[gentoo-dev] Re: [PATCH v2] libretro-core.eclass: An eclass to streamline the construction of Libretro core ebuilds

[Craig Andrews]

On 09.08.2018 16:58, Craig Andrews wrote:
> I'm proposing the addition of a new eclass,  libretro-core.eclass,
> which I'll use when adding a number of libretro ebuilds.
>
> This version incorporates all the changes and suggestions posed so far.
>
> The pull request which includes this eclass as well as a few ebuilds
> using it (with more to come) can be found at
> https://github.com/gentoo/gentoo/pull/9330
>
> Thanks,
> ~Craig
>
> ---
>  eclass/libretro-core.eclass | 197 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 197 insertions(+)
>  create mode 100644 eclass/libretro-core.eclass
>
> diff --git a/eclass/libretro-core.eclass b/eclass/libretro-core.eclass
> new file mode 100644
> index 000000000000..510f905111ce
> --- /dev/null
> +++ b/eclass/libretro-core.eclass
> @@ -0,0 +1,197 @@
> +# Copyright 1999-2018 Gentoo Foundation
> +# Distributed under the terms of the GNU General Public License v2
> +
> +# @ECLASS: libretro-core.eclass
> +# @MAINTAINER:
> +# candrews@g.o
> +# @AUTHOR:
> +# Cecil Curry <leycec@×××××.com>
> +# Craig Andrews <candrews@g.o>
> +# @BLURB: Simplify libretro core ebuilds
> +# @DESCRIPTION:
> +# The libretro eclass is designed to streamline the construction of
> +# ebuilds for Libretro core ebuilds.
> +#
> +# Libretro cores can be found under https://github.com/libretro/
> +#
> +# They all use the same basic make based build system, are located
> +# in the same github account, and do not release named or numbered
> +# versions (so ebuild versions for git commits are keys).
> +# This eclass covers those commonalities reducing much duplication
> +# between the ebuilds.
> +# @EXAMPLE:
> +# @CODE
> +# EAPI=7
> +#
> +# LIBRETRO_CORE_NAME="2048"
> +# LIBRETRO_COMMIT_SHA="45655d3662e4cbcd8afb28e2ee3f5494a75888de"
> +# KEYWORDS="~amd64 ~x86"
> +# inherit libretro-core
> +#
> +# DESCRIPTION="Port of 2048 puzzle game to the libretro API"
> +# LICENSE="Unlicense"
> +# SLOT="0"
> +# @CODE
> +
> +if [[ -z ${_LIBRETRO_CORE_ECLASS} ]]; then
> +_LIBRETRO_CORE_ECLASS=1
> +
> +IUSE="debug"
> +
> +# @ECLASS-VARIABLE: LIBRETRO_CORE_NAME
> +# @REQUIRED
> +# @DESCRIPTION:
> +# Name of this Libretro core. The libretro-core_src_install() phase
> function
> +# will install the shared library
> "${S}/${LIBRETRO_CORE_NAME}_libretro.so" as a
> +# Libretro core. Defaults to the name of the current package excluding
> the
> +# "libretro-" prefix (e.g., "mgba" for the package "libretro-mgba").
> +: ${LIBRETRO_CORE_NAME:=${PN#libretro-}}
> +
> +# @ECLASS-VARIABLE: LIBRETRO_COMMIT_SHA
> +# @DESCRIPTION:
> +# Commit SHA used for SRC_URI will die if not set in <9999 ebuilds.
> +# Needs to be set before inherit.
> +
> +# @ECLASS-VARIABLE: LIBRETRO_REPO_NAME
> +# @REQUIRED
> +# @DESCRIPTION:
> +# Contains the real repo name of the core formatted as
> "repouser/reponame".
> +# Needs to be set before inherit. Otherwise defaults to
> "libretro/${PN}"
> +: ${LIBRETRO_REPO_NAME:="libretro/libretro-${LIBRETRO_CORE_NAME}"}
> +
> +: ${HOMEPAGE:="https://github.com/${LIBRETRO_REPO_NAME}"}
> +
> +if [[ ${PV} == *9999 ]]; then
> +	: ${EGIT_REPO_URI:="https://github.com/${LIBRETRO_REPO_NAME}.git"}
> +	inherit git-r3
> +else
> +	[[ -z "${LIBRETRO_COMMIT_SHA}" ]] && die "LIBRETRO_COMMIT_SHA must
> be set before inherit."
> +	S="${WORKDIR}/${LIBRETRO_REPO_NAME##*/}-${LIBRETRO_COMMIT_SHA}"
> +	:
> ${SRC_URI:="https://github.com/${LIBRETRO_REPO_NAME}/archive/${LIBRETRO_COMMIT_SHA}.tar.gz
> -> ${P}.tar.gz"}
> +fi
> +inherit flag-o-matic
> +
> +# @ECLASS-VARIABLE: LIBRETRO_CORE_LIB_FILE
> +# @REQUIRED
> +# @DESCRIPTION:
> +# Absolute path of this Libretro core's shared library.
> +: ${LIBRETRO_CORE_LIB_FILE:="${S}/${LIBRETRO_CORE_NAME}_libretro.so"}
> +
> +case "${EAPI:-0}" in
> +	6|7)
> +		EXPORT_FUNCTIONS src_unpack src_prepare src_compile src_install
> +		;;
> +	*)
> +		die "EAPI=${EAPI} is not supported" ;;
> +esac
> +
> +# @FUNCTION: libretro-core_src_unpack
> +# @DESCRIPTION:
> +# The libretro-core src_unpack function which is exported.
