Re: [OE-core] [PATCH v2] lib/oe/package: Add strip keep-section support

[Mathieu Othacehe <othacehe@gnu.org>]

Hello Alexander,

> I don't understand. We already have support and tests for
> minidebuginfo, so what additional functionality would the above
> setting enable? Can you adjust the existing tests to showcase that?

When you want to display a backtrace on target you need basically two
things:

1. Symbols
2. Unwind information

The minidebuginfo functionality is covering the first part. It is
providing some symbols in a compressed way, that get appended to every
binary/library at build time.

Then the second part is about how to unwind the stack. That is
architecture dependant. On ARMv7, GCC is producing unwind information in
the .debug_frame section. That section is always removed by
'strip'. It prevents any unwinding based on .debug_frame on the target.

In the first version of that patch[1], I was proposing to introduce a
variable called PACKAGE_KEEP_DEBUG_FRAME to instruct `strip` to keep the
.debug_frame section around.

Quentin, pointed out, that we could be more generic and offer a
PACKAGE_KEEP_SECTIONS variable instead, to prevent specific sections
from being stripped.

That's what is done in this v2. I have proposed a documentation update
here: https://lists.yoctoproject.org/g/docs/message/6243

> Also the patch is changing things all over the place, and so is
> difficult to review. Can you split it up? E.g. first add some new
> thing, then adjust code elsewhere to take it into use.

It is only modifying the run_strip function and its callers, so "all over
the place" seems like an overstatement. I am not really sure how to
break that into more pieces. It's just about instructing "strip" to keep
some sections that are specified in the PACKAGE_KEEP_SECTIONS variable.

I would be glad to bring some more details on the topic if needed.

Thanks,

Mathieu