mesa: Add mesa with tegra support

This ebuild is based off the mesa-9999 ebuild from the x11 overlay

5 files changed, 547 insertions, 0 deletions

diff --git a/media-libs/mesa/Manifest b/media-libs/mesa/Manifest
new file mode 100644
index 0000000..ae66112
--- /dev/null
+++ b/media-libs/mesa/Manifest
@@ -0,0 +1,4 @@
+AUX eselect-mesa.conf.9.2 1676 SHA256 bcf5f77140b4695f147d4cd3c2db4b954fb57eccfd4475c7f7c4866edda8436e SHA512 d0061359638c0d9729ba1035fd7740c84d59f538adc11af2ee671b5ddbc83c420159efbefcc39ea680f06d20507f1e1d76b528712a07baeca901a413ba7b55df WHIRLPOOL 0fc650223a1910305bb2c4b7b946ac8b83b5b1ba0b79b586a96303a369b30c9c03dc658a6e8e9a29c5c4605f3865e245be0a0e6a27c40ac37402e8a2616b3ace
+AUX glx_ro_text_segm.patch 731 SHA256 e36af5b530fdbe2b0e62a035bf4bf4baef267c3dc56133d1a58e56899ebffc5c SHA512 90d04d1268cc90e1c5596b49b143895eba99d4e7f7d9bb5f699725c1308e3995edac44e3f61536c7ce70ebf5df84a5a22c18fa84fb54fbddb339f908975bb43c WHIRLPOOL 42171ef67930bebdcfdfcb0c9370234791c6125be760b6419abfff44bd65899982167d6da4d6eb4198383438e6376b4b695109af158083b903071c545160d883
+AUX mesa-9999-dont-require-llvm-for-r300.patch 524 SHA256 7e57cb037a57c8c4ef49be93d6f53bd9f002d918bf91c77158da4a4980fbbd66 SHA512 c5b4b40636a4bab64338a0be730f10ec546ff1da31fdde83c628485a5569cc021042fdb17e2ddbc39b86ab6e72e805ed28af9a98ebed320d23084e2575d6437b WHIRLPOOL 7c896f1be7353c964247fd60f517bb100779a02f08166ca509d4b2924c3cd45aba4cc5d45f0eeb171c4ef5d105e5a93316bd24af1342510ba8bde385ea709854
+EBUILD mesa-9999.ebuild 12185 SHA256 453def5c33d27e51866ee235ccb6a68ba7cfd754769d66cd3ade47fc447ea5b9 SHA512 8814dec1a93dc2a0dfac18be93b296c53cd9f3478956c0c10b74a7dc0b2227d69d6f955319fb789bfcefc9255c2199498e42c7f7b673e0a08390900ff4f3e7fd WHIRLPOOL 7720258b8d86257fae468fb159f4360b67ce184bc788a9ff8e9329da3c2871127be88b507978530fa900208b4d853066ac35b8723876cca49d665ed15761bc2c
diff --git a/media-libs/mesa/files/eselect-mesa.conf.9.2 b/media-libs/mesa/files/eselect-mesa.conf.9.2
new file mode 100644
index 0000000..ff590f5
--- /dev/null
+++ b/media-libs/mesa/files/eselect-mesa.conf.9.2
@@ -0,0 +1,39 @@
+# mesa classic/gallium implementations in this release
+
+# Syntax description:
+# * MESA_IMPLEMENTATIONS contains a space-delimited list of switchable
+#   classic/gallium implementations.
+# * MESA_DRIVERS is an associative array, for each member "foo" of
+#   MESA_IMPLEMENTATIONS it contains the following elements:
+#   foo,description - Human-readable description of the driver
+#   foo,classicdriver - Filename of the classic driver
+#   foo,galliumdriver - Filename of the gallium driver
+#   foo,default - which of classic or gallium is chosen by default
+
+MESA_IMPLEMENTATIONS="i915 i965 r300 r600 sw"
+declare -A MESA_DRIVERS || die "MESA_DRIVERS already in environment and not associative."
