xref: /openbmc/u-boot/scripts/mailmapper (revision dd84058d24ff54d6b32818ffe44aeb4bba2cfae6) 
1#!/usr/bin/env python
2#
3# Copyright (C) 2014, Masahiro Yamada <yamada.m@jp.panasonic.com>
4#
5# SPDX-License-Identifier:	GPL-2.0+
6#
7
8'''
9A tool to create/update the mailmap file
10
11The command 'git shortlog' summarizes git log output in a format suitable
12for inclusion in release announcements. Each commit will be grouped by
13author and title.
14
15One problem is that the authors' name and/or email address is sometimes
16spelled differently. The .mailmap feature can be used to coalesce together
17commits by the same persion.
18(See 'man git-shortlog' for furthur information of this feature.)
19
20This tool helps to create/update the mailmap file.
21
22It runs 'git shortlog' internally and searches differently spelled author
23names which share the same email address. The author name with the most
24commits is asuumed to be a canonical real name. If the number of commits
25from the cananonical name is equal to or greater than 'MIN_COMMITS',
26the entry for the cananical name will be output. ('MIN_COMMITS' is used
27here because we do not want to create a fat mailmap by adding every author
28with only a few commits.)
29
30If there exists a mailmap file specified by the mailmap.file configuration
31options or '.mailmap' at the toplevel of the repository, it is used as
32a base file. (The mailmap.file configuration takes precedence over the
33'.mailmap' file if both exist.)
34
35The base file and the newly added entries are merged together and sorted
36alphabetically (but the comment block is kept untouched), and then printed
37to standard output.
38
39Usage
40-----
41
42  scripts/mailmapper
43
44prints the mailmapping to standard output.
45
46  scripts/mailmapper > tmp; mv tmp .mailmap
47
48will be useful for updating '.mailmap' file.
49'''
50
51import sys
52import os
53import subprocess
54
55# The entries only for the canonical names with MIN_COMMITS or more commits.
56# This limitation is used so as not to create a too big mailmap file.
57MIN_COMMITS = 50
58
59try:
60    toplevel = subprocess.check_output(['git', 'rev-parse', '--show-toplevel'])
61except subprocess.CalledProcessError:
62    print >> sys.stderr, 'Please run in a git repository.'
63    sys.exit(1)
64
65# strip '\n'
66toplevel = toplevel.rstrip()
67
68# Change the current working directory to the toplevel of the respository
69# for our easier life.
70os.chdir(toplevel)
71
72# First, create 'auther name' vs 'number of commits' database.
73# We assume the name with the most commits as the canonical real name.
74shortlog = subprocess.check_output(['git', 'shortlog', '-s', '-n'])
75
76commits_per_name = {}
77
78for line in shortlog.splitlines():
79    try:
80        commits, name = line.split(None, 1)
81    except ValueError:
82        # ignore lines with an empty author name
83        pass
84    commits_per_name[name] = int(commits)
85
86# Next, coalesce the auther names with the same email address
87shortlog = subprocess.check_output(['git', 'shortlog', '-s', '-n', '-e'])
88
89mail_vs_name = {}
90output = {}
91
92for line in shortlog.splitlines():
93    # tmp, mail = line.rsplit(None, 1) is not safe
94    # because weird email addresses might include whitespaces
95    tmp, mail = line.split('<')
96    mail = '<' + mail.rstrip()
97    try:
98        _, name = tmp.rstrip().split(None, 1)
99    except ValueError:
100        # author name is empty
101        name = ''
102    if mail in mail_vs_name:
103        # another name for the same email address
104        prev_name = mail_vs_name[mail]
105        # Take the name with more commits
106        major_name = sorted([prev_name, name],
107                            key=lambda x: commits_per_name[x] if x else 0)[1]
108        mail_vs_name[mail] = major_name
109        if commits_per_name[major_name] > MIN_COMMITS:
110            output[mail] = major_name
111    else:
112        mail_vs_name[mail] = name
113
114# [1] If there exists a mailmap file at the location pointed to
115#     by the mailmap.file configuration option, update it.
116# [2] If the file .mailmap exists at the toplevel of the repository, update it.
117# [3] Otherwise, create a new mailmap file.
118mailmap_files = []
119
120try:
121    config_mailmap = subprocess.check_output(['git', 'config', 'mailmap.file'])
122except subprocess.CalledProcessError:
123    config_mailmap = ''
124
125config_mailmap = config_mailmap.rstrip()
126if config_mailmap:
127    mailmap_files.append(config_mailmap)
128
129mailmap_files.append('.mailmap')
130
131infile = None
132
133for map_file in mailmap_files:
134    try:
135        infile = open(map_file)
136    except:
137        # Failed to open. Try next.
138        continue
139    break
140
141comment_block = []
142output_lines = []
143
144if infile:
145    for line in infile:
146        if line[0] == '#' or line[0] == '\n':
147            comment_block.append(line)
148        else:
149            output_lines.append(line)
150            break
151    for line in infile:
152        output_lines.append(line)
153    infile.close()
154
155for mail, name in output.items():
156    output_lines.append(name + ' ' + mail + '\n')
157
158output_lines.sort()
159
160sys.stdout.write(''.join(comment_block + output_lines))
161