OpenBSD

[mulle-nat]

Originally posted by @alepi in #1 (comment)

Hi, I am interested in porting mulle objc ecosystem to openbsd and I need some guidance for that.
For example, openbsd makes its own patches to llvm and clang and I may need some help with how mulle-clang is > changed compared to vanilla clang.
Is the community the right place to ask this kind of questions? :-)

[mulle-nat]

It depends on the amount of patches that OpenBSD does. If you're really unlucky, it will hit some common code path. But I would not expect that. Mostly I would expect that you can take a 12.0.0 mulle-clang and apply the OpenBSD patches on top of it without problems. But you only know after trying :)

[alepi]

OpenBSD makes some quite heavy changes to clang from what I saw.

For example, I tried to build a cross compiler to compile code from my Mac to OpenBSD and even the simplest C code crashes when run on OpenBSD.

I have built clang/llvm for Mac targeting linux before, so I have some experience with this... OpenBSD devs discourage anyone from trying to create a cross compiler that targets OpenBSD from what I read. Not impossible but not trivial as well.

Is it possible to have a repo with a set of patches for vanilla clang/llvm to enable mulle instead? Also, have you considered submitting your patches to the official clang/llvm community?

[mulle-nat]

Clang/llvm is so huge, it's just a guess, if there are conflicts. You can grep through the sources looking for @mulle-clang@ and check the files affected and compare with the files affected by the OpenBSD patches. But then you could also just patch and see ;)

Sure it would be nice to have mulle-objc in mainline llvm, but it's still much too niche for that I believe.

The mulle-clang-project is a fork off llvm. The changes are always rebased on llvm on release. So you can use git to get a patch set from mulle/12.0.0 to the respective llvm tag. The actual commands to do this elude me, but probably git diff something ?

Coming to think of it, you could also take llvm with OpenBSD patches and then patch it with mulle/12.0.0. If it goes well, it goes well, if it doesn't, I suggest you abandon it. Doing clang/llvm development is a terrible waste of human lifetime.

[alepi]

ok

[mulle-nat]

And one more thing :) For the releases I use a script to rebase my changes on top of the llvm repository. It's probably not complicated to pull the OpenBSD branch into mulle-clang-project via another git remote and then run an edited version of the script to patch it.

[mulle-nat]

Was it succesful ?

[mulle-nat]

I guess not.