diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs index 05f30f039c8..966cb7ee8d8 100644 --- a/src/librustc_resolve/macros.rs +++ b/src/librustc_resolve/macros.rs @@ -222,8 +222,10 @@ impl<'a> base::Resolver for Resolver<'a> { let name = unwrap_or!(attrs[i].name(), continue); if name == "derive" { - let result = attrs[i].parse_list(&self.session.parse_sess, - |parser| parser.parse_path(PathStyle::Mod)); + let result = attrs[i].parse_list(&self.session.parse_sess, |parser| { + parser.parse_path_allowing_meta(PathStyle::Mod) + }); + let mut traits = match result { Ok(traits) => traits, Err(mut e) => { diff --git a/src/libsyntax/ext/derive.rs b/src/libsyntax/ext/derive.rs index c79040424f6..e7c5d8278d9 100644 --- a/src/libsyntax/ext/derive.rs +++ b/src/libsyntax/ext/derive.rs @@ -26,7 +26,8 @@ pub fn collect_derives(cx: &mut ExtCtxt, attrs: &mut Vec) -> Vec return true; } - match attr.parse_list(cx.parse_sess, |parser| parser.parse_path(PathStyle::Mod)) { + match attr.parse_list(cx.parse_sess, + |parser| parser.parse_path_allowing_meta(PathStyle::Mod)) { Ok(ref traits) if traits.is_empty() => { cx.span_warn(attr.span, "empty trait list in `derive`"); false diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 8595bfc9f79..0dd2c03acb6 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -1767,6 +1767,26 @@ impl<'a> Parser<'a> { }) } + /// Like `parse_path`, but also supports parsing `Word` meta items into paths for back-compat. + /// This is used when parsing derive macro paths in `#[derive]` attributes. + pub fn parse_path_allowing_meta(&mut self, mode: PathStyle) -> PResult<'a, ast::Path> { + let meta_ident = match self.token { + token::Interpolated(ref nt) => match **nt { + token::NtMeta(ref meta) => match meta.node { + ast::MetaItemKind::Word => Some(ast::Ident::with_empty_ctxt(meta.name)), + _ => None, + }, + _ => None, + }, + _ => None, + }; + if let Some(ident) = meta_ident { + self.bump(); + return Ok(ast::Path::from_ident(self.prev_span, ident)); + } + self.parse_path(mode) + } + /// Examples: /// - `a::b::c` /// - `a::b::c(V) -> W` diff --git a/src/test/run-pass/issue-40962.rs b/src/test/run-pass/issue-40962.rs new file mode 100644 index 00000000000..b35cfa12eab --- /dev/null +++ b/src/test/run-pass/issue-40962.rs @@ -0,0 +1,20 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +macro_rules! m { + ($i:meta) => { + #[derive($i)] + struct S; + } +} + +m!(Clone); + +fn main() {}