Improve diagnostic for cases where autoderef is used

Author: sgued

clippy_lints/src/functions/misnamed_getters.rs

@@ -75,7 +75,7 @@ pub fn check_fn(
         }
     };
 
-    let ty = cx.typeck_results().expr_ty(self_data);
+    let ty = cx.typeck_results().expr_ty_adjusted(self_data);
 
     let def = {
         let mut kind = ty.kind();
@@ -102,7 +102,7 @@ pub fn check_fn(
 
     let Some(used_field) = used_field else {
         // FIXME: This can be reached if the field access uses autoderef.
-        // `dec.all_fields()` should be replaced by something that uses autoderef.
+        // `dec.all_fields()` should be replaced by something that uses autoderef on the unajusted type of `self_data`
         return;
     };
 

tests/ui/misnamed_getters.stderr

@@ -126,5 +126,23 @@ LL | |         &mut self.a
 LL | |     }
    | |_____^
 
-error: aborting due to 14 previous errors
+error: getter function appears to return the wrong field
+  --> $DIR/misnamed_getters.rs:92:5
+   |
+LL | /     unsafe fn a(&self) -> &u8 {
+LL | |         &self.inner.b
+   | |         ------------- help: consider using: `&self.inner.a`
+LL | |     }
+   | |_____^
+
+error: getter function appears to return the wrong field
+  --> $DIR/misnamed_getters.rs:95:5
+   |
+LL | /     unsafe fn a_mut(&mut self) -> &mut u8 {
+LL | |         &mut self.inner.b
+   | |         ----------------- help: consider using: `&mut self.inner.a`
+LL | |     }
+   | |_____^
+
+error: aborting due to 16 previous errors