Re: [PATCH v3] gcov: Disable GCOV_PROFILE_ALL on 32-bit UML with Clang 20/21

Johannes Berg
2026-04-09T14:47:43Z

Hi,

Maybe the subject should say "um:" instead of "gcov:" now?

(I'm assuming you want us to apply it to uml tree.)

> Prevent the bad combination by disabling UML's ARCH_HAS_GCOV_PROFILE_ALL
> on 32-bit when using Clang 20.x or 21.x.

You say 20.x or 21.x,

> + # Clang 20 & 21 miscompute __builtin_object_size() under -fprofile-arcs
> + # on 32-bit, causing spurious compile-time errors in check_copy_size().
> + select ARCH_HAS_GCOV_PROFILE_ALL if !(!64BIT && CLANG_VERSION >= 200000 && CLANG_VERSION < 220100)

and I see that 22.0 doesn't even exist, and maybe that's a general
pattern, but it still looks confusing? Wouldn't it be better simpler to
say < 220000? At least to me that more obviously is "up to 21.x". After
all, 20.0 also didn't exist, and you did >=200000, not >200000 or
>=200100?

johannes