+
+MESA_DRIVERS[i915,description]="i915 (Intel 915, 945)"
+MESA_DRIVERS[i915,classicdriver]="i915_dri.so"
+MESA_DRIVERS[i915,galliumdriver]="i915g_dri.so"
+MESA_DRIVERS[i915,default]="gallium"
+
+MESA_DRIVERS[i965,description]="i965 (Intel GMA 965, G/Q3x, G/Q4x, HD)"
+MESA_DRIVERS[i965,classicdriver]="i965_dri.so"
+MESA_DRIVERS[i965,galliumdriver]="ilo_dri.so"
+MESA_DRIVERS[i965,default]="classic"
+
+MESA_DRIVERS[r300,description]="r300 (Radeon R300-R500)"
+MESA_DRIVERS[r300,classicdriver]="r300_dri.so"
+MESA_DRIVERS[r300,galliumdriver]="r300g_dri.so"
+MESA_DRIVERS[r300,default]="gallium"
+
+MESA_DRIVERS[r600,description]="r600 (Radeon R600-R700, Evergreen, Northern Islands)"
+MESA_DRIVERS[r600,classicdriver]="r600_dri.so"
+MESA_DRIVERS[r600,galliumdriver]="r600g_dri.so"
+MESA_DRIVERS[r600,default]="gallium"
+
+MESA_DRIVERS[sw,description]="sw (Software renderer)"
+MESA_DRIVERS[sw,classicdriver]="swrast_dri.so"
+MESA_DRIVERS[sw,galliumdriver]="swrastg_dri.so"
+MESA_DRIVERS[sw,default]="gallium"
diff --git a/media-libs/mesa/files/glx_ro_text_segm.patch b/media-libs/mesa/files/glx_ro_text_segm.patch
new file mode 100644
index 0000000..495b7dc
--- /dev/null
+++ b/media-libs/mesa/files/glx_ro_text_segm.patch
@@ -0,0 +1,28 @@
+2011-02-09	Jeremy Huddleston <jeremyhu@freedesktop.org
+
+	#240956
+	* configure.ac	add support to enable readonly test segment on x86
+
+--- configure.ac.orig	2008-11-17 23:19:38.000000000 +0100
++++ configure.ac	2008-11-17 23:20:17.000000000 +0100
+@@ -499,6 +499,20 @@
+     enable_xcb=no
+ fi
+ 
++
++dnl readonly text segment on x86 hardened platforms
++AC_ARG_ENABLE([glx_rts],
++    [AS_HELP_STRING([--enable-glx-rts],
++        [on x86, use a readonly text segment for libGL @<:@default=disabled@:>@])],
++    [enable_glx_rts="$enableval"],
++    [enable_glx_rts=no])
++if test "x$enable_glx_rts" = xyes; then
++    DEFINES="$DEFINES -DGLX_X86_READONLY_TEXT"
++else
++    enable_glx_rts=no
++fi
++
++
+ dnl
+ dnl libGL configuration per driver
+ dnl
diff --git a/media-libs/mesa/files/mesa-9999-dont-require-llvm-for-r300.patch b/media-libs/mesa/files/mesa-9999-dont-require-llvm-for-r300.patch
new file mode 100644
index 0000000..bd24787
--- /dev/null
+++ b/media-libs/mesa/files/mesa-9999-dont-require-llvm-for-r300.patch
@@ -0,0 +1,12 @@
+diff --git a/configure.ac b/configure.ac
+index 21a1986..94b2247 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -1777,7 +1777,6 @@ if test "x$with_gallium_drivers" != x; then
+         xr300)
+             HAVE_GALLIUM_R300=yes
+             PKG_CHECK_MODULES([RADEON], [libdrm_radeon >= $LIBDRM_RADEON_REQUIRED])
+-            gallium_require_llvm "Gallium R300"
+             GALLIUM_DRIVERS_DIRS="$GALLIUM_DRIVERS_DIRS r300"
+             gallium_check_st "radeon/drm" "dri-r300" "" "" "xvmc-r300" "vdpau-r300"
+             ;;
diff --git a/media-libs/mesa/mesa-9999.ebuild b/media-libs/mesa/mesa-9999.ebuild
new file mode 100644
index 0000000..5299c66
--- /dev/null
+++ b/media-libs/mesa/mesa-9999.ebuild
@@ -0,0 +1,464 @@
+# Copyright 1999-2013 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Header: $
+
+EAPI=5
+
+EGIT_REPO_URI="git://github.com/grate-driver/mesa"
+
+if [[ ${PV} = 9999* ]]; then
+	GIT_ECLASS="git-2"
+	EXPERIMENTAL="true"
+fi
+
+PYTHON_COMPAT=( python{2_6,2_7} )
+
+inherit base autotools multilib flag-o-matic python-single-r1 toolchain-funcs ${GIT_ECLASS}
+
+OPENGL_DIR="xorg-x11"
+
+MY_PN="${PN/m/M}"
+MY_P="${MY_PN}-${PV/_/-}"
+MY_SRC_P="${MY_PN}Lib-${PV/_/-}"
+
+FOLDER="${PV/_rc*/}"
+
+DESCRIPTION="OpenGL-like graphic library for Linux"
+HOMEPAGE="http://mesa3d.sourceforge.net/"
+
+#SRC_PATCHES="mirror://gentoo/${P}-gentoo-patches-01.tar.bz2"
+if [[ $PV = 9999* ]]; then
+	SRC_URI="${SRC_PATCHES}"
+else
+	SRC_URI="ftp://ftp.freedesktop.org/pub/mesa/${FOLDER}/${MY_SRC_P}.tar.bz2
+		${SRC_PATCHES}"
+fi
+
+# The code is MIT/X11.
