-divert(-1)# -*- Autoconf -*-
-# This file is part of Autoconf.
-# Base M4 layer.
-# Requires GNU M4.
-# Copyright 1999, 2000, 2001, 2002 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.
-#
-# 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.
-#
-# As a special exception, the Free Software Foundation gives unlimited
-# permission to copy, distribute and modify the configure scripts that
-# are the output of Autoconf. You need not follow the terms of the GNU
-# General Public License when using or distributing such scripts, even
-# though portions of the text of Autoconf appear in them. The GNU
-# General Public License (GPL) does govern all other use of the material
-# that constitutes the Autoconf program.
-#
-# Certain portions of the Autoconf source text are designed to be copied
-# (in certain cases, depending on the input) into the output of
-# Autoconf. We call these the "data" portions. The rest of the Autoconf
-# source text consists of comments plus executable code that decides which
-# of the data portions to output in any given case. We call these
-# comments and executable code the "non-data" portions. Autoconf never
-# copies any of the non-data portions into its output.
-#
-# This special exception to the GPL applies to versions of Autoconf
-# released by the Free Software Foundation. When you make and
-# distribute a modified version of Autoconf, you may extend this special
-# exception to the GPL to apply to your modified version as well, *unless*
-# your modified version has the potential to copy into its output some
-# of the text that was the non-data portion of the version that you started
-# with. (In other words, unless your change moves or copies text from
-# the non-data portions to the data portions.) If your modification has
-# such potential, you must delete any notice of this special exception
-# to the GPL from your modified version.
-#
-# Written by Akim Demaille.
-#
-
-# Set the quotes, whatever the current quoting system.
-changequote()
-changequote([, ])
-
-# Some old m4's don't support m4exit. But they provide
-# equivalent functionality by core dumping because of the
-# long macros we define.
-ifdef([__gnu__], ,
-[errprint(M4sugar requires GNU M4. Install it before installing M4sugar or
-set the M4 environment variable to its path name.)
-m4exit(2)])
-
-
-## ------------------------------- ##
-## 1. Simulate --prefix-builtins. ##
-## ------------------------------- ##
-
-# m4_define
-# m4_defn
-# m4_undefine
-define([m4_define], defn([define]))
-define([m4_defn], defn([defn]))
-define([m4_undefine], defn([undefine]))
-
-m4_undefine([define])
-m4_undefine([defn])
-m4_undefine([undefine])
-
-
-# m4_copy(SRC, DST)
-# -----------------
-# Define DST as the definition of SRC.
-# What's the difference between:
-# 1. m4_copy([from], [to])
-# 2. m4_define([from], [to($@)])
-# Well, obviously 1 is more expansive in space. Maybe 2 is more expansive
-# in time, but because of the space cost of 1, it's not that obvious.
-# Nevertheless, one huge difference is the handling of `$0'. If `from'
-# uses `$0', then with 1, `to''s `$0' is `to', while it is `from' in 2.
-# The user will certainly prefer see `from'.
-m4_define([m4_copy],
-[m4_define([$2], m4_defn([$1]))])
-
-
-# m4_rename(SRC, DST)
-# -------------------
-# Rename the macro SRC as DST.
-m4_define([m4_rename],
-[m4_copy([$1], [$2])m4_undefine([$1])])
-
-
-# m4_rename_m4(MACRO-NAME)
-# ------------------------
-# Rename MACRO-NAME as m4_MACRO-NAME.
-m4_define([m4_rename_m4],
-[m4_rename([$1], [m4_$1])])
-
-
-# m4_copy_unm4(m4_MACRO-NAME)
-# ---------------------------
-# Copy m4_MACRO-NAME as MACRO-NAME.
-m4_define([m4_copy_unm4],
-[m4_copy([$1], m4_bpatsubst([$1], [^m4_\(.*\)], [[\1]]))])
-
-
-# Some m4 internals have names colliding with tokens we might use.
-# Rename them a` la `m4 --prefix-builtins'.
-m4_rename_m4([builtin])
-m4_rename_m4([changecom])
-m4_rename_m4([changequote])
-m4_rename_m4([debugfile])
-m4_rename_m4([debugmode])
-m4_rename_m4([decr])
-m4_undefine([divert])
-m4_rename_m4([divnum])
-m4_rename_m4([dumpdef])
-m4_rename_m4([errprint])
-m4_rename_m4([esyscmd])
-m4_rename_m4([eval])
-m4_rename_m4([format])
-m4_rename_m4([ifdef])
-m4_rename([ifelse], [m4_if])
-m4_rename_m4([include])
-m4_rename_m4([incr])
-m4_rename_m4([index])
-m4_rename_m4([indir])
-m4_rename_m4([len])
-m4_rename([m4exit], [m4_exit])
-m4_rename([m4wrap], [m4_wrap])
-m4_rename_m4([maketemp])
-m4_rename([patsubst], [m4_bpatsubst])
-m4_undefine([popdef])
-m4_rename_m4([pushdef])
-m4_rename([regexp], [m4_bregexp])
-m4_rename_m4([shift])
-m4_rename_m4([sinclude])
-m4_rename_m4([substr])
-m4_rename_m4([symbols])
-m4_rename_m4([syscmd])
-m4_rename_m4([sysval])
-m4_rename_m4([traceoff])
-m4_rename_m4([traceon])
-m4_rename_m4([translit])
-m4_undefine([undivert])
-
-
-## ------------------- ##
-## 2. Error messages. ##
-## ------------------- ##
-
-
-# m4_location
-# -----------
-m4_define([m4_location],
-[__file__:__line__])
-
-
-# m4_errprintn(MSG)
-# -----------------
-# Same as `errprint', but with the missing end of line.
-m4_define([m4_errprintn],
-[m4_errprint([$1
-])])
-
-
-# m4_warning(MSG)
-# ---------------
-# Warn the user.
-m4_define([m4_warning],
-[m4_errprintn(m4_location[: warning: $1])])
-
-
-# m4_fatal(MSG, [EXIT-STATUS])
-# ----------------------------
-# Fatal the user. :)
-m4_define([m4_fatal],
-[m4_errprintn(m4_location[: error: $1])dnl
-m4_expansion_stack_dump()dnl
-m4_exit(m4_if([$2],, 1, [$2]))])
-
-
-# m4_assert(EXPRESSION, [EXIT-STATUS = 1])
-# ----------------------------------------
-# This macro ensures that EXPRESSION evaluates to true, and exits if
-# EXPRESSION evaluates to false.
-m4_define([m4_assert],
-[m4_if(m4_eval([$1]), 0,
- [m4_fatal([assert failed: $1], [$2])])])
-
-
-## ------------- ##
-## 3. Warnings. ##
-## ------------- ##
-
-
-# m4_warning_ifelse(CATEGORY, IF-TRUE, IF-FALSE)
-# ----------------------------------------------
-# If the CATEGORY of warnings is enabled, expand IF_TRUE otherwise
-# IF-FALSE.
-#
-# The variable `m4_warnings' contains a comma separated list of
-# warnings which order is the converse from the one specified by
-# the user, i.e., if she specified `-W error,none,obsolete',
-# `m4_warnings' is `obsolete,none,error'. We read it from left to
-# right, and:
-# - if none or noCATEGORY is met, run IF-FALSE
-# - if all or CATEGORY is met, run IF-TRUE
-# - if there is nothing left, run IF-FALSE.
-m4_define([m4_warning_ifelse],
-[_m4_warning_ifelse([$1], [$2], [$3], m4_warnings)])
-
-
-# _m4_warning_ifelse(CATEGORY, IF-TRUE, IF-FALSE, WARNING1, ...)
-# --------------------------------------------------------------
-# Implementation of the loop described above.
-m4_define([_m4_warning_ifelse],
-[m4_case([$4],
- [$1], [$2],
- [all], [$2],
- [], [$3],
- [none], [$3],
- [no-$1], [$3],
- [$0([$1], [$2], [$3], m4_shiftn(4, $@))])])
-
-
-# _m4_warning_error_ifelse(IF-TRUE, IF-FALSE)
-# -------------------------------------------
-# The same as m4_warning_ifelse, but scan for `error' only.
-m4_define([_m4_warning_error_ifelse],
-[__m4_warning_error_ifelse([$1], [$2], m4_warnings)])
-
-
-# __m4_warning_error_ifelse(IF-TRUE, IF-FALSE)
-# --------------------------------------------
-# The same as _m4_warning_ifelse, but scan for `error' only.
