druntime redesign

[Denis Feklushkin]

On Tuesday, 25 February 2020 at 00:22:19 UTC, IGotD- wrote:

> This really opens up a second question, with your proposal with 
> an abstract interface we can start to reduce the dependency on 
> the C library. The C library is just there as baggage in order 
> to give basic OS functionality. With an abstract interface we 
> can use the OS primitives directly without going through any C 
> library. This is a huge task but this offers a gradual approach.
>
> We can have the C library as an option through the abstract 
> interface if we still need it.

Yes!

Perhaps  need to introduce option DRUNTIME_LIBC_AVAILABLE for 
druntime so that we can gradually get rid of all libc's symbols 
like "errno" inside of new abstract implementations by wrapping 
some druntime code pieces into version() branches.