+# GLES[2]/gl[2]{,ext,platform}.h are SGI-B-2.0
+LICENSE="MIT SGI-B-2.0"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~hppa ~ia64 ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86 ~amd64-fbsd ~x86-fbsd ~x86-freebsd ~amd64-linux ~arm-linux ~ia64-linux ~x86-linux ~sparc-solaris ~x64-solaris ~x86-solaris"
+
+INTEL_CARDS="i915 i965 ilo intel"
+RADEON_CARDS="r100 r200 r300 r600 radeon radeonsi"
+VIDEO_CARDS="${INTEL_CARDS} ${RADEON_CARDS} freedreno nouveau tegra vmware"
+for card in ${VIDEO_CARDS}; do
+	IUSE_VIDEO_CARDS+=" video_cards_${card}"
+done
+
+IUSE="${IUSE_VIDEO_CARDS}
+	bindist +classic debug +egl +gallium gbm gles1 gles2 +llvm +nptl opencl
+	openvg osmesa pax_kernel pic r600-llvm-compiler selinux vdpau
+	wayland xvmc xa xorg kernel_FreeBSD"
+
+REQUIRED_USE="
+	llvm?   ( gallium )
+	openvg? ( egl gallium )
+	opencl? ( gallium r600-llvm-compiler )
+	gles1?  ( egl )
+	gles2?  ( egl )
+	r600-llvm-compiler? ( gallium llvm || ( video_cards_r600 video_cards_radeonsi video_cards_radeon ) )
+	wayland? ( egl )
+	xa?  ( gallium )
+	xorg?  ( gallium )
+	video_cards_freedreno?  ( gallium )
+	video_cards_intel?  ( || ( classic gallium ) )
+	video_cards_i915?   ( || ( classic gallium ) )
+	video_cards_i965?   ( classic )
+	video_cards_ilo?    ( gallium )
+	video_cards_nouveau? ( || ( classic gallium ) )
+	video_cards_radeon? ( || ( classic gallium ) )
+	video_cards_r100?   ( classic )
+	video_cards_r200?   ( classic )
+	video_cards_r300?   ( gallium )
+	video_cards_r600?   ( gallium )
+	video_cards_radeonsi?   ( gallium llvm )
+	video_cards_tegra?  ( egl gallium gles1 gles2 )
+	video_cards_vmware? ( gallium )
+"
+
+LIBDRM_DEPSTRING=">=x11-libs/libdrm-2.4.46"
+# keep correct libdrm and dri2proto dep
+# keep blocks in rdepend for binpkg
+RDEPEND="
+	!<x11-base/xorg-server-1.7
+	!<=x11-proto/xf86driproto-2.0.3
+	classic? ( app-admin/eselect-mesa )
+	gallium? ( app-admin/eselect-mesa )
+	>=app-admin/eselect-opengl-1.2.7
+	dev-libs/expat
+	gbm? ( virtual/udev )
+	>=x11-libs/libX11-1.3.99.901
+	x11-libs/libXdamage
+	x11-libs/libXext
+	x11-libs/libXxf86vm
+	>=x11-libs/libxcb-1.8.1
+	opencl? (
+				app-admin/eselect-opencl
+				dev-libs/libclc
+			)
+	vdpau? ( >=x11-libs/libvdpau-0.4.1 )
+	wayland? ( >=dev-libs/wayland-1.0.3 )
+	xorg? (
+		x11-base/xorg-server:=
+		x11-libs/libdrm[libkms]
+	)
+	xvmc? ( >=x11-libs/libXvMC-1.0.6 )
+	${LIBDRM_DEPSTRING}[video_cards_freedreno?,video_cards_nouveau?,video_cards_tegra?,video_cards_vmware?]
