Re: {maint} yacc.c: initialize yylval in pure-parser mode

[Paul Eggert]

On 09/21/2012 01:43 AM, Akim Demaille wrote:
> The idea is nice, but there are several issues.

OK, how about the following patch to the trunk?
It attempts to address the issues you mentioned.

diff --git a/data/yacc.c b/data/yacc.c
index a15ef77..f498867 100644
--- a/data/yacc.c
+++ b/data/yacc.c
@@ -1469,7 +1469,21 @@ m4_ifdef([b4_dollar_dollar_used],[[  yyvsp[0] = yylval;
 ]])dnl
 m4_ifdef([b4_at_dollar_used], [[  yylsp[0] = yylloc;
 ]])])dnl
-[  goto yysetstate;
+[  if (yychar != YYEMPTY || yyss + yystacksize - 1 <= yyssp)
+    goto yysetstate;
+
+  *yyssp = yystate;
+
+  YYDPRINTF ((stderr, "Entering state %d\n", yystate));
+
+  if (yystate == YYFINAL)
+    YYACCEPT;
+
+  yyn = yypact[yystate];
+  if (yypact_value_is_default (yyn))
+    goto yydefault;
+
+  goto yyread_token;
 
 /*------------------------------------------------------------.
 | yynewstate -- Push a new state, which is found in yystate.  |
@@ -1572,7 +1586,8 @@ yybackup:
 
   /* YYCHAR is either YYEMPTY or YYEOF or a valid lookahead symbol.  */
   if (yychar == YYEMPTY)
-    {]b4_push_if([[
+    {
+yyread_token:]b4_push_if([[
       if (!yyps->yynew)
         {]b4_use_push_for_pull_if([], [[
           YYDPRINTF ((stderr, "Return for a new token:\n"));]])[