%define push_pull -> %define api.push_pull. Discussed starting at

[bison.git] / data / push.c

diff --git a/data/push.c b/data/push.c
index a154e5e39ec2b28460c3a24cecaf1895312e500f..346b65ffc7a37d296befb6ce7c49330d361f9ac7 100644 (file)
--- a/data/push.c
+++ b/data/push.c
@@ -1,24 +1,40 @@
-m4_divert(-1)                                                -*- C -*-
+                                                             -*- C -*-

 
 # Yacc compatible skeleton for Bison
 
 
 # Yacc compatible skeleton for Bison
 

-# Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006
-# Free Software Foundation, Inc.
+# Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
+# 2007 Free Software Foundation, Inc.

 
 

-# This program is free software; you can redistribute it and/or modify
+# This program is free software: you can redistribute it and/or modify

 # it under the terms of the GNU General Public License as published by
 # it under the terms of the GNU General Public License as published by

-# the Free Software Foundation; either version 2 of the License, or
+# the Free Software Foundation, either version 3 of the License, or

 # (at your option) any later version.
 # (at your option) any later version.

-
+#

 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.

-
+#

 # You should have received a copy of the GNU General Public License
 # You should have received a copy of the GNU General Public License

-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-# 02110-1301  USA
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Check the value of %define api.push_pull.
+b4_percent_define_default([[api.push_pull]], [[pull]])
+b4_percent_define_check_values([[[[api.push_pull]],
+                               [[pull]], [[push]], [[both]]]])
+b4_define_flag_if([pull]) m4_define([b4_pull_flag], [[1]])
+b4_define_flag_if([push]) m4_define([b4_push_flag], [[1]])
+m4_case(b4_percent_define_get([[api.push_pull]]),
+        [pull], [m4_define([b4_push_flag], [[0]])],
+        [push], [m4_define([b4_pull_flag], [[0]])])
+
+# Handle BISON_USE_PUSH_FOR_PULL for the test suite.  So that push parsing
+# tests function as written, don't let BISON_USE_PUSH_FOR_PULL modify Bison's
+# behavior at all when push parsing is already requested.
+b4_define_flag_if([use_push_for_pull])
+b4_use_push_for_pull_if([
+  b4_push_if([m4_define([b4_use_push_for_pull_flag], [[0]])],
+             [m4_define([b4_push_flag], [[1]])])])

 
 m4_include(b4_pkgdatadir/[c.m4])
 
 
 m4_include(b4_pkgdatadir/[c.m4])
 


@@ -63,7 +79,6 @@ b4_locations_if([, [[YYLTYPE *], [&yylloc]]])m4_ifdef([b4_lex_param], [, ])])dnl
 m4_ifdef([b4_lex_param], b4_lex_param)))
 
 
 m4_ifdef([b4_lex_param], b4_lex_param)))
 
 

-

 ## ------------ ##
 ## Data Types.  ##
 ## ------------ ##
 ## ------------ ##
 ## Data Types.  ##
 ## ------------ ##


@@ -133,8 +148,8 @@ m4_define([b4_rhs_location],
 
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()

-m4_divert(0)dnl
-@output b4_parser_file_name
+m4_divert_push(0)dnl
+@output(b4_parser_file_name@)

 b4_copyright([Skeleton implementation for Bison's Yacc-like parsers in C],dnl '
   [1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006])[
 
 b4_copyright([Skeleton implementation for Bison's Yacc-like parsers in C],dnl '
   [1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006])[
 


@@ -148,21 +163,29 @@ b4_copyright([Skeleton implementation for Bison's Yacc-like parsers in C],dnl '
    define necessary library symbols; they are noted "INFRINGES ON
    USER NAME SPACE" below.  */
 
    define necessary library symbols; they are noted "INFRINGES ON
    USER NAME SPACE" below.  */
 

-]b4_identification
+]b4_identification[
+/* Push parsers.  */
+#define YYPUSH ]b4_push_flag[
+
+/* Pull parsers.  */
+#define YYPULL ]b4_pull_flag[
+
+]b4_percent_code_get([[top]])[]dnl

