> FWIW I was commenting on the impossibility
> of dynamically linking Zig libraries that uses comptime.
It doesn't make a difference, AFAICT my explanation on why it can work 
holds equally for static as for shared libraries.

On 03-08-2022 05:35, mcsinyx@disroot.org wrote:
> Compile-time execution must be done at, well, compilation time,
> thus macros in shared objects are just glorified embedded
> source code that are not used at runtime.

My point was that macros and dynamic (or static) linking is compatible 
with generics and macros. Of course, if your Zig code consists purely of 
generics and macros, it's kind of pointless, but presumably there's 
non-generic code too and non-generic library code that chooses a 
particular instance of a generic (monomorphisation?) that could benefit 
from compiling only once instead of being recompiled for every leaf (+- 
application).

> That being said, there may be a Zig ABI in the future, with the cost
> of missing certain features (like comptime) and optimizations:
> https://github.com/ziglang/zig/issues/3786

A fixed, stable, ABI or documented ABI is not required for Guix because 
we have the store and RPATH (or RUNPATH, I always forget which one we 
use) and the store model instead of putting things in /usr/lib and 
searching for them there, so occasional ABI breaks are not a problem for 
Guix.

Distros like, say, Debian, are another matter of course, though they 
could resort to build-from-scratch like done with Rust currently.

You are referring to optimisations, but at least LTO is perfectly 
combinable with static libraries (see, e.g., Rust). Shared libraries 
should be equally possible if it is accepted that it won't be always 
possible anymore to simply replace the shared library with another 
(because of things like inlining).

Greetings,
Maxime