Fix issues with uint64 enums (#5265)

* Fix issues with uint64 enums

- hide the implementation of enums from code generators
- fix uint64 the issue in the cpp-generator
- fix #5108
- new tests
- enums with bit_flags attribute should be unsigned

* Refine objectives of EnumDef's FindByValue and ReverseLookup methods

- move EnumDef::ReverseLookup implementation to idl_parser.cpp
- fix typos

* Make the IsUInt64 method private

include/flatbuffers/code_generators.h

@@ -53,6 +53,11 @@ class CodeWriter {
     value_map_[key] = value;
   }
 
+  std::string GetValue(const std::string &key) const {
+    const auto it = value_map_.find(key);
+    return it == value_map_.end() ? "" : it->second;
+  }
+
   // Appends the given text to the generated code as well as a newline
   // character.  Any text within {{ and }} delimeters is replaced by values
   // previously stored in the CodeWriter by calling SetValue above.  The newline

include/flatbuffers/idl.h

@@ -123,6 +123,13 @@ inline bool IsLong   (BaseType t) { return t == BASE_TYPE_LONG ||
 inline bool IsBool   (BaseType t) { return t == BASE_TYPE_BOOL; }
 inline bool IsOneByte(BaseType t) { return t >= BASE_TYPE_UTYPE &&
                                            t <= BASE_TYPE_UCHAR; }
+
+inline bool IsUnsigned(BaseType t) {
+  return (t == BASE_TYPE_UTYPE)  || (t == BASE_TYPE_UCHAR) ||
+         (t == BASE_TYPE_USHORT) || (t == BASE_TYPE_UINT)  ||
+         (t == BASE_TYPE_ULONG);
+}
+
 // clang-format on
 
 extern const char *const kTypeNames[];
@@ -327,52 +334,96 @@ inline size_t InlineAlignment(const Type &type) {
   return IsStruct(type) ? type.struct_def->minalign : SizeOf(type.base_type);
 }
 
-struct EnumVal {
-  EnumVal(const std::string &_name, int64_t _val) : name(_name), value(_val) {}
-  EnumVal() : value(0) {}
+struct EnumDef;
+struct EnumValBuilder;
 
+struct EnumVal {
   Offset<reflection::EnumVal> Serialize(FlatBufferBuilder *builder, const Parser &parser) const;
 
   bool Deserialize(const Parser &parser, const reflection::EnumVal *val);
+
+  uint64_t GetAsUInt64() const { return static_cast<uint64_t>(value); }
+  int64_t GetAsInt64() const { return value; }
   bool IsZero() const { return 0 == value; }
   bool IsNonZero() const { return !IsZero(); }
 
   std::string name;
   std::vector<std::string> doc_comment;
-  int64_t value;
   Type union_type;
+
+ private:
+  friend EnumDef;
+  friend EnumValBuilder;
+  friend bool operator==(const EnumVal &lhs, const EnumVal &rhs);
+
+  EnumVal(const std::string &_name, int64_t _val) : name(_name), value(_val) {}
+  EnumVal() : value(0) {}
+
+  int64_t value;
 };
 
 struct EnumDef : public Definition {
   EnumDef() : is_union(false), uses_multiple_type_instances(false) {}
 
-  EnumVal *ReverseLookup(int64_t enum_idx, bool skip_union_default = true) {
-    for (auto it = Vals().begin() +
-                   static_cast<int>(is_union && skip_union_default);
-         it != Vals().end(); ++it) {
-      if ((*it)->value == enum_idx) { return *it; }
-    }
-    return nullptr;
-  }
-
-  Offset<reflection::Enum> Serialize(FlatBufferBuilder *builder, const Parser &parser) const;
+  Offset<reflection::Enum> Serialize(FlatBufferBuilder *builder,
+                                     const Parser &parser) const;
 
   bool Deserialize(Parser &parser, const reflection::Enum *values);
 
