Re: [PATCH] Come up with htab_hash_string_vptr and use string-specific if possible.

["Martin Liška" <mliska@suse.cz>]

On 11/9/18 2:28 PM, Michael Matz wrote:
> Hi,
> 
> On Thu, 8 Nov 2018, Martin Liška wrote:
> 
>>> That seems better.  But still, why declare this in system.h?  It seems 
>>> hash-table.h seems more appropriate.
>>
>> I need to declare it before I'll poison it. As system.h is included very 
>> early, one can guarantee that there will be no usage before the 
>> poisoning happens.
> 
> Yes but it's also included everywhere, so adding anything to it comes at a 
> cost, and conceptually it simply doesn't belong there.

Agree.

> 
> There's no fundamental reason why we can't poison identifiers in other 
> headers.  Indeed we do in vec.h.  So move the whole thing including 
> poisoning to hash-table.h?

That's not feasible as gcc/gcc/genhooks.c files use the function and
we don't want to include hash-table.h in the generator files.
So second candidate can be gcc/hash-traits.h, but it's also not working:
/home/marxin/Programming/gcc/gcc/hash-traits.h:270:17: error: ‘gt_pointer_operator’ has not been declared
   pch_nx (T &p, gt_pointer_operator op, void *cookie)
                 ^~~~~~~~~~~~~~~~~~~

so we should eventually come up with "hash.h" and include it in many places as there's following usage
in hash-traits.h:

   212  inline hashval_t
   213  string_hash::hash (const char *id)
   214  {
   215    return hash_string (id);
   216  }

So it's question whether it worth doing that?

Martin

> 
> 
> Ciao,
> Michael.
>