-m4_define([__m4_warning_error_ifelse],
-[m4_case([$3],
- [error], [$1],
- [], [$2],
- [no-error], [$2],
- [$0([$1], [$2], m4_shiftn(3, $@))])])
-
-
-
-# _m4_warn(MESSAGE)
-# -----------------
-# Report MESSAGE as a warning, unless the user requested -W error,
-# in which case report a fatal error.
-m4_define([_m4_warn],
-[_m4_warning_error_ifelse([m4_fatal([$1])],
- [m4_warning([$1])])])
-
-
-# m4_warn(CATEGORY, MESSAGE)
-# --------------------------
-# Report a MESSAGE to the autoconf user if the CATEGORY of warnings
-# is requested (in fact, not disabled).
-m4_define([m4_warn],
-[m4_warning_ifelse([$1], [_m4_warn([$2])])])
-
-
-
-
-## ------------------- ##
-## 4. File inclusion. ##
-## ------------------- ##
-
-
-# We also want to neutralize include (and sinclude for symmetry),
-# but we want to extend them slightly: warn when a file is included
-# several times. This is in general a dangerous operation because
-# quite nobody quotes the first argument of m4_define.
-#
-# For instance in the following case:
-# m4_define(foo, [bar])
-# then a second reading will turn into
-# m4_define(bar, [bar])
-# which is certainly not what was meant.
-
-# m4_include_unique(FILE)
-# -----------------------
-# Declare that the FILE was loading; and warn if it has already
-# been included.
-m4_define([m4_include_unique],
-[m4_ifdef([m4_include($1)],
- [m4_warn([syntax], [file `$1' included several times])])dnl
-m4_define([m4_include($1)])])
-
-
-# m4_include(FILE)
-# ----------------
-# As the builtin include, but warns against multiple inclusions.
-m4_define([m4_include],
-[m4_include_unique([$1])dnl
-m4_builtin([include], [$1])])
-
-
-# m4_sinclude(FILE)
-# -----------------
-# As the builtin sinclude, but warns against multiple inclusions.
-m4_define([m4_sinclude],
-[m4_include_unique([$1])dnl
-m4_builtin([sinclude], [$1])])
-
-
-
-## ------------------------------------ ##
-## 5. Additional branching constructs. ##
-## ------------------------------------ ##
-
-# Both `m4_ifval' and `m4_ifset' tests against the empty string. The
-# difference is that `m4_ifset' is specialized on macros.
-#
-# In case of arguments of macros, eg $[1], it makes little difference.
-# In the case of a macro `FOO', you don't want to check `m4_ifval(FOO,
-# TRUE)', because if `FOO' expands with commas, there is a shifting of
-# the arguments. So you want to run `m4_ifval([FOO])', but then you just
-# compare the *string* `FOO' against `', which, of course fails.
-#
-# So you want a variation of `m4_ifset' that expects a macro name as $[1].
-# If this macro is both defined and defined to a non empty value, then
-# it runs TRUE etc.
-
-
-# m4_ifval(COND, [IF-TRUE], [IF-FALSE])
-# -------------------------------------
-# If COND is not the empty string, expand IF-TRUE, otherwise IF-FALSE.
-# Comparable to m4_ifdef.
-m4_define([m4_ifval],
-[m4_if([$1], [], [$3], [$2])])
-
-
-# m4_n(TEXT)
-# ----------
-# If TEXT is not empty, return TEXT and a new line, otherwise nothing.
-m4_define([m4_n],
-[m4_if([$1],
- [], [],
- [$1
-])])
-
-
-# m4_ifvaln(COND, [IF-TRUE], [IF-FALSE])
-# --------------------------------------
-# Same as `m4_ifval', but add an extra newline to IF-TRUE or IF-FALSE
-# unless that argument is empty.
-m4_define([m4_ifvaln],
-[m4_if([$1],
- [], [m4_n([$3])],
- [m4_n([$2])])])
-
-
-# m4_ifset(MACRO, [IF-TRUE], [IF-FALSE])
-# --------------------------------------
-# If MACRO has no definition, or of its definition is the empty string,
-# expand IF-FALSE, otherwise IF-TRUE.
-m4_define([m4_ifset],
-[m4_ifdef([$1],
- [m4_if(m4_defn([$1]), [], [$3], [$2])],
- [$3])])
-
-
-# m4_ifndef(NAME, [IF-NOT-DEFINED], [IF-DEFINED])
-# -----------------------------------------------
-m4_define([m4_ifndef],
-[m4_ifdef([$1], [$3], [$2])])
-
-
-# m4_case(SWITCH, VAL1, IF-VAL1, VAL2, IF-VAL2, ..., DEFAULT)
-# -----------------------------------------------------------
-# m4 equivalent of
-# switch (SWITCH)
-# {
-# case VAL1:
-# IF-VAL1;
-# break;
-# case VAL2:
-# IF-VAL2;
-# break;
-# ...
-# default:
-# DEFAULT;
-# break;
-# }.
-# All the values are optional, and the macro is robust to active
-# symbols properly quoted.
-m4_define([m4_case],
-[m4_if([$#], 0, [],
- [$#], 1, [],
- [$#], 2, [$2],
- [$1], [$2], [$3],
- [$0([$1], m4_shiftn(3, $@))])])
-
-
-# m4_bmatch(SWITCH, RE1, VAL1, RE2, VAL2, ..., DEFAULT)
-# -----------------------------------------------------
-# m4 equivalent of
-#
-# if (SWITCH =~ RE1)
-# VAL1;
-# elif (SWITCH =~ RE2)
-# VAL2;
-# elif ...
-# ...
-# else
-# DEFAULT
-#
-# All the values are optional, and the macro is robust to active symbols
-# properly quoted.
-m4_define([m4_bmatch],
-[m4_if([$#], 0, [],
- [$#], 1, [],
- [$#], 2, [$2],
- [m4_if(m4_bregexp([$1], [$2]), -1, [$0([$1], m4_shiftn(3, $@))],
- [$3])])])
-
-
-# m4_map(MACRO, LIST)
-# -------------------
-# Invoke MACRO($1), MACRO($2) etc. where $1, $2... are the elements
-# of LIST (which can be lists themselves, for multiple arguments MACROs).
-m4_define([m4_fst], [$1])
-m4_define([m4_map],
-[m4_if([$2], [[]], [],
- [$1(m4_fst($2))[]dnl
-m4_map([$1], m4_cdr($2))])])
-
-
-# m4_map_sep(MACRO, SEPARATOR, LIST)
-# ----------------------------------
-# Invoke MACRO($1), SEPARATOR, MACRO($2), ..., MACRO($N) where $1, $2... $N
-# are the elements of LIST (which can be lists themselves, for multiple
-# arguments MACROs).
-m4_define([m4_map_sep],
-[m4_if([$3], [[]], [],
- [$1(m4_fst($3))[]dnl
-m4_if(m4_cdr($3),
- [[]], [],
- [$2])[]dnl
-m4_map_sep([$1], [$2], m4_cdr($3))])])
-
-
-## ---------------------------------------- ##
-## 6. Enhanced version of some primitives. ##
-## ---------------------------------------- ##
-
-# m4_patsubsts(STRING, RE1, SUBST1, RE2, SUBST2, ...)
-# ---------------------------------------------------
-# m4 equivalent of
-#
-# $_ = STRING;
-# s/RE1/SUBST1/g;
-# s/RE2/SUBST2/g;
-# ...
-#
-# All the values are optional, and the macro is robust to active symbols
-# properly quoted.
-#
-# I would have liked to name this macro `m4_patsubst', unfortunately,
-# due to quotation problems, I need to double quote $1 below, therefore
-# the anchors are broken :( I can't let users be trapped by that.
-m4_define([m4_bpatsubsts],
-[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])],
- [$#], 1, [m4_fatal([$0: too few arguments: $#: $1])],
- [$#], 2, [m4_builtin([patsubst], $@)],
- [$0(m4_builtin([patsubst], [[$1]], [$2], [$3]),
- m4_shiftn(3, $@))])])
-
-
-
-# m4_do(STRING, ...)
-# ------------------
-# This macro invokes all its arguments (in sequence, of course). It is
-# useful for making your macros more structured and readable by dropping
-# unnecessary dnl's and have the macros indented properly.
-m4_define([m4_do],
-[m4_if($#, 0, [],
- $#, 1, [$1],
- [$1[]m4_do(m4_shift($@))])])
-
-
-# m4_define_default(MACRO, VALUE)
-# -------------------------------
-# If MACRO is undefined, set it to VALUE.
-m4_define([m4_define_default],
-[m4_ifndef([$1], [m4_define($@)])])
-
-
-# m4_default(EXP1, EXP2)
-# ----------------------
-# Returns EXP1 if non empty, otherwise EXP2.
-m4_define([m4_default],
-[m4_ifval([$1], [$1], [$2])])
-
-
-# m4_defn(NAME)
-# -------------
-# Unlike to the original, don't tolerate popping something which is
-# undefined.
-m4_define([m4_defn],
-[m4_ifndef([$1],
- [m4_fatal([$0: undefined macro: $1])])dnl
-m4_builtin([defn], $@)])
-
-
-# _m4_dumpdefs_up(NAME)
-# ---------------------
-m4_define([_m4_dumpdefs_up],
-[m4_ifdef([$1],
- [m4_pushdef([_m4_dumpdefs], m4_defn([$1]))dnl
-m4_dumpdef([$1])dnl
-m4_popdef([$1])dnl
-_m4_dumpdefs_up([$1])])])
-
-
-# _m4_dumpdefs_down(NAME)
-# -----------------------
-m4_define([_m4_dumpdefs_down],
-[m4_ifdef([_m4_dumpdefs],
- [m4_pushdef([$1], m4_defn([_m4_dumpdefs]))dnl
-m4_popdef([_m4_dumpdefs])dnl
-_m4_dumpdefs_down([$1])])])
-
-
-# m4_dumpdefs(NAME)
-# -----------------
-# Similar to `m4_dumpdef(NAME)', but if NAME was m4_pushdef'ed, display its
-# value stack (most recent displayed first).
-m4_define([m4_dumpdefs],
-[_m4_dumpdefs_up([$1])dnl
-_m4_dumpdefs_down([$1])])
-
-
-# m4_popdef(NAME)
-# ---------------
-# Unlike to the original, don't tolerate popping something which is
-# undefined.
-m4_define([m4_popdef],
-[m4_ifndef([$1],
- [m4_fatal([$0: undefined macro: $1])])dnl
-m4_builtin([popdef], $@)])
-
-
-# m4_quote(ARGS)
-# --------------
-# Return ARGS as a single arguments.
-#
-# It is important to realize the difference between `m4_quote(exp)' and
-# `[exp]': in the first case you obtain the quoted *result* of the
-# expansion of EXP, while in the latter you just obtain the string
-# `exp'.
-m4_define([m4_quote], [[$*]])
-m4_define([m4_dquote], [[$@]])
-
-
-# m4_noquote(STRING)
-# ------------------
-# Return the result of ignoring all quotes in STRING and invoking the
-# macros it contains. Amongst other things useful for enabling macro
-# invocations inside strings with [] blocks (for instance regexps and
-# help-strings).
-m4_define([m4_noquote],
-[m4_changequote(-=<{,}>=-)$1-=<{}>=-m4_changequote([,])])
-
-
-# m4_shiftn(N, ...)
-# -----------------
-# Returns ... shifted N times. Useful for recursive "varargs" constructs.
-m4_define([m4_shiftn],
-[m4_assert(($1 >= 0) && ($# > $1))dnl
-_m4_shiftn($@)])
-
-m4_define([_m4_shiftn],
-[m4_if([$1], 0,
- [m4_shift($@)],
- [_m4_shiftn(m4_eval([$1]-1), m4_shift(m4_shift($@)))])])
-
-
-# m4_undefine(NAME)
-# -----------------
-# Unlike to the original, don't tolerate undefining something which is
-# undefined.
-m4_define([m4_undefine],
-[m4_ifndef([$1],
- [m4_fatal([$0: undefined macro: $1])])dnl
-m4_builtin([undefine], $@)])
-
-
-## -------------------------- ##
-## 7. Implementing m4 loops. ##
-## -------------------------- ##
-
-
-# m4_for(VARIABLE, FIRST, LAST, [STEP = +/-1], EXPRESSION)
-# --------------------------------------------------------
-# Expand EXPRESSION defining VARIABLE to FROM, FROM + 1, ..., TO.
-# Both limits are included, and bounds are checked for consistency.
-m4_define([m4_for],
-[m4_case(m4_sign(m4_eval($3 - $2)),
- 1, [m4_assert(m4_sign(m4_default($4, 1)) == 1)],
- -1, [m4_assert(m4_sign(m4_default($4, -1)) == -1)])dnl
-m4_pushdef([$1], [$2])dnl
-m4_if(m4_eval([$3 > $2]), 1,
- [_m4_for([$1], [$3], m4_default([$4], 1), [$5])],
- [_m4_for([$1], [$3], m4_default([$4], -1), [$5])])dnl
-m4_popdef([$1])])
-
-
-# _m4_for(VARIABLE, FIRST, LAST, STEP, EXPRESSION)
-# ------------------------------------------------
-# Core of the loop, no consistency checks.
-m4_define([_m4_for],
-[$4[]dnl
-m4_if($1, [$2], [],
- [m4_define([$1], m4_eval($1+[$3]))_m4_for([$1], [$2], [$3], [$4])])])
-
-
-# Implementing `foreach' loops in m4 is much more tricky than it may
-# seem. Actually, the example of a `foreach' loop in the m4
-# documentation is wrong: it does not quote the arguments properly,
-# which leads to undesirable expansions.
-#
-# The example in the documentation is:
-#
-# | # foreach(VAR, (LIST), STMT)
-# | m4_define([foreach],
-# | [m4_pushdef([$1])_foreach([$1], [$2], [$3])m4_popdef([$1])])
-# | m4_define([_arg1], [$1])
-# | m4_define([_foreach],
-# | [m4_if([$2], [()], ,
-# | [m4_define([$1], _arg1$2)$3[]_foreach([$1],
-# | (shift$2),
-# | [$3])])])
-#
-# But then if you run
-#
-# | m4_define(a, 1)
-# | m4_define(b, 2)
-# | m4_define(c, 3)
-# | foreach([f], [([a], [(b], [c)])], [echo f
-# | ])
-#
-# it gives
-#
-# => echo 1
-# => echo (2,3)
-#
-# which is not what is expected.
-#
-# Of course the problem is that many quotes are missing. So you add
-# plenty of quotes at random places, until you reach the expected
-# result. Alternatively, if you are a quoting wizard, you directly
-# reach the following implementation (but if you really did, then
-# apply to the maintenance of m4sugar!).
-#
-# | # foreach(VAR, (LIST), STMT)
-# | m4_define([foreach], [m4_pushdef([$1])_foreach($@)m4_popdef([$1])])
-# | m4_define([_arg1], [[$1]])
-# | m4_define([_foreach],
-# | [m4_if($2, [()], ,
-# | [m4_define([$1], [_arg1$2])$3[]_foreach([$1],
-# | [(shift$2)],
-# | [$3])])])
-#
-# which this time answers
-#
-# => echo a
-# => echo (b
-# => echo c)
-#
-# Bingo!
-#
-# Well, not quite.
-#
-# With a better look, you realize that the parens are more a pain than
-# a help: since anyway you need to quote properly the list, you end up
-# with always using an outermost pair of parens and an outermost pair
-# of quotes. Rejecting the parens both eases the implementation, and
-# simplifies the use:
-#
-# | # foreach(VAR, (LIST), STMT)
-# | m4_define([foreach], [m4_pushdef([$1])_foreach($@)m4_popdef([$1])])
-# | m4_define([_arg1], [$1])
-# | m4_define([_foreach],
-# | [m4_if($2, [], ,
-# | [m4_define([$1], [_arg1($2)])$3[]_foreach([$1],
-# | [shift($2)],
-# | [$3])])])
-#
-#
-# Now, just replace the `$2' with `m4_quote($2)' in the outer `m4_if'
-# to improve robustness, and you come up with a quite satisfactory
-# implementation.
-
-
-# m4_foreach(VARIABLE, LIST, EXPRESSION)
-# --------------------------------------
-#
-# Expand EXPRESSION assigning each value of the LIST to VARIABLE.
-# LIST should have the form `item_1, item_2, ..., item_n', i.e. the
-# whole list must *quoted*. Quote members too if you don't want them
-# to be expanded.
