Tools/scripts/classfix.py

   1 #! /usr/bin/env python
   2
   3 # This script is obsolete -- it is kept for historical purposes only.
   4 #
   5 # Fix Python source files to use the new class definition syntax, i.e.,
   6 # the syntax used in Python versions before 0.9.8:
   7 #       class C() = base(), base(), ...: ...
   8 # is changed to the current syntax:
   9 #       class C(base, base, ...): ...
  10 #
  11 # The script uses heuristics to find class definitions that usually
  12 # work but occasionally can fail; carefully check the output!
  13 #
  14 # Command line arguments are files or directories to be processed.
  15 # Directories are searched recursively for files whose name looks
  16 # like a python module.
  17 # Symbolic links are always ignored (except as explicit directory
  18 # arguments).  Of course, the original file is kept as a back-up
  19 # (with a "~" attached to its name).
  20 #
  21 # Changes made are reported to stdout in a diff-like format.
  22 #
  23 # Undoubtedly you can do this using find and sed or perl, but this is
  24 # a nice example of Python code that recurses down a directory tree
  25 # and uses regular expressions.  Also note several subtleties like
  26 # preserving the file's mode and avoiding to even write a temp file
  27 # when no changes are needed for a file.
  28 #
  29 # NB: by changing only the function fixline() you can turn this
  30 # into a program for a different change to Python programs...
  31
  32 import sys
  33 import regex
  34 import os
  35 from stat import *
  36
  37 err = sys.stderr.write
  38 dbg = err
  39 rep = sys.stdout.write
  40
  41 def main():
  42     bad = 0
  43     if not sys.argv[1:]: # No arguments
  44         err('usage: ' + sys.argv[0] + ' file-or-directory ...\n')
  45         sys.exit(2)
  46     for arg in sys.argv[1:]:
  47         if os.path.isdir(arg):
  48             if recursedown(arg): bad = 1
  49         elif os.path.islink(arg):
  50             err(arg + ': will not process symbolic links\n')
  51             bad = 1
  52         else:
  53             if fix(arg): bad = 1
  54     sys.exit(bad)
  55
  56 ispythonprog = regex.compile('^[a-zA-Z0-9_]+\.py$')
  57 def ispython(name):
  58     return ispythonprog.match(name) >= 0
  59
  60 def recursedown(dirname):
  61     dbg('recursedown(%r)\n' % (dirname,))
  62     bad = 0
  63     try:
  64         names = os.listdir(dirname)
  65     except os.error, msg:
  66         err('%s: cannot list directory: %r\n' % (dirname, msg))
  67         return 1
  68     names.sort()
  69     subdirs = []
  70     for name in names:
  71         if name in (os.curdir, os.pardir): continue
  72         fullname = os.path.join(dirname, name)
  73         if os.path.islink(fullname): pass
  74         elif os.path.isdir(fullname):
  75             subdirs.append(fullname)
  76         elif ispython(name):
  77             if fix(fullname): bad = 1
  78     for fullname in subdirs:
  79         if recursedown(fullname): bad = 1
  80     return bad
  81
  82 def fix(filename):
  83 ##  dbg('fix(%r)\n' % (filename,))
  84     try:
  85         f = open(filename, 'r')
  86     except IOError, msg:
  87         err('%s: cannot open: %r\n' % (filename, msg))
  88         return 1
  89     head, tail = os.path.split(filename)
  90     tempname = os.path.join(head, '@' + tail)
  91     g = None
  92     # If we find a match, we rewind the file and start over but
  93     # now copy everything to a temp file.
  94     lineno = 0
  95     while 1:
  96         line = f.readline()
  97         if not line: break
  98         lineno = lineno + 1
  99         while line[-2:] == '\\\n':
 100             nextline = f.readline()
 101             if not nextline: break
 102             line = line + nextline
 103             lineno = lineno + 1
 104         newline = fixline(line)
 105         if newline != line:
 106             if g is None:
 107                 try:
 108                     g = open(tempname, 'w')
 109                 except IOError, msg:
 110                     f.close()
 111                     err('%s: cannot create: %r\n' % (tempname, msg))
 112                     return 1
 113                 f.seek(0)
 114                 lineno = 0
 115                 rep(filename + ':\n')
 116                 continue # restart from the beginning
 117             rep(repr(lineno) + '\n')
 118             rep('< ' + line)
 119             rep('> ' + newline)
 120         if g is not None:
 121             g.write(newline)
 122
 123     # End of file
 124     f.close()
 125     if not g: return 0 # No changes
 126
 127     # Finishing touch -- move files
 128
 129     # First copy the file's mode to the temp file
 130     try:
 131         statbuf = os.stat(filename)
 132         os.chmod(tempname, statbuf[ST_MODE] & 07777)
 133     except os.error, msg:
 134         err('%s: warning: chmod failed (%r)\n' % (tempname, msg))
 135     # Then make a backup of the original file as filename~
 136     try:
 137         os.rename(filename, filename + '~')
 138     except os.error, msg:
 139         err('%s: warning: backup failed (%r)\n' % (filename, msg))
 140     # Now move the temp file to the original file
 141     try:
 142         os.rename(tempname, filename)
 143     except os.error, msg:
 144         err('%s: rename failed (%r)\n' % (filename, msg))
 145         return 1
 146     # Return succes
 147     return 0
 148
 149 # This expression doesn't catch *all* class definition headers,
 150 # but it's pretty darn close.
 151 classexpr = '^\([ \t]*class +[a-zA-Z0-9_]+\) *( *) *\(\(=.*\)?\):'
 152 classprog = regex.compile(classexpr)
 153
 154 # Expressions for finding base class expressions.
 155 baseexpr = '^ *\(.*\) *( *) *$'
 156 baseprog = regex.compile(baseexpr)
 157
 158 def fixline(line):
 159     if classprog.match(line) < 0: # No 'class' keyword -- no change
 160         return line
 161
 162     (a0, b0), (a1, b1), (a2, b2) = classprog.regs[:3]
 163     # a0, b0 = Whole match (up to ':')
 164     # a1, b1 = First subexpression (up to classname)
 165     # a2, b2 = Second subexpression (=.*)
 166     head = line[:b1]
 167     tail = line[b0:] # Unmatched rest of line
 168
 169     if a2 == b2: # No base classes -- easy case
 170         return head + ':' + tail
 171
 172     # Get rid of leading '='
 173     basepart = line[a2+1:b2]
 174
 175     # Extract list of base expressions
 176     bases = basepart.split(',')
 177
 178     # Strip trailing '()' from each base expression
 179     for i in range(len(bases)):
 180         if baseprog.match(bases[i]) >= 0:
 181             x1, y1 = baseprog.regs[1]
 182             bases[i] = bases[i][x1:y1]
 183
 184     # Join the bases back again and build the new line
 185     basepart = ', '.join(bases)
 186
 187     return head + '(' + basepart + '):' + tail
 188
 189 main()