+"
+for card in ${INTEL_CARDS}; do
+	RDEPEND="${RDEPEND}
+		video_cards_${card}? ( ${LIBDRM_DEPSTRING}[video_cards_intel] )
+	"
+done
+
+for card in ${RADEON_CARDS}; do
+	RDEPEND="${RDEPEND}
+		video_cards_${card}? ( ${LIBDRM_DEPSTRING}[video_cards_radeon] )
+	"
+done
+
+DEPEND="${RDEPEND}
+	llvm? (
+		>=sys-devel/llvm-2.9
+		r600-llvm-compiler? ( sys-devel/llvm[video_cards_radeon] )
+		video_cards_radeonsi? ( sys-devel/llvm[video_cards_radeon] )
+	)
+	opencl? (
+				>=sys-devel/llvm-3.3-r1[video_cards_radeon]
+				>=sys-devel/clang-3.3
+				>=sys-devel/gcc-4.6
+	)
+	${PYTHON_DEPS}
+	dev-libs/libxml2[python,${PYTHON_USEDEP}]
+	sys-devel/bison
+	sys-devel/flex
+	virtual/pkgconfig
+	>=x11-proto/dri2proto-2.6
+	>=x11-proto/glproto-1.4.15-r1
+	>=x11-proto/xextproto-7.0.99.1
+	x11-proto/xf86driproto
+	x11-proto/xf86vidmodeproto
+"
+
+S="${WORKDIR}/${MY_P}"
+
+# It is slow without texrels, if someone wants slow
+# mesa without texrels +pic use is worth the shot
+QA_EXECSTACK="usr/lib*/opengl/xorg-x11/lib/libGL.so*"
+QA_WX_LOAD="usr/lib*/opengl/xorg-x11/lib/libGL.so*"
+
+# Think about: ggi, fbcon, no-X configs
+
+pkg_setup() {
+	# workaround toc-issue wrt #386545
+	use ppc64 && append-flags -mminimal-toc
+
+	python-single-r1_pkg_setup
+}
+
+src_unpack() {
+	default
+	[[ $PV = 9999* ]] && git-2_src_unpack
+}
+
+src_prepare() {
+	# apply patches
+	if [[ ${PV} != 9999* && -n ${SRC_PATCHES} ]]; then
+		EPATCH_FORCE="yes" \
+		EPATCH_SOURCE="${WORKDIR}/patches" \
+		EPATCH_SUFFIX="patch" \
+		epatch
+	fi
+
+	# relax the requirement that r300 must have llvm, bug 380303
+	epatch "${FILESDIR}"/${P}-dont-require-llvm-for-r300.patch
+
+	# fix for hardened pax_kernel, bug 240956
+	[[ ${PV} != 9999* ]] && epatch "${FILESDIR}"/glx_ro_text_segm.patch
+
+	# Solaris needs some recent POSIX stuff in our case
+	if [[ ${CHOST} == *-solaris* ]] ; then
+		sed -i -e "s/-DSVR4/-D_POSIX_C_SOURCE=200112L/" configure.ac || die
+	fi
+
+	# Tests fail against python-3, bug #407887
+	sed -i 's|/usr/bin/env python|/usr/bin/env python2|' src/glsl/tests/compare_ir || die
+
+	base_src_prepare
+
+	eautoreconf
+}
+
+src_configure() {
+	local myconf
+
+	if use classic; then
+	# Configurable DRI drivers
+		driver_enable swrast
+
+	# Intel code
+		driver_enable video_cards_i915 i915
+		driver_enable video_cards_i965 i965
+		if ! use video_cards_i915 && \
+			! use video_cards_i965; then
+			driver_enable video_cards_intel i915 i965
+		fi
+
+		# Nouveau code
+		driver_enable video_cards_nouveau nouveau
+
+		# ATI code
+		driver_enable video_cards_r100 radeon
+		driver_enable video_cards_r200 r200
+		if ! use video_cards_r100 && \
+				! use video_cards_r200; then
+			driver_enable video_cards_radeon radeon r200
+		fi
+	fi
+
+	if use egl; then
+		myconf+="
+			--with-egl-platforms=x11$(use wayland && echo ",wayland")$(use gbm && echo ",drm")
+			$(use_enable gallium gallium-egl)
+		"
+	fi
+
+	if use gallium; then
