moverox_codegen/
attributes.rs

1use std::collections::HashSet;
2
3use move_syn::Attributes;
4use quote::quote;
5use unsynn::{IParse as _, Ident, ToTokens as _, TokenStream};
6
7use crate::Result;
8
9mod grammar {
10    use unsynn::*;
11
12    mod kw {
13        use unsynn::unsynn;
14
15        unsynn! {
16            pub(super) keyword Moverox = "moverox";
17            pub(super) keyword Otw = "OTW";
18            // NOTE: we cannot use `type` here since the Move parser will complain because it's a
19            // reserved keyword
20            pub(super) keyword Type = "type_";
21        }
22    }
23
24    unsynn! {
25        /// Allows parsing `moverox(...)` attributes inside `#[ext(...)]`
26        ///
27        /// # Example
28        ///
29        /// ```move
30        /// #[ext(moverox(type(T = OTW)))]
31        /// public struct BalanceUpdated<phantom T> {}
32        /// ```
33        pub(crate) struct Annotation {
34            kw: kw::Moverox,
35            contents: ParenthesisGroupContaining<CommaDelimitedVec<Setting>>
36        }
37
38        /// The different accepted attributes inside `moverox(...)`
39        pub(super) enum Setting {
40            /// Currrently only type defaults
41            Type(Type)
42        }
43
44        /// Custom attribute to set defaults for type parameters of a datatype.
45        pub(super) struct Type {
46            kw: kw::Type,
47            contents: ParenthesisGroupContaining<CommaDelimitedVec<TypeDefault>>,
48        }
49
50        /// An instance of a type parameter default.
51        struct TypeDefault {
52            /// Identifier of the annotated datatype's type parameter
53            ident: Ident,
54            assign: Assign,
55            /// For now, only defaults like `{T} = OTW` are supported
56            default: kw::Otw,
57        }
58    }
59
60    impl Annotation {
61        pub(super) fn settings(&self) -> impl Iterator<Item = &Setting> + '_ {
62            self.contents
63                .content
64                .iter()
65                .map(|delimited| &delimited.value)
66        }
67    }
68
69    impl Setting {
70        pub(super) fn otw_types(&self) -> impl Iterator<Item = &Ident> + '_ {
71            let Self::Type(ty) = self;
72            ty.contents
73                .content
74                .iter()
75                .map(|delimited| &delimited.value.ident)
76        }
77    }
78}
79
80/// Filter and parse Move attributes into Rust docs (1st) and OTW type defaults (2nd).
81pub(super) fn extract(attrs: &[Attributes]) -> Result<(TokenStream, HashSet<Ident>)> {
82    let (move_docs, other): (Vec<_>, Vec<_>) = attrs.iter().partition(|attr| attr.is_doc());
83
84    let rust_docs = move_docs.into_iter().map(process_doc).collect();
85
86    let custom: Vec<_> = other.into_iter().flat_map(as_moverox).collect();
87    let mut otw_types = HashSet::new();
88    for ident in custom
89        .iter()
90        .flat_map(|custom| custom.settings())
91        .flat_map(|setting| setting.otw_types())
92    {
93        if otw_types.contains(ident) {
94            return Err(format!("Type {ident} declared twice").into());
95        }
96        otw_types.insert(ident.to_owned());
97    }
98
99    Ok((rust_docs, otw_types))
100}
101
102pub(super) fn as_moverox(attr: &Attributes) -> impl Iterator<Item = self::grammar::Annotation> {
103    attr.external_attributes()
104        .filter_map(|ext| ext.to_token_iter().parse_all().ok())
105}
106
107fn process_doc(attr: &Attributes) -> TokenStream {
108    let inner = attr.contents().to_token_stream();
109    // NOTE: disable when compiling doctests to avoid Rust interpreting code blocks as
110    // runnable tests.
111    quote!(#[cfg_attr(not(doctest), #inner)])
112}
moverox_codegen/attributes.rs

moverox_codegen/
attributes.rs
