From a7fc32ceaf4708a26a992f61c4ac4ead1555c8eb Mon Sep 17 00:00:00 2001
From: yukang <moorekang@gmail.com>
Date: Mon, 8 May 2023 11:16:17 +0800
Subject: [PATCH] fix ice in suggesting

---
 .../rustc_parse/src/parser/diagnostics.rs     | 21 ++++++++++++-------
 tests/ui/type/missing-let-in-binding-3.rs     |  5 +++++
 tests/ui/type/missing-let-in-binding-3.stderr | 10 +++++++++
 3 files changed, 29 insertions(+), 7 deletions(-)
 create mode 100644 tests/ui/type/missing-let-in-binding-3.rs
 create mode 100644 tests/ui/type/missing-let-in-binding-3.stderr

diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index bd0ea50b4d8c..456c6243bbbb 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -405,13 +405,20 @@ impl<'a> Parser<'a> {
             let prev_span = self.prev_token.span.shrink_to_lo();
             let snapshot = self.create_snapshot_for_diagnostic();
             self.bump();
-            if self.parse_ty().is_ok() && self.token == token::Eq {
-                err.span_suggestion_verbose(
-                    prev_span,
-                    "you might have meant to introduce a new binding",
-                    "let ".to_string(),
-                    Applicability::MaybeIncorrect,
-                );
+            match self.parse_ty() {
+                Ok(_) => {
+                    if self.token == token::Eq {
+                        err.span_suggestion_verbose(
+                            prev_span,
+                            "you might have meant to introduce a new binding",
+                            "let ".to_string(),
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
+                }
+                Err(err) => {
+                    err.cancel();
+                }
             }
             self.restore_snapshot(snapshot);
         }
diff --git a/tests/ui/type/missing-let-in-binding-3.rs b/tests/ui/type/missing-let-in-binding-3.rs
new file mode 100644
index 000000000000..d56b1393336b
--- /dev/null
+++ b/tests/ui/type/missing-let-in-binding-3.rs
@@ -0,0 +1,5 @@
+struct A {
+    : :u8, //~ ERROR expected identifier, found `:`
+}
+
+fn main() {}
diff --git a/tests/ui/type/missing-let-in-binding-3.stderr b/tests/ui/type/missing-let-in-binding-3.stderr
new file mode 100644
index 000000000000..ca828ce37eb7
--- /dev/null
+++ b/tests/ui/type/missing-let-in-binding-3.stderr
@@ -0,0 +1,10 @@
+error: expected identifier, found `:`
+  --> $DIR/missing-let-in-binding-3.rs:2:5
+   |
+LL | struct A {
+   |        - while parsing this struct
+LL |     : :u8,
+   |     ^ expected identifier
+
+error: aborting due to previous error
+