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3309 lines
119 KiB
3309 lines
119 KiB
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) 1999-2017 Free Software Foundation, Inc.
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# This file is part of Autoconf. This program is free
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# software; you can redistribute it and/or modify it under the
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# terms of the GNU General Public License as published by the
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# 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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# Under Section 7 of GPL version 3, you are granted additional
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# permissions described in the Autoconf Configure Script Exception,
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# version 3.0, as published by the Free Software Foundation.
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#
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# You should have received a copy of the GNU General Public License
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# and a copy of the Autoconf Configure Script Exception along with
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# this program; see the files COPYINGv3 and COPYING.EXCEPTION
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# respectively. If not, see <https://www.gnu.org/licenses/>.
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# Written by Akim Demaille.
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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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#
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# This definition is in effect during m4sugar initialization, when
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# there are no pushdef stacks; later on, we redefine it to something
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# more powerful for all other clients to use.
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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'. Conditionals first, since
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# some subsequent renames are conditional.
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m4_rename_m4([ifdef])
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m4_rename([ifelse], [m4_if])
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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_ifdef([changeword],dnl conditionally available in 1.4.x
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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_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_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_undefine([m4wrap])
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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_rename_m4([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_ifdef([symbols],dnl present only in alpha-quality 1.4o
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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_defn(ARG)
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# -------------
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# _m4_defn is for internal use only - it bypasses the wrapper, so it
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# must only be used on one argument at a time, and only on macros
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# known to be defined. Make sure this still works if the user renames
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# m4_defn but not _m4_defn.
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m4_copy([m4_defn], [_m4_defn])
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# _m4_divert_raw(NUM)
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# -------------------
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# _m4_divert_raw is for internal use only. Use this instead of
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# m4_builtin([divert], NUM), so that tracing diversion flow is easier.
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m4_rename([divert], [_m4_divert_raw])
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# _m4_popdef(ARG...)
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# ------------------
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# _m4_popdef is for internal use only - it bypasses the wrapper, so it
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# must only be used on macros known to be defined. Make sure this
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# still works if the user renames m4_popdef but not _m4_popdef.
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m4_copy([m4_popdef], [_m4_popdef])
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# _m4_undefine(ARG...)
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# --------------------
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# _m4_undefine is for internal use only - it bypasses the wrapper, so
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# it must only be used on macros known to be defined. Make sure this
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# still works if the user renames m4_undefine but not _m4_undefine.
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m4_copy([m4_undefine], [_m4_undefine])
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# _m4_undivert(NUM...)
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# --------------------
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# _m4_undivert is for internal use only, and should always be given
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# arguments. Use this instead of m4_builtin([undivert], NUM...), so
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# that tracing diversion flow is easier.
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m4_rename([undivert], [_m4_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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# Output the current file, colon, and the current line number.
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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]
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m4_expansion_stack)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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# If present, STACK-TRACE is a \n-separated list of "LOCATION: MESSAGE",
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# where the last line (and no other) ends with "the top level".
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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], [m4_expansion_stack]))])
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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_ifblank(COND, [IF-BLANK], [IF-TEXT])
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# m4_ifnblank(COND, [IF-TEXT], [IF-BLANK])
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# ----------------------------------------
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# If COND is empty, or consists only of blanks (space, tab, newline),
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# then expand IF-BLANK, otherwise expand IF-TEXT. This differs from
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# m4_ifval only if COND has just whitespace, but it helps optimize in
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# spite of users who mistakenly leave trailing space after what they
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# thought was an empty argument:
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# macro(
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# []
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# )
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#
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# Writing one macro in terms of the other causes extra overhead, so
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# we inline both definitions.
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m4_define([m4_ifblank],
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[m4_if(m4_translit([[$1]], [ ][ ][
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]), [], [$2], [$3])])
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m4_define([m4_ifnblank],
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[m4_if(m4_translit([[$1]], [ ][ ][
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]), [], [$3], [$2])])
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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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|
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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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|
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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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|
|
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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], [$2])])
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|
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# m4_case(SWITCH, VAL1, IF-VAL1, VAL2, IF-VAL2, ..., DEFAULT)
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# -----------------------------------------------------------
|
|
# m4 equivalent of
|
|
# switch (SWITCH)
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# {
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|
# case VAL1:
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|
# IF-VAL1;
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# break;
|
|
# case VAL2:
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|
# IF-VAL2;
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# break;
|
|
# ...
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|
# default:
|
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# DEFAULT;
|
|
# break;
|
|
# }.
|
|
# All the values are optional, and the macro is robust to active
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|
# symbols properly quoted.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_case],
|
|
[m4_if([$#], 0, [],
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|
[$#], 1, [],
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[$#], 2, [$2],
|
|
[$1], [$2], [$3],
|
|
[$0([$1], m4_shift3($@))])])
|
|
|
|
|
|
# m4_bmatch(SWITCH, RE1, VAL1, RE2, VAL2, ..., DEFAULT)
|
|
# -----------------------------------------------------
|
|
# m4 equivalent of
|
|
#
|
|
# if (SWITCH =~ RE1)
|
|
# VAL1;
|
|
# elif (SWITCH =~ RE2)
|
|
# VAL2;
|
|
# elif ...
|
|
# ...
|
|
# else
|
|
# DEFAULT
|
|
#
|
|
# All the values are optional, and the macro is robust to active symbols
|
|
# properly quoted.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_bmatch],
|
|
[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])],
|
|
[$#], 1, [m4_fatal([$0: too few arguments: $#: $1])],
|
|
[$#], 2, [$2],
|
|
[m4_if(m4_bregexp([$1], [$2]), -1, [$0([$1], m4_shift3($@))],
|
|
[$3])])])
|
|
|
|
# m4_argn(N, ARGS...)
|
|
# -------------------
|
|
# Extract argument N (greater than 0) from ARGS. Example:
|
|
# m4_define([b], [B])
|
|
# m4_argn([2], [a], [b], [c]) => b
|
|
#
|
|
# Rather than using m4_car(m4_shiftn([$1], $@)), we exploit the fact that
|
|
# GNU m4 can directly reference any argument, through an indirect macro.
|
|
m4_define([m4_argn],
|
|
[m4_assert([0 < $1])]dnl
|
|
[m4_pushdef([_$0], [_m4_popdef([_$0])]m4_dquote([$]m4_incr([$1])))_$0($@)])
|
|
|
|
|
|
# m4_car(ARGS...)
|
|
# m4_cdr(ARGS...)
|
|
# ---------------
|
|
# Manipulate m4 lists. m4_car returns the first argument. m4_cdr
|
|
# bundles all but the first argument into a quoted list. These two
|
|
# macros are generally used with list arguments, with quoting removed
|
|
# to break the list into multiple m4 ARGS.
|
|
m4_define([m4_car], [[$1]])
|
|
m4_define([m4_cdr],
|
|
[m4_if([$#], 0, [m4_fatal([$0: cannot be called without arguments])],
|
|
[$#], 1, [],
|
|
[m4_dquote(m4_shift($@))])])
|
|
|
|
# _m4_cdr(ARGS...)
|
|
# ----------------
|
|
# Like m4_cdr, except include a leading comma unless only one argument
|
|
# remains. Why? Because comparing a large list against [] is more
|
|
# expensive in expansion time than comparing the number of arguments; so
|
|
# _m4_cdr can be used to reduce the number of arguments when it is time
|
|
# to end recursion.
|
|
m4_define([_m4_cdr],
|
|
[m4_if([$#], 1, [],
|
|
[, m4_dquote(m4_shift($@))])])
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|
|
|
|
|
|
# m4_cond(TEST1, VAL1, IF-VAL1, TEST2, VAL2, IF-VAL2, ..., [DEFAULT])
|
|
# -------------------------------------------------------------------
|
|
# Similar to m4_if, except that each TEST is expanded when encountered.
|
|
# If the expansion of TESTn matches the string VALn, the result is IF-VALn.
|
|
# The result is DEFAULT if no tests passed. This macro allows
|
|
# short-circuiting of expensive tests, where it pays to arrange quick
|
|
# filter tests to run first.
|
|
#
|
|
# For an example, consider a previous implementation of _AS_QUOTE_IFELSE:
|
|
#
|
|
# m4_if(m4_index([$1], [\]), [-1], [$2],
|
|
# m4_eval(m4_index([$1], [\\]) >= 0), [1], [$2],
|
|
# m4_eval(m4_index([$1], [\$]) >= 0), [1], [$2],
|
|
# m4_eval(m4_index([$1], [\`]) >= 0), [1], [$3],
|
|
# m4_eval(m4_index([$1], [\"]) >= 0), [1], [$3],
|
|
# [$2])
|
|
#
|
|
# Here, m4_index is computed 5 times, and m4_eval 4, even if $1 contains
|
|
# no backslash. It is more efficient to do:
|
|
#
|
|
# m4_cond([m4_index([$1], [\])], [-1], [$2],
|
|
# [m4_eval(m4_index([$1], [\\]) >= 0)], [1], [$2],
|
|
# [m4_eval(m4_index([$1], [\$]) >= 0)], [1], [$2],
|
|
# [m4_eval(m4_index([$1], [\`]) >= 0)], [1], [$3],
|
|
# [m4_eval(m4_index([$1], [\"]) >= 0)], [1], [$3],
|
|
# [$2])
|
|
#
|
|
# In the common case of $1 with no backslash, only one m4_index expansion
|
|
# occurs, and m4_eval is avoided altogether.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_cond],
|
|
[m4_if([$#], [0], [m4_fatal([$0: cannot be called without arguments])],
|
|
[$#], [1], [$1],
|
|
m4_eval([$# % 3]), [2], [m4_fatal([$0: missing an argument])],
|
|
[_$0($@)])])
|
|
|
|
m4_define([_m4_cond],
|
|
[m4_if(($1), [($2)], [$3],
|
|
[$#], [3], [],
|
|
[$#], [4], [$4],
|
|
[$0(m4_shift3($@))])])
|
|
|
|
|
|
## ---------------------------------------- ##
|
|
## 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 $1 below, therefore
|
|
# the anchors are broken :( I can't let users be trapped by that.
|
|
#
|
|
# Recall that m4_shift3 always results in an argument. Hence, we need
|
|
# to distinguish between a final deletion vs. ending recursion.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_bpatsubsts],
|
|
[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])],
|
|
[$#], 1, [m4_fatal([$0: too few arguments: $#: $1])],
|
|
[$#], 2, [m4_unquote(m4_builtin([patsubst], [[$1]], [$2]))],
|
|
[$#], 3, [m4_unquote(m4_builtin([patsubst], [[$1]], [$2], [$3]))],
|
|
[_$0($@m4_if(m4_eval($# & 1), 0, [,]))])])
|
|
m4_define([_m4_bpatsubsts],
|
|
[m4_if([$#], 2, [$1],
|
|
[$0(m4_builtin([patsubst], [[$1]], [$2], [$3]),
|
|
m4_shift3($@))])])
|
|
|
|
|
|
# m4_copy(SRC, DST)
|
|
# -----------------
|
|
# Define the pushdef stack DST as a copy of the pushdef stack SRC;
|
|
# give an error if DST is already defined. This is particularly nice
|
|
# for copying self-modifying pushdef stacks, where the top definition
|
|
# includes one-shot initialization that is later popped to the normal
|
|
# definition. This version intentionally does nothing if SRC is
|
|
# undefined.
|
|
#
|
|
# Some macros simply can't be renamed with this method: namely, anything
|
|
# involved in the implementation of m4_stack_foreach_sep.
|
|
m4_define([m4_copy],
|
|
[m4_ifdef([$2], [m4_fatal([$0: won't overwrite defined macro: $2])],
|
|
[m4_stack_foreach_sep([$1], [m4_pushdef([$2],], [)])])]dnl
|
|
[m4_ifdef([m4_location($1)], [m4_define([m4_location($2)], m4_location)])])
|
|
|
|
|
|
# m4_copy_force(SRC, DST)
|
|
# m4_rename_force(SRC, DST)
|
|
# -------------------------
|
|
# Like m4_copy/m4_rename, except blindly overwrite any existing DST.
|
|
# Note that m4_copy_force tolerates undefined SRC, while m4_rename_force
|
|
# does not.
|
|
m4_define([m4_copy_force],
|
|
[m4_ifdef([$2], [_m4_undefine([$2])])m4_copy($@)])
|
|
|
|
m4_define([m4_rename_force],
|
|
[m4_ifdef([$2], [_m4_undefine([$2])])m4_rename($@)])
|
|
|
|
|
|
# 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)
|
|
# m4_default_nblank(EXP1, EXP2)
|
|
# -----------------------------
|
|
# Returns EXP1 if not empty/blank, otherwise EXP2. Expand the result.
|
|
#
|
|
# m4_default 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_define([m4_default_nblank],
|
|
[m4_ifblank([$1], [$2], [$1])])
