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  CRAMFS  n -> y
  32  EXT2_FS  y -> n
  33  LOG_BUF_SHIFT  14 -> 16
  34  PRINTK_TIME  n -> y
  35 """)
  36     sys.exit(0)
  37
  38 # returns a dictionary of name/value pairs for config items in the file
  39 def readconfig(config_file):
  40     d = {}
  41     for line in config_file:
  42         line = line[:-1]
  43         if line[:7] == "CONFIG_":
  44             name, val = line[7:].split("=", 1)
  45             d[name] = val
  46         if line[-11:] == " is not set":
  47             d[line[9:-11]] = "n"
  48     return d
  49
  50 def print_config(op, config, value, new_value):
  51     global merge_style
  52
  53     if merge_style:
  54         if new_value:
  55             if new_value=="n":
  56                 print("# CONFIG_%s is not set" % config)
  57             else:
  58                 print("CONFIG_%s=%s" % (config, new_value))
  59     else:
  60         if op=="-":
  61             print("-%s %s" % (config, value))
  62         elif op=="+":
  63             print("+%s %s" % (config, new_value))
  64         else:
  65             print(" %s %s -> %s" % (config, value, new_value))
  66
  67 def main():
  68     global merge_style
  69
  70     # parse command line args
  71     if ("-h" in sys.argv or "--help" in sys.argv):
  72         usage()
  73
  74     merge_style = 0
  75     if "-m" in sys.argv:
  76         merge_style = 1
  77         sys.argv.remove("-m")
  78
  79     argc = len(sys.argv)
  80     if not (argc==1 or argc == 3):
  81         print("Error: incorrect number of arguments or unrecognized option")
  82         usage()
  83
  84     if argc == 1:
  85         # if no filenames given, assume .config and .config.old
  86         build_dir=""
  87         if "KBUILD_OUTPUT" in os.environ:
  88             build_dir = os.environ["KBUILD_OUTPUT"]+"/"
  89         configa_filename = build_dir + ".config.old"
  90         configb_filename = build_dir + ".config"
  91     else:
  92         configa_filename = sys.argv[1]
  93         configb_filename = sys.argv[2]
  94
  95     try:
  96         a = readconfig(open(configa_filename))
  97         b = readconfig(open(configb_filename))
  98     except (IOError):
  99         e = sys.exc_info()[1]
 100         print("I/O error[%s]: %s\n" % (e.args[0],e.args[1]))
 101         usage()
 102
 103     # print items in a but not b (accumulate, sort and print)
 104     old = []
 105     for config in a:
 106         if config not in b:
 107             old.append(config)
 108     old.sort()
 109     for config in old:
 110         print_config("-", config, a[config], None)
 111         del a[config]
 112
 113     # print items that changed (accumulate, sort, and print)
 114     changed = []
 115     for config in a:
 116         if a[config] != b[config]:
 117             changed.append(config)
 118         else:
 119             del b[config]
 120     changed.sort()
 121     for config in changed:
 122         print_config("->", config, a[config], b[config])
 123         del b[config]
 124
 125     # now print items in b but not in a
 126     # (items from b that were in a were removed above)
 127     new = sorted(b.keys())
 128     for config in new:
 129         print_config("+", config, None, b[config])
 130
 131 main()