linera_wit_bindgen_guest_rust_macro/
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 wit_bindgen_core::{wit_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: wit_bindgen_gen_guest_rust::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    syn::custom_keyword!(export_macro);
56    syn::custom_keyword!(types_path);
57    syn::custom_keyword!(reexported_crate_path);
58}
59
60impl Parse for Opts {
61    fn parse(input: ParseStream<'_>) -> Result<Opts> {
62        let mut opts = wit_bindgen_gen_guest_rust::Opts::default();
63        let call_site = proc_macro2::Span::call_site();
64        let mut files = Vec::new();
65        let interfaces = if input.peek(token::Brace) {
66            let content;
67            syn::braced!(content in input);
68            let mut interfaces = Vec::new();
69            let fields = Punctuated::<ConfigField, Token![,]>::parse_terminated(&content)?;
70            for field in fields.into_pairs() {
71                match field.into_value() {
72                    ConfigField::Unchecked => opts.unchecked = true,
73                    ConfigField::MultiModule => opts.multi_module = true,
74                    ConfigField::ExportMacro(name) => opts.export_macro = Some(name),
75                    ConfigField::TypesPath(path) => opts.types_path = Some(path),
76                    ConfigField::ReexportedCratePath(path) => {
77                        opts.reexported_crate_path = Some(path)
78                    }
79                    ConfigField::Interfaces(v) => interfaces = v,
80                }
81            }
82            if interfaces.is_empty() {
83                return Err(Error::new(
84                    call_site,
85                    "must either specify `src` or `paths` keys",
86                ));
87            }
88            interfaces
89        } else {
90            while !input.is_empty() {
91                if input.peek(kw::export_macro) {
92                    input.parse::<kw::export_macro>()?;
93                    input.parse::<token::Eq>()?;
94                    let macro_name = input.parse::<syn::LitStr>()?.value();
95                    opts.export_macro = Some(macro_name);
96                } else if input.peek(kw::types_path) {
97                    input.parse::<kw::types_path>()?;
98                    input.parse::<token::Eq>()?;
99                    let path = input.parse::<syn::LitStr>()?.value();
100                    opts.types_path = Some(path);
101                } else if input.peek(kw::reexported_crate_path) {
102                    input.parse::<kw::reexported_crate_path>()?;
103                    input.parse::<token::Eq>()?;
104                    let path = input.parse::<syn::LitStr>()?.value();
105                    opts.reexported_crate_path = Some(path);
106                } else {
107                    let s = input.parse::<syn::LitStr>()?;
108                    files.push(s.value());
109                }
110            }
111            let mut interfaces = Vec::new();
112            let manifest_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
113            for path in files.iter() {
114                let path = manifest_dir.join(path);
115                let iface = Interface::parse_file(path).map_err(|e| Error::new(call_site, e))?;
116                interfaces.push(iface);
117            }
118            interfaces
119        };
120        Ok(Opts {
121            files,
122            opts,
123            interfaces,
124        })
125    }
126}
127
128enum ConfigField {
129    Interfaces(Vec<Interface>),
130    Unchecked,
131    MultiModule,
132    ExportMacro(String),
133    TypesPath(String),
134    ReexportedCratePath(String),
135}
136
137impl Parse for ConfigField {
138    fn parse(input: ParseStream<'_>) -> Result<Self> {
139        let l = input.lookahead1();
140        if l.peek(kw::src) {
141            input.parse::<kw::src>()?;
142            let name;
143            syn::bracketed!(name in input);
144            let name = name.parse::<syn::LitStr>()?;
145            input.parse::<Token![:]>()?;
146            let s = input.parse::<syn::LitStr>()?;
147            let interface =
148                Interface::parse(&name.value(), &s.value()).map_err(|e| Error::new(s.span(), e))?;
149            Ok(ConfigField::Interfaces(vec![interface]))
150        } else if l.peek(kw::paths) {
151            input.parse::<kw::paths>()?;
152            input.parse::<Token![:]>()?;
153            let paths;
154            let bracket = syn::bracketed!(paths in input);
155            let paths = Punctuated::<syn::LitStr, Token![,]>::parse_terminated(&paths)?;
156            let values = paths.iter().map(|s| s.value()).collect::<Vec<_>>();
157            let mut interfaces = Vec::new();
158            let manifest_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
159            for value in &values {
160                let value = manifest_dir.join(value);
161                let interface =
162                    Interface::parse_file(value).map_err(|e| Error::new(bracket.span, e))?;
163                interfaces.push(interface);
164            }
165            Ok(ConfigField::Interfaces(interfaces))
166        } else if l.peek(kw::unchecked) {
167            input.parse::<kw::unchecked>()?;
168            Ok(ConfigField::Unchecked)
169        } else if l.peek(kw::multi_module) {
170            input.parse::<kw::multi_module>()?;
171            Ok(ConfigField::MultiModule)
172        } else if l.peek(kw::export_macro) {
173            input.parse::<kw::export_macro>()?;
174            input.parse::<token::Eq>()?;
175            let macro_name = input.parse::<syn::LitStr>()?.value();
176            Ok(ConfigField::ExportMacro(macro_name))
177        } else if l.peek(kw::types_path) {
178            input.parse::<kw::types_path>()?;
179            input.parse::<token::Eq>()?;
180            let path = input.parse::<syn::LitStr>()?.value();
181            Ok(ConfigField::TypesPath(path))
182        } else if l.peek(kw::reexported_crate_path) {
183            input.parse::<kw::reexported_crate_path>()?;
184            input.parse::<token::Eq>()?;
185            let path = input.parse::<syn::LitStr>()?.value();
186            Ok(ConfigField::ReexportedCratePath(path))
187        } else {
188            Err(l.error())
189        }
190    }
191}
linera_wit_bindgen_guest_rust_macro/lib.rs

linera_wit_bindgen_guest_rust_macro/
lib.rs
