build: look for Perl in configure.

[bison.git] / data / bison.m4

diff --git a/data/bison.m4 b/data/bison.m4
index 00a42e21fe4e3de9035275dc641fc3fd5df48c1e..37bc012f58f9f1822cbba76389ccbc1255b751ce 100644 (file)
--- a/data/bison.m4
+++ b/data/bison.m4
@@ -1,8 +1,8 @@
                                                             -*- Autoconf -*-
 
 # Language-independent M4 Macros for Bison.
                                                             -*- Autoconf -*-
 
 # Language-independent M4 Macros for Bison.

-# Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 2009 Free Software
-# Foundation, Inc.
+
+# 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
 
 # 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


@@ -22,14 +22,17 @@
 ## Identification.  ##
 ## ---------------- ##
 
 ## Identification.  ##
 ## ---------------- ##
 

-# b4_copyright(TITLE, YEARS)
-# --------------------------
+# b4_copyright(TITLE, [YEARS])
+# ----------------------------
+# If YEARS are not defined, use b4_copyright_years.

 m4_define([b4_copyright],
 [b4_comment([A Bison parser, made by GNU Bison b4_version.])
 
 b4_comment([$1
 
 m4_define([b4_copyright],
 [b4_comment([A Bison parser, made by GNU Bison b4_version.])
 
 b4_comment([$1
 

-m4_text_wrap([Copyright (C) $2 Free Software Foundation, Inc.], [   ])
+]m4_dquote(m4_text_wrap([Copyright (C)
+]m4_ifval([$2], [[$2]], [m4_defn([b4_copyright_years])])[
+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
 
 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


@@ -85,7 +88,7 @@ m4_if(m4_sysval, [0], [], [m4_fatal([$0: cannot write to stdout])])])
 #
 # For example:
 #
 #
 # For example:
 #

-#   b4_error([[warn]], [[invalid value for `%s': %s]], [[foo]], [[3]])
+#   b4_error([[warn]], [[invalid value for '%s': %s]], [[foo]], [[3]])

 m4_define([b4_error],
 [b4_cat([[@]$1[(]$2[]]dnl
 [m4_if([$#], [2], [],
 m4_define([b4_error],
 [b4_cat([[@]$1[(]$2[]]dnl
 [m4_if([$#], [2], [],


@@ -114,7 +117,7 @@ m4_define([b4_error_at],
 #
 # For example:
 #
 #
 # For example:
 #

-#   b4_warn([[invalid value for `%s': %s]], [[foo]], [[3]])
+#   b4_warn([[invalid value for '%s': %s]], [[foo]], [[3]])

 #
 # As a simple test suite, this:
 #
 #
 # As a simple test suite, this:
 #


@@ -209,6 +212,87 @@ m4_define([b4_ints_in],
 [m4_eval([$3 <= $1 && $1 <= $4 && $3 <= $2 && $2 <= $4])])
 
 
 [m4_eval([$3 <= $1 && $1 <= $4 && $3 <= $2 && $2 <= $4])])
 
 

