Add an ErrorGuaranteed to ast::TyKind::Err.

nnethercote · nnethercote · commit 6674be96570d · 2024-02-15T09:35:11.000+11:00
This makes it more like `hir::TyKind::Err`, and avoids a
`span_delayed_bug` call in `LoweringContext::lower_ty_direct`.

It also requires adding `ast::TyKind::Dummy`, now that
`ast::TyKind::Err` can't be used for that purpose in the absence of an
error emission.

There are a couple of cases that aren't as neat as I would have liked,
marked with `FIXME` comments.
diff --git a/src/types.rs b/src/types.rs
@@ -859,7 +859,7 @@ impl Rewrite for ast::Ty {
                 })
             }
             ast::TyKind::CVarArgs => Some("...".to_owned()),
-            ast::TyKind::Err => Some(context.snippet(self.span).to_owned()),
+            ast::TyKind::Dummy | ast::TyKind::Err(_) => Some(context.snippet(self.span).to_owned()),
             ast::TyKind::Typeof(ref anon_const) => rewrite_call(
                 context,
                 "typeof",

Original file line number	Diff line number	Diff line change
`@@ -859,7 +859,7 @@ impl Rewrite for ast::Ty {`
`859`	`859`	`})`
`860`	`860`	`}`
`861`	`861`	`ast::TyKind::CVarArgs => Some("...".to_owned()),`
`862`		`- ast::TyKind::Err => Some(context.snippet(self.span).to_owned()),`
	`862`	`+ ast::TyKind::Dummy \| ast::TyKind::Err(_) => Some(context.snippet(self.span).to_owned()),`
`863`	`863`	`ast::TyKind::Typeof(ref anon_const) => rewrite_call(`
`864`	`864`	`context,`
`865`	`865`	`"typeof",`