[C#] Handle keywords (#6775)

* Handle keywords in C#

C# should handle keywords similarly to other languages by appending an underscore after the keyword.

* Fix clang-format for idl_gen_csharp.cpp

* Fix spacing clang-format issue

tests/keyword_test/ABC.cs

@@ -0,0 +1,12 @@
+// <auto-generated>
+//  automatically generated by the FlatBuffers compiler, do not modify
+// </auto-generated>
+
+[Newtonsoft.Json.JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
+public enum ABC : int
+{
+  void_ = 0,
+  where = 1,
+  stackalloc_ = 2,
+};
+

tests/keyword_test/KeywordsInTable.cs

@@ -0,0 +1,70 @@
+// <auto-generated>
+//  automatically generated by the FlatBuffers compiler, do not modify
+// </auto-generated>
+
+using global::System;
+using global::System.Collections.Generic;
+using global::FlatBuffers;
+
+public struct KeywordsInTable : IFlatbufferObject
+{
+  private Table __p;
+  public ByteBuffer ByteBuffer { get { return __p.bb; } }
+  public static void ValidateVersion() { FlatBufferConstants.FLATBUFFERS_2_0_0(); }
+  public static KeywordsInTable GetRootAsKeywordsInTable(ByteBuffer _bb) { return GetRootAsKeywordsInTable(_bb, new KeywordsInTable()); }
+  public static KeywordsInTable GetRootAsKeywordsInTable(ByteBuffer _bb, KeywordsInTable obj) { return (obj.__assign(_bb.GetInt(_bb.Position) + _bb.Position, _bb)); }
+  public void __init(int _i, ByteBuffer _bb) { __p = new Table(_i, _bb); }
+  public KeywordsInTable __assign(int _i, ByteBuffer _bb) { __init(_i, _bb); return this; }
+
+  public ABC Is { get { int o = __p.__offset(4); return o != 0 ? (ABC)__p.bb.GetInt(o + __p.bb_pos) : ABC.void_; } }
+  public bool MutateIs(ABC is_) { int o = __p.__offset(4); if (o != 0) { __p.bb.PutInt(o + __p.bb_pos, (int)is_); return true; } else { return false; } }
+  public public_ Private { get { int o = __p.__offset(6); return o != 0 ? (public_)__p.bb.GetInt(o + __p.bb_pos) : public_.NONE; } }
+  public bool MutatePrivate(public_ private_) { int o = __p.__offset(6); if (o != 0) { __p.bb.PutInt(o + __p.bb_pos, (int)private_); return true; } else { return false; } }
+
+  public static Offset<KeywordsInTable> CreateKeywordsInTable(FlatBufferBuilder builder,
+      ABC is_ = ABC.void_,
+      public_ private_ = public_.NONE) {
+    builder.StartTable(2);
+    KeywordsInTable.AddPrivate(builder, private_);
+    KeywordsInTable.AddIs(builder, is_);
+    return KeywordsInTable.EndKeywordsInTable(builder);
+  }
+
+  public static void StartKeywordsInTable(FlatBufferBuilder builder) { builder.StartTable(2); }
+  public static void AddIs(FlatBufferBuilder builder, ABC is_) { builder.AddInt(0, (int)is_, 0); }
+  public static void AddPrivate(FlatBufferBuilder builder, public_ private_) { builder.AddInt(1, (int)private_, 0); }
+  public static Offset<KeywordsInTable> EndKeywordsInTable(FlatBufferBuilder builder) {
+    int o = builder.EndTable();
+    return new Offset<KeywordsInTable>(o);
+  }
+  public KeywordsInTableT UnPack() {
+    var _o = new KeywordsInTableT();
+    this.UnPackTo(_o);
+    return _o;
+  }
+  public void UnPackTo(KeywordsInTableT _o) {
+    _o.Is = this.Is;
+    _o.Private = this.Private;
+  }
+  public static Offset<KeywordsInTable> Pack(FlatBufferBuilder builder, KeywordsInTableT _o) {
+    if (_o == null) return default(Offset<KeywordsInTable>);
+    return CreateKeywordsInTable(
+      builder,
+      _o.Is,
+      _o.Private);
+  }
+};
+
+public class KeywordsInTableT
+{
+  [Newtonsoft.Json.JsonProperty("is")]
+  public ABC Is { get; set; }
+  [Newtonsoft.Json.JsonProperty("private")]
+  public public_ Private { get; set; }
+
+  public KeywordsInTableT() {
+    this.Is = ABC.void_;
+    this.Private = public_.NONE;
+  }
+}
+

