miden_base_macros/

lib.rs

//! Module for Miden SDK macros
//!
//! ### How to use WIT generation.
//!
//! 1. Add `#[component]` on you `impl MyAccountType {`.
//! 2. Add `#[export_type]` on every defined type that is used in the public(exported) method
//!    signature.
//!
//! Example:
//! ```rust
//!
//! #[export_type]
//! pub struct StructA {
//!     pub foo: Word,
//!     pub asset: Asset,
//! }
//!
//! #[export_type]
//! pub struct StructB {
//!     pub bar: Felt,
//!     pub baz: Felt,
//! }
//!
//! #[component]
//! struct MyAccount;
//!
//! #[component]
//! impl MyAccount {
//!     pub fn (&self, a: StructA) -> StructB {
//!         ...
//!     }
//! }
//! ```
//!

//! ### Escape hatch (disable WIT generation)
//!
//! in a small fraction of the cases where the WIT generation is not possible (think a type defined
//! only in an external WIT file) or not desirable the WIT generation can be disabled:
//!
//! To disable WIT interface generation:
//! - Don't use `#[component]` attribute macro in the `impl MyAccountType` section;
//!
//! To use manually crafted WIT interface:
//! - Put the WIT file in the `wit` folder;
//! - call `miden::generate!();` and `bindings::export!(MyAccountType);`
//! - implement `impl Guest for MyAccountType`;

use crate::script::ScriptConfig;

extern crate proc_macro;

mod account_component_metadata;
mod boilerplate;
mod component_macro;
mod export_type;
mod generate;
mod script;
mod types;
mod util;

/// Generates the WIT interface and storage metadata.
///
/// **NOTE:** Mark each type used in the public method with `#[export_type]` attribute macro.
///
/// To disable WIT interface generation:
/// - don't use `#[component]` attribute macro in the `impl MyAccountType` section;
///
/// To use manually crafted WIT interface:
/// - put WIT interface file in the `wit` folder;
/// - call `miden::generate!();` and `bindings::export!(MyAccountType);`
/// - implement `impl Guest for MyAccountType`;
#[proc_macro_attribute]
pub fn component(
    attr: proc_macro::TokenStream,
    item: proc_macro::TokenStream,
) -> proc_macro::TokenStream {
    component_macro::component(attr, item)
}

/// Generates an equvalent type in the WIT interface.
/// Required for every type mentioned in the public methods of an account component.
///
/// Intended to be used together with `#[component]` attribute macro.
#[proc_macro_attribute]
pub fn export_type(
    attr: proc_macro::TokenStream,
    item: proc_macro::TokenStream,
) -> proc_macro::TokenStream {
    export_type::expand(attr, item)
}

/// Marks the function as a note script
#[proc_macro_attribute]
pub fn note_script(
    attr: proc_macro::TokenStream,
    item: proc_macro::TokenStream,
) -> proc_macro::TokenStream {
    script::expand(
        attr,
        item,
        ScriptConfig {
            export_interface: "miden:base/note-script@1.0.0",
            guest_trait_path: "self::bindings::exports::miden::base::note_script::Guest",
        },
    )
}

/// Marks the function as a transaction script
#[proc_macro_attribute]
pub fn tx_script(
    attr: proc_macro::TokenStream,
    item: proc_macro::TokenStream,
) -> proc_macro::TokenStream {
    script::expand(
        attr,
        item,
        ScriptConfig {
            export_interface: "miden:base/transaction-script@1.0.0",
            guest_trait_path: "self::bindings::exports::miden::base::transaction_script::Guest",
        },
    )
}

