Implement UPB OneOf MiniTable apis.

PiperOrigin-RevId: 506691706

upb/mini_table/common.c

@@ -94,3 +94,35 @@ upb_FieldType upb_MiniTableField_Type(const upb_MiniTableField* field) {
   }
   return field->descriptortype;
 }
+
+static bool upb_MiniTable_Is_Oneof(const upb_MiniTableField* f) {
+  return f->presence < 0;
+}
+
+const upb_MiniTableField* upb_MiniTable_GetOneof(const upb_MiniTable* m,
+                                                 const upb_MiniTableField* f) {
+  if (UPB_UNLIKELY(!upb_MiniTable_Is_Oneof(f))) {
+    return NULL;
+  }
+  const upb_MiniTableField* ptr = &m->fields[0];
+  const upb_MiniTableField* end = &m->fields[m->field_count];
+  while (++ptr < end) {
+    if (ptr->presence == (*f).presence) {
+      return ptr;
+    }
+  }
+  return NULL;
+}
+
+bool upb_MiniTable_NextOneofField(const upb_MiniTable* m,
+                                  const upb_MiniTableField** f) {
+  const upb_MiniTableField* ptr = *f;
+  const upb_MiniTableField* end = &m->fields[m->field_count];
+  while (++ptr < end) {
+    if (ptr->presence == (*f)->presence) {
+      *f = ptr;
+      return true;
+    }
+  }
+  return false;
+}

upb/mini_table/common.h

@@ -117,6 +117,26 @@ UPB_API_INLINE const upb_MiniTableEnum* upb_MiniTable_GetSubEnumTable(
   return mini_table->subs[field->submsg_index].subenum;
 }
 
+// If this field is in a oneof, returns the first field in the oneof.
+//
+// Otherwise returns NULL.
+//
+// Usage:
+//   const upb_MiniTableField* field = upb_MiniTable_GetOneof(m, f);
+//   do {
+//       ..
+//   } while (upb_MiniTable_NextOneofField(m, &field);
+//
+const upb_MiniTableField* upb_MiniTable_GetOneof(const upb_MiniTable* m,
+                                                 const upb_MiniTableField* f);
+
+// Returns the next field in the oneof. If this is the last field in the
+// oneof, returns NULL. The ordering of fields in the oneof is not
+// guaranteed.
+// REQUIRES: |iter| is and iterator.
+bool upb_MiniTable_NextOneofField(const upb_MiniTable* m,
+                                  const upb_MiniTableField** f);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif

upb/test/BUILD

@@ -159,7 +159,9 @@ cc_test(
 
 cc_test(
     name = "test_generated_code",
-    srcs = ["test_generated_code.cc"],
+    srcs = [
+        "test_generated_code.cc",
+    ],
     deps = [
         ":empty_upb_proto_reflection",
         ":test_messages_proto2_upb_proto",
@@ -170,3 +172,20 @@ cc_test(
         "@com_google_googletest//:gtest_main",
     ],
 )
+
+cc_test(
+    name = "test_mini_table_oneof",
+    srcs = [
+        "test_mini_table_oneof.cc",
+    ],
+    deps = [
+        ":empty_upb_proto_reflection",
+        ":test_messages_proto2_upb_proto",
+        ":test_messages_proto3_upb_proto",
+        ":test_upb_proto",
+        "//:upb",
+        "//:mini_table_internal",
+        "//:port",
+        "@com_google_googletest//:gtest_main",
+    ],
+)

upb/test/test_mini_table_oneof.cc

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2009-2021, Google LLC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Google LLC nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "gtest/gtest.h"
+#include "google/protobuf/test_messages_proto2.upb.h"
+#include "google/protobuf/test_messages_proto3.upb.h"
+#include "upb/mini_table/common.h"
+#include "upb/test/test.upb.h"
+#include "upb/upb.hpp"
+
+// Must be last.
+#include "upb/port/def.inc"
+
+TEST(MiniTableOneofTest, OneOfIteratorProto2) {
+  constexpr int oneof_first_field_number = 111;
+  constexpr int oneof_test_field_number = 116;
+
+  const upb_MiniTable* google_protobuf_table =
+      &protobuf_test_messages_proto2_TestAllTypesProto2_msg_init;
+  const upb_MiniTableField* field =
+      upb_MiniTable_FindFieldByNumber(google_protobuf_table, oneof_test_field_number);
+  ASSERT_TRUE(field != nullptr);
+  const upb_MiniTableField* ptr = upb_MiniTable_GetOneof(google_protobuf_table, field);
+  int field_num = oneof_first_field_number;
+  do {
+    EXPECT_EQ(ptr->number, field_num++);
+  } while (upb_MiniTable_NextOneofField(google_protobuf_table, &ptr));
+}
+
+TEST(MiniTableOneofTest, InitialFieldNotOneOf) {
+  constexpr int test_field_number = 1;  // optional int that is not a oneof
+  const upb_MiniTable* google_protobuf_table =
+      &protobuf_test_messages_proto2_TestAllTypesProto2_msg_init;
+  const upb_MiniTableField* field =
+      upb_MiniTable_FindFieldByNumber(google_protobuf_table, test_field_number);
+  ASSERT_TRUE(field != nullptr);
+  const upb_MiniTableField* first_field =
+      upb_MiniTable_GetOneof(google_protobuf_table, field);
+  EXPECT_EQ(first_field, nullptr);
+}