Keep track of parse errors in `mod`s and don't emit resolve errors for paths involving them

When we expand a `mod foo;` and parse `foo.rs`, we now track whether that file had an unrecovered parse error that reached the end of the file. If so, we keep that information around. When resolving a path like `foo::bar`, we do not emit any errors for "`bar` not found in `foo`", as we know that the parse error might have caused `bar` to not be parsed and accounted for.

When this happens in an existing project, every path referencing `foo` would be an irrelevant compile error. Instead, we now skip emitting anything until `foo.rs` is fixed. Tellingly enough, we didn't have any test for errors caused by `mod` expansion.

Fix #97734.

6 files changed, 8 insertions, 9 deletions

diff --git a/src/tools/clippy/clippy_lints/src/duplicate_mod.rs b/src/tools/clippy/clippy_lints/src/duplicate_mod.rs
index ed27e38ef2d..1dac7b971f9 100644
--- a/src/tools/clippy/clippy_lints/src/duplicate_mod.rs
+++ b/src/tools/clippy/clippy_lints/src/duplicate_mod.rs
@@ -63,7 +63,7 @@ impl_lint_pass!(DuplicateMod => [DUPLICATE_MOD]);
 
 impl EarlyLintPass for DuplicateMod {
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
-        if let ItemKind::Mod(_, ModKind::Loaded(_, Inline::No, mod_spans)) = &item.kind
+        if let ItemKind::Mod(_, ModKind::Loaded(_, Inline::No, mod_spans, _)) = &item.kind
             && let FileName::Real(real) = cx.sess().source_map().span_to_filename(mod_spans.inner_span)
             && let Some(local_path) = real.into_local_path()
             && let Ok(absolute_path) = local_path.canonicalize()
diff --git a/src/tools/clippy/clippy_lints/src/excessive_nesting.rs b/src/tools/clippy/clippy_lints/src/excessive_nesting.rs
index ffc76366983..dfea40db182 100644
--- a/src/tools/clippy/clippy_lints/src/excessive_nesting.rs
+++ b/src/tools/clippy/clippy_lints/src/excessive_nesting.rs
@@ -163,7 +163,7 @@ impl Visitor<'_> for NestingVisitor<'_, '_> {
         }
 
         match &item.kind {
-            ItemKind::Trait(_) | ItemKind::Impl(_) | ItemKind::Mod(.., ModKind::Loaded(_, Inline::Yes, _)) => {
+            ItemKind::Trait(_) | ItemKind::Impl(_) | ItemKind::Mod(.., ModKind::Loaded(_, Inline::Yes, _, _)) => {
                 self.nest_level += 1;
 
                 if !self.check_indent(item.span, item.id) {
diff --git a/src/tools/clippy/clippy_utils/src/ast_utils.rs b/src/tools/clippy/clippy_utils/src/ast_utils.rs
index 620a9b56eb5..12074dd16e6 100644
--- a/src/tools/clippy/clippy_utils/src/ast_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/ast_utils.rs
@@ -379,7 +379,7 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
         (Mod(lu, lmk), Mod(ru, rmk)) => {
             lu == ru
                 && match (lmk, rmk) {
-                    (ModKind::Loaded(litems, linline, _), ModKind::Loaded(ritems, rinline, _)) => {
+                    (ModKind::Loaded(litems, linline, _, _), ModKind::Loaded(ritems, rinline, _, _)) => {
                         linline == rinline && over(litems, ritems, |l, r| eq_item(l, r, eq_item_kind))
                     },
                     (ModKind::Unloaded, ModKind::Unloaded) => true,
diff --git a/src/tools/rustfmt/src/items.rs b/src/tools/rustfmt/src/items.rs
index 18932587f1f..c3debc2f4f0 100644
--- a/src/tools/rustfmt/src/items.rs
+++ b/src/tools/rustfmt/src/items.rs
@@ -3597,7 +3597,7 @@ pub(crate) fn rewrite_extern_crate(
 pub(crate) fn is_mod_decl(item: &ast::Item) -> bool {
     !matches!(
         item.kind,
-        ast::ItemKind::Mod(_, ast::ModKind::Loaded(_, ast::Inline::Yes, _))
+        ast::ItemKind::Mod(_, ast::ModKind::Loaded(_, ast::Inline::Yes, _, _))
     )
 }
 
diff --git a/src/tools/rustfmt/src/modules.rs b/src/tools/rustfmt/src/modules.rs
index 493b04f16c6..a40ee7f66a9 100644
--- a/src/tools/rustfmt/src/modules.rs
+++ b/src/tools/rustfmt/src/modules.rs
@@ -316,12 +316,11 @@ impl<'ast, 'psess, 'c> ModResolver<'ast, 'psess> {
             self.directory = directory;
         }
         match (sub_mod.ast_mod_kind, sub_mod.items) {
-            (Some(Cow::Borrowed(ast::ModKind::Loaded(items, _, _))), _) => {
+            (Some(Cow::Borrowed(ast::ModKind::Loaded(items, _, _, _))), _) => {
                 self.visit_mod_from_ast(items)
             }
-            (Some(Cow::Owned(ast::ModKind::Loaded(items, _, _))), _) | (_, Cow::Owned(items)) => {
-                self.visit_mod_outside_ast(items)
-            }
+            (Some(Cow::Owned(ast::ModKind::Loaded(items, _, _, _))), _)
+            | (_, Cow::Owned(items)) => self.visit_mod_outside_ast(items),
             (_, _) => Ok(()),
         }
     }
diff --git a/src/tools/rustfmt/src/visitor.rs b/src/tools/rustfmt/src/visitor.rs
index 9b116b620b7..805e13b7803 100644
--- a/src/tools/rustfmt/src/visitor.rs
+++ b/src/tools/rustfmt/src/visitor.rs
@@ -927,7 +927,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
         let ident_str = rewrite_ident(&self.get_context(), ident).to_owned();
         self.push_str(&ident_str);
 
-        if let ast::ModKind::Loaded(ref items, ast::Inline::Yes, ref spans) = mod_kind {
+        if let ast::ModKind::Loaded(ref items, ast::Inline::Yes, ref spans, _) = mod_kind {
             let ast::ModSpans {
                 inner_span,
                 inject_use_span: _,