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* lib/m4sugar/m4sugar.m4 (m4_join): Just define this, not defun. Ignore empty arguments, using... (_m4_join): ...this new helper. * tests/m4sugar.at (m4@&t@_join): New test. * doc/autoconf.texi (Text processing Macros): Document new semantics of m4_join. Signed-off-by: Eric Blake <ebb9@byu.net>
2045 lines
63 KiB
Plaintext
2045 lines
63 KiB
Plaintext
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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#
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# Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free
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# 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 3 of the License, or
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# (at your option) 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, see <http://www.gnu.org/licenses/>.
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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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# Set the quotes, whatever the current quoting system.
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changequote()
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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(M4sugar requires GNU M4. Install it before installing M4sugar or
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set the M4 environment variable to its absolute file name.)
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m4exit(2)])
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## ------------------------------- ##
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## 1. Simulate --prefix-builtins. ##
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## ------------------------------- ##
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# m4_define
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# m4_defn
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# m4_undefine
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define([m4_define], defn([define]))
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define([m4_defn], defn([defn]))
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define([m4_undefine], defn([undefine]))
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m4_undefine([define])
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m4_undefine([defn])
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m4_undefine([undefine])
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# m4_copy(SRC, DST)
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# -----------------
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# Define DST as the definition of SRC.
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# What's the difference between:
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# 1. m4_copy([from], [to])
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# 2. m4_define([to], [from($@)])
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# Well, obviously 1 is more expensive in space. Maybe 2 is more expensive
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# in time, but because of the space cost of 1, it's not that obvious.
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# Nevertheless, one huge difference is the handling of `$0'. If `from'
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# uses `$0', then with 1, `to''s `$0' is `to', while it is `from' in 2.
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# The user would certainly prefer to see `to'.
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m4_define([m4_copy],
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[m4_define([$2], m4_defn([$1]))])
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# m4_rename(SRC, DST)
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# -------------------
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# Rename the macro SRC to DST.
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m4_define([m4_rename],
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[m4_copy([$1], [$2])m4_undefine([$1])])
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# m4_rename_m4(MACRO-NAME)
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# ------------------------
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# Rename MACRO-NAME to m4_MACRO-NAME.
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m4_define([m4_rename_m4],
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[m4_rename([$1], [m4_$1])])
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# m4_copy_unm4(m4_MACRO-NAME)
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# ---------------------------
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# Copy m4_MACRO-NAME to MACRO-NAME.
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m4_define([m4_copy_unm4],
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[m4_copy([$1], m4_bpatsubst([$1], [^m4_\(.*\)], [[\1]]))])
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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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m4_rename_m4([builtin])
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m4_rename_m4([changecom])
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m4_rename_m4([changequote])
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m4_undefine([changeword])
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m4_rename_m4([debugfile])
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m4_rename_m4([debugmode])
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m4_rename_m4([decr])
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m4_undefine([divert])
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m4_rename_m4([divnum])
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m4_rename_m4([dumpdef])
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m4_rename_m4([errprint])
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m4_rename_m4([esyscmd])
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m4_rename_m4([eval])
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m4_rename_m4([format])
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m4_rename_m4([ifdef])
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m4_rename([ifelse], [m4_if])
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m4_undefine([include])
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m4_rename_m4([incr])
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m4_rename_m4([index])
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m4_rename_m4([indir])
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m4_rename_m4([len])
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m4_rename([m4exit], [m4_exit])
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m4_rename([m4wrap], [m4_wrap])
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m4_ifdef([mkstemp],dnl added in M4 1.4.8
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[m4_rename_m4([mkstemp])
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m4_copy([m4_mkstemp], [m4_maketemp])
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m4_undefine([maketemp])],
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[m4_rename_m4([maketemp])
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m4_copy([m4_maketemp], [m4_mkstemp])])
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m4_rename([patsubst], [m4_bpatsubst])
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m4_undefine([popdef])
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m4_rename_m4([pushdef])
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m4_rename([regexp], [m4_bregexp])
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m4_rename_m4([shift])
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m4_undefine([sinclude])
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m4_rename_m4([substr])
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m4_rename_m4([symbols])
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m4_rename_m4([syscmd])
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m4_rename_m4([sysval])
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m4_rename_m4([traceoff])
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m4_rename_m4([traceon])
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m4_rename_m4([translit])
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m4_undefine([undivert])
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## ------------------- ##
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## 2. Error messages. ##
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## ------------------- ##
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# m4_location
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# -----------
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m4_define([m4_location],
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[__file__:__line__])
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# m4_errprintn(MSG)
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# -----------------
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# Same as `errprint', but with the missing end of line.
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m4_define([m4_errprintn],
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[m4_errprint([$1
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])])
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# m4_warning(MSG)
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# ---------------
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# Warn the user.
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m4_define([m4_warning],
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[m4_errprintn(m4_location[: 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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m4_define([m4_fatal],
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[m4_errprintn(m4_location[: error: $1])dnl
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m4_expansion_stack_dump()dnl
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m4_exit(m4_if([$2],, 1, [$2]))])
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# m4_assert(EXPRESSION, [EXIT-STATUS = 1])
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# ----------------------------------------
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# This macro ensures that EXPRESSION evaluates to true, and exits if
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# EXPRESSION evaluates to false.
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m4_define([m4_assert],
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[m4_if(m4_eval([$1]), 0,
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[m4_fatal([assert failed: $1], [$2])])])
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## ------------- ##
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## 3. Warnings. ##
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## ------------- ##
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# _m4_warn(CATEGORY, MESSAGE, STACK-TRACE)
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# ----------------------------------------
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# Report a MESSAGE to the user if the CATEGORY of warnings is enabled.
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# This is for traces only.
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# The STACK-TRACE is a \n-separated list of "LOCATION: MESSAGE".
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#
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# Within m4, the macro is a no-op. This macro really matters
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# when autom4te post-processes the trace output.
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m4_define([_m4_warn], [])
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# m4_warn(CATEGORY, MESSAGE)
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# --------------------------
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# Report a MESSAGE to the user if the CATEGORY of warnings is enabled.
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m4_define([m4_warn],
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[_m4_warn([$1], [$2],
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m4_ifdef([m4_expansion_stack],
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[m4_defn([m4_expansion_stack])
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m4_location[: the top level]]))dnl
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])
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## ------------------- ##
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## 4. File inclusion. ##
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## ------------------- ##
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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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# too many people forget to quote the first argument of m4_define.
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#
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# For instance in the following case:
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# m4_define(foo, [bar])
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# then a second reading will turn into
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# m4_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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m4_define([m4_include_unique],
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[m4_ifdef([m4_include($1)],
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[m4_warn([syntax], [file `$1' included several times])])dnl
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m4_define([m4_include($1)])])
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# m4_include(FILE)
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# ----------------
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# Like the builtin include, but warns against multiple inclusions.
