Merge #7907

7907: Autoderef with visibility r=cynecx a=cynecx

Fixes https://github.com/rust-analyzer/rust-analyzer/issues/7841.

I am not sure about the general approach here. Right now this simply tries to check whether the autoderef candidate is reachable from the current module. ~~However this doesn't exactly work with traits (see the `tests::macros::infer_derive_clone_in_core` test, which fails right now).~~ see comment below

Refs:

- `rustc_typeck` checking fields: https://github.com/rust-lang/rust/blob/66ec64ccf31883cd2c28d045912a76179c0c6ed2/compiler/rustc_typeck/src/check/expr.rs#L1610 


r? @flodiebold

Co-authored-by: cynecx <[email protected]>

2 files changed, 34 insertions, 12 deletions

diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 19249973c..3f3187ea2 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -443,27 +443,47 @@ impl<'a> InferenceContext<'a> {
                     },
                 )
                 .find_map(|derefed_ty| {
+                    let def_db = self.db.upcast();
+                    let module = self.resolver.module();
+                    let is_visible = |field_id: &FieldId| {
+                        module
+                            .map(|mod_id| {
+                                self.db.field_visibilities(field_id.parent)[field_id.local_id]
+                                    .is_visible_from(def_db, mod_id)
+                            })
+                            .unwrap_or(true)
+                    };
                     match canonicalized.decanonicalize_ty(derefed_ty.value).interned(&Interner) {
                         TyKind::Tuple(_, substs) => {
                             name.as_tuple_index().and_then(|idx| substs.0.get(idx).cloned())
                         }
                         TyKind::Adt(AdtId(hir_def::AdtId::StructId(s)), parameters) => {
-                            self.db.struct_data(*s).variant_data.field(name).map(|local_id| {
-                                let field = FieldId { parent: (*s).into(), local_id };
+                            let local_id = self.db.struct_data(*s).variant_data.field(name)?;
+                            let field = FieldId { parent: (*s).into(), local_id };
+                            if is_visible(&field) {
                                 self.write_field_resolution(tgt_expr, field);
-                                self.db.field_types((*s).into())[field.local_id]
-                                    .clone()
-                                    .subst(&parameters)
-                            })
+                                Some(
+                                    self.db.field_types((*s).into())[field.local_id]
+                                        .clone()
+                                        .subst(&parameters),
+                                )
+                            } else {
+                                None
+                            }
                         }
                         TyKind::Adt(AdtId(hir_def::AdtId::UnionId(u)), parameters) => {
-                            self.db.union_data(*u).variant_data.field(name).map(|local_id| {
-                                let field = FieldId { parent: (*u).into(), local_id };
+                            let local_id = self.db.union_data(*u).variant_data.field(name)?;
+                            let field = FieldId { parent: (*u).into(), local_id };
+                            if is_visible(&field) {
                                 self.write_field_resolution(tgt_expr, field);
-                                self.db.field_types((*u).into())[field.local_id]
-                                    .clone()
-                                    .subst(&parameters)
-                            })
+                                Some(
+                                    self.db.field_types((*u).into())[field.local_id]
+                                        .clone()
+                                        .subst(&parameters),
+                                )
+                            } else {
+                                None
+                            }
                         }
                         _ => None,
                     }
@@ -828,6 +848,7 @@ impl<'a> InferenceContext<'a> {
                 self.trait_env.clone(),
                 krate,
                 &traits_in_scope,
+                self.resolver.module(),
                 method_name,
             )
         });
diff --git a/crates/hir_ty/src/infer/path.rs b/crates/hir_ty/src/infer/path.rs
index 58cce56ab..cefa38509 100644
--- a/crates/hir_ty/src/infer/path.rs
+++ b/crates/hir_ty/src/infer/path.rs
@@ -230,6 +230,7 @@ impl<'a> InferenceContext<'a> {
             self.trait_env.clone(),
             krate,
             &traits_in_scope,
+            None,
             Some(name),
             method_resolution::LookupMode::Path,
             move |_ty, item| {