 m4_if(b4_prefix, [yy], [],
 m4_if(b4_prefix, [yy], [],

-[/* Substitute the variable and function names.  */
-]b4_push_if([#define yypush_parse b4_prefix[]push_parse
-#define yypstate_new b4_prefix[]pstate_new
-#define yypstate_delete b4_prefix[]pstate_delete
-#define yypstate b4_prefix[]pstate],
-[#define yyparse b4_prefix[]parse])[
-#define yylex   b4_prefix[]lex
-#define yyerror b4_prefix[]error
-#define yylval  b4_prefix[]lval
-#define yychar  b4_prefix[]char
-#define yydebug b4_prefix[]debug
-#define yynerrs b4_prefix[]nerrs
-b4_locations_if([#define yylloc b4_prefix[]lloc])])[
+[[/* Substitute the variable and function names.  */
+]b4_pull_if([[#define yyparse         ]b4_prefix[parse
+]])b4_push_if([[#define yypush_parse    ]b4_prefix[push_parse
+]b4_pull_if([[#define yypull_parse    ]b4_prefix[pull_parse
+]])[#define yypstate_new    ]b4_prefix[pstate_new
+#define yypstate_delete ]b4_prefix[pstate_delete
+#define yypstate        ]b4_prefix[pstate
+]])[#define yylex           ]b4_prefix[lex
+#define yyerror         ]b4_prefix[error
+#define yylval          ]b4_prefix[lval
+#define yychar          ]b4_prefix[char
+#define yydebug         ]b4_prefix[debug
+#define yynerrs         ]b4_prefix[nerrs
+]b4_locations_if([[#define yylloc          ]b4_prefix[lloc]])])[

 
 /* Copy the first part of user declarations.  */
 ]b4_user_pre_prologue[
 
 /* Copy the first part of user declarations.  */
 ]b4_user_pre_prologue[


@@ -185,17 +208,16 @@ b4_locations_if([#define yylloc b4_prefix[]lloc])])[
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 

-]m4_ifdef([b4_requires],
-[[/* Copy the %requires blocks.  */
-]b4_user_requires])[]dnl
+]b4_percent_code_get([[requires]])[]dnl

 
 b4_token_enums_defines(b4_tokens)[
 
 #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 ]m4_ifdef([b4_stype],
 [[typedef union ]b4_union_name[
 
 b4_token_enums_defines(b4_tokens)[
 
 #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 ]m4_ifdef([b4_stype],
 [[typedef union ]b4_union_name[

+{

 ]b4_user_stype[
 ]b4_user_stype[

-       YYSTYPE;
+} YYSTYPE;

 # define YYSTYPE_IS_TRIVIAL 1]],
 [m4_if(b4_tag_seen_flag, 0,
 [[typedef int YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1]],
 [m4_if(b4_tag_seen_flag, 0,
 [[typedef int YYSTYPE;


@@ -222,25 +244,29 @@ b4_push_if([[#ifndef YYPUSH_DECLS
 struct yypstate;
 typedef struct yypstate yypstate;
 enum { YYPUSH_MORE = 4 };
 struct yypstate;
 typedef struct yypstate yypstate;
 enum { YYPUSH_MORE = 4 };

-]b4_c_function_decl([[yypstate_new]], [[yypstate *]], [[[void]], []])
+
+]b4_pull_if([b4_c_function_decl([[yyparse]], [[int]], b4_parse_param)
+])b4_c_function_decl([[yypush_parse]], [[int]],
+  [[[yypstate *yyps]], [[yyps]]]b4_pure_if([,
+  [[[int yypushed_char]], [[yypushed_char]]],
+  [[[YYSTYPE const *yypushed_val]], [[yypushed_val]]]b4_locations_if([,
+  [[[YYLTYPE const *yypushed_loc]], [[yypushed_loc]]]])])m4_ifset([b4_parse_param], [,
+  b4_parse_param]))
+b4_pull_if([b4_c_function_decl([[yypull_parse]], [[int]],
+  [[[yypstate *yyps]], [[yyps]]]m4_ifset([b4_parse_param], [,
+  b4_parse_param]))])
+b4_c_function_decl([[yypstate_new]], [[yypstate *]], [[[void]], []])

 b4_c_function_decl([[yypstate_delete]], [[void]],
 b4_c_function_decl([[yypstate_delete]], [[void]],

-                   [[[yypstate *yyps]], [[yyps]]])
-b4_c_function_decl([[yypush_parse]], [[int]],
-  [[[yypstate *yyps]], [[yyps]]],
-  [[[int yynchar]], [[yynchar]]],
-  [[[YYSTYPE const *yynlval]], [[yynlval]]]b4_locations_if([,
-  [[[YYLTYPE const *yynlloc]], [[yynlloc]]]])m4_ifset([b4_parse_param], [,
-  b4_parse_param]))[
+                   [[[yypstate *yyps]], [[yyps]]])[

 #endif
 ]])
 #endif
 ]])

