[yocto] Getting linker -l into a bbappend

[Colin Helliwell]

> On 07 June 2017 at 18:12 Khem Raj <raj.khem at gmail.com> wrote:
> 
> On Wed, Jun 7, 2017 at 9:37 AM, <colin.helliwell at ln-systems.com> wrote:
> 
> > I have an autotools (C++) app which builds fine with my default recipe. But
> > for a particular platform an additional (C) library is needed, so I have a
> > bbappend.
> > I can add in the additional compiler flag here, but I'm struggling to
> > specify the additional library linkage - I think it's because the ordering
> > on the linker command line is wrong.
> > 
> > If I add '-lfoo' to the base Makefile.am then it builds fine (though
> > strangely, "-lfoo" isn't anywhere in the linker command line?).
> > But I'm trying to put this into just the 'append' rather than altering the
> > base [non-platform-specific] Makefile.
> > 
> > I've tried
> >  EXTRA_OEMAKE += " LDFLAGS+="-lfoo" "
> > and
> >  LDFLAGS+="-lrfctrl"
> > but these don't seem to construct the correct linkage order (functions from
> > the library are undefined references)
> > 
> > Is there a way to append this in the right way?
> 
> it depends on components build systems some are more accommodating of
> the env passed to them some are not. So in many
> cases you have to patch the make system of the component to
> allow it to accept changes to variables passed from bitbake env
> from what you explain it seems you might have to look into
> component's build system to accommodate it.
> 

Thanks Khem. I *could* patch the Makefile.am, if there's no other way