraph for each subrou-
tine or function found in the input files. When you give
fflow the -c option, it can take a long time to write the
flowgraph to file if you have fed it a collection of
source files with a huge number of calls. This can be
annoying especially when running fflow on MSDOS.
Currently, fflow only looks at CALL, so although FUNCTION
is found, these do not show up in the flowgraph.
BUGS
The MS-DOS versions of these tools can cause problems
under MS-DOS if you feed them with a large collection of
files, few files with a lot of calls or a combination of
both. This is totally due to the 640kb memory limit MS-DOS
has.
If you think you have found a bug, you can send email to
the author, describing what the bug is, how you generated
it and if you can reproduce it. Also specify the platform
where this bug occured.
AUTHOR
Koen D'Hondt
ripley@xs4all.nl
(C)Copyright 1995-1996 by Ripley Software Development
SEE ALSO
ftags(1), ffscan(1), scan_commons(1), get_common(1),
list_commons(1)