tests/keyword_test/KeywordsInUnion.cs

@@ -0,0 +1,78 @@
+// <auto-generated>
+//  automatically generated by the FlatBuffers compiler, do not modify
+// </auto-generated>
+
+[Newtonsoft.Json.JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
+public enum KeywordsInUnion : byte
+{
+  NONE = 0,
+  static_ = 1,
+  internal_ = 2,
+};
+
+public class KeywordsInUnionUnion {
+  public KeywordsInUnion Type { get; set; }
+  public object Value { get; set; }
+
+  public KeywordsInUnionUnion() {
+    this.Type = KeywordsInUnion.NONE;
+    this.Value = null;
+  }
+
+  public T As<T>() where T : class { return this.Value as T; }
+  public KeywordsInTableT Asstatic() { return this.As<KeywordsInTableT>(); }
+  public static KeywordsInUnionUnion Fromstatic(KeywordsInTableT _static) { return new KeywordsInUnionUnion{ Type = KeywordsInUnion.static_, Value = _static }; }
+  public string Asinternal() { return this.As<string>(); }
+  public static KeywordsInUnionUnion Frominternal(string _internal) { return new KeywordsInUnionUnion{ Type = KeywordsInUnion.internal_, Value = _internal }; }
+
+  public static int Pack(FlatBuffers.FlatBufferBuilder builder, KeywordsInUnionUnion _o) {
+    switch (_o.Type) {
+      default: return 0;
+      case KeywordsInUnion.static_: return KeywordsInTable.Pack(builder, _o.Asstatic()).Value;
+      case KeywordsInUnion.internal_: return builder.CreateString(_o.Asinternal()).Value;
+    }
+  }
+}
+
+public class KeywordsInUnionUnion_JsonConverter : Newtonsoft.Json.JsonConverter {
+  public override bool CanConvert(System.Type objectType) {
+    return objectType == typeof(KeywordsInUnionUnion) || objectType == typeof(System.Collections.Generic.List<KeywordsInUnionUnion>);
+  }
+  public override void WriteJson(Newtonsoft.Json.JsonWriter writer, object value, Newtonsoft.Json.JsonSerializer serializer) {
+    var _olist = value as System.Collections.Generic.List<KeywordsInUnionUnion>;
+    if (_olist != null) {
+      writer.WriteStartArray();
+      foreach (var _o in _olist) { this.WriteJson(writer, _o, serializer); }
+      writer.WriteEndArray();
+    } else {
+      this.WriteJson(writer, value as KeywordsInUnionUnion, serializer);
+    }
+  }
+  public void WriteJson(Newtonsoft.Json.JsonWriter writer, KeywordsInUnionUnion _o, Newtonsoft.Json.JsonSerializer serializer) {
+    if (_o == null) return;
+    serializer.Serialize(writer, _o.Value);
+  }
+  public override object ReadJson(Newtonsoft.Json.JsonReader reader, System.Type objectType, object existingValue, Newtonsoft.Json.JsonSerializer serializer) {
+    var _olist = existingValue as System.Collections.Generic.List<KeywordsInUnionUnion>;
+    if (_olist != null) {
+      for (var _j = 0; _j < _olist.Count; ++_j) {
+        reader.Read();
+        _olist[_j] = this.ReadJson(reader, _olist[_j], serializer);
+      }
+      reader.Read();
+      return _olist;
+    } else {
+      return this.ReadJson(reader, existingValue as KeywordsInUnionUnion, serializer);
+    }
+  }
+  public KeywordsInUnionUnion ReadJson(Newtonsoft.Json.JsonReader reader, KeywordsInUnionUnion _o, Newtonsoft.Json.JsonSerializer serializer) {
+    if (_o == null) return null;
+    switch (_o.Type) {
+      default: break;
+      case KeywordsInUnion.static_: _o.Value = serializer.Deserialize<KeywordsInTableT>(reader); break;
+      case KeywordsInUnion.internal_: _o.Value = serializer.Deserialize<string>(reader); break;
+    }
+    return _o;
+  }
+}
+

tests/keyword_test/public.cs

@@ -0,0 +1,10 @@
+// <auto-generated>
+//  automatically generated by the FlatBuffers compiler, do not modify
+// </auto-generated>
+
+[Newtonsoft.Json.JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
+public enum public_ : int
+{
+  NONE = 0,
+};
+