From d45708fabe1f43b0c229b6b5222b7a2d5420d07e Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukastw97@gmail.com>
Date: Tue, 7 Mar 2023 15:24:43 +0100
Subject: [PATCH] Don't trigger unresolved method/field diagnostics on types
 containing errors

---
 crates/hir-ty/src/chalk_ext.rs                      |  7 ++++++-
 crates/hir-ty/src/infer.rs                          |  4 ++--
 .../src/handlers/unresolved_field.rs                | 13 +++++++++++++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/crates/hir-ty/src/chalk_ext.rs b/crates/hir-ty/src/chalk_ext.rs
index 45c975dfcd..e6aefbf271 100644
--- a/crates/hir-ty/src/chalk_ext.rs
+++ b/crates/hir-ty/src/chalk_ext.rs
@@ -13,7 +13,7 @@ use crate::{
     db::HirDatabase, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
     from_placeholder_idx, to_chalk_trait_id, utils::generics, AdtId, AliasEq, AliasTy, Binders,
     CallableDefId, CallableSig, FnPointer, ImplTraitId, Interner, Lifetime, ProjectionTy,
-    QuantifiedWhereClause, Substitution, TraitRef, Ty, TyBuilder, TyKind, WhereClause,
+    QuantifiedWhereClause, Substitution, TraitRef, Ty, TyBuilder, TyKind, TypeFlags, WhereClause,
 };
 
 pub trait TyExt {
@@ -22,6 +22,7 @@ pub trait TyExt {
     fn is_floating_point(&self) -> bool;
     fn is_never(&self) -> bool;
     fn is_unknown(&self) -> bool;
+    fn contains_unknown(&self) -> bool;
     fn is_ty_var(&self) -> bool;
 
     fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)>;
@@ -76,6 +77,10 @@ impl TyExt for Ty {
         matches!(self.kind(Interner), TyKind::Error)
     }
 
+    fn contains_unknown(&self) -> bool {
+        self.data(Interner).flags.contains(TypeFlags::HAS_ERROR)
+    }
+
     fn is_ty_var(&self) -> bool {
         matches!(self.kind(Interner), TyKind::InferenceVar(_, _))
     }
diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index 869b39ab37..ef15f54d29 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs
@@ -548,7 +548,7 @@ impl<'a> InferenceContext<'a> {
             {
                 *ty = table.resolve_completely(ty.clone());
                 // FIXME: Remove this when we are on par with rustc in terms of inference
-                if ty.is_unknown() {
+                if ty.contains_unknown() {
                     return false;
                 }
 
@@ -557,7 +557,7 @@ impl<'a> InferenceContext<'a> {
                 {
                     let clear = if let Some(ty) = field_with_same_name {
                         *ty = table.resolve_completely(ty.clone());
-                        ty.is_unknown()
+                        ty.contains_unknown()
                     } else {
                         false
                     };
diff --git a/crates/ide-diagnostics/src/handlers/unresolved_field.rs b/crates/ide-diagnostics/src/handlers/unresolved_field.rs
index 9754fc3f68..7de03416e5 100644
--- a/crates/ide-diagnostics/src/handlers/unresolved_field.rs
+++ b/crates/ide-diagnostics/src/handlers/unresolved_field.rs
@@ -129,6 +129,19 @@ fn foo() {
     Foo.bar;
  // ^^^^^^^ 💡 error: no field `bar` on type `Foo`, but a method with a similar name exists
 }
+"#,
+        );
+    }
+
+    #[test]
+    fn no_diagnostic_on_unknown() {
+        check_diagnostics(
+            r#"
+fn foo() {
+    x.foo;
+    (&x).foo;
+    (&((x,),),).foo;
+}
 "#,
         );
     }