Initial revision

Tools/scripts/classfix.py

+#! /usr/local/python
+
+# Fix Python source files to use the new class definition syntax,
+# i.e.,
+#	class C(base, base, ...): ...
+# instead of
+#	class C() = base(), base(), ...: ...
+#
+# Command line arguments are files or directories to be processed.
+# Directories are searched recursively for files whose name looks
+# like a python module.
+# Symbolic links are always ignored (except as explicit directory
+# arguments).  Of course, the original file is kept as a back-up
+# (with a "~" attached to its name).
+#
+# Undoubtedly you can do this using find and sed, but this is
+# a nice example of Python code that recurses down a directory tree
+# and uses regular expressions.  Also note several subtleties like
+# preserving the file's mode and avoiding to even write a temp file
+# when no changes are needed for a file.
+#
+# Changes made are reported to stdout in a diff-like format.
+
+import sys
+import regexp
+import posix
+import path
+import string
+from stat import *
+
+err = sys.stderr.write
+dbg = err
+rep = sys.stdout.write
+
+def main():
+	bad = 0
+	if not sys.argv[1:]: # No arguments
+		err('usage: classfix file-or-directory ...\n')
+		sys.exit(2)
+	for arg in sys.argv[1:]:
+		if path.isdir(arg):
+			if recursedown(arg): bad = 1
+		elif path.islink(arg):
+			err(arg + ': will not process symbolic links\n')
+			bad = 1
+		else:
+			if fix(arg): bad = 1
+	sys.exit(bad)
+
+ispython = regexp.compile('^[a-zA-Z0-9_]+\.py$').match # This is a method!
+
+def recursedown(dirname):
+	dbg('recursedown(' + `dirname` + ')\n')
+	bad = 0
+	try:
+		names = posix.listdir(dirname)
+	except posix.error, msg:
+		err(dirname + ': cannot list directory: ' + `msg` + '\n')
+		return 1
+	for name in names:
+		if name in ('.', '..'): continue
+		fullname = path.join(dirname, name)
+		if path.islink(fullname): pass
+		elif path.isdir(fullname):
+			if recursedown(fullname): bad = 1
+		elif ispython(name):
+			if fix(fullname): bad = 1
+	return bad
+
+# This expression doesn't catch *all* class definition headers,
+# but it's darn pretty close.
+classexpr = '^([ \t]*class +[a-zA-Z0-9_]+) *\( *\) *((=.*)?):'
+findclass = regexp.compile(classexpr).match # This is a method!
+
+baseexpr = '^ *(.*) *\( *\) *$'
+findbase = regexp.compile(baseexpr).match # This is a method, too!
+
+def fix(filename):
+##	dbg('fix(' + `filename` + ')\n')
+	try:
+		f = open(filename, 'r')
+	except IOError, msg:
+		err(filename + ': cannot open: ' + `msg` + '\n')
+		return 1
+	head, tail = path.split(filename)
+	tempname = path.join(head, '@' + tail)
+	tf = None
+	# If we find a match, we rewind the file and start over but
+	# now copy everything to a temp file.
+	while 1:
+		line = f.readline()
+		if not line: break
+		res = findclass(line)
+		if not res:
+			if tf: tf.write(line)
+			continue
+		if not tf:
+			try:
+				tf = open(tempname, 'w')
+			except IOError, msg:
+				f.close()
+				err(tempname+': cannot create: '+`msg`+'\n')
+				return 1
+			rep(filename + ':\n')
+			# Rewind the input file and start all over:
+			f.seek(0)
+			continue
+		a0, b0 = res[0] # Whole match (up to ':')
+		a1, b1 = res[1] # First subexpression (up to classname)
+		a2, b2 = res[2] # Second subexpression (=.*)
+		head = line[:b1]
+		tail = line[b0:] # Unmatched rest of line
+		if a2 = b2: # No base classes -- easy case
+			newline = head + ':' + tail
+		else:
+			# Get rid of leading '='
+			basepart = line[a2+1:b2]
+			# Extract list of base expressions
+			bases = string.splitfields(basepart, ',')
+			# Strip trailing '()' from each base expression
+			for i in range(len(bases)):
+				res = findbase(bases[i])
+				if res:
+					(x0, y0), (x1, y1) = res
+					bases[i] = bases[i][x1:y1]
+			# Join the bases back again and build the new line
+			basepart = string.joinfields(bases, ', ')
+			newline = head + '(' + basepart + '):' + tail
+		rep('< ' + line)
+		rep('> ' + newline)
+		tf.write(newline)
+	f.close()
+	if not tf: return 0 # No changes
+	
+	# Finishing touch -- move files
+
+	# First copy the file's mode to the temp file
+	try:
+		statbuf = posix.stat(filename)
+		posix.chmod(tempname, statbuf[ST_MODE] & 0x7777)
+	except posix.error, msg:
+		err(tempname + ': warning: chmod failed (' + `msg` + ')\n')
+	# Then make a backup of the original file as filename~
+	try:
+		posix.rename(filename, filename + '~')
+	except posix.error, msg:
+		err(filename + ': warning: backup failed (' + `msg` + ')\n')
+	# Now move the temp file to the original file
+	try:
+		posix.rename(tempname, filename)
+	except posix.error, msg:
+		err(filename + ': rename failed (' + `msg` + ')\n')
+		return 1
+	# Return succes
+	return 0
+
+main()