From a01f49e7f32b39b77f6a5804c1ed12aadaa89ec5 Mon Sep 17 00:00:00 2001
From: trevyn <230691+trevyn@users.noreply.github.com>
Date: Thu, 11 Jul 2024 12:12:00 +0400
Subject: [PATCH] check is_ident before parse_ident

---
 compiler/rustc_parse/src/parser/item.rs | 4 ++--
 tests/ui/parser/ice-issue-127600.rs     | 2 ++
 tests/ui/parser/ice-issue-127600.stderr | 8 ++++++++
 3 files changed, 12 insertions(+), 2 deletions(-)
 create mode 100644 tests/ui/parser/ice-issue-127600.rs
 create mode 100644 tests/ui/parser/ice-issue-127600.stderr

diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index f31e634f55c8b..2c98feeece775 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -387,8 +387,8 @@ impl<'a> Parser<'a> {
         let span = if is_pub { self.prev_token.span.to(ident_span) } else { ident_span };
         let insert_span = ident_span.shrink_to_lo();
 
-        let ident = if (!is_const
-            || self.look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Parenthesis)))
+        let ident = if self.token.is_ident()
+            && (!is_const || self.look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Parenthesis)))
             && self.look_ahead(1, |t| {
                 [
                     token::Lt,
diff --git a/tests/ui/parser/ice-issue-127600.rs b/tests/ui/parser/ice-issue-127600.rs
new file mode 100644
index 0000000000000..709c10253266d
--- /dev/null
+++ b/tests/ui/parser/ice-issue-127600.rs
@@ -0,0 +1,2 @@
+const!(&raw mut a);
+//~^ ERROR expected identifier, found `!`
diff --git a/tests/ui/parser/ice-issue-127600.stderr b/tests/ui/parser/ice-issue-127600.stderr
new file mode 100644
index 0000000000000..629fc4ae40b67
--- /dev/null
+++ b/tests/ui/parser/ice-issue-127600.stderr
@@ -0,0 +1,8 @@
+error: expected identifier, found `!`
+  --> $DIR/ice-issue-127600.rs:1:6
+   |
+LL | const!(&raw mut a);
+   |      ^ expected identifier
+
+error: aborting due to 1 previous error
+