[language] Add experimental flag 'static-extensions'

Part of #61485
Part of #61484

Change-Id: I6b88a2df4fd4f01826c178138c21a4b300818e92
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/449300
Reviewed-by: Michael Thomsen <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>

Author: chloestefantsova

pkg/_fe_analyzer_shared/lib/src/experiments/flags.dart

@@ -266,6 +266,14 @@ enum ExperimentalFlag {
     experimentReleasedVersion: const Version(2, 0),
   ),
 
+  staticExtensions(
+    name: 'static-extensions',
+    isEnabledByDefault: false,
+    isExpired: false,
+    experimentEnabledVersion: defaultLanguageVersion,
+    experimentReleasedVersion: defaultLanguageVersion,
+  ),
+
   superParameters(
     name: 'super-parameters',
     isEnabledByDefault: true,

pkg/analyzer/lib/src/dart/analysis/driver.dart

@@ -106,7 +106,7 @@ testFineAfterLibraryAnalyzerHook;
 // TODO(scheglov): Clean up the list of implicitly analyzed files.
 class AnalysisDriver {
   /// The version of data format, should be incremented on every format change.
-  static const int DATA_VERSION = 558;
+  static const int DATA_VERSION = 559;
 
   /// The number of exception contexts allowed to write. Once this field is
   /// zero, we stop writing any new exception contexts in this process.

pkg/analyzer/lib/src/dart/analysis/experiments.g.dart

@@ -52,6 +52,7 @@ final _knownFeatures = <String, ExperimentalFeature>{
   EnableString.set_literals: ExperimentalFeatures.set_literals,
   EnableString.sound_flow_analysis: ExperimentalFeatures.sound_flow_analysis,
   EnableString.spread_collections: ExperimentalFeatures.spread_collections,
+  EnableString.static_extensions: ExperimentalFeatures.static_extensions,
   EnableString.super_parameters: ExperimentalFeatures.super_parameters,
   EnableString.test_experiment: ExperimentalFeatures.test_experiment,
   EnableString.triple_shift: ExperimentalFeatures.triple_shift,
@@ -160,6 +161,9 @@ class EnableString {
   /// String to enable the experiment "spread-collections"
   static const String spread_collections = 'spread-collections';
 
+  /// String to enable the experiment "static-extensions"
+  static const String static_extensions = 'static-extensions';
+
   /// String to enable the experiment "super-parameters"
   static const String super_parameters = 'super-parameters';
 
@@ -543,8 +547,19 @@ class ExperimentalFeatures {
     channels: ["stable", "beta", "dev", "main"],
   );
 
-  static final super_parameters = ExperimentalFeature(
+  static final static_extensions = ExperimentalFeature(
     index: 32,
+    enableString: EnableString.static_extensions,
+    isEnabledByDefault: IsEnabledByDefault.static_extensions,
+    isExpired: IsExpired.static_extensions,
+    documentation: 'Extensions with static capabilities.',
+    experimentalReleaseVersion: null,
+    releaseVersion: null,
+    channels: ["stable", "beta", "dev", "main"],
+  );
+
+  static final super_parameters = ExperimentalFeature(
+    index: 33,
     enableString: EnableString.super_parameters,
     isEnabledByDefault: IsEnabledByDefault.super_parameters,
     isExpired: IsExpired.super_parameters,
@@ -555,7 +570,7 @@ class ExperimentalFeatures {
   );
 
   static final test_experiment = ExperimentalFeature(
-    index: 33,
+    index: 34,
     enableString: EnableString.test_experiment,
     isEnabledByDefault: IsEnabledByDefault.test_experiment,
     isExpired: IsExpired.test_experiment,
@@ -567,7 +582,7 @@ class ExperimentalFeatures {
   );
 
   static final triple_shift = ExperimentalFeature(
-    index: 34,
+    index: 35,
     enableString: EnableString.triple_shift,
     isEnabledByDefault: IsEnabledByDefault.triple_shift,
     isExpired: IsExpired.triple_shift,
@@ -578,7 +593,7 @@ class ExperimentalFeatures {
   );
 
   static final unnamed_libraries = ExperimentalFeature(
-    index: 35,
+    index: 36,
     enableString: EnableString.unnamed_libraries,
     isEnabledByDefault: IsEnabledByDefault.unnamed_libraries,
     isExpired: IsExpired.unnamed_libraries,
@@ -589,7 +604,7 @@ class ExperimentalFeatures {
   );
 
   static final unquoted_imports = ExperimentalFeature(
-    index: 36,
+    index: 37,
     enableString: EnableString.unquoted_imports,
     isEnabledByDefault: IsEnabledByDefault.unquoted_imports,
     isExpired: IsExpired.unquoted_imports,
@@ -600,7 +615,7 @@ class ExperimentalFeatures {
   );
 
   static final variance = ExperimentalFeature(
-    index: 37,
+    index: 38,
     enableString: EnableString.variance,
     isEnabledByDefault: IsEnabledByDefault.variance,
     isExpired: IsExpired.variance,
@@ -611,7 +626,7 @@ class ExperimentalFeatures {
   );
 
   static final wildcard_variables = ExperimentalFeature(
-    index: 38,
+    index: 39,
     enableString: EnableString.wildcard_variables,
     isEnabledByDefault: IsEnabledByDefault.wildcard_variables,
     isExpired: IsExpired.wildcard_variables,
@@ -722,6 +737,9 @@ class IsEnabledByDefault {
   /// Default state of the experiment "spread-collections"
   static const bool spread_collections = true;
 