-#
-# This macro is robust to active symbols:
-# | m4_define(active, [ACT, IVE])
-# | m4_foreach(Var, [active, active], [-Var-])
-# => -ACT--IVE--ACT--IVE-
-#
-# | m4_foreach(Var, [[active], [active]], [-Var-])
-# => -ACT, IVE--ACT, IVE-
-#
-# | m4_foreach(Var, [[[active]], [[active]]], [-Var-])
-# => -active--active-
-m4_define([m4_foreach],
-[m4_pushdef([$1])_m4_foreach($@)m4_popdef([$1])])
-
-# Low level macros used to define m4_foreach.
-m4_define([m4_car], [[$1]])
-m4_define([m4_cdr], [m4_dquote(m4_shift($@))])
-m4_define([_m4_foreach],
-[m4_if([$2], [[]], [],
- [m4_define([$1], m4_car($2))$3[]_m4_foreach([$1],
- m4_cdr($2),
- [$3])])])
-
-
-
-## --------------------------- ##
-## 8. More diversion support. ##
-## --------------------------- ##
-
-
-# _m4_divert(DIVERSION-NAME or NUMBER)
-# ------------------------------------
-# If DIVERSION-NAME is the name of a diversion, return its number,
-# otherwise if is a NUMBER return it.
-m4_define([_m4_divert],
-[m4_ifdef([_m4_divert($1)],
- [m4_indir([_m4_divert($1)])],
- [$1])])
-
-# KILL is only used to suppress output.
-m4_define([_m4_divert(KILL)], -1)
-
-
-# m4_divert(DIVERSION-NAME)
-# -------------------------
-# Change the diversion stream to DIVERSION-NAME.
-m4_define([m4_divert],
-[m4_define([m4_divert_stack],
- m4_location[: $0: $1]m4_ifdef([m4_divert_stack], [
-m4_defn([m4_divert_stack])]))dnl
-m4_builtin([divert], _m4_divert([$1]))dnl
-])
-
-
-# m4_divert_push(DIVERSION-NAME)
-# ------------------------------
-# Change the diversion stream to DIVERSION-NAME, while stacking old values.
-m4_define([m4_divert_push],
-[m4_pushdef([m4_divert_stack],
- m4_location[: $0: $1]m4_ifdef([m4_divert_stack], [
-m4_defn([m4_divert_stack])]))dnl
-m4_pushdef([_m4_divert_diversion], [$1])dnl
-m4_builtin([divert], _m4_divert(_m4_divert_diversion))dnl
-])
-
-
-# m4_divert_pop([DIVERSION-NAME])
-# -------------------------------
-# Change the diversion stream to its previous value, unstacking it.
-# If specified, verify we left DIVERSION-NAME.
-m4_define([m4_divert_pop],
-[m4_ifval([$1],
- [m4_if(_m4_divert([$1]), m4_divnum, [],
- [m4_fatal([$0($1): diversion mismatch: ]
-m4_defn([m4_divert_stack]))])])dnl
-m4_popdef([_m4_divert_diversion])dnl
-dnl m4_ifndef([_m4_divert_diversion],
-dnl [m4_fatal([too many m4_divert_pop])])dnl
-m4_builtin([divert],
- m4_ifdef([_m4_divert_diversion],
- [_m4_divert(_m4_divert_diversion)], -1))dnl
-m4_popdef([m4_divert_stack])dnl
-])
-
-
-# m4_divert_text(DIVERSION-NAME, CONTENT)
-# ---------------------------------------
-# Output CONTENT into DIVERSION-NAME (which may be a number actually).
-# An end of line is appended for free to CONTENT.
-m4_define([m4_divert_text],
-[m4_divert_push([$1])dnl
-$2
-m4_divert_pop([$1])dnl
-])
-
-
-# m4_divert_once(DIVERSION-NAME, CONTENT)
-# ---------------------------------------
-# Output once CONTENT into DIVERSION-NAME (which may be a number
-# actually). An end of line is appended for free to CONTENT.
-m4_define([m4_divert_once],
-[m4_expand_once([m4_divert_text([$1], [$2])])])
-
-
-# m4_undivert(DIVERSION-NAME)
-# ---------------------------
-# Undivert DIVERSION-NAME.
-m4_define([m4_undivert],
-[m4_builtin([undivert], _m4_divert([$1]))])
-
-
-## -------------------------------------------- ##
-## 8. Defining macros with bells and whistles. ##
-## -------------------------------------------- ##
-
-# `m4_defun' is basically `m4_define' but it equips the macro with the
-# needed machinery for `m4_require'. A macro must be m4_defun'd if
-# either it is m4_require'd, or it m4_require's.
-#
-# Two things deserve attention and are detailed below:
-# 1. Implementation of m4_require
-# 2. Keeping track of the expansion stack
-#
-# 1. Implementation of m4_require
-# ===============================
-#
-# Of course m4_defun AC_PROVIDE's the macro, so that a macro which has
-# been expanded is not expanded again when m4_require'd, but the
-# difficult part is the proper expansion of macros when they are
-# m4_require'd.
-#
-# The implementation is based on two ideas, (i) using diversions to
-# prepare the expansion of the macro and its dependencies (by François
-# Pinard), and (ii) expand the most recently m4_require'd macros _after_
-# the previous macros (by Axel Thimm).
-#
-#
-# The first idea: why using diversions?
-# -------------------------------------
-#
-# When a macro requires another, the other macro is expanded in new
-# diversion, GROW. When the outer macro is fully expanded, we first
-# undivert the most nested diversions (GROW - 1...), and finally
-# undivert GROW. To understand why we need several diversions,
-# consider the following example:
-#
-# | m4_defun([TEST1], [Test...REQUIRE([TEST2])1])
-# | m4_defun([TEST2], [Test...REQUIRE([TEST3])2])
-# | m4_defun([TEST3], [Test...3])
-#
-# Because m4_require is not required to be first in the outer macros, we
-# must keep the expansions of the various level of m4_require separated.
-# Right before executing the epilogue of TEST1, we have:
-#
-# GROW - 2: Test...3
-# GROW - 1: Test...2
-# GROW: Test...1
-# BODY:
-#
-# Finally the epilogue of TEST1 undiverts GROW - 2, GROW - 1, and
-# GROW into the regular flow, BODY.
-#
-# GROW - 2:
-# GROW - 1:
-# GROW:
-# BODY: Test...3; Test...2; Test...1
-#
-# (The semicolons are here for clarification, but of course are not
-# emitted.) This is what Autoconf 2.0 (I think) to 2.13 (I'm sure)
-# implement.
-#
-#
-# The second idea: first required first out
-# -----------------------------------------
-#
-# The natural implementation of the idea above is buggy and produces
-# very surprising results in some situations. Let's consider the
-# following example to explain the bug:
-#
-# | m4_defun([TEST1], [REQUIRE([TEST2a])REQUIRE([TEST2b])])
-# | m4_defun([TEST2a], [])
-# | m4_defun([TEST2b], [REQUIRE([TEST3])])
-# | m4_defun([TEST3], [REQUIRE([TEST2a])])
-# |
-# | AC_INIT
-# | TEST1
-#
-# The dependencies between the macros are:
-#
-# 3 --- 2b
-# / \ is m4_require'd by
-# / \ left -------------------- right
-# 2a ------------ 1
-#
-# If you strictly apply the rules given in the previous section you get:
-#
-# GROW - 2: TEST3
-# GROW - 1: TEST2a; TEST2b
-# GROW: TEST1
-# BODY:
-#
-# (TEST2a, although required by TEST3 is not expanded in GROW - 3
-# because is has already been expanded before in GROW - 1, so it has
-# been AC_PROVIDE'd, so it is not expanded again) so when you undivert
-# the stack of diversions, you get:
-#
-# GROW - 2:
-# GROW - 1:
-# GROW:
-# BODY: TEST3; TEST2a; TEST2b; TEST1
-#
-# i.e., TEST2a is expanded after TEST3 although the latter required the
-# former.
-#
-# Starting from 2.50, uses an implementation provided by Axel Thimm.
-# The idea is simple: the order in which macros are emitted must be the
-# same as the one in which macro are expanded. (The bug above can
-# indeed be described as: a macro has been AC_PROVIDE'd, but it is
-# emitted after: the lack of correlation between emission and expansion
-# order is guilty).
-#
-# How to do that? You keeping the stack of diversions to elaborate the
-# macros, but each time a macro is fully expanded, emit it immediately.
