-*- Autoconf -*-
# Language-independent M4 Macros for Bison.
-# Copyright (C) 2002, 2004, 2005, 2006, 2007 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/>.
## ---------------- ##
m4_text_wrap([Copyright (C) $2 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
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+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
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_comment([As a special exception, you may create a larger work that contains
part or all of the Bison parser skeleton and distribute that work
## Error handling. ##
## ---------------- ##
+# The following error handling macros print error directives that should not
+# become arguments of other macro invocations since they would likely then be
+# mangled. Thus, they print to stdout directly.
+
+# b4_cat(TEXT)
+# ------------
+# Write TEXT to stdout. Precede the final newline with an @ so that it's
+# escaped. For example:
+#
+# b4_cat([[@complain(invalid input@)]])
+m4_define([b4_cat],
+[m4_syscmd([cat <<'_m4eof'
+]m4_bpatsubst(m4_dquote($1), [_m4eof], [_m4@`eof])[@
+_m4eof
+])dnl
+m4_if(m4_sysval, [0], [], [m4_fatal([$0: cannot write to stdout])])])
+
# b4_error(KIND, FORMAT, [ARG1], [ARG2], ...)
# -------------------------------------------
-# Write @KIND(FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @KIND(FORMAT@,ARG1@,ARG2@,...@) to stdout.
+#
+# For example:
+#
+# b4_error([[warn]], [[invalid value for '%s': %s]], [[foo]], [[3]])
m4_define([b4_error],
-[m4_divert_push(0)[@]$1[(]$2[]m4_if([$#], [2], [],
-[m4_foreach([b4_arg],
- m4_dquote(m4_shift(m4_shift($@))),
- [[@,]b4_arg])])[@)]m4_divert_pop(0)])
+[b4_cat([[@]$1[(]$2[]]dnl
+[m4_if([$#], [2], [],
+ [m4_foreach([b4_arg],
+ m4_dquote(m4_shift(m4_shift($@))),
+ [[@,]b4_arg])])[@)]])])
# b4_error_at(KIND, START, END, FORMAT, [ARG1], [ARG2], ...)
# ----------------------------------------------------------
-# Write @KIND(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @KIND_at(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to stdout.
+#
+# For example:
+#
+# b4_error_at([[complain]], [[input.y:2.3]], [[input.y:5.4]],
+# [[invalid %s]], [[foo]])
m4_define([b4_error_at],
-[m4_divert_push(0)[@]$1[_at(]$2[@,]$3[@,]$4[]m4_if([$#], [4], [],
-[m4_foreach([b4_arg],
- m4_dquote(m4_shift(m4_shift(m4_shift(m4_shift($@))))),
- [[@,]b4_arg])])[@)]m4_divert_pop(0)])
+[b4_cat([[@]$1[_at(]$2[@,]$3[@,]$4[]]dnl
+[m4_if([$#], [4], [],
+ [m4_foreach([b4_arg],
+ m4_dquote(m4_shift(m4_shift(m4_shift(m4_shift($@))))),
+ [[@,]b4_arg])])[@)]])])
# b4_warn(FORMAT, [ARG1], [ARG2], ...)
# ------------------------------------
-# Write @warn(FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @warn(FORMAT@,ARG1@,ARG2@,...@) to stdout.
+#
+# For example:
+#
+# b4_warn([[invalid value for '%s': %s]], [[foo]], [[3]])
#
# As a simple test suite, this:
#
+# m4_divert(-1)
# m4_define([asdf], [ASDF])
# m4_define([fsa], [FSA])
# m4_define([fdsa], [FDSA])
# b4_warn([[[asdf), asdf]]], [[[fsa), fsa]]], [[[fdsa), fdsa]]])
-# m4_divert(0)
# b4_warn([[asdf), asdf]], [[fsa), fsa]], [[fdsa), fdsa]])
-# m4_divert(0)
-# b4_warn([asdf), asdf], [fsa), fsa], [fdsa), fdsa])
-# m4_divert(0)
# b4_warn()
-# m4_divert(0)
# b4_warn(1)
-# m4_divert(0)
# b4_warn(1, 2)
#
-# Should produce this:
+# Should produce this without newlines:
#
# @warn([asdf), asdf]@,[fsa), fsa]@,[fdsa), fdsa]@)
# @warn(asdf), asdf@,fsa), fsa@,fdsa), fdsa@)
-# @warn(ASDF), ASDF@,FSA), FSA@,FDSA), FDSA@)
# @warn(@)
# @warn(1@)
# @warn(1@,2@)
# b4_warn_at(START, END, FORMAT, [ARG1], [ARG2], ...)
# ---------------------------------------------------
-# Write @warn(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @warn(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to stdout.
+#
+# For example:
+#
+# b4_warn_at([[input.y:2.3]], [[input.y:5.4]], [[invalid %s]], [[foo]])
m4_define([b4_warn_at],
[b4_error_at([[warn]], $@)])
# b4_complain(FORMAT, [ARG1], [ARG2], ...)
# ----------------------------------------
-# Write @complain(FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @complain(FORMAT@,ARG1@,ARG2@,...@) to stdout.
#
-# See the test suite for b4_warn above.
+# See b4_warn example.
m4_define([b4_complain],
[b4_error([[complain]], $@)])
# b4_complain_at(START, END, FORMAT, [ARG1], [ARG2], ...)
# -------------------------------------------------------
-# Write @complain(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @complain(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to stdout.
+#
+# See b4_warn_at example.
m4_define([b4_complain_at],
[b4_error_at([[complain]], $@)])
# b4_fatal(FORMAT, [ARG1], [ARG2], ...)
# -------------------------------------
-# Write @fatal(FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @fatal(FORMAT@,ARG1@,ARG2@,...@) to stdout and exit.
#
-# See the test suite for b4_warn above.
+# See b4_warn example.
m4_define([b4_fatal],
-[b4_error([[fatal]], $@)])
+[b4_error([[fatal]], $@)dnl
+m4_exit(1)])
# b4_fatal_at(START, END, FORMAT, [ARG1], [ARG2], ...)
# ----------------------------------------------------
-# Write @fatal(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to diversion 0.
+# Write @fatal(START@,END@,FORMAT@,ARG1@,ARG2@,...@) to stdout and exit.
+#
+# See b4_warn_at example.
m4_define([b4_fatal_at],
-[b4_error_at([[fatal]], $@)])
-
-
-## ---------------- ##
-## Default values. ##
-## ---------------- ##
-
-# m4_define_default([b4_lex_param], []) dnl breaks other skeletons
-m4_define_default([b4_epilogue], [])
-m4_define_default([b4_parse_param], [])
-
-# The initial column and line.
-m4_define_default([b4_location_initial_column], [1])
-m4_define_default([b4_location_initial_line], [1])
+[b4_error_at([[fatal]], $@)dnl
+m4_exit(1)])
## ------------ ##
# _b4_define_flag_if($1, $2, FLAG)
# --------------------------------
-# This macro works around the impossibility to define macros
-# inside macros, because issuing `[$1]' is not possible in M4 :(.
-# This sucks hard, GNU M4 should really provide M5 like $$1.
+# Work around the impossibility to define macros inside macros,
+# because issuing `[$1]' is not possible in M4. GNU M4 should provide
+# $$1 a la M5/TeX.
m4_define([_b4_define_flag_if],
[m4_if([$1$2], $[1]$[2], [],
[m4_fatal([$0: Invalid arguments: $@])])dnl
# 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([pull]) # Whether pull parsing is requested.
-b4_define_flag_if([pure]) # Whether the interface is pure.
-b4_define_flag_if([push]) # Whether push parsing is requested.
-b4_define_flag_if([use_push_for_pull]) # Whether push parsing should be used
- # in place of pull parsing (where
- # available) for the sake of the test
- # suite.
-b4_define_flag_if([yacc]) # Whether POSIX Yacc is emulated.
-
-
-## ------------------------- ##
-## Assigning token numbers. ##
-## ------------------------- ##
+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([token_table]) # Whether yytoken_table is demanded.
+b4_define_flag_if([yacc]) # Whether POSIX Yacc is emulated.
+
+# yytoken_table is needed to support verbose errors.
+b4_error_verbose_if([m4_define([b4_token_table_flag], [1])])
+
## ----------- ##
# 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_define_user_code([stype])
-# b4_check_for_unrecognized_names(WHAT, LIST, [VALID_NAME], [VALID_NAME])
-# -----------------------------------------------------------------------
-# Complain if any name of type WHAT is used in the grammar (as recorded in
-# LIST) but is not a VALID_NAME.
