Update protobuf's UPB dep to include the most recent changes.

PiperOrigin-RevId: 506093740
2 years ago · 59cfc2f165
parent 0093eb8354
commit 59cfc2f165
5 changed files with 450 additions and 356 deletions
--- a/php/ext/google/protobuf/php-upb.c
+++ b/php/ext/google/protobuf/php-upb.c
@ -6801,64 +6801,48 @@ static void upb_MtDecoder_AssignOffsets(upb_MtDecoder* d) {
  d->table->size = UPB_ALIGN_UP(d->table->size, 8);
 }

-static void upb_MtDecoder_ParseMap(upb_MtDecoder* d, const char* data,
-                                   size_t len) {
-  if (len < 2) {
-    upb_MtDecoder_ErrorFormat(d, "Invalid map encode length: %zu", len);
-    UPB_UNREACHABLE();
+static void upb_MtDecoder_ValidateEntryField(upb_MtDecoder* d,
+                                             const upb_MiniTableField* f,
+                                             int expected_num) {
+  const char* name = expected_num == 1 ? "key" : "val";
+  if (f->number != expected_num) {
+    upb_MtDecoder_ErrorFormat(d,
+                              "map %s did not have expected number (%d vs %d)",
+                              name, expected_num, (int)f->number);
  }
-  const upb_EncodedType key_type = _upb_FromBase92(data[0]);
-  switch (key_type) {
-    case kUpb_EncodedType_Fixed32:
-    case kUpb_EncodedType_Fixed64:
-    case kUpb_EncodedType_SFixed32:
-    case kUpb_EncodedType_SFixed64:
-    case kUpb_EncodedType_Int32:
-    case kUpb_EncodedType_UInt32:
-    case kUpb_EncodedType_SInt32:
-    case kUpb_EncodedType_Int64:
-    case kUpb_EncodedType_UInt64:
-    case kUpb_EncodedType_SInt64:
-    case kUpb_EncodedType_Bool:
-    case kUpb_EncodedType_String:
-      break;

-    default:
-      upb_MtDecoder_ErrorFormat(d, "Invalid map key field type: %d", key_type);
-      UPB_UNREACHABLE();
+  if (upb_IsRepeatedOrMap(f) || f->presence < 0) {
+    upb_MtDecoder_ErrorFormat(
+        d, "map %s cannot be repeated or map, or be in oneof", name);
  }

-  upb_MtDecoder_ParseMessage(d, data, len);
-  upb_MtDecoder_AssignHasbits(d->table);
-
-  if (UPB_UNLIKELY(d->table->field_count != 2)) {
-    upb_MtDecoder_ErrorFormat(d, "%hu fields in map", d->table->field_count);
-    UPB_UNREACHABLE();
+  uint32_t not_ok_types;
+  if (expected_num == 1) {
+    not_ok_types = (1 << kUpb_FieldType_Float) | (1 << kUpb_FieldType_Double) |
+                   (1 << kUpb_FieldType_Message) | (1 << kUpb_FieldType_Group) |
+                   (1 << kUpb_FieldType_Bytes) | (1 << kUpb_FieldType_Enum);
+  } else {
+    not_ok_types = 1 << kUpb_FieldType_Group;
  }

-  const int num0 = d->table->fields[0].number;
-  if (UPB_UNLIKELY(num0 != 1)) {
-    upb_MtDecoder_ErrorFormat(d, "field %d in map key", num0);
-    UPB_UNREACHABLE();
+  if ((1 << upb_MiniTableField_Type(f)) & not_ok_types) {
+    upb_MtDecoder_ErrorFormat(d, "map %s cannot have type %d", name,
+                              (int)f->descriptortype);
  }
+}

-  const int num1 = d->table->fields[1].number;
-  if (UPB_UNLIKELY(num1 != 2)) {
-    upb_MtDecoder_ErrorFormat(d, "field %d in map val", num1);
-    UPB_UNREACHABLE();
-  }
+static void upb_MtDecoder_ParseMap(upb_MtDecoder* d, const char* data,
+                                   size_t len) {
+  upb_MtDecoder_ParseMessage(d, data, len);
+  upb_MtDecoder_AssignHasbits(d->table);

-  const int off0 = d->table->fields[0].offset;
-  if (UPB_UNLIKELY(off0 != kNoPresence && off0 != kHasbitPresence)) {
-    upb_MtDecoder_ErrorFormat(d, "bad offset %d in map key", off0);
+  if (UPB_UNLIKELY(d->table->field_count != 2)) {
+    upb_MtDecoder_ErrorFormat(d, "%hu fields in map", d->table->field_count);
    UPB_UNREACHABLE();
  }

-  const int off1 = d->table->fields[1].offset;
-  if (UPB_UNLIKELY(off1 != kNoPresence && off1 != kHasbitPresence)) {
-    upb_MtDecoder_ErrorFormat(d, "bad offset %d in map val", off1);
-    UPB_UNREACHABLE();
-  }
+  upb_MtDecoder_ValidateEntryField(d, &d->table->fields[0], 1);
+  upb_MtDecoder_ValidateEntryField(d, &d->table->fields[1], 2);

  // Map entries have a pre-determined layout, regardless of types.
  // NOTE: sync with mini_table/message_internal.h.
@ -7109,26 +7093,49 @@ upb_MiniTable* _upb_MiniTable_Build(const char* data, size_t len,
  return ret;
 }

-void upb_MiniTable_SetSubMessage(upb_MiniTable* table,
+bool upb_MiniTable_SetSubMessage(upb_MiniTable* table,
                                 upb_MiniTableField* field,
                                 const upb_MiniTable* sub) {
  UPB_ASSERT((uintptr_t)table->fields <= (uintptr_t)field &&
             (uintptr_t)field <
                 (uintptr_t)(table->fields + table->field_count));
-  if (sub->ext & kUpb_ExtMode_IsMapEntry) {
-    field->mode = (field->mode & ~kUpb_FieldMode_Mask) | kUpb_FieldMode_Map;
+  UPB_ASSERT(sub);
+
+  const bool sub_is_map = sub->ext & kUpb_ExtMode_IsMapEntry;
+
+  switch (field->descriptortype) {
+    case kUpb_FieldType_Message:
+      if (sub_is_map) {
+        const bool table_is_map = table->ext & kUpb_ExtMode_IsMapEntry;
+        if (UPB_UNLIKELY(table_is_map)) return false;
+
+        field->mode = (field->mode & ~kUpb_FieldMode_Mask) | kUpb_FieldMode_Map;
+      }
+      break;
+
+    case kUpb_FieldType_Group:
+      if (UPB_UNLIKELY(sub_is_map)) return false;
+      break;
+
+    default:
+      return false;
  }
+
  upb_MiniTableSub* table_sub = (void*)&table->subs[field->submsg_index];
  table_sub->submsg = sub;
+  return true;
 }

-void upb_MiniTable_SetSubEnum(upb_MiniTable* table, upb_MiniTableField* field,
+bool upb_MiniTable_SetSubEnum(upb_MiniTable* table, upb_MiniTableField* field,
                              const upb_MiniTableEnum* sub) {
  UPB_ASSERT((uintptr_t)table->fields <= (uintptr_t)field &&
             (uintptr_t)field <
                 (uintptr_t)(table->fields + table->field_count));
+  UPB_ASSERT(sub);
+
  upb_MiniTableSub* table_sub = (void*)&table->subs[field->submsg_index];
  table_sub->subenum = sub;
+  return true;
 }

 #include <inttypes.h>
@ -8024,6 +8031,31 @@ static void remove_filedef(upb_DefPool* s, upb_FileDef* file) {
  }
 }

+static const upb_FileDef* upb_DefBuilder_AddFileToPool(
+    upb_DefBuilder* const builder, upb_DefPool* const s,
+    const UPB_DESC(FileDescriptorProto) * const file_proto,
+    const upb_StringView name, upb_Status* const status) {
+  if (UPB_SETJMP(builder->err) != 0) {
+    UPB_ASSERT(!upb_Status_IsOk(status));
+    if (builder->file) {
+      remove_filedef(s, builder->file);
+      builder->file = NULL;
+    }
+  } else if (!builder->arena || !builder->tmp_arena) {
+    _upb_DefBuilder_OomErr(builder);
+  } else {
+    _upb_FileDef_Create(builder, file_proto);
+    upb_strtable_insert(&s->files, name.data, name.size,
+                        upb_value_constptr(builder->file), builder->arena);
+    UPB_ASSERT(upb_Status_IsOk(status));
+    upb_Arena_Fuse(s->arena, builder->arena);
+  }
+
+  if (builder->arena) upb_Arena_Free(builder->arena);
+  if (builder->tmp_arena) upb_Arena_Free(builder->tmp_arena);
+  return builder->file;
+}
+
 static const upb_FileDef* _upb_DefPool_AddFile(
    upb_DefPool* s, const UPB_DESC(FileDescriptorProto) * file_proto,
    const upb_MiniTableFile* layout, upb_Status* status) {
@ -8059,25 +8091,7 @@ static const upb_FileDef* _upb_DefPool_AddFile(
      .tmp_arena = upb_Arena_New(),
  };

