scripts/diffconfig

   1 #!/usr/bin/python
   2 #
   3 # diffconfig - a tool to compare .config files.
   4 #
   5 # originally written in 2006 by Matt Mackall
   6 #  (at least, this was in his bloatwatch source code)
   7 # last worked on 2008 by Tim Bird
   8 #
   9
  10 import sys, os
  11
  12 def usage():
  13     print """Usage: diffconfig [-h] [-m] [<config1> <config2>]
  14
  15 Diffconfig is a simple utility for comparing two .config files.
  16 Using standard diff to compare .config files often includes extraneous and
  17 distracting information.  This utility produces sorted output with only the
  18 changes in configuration values between the two files.
  19
  20 Added and removed items are shown with a leading plus or minus, respectively.
  21 Changed items show the old and new values on a single line.
  22
  23 If -m is specified, then output will be in "merge" style, which has the
  24 changed and new values in kernel config option format.
  25
  26 If no config files are specified, .config and .config.old are used.
  27
  28 Example usage:
  29  $ diffconfig .config config-with-some-changes
  30 -EXT2_FS_XATTR  n
  31 -EXT2_FS_XIP  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 os.environ.has_key("KBUILD_OUTPUT"):
  89             build_dir = os.environ["KBUILD_OUTPUT"]+"/"
  90
  91         configa_filename = build_dir + ".config.old"
  92         configb_filename = build_dir + ".config"
  93     else:
  94         configa_filename = sys.argv[1]
  95         configb_filename = sys.argv[2]
  96
  97     a = readconfig(file(configa_filename))
  98     b = readconfig(file(configb_filename))
  99
 100     # print items in a but not b (accumulate, sort and print)
 101     old = []
 102     for config in a:
 103         if config not in b:
 104             old.append(config)
 105     old.sort()
 106     for config in old:
 107         print_config("-", config, a[config], None)
 108         del a[config]
 109
 110     # print items that changed (accumulate, sort, and print)
 111     changed = []
 112     for config in a:
 113         if a[config] != b[config]:
 114             changed.append(config)
 115         else:
 116             del b[config]
 117     changed.sort()
 118     for config in changed:
 119         print_config("->", config, a[config], b[config])
 120         del b[config]
 121
 122     # now print items in b but not in a
 123     # (items from b that were in a were removed above)
 124     new = b.keys()
 125     new.sort()
 126     for config in new:
 127         print_config("+", config, None, b[config])
 128
 129 main()