format C multiline macros

mmacrofmt.py

#!/bin/python

"""
usage: mmacrofmt.py [tabsize] < infile > outfile
formats something like:
#define X(a)  \
  whatever        \
  missing a backslash
  //some comment
  hmm\
  
into
#define X(a)          \
  whatever            \
  missing a backslash \
  /*some comment*/    \
  hmm                 \
"""

import sys, re

tabsize = 2
if len(sys.argv) > 1:
    tabsize = int(sys.argv[1])

lines = list(sys.stdin.readlines())
col = 0
for i in range(0,len(lines)):
    l = lines[i].replace('\t'," "*tabsize)
    if l[len(l)-2] != '\\':
        l = re.sub("\\/\\/(.*)$", "/*\\1*/", l)
    l = re.sub("\\\\$","",l).rstrip()
    lines[i] = l
    col = len(l)+1 if len(l) > col-1 else col

for l in lines:
    print(l + " "*(col - len(l)) + "\\")