Skip BuildCheck on restore

src/Build/BackEnd/Components/RequestBuilder/RequestBuilder.cs

@@ -1105,9 +1105,13 @@ private async Task<BuildResult> BuildProject()
             ErrorUtilities.VerifyThrow(_targetBuilder != null, "Target builder is null");
 
             // We consider this the entrypoint for the project build for purposes of BuildCheck processing 
+            bool isRestoring = _requestEntry.RequestConfiguration.GlobalProperties[MSBuildConstants.MSBuildIsRestoring] is null;
 
-            var buildCheckManager = (_componentHost.GetComponent(BuildComponentType.BuildCheckManagerProvider) as IBuildCheckManagerProvider)!.Instance;
-            buildCheckManager.SetDataSource(BuildCheckDataSource.BuildExecution);
+            var buildCheckManager = isRestoring
+                ? (_componentHost.GetComponent(BuildComponentType.BuildCheckManagerProvider) as IBuildCheckManagerProvider)!.Instance
+                : null;
+
+            buildCheckManager?.SetDataSource(BuildCheckDataSource.BuildExecution);
 
             // Make sure it is null before loading the configuration into the request, because if there is a problem
             // we do not wand to have an invalid projectLoggingContext floating around. Also if this is null the error will be
@@ -1121,7 +1125,7 @@ private async Task<BuildResult> BuildProject()
                 // Load the project
                 if (!_requestEntry.RequestConfiguration.IsLoaded)
                 {
-                    buildCheckManager.StartProjectEvaluation(
+                    buildCheckManager?.StartProjectEvaluation(
                         BuildCheckDataSource.BuildExecution,
                         new AnalysisLoggingContext(_nodeLoggingContext.LoggingService, _requestEntry.Request.BuildEventContext),
                         _requestEntry.RequestConfiguration.ProjectFullPath);
@@ -1146,13 +1150,13 @@ private async Task<BuildResult> BuildProject()
             }
             finally
             {
-                buildCheckManager.EndProjectEvaluation(
+                buildCheckManager?.EndProjectEvaluation(
                     BuildCheckDataSource.BuildExecution,
                     _requestEntry.Request.BuildEventContext);
             }
 
             _projectLoggingContext = _nodeLoggingContext.LogProjectStarted(_requestEntry);
-            buildCheckManager.StartProjectRequest(
+            buildCheckManager?.StartProjectRequest(
                 BuildCheckDataSource.BuildExecution,
                 _requestEntry.Request.BuildEventContext,
                 _requestEntry.RequestConfiguration.ProjectFullPath);
@@ -1224,7 +1228,7 @@ private async Task<BuildResult> BuildProject()
             }
             finally
             {
-                buildCheckManager.EndProjectRequest(
+                buildCheckManager?.EndProjectRequest(
                     BuildCheckDataSource.BuildExecution,
                     new AnalysisLoggingContext(_nodeLoggingContext.LoggingService, _requestEntry.Request.BuildEventContext),
                     _requestEntry.RequestConfiguration.ProjectFullPath);

src/Build/BuildCheck/Infrastructure/BuildCheckBuildEventHandler.cs

@@ -10,6 +10,7 @@
 using Microsoft.Build.Experimental.BuildCheck.Acquisition;
 using Microsoft.Build.Experimental.BuildCheck.Utilities;
 using Microsoft.Build.Framework;
+using Microsoft.Build.Shared;
 
 namespace Microsoft.Build.Experimental.BuildCheck.Infrastructure;
 
@@ -20,6 +21,8 @@ internal class BuildCheckBuildEventHandler
 
     private readonly Dictionary<Type, Action<BuildEventArgs>> _eventHandlers;
 
+    private bool isRestoring = false;
+
     internal BuildCheckBuildEventHandler(
         IAnalysisContextFactory analyzerContextFactory,
         IBuildCheckManager buildCheckManager)
@@ -29,6 +32,7 @@ internal BuildCheckBuildEventHandler(
 
         _eventHandlers = new()
         {
+            { typeof(BuildSubmissionStartedEventArgs), (BuildEventArgs e) => HandleBuildSubmissionStartedEvent((BuildSubmissionStartedEventArgs)e) },
             { typeof(ProjectEvaluationFinishedEventArgs), (BuildEventArgs e) => HandleProjectEvaluationFinishedEvent((ProjectEvaluationFinishedEventArgs)e) },
             { typeof(ProjectEvaluationStartedEventArgs), (BuildEventArgs e) => HandleProjectEvaluationStartedEvent((ProjectEvaluationStartedEventArgs)e) },
             { typeof(EnvironmentVariableReadEventArgs), (BuildEventArgs e) => HandleEnvironmentVariableReadEvent((EnvironmentVariableReadEventArgs)e) },
@@ -45,12 +49,34 @@ internal BuildCheckBuildEventHandler(
 
     public void HandleBuildEvent(BuildEventArgs e)
     {
+        // Skip event handling during restore phase
+        if (
+            isRestoring &&
+            e.GetType() != typeof(BuildSubmissionStartedEventArgs) &&
+            e.BuildEventContext is not null)
+        {
+            return;
+        }
+
         if (_eventHandlers.TryGetValue(e.GetType(), out Action<BuildEventArgs>? handler))
         {
             handler(e);
         }
     }
 
+    private void HandleBuildSubmissionStartedEvent(BuildSubmissionStartedEventArgs eventArgs)
+    {
+        if (isRestoring)
+        {
+            isRestoring = false;
+        }
+        else
+        {
+            eventArgs.GlobalProperties.TryGetValue(MSBuildConstants.MSBuildIsRestoring, out string? restoreProperty);
+            isRestoring = restoreProperty is not null ? Convert.ToBoolean(restoreProperty) : false;
+        }
+    }
+
     private void HandleProjectEvaluationFinishedEvent(ProjectEvaluationFinishedEventArgs eventArgs)
     {
         if (!IsMetaProjFile(eventArgs.ProjectFile))

src/Build/BuildCheck/Infrastructure/BuildCheckForwardingLogger.cs

@@ -38,6 +38,7 @@ internal class BuildCheckForwardingLogger : IForwardingLogger
     private HashSet<Type> _eventsToForward = new HashSet<Type>
     {
         typeof(EnvironmentVariableReadEventArgs),
+        typeof(BuildSubmissionStartedEventArgs),
         typeof(ProjectEvaluationFinishedEventArgs),
         typeof(ProjectEvaluationStartedEventArgs),
         typeof(ProjectStartedEventArgs),

src/BuildCheck.UnitTests/EndToEndTests.cs

@@ -274,6 +274,23 @@ public void CustomAnalyzerTest_WithEditorConfig(string analysisCandidate, string
         }
     }
 
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void DoesNotRunOnRestore(bool buildInOutOfProcessNode)
+    {
+        PrepareSampleProjectsAndConfig(buildInOutOfProcessNode, out TransientTestFile projectFile, new List<(string, string)>() { ("BC0101", "warning") });
+
+        string output = RunnerUtilities.ExecBootstrapedMSBuild(
+            $"{Path.GetFileName(projectFile.Path)} /m: -nr:False -t:restore -analyze",
+            out bool success);
+
+        success.ShouldBeTrue();
+        output.ShouldNotContain("BC0101");
+        output.ShouldNotContain("BC0102");
+        output.ShouldNotContain("BC0103");
+    }
+
     private void AddCustomDataSourceToNugetConfig(string analysisCandidatePath)
     {
         var nugetTemplatePath = Path.Combine(analysisCandidatePath, "nugetTemplate.config");