dotnet · YuliiaKovalova · Nov 20, 2025 · Nov 19, 2025 · Nov 19, 2025
diff --git a/src/Build.UnitTests/Utilities_Tests.cs b/src/Build.UnitTests/Utilities_Tests.cs
@@ -80,9 +80,17 @@ public void CommentsInPreprocessing()
 
             env.SetEnvironmentVariable("MSBUILDLOADALLFILESASWRITEABLE", "1");
 
+#if FEATURE_GET_COMMANDLINE
             MSBuildApp.Execute(@"c:\bin\msbuild.exe """ + inputFile.Path +
                 (NativeMethodsShared.IsUnixLike ? @""" -pp:""" : @""" /pp:""") + outputFile.Path + @"""")
                 .ShouldBe(MSBuildApp.ExitType.Success);
+#else
+            Assert.Equal(
+                MSBuildApp.ExitType.Success,
+                MSBuildApp.Execute(
+                    new[] { @"c:\bin\msbuild.exe", '"' + inputFile.Path + '"',
+                '"' + (NativeMethodsShared.IsUnixLike ? "-pp:" : "/pp:") + outputFile.Path + '"'}));
+#endif
 
             bool foundDoNotModify = false;
             foreach (string line in File.ReadLines(outputFile.Path))

diff --git a/src/Build/BackEnd/Client/MSBuildClient.cs b/src/Build/BackEnd/Client/MSBuildClient.cs
@@ -48,7 +48,11 @@ public sealed class MSBuildClient
         /// The command line to process.
         /// The first argument on the command line is assumed to be the name/path of the executable, and is ignored.
         /// </summary>
+#if FEATURE_GET_COMMANDLINE
         private readonly string _commandLine;
+#else
+        private readonly string[] _commandLine;
+#endif
 
         /// <summary>
         /// The MSBuild client execution result.
@@ -108,7 +112,13 @@ public sealed class MSBuildClient
         /// on the command line is assumed to be the name/path of the executable, and is ignored</param>
         /// <param name="msbuildLocation"> Full path to current MSBuild.exe if executable is MSBuild.exe,
         /// or to version of MSBuild.dll found to be associated with the current process.</param>
-        public MSBuildClient(string commandLine, string msbuildLocation)
+        public MSBuildClient(
+#if FEATURE_GET_COMMANDLINE
+            string commandLine,
+#else
+            string[] commandLine,
+#endif
+            string msbuildLocation)
         {
             _serverEnvironmentVariables = new();
             _exitResult = new();
@@ -152,7 +162,12 @@ private void CreateNodePipeStream()
         public MSBuildClientExitResult Execute(CancellationToken cancellationToken)
         {
             // Command line in one string used only in human readable content.
-            string descriptiveCommandLine = _commandLine;
+            string descriptiveCommandLine =
+#if FEATURE_GET_COMMANDLINE
+                _commandLine;
+#else
+                string.Join(" ", _commandLine);
+#endif
 
             CommunicationsUtilities.Trace("Executing build with command line '{0}'", descriptiveCommandLine);
 

diff --git a/src/Build/BackEnd/Node/OutOfProcServerNode.cs b/src/Build/BackEnd/Node/OutOfProcServerNode.cs
@@ -25,7 +25,12 @@ public sealed class OutOfProcServerNode : INode, INodePacketFactory, INodePacket
         /// <summary>
         /// A callback used to execute command line build.
         /// </summary>
-        public delegate (int exitCode, string exitType) BuildCallback(string commandLine);
+        public delegate (int exitCode, string exitType) BuildCallback(
+#if FEATURE_GET_COMMANDLINE
+            string commandLine);
+#else
+            string[] commandLine);
+#endif
 
         private readonly BuildCallback _buildFunction;
 

diff --git a/src/Build/BackEnd/Node/ServerNodeBuildCommand.cs b/src/Build/BackEnd/Node/ServerNodeBuildCommand.cs
@@ -14,7 +14,11 @@ namespace Microsoft.Build.BackEnd
     /// </summary>
     internal sealed class ServerNodeBuildCommand : INodePacket
     {
+#if FEATURE_GET_COMMANDLINE
         private string _commandLine = default!;
+#else
+        private string[] _commandLine = default!;
+#endif
         private string _startupDirectory = default!;
         private Dictionary<string, string> _buildProcessEnvironment = default!;
         private CultureInfo _culture = default!;
@@ -30,7 +34,11 @@ internal sealed class ServerNodeBuildCommand : INodePacket
         /// <summary>
         /// Command line including arguments
         /// </summary>
+#if FEATURE_GET_COMMANDLINE
         public string CommandLine => _commandLine;
+#else
+        public string[] CommandLine => _commandLine;
+#endif
 
