define cosntants for csharp parse options.

Barotrauma/BarotraumaShared/SharedSource/LuaCs/Cs/CsScriptBase.cs

@@ -16,6 +16,8 @@ namespace Barotrauma
 {
 	class CsScriptBase : AssemblyLoadContext
 	{
+		public static readonly List<string> PreprocessingSymbols = new List<string>();
+
 		public const string NET_ONE_TIME_SCRIPT_ASSEMBLY = "NetOneTimeScriptAssembly";
 		public const string NET_SCRIPT_ASSEMBLY = "NetScriptAssembly";
 
@@ -27,6 +29,15 @@ namespace Barotrauma
 
 		public CsScriptBase() : base(isCollectible: true) { }
 
+		static CsScriptBase()
+		{
+#if SERVER
+            PreprocessingSymbols.Add("SERVER");
+#else
+			PreprocessingSymbols.Add("CLIENT");
+#endif
+		}
+
 		public static SyntaxTree AssemblyInfoSyntaxTree(string asmName = null)
         {
 			Revision[asmName] = (int)Revision[asmName] + 1;

Barotrauma/BarotraumaShared/SharedSource/LuaCs/Cs/CsScriptLoader.cs

@@ -69,7 +69,7 @@ namespace Barotrauma
 				{
 					foreach (var file in src)
 					{
-						var tree = SyntaxFactory.ParseSyntaxTree(File.ReadAllText(file), CSharpParseOptions.Default, file);
+						var tree = SyntaxFactory.ParseSyntaxTree(File.ReadAllText(file), CSharpParseOptions.Default.WithPreprocessorSymbols(PreprocessingSymbols), file);
 						var error = CsScriptFilter.FilterSyntaxTree(tree as CSharpSyntaxTree); // Check file content for prohibited stuff
 						if (error != null) throw new Exception(error);
 

Barotrauma/BarotraumaShared/SharedSource/LuaCs/Cs/CsScriptRunner.cs

@@ -55,7 +55,7 @@ namespace Barotrauma
 			try
 			{
 				code = ToOneTimeScript(code);
-				var syntaxTree = SyntaxFactory.ParseSyntaxTree(code, CSharpParseOptions.Default);
+				var syntaxTree = SyntaxFactory.ParseSyntaxTree(code, CSharpParseOptions.Default.WithPreprocessorSymbols(PreprocessingSymbols));
 				var compilation = CSharpCompilation.Create(NET_ONE_TIME_SCRIPT_ASSEMBLY, new[] { AssemblyInfoSyntaxTree(NET_ONE_TIME_SCRIPT_ASSEMBLY), syntaxTree }, defaultReferences, compileOptions);
 
 				Assembly assembly = null;