[Patch c++] (__attribute__((deprecated)), part a) Fix PR17729

[IainS]

On 19 Jul 2010, at 18:58, Jason Merrill wrote:

> On 07/19/2010 01:11 PM, IainS wrote:
>> unfortunately, not
>> mark_used is called even more often than build_over_call &  
>> build_call_a
>> (at one stage I ended up with three warning messages)...
>>
>> It seems that there is no nice place to put these diagnostics, that  
>> is
>> only visited once (for the current formulation***);
>> Hence we end up checking in several places (which, I agree, does not
>> seem ideal).
>
> How about just using a hash table, as in  
> maybe_explain_implicit_delete?

I did some more back-tracing yesterday (to find where the duplicate  
calls are coming from);
I'll analyze that a bit more later, and maybe augment it ...

one point that this revealed is the types are not marked as used (at  
least not in this manner).
presumably there is some equivalent action so that we know which ones  
to emit for debug?

cheers,
Iain