Elements. Add ElementDirective super-interface.

It is necessary to support source_gen with annotated directives,
e.g. to support `package:checks` code generator.

Change-Id: Ia6cf97ce7cf9a44158afb5e019805e13ffdbc96e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/402424
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Samuel Rawlins <srawlins@google.com>

Author: scheglov

pkg/analyzer/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 7.2.0-dev
+* Add `ElementDirective` as superinterface for `LibraryExport`, `LibraryImport`,
+  and `PartInclude`. It implements `Annotatable`.
+
 ## 7.1.0
 * New APIs for element model with fragments.
 

pkg/analyzer/lib/dart/element/element2.dart

@@ -524,6 +524,17 @@ abstract class Element2 {
   void visitChildren2<T>(ElementVisitor2<T> visitor);
 }
 
+/// A directive within a library fragment.
+///
+/// Clients may not extend, implement or mix-in this class.
+sealed class ElementDirective implements Annotatable {
+  /// The library fragment that contains this object.
+  LibraryFragment get libraryFragment;
+
+  /// The interpretation of the URI specified in the directive.
+  DirectiveUri get uri;
+}
+
 /// An object that can be used to visit an element structure.
 ///
 /// Clients may not extend, implement or mix-in this class. There are classes
@@ -1619,7 +1630,7 @@ abstract class LibraryElement2 implements Element2, Annotatable {
 /// An `export` directive within a library fragment.
 ///
 /// Clients may not extend, implement or mix-in this class.
-abstract class LibraryExport implements Annotatable {
+abstract class LibraryExport implements ElementDirective {
   /// The combinators that were specified as part of the `export` directive.
   ///
   /// The combinators are in the order in which they were specified.
@@ -1630,9 +1641,6 @@ abstract class LibraryExport implements Annotatable {
 
   /// The offset of the `export` keyword.
   int get exportKeywordOffset;
-
-  /// The interpretation of the URI specified in the directive.
-  DirectiveUri get uri;
 }
 
 /// The portion of a [LibraryElement2] coming from a single compilation unit.
@@ -1718,7 +1726,7 @@ abstract class LibraryFragment implements Fragment, Annotatable {
 /// An `import` directive within a library fragment.
 ///
 /// Clients may not extend, implement or mix-in this class.
-abstract class LibraryImport implements Annotatable {
+abstract class LibraryImport implements ElementDirective {
   /// The combinators that were specified as part of the `import` directive.
   ///
   /// The combinators are in the order in which they were specified.
@@ -1737,19 +1745,13 @@ abstract class LibraryImport implements Annotatable {
   /// an implicit import of `dart:core`.
   bool get isSynthetic;
 
-  /// The library fragment that contains this object.
-  LibraryFragment? get libraryFragment;
-
   /// The [Namespace] that this directive contributes to the containing library.
   Namespace get namespace;
 
   /// The prefix fragment that was specified as part of the import directive.
   ///
   /// Returns `null` if there was no prefix specified.
   PrefixFragment? get prefix2;
-
-  /// The interpretation of the URI specified in the directive.
-  DirectiveUri get uri;
 }
 
 /// An element that can be (but is not required to be) defined within a method
@@ -2090,9 +2092,9 @@ abstract class MultiplyDefinedFragment implements Fragment {
 /// A 'part' directive within a library fragment.
 ///
 /// Clients may not extend, implement or mix-in this class.
-abstract class PartInclude {
-  /// The interpretation of the URI specified in the directive.
-  DirectiveUri get uri;
+abstract class PartInclude implements ElementDirective {
+  /// The [LibraryFragment], if [uri] is a [DirectiveUriWithUnit].
+  LibraryFragment? get includedFragment;
 }
 
 /// A pattern variable.

pkg/analyzer/lib/src/dart/element/element.dart

@@ -7251,6 +7251,9 @@ class LibraryExportElementImpl extends _ExistingElementImpl
   @override
   ElementKind get kind => ElementKind.EXPORT;
 
+  @override
+  LibraryFragment get libraryFragment => enclosingElement3;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) {
     return visitor.visitLibraryExportElement(this);
@@ -7321,7 +7324,7 @@ class LibraryImportElementImpl extends _ExistingElementImpl
   LibraryElementImpl get library2 => super.library2 as LibraryElementImpl;
 
   @override
-  LibraryFragment? get libraryFragment => enclosingElement3;
+  LibraryFragment get libraryFragment => enclosingElement3;
 
   @override
   Namespace get namespace {
@@ -9265,9 +9268,20 @@ class PartElementImpl extends _ExistingElementImpl
   @override
   String get identifier => 'part';
 
+  @override
+  LibraryFragment? get includedFragment {
+    if (uri case DirectiveUriWithUnit uri) {
+      return uri.libraryFragment;
+    }
+    return null;
+  }
+
   @override
   ElementKind get kind => ElementKind.PART;
 
+  @override
+  LibraryFragment get libraryFragment => enclosingUnit;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) => visitor.visitPartElement(this);
 

pkg/analyzer/pubspec.yaml

@@ -1,5 +1,5 @@
 name: analyzer
-version: 7.1.0
+version: 7.2.0-dev
 description: >-
   This package provides a library that performs static analysis of Dart code.
 repository: https://github.com/dart-lang/sdk/tree/main/pkg/analyzer