scripts/maint/annotate_ifdef_directives

   1 #!/usr/bin/python
   2 # Copyright (c) 2017-2019, The Tor Project, Inc.
   3 # See LICENSE for licensing information
   4
   5 import re
   6
   7 LINE_OBVIOUSNESS_LIMIT = 4
   8
   9 class Problem(Exception):
  10     pass
  11
  12 def uncomment(s):
  13     s = re.sub(r'//.*','',s)
  14     s = re.sub(r'/\*.*','',s)
  15     return s.strip()
  16
  17 def translate(f_in, f_out):
  18     whole_file = []
  19     stack = []
  20     cur_level = whole_file
  21     lineno = 0
  22     for line in f_in:
  23         lineno += 1
  24         m = re.match(r'\s*#\s*(if|ifdef|ifndef|else|endif|elif)\b\s*(.*)',
  25                      line)
  26         if not m:
  27             f_out.write(line)
  28             continue
  29         command,rest = m.groups()
  30         if command in ("if", "ifdef", "ifndef"):
  31             # The #if directive pushes us one level lower on the stack.
  32             if command == 'ifdef':
  33                 rest = "defined(%s)"%uncomment(rest)
  34             elif command == 'ifndef':
  35                 rest = "!defined(%s)"%uncomment(rest)
  36             elif rest.endswith("\\"):
  37                 rest = rest[:-1]+"..."
  38
  39             rest = uncomment(rest)
  40
  41             new_level = [ (command, rest, lineno) ]
  42             stack.append(cur_level)
  43             cur_level = new_level
  44             f_out.write(line)
  45         elif command in ("else", "elif"):
  46             if len(cur_level) == 0 or cur_level[-1][0] == 'else':
  47                 raise Problem("Unexpected #%s on %d"% (command,lineno))
  48             if (len(cur_level) == 1 and command == 'else' and
  49                 lineno > cur_level[0][2] + LINE_OBVIOUSNESS_LIMIT):
  50                 f_out.write("#else /* !(%s) */\n"%cur_level[0][1])
  51             else:
  52                 f_out.write(line)
  53             cur_level.append((command, rest, lineno))
  54         else:
  55             assert command == 'endif'
  56             if len(stack) == 0:
  57                 raise Problem("Unmatched #%s on %s"% (command,lineno))
  58             if lineno <= cur_level[0][2] + LINE_OBVIOUSNESS_LIMIT:
  59                 f_out.write(line)
  60             elif len(cur_level) == 1 or (
  61                     len(cur_level) == 2 and cur_level[1][0] == 'else'):
  62                 f_out.write("#endif /* %s */\n"%cur_level[0][1])
  63             else:
  64                 f_out.write("#endif /* %s || ... */\n"%cur_level[0][1])
  65             cur_level = stack.pop()
  66     if len(stack) or cur_level != whole_file:
  67         raise Problem("Missing #endif")
  68
  69 import sys,os
  70 for fn in sys.argv[1:]:
  71     with open(fn+"_OUT", 'w') as output_file:
  72         translate(open(fn, 'r'), output_file)
  73     os.rename(fn+"_OUT", fn)
  74