-  if (UPB_SETJMP(ctx.err)) {
-    UPB_ASSERT(!upb_Status_IsOk(status));
-    if (ctx.file) {
-      remove_filedef(s, ctx.file);
-      ctx.file = NULL;
-    }
-  } else if (!ctx.arena || !ctx.tmp_arena) {
-    _upb_DefBuilder_OomErr(&ctx);
-  } else {
-    _upb_FileDef_Create(&ctx, file_proto);
-    upb_strtable_insert(&s->files, name.data, name.size,
-                        upb_value_constptr(ctx.file), ctx.arena);
-    UPB_ASSERT(upb_Status_IsOk(status));
-    upb_Arena_Fuse(s->arena, ctx.arena);
-  }
-
-  if (ctx.arena) upb_Arena_Free(ctx.arena);
-  if (ctx.tmp_arena) upb_Arena_Free(ctx.tmp_arena);
-  return ctx.file;
+  return upb_DefBuilder_AddFileToPool(&ctx, s, file_proto, name, status);
 }

 const upb_FileDef* upb_DefPool_AddFile(upb_DefPool* s,
@ -8261,6 +8275,7 @@ struct upb_EnumDef {
  int res_range_count;
  int res_name_count;
  int32_t defaultval;
+  bool is_closed;
  bool is_sorted;  // Whether all of the values are defined in ascending order.
 };

@ -8268,15 +8283,6 @@ upb_EnumDef* _upb_EnumDef_At(const upb_EnumDef* e, int i) {
  return (upb_EnumDef*)&e[i];
 }

-// TODO: Maybe implement this on top of a ZCOS instead?
-void _upb_EnumDef_Debug(const upb_EnumDef* e) {
-  fprintf(stderr, "enum %s (%p) {\n", e->full_name, e);
-  fprintf(stderr, " value_count: %d\n", e->value_count);
-  fprintf(stderr, " default:     %d\n", e->defaultval);
-  fprintf(stderr, " is_sorted:   %d\n", e->is_sorted);
-  fprintf(stderr, "}\n");
-}
-
 const upb_MiniTableEnum* _upb_EnumDef_MiniTable(const upb_EnumDef* e) {
  return e->layout;
 }
@ -8372,10 +8378,7 @@ const upb_EnumValueDef* upb_EnumDef_Value(const upb_EnumDef* e, int i) {
  return _upb_EnumValueDef_At(e->values, i);
 }

-bool upb_EnumDef_IsClosed(const upb_EnumDef* e) {
-  if (UPB_TREAT_PROTO2_ENUMS_LIKE_PROTO3) return false;
-  return upb_FileDef_Syntax(e->file) == kUpb_Syntax_Proto2;
-}
+bool upb_EnumDef_IsClosed(const upb_EnumDef* e) { return e->is_closed; }

 bool upb_EnumDef_MiniDescriptorEncode(const upb_EnumDef* e, upb_Arena* a,
                                      upb_StringView* out) {
@ -8461,6 +8464,9 @@ static void create_enumdef(upb_DefBuilder* ctx, const char* prefix,
  _upb_DefBuilder_Add(ctx, e->full_name,
                      _upb_DefType_Pack(e, UPB_DEFTYPE_ENUM));

+  e->is_closed = (!UPB_TREAT_PROTO2_ENUMS_LIKE_PROTO3) &&
+                 (upb_FileDef_Syntax(e->file) == kUpb_Syntax_Proto2);
+
  values = UPB_DESC(EnumDescriptorProto_value)(enum_proto, &n_value);

  bool ok = upb_strtable_init(&e->ntoi, n_value, ctx->arena);
@ -8493,7 +8499,7 @@ static void create_enumdef(upb_DefBuilder* ctx, const char* prefix,

  upb_inttable_compact(&e->iton, ctx->arena);

-  if (upb_FileDef_Syntax(e->file) == kUpb_Syntax_Proto2) {
+  if (e->is_closed) {
    if (ctx->layout) {
      UPB_ASSERT(ctx->enum_count < ctx->layout->enum_count);
      e->layout = ctx->layout->enums[ctx->enum_count++];
@ -8792,10 +8798,11 @@ struct upb_FieldDef {
  uint16_t index_;
  uint16_t layout_index;  // Index into msgdef->layout->fields or file->exts
  bool has_default;
-  bool is_extension_;
-  bool is_packed_;
-  bool proto3_optional_;
-  bool has_json_name_;
+  bool has_json_name;
+  bool has_presence;
+  bool is_extension;
+  bool is_packed;
+  bool is_proto3_optional;
  upb_FieldType type_;
  upb_Label label_;
 #if UINTPTR_MAX == 0xffffffff
@ -8862,11 +8869,9 @@ upb_Label upb_FieldDef_Label(const upb_FieldDef* f) { return f->label_; }

 uint32_t upb_FieldDef_Number(const upb_FieldDef* f) { return f->number_; }

-bool upb_FieldDef_IsExtension(const upb_FieldDef* f) {
-  return f->is_extension_;
-}
+bool upb_FieldDef_IsExtension(const upb_FieldDef* f) { return f->is_extension; }

-bool upb_FieldDef_IsPacked(const upb_FieldDef* f) { return f->is_packed_; }
+bool upb_FieldDef_IsPacked(const upb_FieldDef* f) { return f->is_packed; }

 const char* upb_FieldDef_Name(const upb_FieldDef* f) {
  return _upb_DefBuilder_FullToShort(f->full_name);
@ -8877,7 +8882,7 @@ const char* upb_FieldDef_JsonName(const upb_FieldDef* f) {
 }

 bool upb_FieldDef_HasJsonName(const upb_FieldDef* f) {
-  return f->has_json_name_;
+  return f->has_json_name;
 }

 const upb_FileDef* upb_FieldDef_File(const upb_FieldDef* f) { return f->file; }
@ -8887,11 +8892,11 @@ const upb_MessageDef* upb_FieldDef_ContainingType(const upb_FieldDef* f) {
 }

 const upb_MessageDef* upb_FieldDef_ExtensionScope(const upb_FieldDef* f) {
-  return f->is_extension_ ? f->scope.extension_scope : NULL;
+  return f->is_extension ? f->scope.extension_scope : NULL;
 }

 const upb_OneofDef* upb_FieldDef_ContainingOneof(const upb_FieldDef* f) {
-  return f->is_extension_ ? NULL : f->scope.oneof;
+  return f->is_extension ? NULL : f->scope.oneof;
 }

 const upb_OneofDef* upb_FieldDef_RealContainingOneof(const upb_FieldDef* f) {
@ -8968,22 +8973,18 @@ const upb_MiniTableExtension* _upb_FieldDef_ExtensionMiniTable(
 }

 bool _upb_FieldDef_IsClosedEnum(const upb_FieldDef* f) {
-  if (UPB_TREAT_PROTO2_ENUMS_LIKE_PROTO3) return false;
  if (f->type_ != kUpb_FieldType_Enum) return false;
-
-  // TODO: Maybe make is_proto2 a bool at creation?
-  const upb_FileDef* file = upb_EnumDef_File(f->sub.enumdef);
-  return upb_FileDef_Syntax(file) == kUpb_Syntax_Proto2;
+  return upb_EnumDef_IsClosed(f->sub.enumdef);
 }

 bool _upb_FieldDef_IsProto3Optional(const upb_FieldDef* f) {
-  return f->proto3_optional_;
+  return f->is_proto3_optional;
 }

 int _upb_FieldDef_LayoutIndex(const upb_FieldDef* f) { return f->layout_index; }

 uint64_t _upb_FieldDef_Modifiers(const upb_FieldDef* f) {
-  uint64_t out = f->is_packed_ ? kUpb_FieldModifier_IsPacked : 0;
+  uint64_t out = f->is_packed ? kUpb_FieldModifier_IsPacked : 0;

  switch (f->label_) {
    case kUpb_Label_Optional:
@ -9006,13 +9007,7 @@ uint64_t _upb_FieldDef_Modifiers(const upb_FieldDef* f) {
 }

 bool upb_FieldDef_HasDefault(const upb_FieldDef* f) { return f->has_default; }
-
-bool upb_FieldDef_HasPresence(const upb_FieldDef* f) {
-  if (upb_FieldDef_IsRepeated(f)) return false;
-  const upb_FileDef* file = upb_FieldDef_File(f);
-  return upb_FieldDef_IsSubMessage(f) || upb_FieldDef_ContainingOneof(f) ||
-         upb_FileDef_Syntax(file) == kUpb_Syntax_Proto2;
-}
+bool upb_FieldDef_HasPresence(const upb_FieldDef* f) { return f->has_presence; }

 bool upb_FieldDef_HasSubDef(const upb_FieldDef* f) {
  return upb_FieldDef_IsSubMessage(f) ||
@ -9275,8 +9270,8 @@ static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
  const upb_StringView name = UPB_DESC(FieldDescriptorProto_name)(field_proto);
  _upb_DefBuilder_CheckIdentNotFull(ctx, name);

