Properly report error for certain expressions that must be const

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 7844 matching lines @@
     AstNode* assign_expr =
         CreateAssignmentNode(expr, assigned_value, expr_ident, expr_pos);
     ASSERT(assign_expr != NULL);
     return assign_expr;
   }
 }
 
 
 LiteralNode* Parser::ParseConstExpr() {
   TRACE_PARSER("ParseConstExpr");
+  intptr_t expr_pos = TokenPos();
   AstNode* expr = ParseExpr(kRequireConst, kNoCascades);
-  ASSERT(expr->IsLiteralNode());
+  if (!expr->IsLiteralNode()) {
+    ErrorMsg(expr_pos, "expression must be a compile-time constant");
+  }
   return expr->AsLiteralNode();
 }
 
 
 AstNode* Parser::ParseConditionalExpr() {
   TRACE_PARSER("ParseConditionalExpr");
   const intptr_t expr_pos = TokenPos();
   AstNode* expr = ParseBinaryExpr(Token::Precedence(Token::kOR));
   if (CurrentToken() == Token::kCONDITIONAL) {
     EnsureExpressionTemp();
@@ skipping 2734 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart