* data/c.m4 (b4_yy_symbol_print_generate): In yy_symbol_print, accept

[bison.git] / data / c.m4

diff --git a/data/c.m4 b/data/c.m4
index a5c027a2532b438b1a39ef5fb0c94463c9839fc5..630fdebd118aba45b158e9a2b265da7f01963cc3 100644 (file)
--- a/data/c.m4
+++ b/data/c.m4
@@ -256,7 +256,7 @@ m4_define([b4_token_enums_defines],
 # as 'cc' doesn't define __STDC__ (or __STDC_VERSION__) for pedantic
 # reasons, but it defines __C99__FUNC__ so check that as well.
 # Microsoft C normally doesn't define these macros, but it defines _MSC_VER.
-# Consider a C++ compiler to be modern if it defines __cplusplus.  */
+# Consider a C++ compiler to be modern if it defines __cplusplus.
 #
 m4_define([b4_c_modern],
   [[(defined (__STDC__) || defined (__C99__FUNC__) \
@@ -464,7 +464,8 @@ m4_define_default([b4_yy_symbol_print_generate],
 b4_location_if([, [[const YYLTYPE * const yylocationp], [yylocationp]]])[]dnl
 m4_ifset([b4_parse_param], [, b4_parse_param]))[
 {
-  YYUSE (yyvaluep);
+  if (!yyvaluep)
+    return;
 ]b4_location_if([  YYUSE (yylocationp);
 ])dnl
 b4_parse_param_use[]dnl