[gentoo-dev] Re: [PATCH] go-module.eclass: add functions for use in custom src_unpack phase

[Zac Medico]

On 5/19/21 12:48 PM, William Hubbs wrote:
> If an ebuild uses EGO_SUM and needs to define a custom src_unpack phase,
> these functions will make that easier.
>
> go-module_setup_proxy is used to create a local file proxy of the
> dependencies listed in EGO_SUM and go-module_filter_proxy is used to
> create a new ${A} with the EGO_SUM_SRC_URI values removed.
>
> Signed-off-by: William Hubbs <williamh@g.o>
> ---
>  eclass/go-module.eclass | 69 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 69 insertions(+)
>
> diff --git a/eclass/go-module.eclass b/eclass/go-module.eclass
> index c9a7ab12eaf..80e1f711215 100644
> --- a/eclass/go-module.eclass
> +++ b/eclass/go-module.eclass
> @@ -236,6 +236,75 @@ go-module_set_globals() {
>  	_GO_MODULE_SET_GLOBALS_CALLED=1
>  }
>
> +# @FUNCTION: go-module_filter_proxy
> +# @DESCRIPTION:
> +# If your ebuild redefines src_unpack and uses EGO_SUM, use the return
> +# value of this function in place of ${A} in your src_unpack function.
> +# It filters the EGO_SUM_SRC_URI values out of SRC_URI.
> +go-module_filter_proxy() {
> +	# shellcheck disable=SC2120
> +	debug-print-function "${FUNCNAME}" "$@"
> +
> +	if [[ ! ${_GO_MODULE_SET_GLOBALS_CALLED} ]]; then
> +		die "go-module_set_globals must be called in global scope"
> +	fi
> +
> +	# Skip golang modules and add the rest of the entries to a local
> +	# array.
> +	local f
> +	local -a src
> +	for f in ${A}; do
> +		if [[ -z ${_GOMODULE_GOSUM_REVERSE_MAP["${f}"]} ]]; then
> +		src+=("${f}")
> +		fi
> +	done
> +	echo "${src[@]}"
> +}

While this go-module_filter_proxy might seem like a convenient way for
an ebuild to list distfiles which are not derived from EGO_SUM, I think
it's not the responsibility of go-module.eclass to provide this
information, therefore it's probably better to force the ebuild
developer to provide their own mechanism to track those files if needed,
rather than add a superfluous function to the eclass.

> +# @FUNCTION: go-module_setup_proxy
> +# @DESCRIPTION:
> +# If your ebuild redefines src_unpack and uses EGO_SUM you need to call
> +# this function in src_unpack.
> +# It sets up the go module proxy in the appropriate location and exports
> +# the GOPROXY environment variable so that go calls will be able to
> +# locate the proxy directory.
> +go-module_setup_proxy() {
> +	# shellcheck disable=SC2120
> +	debug-print-function "${FUNCNAME}" "$@"
> +
> +	if [[ ! ${_GO_MODULE_SET_GLOBALS_CALLED} ]]; then
> +		die "go-module_set_globals must be called in global scope"
> +	fi
> +
> +	local goproxy_dir="${T}/go-proxy"
> +	mkdir -p "${goproxy_dir}" || die
> +
> +	# For each Golang module distfile, look up where it's supposed to go and
> +	# symlink it into place.
> +	local f
> +	local goproxy_mod_dir
> +	for f in ${A}; do
> +		goproxy_mod_path="${_GOMODULE_GOSUM_REVERSE_MAP["${f}"]}"
> +		if [[ -n "${goproxy_mod_path}" ]]; then
> +			debug-print-function "Populating go proxy for ${goproxy_mod_path}"
> +			# Build symlink hierarchy
> +			goproxy_mod_dir=$( dirname "${goproxy_dir}"/"${goproxy_mod_path}" )
> +			mkdir -p "${goproxy_mod_dir}" || die
> +			ln -sf "${DISTDIR}"/"${f}" "${goproxy_dir}/${goproxy_mod_path}" ||
> +				die "Failed to ln"
> +			local v=${goproxy_mod_path}
> +			v="${v%.mod}"
> +			v="${v%.zip}"
> +			v="${v//*\/}"
> +			_go-module_gosum_synthesize_files "${goproxy_mod_dir}" "${v}"
> +		fi
> +	done
> +	export GOPROXY="file://${goproxy_dir}"
> +
> +	# Validate the gosum now
> +	_go-module_src_unpack_verify_gosum
> +}
> +
>  # @FUNCTION: go-module_src_unpack
>  # @DESCRIPTION:
>  # If EGO_SUM is set, unpack the base tarball(s) and set up the
>

The go-module_setup_proxy function solves bug 790851 nicely, since
sys-cluster/k3s ebuilds can call that instead of go-module_src_unpack.
-- 
Thanks,
Zac