iree PDLL isn't enabled during llvm_byo (installed llvm/mlir) builds

#17144 adds support for pdll plugins but is disabled during builds that use out of tree llvm/mlir. As noted in the PR, MLIRPDLLParser is not installed by llvm. An upstream change to llvm is needed to be able to install all PDLL deps.

Here is a potential fix:

https://github.com/llvm/llvm-project/pull/90411

At this point, I'm not sure that would fully solve the issue. There might be some issues with mlir-tblgen's ODR violations.

Apr 30 '24 17:04 IanWood1

Does this pass with the upstream PR? (it looks sensible, but didn't try)

May 01 '24 17:05 jpienaar

Same here.. looks sensible to me to do that.

May 02 '24 01:05 MaheshRavishankar

Okay, I did some testing because I was having problems even with an updated upstream. For some reason, byo_llvm is able to build and link successfully but then segfaults on some of the tests. These tests aren't related to PDLL at all either.

May 02 '24 15:05 IanWood1

For some reason, byo_llvm is able to build and link successfully but then segfaults on some of the tests. These tests aren't related to PDLL at all either.

Got logs we can look at?

May 02 '24 15:05 ScottTodd

For some reason, byo_llvm is able to build and link successfully but then segfaults on some of the tests. These tests aren't related to PDLL at all either.

Got logs we can look at?

Yep https://gist.github.com/IanWood1/c2ea38035453b8a17b9d7c8b78fb9cd6

May 02 '24 16:05 IanWood1

I think byo_llvm works in very limited use cases. I expect such things to happen on mismatched LLVM versions.

May 02 '24 22:05 MaheshRavishankar