Suggest a comma if a struct initializer field fails to parse

Currently, we emit a "try adding a comma" suggestion if a comma is
missing in a struct definition. However, we emit no such suggestion if a
comma is missing in a struct initializer.

This commit adds a "try adding a comma" suggestion when we don't find a
comma during the parsing of a struct initializer field.

The change to `src/test/ui/parser/removed-syntax-with-1.stderr` isn't
great, but I don't see a good way of avoiding it.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/librustc_parse/parser/expr.rs b/src/librustc_parse/parser/expr.rs
index 5a4225ece65..20b9df0a2d9 100644
--- a/src/librustc_parse/parser/expr.rs
+++ b/src/librustc_parse/parser/expr.rs
@@ -1832,10 +1832,16 @@ impl<'a> Parser<'a> {
                     }
                 }
                 Err(mut e) => {
+                    e.span_label(struct_sp, "while parsing this struct");
                     if let Some(f) = recovery_field {
                         fields.push(f);
+                        e.span_suggestion(
+                            self.prev_span.shrink_to_hi(),
+                            "try adding a comma",
+                            ",".into(),
+                            Applicability::MachineApplicable,
+                        );
                     }
-                    e.span_label(struct_sp, "while parsing this struct");
                     e.emit();
                     self.recover_stmt_(SemiColonMode::Comma, BlockMode::Ignore);
                     self.eat(&token::Comma);