Remove a layer of indirection from looking up submessages.

It's not clear why this is here - all tests passed removing it, it's immediately derefed...

PiperOrigin-RevId: 728541232

upb/mini_descriptor/decode.c

@@ -399,15 +399,11 @@ static void upb_MtDecoder_AllocateSubs(upb_MtDecoder* d,
                                        upb_SubCounts sub_counts) {
   uint32_t total_count = sub_counts.submsg_count + sub_counts.subenum_count;
   size_t subs_bytes = sizeof(*d->table->UPB_PRIVATE(subs)) * total_count;
-  size_t ptrs_bytes = sizeof(upb_MiniTable*) * sub_counts.submsg_count;
   upb_MiniTableSubInternal* subs = upb_Arena_Malloc(d->arena, subs_bytes);
-  const upb_MiniTable** subs_ptrs = upb_Arena_Malloc(d->arena, ptrs_bytes);
   upb_MdDecoder_CheckOutOfMemory(&d->base, subs);
-  upb_MdDecoder_CheckOutOfMemory(&d->base, subs_ptrs);
   uint32_t i = 0;
   for (; i < sub_counts.submsg_count; i++) {
-    subs_ptrs[i] = UPB_PRIVATE(_upb_MiniTable_Empty)();
+    subs[i].UPB_PRIVATE(submsg) = UPB_PRIVATE(_upb_MiniTable_Empty)();
-    subs[i].UPB_PRIVATE(submsg) = &subs_ptrs[i];
   }
   if (sub_counts.subenum_count) {
     upb_MiniTableField* f = d->fields;
@@ -417,7 +413,7 @@ static void upb_MtDecoder_AllocateSubs(upb_MtDecoder* d,
         f->UPB_PRIVATE(submsg_index) += sub_counts.submsg_count;
       }
     }
-    for (; i < sub_counts.submsg_count + sub_counts.subenum_count; i++) {
+    for (; i < total_count; i++) {
       subs[i].UPB_PRIVATE(subenum) = NULL;
     }
   }

upb/mini_descriptor/link.c

@@ -59,7 +59,7 @@ bool upb_MiniTable_SetSubMessage(upb_MiniTable* table,
   // TODO: Add this assert back once YouTube is updated to not call
   // this function repeatedly.
   // UPB_ASSERT(UPB_PRIVATE(_upb_MiniTable_IsEmpty)(table_sub->submsg));
-  memcpy((void*)table_subs[idx].UPB_PRIVATE(submsg), &sub, sizeof(void*));
+  table_subs[idx].UPB_PRIVATE(submsg) = sub;
   return true;
 }
 

upb/mini_table/internal/message.h

@@ -113,7 +113,7 @@ UPB_API_INLINE const struct upb_MiniTableField* upb_MiniTable_GetFieldByIndex(
 UPB_INLINE const struct upb_MiniTable* UPB_PRIVATE(
     _upb_MiniTable_GetSubTableByIndex)(const struct upb_MiniTable* m,
                                        uint32_t i) {
-  return *m->UPB_PRIVATE(subs)[i].UPB_PRIVATE(submsg);
+  return m->UPB_PRIVATE(subs)[i].UPB_PRIVATE(submsg);
 }
 
 UPB_API_INLINE const struct upb_MiniTable* upb_MiniTable_SubMessage(

upb/mini_table/internal/sub.h

@@ -12,7 +12,7 @@
 #include "upb/port/def.inc"
 
 typedef union {
-  const struct upb_MiniTable* const* UPB_PRIVATE(submsg);
+  const struct upb_MiniTable* UPB_PRIVATE(submsg);
   const struct upb_MiniTableEnum* UPB_PRIVATE(subenum);
 } upb_MiniTableSubInternal;
 

upb/wire/decode.c

@@ -98,7 +98,7 @@ typedef union {
 // from an array of MiniTableSubs.
 static const upb_MiniTable* _upb_MiniTableSubs_MessageByField(
     const upb_MiniTableSubInternal* subs, const upb_MiniTableField* field) {
-  return *subs[field->UPB_PRIVATE(submsg_index)].UPB_PRIVATE(submsg);
+  return subs[field->UPB_PRIVATE(submsg_index)].UPB_PRIVATE(submsg);
 }
 