+  template<typename T> void ChangeEnumValue(EnumVal *ev, T new_val);
+  void SortByValue();
+  void RemoveDuplicates();
+
+  std::string AllFlags() const;
+  const EnumVal *MinValue() const;
+  const EnumVal *MaxValue() const;
+  // Returns the number of integer steps from v1 to v2.
+  uint64_t Distance(const EnumVal *v1, const EnumVal *v2) const;
+  // Returns the number of integer steps from Min to Max.
+  uint64_t Distance() const { return Distance(MinValue(), MaxValue()); }
+
+  EnumVal *ReverseLookup(int64_t enum_idx,
+                         bool skip_union_default = false) const;
+  EnumVal *FindByValue(const std::string &constant) const;
+
+  std::string ToString(const EnumVal &ev) const {
+    return IsUInt64() ? NumToString(ev.GetAsUInt64())
+                      : NumToString(ev.GetAsInt64());
+  }
+
   size_t size() const { return vals.vec.size(); }
 
   const std::vector<EnumVal *> &Vals() const {
+    FLATBUFFERS_ASSERT(false == vals.vec.empty());
     return vals.vec;
   }
 
-  SymbolTable<EnumVal> vals;
+  const EnumVal *Lookup(const std::string &enum_name) const {
+    return vals.Lookup(enum_name);
+  }
+
   bool is_union;
   // Type is a union which uses type aliases where at least one type is
   // available under two different names.
   bool uses_multiple_type_instances;
   Type underlying_type;
+
+ private:
+  bool IsUInt64() const {
+    return (BASE_TYPE_ULONG == underlying_type.base_type);
+  }
+
+  friend EnumValBuilder;
+  SymbolTable<EnumVal> vals;
 };
 
+inline bool operator==(const EnumVal &lhs, const EnumVal &rhs) {
+  return lhs.value == rhs.value;
+}
+inline bool operator!=(const EnumVal &lhs, const EnumVal &rhs) {
+  return !(lhs == rhs);
+}
+
 inline bool EqualByName(const Type &a, const Type &b) {
   return a.base_type == b.base_type && a.element == b.element &&
          (a.struct_def == b.struct_def ||

src/idl_gen_dart.cpp

@@ -242,9 +242,9 @@ class DartGenerator : public BaseGenerator {
     // holes.
     if (!is_bit_flags) {
       code += "  static const int minValue = " +
-              NumToString(enum_def.vals.vec.front()->value) + ";\n";
+              enum_def.ToString(*enum_def.MinValue()) + ";\n";
       code += "  static const int maxValue = " +
-              NumToString(enum_def.vals.vec.back()->value) + ";\n";
+              enum_def.ToString(*enum_def.MaxValue()) + ";\n";
     }
 
     code +=
@@ -259,13 +259,13 @@ class DartGenerator : public BaseGenerator {
         GenDocComment(ev.doc_comment, &code, "", "  ");
       }
       code += "  static const " + name + " " + ev.name + " = ";
-      code += "const " + name + "._(" + NumToString(ev.value) + ");\n";
+      code += "const " + name + "._(" + enum_def.ToString(ev) + ");\n";
     }
 
     code += "  static get values => {";
     for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
       auto &ev = **it;
-      code += NumToString(ev.value) + ": " + ev.name + ",";
+      code += enum_def.ToString(ev) + ": " + ev.name + ",";
     }
     code += "};\n\n";
 
@@ -507,7 +507,7 @@ class DartGenerator : public BaseGenerator {
           auto &ev = **en_it;
 
           auto enum_name = NamespaceAliasFromUnionType(ev.name);
-          code += "      case " + NumToString(ev.value) + ": return " +
+          code += "      case " + enum_def.ToString(ev) + ": return " +
                   enum_name + ".reader.vTableGet(_bc, _bcOffset, " +
                   NumToString(field.value.offset) + ", null);\n";
         }

src/idl_gen_fbs.cpp

@@ -102,7 +102,7 @@ std::string GenerateFBS(const Parser &parser, const std::string &file_name) {
       if (enum_def.is_union)
         schema += "  " + GenType(ev.union_type) + ",\n";
       else
-        schema += "  " + ev.name + " = " + NumToString(ev.value) + ",\n";
+        schema += "  " + ev.name + " = " + enum_def.ToString(ev) + ",\n";
     }
     schema += "}\n\n";
   }

src/idl_gen_general.cpp

@@ -439,21 +439,12 @@ class GeneralGenerator : public BaseGenerator {
   }
 
   std::string GenEnumDefaultValue(const FieldDef &field) const {
-    auto& value = field.value;
-    auto enum_def = value.type.enum_def;
-    auto vec = enum_def->vals.vec;
-    auto default_value = StringToInt(value.constant.c_str());
-
-    auto result = value.constant;
-    for (auto it = vec.begin(); it != vec.end(); ++it) {
-      auto enum_val = **it;
-      if (enum_val.value == default_value) {
-        result = WrapInNameSpace(*enum_def) + "." + enum_val.name;
-        break;
-      }
-    }
-
-    return result;
+    auto &value = field.value;
+    FLATBUFFERS_ASSERT(value.type.enum_def);
+    auto &enum_def = *value.type.enum_def;
+    auto enum_val = enum_def.FindByValue(value.constant);
+    return enum_val ? (WrapInNameSpace(enum_def) + "." + enum_val->name)
+                    : value.constant;
   }
 