+# b4_subtract(LHS, RHS)
+# ---------------------
+# Evaluate LHS - RHS if they are integer literals, otherwise expand
+# to (LHS) - (RHS).
+m4_define([b4_subtract],
+[m4_bmatch([$1$2], [^[0123456789]*$],
+           [m4_eval([$1 - $2])],
+           [($1) - ($2)])])
+
+# b4_args(ARG1, ...)
+# _b4_args(ARG1, ...)
+# -------------------
+# Join with comma, skipping empty arguments.
+# b4_args calls itself recursively until it sees the first non-empty
+# argument, then calls _b4_args which prepends each non-empty argument
+# with a comma.
+m4_define([b4_args],
+[m4_if([$#$1],
+       [1], [],
+       [m4_ifval([$1],
+                 [$1[]_$0(m4_shift($@))],
+                 [$0(m4_shift($@))])])])
+
+# _b4_args(ARGS1, ...)
+# --------------------
+m4_define([_b4_args],
+[m4_if([$#$1],
+       [1], [],
+       [m4_ifval([$1], [, $1])[]$0(m4_shift($@))])])
+
+
+
+
+# b4_integral_parser_tables_map(MACRO)
+# -------------------------------------
+# Map MACRO on all the integral tables.  MACRO is expected to have
+# the signature MACRO(TABLE-NAME, CONTENT, COMMENT).
+m4_define([b4_integral_parser_tables_map],
+[$1([pact], [b4_pact],
+    [[YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
+STATE-NUM.]])
+
+$1([defact], [b4_defact],
+   [[YYDEFACT[S] -- default reduction number in state S.  Performed when
+YYTABLE does not specify something else to do.  Zero means the default
+is an error.]])
+
+$1([pgoto], [b4_pgoto], [[YYPGOTO[NTERM-NUM].]])
+
+$1([defgoto], [b4_defgoto], [[YYDEFGOTO[NTERM-NUM].]])
+
+$1([table], [b4_table],
+   [[YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
+positive, shift that token.  If negative, reduce the rule which
+number is the opposite.  If YYTABLE_NINF, syntax error.]])
+
+$1([check], [b4_check])
+
+$1([stos], [b4_stos],
+   [[STOS_[STATE-NUM] -- The (internal number of the) accessing
+symbol of state STATE-NUM.]])
+
+$1([r1], [b4_r1],
+   [[YYR1[YYN] -- Symbol number of symbol that rule YYN derives.]])
+
+$1([r2], [b4_r2],
+   [[YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.]])
+])
+
+
+# b4_parser_tables_declare
+# b4_parser_tables_define
+# ------------------------
+# Define/declare the (deterministic) parser tables.
+m4_define([b4_parser_tables_declare],
+[b4_integral_parser_tables_map([b4_integral_parser_table_declare])])
+
+m4_define([b4_parser_tables_define],
+[b4_integral_parser_tables_map([b4_integral_parser_table_define])])
+
+

 
 ## ------------------ ##
 ## Decoding options.  ##
 
 ## ------------------ ##
 ## Decoding options.  ##


@@ -220,8 +304,8 @@ m4_define([b4_ints_in],
 m4_define([b4_flag_if],
 [m4_case(b4_$1_flag,
          [0], [$3],
 m4_define([b4_flag_if],
 [m4_case(b4_$1_flag,
          [0], [$3],

-        [1], [$2],
-        [m4_fatal([invalid $1 value: ]$1)])])
+         [1], [$2],
+         [m4_fatal([invalid $1 value: ]$1)])])

 
 
 # b4_define_flag_if(FLAG)
 
 
 # b4_define_flag_if(FLAG)


@@ -246,17 +330,121 @@ m4_define([b4_$3_if],
 # b4_FLAG_if(IF-TRUE, IF-FALSE)
 # -----------------------------
 # Expand IF-TRUE, if FLAG is true, IF-FALSE otherwise.
 # b4_FLAG_if(IF-TRUE, IF-FALSE)
 # -----------------------------
 # Expand IF-TRUE, if FLAG is true, IF-FALSE otherwise.

