[dralley]

>Those mainframes your Bank runs? I'm sure they'd love to see all that "awful" FORTRAN or C or whatever other language rewritten in Rust. But if Rust as a platform doesn't support the architecture? Well then that's a non-starter

But Rust does support S390x?

>Worse still, Rust seems to basically leave anything that isn't i686/x86_64 or ARM64 as "Tier 2" or worse

Rust has an explicit documented support tier list with guarantees laid out for each level of support. Point me to a document where GCC or Clang lists out their own explicit guarantees on a platform-by-platform basis.

Because I strongly suspect that the actual "guarantees" which GCC, clang and so forth provide for most obscure architectures is not that much better than Rust, if at all - just more ambiguous. And I don't find it very likely that the level of quality control for C compilers on m68k or alpha or s390x is not, in practice, at least a bit lower than that provided for x86 and ARM.

[im_down_w_otp]

We made s390x builds of all our tools (http://www.auxon.io) for an early customer that insisted on running their org on a leased machine from IBM.

It was actually a pretty good experience. It mostly just worked.

[cbmuser]

> But Rust does support S390x?

It's not a tier-1 target though.

[dralley]

And?

How extensively is GCC testing on s390x, and do they hard-block merging all patches on s390x support being 100% working, verified by said test suite in a CI that runs on every submitted patchset? Or at least hard-block releases over failing tests on s390x? Do they guarantee this in a written document somewhere?

If they do, then that's great, they can legitimately claim to have something over Rust here. But if they don't, and I cannot find any reference to such a policy despite searching fairly extensively, then GCC isn't providing "tier 1"-equivalent support either.

I work for Red Hat so I'm well aware that there are people out there that care a lot about s390x support and are willing to pay for that support. But I suspect that the upstreams are much looser in what they promise, if they make any promises at all.