|
|
|
|
|
|
# m4_default_quoted(EXP1, EXP2)
|
|
# m4_default_nblank_quoted(EXP1, EXP2)
|
|
# ------------------------------------
|
|
# Returns EXP1 if non empty/blank, otherwise EXP2. Leave the result quoted.
|
|
#
|
|
# For comparison:
|
|
# m4_define([active], [ACTIVE])
|
|
# m4_default([active], [default]) => ACTIVE
|
|
# m4_default([], [active]) => ACTIVE
|
|
# -m4_default([ ], [active])- => - -
|
|
# -m4_default_nblank([ ], [active])- => -ACTIVE-
|
|
# m4_default_quoted([active], [default]) => active
|
|
# m4_default_quoted([], [active]) => active
|
|
# -m4_default_quoted([ ], [active])- => - -
|
|
# -m4_default_nblank_quoted([ ], [active])- => -active-
|
|
#
|
|
# m4_default macro is called on hot paths, so inline the contents of m4_ifval,
|
|
# for one less round of expansion.
|
|
m4_define([m4_default_quoted],
|
|
[m4_if([$1], [], [[$2]], [[$1]])])
|
|
|
|
m4_define([m4_default_nblank_quoted],
|
|
[m4_ifblank([$1], [[$2]], [[$1]])])
|
|
|
|
|
|
# m4_defn(NAME)
|
|
# -------------
|
|
# Like the original, except guarantee a warning when using something which is
|
|
# undefined (unlike M4 1.4.x). This replacement is not a full-featured
|
|
# replacement: if any of the defined macros contain unbalanced quoting, but
|
|
# when pasted together result in a well-quoted string, then only native m4
|
|
# support is able to get it correct. But that's where quadrigraphs come in
|
|
# handy, if you really need unbalanced quotes inside your macros.
|
|
#
|
|
# This macro is called frequently, so minimize the amount of additional
|
|
# expansions by skipping m4_ifndef. Better yet, if __m4_version__ exists,
|
|
# (added in M4 1.6), then let m4 do the job for us (see m4_init).
|
|
m4_define([m4_defn],
|
|
[m4_if([$#], [0], [[$0]],
|
|
[$#], [1], [m4_ifdef([$1], [_m4_defn([$1])],
|
|
[m4_fatal([$0: undefined macro: $1])])],
|
|
[m4_map_args([$0], $@)])])
|
|
|
|
|
|
# m4_dumpdef(NAME...)
|
|
# -------------------
|
|
# In m4 1.4.x, dumpdef writes to the current debugfile, rather than
|
|
# stderr. This in turn royally confuses autom4te; so we follow the
|
|
# lead of newer m4 and always dump to stderr. Unlike the original,
|
|
# this version requires an argument, since there is no convenient way
|
|
# in m4 1.4.x to grab the names of all defined macros. Newer m4
|
|
# always dumps to stderr, regardless of the current debugfile; it also
|
|
# provides m4symbols as a way to grab all current macro names. But
|
|
# dumpdefs is not frequently called, so we don't need to worry about
|
|
# conditionally using these newer features. Also, this version
|
|
# doesn't sort multiple arguments.
|
|
#
|
|
# If we detect m4 1.6 or newer, then provide an alternate definition,
|
|
# installed during m4_init, that allows builtins through.
|
|
# Unfortunately, there is no nice way in m4 1.4.x to dump builtins.
|
|
m4_define([m4_dumpdef],
|
|
[m4_if([$#], [0], [m4_fatal([$0: missing argument])],
|
|
[$#], [1], [m4_ifdef([$1], [m4_errprintn(
|
|
[$1: ]m4_dquote(_m4_defn([$1])))], [m4_fatal([$0: undefined macro: $1])])],
|
|
[m4_map_args([$0], $@)])])
|
|
|
|
m4_define([_m4_dumpdef],
|
|
[m4_if([$#], [0], [m4_fatal([$0: missing argument])],
|
|
[$#], [1], [m4_builtin([dumpdef], [$1])],
|
|
[m4_map_args_sep([m4_builtin([dumpdef],], [)], [], $@)])])
|
|
|
|
|
|
# m4_dumpdefs(NAME...)
|
|
# --------------------
|
|
# Similar to `m4_dumpdef(NAME)', but if NAME was m4_pushdef'ed, display its
|
|
# value stack (most recent displayed first). Also, this version silently
|
|
# ignores undefined macros, rather than erroring out.
|
|
#
|
|
# This macro cheats, because it relies on the current definition of NAME
|
|
# while the second argument of m4_stack_foreach_lifo is evaluated (which
|
|
# would be undefined according to the API).
|
|
m4_define([m4_dumpdefs],
|
|
[m4_if([$#], [0], [m4_fatal([$0: missing argument])],
|
|
[$#], [1], [m4_stack_foreach_lifo([$1], [m4_dumpdef([$1])m4_ignore])],
|
|
[m4_map_args([$0], $@)])])
|
|
|
|
# m4_esyscmd_s(COMMAND)
|
|
# ---------------------
|
|
# Like m4_esyscmd, except strip any trailing newlines, thus behaving
|
|
# more like shell command substitution.
|
|
m4_define([m4_esyscmd_s],
|
|
[m4_chomp_all(m4_esyscmd([$1]))])
|
|
|
|
|
|
# m4_popdef(NAME)
|
|
# ---------------
|
|
# Like the original, except guarantee a warning when using something which is
|
|
# undefined (unlike M4 1.4.x).
|
|
#
|
|
# This macro is called frequently, so minimize the amount of additional
|
|
# expansions by skipping m4_ifndef. Better yet, if __m4_version__ exists,
|
|
# (added in M4 1.6), then let m4 do the job for us (see m4_init).
|
|
m4_define([m4_popdef],
|
|
[m4_if([$#], [0], [[$0]],
|
|
[$#], [1], [m4_ifdef([$1], [_m4_popdef([$1])],
|
|
[m4_fatal([$0: undefined macro: $1])])],
|
|
[m4_map_args([$0], $@)])])
|
|
|
|
|
|
# m4_shiftn(N, ...)
|
|
# -----------------
|
|
# Returns ... shifted N times. Useful for recursive "varargs" constructs.
|
|
#
|
|
# Autoconf does not use this macro, because it is inherently slower than
|
|
# calling the common cases of m4_shift2 or m4_shift3 directly. But it
|
|
# might as well be fast for other clients, such as Libtool. One way to
|
|
# do this is to expand $@ only once in _m4_shiftn (otherwise, for long
|
|
# lists, the expansion of m4_if takes twice as much memory as what the
|
|
# list itself occupies, only to throw away the unused branch). The end
|
|
# result is strictly equivalent to
|
|
# m4_if([$1], 1, [m4_shift(,m4_shift(m4_shift($@)))],
|
|
# [_m4_shiftn(m4_decr([$1]), m4_shift(m4_shift($@)))])
|
|
# but with the final `m4_shift(m4_shift($@)))' shared between the two
|
|
# paths. The first leg uses a no-op m4_shift(,$@) to balance out the ().
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_shiftn],
|
|
[m4_assert(0 < $1 && $1 < $#)_$0($@)])
|
|
|
|
m4_define([_m4_shiftn],
|
|
[m4_if([$1], 1, [m4_shift(],
|
|
[$0(m4_decr([$1])]), m4_shift(m4_shift($@)))])
|
|
|
|
# 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_shift2(...)
|
|
# _m4_shift3(...)
|
|
# ---------------
|
|
# Like m4_shift2 or m4_shift3, except include a leading comma unless shifting
|
|
# consumes all arguments. Why? Because in recursion, it is nice to
|
|
# distinguish between 1 element left and 0 elements left, based on how many
|
|
# arguments this shift expands to.
|
|
m4_define([_m4_shift2],
|
|
[m4_if([$#], [2], [],
|
|
[, m4_shift(m4_shift($@))])])
|
|
m4_define([_m4_shift3],
|
|
[m4_if([$#], [3], [],
|
|
[, m4_shift(m4_shift(m4_shift($@)))])])
|
|
|
|
|
|
# m4_undefine(NAME)
|
|
# -----------------
|
|
# Like the original, except guarantee a warning when using something which is
|
|
# undefined (unlike M4 1.4.x).
|
|
#
|
|
# This macro is called frequently, so minimize the amount of additional
|
|
# expansions by skipping m4_ifndef. Better yet, if __m4_version__ exists,
|
|
# (added in M4 1.6), then let m4 do the job for us (see m4_init).
|
|
m4_define([m4_undefine],
|
|
[m4_if([$#], [0], [[$0]],
|
|
[$#], [1], [m4_ifdef([$1], [_m4_undefine([$1])],
|
|
[m4_fatal([$0: undefined macro: $1])])],
|
|
[m4_map_args([$0], $@)])])
|
|
|
|
# _m4_wrap(PRE, POST)
|
|
# -------------------
|
|
# Helper macro for m4_wrap and m4_wrap_lifo. Allows nested calls to
|
|
# m4_wrap within wrapped text. Use _m4_defn and _m4_popdef for speed.
|
|
m4_define([_m4_wrap],
|
|
[m4_ifdef([$0_text],
|
|
[m4_define([$0_text], [$1]_m4_defn([$0_text])[$2])],
|
|
[m4_builtin([m4wrap], [m4_unquote(
|
|
_m4_defn([$0_text])_m4_popdef([$0_text]))])m4_define([$0_text], [$1$2])])])
|
|
|
|
# m4_wrap(TEXT)
|
|
# -------------
|
|
# Append TEXT to the list of hooks to be executed at the end of input.
|
|
# Whereas the order of the original may be LIFO in the underlying m4,
|
|
# this version is always FIFO.
|
|
m4_define([m4_wrap],
|
|
[_m4_wrap([], [$1[]])])
|
|
|
|
# m4_wrap_lifo(TEXT)
|
|
# ------------------
|
|
# Prepend TEXT to the list of hooks to be executed at the end of input.
|
|
# Whereas the order of m4_wrap may be FIFO in the underlying m4, this
|
|
# version is always LIFO.
|
|
m4_define([m4_wrap_lifo],
|
|
[_m4_wrap([$1[]])])
|
|
|
|
## ------------------------- ##
|
|
## 7. Quoting manipulation. ##
|
|
## ------------------------- ##
|
|
|
|
|
|
# m4_apply(MACRO, LIST)
|
|
# ---------------------
|
|
# Invoke MACRO, with arguments provided from the quoted list of
|
|
# comma-separated quoted arguments. If LIST is empty, invoke MACRO
|
|
# without arguments. The expansion will not be concatenated with
|
|
# subsequent text.
|
|
m4_define([m4_apply],
|
|
[m4_if([$2], [], [$1], [$1($2)])[]])
|
|
|
|
# _m4_apply(MACRO, LIST)
|
|
# ----------------------
|
|
# Like m4_apply, except do nothing if LIST is empty.
|
|
m4_define([_m4_apply],
|
|
[m4_if([$2], [], [], [$1($2)[]])])
|
|
|
|
|
|
# m4_count(ARGS)
|
|
# --------------
|
|
# Return a count of how many ARGS are present.
|
|
m4_define([m4_count], [$#])
|
|
|
|
|
|
# m4_curry(MACRO, ARG...)
|
|
# -----------------------
|
|
# Perform argument currying. The expansion of this macro is another
|
|
# macro that takes exactly one argument, appends it to the end of the
|
|
# original ARG list, then invokes MACRO. For example:
|
|
# m4_curry([m4_curry], [m4_reverse], [1])([2])([3]) => 3, 2, 1
|
|
# Not quite as practical as m4_incr, but you could also do:
|
|
# m4_define([add], [m4_eval(([$1]) + ([$2]))])
|
|
# m4_define([add_one], [m4_curry([add], [1])])
|
|
# add_one()([2]) => 3
|
|
m4_define([m4_curry], [$1(m4_shift($@,)_$0])
|
|
m4_define([_m4_curry], [[$1])])
|
|
|
|
|
|
# m4_do(STRING, ...)
|
|
# ------------------
|
|
# This macro invokes all its arguments (in sequence, of course). It is
|
|
# useful for making your macros more structured and readable by dropping
|
|
# unnecessary dnl's and have the macros indented properly. No concatenation
|
|
# occurs after a STRING; use m4_unquote(m4_join(,STRING)) for that.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_do],
|
|
[m4_if([$#], 0, [],
|
|
[$#], 1, [$1[]],
|
|
[$1[]$0(m4_shift($@))])])
|
|
|
|
|
|
# m4_dquote(ARGS)
|
|
# ---------------
|
|
# Return ARGS as a quoted list of quoted arguments.
|
|
m4_define([m4_dquote], [[$@]])
|
|
|
|
|
|
# m4_dquote_elt(ARGS)
|
|
# -------------------
|
|
# Return ARGS as an unquoted list of double-quoted arguments.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_dquote_elt],
|
|
[m4_if([$#], [0], [],
|
|
[$#], [1], [[[$1]]],
|
|
[[[$1]],$0(m4_shift($@))])])
|
|
|
|
|
|
# m4_echo(ARGS)
|
|
# -------------
|
|
# Return the ARGS, with the same level of quoting. Whitespace after
|
|
# unquoted commas are consumed.
|
|
m4_define([m4_echo], [$@])
