scripts/fill_scrapyard.py

   1 #!/usr/bin/env python2
   2 # SPDX-License-Identifier: GPL-2.0+
   3 #
   4 # Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
   5 #
   6
   7 """
   8 Fill the "Commit" and "Removed" fields of doc/README.scrapyard
   9
  10 The file doc/README.scrapyard is used to keep track of removed boards.
  11
  12 When we remove support for boards, we are supposed to add entries to
  13 doc/README.scrapyard leaving "Commit" and "Removed" fields blank.
  14
  15 The "Commit" field is the commit hash in which the board was removed
  16 and the "Removed" is the date at which the board was removed.  Those
  17 two are known only after the board removal patch was applied, thus they
  18 need to be filled in later.
  19
  20 This effectively means that the person who removes other boards is
  21 supposed to fill in the blank fields before adding new entries to
  22 doc/README.scrapyard.
  23
  24 That is a really tedious task that should be automated.
  25 This script fills the blank fields of doc/README.scrapyard for you!
  26
  27 Usage:
  28
  29 The "Commit" and "Removed" fields must be "-".  The other fields should
  30 have already been filled in by a former commit.
  31
  32 Run
  33     scripts/fill_scrapyard.py
  34 """
  35
  36 import os
  37 import subprocess
  38 import sys
  39 import tempfile
  40
  41 DOC='doc/README.scrapyard'
  42
  43 def get_last_modify_commit(file, line_num):
  44     """Get the commit that last modified the given line.
  45
  46     This function runs "git blame" against the given line of the given
  47     file and returns the commit hash that last modified it.
  48
  49     Arguments:
  50       file: the file to be git-blame'd.
  51       line_num: the line number to be git-blame'd.  This line number
  52                 starts from 1, not 0.
  53
  54     Returns:
  55       Commit hash that last modified the line.  The number of digits is
  56       long enough to form a unique commit.
  57     """
  58     result = subprocess.check_output(['git', 'blame', '-L',
  59                                       '%d,%d' % (line_num, line_num), file])
  60     commit = result.split()[0]
  61
  62     if commit[0] == '^':
  63         sys.exit('%s: line %d: ' % (file, line_num) +
  64                  'this line was modified before the beginning of git history')
  65
  66     if commit == '0' * len(commit):
  67         sys.exit('%s: line %d: locally modified\n' % (file, line_num) +
  68                  'Please run this script in a clean repository.')
  69
  70     return commit
  71
  72 def get_committer_date(commit):
  73     """Get the committer date of the given commit.
  74
  75     This function returns the date when the given commit was applied.
  76
  77     Arguments:
  78       commit: commit-ish object.
  79
  80     Returns:
  81       The committer date of the given commit in the form YY-MM-DD.
  82     """
  83     committer_date = subprocess.check_output(['git', 'show', '-s',
  84                                               '--format=%ci', commit])
  85     return committer_date.split()[0]
  86
  87 def move_to_topdir():
  88     """Change directory to the top of the git repository.
  89
  90     Or, exit with an error message if called out of a git repository.
  91     """
  92     try:
  93         toplevel = subprocess.check_output(['git', 'rev-parse',
  94                                             '--show-toplevel'])
  95     except subprocess.CalledProcessError:
  96         sys.exit('Please run in a git repository.')
  97
  98     # strip '\n'
  99     toplevel = toplevel.rstrip()
 100
 101     # Change the current working directory to the toplevel of the respository
 102     # for our easier life.
 103     os.chdir(toplevel)
 104
 105 class TmpFile:
 106
 107     """Useful class to handle a temporary file.
 108
 109     tempfile.mkstemp() is often used to create a unique temporary file,
 110     but what is inconvenient is that the caller is responsible for
 111     deleting the file when done with it.
 112
 113     Even when the caller errors out on the way, the temporary file must
 114     be deleted somehow.  The idea here is that we delete the file in
 115     the destructor of this class because the destructor is always
 116     invoked when the instance of the class is freed.
 117     """
 118
 119     def __init__(self):
 120         """Constructor - create a temporary file"""
 121         fd, self.filename = tempfile.mkstemp()
 122         self.file = os.fdopen(fd, 'w')
 123
 124     def __del__(self):
 125         """Destructor - delete the temporary file"""
 126         try:
 127             os.remove(self.filename)
 128         except:
 129             pass
 130
 131 def main():
 132     move_to_topdir()
 133
 134     line_num = 1
 135
 136     tmpfile = TmpFile()
 137     for line in open(DOC):
 138         tmp = line.split(None, 5)
 139         modified = False
 140
 141         if len(tmp) >= 5:
 142             # fill "Commit" field
 143             if tmp[3] == '-':
 144                 tmp[3] = get_last_modify_commit(DOC, line_num)
 145                 modified = True
 146             # fill "Removed" field
 147             if tmp[4] == '-':
 148                 tmp[4] = get_committer_date(tmp[3])
 149             if modified:
 150                 line  = tmp[0].ljust(17)
 151                 line += tmp[1].ljust(12)
 152                 line += tmp[2].ljust(15)
 153                 line += tmp[3].ljust(12)
 154                 line += tmp[4].ljust(12)
 155                 if len(tmp) >= 6:
 156                     line += tmp[5]
 157                 line = line.rstrip() + '\n'
 158
 159         tmpfile.file.write(line)
 160         line_num += 1
 161
 162     os.rename(tmpfile.filename, DOC)
 163
 164 if __name__ == '__main__':
 165     main()