wai_bindgen_rust_impl/
lib.rs

1use std::path::{Path, PathBuf};
2
3use proc_macro::TokenStream;
4use syn::parse::{Error, Parse, ParseStream, Result};
5use syn::punctuated::Punctuated;
6use syn::{token, Token};
7use wai_bindgen_gen_core::{wai_parser::Interface, Direction, Files, Generator};
8
9#[proc_macro]
10pub fn import(input: TokenStream) -> TokenStream {
11    run(input, Direction::Import)
12}
13
14#[proc_macro]
15pub fn export(input: TokenStream) -> TokenStream {
16    run(input, Direction::Export)
17}
18
19fn run(input: TokenStream, dir: Direction) -> TokenStream {
20    let input = syn::parse_macro_input!(input as Opts);
21    let mut gen = input.opts.build();
22    let mut files = Files::default();
23    let (imports, exports) = match dir {
24        Direction::Import => (input.interfaces, vec![]),
25        Direction::Export => (vec![], input.interfaces),
26    };
27    gen.generate_all(&imports, &exports, &mut files);
28    let (_, contents) = files.iter().next().unwrap();
29    let mut contents = std::str::from_utf8(contents).unwrap().to_string();
30
31    // Include a dummy `include_str!` for any files we read so rustc knows that
32    // we depend on the contents of those files.
33    let cwd = std::env::var("CARGO_MANIFEST_DIR").unwrap();
34    for file in input.files.iter() {
35        contents.push_str(&format!(
36            "const _: &str = include_str!(r#\"{}\"#);\n",
37            Path::new(&cwd).join(file).display()
38        ));
39    }
40
41    contents.parse().unwrap()
42}
43
44struct Opts {
45    opts: wai_bindgen_gen_rust_wasm::Opts,
46    interfaces: Vec<Interface>,
47    files: Vec<String>,
48}
49
50mod kw {
51    syn::custom_keyword!(src);
52    syn::custom_keyword!(paths);
53    syn::custom_keyword!(unchecked);
54    syn::custom_keyword!(multi_module);
55}
56
57impl Parse for Opts {
58    fn parse(input: ParseStream<'_>) -> Result<Opts> {
59        let mut opts = wai_bindgen_gen_rust_wasm::Opts::default();
60        let call_site = proc_macro2::Span::call_site();
61        let mut files = Vec::new();
62        let interfaces = if input.peek(token::Brace) {
63            let content;
64            syn::braced!(content in input);
65            let mut interfaces = Vec::new();
66            let fields = Punctuated::<ConfigField, Token![,]>::parse_terminated(&content)?;
67            for field in fields.into_pairs() {
68                match field.into_value() {
69                    ConfigField::Unchecked => opts.unchecked = true,
70                    ConfigField::MultiModule => opts.multi_module = true,
71                    ConfigField::Interfaces(v) => interfaces = v,
72                }
73            }
74            if interfaces.is_empty() {
75                return Err(Error::new(
76                    call_site,
77                    "must either specify `src` or `paths` keys",
78                ));
79            }
80            interfaces
81        } else {
82            while !input.is_empty() {
83                let s = input.parse::<syn::LitStr>()?;
84                files.push(s.value());
85            }
86            let mut interfaces = Vec::new();
87            let manifest_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
88            for path in files.iter() {
89                let path = manifest_dir.join(path);
90                let iface = Interface::parse_file(path).map_err(|e| Error::new(call_site, e))?;
91                interfaces.push(iface);
92            }
93            interfaces
94        };
95        Ok(Opts {
96            files,
97            opts,
98            interfaces,
99        })
100    }
101}
102
103enum ConfigField {
104    Interfaces(Vec<Interface>),
105    Unchecked,
106    MultiModule,
107}
108
109impl Parse for ConfigField {
110    fn parse(input: ParseStream<'_>) -> Result<Self> {
111        let l = input.lookahead1();
112        if l.peek(kw::src) {
113            input.parse::<kw::src>()?;
114            let name;
115            syn::bracketed!(name in input);
116            let name = name.parse::<syn::LitStr>()?;
117            input.parse::<Token![:]>()?;
118            let s = input.parse::<syn::LitStr>()?;
119            let interface =
120                Interface::parse(&name.value(), &s.value()).map_err(|e| Error::new(s.span(), e))?;
121            Ok(ConfigField::Interfaces(vec![interface]))
122        } else if l.peek(kw::paths) {
123            input.parse::<kw::paths>()?;
124            input.parse::<Token![:]>()?;
125            let paths;
126            let bracket = syn::bracketed!(paths in input);
127            let paths = Punctuated::<syn::LitStr, Token![,]>::parse_terminated(&paths)?;
128            let values = paths.iter().map(|s| s.value()).collect::<Vec<_>>();
129            let mut interfaces = Vec::new();
130            let manifest_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
131            for value in &values {
132                let value = manifest_dir.join(value);
133                let interface =
134                    Interface::parse_file(value).map_err(|e| Error::new(bracket.span, e))?;
135                interfaces.push(interface);
136            }
137            Ok(ConfigField::Interfaces(interfaces))
138        } else if l.peek(kw::unchecked) {
139            input.parse::<kw::unchecked>()?;
140            Ok(ConfigField::Unchecked)
141        } else if l.peek(kw::multi_module) {
142            input.parse::<kw::multi_module>()?;
143            Ok(ConfigField::MultiModule)
144        } else {
145            Err(l.error())
146        }
147    }
148}
wai_bindgen_rust_impl/lib.rs

wai_bindgen_rust_impl/
lib.rs
