| use crate::syntax::cfg::CfgExpr; |
| use crate::syntax::namespace::Namespace; |
| use crate::syntax::report::Errors; |
| use crate::syntax::Atom::{self, *}; |
| use crate::syntax::{cfg, Derive, Doc, ForeignName}; |
| use proc_macro2::{Ident, TokenStream}; |
| use quote::ToTokens; |
| use syn::parse::ParseStream; |
| use syn::{Attribute, Error, Expr, Lit, LitStr, Meta, Path, Result, Token}; |
| |
| // Intended usage: |
| // |
| // let mut doc = Doc::new(); |
| // let mut cxx_name = None; |
| // let mut rust_name = None; |
| // /* ... */ |
| // let attrs = attrs::parse( |
| // cx, |
| // item.attrs, |
| // attrs::Parser { |
| // doc: Some(&mut doc), |
| // cxx_name: Some(&mut cxx_name), |
| // rust_name: Some(&mut rust_name), |
| // /* ... */ |
| // ..Default::default() |
| // }, |
| // ); |
| // |
| #[derive(Default)] |
| pub(crate) struct Parser<'a> { |
| pub cfg: Option<&'a mut CfgExpr>, |
| pub doc: Option<&'a mut Doc>, |
| pub derives: Option<&'a mut Vec<Derive>>, |
| pub repr: Option<&'a mut Option<Atom>>, |
| pub namespace: Option<&'a mut Namespace>, |
| pub cxx_name: Option<&'a mut Option<ForeignName>>, |
| pub rust_name: Option<&'a mut Option<Ident>>, |
| pub variants_from_header: Option<&'a mut Option<Attribute>>, |
| pub ignore_unrecognized: bool, |
| |
| // Suppress clippy needless_update lint ("struct update has no effect, all |
| // the fields in the struct have already been specified") when preemptively |
| // writing `..Default::default()`. |
| pub(crate) _more: (), |
| } |
| |
| pub(crate) fn parse(cx: &mut Errors, attrs: Vec<Attribute>, mut parser: Parser) -> OtherAttrs { |
| let mut passthrough_attrs = Vec::new(); |
| for attr in attrs { |
| let attr_path = attr.path(); |
| if attr_path.is_ident("doc") { |
| match parse_doc_attribute(&attr.meta) { |
| Ok(attr) => { |
| if let Some(doc) = &mut parser.doc { |
| match attr { |
| DocAttribute::Doc(lit) => doc.push(lit), |
| DocAttribute::Hidden => doc.hidden = true, |
| } |
| continue; |
| } |
| } |
| Err(err) => { |
| cx.push(err); |
| break; |
| } |
| } |
| } else if attr_path.is_ident("derive") { |
| match attr.parse_args_with(|attr: ParseStream| parse_derive_attribute(cx, attr)) { |
| Ok(attr) => { |
| if let Some(derives) = &mut parser.derives { |
| derives.extend(attr); |
| continue; |
| } |
| } |
| Err(err) => { |
| cx.push(err); |
| break; |
| } |
| } |
| } else if attr_path.is_ident("repr") { |
| match attr.parse_args_with(parse_repr_attribute) { |
| Ok(attr) => { |
| if let Some(repr) = &mut parser.repr { |
| **repr = Some(attr); |
| continue; |
| } |
| } |
| Err(err) => { |
| cx.push(err); |
| break; |
| } |
| } |
| } else if attr_path.is_ident("namespace") { |
| match Namespace::parse_meta(&attr.meta) { |
| Ok(attr) => { |
| if let Some(namespace) = &mut parser.namespace { |
| **namespace = attr; |
| continue; |
| } |
| } |
| Err(err) => { |
| cx.push(err); |
| break; |
| } |
| } |
| } else if attr_path.is_ident("cxx_name") { |
| match parse_cxx_name_attribute(&attr.meta) { |
| Ok(attr) => { |
| if let Some(cxx_name) = &mut parser.cxx_name { |
| **cxx_name = Some(attr); |
| continue; |
| } |
| } |
| Err(err) => { |
| cx.push(err); |
| break; |
| } |
| } |
| } else if attr_path.is_ident("rust_name") { |
| match parse_rust_name_attribute(&attr.meta) { |
| Ok(attr) => { |
| if let Some(rust_name) = &mut parser.rust_name { |
| **rust_name = Some(attr); |
| continue; |
| } |
| } |
| Err(err) => { |
| cx.push(err); |
| break; |
| } |
| } |
| } else if attr_path.is_ident("cfg") { |
| match cfg::parse_attribute(&attr) { |
| Ok(cfg_expr) => { |
| if let Some(cfg) = &mut parser.cfg { |
| cfg.merge(cfg_expr); |
| passthrough_attrs.push(attr); |
| continue; |
| } |
| } |
| Err(err) => { |
| cx.push(err); |
| break; |
| } |
| } |
| } else if attr_path.is_ident("variants_from_header") |
| && cfg!(feature = "experimental-enum-variants-from-header") |
| { |
| if let Err(err) = attr.meta.require_path_only() { |
| cx.push(err); |
| } |
| if let Some(variants_from_header) = &mut parser.variants_from_header { |
