scripts/diffconfig

   1 #!/usr/bin/env python
   2 # SPDX-License-Identifier: GPL-2.0
   3 #
   4 # diffconfig - a tool to compare .config files.
   5 #
   6 # originally written in 2006 by Matt Mackall
   7 #  (at least, this was in his bloatwatch source code)
   8 # last worked on 2008 by Tim Bird
   9 #
  10
  11 import sys, os
  12
  13 def usage():
  14     print("""Usage: diffconfig [-h] [-m] [<config1> <config2>]
  15
  16 Diffconfig is a simple utility for comparing two .config files.
  17 Using standard diff to compare .config files often includes extraneous and
  18 distracting information.  This utility produces sorted output with only the
  19 changes in configuration values between the two files.
  20
  21 Added and removed items are shown with a leading plus or minus, respectively.
  22 Changed items show the old and new values on a single line.
  23
  24 If -m is specified, then output will be in "merge" style, which has the
  25 changed and new values in kernel config option format.
  26
  27 If no config files are specified, .config and .config.old are used.
  28
  29 Example usage:
  30  $ diffconfig .config config-with-some-changes
  31 -EXT2_FS_XATTR  n
  32  CRAMFS  n -> y
  33  EXT2_FS  y -> n
  34  LOG_BUF_SHIFT  14 -> 16
  35  PRINTK_TIME  n -> y
  36 """)
  37     sys.exit(0)
  38
  39 # returns a dictionary of name/value pairs for config items in the file
  40 def readconfig(config_file):
  41     d = {}
  42     for line in config_file:
  43         line = line[:-1]
  44         if line[:7] == "CONFIG_":
  45             name, val = line[7:].split("=", 1)
  46             d[name] = val
  47         if line[-11:] == " is not set":
  48             d[line[9:-11]] = "n"
  49     return d
  50
  51 def print_config(op, config, value, new_value):
  52     global merge_style
  53
  54     if merge_style:
  55         if new_value:
  56             if new_value=="n":
  57                 print("# CONFIG_%s is not set" % config)
  58             else:
  59                 print("CONFIG_%s=%s" % (config, new_value))
  60     else:
  61         if op=="-":
  62             print("-%s %s" % (config, value))
  63         elif op=="+":
  64             print("+%s %s" % (config, new_value))
  65         else:
  66             print(" %s %s -> %s" % (config, value, new_value))
  67
  68 def main():
  69     global merge_style
  70
  71     # parse command line args
  72     if ("-h" in sys.argv or "--help" in sys.argv):
  73         usage()
  74
  75     merge_style = 0
  76     if "-m" in sys.argv:
  77         merge_style = 1
  78         sys.argv.remove("-m")
  79
  80     argc = len(sys.argv)
  81     if not (argc==1 or argc == 3):
  82         print("Error: incorrect number of arguments or unrecognized option")
  83         usage()
  84
  85     if argc == 1:
  86         # if no filenames given, assume .config and .config.old
  87         build_dir=""
  88         if "KBUILD_OUTPUT" in os.environ:
  89             build_dir = os.environ["KBUILD_OUTPUT"]+"/"
  90         configa_filename = build_dir + ".config.old"
  91         configb_filename = build_dir + ".config"
  92     else:
  93         configa_filename = sys.argv[1]
  94         configb_filename = sys.argv[2]
  95
  96     try:
  97         a = readconfig(open(configa_filename))
  98         b = readconfig(open(configb_filename))
  99     except (IOError):
 100         e = sys.exc_info()[1]
 101         print("I/O error[%s]: %s\n" % (e.args[0],e.args[1]))
 102         usage()
 103
 104     # print items in a but not b (accumulate, sort and print)
 105     old = []
 106     for config in a:
 107         if config not in b:
 108             old.append(config)
 109     old.sort()
 110     for config in old:
 111         print_config("-", config, a[config], None)
 112         del a[config]
 113
 114     # print items that changed (accumulate, sort, and print)
 115     changed = []
 116     for config in a:
 117         if a[config] != b[config]:
 118             changed.append(config)
 119         else:
 120             del b[config]
 121     changed.sort()
 122     for config in changed:
 123         print_config("->", config, a[config], b[config])
 124         del b[config]
 125
 126     # now print items in b but not in a
 127     # (items from b that were in a were removed above)
 128     new = sorted(b.keys())
 129     for config in new:
 130         print_config("+", config, None, b[config])
 131
 132 main()