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Major refactor of attribute handling

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This commit is contained in:
J Henry Waugh
2020-08-23 17:53:30 -05:00
parent 9fe3672514
commit 5498443517
6 changed files with 363 additions and 307 deletions
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136
codegen/src/function.rs
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@@ -10,11 +10,11 @@ use alloc::format;
#[cfg(not(no_std))]
use std::format;
use std::collections::HashMap;
use quote::{quote, quote_spanned};
use syn::{parse::Parse, parse::ParseStream, parse::Parser, spanned::Spanned};
use crate::attrs::{ExportInfo, ExportedParams};
#[derive(Debug, Default)]
pub(crate) struct ExportedFnParams {
pub name: Option<String>,
@@ -23,14 +23,6 @@ pub(crate) struct ExportedFnParams {
pub span: Option<proc_macro2::Span>,
}
impl ExportedFnParams {
pub fn skip() -> ExportedFnParams {
let mut skip = ExportedFnParams::default();
skip.skip = true;
skip
}
}
pub const FN_IDX_GET: &str = "index$get$";
pub const FN_IDX_SET: &str = "index$set$";
@@ -47,58 +39,44 @@ impl Parse for ExportedFnParams {
return Ok(ExportedFnParams::default());
}
let arg_list = args.call(
syn::punctuated::Punctuated::<syn::Expr, syn::Token![,]>::parse_separated_nonempty,
)?;
let span = arg_list.span();
let info = crate::attrs::parse_attr_items(args)?;
Self::from_info(info)
}
}
let mut attrs: HashMap<proc_macro2::Ident, Option<syn::LitStr>> = HashMap::new();
for arg in arg_list {
let (left, right) = match arg {
syn::Expr::Assign(syn::ExprAssign {
ref left,
ref right,
..
}) => {
let attr_name: syn::Ident = match left.as_ref() {
syn::Expr::Path(syn::ExprPath {
path: attr_path, ..
}) => attr_path.get_ident().cloned().ok_or_else(|| {
syn::Error::new(attr_path.span(), "expecting attribute name")
})?,
x => return Err(syn::Error::new(x.span(), "expecting attribute name")),
};
let attr_value = match right.as_ref() {
syn::Expr::Lit(syn::ExprLit {
lit: syn::Lit::Str(string),
..
}) => string.clone(),
x => return Err(syn::Error::new(x.span(), "expecting string literal")),
};
(attr_name, Some(attr_value))
}
syn::Expr::Path(syn::ExprPath {
path: attr_path, ..
}) => attr_path
.get_ident()
.cloned()
.map(|a| (a, None))
.ok_or_else(|| syn::Error::new(attr_path.span(), "expecting attribute name"))?,
x => return Err(syn::Error::new(x.span(), "expecting identifier")),
};
attrs.insert(left, right);
}
impl ExportedParams for ExportedFnParams {
fn parse_stream(args: ParseStream) -> syn::Result<Self> {
Self::parse(args)
}
fn no_attrs() -> Self {
Default::default()
}
fn from_info(
info: crate::attrs::ExportInfo,
) -> syn::Result<Self> {
let ExportInfo { item_span: span, items: attrs } = info;
let mut name = None;
let mut return_raw = false;
let mut skip = false;
for (ident, value) in attrs.drain() {
match (ident.to_string().as_ref(), value) {
("name", Some(s)) => name = Some(s.value()),
for attr in attrs {
let crate::attrs::AttrItem { key, value } = attr;
match (key.to_string().as_ref(), value) {
("name", Some(s)) => {
// check validity of name
if s.value().contains('.') {
return Err(syn::Error::new(
s.span(),
"Rhai function names may not contain dot",
));
}
name = Some(s.value())
}
("get", Some(s)) => name = Some(make_getter(&s.value())),
("set", Some(s)) => name = Some(make_setter(&s.value())),
("get", None) | ("set", None) | ("name", None) => {
return Err(syn::Error::new(ident.span(), "requires value"))
return Err(syn::Error::new(key.span(), "requires value"))
}
("index_get", None) => name = Some(FN_IDX_GET.to_string()),
("index_set", None) => name = Some(FN_IDX_SET.to_string()),
@@ -110,21 +88,13 @@ impl Parse for ExportedFnParams {
("skip", Some(s)) => return Err(syn::Error::new(s.span(), "extraneous value")),
(attr, _) => {
return Err(syn::Error::new(
ident.span(),
key.span(),
format!("unknown attribute '{}'", attr),
))
}
}
}
// Check validity of name, if present.
if name.as_ref().filter(|n| n.contains('.')).is_some() {
return Err(syn::Error::new(
span,
"Rhai function names may not contain dot"
))
}
Ok(ExportedFnParams {
name,
return_raw,
@@ -151,20 +121,10 @@ impl Parse for ExportedFn {
let str_type_path = syn::parse2::<syn::Path>(quote! { str }).unwrap();
// #[cfg] attributes are not allowed on functions due to what is generated for them
if let Some(cfg_attr) = fn_all.attrs.iter().find(|a| {
a.path
.get_ident()
.map(|i| i.to_string() == "cfg")
.unwrap_or(false)
}) {
return Err(syn::Error::new(cfg_attr.span(), "cfg attributes not allowed on this item"));
}
crate::attrs::deny_cfg_attr(&fn_all.attrs)?;
// Determine if the function is public.
let is_public = match fn_all.vis {
syn::Visibility::Public(_) => true,
_ => false,
};
let is_public = matches!(fn_all.vis, syn::Visibility::Public(_));
// Determine whether function generates a special calling convention for a mutable
// reciever.
let mut_receiver = {
@@ -216,10 +176,7 @@ impl Parse for ExportedFn {
mutability: None,
ref elem,
..
}) => match elem.as_ref() {
&syn::Type::Path(ref p) if p.path == str_type_path => true,
_ => false,
},
}) => matches!(elem.as_ref(), &syn::Type::Path(ref p) if p.path == str_type_path),
&syn::Type::Verbatim(_) => false,
_ => true,
};
@@ -293,17 +250,18 @@ impl ExportedFn {
}
}
pub fn set_params(
&mut self, mut params: ExportedFnParams,
) -> syn::Result<()> {
pub fn set_params(&mut self, mut params: ExportedFnParams) -> syn::Result<()> {
// Do not allow non-returning raw functions.
//
// This is caught now to avoid issues with diagnostics later.
if params.return_raw && mem::discriminant(&self.signature.output) ==
mem::discriminant(&syn::ReturnType::Default) {
return Err(syn::Error::new(self.signature.span(),
"return_raw functions must return Result<T>"));
if params.return_raw
&& mem::discriminant(&self.signature.output)
== mem::discriminant(&syn::ReturnType::Default)
{
return Err(syn::Error::new(
self.signature.span(),
"return_raw functions must return Result<T>",
));
}
self.params = params;
@@ -618,7 +576,7 @@ mod function_tests {
&syn::parse2::<syn::FnArg>(quote! { x: usize }).unwrap()
);
assert_eq!(
item_fn.arg_list().skip(1).next().unwrap(),
item_fn.arg_list().nth(1).unwrap(),
&syn::parse2::<syn::FnArg>(quote! { y: f32 }).unwrap()
);
}
@@ -739,7 +697,7 @@ mod function_tests {
&syn::parse2::<syn::FnArg>(quote! { level: usize }).unwrap()
);
assert_eq!(
item_fn.arg_list().skip(1).next().unwrap(),
item_fn.arg_list().nth(1).unwrap(),
&syn::parse2::<syn::FnArg>(quote! { message: &str }).unwrap()
);
}