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m4_define([m4_include],
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[m4_include_unique([$1])dnl
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m4_builtin([include], [$1])])
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# m4_sinclude(FILE)
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# -----------------
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# Like the builtin sinclude, but warns against multiple inclusions.
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m4_define([m4_sinclude],
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[m4_include_unique([$1])dnl
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m4_builtin([sinclude], [$1])])
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## ------------------------------------ ##
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## 5. Additional branching constructs. ##
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## ------------------------------------ ##
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# Both `m4_ifval' and `m4_ifset' tests against the empty string. The
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# difference is that `m4_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 `m4_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 `m4_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 the variation `m4_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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# m4_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 m4_ifdef.
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m4_define([m4_ifval],
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[m4_if([$1], [], [$3], [$2])])
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# m4_n(TEXT)
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# ----------
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# If TEXT is not empty, return TEXT and a new line, otherwise nothing.
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m4_define([m4_n],
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[m4_if([$1],
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[], [],
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[$1
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])])
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# m4_ifvaln(COND, [IF-TRUE], [IF-FALSE])
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# --------------------------------------
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# Same as `m4_ifval', but add an extra newline to IF-TRUE or IF-FALSE
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# unless that argument is empty.
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m4_define([m4_ifvaln],
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[m4_if([$1],
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[], [m4_n([$3])],
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[m4_n([$2])])])
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# m4_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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m4_define([m4_ifset],
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[m4_ifdef([$1],
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[m4_ifval(m4_defn([$1]), [$2], [$3])],
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[$3])])
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# m4_ifndef(NAME, [IF-NOT-DEFINED], [IF-DEFINED])
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# -----------------------------------------------
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m4_define([m4_ifndef],
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[m4_ifdef([$1], [$3], [$2])])
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# m4_case(SWITCH, VAL1, IF-VAL1, VAL2, IF-VAL2, ..., DEFAULT)
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# -----------------------------------------------------------
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# m4 equivalent of
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# switch (SWITCH)
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# {
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# case VAL1:
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# IF-VAL1;
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# break;
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# case VAL2:
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# IF-VAL2;
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# break;
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# ...
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# default:
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# DEFAULT;
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# break;
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# }.
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# All the values are optional, and the macro is robust to active
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# symbols properly quoted.
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m4_define([m4_case],
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[m4_if([$#], 0, [],
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[$#], 1, [],
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[$#], 2, [$2],
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[$1], [$2], [$3],
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[$0([$1], m4_shift3($@))])])
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# m4_bmatch(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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m4_define([m4_bmatch],
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[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])],
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[$#], 1, [m4_fatal([$0: too few arguments: $#: $1])],
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[$#], 2, [$2],
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[m4_if(m4_bregexp([$1], [$2]), -1, [$0([$1], m4_shift3($@))],
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[$3])])])
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# m4_car(LIST)
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# m4_cdr(LIST)
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# ------------
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# Manipulate m4 lists.
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m4_define([m4_car], [[$1]])
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m4_define([m4_cdr],
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[m4_if([$#], 0, [m4_fatal([$0: cannot be called without arguments])],
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[$#], 1, [],
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[m4_dquote(m4_shift($@))])])
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# m4_cond(TEST1, VAL1, IF-VAL1, TEST2, VAL2, IF-VAL2, ..., [DEFAULT])
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# -------------------------------------------------------------------
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# Similar to m4_if, except that each TEST is expanded when encountered.
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# If the expansion of TESTn matches the string VALn, the result is IF-VALn.
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# The result is DEFAULT if no tests passed. This macro allows
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# short-circuiting of expensive tests, where it pays to arrange quick
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# filter tests to run first.
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#
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# For an example, consider a previous implementation of _AS_QUOTE_IFELSE:
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#
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# m4_if(m4_index([$1], [\]), [-1], [$2],
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# m4_eval(m4_index([$1], [\\]) >= 0), [1], [$2],
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# m4_eval(m4_index([$1], [\$]) >= 0), [1], [$2],
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# m4_eval(m4_index([$1], [\`]) >= 0), [1], [$3],
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# m4_eval(m4_index([$1], [\"]) >= 0), [1], [$3],
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# [$2])
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#
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# Here, m4_index is computed 5 times, and m4_eval 4, even if $1 contains
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# no backslash. It is more efficient to do:
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#
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# m4_cond([m4_index([$1], [\])], [-1], [$2],
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# [m4_eval(m4_index([$1], [\\]) >= 0)], [1], [$2],
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# [m4_eval(m4_index([$1], [\$]) >= 0)], [1], [$2],
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# [m4_eval(m4_index([$1], [\`]) >= 0)], [1], [$3],
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# [m4_eval(m4_index([$1], [\"]) >= 0)], [1], [$3],
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# [$2])
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#
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# In the common case of $1 with no backslash, only one m4_index expansion
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# occurs, and m4_eval is avoided altogether.
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m4_define([m4_cond],
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[m4_if([$#], [0], [m4_fatal([$0: cannot be called without arguments])],
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[$#], [1], [$1],
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|
[$#], [2], [m4_fatal([$0: missing an argument])],
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[m4_if($1, [$2], [$3], [$0(m4_shift3($@))])])])
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# m4_map(MACRO, LIST)
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# -------------------
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# Invoke MACRO($1), MACRO($2) etc. where $1, $2... are the elements
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# of LIST (which can be lists themselves, for multiple arguments MACROs).
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m4_define([m4_fst], [$1])
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m4_define([m4_map],
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[m4_if([$2], [[]], [],
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[_m4_map([$1], [$2])])])
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m4_define([_m4_map],
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[m4_ifval([$2],
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[$1(m4_fst($2))[]_m4_map([$1], m4_cdr($2))])])
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|
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# m4_map_sep(MACRO, SEPARATOR, LIST)
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# ----------------------------------
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# Invoke MACRO($1), SEPARATOR, MACRO($2), ..., MACRO($N) where $1, $2... $N
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# are the elements of LIST (which can be lists themselves, for multiple
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# arguments MACROs).
