scripts/gitlog_to_changelog.py

   1 #!/usr/bin/python3
   2 # Main VCSToChangeLog script.
   3 # Copyright (C) 2019 Free Software Foundation, Inc.
   4 #
   5 # This program is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  17
  18 ''' Generate a ChangeLog style output based on a VCS log.
  19
  20 This script takes two revisions as input and generates a ChangeLog style output
  21 for all revisions between the two revisions.
  22
  23 This script is intended to be executed from the project parent directory.
  24
  25 The vcs_to_changelog directory has a file vcstocl_quirks.py that defines a
  26 function called get_project_quirks that returns a object of class type
  27 ProjectQuirks or a subclass of the same.  The definition of the ProjectQuirks
  28 class is below and it specifies the properties that the project must set to
  29 ensure correct parsing of its contents.
  30
  31 Among other things, ProjectQurks specifies the VCS to read from; the default is
  32 assumed to be git.  The script then studies the VCS log and for each change,
  33 list out the nature of changes in the constituent files.
  34
  35 Each file type may have parser frontends that can read files and construct
  36 objects that may be compared to determine the minimal changes that occured in
  37 each revision.  For files that do not have parsers, we may only know the nature
  38 of changes at the top level depending on the information that the VCS stores.
  39
  40 The parser frontend must have a compare() method that takes the old and new
  41 files as arrays of strings and prints the output in ChangeLog format.
  42
  43 Currently implemented VCS:
  44
  45     git
  46
  47 Currently implemented frontends:
  48
  49     C
  50 '''
  51 import sys
  52 import os
  53 import re
  54 import argparse
  55 from vcs_to_changelog.misc_util import *
  56 from vcs_to_changelog import frontend_c
  57 from vcs_to_changelog.vcs_git import *
  58
  59 debug = DebugUtil(False)
  60
  61 class ProjectQuirks:
  62     # This is a list of regex substitutions for C/C++ macros that are known to
  63     # break parsing of the C programs.  Each member of this list is a dict with
  64     # the key 'orig' having the regex and 'sub' having the substitution of the
  65     # regex.
  66     MACRO_QUIRKS = []
  67
  68     # This is a list of macro definitions that are extensively used and are
  69     # known to break parsing due to some characteristic, mainly the lack of a
  70     # semicolon at the end.
  71     C_MACROS = []
  72
  73     # The repo type, defaults to git.
  74     repo = 'git'
  75
  76     # List of files to ignore either because they are not needed (such as the
  77     # ChangeLog) or because they are non-parseable.  For example, glibc has a
  78     # header file that is only assembly code, which breaks the C parser.
  79     IGNORE_LIST = ['ChangeLog']
  80
  81
  82 # Load quirks file.  We assume that the script is run from the top level source
  83 # directory.
  84 sys.path.append('/'.join([os.getcwd(), 'scripts', 'vcs_to_changelog']))
  85 try:
  86     from vcstocl_quirks import *
  87     project_quirks = get_project_quirks(debug)
  88 except:
  89     project_quirks = ProjectQuirks()
  90
  91 def analyze_diff(filename, oldfile, newfile, frontends):
  92     ''' Parse the output of the old and new files and print the difference.
  93
  94     For input files OLDFILE and NEWFILE with name FILENAME, generate reduced
  95     trees for them and compare them.  We limit our comparison to only C source
  96     files.
  97     '''
  98     name, ext = os.path.splitext(filename)
  99
 100     if not ext in frontends.keys():
 101         return None
 102     else:
 103         frontend = frontends[ext]
 104         frontend.compare(oldfile, newfile)
 105
 106
 107 def main(repo, frontends, refs):
 108     ''' ChangeLog Generator Entry Point.
 109     '''
 110     commits = repo.list_commits(args.refs)
 111     for commit in commits:
 112         repo.list_changes(commit, frontends)
 113
 114
 115 if __name__ == '__main__':
 116     parser = argparse.ArgumentParser()
 117
 118     parser.add_argument('refs', metavar='ref', type=str, nargs=2,
 119                      help='Refs to print ChangeLog entries between')
 120
 121     parser.add_argument('-d', '--debug', required=False, action='store_true',
 122                      help='Run the file parser debugger.')
 123
 124     args = parser.parse_args()
 125
 126     debug.debug = args.debug
 127
 128     if len(args.refs) < 2:
 129         debug.eprint('Two refs needed to get a ChangeLog.')
 130         sys.exit(os.EX_USAGE)
 131
 132     REPO = {'git': GitRepo(project_quirks.IGNORE_LIST, debug)}
 133
 134     fe_c = frontend_c.Frontend(project_quirks, debug)
 135     FRONTENDS = {'.c': fe_c,
 136                  '.h': fe_c}
 137
 138     main(REPO[project_quirks.repo], FRONTENDS, args.refs)