-#
-# In the example above, when TEST2a is expanded, but it's epilogue is
-# not run yet, you have:
-#
-# GROW - 2:
-# GROW - 1: TEST2a
-# GROW: Elaboration of TEST1
-# BODY:
-#
-# The epilogue of TEST2a emits it immediately:
-#
-# GROW - 2:
-# GROW - 1:
-# GROW: Elaboration of TEST1
-# BODY: TEST2a
-#
-# TEST2b then requires TEST3, so right before the epilogue of TEST3, you
-# have:
-#
-# GROW - 2: TEST3
-# GROW - 1: Elaboration of TEST2b
-# GROW: Elaboration of TEST1
-# BODY: TEST2a
-#
-# The epilogue of TEST3 emits it:
-#
-# GROW - 2:
-# GROW - 1: Elaboration of TEST2b
-# GROW: Elaboration of TEST1
-# BODY: TEST2a; TEST3
-#
-# TEST2b is now completely expanded, and emitted:
-#
-# GROW - 2:
-# GROW - 1:
-# GROW: Elaboration of TEST1
-# BODY: TEST2a; TEST3; TEST2b
-#
-# and finally, TEST1 is finished and emitted:
-#
-# GROW - 2:
-# GROW - 1:
-# GROW:
-# BODY: TEST2a; TEST3; TEST2b: TEST1
-#
-# The idea, is simple, but the implementation is a bit evolved. If you
-# are like me, you will want to see the actual functioning of this
-# implementation to be convinced. The next section gives the full
-# details.
-#
-#
-# The Axel Thimm implementation at work
-# -------------------------------------
-#
-# We consider the macros above, and this configure.ac:
-#
-# AC_INIT
-# TEST1
-#
-# You should keep the definitions of _m4_defun_pro, _m4_defun_epi, and
-# m4_require at hand to follow the steps.
-#
-# This implements tries not to assume that of the current diversion is
-# BODY, so as soon as a macro (m4_defun'd) is expanded, we first
-# record the current diversion under the name _m4_divert_dump (denoted
-# DUMP below for short). This introduces an important difference with
-# the previous versions of Autoconf: you cannot use m4_require if you
-# were not inside an m4_defun'd macro, and especially, you cannot
-# m4_require directly from the top level.
-#
-# We have not tried to simulate the old behavior (better yet, we
-# diagnose it), because it is too dangerous: a macro m4_require'd from
-# the top level is expanded before the body of `configure', i.e., before
-# any other test was run. I let you imagine the result of requiring
-# AC_STDC_HEADERS for instance, before AC_PROG_CC was actually run....
-#
-# After AC_INIT was run, the current diversion is BODY.
-# * AC_INIT was run
-# DUMP: undefined
-# diversion stack: BODY |-
-#
-# * TEST1 is expanded
-# The prologue of TEST1 sets AC_DIVERSION_DUMP, which is the diversion
-# where the current elaboration will be dumped, to the current
-# diversion. It also m4_divert_push to GROW, where the full
-# expansion of TEST1 and its dependencies will be elaborated.
-# DUMP: BODY
-# BODY: empty
-# diversions: GROW, BODY |-
-#
-# * TEST1 requires TEST2a: prologue
-# m4_require m4_divert_pushes another temporary diversion GROW - 1 (in
-# fact, the diversion whose number is one less than the current
-# diversion), and expands TEST2a in there.
-# DUMP: BODY
-# BODY: empty
-# diversions: GROW-1, GROW, BODY |-
-#
-# * TEST2a is expanded.
-# Its prologue pushes the current diversion again.
-# DUMP: BODY
-# BODY: empty
-# diversions: GROW - 1, GROW - 1, GROW, BODY |-
-# It is expanded in GROW - 1, and GROW - 1 is popped by the epilogue
-# of TEST2a.
-# DUMP: BODY
-# BODY: nothing
-# GROW - 1: TEST2a
-# diversions: GROW - 1, GROW, BODY |-
-#
-# * TEST1 requires TEST2a: epilogue
-# The content of the current diversion is appended to DUMP (and removed
-# from the current diversion). A diversion is popped.
-# DUMP: BODY
-# BODY: TEST2a
-# diversions: GROW, BODY |-
-#
-# * TEST1 requires TEST2b: prologue
-# m4_require pushes GROW - 1 and expands TEST2b.
-# DUMP: BODY
-# BODY: TEST2a
-# diversions: GROW - 1, GROW, BODY |-
-#
-# * TEST2b is expanded.
-# Its prologue pushes the current diversion again.
-# DUMP: BODY
-# BODY: TEST2a
-# diversions: GROW - 1, GROW - 1, GROW, BODY |-
-# The body is expanded here.
-#
-# * TEST2b requires TEST3: prologue
-# m4_require pushes GROW - 2 and expands TEST3.
-# DUMP: BODY
-# BODY: TEST2a
-# diversions: GROW - 2, GROW - 1, GROW - 1, GROW, BODY |-
-#
-# * TEST3 is expanded.
-# Its prologue pushes the current diversion again.
-# DUMP: BODY
-# BODY: TEST2a
-# diversions: GROW-2, GROW-2, GROW-1, GROW-1, GROW, BODY |-
-# TEST3 requires TEST2a, but TEST2a has already been AC_PROVIDE'd, so
-# nothing happens. It's body is expanded here, and its epilogue pops a
-# diversion.
-# DUMP: BODY
-# BODY: TEST2a
-# GROW - 2: TEST3
-# diversions: GROW - 2, GROW - 1, GROW - 1, GROW, BODY |-
-#
-# * TEST2b requires TEST3: epilogue
-# The current diversion is appended to DUMP, and a diversion is popped.
-# DUMP: BODY
-# BODY: TEST2a; TEST3
-# diversions: GROW - 1, GROW - 1, GROW, BODY |-
-# The content of TEST2b is expanded here.
-# DUMP: BODY
-# BODY: TEST2a; TEST3
-# GROW - 1: TEST2b,
-# diversions: GROW - 1, GROW - 1, GROW, BODY |-
-# The epilogue of TEST2b pops a diversion.
-# DUMP: BODY
-# BODY: TEST2a; TEST3
-# GROW - 1: TEST2b,
-# diversions: GROW - 1, GROW, BODY |-
-#
-# * TEST1 requires TEST2b: epilogue
-# The current diversion is appended to DUMP, and a diversion is popped.
-# DUMP: BODY
-# BODY: TEST2a; TEST3; TEST2b
-# diversions: GROW, BODY |-
-#
-# * TEST1 is expanded: epilogue
-# TEST1's own content is in GROW, and it's epilogue pops a diversion.
-# DUMP: BODY
-# BODY: TEST2a; TEST3; TEST2b
-# GROW: TEST1
-# diversions: BODY |-
-# Here, the epilogue of TEST1 notices the elaboration is done because
-# DUMP and the current diversion are the same, it then undiverts
-# GROW by hand, and undefines DUMP.
-# DUMP: undefined
-# BODY: TEST2a; TEST3; TEST2b; TEST1
-# diversions: BODY |-
-#
-#
-# 2. Keeping track of the expansion stack
-# =======================================
-#
-# When M4 expansion goes wrong it is often extremely hard to find the
-# path amongst macros that drove to the failure. What is needed is
-# the stack of macro `calls'. One could imagine that GNU M4 would
-# maintain a stack of macro expansions, unfortunately it doesn't, so
-# we do it by hand. This is of course extremely costly, but the help
-# this stack provides is worth it. Nevertheless to limit the
-# performance penalty this is implemented only for m4_defun'd macros,
-# not for define'd macros.
-#
-# The scheme is simplistic: each time we enter an m4_defun'd macros,
-# we prepend its name in m4_expansion_stack, and when we exit the
-# macro, we remove it (thanks to pushdef/popdef).
-#
-# In addition, we want to use the expansion stack to detect circular
-# m4_require dependencies. This means we need to browse the stack to
-# check whether a macro being expanded is m4_require'd. For ease of
-# implementation, and certainly for the benefit of performances, we
-# don't browse the m4_expansion_stack, rather each time we expand a
-# macro FOO we define _m4_expanding(FOO). Then m4_require(BAR) simply
-# needs to check whether _m4_expanding(BAR) is defined to diagnose a
-# circular dependency.