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m4_define([m4_map_sep],
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[m4_if([$3], [[]], [],
|
|
[$1(m4_fst($3))[]_m4_map([$2[]$1], m4_cdr($3))])])
|
|
|
|
|
|
## ---------------------------------------- ##
|
|
## 6. Enhanced version of some primitives. ##
|
|
## ---------------------------------------- ##
|
|
|
|
# m4_bpatsubsts(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_bpatsubst', unfortunately,
|
|
# due to quotation problems, I need to double quote $1 below, therefore
|
|
# the anchors are broken :( I can't let users be trapped by that.
|
|
#
|
|
# Recall that m4_shift3 always results in an argument. Hence, we need
|
|
# to distinguish between a final deletion vs. ending recursion.
|
|
m4_define([m4_bpatsubsts],
|
|
[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])],
|
|
[$#], 1, [m4_fatal([$0: too few arguments: $#: $1])],
|
|
[$#], 2, [m4_builtin([patsubst], $@)],
|
|
[_$0($@m4_if(m4_eval($# & 1), 0, [,]))])])
|
|
m4_define([_m4_bpatsubsts],
|
|
[m4_if([$#], 2, [$1],
|
|
[$0(m4_builtin([patsubst], [[$1]], [$2], [$3]),
|
|
m4_shift3($@))])])
|
|
|
|
|
|
# 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.
|
|
#
|
|
# This macro is called on hot paths, so inline the contents of m4_ifval,
|
|
# for one less round of expansion.
|
|
m4_define([m4_default],
|
|
[m4_if([$1], [], [$2], [$1])])
|
|
|
|
|
|
# m4_defn(NAME)
|
|
# -------------
|
|
# Like the original, except don't tolerate popping something which is
|
|
# undefined, and only support one argument.
|
|
#
|
|
# This macro is called frequently, so minimize the amount of additional
|
|
# expansions by skipping m4_ifndef.
|
|
m4_define([m4_defn],
|
|
[m4_ifdef([$1], [],
|
|
[m4_fatal([$0: undefined macro: $1])])]dnl
|
|
[m4_builtin([defn], [$1])])
|
|
|
|
|
|
# _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)
|
|
# ---------------
|
|
# Like the original, except don't tolerate popping something which is
|
|
# undefined, and only support one argument.
|
|
#
|
|
# This macro is called frequently, so minimize the amount of additional
|
|
# expansions by skipping m4_ifndef.
|
|
m4_define([m4_popdef],
|
|
[m4_ifdef([$1], [],
|
|
[m4_fatal([$0: undefined macro: $1])])]dnl
|
|
[m4_builtin([popdef], [$1])])
|
|
|
|
|
|
# m4_shiftn(N, ...)
|
|
# -----------------
|
|
# Returns ... shifted N times. Useful for recursive "varargs" constructs.
|
|
m4_define([m4_shiftn],
|
|
[m4_assert(0 <= $1 && $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_shift2(...)
|
|
# m4_shift3(...)
|
|
# -----------------
|
|
# Returns ... shifted twice, and three times. Faster than m4_shiftn.
|
|
m4_define([m4_shift2], [m4_shift(m4_shift($@))])
|
|
m4_define([m4_shift3], [m4_shift(m4_shift(m4_shift($@)))])
|
|
|
|
# m4_undefine(NAME)
|
|
# -----------------
|
|
# Like the original, except don't tolerate undefining something which is
|
|
# undefined, and only support one argument.
|
|
#
|
|
# This macro is called frequently, so minimize the amount of additional
|
|
# expansions by skipping m4_ifndef.
|
|
m4_define([m4_undefine],
|
|
[m4_ifdef([$1], [],
|
|
[m4_fatal([$0: undefined macro: $1])])]dnl
|
|
[m4_builtin([undefine], [$1])])
|
|
|
|
|
|
## ------------------------- ##
|
|
## 7. Quoting manipulation. ##
|
|
## ------------------------- ##
|
|
|
|
# m4_do(STRING, ...)
|
|
# ------------------
|
|
# This macro invokes all its arguments (in sequence, of course). It is
|
|
# useful for making your macros more structured and readable by dropping
|
|
# unnecessary dnl's and have the macros indented properly.
|
|
m4_define([m4_do],
|
|
[m4_if([$#], 0, [],
|
|
[$#], 1, [$1],
|
|
[$1[]m4_do(m4_shift($@))])])
|
|
|
|
|
|
# m4_dquote(ARGS)
|
|
# ---------------
|
|
# Return ARGS as a quoted list of quoted arguments.
|
|
m4_define([m4_dquote], [[$@]])
|
|
|
|
|
|
# m4_ignore(ARGS)
|
|
# ---------------
|
|
# Expands to nothing. Useful for conditionally ignoring an arbitrary
|
|
# number of arguments (see _m4_list_cmp for an example).
|
|
m4_define([m4_ignore])
|
|
|
|
|
|
# m4_noquote(STRING)
|
|
# ------------------
|
|
# Return the result of ignoring all quotes in STRING and invoking the
|
|
# macros it contains. Amongst other things, this is useful for enabling
|
|
# macro invocations inside strings with [] blocks (for instance regexps
|
|
# and help-strings). On the other hand, since all quotes are disabled,
|
|
# any macro expanded during this time that relies on nested [] quoting
|
|
# will likely crash and burn. This macro is seldom useful; consider
|
|
# m4_unquote instead.
|
|
m4_define([m4_noquote],
|
|
[m4_changequote(-=<{,}>=-)$1-=<{}>=-m4_changequote([,])])
|
|
|
|
|
|
# m4_quote(ARGS)
|
|
# --------------
|
|
# Return ARGS as a single argument. Any whitespace after unquoted commas
|
|
# is stripped.
|
|
#
|
|
# It is important to realize the difference between `m4_quote(exp)' and
|
|
# `[exp]': in the first case you obtain the quoted *result* of the
|
|
# expansion of EXP, while in the latter you just obtain the string
|
|
# `exp'.
|
|
m4_define([m4_quote], [[$*]])
|
|
|
|
|
|
# m4_unquote(ARGS)
|
|
# ----------------
|
|
# Remove one layer of quotes from each ARG, performing one level of
|
|
# expansion. For one argument, m4_unquote([arg]) is more efficient than
|
|
# m4_do([arg]), but for multiple arguments, the difference is that
|
|
# m4_unquote separates arguments with commas while m4_do concatenates.
|
|
m4_define([m4_unquote], [$*])
