I was having a look at a code piece authored by someone else. And I wondered if we could have a tool that would at least find out the code flow. I googled for such tool and found “GNU cflow”.
“cflow” is an open source tool, that can facilitate static analysis in form of code-flow of your program. cflow reports are hierarchical, hence very intuitive. If you desire a GUI form of this data, we have another open source utility called Graphviz.
I found it very useful for:o) Reviewing a new code o) Understanding legacy C code o) Remember, it can’t handle function pointers 😦
A typical cflow invocation look like this:
cflow --format=posix --omit-arguments --level-indent='0=\t' --level-indent='1=\t' --level-indent=start='\t' "source_file" > "out.cf"
Output looks as follows:
$ ./cflow ./my2.c main() : open() printf() read()
By default, “cflow” shows all symbols present in your program. We (Srikanth and I) didn’t like that, and hence changed the “cflow” to accommodate our request to ignore-symbols.
So, you just mention all symbols you’d like to ignore in a file “/tmp/skip_list.txt” in a format like this
The source code and binary are available here.
After collecting the profile, a browser based GUI can be generated with cflow2dot utility.