-m4_ifdef([b4_provides],
-[[/* Copy the %provides blocks.  */
-]b4_user_provides])[]dnl
+b4_percent_code_get([[provides]])[]dnl

 
 [/* Copy the second part of user declarations.  */
 
 [/* Copy the second part of user declarations.  */

-]b4_user_post_prologue[
+]b4_user_post_prologue
+b4_percent_code_get[]dnl

 
 

-#ifdef short
+[#ifdef short

 # undef short
 #endif
 
 # undef short
 #endif
 


@@ -316,7 +342,8 @@ typedef short int yytype_int16;
 
 #if ! defined yyoverflow || YYERROR_VERBOSE
 
 
 #if ! defined yyoverflow || YYERROR_VERBOSE
 

-/* The parser invokes alloca or malloc; define the necessary symbols.  */
+]b4_push_if([],
+[[/* The parser invokes alloca or malloc; define the necessary symbols.  */

 
 # ifdef YYSTACK_USE_ALLOCA
 #  if YYSTACK_USE_ALLOCA
 
 # ifdef YYSTACK_USE_ALLOCA
 #  if YYSTACK_USE_ALLOCA


@@ -341,7 +368,8 @@ typedef short int yytype_int16;
 #  endif
 # endif
 
 #  endif
 # endif
 

-# ifdef YYSTACK_ALLOC
+]])dnl
+[# ifdef YYSTACK_ALLOC

    /* Pacify GCC's `empty if-body' warning.  */
 #  define YYSTACK_FREE(Ptr) do { /* empty */; } while (YYID (0))
 #  ifndef YYSTACK_ALLOC_MAXIMUM
    /* Pacify GCC's `empty if-body' warning.  */
 #  define YYSTACK_FREE(Ptr) do { /* empty */; } while (YYID (0))
 #  ifndef YYSTACK_ALLOC_MAXIMUM


@@ -732,12 +760,12 @@ do {                                                              \
   /* The symbols being reduced.  */
   for (yyi = 0; yyi < yynrhs; yyi++)
     {
   /* The symbols being reduced.  */
   for (yyi = 0; yyi < yynrhs; yyi++)
     {

-      fprintf (stderr, "   $%d = ", yyi + 1);
+      YYFPRINTF (stderr, "   $%d = ", yyi + 1);

       yy_symbol_print (stderr, yyrhs[yyprhs[yyrule] + yyi],
                       &]b4_rhs_value(yynrhs, yyi + 1)[
                       ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
                       b4_user_args[);
       yy_symbol_print (stderr, yyrhs[yyprhs[yyrule] + yyi],
                       &]b4_rhs_value(yynrhs, yyi + 1)[
                       ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
                       b4_user_args[);

-      fprintf (stderr, "\n");
+      YYFPRINTF (stderr, "\n");

     }
 }
 
     }
 }
 


@@ -994,29 +1022,25 @@ int yychar;
 
 /* The semantic value of the lookahead symbol.  */
 YYSTYPE yylval;
 
 /* The semantic value of the lookahead symbol.  */
 YYSTYPE yylval;

-
-/* Number of syntax errors so far.  */
-]b4_push_if([],[
-int yynerrs;])b4_locations_if([[
+]b4_locations_if([[

 /* Location data for the lookahead symbol.  */
 /* Location data for the lookahead symbol.  */

-YYLTYPE yylloc;]])
-])
-
-m4_define([b4_yyerror_range],b4_push_if([yyps->yyerror_range],[yyerror_range]))
+YYLTYPE yylloc;
+]])b4_pure_if([], [[
+/* Number of syntax errors so far.  */
+int yynerrs;
+]])])

 
 # b4_declare_parser_state_variables
 # ---------------------------------
 # Declare all the variables that are needed to maintain the parser state
 # between calls to yypush_parse.
 m4_define([b4_declare_parser_state_variables],
 
 # b4_declare_parser_state_variables
 # ---------------------------------
 # Declare all the variables that are needed to maintain the parser state
 # between calls to yypush_parse.
 m4_define([b4_declare_parser_state_variables],

-[[
+[b4_pure_if([[    /* Number of syntax errors so far.  */
+    int yynerrs;
+]])[

     int yystate;
     int yystate;

-    int yyn;
-    int yyresult;

     /* Number of tokens to shift before error messages enabled.  */
     int yyerrstatus;
     /* Number of tokens to shift before error messages enabled.  */
     int yyerrstatus;

-    /* Look-ahead token as an internal (translated) token number.  */
-    int yytoken;

