From 2ca4575eeb0a6ac3235c4d382a3786e63864840f Mon Sep 17 00:00:00 2001
From: Marek Safar <marek.safar@gmail.com>
Date: Mon, 5 Jun 2017 15:27:28 +0200
Subject: [PATCH] [mcs] Throw expression cannot be placed after any colon.

---
 mcs/mcs/cs-parser.jay        |  9 +++++++++
 mcs/mcs/cs-tokenizer.cs      |  1 -
 mcs/tests/test-946.cs        | 19 +++++++++++++++++++
 mcs/tests/ver-il-net_4_x.xml | 13 +++++++++++++
 4 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 mcs/tests/test-946.cs

diff --git a/mcs/mcs/cs-parser.jay b/mcs/mcs/cs-parser.jay
index 153a6bc7bdb..8d36abae8dc 100644
--- a/mcs/mcs/cs-parser.jay
+++ b/mcs/mcs/cs-parser.jay
@@ -4852,6 +4852,15 @@ conditional_expression
 		$$ = new Conditional (new BooleanExpression ((Expression) $1), (Expression) $3, (Expression) $5, GetLocation ($2));
 		lbag.AddLocation ($$, GetLocation ($4));
 	  }
+	| null_coalescing_expression INTERR expression COLON THROW prefixed_unary_expression
+	  {
+		if (lang_version < LanguageVersion.V_7)
+			FeatureIsNotAvailable (lexer.Location, "throw expression");
+
+		var expr = new ThrowExpression ((Expression) $6, GetLocation ($5));
+		$$ = new Conditional (new BooleanExpression ((Expression) $1), (Expression) $3, expr, GetLocation ($2));
+		lbag.AddLocation ($$, GetLocation ($4));
+	  }
 	| null_coalescing_expression INTERR expression error
 	  {
 		Error_SyntaxError (yyToken);
diff --git a/mcs/mcs/cs-tokenizer.cs b/mcs/mcs/cs-tokenizer.cs
index afa69c86a4b..505173cb4f9 100644
--- a/mcs/mcs/cs-tokenizer.cs
+++ b/mcs/mcs/cs-tokenizer.cs
@@ -899,7 +899,6 @@ namespace Mono.CSharp
 				case Token.ARROW:
 				case Token.OP_COALESCING:
 				case Token.INTERR:
-				case Token.COLON:
 					res = Token.THROW_EXPR;
 					break;
 				}
diff --git a/mcs/tests/test-946.cs b/mcs/tests/test-946.cs
new file mode 100644
index 00000000000..8841f1b8293
--- /dev/null
+++ b/mcs/tests/test-946.cs
@@ -0,0 +1,19 @@
+using System;
+
+class X
+{
+	public static void Main ()
+	{
+
+	}
+
+	int ImportScope (int scope)
+	{
+		switch (scope) {
+		case 200:
+			throw new NotImplementedException ();
+		}
+
+		throw new NotSupportedException ();
+	}	
+}
\ No newline at end of file
diff --git a/mcs/tests/ver-il-net_4_x.xml b/mcs/tests/ver-il-net_4_x.xml
index e2d36914506..a3ef14c1009 100644
--- a/mcs/tests/ver-il-net_4_x.xml
+++ b/mcs/tests/ver-il-net_4_x.xml
@@ -52754,6 +52754,19 @@
       </method>
     </type>
   </test>
+  <test name="test-946.cs">
+    <type name="X">
+      <method name="Void Main()" attrs="150">
+        <size>2</size>
+      </method>
+      <method name="Int32 ImportScope(Int32)" attrs="129">
+        <size>29</size>
+      </method>
+      <method name="Void .ctor()" attrs="6278">
+        <size>7</size>
+      </method>
+    </type>
+  </test>
   <test name="test-95.cs">
     <type name="X">
       <method name="Int32 Main()" attrs="150">
-- 
2.25.1