+# b4_check_user_names(WHAT, USER-LIST, 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).
#
-# LIST must expand to a list specifying all grammar occurrences of all names of
-# type WHAT. Each item in the list is a triplet specifying one occurrence:
-# name, start boundary, and end boundary. Empty string names are fine. An
-# empty list is fine.
+# 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.
#
-# For example, to define b4_foo_list to be used for LIST with three name
-# occurrences and with correct quoting:
+# For example, to define b4_foo_user_names to be used for USER-LIST with three
+# name occurrences and with correct quoting:
#
-# m4_define([b4_foo_list],
+# m4_define([b4_foo_user_names],
# [[[[[[bar]], [[parser.y:1.7]], [[parser.y:1.16]]]],
# [[[[bar]], [[parser.y:5.7]], [[parser.y:5.16]]]],
# [[[[baz]], [[parser.y:8.7]], [[parser.y:8.16]]]]]])
#
-# Each VALID_NAME must expand to a valid name of type WHAT. Multiple
-# occurrences of the same valid name are fine. A VALID_NAME that expands to
-# the empty string will correctly define the empty string as a valid name, but
-# it would be ugly for a Bison skeleton to actually use that.
-#
-# For example, to invoke b4_check_for_unrecognized_names with TYPE foo, with
-# LIST b4_foo_list, with two valid names, and with correct quoting:
-#
-# b4_check_for_unrecognized_names([[foo]], [b4_foo_list],
-# [[bar]], [[baz]])
-#
-# Names and valid names must not contain the character `,'.
-m4_define([b4_check_for_unrecognized_names],
-[m4_foreach([b4_occurrence],
- $2,
- [m4_pushdef([b4_occurrence], b4_occurrence)
- m4_pushdef([b4_name], m4_car(b4_occurrence))
- m4_pushdef([b4_start], m4_car(m4_shift(b4_occurrence)))
- m4_pushdef([b4_end], m4_shift(m4_shift(b4_occurrence)))
- m4_if(m4_index(m4_if($#, 2, [],
- [[,]m4_quote(m4_shift(m4_shift($*)))[,]]),
- [,]b4_name[,]),
- [-1],
- [b4_complain_at([b4_start], [b4_end],
- [[`%s' is not a recognized %s]],
- [b4_name], [$1])
- ])
- m4_popdef([b4_occurrence])
- m4_popdef([b4_name])
- m4_popdef([b4_start])
- m4_popdef([b4_end])
- ])
+# The macro BISON-NAMESPACE(bar) must be defined iff the name bar of type WHAT
+# is used by Bison (in the front-end or in the skeleton). Empty string names
+# are fine, but it would be ugly for Bison to actually use one.
+#
+# For example, to use b4_foo_bison_names for BISON-NAMESPACE and define that
+# the names bar and baz are used by Bison:
+#
+# m4_define([b4_foo_bison_names(bar)])
+# m4_define([b4_foo_bison_names(baz)])
+#
+# To invoke b4_check_user_names with TYPE foo, with USER-LIST
+# b4_foo_user_names, with BISON-NAMESPACE b4_foo_bison_names, and with correct
+# quoting:
+#
+# b4_check_user_names([[foo]], [b4_foo_user_names],
+# [[b4_foo_bison_names]])
+m4_define([b4_check_user_names],
+[m4_foreach([b4_occurrence], $2,
+[m4_pushdef([b4_occurrence], b4_occurrence)dnl
+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)[)],
+ [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
+])])
+
+
+
+
+## --------------------- ##
+## b4_percent_define_*. ##
+## --------------------- ##
+
+
+# b4_percent_define_use(VARIABLE)
+# -------------------------------
+# Declare that VARIABLE was used.
+m4_define([b4_percent_define_use],
+[m4_define([b4_percent_define_bison_variables(]$1[)])dnl
])
-# b4_check_percent_define_variables([VAILD_VARIABLE], [VALID_VARIABLE], ...)
-# --------------------------------------------------------------------------
-# Wrapper around b4_check_for_unrecognized_names for %define variables.
-#
-# b4_used_percent_define_variables must contain a list of all %define variables
-# used in the grammar similar to b4_foo_list from the
-# b4_check_for_unrecognized_names documentation's example. If
-# b4_used_percent_define_variables is undefined, it's treated the same as an
-# empty list.
