Question about recursive dependencies

Question about recursive dependencies

[Jacob Kroon]

Hi,

After many reading attempts I have to admit I still don't understand the 
last section of

https://www.yoctoproject.org/docs/latest/bitbake-user-manual/bitbake-user-manual.html#recursive-dependencies

<quote>
You might want to not only have BitBake look for dependencies of those 
tasks, but also have BitBake look for build-time and runtime 
dependencies of the dependent tasks as well. If that is the case, you 
need to reference the task name itself in the task list:

      do_a[recrdeptask] = "do_a do_b"
</quote>

The text before would suggest this means that

"do_a" and "do_b" in the current recipe, plus "do_a" and "do_b" in all 
its build-time/runtime/inter-task dependencies, recursively, must run 
before the recipe's "do_a" can run. That would mean "do_a" in the 
current recipe depends on itself. What am I not getting here ?

Jacob

Re: [bitbake-devel] Question about recursive dependencies

[Richard Purdie]

On Wed, 2020-05-27 at 09:11 +0200, Jacob Kroon wrote:
> Hi,
> 
> After many reading attempts I have to admit I still don't understand the 
> last section of
> 
> https://www.yoctoproject.org/docs/latest/bitbake-user-manual/bitbake-user-manual.html#recursive-dependencies
> 
> <quote>
> You might want to not only have BitBake look for dependencies of those 
> tasks, but also have BitBake look for build-time and runtime 
> dependencies of the dependent tasks as well. If that is the case, you 
> need to reference the task name itself in the task list:
> 
>       do_a[recrdeptask] = "do_a do_b"
> </quote>
> 
> The text before would suggest this means that
> 
> "do_a" and "do_b" in the current recipe, plus "do_a" and "do_b" in all 
> its build-time/runtime/inter-task dependencies, recursively, must run 
> before the recipe's "do_a" can run. That would mean "do_a" in the 
> current recipe depends on itself. What am I not getting here ?

It does mean that but bitbake will just skip a task depending on itself
in this context as that doesn't make any sense.

We used to have that issue a lot, I can only spot one example of it in
use now in a quick glance at OE-Core, thankfully.

Cheers,

Richard

Re: [bitbake-devel] Question about recursive dependencies

[Jacob Kroon]

On 5/27/20 12:01 PM, Richard Purdie wrote:
> On Wed, 2020-05-27 at 09:11 +0200, Jacob Kroon wrote:
>> Hi,
>>
>> After many reading attempts I have to admit I still don't understand the
>> last section of
>>
>> https://www.yoctoproject.org/docs/latest/bitbake-user-manual/bitbake-user-manual.html#recursive-dependencies
>>
>> <quote>
>> You might want to not only have BitBake look for dependencies of those
>> tasks, but also have BitBake look for build-time and runtime
>> dependencies of the dependent tasks as well. If that is the case, you
>> need to reference the task name itself in the task list:
>>
>>        do_a[recrdeptask] = "do_a do_b"
>> </quote>
>>
>> The text before would suggest this means that
>>
>> "do_a" and "do_b" in the current recipe, plus "do_a" and "do_b" in all
>> its build-time/runtime/inter-task dependencies, recursively, must run
>> before the recipe's "do_a" can run. That would mean "do_a" in the
>> current recipe depends on itself. What am I not getting here ?
> 
> It does mean that but bitbake will just skip a task depending on itself
> in this context as that doesn't make any sense.
> 

Thanks for clarifying. But I'm still not understanding the quoted text.. 
Is the intended meaning basically what I wrote above ? Or is the text 
referring to something else ?

Jacob