a question about recipe style

a question about recipe style

[Robert P. J. Day]

  perusing the bitbake user manual, and ran across the section
discussing the "override style" operators _append, _prepend and
_remove, and thought i'd go looking through the OE recipes for an
actual example of the use of "_remove", and the only example i found
is in meta/recipes-extended/newt, but it looks a bit awkward, so i
just want to know about recommended style.

  there are two recipe files there -- libnewt_0.52.17.bb and
libnewt-python_0.52.17.bb -- with the following structure. that first
recipe file contains (among other things) the following:

PACKAGES_prepend = "whiptail "
...
FILES_whiptail = "${bindir}/whiptail"

  ok, so that recipe defines an additional package, and adds a single
file to that package, whereupon the second recipe file contains:

require recipes-extended/newt/libnewt_${PV}.bb
...
PACKAGES_remove = "whiptail"

  it just seems awkward for recipe 1 to explicitly add a package, only
for recipe 2 to include that recipe file, and subsequently remove that
package.

  it's not a big deal, but from a style perspective, i would have
thought one would first create a generic libnewt.inc file with common
content, then define the two recipe files off of that. does that make
sense in terms of best programming principles?

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: a question about recipe style

[Richard Purdie]

On Tue, 2014-07-08 at 11:34 -0400, Robert P. J. Day wrote:
>   perusing the bitbake user manual, and ran across the section
> discussing the "override style" operators _append, _prepend and
> _remove, and thought i'd go looking through the OE recipes for an
> actual example of the use of "_remove", and the only example i found
> is in meta/recipes-extended/newt, but it looks a bit awkward, so i
> just want to know about recommended style.
> 
>   there are two recipe files there -- libnewt_0.52.17.bb and
> libnewt-python_0.52.17.bb -- with the following structure. that first
> recipe file contains (among other things) the following:
> 
> PACKAGES_prepend = "whiptail "
> ...
> FILES_whiptail = "${bindir}/whiptail"
> 
>   ok, so that recipe defines an additional package, and adds a single
> file to that package, whereupon the second recipe file contains:
> 
> require recipes-extended/newt/libnewt_${PV}.bb
> ...
> PACKAGES_remove = "whiptail"
> 
>   it just seems awkward for recipe 1 to explicitly add a package, only
> for recipe 2 to include that recipe file, and subsequently remove that
> package.
> 
>   it's not a big deal, but from a style perspective, i would have
> thought one would first create a generic libnewt.inc file with common
> content, then define the two recipe files off of that. does that make
> sense in terms of best programming principles?

Yes, it does seem like an odd way to have written the recipes. I'd be
happy enough to see some cleanup patches...

Cheers,

Richard

Re: a question about recipe style

[Robert P. J. Day]

On Wed, 9 Jul 2014, Richard Purdie wrote:

> On Tue, 2014-07-08 at 11:34 -0400, Robert P. J. Day wrote:
> >   perusing the bitbake user manual, and ran across the section
> > discussing the "override style" operators _append, _prepend and
> > _remove, and thought i'd go looking through the OE recipes for an
> > actual example of the use of "_remove", and the only example i found
> > is in meta/recipes-extended/newt, but it looks a bit awkward, so i
> > just want to know about recommended style.
> >
> >   there are two recipe files there -- libnewt_0.52.17.bb and
> > libnewt-python_0.52.17.bb -- with the following structure. that first
> > recipe file contains (among other things) the following:
> >
> > PACKAGES_prepend = "whiptail "
> > ...
> > FILES_whiptail = "${bindir}/whiptail"
> >
> >   ok, so that recipe defines an additional package, and adds a single
> > file to that package, whereupon the second recipe file contains:
> >
> > require recipes-extended/newt/libnewt_${PV}.bb
> > ...
> > PACKAGES_remove = "whiptail"
> >
> >   it just seems awkward for recipe 1 to explicitly add a package, only
> > for recipe 2 to include that recipe file, and subsequently remove that
> > package.
> >
> >   it's not a big deal, but from a style perspective, i would have
> > thought one would first create a generic libnewt.inc file with common
> > content, then define the two recipe files off of that. does that make
> > sense in terms of best programming principles?
>
> Yes, it does seem like an odd way to have written the recipes. I'd be
> happy enough to see some cleanup patches...

  maybe i'll give that as an assignment to my students. :-)  that
oddity clearly isn't a big deal since it works just fine, i just
thought it looked strange enough that i wanted to make sure there
wasn't something subtle going on i didn't understand.

  movin' on ...

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================