Add upb_MiniTableField_IsClosedEnum API.

PiperOrigin-RevId: 494269273

upb/message/accessors.h

@@ -515,6 +515,12 @@ UPB_API_INLINE upb_Array* upb_MiniTable_GetMutableArray(
 void* upb_MiniTable_ResizeArray(upb_Message* msg,
                                 const upb_MiniTableField* field, size_t len,
                                 upb_Arena* arena);
+
+UPB_API_INLINE bool upb_MiniTableField_IsClosedEnum(
+    const upb_MiniTableField* field) {
+  return field->descriptortype == kUpb_FieldType_Enum;
+}
+
 typedef enum {
   kUpb_GetExtension_Ok,
   kUpb_GetExtension_NotPresent,

upb/message/accessors_test.cc

@@ -38,8 +38,10 @@
 #include "google/protobuf/test_messages_proto3.upb.h"
 #include "upb/base/string_view.h"
 #include "upb/collections/array.h"
+#include "upb/mini_table/common.h"
 #include "upb/mini_table/decode.h"
 #include "upb/mini_table/encode_internal.hpp"
+#include "upb/mini_table/field_internal.h"
 #include "upb/test/test.upb.h"
 #include "upb/upb.h"
 #include "upb/wire/decode.h"
@@ -676,4 +678,36 @@ TEST(GeneratedCode, PromoteUnknownRepeatedMessage) {
   upb_Arena_Free(arena);
 }
 
+TEST(GeneratedCode, EnumClosedCheck) {
+  upb_Arena* arena = upb_Arena_New();
+
+  upb::MtDataEncoder e;
+  e.StartMessage(0);
+  e.PutField(kUpb_FieldType_Int32, 4, 0);
+  e.PutField(kUpb_FieldType_Enum, 5, 0);
+
+  upb_Status status;
+  upb_Status_Clear(&status);
+  upb_MiniTable* table =
+      upb_MiniTable_Build(e.data().data(), e.data().size(), arena, &status);
+
+  const upb_MiniTableField* enumField = &table->fields[1];
+  EXPECT_EQ(upb_MiniTableField_Type(enumField), kUpb_FieldType_Enum);
+  EXPECT_FALSE(upb_MiniTableField_IsClosedEnum(enumField));
+
+  upb::MtDataEncoder e2;
+  e2.StartMessage(0);
+  e2.PutField(kUpb_FieldType_Int32, 4, 0);
+  e2.PutField(kUpb_FieldType_Enum, 6, kUpb_FieldModifier_IsClosedEnum);
+
+  upb_Status_Clear(&status);
+  table =
+      upb_MiniTable_Build(e2.data().data(), e2.data().size(), arena, &status);
+
+  const upb_MiniTableField* closedEnumField = &table->fields[1];
+  EXPECT_EQ(upb_MiniTableField_Type(closedEnumField), kUpb_FieldType_Enum);
+  EXPECT_TRUE(upb_MiniTableField_IsClosedEnum(closedEnumField));
+  upb_Arena_Free(arena);
+}
+
 }  // namespace