Remove feature flag as per the offline discussion

src/Compilers/CSharp/Test/CommandLine/CommandLineTests.cs

@@ -10770,7 +10770,7 @@ long M(int i)
             // and info diagnostic is logged with programmatic suppression information.
             var suppressor = new DiagnosticSuppressorForId("CS0078");
             output = VerifyOutput(srcDirectory, srcFile, expectedInfoCount: 1, expectedWarningCount: 0, expectedErrorCount: 0,
-                additionalFlags: new[] { "/warnAsError", "/features:DiagnosticSuppressor" },
+                additionalFlags: new[] { "/warnAsError" },
                 includeCurrentAssemblyAsAnalyzerReference: false,
                 analyzers: suppressor);
             Assert.DoesNotContain($"error CS0078", output, StringComparison.Ordinal);
@@ -10824,21 +10824,20 @@ void M(int i)
                 suppressor.SuppressionDescriptor.Justification);
 
             output = VerifyOutput(srcDirectory, srcFile, expectedInfoCount: 1, expectedWarningCount: 0, includeCurrentAssemblyAsAnalyzerReference: false,
-                analyzers: suppressor,
-                additionalFlags: new[] { "/features:DiagnosticSuppressor" });
+                analyzers: suppressor);
             Assert.DoesNotContain($"warning CS1522", output, StringComparison.Ordinal);
             Assert.Contains($"info SP0001", output, StringComparison.Ordinal);
             Assert.Contains(suppressionMessage, output, StringComparison.Ordinal);
 
             // Verify that compiler warning CS1522 is reported as error for /warnaserror.
             output = VerifyOutput(srcDirectory, srcFile, expectedErrorCount: 1,
-                additionalFlags: new[] { "/warnAsError", "/features:DiagnosticSuppressor" }, includeCurrentAssemblyAsAnalyzerReference: false);
+                additionalFlags: new[] { "/warnAsError" }, includeCurrentAssemblyAsAnalyzerReference: false);
             Assert.Contains("error CS1522", output, StringComparison.Ordinal);
 
             // Verify that compiler warning CS1522 is suppressed with diagnostic suppressor even with /warnaserror
             // and info diagnostic is logged with programmatic suppression information.
             output = VerifyOutput(srcDirectory, srcFile, expectedInfoCount: 1, expectedWarningCount: 0, expectedErrorCount: 0,
-                additionalFlags: new[] { "/warnAsError", "/features:DiagnosticSuppressor" },
+                additionalFlags: new[] { "/warnAsError" },
                 includeCurrentAssemblyAsAnalyzerReference: false,
                 analyzers: suppressor);
             Assert.DoesNotContain($"error CS1522", output, StringComparison.Ordinal);
@@ -10879,21 +10878,20 @@ class C
                 suppressor.SuppressionDescriptor.Justification);
 
             output = VerifyOutput(srcDirectory, srcFile, expectedInfoCount: 1, expectedWarningCount: 0, includeCurrentAssemblyAsAnalyzerReference: false,
-                analyzers: suppressor,
-                additionalFlags: new[] { "/features:DiagnosticSuppressor" });
+                analyzers: suppressor);
             Assert.DoesNotContain($"warning CS0169", output, StringComparison.Ordinal);
             Assert.Contains("info SP0001", output, StringComparison.Ordinal);
             Assert.Contains(suppressionMessage, output, StringComparison.Ordinal);
 
             // Verify that compiler warning CS0169 is reported as error for /warnaserror.
             output = VerifyOutput(srcDirectory, srcFile, expectedErrorCount: 1,
-                additionalFlags: new[] { "/warnAsError", "/features:DiagnosticSuppressor" }, includeCurrentAssemblyAsAnalyzerReference: false);
+                additionalFlags: new[] { "/warnAsError" }, includeCurrentAssemblyAsAnalyzerReference: false);
             Assert.Contains("error CS0169", output, StringComparison.Ordinal);
 