-#
-# To improve the diagnostic, in addition to keeping track of the stack
-# of macro calls, m4_expansion_stack also records the m4_require
-# stack. Note that therefore an m4_defun'd macro being required will
-# appear twice in the stack: the first time because it is required,
-# the second because it is expanded. We can avoid this, but it has
-# two small drawbacks: (i) the implementation is slightly more
-# complex, and (ii) it hides the difference between define'd macros
-# (which don't appear in m4_expansion_stack) and m4_defun'd macros
-# (which do). The more debugging information, the better.
-
-
-# m4_expansion_stack_push(TEXT)
-# -----------------------------
-m4_define([m4_expansion_stack_push],
-[m4_pushdef([m4_expansion_stack],
- [$1]m4_ifdef([m4_expansion_stack], [
-m4_defn([m4_expansion_stack])]))])
-
-
-# m4_expansion_stack_pop
-# ----------------------
-# Dump the expansion stack.
-m4_define([m4_expansion_stack_pop],
-[m4_popdef([m4_expansion_stack])])
-
-
-# m4_expansion_stack_dump
-# -----------------------
-# Dump the expansion stack.
-m4_define([m4_expansion_stack_dump],
-[m4_ifdef([m4_expansion_stack],
- [m4_errprintn(m4_defn([m4_expansion_stack]))])dnl
-m4_errprintn(m4_location[: the top level])])
-
-
-# _m4_divert(GROW)
-# ----------------
-# This diversion is used by the m4_defun/m4_require machinery. It is
-# important to keep room before GROW because for each nested
-# AC_REQUIRE we use an additional diversion (i.e., two m4_require's
-# will use GROW - 2. More than 3 levels has never seemed to be
-# needed.)
-#
-# ...
-# - GROW - 2
-# m4_require'd code, 2 level deep
-# - GROW - 1
-# m4_require'd code, 1 level deep
-# - GROW
-# m4_defun'd macros are elaborated here.
-
-m4_define([_m4_divert(GROW)], 10000)
-
-
-# _m4_defun_pro(MACRO-NAME)
-# -------------------------
-# The prologue for Autoconf macros.
-m4_define([_m4_defun_pro],
-[m4_expansion_stack_push(m4_defn([m4_location($1)])[: $1 is expanded from...])dnl
-m4_pushdef([_m4_expanding($1)])dnl
-m4_ifdef([_m4_divert_dump],
- [m4_divert_push(m4_defn([_m4_divert_diversion]))],
- [m4_copy([_m4_divert_diversion], [_m4_divert_dump])dnl
-m4_divert_push([GROW])])dnl
-])
-
-
-# _m4_defun_epi(MACRO-NAME)
-# -------------------------
-# The Epilogue for Autoconf macros. MACRO-NAME only helps tracing
-# the PRO/EPI pairs.
-m4_define([_m4_defun_epi],
-[m4_divert_pop()dnl
-m4_if(_m4_divert_dump, _m4_divert_diversion,
- [m4_undivert([GROW])dnl
-m4_undefine([_m4_divert_dump])])dnl
-m4_expansion_stack_pop()dnl
-m4_popdef([_m4_expanding($1)])dnl
-m4_provide([$1])dnl
-])
-
-
-# m4_defun(NAME, EXPANSION)
-# -------------------------
-# Define a macro which automatically provides itself. Add machinery
-# so the macro automatically switches expansion to the diversion
-# stack if it is not already using it. In this case, once finished,
-# it will bring back all the code accumulated in the diversion stack.
-# This, combined with m4_require, achieves the topological ordering of
-# macros. We don't use this macro to define some frequently called
-# macros that are not involved in ordering constraints, to save m4
-# processing.
-m4_define([m4_defun],
-[m4_define([m4_location($1)], m4_location)dnl
-m4_define([$1],
- [_m4_defun_pro([$1])$2[]_m4_defun_epi([$1])])])
-
-
-# m4_defun_once(NAME, EXPANSION)
-# ------------------------------
-# As m4_defun, but issues the EXPANSION only once, and warns if used
-# several times.
-m4_define([m4_defun_once],
-[m4_define([m4_location($1)], m4_location)dnl
-m4_define([$1],
- [m4_provide_if([$1],
- [m4_warn([syntax], [$1 invoked multiple times])],
- [_m4_defun_pro([$1])$2[]_m4_defun_epi([$1])])])])
-
-
-# m4_pattern_forbid(ERE, [WHY])
-# -----------------------------
-# Declare that no token matching the extended regular expression ERE
-# should be seen in the output but if...
-m4_define([m4_pattern_forbid], [])
-
-
-# m4_pattern_allow(ERE)
-# ---------------------
-# ... but if that token matches the extended regular expression ERE.
-# Both used via traces.
-m4_define([m4_pattern_allow], [])
-
-
-## ----------------------------- ##
-## Dependencies between macros. ##
-## ----------------------------- ##
-
-
-# m4_before(THIS-MACRO-NAME, CALLED-MACRO-NAME)
-# ---------------------------------------------
-m4_define([m4_before],
-[m4_provide_if([$2],
- [m4_warn([syntax], [$2 was called before $1])])])
-
-
-# m4_require(NAME-TO-CHECK, [BODY-TO-EXPAND = NAME-TO-CHECK])
-# -----------------------------------------------------------
-# If NAME-TO-CHECK has never been expanded (actually, if it is not
-# m4_provide'd), expand BODY-TO-EXPAND *before* the current macro
-# expansion. Once expanded, emit it in _m4_divert_dump. Keep track
-# of the m4_require chain in m4_expansion_stack.
-#
-# The normal cases are:
-#
-# - NAME-TO-CHECK == BODY-TO-EXPAND
-# Which you can use for regular macros with or without arguments, e.g.,
-# m4_require([AC_PROG_CC], [AC_PROG_CC])
-# m4_require([AC_CHECK_HEADERS(limits.h)], [AC_CHECK_HEADERS(limits.h)])
-# which is just the same as
-# m4_require([AC_PROG_CC])
-# m4_require([AC_CHECK_HEADERS(limits.h)])
-#
-# - BODY-TO-EXPAND == m4_indir([NAME-TO-CHECK])
-# In the case of macros with irregular names. For instance:
-# m4_require([AC_LANG_COMPILER(C)], [indir([AC_LANG_COMPILER(C)])])
-# which means `if the macro named `AC_LANG_COMPILER(C)' (the parens are
-# part of the name, it is not an argument) has not been run, then
-# call it.'
-# Had you used
-# m4_require([AC_LANG_COMPILER(C)], [AC_LANG_COMPILER(C)])
-# then m4_require would have tried to expand `AC_LANG_COMPILER(C)', i.e.,
-# call the macro `AC_LANG_COMPILER' with `C' as argument.
-#
-# You could argue that `AC_LANG_COMPILER', when it receives an argument
-# such as `C' should dispatch the call to `AC_LANG_COMPILER(C)'. But this
-# `extension' prevents `AC_LANG_COMPILER' from having actual arguments that
-# it passes to `AC_LANG_COMPILER(C)'.
-m4_define([m4_require],
-[m4_expansion_stack_push(m4_location[: $1 is required by...])dnl
-m4_ifdef([_m4_expanding($1)],
- [m4_fatal([$0: circular dependency of $1])])dnl
-m4_ifndef([_m4_divert_dump],
- [m4_fatal([$0: cannot be used outside of an m4_defun'd macro])])dnl
-m4_provide_if([$1],
- [],
- [m4_divert_push(m4_eval(m4_divnum - 1))dnl
-m4_default([$2], [$1])
-m4_divert(m4_defn([_m4_divert_dump]))dnl
-m4_undivert(m4_defn([_m4_divert_diversion]))dnl
-m4_divert_pop(m4_defn([_m4_divert_dump]))])dnl
-m4_provide_if([$1],
- [],
- [m4_warn([syntax],
- [$1 is m4_require'd but is not m4_defun'd])])dnl
-m4_expansion_stack_pop()dnl
-])
-
-
-# m4_expand_once(TEXT, [WITNESS = TEXT])
-# --------------------------------------
-# If TEXT has never been expanded, expand it *here*. Use WITNESS as
-# as a memory that TEXT has already been expanded.
-m4_define([m4_expand_once],
-[m4_provide_if(m4_ifval([$2], [[$2]], [[$1]]),
- [],
- [m4_provide(m4_ifval([$2], [[$2]], [[$1]]))[]$1])])
-
-
-# m4_provide(MACRO-NAME)
-# ----------------------
-m4_define([m4_provide],
-[m4_define([m4_provide($1)])])
-
-
-# m4_provide_if(MACRO-NAME, IF-PROVIDED, IF-NOT-PROVIDED)
-# -------------------------------------------------------
-# If MACRO-NAME is provided do IF-PROVIDED, else IF-NOT-PROVIDED.
