js/src/frontend/align_stack_comment.py

   1 #!/usr/bin/python -B
   2 # This Source Code Form is subject to the terms of the Mozilla Public
   3 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
   4 # You can obtain one at http://mozilla.org/MPL/2.0/.
   5
   6
   7 """ Usage: align_stack_comment.py FILE
   8
   9     This script aligns the stack transition comment in BytecodeEmitter and
  10     its helper classes.
  11
  12     The stack transition comment looks like the following:
  13       //        [stack] VAL1 VAL2 VAL3
  14 """
  15
  16 import re
  17 import sys
  18
  19 # The column index of '[' of '[stack]'
  20 ALIGNMENT_COLUMN = 20
  21
  22 # The maximum column for comment
  23 MAX_CHARS_PER_LINE = 80
  24
  25 stack_comment_pat = re.compile("^( *//) *(\[stack\].*)$")
  26
  27
  28 def align_stack_comment(path):
  29     lines = []
  30     changed = False
  31
  32     with open(path) as f:
  33         max_head_len = 0
  34         max_comment_len = 0
  35
  36         line_num = 0
  37
  38         for line in f:
  39             line_num += 1
  40             # Python includes \n in lines.
  41             line = line.rstrip("\n")
  42
  43             m = stack_comment_pat.search(line)
  44             if m:
  45                 head = m.group(1) + " "
  46                 head_len = len(head)
  47                 comment = m.group(2)
  48                 comment_len = len(comment)
  49
  50                 if head_len > ALIGNMENT_COLUMN:
  51                     print(
  52                         "Warning: line {} overflows from alignment column {}: {}".format(
  53                             line_num, ALIGNMENT_COLUMN, head_len
  54                         ),
  55                         file=sys.stderr,
  56                     )
  57
  58                 line_len = max(head_len, ALIGNMENT_COLUMN) + comment_len
  59                 if line_len > MAX_CHARS_PER_LINE:
  60                     print(
  61                         "Warning: line {} overflows from {} chars: {}".format(
  62                             line_num, MAX_CHARS_PER_LINE, line_len
  63                         ),
  64                         file=sys.stderr,
  65                     )
  66
  67                 max_head_len = max(max_head_len, head_len)
  68                 max_comment_len = max(max_comment_len, comment_len)
  69
  70                 spaces = max(ALIGNMENT_COLUMN - head_len, 0)
  71                 formatted = head + " " * spaces + comment
  72
  73                 if formatted != line:
  74                     changed = True
  75
  76                 lines.append(formatted)
  77             else:
  78                 lines.append(line)
  79
  80         print(
  81             "Info: Minimum column number for [stack]: {}".format(max_head_len),
  82             file=sys.stderr,
  83         )
  84         print(
  85             "Info: Alignment column number for [stack]: {}".format(ALIGNMENT_COLUMN),
  86             file=sys.stderr,
  87         )
  88         print(
  89             "Info: Max length of stack transition comments: {}".format(max_comment_len),
  90             file=sys.stderr,
  91         )
  92
  93     if changed:
  94         with open(path, "w") as f:
  95             for line in lines:
  96                 print(line, file=f)
  97     else:
  98         print("No change.")
  99
 100
 101 if __name__ == "__main__":
 102     if len(sys.argv) < 2:
 103         print("Usage: align_stack_comment.py FILE", file=sys.stderr)
 104         sys.exit(1)
 105
 106     for path in sys.argv[1:]:
 107         print(path)
 108         align_stack_comment(path)