Remove -n for ignoring system headers. Instead add finer grain shell

macros and document them.

Prompted by:	bde

usr.bin/mkdep/mkdep.1

@@ -39,7 +39,7 @@
 .Nd construct Makefile dependency list
 .Sh SYNOPSIS
 .Nm
-.Op Fl anp
+.Op Fl ap
 .Op Fl f Ar file
 .Op Ar flags
 .Ar file ...
@@ -60,6 +60,15 @@ depend:
 where the macro SRCS is the list of C source files and the macro
 CFLAGS is the list of flags for the C compiler.
 .Pp
+The user has the ability to change the preprocessor and preprocessor options
+used.  For instance, to use Gcc as the preprocessor and to ignore system
+headers, one would use
+.Bd -literal -offset indent
+depend:
+	env MKDEP_CPP="gcc -E" MKDEP_CPP_OPTS=-MM mkdep \\
+		${CFLAGS} ${SRCS}
+.Ed
+.Pp
 The options are as follows:
 .Bl -tag -width Ds
 .It Fl a
@@ -71,8 +80,6 @@ may be run from a single Makefile.
 Write the include file dependencies to 
 .Ar file ,
 instead of the default ``.depend''.
-.It Fl n
-Don't make dependencies on system headers.  I.e. anything in <>'s.
 .It Fl p
 Cause
 .Nm
@@ -88,6 +95,16 @@ directly from its C module rather than using an intermediate
 module.
 This is useful for programs whose source is contained in a single
 module.
+.Sh ENVIRONMENT
+.Bl -tag -width MKDEP_CPP_OPTS
+.It Ev CC
+Specifies the C compiler to use.  The specified compiler is expected to have
+options consistant with the Gnu C compiler.
+.It Ev MKDEP_CPP
+Specifies the preprocessor to use.  The default is "${CC} -E".
+.It Ev MKDEP_CPP_OPTS
+Specifie the non-CFLAGS options for the preprocessor.  The default is
+"-M".
 .El
 .Sh SEE ALSO
 .Xr cc 1 ,

usr.bin/mkdep/mkdep.gcc.sh

@@ -32,11 +32,10 @@
 # SUCH DAMAGE.
 #
 #	@(#)mkdep.gcc.sh	8.1 (Berkeley) 6/6/93
-#	$Id: mkdep.gcc.sh,v 1.15 1998/08/29 07:55:55 obrien 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 :
@@ -51,11 +50,6 @@ 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)
@@ -78,16 +72,13 @@ trap 'rm -f $TMP' 0
 # For C sources, mkdep must use exactly the same cpp and predefined flags
 # as the compiler would.  This is easily arranged by letting the compiler
 # pick the cpp.  mkdep must be told the cpp to use for exceptional cases.
-MKDEP_CPP=${MKDEP_CPP-"cc -E"}
-
-case $nosyshdrs in 
-	0) CC_MKDEP_OPT="-M";;
-	*) CC_MKDEP_OPT="-MM -w";;
-esac
+CC=${CC-"cc"}
+MKDEP_CPP=${MKDEP_CPP-"${CC} -E"}
+MKDEP_CPP_OPTS=${MKDEP_CPP_OPTS-"-M"};
 
 echo "# $@" > $TMP	# store arguments for debugging
 
-if $MKDEP_CPP $CC_MKDEP_OPT "$@" >> $TMP; then :
+if $MKDEP_CPP $MKDEP_CPP_OPTS "$@" >> $TMP; then :
 else
 	echo 'mkdep: compile failed' >&2
 	exit 1