fixed_map_derive/
lib.rs

1//! [<img alt="github" src="https://img.shields.io/badge/github-udoprog/fixed--map-8da0cb?style=for-the-badge&logo=github" height="20">](https://github.com/udoprog/fixed-map)
2//! [<img alt="crates.io" src="https://img.shields.io/crates/v/fixed-map-derive.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/fixed-map-derive)
3//! [<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-fixed--map--derive-66c2a5?style=for-the-badge&logoColor=white&logo=data:image/svg+xml;base64,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" height="20">](https://docs.rs/fixed-map-derive)
4//!
5//! This crate contains the procedural macros used in [fixed-map].
6//!
7//! [fixed-map]: https://github.com/udoprog/fixed-map
8
9#![recursion_limit = "256"]
10#![deny(missing_docs)]
11#![allow(clippy::expl_impl_clone_on_copy)]
12#![allow(clippy::module_name_repetitions)]
13#![allow(clippy::too_many_lines)]
14#![allow(clippy::type_repetition_in_bounds)]
15#![allow(clippy::unnecessary_wraps)]
16#![allow(missing_docs)]
17
18use proc_macro2::TokenStream;
19use quote::quote;
20use syn::spanned::Spanned;
21use syn::{Data, DataEnum, DeriveInput, Fields};
22
23mod any_variants;
24mod attrs;
25mod context;
26mod symbol;
27mod unit_variants;
28
29/// See <https://docs.rs/fixed-map>.
30#[proc_macro_derive(Key, attributes(key))]
31pub fn storage_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
32    let ast = syn::parse_macro_input!(input as DeriveInput);
33
34    let lt = syn::Lifetime::new("'a", ast.span());
35    let crate_prefix = context::leading_path(["fixed_map"]);
36    let tokens = context::Toks::new(&crate_prefix);
37    let cx = context::Ctxt::new(&tokens, &ast, &lt);
38
39    let result = impl_storage(&cx);
40
41    if let Ok(g) = result {
42        return g.into();
43    }
44
45    let errors = cx.into_errors();
46    let compile_errors = errors.iter().map(syn::Error::to_compile_error);
47    quote!(#(#compile_errors)*).into()
48}
49
50fn impl_storage(cx: &context::Ctxt<'_>) -> Result<TokenStream, ()> {
51    let opts = attrs::parse(cx)?;
52
53    if let Data::Enum(en) = &cx.ast.data {
54        if is_all_unit_variants(en) {
55            unit_variants::implement(cx, &opts, en)
56        } else {
57            any_variants::implement(cx, en)
58        }
59    } else {
60        cx.span_error(cx.ast.span(), "named fields are not supported");
61        Err(())
62    }
63}
64
65fn is_all_unit_variants(en: &DataEnum) -> bool {
66    for v in &en.variants {
67        if !matches!(&v.fields, Fields::Unit) {
68            return false;
69        }
70    }
71
72    true
73}
fixed_map_derive/lib.rs

fixed_map_derive/
lib.rs
