app-eselect/eselect-{blas,lapack}: new design for BLAS/LAPACK switch.

  As discussed in the gentoo-dev, it is decided to adopt the runtime
  switching of BLAS/CBLAS that has been proved by the experience of
  Debian.  The Gentoo libgcc-style ld.so.conf runtime switching has
  been adopted as well, so as to avoid changing symlinks in /usr
  ignoring package manager.

  This design solves all the remaining problems regarding BLAS/LAPACK,
  thus making alternative-2.eclass (runtime switching of build
  options) and proposed USE_EXPAND (PYTHON_TARGET like eclass)
  obsolete.

  Finally we are at it.  Thanks to all for years of ideas, debates and
  hard work.

Reference: https://archives.gentoo.org/gentoo-dev/message/0177fea10e3ee06d85713101d17fc8d6

Closes: https://bugs.gentoo.org/632624
Closes: https://bugs.gentoo.org/470908
Closes: https://bugs.gentoo.org/267691
Closes: https://github.com/gentoo/gentoo/pull/12316
Closes: https://github.com/gentoo/gentoo/pull/12318
Closes: https://github.com/gentoo/sci/pull/835
Closes: https://github.com/gentoo/sci/pull/837

Credit: Dominik Schmidt, TheChymera, kiwifb, lkraav, Alessandro-Barbieri
Signed-off-by: Mo Zhou <cdluminate@gmail.com>
Signed-off-by: Benda Xu <heroxbd@gentoo.org>

