Compute exported top-level declarations.

pkg/analyzer/lib/src/dart/analysis/file_state.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.
 
 import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/error/listener.dart';
@@ skipping 84 matching lines @@
   List<FileState> _importedFiles;
   List<FileState> _exportedFiles;
   List<FileState> _partedFiles;
   List<NameFilter> _exportFilters;
 
   Set<FileState> _directReferencedFiles = new Set<FileState>();
   Set<FileState> _transitiveFiles;
   String _transitiveSignature;
 
   List<TopLevelDeclaration> _topLevelDeclarations;
+  List<TopLevelDeclaration> _exportTopLevelDeclarations;
 
   FileState._(this._fsState, this.path, this.uri, this.source);
 
   /**
    * The unlinked API signature of the file.
    */
   List<int> get apiSignature => _apiSignature;
 
   /**
    * The content of the file.
    */
   String get content => _content;
 
   /**
    * The MD5 hash of the [content].
    */
   String get contentHash => _contentHash;
 
   /**
    * Return the set of all directly referenced files - imported, exported or
    * parted.
    */
   Set<FileState> get directReferencedFiles => _directReferencedFiles;
 
   /**
    * The list of files this file exports.
    */
   List<FileState> get exportedFiles => _exportedFiles;
 
+  /**
+   * Return [TopLevelDeclaration]s exported from the this library file.
+   */
+  List<TopLevelDeclaration> get exportTopLevelDeclarations {

[Paul Berry, 2016/12/01 21:16:10]

This sounds like the name of a method with takes some top level declarations and
exports them.  Consider renaming to "exportedTopLevelDeclarations".

[scheglov, 2016/12/01 21:39:56]

Done.

+    if (_exportTopLevelDeclarations == null) {
+      _exportTopLevelDeclarations = <TopLevelDeclaration>[];
+
+      Set<FileState> seenLibraries = new Set<FileState>();
+
+      /**
+       * Compute [TopLevelDeclaration]s exported from the [library].
+       */
+      List<TopLevelDeclaration> computeExported(FileState library) {

[Paul Berry, 2016/12/01 21:16:10]

I think there's a bug.  Consider the following:

a.dart:
export 'b.dart' show Foo;
export 'c.dart' show Bar;

b.dart:
export 'd.dart';

c.dart:
export 'd.dart';

d.dart:
class Foo {}
class Bar {}

The first time we call computeExported() for d.dart, we're calling in the
context of b.dart, so we'll filter out Bar and only find Foo.  The second time
we call computeExported() for d.dart, we're calling in the context of c.dart. 
But since seenLibraries already contains d.dart at that point, we'll return an
empty list.  So Bar will get missed.

[scheglov, 2016/12/01 21:39:56]

You're right.
Fixed.

+        var declarations = <String, TopLevelDeclaration>{};
+        if (seenLibraries.add(library)) {
+          // Append the library declarations.
+          for (TopLevelDeclaration t in library.topLevelDeclarations) {
+            declarations[t.name] = t;

[Brian Wilkerson, 2016/12/01 21:07:47]

I think we need to test for private names both here and on line 156.

[scheglov, 2016/12/01 21:39:56]

Done.

+          }
+          for (FileState part in library.partedFiles) {
+            for (TopLevelDeclaration t in part.topLevelDeclarations) {
+              declarations[t.name] = t;
+            }
+          }
+
+          // Append the exported declarations.
+          for (int i = 0; i < library._exportedFiles.length; i++) {
+            List<TopLevelDeclaration> exported =
+                computeExported(library._exportedFiles[i]);
+            for (TopLevelDeclaration t in exported) {
+              if (!declarations.containsKey(t.name) &&
+                  library._exportFilters[i].accepts(t.name)) {
+                declarations[t.name] = t;
+              }
+            }
+          }
+        }
+
+        return declarations.values.toList();
+      }
+
+      _exportTopLevelDeclarations = computeExported(this);
+    }
+    return _exportTopLevelDeclarations;
+  }
+
   @override
   int get hashCode => uri.hashCode;
 
   /**
    * The list of files this file imports.
    */
   List<FileState> get importedFiles => _importedFiles;
 
   /**
    * Return `true` if the file has a `part of` directive, so is probably a part.
@@ skipping 201 matching lines @@
           _fsState._byteStore.put(unlinkedKey, bytes);
         });
       }
     }
 
     // Read the unlinked bundle.
     var driverUnlinkedUnit = new AnalysisDriverUnlinkedUnit.fromBuffer(bytes);
     _referencedNames = new Set<String>.from(driverUnlinkedUnit.referencedNames);
     _unlinked = driverUnlinkedUnit.unit;
     _lineInfo = new LineInfo(_unlinked.lineStarts);
+    _topLevelDeclarations = null;
+
+    // Prepare API signature.
     List<int> newApiSignature = _unlinked.apiSignature;
     bool apiSignatureChanged = _apiSignature != null &&
         !_equalByteLists(_apiSignature, newApiSignature);
     _apiSignature = newApiSignature;
 
-    // If the API signature changed, flush transitive signatures.
+    // The API signature changed.
+    //   Flush transitive signatures of affected files.
+    //   Flush exported top-level declarations of all files.
     if (apiSignatureChanged) {
       for (FileState file in _fsState._uriToFile.values) {
         if (file._transitiveFiles != null &&
             file._transitiveFiles.contains(this)) {
           file._transitiveSignature = null;
         }
+        file._exportTopLevelDeclarations = null;
       }
     }
 
     // This file is potentially not a library for its previous parts anymore.
     if (_partedFiles != null) {
       for (FileState part in _partedFiles) {
         _fsState._partToLibraries[part]?.remove(this);
       }
     }
 
@@ skipping 235 matching lines @@
         .where((f) => f._transitiveFiles == null)
         .toSet();
   }
 
   Set<FileState> get filesWithoutTransitiveSignature {
     return state._uriToFile.values
         .where((f) => f._transitiveSignature == null)
         .toSet();
   }
 }