   std::string GenDefaultValue(const FieldDef &field, bool enableLangOverrides) const {
@@ -552,7 +543,7 @@ class GeneralGenerator : public BaseGenerator {
         code += GenTypeBasic(enum_def.underlying_type, false);
       }
       code += " " + ev.name + " = ";
-      code += NumToString(ev.value);
+      code += enum_def.ToString(ev);
       code += lang_.enum_separator;
     }
 
@@ -562,21 +553,22 @@ class GeneralGenerator : public BaseGenerator {
       // Problem is, if values are very sparse that could generate really big
       // tables. Ideally in that case we generate a map lookup instead, but for
       // the moment we simply don't output a table at all.
-      auto range = enum_def.vals.vec.back()->value -
-                   enum_def.vals.vec.front()->value + 1;
+      auto range = enum_def.Distance();
       // Average distance between values above which we consider a table
       // "too sparse". Change at will.
-      static const int kMaxSparseness = 5;
-      if (range / static_cast<int64_t>(enum_def.vals.vec.size()) <
-          kMaxSparseness) {
+      static const uint64_t kMaxSparseness = 5;
+      if (range / static_cast<uint64_t>(enum_def.size()) < kMaxSparseness) {
         code += "\n  public static";
         code += lang_.const_decl;
         code += lang_.string_type;
         code += "[] names = { ";
-        auto val = enum_def.Vals().front()->value;
+        auto val = enum_def.Vals().front();
         for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
              ++it) {
-          while (val++ != (*it)->value) code += "\"\", ";
+          auto ev = *it;
+          for (auto k = enum_def.Distance(val, ev); k > 1; --k)
+            code += "\"\", ";
+          val = ev;
           code += "\"" + (*it)->name + "\", ";
         }
         code += "};\n\n";
@@ -584,8 +576,8 @@ class GeneralGenerator : public BaseGenerator {
         code += lang_.string_type;
         code += " " + MakeCamel("name", lang_.first_camel_upper);
         code += "(int e) { return names[e";
-        if (enum_def.vals.vec.front()->value)
-          code += " - " + enum_def.vals.vec.front()->name;
+        if (enum_def.MinValue()->IsNonZero())
+          code += " - " + enum_def.MinValue()->name;
         code += "]; }\n";
       }
     }

src/idl_gen_go.cpp

@@ -162,7 +162,7 @@ class GoGenerator : public BaseGenerator {
     code += " ";
     code += GetEnumTypeName(enum_def);
     code += " = ";
-    code += NumToString(ev.value) + "\n";
+    code += enum_def.ToString(ev) + "\n";
   }
 
   // End enum code.

src/idl_gen_js_ts.cpp

@@ -359,13 +359,13 @@ class JsTsGenerator : public BaseGenerator {
 
       // Generate mapping between EnumName: EnumValue(int)
       if (reverse) {
-        code += "  " + NumToString(ev.value);
+        code += "  " + enum_def.ToString(ev);
         code += lang_.language == IDLOptions::kTs ? "= " : ": ";
         code += "'" + ev.name + "'";
       } else {
         code += "  " + ev.name;
         code += lang_.language == IDLOptions::kTs ? "= " : ": ";
-        code += NumToString(ev.value);
+        code += enum_def.ToString(ev);
       }
 
       code += (it + 1) != enum_def.Vals().end() ? ",\n" : "\n";
@@ -431,8 +431,7 @@ class JsTsGenerator : public BaseGenerator {
 
   std::string GenDefaultValue(const Value &value, const std::string &context) {
     if (value.type.enum_def) {
-      if (auto val = value.type.enum_def->ReverseLookup(
-              StringToInt(value.constant.c_str()), false)) {
+      if (auto val = value.type.enum_def->FindByValue(value.constant)) {
         if (lang_.language == IDLOptions::kTs) {
           return GenPrefixedTypeName(WrapInNameSpace(*value.type.enum_def),
                                      value.type.enum_def->file) +

