X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/c66dfaddf449920bea03c0aa3b55467e2f21c98e..22b081deb7ab1d0ec7a279e5213fa7fdc2c85207:/data/c.m4

diff --git a/data/c.m4 b/data/c.m4
index 6406b9b0..9bd82956 100644
--- a/data/c.m4
+++ b/data/c.m4
@@ -1,86 +1,125 @@
-m4_divert(-1)                                               -*- Autoconf -*-
+                                                            -*- Autoconf -*-
 
 # C M4 Macros for Bison.
-# Copyright (C) 2002, 2004, 2005, 2006 Free Software Foundation, Inc.
 
-# This program is free software; you can redistribute it and/or modify
+# Copyright (C) 2002, 2004-2012 Free Software Foundation, Inc.
+
+# 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
-# 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.
-
+#
 # 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
-# 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/>.
+
+
+# b4_tocpp(STRING)
+# ----------------
+# Convert STRING into a valid C macro name.
+m4_define([b4_tocpp],
+[m4_toupper(m4_bpatsubst(m4_quote($1), [[^a-zA-Z0-9]+], [_]))])
+
+
+# b4_cpp_guard(FILE)
+# ------------------
+# A valid C macro name to use as a CPP header guard for FILE.
+m4_define([b4_cpp_guard],
+[b4_tocpp(m4_defn([b4_prefix])/[$1])])
+
+
+# b4_cpp_guard_open(FILE)
+# b4_cpp_guard_close(FILE)
+# ------------------------
+# Open/close CPP inclusion guards for FILE.
+m4_define([b4_cpp_guard_open],
+[#ifndef b4_cpp_guard([$1])
+# define b4_cpp_guard([$1])])
+
+m4_define([b4_cpp_guard_close],
+[#endif b4_comment([!b4_cpp_guard([$1])])])
 
 
 ## ---------------- ##
 ## Identification.  ##
 ## ---------------- ##
 
-# b4_copyright(TITLE, YEARS)
-# --------------------------
-m4_define([b4_copyright],
-[/* A Bison parser, made by GNU Bison b4_version.  */
+# b4_comment_(TEXT, OPEN, CONTINUE, END)
+# -------------------------------------
+# Put TEXT in comment.  Avoid trailing spaces: don't indent empty lines.
+# Avoid adding indentation to the first line, as the indentation comes
+# from OPEN.  That's why we don't patsubst([$1], [^\(.\)], [   \1]).
+#
+# Prefix all the output lines with PREFIX.
+m4_define([b4_comment_], [$2[]m4_bpatsubst([$1], [
+\(.\)], [
+$3\1])$4])
 
-/* $1,
-   Copyright (C) $2 Free Software Foundation, Inc.
 
-   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
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+# b4_c_comment(TEXT, [PREFIX])
+# ----------------------------
+# Put TEXT in comment.  Avoid trailing spaces: don't indent empty lines.
+# Avoid adding indentation to the first line, as the indentation comes
+# from "/*".  That's why we don't patsubst([$1], [^\(.\)], [   \1]).
+#
+# Prefix all the output lines with PREFIX.
+m4_define([b4_c_comment],
+[b4_comment_([$1], [$2/* ], [$2   ], [$2  */])])
 
-   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
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */])
+# b4_comment(TEXT, [PREFIX])
+# --------------------------
+# By default, C comments.
+m4_define([b4_comment], [b4_c_comment($@)])
 
 
 # b4_identification
 # -----------------
+# Depends on individual skeletons to define b4_pure_flag, b4_push_flag, or
+# b4_pull_flag if they use the values of the %define variables api.pure or
+# api.push-pull.
 m4_define([b4_identification],
-[/* Identify Bison output.  */
-[#]define YYBISON 1
+[[/* Identify Bison output.  */
+#define YYBISON 1
 
 /* Bison version.  */
-[#]define YYBISON_VERSION "b4_version"
+#define YYBISON_VERSION "]b4_version["
 
