Imported Upstream version 6.6.0.89

Former-commit-id: b39a328747c2f3414dc52e009fb6f0aa80ca2492

external/api-doc-tools/mdoc/Mono.Documentation/Updater/Formatters/StandardFlagsEnumFormatter.cs

@@ -0,0 +1,34 @@
+using System.Linq;
+
+using Mono.Cecil;
+
+namespace Mono.Documentation.Updater
+{
+    /// <summary>Flags enum formatter that assumes powers of two values.</summary>
+    /// <remarks>As described here: https://msdn.microsoft.com/en-us/library/vstudio/ms229062(v=vs.100).aspx</remarks>
+    class StandardFlagsEnumFormatter : AttributeValueFormatter
+    {
+        public override bool TryFormatValue (object v, ResolvedTypeInfo type, out string returnvalue)
+        {
+            TypeReference valueType = type.Reference;
+            TypeDefinition valueDef = type.Definition;
+            if (valueDef.CustomAttributes.Any (ca => ca.AttributeType.FullName == "System.FlagsAttribute"))
+            {
+
+                string typename = MDocUpdater.GetDocTypeFullName (valueType);
+                var values = MDocUpdater.GetEnumerationValues (valueDef);
+                long c = MDocUpdater.ToInt64 (v);
+                returnvalue = string.Join (" | ",
+                    (from i in values.Keys
+                     where (c & i) == i && i != 0
+                     select typename + "." + values[i])
+                    .DefaultIfEmpty (c.ToString ()).ToArray ());
+
+                return true;
+            }
+
+            returnvalue = null;
+            return false;
+        }
+    }
+}