[Migrate] dead_code_verifier.dart

Change-Id: I20f2e143b6afed29c7ed222373371c15ffe46405
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/402141
Reviewed-by: Phil Quitslund <[email protected]>

Author: bwilkerson

pkg/analyzer/analyzer_use_new_elements.txt

@@ -92,7 +92,6 @@ lib/src/dart/resolver/yield_statement_resolver.dart
 lib/src/diagnostic/diagnostic_factory.dart
 lib/src/error/best_practices_verifier.dart
 lib/src/error/correct_override.dart
-lib/src/error/dead_code_verifier.dart
 lib/src/error/deprecated_member_use_verifier.dart
 lib/src/error/duplicate_definition_verifier.dart
 lib/src/error/imports_verifier.dart

pkg/analyzer/lib/src/error/dead_code_verifier.dart

@@ -6,7 +6,6 @@ import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
-import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/error/error.dart';
@@ -16,7 +15,6 @@ import 'package:analyzer/src/dart/element/type_system.dart';
 import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
 import 'package:analyzer/src/dart/resolver/scope.dart';
 import 'package:analyzer/src/error/codes.dart';
-import 'package:analyzer/src/utilities/extensions/element.dart';
 
 typedef _CatchClausesVerifierReporter = void Function(
   CatchClause first,
@@ -37,7 +35,7 @@ class DeadCodeVerifier extends RecursiveAstVisitor<void> {
   /// Whether the `wildcard_variables` feature is enabled.
   final bool _wildCardVariablesEnabled;
 
-  DeadCodeVerifier(this._errorReporter, LibraryElement library)
+  DeadCodeVerifier(this._errorReporter, LibraryElement2 library)
       : _wildCardVariablesEnabled =
             library.featureSet.isEnabled(Feature.wildcard_variables);
 
@@ -53,10 +51,10 @@ class DeadCodeVerifier extends RecursiveAstVisitor<void> {
 
   @override
   void visitExportDirective(ExportDirective node) {
-    var exportElement = node.element;
-    if (exportElement != null) {
+    var libraryExport = node.libraryExport;
+    if (libraryExport != null) {
       // The element is null when the URI is invalid.
-      LibraryElement? library = exportElement.exportedLibrary;
+      LibraryElement2? library = libraryExport.exportedLibrary2;
       if (library != null && !library.isSynthetic) {
         for (Combinator combinator in node.combinators) {
           _checkCombinator(library, combinator);
@@ -68,24 +66,23 @@ class DeadCodeVerifier extends RecursiveAstVisitor<void> {
 
   @override
   void visitFunctionDeclaration(FunctionDeclaration node) {
-    var element = node.declaredElement;
+    var element = node.declaredFragment!.element;
     // TODO(pq): ask the FunctionElement once implemented
     if (_wildCardVariablesEnabled &&
-        element is FunctionElement &&
-        element.isLocal &&
-        element.name == '_') {
+        element is LocalFunctionElement &&
+        element.name3 == '_') {
       _errorReporter.atNode(node, WarningCode.DEAD_CODE);
     }
     super.visitFunctionDeclaration(node);
   }
 
   @override
   void visitImportDirective(ImportDirective node) {
-    var importElement = node.element;
-    if (importElement != null) {
+    var libraryImport = node.libraryImport;
+    if (libraryImport != null) {
       // The element is null when the URI is invalid, but not when the URI is
       // valid but refers to a nonexistent file.
-      LibraryElement? library = importElement.importedLibrary;
+      LibraryElement2? library = libraryImport.importedLibrary2;
       if (library != null && !library.isSynthetic) {
         for (Combinator combinator in node.combinators) {
           _checkCombinator(library, combinator);
@@ -117,11 +114,11 @@ class DeadCodeVerifier extends RecursiveAstVisitor<void> {
   void visitVariableDeclaration(VariableDeclaration node) {
     var initializer = node.initializer;
     if (initializer != null && node.isLate) {
-      var element = node.declaredElement;
+      var element = node.declaredFragment!.element;
       // TODO(pq): ask the LocalVariableElement once implemented
       if (_wildCardVariablesEnabled &&
-          element is LocalVariableElement &&
-          element.name == '_') {
+          element is LocalVariableElement2 &&
+          element.name3 == '_') {
         _errorReporter.atNode(initializer,
             WarningCode.DEAD_CODE_LATE_WILDCARD_VARIABLE_INITIALIZER);
       }
@@ -132,9 +129,9 @@ class DeadCodeVerifier extends RecursiveAstVisitor<void> {
 
   /// Resolve the names in the given [combinator] in the scope of the given
   /// [library].
-  void _checkCombinator(LibraryElement library, Combinator combinator) {
+  void _checkCombinator(LibraryElement2 library, Combinator combinator) {
     Namespace namespace =
-        NamespaceBuilder().createExportNamespaceForLibrary(library.asElement2);
+        NamespaceBuilder().createExportNamespaceForLibrary(library);
     NodeList<SimpleIdentifier> names;
     ErrorCode warningCode;
     if (combinator is HideCombinator) {
@@ -146,8 +143,8 @@ class DeadCodeVerifier extends RecursiveAstVisitor<void> {
     }
     for (SimpleIdentifier name in names) {
       String nameStr = name.name;
-      Element? element = namespace.get(nameStr);
-      element ??= namespace.get("$nameStr=");
+      Element2? element = namespace.get2(nameStr);
+      element ??= namespace.get2("$nameStr=");
       if (element == null) {
         _errorReporter.atNode(
           name,
@@ -599,12 +596,6 @@ class _LabelTracker {
   }
 }
 
-extension on FunctionElement {
-  bool get isLocal =>
-      enclosingElement3 is FunctionElement ||
-      enclosingElement3 is MethodElement;
-}
-
 extension DoStatementExtension on DoStatement {
   bool get hasBreakStatement {
     var visitor = _BreakDoStatementVisitor(this);