Changes to make isolate reload functionality work with the --dfe option.

runtime/bin/loader.cc

 // 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.
 
 
 #include "bin/loader.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
+#include "bin/dfe.h"
 #include "bin/extensions.h"
 #include "bin/file.h"
 #include "bin/lockers.h"
 #include "bin/utils.h"
 #include "include/dart_tools_api.h"
 #include "platform/growable_array.h"
 
 namespace dart {
 namespace bin {
 
 // Development flag.
 static bool trace_loader = false;
+#if !defined(DART_PRECOMPILED_RUNTIME)
+extern DFE dfe;
+#endif
+
 // Keep in sync with loader.dart.
 static const intptr_t _Dart_kImportExtension = 9;
 static const intptr_t _Dart_kResolveAsFilePath = 10;
 
 Loader::Loader(IsolateData* isolate_data)
     : port_(ILLEGAL_PORT),
       isolate_data_(isolate_data),
       error_(Dart_Null()),
       monitor_(NULL),
       pending_operations_(0),
@@ skipping 599 matching lines @@
                                                Dart_Handle library,
                                                Dart_Handle url,
                                                const char* library_url_string,
                                                const char* url_string) {
   return Dart_Null();
 }
 #else
 Dart_Handle Loader::LibraryTagHandler(Dart_LibraryTag tag,
                                       Dart_Handle library,
                                       Dart_Handle url) {
+  if (dfe.UseDartFrontend()) {
+    Dart_Isolate current = Dart_CurrentIsolate();
+    if (!Dart_IsServiceIsolate(current) && !Dart_IsKernelIsolate(current)) {
+      // When using DFE the library tag handler should be called only when we
+      // are reloading scripts.
+      // TODO(asiva) We need to ensure that the kernel and service isolates
+      // and the spawnURI paths are always loaded from a kernel IR and do
+      // not use this path.
+      if (tag == Dart_kScriptTag) {
+        return dfe.ReloadScript(current, url);
+      }
+    }
+  }
   if (tag == Dart_kCanonicalizeUrl) {
     Dart_Handle library_url = Dart_LibraryUrl(library);
     if (Dart_IsError(library_url)) {
       return library_url;
     }
     return Dart_DefaultCanonicalizeUrl(library_url, url);
   }
   const char* url_string = NULL;
   Dart_Handle result = Dart_StringToCString(url, &url_string);
   if (Dart_IsError(result)) {
@@ skipping 257 matching lines @@
   MutexLocker ml(loader_infos_lock_);
   Loader* loader = LoaderForLocked(dest_port_id);
   if (loader == NULL) {
     return;
   }
   loader->QueueMessage(message);
 }
 
 }  // namespace bin
 }  // namespace dart