support nested #if/#else/#endif sets, to allow ULTRIX compat code to handle

Mips ULTRIX and VAX ULTRIX from the same syscall table.

sys/kern/makesyscalls.sh

@@ -1,5 +1,5 @@
 #! /bin/sh -
-#	$NetBSD: makesyscalls.sh,v 1.17 1995/10/07 06:28:31 mycroft Exp $
+#	$NetBSD: makesyscalls.sh,v 1.18 1996/03/15 01:25:12 cgd Exp $
 #
 # Copyright (c) 1994 Christopher G. Demetriou
 # All rights reserved.
@@ -108,6 +108,9 @@ s/\$//g
 ' < $2 | $awk "
 $toupper
 BEGIN {
+	# to allow nested #if/#else/#endif sets
+	savedepth = 0
+
 	sysnames = \"$sysnames\"
 	sysprotos = \"$sysprotos\"
 	sysnumhdr = \"$sysnumhdr\"
@@ -177,17 +180,30 @@ $1 ~ /^#[ 	]*if/ {
 	print > sysent
 	print > sysprotos
 	print > sysnames
-	savesyscall = syscall
+	savesyscall[++savedepth] = syscall
 	next
 }
 $1 ~ /^#[ 	]*else/ {
 	print > sysent
 	print > sysprotos
 	print > sysnames
-	syscall = savesyscall
+	if (savedepth <= 0) {
+		printf "%s: line %d: unbalenced #else\n", \
+		    infile, NR
+		exit 1
+	}
+	syscall = savesyscall[savedepth]
 	next
 }
 $1 ~ /^#/ {
+	if ($1 ~ /^#[       ]*endif/) {
+		if (savedepth <= 0) {
+			printf "%s: line %d: unbalenced #endif\n", \
+			    infile, NR
+			exit 1
+		}
+		savedepth--;
+	}
 	print > sysent
 	print > sysprotos
 	print > sysnames