[LLVMdev] ARM/MC/ELF questions on .ARM.attributes section

Rafael Espindola
2010-10-01T19:36:56Z

> 1. What is the preferred method in MC to jump back to a prior section
> already defined? (Or is this not supported?)

SetSection in the MCStreamer if you really want to change the current
section, but maybe all that you need is to setSection in the Symbol?
Similar to what is done in MCELFStreamer::EmitCommonSymbol if the
binding is local.

> 2. It looks like the "correct" way to write out these blobs in
ELF  is
> to add a new virtual interface to MCElfStreamer to emit the ARM
> specific chunks.
> I'd prefer to add a new subclass of MCELFStreamer to do this, but, it
> looks like the registration mechanism for streamer does not encourage
> this.
> The other possibility is to add in special case code to MCELFStreamer
> directly, which seems messy too. I am guessing that the latter
> approach is preferred. Is this the case?

Looks like all you need to do is create a data fragment, no? If so
doing it in MCELFStreamer is the right way to do it.

> 3. For the existing GNU ARM toolchain, what are the supported blobs
> that go into the ARM specific sections in the ELF file? (Renato, could
> you possibly shed light on  this?) I'd like to figure this out before
> I attempt to fill out ARM-specific changes to the MCELFStreamer
>
> Thanks!
>
> -jason
>


Cheers,
--
Rafael Ávila de Espíndola