[analyzer] Migrate ElementDeclarationResult

Change-Id: Iaa18a32075e2dc92d47378d90cfb801bc5884473
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/408702
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/analysis_server/lib/src/lsp/handlers/handler_definition.dart

@@ -334,7 +334,7 @@ class DefinitionHandler
       return null;
     }
 
-    return parsedLibrary.getElementDeclaration2(fragment);
+    return parsedLibrary.getFragmentDeclaration(fragment);
   }
 }
 

pkg/analyzer/api.txt

@@ -154,7 +154,7 @@ package:analyzer/dart/analysis/results.dart:
   ElementDeclarationResult (class extends Object):
     new (constructor: ElementDeclarationResult Function())
     element (getter: Element)
-    element2 (getter: Element2)
+    fragment (getter: Fragment)
     node (getter: AstNode)
     parsedUnit (getter: ParsedUnitResult?)
     resolvedUnit (getter: ResolvedUnitResult?)
@@ -195,6 +195,7 @@ package:analyzer/dart/analysis/results.dart:
     units (getter: List<ParsedUnitResult>)
     getElementDeclaration (method: ElementDeclarationResult? Function(Element))
     getElementDeclaration2 (method: ElementDeclarationResult? Function(Fragment))
+    getFragmentDeclaration (method: ElementDeclarationResult? Function(Fragment))
   ParsedUnitResult (class extends Object implements SomeParsedUnitResult, AnalysisResultWithErrors):
     new (constructor: ParsedUnitResult Function())
     unit (getter: CompilationUnit)

pkg/analyzer/lib/dart/analysis/results.dart

@@ -62,9 +62,8 @@ abstract class ElementDeclarationResult {
   /// The [Element] that this object describes.
   Element get element;
 
-  /// The element that this object describes.
-  @experimental
-  Element2 get element2;
+  /// The [Fragment] that this object describes.
+  Fragment get fragment;
 
   /// The node that declares the [element]. Depending on whether it is returned
   /// from [ResolvedLibraryResult] or [ParsedLibraryResult] it might be resolved
@@ -212,8 +211,17 @@ abstract class ParsedLibraryResult
   /// Returns `null` if the [fragment] is synthetic.
   ///
   /// Throws [ArgumentError] if the [fragment] is not defined in this library.
+  @Deprecated('Use getFragmentDeclaration() instead')
   @experimental
   ElementDeclarationResult? getElementDeclaration2(Fragment fragment);
+
+  /// Returns the declaration of the [fragment].
+  ///
+  /// Returns `null` if the [fragment] is synthetic.
+  ///
+  /// Throws [ArgumentError] if the [fragment] is not defined in this library.
+  @experimental
+  ElementDeclarationResult? getFragmentDeclaration(Fragment fragment);
 }
 
 /// The result of parsing of a single file. The errors returned include only

pkg/analyzer/lib/src/dart/analysis/results.dart

@@ -20,6 +20,21 @@ import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/type_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
 
+/// This returns the offset used for finding the corresponding AST node.
+///
+/// If the fragment is named, the [Fragment.nameOffset2] is used. If the
+/// fragment is a a [ConstructorFragment] for an unnamed constructor, the
+/// [ConstructorFragment.typeNameOffset] is used.
+int? _getFragmentNameOffset(Fragment fragment) {
+  var nameOffset = fragment.nameOffset2;
+  if (nameOffset == null) {
+    if (fragment is ConstructorFragment) {
+      nameOffset = fragment.typeNameOffset;
+    }
+  }
+  return nameOffset;
+}
+
 abstract class AnalysisResultImpl implements AnalysisResult {
   @override
   final AnalysisSession session;
@@ -35,11 +50,11 @@ class DeclarationByElementLocator extends UnifyingAstVisitor<void> {
   // type of [element]. For example, for library-level elements (classes etc),
   // we can iterate over the compilation unit's declarations.
 
