format.py

#!/usr/bin/python3

import pathlib
import re
import subprocess
import argparse
import sys

repo_root_dir = pathlib.Path(__file__).parent.absolute()

dirs_to_format = ["kernel", "userspace/apps", "userspace/drivers"]
extensions_to_format = [".c", ".cpp", ".h"]

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("--check", action='store_true', help = "Check that all files are formatted, and error otherwise.")
    args = parser.parse_args()

    dirs_matched = []

    # Loop through all items in tree, and find directories that match any regex in 'dirs_to_format'
    for d in repo_root_dir.glob('**'):
        if not d.is_dir():
            continue
        for dir_re in dirs_to_format:
            if re.match(dir_re, str(d.relative_to(repo_root_dir))):
                dirs_matched.append(d)
                break

    # Find all files in matched directories with a matching extension and format them
    num_formatted = 0
    for d in dirs_matched:
        for ext in extensions_to_format:            
            for f in d.glob('*' + ext):

                # The first command performs a diff on the original file and the 
                # clang-format output to see if clang-format will change anything
                diff_cmd = ['/bin/bash', '-c', "diff -u <(cat " + str(f) + ") <(clang-format " + str(f) + ")"]
                p = subprocess.Popen(diff_cmd, stdout = subprocess.PIPE)
                stdout = p.communicate()[0]
                
                # If there is any difference, format, or error if the --check option is set
                if len(stdout):
                    if args.check:
                        print("Error:", str(f), "needs formatting.")
                        sys.exit(1)
                    print("Formatting", f.relative_to(repo_root_dir))

                    cmd = ["clang-format", "-i", "-style=LLVM", str(f)]
                    subprocess.run(cmd)

                    num_formatted += 1
    
    if num_formatted == 0:
        print("Nothing needs formatting.")

if __name__ == "__main__":
    main()