Files
wasmtime/crates/wiggle/generate/src/error_transform.rs
Pat Hickey 220733b974 wiggle-generate: add an empty constructor to ErrorTransform
some library users (me, in lucet-wasi) may not care about ErrorTransform YET
2020-06-03 10:54:34 -07:00

76 lines
2.5 KiB
Rust

use crate::config::ErrorConf;
use anyhow::{anyhow, Error};
use proc_macro2::TokenStream;
use quote::quote;
use std::collections::HashMap;
use std::rc::Rc;
use witx::{Document, Id, NamedType, TypeRef};
pub struct ErrorTransform {
m: Vec<UserErrorType>,
}
impl ErrorTransform {
pub fn empty() -> Self {
Self { m: Vec::new() }
}
pub fn new(conf: &ErrorConf, doc: &Document) -> Result<Self, Error> {
let mut richtype_identifiers = HashMap::new();
let m = conf.iter().map(|(ident, field)|
if let Some(abi_type) = doc.typename(&Id::new(ident.to_string())) {
if let Some(ident) = field.rich_error.get_ident() {
if let Some(prior_def) = richtype_identifiers.insert(ident.clone(), field.err_loc.clone())
{
return Err(anyhow!(
"duplicate rich type identifier of {:?} not allowed. prior definition at {:?}",
ident, prior_def
));
}
Ok(UserErrorType {
abi_type,
rich_type: field.rich_error.clone(),
method_fragment: ident.to_string()
})
} else {
return Err(anyhow!(
"rich error type must be identifier for now - TODO add ability to provide a corresponding identifier: {:?}",
field.err_loc
))
}
}
else { Err(anyhow!("No witx typename \"{}\" found", ident.to_string())) }
).collect::<Result<Vec<_>, Error>>()?;
Ok(Self { m })
}
pub fn iter(&self) -> impl Iterator<Item = &UserErrorType> {
self.m.iter()
}
pub fn for_abi_error(&self, tref: &TypeRef) -> Option<&UserErrorType> {
match tref {
TypeRef::Name(nt) => self.m.iter().find(|u| u.abi_type.name == nt.name),
TypeRef::Value { .. } => None,
}
}
}
pub struct UserErrorType {
abi_type: Rc<NamedType>,
rich_type: syn::Path,
method_fragment: String,
}
impl UserErrorType {
pub fn abi_type(&self) -> TypeRef {
TypeRef::Name(self.abi_type.clone())
}
pub fn typename(&self) -> TokenStream {
let t = &self.rich_type;
quote!(#t)
}
pub fn method_fragment(&self) -> &str {
&self.method_fragment
}
}