-#
-# Invoking b4_check_percent_define_variables with empty parens specifies one
-# valid variable that is an empty string. Invoke it without parens to specify
-# that there are no valid variables.
-m4_define([b4_check_percent_define_variables],
-[m4_ifdef([b4_used_percent_define_variables],
-[b4_check_for_unrecognized_names([[%define variable]],
-[b4_used_percent_define_variables]m4_if([$#], [0], [], [, $@]))])])
-
-# b4_check_percent_code_qualifiers([VAILD_QUALIFIER], [VALID_QUALIFIER], ...)
-# ---------------------------------------------------------------------------
-# Same as b4_check_percent_define_variables but for %code qualifiers using
-# b4_used_percent_code_qualifiers.
-m4_define([b4_check_percent_code_qualifiers],
-[m4_ifdef([b4_used_percent_code_qualifiers],
-[b4_check_for_unrecognized_names([[%code qualifier]],
-[b4_used_percent_code_qualifiers]m4_if([$#], [0], [], [, $@]))])])
+# 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).
+#
+# For example:
+#
+# b4_percent_define_get([[foo]])
+m4_define([b4_percent_define_get],
+[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)
+# -----------------------------------
+# 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
+# b4_fatal_at. Don't record this as a Bison usage of VARIABLE as there's no
+# reason to suspect that the user-supplied value has yet influenced the output.
+#
+# For example:
+#
+# b4_complain_at(b4_percent_define_get_loc([[foo]]), [[invalid foo]])
+m4_define([b4_percent_define_get_loc],
+[m4_ifdef([b4_percent_define_loc(]$1[)],
+ [m4_pushdef([b4_loc], m4_indir([b4_percent_define_loc(]$1[)]))dnl
+b4_loc[]dnl
+m4_popdef([b4_loc])],
+ [b4_fatal([[b4_percent_define_get_loc: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_define_get_syncline(VARIABLE)
+# ----------------------------------------
+# 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
+# VARIABLE as there's no reason to suspect that the user-supplied value has yet
+# influenced the output.
+#
+# For example:
+#
+# b4_percent_define_get_syncline([[foo]])
+m4_define([b4_percent_define_get_syncline],
+[m4_ifdef([b4_percent_define_syncline(]$1[)],
+ [m4_indir([b4_percent_define_syncline(]$1[)])],
+ [b4_fatal([[b4_percent_define_get_syncline: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_define_ifdef(VARIABLE, IF-TRUE, [IF-FALSE])
+# ------------------------------------------------------
+# 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).
+#
+# For example:
+#
+# 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_flag_if(VARIABLE, IF-TRUE, [IF-FALSE])
+# --------------------------------------------------------
+# 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
+# already) or defined to any other value (possibly a user error). Also, record
+# Bison's usage of VARIABLE by defining
+# b4_percent_define_bison_variables(VARIABLE).
+#
+# For example:
+#
+# b4_percent_define_flag_if([[foo]], [[it's true]], [[it's false]])
+m4_define([b4_percent_define_flag_if],
+[b4_percent_define_ifdef([$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']],
+ [$1])],
+ [[b4_percent_define_flag_if($1)]])])],
+ [b4_fatal([[b4_percent_define_flag_if: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_define_default(VARIABLE, DEFAULT)
+# --------------------------------------------
+# 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.
+#
+# For example:
+#
+# b4_percent_define_default([[foo]], [[default value]])
+m4_define([b4_percent_define_default],
+[m4_ifndef([b4_percent_define(]$1[)],
+ [m4_define([b4_percent_define(]$1[)], [$2])dnl
+ m4_define([b4_percent_define_loc(]$1[)],
+ [[[[<skeleton default value>:-1.-1]],
+ [[<skeleton default value>:-1.-1]]]])dnl
+ m4_define([b4_percent_define_syncline(]$1[)], [[]])])])
+
+# b4_percent_define_check_values(VALUES)
+# --------------------------------------
+# Mimic muscle_percent_define_check_values in ../src/muscle-tab.h exactly
+# except that the VALUES structure is more appropriate for M4. That is, VALUES
+# is a list of sublists of strings. For each sublist, the first string is the
+# name of a %define variable, and all remaining strings in that sublist are the
+# valid values for that variable. Complain if such a variable is undefined (a
+# Bison error since the default value should have been set already) or defined
+# to any other value (possibly a user error). Don't record this as a Bison
+# usage of the variable as there's no reason to suspect that the value has yet
+# influenced the output.
+#
+# For example:
+#
+# b4_percent_define_check_values([[[[foo]], [[foo-value1]], [[foo-value2]]]],
+# [[[[bar]], [[bar-value1]]]])
+m4_define([b4_percent_define_check_values],
+[m4_foreach([b4_sublist], m4_quote($@),
+ [_b4_percent_define_check_values(b4_sublist)])])
+
+m4_define([_b4_percent_define_check_values],
+[m4_ifdef([b4_percent_define(]$1[)],
+ [m4_pushdef([b4_good_value], [0])dnl
+ m4_if($#, 1, [],
+ [m4_foreach([b4_value], m4_dquote(m4_shift($@)),
+ [m4_if(m4_indir([b4_percent_define(]$1[)]), b4_value,
+ [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']],
+ [$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']],
+ m4_dquote(b4_value))])])dnl
+ m4_popdef([b4_good_value])],
+ [b4_fatal([[b4_percent_define_check_values: undefined %%define variable '%s']], [$1])])])
+
+# b4_percent_code_get([QUALIFIER])
+# --------------------------------
+# If any %code blocks for QUALIFIER are defined, emit them beginning with a
+# comment and ending with synclines and a newline. If QUALIFIER is not
+# specified or empty, do this for the unqualified %code blocks. Also, record
+# Bison's usage of QUALIFIER (if specified) by defining
+# b4_percent_code_bison_qualifiers(QUALIFIER).
+#
+# For example, to emit any unqualified %code blocks followed by any %code
+# blocks for the qualifier foo:
+#
+# b4_percent_code_get
+# b4_percent_code_get([[foo]])
+m4_define([b4_percent_code_get],
+[m4_pushdef([b4_macro_name], [[b4_percent_code(]$1[)]])dnl
+m4_ifval([$1], [m4_define([b4_percent_code_bison_qualifiers(]$1[)])])dnl
+m4_ifdef(b4_macro_name,
+[b4_comment([m4_if([$#], [0], [[Unqualified %code]],
+ [["%code ]$1["]])[ blocks.]])
+b4_user_code([m4_indir(b4_macro_name)])
+])dnl
+m4_popdef([b4_macro_name])])
+
+# b4_percent_code_ifdef(QUALIFIER, IF-TRUE, [IF-FALSE])
+# -----------------------------------------------------
+# If any %code blocks for QUALIFIER (or unqualified %code blocks if
+# QUALIFIER is empty) are defined, expand IF-TRUE, else expand IF-FALSE.
+# Also, record Bison's usage of QUALIFIER (if specified) by defining
+# b4_percent_code_bison_qualifiers(QUALIFIER).
+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])])
+
+
+## ----------------------------------------------------------- ##
+## After processing the skeletons, check that all the user's ##
+## %define variables and %code qualifiers were used by Bison. ##
+## ----------------------------------------------------------- ##
+
+m4_define([b4_check_user_names_wrap],
+[m4_ifdef([b4_percent_]$1[_user_]$2[s],
+ [b4_check_user_names([[%]$1 $2],
+ [b4_percent_]$1[_user_]$2[s],
+ [[b4_percent_]$1[_bison_]$2[s]])])])
+
+m4_wrap_lifo([
+b4_check_user_names_wrap([[define]], [[variable]])
+b4_check_user_names_wrap([[code]], [[qualifier]])
+])
+
+
+## ---------------- ##
+## Default values. ##
+## ---------------- ##
+
+# m4_define_default([b4_lex_param], []) dnl breaks other skeletons
+m4_define_default([b4_pre_prologue], [])
+m4_define_default([b4_post_prologue], [])
+m4_define_default([b4_epilogue], [])
+m4_define_default([b4_parse_param], [])
+
+# The initial column and line.
+m4_define_default([b4_location_initial_column], [1])
+m4_define_default([b4_location_initial_line], [1])
+
+# Sanity checks.
+b4_percent_define_ifdef([api.prefix],
+[m4_ifdef([b4_prefix],
+[b4_complain_at(b4_percent_define_get_loc([api.prefix]),
+ [['%s' and '%s' cannot be used together]],
+ [%name-prefix],
+ [%define api.prefix])])])