src/idl_gen_lobster.cpp

@@ -263,7 +263,7 @@ class LobsterGenerator : public BaseGenerator {
       auto &ev = **it;
       GenComment(ev.doc_comment, code_ptr, nullptr, "    ");
       code += "    " + enum_def.name + "_" + NormalizedName(ev) + " = " +
-              NumToString(ev.value);
+              enum_def.ToString(ev);
       if (it + 1 != enum_def.Vals().end()) code += ",";
       code += "\n";
     }

src/idl_gen_lua.cpp

@@ -111,8 +111,8 @@ namespace lua {
     // A single enum member.
     void EnumMember(const EnumDef &enum_def, const EnumVal &ev, std::string *code_ptr) {
       std::string &code = *code_ptr;
-      code += std::string(Indent) + NormalizedName(ev) + " = " + NumToString(ev.value) + ",\n";
-      (void)enum_def;
+      code += std::string(Indent) + NormalizedName(ev) + " = " +
+              enum_def.ToString(ev) + ",\n";
     }
 
     // End enum code.

src/idl_gen_php.cpp

@@ -125,8 +125,7 @@ class PhpGenerator : public BaseGenerator {
     code += Indent + "const ";
     code += ev.name;
     code += " = ";
-    code += NumToString(ev.value) + ";\n";
-    (void)enum_def;
+    code += enum_def.ToString(ev) + ";\n";
   }
 
   // End enum code.
@@ -875,8 +874,7 @@ class PhpGenerator : public BaseGenerator {
 
   std::string GenDefaultValue(const Value &value) {
     if (value.type.enum_def) {
-      if (auto val = value.type.enum_def->ReverseLookup(
-              StringToInt(value.constant.c_str()), false)) {
+      if (auto val = value.type.enum_def->FindByValue(value.constant)) {
         return WrapInNameSpace(*value.type.enum_def) + "::" + val->name;
       }
     }

src/idl_gen_python.cpp

@@ -118,8 +118,7 @@ class PythonGenerator : public BaseGenerator {
     code += Indent;
     code += NormalizedName(ev);
     code += " = ";
-    code += NumToString(ev.value) + "\n";
-    (void)enum_def;
+    code += enum_def.ToString(ev) + "\n";
   }
 
   // End enum code.

src/idl_gen_rust.cpp

@@ -589,20 +589,17 @@ class RustGenerator : public BaseGenerator {
     code_ += "#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]";
     code_ += "pub enum " + Name(enum_def) + " {";
 
-    int64_t anyv = 0;
-    const EnumVal *minv = nullptr, *maxv = nullptr;
     for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
       const auto &ev = **it;
 
       GenComment(ev.doc_comment, "  ");
       code_.SetValue("KEY", Name(ev));
-      code_.SetValue("VALUE", NumToString(ev.value));
+      code_.SetValue("VALUE", enum_def.ToString(ev));
       code_ += "  {{KEY}} = {{VALUE}},";
-
-      minv = !minv || minv->value > ev.value ? &ev : minv;
-      maxv = !maxv || maxv->value < ev.value ? &ev : maxv;
-      anyv |= ev.value;
     }
+    const EnumVal *minv = enum_def.MinValue();
+    const EnumVal *maxv = enum_def.MaxValue();
+    FLATBUFFERS_ASSERT(minv && maxv);
 
     code_ += "";
     code_ += "}";
@@ -611,8 +608,8 @@ class RustGenerator : public BaseGenerator {
     code_.SetValue("ENUM_NAME", Name(enum_def));
     code_.SetValue("ENUM_NAME_SNAKE", MakeSnakeCase(Name(enum_def)));
     code_.SetValue("ENUM_NAME_CAPS", MakeUpper(MakeSnakeCase(Name(enum_def))));
-    code_.SetValue("ENUM_MIN_BASE_VALUE", NumToString(minv->value));
-    code_.SetValue("ENUM_MAX_BASE_VALUE", NumToString(maxv->value));
+    code_.SetValue("ENUM_MIN_BASE_VALUE", enum_def.ToString(*minv));
+    code_.SetValue("ENUM_MAX_BASE_VALUE", enum_def.ToString(*maxv));
 
