X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/a762e609e70d246018e91b366670ba66184b6173..026816664ff8283a55f91915843a8ff0ac5cf86c:/data/c.m4

diff --git a/data/c.m4 b/data/c.m4
index 7a516e1c..b1b43948 100644
--- a/data/c.m4
+++ b/data/c.m4
@@ -1,130 +1,839 @@
-m4_divert(-1)                                                     -*- C -*-
+                                                            -*- Autoconf -*-
 
 # C M4 Macros for Bison.
-# Copyright (C) 2002 Free Software Foundation, Inc.
 
-# This program is free software; you can redistribute it and/or modify
+# Copyright (C) 2002, 2004-2013 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., 59 Temple Place, Suite 330, Boston, MA
-# 02111-1307  USA
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+m4_include(b4_pkgdatadir/[c-like.m4])
 
-## ----------- ##
-## Copuright.  ##
-## ----------- ##
+# 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_copyright(TITLE, YEARS)
-# --------------------------
-m4_define([b4_copyright],
-[/* A Bison parser, made from b4_filename, by GNU bison b4_version.  */
 
-/* $1,
-   Copyright (C) $2 Free Software Foundation, Inc.
+# b4_cpp_guard(FILE)
+# ------------------
+# A valid C macro name to use as a CPP header guard for FILE.
+m4_define([b4_cpp_guard],
+[[YY_]b4_tocpp(m4_defn([b4_prefix])/[$1])[_INCLUDED]])
 
-   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.
 
-   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.
+# b4_cpp_guard_open(FILE)
+# b4_cpp_guard_close(FILE)
+# ------------------------
+# If FILE does not expand to nothing, open/close CPP inclusion guards for FILE.
+m4_define([b4_cpp_guard_open],
+[m4_ifval(m4_quote($1),
+[#ifndef b4_cpp_guard([$1])
+# define b4_cpp_guard([$1])])])
 
-   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., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
+m4_define([b4_cpp_guard_close],
+[m4_ifval(m4_quote($1),
+[#endif b4_comment([!b4_cpp_guard([$1])])])])
 
-/* As a special exception, when this file is copied by Bison into a
-   Bison output file, you may use that output file without restriction.
-   This special exception was added by the Free Software Foundation
-   in version 1.24 of Bison.  */])
 
+## ---------------- ##
+## Identification.  ##
+## ---------------- ##
+
+# 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
+
+/* Bison version.  */
+#define YYBISON_VERSION "]b4_version["
+
+/* Skeleton name.  */
+#define YYSKELETON_NAME ]b4_skeleton[]m4_ifdef([b4_pure_flag], [[
+
+/* Pure parsers.  */
+#define YYPURE ]b4_pure_flag])[]m4_ifdef([b4_push_flag], [[
+
+/* Push parsers.  */
+#define YYPUSH ]b4_push_flag])[]m4_ifdef([b4_pull_flag], [[
+
+/* Pull parsers.  */
+#define YYPULL ]b4_pull_flag])[
+]])
+
+
+## ---------------- ##
+## Default values.  ##
+## ---------------- ##
+
+# b4_api_prefix, b4_api_PREFIX
+# ----------------------------
+# Corresponds to %define api.prefix
+b4_percent_define_default([[api.prefix]], [[yy]])
+m4_define([b4_api_prefix],
+[b4_percent_define_get([[api.prefix]])])
+m4_define([b4_api_PREFIX],
+[m4_toupper(b4_api_prefix)])
+
+
+# b4_prefix
+# ---------
+# If the %name-prefix is not given, it is api.prefix.
+m4_define_default([b4_prefix], [b4_api_prefix])
+
+# If the %union is not named, its name is YYSTYPE.
+m4_define_default([b4_union_name], [b4_api_PREFIX[]STYPE])
 
-## ------------ ##
-## Data Types.  ##
-## ------------ ##
 
+## ------------------------ ##
+## Pure/impure interfaces.  ##
+## ------------------------ ##
 
-# 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_lex_formals
+# --------------
+# All the yylex formal arguments.
+# b4_lex_param arrives quoted twice, but we want to keep only one level.
+m4_define([b4_lex_formals],
+[b4_pure_if([[[[YYSTYPE *yylvalp]], [[&yylval]]][]dnl
+b4_locations_if([, [[YYLTYPE *yyllocp], [&yylloc]]])])dnl
+m4_ifdef([b4_lex_param], [, ]b4_lex_param)])
 
 
+# b4_lex
+# ------
+# Call yylex.
+m4_define([b4_lex],
+[b4_function_call([yylex], [int], b4_lex_formals)])
+
+
+# b4_user_args
+# ------------
+m4_define([b4_user_args],
+[m4_ifset([b4_parse_param], [, b4_args(b4_parse_param)])])
+
+
+# b4_parse_param
+# --------------
+# If defined, b4_parse_param arrives double quoted, but below we prefer
+# it to be single quoted.
+m4_define([b4_parse_param],
+b4_parse_param)
+
+
+# b4_parse_param_for(DECL, FORMAL, BODY)
+# ---------------------------------------
+# Iterate over the user parameters, binding the declaration to DECL,
+# 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_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([VAL], [LOC])
+# --------------------------------
+# 'YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
+m4_define([b4_parse_param_use],
+[m4_ifvaln([$1], [  YYUSE ([$1]);])dnl
+b4_locations_if([m4_ifvaln([$2], [  YYUSE ([$2]);])])dnl
+b4_parse_param_for([Decl], [Formal], [  YYUSE (Formal);
+])dnl
+])
+
+
+## ------------ ##
+## Data Types.  ##
+## ------------ ##
+
 # b4_int_type(MIN, MAX)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
 # MIN to MAX (included).
 m4_define([b4_int_type],
 [m4_if(b4_ints_in($@,      [0],   [255]), [1], [unsigned char],
-       b4_ints_in($@,   [-128],   [128]), [1], [signed char],
+       b4_ints_in($@,   [-128],   [127]), [1], [signed char],
 
-       b4_ints_in($@,      [0], [65535]), [1], [unsigned short],
-       b4_ints_in($@, [-32768], [32767]), [1], [short],
+       b4_ints_in($@,      [0], [65535]), [1], [unsigned short int],
+       b4_ints_in($@, [-32768], [32767]), [1], [short int],
 
        m4_eval([0 <= $1]),                [1], [unsigned int],
 
- 	                                       [int])])
+                                               [int])])
+
 
 # b4_int_type_for(NAME)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
-# `NAME_min' to `NAME_max' (included).
+# 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])
 
 
+# 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.
+m4_define([b4_table_value_equals],
+[m4_if(m4_eval($3 < m4_indir([b4_]$1[_min])
+               || m4_indir([b4_]$1[_max]) < $3), [1],
+       [[0]],
+       [(!!(($2) == ($3)))])])
+
+
+## ----------------- ##
+## Compiler issues.  ##
+## ----------------- ##
+
+# b4_attribute_define
+# -------------------
+# Provide portability for __attribute__.
+m4_define([b4_attribute_define],
+[#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if (! defined __GNUC__ || __GNUC__ < 2 \
+      || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
+#  define __attribute__(Spec) /* empty */
+# endif
+#endif
+
+/* Suppress unused-variable warnings by "using" E.  */
+#if ! defined lint || defined __GNUC__
+# define YYUSE(E) ((void) (E))
+#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
+])
+
+
+## ---------##
+## Values.  ##
+## ---------##
+
+
+# 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_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>" whose contents is CONTENT.
+m4_define([b4_integral_parser_table_define],
+[m4_ifvaln([$3], [b4_comment([$3], [  ])])dnl
+static const b4_int_type_for([$2]) yy$1[[]] =
+{
+  $2
+};dnl
+])
+
+
 ## ------------------------- ##
 ## Assigning token numbers.  ##
 ## ------------------------- ##
 
-# b4_token_define(TOKEN-NAME, TOKEN-NUMBER)
-# -----------------------------------------
+# b4_token_define(TOKEN-NUM)
+# --------------------------
 # Output the definition of this token as #define.
 m4_define([b4_token_define],
-[#define $1 $2
-])
+[b4_token_format([#define %s %s], [$1])])
+
+# b4_token_defines
+# ----------------
+# Output the definition of the tokens.
+m4_define([b4_token_defines],
+[b4_any_token_visible_if([/* Tokens.  */
+m4_join([
+], b4_symbol_map([b4_token_define]))
+])])
 
 
-# b4_token_enum(TOKEN-NAME, TOKEN-NUMBER)
-# ---------------------------------------
+# b4_token_enum(TOKEN-NUM)
+# ------------------------
 # Output the definition of this token as an enum.
 m4_define([b4_token_enum],
-[$1 = $2])
+[b4_token_format([%s = %s], [$1])])
 
