diff --git a/Tools/scripts/ifdef.py b/Tools/scripts/ifdef.py
new file mode 100755
index 0000000..9d74be2
--- /dev/null
+++ b/Tools/scripts/ifdef.py
@@ -0,0 +1,113 @@
+#! /usr/local/bin/python
+
+# Selectively preprocess #ifdef / #ifndef statements.
+# Usage:
+# ifdef [-Dname] ... [-Uname] ... [file] ...
+# 
+# This scans the file(s), looking for #ifdef and #ifndef preprocessor
+# commands that test for one of the names mentioned in the -D and -U
+# options.  On standard output it writes a copy of the input file(s)
+# minus those code sections that are suppressed by the selected
+# combination of defined/undefined symbols.  The #if(n)def/#else/#else
+# lines themselfs (if the #if(n)def tests for one of the mentioned
+# names) are removed as well.
+
+# Features: Arbitrary nesting of recognized and unrecognized
+# preprocesor statements works correctly.  Unrecognized #if* commands
+# are left in place, so it will never remove too much, only too
+# little.  It does accept whitespace around the '#' character.
+
+# Restrictions: There should be no comments or other symbols on the
+# #if(n)def lines.  The effect of #define/#undef commands in the input
+# file or in included files is not taken into account.  Tests using
+# #if and the defined() pseudo function are not recognized.  The #elif
+# command is not recognized.  Improperly nesting is not detected.
+# Lines that look like preprocessor commands but which are actually
+# part of comments or string literals will be mistaken for
+# preprocessor commands.
+
+import sys
+import regex
+import getopt
+import string
+
+defs = []
+undefs = []
+
+def main():
+	opts, args = getopt.getopt(sys.argv[1:], 'D:U:')
+	for o, a in opts:
+		if o == '-D':
+			defs.append(a)
+		if o == '-U':
+			undefs.append(a)
+	if not args:
+		args = ['-']
+	for file in args:
+		if file == '-':
+			process(sys.stdin, sys.stdout)
+		else:
+			f = open(file, 'r')
+			process(f, sys.stdout)
+			f.close()
+
+def process(fpi, fpo):
+	keywords = ('if', 'ifdef', 'ifndef', 'else', 'endif')
+	ok = 1
+	stack = []
+	while 1:
+		line = fpi.readline()
+		if not line: break
+		while line[-2:] == '\\\n':
+			nextline = fpi.readline()
+			if not nextline: break
+			line = line + nextline
+		tmp = string.strip(line)
+		if tmp[:1] != '#':
+			if ok: fpo.write(line)
+			continue
+		tmp = string.strip(tmp[1:])
+		words = string.split(tmp)
+		keyword = words[0]
+		if keyword not in keywords:
+			if ok: fpo.write(line)
+			continue
+		if keyword in ('ifdef', 'ifndef') and len(words) == 2:
+			if keyword == 'ifdef':
+				ko = 1
+			else:
+				ko = 0
+			word = words[1]
+			if word in defs:
+				stack.append(ok, ko, word)
+				if not ko: ok = 0
+			elif word in undefs:
+				stack.append(ok, not ko, word)
+				if ko: ok = 0
+			else:
+				stack.append(ok, -1, word)
+				if ok: fpo.write(line)
+		elif keyword == 'if':
+			stack.append(ok, -1, '')
+			if ok: fpo.write(line)
+		elif keyword == 'else' and stack:
+			s_ok, s_ko, s_word = stack[-1]
+			if s_ko < 0:
+				if ok: fpo.write(line)
+			else:
+				s_ko = not s_ko
+				ok = s_ok
+				if not s_ko: ok = 0
+				stack[-1] = s_ok, s_ko, s_word
+		elif keyword == 'endif' and stack:
+			s_ok, s_ko, s_word = stack[-1]
+			if s_ko < 0:
+				if ok: fpo.write(line)
+			del stack[-1]
+			ok = s_ok
+		else:
+			sys.stderr.write('Unknown keyword %s\n' % keyword)
+	if stack:
+		sys.stderr.write('stack: %s\n' % stack)
+
+main()