3 files changed, 8 insertions, 7 deletions
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 7ede4fbc3d9..3ecdbc36248 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1309,7 +1309,7 @@ impl<'a> Parser<'a> {
 
     /// Assuming we have just parsed `.`, continue parsing into an expression.
     fn parse_dot_suffix(&mut self, self_arg: P<Expr>, lo: Span) -> PResult<'a, P<Expr>> {
-        if self.token.uninterpolated_span().rust_2018() && self.eat_keyword(kw::Await) {
+        if self.token.uninterpolated_span().at_least_rust_2018() && self.eat_keyword(kw::Await) {
             return Ok(self.mk_await_expr(self_arg, lo));
         }
 
@@ -1442,8 +1442,8 @@ impl<'a> Parser<'a> {
             self.parse_expr_let()
         } else if self.eat_keyword(kw::Underscore) {
             Ok(self.mk_expr(self.prev_token.span, ExprKind::Underscore))
-        } else if self.token.uninterpolated_span().rust_2018() {
-            // `Span::rust_2018()` is somewhat expensive; don't get it repeatedly.
+        } else if self.token.uninterpolated_span().at_least_rust_2018() {
+            // `Span:.at_least_rust_2018()` is somewhat expensive; don't get it repeatedly.
             if self.check_keyword(kw::Async) {
                 if self.is_async_block() {
                     // Check for `async {` and `async move {`.
@@ -2230,7 +2230,7 @@ impl<'a> Parser<'a> {
         let movability =
             if self.eat_keyword(kw::Static) { Movability::Static } else { Movability::Movable };
 
-        let asyncness = if self.token.uninterpolated_span().rust_2018() {
+        let asyncness = if self.token.uninterpolated_span().at_least_rust_2018() {
             self.parse_asyncness(Case::Sensitive)
         } else {
             Async::No
@@ -3014,7 +3014,7 @@ impl<'a> Parser<'a> {
     fn is_try_block(&self) -> bool {
         self.token.is_keyword(kw::Try)
             && self.look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Brace))
-            && self.token.uninterpolated_span().rust_2018()
+            && self.token.uninterpolated_span().at_least_rust_2018()
     }
 
     /// Parses an `async move? {...}` expression.
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index e4d843b7c8b..2e1a61e634e 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -1210,7 +1210,8 @@ impl<'a> Parser<'a> {
     fn parse_constness_(&mut self, case: Case, is_closure: bool) -> Const {
         // Avoid const blocks and const closures to be parsed as const items
         if (self.check_const_closure() == is_closure)
-            && self.look_ahead(1, |t| t != &token::OpenDelim(Delimiter::Brace))
+            && !self
+                .look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Brace) || t.is_whole_block())
             && self.eat_keyword_case(kw::Const, case)
         {
             Const::Yes(self.prev_token.uninterpolated_span())
diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs
index a29b696aea8..3bb50b05aa3 100644
--- a/compiler/rustc_parse/src/parser/ty.rs
+++ b/compiler/rustc_parse/src/parser/ty.rs
@@ -608,7 +608,7 @@ impl<'a> Parser<'a> {
     /// Is a `dyn B0 + ... + Bn` type allowed here?
     fn is_explicit_dyn_type(&mut self) -> bool {
         self.check_keyword(kw::Dyn)
-            && (self.token.uninterpolated_span().rust_2018()
+            && (self.token.uninterpolated_span().at_least_rust_2018()
                 || self.look_ahead(1, |t| {
                     (t.can_begin_bound() || t.kind == TokenKind::BinOp(token::Star))
                         && !can_continue_type_after_non_fn_ident(t)