 
-# b4_token_defines(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
-# -------------------------------------------------------
-# Output the definition of the tokens (if there are) as enums and #define.
-m4_define([b4_token_defines],
-[m4_if([$@], [[]], [],
-[/* Tokens.  */
-#ifndef YYTOKENTYPE
-# if defined (__STDC__) || defined (__cplusplus)
-   /* Put the tokens into the symbol table, so that GDB and other debuggers
-      know about them.  */
-   enum yytokentype {
-m4_map_sep([     b4_token_enum], [,
-],
-           [$@])
-   };
+# b4_token_enums
+# --------------
+# Output the definition of the tokens (if there are) as enums.
+m4_define([b4_token_enums],
+[b4_any_token_visible_if([[/* Token type.  */
+#ifndef ]b4_api_PREFIX[TOKENTYPE
+# define ]b4_api_PREFIX[TOKENTYPE
+  enum ]b4_api_prefix[tokentype
+  {
+    ]m4_join([,
+    ],
+             b4_symbol_map([b4_token_enum]))[
+  };
+#endif
+]])])
+
+
+# b4_token_enums_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_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.  ##
+## ---------------------- ##
+
+
+# b4_function_define(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
+# -----------------------------------------------------------
+# Declare the function NAME in C.
+m4_define([b4_function_define],
+[$2
+$1 (b4_formals(m4_shift2($@)))[]dnl
+])
+
+
+# b4_formals([DECL1, NAME1], ...)
+# -------------------------------
+# The formal arguments of a C function definition.
+m4_define([b4_formals],
+[m4_if([$#], [0], [void],
+       [$#$1], [1], [void],
+               [m4_map_sep([b4_formal], [, ], [$@])])])
+
+m4_define([b4_formal],
+[$1])
+
+
+
+## ----------------------- ##
+## Declaring C functions.  ##
+## ----------------------- ##
+
+
+# b4_function_declare(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
+# ------------------------------------------------------------
+# Declare the function NAME.
+m4_define([b4_function_declare],
+[$2 $1 (b4_formals(m4_shift2($@)));[]dnl
+])
+
+
+
+
+## --------------------- ##
+## Calling C functions.  ##
+## --------------------- ##
+
+
+# b4_function_call(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
+# -----------------------------------------------------------
+# Call the function NAME with arguments NAME1, NAME2 etc.
+m4_define([b4_function_call],
+[$1 (b4_args(m4_shift2($@)))[]dnl
+])
+
+
+# b4_args([DECL1, NAME1], ...)
+# ----------------------------
+# Output the arguments NAME1, NAME2...
+m4_define([b4_args],
+[m4_map_sep([b4_arg], [, ], [$@])])
+
+m4_define([b4_arg],
+[$2])
+
+
+## ----------- ##
+## Synclines.  ##
+## ----------- ##
+
+# b4_sync_start(LINE, FILE)
+# -------------------------
+m4_define([b4_sync_start], [[#]line $1 $2])
+
+
+## -------------- ##
+## User actions.  ##
+## -------------- ##
+
+# b4_case(LABEL, STATEMENTS)
+# --------------------------
+m4_define([b4_case],
+[  case $1:
+$2
+b4_syncline([@oline@], [@ofile@])
+    break;])
+
+
+# b4_predicate_case(LABEL, CONDITIONS)
+# ------------------------------------
+m4_define([b4_predicate_case],
+[  case $1:
+    if (! ($2)) YYERROR;
+b4_syncline([@oline@], [@ofile@])
+    break;])
+
+
+# b4_yydestruct_define
+# --------------------
+# Define the "yydestruct" function.
+m4_define_default([b4_yydestruct_define],
+[[/*-----------------------------------------------.
+| Release the memory associated to this symbol.  |
+`-----------------------------------------------*/
+
+]b4_function_define([yydestruct],
+    [static void],
+    [[const char *yymsg],    [yymsg]],
+    [[int yytype],           [yytype]],
+    [[YYSTYPE *yyvaluep],    [yyvaluep]][]dnl
+b4_locations_if(            [, [[YYLTYPE *yylocationp], [yylocationp]]])[]dnl
+m4_ifset([b4_parse_param], [, b4_parse_param]))[
+{
+]b4_parse_param_use([yyvaluep], [yylocationp])dnl
+[  if (!yymsg)
+    yymsg = "Deleting";
+  YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
+
+  YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+  ]b4_symbol_actions([destructor])[
