Building LLVM-8 on 10.5.8 PPC

[barracuda156]

@iains Your branch mentions PowerPC Darwin: https://github.com/iains/LLVM-8-Branch
However there is no instruction on how to build it. Could you please give a sequence of steps required, so that I can test if it works on my end?

For now, only 10.5.8 PPC is relevant. (Once that succeeds, I could try 10.6.8 Rosetta, and if that also works, then backport it for 10.6 PPC.)

[iains]

To be honest, there is nothing on the LLVM-8 branch to offer anything to you that is not present on the llvm-7.1.1 case. However, the general mechanism to build LLVM is the same.

[barracuda156]

Ok, got it. And to build LLVM-7, is there a tested procedure for Darwin PPC?
Like configure line for gcc, which made everything build.

[kencu]

you might try building a current llvm and clang a few times at least on some current Intel system using their native build systems without using macports to get the general idea of what is involved, where it is still supported and easy.

Once that seems easy, then try perhaps building Iains 7.1.1 branch on some mid-age intel system like 10.9. that would be still sorta easy.

then try building it on an old system like 10.6 intel, which has more hassles but at least is easier still than 10.5. Then ideally try 10.5 Intel.

Once you get 10.5 Intel building, you can take on 10.5 PPC, which is both harder and still broken once you did get a build. At that point, you could float questions if you got build errors.

10.6 rosetta and 10.6 for PPC will have many headaches. But by the time you get there, perhaps you’ll be quite expert and could fix them!

[iains]

@kencu good advice!
(powerpc darwin is a challenging platform for newer c++ stuff).

• LLVM/clang is a cmake project - so you need cmake installed.

• [when you get there] do not try to build with Debug enabled on powerpc darwin - the debug objects will exceed the size of the available address space in the linker (actually, that will apply to any 32b host environment - so also on i686-darwin)

• Instead of having a long command line for cmake, I usually set the relevant variables in a short cmake script: and then invoke cmake -C path/to/cmake/script path/to/llvm - this does at least preserve a record of the configuration you used (which is much harder to deduce from the content of the CMakeCache file)

[barracuda156]

@kencu

• Instead of having a long command line for cmake, I usually set the relevant variables in a short cmake script: and then invoke cmake -C path/to/cmake/script path/to/llvm - this does at least preserve a record of the configuration you used (which is much harder to deduce from the content of the CMakeCache file)

Yes, that’s how I did when building your xtools which also required Cmake.

[barracuda156]

@iains I resurrect this topic in order not to open another, since it is related.

I wanna build your llvm on 10.5.8 either as ppc+ppc64 or just for ppc64. I do not care about clang; the idea is to get llvm built and, possibly, libc++.

Could you say if your llvm-7.1 was tested for ppc64 specifically? From README it appears that llas is functional (if it can build gcc), is that the case?