StatiCFG

Python3 control flow graph generator

StatiCFG is a package that can be used to produce control flow graphs (CFGs) for Python 3 programs. The CFGs it generates can be easily visualised with graphviz and used for static analysis. This analysis is actually the main purpose of the module, hence the name of StatiCFG.

Below is an example of a piece of code that generates the Fibonacci sequence and the CFG produced for it with StatiCFG.

def fib():
    a, b = 0, 1
    while True:
        yield a
        a, b = b, a + b

fib_gen = fib()
for _ in range(10):
    next(fib_gen)

Installation

To install StatiCFG, simply clone this repository and run the command pip3 install --upgrade . inside of it. Please note that you will also need to install Graphviz on your machine to be able to visualise the control flow graphs generated by StatiCFG.

Usage

To use StatiCFG, simply import the module in your Python interpreter or program, and use the staticfg.CFGBuilder class to build CFGs. For example, to build the CFG of a program defined in a file with the path ./example.py, the following code can be used:

from staticfg import CFGBuilder

cfg = CFGBuilder().build_from_file('example.py', './example.py')

This returns the CFG for the code in ./example.py in the cfg variable. The first parameter of build_from_file is the desired name for the CFG, and the second one is the path to the file containing the source code. The produced CFG can then be visualised with:

cfg.build_visual('exampleCFG', 'pdf')

The first paramter of build_visual is the desired name for the DOT file produced by the method, and the second one is the format to use for the visualisation.

The build_cfg.py script present in the /examples folder of this repository can be used to directly generate the CFG of some Python program and visualise it. To do so, simply call the script with the command python3 build_cfg.py <path_to_some_source>.