 /* Skeleton name.  */
-[#]define YYSKELETON_NAME b4_skeleton
+#define YYSKELETON_NAME ]b4_skeleton[]m4_ifdef([b4_pure_flag], [[
 
 /* Pure parsers.  */
-[#]define YYPURE b4_pure
+#define YYPURE ]b4_pure_flag])[]m4_ifdef([b4_push_flag], [[
 
-/* Using locations.  */
-[#]define YYLSP_NEEDED b4_locations_flag
-])
+/* Push parsers.  */
+#define YYPUSH ]b4_push_flag])[]m4_ifdef([b4_pull_flag], [[
+
+/* Pull parsers.  */
+#define YYPULL ]b4_pull_flag])[
 
+/* Using locations.  */
+#define YYLSP_NEEDED ]b4_locations_if([1], [0])[
+]])
 
 
 ## ---------------- ##
 ## Default values.  ##
 ## ---------------- ##
 
-m4_define_default([b4_epilogue], [])
-
+# If the %union is not named, its name is YYSTYPE.
+m4_define_default([b4_union_name], [YYSTYPE])
 
+# If the %name-prefix is not given, it is yy.
+m4_define_default([b4_prefix], [yy])
 
 ## ------------------------ ##
 ## Pure/impure interfaces.  ##
 ## ------------------------ ##
 
-
 # b4_user_args
 # ------------
 m4_define([b4_user_args],
@@ -91,9 +130,8 @@ m4_define([b4_user_args],
 # --------------
 # If defined, b4_parse_param arrives double quoted, but below we prefer
 # it to be single quoted.
-m4_define_default([b4_parse_param])
 m4_define([b4_parse_param],
-b4_parse_param))
+b4_parse_param)
 
 
 # b4_parse_param_for(DECL, FORMAL, BODY)
@@ -102,33 +140,28 @@ b4_parse_param))
 # the formal name to FORMAL, and evaluating the BODY.
 m4_define([b4_parse_param_for],
 [m4_foreach([$1_$2], m4_defn([b4_parse_param]),
-[m4_pushdef([$1], m4_fst($1_$2))dnl
+[m4_pushdef([$1], m4_unquote(m4_car($1_$2)))dnl
 m4_pushdef([$2], m4_shift($1_$2))dnl
 $3[]dnl
 m4_popdef([$2])dnl
 m4_popdef([$1])dnl
 ])])
 
-# b4_parse_param_use
-# ------------------
-# `YYUSE' all the parse-params.
+# b4_parse_param_use([VAL], [LOC])
+# --------------------------------
+# `YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
 m4_define([b4_parse_param_use],
-[b4_parse_param_for([Decl], [Formal], [  YYUSE (Formal);
+[m4_ifvaln([$1], [  YYUSE([$1]);])dnl
+b4_locations_if([m4_ifvaln([$2], [  YYUSE ([$2]);])])dnl
+b4_parse_param_for([Decl], [Formal], [  YYUSE (Formal);
 ])dnl
 ])
 
+
 ## ------------ ##
 ## Data Types.  ##
 ## ------------ ##
 
-
-# b4_ints_in(INT1, INT2, LOW, HIGH)
-# ---------------------------------
-# Return 1 iff both INT1 and INT2 are in [LOW, HIGH], 0 otherwise.
-m4_define([b4_ints_in],
-[m4_eval([$3 <= $1 && $1 <= $4 && $3 <= $2 && $2 <= $4])])
-
-
 # b4_int_type(MIN, MAX)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
@@ -142,7 +175,7 @@ m4_define([b4_int_type],
 
        m4_eval([0 <= $1]),                [1], [unsigned int],
 
-	                                       [int])])
+                                               [int])])
 
 
 # b4_int_type_for(NAME)
@@ -153,37 +186,54 @@ m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])
 
 
-## ------------------ ##
-## Decoding options.  ##
-## ------------------ ##
+# b4_table_value_equals(TABLE, VALUE, LITERAL)
+# --------------------------------------------
+# Without inducing a comparison warning from the compiler, check if the
+# literal value LITERAL equals VALUE from table TABLE, which must have
+# TABLE_min and TABLE_max defined.  YYID must be defined as an identity
+# function that suppresses warnings about constant conditions.
+m4_define([b4_table_value_equals],
+[m4_if(m4_eval($3 < m4_indir([b4_]$1[_min])
+               || m4_indir([b4_]$1[_max]) < $3), [1],
+       [[YYID (0)]],
+       [[((]$2[) == (]$3[))]])])
 
 
-# b4_error_verbose_if(IF-TRUE, IF-FALSE)
-# --------------------------------------
-# Expand IF-TRUE, if errors are verbose, IF-FALSE otherwise.
-m4_define([b4_error_verbose_if],
-[m4_if(b4_error_verbose, [1],
-       [$1],
-       [$2])])
+## ---------##
+## Values.  ##
+## ---------##
 
 
-# b4_location_if(IF-TRUE, IF-FALSE)
-# ---------------------------------
-# Expand IF-TRUE, if locations are used, IF-FALSE otherwise.
-m4_define([b4_location_if],
-[m4_if(b4_locations_flag, [1],
-       [$1],
-       [$2])])
+# b4_null_define
+# --------------
+# Portability issues: define a YY_NULL appropriate for the current
+# language (C, C++98, or C++11).
+m4_define([b4_null_define],
+[# ifndef YY_NULL
+#  if defined __cplusplus && 201103L <= __cplusplus
+#   define YY_NULL nullptr
+#  else
+#   define YY_NULL 0
+#  endif
+# endif[]dnl
+])
 
 
-# b4_pure_if(IF-TRUE, IF-FALSE)
-# -----------------------------
-# Expand IF-TRUE, if %pure-parser, IF-FALSE otherwise.
-m4_define([b4_pure_if],
-[m4_if(b4_pure, [1],
-       [$1],
-       [$2])])
+# b4_null
+# -------
+# Return a null pointer constant.
+m4_define([b4_null], [YY_NULL])
 
+# b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT)
+# -------------------------------------------------------------
+# Define "yy<TABLE-NAME>" which contents is CONTENT.
+m4_define([b4_integral_parser_table_define],
+[m4_ifvaln([$3], [b4_c_comment([$3], [  ])])dnl
+static const b4_int_type_for([$2]) yy$1[[]] =
+{
+  $2
+};dnl
+])
 
 
 ## ------------------------- ##
@@ -194,7 +244,7 @@ m4_define([b4_pure_if],
 # -----------------------------------------
 # Output the definition of this token as #define.
 m4_define([b4_token_define],
-[#define $1 $2
+[#define b4_percent_define_get([api.tokens.prefix])$1 $2
 ])
 
 
@@ -202,7 +252,7 @@ m4_define([b4_token_define],
 # -------------------------------------------------------
 # Output the definition of the tokens (if there are) as #defines.
 m4_define([b4_token_defines],
-[m4_if([$@], [[]], [],
+[m4_if([$#$1], [1], [],
 [/* Tokens.  */
 m4_map([b4_token_define], [$@])])
 ])
@@ -212,14 +262,14 @@ m4_map([b4_token_define], [$@])])
 # ---------------------------------------
 # Output the definition of this token as an enum.
 m4_define([b4_token_enum],
-[$1 = $2])
+[b4_percent_define_get([api.tokens.prefix])$1 = $2])
 
 
 # b4_token_enums(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
 # -----------------------------------------------------
 # Output the definition of the tokens (if there are) as enums.
 m4_define([b4_token_enums],
-[m4_if([$@], [[]], [],
+[m4_if([$#$1], [1], [],
 [/* Tokens.  */
 #ifndef YYTOKENTYPE
 # define YYTOKENTYPE
@@ -236,12 +286,28 @@ m4_map_sep([     b4_token_enum], [,
 