-  final Element element;
+  final Fragment fragment;
   final int _nameOffset;
   AstNode? result;
 
-  DeclarationByElementLocator(this.element) : _nameOffset = element.nameOffset;
+  DeclarationByElementLocator(this.fragment, this._nameOffset);
 
   @override
   void visitNode(AstNode node) {
@@ -49,7 +64,7 @@ class DeclarationByElementLocator extends UnifyingAstVisitor<void> {
       return;
     }
 
-    if (element is InterfaceElement) {
+    if (fragment is InterfaceFragment) {
       if (node is ClassDeclaration) {
         if (_hasOffset2(node.name)) {
           result = node;
@@ -71,7 +86,7 @@ class DeclarationByElementLocator extends UnifyingAstVisitor<void> {
           result = node;
         }
       }
-    } else if (element is ConstructorElement) {
+    } else if (fragment is ConstructorFragment) {
       if (node is ConstructorDeclaration) {
         if (node.name != null) {
           if (_hasOffset2(node.name)) {
@@ -83,13 +98,13 @@ class DeclarationByElementLocator extends UnifyingAstVisitor<void> {
           }
         }
       }
-    } else if (element is ExtensionElement) {
+    } else if (fragment is ExtensionFragment) {
       if (node is ExtensionDeclaration) {
         if (_hasOffset2(node.name)) {
           result = node;
         }
       }
-    } else if (element is FieldElement) {
+    } else if (fragment is FieldFragment) {
       if (node is EnumConstantDeclaration) {
         if (_hasOffset2(node.name)) {
           result = node;
@@ -99,23 +114,27 @@ class DeclarationByElementLocator extends UnifyingAstVisitor<void> {
           result = node;
         }
       }
-    } else if (element is FunctionElement) {
+    } else if (fragment is TopLevelFunctionFragment) {
+      if (node is FunctionDeclaration && _hasOffset2(node.name)) {
+        result = node;
+      }
+    } else if (fragment is LocalFunctionFragment) {
       if (node is FunctionDeclaration && _hasOffset2(node.name)) {
         result = node;
       }
-    } else if (element is LocalVariableElement) {
+    } else if (fragment is LocalVariableFragment) {
       if (node is VariableDeclaration && _hasOffset2(node.name)) {
         result = node;
       }
-    } else if (element is MethodElement) {
+    } else if (fragment is MethodFragment) {
       if (node is MethodDeclaration && _hasOffset2(node.name)) {
         result = node;
       }
-    } else if (element is ParameterElement) {
+    } else if (fragment is FormalParameterFragment) {
       if (node is FormalParameter && _hasOffset2(node.name)) {
         result = node;
       }
-    } else if (element is PropertyAccessorElement) {
+    } else if (fragment is PropertyAccessorFragment) {
       if (node is FunctionDeclaration) {
         if (_hasOffset2(node.name)) {
           result = node;
@@ -125,11 +144,11 @@ class DeclarationByElementLocator extends UnifyingAstVisitor<void> {
           result = node;
         }
       }
-    } else if (element is TopLevelVariableElement) {
+    } else if (fragment is TopLevelVariableFragment) {
       if (node is VariableDeclaration && _hasOffset2(node.name)) {
         result = node;
       }
-    } else if (element is TypeAliasElement) {
+    } else if (fragment is TypeAliasFragment) {
       if (node is GenericTypeAlias) {
         if (_hasOffset2(node.name)) {
           result = node;
@@ -153,7 +172,7 @@ class DeclarationByElementLocator extends UnifyingAstVisitor<void> {
 
 class ElementDeclarationResultImpl implements ElementDeclarationResult {
   @override
-  final Element element;
+  final Fragment fragment;
 
   @override
   final AstNode node;
@@ -165,16 +184,14 @@ class ElementDeclarationResultImpl implements ElementDeclarationResult {
   final ResolvedUnitResult? resolvedUnit;
 