         /// <summary>
         /// The startup directory
@@ -71,7 +79,11 @@ private ServerNodeBuildCommand()
         }
 
         public ServerNodeBuildCommand(
+#if FEATURE_GET_COMMANDLINE
             string commandLine,
+#else
+            string[] commandLine,
+#endif
             string startupDirectory,
             Dictionary<string, string> buildProcessEnvironment,
             CultureInfo culture, CultureInfo uiCulture,

diff --git a/src/Build/CompatibilitySuppressions.xml b/src/Build/CompatibilitySuppressions.xml
@@ -1,48 +1,3 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- https://learn.microsoft.com/dotnet/fundamentals/package-validation/diagnostic-ids -->
-<Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
-  <!-- MSBuildClient is in experimental namespace and not used outside the MSBuild -->
-  <!-- OutOfProcServerNode.BuildCallback is in experimental namespace and not used outside the MSBuild -->
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Microsoft.Build.Experimental.MSBuildClient.#ctor(System.String[],System.String)</Target>
-    <Left>lib/net10.0/Microsoft.Build.dll</Left>
-    <Right>lib/net10.0/Microsoft.Build.dll</Right>
-    <IsBaselineSuppression>true</IsBaselineSuppression>
-  </Suppression>
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Microsoft.Build.Experimental.OutOfProcServerNode.BuildCallback.BeginInvoke(System.String[],System.AsyncCallback,System.Object)</Target>
-    <Left>lib/net10.0/Microsoft.Build.dll</Left>
-    <Right>lib/net10.0/Microsoft.Build.dll</Right>
-    <IsBaselineSuppression>true</IsBaselineSuppression>
-  </Suppression>
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Microsoft.Build.Experimental.OutOfProcServerNode.BuildCallback.Invoke(System.String[])</Target>
-    <Left>lib/net10.0/Microsoft.Build.dll</Left>
-    <Right>lib/net10.0/Microsoft.Build.dll</Right>
-    <IsBaselineSuppression>true</IsBaselineSuppression>
-  </Suppression>
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Microsoft.Build.Experimental.MSBuildClient.#ctor(System.String[],System.String)</Target>
-    <Left>ref/net10.0/Microsoft.Build.dll</Left>
-    <Right>ref/net10.0/Microsoft.Build.dll</Right>
-    <IsBaselineSuppression>true</IsBaselineSuppression>
-  </Suppression>
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Microsoft.Build.Experimental.OutOfProcServerNode.BuildCallback.BeginInvoke(System.String[],System.AsyncCallback,System.Object)</Target>
-    <Left>ref/net10.0/Microsoft.Build.dll</Left>
-    <Right>ref/net10.0/Microsoft.Build.dll</Right>
-    <IsBaselineSuppression>true</IsBaselineSuppression>
-  </Suppression>
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Microsoft.Build.Experimental.OutOfProcServerNode.BuildCallback.Invoke(System.String[])</Target>
-    <Left>ref/net10.0/Microsoft.Build.dll</Left>
-    <Right>ref/net10.0/Microsoft.Build.dll</Right>
-    <IsBaselineSuppression>true</IsBaselineSuppression>
-  </Suppression>
-</Suppressions>
+<Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" />
diff --git a/src/Directory.BeforeCommon.targets b/src/Directory.BeforeCommon.targets
@@ -31,6 +31,7 @@
     <DefineConstants>$(DefineConstants);FEATURE_ENVIRONMENT_SYSTEMDIRECTORY</DefineConstants>
     <DefineConstants>$(DefineConstants);FEATURE_FILE_TRACKER</DefineConstants>
     <DefineConstants Condition="'$(MachineIndependentBuild)' != 'true'">$(DefineConstants);FEATURE_GAC</DefineConstants>
+    <DefineConstants>$(DefineConstants);FEATURE_GET_COMMANDLINE</DefineConstants>
     <DefineConstants>$(DefineConstants);FEATURE_HANDLEPROCESSCORRUPTEDSTATEEXCEPTIONS</DefineConstants>
     <DefineConstants>$(DefineConstants);FEATURE_HTTP_LISTENER</DefineConstants>
     <DefineConstants Condition="'$(MachineIndependentBuild)' != 'true'">$(DefineConstants);FEATURE_INSTALLED_MSBUILD</DefineConstants>

diff --git a/src/MSBuild.UnitTests/CommandLineSwitches_Tests.cs b/src/MSBuild.UnitTests/CommandLineSwitches_Tests.cs
@@ -622,8 +622,7 @@ public void FeatureAvailibilitySwitchIdentificationTest(string switchName)
         public void TargetsSwitchParameter()
         {
             CommandLineSwitches switches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
-            parser.GatherCommandLineSwitches(new List<string>() { "/targets:targets.txt" }, switches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>() { "/targets:targets.txt" }, switches);
 
