[analyzer] Refine types returned by TypeSystemImpl methods.

In the following methods in `TypeSystemImpl`, the return type is changed from `DartType` to `TypeImpl`: - `greatestClosure` - `greatestLowerBound` - `leastClosure` - `leastUpperBound` - `makeNullable` - `promoteToNonNull` This required adding a few casts to `TypeSystemImpl`, `LeastGreatestClosureHelper`, and `InterfaceTypeImpl`, which I believe I will be able to remove in future CLs. It also allowed removing some casts from `GreatestLowerBoundHelper`, `LeastUpperBoundHelper`, and `InterfaceTypeImpl`. This is part of a larger arc of work to change the analyzer's use of the shared code so that the type parameters it supplies are not part of the analyzer public API. See #59763. Change-Id: I24f27090bb2d07ae33be9c2c8d7908ef71a96929 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/404640 Reviewed-by: Konstantin Shcheglov <[email protected]> Commit-Queue: Paul Berry <[email protected]>
dart-lang · Jan 15, 2025 · 749de93 · 749de93
1 parent 3417d1a
commit 749de93
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Showing 6 changed files with 61 additions and 58 deletions.
diff --git a/pkg/analyzer/lib/src/dart/element/greatest_lower_bound.dart b/pkg/analyzer/lib/src/dart/element/greatest_lower_bound.dart
@@ -6,7 +6,6 @@
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
-import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/extensions.dart';
 import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/type_provider.dart';
@@ -27,7 +26,7 @@ class GreatestLowerBoundHelper {
   ///
   /// https://github.com/dart-lang/language
   /// See `resources/type-system/upper-lower-bounds.md`
-  DartType getGreatestLowerBound(DartType T1, DartType T2) {
+  TypeImpl getGreatestLowerBound(TypeImpl T1, TypeImpl T2) {
     // DOWN(T, T) = T
     if (identical(T1, T2)) {
       return T1;
@@ -103,11 +102,8 @@ class GreatestLowerBoundHelper {
       }
     }
 
-    var T1_impl = T1 as TypeImpl;
-    var T2_impl = T2 as TypeImpl;
-
-    var T1_nullability = T1_impl.nullabilitySuffix;
-    var T2_nullability = T2_impl.nullabilitySuffix;
+    var T1_nullability = T1.nullabilitySuffix;
+    var T2_nullability = T2.nullabilitySuffix;
 
     // DOWN(Null, T2)
     if (T1_nullability == NullabilitySuffix.none && T1.isDartCoreNull) {
@@ -153,7 +149,7 @@ class GreatestLowerBoundHelper {
       }
 
       // * NonNull(T2) if NonNull(T2) is non-nullable
-      var T2_nonNull = _typeSystem.promoteToNonNull(T2_impl);
+      var T2_nonNull = _typeSystem.promoteToNonNull(T2);
       if (_typeSystem.isNonNullable(T2_nonNull)) {
         return T2_nonNull;
       }
@@ -170,7 +166,7 @@ class GreatestLowerBoundHelper {
       }
 
       // * NonNull(T1) if NonNull(T1) is non-nullable
-      var T1_nonNull = _typeSystem.promoteToNonNull(T1_impl);
+      var T1_nonNull = _typeSystem.promoteToNonNull(T1);
       if (_typeSystem.isNonNullable(T1_nonNull)) {
         return T1_nonNull;
       }
@@ -184,12 +180,12 @@ class GreatestLowerBoundHelper {
     // DOWN(T1, T2?) = S where S is DOWN(T1, T2)
     if (T1_nullability != NullabilitySuffix.none ||
         T2_nullability != NullabilitySuffix.none) {
-      var T1_none = T1_impl.withNullability(NullabilitySuffix.none);
-      var T2_none = T2_impl.withNullability(NullabilitySuffix.none);
+      var T1_none = T1.withNullability(NullabilitySuffix.none);
+      var T2_none = T2.withNullability(NullabilitySuffix.none);
       var S = getGreatestLowerBound(T1_none, T2_none);
       if (T1_nullability == NullabilitySuffix.question &&
           T2_nullability == NullabilitySuffix.question) {
-        return (S as TypeImpl).withNullability(NullabilitySuffix.question);
+        return S.withNullability(NullabilitySuffix.question);
       }
       return S;
     }
@@ -258,7 +254,7 @@ class GreatestLowerBoundHelper {
   ///
   /// https://github.com/dart-lang/language
   /// See `resources/type-system/upper-lower-bounds.md`
-  DartType _functionType(FunctionType f, FunctionType g) {
+  TypeImpl _functionType(FunctionTypeImpl f, FunctionTypeImpl g) {
     var fTypeFormals = f.typeFormals;
     var gTypeFormals = g.typeFormals;
 
@@ -378,7 +374,7 @@ class GreatestLowerBoundHelper {
     );
   }
 
-  DartType _recordType(RecordTypeImpl T1, RecordTypeImpl T2) {
+  TypeImpl _recordType(RecordTypeImpl T1, RecordTypeImpl T2) {
     var positional1 = T1.positionalFields;
     var positional2 = T2.positionalFields;
     if (positional1.length != positional2.length) {

diff --git a/pkg/analyzer/lib/src/dart/element/least_greatest_closure.dart b/pkg/analyzer/lib/src/dart/element/least_greatest_closure.dart
@@ -47,17 +47,23 @@ class LeastGreatestClosureHelper extends ReplacementVisitor {
   }
 
   /// Returns a supertype of [type] for all values of [eliminationTargets].
-  DartType eliminateToGreatest(DartType type) {
+  TypeImpl eliminateToGreatest(DartType type) {
     _isCovariant = true;
     _isLeastClosure = false;
-    return type.accept(this) ?? type;
+    // TODO(paulberry): make this cast unnecessary by changing the type of
+    // `type` and by changing `ReplacementVisitor` to implement
+    // `TypeVisitor<TypeImpl?>`.
+    return (type.accept(this) ?? type) as TypeImpl;
   }
 
   /// Returns a subtype of [type] for all values of [eliminationTargets].
-  DartType eliminateToLeast(DartType type) {
+  TypeImpl eliminateToLeast(DartType type) {
     _isCovariant = true;
     _isLeastClosure = true;
-    return type.accept(this) ?? type;
+    // TODO(paulberry): make this cast unnecessary by changing the type of
+    // `type` and by changing `ReplacementVisitor` to implement
+    // `TypeVisitor<TypeImpl?>`.
+    return (type.accept(this) ?? type) as TypeImpl;
   }
 
   @override

diff --git a/pkg/analyzer/lib/src/dart/element/least_upper_bound.dart b/pkg/analyzer/lib/src/dart/element/least_upper_bound.dart
@@ -318,7 +318,7 @@ class LeastUpperBoundHelper {
 
   LeastUpperBoundHelper(this._typeSystem);
 
-  InterfaceType get _interfaceTypeFunctionNone {
+  InterfaceTypeImpl get _interfaceTypeFunctionNone {
     return _typeSystem.typeProvider.functionType.element3.instantiate(
       typeArguments: const [],
       nullabilitySuffix: NullabilitySuffix.none,
@@ -329,7 +329,7 @@ class LeastUpperBoundHelper {
   ///
   /// https://github.com/dart-lang/language
   /// See `resources/type-system/upper-lower-bounds.md`
-  DartType getLeastUpperBound(DartType T1, DartType T2) {
+  TypeImpl getLeastUpperBound(TypeImpl T1, TypeImpl T2) {
     // UP(T, T) = T
     if (identical(T1, T2)) {
       return T1;
@@ -439,11 +439,8 @@ class LeastUpperBoundHelper {
       }
     }
 
-    var T1_impl = T1 as TypeImpl;
-    var T2_impl = T2 as TypeImpl;
-
-    var T1_nullability = T1_impl.nullabilitySuffix;
-    var T2_nullability = T2_impl.nullabilitySuffix;
+    var T1_nullability = T1.nullabilitySuffix;
+    var T2_nullability = T2.nullabilitySuffix;
 
     // UP(T1, T2) where NULL(T1)
     if (T1_isNull) {
@@ -508,10 +505,10 @@ class LeastUpperBoundHelper {
     // UP(T1, T2?) = S? where S is UP(T1, T2)
     if (T1_nullability != NullabilitySuffix.none ||
         T2_nullability != NullabilitySuffix.none) {
-      var T1_none = T1_impl.withNullability(NullabilitySuffix.none);
-      var T2_none = T2_impl.withNullability(NullabilitySuffix.none);
+      var T1_none = T1.withNullability(NullabilitySuffix.none);
+      var T2_none = T2.withNullability(NullabilitySuffix.none);
       var S = getLeastUpperBound(T1_none, T2_none);
-      return (S as TypeImpl).withNullability(NullabilitySuffix.question);
+      return S.withNullability(NullabilitySuffix.question);
     }
 
     assert(T1_nullability == NullabilitySuffix.none);
@@ -622,7 +619,7 @@ class LeastUpperBoundHelper {
   ///
   /// https://github.com/dart-lang/language
   /// See `resources/type-system/upper-lower-bounds.md`
-  DartType _functionType(FunctionType f, FunctionType g) {
+  TypeImpl _functionType(FunctionTypeImpl f, FunctionTypeImpl g) {
     var fTypeFormals = f.typeParameters;
     var gTypeFormals = g.typeParameters;
 
