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515 lines
16 KiB
Plaintext
515 lines
16 KiB
Plaintext
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divert(-1) -*- Autoconf -*-
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# This file is part of Autoconf.
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# Base m4 layer.
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# Requires GNU m4.
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# Copyright (C) 1999 Free Software Foundation, Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2, or (at your option)
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# any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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# 02111-1307, USA.
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#
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# As a special exception, the Free Software Foundation gives unlimited
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# permission to copy, distribute and modify the configure scripts that
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# are the output of Autoconf. You need not follow the terms of the GNU
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# General Public License when using or distributing such scripts, even
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# though portions of the text of Autoconf appear in them. The GNU
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# General Public License (GPL) does govern all other use of the material
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# that constitutes the Autoconf program.
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#
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# Certain portions of the Autoconf source text are designed to be copied
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# (in certain cases, depending on the input) into the output of
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# Autoconf. We call these the "data" portions. The rest of the Autoconf
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# source text consists of comments plus executable code that decides which
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# of the data portions to output in any given case. We call these
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# comments and executable code the "non-data" portions. Autoconf never
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# copies any of the non-data portions into its output.
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#
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# This special exception to the GPL applies to versions of Autoconf
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# released by the Free Software Foundation. When you make and
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# distribute a modified version of Autoconf, you may extend this special
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# exception to the GPL to apply to your modified version as well, *unless*
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# your modified version has the potential to copy into its output some
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# of the text that was the non-data portion of the version that you started
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# with. (In other words, unless your change moves or copies text from
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# the non-data portions to the data portions.) If your modification has
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# such potential, you must delete any notice of this special exception
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# to the GPL from your modified version.
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#
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# Written by Akim Demaille.
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#
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changequote([, ])
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# Some old m4's don't support m4exit. But they provide
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# equivalent functionality by core dumping because of the
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# long macros we define.
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ifdef([__gnu__], ,
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[errprint(Autoconf requires GNU m4. Install it before installing Autoconf or
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set the M4 environment variable to its path name.)
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m4exit(2)])
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## --------------------------------------------- ##
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## Move some m4 builtins to a safer name space. ##
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## --------------------------------------------- ##
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# m4_errprint(MSG)
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# ----------------
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# Same as `errprint', but reports the file and line.
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define(m4_errprint, [errprint(__file__:__line__: [$1
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])])
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# m4_warn(MSG)
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# ------------
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# Warn the user.
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define(m4_warn, [m4_errprint([warning: $1])])
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# m4_fatal(MSG, [EXIT-STATUS])
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# ----------------------------
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# Fatal the user. :)
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define(m4_fatal,
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[m4_errprint([error: $1])dnl
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m4exit(ifelse([$2],, 1, [$2]))])
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# Some m4 internals have names colliding with tokens we might use.
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# Rename them a` la `m4 --prefix-builtins'.
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define([m4_prefix],
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[define([m4_$1], defn([$1]))
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undefine([$1])])
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m4_prefix([eval])
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m4_prefix([shift])
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m4_prefix([format])
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# We also want to neutralize include (and sinclude for symmetry),
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# but we want to extend them slightly: warn when a file is included
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# several times. This is in general a dangerous operation because
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# quite nobody quotes the first argument of define.
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#
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# For instance in the following case:
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# define(foo, [bar])
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# then a second reading will turn into
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# define(bar, [bar])
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# which is certainly not what was meant.
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# m4_include_unique(FILE)
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# -----------------------
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# Declare that the FILE was loading; and warn if it has already
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# been included.
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define(m4_include_unique,
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[ifdef([m4_include($1)],
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[m4_warn([file `$1' included several times])])dnl
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define([m4_include($1)])])
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# m4_include(FILE)
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# ----------------
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# As the builtin include, but warns against multiple inclusions.
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define(m4_include,
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[m4_include_unique([$1])dnl
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builtin([include], [$1])])
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# m4_sinclude(FILE)
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# -----------------
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# As the builtin sinclude, but warns against multiple inclusions.
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define(m4_sinclude,
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[m4_include_unique([$1])dnl
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builtin([sinclude], [$1])])
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# Neutralize include and sinclude.
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undefine([include])
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undefine([sinclude])
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## --------------------------------------- ##
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## Some additional m4 structural control. ##
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## --------------------------------------- ##
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# Both `ifval' and `ifset' tests against the empty string. The
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# difference is that `ifset' is specialized on macros.
