Disable SwiftPM for xcode-analyze

script/tool/lib/src/build_examples_command.dart

@@ -118,20 +118,14 @@ class BuildExamplesCommand extends PackageLoopingCommand {
       'arguments.';
 
   /// Returns whether the Swift Package Manager feature should be enabled,
-  /// disabled, or left to the release channel's default value.
+  /// disabled, or left to the default value.
   bool? get _swiftPackageManagerFeatureConfig {
     final List<String> platformFlags = _platforms.keys.toList();
     if (!platformFlags.contains(platformIOS) &&
         !platformFlags.contains(platformMacOS)) {
       return null;
     }
 
-    // TODO(loic-sharma): Allow enabling on stable once Swift Package Manager
-    // feature is available on stable.
-    if (platform.environment['CHANNEL'] != 'master') {
-      return null;
-    }
-
     return getNullableBoolArg(_swiftPackageManagerFlag);
   }
 
@@ -150,23 +144,6 @@ class BuildExamplesCommand extends PackageLoopingCommand {
           'were specified. At least one platform must be provided.');
       throw ToolExit(_exitNoPlatformFlags);
     }
-
-    switch (_swiftPackageManagerFeatureConfig) {
-      case true:
-        await processRunner.runAndStream(
-          flutterCommand,
-          <String>['config', '--enable-swift-package-manager'],
-          exitOnError: true,
-        );
-      case false:
-        await processRunner.runAndStream(
-          flutterCommand,
-          <String>['config', '--no-enable-swift-package-manager'],
-          exitOnError: true,
-        );
-      case null:
-        break;
-    }
   }
 
   @override
@@ -212,8 +189,20 @@ class BuildExamplesCommand extends PackageLoopingCommand {
     }
     print('');
 
+    final bool? swiftPackageManagerOverride =
+        isPlugin ? _swiftPackageManagerFeatureConfig : null;
+
     bool builtSomething = false;
     for (final RepositoryPackage example in package.getExamples()) {
+      // Rather than changing global config state, enable SwiftPM via a
+      // temporary package-level override.
+      if (swiftPackageManagerOverride != null) {
+        print('Overriding enable-swift-package-manager to '
+            '$swiftPackageManagerOverride');
+        setSwiftPackageManagerState(example,
+            enabled: swiftPackageManagerOverride);
+      }
+
       final String packageName =
           getRelativePosixPath(example.directory, from: packagesDir);
 
@@ -240,6 +229,12 @@ class BuildExamplesCommand extends PackageLoopingCommand {
           errors.add('$packageName (${platform.label})');
         }
       }
+
+      // If an override was added, remove it.
+      if (swiftPackageManagerOverride != null) {
+        print('Removing enable-swift-package-manager override');
+        setSwiftPackageManagerState(example, enabled: null);
+      }
     }
 
     if (!builtSomething) {

script/tool/lib/src/common/plugin_utils.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:yaml/yaml.dart';
+import 'package:yaml_edit/yaml_edit.dart';
 
 import 'core.dart';
 import 'repository_package.dart';
@@ -83,6 +84,57 @@ bool pluginHasNativeCodeForPlatform(String platform, RepositoryPackage plugin) {
   return pluginClass != null && pluginClass != 'none';
 }
 
+/// Adds or removes a package-level Swift Package Manager override to the given
+/// package.
+///
+/// A null enabled state clears the package-local override, defaulting to whatever the
+/// global state is.
+void setSwiftPackageManagerState(RepositoryPackage package,
+    {required bool? enabled}) {
+  const String swiftPMFlag = 'enable-swift-package-manager';
+  const String flutterKey = 'flutter';
+  const List<String> flutterPath = <String>[flutterKey];
+  const List<String> configPath = <String>[flutterKey, 'config'];
+
+  final YamlEditor editablePubspec =
+      YamlEditor(package.pubspecFile.readAsStringSync());
+  final YamlMap configMap =
+      editablePubspec.parseAt(configPath, orElse: () => YamlMap()) as YamlMap;
+  if (enabled == null) {
+    if (!configMap.containsKey(swiftPMFlag)) {
+      // Nothing to do.
+      return;
+    } else if (configMap.length == 1) {
+      // The config section only exists for this override, so remove the whole
+      // section.
+      editablePubspec.remove(configPath);
+      // The entire flutter: section may also only have been added for the
+      // config, in which case it should be removed as well.
+      final YamlMap flutterMap = editablePubspec.parseAt(flutterPath,
+          orElse: () => YamlMap()) as YamlMap;
+      if (flutterMap.isEmpty) {
+        editablePubspec.remove(flutterPath);
+      }
+    } else {
+      // Remove the specific entry, leaving the rest of the config section.
+      editablePubspec.remove(<String>[...configPath, swiftPMFlag]);
+    }
+  } else {
+    // Ensure that the section exists.
+    if (configMap.isEmpty) {
+      final YamlMap root = editablePubspec.parseAt(<String>[]) as YamlMap;
+      if (!root.containsKey(flutterKey)) {
+        editablePubspec.update(flutterPath, YamlMap());
+      }
+      editablePubspec.update(configPath, YamlMap());
+    }
+    // Then add the flag.
+    editablePubspec.update(<String>[...configPath, swiftPMFlag], enabled);
+  }
+
+  package.pubspecFile.writeAsStringSync(editablePubspec.toString());
+}
+
 /// Returns the
 ///   flutter:
 ///     plugin:

script/tool/lib/src/xcode_analyze_command.dart

@@ -121,8 +121,14 @@ class XcodeAnalyzeCommand extends PackageLoopingCommand {
         targetPlatform == FlutterPlatform.ios ? 'iOS' : 'macOS';
     bool passing = true;
     for (final RepositoryPackage example in plugin.getExamples()) {
+      // See https://github.com/flutter/flutter/issues/172427 for discussion of
+      // why this is currently necessary.
+      print('Disabling Swift Package Manager...');
+      setSwiftPackageManagerState(example, enabled: false);
+
       // Unconditionally re-run build with --debug --config-only, to ensure that
-      // the project is in a debug state even if it was previously configured.
+      // the project is in a debug state even if it was previously configured,
+      // and that SwiftPM is disabled.
       print('Running flutter build --config-only...');
       final bool buildSuccess = await runConfigOnlyBuild(
         example,
@@ -162,6 +168,9 @@ class XcodeAnalyzeCommand extends PackageLoopingCommand {
         printError('$examplePath ($platformString) failed analysis.');
         passing = false;
       }
+
+      print('Removing Swift Package Manager override...');
+      setSwiftPackageManagerState(example, enabled: null);
     }
     return passing;
   }