|
|
|
|
|
|
## -------------------------- ##
|
|
## 8. Implementing m4 loops. ##
|
|
## -------------------------- ##
|
|
|
|
|
|
# m4_for(VARIABLE, FIRST, LAST, [STEP = +/-1], EXPRESSION)
|
|
# --------------------------------------------------------
|
|
# Expand EXPRESSION defining VARIABLE to FROM, FROM + 1, ..., TO with
|
|
# increments of STEP.
|
|
# Both limits are included, and bounds are checked for consistency.
|
|
# The algorithm is robust to indirect VARIABLE names, and uses m4_builtin
|
|
# to avoid some of the m4_defn overhead.
|
|
m4_define([m4_for],
|
|
[m4_pushdef([$1], m4_eval([$2]))dnl
|
|
m4_cond([m4_eval(([$3]) > m4_builtin([defn], [$1]))], 1,
|
|
[m4_pushdef([_m4_step], m4_eval(m4_default([$4], 1)))dnl
|
|
m4_assert(_m4_step > 0)dnl
|
|
_m4_for([$1], m4_eval((([$3]) - m4_builtin([defn], [$1]))
|
|
/ _m4_step * _m4_step + m4_builtin([defn], [$1])),
|
|
_m4_step, [$5])],
|
|
[m4_eval(([$3]) < m4_builtin([defn], [$1]))], 1,
|
|
[m4_pushdef([_m4_step], m4_eval(m4_default([$4], -1)))dnl
|
|
m4_assert(_m4_step < 0)dnl
|
|
_m4_for([$1], m4_eval((m4_builtin([defn], [$1]) - ([$3]))
|
|
/ -(_m4_step) * _m4_step + m4_builtin([defn], [$1])),
|
|
_m4_step, [$5])],
|
|
[m4_pushdef([_m4_step])dnl
|
|
$5])[]dnl
|
|
m4_popdef([_m4_step])dnl
|
|
m4_popdef([$1])])
|
|
|
|
|
|
# _m4_for(VARIABLE, LAST, STEP, EXPRESSION)
|
|
# -----------------------------------------
|
|
# Core of the loop, no consistency checks, all arguments are plain numbers.
|
|
m4_define([_m4_for],
|
|
[$4[]dnl
|
|
m4_if(m4_defn([$1]), [$2], [],
|
|
[m4_define([$1], m4_eval(m4_defn([$1])+[$3]))$0($@)])])
|
|
|
|
|
|
# Implementing `foreach' loops in m4 is much more tricky than it may
|
|
# seem. For example, the old M4 1.4.4 manual had an incorrect example,
|
|
# which looked like this (when translated to m4sugar):
|
|
#
|
|
# | # 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], (m4_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], [(m4_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], [m4_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 nice implementation
|
|
# that doesn't require extra parenthesis in the user's LIST.
|
|
#
|
|
# But wait - now the algorithm is quadratic, because every recursion of
|
|
# the algorithm keeps the entire LIST and merely adds another m4_shift to
|
|
# the quoted text. If the user has a lot of elements in LIST, you can
|
|
# bring the system to its knees with the memory m4 then requires, or trip
|
|
# the m4 --nesting-limit recursion factor. The only way to avoid
|
|
# quadratic growth is ensure m4_shift is expanded prior to the recursion.
|
|
# Hence the design below.
|
|
#
|
|
# The M4 manual now includes a chapter devoted to this issue, with
|
|
# the lessons learned from m4sugar.
|
|
|
|
|
|
# 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-
|
|
#
|
|
# This macro is called frequently, so avoid extra expansions such as
|
|
# m4_ifval and dnl.
|
|
m4_define([m4_foreach],
|
|
[m4_pushdef([$1])_$0($@)m4_popdef([$1])])
|
|
|
|
m4_define([_m4_foreach],
|
|
[m4_if([$2], [], [],
|
|
[m4_define([$1], m4_car($2))$3[]$0([$1], m4_cdr($2), [$3])])])
|
|
|
|
|
|
# m4_foreach_w(VARIABLE, LIST, EXPRESSION)
|
|
# ----------------------------------------
|
|
#
|
|
# Like m4_foreach, but the list is whitespace separated.
|
|
#
|
|
# This macro is robust to active symbols:
|
|
# m4_foreach_w([Var], [ active
|
|
# b act\
|
|
# ive ], [-Var-])end
|
|
# => -active--b--active-end
|
|
#
|
|
m4_define([m4_foreach_w],
|
|
[m4_foreach([$1], m4_split(m4_normalize([$2]), [ ]), [$3])])
|
|
|
|
|
|
|
|
## --------------------------- ##
|
|
## 9. More diversion support. ##
|
|
## --------------------------- ##
|
|
|
|
|
|
# _m4_divert(DIVERSION-NAME or NUMBER)
|
|
# ------------------------------------
|
|
# If DIVERSION-NAME is the name of a diversion, return its number,
|
|
# otherwise if it 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)
|
|
|
|
# The empty diversion name is a synonym for 0.
|
|
m4_define([_m4_divert()], 0)
|
|
|
|
|
|
# _m4_divert_n_stack
|
|
# ------------------
|
|
# Print m4_divert_stack with newline prepended, if it's nonempty.
|
|
m4_define([_m4_divert_n_stack],
|
|
[m4_ifdef([m4_divert_stack], [
|
|
m4_defn([m4_divert_stack])])])
|
|
|
|
|
|
# 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_divert_n_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_divert_n_stack)dnl
|
|
m4_pushdef([_m4_divert_diversion], [$1])dnl
|
|
m4_builtin([divert], _m4_divert([$1]))dnl
|
|
])
|
|
|
|
|
|
# m4_divert_pop([DIVERSION-NAME])
|
|
# -------------------------------
|
|
# Change the diversion stream to its previous value, unstacking it.
|
|
# If specified, verify we left DIVERSION-NAME.
|
|
# When we pop the last value from the stack, we divert to -1.
|
|
m4_define([m4_divert_pop],
|
|
[m4_ifndef([_m4_divert_diversion],
|
|
[m4_fatal([too many m4_divert_pop])])dnl
|
|
m4_if([$1], [], [],
|
|
[$1], m4_defn([_m4_divert_diversion]), [],
|
|
[m4_fatal([$0($1): diversion mismatch: ]_m4_divert_n_stack)])dnl
|
|
m4_popdef([m4_divert_stack])dnl
|
|
m4_popdef([_m4_divert_diversion])dnl
|
|
m4_builtin([divert],
|
|
m4_ifdef([_m4_divert_diversion],
|
|
[_m4_divert(m4_defn([_m4_divert_diversion]))],
|
|
-1))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 CONTENT into DIVERSION-NAME once, if not already there.
