Re: [PATCH RFC 1/2] Remove "readnow" support

Andrew Burgess
2026-02-12T13:30:26Z

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Tom Tromey <tom@tromey.com>
>> Date: Wed, 11 Feb 2026 11:49:09 -0700
>> Cc: Tom Tromey <tom@tromey.com>
>>
>> I think the "readnow" feature should be removed.
>>
>> "readnow" exists basically to work around potential bugs in any
>> "partial" reader. This used to work ok because gdb would scan all the
>> expanded symtabs in addition to using the "quick" functions. This
>> changed with the "search via psyms" series.
>>
>> So now, "readnow" is basically its own separate implementation. As
>> such, I don't think it carries its weight. It is very slow and uses a
>> lot of memory, and can have its own bugs requiring extra work on our
>> part.
>
> Is there any other way for the user to force GDB to read all of the
> symbols from all of the object files? If not, perhaps this
> functionality still has its value? Maybe we should make it a "maint"
> command instead?

I second this. We do run into bugs with the indexes from time to time,
and it's good to have some way to tell GDB to go read the full debug
information so we can narrow the bug down. Plus it offers a work around
in these cases.

Is 'maint expand-symtabs' the equivalent? When someone uses -readnow
should we maybe guide them towards the new way of doing things, even all
we do is point towards a particular entry in the manual maybe?

Thanks,
Andrew