-b4_define_flag_if([defines])           # Whether headers are requested.
-b4_define_flag_if([error_verbose])     # Whether error are verbose.
-b4_define_flag_if([glr])               # Whether a GLR parser is requested.
-b4_define_flag_if([locations])         # Whether locations are tracked.
-b4_define_flag_if([nondeterministic])  # Whether conflicts should be handled.
-b4_define_flag_if([yacc])              # Whether POSIX Yacc is emulated.
+b4_define_flag_if([defines])            # Whether headers are requested.
+b4_define_flag_if([glr])                # Whether a GLR parser is requested.
+b4_define_flag_if([nondeterministic])   # Whether conflicts should be handled.
+b4_define_flag_if([yacc])               # Whether POSIX Yacc is emulated.
+
+
+## --------- ##
+## Symbols.  ##
+## --------- ##
+
+# b4_symbol_(NUM, FIELD)
+# ----------------------
+# Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
+# undefined.
+m4_define([b4_symbol_],
+[m4_indir([b4_symbol($1, $2)])])
+
+
+# b4_symbol(NUM, FIELD)
+# ---------------------
+# Recover a FIELD about symbol #NUM.  Thanks to m4_indir, fails if
+# undefined.  If FIELD = id, prepend the prefix.
+m4_define([b4_symbol],
+[m4_case([$2],
+         [id],    [m4_do([b4_percent_define_get([api.tokens.prefix])],
+                         [b4_symbol_([$1], [id])])],
+         [b4_symbol_($@)])])
+
+
+# b4_symbol_if(NUM, FIELD, IF-TRUE, IF-FALSE)
+# -------------------------------------------
+# If FIELD about symbol #NUM is 1 expand IF-TRUE, if is 0, expand IF-FALSE.
+# Otherwise an error.
+m4_define([b4_symbol_if],
+[m4_case(b4_symbol([$1], [$2]),
+         [1], [$3],
+         [0], [$4],
+         [m4_fatal([$0: field $2 of $1 is not a Boolean:] b4_symbol([$1], [$2]))])])
+
+
+# b4_symbol_action_location(SYMBOL-NUM, KIND)
+# -------------------------------------------
+# Report the location of the KIND action as FILE:LINE.
+m4_define([b4_symbol_action_location],
+[b4_symbol([$1], [$2_file]):b4_syncline([b4_symbol([$1], [$2_line])])])
+
+
+# b4_symbol_action(SYMBOL-NUM, KIND)
+# ----------------------------------
+# Run the action KIND (destructor or printer) for SYMBOL-NUM.
+# Same as in C, but using references instead of pointers.
+m4_define([b4_symbol_action],
+[b4_symbol_if([$1], [has_$2],
+[m4_pushdef([b4_dollar_dollar],
+    [b4_symbol_value([(*yyvaluep)],
+                     b4_symbol_if([$1], [has_type],
+                                  [b4_symbol([$1], [type])]))])dnl
+m4_pushdef([b4_at_dollar], [(*yylocationp)])dnl
+      b4_symbol_case_([$1])
+b4_syncline([b4_symbol([$1], [$2_line])], ["b4_symbol([$1], [$2_file])"])
+        b4_symbol([$1], [$2])
+b4_syncline([@oline@], [@ofile@])
+        break;
+
+m4_popdef([b4_at_dollar])dnl
+m4_popdef([b4_dollar_dollar])dnl
+])])
+
+
+# b4_symbol_destructor(SYMBOL-NUM)
+# b4_symbol_printer(SYMBOL-NUM)
+# --------------------------------
+m4_define([b4_symbol_destructor], [b4_symbol_action([$1], [destructor])])
+m4_define([b4_symbol_printer],    [b4_symbol_action([$1], [printer])])
+
+
+# b4_symbol_case_(SYMBOL-NUM)
+# ---------------------------
+# Issue a "case NUM" for SYMBOL-NUM.
+m4_define([b4_symbol_case_],
+[      case b4_symbol([$1], [number]): // b4_symbol([$1], [tag])
+])

 
 
 
 

-## ------------------------- ##
-## Assigning token numbers.  ##
-## ------------------------- ##
+# b4_symbol_foreach(MACRO)
+# ------------------------
+# Invoke MACRO(SYMBOL-NUM) for each SYMBOL-NUM.
+m4_define([b4_symbol_foreach],
+          [m4_map([$1], m4_defn([b4_symbol_numbers]))])
+
+
+## ------- ##
+## Types.  ##
+## ------- ##
+
+# b4_type_action_(NUMS)
+# ---------------------
+# Run actions for the symbol NUMS that all have the same type-name.
+# Skip NUMS that have no type-name.
+m4_define([b4_type_action_],
+[b4_symbol_if([$1], [has_type],
+[m4_map([b4_symbol_case_], [$@])[]dnl
+        b4_dollar_dollar([b4_symbol([$1], [number])],
+                         [b4_symbol([$1], [tag])],
+                         [b4_symbol([$1], [type])]);
+        break;
+
+])])
+
+# b4_type_foreach(MACRO)
+# ----------------------
+# Invoke MACRO(SYMBOL-NUMS) for each set of SYMBOL-NUMS for each type set.
+m4_define([b4_type_foreach],
+          [m4_map([$1], m4_defn([b4_type_names]))])
+

 
 
 ## ----------- ##
 
 
 ## ----------- ##


@@ -274,8 +462,8 @@ m4_define([b4_basename],
 # b4_syncline(LINE, FILE)
 # -----------------------
 m4_define([b4_syncline],
 # b4_syncline(LINE, FILE)
 # -----------------------
 m4_define([b4_syncline],

-[b4_flag_if([synclines], [
-b4_sync_end([__line__], [b4_basename(m4_quote(__file__))])
+[b4_flag_if([synclines],
+[b4_sync_end([__line__], [b4_basename(m4_quote(__file__))])

 b4_sync_start([$1], [$2])])])
 
 m4_define([b4_sync_end], [b4_comment([Line $1 of $2])])
 b4_sync_start([$1], [$2])])])
 
 m4_define([b4_sync_end], [b4_comment([Line $1 of $2])])