|
|
|
|
|
|
# m4_expand(ARG)
|
|
# _m4_expand(ARG)
|
|
# ---------------
|
|
# Return the expansion of ARG as a single string. Unlike
|
|
# m4_quote($1), this preserves whitespace following single-quoted
|
|
# commas that appear within ARG. It also deals with shell case
|
|
# statements.
|
|
#
|
|
# m4_define([active], [ACT, IVE])
|
|
# m4_define([active2], [[ACT, IVE]])
|
|
# m4_quote(active, active2)
|
|
# => ACT,IVE,ACT, IVE
|
|
# m4_expand([active, active2])
|
|
# => ACT, IVE, ACT, IVE
|
|
#
|
|
# Unfortunately, due to limitations in m4, ARG must expand to
|
|
# something with balanced quotes (use quadrigraphs to get around
|
|
# this), and should not contain the unlikely delimiters -=<{( or
|
|
# )}>=-. It is possible to have unbalanced quoted `(' or `)', as well
|
|
# as unbalanced unquoted `)'. m4_expand can handle unterminated
|
|
# comments or dnl on the final line, at the expense of speed; it also
|
|
# aids in detecting attempts to incorrectly change the current
|
|
# diversion inside ARG. Meanwhile, _m4_expand is faster but must be
|
|
# given a terminated expansion, and has no safety checks for
|
|
# mis-diverted text.
|
|
#
|
|
# Exploit that extra unquoted () will group unquoted commas and the
|
|
# following whitespace. m4_bpatsubst can't handle newlines inside $1,
|
|
# and m4_substr strips quoting. So we (ab)use m4_changequote, using
|
|
# temporary quotes to remove the delimiters that conveniently included
|
|
# the unquoted () that were added prior to the changequote.
|
|
#
|
|
# Thanks to shell case statements, too many people are prone to pass
|
|
# underquoted `)', so we try to detect that by passing a marker as a
|
|
# fourth argument; if the marker is not present, then we assume that
|
|
# we encountered an early `)', and re-expand the first argument, but
|
|
# this time with one more `(' in the second argument and in the
|
|
# open-quote delimiter. We must also ignore the slop from the
|
|
# previous try. The final macro is thus half line-noise, half art.
|
|
m4_define([m4_expand],
|
|
[m4_pushdef([m4_divert], _m4_defn([_m4_divert_unsafe]))]dnl
|
|
[m4_pushdef([m4_divert_push], _m4_defn([_m4_divert_unsafe]))]dnl
|
|
[m4_chomp(_$0([$1
|
|
]))_m4_popdef([m4_divert], [m4_divert_push])])
|
|
|
|
m4_define([_m4_expand], [$0_([$1], [(], -=<{($1)}>=-, [}>=-])])
|
|
|
|
m4_define([_m4_expand_],
|
|
[m4_if([$4], [}>=-],
|
|
[m4_changequote([-=<{$2], [)}>=-])$3m4_changequote([, ])],
|
|
[$0([$1], [($2], -=<{($2$1)}>=-, [}>=-])m4_ignore$2])])
|
|
|
|
|
|
# m4_ignore(ARGS)
|
|
# ---------------
|
|
# Expands to nothing. Useful for conditionally ignoring an arbitrary
|
|
# number of arguments (see _m4_list_cmp for an example).
|
|
m4_define([m4_ignore])
|
|
|
|
|
|
# m4_make_list(ARGS)
|
|
# ------------------
|
|
# Similar to m4_dquote, this creates a quoted list of quoted ARGS. This
|
|
# version is less efficient than m4_dquote, but separates each argument
|
|
# with a comma and newline, rather than just comma, for readability.
|
|
# When developing an m4sugar algorithm, you could temporarily use
|
|
# m4_pushdef([m4_dquote],m4_defn([m4_make_list]))
|
|
# around your code to make debugging easier.
|
|
m4_define([m4_make_list], [m4_join([,
|
|
], m4_dquote_elt($@))])
|
|
|
|
|
|
# m4_noquote(STRING)
|
|
# ------------------
|
|
# Return the result of ignoring all quotes in STRING and invoking the
|
|
# macros it contains. Among 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 or m4_expand instead.
|
|
m4_define([m4_noquote],
|
|
[m4_changequote([-=<{(],[)}>=-])$1-=<{()}>=-m4_changequote([,])])
|
|
|
|
|
|
# m4_quote(ARGS)
|
|
# --------------
|
|
# Return ARGS as a single argument. Any whitespace after unquoted commas
|
|
# is stripped. There is always output, even when there were no arguments.
|
|
#
|
|
# It is important to realize the difference between `m4_quote(exp)' and
|
|
# `[exp]': in the first case you obtain the quoted *result* of the
|
|
# expansion of EXP, while in the latter you just obtain the string
|
|
# `exp'.
|
|
m4_define([m4_quote], [[$*]])
|
|
|
|
|
|
# _m4_quote(ARGS)
|
|
# ---------------
|
|
# Like m4_quote, except that when there are no arguments, there is no
|
|
# output. For conditional scenarios (such as passing _m4_quote as the
|
|
# macro name in m4_mapall), this feature can be used to distinguish between
|
|
# one argument of the empty string vs. no arguments. However, in the
|
|
# normal case with arguments present, this is less efficient than m4_quote.
|
|
m4_define([_m4_quote],
|
|
[m4_if([$#], [0], [], [[$*]])])
|
|
|
|
|
|
# m4_reverse(ARGS)
|
|
# ----------------
|
|
# Output ARGS in reverse order.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_reverse],
|
|
[m4_if([$#], [0], [], [$#], [1], [[$1]],
|
|
[$0(m4_shift($@)), [$1]])])
|
|
|
|
|
|
# m4_unquote(ARGS)
|
|
# ----------------
|
|
# Remove one layer of quotes from each ARG, performing one level of
|
|
# expansion. For one argument, m4_unquote([arg]) is more efficient than
|
|
# m4_do([arg]), but for multiple arguments, the difference is that
|
|
# m4_unquote separates arguments with commas while m4_do concatenates.
|
|
# Follow this macro with [] if concatenation with subsequent text is
|
|
# undesired.
|
|
m4_define([m4_unquote], [$*])
|
|
|
|
|
|
## -------------------------- ##
|
|
## 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. Changing VARIABLE inside EXPRESSION will not impact
|
|
# the number of iterations.
|
|
#
|
|
# Uses _m4_defn for speed, and avoid dnl in the macro body. Factor
|
|
# the _m4_for call so that EXPRESSION is only parsed once.
|
|
m4_define([m4_for],
|
|
[m4_pushdef([$1], m4_eval([$2]))]dnl
|
|
[m4_cond([m4_eval(([$3]) > ([$2]))], 1,
|
|
[m4_pushdef([_m4_step], m4_eval(m4_default_quoted([$4],
|
|
1)))m4_assert(_m4_step > 0)_$0(_m4_defn([$1]),
|
|
m4_eval((([$3]) - ([$2])) / _m4_step * _m4_step + ([$2])), _m4_step,],
|
|
[m4_eval(([$3]) < ([$2]))], 1,
|
|
[m4_pushdef([_m4_step], m4_eval(m4_default_quoted([$4],
|
|
-1)))m4_assert(_m4_step < 0)_$0(_m4_defn([$1]),
|
|
m4_eval((([$2]) - ([$3])) / -(_m4_step) * _m4_step + ([$2])), _m4_step,],
|
|
[m4_pushdef([_m4_step])_$0(_m4_defn([$1]), _m4_defn([$1]), 0,])]dnl
|
|
[[m4_define([$1],], [)$5])m4_popdef([_m4_step], [$1])])
|
|
|
|
# _m4_for(COUNT, LAST, STEP, PRE, POST)
|
|
# -------------------------------------
|
|
# Core of the loop, no consistency checks, all arguments are plain
|
|
# numbers. Expand PRE[COUNT]POST, then alter COUNT by STEP and
|
|
# iterate if COUNT is not LAST.
|
|
m4_define([_m4_for],
|
|
[$4[$1]$5[]m4_if([$1], [$2], [],
|
|
[$0(m4_eval([$1 + $3]), [$2], [$3], [$4], [$5])])])
|
|
|
|
|
|
# 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 parentheses 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. And still, this design is only
|
|
# optimal for M4 1.6; see foreach.m4 for yet more comments on why
|
|
# M4 1.4.x uses yet another implementation.
|
|
|
|
|
|
# m4_foreach(VARIABLE, LIST, EXPRESSION)
|
|
# --------------------------------------
|
|
#
|
|
# Expand EXPRESSION assigning each value of the LIST to VARIABLE.
|
|
# LIST should have the form `item_1, item_2, ..., item_n', i.e. the
|
|
# whole list must *quoted*. Quote members too if you don't want them
|
|
# to be expanded.
|
|
#
|
|
# This macro is robust to active symbols:
|
|
# | m4_define(active, [ACT, IVE])
|
|
# | m4_foreach(Var, [active, active], [-Var-])
|
|
# => -ACT--IVE--ACT--IVE-
|
|
#
|
|
# | m4_foreach(Var, [[active], [active]], [-Var-])
|
|
# => -ACT, IVE--ACT, IVE-
|
|
#
|
|
# | m4_foreach(Var, [[[active]], [[active]]], [-Var-])
|
|
# => -active--active-
|
|
#
|
|
# This macro is called frequently, so avoid extra expansions such as
|
|
# m4_ifval and dnl. Also, since $2 might be quite large, try to use it
|
|
# as little as possible in _m4_foreach; each extra use requires that much
|
|
# more memory for expansion. So, rather than directly compare $2 against
|
|
# [] and use m4_car/m4_cdr for recursion, we instead unbox the list (which
|
|
# requires swapping the argument order in the helper), insert an ignored
|
|
# third argument, and use m4_shift3 to detect when recursion is complete,
|
|
# at which point this looks very much like m4_map_args.
|
|
m4_define([m4_foreach],
|
|
[m4_if([$2], [], [],
|
|
[m4_pushdef([$1])_$0([m4_define([$1],], [)$3], [],
|
|
$2)m4_popdef([$1])])])
|
|
|
|
# _m4_foreach(PRE, POST, IGNORED, ARG...)
|
|
# ---------------------------------------
|
|
# Form the common basis of the m4_foreach and m4_map macros. For each
|
|
# ARG, expand PRE[ARG]POST[]. The IGNORED argument makes recursion
|
|
# easier, and must be supplied rather than implicit.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([_m4_foreach],
|
|
[m4_if([$#], [3], [],
|
|
[$1[$4]$2[]$0([$1], [$2], m4_shift3($@))])])
|
|
|
|
|
|
# m4_foreach_w(VARIABLE, LIST, EXPRESSION)
|
|
# ----------------------------------------
|
|
# Like m4_foreach, but the list is whitespace separated. Depending on
|
|
# EXPRESSION, it may be more efficient to use m4_map_args_w.
|
|
#
|
|
# This macro is robust to active symbols:
|
|
# m4_foreach_w([Var], [ active
|
|
# b act\
|
|
# ive ], [-Var-])end
|
|
# => -active--b--active-end
|
|
#
|
|
# This used to use a slower implementation based on m4_foreach:
|
|
# m4_foreach([$1], m4_split(m4_normalize([$2]), [ ]), [$3])
|
|
m4_define([m4_foreach_w],
|
|
[m4_pushdef([$1])m4_map_args_w([$2],
|
|
[m4_define([$1],], [)$3])m4_popdef([$1])])
|
|
|
|
|
|
# m4_map(MACRO, LIST)
|
|
# m4_mapall(MACRO, LIST)
|
|
# ----------------------
|
|
# Invoke MACRO($1), MACRO($2) etc. where $1, $2... are the elements of
|
|
# LIST. $1, $2... must in turn be lists, appropriate for m4_apply.
|
|
# If LIST contains an empty sublist, m4_map skips the expansion of
|
|
# MACRO, while m4_mapall expands MACRO with no arguments.
|
|
#
|
|
# Since LIST may be quite large, we want to minimize how often it
|
|
# appears in the expansion. Rather than use m4_car/m4_cdr iteration,
|
|
# we unbox the list, and use _m4_foreach for iteration. For m4_map,
|
|
# an empty list behaves like an empty sublist and gets ignored; for
|
|
# m4_mapall, we must special-case the empty list.
|
|
m4_define([m4_map],
|
|
[_m4_foreach([_m4_apply([$1],], [)], [], $2)])
|
|
|
|
m4_define([m4_mapall],
|
|
[m4_if([$2], [], [],
|
|
[_m4_foreach([m4_apply([$1],], [)], [], $2)])])
|
|
|
|
|
|
# m4_map_sep(MACRO, [SEPARATOR], LIST)
|
|
# m4_mapall_sep(MACRO, [SEPARATOR], LIST)
|
|
# ---------------------------------------
|
|
# Invoke MACRO($1), SEPARATOR, MACRO($2), ..., MACRO($N) where $1,
|
|
# $2... $N are the elements of LIST, and are in turn lists appropriate
|
|
# for m4_apply. SEPARATOR is expanded, in order to allow the creation
|
|
# of a list of arguments by using a single-quoted comma as the
|
|
# separator. For each empty sublist, m4_map_sep skips the expansion
|
|
# of MACRO and SEPARATOR, while m4_mapall_sep expands MACRO with no
|
|
# arguments.
|
|
#
|
|
# For m4_mapall_sep, merely expand the first iteration without the
|
|
# separator, then include separator as part of subsequent recursion;
|
|
# but avoid extra expansion of LIST's side-effects via a helper macro.
|
|
# For m4_map_sep, things are trickier - we don't know if the first
|
|
# list element is an empty sublist, so we must define a self-modifying
|
|
# helper macro and use that as the separator instead.
|
|
m4_define([m4_map_sep],
|
|
[m4_pushdef([m4_Sep], [m4_define([m4_Sep], _m4_defn([m4_unquote]))])]dnl
|
|
[_m4_foreach([_m4_apply([m4_Sep([$2])[]$1],], [)], [], $3)m4_popdef([m4_Sep])])
|
|
|
|
m4_define([m4_mapall_sep],
|
|
[m4_if([$3], [], [], [_$0([$1], [$2], $3)])])
|
|
|
|
m4_define([_m4_mapall_sep],
|
|
[m4_apply([$1], [$3])_m4_foreach([m4_apply([$2[]$1],], [)], m4_shift2($@))])
|
|
|
|
# m4_map_args(EXPRESSION, ARG...)
|
|
# -------------------------------
|
|
# Expand EXPRESSION([ARG]) for each argument. More efficient than
|
|
# m4_foreach([var], [ARG...], [EXPRESSION(m4_defn([var]))])
|
|
# Shorthand for m4_map_args_sep([EXPRESSION(], [)], [], ARG...).
|
|
m4_define([m4_map_args],
|
|
[m4_if([$#], [0], [m4_fatal([$0: too few arguments: $#])],
|
|
[$#], [1], [],
|
|
[$#], [2], [$1([$2])[]],
|
|
[_m4_foreach([$1(], [)], $@)])])
