[C++] Fix err_empty_var_name.mk

1 files changed, 2 insertions, 0 deletions

diff --git a/eval.cc b/eval.cc
index f8a5c90..1f0af87 100644
--- a/eval.cc
+++ b/eval.cc
@@ -98,6 +98,8 @@ void Evaluator::EvalAssign(const AssignAST* ast) {
   loc_ = ast->loc();
   last_rule_ = NULL;
   StringPiece lhs = Intern(*ast->lhs->Eval(this));
+  if (lhs.empty())
+    Error("*** empty variable name.");
   Var* rhs = EvalRHS(lhs, ast->rhs, ast->orig_rhs, ast->op,
                      ast->directive == AssignDirective::OVERRIDE);
   if (rhs)