@@ -312,13 +500,13 @@ b4_define_user_code([stype])
 
 
 # b4_check_user_names(WHAT, USER-LIST, BISON-NAMESPACE)
 
 
 # b4_check_user_names(WHAT, USER-LIST, BISON-NAMESPACE)

-# --------------------------------------------------------
-# Warn if any name of type WHAT is used by the user (as recorded in USER-LIST)
-# but is not used by Bison (as recorded by macros in the namespace
-# BISON-NAMESPACE).
+# -----------------------------------------------------
+# Complain if any name of type WHAT is used by the user (as recorded in
+# USER-LIST) but is not used by Bison (as recorded by macros in the
+# namespace BISON-NAMESPACE).

 #
 #

-# USER-LIST must expand to a list specifying all grammar occurrences of all
-# names of type WHAT.   Each item in the list must be a triplet specifying one
+# USER-LIST must expand to a list specifying all user occurrences of all names
+# of type WHAT.   Each item in the list must be a triplet specifying one

 # occurrence: name, start boundary, and end boundary.  Empty string names are
 # fine.  An empty list is fine.
 #
 # occurrence: name, start boundary, and end boundary.  Empty string names are
 # fine.  An empty list is fine.
 #


@@ -353,19 +541,34 @@ m4_pushdef([b4_user_name], m4_car(b4_occurrence))dnl
 m4_pushdef([b4_start], m4_car(m4_shift(b4_occurrence)))dnl
 m4_pushdef([b4_end], m4_shift(m4_shift(b4_occurrence)))dnl
 m4_ifndef($3[(]m4_quote(b4_user_name)[)],
 m4_pushdef([b4_start], m4_car(m4_shift(b4_occurrence)))dnl
 m4_pushdef([b4_end], m4_shift(m4_shift(b4_occurrence)))dnl
 m4_ifndef($3[(]m4_quote(b4_user_name)[)],

-          [b4_warn_at([b4_start], [b4_end],
-                      [[%s `%s' is not used]],
-                      [$1], [b4_user_name])])[]dnl
+          [b4_complain_at([b4_start], [b4_end],
+                          [[%s '%s' is not used]],
+                          [$1], [b4_user_name])])[]dnl

 m4_popdef([b4_occurrence])dnl
 m4_popdef([b4_user_name])dnl
 m4_popdef([b4_start])dnl
 m4_popdef([b4_end])dnl
 ])])
 
 m4_popdef([b4_occurrence])dnl
 m4_popdef([b4_user_name])dnl
 m4_popdef([b4_start])dnl
 m4_popdef([b4_end])dnl
 ])])
 

-# b4_percent_define_get(VARIABLE)
+
+
+## --------------------- ##
+## b4_percent_define_*.  ##
+## --------------------- ##
+
+
+# b4_percent_define_use(VARIABLE)

 # -------------------------------
 # -------------------------------

-# Mimic muscle_percent_define_get in ../src/muscle_tab.h exactly.  That is, if
-# the %define variable VARIABLE is defined, emit its value.  Also, record
+# Declare that VARIABLE was used.
+m4_define([b4_percent_define_use],
+[m4_define([b4_percent_define_bison_variables(]$1[)])dnl
+])
+
+# b4_percent_define_get(VARIABLE, [DEFAULT])
+# ------------------------------------------
+# Mimic muscle_percent_define_get in ../src/muscle-tab.h.  That is, if
+# the %define variable VARIABLE is defined, emit its value.  Contrary
+# to its C counterpart, return DEFAULT otherwise.  Also, record

 # Bison's usage of VARIABLE by defining
 # b4_percent_define_bison_variables(VARIABLE).
 #
 # Bison's usage of VARIABLE by defining
 # b4_percent_define_bison_variables(VARIABLE).
 #


@@ -373,12 +576,14 @@ m4_popdef([b4_end])dnl
 #
 #   b4_percent_define_get([[foo]])
 m4_define([b4_percent_define_get],
 #
 #   b4_percent_define_get([[foo]])
 m4_define([b4_percent_define_get],

-[m4_define([b4_percent_define_bison_variables(]$1[)])dnl
-m4_ifdef([b4_percent_define(]$1[)], [m4_indir([b4_percent_define(]$1[)])])])
+[b4_percent_define_use([$1])dnl
+m4_ifdef([b4_percent_define(]$1[)],
+         [m4_indir([b4_percent_define(]$1[)])],
+         [$2])])

