Build system does not allow nested features.

[SeppoTakalo]

Description

• Type: Bug
• Priority: Blocker.
  I cannot create Nanostack binary release because of this.

---

Bug

Expected behavior
I should be able to create nested features like FEATURE_NANOSTACK/FEATURE_LOWPAN_ROUTER

Actual behavior
Build system is not picking up the second level of features.

Steps to reproduce
Create a FEATURE_X directory under any known feature. X should be one of allowed from config.py
Files under this FEATURE_X are ignored by build system.

[SeppoTakalo]

CC: @0xc0170 @sg- @kjbracey-arm

[SeppoTakalo]

CC: @TuomoHautamaki

[theotherjimmy]

Yes: This is simply that the Resources object has a Resources object for each feature and assumes that there will be no features nested within those feature objects. Fixing this would require that the build system traverse a DAG of resources objects to collect it's build files. @screamerbg

[sg-]

Can we just remove the top level FEATURE_NANOSTACK and rename to nanostack?

[SeppoTakalo]

CC: @sam-taylor-arm @sg- @rhenson @TuomoHautamaki @tommihei01

This should now be considered as a blocker bug for us.
We cannot do the binary release as we have planned to do it.

+
|
+-+FEATURE_NANOSTACK
|         +
|         +---+FEATURE_LOWPAN_ROUTER
|              FEATURE_LOWPAN_HOST
|              ...
|              FEATURE_THREAD_ROUTER
|
+--+FEATURE_COMMON_PAL

Build system needs to be fixed to handle features a same way as TOOLCHAIN_* and TARGET_* are handled. They allow nesting.

[theotherjimmy]

So, it seems that the nanostack binary has been updated despite this. I'm going to close this issue. Please re-open if you have another use-case that would be broken by this behavior.

[SeppoTakalo]

I don't agree the reason for closing this.
Features don't work as expected, therefore this bug.

I would expect features work in a way how TARGET_* and TOOLCHAIN_* would work. I would like to use the behaviour similar to TARGET_* so that I can, for example, drop RF drivers from example applications when Nanostack is not compiled in.

If we were able to make a workaround and release Nanostack regardless of this bug, it is not a reason for closing this.

Either fix the issue, or document how the FEATURE_* thing works.