     // Generate enum constants, and impls for Follow, EndianScalar, and Push.
     code_ += "const ENUM_MIN_{{ENUM_NAME_CAPS}}: {{BASE_TYPE}} = \\";
@@ -671,34 +668,36 @@ class RustGenerator : public BaseGenerator {
     // Problem is, if values are very sparse that could generate really big
     // tables. Ideally in that case we generate a map lookup instead, but for
     // the moment we simply don't output a table at all.
-    auto range =
-        enum_def.vals.vec.back()->value - enum_def.vals.vec.front()->value + 1;
+    auto range = enum_def.Distance();
     // Average distance between values above which we consider a table
     // "too sparse". Change at will.
-    static const int kMaxSparseness = 5;
-    if (range / static_cast<int64_t>(enum_def.vals.vec.size()) <
-        kMaxSparseness) {
+    static const uint64_t kMaxSparseness = 5;
+    if (range / static_cast<uint64_t>(enum_def.size()) < kMaxSparseness) {
       code_ += "#[allow(non_camel_case_types)]";
       code_ += "const ENUM_NAMES_{{ENUM_NAME_CAPS}}:[&'static str; " +
-                NumToString(range) + "] = [";
+               NumToString(range + 1) + "] = [";
 
-      auto val = enum_def.Vals().front()->value;
+      auto val = enum_def.Vals().front();
       for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
            ++it) {
-        const auto &ev = **it;
-        while (val++ != ev.value) { code_ += "    \"\","; }
-        auto suffix = *it != enum_def.vals.vec.back() ? "," : "";
-        code_ += "    \"" + Name(ev) + "\"" + suffix;
+        auto ev = *it;
+        for (auto k = enum_def.Distance(val, ev); k > 1; --k) {
+          code_ += "    \"\",";
+        }
+        val = ev;
+        auto suffix = *it != enum_def.Vals().back() ? "," : "";
+        code_ += "    \"" + Name(*ev) + "\"" + suffix;
       }
       code_ += "];";
       code_ += "";
 
-      code_ += "pub fn enum_name_{{ENUM_NAME_SNAKE}}(e: {{ENUM_NAME}}) -> "
+      code_ +=
+          "pub fn enum_name_{{ENUM_NAME_SNAKE}}(e: {{ENUM_NAME}}) -> "
           "&'static str {";
 
       code_ += "  let index = e as {{BASE_TYPE}}\\";
-      if (enum_def.vals.vec.front()->value) {
-        auto vals = GetEnumValUse(enum_def, *enum_def.vals.vec.front());
+      if (enum_def.MinValue()->IsNonZero()) {
+        auto vals = GetEnumValUse(enum_def, *enum_def.MinValue());
         code_ += " - " + vals + " as {{BASE_TYPE}}\\";
       }
       code_ += ";";
@@ -735,8 +734,7 @@ class RustGenerator : public BaseGenerator {
       }
       case ftUnionKey:
       case ftEnumKey: {
-        auto ev = field.value.type.enum_def->ReverseLookup(
-            StringToInt(field.value.constant.c_str()), false);
+        auto ev = field.value.type.enum_def->FindByValue(field.value.constant);
         assert(ev);
         return WrapInNameSpace(field.value.type.enum_def->defined_namespace,
                                GetEnumValUse(*field.value.type.enum_def, *ev));

src/idl_gen_text.cpp

@@ -51,10 +51,10 @@ bool Print(T val, Type type, int /*indent*/, Type * /*union_type*/,
            const IDLOptions &opts, std::string *_text) {
   std::string &text = *_text;
   if (type.enum_def && opts.output_enum_identifiers) {
-    auto enum_val = type.enum_def->ReverseLookup(static_cast<int64_t>(val));
-    if (enum_val) {
+    auto ev = type.enum_def->ReverseLookup(static_cast<int64_t>(val));
+    if (ev) {
       text += "\"";
-      text += enum_val->name;
+      text += ev->name;
       text += "\"";
       return true;
     }
@@ -251,7 +251,7 @@ static bool GenStruct(const StructDef &struct_def, const Table *table,
       }
       if (fd.value.type.base_type == BASE_TYPE_UTYPE) {
         auto enum_val = fd.value.type.enum_def->ReverseLookup(
-            table->GetField<uint8_t>(fd.value.offset, 0));
+            table->GetField<uint8_t>(fd.value.offset, 0), true);
         union_type = enum_val ? &enum_val->union_type : nullptr;
       }
     }

