Hey all,
I've been using Bazel (https://bazel.build/) to build TensorFlow for a
while now. Here is a bazel.eclass I'd like to commit to make it easier
for packages that use it to build. It's basically bits that I've
refactored out of the TensorFlow ebuild that would be useful to other
packages as well. I have a bump to sci-libs/tensorflow-1.12.0 prepared
that uses this eclass and have tested a full install.
-- Jason
# Copyright 1999-2018 Jason Zaman
# Distributed under the terms of the GNU General Public License v2
# @ECLASS: bazel.eclass
# @MAINTAINER:
# Jason Zaman <perfin...@gentoo.org>
# @AUTHOR:
# Jason Zaman <perfin...@gentoo.org>
# @BLURB: Utility functions for packages using Bazel Build
# @DESCRIPTION:
# A utility eclass providing functions to run the Bazel Build system.
#
# This eclass does not export any phase functions.
case "${EAPI:-0}" in
0|1|2|3|4|5|6)
die "Unsupported EAPI=${EAPI:-0} (too old) for ${ECLASS}"
;;
7)
;;
*)
die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}"
;;
esac
if [[ ! ${_BAZEL_ECLASS} ]]; then
inherit multiprocessing toolchain-funcs
BDEPEND=">=dev-util/bazel-0.19"
# @FUNCTION: bazel_get_flags
# @DESCRIPTION:
# Obtain and print the bazel flags for target and host *FLAGS.
#
# To add more flags to this, append the flags to the
# appropriate variable before calling this function
bazel_get_flags() {
local i fs=()
for i in ${CFLAGS}; do
fs+=( "--conlyopt=${i}" )
done
for i in ${BUILD_CFLAGS}; do
fs+=( "--host_conlyopt=${i}" )
done
for i in ${CXXFLAGS}; do
fs+=( "--cxxopt=${i}" )
done
for i in ${BUILD_CXXFLAGS}; do
fs+=( "--host_cxxopt=${i}" )
done
for i in ${CPPFLAGS}; do
fs+=( "--conlyopt=${i}" "--cxxopt=${i}" )
done
for i in ${BUILD_CPPFLAGS}; do
fs+=( "--host_conlyopt=${i}" "--host_cxxopt=${i}" )
done
for i in ${LDFLAGS}; do
fs+=( "--linkopt=${i}" )
done
for i in ${BUILD_LDFLAGS}; do
fs+=( "--host_linkopt=${i}" )
done
echo "${fs[*]}"
}
# @FUNCTION: bazel_setup_bazelrc
# @DESCRIPTION:
# Creates the bazelrc with common options that will be passed
# to bazel. This will be called by ebazel automatically so
# does not need to be called from the ebuild.
bazel_setup_bazelrc() {
if [[ -f "${T}/bazelrc" ]]; then
return
fi
# F: fopen_wr
# P: /proc/self/setgroups
# Even with standalone enabled, the Bazel sandbox binary is run for
feature test:
#
https://github.com/bazelbuild/bazel/blob/7b091c1397a82258e26ab5336df6c8dae1d97384/src/main/java/com/google/devtools/build/lib/sandbox/LinuxSandboxedSpawnRunner.java#L61
#
https://github.com/bazelbuild/bazel/blob/76555482873ffcf1d32fb40106f89231b37f850a/src/main/tools/linux-sandbox-pid1.cc#L113
addpredict /proc
mkdir -p "${T}/bazel-cache" || die
mkdir -p "${T}/bazel-distdir" || die
cat > "${T}/bazelrc" <<-EOF || die
startup --batch
# dont strip HOME, portage sets a temp per-package dir
build --action_env HOME
# make bazel respect MAKEOPTS
build --jobs=$(makeopts_jobs)
build --compilation_mode=opt --host_compilation_mode=opt
# FLAGS
build $(bazel_get_flags)
# Use standalone strategy to deactivate the bazel sandbox, since it
# conflicts with FEATURES=sandbox.
build --spawn_strategy=standalone --genrule_strategy=standalone
test --spawn_strategy=standalone --genrule_strategy=standalone
build --strip=never
build --verbose_failures --noshow_loading_progress
test --verbose_test_summary --verbose_failures --noshow_loading_progress
# make bazel only fetch distfiles from the cache
fetch --repository_cache="${T}/bazel-cache/"
--distdir="${T}/bazel-distdir/"
build --repository_cache="${T}/bazel-cache/"
--distdir="${T}/bazel-distdir/"
build --define=PREFIX=${EPREFIX%/}/usr
build --define=LIBDIR=\$(PREFIX)/$(get_libdir)
EOF
tc-is-cross-compiler || \
echo "build --nodistinct_host_configuration" >> "${T}/bazelrc"
|| die
}
# @FUNCTION: ebazel
# @USAGE: [<args>...]
# @DESCRIPTION:
# Run bazel with the bazelrc and output_base.
#
# If $MULTIBUILD_VARIANT is set, this will make an output_base
# specific to that variant.
# bazel_setup_bazelrc will be called and the created bazelrc
# will be passed to bazel.
#
# Will automatically die if bazel does not exit cleanly.
ebazel() {
bazel_setup_bazelrc
# Use different build folders for each multibuild variant.
local base_suffix="${MULTIBUILD_VARIANT+-}${MULTIBUILD_VARIANT}"
local output_base="${WORKDIR}/bazel-base${base_suffix}"
mkdir -p "${output_base}" || die
einfo Running: bazel --output_base="${output_base}" "$@"
bazel --bazelrc="${T}/bazelrc" --output_base="${output_base}" $@ || die
"ebazel $@"
}
# @FUNCTION: bazel_load_distfiles
# @USAGE: <distfiles>...
# @DESCRIPTION:
# Populate the bazel distdir to fetch from since it cannot use
# the network. Bazel looks in distdir but will only look for the
# original filename, not the possibly renamed one that portage
# downloaded. If the line has -> we to rename it back. This also
# handles use-conditionals that SRC_URI does.
#
# Example:
# @CODE
# bazel_external_uris="http://a/file-2.0.tgz
# python? ( http://b/1.0.tgz -> foo-1.0.tgz )"
# SRC_URI="http://c/${PV}.tgz
# ${bazel_external_uris}"
#
# src_unpack() {
# unpack ${PV}.tgz
# bazel_load_distfiles "${bazel_external_uris}"
# }
# @CODE
bazel_load_distfiles() {
local src dst uri rename
[[ "$@" ]] || die "Missing args"
mkdir -p "${T}/bazel-distdir" || die
while read uri rename dst; do
src="${uri##*/}"
[[ -z $src ]] && continue
if [[ "$rename" != "->" ]]; then
dst="${src}"
fi
[[ ${A} =~ ${dst} ]] || continue
if [[ "$dst" == "$src" ]]; then
einfo "Copying $dst to bazel distdir ..."
else
einfo "Copying $dst to bazel distdir $src ..."
fi
dst="$(readlink -f "${DISTDIR}/${dst}")"
ln -s "${dst}" "${T}/bazel-distdir/${src}" || die
done <<< "$(sed -re 's/!?[A-Za-z]+\?\s+\(\s*//g; s/\s+\)//g' <<< "$@")"
}
_BAZEL_ECLASS=1
fi
