[dart2js] migrate powerset_bits.dart

Change-Id: I7abd6781a657ea2564ba08e3b7d4e8274ae3939b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252413
Reviewed-by: Nate Biggs <natebiggs@google.com>

pkg/compiler/lib/src/inferrer/powersets/powerset_bits.dart

@@ -2,8 +2,6 @@
 // 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.
 
-// @dart = 2.10
-
 import '../../common/elements.dart' show CommonElements;
 import '../../constants/values.dart';
 import '../../elements/entities.dart';
@@ -11,7 +9,7 @@ import '../../elements/names.dart';
 import '../../elements/types.dart';
 import '../../ir/class_relation.dart';
 import '../../universe/selector.dart';
-import '../../world.dart';
+import '../../world_interfaces.dart';
 import '../abstract_value_domain.dart';
 
 /// This class is used to store bits information about class entities.
@@ -172,7 +170,7 @@ class PowersetBitsDomain {
 
   // TODO(coam): This currently returns null if we are not sure if it's a primitive.
   // It could be improved because we can also tell when we're certain it's not a primitive.
-  PrimitiveConstantValue getPrimitiveValue(int value) {
+  PrimitiveConstantValue? getPrimitiveValue(int value) {
     if (isDefinitelyTrue(value)) {
       return TrueConstantValue();
     }
@@ -355,7 +353,7 @@ class PowersetBitsDomain {
   }
 
   ClassInfo _computeClassInfo(ClassEntity cls) {
-    ClassInfo classInfo = _storedClassInfo[cls];
+    ClassInfo? classInfo = _storedClassInfo[cls];
     if (classInfo != null) {
       return classInfo;
     }
@@ -442,7 +440,10 @@ class PowersetBitsDomain {
   }
 
   int createFromStaticType(DartType type,
-      {ClassRelation classRelation = ClassRelation.subtype, bool nullable}) {
+      {ClassRelation classRelation = ClassRelation.subtype,
+      required bool nullable}) {
+    // TODO(48820): Remove after sound null safety is enabled.
+    // ignore: unnecessary_null_comparison
     assert(nullable != null);
 
     if ((classRelation == ClassRelation.subtype ||
@@ -481,8 +482,6 @@ class PowersetBitsDomain {
 
   int _createFromStaticType(
       DartType type, ClassRelation classRelation, bool nullable) {
-    assert(nullable != null);
-
     int finish(int value, bool isPrecise) {
       // [isPrecise] is ignored since we only treat singleton partitions as
       // precise.
@@ -576,26 +575,21 @@ class PowersetBitsDomain {
 
   int get emptyType => powersetBottom;
 
-  int _constMapType;
+  late final int constMapType =
-  int get constMapType => _constMapType ??=
       createNonNullSubtype(commonElements.constMapLiteralClass);
 
   int get constSetType => otherValue;
 
-  int _constListType;
+  late final int constListType =
-  int get constListType => _constListType ??=
       createNonNullExact(commonElements.jsUnmodifiableArrayClass);
 
-  int _fixedListType;
+  late final int fixedListType =
-  int get fixedListType =>
+      createNonNullExact(commonElements.jsFixedArrayClass);
-      _fixedListType ??= createNonNullExact(commonElements.jsFixedArrayClass);
 
-  int _growableListType;
+  late final int growableListType =
-  int get growableListType => _growableListType ??=
       createNonNullExact(commonElements.jsExtendableArrayClass);
 
-  int _mutableArrayType;
+  late final int mutableArrayType =
-  int get mutableArrayType => _mutableArrayType ??=
       createNonNullSubtype(commonElements.jsMutableArrayClass);
 
   int get nullType => nullValue;
@@ -605,33 +599,21 @@ class PowersetBitsDomain {
   // TODO(fishythefish): Support tracking late sentinels in the powerset domain.
   int get lateSentinelType => powersetBottom;
 
-  int _mapType;
+  late final int mapType = createNonNullSubtype(commonElements.mapLiteralClass);
-  int get mapType =>
-      _mapType ??= createNonNullSubtype(commonElements.mapLiteralClass);
 
-  int _setType;
+  late final int setType = createNonNullSubtype(commonElements.setLiteralClass);
-  int get setType =>
-      _setType ??= createNonNullSubtype(commonElements.setLiteralClass);
 
-  int _listType;
+  late final int listType = createNonNullExact(commonElements.jsArrayClass);
-  int get listType =>
-      _listType ??= createNonNullExact(commonElements.jsArrayClass);
 
-  int _stringType;
+  late final int stringType =
-  int get stringType =>
+      createNonNullSubtype(commonElements.jsStringClass);
-      _stringType ??= createNonNullSubtype(commonElements.jsStringClass);
 
-  int _numType;
+  late final int numType = createNonNullSubclass(commonElements.jsNumberClass);
-  int get numType =>
-      _numType ??= createNonNullSubclass(commonElements.jsNumberClass);
 
-  int _numNotIntType;
+  late final int numNotIntType =
-  int get numNotIntType =>
+      createNonNullExact(commonElements.jsNumNotIntClass);
-      _numNotIntType ??= createNonNullExact(commonElements.jsNumNotIntClass);
 
-  int _intType;
+  late final int intType = createNonNullSubtype(commonElements.jsIntClass);
-  int get intType =>
-      _intType ??= createNonNullSubtype(commonElements.jsIntClass);
 
   int get positiveIntType => intType;
   int get uint32Type => intType;
@@ -639,9 +621,8 @@ class PowersetBitsDomain {
 
   int get boolType => boolValue;
 
-  int _functionType;
+  late final int functionType =
-  int get functionType =>
+      createNonNullSubtype(commonElements.functionClass);
-      _functionType ??= createNonNullSubtype(commonElements.functionClass);
 
   int get typeType => otherValue;
 }

pkg/compiler/lib/src/world.dart

@@ -48,6 +48,7 @@ abstract class JClosedWorld implements interfaces.JClosedWorld {
 
   InterceptorData get interceptorData;
 
+  @override
   JElementEnvironment get elementEnvironment;
 
   @override
@@ -105,6 +106,7 @@ abstract class JClosedWorld implements interfaces.JClosedWorld {
   Iterable<ClassEntity> mixinUsesOf(ClassEntity cls);
 
   /// Returns `true` if [cls] is mixed into a live class.
+  @override
   bool isUsedAsMixin(ClassEntity cls);
 
   /// Returns `true` if any live class that mixes in [cls] implements [type].

pkg/compiler/lib/src/world_interfaces.dart

@@ -23,10 +23,14 @@ abstract class JClosedWorld implements World {
 
   DartTypes get dartTypes;
 
+  ElementEnvironment get elementEnvironment;
+
   NativeData get nativeData;
 
   AnnotationsData get annotationsData;
 
+  bool isUsedAsMixin(ClassEntity cls);
+
   bool includesClosureCall(Selector selector, AbstractValue? receiver);
 
   Iterable<MemberEntity> locateMembers(