Plan to contribute for supporting split dwarf (-gsplit-dwarf) in dwz

[Mark Wielaard]

Hi Alok,

On Mon, Feb 15, 2021 at 05:26:29PM +0000, Sharma, Alok Kumar via Dwz wrote:
> I am planning to contribute for supporting split DWARF.
> 
> Please let me know if it is already being worked on?

That is great. Nobody is currently working on that as far as I
know. One issue to resolve is knowing how to "unsplit" the DWARF
first. Since it isn't clear (to me) whether it makes sense to do split
DWARF .dwo (sections/files) together with Supplementary DWARF Object
references. One idea might be to handle DWP processed files?

There are a couple of bugs that might be prerequirements for handling
split DWARF, you probably need "split" variants of these bugs:
https://sourceware.org/bugzilla/show_bug.cgi?id=27376
https://sourceware.org/bugzilla/show_bug.cgi?id=27375
https://sourceware.org/bugzilla/show_bug.cgi?id=27373

See also this comment:
https://sourceware.org/bugzilla/show_bug.cgi?id=24726#c5
Which describes some other issues, like DW_FORM_strx, .debug_str_offset, 
DW_FORM_rnglistx and various _base attributes that need supporting.
(This should probabably have their own bugs filed.)

There is already one explicit -gsplit-dwarf variant bug:
https://sourceware.org/bugzilla/show_bug.cgi?id=24756 But that is only
for part of the problem (and might be simply resolved by bug #27375).

Cheers,

Mark