143 lines
4.2 KiB
Rust
143 lines
4.2 KiB
Rust
use syn::{parse::ParseStream, parse::Parser, spanned::Spanned};
|
|
|
|
#[derive(Debug)]
|
|
pub enum ExportScope {
|
|
PubOnly,
|
|
Prefix(String),
|
|
All,
|
|
}
|
|
|
|
impl Default for ExportScope {
|
|
fn default() -> ExportScope {
|
|
ExportScope::PubOnly
|
|
}
|
|
}
|
|
|
|
pub trait ExportedParams: Sized {
|
|
fn parse_stream(args: ParseStream) -> syn::Result<Self>;
|
|
fn no_attrs() -> Self;
|
|
fn from_info(info: ExportInfo) -> syn::Result<Self>;
|
|
}
|
|
|
|
pub struct AttrItem {
|
|
pub key: proc_macro2::Ident,
|
|
pub value: Option<syn::LitStr>,
|
|
pub span: proc_macro2::Span,
|
|
}
|
|
|
|
pub struct ExportInfo {
|
|
pub item_span: proc_macro2::Span,
|
|
pub items: Vec<AttrItem>,
|
|
}
|
|
|
|
pub fn parse_attr_items(args: ParseStream) -> syn::Result<ExportInfo> {
|
|
if args.is_empty() {
|
|
return Ok(ExportInfo {
|
|
item_span: args.span(),
|
|
items: Vec::new(),
|
|
});
|
|
}
|
|
let arg_list = args
|
|
.call(syn::punctuated::Punctuated::<syn::Expr, syn::Token![,]>::parse_separated_nonempty)?;
|
|
|
|
parse_punctuated_items(arg_list)
|
|
}
|
|
|
|
pub fn parse_punctuated_items(
|
|
arg_list: syn::punctuated::Punctuated<syn::Expr, syn::Token![,]>,
|
|
) -> syn::Result<ExportInfo> {
|
|
let list_span = arg_list.span();
|
|
|
|
let mut attrs: Vec<AttrItem> = Vec::new();
|
|
for arg in arg_list {
|
|
let arg_span = arg.span();
|
|
let (key, value) = 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.push(AttrItem {
|
|
key,
|
|
value,
|
|
span: arg_span,
|
|
});
|
|
}
|
|
|
|
Ok(ExportInfo {
|
|
item_span: list_span,
|
|
items: attrs,
|
|
})
|
|
}
|
|
|
|
pub(crate) fn outer_item_attributes<T: ExportedParams>(
|
|
args: proc_macro2::TokenStream,
|
|
_attr_name: &str,
|
|
) -> syn::Result<T> {
|
|
if args.is_empty() {
|
|
return Ok(T::no_attrs());
|
|
}
|
|
|
|
let parser = syn::punctuated::Punctuated::<syn::Expr, syn::Token![,]>::parse_separated_nonempty;
|
|
let arg_list = parser.parse2(args)?;
|
|
|
|
let export_info = parse_punctuated_items(arg_list)?;
|
|
T::from_info(export_info)
|
|
}
|
|
|
|
pub(crate) fn inner_item_attributes<T: ExportedParams>(
|
|
attrs: &mut Vec<syn::Attribute>,
|
|
attr_name: &str,
|
|
) -> syn::Result<T> {
|
|
// Find the #[rhai_fn] attribute which will turn be read for the function parameters.
|
|
if let Some(rhai_fn_idx) = attrs
|
|
.iter()
|
|
.position(|a| a.path.get_ident().map(|i| *i == attr_name).unwrap_or(false))
|
|
{
|
|
let rhai_fn_attr = attrs.remove(rhai_fn_idx);
|
|
rhai_fn_attr.parse_args_with(T::parse_stream)
|
|
} else {
|
|
Ok(T::no_attrs())
|
|
}
|
|
}
|
|
|
|
pub(crate) fn deny_cfg_attr(attrs: &Vec<syn::Attribute>) -> syn::Result<()> {
|
|
if let Some(cfg_attr) = attrs
|
|
.iter()
|
|
.find(|a| a.path.get_ident().map(|i| *i == "cfg").unwrap_or(false))
|
|
{
|
|
Err(syn::Error::new(
|
|
cfg_attr.span(),
|
|
"cfg attributes not allowed on this item",
|
|
))
|
|
} else {
|
|
Ok(())
|
|
}
|
|
}
|