[breaking] Use element2 implementations everywhere, deprecate API with "2".

example/lib/src/member_count_library_generator.dart

@@ -13,7 +13,7 @@ class MemberCountLibraryGenerator extends Generator {
     final topLevelVarCount = topLevelNumVariables(library).length;
 
     return '''
-// Source library: ${library.element2.uri}
+// Source library: ${library.element.uri}
 const topLevelNumVarCount = $topLevelVarCount;
 ''';
   }

example/lib/src/utils.dart

@@ -8,7 +8,7 @@ import 'package:source_gen/source_gen.dart';
 /// Returns all [TopLevelVariableElement2] members in [reader]'s library that
 /// have a type of [num].
 Iterable<TopLevelVariableElement2> topLevelNumVariables(LibraryReader reader) =>
-    reader.allElements2.whereType<TopLevelVariableElement2>().where(
+    reader.allElements.whereType<TopLevelVariableElement2>().where(
           (element) =>
               element.type.isDartCoreNum ||
               element.type.isDartCoreInt ||

source_gen/lib/builder.dart

@@ -121,7 +121,7 @@ class CombiningBuilder implements Builder {
 
     final inputLibrary = await buildStep.inputLibrary2;
     final outputId = buildStep.allowedOutputs.single;
-    final partOfUri = uriOfPartial2(inputLibrary, buildStep.inputId, outputId);
+    final partOfUri = uriOfPartial(inputLibrary, buildStep.inputId, outputId);
 
     // Ensure that the input has a correct `part` statement.
     final libraryUnit =
@@ -143,7 +143,7 @@ class CombiningBuilder implements Builder {
 
     final output = '''
 $defaultFileHeader
-${languageOverrideForLibrary2(inputLibrary)}$ignoreForFile$preamble
+${languageOverrideForLibrary(inputLibrary)}$ignoreForFile$preamble
 part of '$partOfUri';
 
 $assets

source_gen/lib/src/builder.dart

@@ -5,7 +5,6 @@
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/element2.dart';
 import 'package:build/build.dart';
 import 'package:dart_style/dart_style.dart';
@@ -130,12 +129,12 @@ class _Builder extends Builder {
 
     if (!_isLibraryBuilder) {
       final asset = buildStep.inputId;
-      final partOfUri = uriOfPartial2(library2, asset, outputId);
+      final partOfUri = uriOfPartial(library2, asset, outputId);
       contentBuffer.writeln();
 
       if (this is PartBuilder) {
         contentBuffer
-          ..write(languageOverrideForLibrary2(library2))
+          ..write(languageOverrideForLibrary(library2))
           ..writeln('part of \'$partOfUri\';');
         final part = computePartUrl(buildStep.inputId, outputId);
 
@@ -358,7 +357,7 @@ Stream<GeneratedOutput> _generate(
   List<Generator> generators,
   BuildStep buildStep,
 ) async* {
-  final libraryReader = LibraryReader.v2(library2);
+  final libraryReader = LibraryReader(library2);
   for (var i = 0; i < generators.length; i++) {
     final gen = generators[i];
     var msg = 'Running $gen';
@@ -425,20 +424,16 @@ const partIdRegExpLiteral = r'[A-Za-z_\d-]+';
 
 final _partIdRegExp = RegExp('^$partIdRegExpLiteral\$');
 
-@Deprecated('Use languageOverrideForLibrary2 instead')
-String languageOverrideForLibrary(LibraryElement library) {
+String languageOverrideForLibrary(LibraryElement2 library) {
   final override = library.languageVersion.override;
   return override == null
       ? ''
       : '// @dart=${override.major}.${override.minor}\n';
 }
 
-String languageOverrideForLibrary2(LibraryElement2 library) {
-  final override = library.languageVersion.override;
-  return override == null
-      ? ''
-      : '// @dart=${override.major}.${override.minor}\n';
-}
+@Deprecated('Use languageOverrideForLibrary instead')
+String languageOverrideForLibrary2(LibraryElement2 library) =>
+    languageOverrideForLibrary(library);
 
