[PATCH v3 00/12] refactor Rust proc macros with `syn`

[Gary Guo <gary@kernel.org>]

From: Gary Guo <gary@garyguo.net>

This series convert Rust proc macros that we have with `syn`, and replace the
custom `quote!` macro that we have with the vendored `quote!` macro. The
`pin-init` macros are not converted `syn` yet; Benno has a work in progress in
converting them. They're however converted to use `quote` and `proc-macro2`
crate so our custom `quote!` macro can be removed.

Overall this improves the robustness of the macros as we have precise parsing of
the AST rather than relying on heuristics to extract needed information from
there. This is also a quality-of-life improvement to those using language
servers (e.g. Rust analyzer) as the span information of the proc macros are now
preserved which allows the "jump-to-definition" feature to work, even when used
on completely custom macros such as `module!`.

Miguel gave a very good explaination on why `syn` is a good idea in the patch
series that introduced it [1], which I shall not repeat here.

Link: https://lore.kernel.org/rust-for-linux/20251124151837.2184382-1-ojeda@kernel.org/ [1]

Changes since v2:
- Changes are limited to `#[vtable]` and `module!` macros.
- `#[vtable]` macro is reworked per Tamir's suggestion. This makes it easy
  to support `#[cfg]` properly, and hence a new patch is added to do that.
- Avoided variable renames related to `param_name`/`param_type` between
  patches in `module!` macro
- `CString` is now interpolated directly without adding extra
  `Literal::c_string`.
- Fixed an typo that affects only `CONFIG_HAVE_ARCH_PREL32_RELOCATIONS`
  builds.
- Link to v2: https://lore.kernel.org/rust-for-linux/20260107161729.3855851-1-gary@kernel.org/

Changes since v1:
- Fixed clippy warnings when moving from `proc-macro` to `proc-macro2`
  (extra trait impl in `proc-macro2` causes some `.to_string()` to be
  unnecessary).
- A Makefile change to pin-init-internal that is mistakenly included in
  patch 5/11 is moved to the correct patch 1/11.
- `module!` parsing has been completely reworked to support `imports_ns`
  and `params`. As there're two structs that need to parse ordered fields
  (`ModuleInfo` and `Parameter`), a `parse_ordered_field` macro is added
  and it is used to implement the parsing instead of `ModInfoField` and
  custom keywords.
- Link to v1: https://lore.kernel.org/rust-for-linux/20251211185805.2835633-1-gary@kernel.org/

Benno Lossin (1):
  rust: pin-init: internal: remove proc-macro[2] and quote workarounds

Gary Guo (11):
  rust: macros: use `quote!` from vendored crate
  rust: macros: convert `#[vtable]` macro to use `syn`
  rust: macros: use `syn` to parse `module!` macro
  rust: macros: use `quote!` for `module!` macro
  rust: macros: convert `#[export]` to use `syn`
  rust: macros: convert `concat_idents!` to use `syn`
  rust: macros: convert `#[kunit_tests]` macro to use `syn`
  rust: macros: allow arbitrary types to be used in `module!` macro
  rust: macros: rearrange `#[doc(hidden)]` in `module!` macro
  rust: kunit: use `pin_init::zeroed` instead of custom null value
  rust: macros: support `#[cfg]` properly in `#[vtable]` macro.

 rust/Makefile                             |  16 +-
 rust/kernel/kunit.rs                      |  26 +-
 rust/macros/concat_idents.rs              |  39 +-
 rust/macros/export.rs                     |  26 +-
 rust/macros/fmt.rs                        |   4 +-
 rust/macros/helpers.rs                    | 130 +---
 rust/macros/kunit.rs                      | 275 +++----
 rust/macros/lib.rs                        |  41 +-
 rust/macros/module.rs                     | 907 ++++++++++++----------
 rust/macros/paste.rs                      |   2 +-
 rust/macros/quote.rs                      | 182 -----
 rust/macros/vtable.rs                     | 165 ++--
 rust/pin-init/internal/src/helpers.rs     |   7 +-
 rust/pin-init/internal/src/lib.rs         |  16 -
 rust/pin-init/internal/src/pin_data.rs    |  18 +-
 rust/pin-init/internal/src/pinned_drop.rs |  10 +-
 rust/pin-init/internal/src/zeroable.rs    |   6 +-
 scripts/generate_rust_analyzer.py         |   2 +-
 18 files changed, 842 insertions(+), 1030 deletions(-)
 delete mode 100644 rust/macros/quote.rs


base-commit: 9ace4753a5202b02191d54e9fdf7f9e3d02b85eb
-- 
2.51.2