|
|
# 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. Unlike the M4 version, this only takes a single
|
|
# diversion identifier, and should not be used to undivert files.
|
|
m4_define([m4_undivert],
|
|
[m4_builtin([undivert], _m4_divert([$1]))])
|
|
|
|
|
|
## --------------------------------------------- ##
|
|
## 10. 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 Franc,ois
|
|
# Pinard), and (ii) expand the most recently m4_require'd macros _after_
|
|
# the previous macros (by Axel Thimm).
|
|
#
|
|
#
|
|
# The first idea: why use 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 levels 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, we use 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 macros are expanded. (The bug above can
|
|
# indeed be described as: a macro has been AC_PROVIDE'd before its
|
|
# dependent, but it is emitted after: the lack of correlation between
|
|
# emission and expansion order is guilty).
|
|
#
|
|
# How to do that? You keep 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 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
|
|
# are 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 _m4_divert_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
|
|
# _m4_require_call m4_divert_pushes another temporary diversion,
|
|
# GROW - 1, and expands TEST2a in there.
|
|
# DUMP: BODY
|
|
# BODY: empty
|
|
# GROW - 1: TEST2a
|
|
# diversions: GROW - 1, GROW, BODY |-
|
|
# Than the content of the temporary diversion is moved to DUMP and the
|
|
# temporary diversion is popped.
|
|
# DUMP: BODY
|
|
# BODY: TEST2a
|
|
# diversions: GROW, BODY |-
|
|
#
|
|
# * TEST1 requires TEST2b
|
|
# Again, _m4_require_call pushes GROW - 1 and heads to expand TEST2b.
|
|
# DUMP: BODY
|
|
# BODY: TEST2a
|
|
# diversions: GROW - 1, GROW, BODY |-
|
|
#
|
|
# * TEST2b requires TEST3
|
|
# _m4_require_call pushes GROW - 2 and expands TEST3 here.
|
|
# (TEST3 requires TEST2a, but TEST2a has already been m4_provide'd, so
|
|
# nothing happens.)
|
|
# DUMP: BODY
|
|
# BODY: TEST2a
|
|
# GROW - 2: TEST3
|
|
# diversions: GROW - 2, GROW - 1, GROW, BODY |-
|
|
# Than the diversion is appended to DUMP, and popped.
|
|
# DUMP: BODY
|
|
# BODY: TEST2a; TEST3
|
|
# diversions: GROW - 1, GROW, BODY |-
|
|
#
|
|
# * TEST1 requires TEST2b (contd.)
|
|
# The content of TEST2b is expanded...
|
|
# DUMP: BODY
|
|
# BODY: TEST2a; TEST3
|
|
# GROW - 1: TEST2b,
|
|
# diversions: GROW - 1, GROW, BODY |-
|
|
# ... and moved to DUMP.
|
|
# DUMP: BODY
|
|
# BODY: TEST2a; TEST3; TEST2b
|
|
# diversions: GROW, BODY |-
|
|
#
|
|
# * TEST1 is expanded: epilogue
|
|
# TEST1's own content is in GROW...
|
|
# DUMP: BODY
|
|
# BODY: TEST2a; TEST3; TEST2b
|
|
# GROW: TEST1
|
|
# diversions: BODY |-
|
|
# ... and it's epilogue moves it to DUMP and then 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 detect circular m4_require dependencies.
|
|
# Each time we expand a macro FOO we define _m4_expanding(FOO); and
|
|
# m4_require(BAR) simply checks whether _m4_expanding(BAR) is defined.
|
|
|
|
|
|
# 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
|
|
# ----------------------
|
|
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_ifndef([m4_expansion_stack], [_m4_defun_pro_outer[]])dnl
|
|
m4_expansion_stack_push(m4_defn([m4_location($1)])[: $1 is expanded from...])dnl
|
|
m4_pushdef([_m4_expanding($1)])dnl
|
|
])
|
|
|
|
m4_define([_m4_defun_pro_outer],
|
|
[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_popdef([_m4_expanding($1)])dnl
|
|
m4_expansion_stack_pop()dnl
|
|
m4_ifndef([m4_expansion_stack], [_m4_defun_epi_outer[]])dnl
|
|
m4_provide([$1])dnl
|
|
])
|
|
|
|
m4_define([_m4_defun_epi_outer],
|
|
[m4_undefine([_m4_divert_dump])dnl
|
|
m4_divert_pop([GROW])dnl
|
|
m4_undivert([GROW])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 forbidden extended regular
|
|
# expression ERE should be seen in the output unless...
|
|
m4_define([m4_pattern_forbid], [])
|
|
|
|
|
|
# m4_pattern_allow(ERE)
|
|
# ---------------------
|
|
# ... that token also matches the allowed extended regular expression ERE.
|
|
# Both used via traces.
|
|
m4_define([m4_pattern_allow], [])
|
|
|
|
|
|
## --------------------------------- ##
|
|
## 11. Dependencies between macros. ##
|
|
## --------------------------------- ##
|
|
|
|
|
|
# m4_before(THIS-MACRO-NAME, CALLED-MACRO-NAME)
|
|
# ---------------------------------------------
|
|
# Issue a warning if CALLED-MACRO-NAME was called before THIS-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_ifdef([_m4_expanding($1)],
|
|
[m4_fatal([$0: circular dependency of $1])])dnl
|
|
m4_ifndef([_m4_divert_dump],
|
|
[m4_fatal([$0($1): cannot be used outside of an ]dnl
|
|
m4_bmatch([$0], [^AC_], [[AC_DEFUN]], [[m4_defun]])['d macro])])dnl
|
|
m4_provide_if([$1],
|
|
[],
|
|
[_m4_require_call([$1], [$2])])dnl
|
|
])
|
|
|
|
|
|
# _m4_require_call(BODY-TO-EXPAND)
|
|
# --------------------------------
|
|
# If m4_require decides to expand the body, it calls this macro.
|
|
m4_define([_m4_require_call],
|
|
[m4_define([_m4_divert_grow], m4_decr(_m4_divert_grow))dnl
|
|
m4_divert_push(_m4_divert_grow)dnl
|
|
m4_default([$2], [$1])
|
|
m4_provide_if([$1],
|
|
[],
|
|
[m4_warn([syntax],
|
|
[$1 is m4_require'd but not m4_defun'd])])dnl
|
|
m4_divert(m4_defn([_m4_divert_dump]))dnl
|
|
m4_undivert(_m4_divert_grow)dnl
|
|
m4_divert_pop(_m4_divert_grow)dnl
|
|
m4_define([_m4_divert_grow], m4_incr(_m4_divert_grow))dnl
|
|
])
|
|
|
|
|
|
# _m4_divert_grow
|
|
# ---------------
|
|
# The counter for _m4_require_call.
|
|
m4_define([_m4_divert_grow], _m4_divert([GROW]))
|
|
|
|
|
|
# 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])])
|
|
|
|
|
|
## --------------------- ##
|
|
## 12. 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_alnum
|
|
# -----------
|
|
m4_define([m4_cr_alnum],
|
|
m4_defn([m4_cr_Letters])dnl
|
|
m4_defn([m4_cr_digits])dnl
|
|
)
