summaryrefslogtreecommitdiff
path: root/utils/checkstyle.py
blob: b7c4d876a145726c8e953c21c61bc0b525b33339 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
#!/usr/bin/python3
# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2018, Google Inc.
#
# Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
#
# checkstyle.py - A patch style checker script based on astyle
#
# TODO:
#
# - Support other formatting tools (clang-format, ...)
# - Split large hunks to minimize context noise
# - Improve style issues counting
#

import argparse
import difflib
import re
import shutil
import subprocess
import sys

astyle_options = (
    '-n',
    '--style=linux',
    '--indent=force-tab=8',
    '--attach-namespaces',
    '--attach-extern-c',
    '--pad-oper',
    '--align-pointer=name',
    '--align-reference=name',
    '--max-code-length=120'
)

source_extensions = (
    '.c',
    '.cpp',
    '.h'
)

class Colours:
    Default = 0
    Red = 31
    Green = 32
    Cyan = 36

for attr in Colours.__dict__.keys():
    if attr.startswith('_'):
        continue

    if sys.stdout.isatty():
        setattr(Colours, attr, '\033[0;%um' % getattr(Colours, attr))
    else:
        setattr(Colours, attr, '')


class DiffHunkSide(object):
    """A side of a diff hunk, recording line numbers"""
    def __init__(self, start):
        self.start = start
        self.touched = []
        self.untouched = []

    def __len__(self):
        return len(self.touched) + len(self.untouched)


class DiffHunk(object):
    diff_header_regex = re.compile('@@ -([0-9]+),([0-9]+) \+([0-9]+),([0-9]+) @@')

    def __init__(self, line):
        match = DiffHunk.diff_header_regex.match(line)
        if not match:
            raise RuntimeError("Malformed diff hunk header '%s'" % line)

        self.__from_line = int(match.group(1))
        self.__to_line = int(match.group(3))
        self.__from = DiffHunkSide(self.__from_line)
        self.__to = DiffHunkSide(self.__to_line)

        self.lines = []

    def __repr__(self):
        s = '%s@@ -%u,%u +%u,%u @@\n' % \
                (Colours.Cyan,
                 self.__from.start, len(self.__from),
                 self.__to.start, len(self.__to))

        for line in self.lines:
            if line[0] == '-':
                s += Colours.Red
            elif line[0] == '+':
                s += Colours.Green
            else:
                s += Colours.Default
            s += line

        s += Colours.Default
        return s

    def append(self, line):
        if line[0] == ' ':
            self.__from.untouched.append(self.__from_line)
            self.__from_line += 1
            self.__to.untouched.append(self.__to_line)
            self.__to_line += 1
        elif line[0] == '-':
            self.__from.touched.append(self.__from_line)
            self.__from_line += 1
        elif line[0] == '+':
            self.__to.touched.append(self.__to_line)
            self.__to_line += 1

        self.lines.append(line)

    def intersects(self, lines):
        for line in lines:
            if line in self.__from.touched:
                return True
        return False

    def side(self, side):
        if side == 'from':
            return self.__from
        else:
            return self.__to


def parse_diff(diff):
    hunks = []
    hunk = None
    for line in diff:
        if line.startswith('@@'):
            if hunk:
                hunks.append(hunk)
            hunk = DiffHunk(line)

        elif hunk is not None:
            hunk.append(line)

    if hunk:
        hunks.append(hunk)

    return hunks


def check_file(top_level, commit, filename):
    # Extract the line numbers touched by the commit.
    diff = subprocess.run(['git', 'diff', '%s~..%s' % (commit, commit), '--',
                           '%s/%s' % (top_level, filename)],
                          stdout=subprocess.PIPE).stdout
    diff = diff.decode('utf-8').splitlines(True)
    commit_diff = parse_diff(diff)

    lines = []
    for hunk in commit_diff:
        lines.extend(hunk.side('to').touched)

    # Skip commits that don't add any line.
    if len(lines) == 0:
        return 0

    # Format the file after the commit with astyle and compute the diff between
    # the two files.
    after = subprocess.run(['git', 'show', '%s:%s' % (commit, filename)],
                           stdout=subprocess.PIPE).stdout
    formatted = subprocess.run(['astyle', *astyle_options],
                               input=after, stdout=subprocess.PIPE).stdout

    after = after.decode('utf-8').splitlines(True)
    formatted = formatted.decode('utf-8').splitlines(True)

    diff = difflib.unified_diff(after, formatted)

    # Split the diff in hunks, recording line number ranges for each hunk.
    formatted_diff = parse_diff(diff)

    # Filter out hunks that are not touched by the commit.
    formatted_diff = [hunk for hunk in formatted_diff if hunk.intersects(lines)]
    if len(formatted_diff) == 0:
        return 0

    print('%s---' % Colours.Red, filename)
    print('%s+++' % Colours.Green, filename)
    for hunk in formatted_diff:
        print(hunk)

    return len(formatted_diff)


def check_style(top_level, commit):
    # Get the commit title and list of files.
    ret = subprocess.run(['git', 'show', '--pretty=oneline','--name-only', commit],
                         stdout=subprocess.PIPE)
    files = ret.stdout.decode('utf-8').splitlines()
    title = files[0]
    files = files[1:]

    separator = '-' * len(title)
    print(separator)
    print(title)
    print(separator)

    # Filter out non C/C++ files.
    files = [f for f in files if f.endswith(source_extensions)]
    if len(files) == 0:
        print("Commit doesn't touch source files, skipping")
        return

    issues = 0
    for f in files:
        issues += check_file(top_level, commit, f)

    if issues == 0:
        print("No style issue detected")
    else:
        print('---')
        print("%u potential style %s detected, please review" % \
                (issues, 'issue' if issues == 1 else 'issues'))


def extract_revlist(revs):
    """Extract a list of commits on which to operate from a revision or revision
    range.
    """
    ret = subprocess.run(['git', 'rev-parse', revs], stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)
    if ret.returncode != 0:
        print(ret.stderr.decode('utf-8').splitlines()[0])
        return []

    revlist = ret.stdout.decode('utf-8').splitlines()

    # If the revlist contains more than one item, pass it to git rev-list to list
    # each commit individually.
    if len(revlist) > 1:
        ret = subprocess.run(['git', 'rev-list', *revlist], stdout=subprocess.PIPE)
        revlist = ret.stdout.decode('utf-8').splitlines()
        revlist.reverse()

    return revlist


def git_top_level():
    """Get the absolute path of the git top-level directory."""
    ret = subprocess.run(['git', 'rev-parse', '--show-toplevel'],
                         stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)
    if ret.returncode != 0:
        print(ret.stderr.decode('utf-8').splitlines()[0])
        return None

    return ret.stdout.decode('utf-8').strip()


def main(argv):

    # Parse command line arguments
    parser = argparse.ArgumentParser()
    parser.add_argument('revision_range', type=str, default='HEAD', nargs='?',
                        help='Revision range (as defined by git rev-parse). Defaults to HEAD if not specified.')
    args = parser.parse_args(argv[1:])

    # Check for required dependencies.
    dependencies = ('astyle', 'git')

    for dependency in dependencies:
        if not shutil.which(dependency):
            print("Executable %s not found" % dependency)
            return 1

    # Get the top level directory to pass absolute file names to git diff
    # commands, in order to support execution from subdirectories of the git
    # tree.
    top_level = git_top_level()
    if top_level is None:
            return 1

    revlist = extract_revlist(args.revision_range)

    for commit in revlist:
        check_style(top_level, commit)
        print('')

    return 0


if __name__ == '__main__':
    sys.exit(main(sys.argv))