 
     /* Three stacks and their tools:
        `yyss': related to states,
 
     /* Three stacks and their tools:
        `yyss': related to states,


@@ -1040,14 +1064,12 @@ m4_define([b4_declare_parser_state_variables],
     YYLTYPE yylsa[YYINITDEPTH];
     YYLTYPE *yyls;
     YYLTYPE *yylsp;
     YYLTYPE yylsa[YYINITDEPTH];
     YYLTYPE *yyls;
     YYLTYPE *yylsp;

+

     /* The locations where the error started and ended.  */
     /* The locations where the error started and ended.  */

-    YYLTYPE yyerror_range[2];]])[
+    YYLTYPE yyerror_range[2];
+]])[

     YYSIZE_T yystacksize;
     YYSIZE_T yystacksize;

-    /* The variables used to return semantic value and location from the
-       action routines.  */
-    YYSTYPE yyval;
-]b4_locations_if([[  YYLTYPE yyloc;
-]])])
+]])

 
 m4_divert_pop([KILL])dnl# ====================== End of M4 code.
 
 
 m4_divert_pop([KILL])dnl# ====================== End of M4 code.
 


@@ -1062,26 +1084,80 @@ b4_push_if(
     int yynew;
   };
 
     int yynew;
   };
 

+]b4_pull_if([b4_c_function_def([[yyparse]], [[int]], b4_parse_param)[
+{
+  return yypull_parse (0]m4_ifset([b4_parse_param],
+                                  [[, ]b4_c_args(b4_parse_param)])[);
+}]b4_pure_if([], [[
+
+static char yypstate_allocated = 0;]])[
+
+]b4_c_function_def([[yypull_parse]], [[int]],
+  [[[yypstate *yyps]], [[yyps]]]m4_ifset([b4_parse_param], [,
+  b4_parse_param]))[
+{
+  int yystatus;
+  yypstate *yyps_local;
+]b4_pure_if([[  int yychar;
+  YYSTYPE yylval;
+]b4_locations_if([[  YYLTYPE yylloc;
+]])])[
+  if (yyps == 0)
+    {
+      yyps_local = yypstate_new ();
+      if (!yyps_local)
+        {]b4_pure_if([[
+          yyerror (]b4_yyerror_args[YY_("memory exhausted"));]], [[
+          if (!yypstate_allocated)
+            yyerror (]b4_yyerror_args[YY_("memory exhausted"));]])[
+          return 2;
+        }
+    }
+  else
+    yyps_local = yyps;
+  do {
+    yychar = YYLEX;
+    yystatus =
+      yypush_parse (yyps_local]b4_pure_if([[, yychar, &yylval]b4_locations_if([[, &yylloc]])])m4_ifset([b4_parse_param], [, b4_c_args(b4_parse_param)])[);
+  } while (yystatus == YYPUSH_MORE);
+  if (yyps == 0)
+    yypstate_delete (yyps_local);
+  return yystatus;
+}
+]])[

 /* Initialize the parser data structure.  */
 ]b4_c_function_def([[yypstate_new]], [[yypstate *]])[
 {
 /* Initialize the parser data structure.  */
 ]b4_c_function_def([[yypstate_new]], [[yypstate *]])[
 {

-  yypstate *yyps = (yypstate *) malloc (sizeof *yyps);
-  yyps->yyresult = -1;
-  yyps->yynew = 1;
+  yypstate *yyps;]b4_pure_if([], [[
+  if (yypstate_allocated)
+    {
+      yyerror (]b4_yyerror_args[YY_("cannot allocate multiple impure push-parser instances"));
+      return 0;
+    }]])[
+  yyps = (yypstate *) malloc (sizeof *yyps);
+  if (!yyps)
+    return 0;
+  yyps->yynew = 1;]b4_pure_if([], [[
+  yypstate_allocated = 1;]])[

   return yyps;
 }
 
 ]b4_c_function_def([[yypstate_delete]], [[void]],
                    [[[yypstate *yyps]], [[yyps]]])[
 {
   return yyps;
 }
 
 ]b4_c_function_def([[yypstate_delete]], [[void]],
                    [[[yypstate *yyps]], [[yyps]]])[
 {

-  free (yyps);
+#ifndef yyoverflow
+  /* If the stack was reallocated but the parse did not complete, then the
+     stack still needs to be freed.  */
+  if (!yyps->yynew && yyps->yyss != yyps->yyssa)
+    YYSTACK_FREE (yyps->yyss);
+#endif
+  free (yyps);]b4_pure_if([], [[
+  yypstate_allocated = 0;]])[