/// Generate bindings for an input WIT document.
///
/// The macro here will parse [WIT] as input and generate Rust bindings to work with the `world`
/// that's specified in the [WIT]. For a primer on WIT see [this documentation][WIT] and for a
/// primer on worlds see [here][worlds].
///
/// [WIT]: https://component-model.bytecodealliance.org/design/wit.html
/// [worlds]: https://component-model.bytecodealliance.org/design/worlds.html
///
/// For documentation on each option, see below.
///
/// ## Exploring generated bindings
///
/// Once bindings have been generated they can be explored via a number of means
/// to see what was generated:
///
/// * Using `cargo doc` should render all of the generated bindings in addition
///   to the original comments in the WIT format itself.
/// * If your IDE supports `rust-analyzer` code completion should be available
///   to explore and see types.
///
/// ## Namespacing
///
/// The generated bindings are put in `bindings` module.
/// In WIT, worlds can import and export `interface`s, functions, and types. Each
/// `interface` can either be "anonymous" and only named within the context of a
/// `world` or it can have a "package ID" associated with it. Names in Rust take
/// into account all the names associated with a WIT `interface`. For example
/// the package ID `foo:bar/baz` would create a `mod foo` which contains a `mod
/// bar` which contains a `mod baz`.
///
/// WIT imports and exports are additionally separated into their own
/// namespaces. Imports are generated at the level of the `generate!` macro
/// where exports are generated under an `exports` namespace.
///
/// ## Exports: The `export!` macro
///
/// Components are created by having exported WebAssembly functions with
/// specific names, and these functions are not created when `generate!` is
/// invoked. Instead these functions are created afterwards once you've defined
/// your own type an implemented the various `trait`s for it. The
/// `#[unsafe(no_mangle)]` functions that will become the component are created
/// with the generated `export!` macro.
///
/// Each call to `generate!` will itself generate a macro called `export!`.
/// The macro's first argument is the name of a type that implements the traits
/// generated:
///
/// ```
/// use miden::generate;
///
/// generate!({
///     inline: r#"
///         package my:test;
///
///         world my-world {
/// #           export hello: func();
///             // ...
///         }
///     "#,
/// });
///
/// struct MyComponent;
///
/// impl Guest for MyComponent {
/// #   fn hello() {}
///     // ...
/// }
///
/// export!(MyComponent);
/// #
/// # fn main() {}
/// ```
///
/// This argument is a Rust type which implements the `Guest` traits generated
/// by `generate!`. Note that all `Guest` traits must be implemented for the
/// type provided or an error will be generated.
///
/// ## Options to `generate!`
///
/// The full list of options that can be passed to the `generate!` macro are as
/// follows. Note that there are no required options, they all have default
/// values.
///
///
/// ```
/// use miden::generate;
/// # macro_rules! generate { ($($t:tt)*) => () }
///
/// generate!({
///     // Enables passing "inline WIT". If specified this is the default
///     // package that a world is selected from. Any dependencies that this
///     // inline WIT refers to must be defined in the `path` option above.
///     //
///     // By default this is not specified.
///     inline: "
///         world my-world {
///             import wasi:cli/imports;
///
///             export my-run: func()
///         }
///     ",
///
///     // When generating bindings for interfaces that are not defined in the
///     // same package as `world`, this option can be used to either generate
///     // those bindings or point to already generated bindings.
///     // For example, if your world refers to WASI types then the `wasi` crate
///     // already has generated bindings for all WASI types and structures. In this
///     // situation the key `with` here can be used to use those types
///     // elsewhere rather than regenerating types.
///     // If for example your world refers to some type and you want to use
///     // your own custom implementation of that type then you can specify
///     // that here as well. There is a requirement on the remapped (custom)
///     // type to have the same internal structure and identical to what would
///     // wit-bindgen generate (including alignment, etc.), since
///     // lifting/lowering uses its fields directly.
///     //
///     // If, however, your world refers to interfaces for which you don't have
///     // already generated bindings then you can use the special `generate` value
///     // to have those bindings generated.
///     //
///     // The `with` key here works for interfaces and individual types.
///     //
///     // When an interface or type is specified here no bindings will be
///     // generated at all. It's assumed bindings are fully generated
///     // somewhere else. This is an indicator that any further references to types
///     // defined in these interfaces should use the upstream paths specified
///     // here instead.
///     //
///     // Any unused keys in this map are considered an error.
///     with: {
///         "wasi:io/poll": wasi::io::poll,
///         "some:package/my-interface": generate,
///         "some:package/my-interface/my-type": my_crate::types::MyType,
///     },
/// });
/// ```
///
#[proc_macro]
pub fn generate(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
    generate::expand(input)
}