Add option `-n', causing system headers not to be included in dependacy

lists.

This is needed when using a non-stock compiler.

usr.bin/mkdep/Makefile

@@ -1,5 +1,6 @@
 #	@(#)Makefile	8.1 (Berkeley) 6/6/93
 
+BINDIR?=	/usr/bin
 MAN1=	mkdep.1
 
 beforeinstall:

usr.bin/mkdep/mkdep.1

@@ -39,7 +39,7 @@
 .Nd construct Makefile dependency list
 .Sh SYNOPSIS
 .Nm
-.Op Fl ap
+.Op Fl anp
 .Op Fl f Ar file
 .Op Ar flags
 .Ar file ...
@@ -71,6 +71,8 @@ may be run from a single Makefile.
 Write the include file dependencies to 
 .Ar file ,
 instead of the default ``.depend''.
+.It Fl n
+Don't make dependencies on system headers.  I.e. anything in <>'s.
 .It Fl p
 Cause
 .Nm

usr.bin/mkdep/mkdep.gcc.sh

@@ -32,10 +32,11 @@
 # SUCH DAMAGE.
 #
 #	@(#)mkdep.gcc.sh	8.1 (Berkeley) 6/6/93
-#	$Id: mkdep.gcc.sh,v 1.13 1998/08/17 11:43:25 jb Exp $
+#	$Id: mkdep.gcc.sh,v 1.14 1998/08/24 10:16:39 cracauer Exp $
 
 D=.depend			# default dependency file is .depend
 append=0
+nosyshdrs=0
 pflag=
 
 while :
@@ -50,6 +51,11 @@ while :
 			D=$2
 			shift; shift ;;
 
+		# -n does not make dependencies on system headers
+		-n)
+			nosyshdrs=1
+			shift ;;
+
 		# the -p flag produces "program: program.c" style dependencies
 		# so .o's don't get produced
 		-p)
@@ -74,9 +80,14 @@ trap 'rm -f $TMP' 0
 # pick the cpp.  mkdep must be told the cpp to use for exceptional cases.
 MKDEP_CPP=${MKDEP_CPP-"cc -E"}
 
+case $append in 
+	0) CC_MKDEP_OPT="-M";;
+	*) CC_MKDEP_OPT="-MM -w";;
+esac
+
 echo "# $@" > $TMP	# store arguments for debugging
 
-if $MKDEP_CPP -M "$@" >> $TMP; then :
+if $MKDEP_CPP $CC_MKDEP_OPT "$@" >> $TMP; then :
 else
 	echo 'mkdep: compile failed' >&2
 	exit 1