From a500140f1d3b63babdb06185beb53154220e1802 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Fri, 10 Jul 2020 21:26:27 -0400
Subject: [PATCH] Fix Bison 3.6 error messages

---
 src/verilog.y | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/verilog.y b/src/verilog.y
index e8b4fffb6..fa324cdfa 100644
--- a/src/verilog.y
+++ b/src/verilog.y
@@ -31,7 +31,7 @@
 #include <cstdarg>
 #include <stack>
 
-#define YYERROR_VERBOSE 1
+#define YYERROR_VERBOSE 1  // For prior to Bison 3.6
 #define YYINITDEPTH 10000  // Older bisons ignore YYMAXDEPTH
 #define YYMAXDEPTH 10000
 
@@ -322,6 +322,9 @@ class AstSenTree;
 // clang-format off
 %}
 
+// Bison 3.0 and newer
+BISONPRE_VERSION(3.0,%define parse.error verbose)
+
 // When writing Bison patterns we use yTOKEN instead of "token",
 // so Bison will error out on unknown "token"s.