 
 # b4_percent_define_get_loc(VARIABLE)
 # -----------------------------------
 
 # b4_percent_define_get_loc(VARIABLE)
 # -----------------------------------

-# Mimic muscle_percent_define_get_loc in ../src/muscle_tab.h exactly.  That is,
+# Mimic muscle_percent_define_get_loc in ../src/muscle-tab.h exactly.  That is,

 # if the %define variable VARIABLE is undefined, complain fatally since that's
 # a Bison or skeleton error.  Otherwise, return its definition location in a
 # form approriate for the first two arguments of b4_warn_at, b4_complain_at, or
 # if the %define variable VARIABLE is undefined, complain fatally since that's
 # a Bison or skeleton error.  Otherwise, return its definition location in a
 # form approriate for the first two arguments of b4_warn_at, b4_complain_at, or


@@ -393,11 +598,11 @@ m4_define([b4_percent_define_get_loc],
           [m4_pushdef([b4_loc], m4_indir([b4_percent_define_loc(]$1[)]))dnl
 b4_loc[]dnl
 m4_popdef([b4_loc])],
           [m4_pushdef([b4_loc], m4_indir([b4_percent_define_loc(]$1[)]))dnl
 b4_loc[]dnl
 m4_popdef([b4_loc])],

-          [b4_fatal([[undefined %%define variable `%s' passed to b4_percent_define_get_loc]], [$1])])])
+          [b4_fatal([[b4_percent_define_get_loc: undefined %%define variable '%s']], [$1])])])

 
 # b4_percent_define_get_syncline(VARIABLE)
 # ----------------------------------------
 
 # b4_percent_define_get_syncline(VARIABLE)
 # ----------------------------------------

-# Mimic muscle_percent_define_get_syncline in ../src/muscle_tab.h exactly.
+# Mimic muscle_percent_define_get_syncline in ../src/muscle-tab.h exactly.

 # That is, if the %define variable VARIABLE is undefined, complain fatally
 # since that's a Bison or skeleton error.  Otherwise, return its definition
 # location as a b4_syncline invocation.  Don't record this as a Bison usage of
 # That is, if the %define variable VARIABLE is undefined, complain fatally
 # since that's a Bison or skeleton error.  Otherwise, return its definition
 # location as a b4_syncline invocation.  Don't record this as a Bison usage of


@@ -410,11 +615,11 @@ m4_popdef([b4_loc])],
 m4_define([b4_percent_define_get_syncline],
 [m4_ifdef([b4_percent_define_syncline(]$1[)],
           [m4_indir([b4_percent_define_syncline(]$1[)])],
 m4_define([b4_percent_define_get_syncline],
 [m4_ifdef([b4_percent_define_syncline(]$1[)],
           [m4_indir([b4_percent_define_syncline(]$1[)])],

-          [b4_fatal([[undefined %%define variable `%s' passed to b4_percent_define_get_syncline]], [$1])])])
+          [b4_fatal([[b4_percent_define_get_syncline: undefined %%define variable '%s']], [$1])])])

 
 # b4_percent_define_ifdef(VARIABLE, IF-TRUE, [IF-FALSE])
 # ------------------------------------------------------
 
 # b4_percent_define_ifdef(VARIABLE, IF-TRUE, [IF-FALSE])
 # ------------------------------------------------------

-# Mimic muscle_percent_define_ifdef in ../src/muscle_tab.h exactly.  That is,
+# Mimic muscle_percent_define_ifdef in ../src/muscle-tab.h exactly.  That is,

 # if the %define variable VARIABLE is defined, expand IF-TRUE, else expand
 # IF-FALSE.  Also, record Bison's usage of VARIABLE by defining
 # b4_percent_define_bison_variables(VARIABLE).
 # if the %define variable VARIABLE is defined, expand IF-TRUE, else expand
 # IF-FALSE.  Also, record Bison's usage of VARIABLE by defining
 # b4_percent_define_bison_variables(VARIABLE).


