Re: DWARF2 unwinding documentation/help

[Richard Henderson <rth at redhat dot com>]

On Sun, Aug 24, 2003 at 05:53:28PM +0200, Bernardo Innocenti wrote:
> My target is an m68k-elf variant using a surrogate of the ELF format.

At what point are you surrogating?  At the .s level, .o level,
or at final link?  Depending on the nature of the true target
format, waiting until final link to produce the not-ELF format
may be easiest.

> It needs to place the unwinding tables in the data segment and doesn't
> link crtbegin/crtend. I've seen EH related stuff in there, but I'm
> not sure whether they are needed.

Again, depending on the above.  But if you can't wait until
final link (when you can just fold .eh_frame into .data),
then this should be as simple as (1) not providing named
sections, or (2) defining EH_FRAME_IN_DATA_SECTION.

> Also suspicious is that the m68k back-end handling of
> DWARF2 information for function prologues/epilogues is quite
> different from other back-ends (I've looked in i386 and arm).

While the generation is a bit different, because of the way we
currently print prologues as text, the result should be very
similar to x86.

With ELF object files, study the output of readelf -wf and -wF
together with the dwarf2 docs and you should achieve Enlightenment.


r~