diff --git a/data/c.m4 b/data/c.m4
index abc769b9..b1b43948 100644
--- a/data/c.m4
+++ b/data/c.m4
@@ -221,6 +221,25 @@ m4_define([b4_attribute_define],
 #else
 # define YYUSE(E) /* empty */
 #endif
+
+#if defined __GNUC__ && 407 <= __GNUC__ * 100 + __GNUC_MINOR__
+/* Suppress an incorrect diagnostic about yylval being uninitialized.  */
+# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN \
+    _Pragma ("GCC diagnostic push") \
+    _Pragma ("GCC diagnostic ignored \"-Wuninitialized\"")\
+    _Pragma ("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")
+# define YY_IGNORE_MAYBE_UNINITIALIZED_END \
+    _Pragma ("GCC diagnostic pop")
+#else
+# define YY_INITIAL_VALUE(Value) Value
+#endif
+#ifndef YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+# define YY_IGNORE_MAYBE_UNINITIALIZED_END
+#endif
+#ifndef YY_INITIAL_VALUE
+# define YY_INITIAL_VALUE(Value) /* Nothing. */
+#endif
 ])
 
 
@@ -446,7 +465,9 @@ m4_ifset([b4_parse_param], [, b4_parse_param]))[
     yymsg = "Deleting";
   YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
 
+  YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
   ]b4_symbol_actions([destructor])[
+  YY_IGNORE_MAYBE_UNINITIALIZED_END
 }]dnl
 ])
 
@@ -456,9 +477,9 @@ m4_ifset([b4_parse_param], [, b4_parse_param]))[
 # Define the "yy_symbol_print" function.
 m4_define_default([b4_yy_symbol_print_define],
 [[
-/*--------------------------------.
-| Print this symbol on YYOUTPUT.  |
-`--------------------------------*/
+/*----------------------------------------.
+| Print this symbol's value on YYOUTPUT.  |
+`----------------------------------------*/
 
 ]b4_function_define([yy_symbol_value_print],
     [static void],
diff --git a/data/yacc.c b/data/yacc.c
index ab8a1f7f..822656b8 100644
--- a/data/yacc.c
+++ b/data/yacc.c
@@ -175,36 +175,19 @@ m4_define([b4_declare_scanner_communication_variables], [[
 int yychar;
 
 ]b4_pure_if([[
-#if defined __GNUC__ && 407 <= __GNUC__ * 100 + __GNUC_MINOR__
-/* Suppress an incorrect diagnostic about yylval being uninitialized.  */
-# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN \
-    _Pragma ("GCC diagnostic push") \
-    _Pragma ("GCC diagnostic ignored \"-Wuninitialized\"")\
-    _Pragma ("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")
-# define YY_IGNORE_MAYBE_UNINITIALIZED_END \
-    _Pragma ("GCC diagnostic pop")
-#else
+/* The semantic value of the lookahead symbol.  */
 /* Default value used for initialization, for pacifying older GCCs
    or non-GCC compilers.  */
-static YYSTYPE yyval_default;
-# define YY_INITIAL_VALUE(Value) = Value
-#endif]b4_locations_if([[
-static YYLTYPE yyloc_default][]b4_yyloc_default[;]])])[
-#ifndef YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
-# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
-# define YY_IGNORE_MAYBE_UNINITIALIZED_END
-#endif
-#ifndef YY_INITIAL_VALUE
-# define YY_INITIAL_VALUE(Value) /* Nothing. */
-#endif
-
-/* The semantic value of the lookahead symbol.  */
-YYSTYPE yylval YY_INITIAL_VALUE (yyval_default);]b4_locations_if([[
+YY_INITIAL_VALUE (static YYSTYPE yyval_default;)
+YYSTYPE yylval YY_INITIAL_VALUE (= yyval_default);]b4_locations_if([[
 
 /* Location data for the lookahead symbol.  */
-YYLTYPE yylloc]b4_pure_if([ = yyloc_default], [b4_yyloc_default])[;
-]])b4_pure_if([], [[
-
+static YYLTYPE yyloc_default]b4_yyloc_default[;
+YYLTYPE yylloc = yyloc_default;]])],
+[[/* The semantic value of the lookahead symbol.  */
+YYSTYPE yylval;]b4_locations_if([[
+/* Location data for the lookahead symbol.  */
+YYLTYPE yylloc]b4_yyloc_default[;]])[
 /* Number of syntax errors so far.  */
 int yynerrs;]])])