On Thu, Feb 04, 2016 at 05:01:36PM +1100, Richard Henderson wrote: > While attempting to write some code that uses the new x86 named address > space support in gcc 6, I found that __typeof is very unhelpful. In > particular, given > > int __seg_fs *ptr; > __typeof(*ptr) obj; > > OBJ will not be type "int", but "int __seg_fs". Which means that you can't > use it to create temporaries within statement expressions. > > In the process of writing this, I found a hack in __typeof added just to > support _Atomic. Which suggests that one of these variants would be more > generally helpful than the hack. > > I add __typeof_noas and __typeof_noqual. The first strips only the address > space, leaving 'const' and 'volatile' (and, I suppose 'restrict'). The > second strips all qualifiers, essentially yielding the TYPE_MAIN_VARIANT. > > Thoughts?
We've already been asked to add something like __typeof_noqual, e.g. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39985#c3 . In a similar PR, I wanted to modify __typeof to drop all qualifiers, but Joseph suggested instead to add a new typeof variant: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65455#c19 (or adjust __typeof to only drop all qualifiers on rvalues?). So this makes sense, though I don't see the need for __typeof_noas if we can have __typeof_noqual. Marek