|
|
|
|
|
|
# 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_cr_all
|
|
# ---------
|
|
# The character range representing everything, with `-' as the last
|
|
# character, since it is special to m4_translit. Use with care, because
|
|
# it contains characters special to M4 (fortunately, both ASCII and EBCDIC
|
|
# have [] in order, so m4_defn([m4_cr_all]) remains a valid string). It
|
|
# also contains characters special to terminals, so it should never be
|
|
# displayed in an error message. Also, attempts to map [ and ] to other
|
|
# characters via m4_translit must deal with the fact that m4_translit does
|
|
# not add quotes to the output.
|
|
#
|
|
# It is mainly useful in generating inverted character range maps, for use
|
|
# in places where m4_translit is faster than an equivalent m4_bpatsubst;
|
|
# the regex `[^a-z]' is equivalent to:
|
|
# m4_translit(m4_dquote(m4_defn([m4_cr_all])), [a-z])
|
|
m4_define([m4_cr_all],
|
|
m4_translit(m4_dquote(m4_format(m4_dquote(m4_for(
|
|
,1,255,,[[%c]]))m4_for([i],1,255,,[,i]))), [-])-)
|
|
|
|
|
|
# _m4_define_cr_not(CATEGORY)
|
|
# ---------------------------
|
|
# Define m4_cr_not_CATEGORY as the inverse of m4_cr_CATEGORY.
|
|
m4_define([_m4_define_cr_not],
|
|
[m4_define([m4_cr_not_$1],
|
|
m4_translit(m4_dquote(m4_defn([m4_cr_all])),
|
|
m4_defn([m4_cr_$1])))])
|
|
|
|
|
|
# m4_cr_not_letters
|
|
# m4_cr_not_LETTERS
|
|
# m4_cr_not_Letters
|
|
# m4_cr_not_digits
|
|
# m4_cr_not_alnum
|
|
# m4_cr_not_symbols1
|
|
# m4_cr_not_symbols2
|
|
# ------------------
|
|
# Inverse character sets
|
|
_m4_define_cr_not([letters])
|
|
_m4_define_cr_not([LETTERS])
|
|
_m4_define_cr_not([Letters])
|
|
_m4_define_cr_not([digits])
|
|
_m4_define_cr_not([alnum])
|
|
_m4_define_cr_not([symbols1])
|
|
_m4_define_cr_not([symbols2])
|
|
|
|
|
|
# m4_newline
|
|
# ----------
|
|
# Expands to a newline. Exists for formatting reasons.
|
|
m4_define([m4_newline], [
|
|
])
|
|
|
|
|
|
# m4_re_escape(STRING)
|
|
# --------------------
|
|
# Escape RE active characters in STRING.
|
|
m4_define([m4_re_escape],
|
|
[m4_bpatsubst([$1],
|
|
[[][*+.?\^$]], [\\\&])])
|
|
|
|
|
|
# m4_re_string
|
|
# ------------
|
|
# Regexp for `[a-zA-Z_0-9]*'
|
|
# m4_dquote provides literal [] for the character class.
|
|
m4_define([m4_re_string],
|
|
m4_dquote(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_dquote(m4_defn([m4_cr_symbols1]))dnl
|
|
m4_defn([m4_re_string])dnl
|
|
)
|
|
|
|
|
|
# m4_tolower(STRING)
|
|
# m4_toupper(STRING)
|
|
# ------------------
|
|
# These macros convert STRING to lowercase or uppercase.
|
|
#
|
|
# Rather than expand the m4_defn each time, we inline them up front.
|
|
m4_define([m4_tolower],
|
|
[m4_translit([$1], ]m4_dquote(m4_defn([m4_cr_LETTERS]))[,
|
|
]m4_dquote(m4_defn([m4_cr_letters]))[)])
|
|
m4_define([m4_toupper],
|
|
[m4_translit([$1], ]m4_dquote(m4_defn([m4_cr_letters]))[,
|
|
]m4_dquote(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 ]+.
|
|
#
|
|
# If STRING is empty, the result is an empty list.
|
|
#
|
|
# Pay attention to the m4_changequotes. When m4 reads the definition of
|
|
# m4_split, it still has quotes set to [ and ]. Luckily, these are matched
|
|
# in the macro body, so the definition is stored correctly. Use the same
|
|
# alternate quotes as m4_noquote; it must be unlikely to appear in $1.
|
|
#
|
|
# 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
|
|
#
|
|
# Optimize on regex of ` ' (space), since m4_foreach_w already guarantees
|
|
# that the list contains single space separators, and a common case is
|
|
# splitting a single-element list. This macro is called frequently,
|
|
# so avoid unnecessary dnl inside the definition.
|
|
m4_define([m4_split],
|
|
[m4_if([$1], [], [],
|
|
[$2], [ ], [m4_if(m4_index([$1], [ ]), [-1], [[[$1]]], [_$0($@)])],
|
|
[$2], [], [_$0([$1], [[ ]+])],
|
|
[_$0($@)])])
|
|
|
|
m4_define([_m4_split],
|
|
[m4_changequote(-=<{,}>=-)]dnl
|
|
[[m4_bpatsubst(-=<{-=<{$1}>=-}>=-, -=<{$2}>=-,
|
|
-=<{], [}>=-)]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
|
|
#
|
|
# In m4, m4_bpatsubst is expensive, so first check for a newline.
|
|
m4_define([m4_flatten],
|
|
[m4_if(m4_index([$1], [
|
|
]), [-1], [[$1]],
|
|
[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 <tab> <tab>active ])end
|
|
# => active activeend
|
|
#
|
|
# First, notice that we guarantee trailing space. Why? Because regular
|
|
# expressions are greedy, and `.* ?' would alway groups the space into the
|
|
# .* portion. The algorithm is simpler by avoiding `?' at the end. The
|
|
# algorithm correctly strips everything if STRING is just ` '.
|
|
#
|
|
# Then notice the second pattern: it is in charge of removing the
|
|
# leading/trailing spaces. Why not just `[^ ]'? Because they are
|
|
# applied to over-quoted strings, i.e. more or less [STRING], due
|
|
# to the limitations of m4_bpatsubsts. So the leading space in STRING
|
|
# is the *second* character; equally for the trailing space.
|
|
m4_define([m4_strip],
|
|
[m4_bpatsubsts([$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. Avoid back-to-back SEP when a given ARG
|
|
# is the empty string.
|
|
#
|
|
# Since the number of arguments to join can be arbitrarily long, we
|
|
# want to avoid having more than one $@ in the macro definition;
|
|
# otherwise, the expansion would require twice the memory of the already
|
|
# long list. Hence, m4_join merely looks for the first non-empty element,
|
|
# and outputs just that element; while _m4_join looks for all non-empty
|
|
# elements, and outputs them following a separator. The final trick to
|
|
# note is that we decide between recursing with $0 or _$0 based on the
|
|
# nested m4_if ending with `_'.
|
|
m4_define([m4_join],
|
|
[m4_if([$#], [1], [],
|
|
[$#], [2], [[$2]],
|
|
[m4_if([$2], [], [], [[$2]_])$0([$1], m4_shift2($@))])])
|
|
m4_define([_m4_join],
|
|
[m4_if([$#$2], [2], [],
|
|
[m4_if([$2], [], [], [[$1$2]])$0([$1], m4_shift2($@))])])
|
|
|
|
|
|
# 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'.
|
|
#
|
|
# Note that neither STRING nor SEPARATOR are expanded here; rather, when
|
|
# you expand MACRO-NAME, they will be expanded at that point in time.
|
|
#
|
|
# This macro is robust to active symbols. It can be used to grow
|
|
# strings.
|
|
#
|
|
# | m4_define(active, ACTIVE)dnl
|
|
# | m4_append([sentence], [This is an])dnl
|
|
# | m4_append([sentence], [ active ])dnl
|
|
# | m4_append([sentence], [symbol.])dnl
|
|
# | 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)dnl
|
|
# | m4_append([hooks], [m4_define([act1], [act2])])dnl
|
|
# | m4_append([hooks], [m4_define([act2], [active])])dnl
|
|
# | m4_undefine([active])dnl
|
|
# | act1
|
|
# | hooks
|
|
# | act1
|
|
# => act1
|
|
# =>
|
|
# => active
|
|
#
|
|
# It can also be used to create lists, although this particular usage was
|
|
# broken prior to autoconf 2.62.
|
|
# | m4_append([list], [one], [, ])dnl
|
|
# | m4_append([list], [two], [, ])dnl
|
|
# | m4_append([list], [three], [, ])dnl
|
|
# | list
|
|
# | m4_dquote(list)
|
|
# => one, two, three
|
|
# => [one],[two],[three]
|
|
#
|
|
# Use m4_builtin to avoid overhead of m4_defn.
|
|
m4_define([m4_append],
|
|
[m4_define([$1],
|
|
m4_ifdef([$1], [m4_builtin([defn], [$1])[$3]])[$2])])
|
|
|
|
|
|
# m4_append_uniq(MACRO-NAME, STRING, [SEPARATOR], [IF-UNIQ], [IF-DUP])
|
|
# --------------------------------------------------------------------
|
|
# Like `m4_append', but append only if not yet present. Additionally,
|
|
# expand IF-UNIQ if STRING was appended, or IF-DUP if STRING was already
|
|
# present.
|
|
m4_define([m4_append_uniq],
|
|
[m4_ifdef([$1],
|
|
[m4_if(m4_index([$3]m4_builtin([defn], [$1])[$3], [$3$2$3]), [-1],
|
|
[m4_append([$1], [$2], [$3])$4], [$5])],
|
|
[m4_append([$1], [$2], [$3])$4])])
|
|
|
|
|
|
# m4_text_wrap(STRING, [PREFIX], [FIRST-PREFIX], [WIDTH])
|
|
# -------------------------------------------------------
|
|
# Expands into STRING wrapped to hold in WIDTH columns (default = 79).
|
|
# If PREFIX is given, 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 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 of a line,
|
|
# which complicates it a bit. The algorithm is otherwise stupid and 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.
|
|
#
|
|
# The algorithm overquotes m4_Prefix1 to avoid m4_defn overhead, and bypasses
|
|
# m4_popdef overhead with m4_builtin since no user macro expansion occurs in
|
|
# the meantime.
|
|
m4_define([m4_text_wrap],
|
|
[m4_pushdef([m4_Prefix], [$2])dnl
|
|
m4_pushdef([m4_Prefix1], m4_dquote(m4_default([$3], [m4_Prefix])))dnl
|
|
m4_pushdef([m4_Width], m4_default([$4], 79))dnl
|
|
m4_pushdef([m4_Cursor], m4_qlen(m4_Prefix1))dnl
|
|
m4_pushdef([m4_Separator], [])dnl
|
|
m4_Prefix1[]dnl
|
|
m4_cond([m4_eval(m4_qlen(m4_Prefix1) > m4_len(m4_Prefix))],
|
|
[1], [m4_define([m4_Cursor], m4_len(m4_Prefix))
|
|
m4_Prefix],
|
|
[m4_eval(m4_qlen(m4_Prefix1) < m4_len(m4_Prefix))],
|
|
[0], [],
|
|
[m4_define([m4_Cursor], m4_len(m4_Prefix))[]dnl
|
|
m4_format([%*s],
|
|
m4_max([0], m4_eval(m4_len(m4_Prefix) - m4_qlen(m4_Prefix1))),
|
|
[])])[]dnl
|
|
m4_foreach_w([m4_Word], [$1],
|
|
[m4_define([m4_Cursor],
|
|
m4_eval(m4_Cursor + m4_qlen(m4_builtin([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_qlen(m4_builtin([defn], [m4_Word])) + 1))]
|
|
m4_Prefix,
|
|
[m4_Separator])[]dnl
|
|
m4_builtin([defn], [m4_Word])[]dnl
|
|
m4_define([m4_Separator], [ ])])dnl
|
|
m4_builtin([popdef], [m4_Separator])dnl
|
|
m4_builtin([popdef], [m4_Cursor])dnl
|
|
m4_builtin([popdef], [m4_Width])dnl
|
|
m4_builtin([popdef], [m4_Prefix1])dnl
|
|
m4_builtin([popdef], [m4_Prefix])dnl
|
|
])
|
|
|
|
|
|
# m4_text_box(MESSAGE, [FRAME-CHARACTER = `-'])
|
|
# ---------------------------------------------
|
|
# Turn MESSAGE into:
|
|
# ## ------- ##
|
|
# ## MESSAGE ##
|
|
# ## ------- ##
|
|
# using FRAME-CHARACTER in the border.
|
|
m4_define([m4_text_box],
|
|
[m4_pushdef([m4_Border],
|
|
m4_translit(m4_format([%*s], m4_qlen(m4_quote($1)), []),
|
|
[ ], m4_if([$2], [], [[-]], [[$2]])))dnl
|
|
@%:@@%:@ m4_Border @%:@@%:@
|
|
@%:@@%:@ $1 @%:@@%:@
|
|
@%:@@%:@ m4_Border @%:@@%:@dnl
|
|
m4_builtin([popdef], [m4_Border])dnl
|
|
])
|
|
|
|
|
|
# m4_qlen(STRING)
|
|
# ---------------
|
|
# Expands to the length of STRING after autom4te converts all quadrigraphs.
|
|
#
|
|
# Avoid bpatsubsts for the common case of no quadrigraphs.
|
|
m4_define([m4_qlen],
|
|
[m4_if(m4_index([$1], [@]), [-1], [m4_len([$1])],
|
|
[m4_len(m4_bpatsubsts([[$1]], [@\(<:\|:>\|S|\|%:\)@], [P], [@&t@]))])])