+  YY_IGNORE_MAYBE_UNINITIALIZED_END
+}]dnl
+])
+
+
+# b4_yy_symbol_print_define
+# -------------------------
+# Define the "yy_symbol_print" function.
+m4_define_default([b4_yy_symbol_print_define],
+[[
+/*----------------------------------------.
+| Print this symbol's value on YYOUTPUT.  |
+`----------------------------------------*/
+
+]b4_function_define([yy_symbol_value_print],
+    [static void],
+               [[FILE *yyoutput],                       [yyoutput]],
+               [[int yytype],                           [yytype]],
+               [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
+b4_locations_if([, [[YYLTYPE const * const yylocationp], [yylocationp]]])[]dnl
+m4_ifset([b4_parse_param], [, b4_parse_param]))[
+{
+  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);
 # endif
-  /* POSIX requires `int' for tokens in interfaces.  */
-# define YYTOKENTYPE int
-#endif /* !YYTOKENTYPE */
-m4_map([b4_token_define], [$@])
+]])dnl
+  b4_symbol_actions([printer])[
+}
+
+
+/*--------------------------------.
+| Print this symbol on YYOUTPUT.  |
+`--------------------------------*/
+
+]b4_function_define([yy_symbol_print],
+    [static void],
+               [[FILE *yyoutput],                       [yyoutput]],
+               [[int yytype],                           [yytype]],
+               [[YYSTYPE const * const yyvaluep],       [yyvaluep]][]dnl
+b4_locations_if([, [[YYLTYPE const * const yylocationp], [yylocationp]]])[]dnl
+m4_ifset([b4_parse_param], [, b4_parse_param]))[
+{
+  YYFPRINTF (yyoutput, "%s %s (",
+             yytype < YYNTOKENS ? "token" : "nterm", yytname[yytype]);
+
+]b4_locations_if([  YY_LOCATION_PRINT (yyoutput, *yylocationp);
+  YYFPRINTF (yyoutput, ": ");
+])dnl
+[  yy_symbol_value_print (yyoutput, yytype, yyvaluep]dnl
+b4_locations_if([, yylocationp])[]b4_user_args[);
+  YYFPRINTF (yyoutput, ")");
+}]dnl
 ])
+
+
+## ---------------- ##
+## api.value.type.  ##
+## ---------------- ##
+
+
+# ---------------------- #
+# api.value.type=union.  #
+# ---------------------- #
+
+# b4_symbol_type_register(SYMBOL-NUM)
+# -----------------------------------
+# Symbol SYMBOL-NUM has a type (for variant) instead of a type-tag.
+# Extend the definition of %union's body with a field of that type,
+# and extend the symbol's "type" field to point to the field name,
+# instead of the type name.
+m4_define([b4_symbol_type_register],
+[m4_define([b4_symbol($1, type_tag)],
+           [b4_symbol_if([$1], [has_id],
+                         [b4_symbol([$1], [id])],
+                         [yytype_[]b4_symbol([$1], [number])])])dnl
+m4_append([b4_user_union_members],
+m4_expand([
+  b4_symbol_tag_comment([$1])dnl
+  b4_symbol([$1], [type]) b4_symbol([$1], [type_tag]);]))
 ])
+
+
+# b4_type_define_tag(SYMBOL1-NUM, ...)
+# ------------------------------------
+# For the batch of symbols SYMBOL1-NUM... (which all have the same
+# type), enhance the %union definition for each of them, and set
+# there "type" field to the field tag name, instead of the type name.
+m4_define([b4_type_define_tag],
+[b4_symbol_if([$1], [has_type],
+              [m4_map([b4_symbol_type_register], [$@])])
+])
+
+
+# b4_symbol_value_union(VAL, [TYPE])
+# ----------------------------------
+# Same of b4_symbol_value, but when api.value.type=union.
+m4_define([b4_symbol_value_union],
+[m4_ifval([$2],
+          [(*($2*)(&$1))],
+          [$1])])
+])
+
+
+# b4_value_type_setup_union
+# -------------------------
+# Setup support for api.value.type=union.  Symbols are defined with a
+# type instead of a union member name: build the corresponding union,
+# and give the symbols their tag.
+m4_define([b4_value_type_setup_union],
+[m4_define([b4_union_members])
+b4_type_foreach([b4_type_define_tag])
+m4_copy_force([b4_symbol_value_union], [b4_symbol_value])
+])
+
+
+# ---------------- #
+# api.value.type.  #
+# ---------------- #
+
+
+# b4_value_type_setup_variant
+# ---------------------------
+# Setup support for api.value.type=variant.  By default, fail, specialized