 # b4_token_enums_defines(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
 # -------------------------------------------------------------
-# Output the definition of the tokens (if there are) as enums and #defines.
+# Output the definition of the tokens (if there are any) as enums and, if POSIX
+# Yacc is enabled, as #defines.
 m4_define([b4_token_enums_defines],
-[b4_token_enums($@)b4_token_defines($@)
+[b4_token_enums($@)b4_yacc_if([b4_token_defines($@)], [])
 ])
 
 
+## ----------------- ##
+## Semantic Values.  ##
+## ----------------- ##
+
+
+# b4_symbol_value(VAL, [TYPE])
+# ----------------------------
+# Given a semantic value VAL ($$, $1 etc.), extract its value of type
+# TYPE if TYPE is given, otherwise just return VAL.  The result can be
+# used safetly, it is put in parens to avoid nasty precedence issues.
+# TYPE is *not* put in braces, provide some if needed.
+m4_define([b4_symbol_value],
+[($1[]m4_ifval([$2], [.$2]))])
+
+
 
 ## --------------------------------------------- ##
 ## Defining C functions in both K&R and ANSI-C.  ##
@@ -259,8 +325,8 @@ m4_define([b4_token_enums_defines],
 # Consider a C++ compiler to be modern if it defines __cplusplus.
 #
 m4_define([b4_c_modern],
-  [[(defined (__STDC__) || defined (__C99__FUNC__) \
-     || defined (__cplusplus) || defined (_MSC_VER))]])
+  [[(defined __STDC__ || defined __C99__FUNC__ \
+     || defined __cplusplus || defined _MSC_VER)]])
 
 # b4_c_function_def(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
 # ----------------------------------------------------------
@@ -270,8 +336,8 @@ m4_define([b4_c_function_def],
 b4_c_ansi_function_def($@)
 #else
 $2
-$1 (b4_c_knr_formal_names(m4_shiftn(2, $@)))
-b4_c_knr_formal_decls(m4_shiftn(2, $@))
+$1 (b4_c_knr_formal_names(m4_shift2($@)))
+b4_c_knr_formal_decls(m4_shift2($@))
 #endif[]dnl
 ])
 
@@ -281,7 +347,7 @@ b4_c_knr_formal_decls(m4_shiftn(2, $@))
 # Declare the function NAME in ANSI.
 m4_define([b4_c_ansi_function_def],
 [$2
-$1 (b4_c_ansi_formals(m4_shiftn(2, $@)))[]dnl
+$1 (b4_c_ansi_formals(m4_shift2($@)))[]dnl
 ])
 
 
@@ -289,9 +355,8 @@ $1 (b4_c_ansi_formals(m4_shiftn(2, $@)))[]dnl
 # --------------------------------------
 # Output the arguments ANSI-C definition.
 m4_define([b4_c_ansi_formals],
-[m4_case([$@],
-         [],   [void],
-         [[]], [void],
+[m4_if([$#], [0], [void],
+       [$#$1], [1], [void],
                [m4_map_sep([b4_c_ansi_formal], [, ], [$@])])])
 
 m4_define([b4_c_ansi_formal],
@@ -331,7 +396,7 @@ m4_define([b4_c_knr_formal_decl],
 # -----------------------------------------------------------
 # Declare the function NAME.
 m4_define([b4_c_function_decl],
-[#if defined (__STDC__) || defined (__cplusplus)
+[#if b4_c_modern
 b4_c_ansi_function_decl($@)
 #else
 $2 $1 ();
@@ -343,7 +408,7 @@ $2 $1 ();
 # ----------------------------------------------------------------
 # Declare the function NAME.
 m4_define([b4_c_ansi_function_decl],
-[$2 $1 (b4_c_ansi_formals(m4_shiftn(2, $@)));[]dnl
+[$2 $1 (b4_c_ansi_formals(m4_shift2($@)));[]dnl
 ])
 
