On Sat, Jun 10, 2023 at 12:37:40PM +0200, Jakub Jelinek via Gcc-patches wrote:
> I think changing __builtin_classify_type behavior after 35 years
> would be dangerous, shall we introduce a new similar builtin which
> would just never promote the argument/perform array/function/enum
> conversions on it, so that
> __builtin_type_classify (true) == boolean_type_class
> enum E { E1, E2 } e;
> __builtin_type_classify (e) == enumeral_type_class
> int a[2];
> __builtin_type_classify (a) == array_type_class
> etc.?
> Seems clang changed __builtin_type_classify at some point
> so that it e.g. returns enumeral_type_class for enum arguments
> and array_type_class for arrays, but doesn't return boolean_type_class
> for _Bool argument.
Another option would be just extend the current __builtin_classify_type
to be more sizeof like, that the argument could be either expression with
current behavior, or type, and so one could use
__builtin_classify_type (int)
or
__builtin_classify_type (0)
or
__builtin_classify_type (typeof (expr))
and the last way would ensure no argument promotion happens.
Jakub
