[CFE/kernel] Test of relink bug with ExtensionTypeDeclaration

Tests for fix done in
https://dart-review.googlesource.com/c/sdk/+/350801.

Change-Id: I01a6512dc5de3e91f698828d99097a083d392972
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/352061
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>

pkg/kernel/lib/src/tool/find_referenced_libraries.dart

@@ -4,8 +4,10 @@
 
 import 'package:kernel/ast.dart';
 
-Set<Library> findAllReferencedLibraries(List<Library> from) {
-  _LibraryCollector collector = new _LibraryCollector();
+Set<Library> findAllReferencedLibraries(List<Library> from,
+    {bool collectViaReferencesToo = false}) {
+  _LibraryCollector collector =
+      new _LibraryCollector(collectViaReferencesToo: collectViaReferencesToo);
   for (Library library in from) {
     collector.visitLibrary(library);
   }
@@ -21,13 +23,23 @@ bool duplicateLibrariesReachable(List<Library> from) {
 }
 
 class _LibraryCollector extends RecursiveVisitor {
+  final bool collectViaReferencesToo;
   Set<Library> allSeenLibraries = {};
 
+  _LibraryCollector({required this.collectViaReferencesToo});
+
   @override
   void defaultNode(Node node) {
     if (node is NamedNode) {
       // Named nodes can be linked to.
       seen(node);
+      if (collectViaReferencesToo) {
+        TreeNode? refNode = node.reference.node;
+        if (refNode != null && !identical(refNode, node)) {
+          // This is generally pretty bad.
+          seen(refNode);
+        }
+      }
     } else if (node is Name) {
       if (node.library != null) {
         seen(node.library!);

pkg/kernel/test/binary/relink_platform_test.dart

@@ -0,0 +1,87 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// 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 'dart:io';
+
+import 'package:kernel/binary/ast_from_binary.dart';
+import 'package:kernel/kernel.dart';
+import 'package:kernel/src/tool/find_referenced_libraries.dart';
+
+import '../relink_test.dart';
+import 'find_sdk_dills.dart';
+
+void main() {
+  List<File> dills = findSdkDills();
+  print("Found ${dills.length} dills!");
+
+  for (File dill in dills) {
+    readAndRelink(dill);
+  }
+}
+
+void readAndRelink(File dill) {
+  print("Reading $dill");
+  List<int> bytes = dill.readAsBytesSync();
+
+  try {
+    // Loading a component it should be self-contained.
+    Component component1 = new Component();
+    new BinaryBuilder(bytes,
+            alwaysCreateNewNamedNodes: true, disableLazyReading: true)
+        .readComponent(component1);
+    checkReachable(component1);
+
+    // Loading a component it should be self-contained.
+    Component component2 = new Component(nameRoot: component1.root);
+    new BinaryBuilder(bytes,
+            alwaysCreateNewNamedNodes: true, disableLazyReading: true)
+        .readComponent(component2);
+    checkReachable(component2);
+
+    // Now that we read "component 2" on top of "component 1" the 1-version is
+    // no longer self-contained.
+    try {
+      checkReachable(component1);
+      throw "Expected this one to fail.";
+    } catch (e) {
+      // Expected.
+    }
+
+    // Relinking it it should be back to being self contained though.
+    component1.relink();
+    checkReachable(component1);
+
+    // Now that component 1 is relinked component 2 is no longer self contained.
+    try {
+      checkReachable(component2);
+      throw "Expected this one to fail.";
+    } catch (e) {
+      // Expected.
+    }
+
+    // But relinking makes it self-contained again.
+    component2.relink();
+    checkReachable(component2);
+  } catch (e, st) {
+    print("Error for $dill:");
+    print(e);
+    print(st);
+    print("");
+    print("--------------------");
+    print("");
+    exitCode = 1;
+  }
+}
+
+void checkReachable(Component component) {
+  expectReachable(
+      findAllReferencedLibraries(component.libraries), component.libraries);
+  expectReachable(
+      findAllReferencedLibraries(component.libraries,
+          collectViaReferencesToo: true),
+      component.libraries);
+  if (duplicateLibrariesReachable(component.libraries)) {
+    throw "Didn't expect duplicates libraries!";
+  }
+}

pkg/kernel/test/relink_test.dart

@@ -80,6 +80,10 @@ void main() {
     // After the relink only the libs from component1Prime are reachable!
     expectReachable(findAllReferencedLibraries(component1Prime.libraries),
         component1Prime.libraries);
+    expectReachable(
+        findAllReferencedLibraries(component1Prime.libraries,
+            collectViaReferencesToo: true),
+        component1Prime.libraries);
     if (duplicateLibrariesReachable(component1Prime.libraries)) {
       throw "Didn't expect duplicates libraries!";
     }
@@ -103,6 +107,10 @@ void main() {
     // After the relink only the libs from component1Prime are reachable!
     expectReachable(findAllReferencedLibraries(component2Prime.libraries),
         component2Prime.libraries);
+    expectReachable(
+        findAllReferencedLibraries(component2Prime.libraries,
+            collectViaReferencesToo: true),
+        component2Prime.libraries);
     if (duplicateLibrariesReachable(component2Prime.libraries)) {
       throw "Didn't expect duplicates libraries!";
     }
@@ -160,6 +168,21 @@ Component createComponent(int literal) {
       fileUri: libUri);
   lib.addProcedure(libProcedure);
 
+  ExtensionTypeDeclaration extensionTypeDeclaration =
+      new ExtensionTypeDeclaration(name: "Foo", fileUri: libUri);
+  extensionTypeDeclaration.declaredRepresentationType = DynamicType();
+  extensionTypeDeclaration.representationName = "extensionTypeMethod";
+  final Block extensionTypeProcedureBody =
+      new Block([new ReturnStatement(new IntLiteral(literal))]);
+  final Procedure extensionTypeProcedure = new Procedure(
+      new Name("extensionTypeMethod"),
+      ProcedureKind.Method,
+      new FunctionNode(extensionTypeProcedureBody,
+          returnType: new DynamicType()),
+      fileUri: libUri);
+  extensionTypeDeclaration.addProcedure(extensionTypeProcedure);
+  lib.addExtensionTypeDeclaration(extensionTypeDeclaration);
+
   final Uri mainUri = Uri.parse('org-dartlang:///main.dart');
   final Library main = new Library(mainUri, fileUri: mainUri);
   final Block mainProcedureBody = new Block([