Add support for --track-widget-creation back to ios build rules. (#18046)

packages/flutter_tools/bin/xcode_backend.sh

@@ -109,6 +109,11 @@ BuildApp() {
     preview_dart_2_flag="--no-preview-dart-2"
   fi
 
+  local track_widget_creation_flag=""
+  if [[ -n "$TRACK_WIDGET_CREATION" ]]; then
+    track_widget_creation_flag="--track-widget-creation"
+  fi
+
   if [[ "${build_mode}" != "debug" ]]; then
     StreamOutput " ├─Building Dart code..."
     # Transform ARCHS to comma-separated list of target architectures.
@@ -122,7 +127,8 @@ BuildApp() {
       --${build_mode}                                                       \
       --ios-arch="${archs}"                                                 \
       ${local_engine_flag}                                                  \
-      ${preview_dart_2_flag}
+      ${preview_dart_2_flag}                                                \
+      ${track_widget_creation_flag}
 
     if [[ $? -ne 0 ]]; then
       EchoError "Failed to build ${project_path}."
@@ -166,7 +172,8 @@ BuildApp() {
     --asset-dir="${derived_dir}/flutter_assets"                             \
     ${precompilation_flag}                                                  \
     ${local_engine_flag}                                                    \
-    ${preview_dart_2_flag}
+    ${preview_dart_2_flag}                                                  \
+    ${track_widget_creation_flag}
 
   if [[ $? -ne 0 ]]; then
     EchoError "Failed to package ${project_path}."

packages/flutter_tools/lib/src/build_info.dart

@@ -12,7 +12,7 @@ import 'globals.dart';
 class BuildInfo {
   const BuildInfo(this.mode, this.flavor, {
     this.previewDart2: false,
-    this.trackWidgetCreation,
+    this.trackWidgetCreation: false,
     this.extraFrontEndOptions,
     this.extraGenSnapshotOptions,
     this.preferSharedLibrary,

packages/flutter_tools/lib/src/ios/simulators.dart

@@ -363,6 +363,7 @@ class IOSSimulator extends Device {
 
     final BuildInfo debugBuildInfo = new BuildInfo(BuildMode.debug, buildInfo.flavor,
         previewDart2: buildInfo.previewDart2,
+        trackWidgetCreation: buildInfo.trackWidgetCreation,
         extraFrontEndOptions: buildInfo.extraFrontEndOptions,
         extraGenSnapshotOptions: buildInfo.extraGenSnapshotOptions,
         preferSharedLibrary: buildInfo.preferSharedLibrary);

packages/flutter_tools/lib/src/ios/xcodeproj.dart

@@ -117,6 +117,10 @@ Future<void> updateGeneratedXcodeProperties({
     localsBuffer.writeln('PREVIEW_DART_2=true');
   }
 
+  if (buildInfo.trackWidgetCreation) {
+    localsBuffer.writeln('TRACK_WIDGET_CREATION=true');
+  }
+
   final File localsFile = fs.file(_generatedXcodePropertiesPath(projectPath));
   localsFile.createSync(recursive: true);
   localsFile.writeAsStringSync(localsBuffer.toString());

packages/flutter_tools/test/ios/xcodeproj_test.dart

@@ -301,6 +301,47 @@ Information about project "Runner":
       expect(contents.contains('ARCHS=armv7'), isTrue);
     });
 
+    testUsingOsxContext('sets TRACK_WIDGET_CREATION=true when trackWidgetCreation is true', () async {
+      when(mockArtifacts.getArtifactPath(Artifact.flutterFramework, TargetPlatform.ios, any)).thenReturn('engine');
+      when(mockArtifacts.engineOutPath).thenReturn(fs.path.join('out', 'ios_profile_arm'));
+      const BuildInfo buildInfo = const BuildInfo(BuildMode.debug, null,
+        previewDart2: true,
+        trackWidgetCreation: true,
+        targetPlatform: TargetPlatform.ios,
+      );
+      await updateGeneratedXcodeProperties(
+        projectPath: 'path/to/project',
+        buildInfo: buildInfo,
+        previewDart2: true,
+      );
+
+      final File config = fs.file('path/to/project/ios/Flutter/Generated.xcconfig');
+      expect(config.existsSync(), isTrue);
+
+      final String contents = config.readAsStringSync();
+      expect(contents.contains('TRACK_WIDGET_CREATION=true'), isTrue);
+    });
+
+    testUsingOsxContext('does not set TRACK_WIDGET_CREATION when trackWidgetCreation is false', () async {
+      when(mockArtifacts.getArtifactPath(Artifact.flutterFramework, TargetPlatform.ios, any)).thenReturn('engine');
+      when(mockArtifacts.engineOutPath).thenReturn(fs.path.join('out', 'ios_profile_arm'));
+      const BuildInfo buildInfo = const BuildInfo(BuildMode.debug, null,
+        previewDart2: true,
+        targetPlatform: TargetPlatform.ios,
+      );
+      await updateGeneratedXcodeProperties(
+        projectPath: 'path/to/project',
+        buildInfo: buildInfo,
+        previewDart2: true,
+      );
+
+      final File config = fs.file('path/to/project/ios/Flutter/Generated.xcconfig');
+      expect(config.existsSync(), isTrue);
+
+      final String contents = config.readAsStringSync();
+      expect(contents.contains('TRACK_WIDGET_CREATION=true'), isFalse);
+    });
+
     testUsingOsxContext('sets ARCHS=armv7 when armv7 local engine is set', () async {
       when(mockArtifacts.getArtifactPath(Artifact.flutterFramework, TargetPlatform.ios, any)).thenReturn('engine');
       when(mockArtifacts.engineOutPath).thenReturn(fs.path.join('out', 'ios_profile'));