 
@@ -358,7 +423,7 @@ m4_define([b4_c_ansi_function_decl],
 # -----------------------------------------------------------
 # Call the function NAME with arguments NAME1, NAME2 etc.
 m4_define([b4_c_function_call],
-[$1 (b4_c_args(m4_shiftn(2, $@)))[]dnl
+[$1 (b4_c_args(m4_shift2($@)))[]dnl
 ])
 
 
@@ -376,34 +441,31 @@ m4_define([b4_c_arg],
 ## Synclines.  ##
 ## ----------- ##
 
-# b4_syncline(LINE, FILE)
+# b4_sync_start(LINE, FILE)
 # -----------------------
-m4_define([b4_syncline],
-[m4_if(b4_synclines_flag, 1,
-       [[#]line $1 $2])])
-
+m4_define([b4_sync_start], [[#]line $1 $2])
 
 
 ## -------------- ##
 ## User actions.  ##
 ## -------------- ##
 
-# b4_symbol_actions(FILENAME, LINENO,
-#                   SYMBOL-TAG, SYMBOL-NUM,
-#                   SYMBOL-ACTION, SYMBOL-TYPENAME)
-# -------------------------------------------------
-m4_define([b4_symbol_actions],
-[m4_pushdef([b4_dollar_dollar],
-   [m4_ifval([$6], [(yyvaluep->$6)], [(*yyvaluep)])])dnl
-m4_pushdef([b4_at_dollar], [(*yylocationp)])dnl
-      case $4: /* $3 */
-b4_syncline([$2], [$1])
-        $5;
+# b4_case(LABEL, STATEMENTS)
+# --------------------------
+m4_define([b4_case],
+[  case $1:
+$2
 b4_syncline([@oline@], [@ofile@])
-        break;
-m4_popdef([b4_at_dollar])dnl
-m4_popdef([b4_dollar_dollar])dnl
-])
+    break;])
+
+
+# b4_predicate_case(LABEL, CONDITIONS)
+# ------------------------------------
+m4_define([b4_predicate_case],
+[  case $1:
+    if (! ($2)) YYERROR;
+b4_syncline([@oline@], [@ofile@])
+    break;])
 
 
 # b4_yydestruct_generate(FUNCTION-DECLARATOR)
@@ -422,22 +484,18 @@ m4_define_default([b4_yydestruct_generate],
     [[const char *yymsg],    [yymsg]],
     [[int yytype],           [yytype]],
     [[YYSTYPE *yyvaluep],    [yyvaluep]][]dnl
-b4_location_if(            [, [[YYLTYPE *yylocationp], [yylocationp]]])[]dnl
+b4_locations_if(            [, [[YYLTYPE *yylocationp], [yylocationp]]])[]dnl
 m4_ifset([b4_parse_param], [, b4_parse_param]))[
 {
-  YYUSE (yyvaluep);
-]b4_location_if([  YYUSE (yylocationp);
-])dnl
-b4_parse_param_use[]dnl
-[
-  if (!yymsg)
+]b4_parse_param_use([yyvaluep], [yylocationp])dnl
+[  if (!yymsg)
     yymsg = "Deleting";
   YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
 
