[DONOTMERGE] Debug x86 darwin issue

[Zentrik]

Try to debug issue at #57658 (comment)

[gbaraldi]

I would try doing ar -x sys-o.a and then
nm text\#0.o | grep ___extendhfsf2
and
nm text\#1.o | grep ___extendhfsf2
.
Currently these are internal symbols

❯ nm text#0.o | grep ___extendhfsf2
0000000000291284 t ___extendhfsf2
usr/lib/julia on  gb/const-return-param [$?]
❯ nm text#1.o | grep ___extendhfsf2
000000000029b638 t ___extendhfsf2
usr/lib/julia on  gb/const-return-param [$?]
❯ nm text#2.o | grep ___extendhfsf2
000000000028f8e8 t ___extendhfsf2
but maybe something changed in LLVM 20

[Zentrik]

Wait is there a difference between two leading underscores and three, because the error references symbols with 3 but my sys-o.a on linux and the references in jitlayers.cpp use 2.

I'm mostly hoping this just works with the yggy build as I don't have access to a mac nor have I ever done dev work on one.

[giordano]

Wait is there a difference between two leading underscores and three, because the #57658 (comment) references symbols with 3 but my sys-o.a on linux and the references in jitlayers.cpp use 2.

macOS compilers mangle all symbols by adding an extra leading underscore. So you should always expect one extra underscore when comparing symbols between macOS and rest of the world. This is also why c++filt has an option for stripping a leading underscore.

[Zentrik]

The hang is probably just #55844, so looks like it works with the yggy build.
Nvm it's failing now that I cherry picked the fix for that.

[ViralBShah]

These machines are increasingly harder to come by. I am sure we will start seeing projects starting to drop Darwin x86 at some point - perhaps we are still 2-3 years away from that.

[gbaraldi]

More importantly this might be an issue that shows up in different ways

[Zentrik]

Upstream issue at llvm/llvm-project#132055.

Not that it was useful here for me but for future reference, github actions has x86 macs and https://github.com/MatthewCroughan/NixThePlanet provides a easy way to get a x86 mac vm running on linux.