Re: [rfa] delete lookup_symbol_aux_minsyms

[David Carlton <carlton@math.stanford.edu>]

On Sat, 22 Feb 2003 15:50:11 -0500, Daniel Jacobowitz <drow@mvista.com> said:
> On Sat, Feb 22, 2003 at 11:54:40AM -0800, David Carlton wrote:

>> So what's the conclusion?  Performance considerations don't seem to
>> give a clear answer.  So we should go with whatever's cleanest.  My
>> recommendation:
>> 
>> * Delete the 'else' clause: it might cause correctness problems.
>> 
>> * Comment out the remaining part of lookup_symbol_aux_minsyms: if
>> somebody comes up with a situation where we spend lots of time
>> searching for functions that aren't in a loaded symtab, we can
>> consider uncommenting it and adding it back in.

> I'm pretty sure the answer is "none at all" based on skimming the
> code, but what affect does removing lookup_symbol_aux_minsyms have
> when looking for something which turns out not to have debugging
> info?  lookup_symbol would fail, so it doesn't matter - is that
> right?

That's right: lookup_symbol tries to find symbols, so if a function
doesn't have debugging info, then lookup_symbol will return NULL
(unless we're in some sort of bizarre situation like having a static
function elsewhere with the same name), at which point it's the
caller's responsibility to call lookup_minimal_symbol if the caller is
in a position to deal with minimal symbols instead of symbols.  And
lookup_symbol would have returned NULL either before or after my
patch: the call to 'find_pc_sect_symtab' would have failed.

> I don't know if I like this comment-out-part-delete-part business;
> if we don't want the function, let's kill it.

It's not my first choice, either, but Elena has shown a preference in
the past for commenting out code like this instead of deleting it.
(C.f. the already commented-out bit in lookup_symbol_aux.)  This seems
to me a situation where it's not worth arguing about it.  However, if
Elena would rather delete it, I'd be happy to go along with that, too.

David Carlton
carlton@math.stanford.edu