Files
wasmtime/crates/generate/src/config.rs

99 lines
2.5 KiB
Rust

use std::path::PathBuf;
use proc_macro2::Span;
use syn::{
braced, bracketed,
parse::{Parse, ParseStream},
punctuated::Punctuated,
Error, Ident, LitStr, Result, Token,
};
#[derive(Debug, Clone)]
pub struct Config {
pub witx: WitxConf,
pub ctx: CtxConf,
}
enum ConfigField {
Witx(WitxConf),
Ctx(CtxConf),
}
impl Parse for ConfigField {
fn parse(input: ParseStream) -> Result<Self> {
let id: Ident = input.parse()?;
let _colon: Token![:] = input.parse()?;
match id.to_string().as_ref() {
"witx" => Ok(ConfigField::Witx(input.parse()?)),
"ctx" => Ok(ConfigField::Ctx(input.parse()?)),
_ => Err(Error::new(id.span(), "expected `witx` or `ctx`")),
}
}
}
impl Config {
fn build(fields: impl Iterator<Item = ConfigField>, err_loc: Span) -> Result<Self> {
let mut witx = None;
let mut ctx = None;
for f in fields {
match f {
ConfigField::Witx(c) => {
witx = Some(c);
}
ConfigField::Ctx(c) => {
ctx = Some(c);
}
}
}
Ok(Config {
witx: witx
.take()
.ok_or_else(|| Error::new(err_loc, "`witx` field required"))?,
ctx: ctx
.take()
.ok_or_else(|| Error::new(err_loc, "`ctx` field required"))?,
})
}
}
impl Parse for Config {
fn parse(input: ParseStream) -> Result<Self> {
let contents;
let _lbrace = braced!(contents in input);
let fields: Punctuated<ConfigField, Token![,]> =
contents.parse_terminated(ConfigField::parse)?;
Ok(Config::build(fields.into_iter(), input.span())?)
}
}
#[derive(Debug, Clone)]
pub struct WitxConf {
pub paths: Vec<PathBuf>,
}
impl Parse for WitxConf {
fn parse(input: ParseStream) -> Result<Self> {
let content;
let _ = bracketed!(content in input);
let path_lits: Punctuated<LitStr, Token![,]> = content.parse_terminated(Parse::parse)?;
let paths: Vec<PathBuf> = path_lits
.iter()
.map(|lit| PathBuf::from(lit.value()))
.collect();
Ok(WitxConf { paths })
}
}
#[derive(Debug, Clone)]
pub struct CtxConf {
pub name: Ident,
}
impl Parse for CtxConf {
fn parse(input: ParseStream) -> Result<Self> {
Ok(CtxConf {
name: input.parse()?,
})
}
}