This is a remnant from when `Bounded` was called `BitInt` which I didn't
rename. Fix this.
Fixes: 01e345e82e ("rust: num: add Bounded integer wrapping type")
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20251124-bounded_fix-v1-1-d8e34e1c727f@nvidia.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`from_expr` relies on `build_assert` to infer that the passed expression
fits the type's boundaries at build time. That inference can only be
successful its code (and that of `fits_within`, which performs the
check) is inlined, as a dedicated function would need to work with a
variable and cannot verify that property.
While inlining happens as expected in most cases, it is not guaranteed.
In particular, kernel options that optimize for size like
`CONFIG_CC_OPTIMIZE_FOR_SIZE` can result in `from_expr` not being
inlined.
Add `#[inline(always)]` attributes to both `fits_within` and `from_expr`
to make the compiler inline these functions more aggressively, as it
does not make sense to use them non-inlined anyway.
[ For reference, the errors look like:
ld.lld: error: undefined symbol: rust_build_error
>>> referenced by build_assert.rs:83 (rust/kernel/build_assert.rs:83)
>>> rust/doctests_kernel_generated.o:(<kernel::num::bounded::Bounded<u8, 1>>::from_expr) in archive vmlinux.a
- Miguel ]
Fixes: 01e345e82e ("rust: num: add Bounded integer wrapping type")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511210055.RUsFNku1-lkp@intel.com/
Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20251122-bounded_ints_fix-v1-1-1e07589d4955@nvidia.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add the `Bounded` integer wrapper type, which restricts the number of
bits allowed to represent of value.
This is useful to e.g. enforce guarantees when working with bitfields
that have an arbitrary number of bits.
Alongside this type, provide many `From` and `TryFrom` implementations
are to reduce friction when using with regular integer types. Proxy
implementations of common integer operations are also provided.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251108-bounded_ints-v4-2-c9342ac7ebd1@nvidia.com
[ Added intra-doc link. Fixed a few other nits. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Alexandre Courbot