Adapt gen_snapshot to the recent changes in bootstrap sources loading scheme.

runtime/bin/gen_snapshot.cc

 // Copyright (c) 2013, 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.
 
 // Generate a snapshot file after loading all the scripts specified on the
 // command line.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
@@ skipping 249 matching lines @@
     }
   }
 
   Dart_Handle result = failed ? Dart_NewApiError(result_string) :
                                 DartUtils::NewString(result_string);
   free(result_string);
   return result;
 }
 
 
+static Builtin::BuiltinLibraryId BuiltinId(const char* url) {
+  if (DartUtils::IsDartBuiltinLibURL(url)) {
+    return Builtin::kBuiltinLibrary;
+  }
+  if (DartUtils::IsDartIOLibURL(url)) {
+    return Builtin::kIOLibrary;
+  }
+  return Builtin::kInvalidLibrary;
+}
+
+
 static Dart_Handle CreateSnapshotLibraryTagHandler(Dart_LibraryTag tag,
                                                    Dart_Handle library,
                                                    Dart_Handle url) {
   if (!Dart_IsLibrary(library)) {
     return Dart_Error("not a library");
   }
   Dart_Handle library_url = Dart_LibraryUrl(library);
   if (Dart_IsError(library_url)) {
     return Dart_Error("accessing library url failed");
   }
   const char* library_url_string = DartUtils::GetStringValue(library_url);
   const char* mapped_library_url_string = DartUtils::MapLibraryUrl(
       url_mapping, library_url_string);
   if (mapped_library_url_string != NULL) {
     library_url = ResolveScriptUri(mapped_library_url_string);
     library_url_string = DartUtils::GetStringValue(library_url);
   }
 
   if (!Dart_IsString(url)) {
     return Dart_Error("url is not a string");
   }
   const char* url_string = DartUtils::GetStringValue(url);
   const char* mapped_url_string = DartUtils::MapLibraryUrl(url_mapping,
                                                            url_string);
 
+  Builtin::BuiltinLibraryId libraryBuiltinId = BuiltinId(library_url_string);
   if (tag == kCanonicalizeUrl) {
-    // Keep original names for libraries that have a mapping (e.g. dart:io).
     if (mapped_url_string) {
       return url;
     }
+    // Parts of internal libraries are handled internally.
+    if (libraryBuiltinId != Builtin::kInvalidLibrary) {
+      return url;
+    }
     return ResolveUri(library_url_string, url_string);
   }
 
-  if (DartUtils::IsDartIOLibURL(url_string) && mapped_url_string == NULL) {
-    // No url mapping for dart:io. Load original version.
-    return Builtin::LoadAndCheckLibrary(Builtin::kIOLibrary);
+  Builtin::BuiltinLibraryId builtinId = BuiltinId(url_string);
+  if (builtinId != Builtin::kInvalidLibrary) {
+    // Special case for importing a builtin library.
+    if (tag == kImportTag) {
+      return Builtin::LoadAndCheckLibrary(builtinId);
+    }
+    ASSERT(tag == kSourceTag);
+    return Dart_Error("Unable to part '%s' ", url_string);
+  }
+
+  if (libraryBuiltinId != Builtin::kInvalidLibrary) {
+    // Special case for parting sources of a builtin library.
+    if (tag == kSourceTag) {
+      return Dart_LoadSource(
+          library, url, Builtin::PartSource(libraryBuiltinId, url_string));
+    }
+    ASSERT(tag == kImportTag);
+    return Dart_Error("Unable to import '%s' ", url_string);
   }
 
   Dart_Handle resolved_url = url;
   if (mapped_url_string != NULL) {
     // Mapped urls are relative to working directory.
     resolved_url = ResolveScriptUri(mapped_url_string);
     if (Dart_IsError(resolved_url)) {
       return resolved_url;
     }
   }
@@ skipping 219 matching lines @@
   }
   return 0;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   return dart::bin::main(argc, argv);
 }