 /// A comment configuring `dart_style` to use the default code width so no
 /// configuration discovery is required.

source_gen/lib/src/constants/reader.dart

@@ -268,7 +268,7 @@ class _DartObjectConstant extends ConstantReader {
   ConstantReader read(String field) {
     final reader = peek(field);
     if (reader == null) {
-      assertHasField2(objectValue.type!.element3 as InterfaceElement2, field);
+      assertHasField(objectValue.type!.element3 as InterfaceElement2, field);
       return const _NullConstant();
     }
     return reader;

source_gen/lib/src/constants/revive.dart

@@ -33,7 +33,7 @@ Revivable reviveInstance(DartObject object, [LibraryElement2? origin]) {
     }
   }
   origin ??= element!.library2;
-  var url = Uri.parse(urlOfElement2(element!));
+  var url = Uri.parse(urlOfElement(element!));
   if (element is TopLevelFunctionElement || element is LocalFunctionElement) {
     return Revivable._(source: url.removeFragment(), accessor: element.name3!);
   }
@@ -67,8 +67,9 @@ Revivable reviveInstance(DartObject object, [LibraryElement2? origin]) {
   }
 
   for (final type in origin!.classes) {
-    for (final e in type.fields2
-        .where((f) => f.isConst && f.computeConstantValue() == object)) {
+    for (final e in type.fields2.where(
+      (f) => f.isConst && f.computeConstantValue() == object,
+    )) {
       final result = Revivable._(
         source: url.removeFragment(),
         accessor: '${type.name3}.${e.name3}',
@@ -80,7 +81,7 @@ Revivable reviveInstance(DartObject object, [LibraryElement2? origin]) {
   }
   final i = (object as DartObjectImpl).getInvocation();
   if (i != null) {
-    url = Uri.parse(urlOfElement2(i.constructor2.enclosingElement2));
+    url = Uri.parse(urlOfElement(i.constructor2.enclosingElement2));
     final result = Revivable._(
       source: url,
       accessor: i.constructor.name,
@@ -95,7 +96,7 @@ Revivable reviveInstance(DartObject object, [LibraryElement2? origin]) {
     (f) => f.isConst && f.computeConstantValue() == object,
   )) {
     final result = Revivable._(
-      source: Uri.parse(urlOfElement2(origin)).replace(fragment: ''),
+      source: Uri.parse(urlOfElement(origin)).replace(fragment: ''),
       accessor: e.name3!,
     );
     if (tryResult(result)) {

source_gen/lib/src/constants/utils.dart

@@ -3,37 +3,12 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analyzer/dart/constant/value.dart';
-import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/element2.dart';
 
-/// Throws a [FormatException] if [root] does not have a given field [name].
-///
-/// Super types [InterfaceElement.supertype] are also checked before throwing.
-@Deprecated('Use assertHasField2() instead')
-void assertHasField(InterfaceElement root, String name) {
-  InterfaceElement? element = root;
-  while (element != null) {
-    final field = element.getField(name);
-    if (field != null) {
-      return;
-    }
-    element = element.supertype?.element;
-  }
-  final allFields = {
-    ...root.fields,
-    for (var t in root.allSupertypes) ...t.element.fields,
-  };
-
-  throw FormatException(
-    'Class ${root.name} does not have field "$name".',
-    'Fields: \n  - ${allFields.map((e) => e.name).join('\n  - ')}',
-  );
-}
-
 /// Throws a [FormatException] if [root] does not have a given field [name].
 ///
 /// Super types [InterfaceElement2.supertype] are also checked before throwing.
-void assertHasField2(InterfaceElement2 root, String name) {
+void assertHasField(InterfaceElement2 root, String name) {
   InterfaceElement2? element = root;
   while (element != null) {
     final field = element.getField2(name);
@@ -53,6 +28,13 @@ void assertHasField2(InterfaceElement2 root, String name) {
   );
 }
 