|
|
|
|
|
|
# m4_qdelta(STRING)
|
|
# -----------------
|
|
# Expands to the net change in the length of STRING from autom4te converting the
|
|
# quadrigraphs in STRING. This number is always negative or zero.
|
|
m4_define([m4_qdelta],
|
|
[m4_eval(m4_qlen([$1]) - m4_len([$1]))])
|
|
|
|
|
|
|
|
## ----------------------- ##
|
|
## 13. Number processing. ##
|
|
## ----------------------- ##
|
|
|
|
# m4_cmp(A, B)
|
|
# ------------
|
|
# Compare two integer expressions.
|
|
# A < B -> -1
|
|
# A = B -> 0
|
|
# A > B -> 1
|
|
m4_define([m4_cmp],
|
|
[m4_eval((([$1]) > ([$2])) - (([$1]) < ([$2])))])
|
|
|
|
|
|
# m4_list_cmp(A, B)
|
|
# -----------------
|
|
#
|
|
# Compare the two lists of integer expressions 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([xa], [oops])dnl
|
|
# m4_list_cmp([[0xa]], [5+5]) -> 0
|
|
#
|
|
# Rather than face the overhead of m4_case, we use a helper function whose
|
|
# expansion includes the name of the macro to invoke on the tail, either
|
|
# m4_ignore or m4_unquote. This is particularly useful when comparing
|
|
# long lists, since less text is being expanded to determine when to recurse.
|
|
m4_define([m4_list_cmp],
|
|
[m4_if([$1$2], [], 0,
|
|
[$1], [], [$0(0, [$2])],
|
|
[$2], [], [$0([$1], 0)],
|
|
[$1], [$2], 0,
|
|
[_$0(m4_cmp(m4_car($1), m4_car($2)))([$0(m4_cdr($1), m4_cdr($2))])])])
|
|
m4_define([_m4_list_cmp],
|
|
[m4_if([$1], 0, [m4_unquote], [$1m4_ignore])])
|
|
|
|
# m4_max(EXPR, ...)
|
|
# m4_min(EXPR, ...)
|
|
# -----------------
|
|
# Return the decimal value of the maximum (or minimum) in a series of
|
|
# integer expressions.
|
|
#
|
|
# M4 1.4.x doesn't provide ?:. Hence this huge m4_eval. Avoid m4_eval
|
|
# if both arguments are identical, but be aware of m4_max(0xa, 10) (hence
|
|
# the use of <=, not just <, in the second multiply).
|
|
m4_define([m4_max],
|
|
[m4_if([$#], [0], [m4_fatal([too few arguments to $0])],
|
|
[$#], [1], [m4_eval([$1])],
|
|
[$#$1], [2$2], [m4_eval([$1])],
|
|
[$#], [2],
|
|
[m4_eval((([$1]) > ([$2])) * ([$1]) + (([$1]) <= ([$2])) * ([$2]))],
|
|
[$0($0([$1], [$2]), m4_shift2($@))])])
|
|
m4_define([m4_min],
|
|
[m4_if([$#], [0], [m4_fatal([too few arguments to $0])],
|
|
[$#], [1], [m4_eval([$1])],
|
|
[$#$1], [2$2], [m4_eval([$1])],
|
|
[$#], [2],
|
|
[m4_eval((([$1]) < ([$2])) * ([$1]) + (([$1]) >= ([$2])) * ([$2]))],
|
|
[$0($0([$1], [$2]), m4_shift2($@))])])
|
|
|
|
|
|
# m4_sign(A)
|
|
# ----------
|
|
# The sign of the integer expression A.
|
|
m4_define([m4_sign],
|
|
[m4_eval((([$1]) > 0) - (([$1]) < 0))])
|
|
|
|
|
|
|
|
## ------------------------ ##
|
|
## 14. Version processing. ##
|
|
## ------------------------ ##
|
|
|
|
|
|
# m4_version_unletter(VERSION)
|
|
# ----------------------------
|
|
# Normalize beta version numbers with letters to numeric expressions, which
|
|
# can then be handed to m4_eval for the purpose of comparison.
|
|
#
|
|
# Nl -> (N+1).-1.(l#)
|
|
#
|
|
# for example:
|
|
# [2.14a] -> [2.14+1.-1.[0r36:a]] -> 2.15.-1.10
|
|
# [2.14b] -> [2.15+1.-1.[0r36:b]] -> 2.15.-1.11
|
|
# [2.61aa.b] -> [2.61+1.-1.[0r36:aa],+1.-1.[0r36:b]] -> 2.62.-1.370.1.-1.11
|
|
#
|
|
# This macro expects reasonable version numbers, but can handle double
|
|
# letters and does not expand one-letter macros. Inline constant expansions,
|
|
# to avoid m4_defn overhead. _m4_version_unletter is the real workhorse
|
|
# used by m4_version_compare, but since [0r36:a] is less readable than 10,
|
|
# we provide a wrapper for human use.
|
|
m4_define([m4_version_unletter],
|
|
[m4_map_sep([m4_eval], [.], _$0([$1]))])
|
|
m4_define([_m4_version_unletter],
|
|
[m4_translit(m4_bpatsubst([[[$1]]], ]dnl
|
|
m4_dquote(m4_dquote(m4_defn([m4_cr_Letters])))[[+],
|
|
[+1.-1.[0r36:\&]]),
|
|
[.], [,])])
|
|
|
|
|
|
# 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_version_unletter([$1]), _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_dquote(m4_defn([m4_PACKAGE_VERSION]))[, [$1]),
|
|
[-1],
|
|
[m4_default([$3],
|
|
[m4_fatal([Autoconf version $1 or higher is required],
|
|
[63])])],
|
|
[$2])])
|
|
|
|
|
|
|
|
## ------------------- ##
|
|
## 15. 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 than 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: $1])])])
|
|
|
|
|
|
|
|
## ------------------------ ##
|
|
## 16. Setting M4sugar up. ##
|
|
## ------------------------ ##
|
|
|
|
|
|
# m4_init
|
|
# -------
|
|
m4_define([m4_init],
|
|
[# All the M4sugar macros start with `m4_', except `dnl' kept as is
|
|
# for sake of simplicity.
|
|
m4_pattern_forbid([^_?m4_])
|
|
m4_pattern_forbid([^dnl$])
|
|
|
|
# _m4_divert_diversion should be defined:
|
|
m4_divert_push([KILL])
|
|
|
|
# Check the divert push/pop perfect balance.
|
|
m4_wrap([m4_divert_pop([])
|
|
m4_ifdef([_m4_divert_diversion],
|
|
[m4_fatal([$0: unbalanced m4_divert_push:]_m4_divert_n_stack)])[]])
|
|
])
|