Re: [PATCH bpf-next v4] tools/bpf: generate pkg-config file for libbpf

[Luca Boccassi <bluca@debian.org>]

On Thu, 2019-03-21 at 23:19 +0100, Daniel Borkmann wrote:
> On 03/21/2019 11:01 PM, Alexei Starovoitov wrote:
> > On Thu, Mar 21, 2019 at 04:00:46PM +0000, Andrey Ignatov wrote:
> > > luca.boccassi@gmail.com <luca.boccassi@gmail.com> [Thu, 2019-03-
> > > 21 03:26 -0700]:
> > > > From: Luca Boccassi <bluca@debian.org>
> > > > 
> > > > Generate a libbpf.pc file at build time so that users can rely
> > > > on pkg-config to find the library, its CFLAGS and LDFLAGS.
> > > > 
> > > > Signed-off-by: Luca Boccassi <bluca@debian.org>
> > ...
> > > > diff --git a/tools/lib/bpf/libbpf.pc.template
> > > > b/tools/lib/bpf/libbpf.pc.template
> > > > new file mode 100644
> > > > index 000000000000..0ecd334c109f
> > > > --- /dev/null
> > > > +++ b/tools/lib/bpf/libbpf.pc.template
> > > > @@ -0,0 +1,11 @@
> > > > +prefix=@PREFIX@
> > > > +libdir=@LIBDIR@
> > > > +includedir=${prefix}/include
> > > > +
> > > > +Name: libbpf
> > > > +URL: 
> > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > > > +Description: Linux kernel BPF library
> > 
> > github/libbpf/libbpf is a true mirror of kernel's libbpf.
> > I think if we start shipping libbpf.so from kernel and from github
> > it will be very confusing to the users...
> > Which one is the true libbpf?
> > Also the package should mention the license.
> > And the license for libbpf is dual lgpl/bsd.
> > But if we point to the url above it will not make much sense.
> > I think the packages URL should point to github/libbpf/libbpf
> > and packaging scripts should be in github only.
> > 
> > Daniel,
> > what do you think?
> 
> Looking at [0], I don't see where license would be part of the
> keyword. Given
> this is just a pkg-config file where folks using it care mainly about
> the
> needed cflags/libs, it would make sense to me to ship it and have it
> under
> tools/lib/bpf/ in kernel tree (since this is distro independent). If
> the URL
> and Description causes confusion, I would probably just remove the
> URL field
> since it's not mandatory either. And description, I'd put something
> like
> 'official BPF library' or such, so it's generic enough.
> 
>   [0] https://autotools.io/pkgconfig/file-format.html
>       https://dev.gentoo.org/~mgorny/pkg-config-spec.html#keywords

I assumed the license referred to the file itself, so I added the SDPX
comment. It's not too uncommon for pc files to have the license comment
at the top.

Removed URL and changed Descriptin in v6, thanks for reviewing!

-- 
Kind regards,
Luca Boccassi