             // Verify that compiler warning CS0169 is suppressed with diagnostic suppressor even with /warnaserror
             // and info diagnostic is logged with programmatic suppression information.
             output = VerifyOutput(srcDirectory, srcFile, expectedInfoCount: 1, expectedWarningCount: 0, expectedErrorCount: 0,
-                additionalFlags: new[] { "/warnAsError", "/features:DiagnosticSuppressor" },
+                additionalFlags: new[] { "/warnAsError" },
                 includeCurrentAssemblyAsAnalyzerReference: false,
                 analyzers: suppressor);
             Assert.DoesNotContain($"error CS0169", output, StringComparison.Ordinal);
@@ -10921,8 +10919,7 @@ class { }";
 
             // Verify that compiler syntax error CS1001 cannot be suppressed with diagnostic suppressor.
             output = VerifyOutput(srcDirectory, srcFile, expectedErrorCount: 1, includeCurrentAssemblyAsAnalyzerReference: false,
-                analyzers: new DiagnosticSuppressorForId("CS1001"),
-                additionalFlags: new[] { "/features:DiagnosticSuppressor" });
+                analyzers: new DiagnosticSuppressorForId("CS1001"));
             Assert.Contains("error CS1001", output, StringComparison.Ordinal);
 
             CleanupAllGeneratedFiles(srcFile.Path);
@@ -10948,8 +10945,7 @@ class C
 
             // Verify that compiler error CS0246 cannot be suppressed with diagnostic suppressor.
             output = VerifyOutput(srcDirectory, srcFile, expectedErrorCount: 1, includeCurrentAssemblyAsAnalyzerReference: false,
-                analyzers: new DiagnosticSuppressorForId("CS0246"),
-                additionalFlags: new[] { "/features:DiagnosticSuppressor" });
+                analyzers: new DiagnosticSuppressorForId("CS0246"));
             Assert.Contains("error CS0246", output, StringComparison.Ordinal);
 
             CleanupAllGeneratedFiles(srcFile.Path);
@@ -10986,15 +10982,14 @@ class C { }";
             var analyzerAndSuppressor = new DiagnosticAnalyzer[] { analyzer, suppressor };
             output = VerifyOutput(srcDirectory, srcFile, expectedInfoCount: 1, expectedWarningCount: 0,
                 includeCurrentAssemblyAsAnalyzerReference: false,
-                analyzers: analyzerAndSuppressor,
-                additionalFlags: new[] { "/features:DiagnosticSuppressor" });
+                analyzers: analyzerAndSuppressor);
             Assert.DoesNotContain($"warning {analyzer.Descriptor.Id}", output, StringComparison.Ordinal);
             Assert.Contains("info SP0001", output, StringComparison.Ordinal);
             Assert.Contains(suppressionMessage, output, StringComparison.Ordinal);
 
             // Verify that analyzer warning is reported as error for /warnaserror.
             output = VerifyOutput(srcDirectory, srcFile, expectedErrorCount: 1,
-                additionalFlags: new[] { "/warnAsError", "/features:DiagnosticSuppressor" },
+                additionalFlags: new[] { "/warnAsError" },
                 includeCurrentAssemblyAsAnalyzerReference: false,
                 analyzers: analyzer);
             Assert.Contains($"error {analyzer.Descriptor.Id}", output, StringComparison.Ordinal);
@@ -11002,7 +10997,7 @@ class C { }";
             // Verify that analyzer warning is suppressed with diagnostic suppressor even with /warnaserror
             // and info diagnostic is logged with programmatic suppression information.
             output = VerifyOutput(srcDirectory, srcFile, expectedInfoCount: 1, expectedWarningCount: 0,
-                additionalFlags: new[] { "/warnAsError", "/features:DiagnosticSuppressor" },
+                additionalFlags: new[] { "/warnAsError" },
                 includeCurrentAssemblyAsAnalyzerReference: false,
                 analyzers: analyzerAndSuppressor);
             Assert.DoesNotContain($"warning {analyzer.Descriptor.Id}", output, StringComparison.Ordinal);
@@ -11015,8 +11010,7 @@ class C { }";
             analyzerAndSuppressor = new DiagnosticAnalyzer[] { analyzer, suppressor };
             output = VerifyOutput(srcDirectory, srcFile, expectedWarningCount: 1,
                 includeCurrentAssemblyAsAnalyzerReference: false,
-                analyzers: analyzerAndSuppressor,
-                additionalFlags: new[] { "/features:DiagnosticSuppressor" });
+                analyzers: analyzerAndSuppressor);
             Assert.Contains($"warning {analyzer.Descriptor.Id}", output, StringComparison.Ordinal);
 