 // Returns the MiniTableEnum corresponding to a given MiniTableField
@@ -1033,7 +1033,7 @@ void _upb_Decoder_CheckUnlinked(upb_Decoder* d, const upb_MiniTable* mt,
     do {
       UPB_ASSERT(upb_MiniTableField_CType(oneof) == kUpb_CType_Message);
       const upb_MiniTable* oneof_sub =
-          *mt->UPB_PRIVATE(subs)[oneof->UPB_PRIVATE(submsg_index)].UPB_PRIVATE(
+          mt->UPB_PRIVATE(subs)[oneof->UPB_PRIVATE(submsg_index)].UPB_PRIVATE(
               submsg);
       UPB_ASSERT(!oneof_sub);
     } while (upb_MiniTable_NextOneofField(mt, &oneof));
@@ -1188,7 +1188,7 @@ const char* _upb_Decoder_DecodeKnownField(upb_Decoder* d, const char* ptr,
     msg = &ext->data.UPB_PRIVATE(ext_msg_val);
     if (upb_MiniTableField_IsSubMessage(&ext->ext->UPB_PRIVATE(field))) {
       ext_sub.UPB_PRIVATE(submsg) =
-          &ext->ext->UPB_PRIVATE(sub).UPB_PRIVATE(submsg);
+          ext->ext->UPB_PRIVATE(sub).UPB_PRIVATE(submsg);
     } else {
       ext_sub.UPB_PRIVATE(subenum) =
           ext->ext->UPB_PRIVATE(sub).UPB_PRIVATE(subenum);

upb/wire/encode.c

@@ -49,7 +49,7 @@
 // from an array of MiniTableSubs.
 static const upb_MiniTable* _upb_Encoder_GetSubMiniTable(
     const upb_MiniTableSubInternal* subs, const upb_MiniTableField* field) {
-  return *subs[field->UPB_PRIVATE(submsg_index)].UPB_PRIVATE(submsg);
+  return subs[field->UPB_PRIVATE(submsg_index)].UPB_PRIVATE(submsg);
 }
 
 #define UPB_PB_VARINT_MAX_LEN 10
@@ -546,7 +546,7 @@ static void encode_ext(upb_encstate* e, const upb_MiniTableExtension* ext,
   } else {
     upb_MiniTableSubInternal sub;
     if (upb_MiniTableField_IsSubMessage(&ext->UPB_PRIVATE(field))) {
-      sub.UPB_PRIVATE(submsg) = &ext->UPB_PRIVATE(sub).UPB_PRIVATE(submsg);
+      sub.UPB_PRIVATE(submsg) = ext->UPB_PRIVATE(sub).UPB_PRIVATE(submsg);
     } else {
       sub.UPB_PRIVATE(subenum) = ext->UPB_PRIVATE(sub).UPB_PRIVATE(subenum);
     }

upb_generator/minitable/generator.cc

@@ -1,4 +1,4 @@
-// Protocol Buffers - Google's data interrdchange format
+// Protocol Buffers - Google's data interchange format
 // Copyright 2023 Google LLC.  All rights reserved.
 //
 // Use of this source code is governed by a BSD-style
@@ -83,11 +83,10 @@ void WriteMessageField(upb::FieldDefPtr field,
   output("  $0,\n", upb::generator::FieldInitializer(field, field64, field32));
 }
 
-std::string GetSub(upb::FieldDefPtr field, bool is_extension) {
+std::string GetSub(upb::FieldDefPtr field) {
   if (auto message_def = field.message_type()) {
     return absl::Substitute("{.UPB_PRIVATE(submsg) = &$0}",
-                            is_extension ? MessageVarName(message_def)
+                            MessageVarName(message_def));
-                                         : MessagePtrVarName(message_def));
   }
 
   if (auto enum_def = field.enum_subdef()) {
@@ -122,7 +121,7 @@ void WriteMessage(upb::MessageDefPtr message, const DefPoolPair& pools,
     if (index != kUpb_NoSub) {
       const int f_number = upb_MiniTableField_Number(f);
       upb::FieldDefPtr field = message.FindFieldByNumber(f_number);
-      auto pair = subs.emplace(index, GetSub(field, false));
+      auto pair = subs.emplace(index, GetSub(field));
       ABSL_CHECK(pair.second);
       if (options.one_output_per_message && field.IsSubMessage() &&
           IsCrossFile(field) && !upb_MiniTableField_IsMap(f)) {
@@ -242,7 +241,7 @@ void WriteExtension(const DefPoolPair& pools, upb::FieldDefPtr ext,
   output("const upb_MiniTableExtension $0 = {\n  ", ExtensionVarName(ext));
   output("$0,\n", FieldInitializer(pools, ext));
   output("  &$0,\n", MessageVarName(ext.containing_type()));
-  output("  $0,\n", GetSub(ext, true));
+  output("  $0,\n", GetSub(ext));
   output("\n};\n");
 }