Rollup merge of #107493 - clubby789:range-fat-arrow-followup, r=estebank

Improve diagnostic for missing space in range pattern

Improves the diagnostic in #107425 by turning it into a note explaining the parsing issue.

r? `@compiler-errors`

3 files changed, 12 insertions, 7 deletions

diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index 20da8ce5b6e..fd4333dbbec 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -670,13 +670,10 @@ pub(crate) struct InclusiveRangeExtraEquals {
 #[diag(parse_inclusive_range_match_arrow)]
 pub(crate) struct InclusiveRangeMatchArrow {
     #[primary_span]
+    pub arrow: Span,
+    #[label]
     pub span: Span,
-    #[suggestion(
-        suggestion_add_space,
-        style = "verbose",
-        code = " ",
-        applicability = "machine-applicable"
-    )]
+    #[suggestion(style = "verbose", code = " ", applicability = "machine-applicable")]
     pub after_pat: Span,
 }
 
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index b7a023868fc..3d42a9dcbbe 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -2717,6 +2717,14 @@ impl<'a> Parser<'a> {
                     );
                     err.emit();
                     this.bump();
+                } else if matches!(
+                    (&this.prev_token.kind, &this.token.kind),
+                    (token::DotDotEq, token::Gt)
+                ) {
+                    // `error_inclusive_range_match_arrow` handles cases like `0..=> {}`,
+                    // so we supress the error here
+                    err.delay_as_bug();
+                    this.bump();
                 } else {
                     return Err(err);
                 }
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index 0e8b549b438..b054dc59a0c 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -743,7 +743,7 @@ impl<'a> Parser<'a> {
             }
             token::Gt if no_space => {
                 let after_pat = span.with_hi(span.hi() - rustc_span::BytePos(1)).shrink_to_hi();
-                self.sess.emit_err(InclusiveRangeMatchArrow { span, after_pat });
+                self.sess.emit_err(InclusiveRangeMatchArrow { span, arrow: tok.span, after_pat });
             }
             _ => {
                 self.sess.emit_err(InclusiveRangeNoEnd { span });