From 8abe4c630910b98df7e8f96118d21216e0bc1c30 Mon Sep 17 00:00:00 2001
From: Christopher Celio <celio@eecs.berkeley.edu>
Date: Thu, 30 Jul 2015 13:08:46 -0700
Subject: [PATCH] Added error message when trying to use histogram

---
 riscv/processor.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/riscv/processor.cc b/riscv/processor.cc
index 69a63f0..5b53391 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -121,6 +121,12 @@ void processor_t::set_debug(bool value)
 void processor_t::set_histogram(bool value)
 {
   histogram_enabled = value;
+#ifndef RISCV_ENABLE_HISTOGRAM
+  if (value) {
+    fprintf(stderr, "PC Histogram support has not been properly enabled;");
+    fprintf(stderr, " please re-build the riscv-isa-run project using \"configure --enable-histogram\".\n");
+  }
+#endif
 }
 
 void processor_t::reset(bool value)
-- 
2.30.2