From a6edce193de4c163bcd6e83b5183da0fadad939a Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Sun, 14 Jun 2020 13:53:05 +0200
Subject: [PATCH] Make PPerror message more verbose: give hint to buggy line
 segment

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

diff --git a/src/frontend/parse-bison.y b/src/frontend/parse-bison.y
index bc3b55af9..bd3bd78d4 100644
--- a/src/frontend/parse-bison.y
+++ b/src/frontend/parse-bison.y
@@ -27,6 +27,8 @@
      while (0)
 
   static void PPerror (YYLTYPE *locp, char **line, struct pnode **retval, char const *);
+
+  static char keepline[256];
 %}
 
 %name-prefix "PP"
@@ -96,6 +98,7 @@
 {
     $$.num = 0.0;
     yylloc.start = yylloc.stop = NULL;
+    strncpy(keepline, *line, 255);
 };
 
 %%
@@ -171,5 +174,5 @@ PPerror (YYLTYPE *locp, char **line, struct pnode **retval, char const *s)
   NG_IGNORE(line);
   NG_IGNORE(retval);
 
-  fprintf (stderr, "%s: %s\n", __func__, s);
+  fprintf (stderr, "%s: %s\n  in line segment  %s\n", __func__, s, keepline);
 }