 }
 
 }
 

-#define yystate yyps->yystate
-#define yyn yyps->yyn
-#define yyresult yyps->yyresult
+]b4_pure_if([[#define ]b4_prefix[nerrs yyps->]b4_prefix[nerrs
+]])[#define yystate yyps->yystate

 #define yyerrstatus yyps->yyerrstatus
 #define yyerrstatus yyps->yyerrstatus

-#define yytoken yyps->yytoken

 #define yyssa yyps->yyssa
 #define yyss yyps->yyss
 #define yyssp yyps->yyssp
 #define yyssa yyps->yyssa
 #define yyss yyps->yyss
 #define yyssp yyps->yyssp


@@ -1091,20 +1167,20 @@ b4_push_if(
 ]b4_locations_if([[#define yylsa yyps->yylsa
 #define yyls yyps->yyls
 #define yylsp yyps->yylsp
 ]b4_locations_if([[#define yylsa yyps->yylsa
 #define yyls yyps->yyls
 #define yylsp yyps->yylsp

+#define yyerror_range yyps->yyerror_range

 ]])[#define yystacksize yyps->yystacksize
 ]])[#define yystacksize yyps->yystacksize

-#define yyval yyps->yyval
-]b4_locations_if([[#define yyloc yyps->yyloc
-]])])[
+]])[

 
 /*-------------------------.
 | yyparse or yypush_parse.  |
 `-------------------------*/
 
 ]b4_push_if([
 
 /*-------------------------.
 | yyparse or yypush_parse.  |
 `-------------------------*/
 
 ]b4_push_if([

-b4_c_function_def([[yypush_parse]], [[int]], [[[yypstate *yyps]], [[yyps]]], 
-  [[[int yynchar]], [[yynchar]]],
-  [[[YYSTYPE const *yynlval]], [[yynlval]]]b4_locations_if([,
-  [[[YYLTYPE const *yynlloc]], [[yynlloc]]]])m4_ifset([b4_parse_param], [,
+b4_c_function_def([[yypush_parse]], [[int]],
+  [[[yypstate *yyps]], [[yyps]]]b4_pure_if([,
+  [[[int yypushed_char]], [[yypushed_char]]],
+  [[[YYSTYPE const *yypushed_val]], [[yypushed_val]]]b4_locations_if([,
+  [[[YYLTYPE const *yypushed_loc]], [[yypushed_loc]]]])])m4_ifset([b4_parse_param], [,

   b4_parse_param]))], [
 #ifdef YYPARSE_PARAM
 b4_c_function_def([yyparse], [int], [[void *YYPARSE_PARAM], [YYPARSE_PARAM]])
   b4_parse_param]))], [
 #ifdef YYPARSE_PARAM
 b4_c_function_def([yyparse], [int], [[void *YYPARSE_PARAM], [YYPARSE_PARAM]])


@@ -1112,9 +1188,21 @@ b4_c_function_def([yyparse], [int], [[void *YYPARSE_PARAM], [YYPARSE_PARAM]])
 b4_c_function_def([yyparse], [int], b4_parse_param)
 #endif])[
 {
 b4_c_function_def([yyparse], [int], b4_parse_param)
 #endif])[
 {

-  ]b4_pure_if([b4_declare_scanner_communication_variables])
-  b4_push_if([], [b4_declare_parser_state_variables])[
-
+]b4_pure_if([b4_declare_scanner_communication_variables])
+b4_push_if([b4_pure_if([], [[  int yypushed_char = yychar;
+  YYSTYPE yypushed_val = yylval;
+  ]b4_locations_if([[YYLTYPE yypushed_loc = yylloc;
+]])])],
+  [b4_declare_parser_state_variables])[
+  int yyn;
+  int yyresult;
+  /* Look-ahead token as an internal (translated) token number.  */
+  int yytoken;
+  /* The variables used to return semantic value and location from the
+     action routines.  */
+  YYSTYPE yyval;
+]b4_locations_if([[  YYLTYPE yyloc;
+]])[

 #if YYERROR_VERBOSE
   /* Buffer for error messages, and its allocated size.  */
   char yymsgbuf[128];
 #if YYERROR_VERBOSE
   /* Buffer for error messages, and its allocated size.  */
   char yymsgbuf[128];


@@ -1127,20 +1215,13 @@ b4_c_function_def([yyparse], [int], b4_parse_param)
   /* The number of symbols on the RHS of the reduced rule.
      Keep to zero when no symbol should be popped.  */
   int yylen = 0;
   /* The number of symbols on the RHS of the reduced rule.
      Keep to zero when no symbol should be popped.  */
   int yylen = 0;

