Remove unnecessary _nonNullable() invocations.

We made TypeProvider legacy or null-safe long time ago, so we already
provide correct types.

R=brianwilkerson@google.com

Change-Id: I3bb7f9c6d8b2292fcb62df1820abbd84d142340d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/164720
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

Author: scheglov

pkg/analyzer/lib/src/dart/resolver/prefix_expression_resolver.dart

@@ -41,8 +41,6 @@ class PrefixExpressionResolver {
 
   ErrorReporter get _errorReporter => _resolver.errorReporter;
 
-  bool get _isNonNullableByDefault => _typeSystem.isNonNullableByDefault;
-
   TypeProvider get _typeProvider => _resolver.typeProvider;
 
   TypeSystemImpl get _typeSystem => _resolver.typeSystem;
@@ -138,17 +136,6 @@ class PrefixExpressionResolver {
     }
   }
 
-  /// Return the non-nullable variant of the [type] if NNBD is enabled, otherwise
-  /// return the type itself.
-  ///
-  /// TODO(scheglov) this is duplicate
-  DartType _nonNullable(DartType type) {
-    if (_isNonNullableByDefault) {
-      return _typeSystem.promoteToNonNull(type);
-    }
-    return type;
-  }
-
   /// Record that the static type of the given node is the given type.
   ///
   /// @param expression the node whose type is to be recorded
@@ -227,7 +214,7 @@ class PrefixExpressionResolver {
         // No special handling for incremental operators.
       } else if (operator.isIncrementOperator) {
         if (node.readType.isDartCoreInt) {
-          staticType = _nonNullable(_typeProvider.intType);
+          staticType = _typeProvider.intType;
         } else {
           _checkForInvalidAssignmentIncDec(node, staticType);
         }
@@ -252,7 +239,7 @@ class PrefixExpressionResolver {
 
     _resolver.boolExpressionVerifier.checkForNonBoolNegationExpression(operand);
 
-    _recordStaticType(node, _nonNullable(_typeProvider.boolType));
+    _recordStaticType(node, _typeProvider.boolType);
 
     _flowAnalysis?.flow?.logicalNot_end(node, operand);
   }

pkg/analyzer/lib/src/generated/resolver.dart

@@ -377,8 +377,8 @@ class ResolverVisitor extends ScopedVisitor {
         reportConstEvaluationErrors: reportConstEvaluationErrors,
         migratableAstInfoProvider: _migratableAstInfoProvider);
     inferenceContext = InferenceContext._(this);
-    typeAnalyzer = StaticTypeAnalyzer(
-        this, featureSet, _flowAnalysis, migrationResolutionHooks);
+    typeAnalyzer =
+        StaticTypeAnalyzer(this, _flowAnalysis, migrationResolutionHooks);
   }
 
   /// Return the element representing the function containing the current node,

pkg/analyzer/lib/src/generated/static_type_analyzer.dart

@@ -2,7 +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.
 
-import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ -28,9 +27,6 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
   /// The resolver driving the resolution and type analysis.
   final ResolverVisitor _resolver;
 
-  /// The feature set that should be used to resolve types.
-  final FeatureSet _featureSet;
-
   final MigrationResolutionHooks _migrationResolutionHooks;
 
   /// The object providing access to the types defined by the language.
@@ -48,17 +44,13 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
   /// [_resolver] based on the
   ///
   /// @param resolver the resolver driving this participant
-  StaticTypeAnalyzer(this._resolver, this._featureSet, this._flowAnalysis,
-      this._migrationResolutionHooks) {
+  StaticTypeAnalyzer(
+      this._resolver, this._flowAnalysis, this._migrationResolutionHooks) {
     _typeProvider = _resolver.typeProvider;
     _typeSystem = _resolver.typeSystem;
     _dynamicType = _typeProvider.dynamicType;
   }
 
-  /// Is `true` if the library being analyzed is non-nullable by default.
-  bool get _isNonNullableByDefault =>
-      _featureSet.isEnabled(Feature.non_nullable);
-
   /// Given a constructor for a generic type, returns the equivalent generic
   /// function type that we could use to forward to the constructor, or for a
   /// non-generic type simply returns the constructor type.
@@ -111,7 +103,7 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
   /// `String`.</blockquote>
   @override
   void visitAdjacentStrings(AdjacentStrings node) {
-    recordStaticType(node, _nonNullable(_typeProvider.stringType));
+    recordStaticType(node, _typeProvider.stringType);
   }
 
   /// The Dart Language Specification, 12.32: <blockquote>... the cast expression <i>e as T</i> ...
@@ -140,7 +132,7 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
   /// bool.</blockquote>
   @override
   void visitBooleanLiteral(BooleanLiteral node) {
-    recordStaticType(node, _nonNullable(_typeProvider.boolType));
+    recordStaticType(node, _typeProvider.boolType);
   }
 
   /// The Dart Language Specification, 12.15.2: <blockquote>A cascaded method invocation expression
@@ -167,7 +159,7 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
   /// double.</blockquote>
   @override
   void visitDoubleLiteral(DoubleLiteral node) {
-    recordStaticType(node, _nonNullable(_typeProvider.doubleType));
+    recordStaticType(node, _typeProvider.doubleType);
   }
 
   @override
@@ -242,9 +234,9 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
     if (context == null ||
         _typeSystem.isAssignableTo2(_typeProvider.intType, context) ||
         !_typeSystem.isAssignableTo2(_typeProvider.doubleType, context)) {
-      recordStaticType(node, _nonNullable(_typeProvider.intType));
+      recordStaticType(node, _typeProvider.intType);
     } else {
-      recordStaticType(node, _nonNullable(_typeProvider.doubleType));
+      recordStaticType(node, _typeProvider.doubleType);
     }
   }
 
@@ -254,7 +246,7 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
   /// The static type of an is-expression is `bool`.</blockquote>
   @override
   void visitIsExpression(IsExpression node) {
-    recordStaticType(node, _nonNullable(_typeProvider.boolType));
+    recordStaticType(node, _typeProvider.boolType);
   }
 
   @override
@@ -292,14 +284,14 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
   /// `String`.</blockquote>
   @override
   void visitSimpleStringLiteral(SimpleStringLiteral node) {
-    recordStaticType(node, _nonNullable(_typeProvider.stringType));
+    recordStaticType(node, _typeProvider.stringType);
   }
 
   /// The Dart Language Specification, 12.5: <blockquote>The static type of a string literal is
   /// `String`.</blockquote>
   @override
   void visitStringInterpolation(StringInterpolation node) {
-    recordStaticType(node, _nonNullable(_typeProvider.stringType));
+    recordStaticType(node, _typeProvider.stringType);
   }
 
   @override
@@ -316,7 +308,7 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
 
   @override
   void visitSymbolLiteral(SymbolLiteral node) {
-    recordStaticType(node, _nonNullable(_typeProvider.symbolType));
+    recordStaticType(node, _typeProvider.symbolType);
   }
 
   /// The Dart Language Specification, 12.10: <blockquote>The static type of `this` is the
@@ -461,13 +453,4 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<void> {
       constructor.staticElement = constructorElement;
     }
   }
-
-  /// Return the non-nullable variant of the [type] if NNBD is enabled, otherwise
-  /// return the type itself.
-  DartType _nonNullable(DartType type) {
-    if (_isNonNullableByDefault) {
-      return _typeSystem.promoteToNonNull(type);
-    }
-    return type;
-  }
 }