Enforce proper library/import syntax

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 4456 matching lines @@
     if (!library_.ImportsCorelib()) {
       Library& core_lib = Library::Handle(Library::CoreLibrary());
       ASSERT(!core_lib.IsNull());
       const Namespace& core_ns = Namespace::Handle(
           Namespace::New(core_lib, Array::Handle(), Array::Handle()));
       library_.AddImport(core_ns);
     }
     return;
   }
 
+  const bool is_script = (script_.kind() == RawScript::kScriptTag);
+  const bool is_library = (script_.kind() == RawScript::kLibraryTag);
+  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();
   if (CurrentToken() == Token::kLIBRARY) {
     ParseLibraryName();
     metadata_pos = TokenPos();
     SkipMetadata();
-  } else if (script_.kind() == RawScript::kLibraryTag) {
+  } else if (is_library) {

[siva, 2012/11/13 00:21:53]

isn't this equivalent to
else if (!is_script) {
...
}
as you have already asserted that kind is
!RawScript::kSourceTag

[hausner, 2012/11/13 01:07:13]

Keeping as is, as per our offline discussion.

On 2012/11/13 00:21:53, siva wrote:

     ErrorMsg("library name definition expected");
   }
   while ((CurrentToken() == Token::kIMPORT) ||
       (CurrentToken() == Token::kEXPORT)) {
+    if (is_script && (CurrentToken() == Token::kEXPORT)) {
+      ErrorMsg("export not allowed in scripts");
+    }
     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());
     const Namespace& core_ns = Namespace::Handle(
@@ skipping 5472 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart