diff --git a/pkg/analysis_server/test/context_manager_test.dart b/pkg/analysis_server/test/context_manager_test.dart
index 3fa52ffbc6b..bf3f07d8757 100644
--- a/pkg/analysis_server/test/context_manager_test.dart
+++ b/pkg/analysis_server/test/context_manager_test.dart
@@ -7,6 +7,7 @@ import 'dart:async';
 import 'package:analysis_server/src/context_manager.dart';
 import 'package:analysis_server/src/plugin/notification_manager.dart';
 import 'package:analysis_server/src/utilities/null_string_sink.dart';
+import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/exception/exception.dart';
 import 'package:analyzer/file_system/file_system.dart';
@@ -1939,7 +1940,7 @@ include: package:boo/other_options.yaml
     var synchronousSession = SynchronousSession(analysisOptions, null);
     List<int> bytes =
         SummaryBuilder([], AnalysisContextImpl(synchronousSession, null))
-            .build();
+            .build(featureSet: FeatureSet.fromEnableFlags([]));
     newFileWithBytes('$projPath/sdk.ds', bytes);
     // Setup _embedder.yaml.
     newFile('$libPath/_embedder.yaml', content: r'''
diff --git a/pkg/analyzer/lib/src/summary/summary_file_builder.dart b/pkg/analyzer/lib/src/summary/summary_file_builder.dart
index 539395171f6..0083fedcdc6 100644
--- a/pkg/analyzer/lib/src/summary/summary_file_builder.dart
+++ b/pkg/analyzer/lib/src/summary/summary_file_builder.dart
@@ -22,6 +22,7 @@ import 'package:analyzer/src/summary/summarize_elements.dart';
 import 'package:analyzer/src/summary2/link.dart' as summary2;
 import 'package:analyzer/src/summary2/linked_element_factory.dart' as summary2;
 import 'package:analyzer/src/summary2/reference.dart' as summary2;
+import 'package:meta/meta.dart';
 
 class SummaryBuilder {
   final Iterable<Source> librarySources;
@@ -63,11 +64,16 @@ class SummaryBuilder {
   /**
    * Build the linked bundle and return its bytes.
    */
-  List<int> build() => _Builder(context, librarySources).build();
+  List<int> build({
+    @required FeatureSet featureSet,
+  }) {
+    return _Builder(context, featureSet, librarySources).build();
+  }
 }
 
 class _Builder {
   final AnalysisContext context;
+  final FeatureSet featureSet;
   final Iterable<Source> librarySources;
 
   final Set<String> libraryUris = <String>{};
@@ -75,7 +81,7 @@ class _Builder {
 
   final PackageBundleAssembler bundleAssembler = PackageBundleAssembler();
 
-  _Builder(this.context, this.librarySources);
+  _Builder(this.context, this.featureSet, this.librarySources);
 
   /**
    * Build the linked bundle and return its bytes.
@@ -132,14 +138,12 @@ class _Builder {
     AnalysisErrorListener errorListener = AnalysisErrorListener.NULL_LISTENER;
     String code = source.contents.data;
     CharSequenceReader reader = CharSequenceReader(code);
-    // TODO(paulberry): figure out the appropriate featureSet to use here
-    var featureSet = FeatureSet.fromEnableFlags([]);
     Scanner scanner = Scanner(source, reader, errorListener)
       ..configureFeatures(featureSet);
     Token token = scanner.tokenize();
     LineInfo lineInfo = LineInfo(scanner.lineStarts);
     Parser parser = Parser(source, errorListener,
-        featureSet: featureSet,
+        featureSet: scanner.featureSet,
         useFasta: context.analysisOptions.useFastaParser);
     parser.enableOptionalNewAndConst = true;
     CompilationUnit unit = parser.parseCompilationUnit(token);
diff --git a/pkg/analyzer/lib/src/test_utilities/mock_sdk.dart b/pkg/analyzer/lib/src/test_utilities/mock_sdk.dart
index b3fcd5860de..546b07bf847 100644
--- a/pkg/analyzer/lib/src/test_utilities/mock_sdk.dart
+++ b/pkg/analyzer/lib/src/test_utilities/mock_sdk.dart
@@ -2,6 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/context/context.dart';
@@ -1022,7 +1023,10 @@ class MockSdk implements DartSdk {
     List<Source> librarySources = sdkLibraries
         .map((SdkLibrary library) => mapDartUri(library.shortName))
         .toList();
-    return SummaryBuilder(librarySources, context).build();
+    var featureSet = FeatureSet.fromEnableFlags([]);
+    return SummaryBuilder(librarySources, context).build(
+      featureSet: featureSet,
+    );
   }
 }
 
diff --git a/pkg/analyzer/tool/summary/build_sdk_summaries.dart b/pkg/analyzer/tool/summary/build_sdk_summaries.dart
index 8292a9f78a1..7bfc71e1fb0 100644
--- a/pkg/analyzer/tool/summary/build_sdk_summaries.dart
+++ b/pkg/analyzer/tool/summary/build_sdk_summaries.dart
@@ -1,8 +1,14 @@
+// Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
 import 'dart:io';
 
+import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart';
 import 'package:analyzer/src/summary/summary_file_builder.dart';
+import 'package:meta/meta.dart';
 
 void main(List<String> args) {
   String command;
@@ -36,8 +42,20 @@ void main(List<String> args) {
   //
   // Handle commands.
   //
-  if (command == 'build-strong') {
-    _buildSummary(sdkPath, outFilePath);
+  if (command == 'build-non-nullable') {
+    _buildSummary(
+      sdkPath,
+      outFilePath,
+      enabledExperiments: ['non-nullable'],
+      title: 'non-nullable',
+    );
+  } else if (command == 'build-legacy' || command == 'build-strong') {
+    _buildSummary(
+      sdkPath,
+      outFilePath,
+      enabledExperiments: [],
+      title: 'legacy',
+    );
   } else {
     _printUsage();
     return;
@@ -49,10 +67,18 @@ void main(List<String> args) {
  */
 const BINARY_NAME = "build_sdk_summaries";
 
-void _buildSummary(String sdkPath, String outPath) {
-  print('Generating strong mode summary.');
+void _buildSummary(
+  String sdkPath,
+  String outPath, {
+  @required List<String> enabledExperiments,
+  @required String title,
+}) {
+  print('Generating $title summary.');
   Stopwatch sw = Stopwatch()..start();
-  List<int> bytes = SummaryBuilder.forSdk(sdkPath).build();
+  var featureSet = FeatureSet.fromEnableFlags(enabledExperiments);
+  List<int> bytes = SummaryBuilder.forSdk(sdkPath).build(
+    featureSet: featureSet,
+  );
   File(outPath).writeAsBytesSync(bytes, mode: FileMode.writeOnly);
   print('\tDone in ${sw.elapsedMilliseconds} ms.');
 }
@@ -63,6 +89,8 @@ void _buildSummary(String sdkPath, String outPath) {
 void _printUsage() {
   print('Usage: $BINARY_NAME command arguments');
   print('Where command can be one of the following:');
-  print('  build-strong output_file [sdk_path]');
-  print('    Generate strong mode summary file.');
+  print('  build-non-nullable output_file [sdk_path]');
+  print('    Generate non-nullable summary file.');
+  print('  build-legacy output_file [sdk_path]');
+  print('    Generate legacy summary file.');
 }
diff --git a/pkg/analyzer_cli/lib/src/driver.dart b/pkg/analyzer_cli/lib/src/driver.dart
index f3dc01d6fa4..e92cb2c3535 100644
--- a/pkg/analyzer_cli/lib/src/driver.dart
+++ b/pkg/analyzer_cli/lib/src/driver.dart
@@ -6,6 +6,7 @@ import 'dart:async';
 import 'dart:io' as io;
 import 'dart:isolate';
 
+import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
@@ -158,9 +159,12 @@ class Driver with HasContextMixin implements CommandLineStarter {
       print('\nGenerating strong mode summary...');
       final Stopwatch stopwatch = Stopwatch()..start();
 
-      SummaryBuilder.forSdk(options.dartSdkPath).build();
-      SummaryBuilder.forSdk(options.dartSdkPath).build();
-      SummaryBuilder.forSdk(options.dartSdkPath).build();
+      for (var i = 0; i < 3; i++) {
+        var featureSet = FeatureSet.fromEnableFlags([]);
+        SummaryBuilder.forSdk(options.dartSdkPath).build(
+          featureSet: featureSet,
+        );
+      }
 
       print('Done in ${stopwatch.elapsedMilliseconds} ms.');
     }
diff --git a/utils/dartanalyzer/BUILD.gn b/utils/dartanalyzer/BUILD.gn
index 7665d74821b..35b88d75497 100644
--- a/utils/dartanalyzer/BUILD.gn
+++ b/utils/dartanalyzer/BUILD.gn
@@ -46,9 +46,17 @@ prebuilt_dart_action("generate_summary_strong") {
   outputs = [
     output,
   ]
-  args = [
-    "build-strong",
-    rebase_path(output),
-    rebase_path("../../sdk"),
-  ]
+  if (use_nnbd) {
+    args = [
+      "build-non-nullable",
+      rebase_path(output),
+      rebase_path("../../sdk_nnbd"),
+    ]
+  } else {
+    args = [
+      "build-legacy",
+      rebase_path(output),
+      rebase_path("../../sdk"),
+    ]
+  }
 }