Fix attempt to find metadata of a library with no metadata.

runtime/vm/parser.cc

 // Copyright (c) 2012, 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 "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 4725 matching lines @@
     // Nothing to do for script tags except to skip them.
     ConsumeToken();
   }
 
   ASSERT(script_.kind() != RawScript::kSourceTag);
 
   // We may read metadata tokens that are part of the toplevel
   // declaration that follows the library definitions. Therefore, we
   // need to remember the position of the last token that was
   // successfully consumed.
-  intptr_t metadata_pos = TokenPos();
-  SkipMetadata();
+  intptr_t pre_metadata_pos = TokenPos();

[rmacnak, 2013/08/07 23:30:37]

Questionable name

[hausner, 2013/08/08 07:55:17]

How about naming it rewind_pos or fallback_pos?

On 2013/08/07 23:30:37, Ryan Macnak wrote:

[rmacnak, 2013/08/08 16:49:28]

Much better.

+  intptr_t metadata_pos = SkipMetadata();
   if (CurrentToken() == Token::kLIBRARY) {
     if (is_patch_source()) {
       ErrorMsg("patch cannot override library name");
     }
     ParseLibraryName();
     if (metadata_pos >= 0) {
       library_.AddLibraryMetadata(current_class(), metadata_pos);
     }
-    metadata_pos = TokenPos();
+    pre_metadata_pos = TokenPos();
     SkipMetadata();

[hausner, 2013/08/08 07:55:17]

Even though we are not using the metadata for import/export yet, I think you
should do:

metadata_pos = SkipMetadata()

[rmacnak, 2013/08/08 16:49:28]

Got 'em.

   }
   while ((CurrentToken() == Token::kIMPORT) ||
       (CurrentToken() == Token::kEXPORT)) {
     ParseLibraryImportExport();
-    metadata_pos = TokenPos();
+    pre_metadata_pos = TokenPos();
     SkipMetadata();

[hausner, 2013/08/08 07:55:17]

ditto

   }
   // Core lib has not been explicitly imported, so we implicitly
   // import it here.
   if (!library_.ImportsCorelib()) {
     Library& core_lib = Library::Handle(Library::CoreLibrary());
     ASSERT(!core_lib.IsNull());
     const Namespace& core_ns = Namespace::Handle(
         Namespace::New(core_lib, Object::null_array(), Object::null_array()));
     library_.AddImport(core_ns);
   }
   while (CurrentToken() == Token::kPART) {
     ParseLibraryPart();
-    metadata_pos = TokenPos();
+    pre_metadata_pos = TokenPos();
     SkipMetadata();

[hausner, 2013/08/08 07:55:17]

ditto

   }
-  SetPosition(metadata_pos);
+  SetPosition(pre_metadata_pos);
 }
 
 
 void Parser::ParsePartHeader() {
   SkipMetadata();
   if (CurrentToken() != Token::kPART) {
     ErrorMsg("'part of' expected");
   }
   ConsumeToken();
   if (!IsLiteral("of")) {
@@ skipping 5501 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart