[Dwarf-discuss] Duplicate frames?

[David Anderson]

Todd
|> I've never found any comprehensive document describing .eh_frame.  You'll
|> find some text in the AMD64 ABI: http://www.x86-64.org/documentation/abi.pdf.

Daniel
|It's now covered in the LSB.  Although, there was a discussion last
|month on the GCC mailing lists that suggests the LSB documentation has
|a serious typo in it.  I think relating to where offsets are relative to,
|i.e. this:

The LSB definitely helps, but it is far from sufficient.
It was not enough to enable interpreting zR for example.
Of course I may simply have not understood something there.

And I did not find  http://www.x86-64.org/documentation/abi.pdf
earlier (Thanks Todd, I'll take a look at it).


DW_DLE_DEBUG_FRAME_DUPLICATE
means (in libdwarf) that there are multiple .debug_frame sections
in a single object.   That could make sense  in a .o if
comdat-style duplicate-elimination is in use. But in a .so or
executable it does not make sense (to me).

libdwarf does not yet understand comdat-style section groups.

Is there a gcc that will emit such at this time?
Is that the ONLY way multiple .debug_frame are possible
legitimately (I think it is true, but am I wrong?)?
{And of course the other .debug_* section names  duplicated too
in that case.}

If I had something to work with (I mean test with)
I'd fix libdwarf to handle things...


Regards,
David B. Anderson davea at sgi dot com http://reality.sgiweb.org/davea