commit 58663bc33f553f6f0af8df277dbae5d691eea88d
Author: Joakim Nohlgård <joakim.nohlgard@eistec.se>
Date:   Mon Jan 18 11:10:00 2016 +0100

    newlib: add newlib-nano support

diff --git a/sys-libs/newlib/newlib-9999.ebuild b/sys-libs/newlib/newlib-9999.ebuild
index 44815ad..4cb5b56 100644
--- a/sys-libs/newlib/newlib-9999.ebuild
+++ b/sys-libs/newlib/newlib-9999.ebuild
@@ -29,10 +29,12 @@ HOMEPAGE="http://sourceware.org/newlib/"
 
 LICENSE="NEWLIB LIBGLOSS GPL-2"
 SLOT="0"
-IUSE="nls threads unicode crosscompile_opts_headers-only"
+IUSE="nls threads unicode crosscompile_opts_headers-only newlib-nano"
 RESTRICT="strip"
 
 NEWLIBBUILD="${WORKDIR}/build"
+NEWLIBNANOBUILD="${WORKDIR}/build.nano"
+NEWLIBNANOTMPINSTALL="${WORKDIR}/nano_tmp_install"
 
 pkg_setup() {
 	# Reject newlib-on-glibc type installs
@@ -65,17 +67,62 @@ src_configure() {
 	econf \
 		$(use_enable unicode newlib-mb) \
 		$(use_enable nls) \
+		--enable-newlib-io-long-long \
+		--enable-newlib-register-fini \
 		${myconf}
+
+	# Build newlib-nano beside newlib (original)
+	# Based on https://tracker.debian.org/media/packages/n/newlib/rules-2.1.0%2Bgit20140818.1a8323b-2
+	if use newlib-nano ; then
+		mkdir -p "${NEWLIBNANOBUILD}"
+		cd "${NEWLIBNANOBUILD}"
+
+		ECONF_SOURCE=${S} \
+		econf \
+			$(use_enable unicode newlib-mb) \
+			$(use_enable nls) \
+			--enable-newlib-reent-small \
+			--disable-newlib-fvwrite-in-streamio \
+			--disable-newlib-fseek-optimization \
+			--disable-newlib-wide-orient \
+			--enable-newlib-nano-malloc \
+			--disable-newlib-unbuf-stream-opt \
+			--enable-lite-exit \
+			--enable-newlib-global-atexit \
+			--enable-newlib-nano-formatted-io \
+			${myconf}
+	fi
 }
 
 src_compile() {
 	emake -C "${NEWLIBBUILD}"
+	use newlib-nano && emake -C "${NEWLIBNANOBUILD}"
 }
 
 src_install() {
 	cd "${NEWLIBBUILD}"
 	emake -j1 DESTDIR="${D}" install
 #	env -uRESTRICT CHOST=${CTARGET} prepallstrip
+
+	if use newlib-nano ; then
+		cd "${NEWLIBNANOBUILD}"
+		emake -j1 DESTDIR="${NEWLIBNANOTMPINSTALL}" install
+		# Rename nano lib* files to lib*_nano and move to the real ${D}
+		# Avoid dependency on perl-rename by using a for loop instead.
+		local nanolibfiles=""
+		nanolibfiles=$(find "${NEWLIBNANOTMPINSTALL}" -regex ".*/lib\(c\|g\|rdimon\)\.a" -print)
+		for f in ${nanolibfiles}; do
+			local l="${f##${NEWLIBNANOTMPINSTALL}}"
+			echo mv "${f}" "${D}/${l%%\.a}_nano.a"
+			mv "${f}" "${D}/${l%%\.a}_nano.a"
+		done
+		# Move nano's version of newlib.h to nano/newlib.h
+		mkdir -p ${D}/usr/${CTARGET}/include/nano
+		mv ${NEWLIBNANOTMPINSTALL}/usr/${CTARGET}/include/newlib.h \
+			${D}/usr/${CTARGET}/include/nano/newlib.h
+
+	fi
+
 	# minor hack to keep things clean
 	rm -fR "${D}"/usr/share/info
 	rm -fR "${D}"/usr/info