Feature Query API

src/Framework/FeatureAvailabilityChecker.cs

@@ -0,0 +1,60 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Microsoft.Build.Framework
+{
+    /// <summary>
+    /// The status of a feature.
+    /// </summary>
+    public enum FeatureStatus
+    {
+        /// <summary>
+        /// The feature is available.
+        /// </summary>
+        Available,
+
+        /// <summary>
+        /// The feature is not available.
+        /// </summary>
+        NotAvailable,
+
+        /// <summary>
+        /// The feature is not found.
+        /// </summary>
+        NotFound,
+
+        // TODO: Add more status if needed
+        // Preview,
+        // Deprecated,
+    }
+
+    /// <summary>
+    /// This class is used to check if a feature is available or not.
+    /// </summary>
+    public static class FeatureAvailabilityChecker
+    {
+        private static Dictionary<string, FeatureStatus> _featureStatusMap = new Dictionary<string, FeatureStatus>
+        {
+            // TODO: Fill in the dictionary with the features and their status
+            { "Feature1", FeatureStatus.Available },
+            { "Feature2", FeatureStatus.NotAvailable },
+        };
+
+        /// <summary>
+        /// Checks if a feature is available or not.
+        /// </summary>
+        /// <param name="featureName">The name of the feature.</param>
+        /// <returns>A feature status <see cref="FeatureStatus"/>.</returns>
+        public static FeatureStatus CheckFeatureAvailability(string featureName)
+        {
+            return _featureStatusMap.ContainsKey(featureName) ?
+                _featureStatusMap[featureName] : FeatureStatus.NotFound;
+        }
+    }
+}

src/MSBuild/CommandLineSwitches.cs

@@ -50,7 +50,8 @@ internal enum ParameterlessSwitch
 #if DEBUG
             WaitForDebugger,
 #endif
-            NumberOfParameterlessSwitches
+            NumberOfParameterlessSwitches,
+            FeautureAvailability
         }
 
         /// <summary>
@@ -115,6 +116,7 @@ internal enum ParameterizedSwitch
             GetProperty,
             GetItem,
             GetTargetResult,
+            FeatureAvailability,
             NumberOfParameterizedSwitches,
         }
 
@@ -280,6 +282,7 @@ internal ParameterizedSwitchInfo(
             new ParameterizedSwitchInfo(  new string[] { "getProperty" },                       ParameterizedSwitch.GetProperty,                null,                           true,           "MissingGetPropertyError",             true,   false),
             new ParameterizedSwitchInfo(  new string[] { "getItem" },                           ParameterizedSwitch.GetItem,                    null,                           true,           "MissingGetItemError",                 true,   false),
             new ParameterizedSwitchInfo(  new string[] { "getTargetResult" },                   ParameterizedSwitch.GetTargetResult,            null,                           true,           "MissingGetTargetResultError",         true,   false),
+            new ParameterizedSwitchInfo(  new string[] { "featureavailability", "fa" },         ParameterizedSwitch.FeatureAvailability,        "DuplicateFeatureAvailability", false,          "MissingFeatureAvailabilityError",     true,   false),
         };
 
         /// <summary>

src/MSBuild/Resources/Strings.resx

@@ -1053,6 +1053,14 @@
       LOCALIZATION: The prefix "MSBUILD : error MSBxxxx:" should not be localized.
     </comment>
   </data>
+  <data name="MissingFeatureAvailabilityError" UESanitized="true" Visibility="Public">
+    <value>MSBUILD : error MSB1067: Must provide a property name for the featureavailability switch.</value>
+    <comment>
+      {StrBegin="MSBUILD : error MSB1067: "}UE: This happens if the user does something like "msbuild.exe -featureavailability". The user must pass in an actual property name
+      following the switch, as in "msbuild.exe -featureavailability:blah".
+      LOCALIZATION: The prefix "MSBUILD : error MSBxxxx:" should not be localized.
+    </comment>
+  </data>
   <data name="MissingGetItemError" UESanitized="true" Visibility="Public">
     <value>MSBUILD : error MSB1014: Must provide an item name for the getItem switch.</value>
     <comment>
@@ -1397,6 +1405,10 @@
     <value>MSBUILD : error MSB1058: Only one output results cache can be specified.</value>
     <comment>{StrBegin="MSBUILD : error MSB1058: "}</comment>
   </data>
+  <data name="DuplicateFeatureAvailability" UESanitized="true" Visibility="Public">
+    <value>MSBUILD : error MSB1068: Only one feature availability can be specified.</value>
+    <comment>{StrBegin="MSBUILD : error MSB1068: "}</comment>
+  </data>
   <data name="OptionalLoggerCreationMessage" UESanitized="true" Visibility="Public">
     <value>The specified logger "{0}" could not be created and will not be used. {1}</value>
     <comment>
@@ -1559,7 +1571,7 @@
     <!--
         The command line message bucket is: MSB1001 - MSB1999
 
-        Next error code should be MSB1067.
+        Next error code should be MSB1069.
 
         Don't forget to update this comment after using the new code.
   -->