Fix VM crash when parsing what looks like a closure call during metadata evaluation.

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 "platform/utils.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 8552 matching lines @@
               current_class(), type, ClassFinalizer::kCanonicalize);
           // Type may be malbounded, but not malformed.
           ASSERT(!type.IsMalformed());
           selector = new TypeNode(primary_pos, type);
         } else {
           UNREACHABLE();  // Internal parser error.
         }
       } else {
         // Left is not a primary node; this must be a closure call.
         AstNode* closure = left;
+        if (parsing_metadata_) {
+            // Compiling closure calls involves saving the current context based
+            // on the current function, and metadata has no current function.
+            // Fail early rather than limping along only to discover later that
+            // we parsed something that isn't a compile-time constant.
+            ErrorMsg(closure->token_pos(),
+              "expression is not a valid compile-time constant");
+        }
         selector = ParseClosureCall(closure);
       }
     } else {
       // No (more) selectors to parse.
       left = LoadFieldIfUnresolved(left);
       if (left->IsPrimaryNode()) {
         PrimaryNode* primary_node = left->AsPrimaryNode();
         const intptr_t primary_pos = primary->token_pos();
         if (primary_node->primary().IsFunction()) {
           // Treat as implicit closure.
@@ skipping 2195 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart