diff --git a/src/libsyntax/attr/mod.rs b/src/libsyntax/attr/mod.rs index d291e502c255..965d4597430f 100644 --- a/src/libsyntax/attr/mod.rs +++ b/src/libsyntax/attr/mod.rs @@ -298,24 +298,12 @@ impl Attribute { Ok(result) } - pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec> - where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>, - { + pub fn parse_derive_paths<'a>(&self, sess: &'a ParseSess) -> PResult<'a, Vec> { if self.tokens.is_empty() { return Ok(Vec::new()); } - self.parse(sess, |parser| { - parser.expect(&token::OpenDelim(token::Paren))?; - let mut list = Vec::new(); - while !parser.eat(&token::CloseDelim(token::Paren)) { - list.push(f(parser)?); - if !parser.eat(&token::Comma) { - parser.expect(&token::CloseDelim(token::Paren))?; - break - } - } - Ok(list) - }) + + self.parse(sess, |p| p.parse_derive_paths()) } pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> { diff --git a/src/libsyntax/ext/proc_macro.rs b/src/libsyntax/ext/proc_macro.rs index e17bbf79fd5e..72062d2ffbf5 100644 --- a/src/libsyntax/ext/proc_macro.rs +++ b/src/libsyntax/ext/proc_macro.rs @@ -4,7 +4,6 @@ use crate::errors::{Applicability, FatalError}; use crate::ext::base::{self, *}; use crate::ext::proc_macro_server; use crate::parse::{self, token}; -use crate::parse::parser::PathStyle; use crate::symbol::sym; use crate::tokenstream::{self, TokenStream}; use crate::visit::Visitor; @@ -205,8 +204,7 @@ crate fn collect_derives(cx: &mut ExtCtxt<'_>, attrs: &mut Vec) return false; } - match attr.parse_list(cx.parse_sess, - |parser| parser.parse_path_allowing_meta(PathStyle::Mod)) { + match attr.parse_derive_paths(cx.parse_sess) { Ok(traits) => { result.extend(traits); true diff --git a/src/libsyntax/parse/parser/path.rs b/src/libsyntax/parse/parser/path.rs index ca823991a2e5..1f48cc753048 100644 --- a/src/libsyntax/parse/parser/path.rs +++ b/src/libsyntax/parse/parser/path.rs @@ -111,7 +111,7 @@ impl<'a> Parser<'a> { /// Like `parse_path`, but also supports parsing `Word` meta items into paths for /// backwards-compatibility. This is used when parsing derive macro paths in `#[derive]` /// attributes. - pub fn parse_path_allowing_meta(&mut self, style: PathStyle) -> PResult<'a, Path> { + fn parse_path_allowing_meta(&mut self, style: PathStyle) -> PResult<'a, Path> { let meta_ident = match self.token.kind { token::Interpolated(ref nt) => match **nt { token::NtMeta(ref item) => match item.tokens.is_empty() { @@ -129,6 +129,21 @@ impl<'a> Parser<'a> { self.parse_path(style) } + /// Parse a list of paths inside `#[derive(path_0, ..., path_n)]`. + crate fn parse_derive_paths(&mut self) -> PResult<'a, Vec> { + self.expect(&token::OpenDelim(token::Paren))?; + let mut list = Vec::new(); + while !self.eat(&token::CloseDelim(token::Paren)) { + let path = self.parse_path_allowing_meta(PathStyle::Mod)?; + list.push(path); + if !self.eat(&token::Comma) { + self.expect(&token::CloseDelim(token::Paren))?; + break + } + } + Ok(list) + } + crate fn parse_path_segments( &mut self, segments: &mut Vec,