# Copyright 1999-2020 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

EAPI="7"

inherit flag-o-matic linux-mod

if [[ "${PV}" == "9999" ]]; then
	inherit git-r3
	EGIT_REPO_URI="https://github.com/dynup/${PN}.git"
else
	SRC_URI="https://github.com/dynup/${PN}/archive/v${PV}.tar.gz -> ${P}.tar.gz"
	KEYWORDS="~amd64"
fi

DESCRIPTION="Dynamic kernel patching for Linux"
HOMEPAGE="https://github.com/dynup/kpatch"

LICENSE="GPL-2+"
SLOT="0"
IUSE="+kpatch-build +kpatch kmod doc contrib test"
RESTRICT="!test? ( test )"

RDEPEND="
	app-crypt/pesign
	dev-libs/openssl:0=
	sys-libs/zlib
	sys-apps/pciutils
"

DEPEND="
	${RDEPEND}
	dev-libs/elfutils
	sys-devel/bison
	test? ( dev-util/shellcheck-bin )
"

pkg_setup() {
	if use kmod; then
		if kernel_is gt 3 9 0; then
			if ! linux_config_exists; then
				eerror "Unable to check the currently running kernel for kpatch support"
				eerror "Please be sure a .config file is available in the kernel src dir"
				eerror "and ensure the kernel has been built."
			else
				# Fail to build if these kernel options are not enabled (see kpatch/kmod/core/Makefile)
				CONFIG_CHECK="FUNCTION_TRACER HAVE_FENTRY MODULES SYSFS KALLSYMS_ALL"
				ERROR_FUNCTION_TRACER="CONFIG_FUNCTION_TRACER must be enabled in the kernel's config file"
				ERROR_HAVE_FENTRY="CONFIG_HAVE_FENTRY must be enabled in the kernel's config file"
				ERROR_MODULES="CONFIG_MODULES must be enabled in the kernel's config file"
				ERROR_SYSFS="CONFIG_SYSFS must be enabled in the kernel's config file"
				ERROR_KALLSYMS_ALL="CONFIG_KALLSYMS_ALL must be enabled in the kernel's config file"
			fi
		else
			eerror
			eerror "kpatch is not available for Linux kernels below 4.0.0"
			eerror
			die "Upgrade the kernel sources before installing kpatch."
		fi
	check_extra_config
	fi

}

src_prepare() {
	replace-flags '-O?' '-O1'
	default
}

src_compile() {
	use kpatch-build && emake -C kpatch-build
	use kpatch && emake -C kpatch
	use kmod && set_arch_to_kernel && emake -C kmod
	use doc && emake -C doc
	use contrib && emake -C contrib
	use test && emake check
}

src_install() {
	use kpatch-build && emake DESTDIR="${D}" PREFIX="/usr" install -C kpatch-build
	use kpatch && emake DESTDIR="${D}" PREFIX="/usr" install -C kpatch
	use kmod && set_arch_to_kernel && emake DESTDIR="${D}" PREFIX="/usr" install -C kmod
	use contrib && emake DESTDIR="${D}" PREFIX="/usr" install -C contrib
	use doc && einstalldocs
}