[Bug gdb/23710] gdb is slow and memory hungry consuming debug generated with LTO by GCC

["rguenth at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=23710

--- Comment #26 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Tom Tromey from comment #25)
> Changing the full reader to read DIEs on demand is almost doable.
> The major problem I see here is that some code looks at a DIE's
> parent -- but due to the nature of DWARF, this requires a more
> full scan of the DIE tree (there are no parent links in the
> .debug_info itself)

That's indeed an issue.  Still even here scanning for the parent
chain up to the CU header shouldn't be too expensive if you do not
materialize all other objects (maybe avoid redundant work by having
'placeholder' DIEs read-in with just TAG and sibling info, not populating
any of its actual content to avoid reading other DIEs).  mmap vs. read
might be another thing to consider here (I also wonder if the actual
DWARF might be good enough of a data format to work with for most parts
of a DIE to avoid duplicating/exploding this already large data in memory).

> Longer term I would like to have gdb make a symtab directly
> from the index, and then lazily instantiate symbol contents
> when needed.  I think this would be much faster.

-- 
You are receiving this mail because:
You are on the CC list for the bug.