Auto merge of #117565 - estebank:issue-100825, r=Nilstrieb

Tweak parsing recovery of enums, for exprs and match arm patterns

Tweak recovery of `for (pat in expr) {}` for more accurate spans.

When encountering `match` arm `(pat if expr) => {}`, recover and suggest removing parentheses. Fix #100825.

When encountering malformed enums, try more localized per-variant parse recovery.

Move parser recovery tests to subdirectory.

1 files changed, 20 insertions, 4 deletions

diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index e5d4cb6f4da..03e047b297d 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -1275,12 +1275,28 @@ pub(crate) struct ParenthesesInForHead {
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(parse_suggestion, applicability = "machine-applicable")]
 pub(crate) struct ParenthesesInForHeadSugg {
-    #[suggestion_part(code = "{left_snippet}")]
+    #[suggestion_part(code = " ")]
+    pub left: Span,
+    #[suggestion_part(code = " ")]
+    pub right: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(parse_unexpected_parentheses_in_match_arm_pattern)]
+pub(crate) struct ParenthesesInMatchPat {
+    #[primary_span]
+    pub span: Vec<Span>,
+    #[subdiagnostic]
+    pub sugg: ParenthesesInMatchPatSugg,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(parse_suggestion, applicability = "machine-applicable")]
+pub(crate) struct ParenthesesInMatchPatSugg {
+    #[suggestion_part(code = "")]
     pub left: Span,
-    pub left_snippet: String,
-    #[suggestion_part(code = "{right_snippet}")]
+    #[suggestion_part(code = "")]
     pub right: Span,
-    pub right_snippet: String,
 }
 
 #[derive(Diagnostic)]