   ElementDeclarationResultImpl(
-      this.element, this.node, this.parsedUnit, this.resolvedUnit);
+      this.fragment, this.node, this.parsedUnit, this.resolvedUnit);
 
   @override
-  Element2 get element2 {
-    if (element case Fragment fragment) {
-      return fragment.element;
-    } else if (element case Element2 element) {
+  Element get element {
+    if (fragment case Element element) {
       return element;
     }
-    throw UnimplementedError('Could not compute and element');
+    throw UnsupportedError('${fragment.runtimeType}');
   }
 }
 
@@ -280,40 +297,44 @@ class ParsedLibraryResultImpl extends AnalysisResultImpl
 
   @override
   ElementDeclarationResult? getElementDeclaration(Element element) {
-    if (element is CompilationUnitElement ||
-        element is LibraryElement ||
-        element.isSynthetic ||
-        element.nameOffset == -1) {
+    if (element case Fragment fragment) {
+      return getFragmentDeclaration(fragment);
+    }
+    throw UnsupportedError('$runtimeType.getElementDeclaration($element)');
+  }
+
+  @override
+  ElementDeclarationResult? getElementDeclaration2(Fragment fragment) {
+    return getFragmentDeclaration(fragment);
+  }
+
+  @override
+  ElementDeclarationResult? getFragmentDeclaration(Fragment fragment) {
+    var nameOffset = _getFragmentNameOffset(fragment);
+    if (fragment is LibraryFragment || nameOffset == null) {
       return null;
     }
 
-    var elementPath = element.source!.fullName;
+    var elementPath = fragment.libraryFragment!.source.fullName;
     var unitResult = units.firstWhere(
       (r) => r.path == elementPath,
       orElse: () {
-        var elementStr = element.getDisplayString();
-        throw ArgumentError('Element (${element.runtimeType}) $elementStr is '
+        var elementStr = fragment.element.displayName;
+        throw ArgumentError('Element (${fragment.runtimeType}) $elementStr is '
             'not defined in this library.');
       },
     );
 
-    var locator = DeclarationByElementLocator(element);
+    var locator = DeclarationByElementLocator(fragment, nameOffset);
     unitResult.unit.accept(locator);
     var declaration = locator.result;
 
     if (declaration == null) {
       return null;
     }
 
-    return ElementDeclarationResultImpl(element, declaration, unitResult, null);
-  }
-
-  @override
-  ElementDeclarationResult? getElementDeclaration2(Fragment fragment) {
-    if (fragment case Element element) {
-      return getElementDeclaration(element);
-    }
-    throw UnimplementedError();
+    return ElementDeclarationResultImpl(
+        fragment, declaration, unitResult, null);
   }
 }
 
@@ -414,40 +435,44 @@ class ResolvedLibraryResultImpl extends AnalysisResultImpl
 
   @override
   ElementDeclarationResult? getElementDeclaration(Element element) {
-    if (element is CompilationUnitElement ||
-        element is LibraryElement ||
-        element.isSynthetic ||
-        element.nameOffset == -1) {
+    if (element case Fragment fragment) {
+      return getFragmentDeclaration(fragment);
+    }
+    throw UnsupportedError('$runtimeType.getElementDeclaration($element)');
+  }
+
+  @override
+  ElementDeclarationResult? getElementDeclaration2(Fragment fragment) {
+    return getFragmentDeclaration(fragment);
+  }
+
+  @override
+  ElementDeclarationResult? getFragmentDeclaration(Fragment fragment) {
+    var nameOffset = _getFragmentNameOffset(fragment);
+    if (fragment is LibraryFragment || nameOffset == null) {
       return null;
     }
 
-    var elementPath = element.source!.fullName;
+    var elementPath = fragment.libraryFragment!.source.fullName;
     var unitResult = units.firstWhere(
       (r) => r.path == elementPath,
       orElse: () {
-        var elementStr = element.getDisplayString();
-        throw ArgumentError('Element (${element.runtimeType}) $elementStr is '
+        var elementStr = fragment.element.displayName;
+        throw ArgumentError('Element (${fragment.runtimeType}) $elementStr is '
             'not defined in this library.');
       },
     );
 