|
|
|
|
|
|
# m4_map_args_pair(EXPRESSION, [END-EXPR = EXPRESSION], ARG...)
|
|
# -------------------------------------------------------------
|
|
# Perform a pairwise grouping of consecutive ARGs, by expanding
|
|
# EXPRESSION([ARG1], [ARG2]). If there are an odd number of ARGs, the
|
|
# final argument is expanded with END-EXPR([ARGn]).
|
|
#
|
|
# For example:
|
|
# m4_define([show], [($*)m4_newline])dnl
|
|
# m4_map_args_pair([show], [], [a], [b], [c], [d], [e])dnl
|
|
# => (a,b)
|
|
# => (c,d)
|
|
# => (e)
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_map_args_pair],
|
|
[m4_if([$#], [0], [m4_fatal([$0: too few arguments: $#])],
|
|
[$#], [1], [m4_fatal([$0: too few arguments: $#: $1])],
|
|
[$#], [2], [],
|
|
[$#], [3], [m4_default([$2], [$1])([$3])[]],
|
|
[$#], [4], [$1([$3], [$4])[]],
|
|
[$1([$3], [$4])[]$0([$1], [$2], m4_shift(m4_shift3($@)))])])
|
|
|
|
|
|
# m4_map_args_sep([PRE], [POST], [SEP], ARG...)
|
|
# ---------------------------------------------
|
|
# Expand PRE[ARG]POST for each argument, with SEP between arguments.
|
|
m4_define([m4_map_args_sep],
|
|
[m4_if([$#], [0], [m4_fatal([$0: too few arguments: $#])],
|
|
[$#], [1], [],
|
|
[$#], [2], [],
|
|
[$#], [3], [],
|
|
[$#], [4], [$1[$4]$2[]],
|
|
[$1[$4]$2[]_m4_foreach([$3[]$1], [$2], m4_shift3($@))])])
|
|
|
|
|
|
# m4_map_args_w(STRING, [PRE], [POST], [SEP])
|
|
# -------------------------------------------
|
|
# Perform the expansion of PRE[word]POST[] for each word in STRING
|
|
# separated by whitespace. More efficient than:
|
|
# m4_foreach_w([var], [STRING], [PRE[]m4_defn([var])POST])
|
|
# Additionally, expand SEP between words.
|
|
#
|
|
# As long as we have to use m4_bpatsubst to split the string, we might
|
|
# as well make it also apply PRE and POST; this avoids iteration
|
|
# altogether. But we must be careful of any \ in PRE or POST.
|
|
# _m4_strip returns a quoted string, but that's okay, since it also
|
|
# supplies an empty leading and trailing argument due to our
|
|
# intentional whitespace around STRING. We use m4_substr to strip the
|
|
# empty elements and remove the extra layer of quoting.
|
|
m4_define([m4_map_args_w],
|
|
[_$0(_m4_split([ ]m4_flatten([$1])[ ], [[ ]+],
|
|
m4_if(m4_index([$2$3$4], [\]), [-1], [[$3[]$4[]$2]],
|
|
[m4_bpatsubst([[$3[]$4[]$2]], [\\], [\\\\])])),
|
|
m4_len([[]$3[]$4]), m4_len([$4[]$2[]]))])
|
|
|
|
m4_define([_m4_map_args_w],
|
|
[m4_substr([$1], [$2], m4_eval(m4_len([$1]) - [$2] - [$3]))])
|
|
|
|
|
|
# m4_stack_foreach(MACRO, FUNC)
|
|
# m4_stack_foreach_lifo(MACRO, FUNC)
|
|
# ----------------------------------
|
|
# Pass each stacked definition of MACRO to the one-argument macro FUNC.
|
|
# m4_stack_foreach proceeds in FIFO order, while m4_stack_foreach_lifo
|
|
# processes the topmost definitions first. In addition, FUNC should
|
|
# not push or pop definitions of MACRO, and should not expect anything about
|
|
# the active definition of MACRO (it will not be the topmost, and may not
|
|
# be the one passed to FUNC either).
|
|
#
|
|
# Some macros simply can't be examined with this method: namely,
|
|
# anything involved in the implementation of _m4_stack_reverse.
|
|
m4_define([m4_stack_foreach],
|
|
[_m4_stack_reverse([$1], [m4_tmp-$1])]dnl
|
|
[_m4_stack_reverse([m4_tmp-$1], [$1], [$2(_m4_defn([m4_tmp-$1]))])])
|
|
|
|
m4_define([m4_stack_foreach_lifo],
|
|
[_m4_stack_reverse([$1], [m4_tmp-$1], [$2(_m4_defn([m4_tmp-$1]))])]dnl
|
|
[_m4_stack_reverse([m4_tmp-$1], [$1])])
|
|
|
|
# m4_stack_foreach_sep(MACRO, [PRE], [POST], [SEP])
|
|
# m4_stack_foreach_sep_lifo(MACRO, [PRE], [POST], [SEP])
|
|
# ------------------------------------------------------
|
|
# Similar to m4_stack_foreach and m4_stack_foreach_lifo, in that every
|
|
# definition of a pushdef stack will be visited. But rather than
|
|
# passing the definition as a single argument to a macro, this variant
|
|
# expands the concatenation of PRE[]definition[]POST, and expands SEP
|
|
# between consecutive expansions. Note that m4_stack_foreach([a], [b])
|
|
# is equivalent to m4_stack_foreach_sep([a], [b(], [)]).
|
|
m4_define([m4_stack_foreach_sep],
|
|
[_m4_stack_reverse([$1], [m4_tmp-$1])]dnl
|
|
[_m4_stack_reverse([m4_tmp-$1], [$1], [$2[]_m4_defn([m4_tmp-$1])$3], [$4[]])])
|
|
|
|
m4_define([m4_stack_foreach_sep_lifo],
|
|
[_m4_stack_reverse([$1], [m4_tmp-$1], [$2[]_m4_defn([m4_tmp-$1])$3], [$4[]])]dnl
|
|
[_m4_stack_reverse([m4_tmp-$1], [$1])])
|
|
|
|
|
|
# _m4_stack_reverse(OLD, NEW, [ACTION], [SEP])
|
|
# --------------------------------------------
|
|
# A recursive worker for pushdef stack manipulation. Destructively
|
|
# copy the OLD stack into the NEW, and expanding ACTION for each
|
|
# iteration. After the first iteration, SEP is promoted to the front
|
|
# of ACTION (note that SEP should include a trailing [] if it is to
|
|
# avoid interfering with ACTION). The current definition is examined
|
|
# after the NEW has been pushed but before OLD has been popped; this
|
|
# order is important, as ACTION is permitted to operate on either
|
|
# _m4_defn([OLD]) or _m4_defn([NEW]). Since the operation is
|
|
# destructive, this macro is generally used twice, with a temporary
|
|
# macro name holding the swapped copy.
|
|
m4_define([_m4_stack_reverse],
|
|
[m4_ifdef([$1], [m4_pushdef([$2],
|
|
_m4_defn([$1]))$3[]_m4_popdef([$1])$0([$1], [$2], [$4$3])])])
|
|
|
|
|
|
|
|
## --------------------------- ##
|
|
## 9. More diversion support. ##
|
|
## --------------------------- ##
|
|
|
|
|
|
# m4_cleardivert(DIVERSION-NAME...)
|
|
# ---------------------------------
|
|
# Discard any text in DIVERSION-NAME.
|
|
#
|
|
# This works even inside m4_expand.
|
|
m4_define([m4_cleardivert],
|
|
[m4_if([$#], [0], [m4_fatal([$0: missing argument])],
|
|
[_m4_divert_raw([-1])m4_undivert($@)_m4_divert_raw(
|
|
_m4_divert(_m4_defn([_m4_divert_diversion]), [-]))])])
|
|
|
|
|
|
# _m4_divert(DIVERSION-NAME or NUMBER, [NOWARN])
|
|
# ----------------------------------------------
|
|
# If DIVERSION-NAME is the name of a diversion, return its number,
|
|
# otherwise if it is a NUMBER return it. Issue a warning about
|
|
# the use of a number instead of a name, unless NOWARN is provided.
|
|
m4_define([_m4_divert],
|
|
[m4_ifdef([_m4_divert($1)],
|
|
[m4_indir([_m4_divert($1)])],
|
|
[m4_if([$2], [], [m4_warn([syntax],
|
|
[prefer named diversions])])$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_stack
|
|
# ---------------
|
|
# Print the diversion stack, if it's nonempty. The caller is
|
|
# responsible for any leading or trailing newline.
|
|
m4_define([m4_divert_stack],
|
|
[m4_stack_foreach_sep_lifo([_m4_divert_stack], [], [], [
|
|
])])
|
|
|
|
|
|
# m4_divert_stack_push(MACRO-NAME, DIVERSION-NAME)
|
|
# ------------------------------------------------
|
|
# Form an entry of the diversion stack from caller MACRO-NAME and
|
|
# entering DIVERSION-NAME and push it.
|
|
m4_define([m4_divert_stack_push],
|
|
[m4_pushdef([_m4_divert_stack], m4_location[: $1: $2])])
|
|
|
|
|
|
# m4_divert(DIVERSION-NAME)
|
|
# -------------------------
|
|
# Change the diversion stream to DIVERSION-NAME.
|
|
m4_define([m4_divert],
|
|
[m4_popdef([_m4_divert_stack])]dnl
|
|
[m4_define([_m4_divert_diversion], [$1])]dnl
|
|
[m4_divert_stack_push([$0], [$1])]dnl
|
|
[_m4_divert_raw(_m4_divert([$1]))])
|
|
|
|
|
|
# m4_divert_push(DIVERSION-NAME, [NOWARN])
|
|
# ----------------------------------------
|
|
# Change the diversion stream to DIVERSION-NAME, while stacking old values.
|
|
# For internal use only: if NOWARN is not empty, DIVERSION-NAME can be a
|
|
# number instead of a name.
|
|
m4_define([m4_divert_push],
|
|
[m4_divert_stack_push([$0], [$1])]dnl
|
|
[m4_pushdef([_m4_divert_diversion], [$1])]dnl
|
|
[_m4_divert_raw(_m4_divert([$1], [$2]))])
|
|
|
|
|
|
# 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_if([$1], [], [],
|
|
[$1], _m4_defn([_m4_divert_diversion]), [],
|
|
[m4_fatal([$0($1): diversion mismatch:
|
|
]m4_divert_stack)])]dnl
|
|
[_m4_popdef([_m4_divert_stack], [_m4_divert_diversion])]dnl
|
|
[m4_ifdef([_m4_divert_diversion], [],
|
|
[m4_fatal([too many m4_divert_pop])])]dnl
|
|
[_m4_divert_raw(_m4_divert(_m4_defn([_m4_divert_diversion]), [-]))])
|
|
|
|
|
|
# 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])$2
|
|
m4_divert_pop([$1])])
|
|
|
|
|
|
# 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_divert_unsafe(DIVERSION-NAME)
|
|
# ---------------------------------
|
|
# Issue a warning that the attempt to change the current diversion to
|
|
# DIVERSION-NAME is unsafe, because this macro is being expanded
|
|
# during argument collection of m4_expand.
|
|
m4_define([_m4_divert_unsafe],
|
|
[m4_fatal([$0: cannot change diversion to `$1' inside m4_expand])])
|
|
|
|
|
|
# m4_undivert(DIVERSION-NAME...)
|
|
# ------------------------------
|
|
# Undivert DIVERSION-NAME. Unlike the M4 version, this requires at
|
|
# least one DIVERSION-NAME; also, due to support for named diversions,
|
|
# this should not be used to undivert files.
|
|
m4_define([m4_undivert],
|
|
[m4_if([$#], [0], [m4_fatal([$0: missing argument])],
|
|
[$#], [1], [_m4_undivert(_m4_divert([$1]))],
|
|
[m4_map_args([$0], $@)])])
|
|
|
|
|
|
## --------------------------------------------- ##
|
|
## 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 calls m4_provide, 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 three ideas, (i) using diversions to
|
|
# prepare the expansion of the macro and its dependencies (by Franc,ois
|
|
# Pinard), (ii) expand the most recently m4_require'd macros _after_
|
|
# the previous macros (by Axel Thimm), and (iii) track instances of
|
|
# provide before require (by Eric Blake).
|
|
#
|
|
#
|
|
# 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...m4_require([TEST2])1])
|
|
# | m4_defun([TEST2], [Test...m4_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], [m4_require([TEST2a])m4_require([TEST2b])])
|
|
# | m4_defun([TEST2a], [])
|
|
# | m4_defun([TEST2b], [m4_require([TEST3])])
|
|
# | m4_defun([TEST3], [m4_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 m4_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 involved. 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 implementation 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 |-
|
|
# Then 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 |-
|
|
# Then 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 |-
|
|
#
|
|
#
|
|
# The third idea: track macros provided before they were required
|
|
# ---------------------------------------------------------------
|
|
#
|
|
# Using just the first two ideas, Autoconf 2.50 through 2.63 still had
|
|
# a subtle bug for more than seven years. Let's consider the
|
|
# following example to explain the bug:
|
|
#
|
|
# | m4_defun([TEST1], [1])
|
|
# | m4_defun([TEST2], [2[]m4_require([TEST1])])
|
|
# | m4_defun([TEST3], [3 TEST1 m4_require([TEST2])])
|
|
# | TEST3
|
|
#
|
|
# After the prologue of TEST3, we are collecting text in GROW with the
|
|
# intent of dumping it in BODY during the epilogue. Next, we
|
|
# encounter the direct invocation of TEST1, which provides the macro
|
|
# in place in GROW. From there, we encounter a requirement for TEST2,
|
|
# which must be collected in a new diversion. While expanding TEST2,
|
|
# we encounter a requirement for TEST1, but since it has already been
|
|
# expanded, the Axel Thimm algorithm states that we can treat it as a
|
|
# no-op. But that would lead to an end result of `2 3 1', meaning
|
|
# that we have once again output a macro (TEST2) prior to its
|
|
# requirements (TEST1).
|
|
#
|
|
# The problem can only occur if a single defun'd macro first provides,
|
|
# then later indirectly requires, the same macro. Note that directly
|
|
# expanding then requiring a macro is okay: because the dependency was
|
|
# met, the require phase can be a no-op. For that matter, the outer
|
|
# macro can even require two helpers, where the first helper expands
|
|
# the macro, and the second helper indirectly requires the macro.
|
|
# Out-of-order expansion is only present if the inner macro is
|
|
# required by something that will be hoisted in front of where the
|
|
# direct expansion occurred. In other words, we must be careful not
|
|
# to warn on:
|
|
#
|
|
# | m4_defun([TEST4], [4])
|
|
# | m4_defun([TEST5], [5 TEST4 m4_require([TEST4])])
|
|
# | TEST5 => 5 4
|
|
#
|
|
# or even the more complex:
|
|
#
|
|
# | m4_defun([TEST6], [6])
|
|
# | m4_defun([TEST7], [7 TEST6])
|
|
# | m4_defun([TEST8], [8 m4_require([TEST6])])
|
|
# | m4_defun([TEST9], [9 m4_require([TEST8])])
|
|
# | m4_defun([TEST10], [10 m4_require([TEST7]) m4_require([TEST9])])
|
|
# | TEST10 => 7 6 8 9 10
|
|
#
|
|
# So, to detect whether a require was direct or indirect, m4_defun and
|
|
# m4_require track the name of the macro that caused a diversion to be
|
|
# created (using the stack _m4_diverting, coupled with an O(1) lookup
|
|
# _m4_diverting([NAME])), and m4_provide stores the name associated
|
|
# with the diversion at which a macro was provided. A require call is
|
|
# direct if it occurs within the same diversion where the macro was
|
|
# provided, or if the diversion associated with the providing context
|
|
# has been collected.
|
|
#
|
|
# The implementation of the warning involves tracking the set of
|
|
# macros which have been provided since the start of the outermost
|
|
# defun'd macro (the set is named _m4_provide). When starting an
|
|
# outermost macro, the set is emptied; when a macro is provided, it is
|
|
# added to the set; when require expands the body of a macro, it is
|
|
# removed from the set; and when a macro is indirectly required, the
|
|
# set is checked. If a macro is in the set, then it has been provided
|
|
# before it was required, and we satisfy dependencies by expanding the
|
|
# macro as if it had never been provided; in the example given above,
|
|
# this means we now output `1 2 3 1'. Meanwhile, a warning is issued
|
|
# to inform the user that her macros trigger the bug in older autoconf
|
|
# versions, and that her output file now contains redundant contents
|
|
# (and possibly new problems, if the repeated macro was not
|
|
# idempotent). Meanwhile, macros defined by m4_defun_once instead of
|
|
# m4_defun are idempotent, avoiding any warning or duplicate output.
|
|
#
|
|
#
|
|
# 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.
|
|
#
|
|
# Each time we enter an m4_defun'd macros, we add a definition in
|
|
# _m4_expansion_stack, and when we exit the macro, we remove it (thanks
|
|
# to pushdef/popdef). m4_stack_foreach is used to print the expansion
|
|
# stack in the rare cases when it's needed.
|
|
#
|
|
# 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
|
|
# ------------------
|
|
# Expands to the entire contents of the expansion stack. The caller
|
|
# must supply a trailing newline. This macro always prints a
|
|
# location; check whether _m4_expansion_stack is defined to filter out
|
|
# the case when no defun'd macro is in force.
|
|
m4_define([m4_expansion_stack],
|
|
[m4_stack_foreach_sep_lifo([_$0], [_$0_entry(], [)
|
|
])m4_location[: the top level]])
|
|
|
|
# _m4_expansion_stack_entry(MACRO)
|
|
# --------------------------------
|
|
# Format an entry for MACRO found on the expansion stack.
|
|
m4_define([_m4_expansion_stack_entry],
|
|
[_m4_defn([m4_location($1)])[: $1 is expanded from...]])
|
|
|
|
# m4_expansion_stack_push(MACRO)
|
|
# ------------------------------
|
|
# Form an entry of the expansion stack on entry to MACRO and push it.
|
|
m4_define([m4_expansion_stack_push],
|
|
[m4_pushdef([_m4_expansion_stack], [$1])])
|
|
|
|
|
|
# _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.
|
|
#
|
|
# This is called frequently, so minimize the number of macro invocations
|
|
# by avoiding dnl and m4_defn overhead.
|
|
m4_define([_m4_defun_pro],
|
|
[m4_ifdef([_m4_expansion_stack], [], [_m4_defun_pro_outer([$1])])]dnl
|
|
[m4_expansion_stack_push([$1])m4_pushdef([_m4_expanding($1)])])
|
|
|
|
m4_define([_m4_defun_pro_outer],
|
|
[m4_set_delete([_m4_provide])]dnl
|
|
[m4_pushdef([_m4_diverting([$1])])m4_pushdef([_m4_diverting], [$1])]dnl
|
|
[m4_pushdef([_m4_divert_dump], m4_divnum)m4_divert_push([GROW])])
|
|
|
|
# _m4_defun_epi(MACRO-NAME)
|
|
# -------------------------
|
|
# The Epilogue for Autoconf macros. MACRO-NAME only helps tracing
|
|
# the PRO/EPI pairs.
|
|
#
|
|
# This is called frequently, so minimize the number of macro invocations
|
|
# by avoiding dnl and m4_popdef overhead.
|
|
m4_define([_m4_defun_epi],
|
|
[_m4_popdef([_m4_expanding($1)], [_m4_expansion_stack])]dnl
|
|
[m4_ifdef([_m4_expansion_stack], [], [_m4_defun_epi_outer([$1])])]dnl
|
|
[m4_provide([$1])])
|
|
|
|
m4_define([_m4_defun_epi_outer],
|
|
[_m4_popdef([_m4_divert_dump], [_m4_diverting([$1])], [_m4_diverting])]dnl
|
|
[m4_divert_pop([GROW])m4_undivert([GROW])])
|
|
|
|
|
|
# _m4_divert_dump
|
|
# ---------------
|
|
# If blank, we are outside of any defun'd macro. Otherwise, expands
|
|
# to the diversion number (not name) where require'd macros should be
|
|
# moved once completed.
|
|
m4_define([_m4_divert_dump])
|
|
|
|
|
|
# m4_divert_require(DIVERSION, NAME-TO-CHECK, [BODY-TO-EXPAND])
|
|
# -------------------------------------------------------------
|
|
# Same as m4_require, but BODY-TO-EXPAND goes into the named DIVERSION;
|
|
# requirements still go in the current diversion though.
|
|
#
|
|
m4_define([m4_divert_require],
|
|
[m4_ifdef([_m4_expanding($2)],
|
|
[m4_fatal([$0: circular dependency of $2])])]dnl
|
|
[m4_if(_m4_divert_dump, [],
|
|
[m4_fatal([$0($2): cannot be used outside of an m4_defun'd macro])])]dnl
|
|
[m4_provide_if([$2], [],
|
|
[_m4_require_call([$2], [$3], _m4_divert([$1], [-]))])])
|
|
|
|
|
|
# m4_defun(NAME, EXPANSION, [MACRO = m4_define])
|
|
# ----------------------------------------------
|
|
# Define a macro NAME which automatically provides itself. Add
|
|
# machinery so the macro automatically switches expansion to the
|
|
# diversion stack if it is not already using it, prior to EXPANSION.
|
|
# 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.
|
|
#
|
|
# MACRO is an undocumented argument; when set to m4_pushdef, and NAME
|
|
# is already defined, the new definition is added to the pushdef
|
|
# stack, rather than overwriting the current definition. It can thus
|
|
# be used to write self-modifying macros, which pop themselves to a
|
|
# previously m4_define'd definition so that subsequent use of the
|
|
# macro is faster.
|
|
m4_define([m4_defun],
|
|
[m4_define([m4_location($1)], m4_location)]dnl
|
|
[m4_default([$3], [m4_define])([$1],
|
|
[_m4_defun_pro(]m4_dquote($[0])[)$2[]_m4_defun_epi(]m4_dquote($[0])[)])])
|
|
|
|
|
|
# m4_defun_init(NAME, INIT, COMMON)
|
|
# ---------------------------------
|
|
# Like m4_defun, but split EXPANSION into two portions: INIT which is
|
|
# done only the first time NAME is invoked, and COMMON which is
|
|
# expanded every time.
|
|
#
|
|
# For now, the COMMON definition is always m4_define'd, giving an even
|
|
# lighter-weight definition. m4_defun allows self-providing, but once
|
|
# a macro is provided, m4_require no longer cares if it is m4_define'd
|
|
# or m4_defun'd. m4_defun also provides location tracking to identify
|
|
# dependency bugs, but once the INIT has been expanded, we know there
|
|
# are no dependency bugs. However, if a future use needs COMMON to be
|
|
# m4_defun'd, we can add a parameter, similar to the third parameter
|
|
# to m4_defun.
|
|
m4_define([m4_defun_init],
|
|
[m4_define([$1], [$3[]])m4_defun([$1],
|
|
[$2[]_m4_popdef(]m4_dquote($[0])[)m4_indir(]m4_dquote($[0])dnl
|
|
[m4_if(]m4_dquote($[#])[, [0], [], ]m4_dquote([,$]@)[))], [m4_pushdef])])
|
|
|
|
|
|
# m4_defun_once(NAME, EXPANSION)
|
|
# ------------------------------
|
|
# Like m4_defun, but guarantee that EXPANSION only happens once
|
|
# (thereafter, using NAME is a no-op).
|
|
#
|
|
# If _m4_divert_dump is empty, we are called at the top level;
|
|
# otherwise, we must ensure that we are required in front of the
|
|
# current defun'd macro. Use a helper macro so that EXPANSION need
|
|
# only occur once in the definition of NAME, since it might be large.
|
|
m4_define([m4_defun_once],
|
|
[m4_define([m4_location($1)], m4_location)]dnl
|
|
[m4_define([$1], [_m4_defun_once([$1], [$2], m4_if(_m4_divert_dump, [],
|
|
[[_m4_defun_pro([$1])m4_unquote(], [)_m4_defun_epi([$1])]],
|
|
m4_ifdef([_m4_diverting([$1])], [-]), [-], [[m4_unquote(], [)]],
|
|
[[_m4_require_call([$1],], [, _m4_divert_dump)]]))])])
|
|
|
|
m4_define([_m4_defun_once],
|
|
[m4_pushdef([$1])$3[$2[]m4_provide([$1])]$4])
|
|
|
|
|
|
# m4_pattern_forbid(ERE, [WHY])
|
|
# -----------------------------
|
|
# Declare that no token matching the forbidden perl 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, by autom4te post-processing.
|
|
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; follow the expansion with a newline. 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(threads.h)], [AC_CHECK_HEADERS(threads.h)])
|
|
# which is just the same as
|
|
# m4_require([AC_PROG_CC])
|
|
# m4_require([AC_CHECK_HEADERS(threads.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)'.
|
|
#
|
|
# This is called frequently, so minimize the number of macro invocations
|
|
# by avoiding dnl and other overhead on the common path.
|
|
m4_define([m4_require],
|
|
[m4_ifdef([_m4_expanding($1)],
|
|
[m4_fatal([$0: circular dependency of $1])])]dnl
|
|
[m4_if(_m4_divert_dump, [],
|
|
[m4_fatal([$0($1): cannot be used outside of an ]dnl
|
|
m4_if([$0], [m4_require], [[m4_defun]], [[AC_DEFUN]])['d macro])])]dnl
|
|
[m4_provide_if([$1], [m4_set_contains([_m4_provide], [$1],
|
|
[_m4_require_check([$1], _m4_defn([m4_provide($1)]), [$0])], [m4_ignore])],
|
|
[_m4_require_call])([$1], [$2], _m4_divert_dump)])
|
|
|
|
|
|
# _m4_require_call(NAME-TO-CHECK, [BODY-TO-EXPAND = NAME-TO-CHECK],
|
|
# DIVERSION-NUMBER)
|
|
# -----------------------------------------------------------------
|
|
# If m4_require decides to expand the body, it calls this macro. The
|
|
# expansion is placed in DIVERSION-NUMBER.
|
|
#
|
|
# This is called frequently, so minimize the number of macro invocations
|
|
# by avoiding dnl and other overhead on the common path.
|
|
# The use of a witness macro protecting the warning allows aclocal
|
|
# to silence any warnings when probing for what macros are required
|
|
# and must therefore be located, when using the Autoconf-without-aclocal-m4
|
|
# autom4te language. For more background, see:
|
|
# https://lists.gnu.org/archive/html/automake-patches/2012-11/msg00035.html
|
|
m4_define([_m4_require_call],
|
|
[m4_pushdef([_m4_divert_grow], m4_decr(_m4_divert_grow))]dnl
|
|
[m4_pushdef([_m4_diverting([$1])])m4_pushdef([_m4_diverting], [$1])]dnl
|
|
[m4_divert_push(_m4_divert_grow, [-])]dnl
|
|
[m4_if([$2], [], [$1], [$2])
|
|
m4_provide_if([$1], [m4_set_remove([_m4_provide], [$1])],
|
|
[m4_ifndef([m4_require_silent_probe],
|
|
[m4_warn([syntax], [$1 is m4_require'd but not m4_defun'd])])])]dnl
|
|
[_m4_divert_raw($3)_m4_undivert(_m4_divert_grow)]dnl
|
|
[m4_divert_pop(_m4_divert_grow)_m4_popdef([_m4_divert_grow],
|
|
[_m4_diverting([$1])], [_m4_diverting])])
|
|
|
|
|
|
# _m4_require_check(NAME-TO-CHECK, OWNER, CALLER)
|
|
# -----------------------------------------------
|
|
# NAME-TO-CHECK has been identified as previously expanded in the
|
|
# diversion owned by OWNER. If this is a problem, warn on behalf of
|
|
# CALLER and return _m4_require_call; otherwise return m4_ignore.
|
|
m4_define([_m4_require_check],
|
|
[m4_if(_m4_defn([_m4_diverting]), [$2], [m4_ignore],
|
|
m4_ifdef([_m4_diverting([$2])], [-]), [-], [m4_warn([syntax],
|
|
[$3: `$1' was expanded before it was required
|
|
https://www.gnu.org/software/autoconf/manual/autoconf.html#Expanded-Before-Required])_m4_require_call],
|
|
[m4_ignore])])
|
|
|
|
|
|
# _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_default_quoted([$2], [$1]),
|
|
[],
|
|
[m4_provide(m4_default_quoted([$2], [$1]))[]$1])])
|
|
|
|
|
|
# m4_provide(MACRO-NAME)
|
|
# ----------------------
|
|
m4_define([m4_provide],
|
|
[m4_ifdef([m4_provide($1)], [],
|
|
[m4_set_add([_m4_provide], [$1], [m4_define([m4_provide($1)],
|
|
m4_ifdef([_m4_diverting], [_m4_defn([_m4_diverting])]))])])])
|
|
|
|
|
|
# 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.
|
|
#
|
|
# In EBCDIC, $ is immediately followed by *, which leads to problems
|
|
# if m4_cr_all is inlined into a macro definition; so swap them.
|
|
#
|
|
# 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([STRING])
|
|
# --------------------
|
|
# Expands to a newline, possibly followed by STRING. Exists mostly for
|
|
# formatting reasons.
|
|
m4_define([m4_newline], [
|
|
$1])
|
|
|
|
|
|
# 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([$1], [$2], [, ])])],
|
|
[$2], [], [_$0([$1], [[ ]+], [, ])],
|
|
[_$0([$1], [$2], [, ])])])
|
|
|
|
m4_define([_m4_split],
|
|
[m4_changequote([-=<{(],[)}>=-])]dnl
|
|
[[m4_bpatsubst(-=<{(-=<{($1)}>=-)}>=-, -=<{($2)}>=-,
|
|
-=<{(]$3[)}>=-)]m4_changequote([, ])])
|
|
|
|
|
|
# m4_chomp(STRING)
|
|
# m4_chomp_all(STRING)
|
|
# --------------------
|
|
# Return STRING quoted, but without a trailing newline. m4_chomp
|
|
# removes at most one newline, while m4_chomp_all removes all
|
|
# consecutive trailing newlines. Embedded newlines are not touched,
|
|
# and a trailing backslash-newline leaves just a trailing backslash.
|
|
#
|
|
# m4_bregexp is slower than m4_index, and we don't always want to
|
|
# remove all newlines; hence the two variants. We massage characters
|
|
# to give a nicer pattern to match, particularly since m4_bregexp is
|
|
# line-oriented. Both versions must guarantee a match, to avoid bugs
|
|
# with precision -1 in m4_format in older m4.
|
|
m4_define([m4_chomp],
|
|
[m4_format([[%.*s]], m4_index(m4_translit([[$1]], [
|
|
/.], [/ ])[./.], [/.]), [$1])])
|
|
|
|
m4_define([m4_chomp_all],
|
|
[m4_format([[%.*s]], m4_bregexp(m4_translit([[$1]], [
|
|
/], [/ ]), [/*$]), [$1])])
|
|
|
|
|
|
# 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 always group 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. No expansion is performed on SEP or ARGs.
|
|
#
|
|
# 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 _$0 based on the
|
|
# nested m4_if ending with `_'.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_join],
|
|
[m4_if([$#], [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_joinall(SEP, ARG1, ARG2...)
|
|
# ------------------------------
|
|
# Produce ARG1SEPARG2...SEPARGn. An empty ARG results in back-to-back SEP.
|
|
# No expansion is performed on SEP or ARGs.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_joinall], [[$2]_$0([$1], m4_shift($@))])
|
|
m4_define([_m4_joinall],
|
|
[m4_if([$#], [2], [], [[$1$3]$0([$1], m4_shift2($@))])])
|
|
|
|
# m4_combine([SEPARATOR], PREFIX-LIST, [INFIX], SUFFIX...)
|
|
# --------------------------------------------------------
|
|
# Produce the pairwise combination of every element in the quoted,
|
|
# comma-separated PREFIX-LIST with every element from the SUFFIX arguments.
|
|
# Each pair is joined with INFIX, and pairs are separated by SEPARATOR.
|
|
# No expansion occurs on SEPARATOR, INFIX, or elements of either list.
|
|
#
|
|
# For example:
|
|
# m4_combine([, ], [[a], [b], [c]], [-], [1], [2], [3])
|
|
# => a-1, a-2, a-3, b-1, b-2, b-3, c-1, c-2, c-3
|
|
#
|
|
# This definition is a bit hairy; the thing to realize is that we want
|
|
# to construct m4_map_args_sep([[prefix$3]], [], [[$1]], m4_shift3($@))
|
|
# as the inner loop, using each prefix generated by the outer loop,
|
|
# and without recalculating m4_shift3 every outer iteration.
|
|
m4_define([m4_combine],
|
|
[m4_if([$2], [], [], m4_eval([$# > 3]), [1],
|
|
[m4_map_args_sep([m4_map_args_sep(m4_dquote(], [)[[$3]], [], [[$1]],]]]dnl
|
|
[m4_dquote(m4_dquote(m4_shift3($@)))[[)], [[$1]], $2)])])
|
|
|
|
|
|
# m4_append(MACRO-NAME, STRING, [SEPARATOR])
|
|
# ------------------------------------------
|
|
# Redefine MACRO-NAME to hold its former content plus `SEPARATOR`'STRING'
|
|
# at the end. It is valid to use this macro with MACRO-NAME undefined,
|
|
# in which case no SEPARATOR is added. Be aware that the criterion is
|
|
# `not being defined', and not `not being empty'.
|
|
#
|
|
# 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]
|
|
#
|
|
# Note that m4_append can benefit from amortized O(n) m4 behavior, if
|
|
# the underlying m4 implementation is smart enough to avoid copying existing
|
|
# contents when enlarging a macro's definition into any pre-allocated storage
|
|
# (m4 1.4.x unfortunately does not implement this optimization). We do
|
|
# not implement m4_prepend, since it is inherently O(n^2) (pre-allocated
|
|
# storage only occurs at the end of a macro, so the existing contents must
|
|
# always be moved).
|
|
#
|
|
# Use _m4_defn for speed.
|
|
m4_define([m4_append],
|
|
[m4_define([$1], m4_ifdef([$1], [_m4_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. Also, warn if SEPARATOR is not empty and occurs within STRING,
|
|
# as the algorithm no longer guarantees uniqueness.
|
|
#
|
|
# Note that while m4_append can be O(n) (depending on the quality of the
|
|
# underlying M4 implementation), m4_append_uniq is inherently O(n^2)
|
|
# because each append operation searches the entire string.
|
|
m4_define([m4_append_uniq],
|
|
[m4_ifval([$3], [m4_if(m4_index([$2], [$3]), [-1], [],
|
|
[m4_warn([syntax],
|
|
[$0: `$2' contains `$3'])])])_$0($@)])
|
|
m4_define([_m4_append_uniq],
|
|
[m4_ifdef([$1],
|
|
[m4_if(m4_index([$3]_m4_defn([$1])[$3], [$3$2$3]), [-1],
|
|
[m4_append([$1], [$2], [$3])$4], [$5])],
|
|
[m4_define([$1], [$2])$4])])
|
|
|
|
# m4_append_uniq_w(MACRO-NAME, STRINGS)
|
|
# -------------------------------------
|
|
# For each of the words in the whitespace separated list STRINGS, append
|
|
# only the unique strings to the definition of MACRO-NAME.
|
|
#
|
|
# Use _m4_defn for speed.
|
|
m4_define([m4_append_uniq_w],
|
|
[m4_map_args_w([$2], [_m4_append_uniq([$1],], [, [ ])])])
|
|
|
|
|
|
# m4_escape(STRING)
|
|
# -----------------
|
|
# Output quoted STRING, but with embedded #, $, [ and ] turned into
|
|
# quadrigraphs.
|
|
#
|
|
# It is faster to check if STRING is already good using m4_translit
|
|
# than to blindly perform four m4_bpatsubst.
|
|
#
|
|
# Because the translit is stripping quotes, it must also neutralize
|
|
# anything that might be in a macro name, as well as comments, commas,
|
|
# and parentheses. All the problem characters are unified so that a
|
|
# single m4_index can scan the result.
|
|
#
|
|
# Rather than expand m4_defn every time m4_escape is expanded, we
|
|
# inline its expansion up front.
|
|
m4_define([m4_escape],
|
|
[m4_if(m4_index(m4_translit([$1],
|
|
[[]#,()]]m4_dquote(m4_defn([m4_cr_symbols2]))[, [$$$]), [$]),
|
|
[-1], [m4_echo], [_$0])([$1])])
|
|
|
|
m4_define([_m4_escape],
|
|
[m4_changequote([-=<{(],[)}>=-])]dnl
|
|
[m4_bpatsubst(m4_bpatsubst(m4_bpatsubst(m4_bpatsubst(
|
|
-=<{(-=<{(-=<{(-=<{(-=<{($1)}>=-)}>=-)}>=-)}>=-)}>=-,
|
|
-=<{(#)}>=-, -=<{(@%:@)}>=-),
|
|
-=<{(\[)}>=-, -=<{(@<:@)}>=-),
|
|
-=<{(\])}>=-, -=<{(@:>@)}>=-),
|
|
-=<{(\$)}>=-, -=<{(@S|@)}>=-)m4_changequote([,])])
|
|
|
|
|
|
# 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.
|
|
#
|
|
# No expansion occurs on the contents STRING, PREFIX, or FIRST-PREFIX,
|
|
# although quadrigraphs are correctly recognized. More precisely,
|
|
# you may redefine m4_qlen to recognize whatever escape sequences that
|
|
# you will post-process.
|
|
#
|
|
# 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 uses a helper that uses $2 through $4 directly, rather than
|
|
# using local variables, to avoid m4_defn overhead, or expansion swallowing
|
|
# any $. It also bypasses m4_popdef overhead with _m4_popdef since no user
|
|
# macro expansion occurs in the meantime. Also, the definition is written
|
|
# with m4_do, to avoid time wasted on dnl during expansion (since this is
|
|
# already a time-consuming macro).
|
|
m4_define([m4_text_wrap],
|
|
[_$0(m4_escape([$1]), [$2], m4_default_quoted([$3], [$2]),
|
|
m4_default_quoted([$4], [79]))])
|
|
|
|
m4_define([_m4_text_wrap],
|
|
m4_do(dnl set up local variables, to avoid repeated calculations
|
|
[[m4_pushdef([m4_Indent], m4_qlen([$2]))]],
|
|
[[m4_pushdef([m4_Cursor], m4_qlen([$3]))]],
|
|
[[m4_pushdef([m4_Separator], [m4_define([m4_Separator], [ ])])]],
|
|
dnl expand the first prefix, then check its length vs. regular prefix
|
|
dnl same length: nothing special
|
|
dnl prefix1 longer: output on line by itself, and reset cursor
|
|
dnl prefix1 shorter: pad to length of prefix, and reset cursor
|
|
[[[$3]m4_cond([m4_Cursor], m4_Indent, [],
|
|
[m4_eval(m4_Cursor > m4_Indent)], [1], [
|
|
[$2]m4_define([m4_Cursor], m4_Indent)],
|
|
[m4_format([%*s], m4_max([0],
|
|
m4_eval(m4_Indent - m4_Cursor)), [])m4_define([m4_Cursor], m4_Indent)])]],
|
|
dnl now, for each word, compute the cursor after the word is output, then
|
|
dnl check if the cursor would exceed the wrap column
|
|
dnl if so, reset cursor, and insert newline and prefix
|
|
dnl if not, insert the separator (usually a space)
|
|
dnl either way, insert the word
|
|
[[m4_map_args_w([$1], [$0_word(], [, [$2], [$4])])]],
|
|
dnl finally, clean up the local variables
|
|
[[_m4_popdef([m4_Separator], [m4_Cursor], [m4_Indent])]]))
|
|
|
|
m4_define([_m4_text_wrap_word],
|
|
[m4_define([m4_Cursor], m4_eval(m4_Cursor + m4_qlen([$1]) + 1))]dnl
|
|
[m4_if(m4_eval(m4_Cursor > ([$3])),
|
|
[1], [m4_define([m4_Cursor], m4_eval(m4_Indent + m4_qlen([$1]) + 1))
|
|
[$2]],
|
|
[m4_Separator[]])[$1]])
|
|
|
|
# m4_text_box(MESSAGE, [FRAME-CHARACTER = `-'])
|
|
# ---------------------------------------------
|
|
# Turn MESSAGE into:
|
|
# ## ------- ##
|
|
# ## MESSAGE ##
|
|
# ## ------- ##
|
|
# using FRAME-CHARACTER in the border.
|
|
#
|
|
# Quadrigraphs are correctly recognized. More precisely, you may
|
|
# redefine m4_qlen to recognize whatever escape sequences that you
|
|
# will post-process.
|
|
m4_define([m4_text_box],
|
|
[m4_pushdef([m4_Border],
|
|
m4_translit(m4_format([[[%*s]]], m4_decr(m4_qlen(_m4_expand([$1
|
|
]))), []), [ ], m4_default_quoted([$2], [-])))]dnl
|
|
[[##] _m4_defn([m4_Border]) [##]
|
|
[##] $1 [##]
|
|
[##] _m4_defn([m4_Border]) [##]_m4_popdef([m4_Border])])
|
|
|
|
|
|
# m4_qlen(STRING)
|
|
# ---------------
|
|
# Expands to the length of STRING after autom4te converts all quadrigraphs.
|
|
#
|
|
# If you use some other means of post-processing m4 output rather than
|
|
# autom4te, then you may redefine this macro to recognize whatever
|
|
# escape sequences your post-processor will handle. For that matter,
|
|
# m4_define([m4_qlen], m4_defn([m4_len])) is sufficient if you don't
|
|
# do any post-processing.
|
|
#
|
|
# Avoid bpatsubsts for the common case of no quadrigraphs. Cache
|
|
# results, as configure scripts tend to ask about lengths of common
|
|
# strings like `/*' and `*/' rather frequently. Minimize the number
|
|
# of times that $1 occurs in m4_qlen, so there is less text to parse
|
|
# on a cache hit.
|
|
m4_define([m4_qlen],
|
|
[m4_ifdef([$0-$1], [_m4_defn([$0-]], [_$0(])[$1])])
|
|
m4_define([_m4_qlen],
|
|
[m4_define([m4_qlen-$1],
|
|
m4_if(m4_index([$1], [@]), [-1], [m4_len([$1])],
|
|
[m4_len(m4_bpatsubst([[$1]],
|
|
[@\(\(<:\|:>\|S|\|%:\|\{:\|:\}\)\(@\)\|&t@\)],
|
|
[\3]))]))_m4_defn([m4_qlen-$1])])
|
|
|
|
# m4_copyright_condense(TEXT)
|
|
# ---------------------------
|
|
# Condense the copyright notice in TEXT to only display the final
|
|
# year, wrapping the results to fit in 80 columns.
|
|
m4_define([m4_copyright_condense],
|
|
[m4_text_wrap(m4_bpatsubst(m4_flatten([[$1]]),
|
|
[(C)[- ,0-9]*\([1-9][0-9][0-9][0-9]\)], [(C) \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 for deciding when to end
|
|
# recursion. The recursion is between a pair of macros that alternate
|
|
# which list is trimmed by one element; this is more efficient than
|
|
# calling m4_cdr on both lists from a single macro. Guarantee exactly
|
|
# one expansion of both lists' side effects.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_list_cmp],
|
|
[_$0_raw(m4_dquote($1), m4_dquote($2))])
|
|
|
|
m4_define([_m4_list_cmp_raw],
|
|
[m4_if([$1], [$2], [0], [_m4_list_cmp_1([$1], $2)])])
|
|
|
|
m4_define([_m4_list_cmp],
|
|
[m4_if([$1], [], [0m4_ignore], [$2], [0], [m4_unquote], [$2m4_ignore])])
|
|
|
|
m4_define([_m4_list_cmp_1],
|
|
[_m4_list_cmp_2([$2], [m4_shift2($@)], $1)])
|
|
|
|
m4_define([_m4_list_cmp_2],
|
|
[_m4_list_cmp([$1$3], m4_cmp([$3+0], [$1+0]))(
|
|
[_m4_list_cmp_1(m4_dquote(m4_shift3($@)), $2)])])
|
|
|
|
# m4_max(EXPR, ...)
|
|
# m4_min(EXPR, ...)
|
|
# -----------------
|
|
# Return the decimal value of the maximum (or minimum) in a series of
|
|
# integer expressions.
|
|
#
|
|
# M4 1.4.x doesn't provide ?:. Hence this huge m4_eval. Avoid m4_eval
|
|
# if both arguments are identical, but be aware of m4_max(0xa, 10) (hence
|
|
# the use of <=, not just <, in the second multiply).
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_max],
|
|
[m4_if([$#], [0], [m4_fatal([too few arguments to $0])],
|
|
[$#], [1], [m4_eval([$1])],
|
|
[$#$1], [2$2], [m4_eval([$1])],
|
|
[$#], [2], [_$0($@)],
|
|
[_m4_minmax([_$0], $@)])])
|
|
|
|
m4_define([_m4_max],
|
|
[m4_eval((([$1]) > ([$2])) * ([$1]) + (([$1]) <= ([$2])) * ([$2]))])
|
|
|
|
m4_define([m4_min],
|
|
[m4_if([$#], [0], [m4_fatal([too few arguments to $0])],
|
|
[$#], [1], [m4_eval([$1])],
|
|
[$#$1], [2$2], [m4_eval([$1])],
|
|
[$#], [2], [_$0($@)],
|
|
[_m4_minmax([_$0], $@)])])
|
|
|
|
m4_define([_m4_min],
|
|
[m4_eval((([$1]) < ([$2])) * ([$1]) + (([$1]) >= ([$2])) * ([$2]))])
|
|
|
|
# _m4_minmax(METHOD, ARG1, ARG2...)
|
|
# ---------------------------------
|
|
# Common recursion code for m4_max and m4_min. METHOD must be _m4_max
|
|
# or _m4_min, and there must be at least two arguments to combine.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([_m4_minmax],
|
|
[m4_if([$#], [3], [$1([$2], [$3])],
|
|
[$0([$1], $1([$2], [$3]), m4_shift3($@))])])
|
|
|
|
|
|
# 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] -> [0,2,14+1,-1,[0r36:a]] -> 2.15.-1.10
|
|
# [2.14b] -> [0,2,15+1,-1,[0r36:b]] -> 2.15.-1.11
|
|
# [2.61aa.b] -> [0,2.61,1,-1,[0r36:aa],+1,-1,[0r36:b]] -> 2.62.-1.370.1.-1.11
|
|
# [08] -> [0,[0r10:0]8] -> 8
|
|
#
|
|
# This macro expects reasonable version numbers, but can handle double
|
|
# letters and does not expand any macros. Original version strings can
|
|
# use both `.' and `-' separators.
|
|
#
|
|
# Inline constant expansions, to avoid m4_defn overhead.
|
|
# _m4_version_unletter is the real workhorse used by m4_version_compare,
|
|
# but since [0r36:a] and commas are less readable than 10 and dots, we
|
|
# provide a wrapper for human use.
|
|
m4_define([m4_version_unletter],
|
|
[m4_substr(m4_map_args([.m4_eval], m4_unquote(_$0([$1]))), [3])])
|
|
m4_define([_m4_version_unletter],
|
|
[m4_bpatsubst(m4_bpatsubst(m4_translit([[[[0,$1]]]], [.-], [,,]),]dnl
|
|
m4_dquote(m4_dquote(m4_defn([m4_cr_Letters])))[[+],
|
|
[+1,-1,[0r36:\&]]), [,0], [,[0r10:0]])])
|
|
|
|
|
|
# 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 >
|
|
#
|
|
# Since _m4_version_unletter does not output side effects, we can
|
|
# safely bypass the overhead of m4_version_cmp.
|
|
m4_define([m4_version_compare],
|
|
[_m4_list_cmp_raw(_m4_version_unletter([$1]), _m4_version_unletter([$2]))])
|
|
|
|
|
|
# m4_PACKAGE_NAME
|
|
# m4_PACKAGE_TARNAME
|
|
# m4_PACKAGE_VERSION
|
|
# m4_PACKAGE_STRING
|
|
# m4_PACKAGE_BUGREPORT
|
|
# --------------------
|
|
# If m4sugar/version.m4 is present, then define version strings. This
|
|
# file is optional, provided by Autoconf but absent in Bison.
|
|
m4_sinclude([m4sugar/version.m4])
|
|
|
|
|
|
# m4_version_prereq(VERSION, [IF-OK], [IF-NOT = FAIL])
|
|
# ----------------------------------------------------
|
|
# Check this Autoconf version against VERSION.
|
|
m4_define([m4_version_prereq],
|
|
m4_ifdef([m4_PACKAGE_VERSION],
|
|
[[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])]],
|
|
[[m4_fatal([m4sugar/version.m4 not found])]]))
|
|
|
|
|
|
## ------------------ ##
|
|
## 15. Set handling. ##
|
|
## ------------------ ##
|
|
|
|
# Autoconf likes to create arbitrarily large sets; for example, as of
|
|
# this writing, the configure.ac for coreutils tracks a set of more
|
|
# than 400 AC_SUBST. How do we track all of these set members,
|
|
# without introducing duplicates? We could use m4_append_uniq, with
|
|
# the set NAME residing in the contents of the macro NAME.
|
|
# Unfortunately, m4_append_uniq is quadratic for set creation, because
|
|
# it costs O(n) to search the string for each of O(n) insertions; not
|
|
# to mention that with m4 1.4.x, even using m4_append is slow, costing
|
|
# O(n) rather than O(1) per insertion. Other set operations, not used
|
|
# by Autoconf but still possible by manipulation of the definition
|
|
# tracked in macro NAME, include O(n) deletion of one element and O(n)
|
|
# computation of set size. Because the set is exposed to the user via
|
|
# the definition of a single macro, we cannot cache any data about the
|
|
# set without risking the cache being invalidated by the user
|
|
# redefining NAME.
|
|
#
|
|
# Can we do better? Yes, because m4 gives us an O(1) search function
|
|
# for free: ifdef. Additionally, even m4 1.4.x gives us an O(1)
|
|
# insert operation for free: pushdef. But to use these, we must
|
|
# represent the set via a group of macros; to keep the set consistent,
|
|
# we must hide the set so that the user can only manipulate it through
|
|
# accessor macros. The contents of the set are maintained through two
|
|
# access points; _m4_set([name]) is a pushdef stack of values in the
|
|
# set, useful for O(n) traversal of the set contents; while the
|
|
# existence of _m4_set([name],value) with no particular value is
|
|
# useful for O(1) querying of set membership. And since the user
|
|
# cannot externally manipulate the set, we are free to add additional
|
|
# caching macros for other performance improvements. Deletion can be
|
|
# O(1) per element rather than O(n), by reworking the definition of
|
|
# _m4_set([name],value) to be 0 or 1 based on current membership, and
|
|
# adding _m4_set_cleanup(name) to defer the O(n) cleanup of
|
|
# _m4_set([name]) until we have another reason to do an O(n)
|
|
# traversal. The existence of _m4_set_cleanup(name) can then be used
|
|
# elsewhere to determine if we must dereference _m4_set([name],value),
|
|
# or assume that definition implies set membership. Finally, size can
|
|
# be tracked in an O(1) fashion with _m4_set_size(name).
|
|
#
|
|
# The quoting in _m4_set([name],value) is chosen so that there is no
|
|
# ambiguity with a set whose name contains a comma, and so that we can
|
|
# supply the value via _m4_defn([_m4_set([name])]) without needing any
|
|
# quote manipulation.
|
|
|
|
# m4_set_add(SET, VALUE, [IF-UNIQ], [IF-DUP])
|
|
# -------------------------------------------
|
|
# Add VALUE as an element of SET. Expand IF-UNIQ on the first
|
|
# addition, and IF-DUP if it is already in the set. Addition of one
|
|
# element is O(1), such that overall set creation is O(n).
|
|
#
|
|
# We do not want to add a duplicate for a previously deleted but
|
|
# unpruned element, but it is just as easy to check existence directly
|
|
# as it is to query _m4_set_cleanup($1).
|
|
m4_define([m4_set_add],
|
|
[m4_ifdef([_m4_set([$1],$2)],
|
|
[m4_if(m4_indir([_m4_set([$1],$2)]), [0],
|
|
[m4_define([_m4_set([$1],$2)],
|
|
[1])_m4_set_size([$1], [m4_incr])$3], [$4])],
|
|
[m4_define([_m4_set([$1],$2)],
|
|
[1])m4_pushdef([_m4_set([$1])],
|
|
[$2])_m4_set_size([$1], [m4_incr])$3])])
|
|
|
|
# m4_set_add_all(SET, VALUE...)
|
|
# -----------------------------
|
|
# Add each VALUE into SET. This is O(n) in the number of VALUEs, and
|
|
# can be faster than calling m4_set_add for each VALUE.
|
|
#
|
|
# Implement two recursion helpers; the check variant is slower but
|
|
# handles the case where an element has previously been removed but
|
|
# not pruned. The recursion helpers ignore their second argument, so
|
|
# that we can use the faster m4_shift2 and 2 arguments, rather than
|
|
# _m4_shift2 and one argument, as the signal to end recursion.
|
|
#
|
|
# Please keep foreach.m4 in sync with any adjustments made here.
|
|
m4_define([m4_set_add_all],
|
|
[m4_define([_m4_set_size($1)], m4_eval(m4_set_size([$1])
|
|
+ m4_len(m4_ifdef([_m4_set_cleanup($1)], [_$0_check], [_$0])([$1], $@))))])
|
|
|
|
m4_define([_m4_set_add_all],
|
|
[m4_if([$#], [2], [],
|
|
[m4_ifdef([_m4_set([$1],$3)], [],
|
|
[m4_define([_m4_set([$1],$3)], [1])m4_pushdef([_m4_set([$1])],
|
|
[$3])-])$0([$1], m4_shift2($@))])])
|
|
|
|
m4_define([_m4_set_add_all_check],
|
|
[m4_if([$#], [2], [],
|
|
[m4_set_add([$1], [$3])$0([$1], m4_shift2($@))])])
