> Compiler interoperability is the only ABI related problem area that's remotely in the scope for the C standard

idk, given how ABI impacts the evolution of C I think it's not unreasonable to provide a mechanism by which ABI can be evolved even if it's not specifically for compiler interop.

> Ultimately any ABI discussions need to happen between CPU and OS vendors, compiler toolchains implement whatever comes out of those discussions.

I think part of the article author's reasoning for proposing this feature is that toolchains have implemented something like this feature to try to address ABI issues and that the rest of the ecosystem could benefit from a similar technique.

Huh, compiler interoperability is extremely useful. It usually works by ABI groups defining a common ABI for each architecture and compilers then following these ABIs (although not required a compilers that does not is poor)

It's useful for closed-source developers who want to sell their libraries as precompiled binary blobs for static linking, but as soon as MSVC is involved that idea of "one library for different compilers" is out the window anyway ;)

For areas like application plugins via DLLs it's the OS ABI that matters.

It is also relevant for dynamic linking on all Linux binary distributions.

Hmm yeah ok, because Linux distros and glibc apparently never cared about defining a proper system ABI outside of 'whatever gcc happens to do'.

I don't understand this comment. There are well-defined ABIs for many platforms. Sometimes there is a defacto ABI defined by the first compiler supporting this platform, but generally there ABI groups that agree on a common ABI for each architecture. This then allows code compiled by different compiler to be linked against common libraries - not just glibc. I can compile my projects with either clang, gcc, or some other compiler and link statically or dynamically against all the same libraries distributed by my distribution regardless of which compiler was used to compile them. This is extremely useful.