-  f->has_json_name_ = UPB_DESC(FieldDescriptorProto_has_json_name)(field_proto);
-  if (f->has_json_name_) {
+  f->has_json_name = UPB_DESC(FieldDescriptorProto_has_json_name)(field_proto);
+  if (f->has_json_name) {
    const upb_StringView sv =
        UPB_DESC(FieldDescriptorProto_json_name)(field_proto);
    f->json_name = upb_strdup2(sv.data, sv.size, ctx->arena);
@ -9288,7 +9283,7 @@ static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
  f->full_name = _upb_DefBuilder_MakeFullName(ctx, prefix, name);
  f->label_ = (int)UPB_DESC(FieldDescriptorProto_label)(field_proto);
  f->number_ = UPB_DESC(FieldDescriptorProto_number)(field_proto);
-  f->proto3_optional_ =
+  f->is_proto3_optional =
      UPB_DESC(FieldDescriptorProto_proto3_optional)(field_proto);
  f->msgdef = m;
  f->scope.oneof = NULL;
@ -9370,21 +9365,26 @@ static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
  UPB_DEF_SET_OPTIONS(f->opts, FieldDescriptorProto, FieldOptions, field_proto);

  if (UPB_DESC(FieldOptions_has_packed)(f->opts)) {
-    f->is_packed_ = UPB_DESC(FieldOptions_packed)(f->opts);
+    f->is_packed = UPB_DESC(FieldOptions_packed)(f->opts);
  } else {
    // Repeated fields default to packed for proto3 only.
-    f->is_packed_ = upb_FieldDef_IsPrimitive(f) &&
-                    f->label_ == kUpb_Label_Repeated &&
-                    upb_FileDef_Syntax(f->file) == kUpb_Syntax_Proto3;
+    f->is_packed = upb_FieldDef_IsPrimitive(f) &&
+                   f->label_ == kUpb_Label_Repeated &&
+                   upb_FileDef_Syntax(f->file) == kUpb_Syntax_Proto3;
  }
+
+  f->has_presence =
+      (!upb_FieldDef_IsRepeated(f)) &&
+      (upb_FieldDef_IsSubMessage(f) || upb_FieldDef_ContainingOneof(f) ||
+       (upb_FileDef_Syntax(f->file) == kUpb_Syntax_Proto2));
 }

 static void _upb_FieldDef_CreateExt(upb_DefBuilder* ctx, const char* prefix,
                                    const UPB_DESC(FieldDescriptorProto) *
                                        field_proto,
                                    upb_MessageDef* m, upb_FieldDef* f) {
+  f->is_extension = true;
  _upb_FieldDef_Create(ctx, prefix, field_proto, m, f);
-  f->is_extension_ = true;

  if (UPB_DESC(FieldDescriptorProto_has_oneof_index)(field_proto)) {
    _upb_DefBuilder_Errf(ctx, "oneof_index provided for extension field (%s)",
@ -9404,11 +9404,11 @@ static void _upb_FieldDef_CreateNotExt(upb_DefBuilder* ctx, const char* prefix,
                                       const UPB_DESC(FieldDescriptorProto) *
                                           field_proto,
                                       upb_MessageDef* m, upb_FieldDef* f) {
+  f->is_extension = false;
  _upb_FieldDef_Create(ctx, prefix, field_proto, m, f);
-  f->is_extension_ = false;

  if (!UPB_DESC(FieldDescriptorProto_has_oneof_index)(field_proto)) {
-    if (f->proto3_optional_) {
+    if (f->is_proto3_optional) {
      _upb_DefBuilder_Errf(
          ctx,
          "non-extension field (%s) with proto3_optional was not in a oneof",
@ -9519,7 +9519,7 @@ static int _upb_FieldDef_Compare(const void* p1, const void* p2) {

 const upb_FieldDef** _upb_FieldDefs_Sorted(const upb_FieldDef* f, int n,
                                           upb_Arena* a) {
-  // TODO: Try to replace this arena alloc with a persistent scratch buffer.
+  // TODO(salo): Replace this arena alloc with a persistent scratch buffer.
  upb_FieldDef** out = (upb_FieldDef**)upb_Arena_Malloc(a, n * sizeof(void*));
  if (!out) return NULL;

@ -9536,7 +9536,7 @@ const upb_FieldDef** _upb_FieldDefs_Sorted(const upb_FieldDef* f, int n,

 bool upb_FieldDef_MiniDescriptorEncode(const upb_FieldDef* f, upb_Arena* a,
                                       upb_StringView* out) {
-  UPB_ASSERT(f->is_extension_);
+  UPB_ASSERT(f->is_extension);

  upb_DescState s;
  _upb_DescState_Init(&s);
@ -9639,7 +9639,7 @@ void _upb_FieldDef_Resolve(upb_DefBuilder* ctx, const char* prefix,
  resolve_subdef(ctx, prefix, f);
  resolve_default(ctx, f, field_proto);

-  if (f->is_extension_) {
+  if (f->is_extension) {
    resolve_extension(ctx, prefix, f, field_proto);
  }
 }
@ -10570,13 +10570,18 @@ void _upb_MessageDef_LinkMiniTable(upb_DefBuilder* ctx,
        (upb_MiniTableField*)&m->layout->fields[layout_index];
    if (sub_m) {
      if (!mt->subs) {
-        _upb_DefBuilder_Errf(ctx, "invalid submsg for (%s)", m->full_name);
+        _upb_DefBuilder_Errf(ctx, "unexpected submsg for (%s)", m->full_name);
      }
      UPB_ASSERT(mt_f);
      UPB_ASSERT(sub_m->layout);
-      upb_MiniTable_SetSubMessage(mt, mt_f, sub_m->layout);
+      if (UPB_UNLIKELY(!upb_MiniTable_SetSubMessage(mt, mt_f, sub_m->layout))) {
+        _upb_DefBuilder_Errf(ctx, "invalid submsg for (%s)", m->full_name);
+      }
    } else if (_upb_FieldDef_IsClosedEnum(f)) {
-      upb_MiniTable_SetSubEnum(mt, mt_f, _upb_EnumDef_MiniTable(sub_e));
+      const upb_MiniTableEnum* mt_e = _upb_EnumDef_MiniTable(sub_e);
+      if (UPB_UNLIKELY(!upb_MiniTable_SetSubEnum(mt, mt_f, mt_e))) {
+        _upb_DefBuilder_Errf(ctx, "invalid subenum for (%s)", m->full_name);
+      }
    }
  }

@ -11764,33 +11769,48 @@ static const char* _upb_Decoder_DecodeToMap(upb_Decoder* d, const char* ptr,
  upb_Map** map_p = UPB_PTR_AT(msg, field->offset, upb_Map*);
  upb_Map* map = *map_p;
  upb_MapEntry ent;
+  UPB_ASSERT(upb_MiniTableField_Type(field) == kUpb_FieldType_Message);
  const upb_MiniTable* entry = subs[field->submsg_index].submsg;

+  UPB_ASSERT(entry->field_count == 2);
+  UPB_ASSERT(!upb_IsRepeatedOrMap(&entry->fields[0]));
+  UPB_ASSERT(!upb_IsRepeatedOrMap(&entry->fields[1]));
+
  if (!map) {
    map = _upb_Decoder_CreateMap(d, entry);
    *map_p = map;
  }

-  /* Parse map entry. */
+  // Parse map entry.
  memset(&ent, 0, sizeof(ent));

  if (entry->fields[1].descriptortype == kUpb_FieldType_Message ||
      entry->fields[1].descriptortype == kUpb_FieldType_Group) {
-    /* Create proactively to handle the case where it doesn't appear. */
-    ent.data.v.val =
-        upb_value_ptr(_upb_Message_New(entry->subs[0].submsg, &d->arena));
+    const upb_MiniTable* submsg_table = entry->subs[0].submsg;
+    // Any sub-message entry must be linked.  We do not allow dynamic tree
+    // shaking in this case.
+    UPB_ASSERT(submsg_table);
+
+    // Create proactively to handle the case where it doesn't appear. */
+    ent.data.v.val = upb_value_ptr(_upb_Message_New(submsg_table, &d->arena));
  }

-  const char* start = ptr;
  ptr =
      _upb_Decoder_DecodeSubMessage(d, ptr, &ent.data, subs, field, val->size);
  // check if ent had any unknown fields
  size_t size;
  upb_Message_GetUnknown(&ent.data, &size);
  if (size != 0) {
+    char* buf;
+    size_t size;
    uint32_t tag = ((uint32_t)field->number << 3) | kUpb_WireType_Delimited;
-    _upb_Decoder_AddUnknownVarints(d, msg, tag, (uint32_t)(ptr - start));
-    if (!_upb_Message_AddUnknown(msg, start, ptr - start, &d->arena)) {
+    upb_EncodeStatus status =
+        upb_Encode(&ent.data, entry, 0, &d->arena, &buf, &size);
+    if (status != kUpb_EncodeStatus_Ok) {
+      _upb_Decoder_ErrorJmp(d, kUpb_DecodeStatus_OutOfMemory);
+    }
+    _upb_Decoder_AddUnknownVarints(d, msg, tag, size);
+    if (!_upb_Message_AddUnknown(msg, buf, size, &d->arena)) {
      _upb_Decoder_ErrorJmp(d, kUpb_DecodeStatus_OutOfMemory);
    }
  } else {
@ -12121,6 +12141,16 @@ int _upb_Decoder_GetVarintOp(const upb_MiniTableField* field) {
  return kVarintOps[field->descriptortype];
 }

+UPB_FORCEINLINE
+static void _upb_Decoder_CheckUnlinked(const upb_MiniTable* mt,
+                                       const upb_MiniTableField* field,
+                                       int* op) {
+  // If sub-message is not linked, treat as unknown.
+  if (field->mode & kUpb_LabelFlags_IsExtension) return;
+  const upb_MiniTableSub* sub = &mt->subs[field->submsg_index];
+  if (!sub->submsg) *op = kUpb_DecodeOp_UnknownField;
+}
+
 int _upb_Decoder_GetDelimitedOp(const upb_MiniTable* mt,
                                const upb_MiniTableField* field) {
  enum { kRepeatedBase = 19 };
@ -12175,13 +12205,8 @@ int _upb_Decoder_GetDelimitedOp(const upb_MiniTable* mt,
  if (upb_FieldMode_Get(field) == kUpb_FieldMode_Array) ndx += kRepeatedBase;
  int op = kDelimitedOps[ndx];

-  // If sub-message is not linked, treat as unknown.
-  if (op == kUpb_DecodeOp_SubMessage &&
-      !(field->mode & kUpb_LabelFlags_IsExtension)) {
-    const upb_MiniTableSub* sub = &mt->subs[field->submsg_index];
-    if (!sub->submsg) {
-      op = kUpb_DecodeOp_UnknownField;
-    }
+  if (op == kUpb_DecodeOp_SubMessage) {
+    _upb_Decoder_CheckUnlinked(mt, field, &op);
  }

  return op;
@ -12227,6 +12252,7 @@ static const char* _upb_Decoder_DecodeWireValue(upb_Decoder* d, const char* ptr,
      val->uint32_val = field->number;
      if (field->descriptortype == kUpb_FieldType_Group) {
        *op = kUpb_DecodeOp_SubMessage;
+        _upb_Decoder_CheckUnlinked(mt, field, op);
      } else if (field->descriptortype == kUpb_FakeFieldType_MessageSetItem) {
        *op = kUpb_DecodeOp_MessageSetItem;
      } else {
@ -12430,6 +12456,23 @@ const char* _upb_Decoder_IsDoneFallback(upb_EpsCopyInputStream* e,
      e, ptr, overrun, _upb_Decoder_BufferFlipCallback);
 }

+static upb_DecodeStatus upb_Decoder_Decode(upb_Decoder* const decoder,
+                                           const char* const buf,
+                                           void* const msg,
+                                           const upb_MiniTable* const l,
+                                           upb_Arena* const arena) {
+  if (UPB_SETJMP(decoder->err) == 0) {
+    decoder->status = _upb_Decoder_DecodeTop(decoder, buf, msg, l);
+  } else {
+    UPB_ASSERT(decoder->status != kUpb_DecodeStatus_Ok);
+  }
+
+  arena->head.ptr = decoder->arena.head.ptr;
+  arena->head.end = decoder->arena.head.end;
+  arena->cleanup_metadata = decoder->arena.cleanup_metadata;
+  return decoder->status;
+}
+
 upb_DecodeStatus upb_Decode(const char* buf, size_t size, void* msg,
                            const upb_MiniTable* l,
                            const upb_ExtensionRegistry* extreg, int options,
@ -12452,16 +12495,7 @@ upb_DecodeStatus upb_Decode(const char* buf, size_t size, void* msg,
  state.arena.parent = arena;
  state.status = kUpb_DecodeStatus_Ok;

-  if (UPB_SETJMP(state.err) == 0) {
-    state.status = _upb_Decoder_DecodeTop(&state, buf, msg, l);
-  } else {
-    UPB_ASSERT(state.status != kUpb_DecodeStatus_Ok);
-  }
-
-  arena->head.ptr = state.arena.head.ptr;
-  arena->head.end = state.arena.head.end;
-  arena->cleanup_metadata = state.arena.cleanup_metadata;
-  return state.status;
+  return upb_Decoder_Decode(&state, buf, msg, l, arena);
 }

 #undef OP_FIXPCK_LG2
@ -13985,6 +14019,35 @@ static void encode_message(upb_encstate* e, const upb_Message* msg,
  *size = (e->limit - e->ptr) - pre_len;
 }

+static upb_EncodeStatus upb_Encoder_Encode(upb_encstate* const encoder,
+                                           const void* const msg,
+                                           const upb_MiniTable* const l,
+                                           char** const buf,
+                                           size_t* const size) {
+  // Unfortunately we must continue to perform hackery here because there are
+  // code paths which blindly copy the returned pointer without bothering to
+  // check for errors until much later (b/235839510). So we still set *buf to
+  // NULL on error and we still set it to non-NULL on a successful empty result.
+  if (UPB_SETJMP(encoder->err) == 0) {
+    encode_message(encoder, msg, l, size);
+    *size = encoder->limit - encoder->ptr;
+    if (*size == 0) {
+      static char ch;
+      *buf = &ch;
+    } else {
+      UPB_ASSERT(encoder->ptr);
+      *buf = encoder->ptr;
+    }
+  } else {
+    UPB_ASSERT(encoder->status != kUpb_EncodeStatus_Ok);
+    *buf = NULL;
+    *size = 0;
+  }
+
+  _upb_mapsorter_destroy(&encoder->sorter);
+  return encoder->status;
+}
+
 upb_EncodeStatus upb_Encode(const void* msg, const upb_MiniTable* l,
                            int options, upb_Arena* arena, char** buf,
                            size_t* size) {
@ -14000,28 +14063,7 @@ upb_EncodeStatus upb_Encode(const void* msg, const upb_MiniTable* l,
  e.options = options;
  _upb_mapsorter_init(&e.sorter);

-  // Unfortunately we must continue to perform hackery here because there are
-  // code paths which blindly copy the returned pointer without bothering to
-  // check for errors until much later (b/235839510). So we still set *buf to
-  // NULL on error and we still set it to non-NULL on a successful empty result.
-  if (UPB_SETJMP(e.err) == 0) {
-    encode_message(&e, msg, l, size);
-    *size = e.limit - e.ptr;
-    if (*size == 0) {
-      static char ch;
-      *buf = &ch;
-    } else {
-      UPB_ASSERT(e.ptr);
-      *buf = e.ptr;
-    }
-  } else {
-    UPB_ASSERT(e.status != kUpb_EncodeStatus_Ok);
-    *buf = NULL;
-    *size = 0;
-  }
-
-  _upb_mapsorter_destroy(&e.sorter);
-  return e.status;
+  return upb_Encoder_Encode(&e, msg, l, buf, size);
 }


--- a/php/ext/google/protobuf/php-upb.h
+++ b/php/ext/google/protobuf/php-upb.h
@ -1811,7 +1811,9 @@ union upb_MiniTableSub {
 // Must be last.

 struct upb_MiniTableExtension {
+  // Do not move this field. We need to be able to alias pointers.
  upb_MiniTableField field;
+
  const upb_MiniTable* extendee;
  upb_MiniTableSub sub;  // NULL unless submessage or proto2 enum
 };
@ -8622,19 +8624,21 @@ UPB_API_INLINE upb_MiniTable* upb_MiniTable_Build(const char* data, size_t len,
                              status);
 }

-// Links a sub-message field to a MiniTable for that sub-message.  If a
+// Links a sub-message field to a MiniTable for that sub-message. If a
 // sub-message field is not linked, it will be treated as an unknown field
-// during parsing, and setting the field will not be allowed.  It is possible
+// during parsing, and setting the field will not be allowed. It is possible
 // to link the message field later, at which point it will no longer be treated
-// as unknown.  However there is no synchronization for this operation, which
+// as unknown. However there is no synchronization for this operation, which
 // means parallel mutation requires external synchronization.
-UPB_API void upb_MiniTable_SetSubMessage(upb_MiniTable* table,
+// Returns success/failure.
+UPB_API bool upb_MiniTable_SetSubMessage(upb_MiniTable* table,
                                         upb_MiniTableField* field,
                                         const upb_MiniTable* sub);

-// Links an enum field to a MiniTable for that enum.  All enum fields must
-// be linked prior to parsing.
-UPB_API void upb_MiniTable_SetSubEnum(upb_MiniTable* table,
+// Links an enum field to a MiniTable for that enum.
+// All enum fields must be linked prior to parsing.
+// Returns success/failure.
+UPB_API bool upb_MiniTable_SetSubEnum(upb_MiniTable* table,
                                      upb_MiniTableField* field,
                                      const upb_MiniTableEnum* sub);

@ -9179,6 +9183,7 @@ UPB_INLINE int upb_EpsCopyInputStream_PushLimit(upb_EpsCopyInputStream* e,
  int limit = size + (int)(ptr - e->end);
  int delta = e->limit - limit;
  _upb_EpsCopyInputStream_CheckLimit(e);
+  UPB_ASSERT(limit <= e->limit);
  e->limit = limit;
  e->limit_ptr = e->end + UPB_MIN(0, limit);
  _upb_EpsCopyInputStream_CheckLimit(e);
--- a/protobuf_deps.bzl
+++ b/protobuf_deps.bzl
@ -149,7 +149,7 @@ def protobuf_deps():
        _github_archive(
            name = "upb",
            repo = "https://github.com/protocolbuffers/upb",
-            commit = "1881a390b0425f8e255df9ca95a8b5d8104c66a0",
-            sha256 = "d3ffcaa629893fb74a1459ef28c69f84bb2d6f51feed654941b32ead412a99a1",
+            commit = "702d95891d70547397e9d45edc00cd7c36f476e1",
+            sha256 = "27f0b1d48c58ffd03081516ba6cdf163e93f74376ba13b18a92d80631fb94bba",
            patches = ["@com_google_protobuf//build_defs:upb.patch"],
        )
--- a/ruby/ext/google/protobuf_c/ruby-upb.c
+++ b/ruby/ext/google/protobuf_c/ruby-upb.c
@ -6438,64 +6438,48 @@ static void upb_MtDecoder_AssignOffsets(upb_MtDecoder* d) {
  d->table->size = UPB_ALIGN_UP(d->table->size, 8);
 }

-static void upb_MtDecoder_ParseMap(upb_MtDecoder* d, const char* data,
-                                   size_t len) {
-  if (len < 2) {
-    upb_MtDecoder_ErrorFormat(d, "Invalid map encode length: %zu", len);
-    UPB_UNREACHABLE();
+static void upb_MtDecoder_ValidateEntryField(upb_MtDecoder* d,
+                                             const upb_MiniTableField* f,
+                                             int expected_num) {
+  const char* name = expected_num == 1 ? "key" : "val";
+  if (f->number != expected_num) {
+    upb_MtDecoder_ErrorFormat(d,
+                              "map %s did not have expected number (%d vs %d)",
+                              name, expected_num, (int)f->number);
  }
-  const upb_EncodedType key_type = _upb_FromBase92(data[0]);
-  switch (key_type) {
-    case kUpb_EncodedType_Fixed32:
-    case kUpb_EncodedType_Fixed64:
-    case kUpb_EncodedType_SFixed32:
-    case kUpb_EncodedType_SFixed64:
-    case kUpb_EncodedType_Int32:
-    case kUpb_EncodedType_UInt32:
-    case kUpb_EncodedType_SInt32:
-    case kUpb_EncodedType_Int64:
-    case kUpb_EncodedType_UInt64:
-    case kUpb_EncodedType_SInt64:
-    case kUpb_EncodedType_Bool:
-    case kUpb_EncodedType_String:
-      break;

-    default:
-      upb_MtDecoder_ErrorFormat(d, "Invalid map key field type: %d", key_type);
-      UPB_UNREACHABLE();
+  if (upb_IsRepeatedOrMap(f) || f->presence < 0) {
+    upb_MtDecoder_ErrorFormat(
+        d, "map %s cannot be repeated or map, or be in oneof", name);
  }

-  upb_MtDecoder_ParseMessage(d, data, len);
-  upb_MtDecoder_AssignHasbits(d->table);
-
-  if (UPB_UNLIKELY(d->table->field_count != 2)) {
-    upb_MtDecoder_ErrorFormat(d, "%hu fields in map", d->table->field_count);
-    UPB_UNREACHABLE();
+  uint32_t not_ok_types;
+  if (expected_num == 1) {
+    not_ok_types = (1 << kUpb_FieldType_Float) | (1 << kUpb_FieldType_Double) |
+                   (1 << kUpb_FieldType_Message) | (1 << kUpb_FieldType_Group) |
+                   (1 << kUpb_FieldType_Bytes) | (1 << kUpb_FieldType_Enum);
+  } else {
+    not_ok_types = 1 << kUpb_FieldType_Group;
  }

-  const int num0 = d->table->fields[0].number;
-  if (UPB_UNLIKELY(num0 != 1)) {
-    upb_MtDecoder_ErrorFormat(d, "field %d in map key", num0);
-    UPB_UNREACHABLE();
+  if ((1 << upb_MiniTableField_Type(f)) & not_ok_types) {
+    upb_MtDecoder_ErrorFormat(d, "map %s cannot have type %d", name,
+                              (int)f->descriptortype);
  }
+}

-  const int num1 = d->table->fields[1].number;
-  if (UPB_UNLIKELY(num1 != 2)) {
-    upb_MtDecoder_ErrorFormat(d, "field %d in map val", num1);
-    UPB_UNREACHABLE();
-  }
+static void upb_MtDecoder_ParseMap(upb_MtDecoder* d, const char* data,
+                                   size_t len) {
+  upb_MtDecoder_ParseMessage(d, data, len);
+  upb_MtDecoder_AssignHasbits(d->table);

-  const int off0 = d->table->fields[0].offset;
-  if (UPB_UNLIKELY(off0 != kNoPresence && off0 != kHasbitPresence)) {
-    upb_MtDecoder_ErrorFormat(d, "bad offset %d in map key", off0);
+  if (UPB_UNLIKELY(d->table->field_count != 2)) {
+    upb_MtDecoder_ErrorFormat(d, "%hu fields in map", d->table->field_count);
    UPB_UNREACHABLE();
  }

-  const int off1 = d->table->fields[1].offset;
-  if (UPB_UNLIKELY(off1 != kNoPresence && off1 != kHasbitPresence)) {
-    upb_MtDecoder_ErrorFormat(d, "bad offset %d in map val", off1);
-    UPB_UNREACHABLE();
-  }
+  upb_MtDecoder_ValidateEntryField(d, &d->table->fields[0], 1);
+  upb_MtDecoder_ValidateEntryField(d, &d->table->fields[1], 2);

  // Map entries have a pre-determined layout, regardless of types.
  // NOTE: sync with mini_table/message_internal.h.
@ -6746,26 +6730,49 @@ upb_MiniTable* _upb_MiniTable_Build(const char* data, size_t len,
  return ret;
 }

-void upb_MiniTable_SetSubMessage(upb_MiniTable* table,
+bool upb_MiniTable_SetSubMessage(upb_MiniTable* table,
                                 upb_MiniTableField* field,
                                 const upb_MiniTable* sub) {
  UPB_ASSERT((uintptr_t)table->fields <= (uintptr_t)field &&
             (uintptr_t)field <
                 (uintptr_t)(table->fields + table->field_count));
-  if (sub->ext & kUpb_ExtMode_IsMapEntry) {
-    field->mode = (field->mode & ~kUpb_FieldMode_Mask) | kUpb_FieldMode_Map;
+  UPB_ASSERT(sub);
+
+  const bool sub_is_map = sub->ext & kUpb_ExtMode_IsMapEntry;
+
+  switch (field->descriptortype) {
+    case kUpb_FieldType_Message:
+      if (sub_is_map) {
+        const bool table_is_map = table->ext & kUpb_ExtMode_IsMapEntry;
+        if (UPB_UNLIKELY(table_is_map)) return false;
+
+        field->mode = (field->mode & ~kUpb_FieldMode_Mask) | kUpb_FieldMode_Map;
+      }
+      break;
+
+    case kUpb_FieldType_Group:
+      if (UPB_UNLIKELY(sub_is_map)) return false;
+      break;
+
+    default:
+      return false;
  }
+
  upb_MiniTableSub* table_sub = (void*)&table->subs[field->submsg_index];
  table_sub->submsg = sub;
+  return true;
 }

-void upb_MiniTable_SetSubEnum(upb_MiniTable* table, upb_MiniTableField* field,
+bool upb_MiniTable_SetSubEnum(upb_MiniTable* table, upb_MiniTableField* field,
                              const upb_MiniTableEnum* sub) {
  UPB_ASSERT((uintptr_t)table->fields <= (uintptr_t)field &&
             (uintptr_t)field <
                 (uintptr_t)(table->fields + table->field_count));
+  UPB_ASSERT(sub);
+
  upb_MiniTableSub* table_sub = (void*)&table->subs[field->submsg_index];
  table_sub->subenum = sub;
+  return true;
 }

 #include <inttypes.h>
@ -7661,6 +7668,31 @@ static void remove_filedef(upb_DefPool* s, upb_FileDef* file) {
  }
 }

+static const upb_FileDef* upb_DefBuilder_AddFileToPool(
+    upb_DefBuilder* const builder, upb_DefPool* const s,
+    const UPB_DESC(FileDescriptorProto) * const file_proto,
+    const upb_StringView name, upb_Status* const status) {
+  if (UPB_SETJMP(builder->err) != 0) {
+    UPB_ASSERT(!upb_Status_IsOk(status));
+    if (builder->file) {
+      remove_filedef(s, builder->file);
+      builder->file = NULL;
+    }
+  } else if (!builder->arena || !builder->tmp_arena) {
+    _upb_DefBuilder_OomErr(builder);
+  } else {
+    _upb_FileDef_Create(builder, file_proto);
+    upb_strtable_insert(&s->files, name.data, name.size,
+                        upb_value_constptr(builder->file), builder->arena);
+    UPB_ASSERT(upb_Status_IsOk(status));
+    upb_Arena_Fuse(s->arena, builder->arena);
+  }
+
+  if (builder->arena) upb_Arena_Free(builder->arena);
+  if (builder->tmp_arena) upb_Arena_Free(builder->tmp_arena);
+  return builder->file;
+}
+
 static const upb_FileDef* _upb_DefPool_AddFile(
    upb_DefPool* s, const UPB_DESC(FileDescriptorProto) * file_proto,
    const upb_MiniTableFile* layout, upb_Status* status) {
@ -7696,25 +7728,7 @@ static const upb_FileDef* _upb_DefPool_AddFile(
      .tmp_arena = upb_Arena_New(),
  };

-  if (UPB_SETJMP(ctx.err)) {
-    UPB_ASSERT(!upb_Status_IsOk(status));
-    if (ctx.file) {
-      remove_filedef(s, ctx.file);
-      ctx.file = NULL;
-    }
-  } else if (!ctx.arena || !ctx.tmp_arena) {
-    _upb_DefBuilder_OomErr(&ctx);
-  } else {
-    _upb_FileDef_Create(&ctx, file_proto);
-    upb_strtable_insert(&s->files, name.data, name.size,
-                        upb_value_constptr(ctx.file), ctx.arena);
-    UPB_ASSERT(upb_Status_IsOk(status));
-    upb_Arena_Fuse(s->arena, ctx.arena);
-  }
-
-  if (ctx.arena) upb_Arena_Free(ctx.arena);
-  if (ctx.tmp_arena) upb_Arena_Free(ctx.tmp_arena);
-  return ctx.file;
+  return upb_DefBuilder_AddFileToPool(&ctx, s, file_proto, name, status);
 }

 const upb_FileDef* upb_DefPool_AddFile(upb_DefPool* s,
@ -7898,6 +7912,7 @@ struct upb_EnumDef {
  int res_range_count;
  int res_name_count;
  int32_t defaultval;
+  bool is_closed;
  bool is_sorted;  // Whether all of the values are defined in ascending order.
 };

@ -7905,15 +7920,6 @@ upb_EnumDef* _upb_EnumDef_At(const upb_EnumDef* e, int i) {
  return (upb_EnumDef*)&e[i];
 }

-// TODO: Maybe implement this on top of a ZCOS instead?
-void _upb_EnumDef_Debug(const upb_EnumDef* e) {
-  fprintf(stderr, "enum %s (%p) {\n", e->full_name, e);
-  fprintf(stderr, " value_count: %d\n", e->value_count);
-  fprintf(stderr, " default:     %d\n", e->defaultval);
-  fprintf(stderr, " is_sorted:   %d\n", e->is_sorted);
-  fprintf(stderr, "}\n");
-}
-
 const upb_MiniTableEnum* _upb_EnumDef_MiniTable(const upb_EnumDef* e) {
  return e->layout;
 }
@ -8009,10 +8015,7 @@ const upb_EnumValueDef* upb_EnumDef_Value(const upb_EnumDef* e, int i) {
  return _upb_EnumValueDef_At(e->values, i);
 }

-bool upb_EnumDef_IsClosed(const upb_EnumDef* e) {
-  if (UPB_TREAT_PROTO2_ENUMS_LIKE_PROTO3) return false;
-  return upb_FileDef_Syntax(e->file) == kUpb_Syntax_Proto2;
-}
+bool upb_EnumDef_IsClosed(const upb_EnumDef* e) { return e->is_closed; }

 bool upb_EnumDef_MiniDescriptorEncode(const upb_EnumDef* e, upb_Arena* a,
                                      upb_StringView* out) {
@ -8098,6 +8101,9 @@ static void create_enumdef(upb_DefBuilder* ctx, const char* prefix,
  _upb_DefBuilder_Add(ctx, e->full_name,
                      _upb_DefType_Pack(e, UPB_DEFTYPE_ENUM));

+  e->is_closed = (!UPB_TREAT_PROTO2_ENUMS_LIKE_PROTO3) &&
+                 (upb_FileDef_Syntax(e->file) == kUpb_Syntax_Proto2);
+
  values = UPB_DESC(EnumDescriptorProto_value)(enum_proto, &n_value);

  bool ok = upb_strtable_init(&e->ntoi, n_value, ctx->arena);
@ -8130,7 +8136,7 @@ static void create_enumdef(upb_DefBuilder* ctx, const char* prefix,

  upb_inttable_compact(&e->iton, ctx->arena);

-  if (upb_FileDef_Syntax(e->file) == kUpb_Syntax_Proto2) {
+  if (e->is_closed) {
    if (ctx->layout) {
      UPB_ASSERT(ctx->enum_count < ctx->layout->enum_count);
      e->layout = ctx->layout->enums[ctx->enum_count++];
@ -8429,10 +8435,11 @@ struct upb_FieldDef {
  uint16_t index_;
  uint16_t layout_index;  // Index into msgdef->layout->fields or file->exts
  bool has_default;
-  bool is_extension_;
-  bool is_packed_;
-  bool proto3_optional_;
-  bool has_json_name_;
+  bool has_json_name;
+  bool has_presence;
+  bool is_extension;
+  bool is_packed;
+  bool is_proto3_optional;
  upb_FieldType type_;
  upb_Label label_;
 #if UINTPTR_MAX == 0xffffffff
@ -8499,11 +8506,9 @@ upb_Label upb_FieldDef_Label(const upb_FieldDef* f) { return f->label_; }

 uint32_t upb_FieldDef_Number(const upb_FieldDef* f) { return f->number_; }

-bool upb_FieldDef_IsExtension(const upb_FieldDef* f) {
-  return f->is_extension_;
-}
+bool upb_FieldDef_IsExtension(const upb_FieldDef* f) { return f->is_extension; }

-bool upb_FieldDef_IsPacked(const upb_FieldDef* f) { return f->is_packed_; }
+bool upb_FieldDef_IsPacked(const upb_FieldDef* f) { return f->is_packed; }

 const char* upb_FieldDef_Name(const upb_FieldDef* f) {
  return _upb_DefBuilder_FullToShort(f->full_name);
@ -8514,7 +8519,7 @@ const char* upb_FieldDef_JsonName(const upb_FieldDef* f) {
 }

 bool upb_FieldDef_HasJsonName(const upb_FieldDef* f) {
-  return f->has_json_name_;
+  return f->has_json_name;
 }

 const upb_FileDef* upb_FieldDef_File(const upb_FieldDef* f) { return f->file; }
@ -8524,11 +8529,11 @@ const upb_MessageDef* upb_FieldDef_ContainingType(const upb_FieldDef* f) {
 }

 const upb_MessageDef* upb_FieldDef_ExtensionScope(const upb_FieldDef* f) {
-  return f->is_extension_ ? f->scope.extension_scope : NULL;
+  return f->is_extension ? f->scope.extension_scope : NULL;
 }

 const upb_OneofDef* upb_FieldDef_ContainingOneof(const upb_FieldDef* f) {
-  return f->is_extension_ ? NULL : f->scope.oneof;
+  return f->is_extension ? NULL : f->scope.oneof;
 }

 const upb_OneofDef* upb_FieldDef_RealContainingOneof(const upb_FieldDef* f) {
@ -8605,22 +8610,18 @@ const upb_MiniTableExtension* _upb_FieldDef_ExtensionMiniTable(
 }

 bool _upb_FieldDef_IsClosedEnum(const upb_FieldDef* f) {
-  if (UPB_TREAT_PROTO2_ENUMS_LIKE_PROTO3) return false;
  if (f->type_ != kUpb_FieldType_Enum) return false;
-
-  // TODO: Maybe make is_proto2 a bool at creation?
-  const upb_FileDef* file = upb_EnumDef_File(f->sub.enumdef);
-  return upb_FileDef_Syntax(file) == kUpb_Syntax_Proto2;
+  return upb_EnumDef_IsClosed(f->sub.enumdef);
 }

 bool _upb_FieldDef_IsProto3Optional(const upb_FieldDef* f) {
-  return f->proto3_optional_;
+  return f->is_proto3_optional;
 }

 int _upb_FieldDef_LayoutIndex(const upb_FieldDef* f) { return f->layout_index; }

 uint64_t _upb_FieldDef_Modifiers(const upb_FieldDef* f) {
-  uint64_t out = f->is_packed_ ? kUpb_FieldModifier_IsPacked : 0;
+  uint64_t out = f->is_packed ? kUpb_FieldModifier_IsPacked : 0;

  switch (f->label_) {
    case kUpb_Label_Optional:
@ -8643,13 +8644,7 @@ uint64_t _upb_FieldDef_Modifiers(const upb_FieldDef* f) {
 }

 bool upb_FieldDef_HasDefault(const upb_FieldDef* f) { return f->has_default; }
-
-bool upb_FieldDef_HasPresence(const upb_FieldDef* f) {
-  if (upb_FieldDef_IsRepeated(f)) return false;
-  const upb_FileDef* file = upb_FieldDef_File(f);
-  return upb_FieldDef_IsSubMessage(f) || upb_FieldDef_ContainingOneof(f) ||
-         upb_FileDef_Syntax(file) == kUpb_Syntax_Proto2;
-}
+bool upb_FieldDef_HasPresence(const upb_FieldDef* f) { return f->has_presence; }

 bool upb_FieldDef_HasSubDef(const upb_FieldDef* f) {
  return upb_FieldDef_IsSubMessage(f) ||
@ -8912,8 +8907,8 @@ static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
  const upb_StringView name = UPB_DESC(FieldDescriptorProto_name)(field_proto);
  _upb_DefBuilder_CheckIdentNotFull(ctx, name);