> +#
> +# This function retrieves the remote Libretro core info files.
> +libretro-core_src_unpack() {
> +	# If this is a live ebuild, retrieve this core's remote repository.
> +	if [[ ${PV} == *9999 ]]; then
> +		git-r3_src_unpack
> +		# Add used commit SHA for version information, the above could also
> work.
> +		LIBRETRO_COMMIT_SHA=$(git -C "${WORKDIR}/${P}" rev-parse HEAD)
> +	# Else, unpack this core's local tarball.
> +	else
> +		default_src_unpack
> +	fi
> +}
> +
> +# @FUNCTION: libretro-core_src_prepare
> +# @DESCRIPTION:
> +# The libretro-core src_prepare function which is exported.
> +#
> +# This function prepares the source by making custom modifications.
> +libretro-core_src_prepare() {
> +	ebegin "Attempting to hack Makefiles to use custom cflags"
> +	# Populate COMMIT for GIT_VERSION
> +	CUSTOM_LIBRETRO_COMMIT_SHA="\" ${LIBRETRO_COMMIT_SHA:0:7}\""
> +	local makefile
> +	local flags_modified=0
> +	local shopt_saved=$(shopt -p nullglob)
> +	shopt -s nullglob
> +	for makefile in "${S}"/[Mm]akefile*
> "${S}"/target-libretro/[Mm]akefile*; do
> +		# * Convert CRLF to LF
> +		# * Expand *FLAGS to prevent potential self-references
> +		# * Where LDFLAGS directly define the link version
> +		#   script append LDFLAGS and LIBS
> +		# * Where SHARED is used to provide shared linking
> +		#   flags ensure final link command includes LDFLAGS
> +		#   and LIBS
> +		# * Always use $(CFLAGS) when calling $(CC)
> +		# * Add short-rev to Makefile
> +		[[ -e "${makefile}" ]] && sed \
> +			-e 's/\r$//g' \
> +			-e "/flags.*=/s:-O[[:digit:]]:${CFLAGS}:g" \
> +			-e "/CFLAGS.*=/s:-O[[:digit:]]:${CFLAGS}:g" \
> +			-e "/.*,--version-script=.*/s:$: ${LDFLAGS} ${LIBS}:g" \
> +			-e "/\$(CC)/s:\(\$(SHARED)\):\1 ${LDFLAGS} ${LIBS}:" \
> +			-e 's:\(\$(CC)\):\1 \$(CFLAGS):g' \
> +			-e
> "s/GIT_VERSION\s.=.*$/GIT_VERSION=${CUSTOM_LIBRETRO_COMMIT_SHA}/g" \
> +			-i "${makefile}" || die "Failed to use custom cflags in
> ${makefile}"
> +	done
> +	${shopt_saved}
> +	eend
> +	export OPTFLAGS="${CFLAGS}"
> +	default_src_prepare
> +}
> +
> +# @VARIABLE: myemakeargs
> +# @DEFAULT_UNSET
> +# @DESCRIPTION:
> +# Optional emake arguments as a bash array. Should be defined before
> calling
> +# src_compile.
> +# @CODE
> +# src_compile() {
> +#       local myemakeargs=(
> +#		$(usex neon "HAVE_NEON=1" "")
> +#	)
> +#       libretro-core_src_configure
> +# }
> +# @CODE
> +
> +# @FUNCTION: libretro-core_src_compile
> +# @DESCRIPTION:
> +# The libretro-core src_compile function which is exported.
> +#
> +# This function compiles the shared library for this Libretro core.
> +libretro-core_src_compile() {
> +	# most (if not all) libretro makefiles use DEBUG=1
> +	# to enable additional debug features.
> +	emake CC=$(tc-getCC) CXX=$(tc-getCXX) \
> +		$(usex debug "DEBUG=1" "") "${myemakeargs[@]}" \
> +		$([[ -f makefile.libretro ]] && echo '-f makefile.libretro') \
> +		$([[ -f Makefile.libretro ]] && echo '-f Makefile.libretro')
> +}
> +
> +# @FUNCTION: libretro-core_src_install
> +# @DESCRIPTION:
> +# The libretro-core src_install function which is exported.
> +#
> +# This function installs the shared library for this Libretro core.
> +libretro-core_src_install() {
> +	# Absolute path of the directory containing Libretro shared
> libraries.
> +	local LIBRETRO_LIB_DIR="/usr/$(get_libdir)/libretro"
> +	# If this core's shared library exists, install that.
> +	if [[ -f "${LIBRETRO_CORE_LIB_FILE}" ]]; then
> +		insinto "${LIBRETRO_LIB_DIR}"
> +		doexe "${LIBRETRO_CORE_LIB_FILE}"
> +	else
> +		# Basename of this library.
> +		local lib_basename="${LIBRETRO_CORE_LIB_FILE##*/}"
> +
> +		# Absolute path to which this library was installed.
> +		local lib_file_target="${ED}${LIBRETRO_LIB_DIR}/${lib_basename}"
> +
> +		# If this library was *NOT* installed, fail.
> +		[[ -f "${lib_file_target}" ]] ||
> +			die "Libretro core shared library \"${lib_file_target}\" not
> installed."
> +	fi
> +}
> +
> +fi # end _LIBRETRO_CORE_ECLASS guard


Merged with a few tweaks: commit 
532441d38e4bc6fe2445385ab177f7ed6b1ec2c1

Thank you to everyone who reviewed this work and provided feedback!

~Craig