Auto merge of #99210 - Dylan-DPC:rollup-879cp1t, r=Dylan-DPC

Rollup of 5 pull requests

Successful merges:

 - #98574 (Lower let-else in MIR)
 - #99011 (`UnsafeCell` blocks niches inside its nested type from being available outside)
 - #99030 (diagnostics: error messages when struct literals fail to parse)
 - #99155 (Keep unstable target features for asm feature checking)
 - #99199 (Refactor: remove an unnecessary `span_to_snippet`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 18 insertions, 0 deletions

diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index f9387e29262..0d9c57908c1 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -3028,6 +3028,11 @@ impl<'a> Parser<'a> {
                 }
             };
 
+            let is_shorthand = parsed_field.as_ref().map_or(false, |f| f.is_shorthand);
+            // A shorthand field can be turned into a full field with `:`.
+            // We should point this out.
+            self.check_or_expected(!is_shorthand, TokenType::Token(token::Colon));
+
             match self.expect_one_of(&[token::Comma], &[token::CloseDelim(close_delim)]) {
                 Ok(_) => {
                     if let Some(f) = parsed_field.or(recovery_field) {
@@ -3048,6 +3053,19 @@ impl<'a> Parser<'a> {
                                 ",",
                                 Applicability::MachineApplicable,
                             );
+                        } else if is_shorthand
+                            && (AssocOp::from_token(&self.token).is_some()
+                                || matches!(&self.token.kind, token::OpenDelim(_))
+                                || self.token.kind == token::Dot)
+                        {
+                            // Looks like they tried to write a shorthand, complex expression.
+                            let ident = parsed_field.expect("is_shorthand implies Some").ident;
+                            e.span_suggestion(
+                                ident.span.shrink_to_lo(),
+                                "try naming a field",
+                                &format!("{ident}: "),
+                                Applicability::HasPlaceholders,
+                            );
                         }
                     }
                     if !recover {