[Buildroot] [RFC v2 2/4] package/pkg-golang: new package infrastructure

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

On Mon, 16 Oct 2017 19:08:46 +0200, Angelo Compagnucci wrote:
> This patch adds a new infrastructure for golang based packages.
> 
> Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>

As Christian said, it seems that this infrastructure isn't "general"
enough to really be useful. We would to see it applied to several
packages and see that there is a real benefit to several packages to
apply it.

So I'd be happy to take a go package infrastructure, but it needs to be
usable by more than one package in a useful way.

> +# Target packages need the Go compiler on the host.
> +$(2)_DEPENDENCIES += host-go
> +
> +#
> +# go install command doesn't work well when cross compilation is enabled,
> +# we set the executable output of the compilation to a specific location.
> +# We set this variable here to be used by packages if needed.
> +#
> +$(2)_EXECUTABLE = $$(@D)/gopath/bin/$(1)

This seems to make the assumption that a given package can only install
a single executable, and that this executable is named after the
package. It is true for flannel, but what about other Go packages ?

> +# Source files in Go should be uncompressed in a precise folder in the
> +# hiearchy of GOPATH. It usually resolves around domain/vendor/software.
> +#
> +$(1)_src_path ?= $$(call domain,$($(2)_SITE))/$$(firstword $$(subst /, ,$$(call notdomain,$($(2)_SITE))))
> +$(2)_SRC_PATH  = $$(@D)/gopath/src/$$($(1)_src_path)/$(1)

We don't use lower-case variables in Buildroot, especially if there is
a variable with the same name upper-case.

Best regards,

Thomas Petazzoni
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com