[CFE] Fix crash when serializing expression compilation procedure with deferred import

#48587

Change-Id: I37cc8313886d626edafbe04acfef90b0fe666622
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/238043
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Jens Johansen <[email protected]>

Author: jensjoha

pkg/front_end/lib/src/fasta/kernel/utils.dart

@@ -96,6 +96,20 @@ Uint8List serializeComponent(Component component,
 
 const String kDebugClassName = "#DebugClass";
 
+class _CollectLibraryDependencies extends RecursiveVisitor {
+  Set<LibraryDependency> foundLibraryDependencies = {};
+
+  @override
+  void visitLoadLibrary(LoadLibrary node) {
+    foundLibraryDependencies.add(node.import);
+  }
+
+  @override
+  void visitCheckLibraryIsLoaded(CheckLibraryIsLoaded node) {
+    foundLibraryDependencies.add(node.import);
+  }
+}
+
 Component createExpressionEvaluationComponent(Procedure procedure) {
   Library realLibrary = procedure.enclosingLibrary;
 
@@ -106,6 +120,17 @@ Component createExpressionEvaluationComponent(Procedure procedure) {
     ..nonNullableByDefaultCompiledMode =
         realLibrary.nonNullableByDefaultCompiledMode;
 
+  // Add deferred library dependencies. They are needed for serializing
+  // references to deferred libraries. We can just claim ownership of the ones
+  // we find as they were created when doing the expression compilation.
+  _CollectLibraryDependencies collectLibraryDependencies =
+      new _CollectLibraryDependencies();
+  procedure.accept(collectLibraryDependencies);
+  for (LibraryDependency libraryDependency
+      in collectLibraryDependencies.foundLibraryDependencies) {
+    fakeLibrary.addDependency(libraryDependency);
+  }
+
   TreeNode? realClass = procedure.parent;
   if (realClass is Class) {
     Class fakeClass = new Class(name: kDebugClassName, fileUri: uri)

pkg/front_end/testcases/expression/issue_48587.expression.yaml

@@ -0,0 +1,27 @@
+# Copyright (c) 2018, 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.
+
+# Check the expression compilation (including serialization) of usage of a
+# deferred import works.
+
+sources:
+  main.dart: |
+    import 'import.dart' deferred as d;
+
+    void main() {
+      print('hello');
+    }
+
+    Future<void> printDeferred() async {
+      d.deferredPrintLocal();
+    }
+
+  import.dart: |
+    void deferredPrintLocal() {
+      print('hello from deferred library');
+    }
+definitions: []
+position: "main.dart"
+expression: |
+  d.deferredPrintLocal()

pkg/front_end/testcases/expression/issue_48587.expression.yaml.expect

@@ -0,0 +1,4 @@
+Errors: {
+}
+method /* from org-dartlang-debug:synthetic_debug_expression */ debugExpr() → dynamic
+  return let final dynamic #t1 = CheckLibraryIsLoaded(d) in #lib1::deferredPrintLocal();