diff --git a/tools/qfcc/source/qfpreqcc b/tools/qfcc/source/qfpreqcc
index ba5c713ba..ce2521b1d 100755
--- a/tools/qfcc/source/qfpreqcc
+++ b/tools/qfcc/source/qfpreqcc
@@ -65,43 +65,13 @@ def parse_pragma (pragma, args):
 		keep_newlines = parse_on_off (args)
 	elif pragma == 'CHECK_REDEFINES':
 		check_redefines = parse_on_off (args)
+	elif pragma == 'CHECK_UNUSED_ON':
+		pass
+	elif pragma == 'CHECK_UNUSED_OFF':
+		pass
 	else:
 		print "ignoring " + pragma
 
-def do_preprogs_src ():
-	global current_file
-	current_file = []
-	append_file ("preprogs.src")
-	preprogs = current_file
-	for p in preprogs:
-		m = directive_re.match (p)
-		if (m):
-			g = m.groups()
-			directive = g[0]
-			arg1 = string.strip (g[1])
-			margs = string.strip (g[4])
-			#pprint ((directive, arg1, margs))
-			if directive == 'pragma':
-				parse_pragma (arg1, margs)
-			elif directive == 'includelist':
-				fname = parse_filename (arg1)
-				if fname:
-					source_list.append (fname)
-			elif directive == 'endlist':
-				pass
-			else:
-				print "ignoring " + p
-		else:
-			fname = parse_filename (p)
-			if fname:
-				source_list.append (fname)
-				
-def include_file (fname):
-	global current_file
-	fname = parse_filename (fname)
-	if fname:
-		append_file (fname)
-
 def comment_string (string_list, start, end):
 	i = 0
 	while i < len (string_list):
@@ -111,6 +81,90 @@ def comment_string (string_list, start, end):
 		i += 1
 	return string_list
 
+def parse_strings_and_comments (l, incomment):
+	#print source_file + ":" + `i` + ":" + l
+	string_list = []
+	s = string_re.search (l)
+	while s:
+		string_list.append ((l[s.start():s.end()], s.start(), s.end()))
+		l = l[:s.start()] + ((s.end() - s.start()) * ' ') + l[s.end():]
+		s = string_re.search (l)
+	if incomment:
+		s = comment_end.search (l)
+		if s:
+			l = (s.end() * ' ') + l[s.end():]
+			incomment = 0
+			string_list = comment_string (string_list, s.start(), s.end())
+		else:
+			string_list = comment_string (string_list, 0, len(l))
+			l = ""
+	s = comment_whole.search (l)
+	if s:
+		l = l[:s.start()] + ((s.end() - s.start()) * ' ') + l[s.end():]
+		string_list = comment_string (string_list, s.start(), s.end())
+	s = comment_start.search (l)
+	if s:
+		l = l[:s.start()] + ((s.end() - s.start()) * ' ')
+		string_list = comment_string (string_list, s.start(), s.end())
+		incomment = 1
+	for str in string_list:
+		l = l[:str[1]] + str[0] + l[str[2]:]
+	#print l
+	return l, incomment
+
+def do_preprogs_src ():
+	global current_file
+	current_file = []
+	condition = [1]
+	incomment = 0
+	append_file ("preprogs.src")
+	preprogs = current_file
+	for p in preprogs:
+		p, incomment = parse_strings_and_comments (p, incomment)
+		m = directive_re.match (p)
+		if (m):
+			g = m.groups()
+			directive = g[0]
+			arg1 = string.strip (g[1])
+			margs = string.strip (g[4])
+			#pprint ((directive, arg1, margs))
+			if directive == 'pragma':
+				if condition[-1]:
+					parse_pragma (arg1, margs)
+			elif directive == 'includelist':
+				if condition[-1]:
+					fname = parse_filename (arg1)
+					if fname:
+						source_list.append (fname)
+			elif directive == 'endlist':
+				pass
+			elif directive == 'ifdef':
+				condition.append (condition[-1])
+				if not defines.has_key (arg1):
+					condition[-1]=0
+			elif directive == 'ifndef':
+				condition.append (condition[-1])
+				if defines.has_key (arg1):
+					condition[-1]=0
+			elif directive == 'else':
+				condition[-1] = condition [-2] and not condition[-1]
+			elif directive == 'endif':
+				del condition[-1]
+			else:
+				if condition[-1]:
+					print "ignoring " + p
+		else:
+			if condition[-1]:
+				fname = parse_filename (p)
+				if fname:
+					source_list.append (fname)
+				
+def include_file (fname):
+	global current_file
+	fname = parse_filename (fname)
+	if fname:
+		append_file (fname)
+
 def process_source (source_file):
 	global compile_this_file, current_file
 	if verbose:
@@ -125,34 +179,7 @@ def process_source (source_file):
 	i = 0
 	while i < len (current_file):
 		l = current_file[i]
-		#print source_file + ":" + `i` + ":" + l
-		string_list = []
-		s = string_re.search (l)
-		while s:
-			string_list.append ((l[s.start():s.end()], s.start(), s.end()))
-			l = l[:s.start()] + ((s.end() - s.start()) * ' ') + l[s.end():]
-			s = string_re.search (l)
-		if incomment:
-			s = comment_end.search (l)
-			if s:
-				l = (s.end() * ' ') + l[s.end():]
-				incomment = 0
-				string_list = comment_string (string_list, s.start(), s.end())
-			else:
-				string_list = comment_string (string_list, 0, len(l))
-				l = ""
-		s = comment_whole.search (l)
-		if s:
-			l = l[:s.start()] + ((s.end() - s.start()) * ' ') + l[s.end():]
-			string_list = comment_string (string_list, s.start(), s.end())
-		s = comment_start.search (l)
-		if s:
-			l = l[:s.start()] + ((s.end() - s.start()) * ' ')
-			string_list = comment_string (string_list, s.start(), s.end())
-			incomment = 1
-		for str in string_list:
-			l = l[:str[1]] + str[0] + l[str[2]:]
-		#print l
+		l, incomment = parse_strings_and_comments (l, incomment)
 		m = directive_re.match (l)
 		if (m):
 			g = m.groups()