Parts. Support for exports from library fragments in ExportLocation.

Change-Id: I1f489dbbfe96b0d17e6b8bdb1df262d057f8a4b6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/386362
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

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

@@ -96,7 +96,7 @@ import 'package:meta/meta.dart';
 // TODO(scheglov): Clean up the list of implicitly analyzed files.
 class AnalysisDriver {
   /// The version of data format, should be incremented on every format change.
-  static const int DATA_VERSION = 386;
+  static const int DATA_VERSION = 387;
 
   /// The number of exception contexts allowed to write. Once this field is
   /// zero, we stop writing any new exception contexts in this process.

pkg/analyzer/lib/src/summary2/bundle_reader.dart

@@ -1016,7 +1016,7 @@ class LibraryReader {
 
   ExportLocation _readExportLocation() {
     return ExportLocation(
-      containerIndex: _reader.readUInt30(),
+      fragmentIndex: _reader.readUInt30(),
       exportIndex: _reader.readUInt30(),
     );
   }

pkg/analyzer/lib/src/summary2/bundle_writer.dart

@@ -317,7 +317,7 @@ class BundleWriter {
   }
 
   void _writeExportLocation(ExportLocation location) {
-    _sink.writeUInt30(location.containerIndex);
+    _sink.writeUInt30(location.fragmentIndex);
     _sink.writeUInt30(location.exportIndex);
   }
 

pkg/analyzer/lib/src/summary2/export.dart

@@ -76,39 +76,33 @@ class ExportedReferenceExported extends ExportedReference {
 }
 
 class ExportLocation {
-  /// The index of the container with the `export` directive, `0` means the
-  /// library itself, a positive value means a `+1` index in the library
-  /// augmentations.
-  final int containerIndex;
+  /// The index of the fragment with the `export` directive, `0` means the
+  /// library file, a positive value means an included fragment.
+  final int fragmentIndex;
 
   /// The index in [LibraryElementImpl.libraryExports].
   final int exportIndex;
 
   ExportLocation({
-    required this.containerIndex,
+    required this.fragmentIndex,
     required this.exportIndex,
   });
 
   @override
   bool operator ==(Object other) {
     return other is ExportLocation &&
-        other.containerIndex == containerIndex &&
+        other.fragmentIndex == fragmentIndex &&
         other.exportIndex == exportIndex;
   }
 
   LibraryExportElementImpl exportOf(LibraryElementImpl library) {
-    // TODO(scheglov): support for exports from parts
-    assert(containerIndex == 0);
-    return library.libraryExports[exportIndex];
-    // var container = containerIndex == 0
-    //     ? library
-    //     : library.augmentations[containerIndex - 1];
-    // return container.libraryExports[exportIndex];
+    var fragment = library.units[fragmentIndex];
+    return fragment.libraryExports[exportIndex];
   }
 
   @override
   String toString() {
-    return '($containerIndex, $exportIndex)';
+    return '($fragmentIndex, $exportIndex)';
   }
 }
 

pkg/analyzer/lib/src/summary2/library_builder.dart

@@ -142,7 +142,7 @@ class LibraryBuilder with MacroApplicationsContainer {
         var export = Export(
           exporter: this,
           location: ExportLocation(
-            containerIndex: fragmentIndex,
+            fragmentIndex: fragmentIndex,
             exportIndex: exportIndex,
           ),
           combinators: combinators,

pkg/analyzer/test/src/diagnostics/deprecated_export_use_test.dart

@@ -330,6 +330,27 @@ void f() {
     ]);
   }
 
+  test_notDeprecated_class_exportedFromPart() async {
+    newFile('$testPackageLibPath/a.dart', r'''
+class A {}
+''');
+
+    newFile('$testPackageLibPath/b.dart', r'''
+part of 'c.dart';
+export 'a.dart';
+''');
+
+    newFile('$testPackageLibPath/c.dart', r'''
+part 'b.dart';
+''');
+
+    await assertNoErrorsInCode('''
+import 'c.dart';
+
+void f(A a) {}
+''');
+  }
+
   test_notDeprecated_class_hasDirectImport() async {
     newFile('$testPackageLibPath/a.dart', r'''
 class A {}