Fixed a bug in enum layout generation.

upb/def.c

@@ -2411,7 +2411,7 @@ upb_MiniTable_Enum* create_enumlayout(symtab_addctx* ctx,
   for (int i = 0; i < e->value_count; i++) {
     uint32_t val = (uint32_t)e->values[i].number;
     if (val < 64) {
-      mask |= 1 << val;
+      mask |= 1ULL << val;
     } else {
       n++;
     }
@@ -3102,7 +3102,8 @@ const upb_FileDef* upb_DefPool_AddFile(
 /* Include here since we want most of this file to be stdio-free. */
 #include <stdio.h>
 
-bool _upb_DefPool_LoadDefInit(upb_DefPool* s, const _upb_DefPool_Init* init) {
+bool _upb_DefPool_LoadDefInitEx(upb_DefPool* s, const _upb_DefPool_Init* init,
+                                bool rebuild_minitable) {
   /* Since this function should never fail (it would indicate a bug in upb) we
    * print errors to stderr instead of returning error status to the user. */
   _upb_DefPool_Init** deps = init->deps;
@@ -3119,7 +3120,7 @@ bool _upb_DefPool_LoadDefInit(upb_DefPool* s, const _upb_DefPool_Init* init) {
   arena = upb_Arena_New();
 
   for (; *deps; deps++) {
-    if (!_upb_DefPool_LoadDefInit(s, *deps)) goto err;
+    if (!_upb_DefPool_LoadDefInitEx(s, *deps, rebuild_minitable)) goto err;
   }
 
   file = google_protobuf_FileDescriptorProto_parse_ex(
@@ -3136,7 +3137,8 @@ bool _upb_DefPool_LoadDefInit(upb_DefPool* s, const _upb_DefPool_Init* init) {
     goto err;
   }
 
-  if (!_upb_DefPool_AddFile(s, file, init->layout, &status)) {
+  const upb_MiniTable_File* mt = rebuild_minitable ? NULL : init->layout;
+  if (!_upb_DefPool_AddFile(s, file, mt, &status)) {
     goto err;
   }
 

upb/def.h

@@ -389,7 +389,15 @@ typedef struct _upb_DefPool_Init {
   upb_StringView descriptor; /* Serialized descriptor. */
 } _upb_DefPool_Init;
 
-bool _upb_DefPool_LoadDefInit(upb_DefPool* s, const _upb_DefPool_Init* init);
+// Should only be directly called by tests.  This varant lets us suppress
+// the use of compiled-in tables, forcing a rebuild of the tables at runtime.
+bool _upb_DefPool_LoadDefInitEx(upb_DefPool* s, const _upb_DefPool_Init* init,
+                                bool rebuild_minitable);
+
+UPB_INLINE bool _upb_DefPool_LoadDefInit(upb_DefPool* s,
+                                         const _upb_DefPool_Init* init) {
+  return _upb_DefPool_LoadDefInitEx(s, init, false);
+}
 
 #include "upb/port_undef.inc"
 

upb/util/def_to_proto_test.cc

@@ -125,3 +125,19 @@ TEST(DefToProto, Test) {
   upb::FileDefPtr file = msgdef.file();
   CheckFile(file, file_desc);
 }
+
+// Like the previous test, but uses a message layout built at runtime.
+TEST(DefToProto, TestRuntimeReflection) {
+  upb::Arena arena;
+  upb::SymbolTable symtab;
+  upb_StringView test_file_desc =
+      upb_util_def_to_proto_test_proto_upbdefinit.descriptor;
+  const auto* file_desc = google_protobuf_FileDescriptorProto_parse(
+      test_file_desc.data, test_file_desc.size, arena.ptr());
+
+  _upb_DefPool_LoadDefInitEx(
+      symtab.ptr(), &upb_util_def_to_proto_test_proto_upbdefinit, true);
+  upb::FileDefPtr file = symtab.FindFileByName(
+      upb_util_def_to_proto_test_proto_upbdefinit.filename);
+  CheckFile(file, file_desc);
+}

upb/util/def_to_proto_test.proto

@@ -97,6 +97,10 @@ extend Message {
   optional int32 ext = 1001;
 }
 
+enum Has31 {
+  VALUE_31 = 31;
+}
+
 message PretendMessageSet {
   option message_set_wire_format = true;
   // Since this is message_set_wire_format, "max" here means INT32_MAX.

upbc/protoc-gen-upb.cc

@@ -1314,7 +1314,7 @@ int WriteEnums(const protobuf::FileDescriptor* file, Output& output) {
     absl::flat_hash_set<int32_t> values;
     for (auto number : SortedUniqueEnumNumbers(e)) {
       if (static_cast<uint32_t>(number) < 64) {
-        mask |= 1 << number;
+        mask |= 1ULL << number;
       } else {
         values.insert(number);
       }