@@ -744,20 +741,20 @@ class LeastUpperBoundHelper {
     );
   }
 
-  DartType? _futureOr(DartType T1, DartType T2) {
-    var T1_futureOr = T1 is InterfaceType && T1.isDartAsyncFutureOr
+  TypeImpl? _futureOr(TypeImpl T1, TypeImpl T2) {
+    var T1_futureOr = T1 is InterfaceTypeImpl && T1.isDartAsyncFutureOr
         ? T1.typeArguments[0]
         : null;
 
-    var T1_future = T1 is InterfaceType && T1.isDartAsyncFuture
+    var T1_future = T1 is InterfaceTypeImpl && T1.isDartAsyncFuture
         ? T1.typeArguments[0]
         : null;
 
-    var T2_futureOr = T2 is InterfaceType && T2.isDartAsyncFutureOr
+    var T2_futureOr = T2 is InterfaceTypeImpl && T2.isDartAsyncFutureOr
         ? T2.typeArguments[0]
         : null;
 
-    var T2_future = T2 is InterfaceType && T2.isDartAsyncFuture
+    var T2_future = T2 is InterfaceTypeImpl && T2.isDartAsyncFuture
         ? T2.typeArguments[0]
         : null;
 
@@ -798,7 +795,7 @@ class LeastUpperBoundHelper {
     return _typeSystem.greatestLowerBound(a.type, b.type);
   }
 
-  DartType _recordType(RecordTypeImpl T1, RecordTypeImpl T2) {
+  TypeImpl _recordType(RecordTypeImpl T1, RecordTypeImpl T2) {
     var positional1 = T1.positionalFields;
     var positional2 = T2.positionalFields;
     if (positional1.length != positional2.length) {

diff --git a/pkg/analyzer/lib/src/dart/element/type.dart b/pkg/analyzer/lib/src/dart/element/type.dart
@@ -538,7 +538,7 @@ class FutureOrTypeImpl extends InterfaceTypeImpl {
   @override
   bool get isDartAsyncFutureOr => true;
 
-  DartType get typeArgument => typeArguments[0];
+  TypeImpl get typeArgument => typeArguments[0];
 
   @override
   InterfaceTypeImpl withNullability(NullabilitySuffix nullabilitySuffix) {
@@ -575,7 +575,7 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
   final InterfaceElementImpl2 element3;
 
   @override
-  final List<DartType> typeArguments;
+  final List<TypeImpl> typeArguments;
 
   @override
   final NullabilitySuffix nullabilitySuffix;
@@ -614,8 +614,10 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
     if (element.name3 == 'FutureOr' && element.library2.isDartAsync) {
       return FutureOrTypeImpl(
         element3: element,
+        // TODO(paulberry): avoid this cast by changing the type of
+        // `typeArguments`.
         typeArgument: typeArguments.isNotEmpty
-            ? typeArguments[0]
+            ? typeArguments[0] as TypeImpl
             : InvalidTypeImpl.instance,
         nullabilitySuffix: nullabilitySuffix,
         alias: alias,
@@ -626,9 +628,11 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
         alias: alias,
       );
     } else {
+      // TODO(paulberry): avoid this cast by changing the type of
+      // `typeArguments`.
       return InterfaceTypeImpl._(
         element3: element,
-        typeArguments: typeArguments,
+        typeArguments: typeArguments.cast(),
         nullabilitySuffix: nullabilitySuffix,
         alias: alias,
       );
@@ -644,7 +648,7 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
 
   InterfaceTypeImpl._futureOr({
     required this.element3,
-    required DartType typeArgument,
+    required TypeImpl typeArgument,
     required this.nullabilitySuffix,
     super.alias,
   }) : typeArguments = [typeArgument] {
@@ -1161,18 +1165,12 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
 
