How to reuse code in oe-core environment

How to reuse code in oe-core environment

[Andreas Mueller]

Hi,

I am playing around with oe-core try to find a way of reusing code for multiple 
recipes. In oe I did create foo.inc with

foo() {
	# code to reuse
}

and called foo from several recipes. In oe-core the run.* scripts are much more 
stripped of unnecessary.  All the code included by 'require' seems to miss, so 
the function foo() will not be found. 

My searches for examples did not lead to a hook so what is the suggested 
solution for reusing code for multiple recipes in oe-core?

regards

Andreas

Re: How to reuse code in oe-core environment

[Khem Raj]

On Wed, Jun 29, 2011 at 4:02 PM, Andreas Mueller <schnitzeltony@gmx.de> wrote:
> Hi,
>
> I am playing around with oe-core try to find a way of reusing code for multiple
> recipes. In oe I did create foo.inc with
>
> foo() {
>        # code to reuse
> }
>
> and called foo from several recipes. In oe-core the run.* scripts are much more
> stripped of unnecessary.  All the code included by 'require' seems to miss, so
> the function foo() will not be found.
>
> My searches for examples did not lead to a hook so what is the suggested
> solution for reusing code for multiple recipes in oe-core?
>

hmm do u mean something like what busybox recipe is doing as an example.

or did I misunderstand

> regards
>
> Andreas
>
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> Openembedded-core mailing list
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>

Re: How to reuse code in oe-core environment

[Chris Larson]

On Wed, Jun 29, 2011 at 4:02 PM, Andreas Mueller <schnitzeltony@gmx.de> wrote:
> foo() {
>        # code to reuse
> }
>
> and called foo from several recipes. In oe-core the run.* scripts are much more
> stripped of unnecessary.  All the code included by 'require' seems to miss, so
> the function foo() will not be found.
>
> My searches for examples did not lead to a hook so what is the suggested
> solution for reusing code for multiple recipes in oe-core?

The require doesn't have to do with anything. bitbake emits only the
functions which get called somewhere from the task being run. It
tracks what variables reference what other variables. If you call a
shell function from another shell function, it tracks this, and
realizes that both need to be emitted. Either you're doing something
wrong, or you're doing something in a way that bitbake can't track.
There's a variable flag you can set to explicitly add variable
dependencies.
-- 
Christopher Larson
clarson at kergoth dot com
Founder - BitBake, OpenEmbedded, OpenZaurus
Maintainer - Tslib
Senior Software Engineer, Mentor Graphics

Re: How to reuse code in oe-core environment

[Mark Hatle]

On 6/29/11 6:59 PM, Chris Larson wrote:
> On Wed, Jun 29, 2011 at 4:02 PM, Andreas Mueller <schnitzeltony@gmx.de> wrote:
>> foo() {
>>        # code to reuse
>> }
>>
>> and called foo from several recipes. In oe-core the run.* scripts are much more
>> stripped of unnecessary.  All the code included by 'require' seems to miss, so
>> the function foo() will not be found.
>>
>> My searches for examples did not lead to a hook so what is the suggested
>> solution for reusing code for multiple recipes in oe-core?
> 
> The require doesn't have to do with anything. bitbake emits only the
> functions which get called somewhere from the task being run. It
> tracks what variables reference what other variables. If you call a
> shell function from another shell function, it tracks this, and
> realizes that both need to be emitted. Either you're doing something
> wrong, or you're doing something in a way that bitbake can't track.
> There's a variable flag you can set to explicitly add variable
> dependencies.

There is an example of how to work around this in the rootfs_rpm.bbclass..  It's
a bit odd, but it has to do with the way the function is called:

        # Workaround so the parser knows we need the resolve_package function!
        if false ; then
                resolve_package_rpm foo ${RPMCONF_TARGET_BASE}.conf || true
        fi


....

        pkg_name=$(resolve_package_rpm $pkg-locale-$lang
${RPMCONF_TARGET_BASE}.conf)


So if the function is called within a subshell, the parser doesn't appear to
know it's there.. so you have to reference it in the function somewhere (the if
false works well for this) in order for it to be available to call.

Re: How to reuse code in oe-core environment

[Andreas Mueller]

On Thursday, June 30, 2011 02:32:56 AM Mark Hatle wrote:
> On 6/29/11 6:59 PM, Chris Larson wrote:
> > On Wed, Jun 29, 2011 at 4:02 PM, Andreas Mueller <schnitzeltony@gmx.de> 
wrote:
> >> foo() {
> >> 
> >>        # code to reuse
> >> 
> >> }
> >> 
> >> and called foo from several recipes. In oe-core the run.* scripts are
> >> much more stripped of unnecessary.  All the code included by 'require'
> >> seems to miss, so the function foo() will not be found.
> >> 
> >> My searches for examples did not lead to a hook so what is the suggested
> >> solution for reusing code for multiple recipes in oe-core?
> > 
> > The require doesn't have to do with anything. bitbake emits only the
> > functions which get called somewhere from the task being run. It
> > tracks what variables reference what other variables. If you call a
> > shell function from another shell function, it tracks this, and
> > realizes that both need to be emitted. Either you're doing something
> > wrong, or you're doing something in a way that bitbake can't track.
> > There's a variable flag you can set to explicitly add variable
> > dependencies.
> 
> There is an example of how to work around this in the rootfs_rpm.bbclass.. 
> It's a bit odd, but it has to do with the way the function is called:
> 
>         # Workaround so the parser knows we need the resolve_package
> function! if false ; then
>                 resolve_package_rpm foo ${RPMCONF_TARGET_BASE}.conf || true
>         fi
> 
> 
> ....
> 
>         pkg_name=$(resolve_package_rpm $pkg-locale-$lang
> ${RPMCONF_TARGET_BASE}.conf)
> 
> 
> So if the function is called within a subshell, the parser doesn't appear
> to know it's there.. so you have to reference it in the function somewhere
> (the if false works well for this) in order for it to be available to
> call.
I'll try to understand that tomorrow zzzzz

Andreas

Re: How to reuse code in oe-core environment

[Andreas Mueller]

On Thursday, June 30, 2011 01:59:33 AM Chris Larson wrote:
> On Wed, Jun 29, 2011 at 4:02 PM, Andreas Mueller <schnitzeltony@gmx.de> wrote:
> > foo() {
> >        # code to reuse
> > }
> > 
> > and called foo from several recipes. In oe-core the run.* scripts are
> > much more stripped of unnecessary.  All the code included by 'require'
> > seems to miss, so the function foo() will not be found.
> > 
> > My searches for examples did not lead to a hook so what is the suggested
> > solution for reusing code for multiple recipes in oe-core?
> 
> The require doesn't have to do with anything. bitbake emits only the
> functions which get called somewhere from the task being run. It
> tracks what variables reference what other variables. If you call a
> shell function from another shell function, it tracks this, and
> realizes that both need to be emitted. Either you're doing something
> wrong, or you're doing something in a way that bitbake can't track.
> There's a variable flag you can set to explicitly add variable
> dependencies.
the scenario I wrote was not the whole truth - sorry:

I am making a new layer. There I have created u-boot_git.bbappend. In the build 
log I see that this extends u-boot_git.bb coming from meta-texasinstruments. In 
u-boot_git.bbappend there is (besides other showing me that bbappending works)

| require foo.inc

and

| do_deploy_append_<mynewmachine> {
|	foo
| }

the code in foo.inc is something like

| foo() {
|	sed ..
|	install ...
| }

Build stops complaining that foo cannot be found and the only function I see in 
run.do_deploy.nnnnn is do_deploy(). 

All code was taken from oe and builds fine there. Only difference to oe is that 
the lines now found in u-boot_git.bbappend were part of the one and only u-
boot_git.bb recipe.

Is it possible that that the dependency checks ignore functions brought in by 
bbappend - or where am I going wrong?

regards

Andreas