+  /// Default state of the experiment "static-extensions"
+  static const bool static_extensions = false;
+
   /// Default state of the experiment "super-parameters"
   static const bool super_parameters = true;
 
@@ -844,6 +862,9 @@ class IsExpired {
   /// Expiration status of the experiment "spread-collections"
   static const bool spread_collections = true;
 
+  /// Expiration status of the experiment "static-extensions"
+  static const bool static_extensions = false;
+
   /// Expiration status of the experiment "super-parameters"
   static const bool super_parameters = true;
 
@@ -978,6 +999,10 @@ mixin _CurrentState {
   bool get spread_collections =>
       isEnabled(ExperimentalFeatures.spread_collections);
 
+  /// Current state for the flag "static-extensions"
+  bool get static_extensions =>
+      isEnabled(ExperimentalFeatures.static_extensions);
+
   /// Current state for the flag "super-parameters"
   bool get super_parameters => isEnabled(ExperimentalFeatures.super_parameters);
 

pkg/front_end/lib/src/api_prototype/experimental_flags_generated.dart

@@ -350,6 +350,15 @@ class ExperimentalFlag {
     experimentReleasedVersion: const Version(2, 0),
   );
 
+  static const ExperimentalFlag staticExtensions = const ExperimentalFlag(
+    name: 'static-extensions',
+    isEnabledByDefault: false,
+    isExpired: false,
+    enabledVersion: defaultLanguageVersion,
+    experimentEnabledVersion: defaultLanguageVersion,
+    experimentReleasedVersion: defaultLanguageVersion,
+  );
+
   static const ExperimentalFlag superParameters = const ExperimentalFlag(
     name: 'super-parameters',
     isEnabledByDefault: true,
@@ -612,6 +621,10 @@ class GlobalFeatures {
   GlobalFeature get spreadCollections => _spreadCollections ??=
       _computeGlobalFeature(ExperimentalFlag.spreadCollections);
 
+  GlobalFeature? _staticExtensions;
+  GlobalFeature get staticExtensions => _staticExtensions ??=
+      _computeGlobalFeature(ExperimentalFlag.staticExtensions);
+
   GlobalFeature? _superParameters;
   GlobalFeature get superParameters => _superParameters ??=
       _computeGlobalFeature(ExperimentalFlag.superParameters);
@@ -916,6 +929,14 @@ class LibraryFeatures {
         libraryVersion,
       );
 
+  LibraryFeature? _staticExtensions;
+  LibraryFeature get staticExtensions =>
+      _staticExtensions ??= globalFeatures._computeLibraryFeature(
+        ExperimentalFlag.staticExtensions,
+        canonicalUri,
+        libraryVersion,
+      );
+
   LibraryFeature? _superParameters;
   LibraryFeature get superParameters =>
       _superParameters ??= globalFeatures._computeLibraryFeature(
@@ -1041,6 +1062,8 @@ class LibraryFeatures {
         return soundFlowAnalysis;
       case shared.ExperimentalFlag.spreadCollections:
         return spreadCollections;
+      case shared.ExperimentalFlag.staticExtensions:
+        return staticExtensions;
       case shared.ExperimentalFlag.superParameters:
         return superParameters;
       case shared.ExperimentalFlag.testExperiment:
@@ -1127,6 +1150,8 @@ ExperimentalFlag? parseExperimentalFlag(String flag) {
       return ExperimentalFlag.soundFlowAnalysis;
     case "spread-collections":
       return ExperimentalFlag.spreadCollections;
+    case "static-extensions":
+      return ExperimentalFlag.staticExtensions;
     case "super-parameters":
       return ExperimentalFlag.superParameters;
     case "test-experiment":
@@ -1204,6 +1229,8 @@ final Map<ExperimentalFlag, bool> defaultExperimentalFlags = {
       ExperimentalFlag.soundFlowAnalysis.isEnabledByDefault,
   ExperimentalFlag.spreadCollections:
       ExperimentalFlag.spreadCollections.isEnabledByDefault,
+  ExperimentalFlag.staticExtensions:
+      ExperimentalFlag.staticExtensions.isEnabledByDefault,
   ExperimentalFlag.superParameters:
       ExperimentalFlag.superParameters.isEnabledByDefault,
   ExperimentalFlag.testExperiment:
@@ -1264,6 +1291,7 @@ const Map<shared.ExperimentalFlag, ExperimentalFlag> sharedExperimentalFlags = {
   shared.ExperimentalFlag.setLiterals: ExperimentalFlag.setLiterals,
   shared.ExperimentalFlag.soundFlowAnalysis: ExperimentalFlag.soundFlowAnalysis,
   shared.ExperimentalFlag.spreadCollections: ExperimentalFlag.spreadCollections,
+  shared.ExperimentalFlag.staticExtensions: ExperimentalFlag.staticExtensions,
   shared.ExperimentalFlag.superParameters: ExperimentalFlag.superParameters,
   shared.ExperimentalFlag.testExperiment: ExperimentalFlag.testExperiment,
   shared.ExperimentalFlag.tripleShift: ExperimentalFlag.tripleShift,

tools/experimental_features.yaml

@@ -153,6 +153,9 @@ features:
   inference-update-4:
     help: "A bundle of updates to type inference."
 
+  static-extensions:
+    help: "Extensions with static capabilities."
+
 # Experiment flag only used for testing.
   test-experiment:
     help: >-