+/// Throws a [FormatException] if [root] does not have a given field [name].
+///
+/// Super types [InterfaceElement2.supertype] are also checked before throwing.
+@Deprecated('Use assertHasField() instead')
+void assertHasField2(InterfaceElement2 root, String name) =>
+    assertHasField(root, name);
+
 /// Returns whether or not [object] is or represents a `null` value.
 bool isNullLike(DartObject? object) => object?.isNull != false;
 

source_gen/lib/src/generator.dart

@@ -5,10 +5,7 @@
 import 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/element2.dart';
-// ignore: implementation_imports
-import 'package:analyzer/src/utilities/extensions/element.dart';
 import 'package:build/build.dart';
 
 import 'library.dart';
@@ -52,39 +49,39 @@ class InvalidGenerationSource implements Exception {
   ///
   /// May be `null` if the error had no associated element, or if the location
   /// was passed with [node].
-  final Element2? element2;
+  final Element2? element;
 
   /// The AST Node associated with this error.
   ///
   /// May be `null` if the error has no associated node in the input source
   /// code, or if the location was passed with [element].
   final AstNode? node;
 
-  @Deprecated('use v2 instead')
   InvalidGenerationSource(
     this.message, {
     this.todo = '',
-    Element? element,
+    this.element,
     this.node,
-  }) : element2 = element?.asElement2;
+  });
 
+  @Deprecated('use the unnamed constructor instead')
   InvalidGenerationSource.v2(
     this.message, {
     this.todo = '',
-    Element2? element,
+    this.element,
     this.node,
-  }) : element2 = element;
+  });
 
-  @Deprecated('use element2 instead')
-  Element? get element => element2?.asElement;
+  @Deprecated('use element instead')
+  Element2? get element2 => element;
 
   @override
   String toString() {
     final buffer = StringBuffer(message);
 
-    if (element2 case final element2?) {
+    if (element case final element2?) {
       try {
-        final span = spanForElement2(element2);
+        final span = spanForElement(element2);
         buffer
           ..writeln()
           ..writeln(span.start.toolString)

source_gen/lib/src/generator_for_annotation.dart

@@ -4,7 +4,6 @@
 
 import 'dart:async';
 
-import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/element2.dart';
 import 'package:build/build.dart';
 
@@ -74,14 +73,12 @@ abstract class GeneratorForAnnotation<T> extends Generator {
       typeChecker,
       throwOnUnresolved: throwOnUnresolved,
     )) {
-      var generatedValue = generateForAnnotatedElement2(
-        annotatedElement.element2,
+      var generatedValue = generateForAnnotatedElement(
+        annotatedElement.element,
         annotatedElement.annotation,
         buildStep,
       );
-      generatedValue ??= generateForAnnotatedElement(
-        // Support "generateForAnnotatedElements" until it's removed.
-        // ignore: analyzer_use_new_elements
+      generatedValue ??= generateForAnnotatedElement2(
         annotatedElement.element,
         annotatedElement.annotation,
         buildStep,
@@ -112,9 +109,8 @@ abstract class GeneratorForAnnotation<T> extends Generator {
   ///
   /// Implementations should return `null` when no content is generated. Empty
   /// or whitespace-only [String] instances are also ignored.
-  @Deprecated('use generateForAnnotatedElement2 instead')
   dynamic generateForAnnotatedElement(
-    Element element,
+    Element2 element,
     ConstantReader annotation,
     BuildStep buildStep,
   ) {}
@@ -136,6 +132,7 @@ abstract class GeneratorForAnnotation<T> extends Generator {
   ///
   /// Implementations should return `null` when no content is generated. Empty
   /// or whitespace-only [String] instances are also ignored.
+  @Deprecated('use generateForAnnotatedElement instead')
   dynamic generateForAnnotatedElement2(
     Element2 element,
     ConstantReader annotation,