Serialize exports scopes.

pkg/front_end/lib/src/fasta/dill/dill_library_builder.dart

 // Copyright (c) 2016, 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.
 
 library fasta.dill_library_builder;
 
+import 'dart:convert' show JSON;
+
 import 'package:kernel/ast.dart'
-    show Class, Field, Library, ListLiteral, Member, StaticGet, Typedef;
+    show
+        Class,
+        Field,
+        Library,
+        ListLiteral,
+        Member,
+        StaticGet,
+        StringLiteral,
+        Typedef;
+
+import '../fasta_codes.dart' show templateUnspecified;
 
 import '../problems.dart' show unimplemented;
 
 import '../kernel/kernel_builder.dart'
     show
         Builder,
         InvalidTypeBuilder,
         KernelInvalidTypeBuilder,
         KernelTypeBuilder,
         LibraryBuilder,
         Scope;
 
 import '../kernel/redirecting_factory_body.dart' show RedirectingFactoryBody;
 
 import 'dill_class_builder.dart' show DillClassBuilder;
 
 import 'dill_member_builder.dart' show DillMemberBuilder;
 
 import 'dill_loader.dart' show DillLoader;
 
 import 'dill_typedef_builder.dart' show DillFunctionTypeAliasBuilder;
 
 class DillLibraryBuilder extends LibraryBuilder<KernelTypeBuilder, Library> {
   final Uri uri;
 
   final DillLoader loader;
 
   Library library;
 
+  /// Exports in addition to the members declared in this library.
+  ///
+  /// Each entry in the list is either two or three elements long.
+  ///
+  /// The first element is the library URI, if it is null, this is an ambiguous
+  /// export and the list has three elements. Otherwise the list has two
+  /// elements.
+  ///
+  /// The second element is the name of the exported element.
+  ///
+  /// The third element (if present) is an error message.
+  List<List<String>> additionalExports;
+
   DillLibraryBuilder(this.uri, this.loader)
       : super(uri, new Scope.top(), new Scope.top());
 
   Uri get fileUri => uri;
 
   @override
   Library get target => library;
 
   void addClass(Class cls) {
     DillClassBuilder classBulder = new DillClassBuilder(cls, this);
     addBuilder(cls.name, classBulder, cls.fileOffset);
     cls.procedures.forEach(classBulder.addMember);
     cls.constructors.forEach(classBulder.addMember);
     for (Field field in cls.fields) {
       if (field.name.name == "_redirecting#") {
         ListLiteral initializer = field.initializer;
         for (StaticGet get in initializer.expressions) {
           RedirectingFactoryBody.restoreFromDill(get.target);
         }
         initializer.expressions.clear();
       } else {
         classBulder.addMember(field);
       }
     }
   }
 
   void addMember(Member member) {
     String name = member.name.name;
     if (name == "_exports#") {
-      // TODO(ahe): Add this to exportScope.
-      // This is a hack / work around for storing exports in dill files. See
-      // [compile_platform_dartk.dart](../analyzer/compile_platform_dartk.dart).
+      Field field = member;
+      StringLiteral string = field.initializer;
+      additionalExports = JSON.decode(string.value);
     } else {
       addBuilder(name, new DillMemberBuilder(member, this), member.fileOffset);
     }
   }
 
   Builder addBuilder(String name, Builder builder, int charOffset) {
     if (name == null || name.isEmpty) return null;
     bool isSetter = builder.isSetter;
     if (isSetter) {
       scopeBuilder.addSetter(name, builder);
@@ skipping 31 matching lines @@
     // mapping `k` to `d` is added to the exported namespace of `L` unless a
     // top-level declaration with the name `k` exists in `L`.
     if (builder.parent == this) return builder;
     return new KernelInvalidTypeBuilder(name, charOffset, fileUri);
   }
 
   @override
   String get fullNameForErrors {
     return library.name ?? "<library '${library.fileUri}'>";
   }
+
+  void finalizeExports() {
+    if (additionalExports != null) {
+      for (List<String> additionalExport in additionalExports) {
+        Uri originUri = Uri.parse(additionalExport[0]);

[Johnni Winther, 2017/08/25 11:20:42]

Test `additionalExport[0]` for `null`. Uri.parse throws otherwise.

[Siggi Cherem (dart-lang), 2017/08/25 18:50:17]

BTW - seems that flutter tools is hitting this already :(

+        String name = additionalExport[1];
+        Builder builder;
+        if (originUri == null) {
+          builder = new KernelInvalidTypeBuilder(name, -1, null,
+              templateUnspecified.withArguments(additionalExport[2]));
+        } else {
+          DillLibraryBuilder library = loader.read(originUri, -1);
+          builder = library.exportScopeBuilder[name];

[Johnni Winther, 2017/08/25 11:20:42]

-> library?.exportScopeBuilder[name];

+          if (library != null) {

[Johnni Winther, 2017/08/25 11:20:42]

Remove this if statement

+            builder = library.exportScopeBuilder[name];
+          }
+          if (builder == null) {
+            builder = new KernelInvalidTypeBuilder(name, -1, null);
+          }
+        }
+        exportScopeBuilder.addMember(name, builder);
+      }
+    }
+  }
 }