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      1 #!/usr/bin/env python
      2 
      3 # Copyright (c) 2012 Google Inc. All rights reserved.
      4 # Use of this source code is governed by a BSD-style license that can be
      5 # found in the LICENSE file.
      6 
      7 """Pretty-prints the contents of a GYP file."""
      8 
      9 import sys
     10 import re
     11 
     12 
     13 # Regex to remove comments when we're counting braces.
     14 COMMENT_RE = re.compile(r'\s*#.*')
     15 
     16 # Regex to remove quoted strings when we're counting braces.
     17 # It takes into account quoted quotes, and makes sure that the quotes match.
     18 # NOTE: It does not handle quotes that span more than one line, or
     19 # cases where an escaped quote is preceeded by an escaped backslash.
     20 QUOTE_RE_STR = r'(?P<q>[\'"])(.*?)(?<![^\\][\\])(?P=q)'
     21 QUOTE_RE = re.compile(QUOTE_RE_STR)
     22 
     23 
     24 def comment_replace(matchobj):
     25   return matchobj.group(1) + matchobj.group(2) + '#' * len(matchobj.group(3))
     26 
     27 
     28 def mask_comments(input):
     29   """Mask the quoted strings so we skip braces inside quoted strings."""
     30   search_re = re.compile(r'(.*?)(#)(.*)')
     31   return [search_re.sub(comment_replace, line) for line in input]
     32 
     33 
     34 def quote_replace(matchobj):
     35   return "%s%s%s%s" % (matchobj.group(1),
     36                        matchobj.group(2),
     37                        'x'*len(matchobj.group(3)),
     38                        matchobj.group(2))
     39 
     40 
     41 def mask_quotes(input):
     42   """Mask the quoted strings so we skip braces inside quoted strings."""
     43   search_re = re.compile(r'(.*?)' + QUOTE_RE_STR)
     44   return [search_re.sub(quote_replace, line) for line in input]
     45 
     46 
     47 def do_split(input, masked_input, search_re):
     48   output = []
     49   mask_output = []
     50   for (line, masked_line) in zip(input, masked_input):
     51     m = search_re.match(masked_line)
     52     while m:
     53       split = len(m.group(1))
     54       line = line[:split] + r'\n' + line[split:]
     55       masked_line = masked_line[:split] + r'\n' + masked_line[split:]
     56       m = search_re.match(masked_line)
     57     output.extend(line.split(r'\n'))
     58     mask_output.extend(masked_line.split(r'\n'))
     59   return (output, mask_output)
     60 
     61 
     62 def split_double_braces(input):
     63   """Masks out the quotes and comments, and then splits appropriate
     64   lines (lines that matche the double_*_brace re's above) before
     65   indenting them below.
     66 
     67   These are used to split lines which have multiple braces on them, so
     68   that the indentation looks prettier when all laid out (e.g. closing
     69   braces make a nice diagonal line).
     70   """
     71   double_open_brace_re = re.compile(r'(.*?[\[\{\(,])(\s*)([\[\{\(])')
     72   double_close_brace_re = re.compile(r'(.*?[\]\}\)],?)(\s*)([\]\}\)])')
     73 
     74   masked_input = mask_quotes(input)
     75   masked_input = mask_comments(masked_input)
     76 
     77   (output, mask_output) = do_split(input, masked_input, double_open_brace_re)
     78   (output, mask_output) = do_split(output, mask_output, double_close_brace_re)
     79 
     80   return output
     81 
     82 
     83 def count_braces(line):
     84   """keeps track of the number of braces on a given line and returns the result.
     85 
     86   It starts at zero and subtracts for closed braces, and adds for open braces.
     87   """
     88   open_braces = ['[', '(', '{']
     89   close_braces = [']', ')', '}']
     90   closing_prefix_re = re.compile(r'(.*?[^\s\]\}\)]+.*?)([\]\}\)],?)\s*$')
     91   cnt = 0
     92   stripline = COMMENT_RE.sub(r'', line)
     93   stripline = QUOTE_RE.sub(r"''", stripline)
     94   for char in stripline:
     95     for brace in open_braces:
     96       if char == brace:
     97         cnt += 1
     98     for brace in close_braces:
     99       if char == brace:
    100         cnt -= 1
    101 
    102   after = False
    103   if cnt > 0:
    104     after = True
    105 
    106   # This catches the special case of a closing brace having something
    107   # other than just whitespace ahead of it -- we don't want to
    108   # unindent that until after this line is printed so it stays with
    109   # the previous indentation level.
    110   if cnt < 0 and closing_prefix_re.match(stripline):
    111     after = True
    112   return (cnt, after)
    113 
    114 
    115 def prettyprint_input(lines):
    116   """Does the main work of indenting the input based on the brace counts."""
    117   indent = 0
    118   basic_offset = 2
    119   last_line = ""
    120   for line in lines:
    121     if COMMENT_RE.match(line):
    122       print line
    123     else:
    124       line = line.strip('\r\n\t ')  # Otherwise doesn't strip \r on Unix.
    125       if len(line) > 0:
    126         (brace_diff, after) = count_braces(line)
    127         if brace_diff != 0:
    128           if after:
    129             print " " * (basic_offset * indent) + line
    130             indent += brace_diff
    131           else:
    132             indent += brace_diff
    133             print " " * (basic_offset * indent) + line
    134         else:
    135           print " " * (basic_offset * indent) + line
    136       else:
    137         print ""
    138       last_line = line
    139 
    140 
    141 def main():
    142   if len(sys.argv) > 1:
    143     data = open(sys.argv[1]).read().splitlines()
    144   else:
    145     data = sys.stdin.read().splitlines()
    146   # Split up the double braces.
    147   lines = split_double_braces(data)
    148 
    149   # Indent and print the output.
    150   prettyprint_input(lines)
    151   return 0
    152 
    153 
    154 if __name__ == '__main__':
    155   sys.exit(main())
    156