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   3 # This script is obsolete -- it is kept for historical purposes only.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(' + `dirname` + ')\n')
  62     bad = 0
  63     try:
  64         names = os.listdir(dirname)
  65     except os.error, msg:
  66         err(dirname + ': cannot list directory: ' + `msg` + '\n')
  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(' + `filename` + ')\n')
  84     try:
  85         f = open(filename, 'r')
  86     except IOError, msg:
  87         err(filename + ': cannot open: ' + `msg` + '\n')
  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(tempname+': cannot create: '+\
 112                         `msg`+'\n')
 113                     return 1
 114                 f.seek(0)
 115                 lineno = 0
 116                 rep(filename + ':\n')
 117                 continue # restart from the beginning
 118             rep(`lineno` + '\n')
 119             rep('< ' + line)
 120             rep('> ' + newline)
 121         if g is not None:
 122             g.write(newline)
 123
 124     # End of file
 125     f.close()
 126     if not g: return 0 # No changes
 127
 128     # Finishing touch -- move files
 129
 130     # First copy the file's mode to the temp file
 131     try:
 132         statbuf = os.stat(filename)
 133         os.chmod(tempname, statbuf[ST_MODE] & 07777)
 134     except os.error, msg:
 135         err(tempname + ': warning: chmod failed (' + `msg` + ')\n')
 136     # Then make a backup of the original file as filename~
 137     try:
 138         os.rename(filename, filename + '~')
 139     except os.error, msg:
 140         err(filename + ': warning: backup failed (' + `msg` + ')\n')
 141     # Now move the temp file to the original file
 142     try:
 143         os.rename(tempname, filename)
 144     except os.error, msg:
 145         err(filename + ': rename failed (' + `msg` + ')\n')
 146         return 1
 147     # Return succes
 148     return 0
 149
 150 # This expression doesn't catch *all* class definition headers,
 151 # but it's pretty darn close.
 152 classexpr = '^\([ \t]*class +[a-zA-Z0-9_]+\) *( *) *\(\(=.*\)?\):'
 153 classprog = regex.compile(classexpr)
 154
 155 # Expressions for finding base class expressions.
 156 baseexpr = '^ *\(.*\) *( *) *$'
 157 baseprog = regex.compile(baseexpr)
 158
 159 import string
 160
 161 def fixline(line):
 162     if classprog.match(line) < 0: # No 'class' keyword -- no change
 163         return line
 164
 165     (a0, b0), (a1, b1), (a2, b2) = classprog.regs[:3]
 166     # a0, b0 = Whole match (up to ':')
 167     # a1, b1 = First subexpression (up to classname)
 168     # a2, b2 = Second subexpression (=.*)
 169     head = line[:b1]
 170     tail = line[b0:] # Unmatched rest of line
 171
 172     if a2 == b2: # No base classes -- easy case
 173         return head + ':' + tail
 174
 175     # Get rid of leading '='
 176     basepart = line[a2+1:b2]
 177
 178     # Extract list of base expressions
 179     bases = string.splitfields(basepart, ',')
 180
 181     # Strip trailing '()' from each base expression
 182     for i in range(len(bases)):
 183         if baseprog.match(bases[i]) >= 0:
 184             x1, y1 = baseprog.regs[1]
 185             bases[i] = bases[i][x1:y1]
 186
 187     # Join the bases back again and build the new line
 188     basepart = string.joinfields(bases, ', ')
 189
 190     return head + '(' + basepart + '):' + tail
 191
 192 main()