-# The purpose of this macro is to provide the user with a means to
-# check macros which are provided without letting her know how the
-# information is coded.
-m4_define([m4_provide_if],
-[m4_ifdef([m4_provide($1)],
- [$2], [$3])])
-
-
-## -------------------- ##
-## 9. Text processing. ##
-## -------------------- ##
-
-
-# m4_cr_letters
-# m4_cr_LETTERS
-# m4_cr_Letters
-# -------------
-m4_define([m4_cr_letters], [abcdefghijklmnopqrstuvwxyz])
-m4_define([m4_cr_LETTERS], [ABCDEFGHIJKLMNOPQRSTUVWXYZ])
-m4_define([m4_cr_Letters],
-m4_defn([m4_cr_letters])dnl
-m4_defn([m4_cr_LETTERS])dnl
-)
-
-
-# m4_cr_digits
-# ------------
-m4_define([m4_cr_digits], [0123456789])
-
-
-# m4_cr_symbols1 & m4_cr_symbols2
-# -------------------------------
-m4_define([m4_cr_symbols1],
-m4_defn([m4_cr_Letters])dnl
-_)
-
-m4_define([m4_cr_symbols2],
-m4_defn([m4_cr_symbols1])dnl
-m4_defn([m4_cr_digits])dnl
-)
-
-
-# m4_re_escape(STRING)
-# --------------------
-# Escape BRE active characters in STRING.
-m4_define([m4_re_escape],
-[m4_bpatsubst([$1],
- [[][+*.]], [\\\&])])
-
-
-# m4_re_string
-# ------------
-# Regexp for `[a-zA-Z_0-9]*'
-m4_define([m4_re_string],
-m4_defn([m4_cr_symbols2])dnl
-[*]dnl
-)
-
-
-# m4_re_word
-# ----------
-# Regexp for `[a-zA-Z_][a-zA-Z_0-9]*'
-m4_define([m4_re_word],
-m4_defn([m4_cr_symbols1])dnl
-m4_defn([m4_re_string])dnl
-)
-
-
-# m4_tolower(STRING)
-# m4_toupper(STRING)
-# ------------------
-# These macros lowercase and uppercase strings.
-m4_define([m4_tolower],
-[m4_translit([$1], m4_defn([m4_cr_LETTERS]), m4_defn([m4_cr_letters]))])
-m4_define([m4_toupper],
-[m4_translit([$1], m4_defn([m4_cr_letters]), m4_defn([m4_cr_LETTERS]))])
-
-
-# m4_split(STRING, [REGEXP])
-# --------------------------
-#
-# Split STRING into an m4 list of quoted elements. The elements are
-# quoted with [ and ]. Beginning spaces and end spaces *are kept*.
-# Use m4_strip to remove them.
-#
-# REGEXP specifies where to split. Default is [\t ]+.
-#
-# Pay attention to the m4_changequotes. Inner m4_changequotes exist for
-# obvious reasons (we want to insert square brackets). Outer
-# m4_changequotes are needed because otherwise the m4 parser, when it
-# sees the closing bracket we add to the result, believes it is the
-# end of the body of the macro we define.
-#
-# Also, notice that $1 is quoted twice, since we want the result to
-# be quoted. Then you should understand that the argument of
-# patsubst is ``STRING'' (i.e., with additional `` and '').
-#
-# This macro is safe on active symbols, i.e.:
-# m4_define(active, ACTIVE)
-# m4_split([active active ])end
-# => [active], [active], []end
-
-m4_changequote(<<, >>)
-m4_define(<<m4_split>>,
-<<m4_changequote(``, '')dnl
-[dnl Can't use m4_default here instead of m4_if, because m4_default uses
-dnl [ and ] as quotes.
-m4_bpatsubst(````$1'''',
- m4_if(``$2'',, ``[ ]+'', ``$2''),
- ``], ['')]dnl
-m4_changequote([, ])>>)
-m4_changequote([, ])
-
-
-
-# m4_flatten(STRING)
-# ------------------
-# If STRING contains end of lines, replace them with spaces. If there
-# are backslashed end of lines, remove them. This macro is safe with
-# active symbols.
-# m4_define(active, ACTIVE)
-# m4_flatten([active
-# act\
-# ive])end
-# => active activeend
-m4_define([m4_flatten],
-[m4_translit(m4_bpatsubst([[[$1]]], [\\
-]), [
-], [ ])])
-
-
-# m4_strip(STRING)
-# ----------------
-# Expands into STRING with tabs and spaces singled out into a single
-# space, and removing leading and trailing spaces.
-#
-# This macro is robust to active symbols.
-# m4_define(active, ACTIVE)
-# m4_strip([ active active ])end
-# => active activeend
-#
-# This macro is fun! Because we want to preserve active symbols, STRING
-# must be quoted for each evaluation, which explains there are 4 levels
-# of brackets around $1 (don't forget that the result must be quoted
-# too, hence one more quoting than applications).
-#
-# Then notice the 2 last patterns: they are in charge of removing the
-# leading/trailing spaces. Why not just `[^ ]'? Because they are
-# applied to doubly quoted strings, i.e. more or less [[STRING]]. So
-# if there is a leading space in STRING, then it is the *third*
-# character, since there are two leading `['; equally for the last pattern.
-m4_define([m4_strip],
-[m4_bpatsubsts([[$1]],
- [[ ]+], [ ],
- [^\(..\) ], [\1],
- [ \(..\)$], [\1])])
-
-
-# m4_normalize(STRING)
-# --------------------
-# Apply m4_flatten and m4_strip to STRING.
-#
-# The argument is quoted, so that the macro is robust to active symbols:
-#
-# m4_define(active, ACTIVE)
-# m4_normalize([ act\
-# ive
-# active ])end
-# => active activeend
-
-m4_define([m4_normalize],
-[m4_strip(m4_flatten([$1]))])
-
-
-
-# m4_join(SEP, ARG1, ARG2...)
-# ---------------------------
-# Produce ARG1SEPARG2...SEPARGn.
-m4_defun([m4_join],
-[m4_case([$#],
- [1], [],
- [2], [[$2]],
- [[$2][$1]$0([$1], m4_shiftn(2, $@))])])
-
-
-
-# m4_append(MACRO-NAME, STRING, [SEPARATOR])
-# ------------------------------------------
-# Redefine MACRO-NAME to hold its former content plus `SEPARATOR`'STRING'
-# at the end. It is valid to use this macro with MACRO-NAME undefined,
-# in which case no SEPARATOR is added. Be aware that the criterion is
-# `not being defined', and not `not being empty'.
-#
-# This macro is robust to active symbols. It can be used to grow
-# strings.
-#
-# | m4_define(active, ACTIVE)
-# | m4_append([sentence], [This is an])
-# | m4_append([sentence], [ active ])
-# | m4_append([sentence], [symbol.])
-# | sentence
-# | m4_undefine([active])dnl
-# | sentence
-# => This is an ACTIVE symbol.
-# => This is an active symbol.
-#
-# It can be used to define hooks.
-#
-# | m4_define(active, ACTIVE)
-# | m4_append([hooks], [m4_define([act1], [act2])])
-# | m4_append([hooks], [m4_define([act2], [active])])
-# | m4_undefine([active])
-# | act1
-# | hooks
-# | act1
-# => act1
-# =>
-# => active
-m4_define([m4_append],
-[m4_define([$1],
- m4_ifdef([$1], [m4_defn([$1])$3])[$2])])
-
-
-# m4_append_uniq(MACRO-NAME, STRING, [SEPARATOR])
-# -----------------------------------------------
-# As `m4_append', but append only if not yet present.
-m4_define([m4_append_uniq],
-[m4_ifdef([$1],
- [m4_bmatch([$3]m4_defn([$1])[$3], m4_re_escape([$3$2$3]), [],
- [m4_append($@)])],
- [m4_append($@)])])
-
-
-# m4_text_wrap(STRING, [PREFIX], [FIRST-PREFIX], [WIDTH])
-# -------------------------------------------------------
-# Expands into STRING wrapped to hold in WIDTH columns (default = 79).
-# If prefix is set, each line is prefixed with it. If FIRST-PREFIX is
-# specified, then the first line is prefixed with it. As a special
-# case, if the length of the first prefix is greater than that of
-# PREFIX, then FIRST-PREFIX will be left alone on the first line.
