Add fast-paths for ToolLocationHelper property functions

src/Build.UnitTests/Evaluation/Expander_Tests.cs

@@ -1991,6 +1991,28 @@ public void TestGetPathToReferenceAssembliesAsFunction()
             log.AssertLogDoesntContain("Reference assembly paths do not match");
         }
 
+        /// <summary>
+        /// Test that ToolLocationHelper fast-path methods work correctly
+        /// </summary>
+        [Fact]
+        public void TestToolLocationHelperFastPaths()
+        {
+            PropertyDictionary<ProjectPropertyInstance> pg = new PropertyDictionary<ProjectPropertyInstance>();
+
+            Expander<ProjectPropertyInstance, ProjectItemInstance> expander = new Expander<ProjectPropertyInstance, ProjectItemInstance>(pg, FileSystems.Default);
+
+            // Test GetPlatformSDKLocation with fast-path
+            string result1 = expander.ExpandIntoStringLeaveEscaped("$([Microsoft.Build.Utilities.ToolLocationHelper]::GetPlatformSDKLocation('Windows', '10.0'))", ExpanderOptions.ExpandProperties, MockElementLocation.Instance);
+
+            // Test GetPlatformSDKDisplayName with fast-path
+            string result2 = expander.ExpandIntoStringLeaveEscaped("$([Microsoft.Build.Utilities.ToolLocationHelper]::GetPlatformSDKDisplayName('Windows', '10.0'))", ExpanderOptions.ExpandProperties, MockElementLocation.Instance);
+
+            // The results should be non-null strings (actual values depend on system configuration)
+            // We're mainly testing that the methods execute without errors through the fast-path
+            Assert.True(result1 != null, "GetPlatformSDKLocation should not return null");
+            Assert.True(result2 != null, "GetPlatformSDKDisplayName should not return null");
+        }
+
         /// <summary>
         /// Expand property function that takes a null argument
         /// </summary>

src/Build/Evaluation/Expander/WellKnownFunctions.cs

@@ -10,6 +10,7 @@
 using Microsoft.Build.Framework;
 using Microsoft.Build.Shared;
 using Microsoft.Build.Shared.FileSystem;
+using Microsoft.Build.Utilities;
 
 using ParseArgs = Microsoft.Build.Evaluation.Expander.ArgumentParser;
 
@@ -875,6 +876,25 @@ internal static bool TryExecuteWellKnownFunction(string methodName, Type receive
                         }
                     }
                 }
+                else if (receiverType == typeof(ToolLocationHelper))
+                {
+                    if (string.Equals(methodName, nameof(ToolLocationHelper.GetPlatformSDKLocation), StringComparison.OrdinalIgnoreCase))
+                    {
+                        if (ParseArgs.TryGetArgs(args, out string? arg0, out string? arg1) && arg0 != null && arg1 != null)
+                        {
+                            returnVal = ToolLocationHelper.GetPlatformSDKLocation(arg0, arg1);
+                            return true;
+                        }
+                    }
+                    else if (string.Equals(methodName, nameof(ToolLocationHelper.GetPlatformSDKDisplayName), StringComparison.OrdinalIgnoreCase))
+                    {
+                        if (ParseArgs.TryGetArgs(args, out string? arg0, out string? arg1) && arg0 != null && arg1 != null)
+                        {
+                            returnVal = ToolLocationHelper.GetPlatformSDKDisplayName(arg0, arg1);
+                            return true;
+                        }
+                    }
+                }
                 else if (string.Equals(methodName, nameof(Regex.Replace), StringComparison.OrdinalIgnoreCase) && args.Length == 3)
                 {
                     if (ParseArgs.TryGetArgs(args, out string? arg1, out string? arg2, out string? arg3) && arg1 != null && arg2 != null && arg3 != null)

src/Build/Microsoft.Build.csproj

@@ -30,6 +30,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\Framework\Microsoft.Build.Framework.csproj" />
+    <ProjectReference Include="..\Utilities\Microsoft.Build.Utilities.csproj" />
     <ProjectReference Include="..\StringTools\StringTools.csproj" />
     <PackageReference Include="Microsoft.VisualStudio.SolutionPersistence" PrivateAssets="all"/>
     <PackageReference Include="System.Configuration.ConfigurationManager" />