Merge the work on Generic Types Reification from 'dart-lang/reify' repo

pkg/kernel/lib/transformations/reify/reify_transformer.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.transformations.reify.standalone_runner;
+
+import 'analysis/program_analysis.dart';
+import 'dart:io' show File, IOSink;
+
+import 'package:kernel/binary/ast_to_binary.dart' show BinaryPrinter;
+
+import 'package:kernel/ast.dart';
+
+import 'package:kernel/verifier.dart';
+import 'package:kernel/text/ast_to_text.dart' show Printer;
+
+import 'package:kernel/repository.dart' show Repository;
+
+import 'package:kernel/binary/loader.dart' show BinaryLoader;
+
+import 'transformation/remove_generics.dart';
+import 'transformation/transformer.dart'
+    show ReifyVisitor, RuntimeLibrary, RuntimeTypeSupportBuilder;
+
+import 'package:kernel/core_types.dart' show CoreTypes;
+
+RuntimeLibrary findRuntimeTypeLibrary(Program p) {
+  Library findLibraryEndingWith(String postfix) {
+    Iterable<Library> candidates = p.libraries.where((Library l) {
+      return l.importUri.toString().endsWith(postfix);
+    });
+    if (candidates.length != 1) {
+      String howMany = candidates.isEmpty ? "No" : "Multiple";
+      throw new Exception(
+          "$howMany candidates for runtime support library found.");
+    }
+    return candidates.single;
+  }
+
+  Library types = findLibraryEndingWith("reify/types.dart");
+  Library declarations = findLibraryEndingWith("reify/declarations.dart");
+  Library interceptors = findLibraryEndingWith("reify/interceptors.dart");
+  return new RuntimeLibrary(types, declarations, interceptors);
+}
+
+Program transformProgramUsingLibraries(
+    Program program, RuntimeLibrary runtimeLibrary,
+    [Library libraryToTransform]) {
+  LibraryFilter filter = libraryToTransform != null
+      ? (Library library) => library == libraryToTransform
+      : (_) => true;
+  ProgramKnowledge knowledge = analyze(program, analyzeLibrary: filter);
+  Library mainLibrary = program.mainMethod.parent;
+  RuntimeTypeSupportBuilder builder = new RuntimeTypeSupportBuilder(
+      runtimeLibrary, new CoreTypes(program), mainLibrary);
+  ReifyVisitor transformer =
+      new ReifyVisitor(runtimeLibrary, builder, knowledge, libraryToTransform);
+  // Transform the main program.
+  program = program.accept(transformer);
+  if (!filter(runtimeLibrary.interceptorsLibrary)) {
+    // We need to transform the interceptor function in any case to make sure
+    // that the type literals in the interceptor function are rewritten.
+    runtimeLibrary.interceptorFunction.accept(transformer);
+  }
+  builder.createDeclarations();
+  program = program.accept(new Erasure(transformer));
+  // TODO(karlklose): skip checks in debug mode
+  verifyProgram(program);
+  return program;
+}
+
+Program transformProgram(Program program) {
+  RuntimeLibrary runtimeLibrary = findRuntimeTypeLibrary(program);
+  Library mainLibrary = program.mainMethod.enclosingLibrary;
+  return transformProgramUsingLibraries(program, runtimeLibrary, mainLibrary);
+}
+
+main(List<String> arguments) async {
+  String path = arguments.first;
+  Uri output;
+  if (arguments.length > 1) {
+    output = Uri.base.resolve(arguments[1]);
+  }
+  Uri uri = Uri.base.resolve(path);
+  Repository repository = new Repository();
+  Program program = new BinaryLoader(repository).loadProgram(uri.toFilePath());
+
+  RuntimeLibrary runtimeLibrary = findRuntimeTypeLibrary(program);
+  Library mainLibrary = program.mainMethod.enclosingLibrary;
+  program =
+      transformProgramUsingLibraries(program, runtimeLibrary, mainLibrary);
+
+  if (output == null) {
+    // Print result
+    StringBuffer sb = new StringBuffer();
+    Printer printer = new Printer(sb);
+    printer.writeLibraryFile(mainLibrary);
+    print("$sb");
+  } else {
+    IOSink sink = new File.fromUri(output).openWrite();
+    try {
+      new BinaryPrinter(sink).writeProgramFile(program);
+    } finally {
+      await sink.close();
+    }
+    try {
+      // Check that we can read the binary file.
+      new BinaryLoader(new Repository()).loadProgram(output.toFilePath());
+    } catch (e) {
+      print("Error when attempting to read $output.");
+      rethrow;
+    }
+  }
+}