Re: [C++ Patch/RFC] PR 57092

[Paolo Carlini <paolo dot carlini at oracle dot com>]

Hi,

On 04/29/2013 04:48 PM, Jason Merrill wrote:
> On 04/29/2013 05:05 AM, Paolo Carlini wrote:
> > in this 4.8/4.9 Regression, finish_decltype_type doesn't handle
> > ADDR_EXPR.
>
> Hmm...we're seeing the regression because previously 
> finish_decltype_type would have just returned the type of the template 
> parameter so it wouldn't ever see the ADDR_EXPR at instantiation time. 
> But we want to form a DECLTYPE_TYPE so that the mangling is correct. 
> Perhaps the right solution is to handle this case specially in 
> tsubst/DECLTYPE_TYPE: If id is true and the original expr is a 
> TEMPLATE_PARM_INDEX, just instantiate the type of the template parm 
> rather than its value.
thanks for your feedback. Are we sure that tsubst_copy_and_build, as 
called by tsubst/DECLTYPE_TYPE, can't return an ADDR_EXPR in other cases 
besides TEMPLATE_PARM_INDEX as input? I'm wondering if handling the 
additional TREE_CODE in finish_decltype_type isn't overall preferable 
(assuming we wouldn't end up soon handling all sorts of *_EXPR ;)

Paolo.