Add 'variance' experimental flag.

Generated flag code

Change-Id: I61e6b8fd0a21c511c93afb9b334dc8c17eb69272
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117041
Reviewed-by: Leaf Petersen <[email protected]>
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Kallen Tu <[email protected]>

Author: kallentu

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

@@ -16,6 +16,7 @@ const _knownFeatures = <String, ExperimentalFeature>{
   EnableString.set_literals: ExperimentalFeatures.set_literals,
   EnableString.spread_collections: ExperimentalFeatures.spread_collections,
   EnableString.triple_shift: ExperimentalFeatures.triple_shift,
+  EnableString.variance: ExperimentalFeatures.variance,
 
   // ignore: deprecated_member_use_from_same_package
   EnableString.bogus_disabled: ExperimentalFeatures.bogus_disabled,
@@ -31,6 +32,7 @@ List<bool> _buildExperimentalFlagsArray() => <bool>[
       true, // set-literals
       true, // spread-collections
       IsEnabledByDefault.triple_shift,
+      IsEnabledByDefault.variance,
       false, // bogus-disabled
       true, // bogus-enabled
     ];
@@ -59,6 +61,9 @@ class EnableString {
   /// String to enable the experiment "triple-shift"
   static const String triple_shift = 'triple-shift';
 
+  /// String to enable the experiment "variance"
+  static const String variance = 'variance';
+
   /// String to enable the experiment "bogus-disabled"
   @deprecated
   static const String bogus_disabled = 'bogus-disabled';
@@ -122,9 +127,12 @@ class ExperimentalFeatures {
       IsExpired.triple_shift,
       'Triple-shift operator');
 
+  static const variance = const ExperimentalFeature(7, EnableString.variance,
+      IsEnabledByDefault.variance, IsExpired.variance, 'Sound variance.');
+
   @deprecated
   static const bogus_disabled = const ExperimentalFeature(
-      7,
+      8,
       // ignore: deprecated_member_use_from_same_package
       EnableString.bogus_disabled,
       IsEnabledByDefault.bogus_disabled,
@@ -133,7 +141,7 @@ class ExperimentalFeatures {
 
   @deprecated
   static const bogus_enabled = const ExperimentalFeature(
-      8,
+      9,
       // ignore: deprecated_member_use_from_same_package
       EnableString.bogus_enabled,
       IsEnabledByDefault.bogus_enabled,
@@ -166,6 +174,9 @@ class IsEnabledByDefault {
   /// Default state of the experiment "triple-shift"
   static const bool triple_shift = false;
 
+  /// Default state of the experiment "variance"
+  static const bool variance = false;
+
   /// Default state of the experiment "bogus-disabled"
   @deprecated
   static const bool bogus_disabled = false;
@@ -200,6 +211,9 @@ class IsExpired {
   /// Expiration status of the experiment "triple-shift"
   static const bool triple_shift = false;
 
+  /// Expiration status of the experiment "variance"
+  static const bool variance = false;
+
   /// Expiration status of the experiment "bogus-disabled"
   static const bool bogus_disabled = true;
 
@@ -241,5 +255,8 @@ mixin _CurrentState {
   /// Current state for the flag "triple-shift"
   bool get triple_shift => isEnabled(ExperimentalFeatures.triple_shift);
 
+  /// Current state for the flag "variance"
+  bool get variance => isEnabled(ExperimentalFeatures.variance);
+
   bool isEnabled(covariant ExperimentalFeature feature);
 }

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

@@ -15,6 +15,7 @@ enum ExperimentalFlag {
   setLiterals,
   spreadCollections,
   tripleShift,
+  variance,
 }
 
 ExperimentalFlag parseExperimentalFlag(String flag) {
@@ -33,6 +34,8 @@ ExperimentalFlag parseExperimentalFlag(String flag) {
       return ExperimentalFlag.spreadCollections;
     case "triple-shift":
       return ExperimentalFlag.tripleShift;
+    case "variance":
+      return ExperimentalFlag.variance;
   }
   return null;
 }
@@ -45,6 +48,7 @@ const Map<ExperimentalFlag, bool> defaultExperimentalFlags = {
   ExperimentalFlag.setLiterals: true,
   ExperimentalFlag.spreadCollections: true,
   ExperimentalFlag.tripleShift: false,
+  ExperimentalFlag.variance: false,
 };
 
 const Map<ExperimentalFlag, bool> expiredExperimentalFlags = {
@@ -55,4 +59,5 @@ const Map<ExperimentalFlag, bool> expiredExperimentalFlags = {
   ExperimentalFlag.setLiterals: true,
   ExperimentalFlag.spreadCollections: true,
   ExperimentalFlag.tripleShift: false,
+  ExperimentalFlag.variance: false,
 };

tools/experimental_features.yaml

@@ -79,6 +79,9 @@ non-nullable:
 triple-shift:
   help: "Triple-shift operator"
 
+variance:
+  help: "Sound variance."
+
 #
 # Flags below this line are shipped, retired, or rejected, cannot be specified
 # on the command line, and will eventually be removed.