FreeBSD fbsd13 13.0-CURRENT FreeBSD 13.0-CURRENT #0 r357042: Fri Jan 24 01:38:31 CET 2020     root@fbsd13:/usr/obj/usr/src/amd64.amd64/sys/FBSD13  amd64

Kernel sources as of Feb., 11th 2020, r357761 do not compile:

llvm-tblgen -gen-disassembler  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc 
 -d SparcGenDisassemblerTables.inc.d -o SparcGenDisassemblerTables.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc/Sparc.td
llvm-tblgen -gen-instr-info  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc  -
d SparcGenInstrInfo.inc.d -o SparcGenInstrInfo.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc/Sparc.td                    
llvm-tblgen -gen-emitter  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc  -d S
parcGenMCCodeEmitter.inc.d -o SparcGenMCCodeEmitter.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc/Sparc.td               
llvm-tblgen -gen-register-info  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc
  -d SparcGenRegisterInfo.inc.d -o SparcGenRegisterInfo.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc/Sparc.td           
llvm-tblgen -gen-subtarget  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc  -d
 SparcGenSubtargetInfo.inc.d -o SparcGenSubtargetInfo.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/Sparc/Sparc.td             
llvm-tblgen -gen-asm-matcher  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/X86  -d X86GenAsmMatcher.inc.d -o X86GenAsmMatcher.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/X86/X86.td
llvm-tblgen -gen-asm-writer  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/X86  -d X86GenAsmWriter.inc.d -o X86GenAsmWriter.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/X86/X86.td
llvm-tblgen -gen-asm-writer -asmwriternum=1  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/X86  -d X86GenAsmWriter1.inc.d -o X86GenAsmWriter1.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/X86/X86.td
llvm-tblgen -gen-callingconv  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/X86  -d X86GenCallingConv.inc.d -o X86GenCallingConv.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/X86/X86.td
llvm-tblgen -gen-dag-isel  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/X86  -d X86GenDAGISel.inc.d -o X86GenDAGISel.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/X86/X86.td
llvm-tblgen -gen-disassembler  -I /usr/src/contrib/llvm-project/llvm/include -I /usr/src/contrib/llvm-project/llvm/lib/Target/X86  -d X86GenDisassemblerTables.inc.d -o X86GenDisassemblerTables.inc  /usr/src/contrib/llvm-project/llvm/lib/Target/X86/X86.td
*** Signal 9

Stop.
make[6]: stopped in /usr/src/lib/clang/libllvm
*** Error code 1

Stop.
make[5]: stopped in /usr/src/lib/clang
*** Error code 1

Stop.
make[4]: stopped in /usr/src/lib
*** Error code 1

Stop.
make[3]: stopped in /usr/src
*** Error code 1

Stop.
make[2]: stopped in /usr/src
*** Error code 1

Stop.
make[1]: stopped in /usr/src
*** Error code 1

Stop.
make: stopped in /usr/src

Out of memory error. This is with zfs, not ufs. It does not mater how many ram there is. If there are 8G it'll stop with the very same error. If I'm right it would compile with 32G ram or swap, but I do not, at the moment, have the machine to test this ...!