tests/test.cpp

@@ -1297,7 +1297,6 @@ void ErrorTest() {
   TestError("enum X:float {}", "underlying");
   TestError("enum X:byte { Y, Y }", "value already");
   TestError("enum X:byte { Y=2, Z=1 }", "ascending");
-  TestError("enum X:byte (bit_flags) { Y=8 }", "bit flag out");
   TestError("table X { Y:int; } table X {", "datatype already");
   TestError("struct X (force_align: 7) { Y:int; }", "force_align");
   TestError("struct X {}", "size 0");
@@ -1416,6 +1415,13 @@ void EnumStringsTest() {
                         "root_type T;"
                         "{ F:[ \"E.C\", \"E.A E.B E.C\" ] }"),
           true);
+  // unsigned bit_flags
+  flatbuffers::Parser parser3;
+  TEST_EQ(
+      parser3.Parse("enum E:uint16 (bit_flags) { F0, F07=7, F08, F14=14, F15 }"
+                    " table T { F: E = \"F15 F08\"; }"
+                    "root_type T;"),
+      true);
 }
 
 void EnumNamesTest() {
@@ -1436,9 +1442,10 @@ void EnumNamesTest() {
 void EnumOutOfRangeTest() {
   TestError("enum X:byte { Y = 128 }", "enum value does not fit");
   TestError("enum X:byte { Y = -129 }", "enum value does not fit");
-  TestError("enum X:byte { Y = 127, Z }", "enum value does not fit");
+  TestError("enum X:byte { Y = 126, Z0, Z1 }", "enum value does not fit");
   TestError("enum X:ubyte { Y = -1 }", "enum value does not fit");
   TestError("enum X:ubyte { Y = 256 }", "enum value does not fit");
+  TestError("enum X:ubyte { Y = 255, Z }", "enum value does not fit");
   // Unions begin with an implicit "NONE = 0".
   TestError("table Y{} union X { Y = -1 }",
             "enum values must be specified in ascending order");
@@ -1448,12 +1455,13 @@ void EnumOutOfRangeTest() {
   TestError("enum X:int { Y = 2147483648 }", "enum value does not fit");
   TestError("enum X:uint { Y = -1 }", "enum value does not fit");
   TestError("enum X:uint { Y = 4294967297 }", "enum value does not fit");
-  TestError("enum X:long { Y = 9223372036854775808 }", "constant does not fit");
-  TestError("enum X:long { Y = 9223372036854775807, Z }", "enum value overflows");
-  TestError("enum X:ulong { Y = -1 }", "enum value does not fit");
-  // TODO: these are perfectly valid constants that shouldn't fail
-  TestError("enum X:ulong { Y = 13835058055282163712 }", "constant does not fit");
-  TestError("enum X:ulong { Y = 18446744073709551615 }", "constant does not fit");
+  TestError("enum X:long { Y = 9223372036854775808 }", "does not fit");
+  TestError("enum X:long { Y = 9223372036854775807, Z }", "enum value does not fit");
+  TestError("enum X:ulong { Y = -1 }", "does not fit");
+  TestError("enum X:ubyte (bit_flags) { Y=8 }", "bit flag out");
+  TestError("enum X:byte (bit_flags) { Y=7 }", "must be unsigned"); // -128
+  // bit_flgs out of range
+  TestError("enum X:ubyte (bit_flags) { Y0,Y1,Y2,Y3,Y4,Y5,Y6,Y7,Y8 }", "out of range");
 }
 
 void EnumValueTest() {
@@ -1472,6 +1480,15 @@ void EnumValueTest() {
   // Generate json with defaults and check.
   TEST_EQ(TestValue<int>(nullptr, "E", "enum E:int { Z, V=5 }"), 0);
   TEST_EQ(TestValue<int>(nullptr, "E=V", "enum E:int { Z, V=5 }"), 5);
+  // u84 test
+  TEST_EQ(TestValue<uint64_t>(nullptr, "E=V",
+                              "enum E:ulong { V = 13835058055282163712 }"),
+          13835058055282163712ULL);
+  TEST_EQ(TestValue<uint64_t>(nullptr, "E=V",
+                              "enum E:ulong { V = 18446744073709551615 }"),
+          18446744073709551615ULL);
+  // Assign non-enum value to enum field. Is it right?
+  TEST_EQ(TestValue<int>("{ Y:7 }", "E", "enum E:int { V = 0 }"), 7);
 }
 
 void IntegerOutOfRangeTest() {