3 files changed, 220 insertions, 10 deletions

diff --git a/app-eselect/eselect-blas/eselect-blas-0.2.ebuild b/app-eselect/eselect-blas/eselect-blas-0.2.ebuild
new file mode 100644
index 000000000000..083ca34022d9
--- /dev/null
+++ b/app-eselect/eselect-blas/eselect-blas-0.2.ebuild
@@ -0,0 +1,28 @@
+# Copyright 1999-2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+DESCRIPTION="BLAS/CBLAS module for eselect"
+HOMEPAGE="https://www.gentoo.org"
+SRC_URI=""
+
+LICENSE="GPL-2"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~mips ~ppc ~ppc64 ~s390 ~sparc ~x86 ~amd64-fbsd ~x86-fbsd ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos ~sparc-solaris"
+IUSE=""
+
+# Need skel.bash lib
+RDEPEND=( ">=app-admin/eselect-1.0.5"
+          "!app-eselect/eselect-cblas" )
+DEPEND="${RDEPEND}"
+
+S="${WORKDIR}"
+
+src_install() {
+	local MODULEDIR="/usr/share/eselect/modules"
+	local MODULE="blas"
+	insinto ${MODULEDIR}
+	newins "${FILESDIR}"/${MODULE}.eselect-${PVR} ${MODULE}.eselect
+	doman "${FILESDIR}"/blas.eselect.5
+}
diff --git a/app-eselect/eselect-blas/files/blas.eselect-0.2 b/app-eselect/eselect-blas/files/blas.eselect-0.2
new file mode 100644
index 000000000000..001ddb941e82
--- /dev/null
+++ b/app-eselect/eselect-blas/files/blas.eselect-0.2
@@ -0,0 +1,168 @@
+# -*-eselect-*-  vim: ft=eselect
+# Copyright 2019 Gentoo Foundation
+# Distributed under the terms of the GNU GPL version 2 or later
+
+inherit config tests multilib skel
+
+MODULE="BLAS/CBLAS"
+IFACE="blas"
+DESCRIPTION="Manage installed alternatives of $MODULE shared objects"
+MAINTAINER="lumin@debian.org"
+VERSION="20190621"
+
+### helper utility to find all available BLAS/CBLAS implementations
+find_targets_in() {
+	[[ $# -eq 1 ]] || die -q "in which libdir?"
+
+	local cand
+	for cand in ${EROOT}/etc/env.d/blas/$1/*; do
+		[[ "config" = $(basename ${cand}) ]] && continue
+		[[ -r ${cand} ]] && basename ${cand}
+	done
+}
+
+### helper utility to validate a BLAS/CBLAS library directory
+validate_blaslibdir() {
+	[[ -d $1 ]] || return 2  # dir doesn't exist
+	[[ -r "${1}/libblas.so.3" ]] && [[ -r "${1}/libblas.so" ]] \
+	&& [[ -r "${1}/libcblas.so.3" ]] && [[ -r "${1}/libcblas.so" ]] \
+	|| return 1
+}
+
+### show action
+do_show() {
+	# do_show -- show both lib64 and lib32 selection
+	# do_show libxx -- show libxx selection
+	local libdir cur libdirs=( $(list_libdirs) )
+
+	# if manually specified libdirs
+	if [[ ! $# -eq 0 ]]; then
+		for libdir in $@; do
+			has $libdir ${libdirs[@]} || die -q "invalid libdir '$libdir'!"
+		done
+		libdirs=( $@ )
+	fi
+
+	for libdir in ${libdirs[@]}; do
+		[[ ! -d ${EROOT}/usr/$libdir ]] && continue
+		[[ ! -r ${EROOT}/etc/env.d/blas/${libdir}/config ]] && continue
+		cur=$(load_config ${EROOT}/etc/env.d/blas/${libdir}/config CURRENT)
+		echo ${libdir}: $cur
+	done
+}
+
+### list action
+do_list() {
+	local i cur targets
+	local libdir libdirs=( $(list_libdirs) )
+
+	# if manually specified libdirs
+	if [[ ! $# -eq 0 ]]; then
+		for libdir in $@; do
+			has $libdir ${libdirs[@]} || die -q "invalid libdir '$libdir'!"
+		done
+		libdirs=( $@ )
+	fi
+	
+	for libdir in ${libdirs[@]}; do
+		[[ ! -d ${EROOT}/usr/$libdir ]] || [[ -L ${EROOT}/usr/$libdir ]] && continue
+		targets=( $(find_targets_in $libdir) )
+		cur=$(load_config ${EROOT}/etc/env.d/blas/${libdir}/config CURRENT)
+
+		write_list_start "Available BLAS/CBLAS ($libdir) candidates:"
+		for (( i = 0; i < ${#targets[@]}; i++ )); do
+			[[ ${targets[i]} = $cur ]] \
+			&& targets[i]=$(highlight_marker "${targets[i]}")
+		done
+		write_numbered_list -m "(none found)" "${targets[@]}"
+	done
+}
+
+### validate action
+describe_validate() {
+	echo "validate candidates and remove invalid ones"
+}
+
+do_validate() {
+	local i ldpath targets target candidate
+	local libdir libdirs=( $(list_libdirs) )
+	for libdir in ${libdirs[@]}; do
+		[[ ! -d ${EROOT}/usr/$libdir ]] || [[ -L ${EROOT}/usr/$libdir ]] && continue
+		targets=( $(find_targets_in $libdir) )
+		for target in ${targets[@]}; do
+			candidate=${EROOT}/etc/env.d/blas/${libdir}/${target}
+			ldpath=$(load_config $candidate LDPATH)
+			if ! validate_blaslibdir $ldpath; then
+				echo "Removing invalid BLAS/CBLAS candidate ($candidate) ..."
+				rm -v $candidate
+			fi
+		done
+	done
+}
+
+### set action
+
+describe_set() {
+        echo "Activate one of the installed $MODULE implementations"
+}
+
+describe_set_parameters() {
+        echo "[<libdir>] <implementation>"
+}
+
+describe_set_options() {
+	echo "libdir: lib64 or lib32. Will use the native one when omitted."
+        echo "implementation : implementation name or number (from 'list' action)"
+}
+
+do_set() {
+	local libdirs=( $(list_libdirs) )
+	local targets libdir ldconf libpath impl
+
+	# check argument existence
+	[[ $# -eq 1 ]] || [[ $# -eq 2 ]] || \
+		die -q "Please specify [<libdir>] <impl> to activate!"
+	# read argumenets
+	if [[ $# -eq 2 ]]; then libdir="$1"; else libdir="$(get_libdir)"; fi
+	if [[ $# -eq 2 ]]; then impl="$2"; else impl="$1"; fi
+	# validate arguments
+	has "$libdir" "${libdirs[@]}" || die -q "Invalid libdir ($libdir) !"
+	targets=( $(find_targets_in $libdir) )
+	if ! has "$impl" "${targets[@]}"; then
+		if [[ ${impl} -gt 0 ]] && [[ ${impl} -le ${#targets[@]} ]]; then
+			impl=${targets[(${impl} - 1)]}
+		else
+			die -q "Invalid impl ($impl) !"
+		fi
+	fi
+	# store the configuration to env.d
+	store_config ${EROOT}/etc/env.d/blas/${libdir}/config CURRENT "${impl}"
+	# generate ld.so.conf file
+	ldconf="${EROOT}/etc/ld.so.conf.d/81-blas-${libdir}.conf"
+	libpath=$(load_config ${EROOT}/etc/env.d/blas/${libdir}/${impl} LDPATH)
+	truncate -s0 $ldconf
+	echo "# Auto-generated by eselect::blas. DON'T EDIT." >> $ldconf
+	echo "$libpath" >> $ldconf
+
+	# refresh cache. env-update will call ldconfig (see
+	# portage::env_update.py) so we don't need to call it explicitly.
+	env-update
+}
+
+### add action
+describe_add_parameters() {
+	echo "<libdir> <dir> <impl>"
+}
+
+describe_add_options() {
+	echo "libdir : library directory where $MODULE implementation is installed (lib, lib64, etc.)"
+	echo "dir : directory containing lib{,c}blas.so{.3}"
+	echo "impl : name of the $MODULE implementation"
+}
+
+do_add() {
+	[[ $# -eq 3 ]] \
+		|| die -q "Please specify <libdir> <dir> <impl> to activate!"
+	validate_blaslibdir $2 || die -q "invalid blas libdir!"
+	store_config ${EROOT}/etc/env.d/blas/$1/$3 LDPATH $2
+}
diff --git a/app-eselect/eselect-blas/files/blas.eselect.5 b/app-eselect/eselect-blas/files/blas.eselect.5
index c9df9fde8d7f..9779268bc65b 100644
--- a/app-eselect/eselect-blas/files/blas.eselect.5
+++ b/app-eselect/eselect-blas/files/blas.eselect.5
@@ -1,22 +1,22 @@
-.TH "ESELECT" "5" "June 2006" "Gentoo Linux" "eselect"
+.TH "ESELECT" "5" "June 2019" "Gentoo Linux" "eselect"
 .SH "NAME"
 blas.eselect \- The BLAS management module for Gentoo's eselect
 .SH "SYNOPSIS"
 \fBeselect blas\fR [\fBhelp\fR|\fBusage\fR]
 .br 
-\fBeselect blas\fR \fBlist\fR [\fIoptions\fR]
+\fBeselect blas\fR \fBlist\fR [\fIlibdir\fR]
 .br 
 \fBeselect blas\fR \fBadd\fR
 .br 
-\fBeselect blas\fR \fBset\fR \fIimplementation\fR [\fIoptions\fR]
+\fBeselect blas\fR \fBset\fR  [\fIlibdir\fR] \fIimplementation\fR
 .br 
-\fBeselect blas\fR \fBshow\fR [\fIoptions\fR]
+\fBeselect blas\fR \fBshow\fR [\fIlibdir\fR]
 
