llvm-3.4: Invalid configuration `arm64-apple-darwin20': machine `arm64-apple' not recognized

[ryandesign (Ryan Carsten Schmidt)]

llvm-3.4 doesn't build on arm64:

​https://build.macports.org/builders/ports-11_arm64-builder/builds/23259/steps/install-port/logs/stdio

checking build system type... Invalid configuration `arm64-apple-darwin20': machine `arm64-apple' not recognized

Maybe using a newer config.guess / config.sub helps?

llvm-3.4 is a dependency of pure.

pure could use llvm-3.5 if that still existed in MacPorts but it cannot use llvm 3.6 or newer because llvm 3.6 removed a fundamental llvm feature upon which pure was built:

​https://groups.google.com/g/pure-lang/c/nd__RPNI36I/m/NjZHjgyOAwAJ

[kencu (Ken)]

The llvm subproject itself is much more forgiving to build than the rest of the llvm projects, so I would not be surprised if it could be done.

Sounds like, even if that were done, pure is not going to work on arm systems anyway, so it would be more of an experiment for fun than something that would get pure working on arm Macs:

" One pain point is ARM based computers, though, which are getting much more popular these days. The old JIT never worked properly there, so Pure can't support the Raspberry Pi, ARM Chromebooks, and the new Mac M1 computers. To make Pure work there will definitely require an update to the MCJIT. ""

[ryandesign (Ryan Carsten Schmidt)]

Oh, I forgot that part. In that case, one could either fix llvm-3.4 for Apple Silicon or mark it as incompatible with Apple Silicon (using supported_archs).

[kencu (Ken)]

In 63e83a0d379373fdedf55fafdac5209e92c47ccb/macports-ports (master):

llvm/clang-3.[3-4]: spec supported archs

closes: #63140