rebar3.eclass: new eclass for dev-util/rebar:3

Signed-off-by: Anna (cybertailor) Vyalkova <cyber+gentoo@sysrq.in>

1 files changed, 295 insertions, 0 deletions

diff --git a/eclass/rebar3.eclass b/eclass/rebar3.eclass
new file mode 100644
index 000000000..4104bdcf6
--- /dev/null
+++ b/eclass/rebar3.eclass
@@ -0,0 +1,295 @@
+# Copyright 1999-2023 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# @ECLASS: rebar3.eclass
+# @MAINTAINER:
+# Anna (cybertailor) Vyalkova <cyber+gentoo@sysrq.in>
+# @AUTHOR:
+# Amadeusz Żołnowski <aidecoe@gentoo.org>
+# @SUPPORTED_EAPIS: 8
+# @BLURB: Build Erlang/OTP projects using dev-util/rebar:3.
+# @DESCRIPTION:
+# An eclass providing functions to build Erlang/OTP projects using
+# dev-util/rebar:3.
+#
+# rebar is a tool which tries to resolve dependencies itself which is by
+# cloning remote git repositories. Dependent projects are usually expected to
+# be in sub-directory 'deps' rather than looking at system Erlang lib
+# directory. Projects relying on rebar usually don't have 'install' make
+# targets. The eclass workarounds some of these problems. It handles
+# installation in a generic way for Erlang/OTP structured projects.
+
+case ${EAPI} in
+	8) ;;
+	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
+esac
+
+if [[ -z ${_REBAR3_ECLASS} ]]; then
+
+inherit edo
+
+RDEPEND="dev-lang/erlang:="
+DEPEND="${RDEPEND}"
+BDEPEND="
+	dev-util/rebar:3
+	>=sys-apps/gawk-4.1
+"
+
+# @ECLASS_VARIABLE: REBAR_PROFILE
+# @DESCRIPTION:
+# Rebar profile to use.
+: "${REBAR_PROFILE:=default}"
+
+# @ECLASS_VARIABLE: REBAR_APP_SRC
+# @DESCRIPTION:
+# Relative path to .app.src description file.
+: "${REBAR_APP_SRC:=src/${PN}.app.src}"
+
+# @FUNCTION: get_erl_libs
+# @RETURN: the path to Erlang lib directory
+# @DESCRIPTION:
+# Get the full path without EPREFIX to Erlang lib directory.
+get_erl_libs() {
+	echo "/usr/$(get_libdir)/erlang/lib"
+}
+
+# @FUNCTION: _rebar_find_dep
+# @INTERNAL
+# @USAGE: <project_name>
+# @RETURN: 0 success, 1 dependency not found, 2 multiple versions found
+# @DESCRIPTION:
+# Find a Erlang package/project by name in Erlang lib directory. Project
+# directory is usually suffixed with version. It is matched to '<project_name>'
+# or '<project_name>-*'.
+_rebar_find_dep() {
+	local pn="${1}"
+	local p
+	local result
+
+	pushd "${EPREFIX}/$(get_erl_libs)" >/dev/null || return 1
+	for p in ${pn} ${pn}-*; do
+		if [[ -d ${p} ]]; then
+			# Ensure there's at most one matching.
+			[[ ${result} ]] && return 2
+			result="${p}"
+		fi
+	done
+	popd >/dev/null || die
+
+	[[ ${result} ]] || return 1
+	echo "${result}"
+}
+
+# @FUNCTION: rebar_disable_coverage
+# @USAGE: [<rebar_config>]
+# @DESCRIPTION:
+# Disable coverage in rebar.config. This is a workaround for failing coverage.
+# Coverage is not relevant in this context, so there's no harm to disable it,
+# although the issue should be fixed.
+rebar_disable_coverage() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local rebar_config="${1:-rebar.config}"
+
+	sed -e 's/{cover_enabled, true}/{cover_enabled, false}/' \
+		-i "${rebar_config}" \
+		|| die "failed to disable coverage in ${rebar_config}"
+}
+
+# @FUNCTION: erebar3
+# @USAGE: <targets>
+# @DESCRIPTION:
+# Run rebar with verbose flag. Die on failure.
+erebar3() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	(( $# > 0 )) || die "erebar: at least one target is required"
+
+	case ${1} in
+		eunit|ct)
+			local -x ERL_LIBS="." ;;
+		*)
+			local -x ERL_LIBS="${EPREFIX}/$(get_erl_libs)" ;;
+	esac
+
+	edo rebar3 "$@"
+}
+
+# @FUNCTION: rebar_fix_include_path
+# @USAGE: <project_name> [<rebar_config>]
+# @DESCRIPTION:
+# Fix path in rebar.config to 'include' directory of dependent project/package,
+# so it points to installation in system Erlang lib rather than relative 'deps'
+# directory.
+#
+# <rebar_config> is optional. Default is 'rebar.config'.
+#
+# The function dies on failure.
+rebar_fix_include_path() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local pn="${1}"
+	local rebar_config="${2:-rebar.config}"
+	local erl_libs="${EPREFIX}/$(get_erl_libs)"
+	local p
+
+	p="$(_rebar_find_dep "${pn}")" \
+		|| die "failed to unambiguously resolve dependency of '${pn}'"
