dart2js: Emit libraries that are only used for typedefs.

pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart

 // Copyright (c) 2014, 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.
 
 part of dart2js.js_emitter;
 
 
 class OldEmitter implements Emitter {
   final Compiler compiler;
   final CodeEmitterTask task;
@@ skipping 1111 matching lines @@
         MyClass.prototype = properties;
         new MyClass();
         #;
         return properties;
       }''', [debugCode]);
 
     output.addBuffer(jsAst.prettyPrint(convertToFastObject, compiler));
     output.add(N);
   }
 
-  void writeLibraryDescriptors(CodeOutput output, LibraryElement library) {
+  void writeLibraryDescriptor(CodeOutput output, LibraryElement library) {
     var uri = "";
     if (!compiler.enableMinification || backend.mustPreserveUris) {
       uri = library.canonicalUri;
       if (uri.scheme == 'file' && compiler.outputUri != null) {
         uri = relativize(compiler.outputUri, library.canonicalUri, false);
       }
     }
     ClassBuilder descriptor = elementDescriptors[library];
     if (descriptor == null) {
       // Nothing of the library was emitted.
@@ skipping 282 matching lines @@
     Iterable<LibraryElement> libraries =
         task.outputLibraryLists[mainOutputUnit];
     if (libraries == null) libraries = [];
     emitTypedefs();
     emitMangledNames(mainOutput);
 
     checkEverythingEmitted(elementDescriptors.keys);
 
     CodeBuffer libraryBuffer = new CodeBuffer();
     for (LibraryElement library in Elements.sortedByPosition(libraries)) {
-      writeLibraryDescriptors(libraryBuffer, library);
+      writeLibraryDescriptor(libraryBuffer, library);
       elementDescriptors.remove(library);
     }
 
+    if (elementDescriptors.isNotEmpty) {
+      List<Element> remainingLibraries = elementDescriptors.keys
+          .where((Element e) => e is LibraryElement)
+          .toList();
+
+      // The remaining descriptors are only accessible through reflection.
+      // The program builder does not collect libraries that only
+      // contain typedefs that are used for reflection.
+      for (LibraryElement element in remainingLibraries) {
+        assert(element is LibraryElement || compiler.hasIncrementalSupport);
+        if (element is LibraryElement) {
+          writeLibraryDescriptor(libraryBuffer, element);
+          elementDescriptors.remove(element);
+        }
+      }
+    }
+
     bool needsNativeSupport = program.needsNativeSupport;
     mainOutput
         ..addBuffer(
             jsAst.prettyPrint(
                 getReflectionDataParser(this, backend, needsNativeSupport),
                 compiler))
         ..add(n);
 
     // The argument to reflectionDataParser is assigned to a temporary 'dart'
     // so that 'dart.' will appear as the prefix to dart methods in stack
@@ skipping 249 matching lines @@
 
       if (elementDescriptors.isNotEmpty) {
         Iterable<LibraryElement> libraries =
             task.outputLibraryLists[outputUnit];
         if (libraries == null) libraries = [];
 
         // TODO(johnniwinther): Avoid creating [CodeBuffer]s.
         CodeBuffer buffer = new CodeBuffer();
         outputBuffers[outputUnit] = buffer;
         for (LibraryElement library in Elements.sortedByPosition(libraries)) {
-          writeLibraryDescriptors(buffer, library);
+          writeLibraryDescriptor(buffer, library);
           elementDescriptors.remove(library);
         }
       }
     }
 
     return emitDeferredCode(program, outputBuffers);
   }
 
   int emitProgram(ProgramBuilder programBuilder) {
     Program program = programBuilder.buildProgram(
@@ skipping 302 matching lines @@
     for (Element element in compiler.enqueuer.codegen.newlyEnqueuedElements) {
       if (element.isInstanceMember) {
         cachedClassBuilders.remove(element.enclosingClass);
 
         nativeEmitter.cachedBuilders.remove(element.enclosingClass);
 
       }
     }
   }
 }