dev-util/bpftool: add rewritten live ebuild for Github-based bpftool mirror

This new ebuild for bpftool gets rid of the fragile kernel-tree
based build and uses the Github-based mirror repository.
Unlike the previous ebuilds it allows well-defined version upgrades
and optionally makes bundling a newer, properly versioned libbpf
easy and reproducible. No more mystery meat!

Closes: https://bugs.gentoo.org/941248
Signed-off-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 124 insertions, 0 deletions

diff --git a/dev-util/bpftool/bpftool-9999.ebuild b/dev-util/bpftool/bpftool-9999.ebuild
new file mode 100644
index 000000000000..03f97becf881
--- /dev/null
+++ b/dev-util/bpftool/bpftool-9999.ebuild
@@ -0,0 +1,121 @@
+# Copyright 2021-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( {15..19} )
+LLVM_OPTIONAL=1
+PYTHON_COMPAT=( python3_{10..13} )
+
+inherit bash-completion-r1 linux-info llvm-r1 optfeature python-any-r1 toolchain-funcs
+
+DESCRIPTION="Tool for inspection and simple manipulation of eBPF programs and maps"
+HOMEPAGE="https://github.com/libbpf/bpftool"
+
+if [[ ${PV} == *9999* ]] ; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/libbpf/bpftool.git"
+	EGIT_SUBMODULES=(libbpf)
+else
+	# bpftool typically vendors whatever libbpf is current at the time
+	# of a release, while libbpf publishes minor updates more frequently.
+	# Uncomment the following to bundle an updated libbpf e.g. in case of
+	# security or crasher bugs in libbpf and to keep the two synchronized.
+	# This allows us to quickly update the vendored lib with a revbump.
+	# Currently bpftool-x.y vendors libbpf-1.y; DO NOT mix different y versions.
+	# See the libbpf repo (https://github.com/libbpf/libbpf) for possible updates.
+	# LIBBPF_VERSION=1.5.0
+
+	if [[ ! -z ${LIBBPF_VERSION} ]] ; then
+		SRC_URI="https://github.com/libbpf/bpftool/archive/refs/tags/v${PV}.tar.gz -> bpftool-${PV}.tar.gz
+			https://github.com/libbpf/libbpf/archive/refs/tags/v${LIBBPF_VERSION}.tar.gz
+			  -> libbpf-${LIBBPF_VERSION}.tar.gz"
+	else
+		# use tarball with bundled libbpf
+		SRC_URI="https://github.com/libbpf/bpftool/releases/download/v${PV}/bpftool-libbpf-v${PV}-sources.tar.gz"
+		S="${WORKDIR}/bpftool-libbpf-v${PV}-sources"
+	fi
+
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~ppc ~ppc64 ~riscv ~x86"
+fi
+
+LICENSE="|| ( GPL-2 BSD-2 )"
+SLOT="0"
+IUSE="caps llvm"
+REQUIRED_USE="llvm? ( ${LLVM_REQUIRED_USE} )"
+
+RDEPEND="
+	caps? ( sys-libs/libcap:= )
+	llvm? ( $(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}') )
+	!llvm? ( sys-libs/binutils-libs:= )
+	sys-libs/zlib:=
+	virtual/libelf:=
+"
+DEPEND="
+	${RDEPEND}
+	>=sys-kernel/linux-headers-5.8
+"
+BDEPEND="
+	${PYTHON_DEPS}
+	app-arch/tar
+	dev-python/docutils
+"
+
+CONFIG_CHECK="~DEBUG_INFO_BTF"
+
+pkg_setup() {
+	python-any-r1_pkg_setup
+	use llvm && llvm-r1_pkg_setup
+}
+
+src_prepare() {
+	default
+
+	# prepare libbpf if necessary
+	if [[ ! -z ${LIBBPF_VERSION} ]] ; then
+		rm -rf libbpf || die
+		ln -s "${WORKDIR}/libbpf-${LIBBPF_VERSION}" libbpf || die
+	fi
+
+	# remove -Werror from libbpf (bug 887981)
+	sed -i -e 's/\-Werror//g' libbpf/src/Makefile || die
+
+	# remove -Werror from bpftool feature detection
+	sed -i -e 's/-Werror//g' src/Makefile.feature || die
+
+	# remove hardcoded/unhelpful flags from bpftool
+	sed -i -e '/CFLAGS += -O2/d' -e 's/-W //g' -e 's/-Wextra //g' src/Makefile || die
+
+	# Use rst2man or rst2man.py depending on which one exists (#930076)
+	type -P rst2man >/dev/null || sed -i -e 's/rst2man/rst2man.py/g' docs/Makefile || die
+}
+
+bpftool_make() {
+	tc-export AR CC LD
+
+	emake \
+		ARCH="$(tc-arch-kernel)" \
+		HOSTAR="$(tc-getBUILD_AR)" \
+		HOSTCC="$(tc-getBUILD_CC)" \
+		HOSTLD="$(tc-getBUILD_LD)" \
+		bash_compdir="$(get_bashcompdir)" \
+		feature-libcap="$(usex caps 1 0)" \
+		feature-llvm="$(usex llvm 1 0)" \
+		prefix="${EPREFIX}"/usr \
+		V=1 \
+		"$@"
+}
+
+src_compile() {
+	bpftool_make -C src
+	bpftool_make -C docs
+}
+
+src_install() {
+	bpftool_make DESTDIR="${D}" -C src install
+	bpftool_make mandir="${ED}"/usr/share/man -C docs install
+}
+
+pkg_postinst() {
+	optfeature "clang-bpf-co-re support" sys-devel/clang[llvm_targets_BPF]
+}
diff --git a/dev-util/bpftool/metadata.xml b/dev-util/bpftool/metadata.xml
index a09ffc7b9425..1e8c354ad0e2 100644
--- a/dev-util/bpftool/metadata.xml
+++ b/dev-util/bpftool/metadata.xml
@@ -13,4 +13,7 @@
 		<flag name="caps">Use <pkg>sys-libs/libcap</pkg> to enable unprivileged run support</flag>
 		<flag name="llvm">Use <pkg>sys-devel/llvm</pkg> instead of libbfd (<pkg>sys-libs/binutils-libs</pkg>) for JIT disassembly</flag>
 	</use>
+	<upstream>
+		<remote-id type="github">libbpf/bpftool</remote-id>
+	</upstream>
 </pkgmetadata>