Re: [PATCH] lto: Set resolution to LDPR_PREVAILING_DEF for non-IR common symbol

On 27.08.2026 14:04, H.J. Lu wrote:
> On Thu, Aug 27, 2026 at 7:52 PM Jan Beulich <[email protected]> wrote:
>>
>> On 27.08.2026 10:31, H.J. Lu wrote:
>>> Since size or alignment of common symbol may be overridden by another
>>> common symbol, set symbol resolution to LDPR_PREVAILING_DEF, instead of
>>> LDPR_RESOLVED_EXEC, for common symbol in regular object when seeing an
>>> undefined or common symbol from an IR object.
>>
>> Is this correct for the LDPK_COMMON case that's also covered by the if()
>> that you alter in get_symbols()?
> 
> My patch covers the case of
> 
> syms[n].def == LDPK_COMMON && blhe->type == bfd_link_hash_common.
> 
> which wasn't handled before.

Right, but that doesn't answer my question, hinting towards a situation where
two instances of a common symbol collide. And I can't really resolve that for
myself because ...

>> Adding to the (my?) confusion is that after said
>>
>>       if (syms[n].def == LDPK_UNDEF
>>           || syms[n].def == LDPK_WEAKUNDEF
>>           || syms[n].def == LDPK_COMMON)
>>
>> there's an "else if" with this comment:
>>
>>       /* Was originally def, weakdef, or common, but has been pre-empted.  */
>>
>> With the cited if(), no originally common symbol can make it there, can it?

... there's this comment which irritates me.

> My patch covers
> 
>       if (syms[n].def == LDPK_UNDEF
>           || syms[n].def == LDPK_WEAKUNDEF
>           || syms[n].def == LDPK_COMMON)
>         {
>              ...
> 
> It has nothing to do with the else clause.

Correct, and I didn't mean to say anything to the contrary.

Jan