+
+	gawk -i inplace \
+		-v erl_libs="${erl_libs}" -v pn="${pn}" -v p="${p}" '
+/^{[[:space:]]*erl_opts[[:space:]]*,/, /}[[:space:]]*\.$/ {
+	pattern = "\"(./)?deps/" pn "/include\"";
+	if (match($0, "{i,[[:space:]]*" pattern "[[:space:]]*}")) {
+		sub(pattern, "\"" erl_libs "/" p "/include\"");
+	}
+	print $0;
+	next;
+}
+1
+' "${rebar_config}" || die "failed to fix include paths in ${rebar_config} for '${pn}'"
+}
+
+# @FUNCTION: rebar_remove_deps
+# @USAGE: [<rebar_config>]
+# @DESCRIPTION:
+# Remove dependencies list from rebar.config and deceive build rules that any
+# dependencies are already fetched and built. Otherwise rebar tries to fetch
+# dependencies and compile them.
+#
+# <rebar_config> is optional. Default is 'rebar.config'.
+#
+# The function dies on failure.
+rebar_remove_deps() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local rebar_config="${1:-rebar.config}"
+
+	mkdir -p "${S}/deps" && :>"${S}/deps/.got" && :>"${S}/deps/.built" || die
+	gawk -i inplace '
+/^{[[:space:]]*deps[[:space:]]*,/, /}[[:space:]]*\.$/ {
+	if ($0 ~ /}[[:space:]]*\.$/) {
+		print "{deps, []}.";
+	}
+	next;
+}
+1
+' "${rebar_config}" || die "failed to remove deps from ${rebar_config}"
+}
+
+# @FUNCTION: rebar_set_vsn
+# @USAGE: [<version>]
+# @DESCRIPTION:
+# Set version in project description file if it's not set.
+#
+# <version> is optional. Default is PV stripped from version suffix.
+#
+# The function dies on failure.
+rebar_set_vsn() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local version="${1:-${PV%_*}}"
+
+	sed -e "s/vsn, git/vsn, \"${version}\"/" \
+		-i "${S}/${REBAR_APP_SRC}" \
+		|| die "failed to set version in src/${PN}.app.src"
+}
+
+# @FUNCTION: rebar3_src_prepare
+# @DESCRIPTION:
+# Prevent rebar from fetching and compiling dependencies. Set version in
+# project description file if it's not set.
+#
+# Existence of rebar.config is optional, but file description file must exist
+# at 'src/${PN}.app.src'.
+rebar3_src_prepare() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	default_src_prepare
+	rebar_set_vsn
+	rm -f rebar.lock
+	if [[ -f rebar.config ]]; then
+		rebar_disable_coverage
+		rebar_remove_deps
+	fi
+}
+
+# @FUNCTION: rebar3_src_configure
+# @DESCRIPTION:
+# Configure with ERL_LIBS set.
+rebar3_src_configure() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local -x ERL_LIBS="${EPREFIX}/$(get_erl_libs)"
+	default_src_configure
+}
+
+# @FUNCTION: rebar3_src_compile
+# @DESCRIPTION:
+# Compile project with rebar.
+rebar3_src_compile() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	erebar3 as "${REBAR_PROFILE}" release --all
+}
+
+# @FUNCTION: rebar3_src_test
+# @DESCRIPTION:
+# Run unit tests.
+rebar3_src_test() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	erebar3 eunit -v
+}
+
+# @FUNCTION: rebar3_install_lib
+# @USAGE: <dir>
+# @DESCRIPTION:
+# Install BEAM files, include headers and native libraries.
+#
+# Function expects that project conforms to Erlang/OTP structure.
+rebar3_install_lib() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local dest="$(get_erl_libs)/${P}"
+	insinto "${dest}"
+
+	pushd "${1?}" >/dev/null || die
+	for dir in ebin include priv; do
+		if [[ -d ${dir} && ! -L ${dir} ]]; then
+			cp -pR ${dir} "${ED%/}/${dest}/" || die "failed to install ${dir}/"
+		fi
+	done
+	popd >/dev/null || die
+}
+
+# @FUNCTION: rebar3_src_install
+# @DESCRIPTION:
+# Install built release or library.
+#
+# Function expects that project conforms to Erlang/OTP structure.
+rebar3_src_install() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	pushd "_build/${REBAR_PROFILE}" >/dev/null || die
+	if [[ -d rel/${PN} ]]; then
+		if ! declare -f rebar3_install_release >/dev/null; then
+			die "${FUNCNAME}: a custom function named 'rebar3_install_release' is required to install a release"
+		fi
+		pushd rel/${PN} >/dev/null || die
+		rebar3_install_release || die
+		popd >/dev/null || die
+	elif [[ -d lib/${PN} ]]; then
+		rebar3_install_lib lib/${PN}
+	else
+		die "No releases or libraries to install"
+	fi
+	popd >/dev/null || die
+
+	einstalldocs
+}
+
+_REBAR3_ECLASS=1
+fi
+
+EXPORT_FUNCTIONS src_prepare src_compile src_test src_install