-#
-# Typical outputs are:
-#
-# m4_text_wrap([Short string */], [ ], [/* ], 20)
-# => /* Short string */
-#
-# m4_text_wrap([Much longer string */], [ ], [/* ], 20)
-# => /* Much longer
-# => string */
-#
-# m4_text_wrap([Short doc.], [ ], [ --short ], 30)
-# => --short Short doc.
-#
-# m4_text_wrap([Short doc.], [ ], [ --too-wide ], 30)
-# => --too-wide
-# => Short doc.
-#
-# m4_text_wrap([Super long documentation.], [ ], [ --too-wide ], 30)
-# => --too-wide
-# => Super long
-# => documentation.
-#
-# FIXME: there is no checking of a longer PREFIX than WIDTH, but do
-# we really want to bother with people trying each single corner
-# of a software?
-#
-# This macro does not leave a trailing space behind the last word,
-# what complicates it a bit. The algorithm is stupid simple: all the
-# words are preceded by m4_Separator which is defined to empty for the
-# first word, and then ` ' (single space) for all the others.
-m4_define([m4_text_wrap],
-[m4_pushdef([m4_Prefix], m4_default([$2], []))dnl
-m4_pushdef([m4_Prefix1], m4_default([$3], [m4_Prefix]))dnl
-m4_pushdef([m4_Width], m4_default([$4], 79))dnl
-m4_pushdef([m4_Cursor], m4_len(m4_Prefix1))dnl
-m4_pushdef([m4_Separator], [])dnl
-m4_Prefix1[]dnl
-m4_if(m4_eval(m4_Cursor > m4_len(m4_Prefix)),
- 1, [m4_define([m4_Cursor], m4_len(m4_Prefix))
-m4_Prefix])[]dnl
-m4_foreach([m4_Word], m4_quote(m4_split(m4_normalize([$1]))),
-[m4_define([m4_Cursor], m4_eval(m4_Cursor + m4_len(m4_defn([m4_Word])) + 1))dnl
-dnl New line if too long, else insert a space unless it is the first
-dnl of the words.
-m4_if(m4_eval(m4_Cursor > m4_Width),
- 1, [m4_define([m4_Cursor],
- m4_eval(m4_len(m4_Prefix) + m4_len(m4_defn([m4_Word])) + 1))]
-m4_Prefix,
- [m4_Separator])[]dnl
-m4_defn([m4_Word])[]dnl
-m4_define([m4_Separator], [ ])])dnl
-m4_popdef([m4_Separator])dnl
-m4_popdef([m4_Cursor])dnl
-m4_popdef([m4_Width])dnl
-m4_popdef([m4_Prefix1])dnl
-m4_popdef([m4_Prefix])dnl
-])
-
-
-# m4_text_box(MESSAGE, [FRAME-CHARACTER = `-'])
-# ---------------------------------------------
-m4_define([m4_text_box],
-[@%:@@%:@ m4_bpatsubst([$1], [.], m4_if([$2], [], [[-]], [[$2]])) @%:@@%:@
-@%:@@%:@ $1 @%:@@%:@
-@%:@@%:@ m4_bpatsubst([$1], [.], m4_if([$2], [], [[-]], [[$2]])) @%:@@%:@[]dnl
-])
-
-
-
-## ----------------------- ##
-## 10. Number processing. ##
-## ----------------------- ##
-
-# m4_sign(A)
-# ----------
-#
-# The sign of the integer A.
-m4_define([m4_sign],
-[m4_bmatch([$1],
- [^-], -1,
- [^0+], 0,
- 1)])
-
-# m4_cmp(A, B)
-# ------------
-#
-# Compare two integers.
-# A < B -> -1
-# A = B -> 0
-# A > B -> 1
-m4_define([m4_cmp],
-[m4_sign(m4_eval([$1 - $2]))])
-
-
-# m4_list_cmp(A, B)
-# -----------------
-#
-# Compare the two lists of integers A and B. For instance:
-# m4_list_cmp((1, 0), (1)) -> 0
-# m4_list_cmp((1, 0), (1, 0)) -> 0
-# m4_list_cmp((1, 2), (1, 0)) -> 1
-# m4_list_cmp((1, 2, 3), (1, 2)) -> 1
-# m4_list_cmp((1, 2, -3), (1, 2)) -> -1
-# m4_list_cmp((1, 0), (1, 2)) -> -1
-# m4_list_cmp((1), (1, 2)) -> -1
-m4_define([m4_list_cmp],
-[m4_if([$1$2], [()()], 0,
- [$1], [()], [$0((0), [$2])],
- [$2], [()], [$0([$1], (0))],
- [m4_case(m4_cmp(m4_car$1, m4_car$2),
- -1, -1,
- 1, 1,
- 0, [$0((m4_shift$1), (m4_shift$2))])])])
-
-
-
-## ------------------------ ##
-## 11. Version processing. ##
-## ------------------------ ##
-
-
-# m4_version_unletter(VERSION)
-# ----------------------------
-# Normalize beta version numbers with letters to numbers only for comparison.
-#
-# Nl -> (N+1).-1.(l#)
-#
-#i.e., 2.14a -> 2.15.-1.1, 2.14b -> 2.15.-1.2, etc.
-# This macro is absolutely not robust to active macro, it expects
-# reasonable version numbers and is valid up to `z', no double letters.
-m4_define([m4_version_unletter],
-[m4_translit(m4_bpatsubsts([$1],
- [\([0-9]+\)\([abcdefghi]\)],
- [m4_eval(\1 + 1).-1.\2],
- [\([0-9]+\)\([jklmnopqrs]\)],
- [m4_eval(\1 + 1).-1.1\2],
- [\([0-9]+\)\([tuvwxyz]\)],
- [m4_eval(\1 + 1).-1.2\2]),
- [abcdefghijklmnopqrstuvwxyz],
- [12345678901234567890123456])])
-
-
-# m4_version_compare(VERSION-1, VERSION-2)
-# ----------------------------------------
-# Compare the two version numbers and expand into
-# -1 if VERSION-1 < VERSION-2
-# 0 if =
-# 1 if >
-m4_define([m4_version_compare],
-[m4_list_cmp((m4_split(m4_version_unletter([$1]), [\.])),
- (m4_split(m4_version_unletter([$2]), [\.])))])
-
-
-# m4_PACKAGE_NAME
-# m4_PACKAGE_TARNAME
-# m4_PACKAGE_VERSION
-# m4_PACKAGE_STRING
-# m4_PACKAGE_BUGREPORT
-# --------------------
-m4_include([m4sugar/version.m4])
-
-
-# m4_version_prereq(VERSION, [IF-OK], [IF-NOT = FAIL])
-# ----------------------------------------------------
-# Check this Autoconf version against VERSION.
-m4_define([m4_version_prereq],
-[m4_if(m4_version_compare(m4_defn([m4_PACKAGE_VERSION]), [$1]), -1,
- [m4_default([$3],
- [m4_fatal([Autoconf version $1 or higher is required])])],
- [$2])[]dnl
-])
-
-
-
-## ------------------- ##
-## 12. File handling. ##
-## ------------------- ##
-
-
-# It is a real pity that M4 comes with no macros to bind a diversion
-# to a file. So we have to deal without, which makes us a lot more
-# fragile that we should.
-
-
-# m4_file_append(FILE-NAME, CONTENT)
-# ----------------------------------
-m4_define([m4_file_append],
-[m4_syscmd([cat >>$1 <<_m4eof
-$2
-_m4eof
-])
-m4_if(m4_sysval, [0], [],
- [m4_fatal([$0: cannot write: $1])])])
-
-
-
-## ------------------------ ##
-## 13. Setting M4sugar up. ##
-## ------------------------ ##
-
-
-# m4_init
-# -------
-m4_define([m4_init],
-[# All the M4sugar macros start with `m4_', except `dnl' kept as is
-# for sake of simplicity.
-m4_pattern_forbid([^_?m4_])
-m4_pattern_forbid([^dnl$])
-
-# Check the divert push/pop perfect balance.
-m4_wrap([m4_ifdef([_m4_divert_diversion],
- [m4_fatal([$0: unbalanced m4_divert_push:]
-m4_defn([m4_divert_stack]))])[]])
-
-m4_divert_push([KILL])
-m4_wrap([m4_divert_pop([KILL])[]])
-])
projects / bison.git / blobdiff