Can we add PREFER_* options to mk/platform/*mk files?

For example, it could be nice for mk/platform/Linux.mk to have:

# GNU libc usually provides a good enough iconv
PREFER_NATIVE+=        iconv

I have PREFER_PKGSRC=YES so converters/libiconv/builtin.mk ends up
skipping the Linux check. I want to have PREFER_PKGSRC=YES while using
PREFER_NATIVE+=iconv.

My workaround is
--- converters/libiconv/builtin.mk	28 Aug 2004 06:05:31 -0000	1.6
+++ converters/libiconv/builtin.mk	27 Oct 2004 01:16:14 -0000
@@ -55,6 +55,15 @@
 BUILDLINK_VARS+=	IS_BUILTIN.iconv
 .endif	# IS_BUILTIN.iconv

+.if (${OPSYS} == "Linux") && exists(${_ICONV_H})
+USE_BUILTIN.iconv!=	\
+	if ${GREP} -q "This file is part of the GNU C Library" ${_ICONV_H}; then \
+		${ECHO} "yes";						\
+	else								\
+		${ECHO} "no";						\
+	fi
+.endif
+
 .if !defined(USE_BUILTIN.iconv)
 USE_BUILTIN.iconv?=	${IS_BUILTIN.iconv}
 PREFER.iconv?=		pkgsrc


(But that is not correct because now it always overrides PREFER_* I
think.)

Also, what specific feature (or function) does abiword require of GNU
libiconv?

Anyways, I use abiword (various versions) under Linux using GNU libc that
provides iconv. I don't need nor have any GNU iconv installed.

Our pkgsrc doesn't allow converters/iconv

--- editors/abiword/Makefile.common	21 Oct 2004 06:30:39 -0000	1.1
+++ editors/abiword/Makefile.common	27 Oct 2004 00:23:49 -0000
@@ -23,7 +23,10 @@
 USE_PERL5=		run
 USE_X11=		yes

+.include "../../mk/bsd.prefs.mk"
+.if ${OPSYS} != "Linux" # iconv is not needed for Linux; it is included in glibc
 USE_BUILTIN.iconv=      no # Make sure we get libiconv dependency.
+.endif

 CONFIGURE_ARGS+=        --enable-threads
 CONFIGURE_ARGS+=        --with-libxml2



Jeremy C. Reed