Rollup merge of #145590 - nnethercote:ModKind-Inline, r=petrochenkov

Prevent impossible combinations in `ast::ModKind`.

`ModKind::Loaded` has an `inline` field and a `had_parse_error` field. If the `inline` field is `Inline::Yes` then `had_parse_error` must be `Ok(())`.

This commit moves the `had_parse_error` field into the `Inline::No` variant. This makes it impossible to create the nonsensical combination of `inline == Inline::Yes` and `had_parse_error = Err(_)`.

r? ```@Urgau```

2 files changed, 7 insertions, 6 deletions

diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index 1f7f4c7d856..755275d3cda 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -801,7 +801,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                                     ItemKind::Mod(
                                         _,
                                         _,
-                                        ModKind::Unloaded | ModKind::Loaded(_, Inline::No, _, _),
+                                        ModKind::Unloaded
+                                            | ModKind::Loaded(_, Inline::No { .. }, _),
                                     )
                                 ) =>
                         {
@@ -1035,7 +1036,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             fn visit_item(&mut self, item: &'ast ast::Item) {
                 match &item.kind {
                     ItemKind::Mod(_, _, mod_kind)
-                        if !matches!(mod_kind, ModKind::Loaded(_, Inline::Yes, _, _)) =>
+                        if !matches!(mod_kind, ModKind::Loaded(_, Inline::Yes, _)) =>
                     {
                         feature_err(
                             self.sess,
@@ -1346,7 +1347,7 @@ impl InvocationCollectorNode for Box<ast::Item> {
         let ItemKind::Mod(_, ident, ref mut mod_kind) = node.kind else { unreachable!() };
         let ecx = &mut collector.cx;
         let (file_path, dir_path, dir_ownership) = match mod_kind {
-            ModKind::Loaded(_, inline, _, _) => {
+            ModKind::Loaded(_, inline, _) => {
                 // Inline `mod foo { ... }`, but we still need to push directories.
                 let (dir_path, dir_ownership) = mod_dir_path(
                     ecx.sess,
@@ -1360,7 +1361,7 @@ impl InvocationCollectorNode for Box<ast::Item> {
                 // This lets `parse_external_mod` catch cycles if it's self-referential.
                 let file_path = match inline {
                     Inline::Yes => None,
-                    Inline::No => mod_file_path_from_attr(ecx.sess, &attrs, &dir_path),
+                    Inline::No { .. } => mod_file_path_from_attr(ecx.sess, &attrs, &dir_path),
                 };
                 node.attrs = attrs;
                 (file_path, dir_path, dir_ownership)
@@ -1396,7 +1397,7 @@ impl InvocationCollectorNode for Box<ast::Item> {
                     );
                 }
 
-                *mod_kind = ModKind::Loaded(items, Inline::No, spans, had_parse_error);
+                *mod_kind = ModKind::Loaded(items, Inline::No { had_parse_error }, spans);
                 node.attrs = attrs;
                 if node.attrs.len() > old_attrs_len {
                     // If we loaded an out-of-line module and added some inner attributes,
diff --git a/compiler/rustc_expand/src/module.rs b/compiler/rustc_expand/src/module.rs
index 662c67f2d3f..6666ea33cd3 100644
--- a/compiler/rustc_expand/src/module.rs
+++ b/compiler/rustc_expand/src/module.rs
@@ -120,7 +120,7 @@ pub(crate) fn mod_dir_path(
 
             (dir_path, dir_ownership)
         }
-        Inline::No => {
+        Inline::No { .. } => {
             // FIXME: This is a subset of `parse_external_mod` without actual parsing,
             // check whether the logic for unloaded, loaded and inline modules can be unified.
             let file_path = mod_file_path(sess, ident, attrs, &module.dir_path, dir_ownership)