I do not think I like this author...
> A critical piece of history here is to understand the really stupid way in which GCC does cross compiling. Traditionally, each GCC binary would be built for one target triple. [...] Nobody with a brain does this ^2
You're doing GCC a great disservice by ignoring its storied and essential history. It's over 40 years old, and was created at a time where there were no free/libre compilers. Computers were small and slow. Of course you wouldn't bundle multiple targets in one distribution.
LLVM benefitted from a completely different architecture and starting from a blank slate when computers were already faster and much larger, and was heavily sponsored by a vendor that was innately interested in cross-compiling: Apple. (Guess where LLVM's creator worked for years and lead the development tools team)
The older I get the more this kind of commentary (the OP, not you!) is a total turn off. Systems evolve and there's usually, not always, a reason for why "things are the way they are". It's typically arrogance to have this kind of tone. That said I was a bit like that when I was younger, and it took a few knockings down to realise the world is complex.
"This was the right way to do it forty years ago, so that's why the experience is worse" isn't a compelling reason for a user to suffer today.
Also, in this specific case, this ignores the history around LLVM offering itself up to the FSF. gcc could have benefitted from this fresh start too. But purely by accident, it did not.
> "This was the right way to do it forty years ago, so that's why the experience is worse" isn't a compelling reason for a user to suffer today.
On my system, "dnf repoquery --whatrequires cross-gcc-common" lists 26 gcc-*-linux-gnu packages (that is, kernel / firmware cross compilers for 26 architectures). The command "dnf repoquery --whatrequires cross-binutils-common" lists 31 binutils-*-linux-gnu packages.
The author writes, "LLVM and all cross compilers that follow it instead put all of the backends in one binary". Do those compilers support 25+ back-ends? And if they do, is it good design to install back-ends for (say) 23 such target architectures that you're never going to cross-compile for, in practice? Does that benefit the user?
My impression is that the author does not understand the modularity of gcc cross compilers / packages because he's unaware of (or doesn't care for) the scale that gcc aims at.
> And if they do, is it good design to install back-ends for (say) 23 such target architectures that you're never going to cross-compile for, in practice? Does that benefit the user?
I'm kinda surprised at how large that is, actually. But yeah, I don't mind if I have the capability to cross-compile to x86_64-wrs-vxworks that I'm never going to use.I am not an expert on all of these details in clang specifically, but with rustc, we take advantage of llvm's target specifications, so you that you can even configure a backend that the compiler doesn't yet know about by simply giving it a json file with a description. https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target...
While these built-in ones aren't defined as JSON, you can ask the compiler to print one for you:
It's lengthy so instead of pasting here, I've put this in a gist: https://gist.github.com/steveklabnik/a25cdefda1aef25d7b40df3...Anyway, it is true that gcc supports more targets than llvm, at least in theory. https://blog.yossarian.net/2021/02/28/Weird-architectures-we...
I'd love to learn what accident you're referring to, Steve!
I vaguely recall the FSF (or maybe only Stallman) arguing against the modular nature of LLVM because a monolothic structure (like GCC's) makes it harder for anti-GPL actors (Apple!) to undermine it. Was this related?
That is true history, in my understanding, but it's not related.
Chris Lattner offered to donate the copyright of LLVM to the FSF at one point: https://gcc.gnu.org/legacy-ml/gcc/2005-11/msg00888.html
He even wrote some patches: https://gcc.gnu.org/legacy-ml/gcc/2005-11/msg01112.html
However, due to Stallman's... idiosyncratic email setup, he missed this: https://lists.gnu.org/archive/html/emacs-devel/2015-02/msg00...
> I am stunned to see that we had this offer.
> Now, based on hindsight, I wish we had accepted it.
Note this email is in 2015, ten years after the initial one.
Incredible. Thank you for sharing.
You're welcome! It's a wild story. Sometimes, history happens by accident.
Wow that is wild. Imagine how different things could have been...
> and was heavily sponsored by a vendor that was innately interested in cross-compiling
and innately disinterested in Free Software, too