Fix for issue 5223 : Import 'dart:core' implicitly only if it has not been

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 "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/compiler_stats.h"
@@ skipping 4201 matching lines @@
     ConsumeToken();
   }
 
   // TODO(hausner): Remove support for old library definition syntax.
   if ((CurrentToken() == Token::kLIBRARY) ||
       (CurrentToken() == Token::kIMPORT) ||
       (CurrentToken() == Token::kSOURCE)) {
     ParseLibraryNameObsoleteSyntax();
     ParseLibraryImportObsoleteSyntax();
     ParseLibraryIncludeObsoleteSyntax();
+    // 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());
+      library_.AddImport(core_lib);
+    }
     return;
   }
 
   // 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();
   if (IsLiteral("library")) {
     ParseLibraryName();
     metadata_pos = TokenPos();
     SkipMetadata();
   } else if (script_.kind() == RawScript::kLibraryTag) {
     ErrorMsg("library name definition expected");
   }
   while (IsLiteral("import") || IsLiteral("export")) {
     ParseLibraryImportExport();
     metadata_pos = TokenPos();
     SkipMetadata();
   }
+  // 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());
+    library_.AddImport(core_lib);
+  }
   while (IsLiteral("part")) {
     ParseLibraryPart();
     metadata_pos = TokenPos();
     SkipMetadata();
   }
   if (IsLiteral("library") || IsLiteral("import") || IsLiteral("export")) {
     ErrorMsg("unexpected token '%s'", CurrentLiteral()->ToCString());
   }
   SetPosition(metadata_pos);
 }
@@ skipping 5262 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart