Emit item no type error even if type inference fails

compiler/rustc_typeck/src/collect/type_of.rs

@@ -752,29 +752,31 @@ fn infer_placeholder_type<'a>(
     // us to improve in typeck so we do that now.
     match tcx.sess.diagnostic().steal_diagnostic(span, StashKey::ItemNoType) {
         Some(mut err) => {
-            // The parser provided a sub-optimal `HasPlaceholders` suggestion for the type.
-            // We are typeck and have the real type, so remove that and suggest the actual type.
-            err.suggestions.clear();
-
-            // Suggesting unnameable types won't help.
-            let mut mk_nameable = MakeNameable::new(tcx);
-            let ty = mk_nameable.fold_ty(ty);
-            let sugg_ty = if mk_nameable.success { Some(ty) } else { None };
-            if let Some(sugg_ty) = sugg_ty {
-                err.span_suggestion(
-                    span,
-                    &format!("provide a type for the {item}", item = kind),
-                    format!("{}: {}", item_ident, sugg_ty),
-                    Applicability::MachineApplicable,
-                );
-            } else {
-                err.span_note(
-                    tcx.hir().body(body_id).value.span,
-                    &format!("however, the inferred type `{}` cannot be named", ty.to_string()),
-                );
+            if !ty.references_error() {
+                // The parser provided a sub-optimal `HasPlaceholders` suggestion for the type.
+                // We are typeck and have the real type, so remove that and suggest the actual type.
+                err.suggestions.clear();
+
+                // Suggesting unnameable types won't help.
+                let mut mk_nameable = MakeNameable::new(tcx);
+                let ty = mk_nameable.fold_ty(ty);
+                let sugg_ty = if mk_nameable.success { Some(ty) } else { None };
+                if let Some(sugg_ty) = sugg_ty {
+                    err.span_suggestion(
+                        span,
+                        &format!("provide a type for the {item}", item = kind),
+                        format!("{}: {}", item_ident, sugg_ty),
+                        Applicability::MachineApplicable,
+                    );
+                } else {
+                    err.span_note(
+                        tcx.hir().body(body_id).value.span,
+                        &format!("however, the inferred type `{}` cannot be named", ty.to_string()),
+                    );
+                }
             }
 
-            err.emit_unless(ty.references_error());
+            err.emit();
         }
         None => {
             let mut diag = bad_placeholder_type(tcx, vec![span], kind);

src/test/ui/parser/issue-89574.rs

@@ -0,0 +1,4 @@
+fn main() {
+    const EMPTY_ARRAY = [];
+    //~^ missing type for `const` item
+}

src/test/ui/parser/issue-89574.stderr

@@ -0,0 +1,8 @@
+error: missing type for `const` item
+  --> $DIR/issue-89574.rs:2:11
+   |
+LL |     const EMPTY_ARRAY = [];
+   |           ^^^^^^^^^^^ help: provide a type for the item: `EMPTY_ARRAY: <type>`
+
+error: aborting due to previous error
+

src/test/ui/parser/item-free-const-no-body-semantic-fail.rs

@@ -4,3 +4,4 @@ fn main() {}
 
 const A: u8; //~ ERROR free constant item without body
 const B; //~ ERROR free constant item without body
+//~^ ERROR missing type for `const` item

src/test/ui/parser/item-free-const-no-body-semantic-fail.stderr

@@ -14,5 +14,11 @@ LL | const B;
    |        |
    |        help: provide a definition for the constant: `= <expr>;`
 
-error: aborting due to 2 previous errors
+error: missing type for `const` item
+  --> $DIR/item-free-const-no-body-semantic-fail.rs:6:7
+   |
+LL | const B;
+   |       ^ help: provide a type for the item: `B: <type>`
+
+error: aborting due to 3 previous errors
 

src/test/ui/parser/item-free-static-no-body-semantic-fail.rs

@@ -4,6 +4,8 @@ fn main() {}
 
 static A: u8; //~ ERROR free static item without body
 static B; //~ ERROR free static item without body
+//~^ ERROR missing type for `static` item
 
 static mut C: u8; //~ ERROR free static item without body
 static mut D; //~ ERROR free static item without body
+//~^ ERROR missing type for `static mut` item

src/test/ui/parser/item-free-static-no-body-semantic-fail.stderr

@@ -15,20 +15,32 @@ LL | static B;
    |         help: provide a definition for the static: `= <expr>;`
 
 error: free static item without body
-  --> $DIR/item-free-static-no-body-semantic-fail.rs:8:1
+  --> $DIR/item-free-static-no-body-semantic-fail.rs:9:1
    |
 LL | static mut C: u8;
    | ^^^^^^^^^^^^^^^^-
    |                 |
    |                 help: provide a definition for the static: `= <expr>;`
 
 error: free static item without body
-  --> $DIR/item-free-static-no-body-semantic-fail.rs:9:1
+  --> $DIR/item-free-static-no-body-semantic-fail.rs:10:1
    |
 LL | static mut D;
    | ^^^^^^^^^^^^-
    |             |
    |             help: provide a definition for the static: `= <expr>;`
 
-error: aborting due to 4 previous errors
+error: missing type for `static` item
+  --> $DIR/item-free-static-no-body-semantic-fail.rs:6:8
+   |
+LL | static B;
+   |        ^ help: provide a type for the item: `B: <type>`
+
+error: missing type for `static mut` item
+  --> $DIR/item-free-static-no-body-semantic-fail.rs:10:12
+   |
+LL | static mut D;
+   |            ^ help: provide a type for the item: `D: <type>`
+
+error: aborting due to 6 previous errors
 

src/test/ui/typeck/issue-79040.rs

@@ -1,5 +1,5 @@
 fn main() {
     const FOO = "hello" + 1; //~ ERROR cannot add `{integer}` to `&str`
-    //~^ ERROR cannot add `{integer}` to `&str`
+    //~^ missing type for `const` item
     println!("{}", FOO);
 }

src/test/ui/typeck/issue-79040.stderr

@@ -6,13 +6,11 @@ LL |     const FOO = "hello" + 1;
    |                 |
    |                 &str
 
-error[E0369]: cannot add `{integer}` to `&str`
-  --> $DIR/issue-79040.rs:2:25
+error: missing type for `const` item
+  --> $DIR/issue-79040.rs:2:11
    |
 LL |     const FOO = "hello" + 1;
-   |                 ------- ^ - {integer}
-   |                 |
-   |                 &str
+   |           ^^^ help: provide a type for the item: `FOO: <type>`
 
 error: aborting due to 2 previous errors