Embed AnalyzerConfigFiles in binlog

src/Compilers/Core/MSBuildTask/Microsoft.CSharp.Core.targets

@@ -59,6 +59,14 @@
                    @(CustomAdditionalCompileOutputs)"
           Returns="@(CscCommandLineArgs)"
           DependsOnTargets="$(CoreCompileDependsOn);_BeforeVBCSCoreCompile">
+
+    <!-- Embed EditorConfigFiles into the binary log. This is done here (inside CoreCompile rather than
+         a static ItemGroup) to ensure EditorConfigFiles added by analyzer packages in
+         BeforeTargets="CoreCompile" targets (e.g. NetAnalyzers, CodeStyle) are captured. -->
+    <ItemGroup>
+      <EmbedInBinlog Include="@(EditorConfigFiles)" />
+    </ItemGroup>
+
     <!-- These two compiler warnings are raised when a reference is bound to a different version
              than specified in the assembly reference version number.  MSBuild raises the same warning in this case,
              so the compiler warning would be redundant. -->

src/Compilers/Core/MSBuildTask/Microsoft.VisualBasic.Core.targets

@@ -30,6 +30,14 @@
                    @(CustomAdditionalCompileOutputs)"
           Returns="@(VbcCommandLineArgs)"
           DependsOnTargets="$(CoreCompileDependsOn);_BeforeVBCSCoreCompile">
+
+    <!-- Embed EditorConfigFiles into the binary log. This is done here (inside CoreCompile rather than
+         a static ItemGroup) to ensure EditorConfigFiles added by analyzer packages in
+         BeforeTargets="CoreCompile" targets (e.g. NetAnalyzers, CodeStyle) are captured. -->
+    <ItemGroup>
+      <EmbedInBinlog Include="@(EditorConfigFiles)" />
+    </ItemGroup>
+
     <PropertyGroup>
       <_NoWarnings Condition="'$(WarningLevel)' == '0'">true</_NoWarnings>
       <_NoWarnings Condition="'$(WarningLevel)' == '1'">false</_NoWarnings>

src/Compilers/Core/MSBuildTaskTests/DotNetSdkTests.cs

@@ -654,5 +654,49 @@ public void TestGlobalConfigsCanBeManuallyAdded()
                     "mycustom.config"
                 }));
         }
+
+        [ConditionalFact(typeof(DotNetSdkAvailable))]
+        public void TestEditorConfigFilesAddedByAnalyzerPackagesAreEmbeddedInBinlog()
+        {
+            // Simulate the behavior of analyzer packages (e.g., NetAnalyzers, CodeStyle) that add
+            // EditorConfigFiles in a target that runs BeforeTargets="CoreCompile". Verify those files
+            // are included in @(EmbedInBinlog) so they are captured in the binary log.
+            var srcFile = ProjectDir.CreateFile("lib1.cs").WriteAllText("class C { }");
+            var analyzerGlobalConfig = ProjectDir.CreateFile("analyzer.globalconfig").WriteAllText("""
+                is_global = true
+                some_prop = some_val
+                """);
+
+            VerifyValues(
+                customProps: """
+                  <PropertyGroup>
+                    <!-- Disable automatic discovery and MSBuild EditorConfig generation for deterministic results -->
+                    <DiscoverEditorConfigFiles>false</DiscoverEditorConfigFiles>
+                    <DiscoverGlobalAnalyzerConfigFiles>false</DiscoverGlobalAnalyzerConfigFiles>
+                    <GenerateMSBuildEditorConfigFile>false</GenerateMSBuildEditorConfigFile>
+                  </PropertyGroup>
+                  """,
+                customTargets: $"""
+                  <!-- Simulate an analyzer package (e.g. NetAnalyzers) adding an EditorConfigFile
+                       in a target that runs before CoreCompile. -->
+                  <Target Name="AddAnalyzerPackageEditorConfigFile" BeforeTargets="CoreCompile">
+                    <ItemGroup>
+                      <EditorConfigFiles Include="{analyzerGlobalConfig.Path}" />
+                    </ItemGroup>
+                  </Target>
+                  """,
+                targets: new[]
+                {
+                    "CoreCompile"
+                },
+                expressions: new[]
+                {
+                    "@(EmbedInBinlog)"
+                },
+                expectedResults: new[]
+                {
+                    analyzerGlobalConfig.Path
+                });
+        }
     }
 }

src/Compilers/Core/MSBuildTaskTests/TargetTests.cs

@@ -540,6 +540,35 @@ public void GenerateEditorConfigIsPassedToTheCompiler()
             Assert.Single(items);
         }
 
+        [Fact]
+        [WorkItem("https://github.com/dotnet/roslyn/issues/82721")]
+        public void GenerateEditorConfigIsEmbeddedInBinlog()
+        {
+            XmlReader xmlReader = XmlReader.Create(new StringReader($"""
+<Project>
+    <Import Project="Microsoft.Managed.Core.targets" />
+
+    <ItemGroup>
+        <CompilerVisibleProperty Include="prop" />
+    </ItemGroup>
+</Project>
+"""));
+
+            var instance = CreateProjectInstance(xmlReader);
+
+            bool runSuccess = instance.Build(target: "GenerateMSBuildEditorConfigFile", GetTestLoggers());
+            Assert.True(runSuccess);
+
+            var editorConfigItems = instance.GetItems("EditorConfigFiles");
+            var embedInBinlogItems = instance.GetItems("EmbedInBinlog");
+            Assert.Single(editorConfigItems);
+
+            var embeddedEditorConfig = embedInBinlogItems.Single(item => item.EvaluatedInclude == editorConfigItems.Single().EvaluatedInclude);
+            var fileContents = File.ReadAllText(embeddedEditorConfig.EvaluatedInclude);
+            Assert.Contains("is_global = true", fileContents);
+            Assert.Contains("build_property.prop", fileContents);
+        }
+
         [Fact]
         public void AdditionalFilesAreAddedToNoneWhenCopied()
         {

src/Compilers/Core/MSBuildTaskTests/TestUtilities/DotNetSdkTestBase.cs

@@ -133,6 +133,9 @@ private static void EmitTestHelperTargets(
   <!-- Overwrite CoreCompile target to avoid triggering the compiler -->
   <Target Name=""CoreCompile""
           DependsOnTargets=""$(CoreCompileDependsOn);_BeforeVBCSCoreCompile"">
+    <ItemGroup>
+      <EmbedInBinlog Include=""@(EditorConfigFiles)"" />
+    </ItemGroup>
   </Target>
 
   <Target Name=""InitializeSourceControlInformation""/>