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#
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# In case of arguments of macros, eg $[1], it makes little difference.
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# In the case of a macro `FOO', you don't want to check `ifval(FOO,
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# TRUE)', because if `FOO' expands with commas, there is a shifting of
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# the arguments. So you want to run `ifval([FOO])', but then you just
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# compare the *string* `FOO' against `', which, of course fails.
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#
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# So you want a variation of `ifset' that expects a macro name as $[1].
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# If this macro is both defined and defined to a non empty value, then
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# it runs TRUE etc.
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# ifval(COND, IF-TRUE[, IF-FALSE])
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# --------------------------------
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# If COND is not the empty string, expand IF-TRUE, otherwise IF-FALSE.
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# Comparable to ifdef.
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define([ifval], [ifelse([$1],[],[$3],[$2])])
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# ifset(MACRO, IF-TRUE[, IF-FALSE])
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# --------------------------------
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# If MACRO has no definition, or of its definition is the empty string,
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# expand IF-FALSE, otherwise IF-TRUE.
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define([ifset],
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[ifdef([$1],
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[ifelse(defn([$1]), [], [$3], [$2])],
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[$3])])
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# m4_default(EXP1, EXP2)
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# ----------------------
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# Returns EXP1 if non empty, otherwise EXP2.
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define([m4_default], [ifval([$1], [$1], [$2])])
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# m4_case(SWITCH, VAL1, IF-VAL1, VAL2, IF-VAL2, ..., DEFAULT)
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# -----------------------------------------------------------
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# m4 equivalent of
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# switch (SWITCH)
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# {
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# case VAL1:
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# IF-VAL1;
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# break;
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# case VAL2:
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# IF-VAL2;
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# break;
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# ...
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# default:
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# DEFAULT;
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# break;
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# }.
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# All the values are optional, and the macro is robust to active
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# symbols properly quoted.
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define(m4_case,
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[ifelse([$#], 0, [],
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[$#], 1, [],
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[$#], 2, [$2],
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[$1], [$2], [$3],
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[m4_case([$1], m4_shift(m4_shift(m4_shift($@))))])])
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# m4_match(SWITCH, RE1, VAL1, RE2, VAL2, ..., DEFAULT)
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# ----------------------------------------------------
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# m4 equivalent of
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#
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# if (SWITCH =~ RE1)
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# VAL1;
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# elif (SWITCH =~ RE2)
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# VAL2;
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# elif ...
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# ...
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# else
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# DEFAULT
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#
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# All the values are optional, and the macro is robust to active symbols
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# properly quoted.
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define(m4_match,
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[ifelse([$#], 0, [],
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[$#], 1, [],
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[$#], 2, [$2],
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regexp([$1], [$2]), -1, [m4_match([$1],
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m4_shift(m4_shift(m4_shift($@))))],
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[$3])])
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## --------------------- ##
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## Implementing m4 loops ##
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## --------------------- ##
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# Implementing loops (`foreach' loops) in m4 is much more tricky than it
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# may seem. Actually, the example of a `foreach' loop in the m4
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# documentation is wrong: it does not quote the arguments properly,
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# which leads to undesired expansions.
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#
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# The example in the documentation is:
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#
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# | # foreach(x, (item_1, item_2, ..., item_n), stmt)
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# | define(`foreach',
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# | `pushdef(`$1', `')_foreach(`$1', `$2', `$3')popdef(`$1')')
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# | define(`_arg1', `$1')
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# | define(`_foreach',
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# | `ifelse(`$2', `()', ,
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# | `define(`$1', _arg1$2)$3`'_foreach(`$1', (shift$2), `$3')')')
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#
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# But then if you run
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#
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# | define(a, 1)
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# | define(b, 2)
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# | define(c, 3)
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# | foreach(`f', `(`a', `(b', `c)')', `echo f
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# | ')
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#
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# it gives
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#
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# => echo 1
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# => echo (2,3)
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#
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# which is not what is expected.
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#
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# Once you understood this, you turn yourself into a quoting wizard,
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# and come up with the following solution:
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#
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# | # foreach(x, (item_1, item_2, ..., item_n), stmt)
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# | define(`foreach', `pushdef(`$1', `')_foreach($@)popdef(`$1')')
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# | define(`_arg1', ``$1'')
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# | define(`_foreach',
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# | `ifelse($2, `()', ,
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# | `define(`$1', `_arg1$2')$3`'_foreach(`$1', `(shift$2)', `$3')')')
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#
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# which this time answers
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#
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# => echo a
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# => echo (b
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# => echo c)
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#
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# Bingo!
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# m4_foreach(VARIABLE, LIST, EXPRESSION)
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# --------------------------------------
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# Expand EXPRESSION assigning to VARIABLE each value of the LIST
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# (LIST should have the form `[(item_1, item_2, ..., item_n)]'),
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# i.e. the whole list should be *quoted*. Quote members too if
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# you don't want them to be expanded.
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#
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# This macro is robust to active symbols:
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# define(active, ACTIVE)
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# m4_foreach([Var], [([active], [b], [active])], [-Var-])end
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# => -active--b--active-end
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define(m4_foreach,
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[pushdef([$1], [])_m4_foreach($@)popdef([$1])])
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# Low level macros used to define m4_foreach
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define(m4_car, [[$1]])
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define(_m4_foreach,
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[ifelse($2, [()], ,
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[define([$1], [m4_car$2])$3[]_m4_foreach([$1],
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[(m4_shift$2)],
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[$3])])])
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## ----------------------- ##
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## Text processing in m4. ##
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## ----------------------- ##
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# m4_quote(STRING)
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# ----------------
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# Return STRING quoted.
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#
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# It is important to realize the difference between `quote(exp)' and
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# `[exp]': in the first case you obtain the quoted *result* of the
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# expansion of EXP, while in the latter you just obtain the string
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# `exp'.
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define([m4_quote], [[$@]])
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# m4_split(STRING, [REGEXP])
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# --------------------------
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# Split STRING into an m4 list of quoted elements. The elements are
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# quoted with [ and ]. Beginning spaces and end spaces *are kept*.
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# Use m4_strip to remove them.
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#
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# REGEXP specifies where to split. Default is [\t ]+.
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#
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# Pay attention to the changequotes. Inner changequotes exist for
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# obvious reasons (we want to insert square brackets). Outer
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# changequotes are needed because otherwise the m4 parser, when it
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# sees the closing bracket we add to the result, believes it is the
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# end of the body of the macro we define.
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#
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# Also, notice that $1 is quoted twice, since we want the result to be
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# quoted. Then you should understand that the argument of patsubst is
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# ``STRING'' (i.e., with additional `` and '').
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#
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# This macro is safe on active symbols, i.e.:
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# define(active, ACTIVE)
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# m4_split([active active ])end
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# => [active], [active], []end
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changequote(<<, >>)
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define(<<m4_split>>,
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<<changequote(``, '')dnl
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[dnl Can't use m4_default here instead of ifelse, because m4_default uses
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dnl [ and ] as quotes.
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patsubst(````$1'''',
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ifelse(``$2'',, ``[ ]+'', ``$2''),
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``], ['')]dnl
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changequote([, ])>>)
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changequote([, ])
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# m4_join(STRING)
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# ---------------
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# If STRING contains end of lines, replace them with spaces. If there
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# are backslashed end of lines, remove them. This macro is safe with
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# active symbols.
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# define(active, ACTIVE)
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# m4_join([active
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# act\
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# ive])end
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# => active activeend
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define([m4_join],
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[translit(patsubst([[[$1]]], [\\
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]), [
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], [ ])])
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# m4_strip(STRING)
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# ----------------
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# Expands into STRING with tabs and spaces singled out into a single
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# space, and removing leading and trailing spaces.
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#
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# This macro is robust to active symbols.
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# define(active, ACTIVE)
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# m4_strip([ active active ])end
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# => active activeend
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#
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# This macro is fun! Because we want to preserve active symbols, STRING
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# must be quoted for each evaluation, which explains there are 4 levels
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# of brackets around $1 (don't forget that the result must be quoted
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# too, hence one more quoting than applications).
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#
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# Then notice the patsubst of the middle: it is in charge of removing
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# the leading space. Why not just `patsubst(..., [^ ])'? Because this
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# macro will receive the output of the preceding patsubst, i.e. more or
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# less [[STRING]]. So if there is a leading space in STRING, then it is
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# the *third* character, since there are two leading `['; Equally for
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# the outer patsubst.
