[PATCH v3 0/4] rust: extend `module!` macro with integer parameter support

[Andreas Hindborg <a.hindborg@kernel.org>]

This series extends the `module!` macro with support module parameters. It
also adds some string to integer parsing functions and updates `BStr` with
a method to strip a string prefix.

This series stated out as code by Adam Bratschi-Kaye lifted from the original
`rust` branch [1].

Link: https://github.com/Rust-for-Linux/linux/tree/bc22545f38d74473cfef3e9fd65432733435b79f [1]
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
Changes since v2 [1]:
- use `SyncUnsafeCell` rather than `static mut` and simplify parameter access
- remove `Display` bound from `ModuleParam`
- automatically generate documentation for `PARAM_OPS_.*`
- remove `as *const _ as *mut_` phrasing
- inline parameter name in struct instantiation in  `emit_params`
- move `RacyKernelParam` out of macro template
- use C string literals rather than byte string literals with explicit null
- template out `__{name}_{param_name}` in `emit_param`
- indent template in `emit_params`
- use let-else expression in `emit_params` to get rid of an indentation level
- document `expect_string_field`
- move invication of `impl_int_module_param` to be closer to macro def
- move attributes after docs in `make_param_ops`
- rename `impl_module_param` to impl_int_module_param`
- use `ty` instead of `ident` in `impl_parse_int`
- use `BStr` instead of `&str` for string manipulation
- move string parsing functions to seperate patch and add examples, fix bugs
- degrade comment about future support from doc comment to regular comment
- remove std lib path from `Sized` marker
- update documentation for `trait ModuleParam`

Changes since v1 [2]:
- Remove support for params without values (`NOARG_ALLOWED`).
- Improve documentation for `try_from_param_arg`.
- Use prelude import.
- Refactor `try_from_param_arg` to return `Result`.
- Refactor `ParseInt::from_str` to return `Result`.
- Move C callable functions out of `ModuleParam` trait.
- Rename literal string field parser to `expect_string_field`.
- Move parameter parsing from generation to parsing stage.
- Use absolute type paths in macro code.
- Inline `kparam`and `read_func` values.
- Resolve TODO regarding alignment attributes.
- Remove unnecessary unsafe blocks in macro code.
- Improve error message for unrecognized parameter types.
- Do not use `self` receiver when reading parameter value.
- Add parameter documentation to `module!` macro.
- Use empty `enum` for parameter type.
- Use `addr_of_mut` to get address of parameter value variable.
- Enabled building of docs for for `module_param` module.

Link: https://lore.kernel.org/rust-for-linux/20240705111455.142790-1-nmi@metaspace.dk/ [2]
Link: https://lore.kernel.org/all/20240819133345.3438739-1-nmi@metaspace.dk/ [1]

---

---
Andreas Hindborg (4):
      rust: str: implement `PartialEq` for `BStr`
      rust: str: implement `strip_prefix` for `BStr`
      rust: str: add radix prefixed integer parsing functions
      rust: add parameter support to the `module!` macro

 rust/kernel/lib.rs           |   2 +
 rust/kernel/module_param.rs  | 238 +++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/str.rs           | 138 +++++++++++++++++++++++++
 rust/macros/helpers.rs       |  10 ++
 rust/macros/lib.rs           |  31 ++++++
 rust/macros/module.rs        | 188 ++++++++++++++++++++++++++++++----
 samples/rust/rust_minimal.rs |  10 ++
 scripts/Makefile.build       |   2 +-
 8 files changed, 600 insertions(+), 19 deletions(-)
---
base-commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4
change-id: 20241211-module-params-v3-ae7e5c8d8b5a

Best regards,
-- 
Andreas Hindborg <a.hindborg@kernel.org>