Re: [gentoo-dev] [PATCH 1/3] go-module.eclass: introduce new eclass to handle go modules

[William Hubbs]

On Wed, Sep 11, 2019 at 08:31:16PM +0200, Michał Górny wrote:
> On Wed, 2019-09-11 at 13:22 -0500, William Hubbs wrote:
> > On Wed, Sep 11, 2019 at 07:38:17PM +0200, Michał Górny wrote:
> > > On Wed, 2019-09-11 at 12:21 -0500, William Hubbs wrote:
> > > > Copyright: Sony Interactive Entertainment Inc.
> > > > Signed-off-by: William Hubbs <williamh@g.o>
> > > > ---
> > > >  eclass/go-module.eclass | 76 +++++++++++++++++++++++++++++++++++++++++
> > > >  1 file changed, 76 insertions(+)
> > > >  create mode 100644 eclass/go-module.eclass
> > > >
> > > > diff --git a/eclass/go-module.eclass b/eclass/go-module.eclass
> > > > new file mode 100644
> > > > index 00000000000..7009fcd3beb
> > > > --- /dev/null
> > > > +++ b/eclass/go-module.eclass
> > > > @@ -0,0 +1,76 @@
> > > > +# Copyright 1999-2015 Gentoo Foundation
> > >
> > > You need to replace your calendar.  And copyright holder.
> >
> > Sure, I thought I ffixed that.
> >
> > > > +# Distributed under the terms of the GNU General Public License v2
> > > > +
> > > > +# @ECLASS: go-module.eclass
> > >
> > > Any reason to change naming from golang-* to go-* now?
> >
> > Well, "lang" is sort of redundant, and there will be only one eclass, so
> > I thought I would make things a bit more simple.
> >
> > > > +# @MAINTAINER:
> > > > +# William Hubbs <williamh@g.o>
> > > > +# @SUPPORTED_EAPIS: 7
> > > > +# @BLURB: basic eclass for building software written in the go
> > > > +# programming language that uses go modules.
> > > > +# @DESCRIPTION:
> > > > +# This eclass provides a convenience src_prepare() phase and some basic
> > > > +# settings needed for all software written in the go programming
> > > > +# language that uses go modules.
> > > > +#
> > > > +# You will know the software you are packaging uses modules because
> > > > +# it will have files named go.sum and go.mod in its top-level source
> > > > +# directory. If it does not have these files, use the golang-* eclasses.
> > > > +#
> > > > +# If the software you are packaging uses modules, the next question is
> > > > +# whether it has a directory named "vendor" at the top-level of the source tree.
> > > > +#
> > > > +# If it doesn't, you need to create a tarball of what would be in the
> > > > +# vendor directory and mirror it locally. This is done with the
> > > > +# following commands if upstream is using a git repository:
> > > > +#
> > > > +# @CODE:
> > > > +#
> > > > +# $ cd /my/clone/of/upstream
> > > > +# $ git checkout <release>
> > > > +# $ go mod vendor
> > > > +# $ tar cvf project-version-vendor.tar.gz vendor
> > > > +#
> > > > +# @CODE:
> > > > +#
> > > > +# Other than this, all you need to do is inherit this eclass then
> > > > +# make sure  the exported src_prepare function is run.
> > > > +
> > > > +case ${EAPI:-0} in
> > > > +	7) ;;
> > > > +	*) die "${ECLASS} API in EAPI ${EAPI} not yet established."
> > > > +esac
> > > > +
> > > > +if [[ -z ${_GO_MODULE} ]]; then
> > > > +
> > > > +_GO_MODULE=1
> > > > +
> > > > +BDEPEND=">=dev-lang/go-1.12"
> > > > +
> > > > +# Do not download dependencies from the internet
> > > > +# make build output verbose by default
> > > > +export GOFLAGS="-mod=vendor -v -x"
> > > > +
> > > > +# Do not complain about CFLAGS etc since go projects do not use them.
> > > > +QA_FLAGS_IGNORED='.*'
> > > > +
> > > > +# Upstream does not support stripping go packages
> > > > +RESTRICT="strip"
> > > > +
> > > > +EXPORT_FUNCTIONS src_prepare
> > >
> > > Don't you need to inherit some other eclass to make it build?
> >
> > The primary reason for all of the golang-* eclasses was the GOPATH
> > variable, which is not relevant when you are using modules.
> >
> > I can look at adding a src_compile to this eclass, but I haven't thought
> > about what it would contain yet.
> >
> > > > +
> > > > +# @FUNCTION: go-module_src_prepare
> > > > +# @DESCRIPTION:
> > > > +# Run a default src_prepare then move our provided vendor directory to
> > > > +# the appropriate spot if upstream doesn't provide a vendor directory.
> > > > +go-module_src_prepare() {
> > > > +	default
> > > > +	# Use the upstream provided vendor directory if it exists.
> > > > +	[[ -d vendor ]] && return
> > > > +	# If we are not providing a mirror of a vendor directory we created
> > > > +	# manually, return since there may be nothing to vendor.
> > > > +	[[ ! -d ../vendor ]] && return
> > > > +	# At this point, we know we are providing a vendor mirror.
> > > > +	mv ../vendor . || die "Unable to move ../vendor directory"
> > >
> > > Wouldn't it be much simpler to create appropriate directory structure
> > > in the tarball?  Then you wouldn't need a new eclass at all.
> >
> > You would definitely need an eclass (see the settings and dependencies).
> >
> > Take a look at the differences in the spire and hub ebuilds in this
> > series. I'm not sure what you mean by adding the directory structure to
> > the tarball? I guess you could add something to the vendor tarball when
> > you create it.
>
> I mean packing it as 'spire-1.2.3/vendor' or whatever the package
> directory is, so that it extracts correctly instead of making a tarball
> that needs to be moved afterwards.

That would clobber the upstream provided vendor directory and that's
what I want to avoid with the first test in src_prepare.

>
> >
> > What I tried to avoid was stomping on the vendor directory if it is
> > included upstream.
>
> You do that anyway by moving files.

See the first test in src_prepare. I go out of my way to not overwrite
the upstream vendor directory.

William