   switch (yytype)
     {
-]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
-      default:
+]b4_symbol_foreach([b4_symbol_destructor])dnl
+[      default:
         break;
     }
 }]dnl
@@ -460,24 +518,24 @@ m4_define_default([b4_yy_symbol_print_generate],
     [static void],
                [[FILE *yyoutput],                       [yyoutput]],
                [[int yytype],                           [yytype]],
-               [[const YYSTYPE * const yyvaluep],       [yyvaluep]][]dnl
-b4_location_if([, [[const YYLTYPE * const yylocationp], [yylocationp]]])[]dnl
+               [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
+b4_locations_if([, [[YYLTYPE const * const yylocationp], [yylocationp]]])[]dnl
 m4_ifset([b4_parse_param], [, b4_parse_param]))[
 {
-  if (!yyvaluep)
-    return;
-]b4_location_if([  YYUSE (yylocationp);
-])dnl
-b4_parse_param_use[]dnl
-[# ifdef YYPRINT
+  FILE *yyo = yyoutput;
+]b4_parse_param_use([yyo], [yylocationp])dnl
+[  if (!yyvaluep)
+    return;]
+dnl glr.c does not feature yytoknum.
+m4_if(b4_skeleton, ["yacc.c"],
+[[# ifdef YYPRINT
   if (yytype < YYNTOKENS)
     YYPRINT (yyoutput, yytoknum[yytype], *yyvaluep);
-# else
-  YYUSE (yyoutput);
 # endif
-  switch (yytype)
+]])dnl
+[  switch (yytype)
     {
-]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
+]b4_symbol_foreach([b4_symbol_printer])dnl
 [      default:
         break;
     }
@@ -492,8 +550,8 @@ b4_parse_param_use[]dnl
     [static void],
                [[FILE *yyoutput],                       [yyoutput]],
                [[int yytype],                           [yytype]],
-               [[const YYSTYPE * const yyvaluep],       [yyvaluep]][]dnl
-b4_location_if([, [[const YYLTYPE * const yylocationp], [yylocationp]]])[]dnl
+               [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
+b4_locations_if([, [[YYLTYPE const * const yylocationp], [yylocationp]]])[]dnl
 m4_ifset([b4_parse_param], [, b4_parse_param]))[
 {
   if (yytype < YYNTOKENS)
@@ -501,11 +559,63 @@ m4_ifset([b4_parse_param], [, b4_parse_param]))[
   else
     YYFPRINTF (yyoutput, "nterm %s (", yytname[yytype]);
 
-]b4_location_if([  YY_LOCATION_PRINT (yyoutput, *yylocationp);
+]b4_locations_if([  YY_LOCATION_PRINT (yyoutput, *yylocationp);
   YYFPRINTF (yyoutput, ": ");
 ])dnl
 [  yy_symbol_value_print (yyoutput, yytype, yyvaluep]dnl
-b4_location_if([, yylocationp])[]b4_user_args[);
+b4_locations_if([, yylocationp])[]b4_user_args[);
   YYFPRINTF (yyoutput, ")");
 }]dnl
 ])
+
+## -------------- ##
+## Declarations.  ##
+## -------------- ##
+
+# b4_declare_yylstype
+# ------------------
+# Declarations that might either go into the header (if --defines) or
+# in the parser body.  Declare YYSTYPE/YYLTYPE, and yylval/yylloc.
+m4_define([b4_declare_yylstype],
+[[#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
+]m4_ifdef([b4_stype],
+[[typedef union ]b4_union_name[
+{
+]b4_user_stype[
+} YYSTYPE;
+# define YYSTYPE_IS_TRIVIAL 1]],
+[m4_if(b4_tag_seen_flag, 0,
+[[typedef int YYSTYPE;
+# define YYSTYPE_IS_TRIVIAL 1]])])[
+# define yystype YYSTYPE /* obsolescent; will be withdrawn */
+# define YYSTYPE_IS_DECLARED 1
+#endif]b4_locations_if([[
+
+#if ! defined YYLTYPE && ! defined YYLTYPE_IS_DECLARED
+typedef struct YYLTYPE
+{
+  int first_line;
+  int first_column;
+  int last_line;
+  int last_column;
+} YYLTYPE;
+# define yyltype YYLTYPE /* obsolescent; will be withdrawn */
+# define YYLTYPE_IS_DECLARED 1
+# define YYLTYPE_IS_TRIVIAL 1
+#endif]])
+
+b4_pure_if([], [[extern YYSTYPE ]b4_prefix[lval;
+]b4_locations_if([[extern YYLTYPE ]b4_prefix[lloc;]])])[]dnl
+])
+
+# b4_declare_yydebug
+# ------------------
+m4_define([b4_declare_yydebug],
+[[/* Enabling traces.  */
+#ifndef YYDEBUG
+# define YYDEBUG ]b4_parse_trace_if([1], [0])[
+#endif
+#if YYDEBUG
+extern int ]b4_prefix[debug;
+#endif][]dnl
+])