Re: [PATCH 1/1] archiver: execute the probable tasks between do_unpack and do_patch

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Wed, 2014-12-03 at 16:16 +0800, Hongxu Jia wrote:
> While archiver inherited, we edit a recipe (such
> as gzip) to insert four tasks between do_patch and
> do_unpack:
> ...
> addtask test1 after do_unpack before do_patch
> addtask test2 after do_unpack before do_test1
> addtask test3 after do_test2 before do_test1
> addtask test4 after do_test2 before do_test1
> ...
> 
> While building the recipe, the archiver will
> missing these four task in do_unpack_and_patch.
> Because it is hardcoded to execute do_unpach and
> do_patch, did not consider the probable tasks
> between them.
> 
> We make use of the value of _task_deps which
> provided by metadata to compute the probable
> tasks between do_unpack and do_patch and execute
> them.

_task_deps is not provided by the metadata, its a bitbake internal
variable and it should not be being used in public API like this. The
bitbake maintainers reserve the right to change structure and existence
of _task_deps freely. So this patch *cannot* merge in this form.

I do appreciate the problem you're trying to solve and that its a hard
one to deal with.

We should probably add some API to bb.build which allows the code to
query information about tasks. I would prefer to only expose the
information we need (the parents) rather than the whole contents of
_task_deps since that may change over time. The main reason that
structure exists at all is a performance optimisation inside the core of
bitbake.

Thinking about this further, have you looked at BB_TASKDEPDATA? You may
well be able to extract the information you need from that and that *is*
public API.

Cheers,

Richard