             switches.HaveErrors().ShouldBeFalse();
             switches[CommandLineSwitches.ParameterizedSwitch.Targets].ShouldBe(new[] { "targets.txt" });
@@ -633,8 +632,7 @@ public void TargetsSwitchParameter()
         public void TargetsSwitchDoesNotSupportMultipleOccurrences()
         {
             CommandLineSwitches switches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
-            parser.GatherCommandLineSwitches(new List<string>() { "/targets /targets" }, switches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>() { "/targets /targets" }, switches);
 
             switches.HaveErrors().ShouldBeTrue();
         }
@@ -711,9 +709,8 @@ public void LowPrioritySwitchIdentificationTests(string lowpriority)
         public void GraphBuildSwitchCanHaveParameters()
         {
             CommandLineSwitches switches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string> { "/graph", "/graph:true;  NoBuild  ;;  ;", "/graph:foo" }, switches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string> { "/graph", "/graph:true;  NoBuild  ;;  ;", "/graph:foo" }, switches);
 
             switches[CommandLineSwitches.ParameterizedSwitch.GraphBuild].ShouldBe(new[] { "true", "  NoBuild  ", "  ", "foo" });
 
@@ -724,9 +721,8 @@ public void GraphBuildSwitchCanHaveParameters()
         public void GraphBuildSwitchCanBeParameterless()
         {
             CommandLineSwitches switches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string> { "/graph" }, switches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string> { "/graph" }, switches);
 
             switches[CommandLineSwitches.ParameterizedSwitch.GraphBuild].ShouldBe(Array.Empty<string>());
 
@@ -737,9 +733,8 @@ public void GraphBuildSwitchCanBeParameterless()
         public void InputResultsCachesSupportsMultipleOccurrence()
         {
             CommandLineSwitches switches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>() { "/irc", "/irc:a;b", "/irc:c;d" }, switches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>() { "/irc", "/irc:a;b", "/irc:c;d" }, switches);
 
             switches[CommandLineSwitches.ParameterizedSwitch.InputResultsCaches].ShouldBe(new[] { null, "a", "b", "c", "d" });
 
@@ -750,9 +745,8 @@ public void InputResultsCachesSupportsMultipleOccurrence()
         public void OutputResultsCache()
         {
             CommandLineSwitches switches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>() { "/orc:a" }, switches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>() { "/orc:a" }, switches);
 
             switches[CommandLineSwitches.ParameterizedSwitch.OutputResultsCache].ShouldBe(new[] { "a" });
 
@@ -763,9 +757,8 @@ public void OutputResultsCache()
         public void OutputResultsCachesDoesNotSupportMultipleOccurrences()
         {
             CommandLineSwitches switches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>() { "/orc:a", "/orc:b" }, switches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>() { "/orc:a", "/orc:b" }, switches);
 
             switches.HaveErrors().ShouldBeTrue();
         }
@@ -1295,9 +1288,8 @@ public void ExtractAnyLoggerParameterPickLast()
         public void ProcessWarnAsErrorSwitchNotSpecified()
         {
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>(new[] { "" }), commandLineSwitches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[] { "" }), commandLineSwitches);
 
             Assert.Null(MSBuildApp.ProcessWarnAsErrorSwitch(commandLineSwitches));
         }
@@ -1311,9 +1303,8 @@ public void ProcessWarnAsErrorSwitchWithCodes()
             ISet<string> expectedWarningsAsErrors = new HashSet<string>(StringComparer.OrdinalIgnoreCase) { "a", "B", "c", "D", "e" };
 
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>(new[]
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[]
             {
                 "\"/warnaserror: a,B ; c \"", // Leading, trailing, leading and trailing whitespace
                 "/warnaserror:A,b,C",         // Repeats of different case
@@ -1337,9 +1328,8 @@ public void ProcessWarnAsErrorSwitchWithCodes()
         public void ProcessWarnAsErrorSwitchEmptySwitchClearsSet()
         {
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>(new[]
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[]
             {
                 "/warnaserror:a;b;c",
                 "/warnaserror",
@@ -1361,9 +1351,8 @@ public void ProcessWarnAsErrorSwitchValuesAfterEmptyAddOn()
             ISet<string> expectedWarningsAsErors = new HashSet<string>(StringComparer.OrdinalIgnoreCase) { "e", "f", "g" };
 
