[PATCH] add g_nonstandard_bool attribute for GIMPLE FE use

[Joseph Myers]

On Tue, 5 Jan 2021, Richard Biener wrote:

> would maybe result in a surprising result.  One alternative
> would be to make the attribute have the signedness specified as well
> (C doesn't accept 'unsigned _Bool' or 'signed _Bool') or
> simply name the attribute "signed_bool_precision".  I guess the bool case
> is really special compared to the desire to eventually allow
> declaring of a 3 bit precision signed/unsigned integer type.
> 
> Allowing 'signed _Bool' with -fgimple might be another option
> of course.

Something that makes clear it's a signed boolean type with the given 
precision seems a good idea (I'd have assumed a nonstandard boolean type 
with a given precision was unsigned).

-- 
Joseph S. Myers
joseph@codesourcery.com