jammed.py

   1 #!/usr/bin/python
   2
   3 import re
   4 import sys
   5
   6 tables = dict()
   7 defines = dict()
   8
   9 with open(sys.argv[1], 'r') as file:
  10     while True:
  11         line = file.readline()
  12         if line == '':
  13             break
  14
  15         define = re.match('#define ([A-Za-z_]*) ([0-9]+)', line)
  16         if define != None:
  17             defines[define.group(1)] = int(define.group(2))
  18             continue
  19
  20         if not line.startswith('static yyconst '):
  21             continue
  22
  23         end = line.index('[')
  24         begin = line.rindex(' ', 0, end)
  25         name = line[begin+1:end]
  26
  27         code = ''
  28         while True:
  29             line = file.readline()
  30             code += line
  31             if line.find(';') != -1:
  32                 break
  33
  34         code = code.replace('{', '[')
  35         code = code.replace('}', ']')
  36         code = code.replace(';', ' ')
  37         tables[name] = eval(code)
  38
  39 yy_nxt = tables['yy_nxt']
  40 yy_accept = tables['yy_accept']
  41 yy_ec = tables['yy_ec']
  42
  43 YY_NUM_RULES = defines['YY_NUM_RULES']
  44 try:
  45     jammed = yy_accept.index(YY_NUM_RULES)
  46 except ValueError:
  47     sys.exit(0)
  48
  49 equivs = dict()
  50 for ordinal, equiv in enumerate(yy_ec):
  51     equivs[equiv] = equivs.get(equiv, '') + chr(ordinal)
  52
  53 starts = set(range(1, len(yy_nxt)))
  54 for source, table in enumerate(yy_nxt):
  55     if source == 0:
  56         continue
  57     for equiv, target in enumerate(table):
  58         if target in starts:
  59             starts.remove(target)
  60
  61 after = dict()
  62 after[jammed] = [[]]
  63
  64 while True:
  65     finish = dict()
  66     for start in starts:
  67         suffix = after.get(start)
  68         if suffix == None:
  69             continue
  70         finish[start] = [[equivs[c] for c in s] for s in suffix]
  71     if len(finish) != 0:
  72         print finish
  73         break
  74
  75     before = after
  76     after = dict()
  77
  78     for source, table in enumerate(yy_nxt):
  79         if source == 0:
  80             continue
  81         string = []
  82         for equiv, target in enumerate(table):
  83             suffix = before.get(target)
  84             if suffix == None:
  85                 continue
  86             string.extend([[equiv] + s for s in suffix])
  87         if len(string) == 0:
  88             continue
  89         after[source] = string
  90
  91 sys.exit(1)