+		myconf+="
+			$(use_enable llvm gallium-llvm)
+			$(use_enable openvg)
+			$(use_enable r600-llvm-compiler)
+			$(use_enable vdpau)
+			$(use_enable xvmc)
+		"
+		gallium_enable swrast
+		gallium_enable video_cards_vmware svga
+		gallium_enable video_cards_nouveau nouveau
+		gallium_enable video_cards_i915 i915
+		gallium_enable video_cards_ilo ilo
+		if ! use video_cards_i915 && \
+			! use video_cards_i965; then
+			gallium_enable video_cards_intel i915
+		fi
+
+		gallium_enable video_cards_r300 r300
+		gallium_enable video_cards_r600 r600
+		gallium_enable video_cards_radeonsi radeonsi
+		if ! use video_cards_r300 && \
+				! use video_cards_r600; then
+			gallium_enable video_cards_radeon r300 r600
+		fi
+
+		gallium_enable video_cards_freedreno freedreno
+		# opencl stuff
+		if use opencl; then
+			myconf+="
+				$(use_enable opencl)
+				--with-opencl-libdir="${EPREFIX}/usr/$(get_libdir)/OpenCL/vendors/mesa"
+				--with-clang-libdir="${EPREFIX}/usr/$(get_libdir)"
+				"
+		fi
+
+		gallium_enable video_cards_tegra tegra
+	fi
+
+	# x86 hardened pax_kernel needs glx-rts, bug 240956
+	if use pax_kernel; then
+		myconf+="
+			$(use_enable x86 glx-rts)
+		"
+	fi
+
+	# build fails with BSD indent, bug #428112
+	use userland_GNU || export INDENT=cat
+
+	econf \
+		--enable-dri \
+		--enable-glx \
+		--enable-shared-glapi \
+		$(use_enable !bindist texture-float) \
+		$(use_enable debug) \
+		$(use_enable egl) \
+		$(use_enable gbm) \
+		$(use_enable gles1) \
+		$(use_enable gles2) \
+		$(use_enable nptl glx-tls) \
+		$(use_enable osmesa) \
+		$(use_enable !pic asm) \
+		$(use_enable xa) \
+		$(use_enable xorg) \
+		--with-dri-drivers=${DRI_DRIVERS} \
+		--with-gallium-drivers=${GALLIUM_DRIVERS} \
+		PYTHON2="${PYTHON}" \
+		${myconf}
+}
+
+src_install() {
+	base_src_install
+
+	find "${ED}" -name '*.la' -exec rm -f {} + || die
+
+	if use !bindist; then
+		dodoc docs/patents.txt
+	fi
+
+	# Install config file for eselect mesa
+	insinto /usr/share/mesa
+	newins "${FILESDIR}/eselect-mesa.conf.9.2" eselect-mesa.conf
+
+	# Move libGL and others from /usr/lib to /usr/lib/opengl/blah/lib
+	# because user can eselect desired GL provider.
+	ebegin "Moving libGL and friends for dynamic switching"
+		local x
+		local gl_dir="/usr/$(get_libdir)/opengl/${OPENGL_DIR}/"
+		dodir ${gl_dir}/{lib,extensions,include/GL}
+		for x in "${ED}"/usr/$(get_libdir)/lib{EGL,GL*,OpenVG}.{la,a,so*}; do
+			if [ -f ${x} -o -L ${x} ]; then
+				mv -f "${x}" "${ED}${gl_dir}"/lib \
+					|| die "Failed to move ${x}"
+			fi
+		done
+		for x in "${ED}"/usr/include/GL/{gl.h,glx.h,glext.h,glxext.h}; do
+			if [ -f ${x} -o -L ${x} ]; then
+				mv -f "${x}" "${ED}${gl_dir}"/include/GL \
+					|| die "Failed to move ${x}"
+			fi
+		done
+		for x in "${ED}"/usr/include/{EGL,GLES*,VG,KHR}; do
+			if [ -d ${x} ]; then
+				mv -f "${x}" "${ED}${gl_dir}"/include \
+					|| die "Failed to move ${x}"
+			fi
+		done
+	eend $?
+
+	if use classic || use gallium; then
+			ebegin "Moving DRI/Gallium drivers for dynamic switching"
+			local gallium_drivers=( i915_dri.so i965_dri.so r300_dri.so r600_dri.so swrast_dri.so )
+			keepdir /usr/$(get_libdir)/dri
+			dodir /usr/$(get_libdir)/mesa
+			for x in ${gallium_drivers[@]}; do
+				if [ -f "${S}/$(get_libdir)/gallium/${x}" ]; then
+					mv -f "${ED}/usr/$(get_libdir)/dri/${x}" "${ED}/usr/$(get_libdir)/dri/${x/_dri.so/g_dri.so}" \
+						|| die "Failed to move ${x}"
+					insinto "/usr/$(get_libdir)/dri/"
+					if [ -f "${S}/$(get_libdir)/${x}" ]; then
+						insopts -m0755
+						doins "${S}/$(get_libdir)/${x}"
+					fi
+				fi
+			done
+			for x in "${ED}"/usr/$(get_libdir)/dri/*.so; do
+				if [ -f ${x} -o -L ${x} ]; then
+					mv -f "${x}" "${x/dri/mesa}" \
+						|| die "Failed to move ${x}"
+				fi
+			done
+			pushd "${ED}"/usr/$(get_libdir)/dri || die "pushd failed"
+			ln -s ../mesa/*.so . || die "Creating symlink failed"
+			# remove symlinks to drivers known to eselect
+			for x in ${gallium_drivers[@]}; do
+				if [ -f ${x} -o -L ${x} ]; then
+					rm "${x}" || die "Failed to remove ${x}"
+				fi
+			done
+			popd
+		eend $?
+	fi
+	if use opencl; then
+		ebegin "Moving Gallium/Clover OpenCL implementation for dynamic switching"
+		local cl_dir="/usr/$(get_libdir)/OpenCL/vendors/mesa"
+		dodir ${cl_dir}/{lib,include}
+		if [ -f "${ED}/usr/$(get_libdir)/libOpenCL.so" ]; then
+			mv -f "${ED}"/usr/$(get_libdir)/libOpenCL.so* \
+			"${ED}"${cl_dir}
+		fi
+		if [ -f "${ED}/usr/include/CL/opencl.h" ]; then
+			mv -f "${ED}"/usr/include/CL \
+			"${ED}"${cl_dir}/include
+		fi
+		eend $?
+	fi
+}
+
+pkg_postinst() {
+	# Switch to the xorg implementation.
+	echo
+	eselect opengl set --use-old ${OPENGL_DIR}
+
+	# switch to xorg-x11 and back if necessary, bug #374647 comment 11
+	OLD_IMPLEM="$(eselect opengl show)"
+	if [[ ${OPENGL_DIR}x != ${OLD_IMPLEM}x ]]; then
+		eselect opengl set ${OPENGL_DIR}
+		eselect opengl set ${OLD_IMPLEM}
+	fi
+
+	# Select classic/gallium drivers
+	if use classic || use gallium; then
+		eselect mesa set --auto
+	fi
+
+	# Switch to mesa opencl
+	if use opencl; then
+		eselect opencl set --use-old ${PN}
+	fi
+
+	# warn about patent encumbered texture-float
+	if use !bindist; then
+		elog "USE=\"bindist\" was not set. Potentially patent encumbered code was"
+		elog "enabled. Please see patents.txt for an explanation."
+	fi
+
+	local using_radeon r_flag
+	for r_flag in ${RADEON_CARDS}; do
+		if use video_cards_${r_flag}; then
+			using_radeon=1
+			break
+		fi
+	done
+
+	if [[ ${using_radeon} = 1 ]] && ! has_version media-libs/libtxc_dxtn; then
+		elog "Note that in order to have full S3TC support, it is necessary to install"
+		elog "media-libs/libtxc_dxtn as well. This may be necessary to get nice"
+		elog "textures in some apps, and some others even require this to run."
+	fi
+}
+
+# $1 - VIDEO_CARDS flag
+# other args - names of DRI drivers to enable
+# TODO: avoid code duplication for a more elegant implementation
+driver_enable() {
+	case $# in
+		# for enabling unconditionally
+		1)
+			DRI_DRIVERS+=",$1"
+			;;
+		*)
+			if use $1; then
+				shift
+				for i in $@; do
+					DRI_DRIVERS+=",${i}"
+				done
+			fi
+			;;
+	esac
+}
+
+gallium_enable() {
+	case $# in
+		# for enabling unconditionally
+		1)
+			GALLIUM_DRIVERS+=",$1"
+			;;
+		*)
+			if use $1; then
+				shift
+				for i in $@; do
+					GALLIUM_DRIVERS+=",${i}"
+				done
+			fi
+			;;
+	esac
+}