             CleanupAllGeneratedFiles(srcFile.Path);
@@ -11044,8 +11038,7 @@ class C { }";
             var analyzerAndSuppressor = new DiagnosticAnalyzer[] { analyzer, suppressor };
             output = VerifyOutput(srcDirectory, srcFile, expectedErrorCount: 1,
                 includeCurrentAssemblyAsAnalyzerReference: false,
-                analyzers: analyzerAndSuppressor,
-                additionalFlags: new[] { "/features:DiagnosticSuppressor" });
+                analyzers: analyzerAndSuppressor);
             Assert.Contains($"error {analyzer.Descriptor.Id}", output, StringComparison.Ordinal);
 
             CleanupAllGeneratedFiles(srcFile.Path);

src/Compilers/CSharp/Test/Semantic/Diagnostics/DiagnosticSuppressorTests.cs

@@ -42,7 +42,7 @@ void M(int i)
     }
 }";
 
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics(
                 // (7,9): warning CS1522: Empty switch block
                 //         {
@@ -65,7 +65,7 @@ class C
     // warning CS0169: The field 'C.f' is never used
     private readonly int f;
 }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics(
                 // (5,26): warning CS0169: The field 'C.f' is never used
                 //     private readonly int f;
@@ -85,7 +85,7 @@ public void TestNoSuppression_CompilerSyntaxError()
             string source = @"
 class { }";
 
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
 
             compilation.VerifyDiagnostics(
                 // (2,7): error CS1001: Identifier expected
@@ -106,7 +106,7 @@ class C
     void M(UndefinedType x) { }
 }";
 
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
 
             compilation.VerifyDiagnostics(
                 // (4,12): error CS0246: The type or namespace name 'UndefinedType' could not be found (are you missing a using directive or an assembly reference?)
@@ -123,7 +123,7 @@ public void TestSuppression_MultipleDiagnostics()
         {
             string source1 = @"class C1 { }";
             string source2 = @"class C2 { }";
-            var compilation = CreateCompilation(new[] { source1, source2 }, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(new[] { source1, source2 });
             compilation.VerifyDiagnostics();
 
             var analyzer = new CompilationAnalyzerWithSeverity(DiagnosticSeverity.Warning, configurable: true);
@@ -141,7 +141,7 @@ public void TestSuppression_MultipleDiagnostics()
         public void TestSuppression_MultipleSuppressors_SameDiagnostic()
         {
             string source = @"class C1 { }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             var analyzer = new CompilationAnalyzerWithSeverity(DiagnosticSeverity.Warning, configurable: true);
@@ -161,7 +161,7 @@ public void TestSuppression_MultipleSuppressors_SameDiagnostic()
         public void TestSuppression_MultipleSuppressors_DifferentDiagnostic()
         {
             string source = @"class C1 { private readonly int f; }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics(
                 // (1,33): warning CS0169: The field 'C1.f' is never used
                 // class C1 { private readonly int f; }
@@ -184,7 +184,7 @@ public void TestSuppression_MultipleSuppressors_DifferentDiagnostic()
         public void TestNoSuppression_SpecificOptionsTurnsOffSuppressor()
         {
             string source = @"class C1 { }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             var analyzer = new CompilationAnalyzerWithSeverity(DiagnosticSeverity.Warning, configurable: true);
@@ -200,34 +200,12 @@ public void TestNoSuppression_SpecificOptionsTurnsOffSuppressor()
             VerifySuppressedDiagnostics(compilation, analyzersAndSuppressors);
         }
 
