trailer2.py

trailer2.py

#!/usr/bin/env python
"""Subroutines for Validating the whitespace of the source code."""

import argparse
import sys

import flint


def parse_command_line():
    """Parse the command line positional and optional arguments.

    This is the highest level procedure invoked from the very end of the
    script.
    """
    # Arguments
    parser = argparse.ArgumentParser(
        description='trailer.py checks Fortran files for trailing white '
                    'space.',
        epilog='Written by A.Adcroft, 2017.'
    )
    parser.add_argument(
        'files_or_dirs', type=str, nargs='+',
        metavar='FILE|DIR',
        help='Fortran files or directory in which to search for Fortran files '
             '(with .f, .f90, .F90 suffixes).'''
    )
    parser.add_argument(
        '-e', '--exclude_dir', type=str, action='append',
        metavar='DIR',
        help='''Exclude directories from search that end in DIR.'''
    )
    parser.add_argument(
        '-l', '--line_length', type=int, default=512,
        help='''Maximum allowed length of a line.'''
    )
    parser.add_argument(
        '-s', '--source_line_length', type=int, default=132,
        help='''Maximum allowed length of a source line excluding comments.'''
    )
    parser.add_argument(
        '-d', '--debug', action='store_true',
        help='turn on debugging information.'
    )
    args = parser.parse_args()
    main(args)


def main(args):
    """Do the actual work."""
    if args.debug:
        print(args)

    proj = flint.parse(*args.files_or_dirs, excludes=args.exclude_dir)
    if args.debug:
        print('Found: ', [src.path for src in proj.sources])

    # For each file, check for trailing white space
    fail = False
    for src in proj.sources:
        this = scan_file(src, line_length=args.line_length,
                         source_line_length=args.source_line_length)
        fail = fail or this

    if fail:
        sys.exit(1)


def scan_file(source, line_length=512, source_line_length=132):
    """Scan file for trailing white space."""

    def msg(filename, lineno, mesg, line=None):
        log = '{}, line {}: {}'.format(filename, lineno, mesg)
        if line is not None:
            log += ' "{}"'.format(''.join(line))

        print(log)

    white_space_detected = False
    tabs_space_detected = False
    long_line_detected = False

    lineno = 0
    for line in source.lines:
        lineno += 1

        # Report trailing whitespace
        if line and line[-1] and line[-1][-1].isspace():
            white_space_detected = True

            if all(tok.isspace() for tok in line):
                msg(source.path, lineno, 'Blank line contains spaces')
            else:
                msg(source.path, lineno, 'Trailing space detected', line)

        # Report any tab stop characters
        # NOTE: This also reports tab stops in comments and strings.
        if any('\t' in tok for tok in line):
            tab_space_detected = True

            if all(tok.isspace() for tok in line):
                msg(source.path, lineno, 'Blank line contains tabs')
            else:
                msg(source.path, lineno, 'Tab detected', line)

        # Report excessive line length
        if sum(len(tok) for tok in line) > line_length:
            long_line_detected = True

            if all(tok.isspace() for tok in line):
                msg(source.path, lineno,
                    'Blank line exceeds line length limit')
            else:
                msg(source.path, lineno, 'Line length exceeded', line)

        # Report excessive source line length
        # NOTE: Source line test includes whitespace preceding comments
        srclen = sum(len(tok) for tok in line if not tok.startswith('!'))
        if srclen > source_line_length:
            msg(source.path, lineno, 'Non-comment line length exceeded', line)

    return white_space_detected or tabs_space_detected or long_line_detected


# Invoke parse_command_line(), the top-level procedure
if __name__ == '__main__':
    parse_command_line()