Just make random edits until it compiles.

compile_xkcd.py

#!/usr/bin/env python
"""
XKCD Compile
Usage: compile_xkcd.py [FILE.c]
Compile your C code XKCD style.

Exactly one file must be specified.

Inspired by XKCD: https://xkcd.com/1513/

UNDER CONSTRUCTION

Probable Path: Clang exposes their AST parser/lexer
    https://stackoverflow.com/questions/18560019/how-to-view-clang-ast
"""
import os
import sys


def main():
    """ parse command-line and direct the primary tasks
    """
    if len(sys.argv) > 1:
        file_path = sys.argv[1]
    else:
        usage()

    # execute code
    xkcd = XKCD_Compiler(file_path)
    xkcd.compile()


def usage():
    ''' Print the help menu.
    '''
    print(__doc__.strip())
    exit()


class XKCD_Compiler(object):

    def __init__(self, file_path, max_iter=10000):
        self.original = file_path
        self.file_path = file_path.rstrip('.c') + '_new.c'
        self.code = list(open(self.original, 'r').readlines())
        self.max_iterations = max_iter

    def compile(self):
        ''' Make random edits to a file
            until it compiles using GCC.
        '''
        i = 0
        while self.does_compile() and i < self.max_iterations:
            self.random_edits()
            i += 1

    def does_compile(self):
        ''' Try to compile the file
            (assumes you have GCC and a Linux env)
        '''
        # TODO: turn off some safety flags
        return os.system('gcc ' + self.file_path + ' 2> /dev/null')

    def random_edits(self):
        ''' Make random C-esque edits to the code.
        '''
        # TODO: Magic
        # TODO: 1) Remove comments: gcc -fpreprocessed -dD -E test.c
        #     https://stackoverflow.com/questions/2394017/remove-comments-from-c-c-code
        # TODO: 2) remove whitespace and obfuscate variables?
        # TODO: 3) make "random" C-like edits?
        pass


if __name__ == '__main__':
    main()