-        [Fact, WorkItem(20242, "https://github.com/dotnet/roslyn/issues/20242")]
-        public void TestDiagnosticOnMissingFeatureFlag()
-        {
-            string source = @"class C1 { }";
-            var compilation = CreateCompilation(source);
-            compilation.VerifyDiagnostics();
-
-            var analyzer = new CompilationAnalyzerWithSeverity(DiagnosticSeverity.Warning, configurable: true);
-            var analyzerDiagnostic = Diagnostic(analyzer.Descriptor.Id, source);
-            VerifyAnalyzerDiagnostics(compilation, new DiagnosticAnalyzer[] { analyzer }, analyzerDiagnostic);
-
-            var analyzersAndSuppressors = new DiagnosticAnalyzer[] { analyzer, new DiagnosticSuppressorForId(analyzer.Descriptor.Id, "SPR1001") };
-            var expectedDiagnostics = new[]
-            {
-                analyzerDiagnostic,
-                Diagnostic("AD0001").WithArguments("Microsoft.CodeAnalysis.CommonDiagnosticAnalyzers+DiagnosticSuppressorForId",
-                                                   "System.ArgumentException",
-                                                   CodeAnalysisResources.DiagnosticSuppressorFeatureDisabled).WithLocation(1, 1)
-            };
-            VerifyAnalyzerDiagnostics(compilation, analyzersAndSuppressors, expectedDiagnostics);
-        }
-
         [Fact, WorkItem(20242, "https://github.com/dotnet/roslyn/issues/20242")]
         public void TestSuppression_AnalyzerDiagnostics_SeveritiesAndConfigurableMatrix()
         {
             string source = @"
 class C { }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             var configurations = new[] { false, true };
@@ -286,7 +264,7 @@ public void TestExceptionFromSuppressor()
             string source = @"
 class C { }";
 
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             var analyzer = new CompilationAnalyzerWithSeverity(DiagnosticSeverity.Warning, configurable: true);
@@ -315,7 +293,7 @@ public void TestUnsupportedSuppressionReported()
             string source = @"
 class C { }";
 
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             const string supportedSuppressionId = "supportedId";
@@ -342,7 +320,7 @@ public void TestInvalidDiagnosticSuppressionReported()
         {
             string source = @"
 class C { }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             const string unsupportedSuppressedId = "UnsupportedId";
@@ -368,7 +346,7 @@ public void TestNonReportedDiagnosticCannotBeSuppressed()
         {
             string source = @"
 class C { }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             const string nonReportedDiagnosticId = "NonReportedId";
@@ -393,7 +371,7 @@ class C { }";
         public void TestProgrammaticSuppressionInfo_DiagnosticSuppressor()
         {
             string source = @"class C1 { }";
-            var compilation = CreateCompilation(source, parseOptions: TestOptions.RegularWithDiagnosticSuppressorFeature);
+            var compilation = CreateCompilation(source);
             compilation.VerifyDiagnostics();
 
             var analyzer = new CompilationAnalyzerWithSeverity(DiagnosticSeverity.Warning, configurable: true);

src/Compilers/Core/Portable/CodeAnalysisResources.Designer.cs

@@ -458,15 +458,6 @@ internal class CodeAnalysisResources {
             }
         }
         
-        /// <summary>
-        ///   Looks up a localized string similar to Feature &apos;DiagnosticSuppressor&apos; is disabled..
-        /// </summary>
-        internal static string DiagnosticSuppressorFeatureDisabled {
-            get {
-                return ResourceManager.GetString("DiagnosticSuppressorFeatureDisabled", resourceCulture);
-            }
-        }
-        
         /// <summary>
         ///   Looks up a localized string similar to Argument contains duplicate analyzer instances..
         /// </summary>

src/Compilers/Core/Portable/CodeAnalysisResources.resx

@@ -660,9 +660,6 @@
   <data name="WRN_InvalidSeverityInAnalyzerConfig_Title" xml:space="preserve">
     <value>Invalid severity in analyzer config file.</value>
   </data>
-  <data name="DiagnosticSuppressorFeatureDisabled" xml:space="preserve">
-    <value>Feature 'DiagnosticSuppressor' is disabled.</value>
-  </data>
   <data name="SuppressionDiagnosticDescriptorTitle" xml:space="preserve">
     <value>Programmatic suppression of an analyzer diagnostic</value>
   </data>

src/Compilers/Core/Portable/DiagnosticAnalyzer/AnalyzerDriver.cs

@@ -25,9 +25,6 @@ internal abstract partial class AnalyzerDriver : IDisposable
         // Protect against vicious analyzers that provide large values for SymbolKind.
         private const int MaxSymbolKind = 100;
 
