[PATCH v4 0/2] rust: take advantage of newer rust-analyzer features

[Jesung Yang via B4 Relay <devnull+y.j3ms.n.gmail.com@kernel.org>]

As discussed in [1], we need to support multiple versions of
rust-analyzer to take advantage of newer features without breaking
compatibility for users on older toolchains.

In this specific patch series addressing IDE support for inherent methods
of primitive types, the main compatibility issue arises from using
`sysroot_src`, which brings `std` as a dependency for crates in
`drivers/` and `samples/` (please see PATCH [2/2] for more details). This
causes rust-analyzer to incorrectly resolve symbols from `std` in those
crates.

It turns out that rust-analyzer v0.3.1877 (2024-03-11), which
corresponds to our current MSRV of 1.78, has the same `std` resolution
issue regardless of whether `sysroot_src` is used. However, as far as I
know, we're likely to bump the MSRV to 1.85, where the corresponding
rust-analyzer release indeed needs the versioning infrastructure to fix
the `std` issue.

Hence, this series revises the approach taken in [2] by first adding
multi-version support for rust-analyzer. Specifically, it enables
support for the v0.3.2727 (2025-12-22) release and newer, which is
required to resolve inherent method resolution issues for primitive
types found in recent versions of rust-analyzer.

As Eliot mentioned in [3], we might also want to do the `include_dirs`
trick on top of this series to support rust-analyzer releases older than
v0.3.2727, but it should be handled in a dedicated patch series.

[1] https://lore.kernel.org/rust-for-linux/20260101-rust-project-reduce-size-v1-1-4cd66e9e02d9@gmail.com/
[2] https://lore.kernel.org/r/20260101-ra-fix-primitive-v1-1-def809357b4e@gmail.com/
[3] https://lore.kernel.org/rust-for-linux/DFVQBFD54CJO.2D3VQ091URH2B@nvidia.com/

Signed-off-by: Jesung Yang <y.j3ms.n@gmail.com>
---
Changes in v4:
- Use `dataclass` for internal data structures.
- Change `RaVersionInfo` to an enum.
- Move `RaVersionInfo` closer to its point of use.
- Statically check if all `RaVersionInfo` variants are properly handled
  (using mypy).
- Relocate `ctx.manual_sysroot_crates` check in `append_sysroot_crate`.
- Move `crate_attrs=["no_std"]` addition to `scripts:
  generate_rust_analyzer.py: fix IDE support for primitive types`.
- Move `typing.NotRequired` closer to the relevant field.
- Link to v3: https://lore.kernel.org/r/20260308-ra-fix-primitive-v3-0-598017bcefd8@gmail.com

Changes in v3:
- Remove extra `crate_attrs=["no_std"]` for crates that specify
  `#![no_std]` by themselves.
- Fix rust-analyzer version for Rust 1.78.
- Tweak `map_ra_version_baseline` to distinguish between Rust version
  and rust-analyzer version.
- Simplify overall structure.
- Rebase on 6c02871d258 ("scripts: generate_rust_analyzer.py: reduce cfg
  plumbing")
- Link to v2: https://lore.kernel.org/r/20260109-ra-fix-primitive-v2-0-249852a4145a@gmail.com

Changes in v2:
- Implement multiple rust-analyzer version support.
- Rebase on 9ace4753a520 (Linux 6.19-rc4).
- Remove an unnecessary new line between tags.
- Link to v1: https://lore.kernel.org/r/20260101-ra-fix-primitive-v1-1-def809357b4e@gmail.com

---
Jesung Yang (2):
      scripts: generate_rust_analyzer.py: add versioning infrastructure
      scripts: generate_rust_analyzer.py: fix IDE support for primitive types

 scripts/generate_rust_analyzer.py | 220 ++++++++++++++++++++++++++++++++++----
 1 file changed, 198 insertions(+), 22 deletions(-)
---
base-commit: 6c02871d2585bca9d43cea239f908c05ef55a89d
change-id: 20260101-ra-fix-primitive-78154fe8173f

Best regards,
-- 
Jesung Yang <y.j3ms.n@gmail.com>