Commit 784be05a1a

@@ -4134,7 +4134,7 @@ fn unionDeclInner(
         if (member.comptime_token) |comptime_token| {
             return astgen.failTok(comptime_token, "union fields cannot be marked comptime", .{});
         }
-        try fields_data.ensureUnusedCapacity(gpa, if (node_tags[member.ast.type_expr] != .@"anytype") 4 else 3);
+        try fields_data.ensureUnusedCapacity(gpa, 4);
 
         const field_name = try astgen.identAsString(member.ast.name_token);
         fields_data.appendAssumeCapacity(field_name);
@@ -4149,8 +4149,11 @@ fn unionDeclInner(
             (@as(u32, @boolToInt(have_value)) << 30) |
             (@as(u32, @boolToInt(unused)) << 31);
 
-        if (have_type and node_tags[member.ast.type_expr] != .@"anytype") {
-            const field_type = try typeExpr(&block_scope, &namespace.base, member.ast.type_expr);
+        if (have_type) {
+            const field_type: Zir.Inst.Ref = if (node_tags[member.ast.type_expr] == .@"anytype")
+                .none
+            else
+                try typeExpr(&block_scope, &namespace.base, member.ast.type_expr);
             fields_data.appendAssumeCapacity(@enumToInt(field_type));
         }
         if (have_align) {

@@ -12629,8 +12629,10 @@ fn semaUnionFields(
             set.putAssumeCapacity(field_name, {});
         }
 
-        const field_ty: Type = if (field_type_ref == .none)
+        const field_ty: Type = if (!has_type)
             Type.initTag(.void)
+        else if (field_type_ref == .none)
+            Type.initTag(.noreturn)
         else
             // TODO: if we need to report an error here, use a source location
             // that points to this type expression rather than the union.

@@ -2686,6 +2686,7 @@ pub const Inst = struct {
     /// 9. fields: { // for every fields_len
     ///        field_name: u32, // null terminated string index
     ///        field_type: Ref, // if corresponding bit is set
+    ///        - if none, means `anytype`.
     ///        align: Ref, // if corresponding bit is set
     ///        tag_value: Ref, // if corresponding bit is set
     ///    }