Read platform.dill in the VM.

pkg/kernel/lib/binary/ast_to_binary.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 kernel.ast_to_binary;
 
 import '../ast.dart';
 import '../import_table.dart';
 import 'tag.dart';
 import 'dart:convert';
 import 'dart:typed_data';
@@ skipping 1001 matching lines @@
   visitTypeParameter(TypeParameter node) {
     writeStringReference(node.name ?? '');
     writeNode(node.bound);
   }
 
   defaultNode(Node node) {
     throw 'Unsupported node: $node';
   }
 }
 
+/// A [LibraryFilteringBinaryPrinter] can write a subset of libraries.
+///
+/// This printer writes a Kernel binary but includes only libraries that match a
+/// predicate.
+class LibraryFilteringBinaryPrinter extends BinaryPrinter {
+  final Function predicate;
+
+  LibraryFilteringBinaryPrinter(
+      Sink<List<int>> sink, bool predicate(Library library))
+      : predicate = predicate,
+        super(sink);
+
+  void writeProgramFile(Program program) {
+    program.computeCanonicalNames();
+    writeMagicWord(Tag.ProgramFile);
+    _stringIndexer.scanProgram(program);
+    writeStringTable(_stringIndexer);
+    writeUriToSource(program);
+    writeLinkTable(program);
+    writeList(program.libraries.where(predicate), writeNode);
+    writeMemberReference(program.mainMethod, allowNull: true);
+    _flush();
+  }
+}
+
 class VariableIndexer {
   final Map<VariableDeclaration, int> index = <VariableDeclaration, int>{};
   final List<int> scopes = <int>[];
   int stackHeight = 0;
 
   void declare(VariableDeclaration node) {
     index[node] = stackHeight++;
   }
 
   void pushScope() {
@@ skipping 276 matching lines @@
   void flush() {
     _sink.add(_buffer.sublist(0, length));
     _buffer = new Uint8List(SIZE);
     length = 0;
   }
 
   void flushAndDestroy() {
     _sink.add(_buffer.sublist(0, length));
   }
 }