-  f->has_json_name_ = UPB_DESC(FieldDescriptorProto_has_json_name)(field_proto);
-  if (f->has_json_name_) {
+  f->has_json_name = UPB_DESC(FieldDescriptorProto_has_json_name)(field_proto);
+  if (f->has_json_name) {
    const upb_StringView sv =
        UPB_DESC(FieldDescriptorProto_json_name)(field_proto);
    f->json_name = upb_strdup2(sv.data, sv.size, ctx->arena);
@ -8925,7 +8920,7 @@ static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
  f->full_name = _upb_DefBuilder_MakeFullName(ctx, prefix, name);
  f->label_ = (int)UPB_DESC(FieldDescriptorProto_label)(field_proto);
  f->number_ = UPB_DESC(FieldDescriptorProto_number)(field_proto);
-  f->proto3_optional_ =
+  f->is_proto3_optional =
      UPB_DESC(FieldDescriptorProto_proto3_optional)(field_proto);
  f->msgdef = m;
  f->scope.oneof = NULL;
@ -9007,21 +9002,26 @@ static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
  UPB_DEF_SET_OPTIONS(f->opts, FieldDescriptorProto, FieldOptions, field_proto);

  if (UPB_DESC(FieldOptions_has_packed)(f->opts)) {
-    f->is_packed_ = UPB_DESC(FieldOptions_packed)(f->opts);
+    f->is_packed = UPB_DESC(FieldOptions_packed)(f->opts);
  } else {
    // Repeated fields default to packed for proto3 only.
-    f->is_packed_ = upb_FieldDef_IsPrimitive(f) &&
-                    f->label_ == kUpb_Label_Repeated &&
-                    upb_FileDef_Syntax(f->file) == kUpb_Syntax_Proto3;
+    f->is_packed = upb_FieldDef_IsPrimitive(f) &&
+                   f->label_ == kUpb_Label_Repeated &&
+                   upb_FileDef_Syntax(f->file) == kUpb_Syntax_Proto3;
  }
+
+  f->has_presence =
+      (!upb_FieldDef_IsRepeated(f)) &&
+      (upb_FieldDef_IsSubMessage(f) || upb_FieldDef_ContainingOneof(f) ||
+       (upb_FileDef_Syntax(f->file) == kUpb_Syntax_Proto2));
 }

 static void _upb_FieldDef_CreateExt(upb_DefBuilder* ctx, const char* prefix,
                                    const UPB_DESC(FieldDescriptorProto) *
                                        field_proto,
                                    upb_MessageDef* m, upb_FieldDef* f) {
+  f->is_extension = true;
  _upb_FieldDef_Create(ctx, prefix, field_proto, m, f);
-  f->is_extension_ = true;

  if (UPB_DESC(FieldDescriptorProto_has_oneof_index)(field_proto)) {
    _upb_DefBuilder_Errf(ctx, "oneof_index provided for extension field (%s)",
@ -9041,11 +9041,11 @@ static void _upb_FieldDef_CreateNotExt(upb_DefBuilder* ctx, const char* prefix,
                                       const UPB_DESC(FieldDescriptorProto) *
                                           field_proto,
                                       upb_MessageDef* m, upb_FieldDef* f) {
+  f->is_extension = false;
  _upb_FieldDef_Create(ctx, prefix, field_proto, m, f);
-  f->is_extension_ = false;

  if (!UPB_DESC(FieldDescriptorProto_has_oneof_index)(field_proto)) {
-    if (f->proto3_optional_) {
+    if (f->is_proto3_optional) {
      _upb_DefBuilder_Errf(
          ctx,
          "non-extension field (%s) with proto3_optional was not in a oneof",
@ -9156,7 +9156,7 @@ static int _upb_FieldDef_Compare(const void* p1, const void* p2) {

 const upb_FieldDef** _upb_FieldDefs_Sorted(const upb_FieldDef* f, int n,
                                           upb_Arena* a) {
-  // TODO: Try to replace this arena alloc with a persistent scratch buffer.
+  // TODO(salo): Replace this arena alloc with a persistent scratch buffer.
  upb_FieldDef** out = (upb_FieldDef**)upb_Arena_Malloc(a, n * sizeof(void*));
  if (!out) return NULL;

@ -9173,7 +9173,7 @@ const upb_FieldDef** _upb_FieldDefs_Sorted(const upb_FieldDef* f, int n,

 bool upb_FieldDef_MiniDescriptorEncode(const upb_FieldDef* f, upb_Arena* a,
                                       upb_StringView* out) {
-  UPB_ASSERT(f->is_extension_);
+  UPB_ASSERT(f->is_extension);

  upb_DescState s;
  _upb_DescState_Init(&s);
@ -9276,7 +9276,7 @@ void _upb_FieldDef_Resolve(upb_DefBuilder* ctx, const char* prefix,
  resolve_subdef(ctx, prefix, f);
  resolve_default(ctx, f, field_proto);

-  if (f->is_extension_) {
+  if (f->is_extension) {
    resolve_extension(ctx, prefix, f, field_proto);
  }
 }
@ -10207,13 +10207,18 @@ void _upb_MessageDef_LinkMiniTable(upb_DefBuilder* ctx,
        (upb_MiniTableField*)&m->layout->fields[layout_index];
    if (sub_m) {
      if (!mt->subs) {
-        _upb_DefBuilder_Errf(ctx, "invalid submsg for (%s)", m->full_name);
+        _upb_DefBuilder_Errf(ctx, "unexpected submsg for (%s)", m->full_name);
      }
      UPB_ASSERT(mt_f);
      UPB_ASSERT(sub_m->layout);
-      upb_MiniTable_SetSubMessage(mt, mt_f, sub_m->layout);
+      if (UPB_UNLIKELY(!upb_MiniTable_SetSubMessage(mt, mt_f, sub_m->layout))) {
+        _upb_DefBuilder_Errf(ctx, "invalid submsg for (%s)", m->full_name);
+      }
    } else if (_upb_FieldDef_IsClosedEnum(f)) {
-      upb_MiniTable_SetSubEnum(mt, mt_f, _upb_EnumDef_MiniTable(sub_e));
+      const upb_MiniTableEnum* mt_e = _upb_EnumDef_MiniTable(sub_e);
+      if (UPB_UNLIKELY(!upb_MiniTable_SetSubEnum(mt, mt_f, mt_e))) {
+        _upb_DefBuilder_Errf(ctx, "invalid subenum for (%s)", m->full_name);
+      }
    }
  }

@ -11401,33 +11406,48 @@ static const char* _upb_Decoder_DecodeToMap(upb_Decoder* d, const char* ptr,
  upb_Map** map_p = UPB_PTR_AT(msg, field->offset, upb_Map*);
  upb_Map* map = *map_p;
  upb_MapEntry ent;
+  UPB_ASSERT(upb_MiniTableField_Type(field) == kUpb_FieldType_Message);
  const upb_MiniTable* entry = subs[field->submsg_index].submsg;

+  UPB_ASSERT(entry->field_count == 2);
+  UPB_ASSERT(!upb_IsRepeatedOrMap(&entry->fields[0]));
+  UPB_ASSERT(!upb_IsRepeatedOrMap(&entry->fields[1]));
+
  if (!map) {
    map = _upb_Decoder_CreateMap(d, entry);
    *map_p = map;
  }

-  /* Parse map entry. */
+  // Parse map entry.
  memset(&ent, 0, sizeof(ent));

  if (entry->fields[1].descriptortype == kUpb_FieldType_Message ||
      entry->fields[1].descriptortype == kUpb_FieldType_Group) {
-    /* Create proactively to handle the case where it doesn't appear. */
-    ent.data.v.val =
-        upb_value_ptr(_upb_Message_New(entry->subs[0].submsg, &d->arena));
+    const upb_MiniTable* submsg_table = entry->subs[0].submsg;
+    // Any sub-message entry must be linked.  We do not allow dynamic tree
+    // shaking in this case.
+    UPB_ASSERT(submsg_table);
+
+    // Create proactively to handle the case where it doesn't appear. */
+    ent.data.v.val = upb_value_ptr(_upb_Message_New(submsg_table, &d->arena));
  }

-  const char* start = ptr;
  ptr =
      _upb_Decoder_DecodeSubMessage(d, ptr, &ent.data, subs, field, val->size);
  // check if ent had any unknown fields
  size_t size;
  upb_Message_GetUnknown(&ent.data, &size);
  if (size != 0) {
+    char* buf;
+    size_t size;
    uint32_t tag = ((uint32_t)field->number << 3) | kUpb_WireType_Delimited;
-    _upb_Decoder_AddUnknownVarints(d, msg, tag, (uint32_t)(ptr - start));
-    if (!_upb_Message_AddUnknown(msg, start, ptr - start, &d->arena)) {
+    upb_EncodeStatus status =
+        upb_Encode(&ent.data, entry, 0, &d->arena, &buf, &size);
+    if (status != kUpb_EncodeStatus_Ok) {
+      _upb_Decoder_ErrorJmp(d, kUpb_DecodeStatus_OutOfMemory);
+    }
+    _upb_Decoder_AddUnknownVarints(d, msg, tag, size);
+    if (!_upb_Message_AddUnknown(msg, buf, size, &d->arena)) {
      _upb_Decoder_ErrorJmp(d, kUpb_DecodeStatus_OutOfMemory);
    }
  } else {
@ -11758,6 +11778,16 @@ int _upb_Decoder_GetVarintOp(const upb_MiniTableField* field) {
  return kVarintOps[field->descriptortype];
 }