-]b4_push_if([  yychar = yynchar;
-  if (yynlval)
-    yylval = *yynlval;
-]b4_locations_if([  if (yynlloc)
-     yylloc = *yynlloc;])[],[yynerrs = 0;
-  yychar = YYEMPTY; /* Cause a token to be read.  */])[
-
-  ]b4_push_if([
-      if (yyps->yynew == 0)
-      {
-       goto gottoken;
-      }
-      yyps->yynew= 0;])[
-
+]b4_push_if([[
+  if (!yyps->yynew)
+    {
+      yyn = yypact[yystate];
+      goto yyread_pushed_token;
+    }
+]])[

   yytoken = 0;
   yyss = yyssa;
   yyvs = yyvsa;
   yytoken = 0;
   yyss = yyssa;
   yyvs = yyvsa;


@@ -1152,6 +1233,8 @@ b4_c_function_def([yyparse], [int], b4_parse_param)
 
   yystate = 0;
   yyerrstatus = 0;
 
   yystate = 0;
   yyerrstatus = 0;

+  yynerrs = 0;
+  yychar = YYEMPTY; /* Cause a token to be read.  */

 
   /* Initialize stack pointers.
      Waste one element of value and location stack
 
   /* Initialize stack pointers.
      Waste one element of value and location stack


@@ -1170,7 +1253,7 @@ b4_c_function_def([yyparse], [int], b4_parse_param)
 m4_ifdef([b4_initial_action], [
 m4_pushdef([b4_at_dollar],     [m4_define([b4_at_dollar_used])yylloc])dnl
 m4_pushdef([b4_dollar_dollar], [m4_define([b4_dollar_dollar_used])yylval])dnl
 m4_ifdef([b4_initial_action], [
 m4_pushdef([b4_at_dollar],     [m4_define([b4_at_dollar_used])yylloc])dnl
 m4_pushdef([b4_dollar_dollar], [m4_define([b4_dollar_dollar_used])yylval])dnl

-  /* User initialization code.  */
+/* User initialization code.  */

 b4_user_initial_action
 m4_popdef([b4_dollar_dollar])dnl
 m4_popdef([b4_at_dollar])])dnl
 b4_user_initial_action
 m4_popdef([b4_dollar_dollar])dnl
 m4_popdef([b4_at_dollar])])dnl


@@ -1282,14 +1365,32 @@ yybackup:
   /* YYCHAR is either YYEMPTY or YYEOF or a valid lookahead symbol.  */
   if (yychar == YYEMPTY)
     {
   /* YYCHAR is either YYEMPTY or YYEOF or a valid lookahead symbol.  */
   if (yychar == YYEMPTY)
     {

-      ]b4_push_if([
-       YYDPRINTF ((stderr, "Return for a new token:\n"));
-       yyresult = YYPUSH_MORE;
-       goto yypushreturn;
-gottoken:])[
-      YYDPRINTF ((stderr, "Reading a token: "));
-      ]b4_push_if([], [yychar = YYLEX;])[
-    }
+]b4_push_if([[      if (!yyps->yynew)
+        {
+]b4_use_push_for_pull_if([],
+[[          YYDPRINTF ((stderr, "Return for a new token:\n"));
+]])[          yyresult = YYPUSH_MORE;
+          goto yypushreturn;
+        }
+      yyps->yynew = 0;
+]b4_pure_if([], [[
+      /* Restoring the pushed token is only necessary for the first
+         yypush_parse invocation since subsequent invocations don't overwrite
+         it before jumping to yyread_pushed_token.  */
+      yychar = yypushed_char;
+      yylval = yypushed_val;
+      ]b4_locations_if([[yylloc = yypushed_loc;
+]])])[
+yyread_pushed_token:
+]])[      YYDPRINTF ((stderr, "Reading a token: "));
+]b4_push_if([b4_pure_if([[      yychar = yypushed_char;
+      if (yypushed_val)
+        yylval = *yypushed_val;
+]b4_locations_if([[      if (yypushed_loc)
+        yylloc = *yypushed_loc;
+]])])],
+[[      yychar = YYLEX;
+]])[    }

 
   if (yychar <= YYEOF)
     {
 
   if (yychar <= YYEOF)
     {


@@ -1400,7 +1501,7 @@ yyerrlab:
   /* If not already recovering from an error, report this error.  */
   if (!yyerrstatus)
     {
   /* If not already recovering from an error, report this error.  */
   if (!yyerrstatus)
     {

-]b4_push_if([],[ ++yynerrs;])[
+      ++yynerrs;

