Migrate 'rust-call incorrect arguments' diagnostic

Author: clubby789

compiler/rustc_hir_typeck/messages.ftl

@@ -90,6 +90,9 @@ hir_typeck_return_stmt_outside_of_fn_body =
     .encl_body_label = the {$statement_kind} is part of this body...
     .encl_fn_label = ...not the enclosing function body
 
+hir_typeck_rustcall_incorrect_args =
+    functions with the "rust-call" ABI must take a single non-self tuple argument
+
 hir_typeck_struct_expr_non_exhaustive =
     cannot create non-exhaustive {$what} using struct expression
 

compiler/rustc_hir_typeck/src/callee.rs

@@ -382,7 +382,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // to let us test the trait evaluation system.
                 // Untranslatable diagnostics are okay for rustc internals
                 #[allow(rustc::untranslatable_diagnostic)]
-                #[allow(rustc::diagnostic_outside_of_impl)]                
+                #[allow(rustc::diagnostic_outside_of_impl)]
                 if self.tcx.has_attr(def_id, sym::rustc_evaluate_where_clauses) {
                     let predicates = self.tcx.predicates_of(def_id);
                     let predicates = predicates.instantiate(self.tcx, args);
@@ -474,10 +474,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 );
                 self.require_type_is_sized(ty, sp, traits::RustCall);
             } else {
-                self.tcx.sess.span_err(
-                        sp,
-                        "functions with the \"rust-call\" ABI must take a single non-self tuple argument",
-                    );
+                self.tcx.sess.emit_err(errors::RustCallIncorrectArgs { span: sp });
             }
         }
 

compiler/rustc_hir_typeck/src/errors.rs

@@ -54,6 +54,13 @@ impl IntoDiagnosticArg for ReturnLikeStatementKind {
     }
 }
 
+#[derive(Diagnostic)]
+#[diag(hir_typeck_rustcall_incorrect_args)]
+pub struct RustCallIncorrectArgs {
+    #[primary_span]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(hir_typeck_yield_expr_outside_of_generator, code = "E0627")]
 pub struct YieldExprOutsideOfGenerator {