+UPB_FORCEINLINE
+static void _upb_Decoder_CheckUnlinked(const upb_MiniTable* mt,
+                                       const upb_MiniTableField* field,
+                                       int* op) {
+  // If sub-message is not linked, treat as unknown.
+  if (field->mode & kUpb_LabelFlags_IsExtension) return;
+  const upb_MiniTableSub* sub = &mt->subs[field->submsg_index];
+  if (!sub->submsg) *op = kUpb_DecodeOp_UnknownField;
+}
+
 int _upb_Decoder_GetDelimitedOp(const upb_MiniTable* mt,
                                const upb_MiniTableField* field) {
  enum { kRepeatedBase = 19 };
@ -11812,13 +11842,8 @@ int _upb_Decoder_GetDelimitedOp(const upb_MiniTable* mt,
  if (upb_FieldMode_Get(field) == kUpb_FieldMode_Array) ndx += kRepeatedBase;
  int op = kDelimitedOps[ndx];

-  // If sub-message is not linked, treat as unknown.
-  if (op == kUpb_DecodeOp_SubMessage &&
-      !(field->mode & kUpb_LabelFlags_IsExtension)) {
-    const upb_MiniTableSub* sub = &mt->subs[field->submsg_index];
-    if (!sub->submsg) {
-      op = kUpb_DecodeOp_UnknownField;
-    }
+  if (op == kUpb_DecodeOp_SubMessage) {
+    _upb_Decoder_CheckUnlinked(mt, field, &op);
  }

  return op;
@ -11864,6 +11889,7 @@ static const char* _upb_Decoder_DecodeWireValue(upb_Decoder* d, const char* ptr,
      val->uint32_val = field->number;
      if (field->descriptortype == kUpb_FieldType_Group) {
        *op = kUpb_DecodeOp_SubMessage;
+        _upb_Decoder_CheckUnlinked(mt, field, op);
      } else if (field->descriptortype == kUpb_FakeFieldType_MessageSetItem) {
        *op = kUpb_DecodeOp_MessageSetItem;
      } else {
@ -12067,6 +12093,23 @@ const char* _upb_Decoder_IsDoneFallback(upb_EpsCopyInputStream* e,
      e, ptr, overrun, _upb_Decoder_BufferFlipCallback);
 }

+static upb_DecodeStatus upb_Decoder_Decode(upb_Decoder* const decoder,
+                                           const char* const buf,
+                                           void* const msg,
+                                           const upb_MiniTable* const l,
+                                           upb_Arena* const arena) {
+  if (UPB_SETJMP(decoder->err) == 0) {
+    decoder->status = _upb_Decoder_DecodeTop(decoder, buf, msg, l);
+  } else {
+    UPB_ASSERT(decoder->status != kUpb_DecodeStatus_Ok);
+  }
+
+  arena->head.ptr = decoder->arena.head.ptr;
+  arena->head.end = decoder->arena.head.end;
+  arena->cleanup_metadata = decoder->arena.cleanup_metadata;
+  return decoder->status;
+}
+
 upb_DecodeStatus upb_Decode(const char* buf, size_t size, void* msg,
                            const upb_MiniTable* l,
                            const upb_ExtensionRegistry* extreg, int options,
@ -12089,16 +12132,7 @@ upb_DecodeStatus upb_Decode(const char* buf, size_t size, void* msg,
  state.arena.parent = arena;
  state.status = kUpb_DecodeStatus_Ok;

-  if (UPB_SETJMP(state.err) == 0) {
-    state.status = _upb_Decoder_DecodeTop(&state, buf, msg, l);
-  } else {
-    UPB_ASSERT(state.status != kUpb_DecodeStatus_Ok);
-  }
-
-  arena->head.ptr = state.arena.head.ptr;
-  arena->head.end = state.arena.head.end;
-  arena->cleanup_metadata = state.arena.cleanup_metadata;
-  return state.status;
+  return upb_Decoder_Decode(&state, buf, msg, l, arena);
 }

 #undef OP_FIXPCK_LG2
@ -13622,6 +13656,35 @@ static void encode_message(upb_encstate* e, const upb_Message* msg,
  *size = (e->limit - e->ptr) - pre_len;
 }

+static upb_EncodeStatus upb_Encoder_Encode(upb_encstate* const encoder,
+                                           const void* const msg,
+                                           const upb_MiniTable* const l,
+                                           char** const buf,
+                                           size_t* const size) {
+  // Unfortunately we must continue to perform hackery here because there are
+  // code paths which blindly copy the returned pointer without bothering to
+  // check for errors until much later (b/235839510). So we still set *buf to
+  // NULL on error and we still set it to non-NULL on a successful empty result.
+  if (UPB_SETJMP(encoder->err) == 0) {
+    encode_message(encoder, msg, l, size);
+    *size = encoder->limit - encoder->ptr;
+    if (*size == 0) {
+      static char ch;
+      *buf = &ch;
+    } else {
+      UPB_ASSERT(encoder->ptr);
+      *buf = encoder->ptr;
+    }
+  } else {
+    UPB_ASSERT(encoder->status != kUpb_EncodeStatus_Ok);
+    *buf = NULL;
+    *size = 0;
+  }
+
+  _upb_mapsorter_destroy(&encoder->sorter);
+  return encoder->status;
+}
+
 upb_EncodeStatus upb_Encode(const void* msg, const upb_MiniTable* l,
                            int options, upb_Arena* arena, char** buf,
                            size_t* size) {
@ -13637,28 +13700,7 @@ upb_EncodeStatus upb_Encode(const void* msg, const upb_MiniTable* l,
  e.options = options;
  _upb_mapsorter_init(&e.sorter);

-  // Unfortunately we must continue to perform hackery here because there are
-  // code paths which blindly copy the returned pointer without bothering to
-  // check for errors until much later (b/235839510). So we still set *buf to
-  // NULL on error and we still set it to non-NULL on a successful empty result.
-  if (UPB_SETJMP(e.err) == 0) {
-    encode_message(&e, msg, l, size);
-    *size = e.limit - e.ptr;
-    if (*size == 0) {
-      static char ch;
-      *buf = &ch;
-    } else {
-      UPB_ASSERT(e.ptr);
-      *buf = e.ptr;
-    }
-  } else {
-    UPB_ASSERT(e.status != kUpb_EncodeStatus_Ok);
-    *buf = NULL;
-    *size = 0;
-  }
-
-  _upb_mapsorter_destroy(&e.sorter);
-  return e.status;
+  return upb_Encoder_Encode(&e, msg, l, buf, size);
 }


--- a/ruby/ext/google/protobuf_c/ruby-upb.h
+++ b/ruby/ext/google/protobuf_c/ruby-upb.h
@ -1813,7 +1813,9 @@ union upb_MiniTableSub {
 // Must be last.

 struct upb_MiniTableExtension {
+  // Do not move this field. We need to be able to alias pointers.
  upb_MiniTableField field;
+
  const upb_MiniTable* extendee;
  upb_MiniTableSub sub;  // NULL unless submessage or proto2 enum
 };
@ -8262,6 +8264,7 @@ UPB_INLINE int upb_EpsCopyInputStream_PushLimit(upb_EpsCopyInputStream* e,
  int limit = size + (int)(ptr - e->end);
  int delta = e->limit - limit;
  _upb_EpsCopyInputStream_CheckLimit(e);
+  UPB_ASSERT(limit <= e->limit);
  e->limit = limit;
  e->limit_ptr = e->end + UPB_MIN(0, limit);
  _upb_EpsCopyInputStream_CheckLimit(e);
@ -9734,19 +9737,21 @@ UPB_API_INLINE upb_MiniTable* upb_MiniTable_Build(const char* data, size_t len,
                              status);
 }

-// Links a sub-message field to a MiniTable for that sub-message.  If a
+// Links a sub-message field to a MiniTable for that sub-message. If a
 // sub-message field is not linked, it will be treated as an unknown field
-// during parsing, and setting the field will not be allowed.  It is possible
+// during parsing, and setting the field will not be allowed. It is possible
 // to link the message field later, at which point it will no longer be treated
-// as unknown.  However there is no synchronization for this operation, which
+// as unknown. However there is no synchronization for this operation, which
 // means parallel mutation requires external synchronization.
-UPB_API void upb_MiniTable_SetSubMessage(upb_MiniTable* table,
+// Returns success/failure.
+UPB_API bool upb_MiniTable_SetSubMessage(upb_MiniTable* table,
                                         upb_MiniTableField* field,
                                         const upb_MiniTable* sub);

-// Links an enum field to a MiniTable for that enum.  All enum fields must
-// be linked prior to parsing.
-UPB_API void upb_MiniTable_SetSubEnum(upb_MiniTable* table,
+// Links an enum field to a MiniTable for that enum.
+// All enum fields must be linked prior to parsing.
+// Returns success/failure.
+UPB_API bool upb_MiniTable_SetSubEnum(upb_MiniTable* table,
                                      upb_MiniTableField* field,
                                      const upb_MiniTableEnum* sub);