Re: Setting up NetBSD/m68k on qemu-virt for LLVM CI

Hi,

> Currently that buildbot is running Linux/m68k which means that it's currently impossible
> to build LLVM natively due the two bytes alignment used on Linux/m68k by default:
>
> https://lab.llvm.org/staging/#/builders/91
>
> Would someone here be willing to help me set up the buildbot on NetBSD? My plan
> would be to shut down the Linux/m68k virtual machine, move it out of the way and
> replace with a NetBSD/m68k virtual machine and switch the CI to build on NetBSD.

Happy to help, but as you can see in the discussions here:

https://mail-index.netbsd.org/port-m68k/tindex.html

virt68k can't currently use more than a certain amount of memory, but 
getting it set up now for when that'll be fixed wouldn't hurt.

> FWIW, has anyone here tried building LLVM on NetBSD/m68k? At least a 
> stage1 build should just work while there might still be some issues 
> that prevent a two-stage build.

It was attempted as part of a pbulk build and failed pretty quickly:

[ 12%] Building CXX object 
tools/llvm-config/CMakeFiles/llvm-config.dir/llvm-config.cpp.o
[ 12%] Linking CXX executable ../../bin/llvm-config
[ 12%] Built target llvm-config
[ 12%] Building COFFOptions.inc...
[ 12%] Built target JITLinkTableGen
[ 12%] Building AArch64GenAsmWriter.inc...
[ 12%] Building AArch64GenAsmWriter1.inc...
[ 12%] Building AArch64GenCallingConv.inc...
[ 12%] Building AArch64GenDAGISel.inc...
[ 12%] Building AArch64GenDisassemblerTables.inc...
[ 12%] Building AArch64GenExegesis.inc...
[ 12%] Building AArch64GenFastISel.inc...
[ 12%] Building AArch64GenGlobalISel.inc...
LLVM ERROR: out of memory
Allocation failed
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ 
and include the crash backtrace.
Stack dump:
0.	Program arguments: ../../../bin/llvm-tblgen -gen-global-isel -I 
/tmp/pkgbuild/lang/llvm/work.m68k/llvm-18.1.8.src/lib/Target/AArch64 
-I/tmp/pkgbuild/lang/llvm/work.m68k/llvm-18.1.8.src/cmake-pkgsrc-build/include 
-I/tmp/pkgbuild/lang/llvm/work.m68k/llvm-18.1.8.src/include -I 
/tmp/pkgbuild/lang/llvm/work.m68k/llvm-18.1.8.src/lib/Target 
/tmp/pkgbuild/lang/llvm/work.m68k/llvm-18.1.8.src/lib/Target/AArch64/AArch64.td 
--write-if-changed -o 
/tmp/pkgbuild/lang/llvm/work.m68k/llvm-18.1.8.src/cmake-pkgsrc-build/lib/Target/AArch64/AArch64GenGlobalISel.inc
Stack dump without symbol names (ensure you have llvm-symbolizer in your 
PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  llvm-tblgen 0x00273c96 llvm::sys::DefaultOneShotPipeSignalHandler() + 
5422
1  llvm-tblgen 0x00273fd4 llvm::sys::DefaultOneShotPipeSignalHandler() + 
6252
2  llvm-tblgen 0x002722d0 llvm::raw_fd_ostream::~raw_fd_ostream() + 68860
3  llvm-tblgen 0x0027264e llvm::raw_fd_ostream::~raw_fd_ostream() + 69754
4  libc.so.12  0x0e7c407e __sigtramp_siginfo_2 + 0
[1]   Abort trap (core dumped) ../../../bin/llvm-tblgen -gen-global-isel 
-I /...
*** [lib/Target/AArch64/AArch64GenGlobalISel.inc] Error code 134

make[2]: stopped in 
/tmp/pkgbuild/lang/llvm/work.m68k/llvm-18.1.8.src/cmake-pkgsrc-build
1 error

The pbulk stuff takes lots of memory itself, so many things that don't 
compile as part of a bulk build work when compiled by itself.

This particular machine is compiling erlang at the moment. When that's 
finished, I'll give llvm another try.

But what I really think you're interested in is llvm-target-m68k. With all 
the default targets, it'd probably take ages, and llvm-target-m68k isn't 
even enabled by default.

John