[LLVMdev] DWARF 2/3 backwards compatibility?

[Eric Christopher]

On Wed, Oct 17, 2012 at 9:11 PM, Rick Foos <rfoos at codeaurora.org> wrote:
> I'd like to summarize what we've discussed for a moment, and propose a patch
> tomorrow. It will clear a problem we have, and provide a way to handle a lot
> more of these that will come up as we go to Dwarf 5, and the next GDB.
>

Sounds good.

> The framework is a set of GCC like gdwarf[2,3,4,5] flags. I can see cases
> where compatibility is 2,3 or 2,3,4, so maybe the flag is a number to allow
> <=3 tests, have to sleep on that. This flag must go to the backend.
>

Yep. Sounds like what we were talking about yesterday. It'll need to
be both in the front and back end because there are features used in
the front end as well as encoding differences in the backend.

> Then the patch will change the conditional for DW_FORM_flag_present that
> caused the problem back to the old DW_FORM_flag when -gdwarf2 or 3 is set.
>

There are a few other bits that it should change as well, I'm guessing
you haven't tried compiling too much c++11 code for your restricted
dwarf set yet :)

-eric