+# by other skeletons.
+m4_define([b4_value_type_setup_variant],
+[b4_complain_at(b4_percent_define_get_loc([[api.value.type]]),
+                [['%s' does not support '%s']],
+                [b4_skeleton],
+                [%define api.value.type variant])])
+
+
+# _b4_value_type_setup_keyword
+# ----------------------------
+# api.value.type is defined with a keyword/string syntax.  Check if
+# that is properly defined, and prepare its use.
+m4_define([_b4_value_type_setup_keyword],
+[b4_percent_define_check_values([[[[api.value.type]],
+                                  [[none]],
+                                  [[union]],
+                                  [[union-directive]],
+                                  [[variant]],
+                                  [[yystype]]]])dnl
+m4_case(b4_percent_define_get([[api.value.type]]),
+        [union],   [b4_value_type_setup_union],
+        [variant], [b4_value_type_setup_variant])])
+
+
+# b4_value_type_setup
+# -------------------
+# Check if api.value.type is properly defined, and possibly prepare
+# its use.
+b4_define_silent([b4_value_type_setup],
+[# Define default value.
+b4_percent_define_ifdef([[api.value.type]], [],
+[# %union => api.value.type=union-directive
+m4_ifdef([b4_union_members],
+[m4_define([b4_percent_define_kind(api.value.type)], [keyword])
+m4_define([b4_percent_define(api.value.type)], [union-directive])],
+[# no tag seen => api.value.type={int}
+m4_if(b4_tag_seen_flag, 0,
+[m4_define([b4_percent_define_kind(api.value.type)], [code])
+m4_define([b4_percent_define(api.value.type)], [int])],
+[# otherwise api.value.type=yystype
+m4_define([b4_percent_define_kind(api.value.type)], [keyword])
+m4_define([b4_percent_define(api.value.type)], [yystype])])])])
+
+# Set up.
+m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+   [keyword\|string], [_b4_value_type_setup_keyword])
+])
+
+
+## -------------- ##
+## Declarations.  ##
+## -------------- ##
+
+
+# b4_value_type_define
+# --------------------
+m4_define([b4_value_type_define],
+[b4_value_type_setup[]dnl
+/* Value type.  */
+m4_bmatch(b4_percent_define_get_kind([[api.value.type]]),
+[code],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+typedef ]b4_percent_define_get([[api.value.type]])[ ]b4_api_PREFIX[STYPE;
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
+# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
+#endif
+]],
+[m4_bmatch(b4_percent_define_get([[api.value.type]]),
+[union\|union-directive],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+typedef union ]b4_union_name[ ]b4_api_PREFIX[STYPE;
+union ]b4_union_name[
+{
+]b4_user_union_members[
+};
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
+# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
+#endif
+]])])])
+
+
+# b4_location_type_define
+# -----------------------
+m4_define([b4_location_type_define],
+[[/* Location type.  */
+#if ! defined ]b4_api_PREFIX[LTYPE && ! defined ]b4_api_PREFIX[LTYPE_IS_DECLARED
+typedef struct ]b4_api_PREFIX[LTYPE ]b4_api_PREFIX[LTYPE;
+struct ]b4_api_PREFIX[LTYPE
+{
+  int first_line;
+  int first_column;
+  int last_line;
+  int last_column;
+};
+# define ]b4_api_PREFIX[LTYPE_IS_DECLARED 1
+# define ]b4_api_PREFIX[LTYPE_IS_TRIVIAL 1
+#endif
+]])
+
+
+# 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],
+[b4_value_type_define[]b4_locations_if([
+b4_location_type_define])
+
+b4_pure_if([], [[extern ]b4_api_PREFIX[STYPE ]b4_prefix[lval;
+]b4_locations_if([[extern ]b4_api_PREFIX[LTYPE ]b4_prefix[lloc;]])])[]dnl
+])
+
+
+# b4_YYDEBUG_define
+# -----------------
+m4_define([b4_YYDEBUG_define],
+[[/* Debug traces.  */
+]m4_if(b4_api_prefix, [yy],
+[[#ifndef YYDEBUG
+# define YYDEBUG ]b4_parse_trace_if([1], [0])[
+#endif]],
+[[#ifndef ]b4_api_PREFIX[DEBUG
+# if defined YYDEBUG
+#if YYDEBUG
+#   define ]b4_api_PREFIX[DEBUG 1
+#  else
+#   define ]b4_api_PREFIX[DEBUG 0
+#  endif
+# else /* ! defined YYDEBUG */
+#  define ]b4_api_PREFIX[DEBUG ]b4_parse_trace_if([1], [0])[
+# endif /* ! defined YYDEBUG */