-        // Feature flag for DiagnosticSuppressor feature
-        internal const string DiagnosticSuppressorFeatureName = "DiagnosticSuppressor";
-
         // Cache delegates for static methods
         private static readonly Func<DiagnosticAnalyzer, bool> s_IsCompilerAnalyzerFunc = IsCompilerAnalyzer;
 

src/Compilers/Core/Portable/DiagnosticAnalyzer/DiagnosticAnalysisContext.cs

@@ -1528,11 +1528,6 @@ public void ReportSuppression(Suppression suppression)
                 throw new ArgumentException(message);
             }
 
-            if (!Compilation.SyntaxTrees.Any(t => t.Options.Features.ContainsKey(AnalyzerDriver.DiagnosticSuppressorFeatureName)))
-            {
-                throw new ArgumentException(CodeAnalysisResources.DiagnosticSuppressorFeatureDisabled);
-            }
-
             if (suppression.Descriptor.IsDisabled(Compilation.Options))
             {
                 // Suppression has been disabled by the end user through compilation options.

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.cs.xlf

@@ -19,11 +19,6 @@
 {1}.</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.de.xlf

@@ -19,11 +19,6 @@
 "{1}".</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.es.xlf

@@ -19,11 +19,6 @@
 '{1}'.</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.fr.xlf

@@ -19,11 +19,6 @@
 '{1}'.</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.it.xlf

@@ -19,11 +19,6 @@
 '{1}'.</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ja.xlf

@@ -19,11 +19,6 @@
 '{1}'。</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ko.xlf

@@ -19,11 +19,6 @@
 '{1}'</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.pl.xlf

@@ -19,11 +19,6 @@
 „{1}”.</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.pt-BR.xlf

@@ -19,11 +19,6 @@
 '{1}'.</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ru.xlf

@@ -19,11 +19,6 @@
 "{1}".</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.tr.xlf

@@ -19,11 +19,6 @@
 '{1}'.</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.zh-Hans.xlf

@@ -19,11 +19,6 @@
 “{1}”。</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.zh-Hant.xlf

@@ -19,11 +19,6 @@
 '{1}'。</target>
         <note />
       </trans-unit>
-      <trans-unit id="DiagnosticSuppressorFeatureDisabled">
-        <source>Feature 'DiagnosticSuppressor' is disabled.</source>
-        <target state="new">Feature 'DiagnosticSuppressor' is disabled.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="InvalidDiagnosticSuppressionReported">
         <source>Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</source>
         <target state="new">Suppressed diagnostic ID '{0}' does not match suppressable ID '{1}' for the given suppression descriptor.</target>

src/Compilers/Test/Utilities/CSharp/TestOptions.cs

@@ -43,8 +43,6 @@ public static class TestOptions
         public static readonly CSharpParseOptions RegularWithoutRecursivePatterns = Regular7_3;
         public static readonly CSharpParseOptions RegularWithRecursivePatterns = Regular8;
 
-        public static readonly CSharpParseOptions RegularWithDiagnosticSuppressorFeature = Regular.WithDiagnosticSuppressorFeature();
-
         public static readonly CSharpCompilationOptions ReleaseDll = new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary, optimizationLevel: OptimizationLevel.Release);
         public static readonly CSharpCompilationOptions ReleaseExe = new CSharpCompilationOptions(OutputKind.ConsoleApplication, optimizationLevel: OptimizationLevel.Release);
 
