1# Copyright (C) 2011 by the Massachusetts Institute of Technology.
2# All rights reserved.
3#
4# Export of this software from the United States of America may
5#   require a specific license from the United States Government.
6#   It is the responsibility of any person or organization contemplating
7#   export to obtain such a license before exporting.
8#
9# WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
10# distribute this software and its documentation for any purpose and
11# without fee is hereby granted, provided that the above copyright
12# notice appear in all copies and that both that copyright notice and
13# this permission notice appear in supporting documentation, and that
14# the name of M.I.T. not be used in advertising or publicity pertaining
15# to distribution of the software without specific, written prior
16# permission.  Furthermore if you modify this software you must label
17# your software as modified software and not distribute it in such a
18# fashion that it might be confused with the original M.I.T. software.
19# M.I.T. makes no representations about the suitability of
20# this software for any purpose.  It is provided "as is" without express
21# or implied warranty.
22
23# This program is intended to be used by "make check-copyright".  It
24# checks for violations of the coding standards related to copyright
25# and license statements in source code comments.
26
27import os
28import sys
29import re
30
31def warn(fname, ln, msg):
32    print('%s: %d: %s' % (fname, ln + 1, msg))
33
34def indicates_license(line):
35    return 'Copyright' in line or 'COPYRIGHT' in line or 'License' in line
36
37# Check a comment for boilerplate violations.  Return true if the comment
38# is a license statement.
39def check_comment(comment, fname, ln, code_seen, nonlicense_seen):
40    text_seen = False
41    is_license = False
42    for line in comment:
43        if not is_license and indicates_license(line):
44            is_license = True
45            if text_seen:
46                warn(fname, ln, 'License begins after first line of comment')
47            elif code_seen:
48                warn(fname, ln, 'License after code')
49            elif nonlicense_seen:
50                warn(fname, ln, 'License after non-license comments')
51            break
52        # DB2 licenses start with '/*-' and we don't want to change them.
53        if line != '' and line != '-':
54            text_seen = True
55    return is_license
56
57def check_file(lines, fname):
58    # Skip emacs mode line if present.
59    ln = 0
60    if '-*- mode: c;' in lines[ln]:
61        ln += 1
62
63    # Check filename comment if present.
64    m = re.match(r'/\* ([^ ]*)( - .*)? \*/', lines[ln])
65    if m:
66        if m.group(1) != fname:
67            warn(fname, ln, 'Wrong filename in comment')
68        ln += 1
69
70    # Scan for license statements.
71    in_comment = False
72    code_seen = False
73    nonlicense_seen = False
74    for line in lines[ln:]:
75        # Strip out whitespace and comments contained within a line.
76        if not in_comment:
77            line = re.sub(r'/\*.*?\*/', '', line)
78        line = line.strip()
79
80        if not in_comment and '/*' in line:
81            (line, sep, comment_part) = line.partition('/*')
82            comment = [comment_part.strip()]
83            comment_starts_at = ln
84            in_comment = True
85        elif in_comment and '*/' not in line:
86            comment.append(line.lstrip('*').lstrip())
87        elif in_comment:
88            (comment_part, sep, line) = line.partition('*/')
89            comment.append(comment_part.strip())
90            is_license = check_comment(comment, fname, comment_starts_at,
91                                       code_seen, nonlicense_seen)
92            nonlicense_seen = nonlicense_seen or not is_license
93            in_comment = False
94        elif line.strip() != '':
95            code_seen = True
96
97        ln += 1
98
99for fname in sys.argv[1:]:
100    if fname.startswith('./'):
101        fname = fname[2:]
102    f = open(fname)
103    lines = f.readlines()
104    f.close()
105    check_file(lines, fname)
106