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

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index 0e38fdae88fab86ffc3a8738006b367bc90e3f49..3041bbaba7ac6864b6ff17491c2592f05d93e093 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -4743,8 +4743,8 @@ void Parser::ParseLibraryDefinition() {
   // 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");
@@ -4753,13 +4753,13 @@ void Parser::ParseLibraryDefinition() {
     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
@@ -4773,10 +4773,10 @@ void Parser::ParseLibraryDefinition() {
   }
   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);
 }