LLVM 4.0 support status?


#1

Hi,

Considering Upgrade to LLVM 4.0 #37609 github issue, I see some work in progress for making rustc supporting upcoming LLVM 4.0.0.

Currently, LLVM 4.0.0 has RC1 release out, RC2 will arrive soon (Feb 2), and final realase is expected for near Feb 21.

I recently tried to compile rustc with LLVM 4.0.0-rc1 to see the status (at OpenBSD, we expect to ship LLVM 4.0.0 in ports quickly, and as rustc is by default linked with LLVM from ports, I take a look at it), and I was suprised to see that rustllvm doesn’t link at all with nightly for now.

For now, I think rustc port under OpenBSD will be build with embedded LLVM version, but I hope it is only a temporary measure (the build time grows a lot).

So I would like to know the current status of supporting LLVM 4.0.0, to know if I mess myself in some way to not be able to just link, or if it is currently expected.

And thanks for your work !


#2

Looks like people have been working on supporting it


#3

yes, lot of them are in the list of gh37609, and are already merged.


#4

It is expected (by me, at least) that LLVM 4.0 + rust master currently doesn’t work. My Rust fork has some rustllvm patches to make it work with the LLVM version I’m working with, which is very close to the 4.0 release branch, so I expect these patches (or something similar) will be need to be upstreamed before Rust can work with LLVM 4.0. I’ll try to find the time to polish these patches and submit them as PRs some time soon. But if anyone else is interested in working towards LLVM 4.0 compatibility, I can also share these patches and whatever info I have.