[yocto] Dumping (inferred) do_task[vardeps] for some do_task

[Ulf Magnusson]

On Wed, Apr 27, 2016 at 6:19 PM, Christopher Larson <clarson at kergoth.com> wrote:
>
>
> On Wed, Apr 27, 2016 at 9:11 AM, Ulf Magnusson <ulfalizer at gmail.com> wrote:
>>
>> I'm trying to get a feel for how BitBake infers task dependencies. The
>> easiest way (but I'm open to suggestions) seems to be to dump the
>> value of do_task[vardeps] for a particular recipe after the inferred
>> dependencies are added.
>>
>> What's a good way to dump do_task[vardeps]? I tried using getVarFlag()
>> in an anonymous Python function, but it only catches dependencies
>> explicitly added to do_task[vardeps]. Maybe [vardeps] is never
>> assigned the complete set of dependencies internally, or maybe the
>> anonymous Python function is called too early.
>
>
> That's correct, the full list is not stored in the vardeps.
>

That was what I was starting to suspect. Thanks for conforming.

>> generate_dependencies() in bitbake/lib/bb/data.py also looked
>> promising, but maybe there's a better places further up the callstack.
>
>
> That is a reasonable place in the code, yes. You can inspect a certain
> amount of information in the signature data files, but I'm not sure it
> drills down to the level you desire.
>
> My 'bb' tool's 'show' subcommand can show not just a variable but also its
> dependencies, perhaps that might be of use? I haven't touched it in ages,
> but in theory it should work.

>From some quick experimentation,

  $ bb show -d -r test_recipe do_compile

only gave me the source code and not the dependencies.

I found a hackish method that seems to work however. Adding

python () {
    deps, _ = bb.data.build_dependencies("do_compile", set(), set(), set(), d)
    bb.note("do_compile deps: ", str(deps))
}

to the recipe also prints all the inferred dependencies.

Thanks,
Ulf