@@ -424,12 +629,18 @@ m4_define([b4_percent_define_get_syncline],
 #   b4_percent_define_ifdef([[foo]], [[it's defined]], [[it's undefined]])
 m4_define([b4_percent_define_ifdef],
 [m4_ifdef([b4_percent_define(]$1[)],
 #   b4_percent_define_ifdef([[foo]], [[it's defined]], [[it's undefined]])
 m4_define([b4_percent_define_ifdef],
 [m4_ifdef([b4_percent_define(]$1[)],

-         [m4_define([b4_percent_define_bison_variables(]$1[)])$2],
-         [$3])])
+          [b4_percent_define_use([$1])$2],
+          [$3])])
+
+
+## --------- ##
+## Options.  ##
+## --------- ##
+

 
 # b4_percent_define_flag_if(VARIABLE, IF-TRUE, [IF-FALSE])
 # --------------------------------------------------------
 
 # b4_percent_define_flag_if(VARIABLE, IF-TRUE, [IF-FALSE])
 # --------------------------------------------------------

-# Mimic muscle_percent_define_flag_if in ../src/muscle_tab.h exactly.  That is,
+# Mimic muscle_percent_define_flag_if in ../src/muscle-tab.h exactly.  That is,

 # if the %define variable VARIABLE is defined to "" or "true", expand IF-TRUE.
 # If it is defined to "false", expand IF-FALSE.  Complain if it is undefined
 # (a Bison or skeleton error since the default value should have been set
 # if the %define variable VARIABLE is defined to "" or "true", expand IF-TRUE.
 # If it is defined to "false", expand IF-FALSE.  Complain if it is undefined
 # (a Bison or skeleton error since the default value should have been set


@@ -445,14 +656,15 @@ m4_define([b4_percent_define_flag_if],
   [m4_case(b4_percent_define_get([$1]),
            [], [$2], [true], [$2], [false], [$3],
            [m4_expand_once([b4_complain_at(b4_percent_define_get_loc([$1]),
   [m4_case(b4_percent_define_get([$1]),
            [], [$2], [true], [$2], [false], [$3],
            [m4_expand_once([b4_complain_at(b4_percent_define_get_loc([$1]),

-                                           [[invalid value for %%define Boolean variable `%s']],
+                                           [[invalid value for %%define Boolean variable '%s']],

                                            [$1])],
                            [[b4_percent_define_flag_if($1)]])])],
                                            [$1])],
                            [[b4_percent_define_flag_if($1)]])])],

-  [b4_fatal([[undefined %%define variable `%s' passed to b4_percent_define_flag_if]], [$1])])])
+  [b4_fatal([[b4_percent_define_flag_if: undefined %%define variable '%s']], [$1])])])
+

 
 # b4_percent_define_default(VARIABLE, DEFAULT)
 # --------------------------------------------
 
 # b4_percent_define_default(VARIABLE, DEFAULT)
 # --------------------------------------------

-# Mimic muscle_percent_define_default in ../src/muscle_tab.h exactly.  That is,
+# Mimic muscle_percent_define_default in ../src/muscle-tab.h exactly.  That is,

 # if the %define variable VARIABLE is undefined, set its value to DEFAULT.
 # Don't record this as a Bison usage of VARIABLE as there's no reason to
 # suspect that the value has yet influenced the output.
 # if the %define variable VARIABLE is undefined, set its value to DEFAULT.
 # Don't record this as a Bison usage of VARIABLE as there's no reason to
 # suspect that the value has yet influenced the output.


@@ -468,9 +680,23 @@ m4_define([b4_percent_define_default],
                         [[<skeleton default value>:-1.-1]]]])dnl
             m4_define([b4_percent_define_syncline(]$1[)], [[]])])])
 
                         [[<skeleton default value>:-1.-1]]]])dnl
             m4_define([b4_percent_define_syncline(]$1[)], [[]])])])
 

+
+# b4_percent_define_if_define(VARIABLE)
+# -------------------------------------
+# Define b4_VARIABLE_if that executes its $1 or $2 depending whether
+# VARIABLE was %defined.  The characters `.' and `-' in VARIABLE are mapped
+# to `_'.
+m4_define([b4_percent_define_if_define_],
+[m4_define(m4_bpatsubst([b4_$1_if], [[-.]], [_]),
+           [b4_percent_define_flag_if([$1], [$2], [$3])])])
+m4_define([b4_percent_define_if_define],
+[b4_percent_define_default([[$1]], [[false]])
+b4_percent_define_if_define_([$1], $[1], $[2])])
+
+

 # b4_percent_define_check_values(VALUES)
 # --------------------------------------
 # b4_percent_define_check_values(VALUES)
 # --------------------------------------

-# Mimic muscle_percent_define_check_values in ../src/muscle_tab.h exactly
+# Mimic muscle_percent_define_check_values in ../src/muscle-tab.h exactly

