diff options
Diffstat (limited to 'src/libsyntax/parse')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index fe5ff5c47b2..3c561780085 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -1958,7 +1958,7 @@ impl<'a> Parser<'a> { assert!(recv.is_empty()); *recv = attrs; } else { - let msg = "encountered trailing attributes after lifetime parameters"; + let msg = "trailing attribute after lifetime parameters"; return Err(self.fatal(msg)); } debug!("parse_lifetime_defs ret {:?}", res); @@ -4294,12 +4294,21 @@ impl<'a> Parser<'a> { let span_lo = self.span.lo; if self.eat(&token::Lt) { + // Upon encountering attribute in generics list, we do not + // know if it is attached to lifetime or to type param. + // + // Solution: 1. eagerly parse attributes in tandem with + // lifetime defs, 2. store last set of parsed (and unused) + // attributes in `attrs`, and 3. pass in those attributes + // when parsing formal type param after lifetime defs. let mut attrs = vec![]; let lifetime_defs = self.parse_lifetime_defs(Some(&mut attrs))?; let mut seen_default = false; let mut post_lifetime_attrs = Some(attrs); let ty_params = self.parse_seq_to_gt(Some(token::Comma), |p| { p.forbid_lifetime()?; + // Move out of `post_lifetime_attrs` if present. O/w + // not first type param: parse attributes anew. let attrs = match post_lifetime_attrs.as_mut() { None => p.parse_outer_attributes()?, Some(attrs) => mem::replace(attrs, vec![]), @@ -4315,6 +4324,12 @@ impl<'a> Parser<'a> { } Ok(ty_param) })?; + if let Some(attrs) = post_lifetime_attrs { + if !attrs.is_empty() { + self.span_err(attrs[0].span, + "trailing attribute after lifetime parameters"); + } + } Ok(ast::Generics { lifetimes: lifetime_defs, ty_params: ty_params, |