-    var locator = DeclarationByElementLocator(element);
+    var locator = DeclarationByElementLocator(fragment, nameOffset);
     unitResult.unit.accept(locator);
     var declaration = locator.result;
 
     if (declaration == null) {
       return null;
     }
 
-    return ElementDeclarationResultImpl(element, declaration, null, unitResult);
-  }
-
-  @override
-  ElementDeclarationResult? getElementDeclaration2(Fragment fragment) {
-    if (fragment case Element element) {
-      return getElementDeclaration(element);
-    }
-    throw UnimplementedError();
+    return ElementDeclarationResultImpl(
+        fragment, declaration, null, unitResult);
   }
 
   @override

pkg/analyzer/lib/src/dart/analysis/session_helper.dart

@@ -45,7 +45,7 @@ class AnalysisSessionHelper {
       Fragment fragment) async {
     var libraryPath = fragment.libraryFragment!.source.fullName;
     var resolvedLibrary = await _getResolvedLibrary(libraryPath);
-    return resolvedLibrary?.getElementDeclaration2(fragment);
+    return resolvedLibrary?.getFragmentDeclaration(fragment);
   }
 
   /// Return the [EnumElement2] with the given [className] that is exported

pkg/analyzer/test/src/dart/analysis/results/get_element_declaration_test.dart

@@ -83,9 +83,8 @@ class {}
     var element =
         findNode.classDeclaration('class {}').declaredFragment!.element;
     var result = await getElementDeclaration(element);
-    var node = result!.node as ClassDeclaration;
-    expect(node.name.lexeme, '');
-    expect(node.name.offset, 6);
+    // Without a name, the class declaration cannot be found.
+    expect(result, null);
   }
 
   test_classTypeAlias() async {
@@ -367,7 +366,6 @@ void f(int a) {}
     var node = result!.node as SimpleFormalParameter;
     expect(node.name!.lexeme, 'a');
   }
-
   test_parameter_missingName_named() async {
     await resolveTestCode(r'''
 void f({@a}) {}
@@ -378,8 +376,8 @@ void f({@a}) {}
     expect(element.isNamed, isTrue);
 
     var result = await getElementDeclaration(element);
-    var node = result!.node as DefaultFormalParameter;
-    expect(node.name!.lexeme, '');
+    // Without a name, the parameter declaration cannot be found.
+    expect(result, null);
   }
 
   test_parameter_missingName_required() async {
@@ -392,8 +390,8 @@ void f(@a) {}
     expect(element.isPositional, isTrue);
 
     var result = await getElementDeclaration(element);
-    var node = result!.node as SimpleFormalParameter;
-    expect(node.name!.lexeme, '');
+    // Without a name, the parameter declaration cannot be found.
+    expect(result, null);
   }
 
   test_setter_class() async {
@@ -451,7 +449,7 @@ class GetElementDeclarationParsedTest extends PubPackageResolutionTest
     var path = element.library2!.firstFragment.source.fullName;
     var file = getFile(path);
     var library = await _getParsedLibrary(file);
-    return library.getElementDeclaration2(element.firstFragment);
+    return library.getFragmentDeclaration(element.firstFragment);
   }
 
   Future<ParsedLibraryResult> _getParsedLibrary(File file) async {
@@ -469,7 +467,7 @@ class GetElementDeclarationResolvedTest extends PubPackageResolutionTest
     var path = element.library2!.firstFragment.source.fullName;
     var file = getFile(path);
     var library = await _getResolvedLibrary(file);
-    return library.getElementDeclaration2(element.firstFragment);
+    return library.getFragmentDeclaration(element.firstFragment);
   }
 
   Future<ResolvedLibraryResult> _getResolvedLibrary(File file) async {