Use inner span ctxt when lowering paren

camsteffen · camsteffen · commit 3f4da0db4a8c · 2025-10-21T09:59:28.000-05:00
The need for this arose when encountering range expressions surrounded
by parenthesis, where we want the span desugaring mark to be preserved.
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
@@ -68,7 +68,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     let mut ex = self.lower_expr_mut(ex);
                     // Include parens in span, but only if it is a super-span.
                     if e.span.contains(ex.span) {
-                        ex.span = self.lower_span(e.span);
+                        ex.span = self.lower_span(e.span.with_ctxt(ex.span.ctxt()));
                     }
                     // Merge attributes into the inner expression.
                     if !e.attrs.is_empty() {

Original file line number	Diff line number	Diff line change
`@@ -68,7 +68,7 @@ impl<'hir> LoweringContext<'_, 'hir> {`
`68`	`68`	`let mut ex = self.lower_expr_mut(ex);`
`69`	`69`	`// Include parens in span, but only if it is a super-span.`
`70`	`70`	`if e.span.contains(ex.span) {`
`71`		`- ex.span = self.lower_span(e.span);`
	`71`	`+ ex.span = self.lower_span(e.span.with_ctxt(ex.span.ctxt()));`
`72`	`72`	`}`
`73`	`73`	`// Merge attributes into the inner expression.`
`74`	`74`	`if !e.attrs.is_empty() {`