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define([m4_strip],
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[patsubst(patsubst(patsubst([[[[$1]]]],
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[[ ]+], [ ]),
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[^\(..\) ], [\1]),
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[ \(.\)$], [\1])])
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# m4_append(MACRO-NAME, STRING)
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# -----------------------------
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# Redefine MACRO-NAME to hold its former content plus STRING at the
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# end. It is valid to use this macro with MACRO-NAME undefined.
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#
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# This macro is robust to active symbols. It can be used to grow
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# strings.
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#
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# | define(active, ACTIVE)
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# | m4_append([sentence], [This is an])
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# | m4_append([sentence], [ active ])
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# | m4_append([sentence], [symbol.])
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# | sentence
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# | undefine([active])dnl
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# | sentence
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# => This is an ACTIVE symbol.
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# => This is an active symbol.
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#
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# It can be used to define hooks.
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#
|
||
|
# | define(active, ACTIVE)
|
||
|
# | m4_append([hooks], [define([act1], [act2])])
|
||
|
# | m4_append([hooks], [define([act2], [active])])
|
||
|
# | undefine([active])
|
||
|
# | act1
|
||
|
# | hooks
|
||
|
# | act1
|
||
|
# => act1
|
||
|
# =>
|
||
|
# => active
|
||
|
define(m4_append,
|
||
|
[define([$1],
|
||
|
ifdef([$1], [defn([$1])])[$2])])
|
||
|
|
||
|
|
||
|
# m4_list_append(MACRO-NAME, STRING)
|
||
|
# ----------------------------------
|
||
|
# Same as `m4_append', but each element is separated by `, '.
|
||
|
define(m4_list_append,
|
||
|
[define([$1],
|
||
|
ifdef([$1], [defn([$1]), ])[$2])])
|
||
|
|
||
|
|
||
|
|
||
|
|
||
|
## --------------------------------- ##
|
||
|
## Helping macros to display strings ##
|
||
|
## --------------------------------- ##
|
||
|
|
||
|
|
||
|
# m4_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_wrap([Short string */], [ ], [/* ], 20)
|
||
|
# => /* Short string */
|
||
|
#
|
||
|
# m4_wrap([Much longer string */], [ ], [/* ], 20)
|
||
|
# => /* Much longer
|
||
|
# => string */
|
||
|
#
|
||
|
# m4_wrap([Short doc.], [ ], [ --short ], 30)
|
||
|
# => --short Short doc.
|
||
|
#
|
||
|
# m4_wrap([Short doc.], [ ], [ --too-wide ], 30)
|
||
|
# => --too-wide
|
||
|
# => Short doc.
|
||
|
#
|
||
|
# m4_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.
|
||
|
define([m4_wrap],
|
||
|
[pushdef([m4_Prefix], m4_default([$2], []))dnl
|
||
|
pushdef([m4_Prefix1], m4_default([$3], [m4_Prefix]))dnl
|
||
|
pushdef([m4_Width], m4_default([$4], 79))dnl
|
||
|
pushdef([m4_Cursor], len(m4_Prefix1))dnl
|
||
|
pushdef([m4_Separator], [])dnl
|
||
|
m4_Prefix1[]dnl
|
||
|
ifelse(m4_eval(m4_Cursor > len(m4_Prefix)),
|
||
|
1, [define([m4_Cursor], len(m4_Prefix))
|
||
|
m4_Prefix])[]dnl
|
||
|
m4_foreach([m4_Word], (m4_split(m4_strip(m4_join([$1])))),
|
||
|
[define([m4_Cursor], m4_eval(m4_Cursor + len(m4_Word) + 1))dnl
|
||
|
dnl New line if too long, else insert a space unless it is the first
|
||
|
dnl of the words.
|
||
|
ifelse(m4_eval(m4_Cursor > m4_Width),
|
||
|
1, [define([m4_Cursor], m4_eval(len(m4_Prefix) + len(m4_Word) + 1))]
|
||
|
m4_Prefix,
|
||
|
[m4_Separator])[]dnl
|
||
|
m4_Word[]dnl
|
||
|
define([m4_Separator], [ ])])dnl
|
||
|
popdef([m4_Separator])dnl
|
||
|
popdef([m4_Cursor])dnl
|
||
|
popdef([m4_Width])dnl
|
||
|
popdef([m4_Prefix1])dnl
|
||
|
popdef([m4_Prefix])dnl
|
||
|
])
|