Build up and pass MemoryFileSystem to fasta frontend.

utils/kernel-service/kernel-service.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.
 
 /// This is an interface to the Dart Kernel parser and Kernel binary generator.
 ///
 /// It is used by the kernel-isolate to load Dart source code and generate
 /// Kernel binary format.
 ///
 /// This is either invoked as the root script of the Kernel isolate when used
 /// as a part of
 ///
 ///         dart --dfe=utils/kernel-service/kernel-service.dart ...
 ///
 /// invocation or it is invoked as a standalone script to perform training for
 /// the app-jit snapshot
 ///
 ///         dart utils/kernel-service/kernel-service.dart --train <source-file>
 ///
 ///
 library runtime.tools.kernel_service;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
 
+import 'package:front_end/memory_file_system.dart';
+import 'package:front_end/physical_file_system.dart';
 import 'package:front_end/src/fasta/vm.dart'
-    show CompilationResult, Status, parseScript;
+    show CompilationResult, Status, parseScriptInFileSystem;
 
 const bool verbose = const bool.fromEnvironment('DFE_VERBOSE');
 
 const bool strongMode = const bool.fromEnvironment('DFE_STRONG_MODE');
 
-Future<CompilationResult> _processLoadRequestImpl(String inputFilePathOrUri) {
+Future<CompilationResult> _processLoadRequestImpl(
+    String inputFilePathOrUri, FileSystem fileSystem) {
   Uri scriptUri = Uri.parse(inputFilePathOrUri);
 
   // Because we serve both Loader and bootstrapping requests we need to
   // duplicate the logic from _resolveScriptUri(...) here and attempt to
   // resolve schemaless uris using current working directory.
   if (!scriptUri.hasScheme) {
     // Script does not have a scheme, assume that it is a path,
     // resolve it against the working directory.
     scriptUri = Uri.base.resolveUri(new Uri.file(inputFilePathOrUri));
   }
 
   if (!scriptUri.isScheme('file')) {
     // TODO(vegorov): Reuse loader code to support other schemes.
     return new Future<CompilationResult>.value(new CompilationResult.error(
         "Expected 'file' scheme for a script uri: got ${scriptUri.scheme}"));
   }
-
-  return parseScript(scriptUri, verbose: verbose, strongMode: strongMode);
+  return parseScriptInFileSystem(scriptUri, fileSystem,
+      verbose: verbose, strongMode: strongMode);
 }
 
 // Process a request from the runtime. See KernelIsolate::CompileToKernel in
 // kernel_isolate.cc and Loader::SendKernelRequest in loader.cc.
 Future _processLoadRequest(request) async {
   if (verbose) {
     print("DFE: request: $request");
     print("DFE: Platform.packageConfig: ${Platform.packageConfig}");
     print("DFE: Platform.resolvedExecutable: ${Platform.resolvedExecutable}");
   }
 
   int tag = request[0];
   final SendPort port = request[1];
   final String inputFileUrl = request[2];
+  FileSystem fileSystem = request.length > 3
+      ? _buildMemoryFileSystem(request[3])
+      : PhysicalFileSystem.instance;
 
   CompilationResult result;
   try {
-    result = await _processLoadRequestImpl(inputFileUrl);
+    result = await _processLoadRequestImpl(inputFileUrl, fileSystem);
   } catch (error, stack) {
     result = new CompilationResult.crash(error, stack);
   }
 
   if (verbose) {
     print("DFE:> ${result}");
   }
 
   // Check whether this is a Loader request or a bootstrapping request from
   // KernelIsolate::CompileToKernel.
   final isBootstrapRequest = tag == null;
   if (isBootstrapRequest) {
     port.send(result.toResponse());
   } else {
     // See loader.cc for the code that handles these replies.
     if (result.status != Status.ok) {
       tag = -tag;
     }
     port.send([tag, inputFileUrl, inputFileUrl, null, result.payload]);
   }
 }
 
+// Given namedSources list of interleaved file name string and
+// raw file content Uint8List this function builds up and returns
+// MemoryFileSystem instance that can be used instead of
+// PhysicalFileSystem.instance by the frontend.
+FileSystem _buildMemoryFileSystem(List namedSources) {
+  FileSystem fileSystem = new MemoryFileSystem(Uri.parse('file:///'));
+  for (int i = 0; i < namedSources.length ~/ 2; i++) {
+    fileSystem
+        .entityForUri(Uri.parse(namedSources[i * 2]))
+        .writeAsBytesSync(namedSources[i * 2 + 1]);
+  }
+  return fileSystem;
+}
+
 train(String scriptUri) {
   // TODO(28532): Enable on Windows.
   if (Platform.isWindows) return;
 
   var tag = 1;
   var responsePort = new RawReceivePort();
   responsePort.handler = (response) {
     if (response[0] == tag) {
       // Success.
       responsePort.close();
@@ skipping 11 matching lines @@
 main([args]) {
   if (args?.length == 2 && args[0] == '--train') {
     // This entry point is used when creating an app snapshot. The argument
     // provides a script to compile to warm-up generated code.
     train(args[1]);
   } else {
     // Entry point for the Kernel isolate.
     return new RawReceivePort()..handler = _processLoadRequest;
   }
 }