Re: [PATCH v8 7/8] rust: add utility procedural macro crate

[Junjie Mao]

On 8/23/2024 4:11 PM, Manos Pitsidianakis wrote:
> This commit adds a helper crate library, qemu-api-macros for derive (and
> other procedural) macros to be used along qemu-api.
>
> It needs to be a separate library because in Rust, procedural macros, or
> macros that can generate arbitrary code, need to be special separate
> compilation units.
>
> Only one macro is introduced in this patch, #[derive(Object)]. It
> generates a constructor to register a QOM TypeInfo on init and it must
> be used on types that implement qemu_api::definitions::ObjectImpl trait.
>
> Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> ---
>   MAINTAINERS                            |   1 +
>   rust/meson.build                       |   1 +
>   rust/qemu-api-macros/Cargo.lock        |  47 +++++++
>   rust/qemu-api-macros/Cargo.toml        |  25 ++++
>   rust/qemu-api-macros/README.md         |   1 +
>   rust/qemu-api-macros/meson.build       |  25 ++++
>   rust/qemu-api-macros/src/cstr/mod.rs   |  55 ++++++++
>   rust/qemu-api-macros/src/cstr/parse.rs | 225 +++++++++++++++++++++++++++++++++

Since Rust 1.77.0 C-string literals are stabilized [1]. I don't think we need to 
include this cstr crate as we require Rust >= 1.80.0.

[1] https://crates.io/crates/cstr

>   rust/qemu-api-macros/src/lib.rs        |  43 +++++++
>   rust/qemu-api/meson.build              |   3 +
>   10 files changed, 426 insertions(+)
[snip]
> diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build
> index 85838d31b4..a0802ad858 100644
> --- a/rust/qemu-api/meson.build
> +++ b/rust/qemu-api/meson.build
> @@ -13,6 +13,9 @@ _qemu_api_rs = static_library(
>     rust_args: [
>       '--cfg', 'MESON',
>     ],
> +  dependencies: [
> +    qemu_api_macros,
> +  ],
>   )
>   
>   qemu_api = declare_dependency(

qemu-api does not use macros provided by qemu-api-macros, but the later 
generates code that uses types defined by the former. So to me qemu-api-macros 
should depend on qemu-api, not vice versa.

---
Best Regards
Junjie Mao