Rust and GCC, two different ways [LWN.net]

Rust and GCC, two different ways

Posted Oct 5, 2021 1:12 UTC (Tue) by willy (subscriber, #9762)
In reply to: Rust and GCC, two different ways by roc
Parent article: Rust and GCC, two different ways

So, I'm confused. I think it's fine to dismiss/merge multiple compilers based on being substantially the same. But I'm not clear on what "counts" as being "a C++ compiler". Is it the front end, the back end or the IR?

I'd argue the front end (everything from calling read() on the .cpp file to generating IR) is the important bit for "being a C++ compiler". IR to assembly/binary is code generation and essentially language independent.

So if a compiler uses g++ as its front end and does magic stuff afterwards, fine, let's dismiss it, but there are some compilers in this list being lumped together because they use the same back end, and I think that's bad logic. eg EDG should count, even though it doesn't do code gen.

to post comments

Rust and GCC, two different ways

Posted Oct 5, 2021 2:13 UTC (Tue) by roc (subscriber, #30627) [Link] (2 responses)

That's fair. That possible adds Embarcadero C++ and EDG to the list of "C++ compilers". But I don't know how many compilers on that list use EDG.

Another issue is that some of those compilers are hardly used. The mere existence of a compiler that hardly anyone uses or even tests against is not really significant.

Rust and GCC, two different ways

Posted Oct 5, 2021 5:26 UTC (Tue) by joib (subscriber, #8541) [Link]

IIRC PGI and pre-LLVM Intel use EDG?

That being said, it seems nowadays there's not that much interest in proprietary language extensions, and thus the focus on these proprietary LLVM forks seem to be in tuning (including new optimization passes?) for the particular vendor's CPU's. And maybe some improved runtime libraries. So in that sense it makes sense for the vendors to collaborate on an open source frontend (clang(++)) , as the secret proprietary juice is elsewhere.

Rust and GCC, two different ways

Posted Oct 5, 2021 10:25 UTC (Tue) by andrewsh (subscriber, #71043) [Link]

Apparently Embarcadero switched to Clang some time ago.