 # except that the VALUES structure is more appropriate for M4.  That is, VALUES
 # is a list of sublists of strings.  For each sublist, the first string is the
 # name of a %define variable, and all remaining strings in that sublist are the
 # except that the VALUES structure is more appropriate for M4.  That is, VALUES
 # is a list of sublists of strings.  For each sublist, the first string is the
 # name of a %define variable, and all remaining strings in that sublist are the


@@ -497,15 +723,15 @@ m4_define([_b4_percent_define_check_values],
                             [m4_define([b4_good_value], [1])])])])dnl
    m4_if(b4_good_value, [0],
          [b4_complain_at(b4_percent_define_get_loc([$1]),
                             [m4_define([b4_good_value], [1])])])])dnl
    m4_if(b4_good_value, [0],
          [b4_complain_at(b4_percent_define_get_loc([$1]),

-                         [[invalid value for %%define variable `%s': `%s']],
+                         [[invalid value for %%define variable '%s': '%s']],

                          [$1],
                          m4_dquote(m4_indir([b4_percent_define(]$1[)])))
           m4_foreach([b4_value], m4_dquote(m4_shift($@)),
                      [b4_complain_at(b4_percent_define_get_loc([$1]),
                          [$1],
                          m4_dquote(m4_indir([b4_percent_define(]$1[)])))
           m4_foreach([b4_value], m4_dquote(m4_shift($@)),
                      [b4_complain_at(b4_percent_define_get_loc([$1]),

-                                     [[accepted value: `%s']],
+                                     [[accepted value: '%s']],

                                      m4_dquote(b4_value))])])dnl
    m4_popdef([b4_good_value])],
                                      m4_dquote(b4_value))])])dnl
    m4_popdef([b4_good_value])],

-  [b4_fatal([[undefined %%define variable `%s' passed to b4_percent_define_check_values]], [$1])])])
+  [b4_fatal([[b4_percent_define_check_values: undefined %%define variable '%s']], [$1])])])

 
 # b4_percent_code_get([QUALIFIER])
 # --------------------------------
 
 # b4_percent_code_get([QUALIFIER])
 # --------------------------------


@@ -539,7 +765,42 @@ m4_popdef([b4_macro_name])])
 m4_define([b4_percent_code_ifdef],
 [m4_ifdef([b4_percent_code(]$1[)],
           [m4_ifval([$1], [m4_define([b4_percent_code_bison_qualifiers(]$1[)])])$2],
 m4_define([b4_percent_code_ifdef],
 [m4_ifdef([b4_percent_code(]$1[)],
           [m4_ifval([$1], [m4_define([b4_percent_code_bison_qualifiers(]$1[)])])$2],

-         [$3])])
+          [$3])])
+
+
+## ------------------ ##
+## Common variables.  ##
+## ------------------ ##
+
+# Default values for %define.
+# ---------------------------
+# If the api.tokens.prefix, it is empty.
+m4_percent_define_default([[api.tokens.prefix]], [[]])
+
+# b4_parse_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
+# b4_parse_trace_if([IF-DEBUG-TRACES-ARE-ENABLED], [IF-NOT])
+# b4_lex_symbol_if([IF-YYLEX-RETURNS-A-COMPLETE-SYMBOL], [IF-NOT])
+# b4_variant_if([IF-VARIANT-ARE-USED], [IF-NOT])
+# ----------------------------------------------
+b4_percent_define_if_define([lex_symbol])
+b4_percent_define_if_define([locations])     # Whether locations are tracked.
+b4_percent_define_if_define([parse.assert])
+b4_percent_define_if_define([parse.trace])
+b4_percent_define_if_define([variant])
+
+
+# b4_error_verbose_if([IF-ERRORS-ARE-VERBOSE], [IF-NOT])
+# ------------------------------------------------------
+# Map %define parse.error "(simple|verbose)" to b4_error_verbose_if and
+# b4_error_verbose_flag.
+b4_percent_define_default([[parse.error]], [[simple]])
+b4_percent_define_check_values([[[[parse.error]],
+                                 [[simple]], [[verbose]]]])
+m4_define([b4_error_verbose_flag],
+          [m4_case(b4_percent_define_get([[parse.error]]),
+                   [simple],  [[0]],
+                   [verbose], [[1]])])
+b4_define_flag_if([error_verbose])

 
 
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