From 78a19d9b88d499449e53ebfb89301b36810e3c34 Mon Sep 17 00:00:00 2001
From: Seiichi Uchida <seiichi.uchida@dena.com>
Date: Fri, 27 Apr 2018 17:32:54 +0900
Subject: [PATCH] Include parens to type parameter

---
 src/libsyntax/parse/parser.rs   |  9 +++++++--
 src/test/ui/maybe-bounds.stderr | 12 ++++++------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 53d0b5529ef..5428842c7f7 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4875,6 +4875,7 @@ fn parse_ty_param_bounds_common(&mut self, allow_plus: bool) -> PResult<'a, TyPa
                                  self.check_keyword(keywords::For) ||
                                  self.check(&token::OpenDelim(token::Paren));
             if is_bound_start {
+                let lo = self.span;
                 let has_parens = self.eat(&token::OpenDelim(token::Paren));
                 let question = if self.eat(&token::Question) { Some(self.prev_span) } else { None };
                 if self.token.is_lifetime() {
@@ -4883,10 +4884,15 @@ fn parse_ty_param_bounds_common(&mut self, allow_plus: bool) -> PResult<'a, TyPa
                                       "`?` may only modify trait bounds, not lifetime bounds");
                     }
                     bounds.push(RegionTyParamBound(self.expect_lifetime()));
+                    if has_parens {
+                        self.expect(&token::CloseDelim(token::Paren))?;
+                    }
                 } else {
-                    let lo = self.span;
                     let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
                     let path = self.parse_path(PathStyle::Type)?;
+                    if has_parens {
+                        self.expect(&token::CloseDelim(token::Paren))?;
+                    }
                     let poly_trait = PolyTraitRef::new(lifetime_defs, path, lo.to(self.prev_span));
                     let modifier = if question.is_some() {
                         TraitBoundModifier::Maybe
@@ -4896,7 +4902,6 @@ fn parse_ty_param_bounds_common(&mut self, allow_plus: bool) -> PResult<'a, TyPa
                     bounds.push(TraitTyParamBound(poly_trait, modifier));
                 }
                 if has_parens {
-                    self.expect(&token::CloseDelim(token::Paren))?;
                     if let Some(&RegionTyParamBound(..)) = bounds.last() {
                         self.span_err(self.prev_span,
                                       "parenthesized lifetime bounds are not supported");
diff --git a/src/test/ui/maybe-bounds.stderr b/src/test/ui/maybe-bounds.stderr
index 72f052b75e3..763fec77be3 100644
--- a/src/test/ui/maybe-bounds.stderr
+++ b/src/test/ui/maybe-bounds.stderr
@@ -1,22 +1,22 @@
 error: `?Trait` is not permitted in supertraits
-  --> $DIR/maybe-bounds.rs:11:12
+  --> $DIR/maybe-bounds.rs:11:11
    |
 LL | trait Tr: ?Sized {} //~ ERROR `?Trait` is not permitted in supertraits
-   |            ^^^^^
+   |           ^^^^^^
    |
    = note: traits are `?Sized` by default
 
 error: `?Trait` is not permitted in trait object types
-  --> $DIR/maybe-bounds.rs:13:17
+  --> $DIR/maybe-bounds.rs:13:16
    |
 LL | type A1 = Tr + ?Sized; //~ ERROR `?Trait` is not permitted in trait object types
-   |                 ^^^^^
+   |                ^^^^^^
 
 error: `?Trait` is not permitted in trait object types
-  --> $DIR/maybe-bounds.rs:14:25
+  --> $DIR/maybe-bounds.rs:14:24
    |
 LL | type A2 = for<'a> Tr + ?Sized; //~ ERROR `?Trait` is not permitted in trait object types
-   |                         ^^^^^
+   |                        ^^^^^^
 
 error: aborting due to 3 previous errors