| **variants_from_header = Some(attr); |
| continue; |
| } |
| } else if attr_path.is_ident("allow") |
| || attr_path.is_ident("warn") |
| || attr_path.is_ident("deny") |
| || attr_path.is_ident("forbid") |
| || attr_path.is_ident("deprecated") |
| || attr_path.is_ident("must_use") |
| { |
| // https://doc.rust-lang.org/reference/attributes/diagnostics.html |
| passthrough_attrs.push(attr); |
| continue; |
| } else if attr_path.is_ident("serde") { |
| passthrough_attrs.push(attr); |
| continue; |
| } else if attr_path.segments.len() > 1 { |
| let tool = &attr_path.segments.first().unwrap().ident; |
| if tool == "rustfmt" { |
| // Skip, rustfmt only needs to find it in the pre-expansion source file. |
| continue; |
| } else if tool == "clippy" { |
| passthrough_attrs.push(attr); |
| continue; |
| } |
| } |
| if !parser.ignore_unrecognized { |
| cx.error(attr, "unsupported attribute"); |
| break; |
| } |
| } |
| OtherAttrs(passthrough_attrs) |
| } |
| |
| enum DocAttribute { |
| Doc(LitStr), |
| Hidden, |
| } |
| |
| mod kw { |
| syn::custom_keyword!(hidden); |
| } |
| |
| fn parse_doc_attribute(meta: &Meta) -> Result<DocAttribute> { |
| match meta { |
| Meta::NameValue(meta) => { |
| if let Expr::Lit(expr) = &meta.value { |
| if let Lit::Str(lit) = &expr.lit { |
| return Ok(DocAttribute::Doc(lit.clone())); |
| } |
| } |
| } |
| Meta::List(meta) => { |
| meta.parse_args::<kw::hidden>()?; |
| return Ok(DocAttribute::Hidden); |
| } |
| Meta::Path(_) => {} |
| } |
| Err(Error::new_spanned(meta, "unsupported doc attribute")) |
| } |
| |
| fn parse_derive_attribute(cx: &mut Errors, input: ParseStream) -> Result<Vec<Derive>> { |
| let paths = input.parse_terminated(Path::parse_mod_style, Token![,])?; |
| |
| let mut derives = Vec::new(); |
| for path in paths { |
| if let Some(ident) = path.get_ident() { |
| if let Some(derive) = Derive::from(ident) { |
| derives.push(derive); |
| continue; |
| } |
| } |
| cx.error(path, "unsupported derive"); |
| } |
| Ok(derives) |
| } |
| |
| fn parse_repr_attribute(input: ParseStream) -> Result<Atom> { |
| let begin = input.cursor(); |
| let ident: Ident = input.parse()?; |
| if let Some(atom) = Atom::from(&ident) { |
| match atom { |
| U8 | U16 | U32 | U64 | Usize | I8 | I16 | I32 | I64 | Isize if input.is_empty() => { |
| return Ok(atom); |
| } |
| _ => {} |
| } |
| } |
| Err(Error::new_spanned( |
| begin.token_stream(), |
| "unrecognized repr", |
| )) |
| } |
| |
| fn parse_cxx_name_attribute(meta: &Meta) -> Result<ForeignName> { |
| if let Meta::NameValue(meta) = meta { |
| match &meta.value { |
| Expr::Lit(expr) => { |
| if let Lit::Str(lit) = &expr.lit { |
| return ForeignName::parse(&lit.value(), lit.span()); |
| } |
| } |
| Expr::Path(expr) => { |
| if let Some(ident) = expr.path.get_ident() { |
| return ForeignName::parse(&ident.to_string(), ident.span()); |
| } |
| } |
| _ => {} |
| } |
| } |
| Err(Error::new_spanned(meta, "unsupported cxx_name attribute")) |
| } |
| |
| fn parse_rust_name_attribute(meta: &Meta) -> Result<Ident> { |
| if let Meta::NameValue(meta) = meta { |
| match &meta.value { |
| Expr::Lit(expr) => { |
| if let Lit::Str(lit) = &expr.lit { |
| return lit.parse(); |
| } |
| } |
| Expr::Path(expr) => { |
| if let Some(ident) = expr.path.get_ident() { |
| return Ok(ident.clone()); |
| } |
| } |
| _ => {} |
| } |
| } |
| Err(Error::new_spanned(meta, "unsupported rust_name attribute")) |
| } |
| |
| #[derive(Clone)] |
| pub(crate) struct OtherAttrs(Vec<Attribute>); |
| |
| impl OtherAttrs { |
| pub(crate) fn none() -> Self { |
| OtherAttrs(Vec::new()) |
| } |
| |
| pub(crate) fn extend(&mut self, other: Self) { |
| self.0.extend(other.0); |
| } |
| } |
| |
| impl ToTokens for OtherAttrs { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| for attr in &self.0 { |
| let Attribute { |
| pound_token, |
| style, |
| bracket_token, |
| meta, |
| } = attr; |
| pound_token.to_tokens(tokens); |
| let _ = style; // ignore; render outer and inner attrs both as outer |
| bracket_token.surround(tokens, |tokens| meta.to_tokens(tokens)); |
| } |
| } |
| } |