Re: [PATCH] DWARF: Add .debug_addr table header for dwarf_version >= 5.

[Mark Wielaard <mark at klomp dot org>]

Hi Eric,

On Sat, 2018-04-28 at 18:00 +0200, Eric Botcazou wrote:
> > index d3d925d..51d0ca4 100644
> > --- a/gcc/dwarf2out.c
> > +++ b/gcc/dwarf2out.c
> > @@ -31293,6 +31293,21 @@ dwarf2out_finish (const char *)
> >  	}
> > 
> >        switch_to_section (debug_addr_section);
> > +      /* GNU DebugFission didn't have a header for .debug_addr.  */
> > +      if (dwarf_version >= 5)
> 
> That sounds LLVMish...  Did you mean -gsplit-dwarf instead?

I don't know what LLVMish does, or whether it implements the GNU
DebugFission variant of split DWARF, the DWARF5 variant or something
else. For GCC -gsplit-dwarf generates GNU DebugFission output
(including .debug_addr) for older DWARF versions.
It is described here: https://gcc.gnu.org/wiki/DebugFission

This got standardized for DWARF5. But there are some differences. One
particular change is that GNU DebugFission doesn't have address table
headers in .debug_addr sections. But DWARF5 does. This patch fixes
that.

Or did you mean that you expected the code to be guarded by 
if (dwarf_split_debug_info)? It is, just a bit higher up in the code.

Cheers,

Mark