+#endif  /* ! defined ]b4_api_PREFIX[DEBUG */]])[]dnl
+])
+
+# b4_declare_yydebug
+# ------------------
+m4_define([b4_declare_yydebug],
+[b4_YYDEBUG_define[
+#if ]b4_api_PREFIX[DEBUG
+extern int ]b4_prefix[debug;
+#endif][]dnl
+])
+
+# b4_yylloc_default_define
+# ------------------------
+# Define YYLLOC_DEFAULT.
+m4_define([b4_yylloc_default_define],
+[[/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
+   If N is 0, then set CURRENT to the empty location which ends
+   the previous symbol: RHS[0] (always defined).  */
+
+#ifndef YYLLOC_DEFAULT
+# define YYLLOC_DEFAULT(Current, Rhs, N)                                \
+    do                                                                  \
+      if (N)                                                            \
+        {                                                               \
+          (Current).first_line   = YYRHSLOC (Rhs, 1).first_line;        \
+          (Current).first_column = YYRHSLOC (Rhs, 1).first_column;      \
+          (Current).last_line    = YYRHSLOC (Rhs, N).last_line;         \
+          (Current).last_column  = YYRHSLOC (Rhs, N).last_column;       \
+        }                                                               \
+      else                                                              \
+        {                                                               \
+          (Current).first_line   = (Current).last_line   =              \
+            YYRHSLOC (Rhs, 0).last_line;                                \
+          (Current).first_column = (Current).last_column =              \
+            YYRHSLOC (Rhs, 0).last_column;                              \
+        }                                                               \
+    while (0)
+#endif
+]])
+
+# b4_yy_location_print_define
+# ---------------------------
+# Define YY_LOCATION_PRINT.
+m4_define([b4_yy_location_print_define],
+[b4_locations_if([[
+/* YY_LOCATION_PRINT -- Print the location on the stream.
+   This macro was not mandated originally: define only if we know
+   we won't break user code: when these are the locations we know.  */
+
+#ifndef YY_LOCATION_PRINT
+# if defined ]b4_api_PREFIX[LTYPE_IS_TRIVIAL && ]b4_api_PREFIX[LTYPE_IS_TRIVIAL
+
+/* Print *YYLOCP on YYO.  Private, do not rely on its existence. */
+
+__attribute__((__unused__))
+]b4_function_define([yy_location_print_],
+    [static unsigned],
+               [[FILE *yyo],                    [yyo]],
+               [[YYLTYPE const * const yylocp], [yylocp]])[
+{
+  unsigned res = 0;
+  int end_col = 0 != yylocp->last_column ? yylocp->last_column - 1 : 0;
+  if (0 <= yylocp->first_line)
+    {
+      res += YYFPRINTF (yyo, "%d", yylocp->first_line);
+      if (0 <= yylocp->first_column)
+        res += YYFPRINTF (yyo, ".%d", yylocp->first_column);
+    }
+  if (0 <= yylocp->last_line)
+    {
+      if (yylocp->first_line < yylocp->last_line)
+        {
+          res += YYFPRINTF (yyo, "-%d", yylocp->last_line);
+          if (0 <= end_col)
+            res += YYFPRINTF (yyo, ".%d", end_col);
+        }
+      else if (0 <= end_col && yylocp->first_column < end_col)
+        res += YYFPRINTF (yyo, "-%d", end_col);
+    }
+  return res;
+ }
+
+#  define YY_LOCATION_PRINT(File, Loc)          \
+  yy_location_print_ (File, &(Loc))
+
+# else
+#  define YY_LOCATION_PRINT(File, Loc) ((void) 0)
+# endif
+#endif]],
+[[/* This macro is provided for backward compatibility. */
+#ifndef YY_LOCATION_PRINT
+# define YY_LOCATION_PRINT(File, Loc) ((void) 0)
+#endif]])
+])
+
+# b4_yyloc_default
+# ----------------
+# Expand to a possible default value for yylloc.
+m4_define([b4_yyloc_default],
+[[
+# if defined ]b4_api_PREFIX[LTYPE_IS_TRIVIAL && ]b4_api_PREFIX[LTYPE_IS_TRIVIAL
+  = { ]m4_join([, ],
+               m4_defn([b4_location_initial_line]),
+               m4_defn([b4_location_initial_column]),
+               m4_defn([b4_location_initial_line]),
+               m4_defn([b4_location_initial_column]))[ }
+# endif
+]])