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>(new[]
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[]
             {
                 "/warnaserror:a;b;c",
                 "/warnaserror",
@@ -1384,9 +1373,8 @@ public void ProcessWarnAsErrorSwitchValuesAfterEmptyAddOn()
         public void ProcessWarnAsErrorSwitchEmpty()
         {
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>(new[] { "/warnaserror" }), commandLineSwitches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[] { "/warnaserror" }), commandLineSwitches);
 
             ISet<string> actualWarningsAsErrors = MSBuildApp.ProcessWarnAsErrorSwitch(commandLineSwitches);
 
@@ -1402,11 +1390,10 @@ public void ProcessWarnAsErrorSwitchEmpty()
         public void ProcessWarnAsMessageSwitchEmpty()
         {
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
             // Set "expanded" content to match the placeholder so the verify can use the exact resource string as "expected."
             string command = "{0}";
-            parser.GatherCommandLineSwitches(new List<string>(new[] { "/warnasmessage" }), commandLineSwitches, command);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[] { "/warnasmessage" }), commandLineSwitches, command);
 
             VerifySwitchError(commandLineSwitches, "/warnasmessage", AssemblyResources.GetString("MissingWarnAsMessageParameterError"));
         }
@@ -1423,15 +1410,13 @@ public void ProcessEnvironmentVariableSwitch()
                 env.SetEnvironmentVariable("ENVIRONMENTVARIABLE", string.Empty);
 
                 CommandLineSwitches commandLineSwitches = new();
-                CommandLineParser parser = new CommandLineParser();
-
                 string fullCommandLine = "msbuild validProject.csproj %ENVIRONMENTVARIABLE%";
-                parser.GatherCommandLineSwitches(new List<string>() { "validProject.csproj", "%ENVIRONMENTVARIABLE%" }, commandLineSwitches, fullCommandLine);
+                MSBuildApp.GatherCommandLineSwitches(new List<string>() { "validProject.csproj", "%ENVIRONMENTVARIABLE%" }, commandLineSwitches, fullCommandLine);
                 VerifySwitchError(commandLineSwitches, "%ENVIRONMENTVARIABLE%", String.Format(AssemblyResources.GetString("EnvironmentVariableAsSwitch"), fullCommandLine));
 
                 commandLineSwitches = new();
                 fullCommandLine = "msbuild %ENVIRONMENTVARIABLE% validProject.csproj";
-                parser.GatherCommandLineSwitches(new List<string>() { "%ENVIRONMENTVARIABLE%", "validProject.csproj" }, commandLineSwitches, fullCommandLine);
+                MSBuildApp.GatherCommandLineSwitches(new List<string>() { "%ENVIRONMENTVARIABLE%", "validProject.csproj" }, commandLineSwitches, fullCommandLine);
                 VerifySwitchError(commandLineSwitches, "%ENVIRONMENTVARIABLE%", String.Format(AssemblyResources.GetString("EnvironmentVariableAsSwitch"), fullCommandLine));
             }
         }
@@ -1445,9 +1430,8 @@ public void ProcessWarnAsMessageSwitchWithCodes()
             ISet<string> expectedWarningsAsMessages = new HashSet<string>(StringComparer.OrdinalIgnoreCase) { "a", "B", "c", "D", "e" };
 
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>(new[]
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[]
             {
                 "\"/warnasmessage: a,B ; c \"", // Leading, trailing, leading and trailing whitespace
                 "/warnasmessage:A,b,C",         // Repeats of different case
@@ -1471,9 +1455,8 @@ public void ProcessWarnAsMessageSwitchWithCodes()
         public void ProcessProfileEvaluationEmpty()
         {
             CommandLineSwitches commandLineSwitches = new CommandLineSwitches();
-            CommandLineParser parser = new CommandLineParser();
 
-            parser.GatherCommandLineSwitches(new List<string>(new[] { "/profileevaluation" }), commandLineSwitches);
+            MSBuildApp.GatherCommandLineSwitches(new List<string>(new[] { "/profileevaluation" }), commandLineSwitches);
             commandLineSwitches[CommandLineSwitches.ParameterizedSwitch.ProfileEvaluation][0].ShouldBe("no-file");
         }
 
@@ -1565,7 +1548,11 @@ public void ProcessInvalidTargetSwitch()
             using TestEnvironment testEnvironment = TestEnvironment.Create();
             string project = testEnvironment.CreateTestProjectWithFiles("project.proj", projectContent).ProjectFile;
 
+#if FEATURE_GET_COMMANDLINE
             MSBuildApp.Execute(@"msbuild.exe " + project + " /t:foo.bar").ShouldBe(MSBuildApp.ExitType.SwitchError);
+#else
+            MSBuildApp.Execute(new[] { @"msbuild.exe", project, "/t:foo.bar" }).ShouldBe(MSBuildApp.ExitType.SwitchError);
+#endif
         }
 
         /// <summary>