glr.c, yacc.c: declare yydebug in the header.

[bison.git] / data / c.m4

diff --git a/data/c.m4 b/data/c.m4
index 64f68fec24f86f26b53a09d4dd31a9389be83e87..78b123252833690f0df1d8aa44611ec32e8deb07 100644 (file)
--- a/data/c.m4
+++ b/data/c.m4
@@ -567,3 +567,15 @@ typedef struct YYLTYPE
 # define YYLTYPE_IS_TRIVIAL 1
 #endif]])
 ])
+
+# b4_declare_yydebug
+# ------------------
+m4_define([b4_declare_yydebug],
+[[/* Enabling traces.  */
+#ifndef YYDEBUG
+# define YYDEBUG ]b4_debug_flag[
+#endif
+#if YYDEBUG
+extern int ]b4_prefix[debug;
+#endif][]dnl
+])