 #if ! YYERROR_VERBOSE
       yyerror (]b4_yyerror_args[YY_("syntax error"));
 #else
 #if ! YYERROR_VERBOSE
       yyerror (]b4_yyerror_args[YY_("syntax error"));
 #else


@@ -1438,7 +1539,7 @@ yyerrlab:
 #endif
     }
 
 #endif
     }
 

-]b4_locations_if([[  ]b4_yyerror_range[[0] = yylloc;]])[
+]b4_locations_if([[  yyerror_range[0] = yylloc;]])[

 
   if (yyerrstatus == 3)
     {
 
   if (yyerrstatus == 3)
     {


@@ -1475,7 +1576,7 @@ yyerrorlab:
   if (/*CONSTCOND*/ 0)
      goto yyerrorlab;
 
   if (/*CONSTCOND*/ 0)
      goto yyerrorlab;
 

-]b4_locations_if([[  ]b4_yyerror_range[[0] = yylsp[1-yylen];
+]b4_locations_if([[  yyerror_range[0] = yylsp[1-yylen];

 ]])[  /* Do not reclaim the symbols of the rule which action triggered
      this YYERROR.  */
   YYPOPSTACK (yylen);
 ]])[  /* Do not reclaim the symbols of the rule which action triggered
      this YYERROR.  */
   YYPOPSTACK (yylen);


@@ -1509,7 +1610,7 @@ yyerrlab1:
       if (yyssp == yyss)
        YYABORT;
 
       if (yyssp == yyss)
        YYABORT;
 

-]b4_locations_if([[      ]b4_yyerror_range[[0] = *yylsp;]])[
+]b4_locations_if([[      yyerror_range[0] = *yylsp;]])[

       yydestruct ("Error: popping",
                  yystos[yystate], yyvsp]b4_locations_if([, yylsp])[]b4_user_args[);
       YYPOPSTACK (1);
       yydestruct ("Error: popping",
                  yystos[yystate], yyvsp]b4_locations_if([, yylsp])[]b4_user_args[);
       YYPOPSTACK (1);


@@ -1519,10 +1620,10 @@ yyerrlab1:
 
   *++yyvsp = yylval;
 ]b4_locations_if([[
 
   *++yyvsp = yylval;
 ]b4_locations_if([[

-  ]b4_yyerror_range[[1] = yylloc;
+  yyerror_range[1] = yylloc;

   /* Using YYLLOC is tempting, but would change the location of
      the lookahead.  YYLOC is available though.  */
   /* Using YYLLOC is tempting, but would change the location of
      the lookahead.  YYLOC is available though.  */

-  YYLLOC_DEFAULT (yyloc, (]b4_yyerror_range[- 1), 2);
+  YYLLOC_DEFAULT (yyloc, (yyerror_range - 1), 2);

   *++yylsp = yyloc;]])[
 
   /* Shift the error token.  */
   *++yylsp = yyloc;]])[
 
   /* Shift the error token.  */


@@ -1574,32 +1675,34 @@ yyreturn:
   if (yyss != yyssa)
     YYSTACK_FREE (yyss);
 #endif
   if (yyss != yyssa)
     YYSTACK_FREE (yyss);
 #endif

-]b4_push_if([yypushreturn:])[
-#if YYERROR_VERBOSE
+]b4_push_if([[  yyps->yynew = 1;
+
+yypushreturn:
+]])[#if YYERROR_VERBOSE

   if (yymsg != yymsgbuf)
     YYSTACK_FREE (yymsg);
 #endif
   /* Make sure YYID is used.  */
   return YYID (yyresult);
   if (yymsg != yymsgbuf)
     YYSTACK_FREE (yymsg);
 #endif
   /* Make sure YYID is used.  */
   return YYID (yyresult);

-]}
+}

 
 

-b4_epilogue
+
+]b4_epilogue

 b4_defines_if(
 b4_defines_if(

-[@output b4_spec_defines_file
+[@output(b4_spec_defines_file@)

 b4_copyright([Skeleton interface for Bison's Yacc-like parsers in C],dnl '
   [1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006])
 
 b4_copyright([Skeleton interface for Bison's Yacc-like parsers in C],dnl '
   [1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006])
 

-m4_ifdef([b4_requires],
-[[/* Copy the %requires blocks.  */
-]b4_user_requires])[]dnl
+b4_percent_code_get([[requires]])[]dnl

 
 b4_token_enums_defines(b4_tokens)
 
 [#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 ]m4_ifdef([b4_stype],
 [[typedef union ]b4_union_name[
 
 b4_token_enums_defines(b4_tokens)
 