@@ -136,11 +134,6 @@ public static CSharpCompilationOptions WithSpecificDiagnosticOptions(this CSharp
         {
             return options.WithSpecificDiagnosticOptions(ImmutableDictionary<string, ReportDiagnostic>.Empty.Add(key1, value).Add(key2, value));
         }
-
-        public static CSharpParseOptions WithDiagnosticSuppressorFeature(this CSharpParseOptions options)
-        {
-            return options.WithFeatures(options.Features.Concat(new[] { new KeyValuePair<string, string>(AnalyzerDriver.DiagnosticSuppressorFeatureName, "true") }));
-        }
     }
 }
 

src/Compilers/Test/Utilities/VisualBasic/TestOptions.vb

@@ -11,7 +11,6 @@ Public Class TestOptions
     Public Shared ReadOnly Regular As New VisualBasicParseOptions(kind:=SourceCodeKind.Regular, languageVersion:=LanguageVersion.VisualBasic16)
     Public Shared ReadOnly Regular15_5 As VisualBasicParseOptions = Regular.WithLanguageVersion(LanguageVersion.VisualBasic15_5)
     Public Shared ReadOnly RegularWithLegacyStrongName As VisualBasicParseOptions = Regular.WithFeature("UseLegacyStrongNameProvider")
-    Public Shared ReadOnly RegularWithDiagnosticSuppressorFeature As VisualBasicParseOptions = Regular.WithDiagnosticSuppressorFeature()
 
     Public Shared ReadOnly ReleaseDll As VisualBasicCompilationOptions = New VisualBasicCompilationOptions(OutputKind.DynamicallyLinkedLibrary, optimizationLevel:=OptimizationLevel.Release).WithParseOptions(Regular)
     Public Shared ReadOnly ReleaseExe As VisualBasicCompilationOptions = New VisualBasicCompilationOptions(OutputKind.ConsoleApplication, optimizationLevel:=OptimizationLevel.Release).WithParseOptions(Regular)
@@ -62,9 +61,4 @@ Friend Module TestOptionExtensions
         Next
         Return options.WithFeatures(options.Features.Concat(list))
     End Function
-
-    <Extension()>
-    Public Function WithDiagnosticSuppressorFeature(options As VisualBasicParseOptions) As VisualBasicParseOptions
-        Return options.WithFeatures(options.Features.Concat({New KeyValuePair(Of String, String)(AnalyzerDriver.DiagnosticSuppressorFeatureName, "true")}))
-    End Function
 End Module

src/Compilers/VisualBasic/Test/CommandLine/CommandLineTests.vb

@@ -9377,8 +9377,7 @@ End Class"
             Dim suppressors = ImmutableArray.Create(Of DiagnosticAnalyzer)(suppressor)
             output = VerifyOutput(dir, file, expectedInfoCount:=1, expectedWarningCount:=0,
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
-                                  analyzers:=suppressors,
-                                  additionalFlags:={"/features:DiagnosticSuppressor"})
+                                  analyzers:=suppressors)
             Assert.DoesNotContain("warning BC40008", output, StringComparison.Ordinal)
             Assert.Contains("info SP0001", output, StringComparison.Ordinal)
             Assert.Contains(suppressionMessage, output, StringComparison.Ordinal)
@@ -9410,7 +9409,7 @@ End Class"
             Assert.Contains("warning BC40008", output, StringComparison.Ordinal)
 
             ' Verify that compiler warning BC40008 is reported as error for /warnaserror.
-            output = VerifyOutput(dir, file, expectedErrorCount:=1, additionalFlags:={"/warnaserror+", "/features:DiagnosticSuppressor"},
+            output = VerifyOutput(dir, file, expectedErrorCount:=1, additionalFlags:={"/warnaserror+"},
                                   includeCurrentAssemblyAsAnalyzerReference:=False)
             Assert.Contains("error BC40008", output, StringComparison.Ordinal)
 
@@ -9420,7 +9419,7 @@ End Class"
 
