diff options
Diffstat (limited to 'src/libsyntax/parse')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index afdb0cc4fdb..cba77335143 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -4865,7 +4865,9 @@ impl<'a> Parser<'a> { /// impl<T> Foo { ... } /// impl<T> ToString for &'static T { ... } /// impl Send for .. {} - fn parse_item_impl(&mut self, unsafety: ast::Unsafety) -> PResult<'a, ItemInfo> { + fn parse_item_impl(&mut self, + unsafety: ast::Unsafety, + defaultness: Defaultness) -> PResult<'a, ItemInfo> { let impl_span = self.span; // First, parse type parameters if necessary. @@ -4918,6 +4920,11 @@ impl<'a> Parser<'a> { allowed to have generics"); } + if let ast::Defaultness::Default = defaultness { + self.span_err(impl_span, "`default impl` is not allowed for \ + default trait implementations"); + } + self.expect(&token::OpenDelim(token::Brace))?; self.expect(&token::CloseDelim(token::Brace))?; Ok((keywords::Invalid.ident(), @@ -4946,7 +4953,7 @@ impl<'a> Parser<'a> { } Ok((keywords::Invalid.ident(), - ItemKind::Impl(unsafety, polarity, generics, opt_trait, ty, impl_items), + ItemKind::Impl(unsafety, polarity, defaultness, generics, opt_trait, ty, impl_items), Some(attrs))) } } @@ -5759,13 +5766,19 @@ impl<'a> Parser<'a> { maybe_append(attrs, extra_attrs)); return Ok(Some(item)); } - if self.check_keyword(keywords::Unsafe) && - self.look_ahead(1, |t| t.is_keyword(keywords::Impl)) + if (self.check_keyword(keywords::Unsafe) && + self.look_ahead(1, |t| t.is_keyword(keywords::Impl))) || + (self.check_keyword(keywords::Default) && + self.look_ahead(1, |t| t.is_keyword(keywords::Unsafe)) && + self.look_ahead(2, |t| t.is_keyword(keywords::Impl))) { // IMPL ITEM + let defaultness = self.parse_defaultness()?; self.expect_keyword(keywords::Unsafe)?; self.expect_keyword(keywords::Impl)?; - let (ident, item_, extra_attrs) = self.parse_item_impl(ast::Unsafety::Unsafe)?; + let (ident, + item_, + extra_attrs) = self.parse_item_impl(ast::Unsafety::Unsafe, defaultness)?; let prev_span = self.prev_span; let item = self.mk_item(lo.to(prev_span), ident, @@ -5859,9 +5872,16 @@ impl<'a> Parser<'a> { maybe_append(attrs, extra_attrs)); return Ok(Some(item)); } - if self.eat_keyword(keywords::Impl) { + if (self.check_keyword(keywords::Impl)) || + (self.check_keyword(keywords::Default) && + self.look_ahead(1, |t| t.is_keyword(keywords::Impl))) + { // IMPL ITEM - let (ident, item_, extra_attrs) = self.parse_item_impl(ast::Unsafety::Normal)?; + let defaultness = self.parse_defaultness()?; + self.expect_keyword(keywords::Impl)?; + let (ident, + item_, + extra_attrs) = self.parse_item_impl(ast::Unsafety::Normal, defaultness)?; let prev_span = self.prev_span; let item = self.mk_item(lo.to(prev_span), ident, |