 [#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 ]m4_ifdef([b4_stype],
 [[typedef union ]b4_union_name[

+{

 ]b4_user_stype[
 ]b4_user_stype[

-       YYSTYPE;
+} YYSTYPE;

 # define YYSTYPE_IS_TRIVIAL 1]],
 [m4_if(b4_tag_seen_flag, 0,
 [[typedef int YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1]],
 [m4_if(b4_tag_seen_flag, 0,
 [[typedef int YYSTYPE;


@@ -1608,8 +1711,7 @@ b4_token_enums_defines(b4_tokens)
 # define YYSTYPE_IS_DECLARED 1
 #endif
 
 # define YYSTYPE_IS_DECLARED 1
 #endif
 

-]b4_pure_if([],
-[extern YYSTYPE b4_prefix[]lval;])
+]b4_pure_if([], [[extern YYSTYPE ]b4_prefix[lval;]])

 
 b4_locations_if(
 [#if ! defined YYLTYPE && ! defined YYLTYPE_IS_DECLARED
 
 b4_locations_if(
 [#if ! defined YYLTYPE && ! defined YYLTYPE_IS_DECLARED


@@ -1625,8 +1727,7 @@ typedef struct YYLTYPE
 # define YYLTYPE_IS_TRIVIAL 1
 #endif
 
 # define YYLTYPE_IS_TRIVIAL 1
 #endif
 

-]b4_pure_if([],
-          [extern YYLTYPE b4_prefix[]lloc;])
+]b4_pure_if([], [[extern YYLTYPE ]b4_prefix[lloc;]])

 )dnl b4_locations_if
 
 b4_push_if([[#ifndef YYPUSH_DECLS
 )dnl b4_locations_if
 
 b4_push_if([[#ifndef YYPUSH_DECLS


@@ -1634,19 +1735,22 @@ b4_push_if([[#ifndef YYPUSH_DECLS
 struct ]b4_prefix[pstate;
 typedef struct ]b4_prefix[pstate ]b4_prefix[pstate;
 enum { YYPUSH_MORE = 4 };
 struct ]b4_prefix[pstate;
 typedef struct ]b4_prefix[pstate ]b4_prefix[pstate;
 enum { YYPUSH_MORE = 4 };

-]b4_c_function_decl([b4_prefix[pstate_new]], [b4_prefix[pstate *]],
+]b4_pull_if([b4_c_function_decl([b4_prefix[parse]], [[int]], b4_parse_param)
+])b4_c_function_decl([b4_prefix[push_parse]], [[int]],
+  [[b4_prefix[pstate *yyps]], [[yyps]]]b4_pure_if([,
+  [[[int yypushed_char]], [[yypushed_char]]],
+  [[[YYSTYPE const *yypushed_val]], [[yypushed_val]]]b4_locations_if([,
+  [[[YYLTYPE const *yypushed_loc]], [[yypushed_loc]]]])])m4_ifset([b4_parse_param], [,
+  b4_parse_param]))
+b4_pull_if([b4_c_function_decl([b4_prefix[pull_parse]], [[int]],
+  [[b4_prefix[pstate *yyps]], [[yyps]]]m4_ifset([b4_parse_param], [,
+  b4_parse_param]))])
+b4_c_function_decl([b4_prefix[pstate_new]], [b4_prefix[pstate *]],

                     [[[void]], []])
 b4_c_function_decl([b4_prefix[pstate_delete]], [[void]],
                     [[[void]], []])
 b4_c_function_decl([b4_prefix[pstate_delete]], [[void]],

-                   [[b4_prefix[pstate *yyps]], [[yyps]]])
-b4_c_function_decl([b4_prefix[push_parse]], [[int]],
-  [[b4_prefix[pstate *yyps]], [[yyps]]],
-  [[[int yynchar]], [[yynchar]]],
-  [[[YYSTYPE const *yynlval]], [[yynlval]]]b4_locations_if([,
-  [[[YYLTYPE const *yynlloc]], [[yynlloc]]]])m4_ifset([b4_parse_param], [,
-  b4_parse_param]))[
+                   [[b4_prefix[pstate *yyps]], [[yyps]]])[

 #endif
 ]])
 #endif
 ]])

-m4_ifdef([b4_provides],
-[[/* Copy the %provides blocks.  */
-]b4_user_provides])[]
+b4_percent_code_get([[provides]])[]dnl

 ])dnl b4_defines_if
 ])dnl b4_defines_if

+m4_divert_pop(0)