sabl_cfg2pseudoc.py

   1 #!/usr/bin/env python3
   2 import sys
   3 import re
   4 from collections import defaultdict
   5
   6 from graph import Graph
   7 from utils import pairwise, natural_sort_key
   8
   9
  10 def node_name_strip(s):
  11     s = s.strip()
  12     if s[0] == '"' and s[-1] == '"':
  13         s = s[1:-1]
  14     return s
  15
  16
  17 def parse_dot(f):
  18     cfg = Graph()
  19
  20     for l in f:
  21         l = l.strip()
  22         if l.startswith("digraph"):
  23             continue
  24         if l == "}":
  25             break
  26         l = re.sub(r"\[.+\]$", "", l)
  27         if "->" not in l:
  28             continue
  29         nodes = [node_name_strip(n) for n in l.split("->")]
  30
  31         for from_n, to_n in pairwise(nodes, trailing=False):
  32             cfg.add_edge(from_n, to_n)
  33
  34     return cfg
  35
  36
  37 def __main__():
  38     with open(sys.argv[1]) as f:
  39         cfg = parse_dot(f)
  40
  41     all_nodes = sorted(cfg.nodes(), key=natural_sort_key)
  42
  43     for n, next_n in pairwise(all_nodes):
  44         print("%s:" % n)
  45         print("  nop()")
  46         succ = cfg.succ(n)
  47         if len(succ) == 0:
  48             print("  return")
  49         elif len(succ) == 1:
  50             if succ[0] != next_n:
  51                 print("  goto %s" % succ[0])
  52         else:
  53             old_len = len(succ)
  54             succ = [x for x in succ if x != next_n]
  55             else_node = None
  56             if len(succ) == old_len:
  57                 # next_n wasn't in succ
  58                 else_node = succ[-1]
  59                 succ = succ[:-1]
  60             s = ", ".join(["($cond) goto %s" % x for x in succ])
  61             if else_node:
  62                 s += ", else goto %s" % else_node
  63             print("  if " + s)
  64
  65
  66 if __name__ == "__main__":
  67     __main__()