             Dim suppressors = ImmutableArray.Create(Of DiagnosticAnalyzer)(suppressor)
             output = VerifyOutput(dir, file, expectedInfoCount:=1, expectedWarningCount:=0, expectedErrorCount:=0,
-                                  additionalFlags:={"/warnaserror+", "/features:DiagnosticSuppressor"},
+                                  additionalFlags:={"/warnaserror+"},
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
                                   analyzers:=suppressors)
             Assert.DoesNotContain($"warning BC40008", output, StringComparison.Ordinal)
@@ -9458,8 +9457,7 @@ End Class"
             Dim analyzers = ImmutableArray.Create(Of DiagnosticAnalyzer)(New DiagnosticSuppressorForId("BC30203"))
             output = VerifyOutput(dir, file, expectedErrorCount:=1,
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
-                                  analyzers:=analyzers,
-                                  additionalFlags:={"/features:DiagnosticSuppressor"})
+                                  analyzers:=analyzers)
             Assert.Contains("error BC30203", output, StringComparison.Ordinal)
 
             CleanupAllGeneratedFiles(file.Path)
@@ -9497,15 +9495,14 @@ End Class"
             Dim analyzerAndSuppressor = ImmutableArray.Create(Of DiagnosticAnalyzer)(analyzer, suppressor)
             output = VerifyOutput(dir, file, expectedInfoCount:=1, expectedWarningCount:=0,
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
-                                  analyzers:=analyzerAndSuppressor,
-                                  additionalFlags:={"/features:DiagnosticSuppressor"})
+                                  analyzers:=analyzerAndSuppressor)
             Assert.DoesNotContain($"warning {analyzer.Descriptor.Id}", output, StringComparison.Ordinal)
             Assert.Contains("info SP0001", output, StringComparison.Ordinal)
             Assert.Contains(suppressionMessage, output, StringComparison.Ordinal)
 
             ' Verify that analyzer warning is reported as error for /warnaserror.
             output = VerifyOutput(dir, file, expectedErrorCount:=1,
-                                  additionalFlags:={"/warnaserror+", "/features:DiagnosticSuppressor"},
+                                  additionalFlags:={"/warnaserror+"},
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
                                   analyzers:=analyzers)
             Assert.Contains($"error {analyzer.Descriptor.Id}", output, StringComparison.Ordinal)
@@ -9513,7 +9510,7 @@ End Class"
             ' Verify that analyzer warning is suppressed with diagnostic suppressor even with /warnaserror
             ' and info diagnostic is logged with programmatic suppression information.
             output = VerifyOutput(dir, file, expectedInfoCount:=1, expectedWarningCount:=0, expectedErrorCount:=0,
-                                  additionalFlags:={"/warnaserror+", "/features:DiagnosticSuppressor"},
+                                  additionalFlags:={"/warnaserror+"},
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
                                   analyzers:=analyzerAndSuppressor)
             Assert.DoesNotContain($"warning {analyzer.Descriptor.Id}", output, StringComparison.Ordinal)
@@ -9526,8 +9523,7 @@ End Class"
             analyzerAndSuppressor = ImmutableArray.Create(Of DiagnosticAnalyzer)(analyzer, suppressor)
             output = VerifyOutput(dir, file, expectedWarningCount:=1,
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
-                                  analyzers:=analyzerAndSuppressor,
-                                  additionalFlags:={"/features:DiagnosticSuppressor"})
+                                  analyzers:=analyzerAndSuppressor)
             Assert.Contains($"warning {analyzer.Descriptor.Id}", output, StringComparison.Ordinal)
 
             CleanupAllGeneratedFiles(file.Path)
@@ -9556,8 +9552,7 @@ End Class"
             Dim analyzerAndSuppressor = ImmutableArray.Create(Of DiagnosticAnalyzer)(analyzer, suppressor)
             output = VerifyOutput(dir, file, expectedErrorCount:=1,
                                   includeCurrentAssemblyAsAnalyzerReference:=False,
-                                  analyzers:=analyzerAndSuppressor,
-                                  additionalFlags:={"/features:DiagnosticSuppressor"})
+                                  analyzers:=analyzerAndSuppressor)
             Assert.Contains($"error {analyzer.Descriptor.Id}", output, StringComparison.Ordinal)
 
             CleanupAllGeneratedFiles(file.Path)