Tweak "field not found" suggestion when giving struct literal for tuple struct type

```
error[E0560]: struct `S` has no field named `x`
  --> $DIR/nested-non-tuple-tuple-struct.rs:8:19
   |
LL | pub struct S(f32, f32);
   |            - `S` defined here
...
LL |     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
   |                   ^ field does not exist
   |
help: `S` is a tuple struct, use the appropriate syntax
   |
LL -     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
LL +     let _x = (S(/* f32 */, /* f32 */), S { x: 3.0, y: 4.0 });
   |
```

Author: estebank

compiler/rustc_hir_typeck/src/expr.rs

@@ -2216,8 +2216,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
 
         let variant_ident_span = self.tcx.def_ident_span(variant.def_id).unwrap();
-        match variant.ctor_kind() {
-            Some(CtorKind::Fn) => match ty.kind() {
+        match variant.ctor {
+            Some((CtorKind::Fn, def_id)) => match ty.kind() {
                 ty::Adt(adt, ..) if adt.is_enum() => {
                     err.span_label(
                         variant_ident_span,
@@ -2228,28 +2228,45 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         ),
                     );
                     err.span_label(field.ident.span, "field does not exist");
+                    // err.note(format!("{expr:#?}"));
+                    let fn_sig = self.tcx.fn_sig(def_id).instantiate_identity();
+                    let inputs = fn_sig.inputs().skip_binder();
+                    let fields = format!(
+                        "({})",
+                        inputs.iter().map(|i| format!("/* {i} */")).collect::<Vec<_>>().join(", ")
+                    );
+                    let (replace_span, sugg) = match expr.kind {
+                        hir::ExprKind::Struct(qpath, ..) => {
+                            (qpath.span().shrink_to_hi().with_hi(expr.span.hi()), fields)
+                        }
+                        _ => {
+                            (expr.span, format!("{ty}::{variant}{fields}", variant = variant.name))
+                        }
+                    };
                     err.span_suggestion_verbose(
-                        expr.span,
+                        replace_span,
                         format!(
                             "`{adt}::{variant}` is a tuple {kind_name}, use the appropriate syntax",
                             adt = ty,
                             variant = variant.name,
                         ),
-                        format!(
-                            "{adt}::{variant}(/* fields */)",
-                            adt = ty,
-                            variant = variant.name,
-                        ),
+                        sugg,
                         Applicability::HasPlaceholders,
                     );
                 }
                 _ => {
                     err.span_label(variant_ident_span, format!("`{ty}` defined here"));
                     err.span_label(field.ident.span, "field does not exist");
+                    let fn_sig = self.tcx.fn_sig(def_id).instantiate_identity();
+                    let inputs = fn_sig.inputs().skip_binder();
+                    let fields = format!(
+                        "({})",
+                        inputs.iter().map(|i| format!("/* {i} */")).collect::<Vec<_>>().join(", ")
+                    );
                     err.span_suggestion_verbose(
                         expr.span,
                         format!("`{ty}` is a tuple {kind_name}, use the appropriate syntax",),
-                        format!("{ty}(/* fields */)"),
+                        format!("{ty}{fields}"),
                         Applicability::HasPlaceholders,
                     );
                 }

tests/ui/suggestions/incorrect-variant-literal.svg

@@ -10,7 +10,7 @@ LL |     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
 help: `S` is a tuple struct, use the appropriate syntax
    |
 LL -     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
-LL +     let _x = (S(/* fields */), S { x: 3.0, y: 4.0 });
+LL +     let _x = (S(/* f32 */, /* f32 */), S { x: 3.0, y: 4.0 });
    |
 
 error[E0560]: struct `S` has no field named `y`
@@ -25,7 +25,7 @@ LL |     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
 help: `S` is a tuple struct, use the appropriate syntax
    |
 LL -     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
-LL +     let _x = (S(/* fields */), S { x: 3.0, y: 4.0 });
+LL +     let _x = (S(/* f32 */, /* f32 */), S { x: 3.0, y: 4.0 });
    |
 
 error[E0560]: struct `S` has no field named `x`
@@ -40,7 +40,7 @@ LL |     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
 help: `S` is a tuple struct, use the appropriate syntax
    |
 LL -     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
-LL +     let _x = (S { x: 1.0, y: 2.0 }, S(/* fields */));
+LL +     let _x = (S { x: 1.0, y: 2.0 }, S(/* f32 */, /* f32 */));
    |
 
 error[E0560]: struct `S` has no field named `y`
@@ -55,7 +55,7 @@ LL |     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
 help: `S` is a tuple struct, use the appropriate syntax
    |
 LL -     let _x = (S { x: 1.0, y: 2.0 }, S { x: 3.0, y: 4.0 });
-LL +     let _x = (S { x: 1.0, y: 2.0 }, S(/* fields */));
+LL +     let _x = (S { x: 1.0, y: 2.0 }, S(/* f32 */, /* f32 */));
    |
 
 error[E0559]: variant `E::V` has no field named `x`
@@ -70,7 +70,7 @@ LL |     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
 help: `E::V` is a tuple variant, use the appropriate syntax
    |
 LL -     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
-LL +     let _y = (E::V(/* fields */), E::V { x: 3.0, y: 4.0 });
+LL +     let _y = (E::V(/* f32 */, /* f32 */), E::V { x: 3.0, y: 4.0 });
    |
 
 error[E0559]: variant `E::V` has no field named `y`
@@ -85,7 +85,7 @@ LL |     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
 help: `E::V` is a tuple variant, use the appropriate syntax
    |
 LL -     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
-LL +     let _y = (E::V(/* fields */), E::V { x: 3.0, y: 4.0 });
+LL +     let _y = (E::V(/* f32 */, /* f32 */), E::V { x: 3.0, y: 4.0 });
    |
 
 error[E0559]: variant `E::V` has no field named `x`
@@ -100,7 +100,7 @@ LL |     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
 help: `E::V` is a tuple variant, use the appropriate syntax
    |
 LL -     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
-LL +     let _y = (E::V { x: 1.0, y: 2.0 }, E::V(/* fields */));
+LL +     let _y = (E::V { x: 1.0, y: 2.0 }, E::V(/* f32 */, /* f32 */));
    |
 
 error[E0559]: variant `E::V` has no field named `y`
@@ -115,7 +115,7 @@ LL |     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
 help: `E::V` is a tuple variant, use the appropriate syntax
    |
 LL -     let _y = (E::V { x: 1.0, y: 2.0 }, E::V { x: 3.0, y: 4.0 });
-LL +     let _y = (E::V { x: 1.0, y: 2.0 }, E::V(/* fields */));
+LL +     let _y = (E::V { x: 1.0, y: 2.0 }, E::V(/* f32 */, /* f32 */));
    |
 
 error: aborting due to 8 previous errors