[RFC 0/1] Add bblock helper script

[Julien Stephan <jstephan@baylibre.com>]

Hi all,

I am currently working on bug #13425 and I would like to post my wip
script as an RFC to get feedback on it, before going further in the
development.

The script `script/bblock` can be used with the following command:

bblock [list of recipes to lock]

Here is a summary of what is currently implemented:
* can lock several recipes at once
* on first execution bblock will append `require bblock.inc` in
  `build/conf/auto.conf` (creates `auto.conf` if it doesn't exist)
* on first execution creates the file `build/conf/bblock.inc` with a
  dedicated header and:
	 - adds SIGGEN_LOCKEDSIGS_TYPES += "t-bblock"
	 - adds SIGGEN_LOCKEDSIGS_TASKSIG_CHECK = "warn" to display warning but
	   do not stop the build
* loops over all recipes to lock and adds entry with latest "do_compile"
  signature in `conf/bblock.inc`, such as: SIGGEN_LOCKEDSIGS_t-bblock += "bc:do_compile:e233cd793137a92dd575a417a2877e324ce526c4dc4a7db652abb9512f406f1f"

Limitations:
* only gets do_compile signature for now as a POC
* `bblock reset [list of recipes]` not yet implemented
* no check if a recipe is already locked

Steps to test the script:
bitbake bc --> generate a signature for bc's tasks
bblock bc
# modify do_compile in bc recipe to force signature change
bitbake bc --> throws the following warning: `WARNING: The bc:do_compile sig is computed to be 680bd6c291bf88e379e0c405a773cf5f81851e1a52570398cefd0196000ac1ef, but the sig is locked to e233cd793137a92dd575a417a2877e324ce526c4dc4a7db652abb9512f406f1f in SIGGEN_LOCKEDSIGS_t-bblock`

I also have a point I would like to discuss: I only get signature for
do_compile for the POC but wondering what should I do here:
* have a set of predefined task to lock, in that case how to choose the
  tasks?
* compute the list of all available tasks for a given recipe and get
  signature for all? Is there a way to get such list without using
  `infoil.build_targets(pn, "listtasks", handle_events=True)` as this
  will start bitbake, takes some time and requires some processing of
  the output
* add an option for the user to specify the task he wants to lock? (this
  may be useful to add anyway)

My branch is available here [1]

Am I going into the right direction?

Cheers
Julien

[1]: https://git.yoctoproject.org/poky-contrib/commit/?h=jstephan/bblock

Julien Stephan (1):
  scripts/bblock: add a script to lock/unlock recipes

 scripts/bblock | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100755 scripts/bblock

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2.41.0