SerializableAttribute is not available in the portable class library

runtime/CSharp/Antlr4.Runtime/Atn/PredictionMode.cs

@@ -34,7 +34,9 @@ using Sharpen;
 
 namespace Antlr4.Runtime.Atn
 {
+#if !PORTABLE
     [System.Serializable]
+#endif
     public sealed class PredictionMode
     {
         /// <summary>

runtime/CSharp/Antlr4.Runtime/CommonToken.cs

@@ -34,7 +34,9 @@ using Sharpen;
 
 namespace Antlr4.Runtime
 {
+#if !PORTABLE
     [System.Serializable]
+#endif
     public class CommonToken : IWritableToken
     {
         private const long serialVersionUID = -6708843461296520577L;

runtime/CSharp/Antlr4.Runtime/FailedPredicateException.cs

@@ -41,7 +41,9 @@ namespace Antlr4.Runtime
     /// Disambiguating predicate evaluation occurs when we test a predicate during
     /// prediction.
     /// </remarks>
+#if !PORTABLE
     [System.Serializable]
+#endif
     public class FailedPredicateException : RecognitionException
     {
         private const long serialVersionUID = 5379330841495778709L;

runtime/CSharp/Antlr4.Runtime/InputMismatchException.cs

@@ -40,7 +40,9 @@ namespace Antlr4.Runtime
     /// This signifies any kind of mismatched input exceptions such as
     /// when the current input does not match the expected token.
     /// </remarks>
+#if !PORTABLE
     [System.Serializable]
+#endif
     public class InputMismatchException : RecognitionException
     {
         private const long serialVersionUID = 1532568338707443067L;

runtime/CSharp/Antlr4.Runtime/LexerNoViableAltException.cs

@@ -34,7 +34,9 @@ using Sharpen;
 
 namespace Antlr4.Runtime
 {
+#if !PORTABLE
     [System.Serializable]
+#endif
     public class LexerNoViableAltException : RecognitionException
     {
         private const long serialVersionUID = -730999203913001726L;

runtime/CSharp/Antlr4.Runtime/Misc/ParseCanceledException.cs

@@ -45,7 +45,9 @@ namespace Antlr4.Runtime.Misc
     /// response to a parse error.
     /// </remarks>
     /// <author>Sam Harwell</author>
+#if !PORTABLE
     [System.Serializable]
+#endif
     public class ParseCanceledException : OperationCanceledException
     {
         public ParseCanceledException()

runtime/CSharp/Antlr4.Runtime/NoViableAltException.cs

@@ -44,7 +44,9 @@ namespace Antlr4.Runtime
     /// of the offending input and also knows where the parser was
     /// in the various paths when the error. Reported by reportNoViableAlternative()
     /// </remarks>
+#if !PORTABLE
     [System.Serializable]
+#endif
     public class NoViableAltException : RecognitionException
     {
         private const long serialVersionUID = 5096000008992867052L;

runtime/CSharp/Antlr4.Runtime/RecognitionException.cs

@@ -43,7 +43,9 @@ namespace Antlr4.Runtime
     /// in the input, where it is in the ATN, the rule invocation stack,
     /// and what kind of problem occurred.
     /// </remarks>
+#if !PORTABLE
     [System.Serializable]
+#endif
     public class RecognitionException : Exception
     {
         private const long serialVersionUID = -3861826954750022374L;