 .SH "DESCRIPTION"
 \fBeselect\fR is Gentoo's configuration and management tool. It features
 modules that care for the individual administrative tasks.
 .SH "ACTION: LIST"
-\fBeselect blas list\fR [\fIoptions\fR]
+\fBeselect blas list\fR [\fIlibdir\fR]
 .br 
 Displays an ordered list of installed BLAS implementations. It distinguishes between versions with different
 Application Binary Interfaces (e.g. x86/AMD64). Furthermore, it also distinguishes
@@ -31,7 +31,7 @@ Installed BLAS for libdir \fBlib\fR
   [1]   atlas *
   [2]   reference
 
-Possible \fIoptions\fR to the \fBlist\fR action are restrictions to
+Possible \fIlibdir\fR to the \fBlist\fR action are restrictions to
 handle only certain ABI\-specific library directories. For example,
  
 \fBeselect blas list lib64\fR
@@ -39,7 +39,7 @@ handle only certain ABI\-specific library directories. For example,
 lists only BLAS implementations found in \fB/usr/lib64\fR.
 
 .SH "ACTION: SHOW"
-\fBeselect blas show\fR [\fIoptions\fR]
+\fBeselect blas show\fR [\fIlibdir\fR]
 .br 
 Shows your system's currently active BLAS implementations.
 
@@ -49,17 +49,31 @@ lib: atlas
 .br
 lib64: reference
 
-The same \fIoptions\fR that apply to the \fBlist\fR action can be used
+The same \fIlibdir\fR that apply to the \fBlist\fR action can be used
 with the \fBshow\fR action to restrict it to given ABIs.
 .SH "ACTION: SET"
-\fBeselect blas set\fR \fIimplementation\fR [\fIoptions\fR]
+\fBeselect blas set\fR [\fIlibdir\fR] \fIimplementation\fR
 .br 
 Sets your system's currently active BLAS implementations to \fIimplementation\fR. 
-The same \fIoptions\fR that apply to the \fBlist\fR action can be used
+The same \fIlibdir\fR that apply to the \fBlist\fR action can be used
 with the \fBset\fR action to restrict it to given ABIs.
 
 phi / # eselect blas set atlas
+
+.SH "ACTION: VALIDATE"
+\fBeselect blas validate\fR
+.br
+Validates BLAS/CBLAS candidates under the /etc/env.d directory and automatically
+remove the invalid ones.
+
+.SH "ACTION: ADD"
+\fBeselect blas add\fR \fIlibdir\fR \fIdir\fR \fIimpl\fR
+.br
+Add a new BLAS/CBLAS implementation.
+
 .SH "AUTHOR"
 Danny van Dyk <kugelfang@gentoo.org>
 .br
 Donnie Berkholz <spyderous@gentoo.org>
+.br
+Mo Zhou <lumin@debian.org>