   @override
   bool referencesAny(Set<TypeParameterElement> parameters) {
-    return typeArguments.any((argument) {
-      var argumentImpl = argument as TypeImpl;
-      return argumentImpl.referencesAny(parameters);
-    });
+    return typeArguments.any((argument) => argument.referencesAny(parameters));
   }
 
   @override
   bool referencesAny2(Set<TypeParameterElementImpl2> parameters) {
-    return typeArguments.any((argument) {
-      var argumentImpl = argument as TypeImpl;
-      return argumentImpl.referencesAny2(parameters);
-    });
+    return typeArguments.any((argument) => argument.referencesAny2(parameters));
   }
 
   @override

diff --git a/pkg/analyzer/lib/src/dart/element/type_system.dart b/pkg/analyzer/lib/src/dart/element/type_system.dart
@@ -598,7 +598,7 @@ class TypeSystemImpl implements TypeSystem {
   ///
   /// https://github.com/dart-lang/language
   /// See `resources/type-system/inference.md`
-  DartType greatestClosure(
+  TypeImpl greatestClosure(
     DartType type,
     List<TypeParameterElementImpl2> typeParameters,
   ) {
@@ -638,8 +638,11 @@ class TypeSystemImpl implements TypeSystem {
   }
 
   @override
-  DartType greatestLowerBound(DartType T1, DartType T2) {
-    return _greatestLowerBoundHelper.getGreatestLowerBound(T1, T2);
+  TypeImpl greatestLowerBound(DartType T1, DartType T2) {
+    // TODO(paulberry): make these casts unnecessary by changing the type of
+    // `T1` and `T2`.
+    return _greatestLowerBoundHelper.getGreatestLowerBound(
+        T1 as TypeImpl, T2 as TypeImpl);
   }
 
   /// Given a generic function type `F<T0, T1, ... Tn>` and a context type C,
@@ -1380,7 +1383,7 @@ class TypeSystemImpl implements TypeSystem {
   ///
   /// https://github.com/dart-lang/language
   /// See `resources/type-system/inference.md`
-  DartType leastClosure(
+  TypeImpl leastClosure(
     DartType type,
     List<TypeParameterElementImpl2> typeParameters,
   ) {
@@ -1419,13 +1422,16 @@ class TypeSystemImpl implements TypeSystem {
   }
 
   @override
-  DartType leastUpperBound(DartType T1, DartType T2) {
-    return _leastUpperBoundHelper.getLeastUpperBound(T1, T2);
+  TypeImpl leastUpperBound(DartType T1, DartType T2) {
+    // TODO(paulberry): make these casts unnecessary by changing the type of
+    // `T1` and `T2`.
+    return _leastUpperBoundHelper.getLeastUpperBound(
+        T1 as TypeImpl, T2 as TypeImpl);
   }
 
   /// Returns a nullable version of [type].  The result would be equivalent to
   /// the union `type | Null` (if we supported union types).
-  DartType makeNullable(DartType type) {
+  TypeImpl makeNullable(DartType type) {
     // TODO(paulberry): handle type parameter types
     return (type as TypeImpl).withNullability(NullabilitySuffix.question);
   }
@@ -1485,7 +1491,7 @@ class TypeSystemImpl implements TypeSystem {
   /// Returns a non-nullable version of [type].  This is equivalent to the
   /// operation `NonNull` defined in the spec.
   @override
-  DartType promoteToNonNull(DartType type) {
+  TypeImpl promoteToNonNull(DartType type) {
     if (type.isDartCoreNull) return NeverTypeImpl.instance;
 
     if (type is TypeParameterTypeImpl) {

diff --git a/pkg/linter/lib/src/rules/invalid_runtime_check_with_js_interop_types.dart b/pkg/linter/lib/src/rules/invalid_runtime_check_with_js_interop_types.dart
@@ -296,10 +296,10 @@ class _Visitor extends SimpleAstVisitor<void> {
   }) {
     LintCode? lintCode;
     (DartType, DartType) eraseTypes(DartType left, DartType right) {
-      var erasedLeft = typeSystem.promoteToNonNull(
+      DartType erasedLeft = typeSystem.promoteToNonNull(
         eraseNonJsInteropTypes.perform(left),
       );
-      var erasedRight = typeSystem.promoteToNonNull(
+      DartType erasedRight = typeSystem.promoteToNonNull(
         eraseNonJsInteropTypes.perform(right),
       );
       var leftIsInteropType = _isJsInteropType(