|
|
|
|
# m4_set_contains(SET, VALUE, [IF-PRESENT], [IF-ABSENT])
|
|
# ------------------------------------------------------
|
|
# Expand IF-PRESENT if SET contains VALUE, otherwise expand IF-ABSENT.
|
|
# This is always O(1).
|
|
m4_define([m4_set_contains],
|
|
[m4_ifdef([_m4_set_cleanup($1)],
|
|
[m4_if(m4_ifdef([_m4_set([$1],$2)],
|
|
[m4_indir([_m4_set([$1],$2)])], [0]), [1], [$3], [$4])],
|
|
[m4_ifdef([_m4_set([$1],$2)], [$3], [$4])])])
|
|
|
|
# m4_set_contents(SET, [SEP])
|
|
# ---------------------------
|
|
# Expand to a single string containing all the elements in SET,
|
|
# separated by SEP, without modifying SET. No provision is made for
|
|
# disambiguating set elements that contain non-empty SEP as a
|
|
# sub-string, or for recognizing a set that contains only the empty
|
|
# string. Order of the output is not guaranteed. If any elements
|
|
# have been previously removed from the set, this action will prune
|
|
# the unused memory. This is O(n) in the size of the set before
|
|
# pruning.
|
|
#
|
|
# Use _m4_popdef for speed. The existence of _m4_set_cleanup($1)
|
|
# determines which version of _1 helper we use.
|
|
m4_define([m4_set_contents],
|
|
[m4_set_map_sep([$1], [], [], [[$2]])])
|
|
|
|
# _m4_set_contents_1(SET)
|
|
# _m4_set_contents_1c(SET)
|
|
# _m4_set_contents_2(SET, [PRE], [POST], [SEP])
|
|
# ---------------------------------------------
|
|
# Expand to a list of quoted elements currently in the set, each
|
|
# surrounded by PRE and POST, and moving SEP in front of PRE on
|
|
# recursion. To avoid nesting limit restrictions, the algorithm must
|
|
# be broken into two parts; _1 destructively copies the stack in
|
|
# reverse into _m4_set_($1), producing no output; then _2
|
|
# destructively copies _m4_set_($1) back into the stack in reverse.
|
|
# If no elements were deleted, then this visits the set in the order
|
|
# that elements were inserted. Behavior is undefined if PRE/POST/SEP
|
|
# tries to recursively list or modify SET in any way other than
|
|
# calling m4_set_remove on the current element. Use _1 if all entries
|
|
# in the stack are guaranteed to be in the set, and _1c to prune
|
|
# removed entries. Uses _m4_defn and _m4_popdef for speed.
|
|
m4_define([_m4_set_contents_1],
|
|
[_m4_stack_reverse([_m4_set([$1])], [_m4_set_($1)])])
|
|
|
|
m4_define([_m4_set_contents_1c],
|
|
[m4_ifdef([_m4_set([$1])],
|
|
[m4_set_contains([$1], _m4_defn([_m4_set([$1])]),
|
|
[m4_pushdef([_m4_set_($1)], _m4_defn([_m4_set([$1])]))],
|
|
[_m4_popdef([_m4_set([$1],]_m4_defn(
|
|
[_m4_set([$1])])[)])])_m4_popdef([_m4_set([$1])])$0([$1])],
|
|
[_m4_popdef([_m4_set_cleanup($1)])])])
|
|
|
|
m4_define([_m4_set_contents_2],
|
|
[_m4_stack_reverse([_m4_set_($1)], [_m4_set([$1])],
|
|
[$2[]_m4_defn([_m4_set_($1)])$3], [$4[]])])
|
|
|
|
# m4_set_delete(SET)
|
|
# ------------------
|
|
# Delete all elements in SET, and reclaim any memory occupied by the
|
|
# set. This is O(n) in the set size.
|
|
#
|
|
# Use _m4_defn and _m4_popdef for speed.
|
|
m4_define([m4_set_delete],
|
|
[m4_ifdef([_m4_set([$1])],
|
|
[_m4_popdef([_m4_set([$1],]_m4_defn([_m4_set([$1])])[)],
|
|
[_m4_set([$1])])$0([$1])],
|
|
[m4_ifdef([_m4_set_cleanup($1)],
|
|
[_m4_popdef([_m4_set_cleanup($1)])])m4_ifdef(
|
|
[_m4_set_size($1)],
|
|
[_m4_popdef([_m4_set_size($1)])])])])
|
|
|
|
# m4_set_difference(SET1, SET2)
|
|
# -----------------------------
|
|
# Produce a LIST of quoted elements that occur in SET1 but not SET2.
|
|
# Output a comma prior to any elements, to distinguish the empty
|
|
# string from no elements. This can be directly used as a series of
|
|
# arguments, such as for m4_join, or wrapped inside quotes for use in
|
|
# m4_foreach. Order of the output is not guaranteed.
|
|
#
|
|
# Short-circuit the idempotence relation.
|
|
m4_define([m4_set_difference],
|
|
[m4_if([$1], [$2], [], [m4_set_map_sep([$1], [_$0([$2],], [)])])])
|
|
|
|
m4_define([_m4_set_difference],
|
|
[m4_set_contains([$1], [$2], [], [,[$2]])])
|
|
|
|
# m4_set_dump(SET, [SEP])
|
|
# -----------------------
|
|
# Expand to a single string containing all the elements in SET,
|
|
# separated by SEP, then delete SET. In general, if you only need to
|
|
# list the contents once, this is faster than m4_set_contents. No
|
|
# provision is made for disambiguating set elements that contain
|
|
# non-empty SEP as a sub-string. Order of the output is not
|
|
# guaranteed. This is O(n) in the size of the set before pruning.
|
|
#
|
|
# Use _m4_popdef for speed. Use existence of _m4_set_cleanup($1) to
|
|
# decide if more expensive recursion is needed.
|
|
m4_define([m4_set_dump],
|
|
[m4_ifdef([_m4_set_size($1)],
|
|
[_m4_popdef([_m4_set_size($1)])])m4_ifdef([_m4_set_cleanup($1)],
|
|
[_$0_check], [_$0])([$1], [], [$2])])
|
|
|
|
# _m4_set_dump(SET, [SEP], [PREP])
|
|
# _m4_set_dump_check(SET, [SEP], [PREP])
|
|
# --------------------------------------
|
|
# Print SEP and the current element, then delete the element and
|
|
# recurse with empty SEP changed to PREP. The check variant checks
|
|
# whether the element has been previously removed. Use _m4_defn and
|
|
# _m4_popdef for speed.
|
|
m4_define([_m4_set_dump],
|
|
[m4_ifdef([_m4_set([$1])],
|
|
[[$2]_m4_defn([_m4_set([$1])])_m4_popdef([_m4_set([$1],]_m4_defn(
|
|
[_m4_set([$1])])[)], [_m4_set([$1])])$0([$1], [$2$3])])])
|
|
|
|
m4_define([_m4_set_dump_check],
|
|
[m4_ifdef([_m4_set([$1])],
|
|
[m4_set_contains([$1], _m4_defn([_m4_set([$1])]),
|
|
[[$2]_m4_defn([_m4_set([$1])])])_m4_popdef(
|
|
[_m4_set([$1],]_m4_defn([_m4_set([$1])])[)],
|
|
[_m4_set([$1])])$0([$1], [$2$3])],
|
|
[_m4_popdef([_m4_set_cleanup($1)])])])
|
|
|
|
# m4_set_empty(SET, [IF-EMPTY], [IF-ELEMENTS])
|
|
# --------------------------------------------
|
|
# Expand IF-EMPTY if SET has no elements, otherwise IF-ELEMENTS.
|
|
m4_define([m4_set_empty],
|
|
[m4_ifdef([_m4_set_size($1)],
|
|
[m4_if(m4_indir([_m4_set_size($1)]), [0], [$2], [$3])], [$2])])
|
|
|
|
# m4_set_foreach(SET, VAR, ACTION)
|
|
# --------------------------------
|
|
# For each element of SET, define VAR to the element and expand
|
|
# ACTION. ACTION should not recursively list SET's contents, add
|
|
# elements to SET, nor delete any element from SET except the one
|
|
# currently in VAR. The order that the elements are visited in is not
|
|
# guaranteed. This is faster than the corresponding m4_foreach([VAR],
|
|
# m4_indir([m4_dquote]m4_set_listc([SET])), [ACTION])
|
|
m4_define([m4_set_foreach],
|
|
[m4_pushdef([$2])m4_set_map_sep([$1],
|
|
[m4_define([$2],], [)$3])m4_popdef([$2])])
|
|
|
|
# m4_set_intersection(SET1, SET2)
|
|
# -------------------------------
|
|
# Produce a LIST of quoted elements that occur in both SET1 or SET2.
|
|
# Output a comma prior to any elements, to distinguish the empty
|
|
# string from no elements. This can be directly used as a series of
|
|
# arguments, such as for m4_join, or wrapped inside quotes for use in
|
|
# m4_foreach. Order of the output is not guaranteed.
|
|
#
|
|
# Iterate over the smaller set, and short-circuit the idempotence
|
|
# relation.
|
|
m4_define([m4_set_intersection],
|
|
[m4_if([$1], [$2], [m4_set_listc([$1])],
|
|
m4_eval(m4_set_size([$2]) < m4_set_size([$1])), [1], [$0([$2], [$1])],
|
|
[m4_set_map_sep([$1], [_$0([$2],], [)])])])
|
|
|
|
m4_define([_m4_set_intersection],
|
|
[m4_set_contains([$1], [$2], [,[$2]])])
|
|
|
|
# m4_set_list(SET)
|
|
# m4_set_listc(SET)
|
|
# -----------------
|
|
# Produce a LIST of quoted elements of SET. This can be directly used
|
|
# as a series of arguments, such as for m4_join or m4_set_add_all, or
|
|
# wrapped inside quotes for use in m4_foreach or m4_map. With
|
|
# m4_set_list, there is no way to distinguish an empty set from a set
|
|
# containing only the empty string; with m4_set_listc, a leading comma
|
|
# is output if there are any elements.
|
|
m4_define([m4_set_list],
|
|
[m4_set_map_sep([$1], [], [], [,])])
|
|
|
|
m4_define([m4_set_listc],
|
|
[m4_set_map_sep([$1], [,])])
|
|
|
|
# m4_set_map(SET, ACTION)
|
|
# -----------------------
|
|
# For each element of SET, expand ACTION with a single argument of the
|
|
# current element. ACTION should not recursively list SET's contents,
|
|
# add elements to SET, nor delete any element from SET except the one
|
|
# passed as an argument. The order that the elements are visited in
|
|
# is not guaranteed. This is faster than either of the corresponding
|
|
# m4_map_args([ACTION]m4_set_listc([SET]))
|
|
# m4_set_foreach([SET], [VAR], [ACTION(m4_defn([VAR]))])
|
|
m4_define([m4_set_map],
|
|
[m4_set_map_sep([$1], [$2(], [)])])
|
|
|
|
# m4_set_map_sep(SET, [PRE], [POST], [SEP])
|
|
# -----------------------------------------
|
|
# For each element of SET, expand PRE[value]POST[], and expand SEP
|
|
# between elements.
|
|
m4_define([m4_set_map_sep],
|
|
[m4_ifdef([_m4_set_cleanup($1)], [_m4_set_contents_1c],
|
|
[_m4_set_contents_1])([$1])_m4_set_contents_2($@)])
|
|
|
|
# m4_set_remove(SET, VALUE, [IF-PRESENT], [IF-ABSENT])
|
|
# ----------------------------------------------------
|
|
# If VALUE is an element of SET, delete it and expand IF-PRESENT.
|
|
# Otherwise expand IF-ABSENT. Deleting a single value is O(1),
|
|
# although it leaves memory occupied until the next O(n) traversal of
|
|
# the set which will compact the set.
|
|
#
|
|
# Optimize if the element being removed is the most recently added,
|
|
# since defining _m4_set_cleanup($1) slows down so many other macros.
|
|
# In particular, this plays well with m4_set_foreach and m4_set_map.
|
|
m4_define([m4_set_remove],
|
|
[m4_set_contains([$1], [$2], [_m4_set_size([$1],
|
|
[m4_decr])m4_if(_m4_defn([_m4_set([$1])]), [$2],
|
|
[_m4_popdef([_m4_set([$1],$2)], [_m4_set([$1])])],
|
|
[m4_define([_m4_set_cleanup($1)])m4_define(
|
|
[_m4_set([$1],$2)], [0])])$3], [$4])])
|
|
|
|
# m4_set_size(SET)
|
|
# ----------------
|
|
# Expand to the number of elements currently in SET. This operation
|
|
# is O(1), and thus more efficient than m4_count(m4_set_list([SET])).
|
|
m4_define([m4_set_size],
|
|
[m4_ifdef([_m4_set_size($1)], [m4_indir([_m4_set_size($1)])], [0])])
|
|
|
|
# _m4_set_size(SET, ACTION)
|
|
# -------------------------
|
|
# ACTION must be either m4_incr or m4_decr, and the size of SET is
|
|
# changed accordingly. If the set is empty, ACTION must not be
|
|
# m4_decr.
|
|
m4_define([_m4_set_size],
|
|
[m4_define([_m4_set_size($1)],
|
|
m4_ifdef([_m4_set_size($1)], [$2(m4_indir([_m4_set_size($1)]))],
|
|
[1]))])
|
|
|
|
# m4_set_union(SET1, SET2)
|
|
# ------------------------
|
|
# Produce a LIST of double quoted elements that occur in either SET1
|
|
# or SET2, without duplicates. Output a comma prior to any elements,
|
|
# to distinguish the empty string from no elements. This can be
|
|
# directly used as a series of arguments, such as for m4_join, or
|
|
# wrapped inside quotes for use in m4_foreach. Order of the output is
|
|
# not guaranteed.
|
|
#
|
|
# We can rely on the fact that m4_set_listc prunes SET1, so we don't
|
|
# need to check _m4_set([$1],element) for 0. Short-circuit the
|
|
# idempotence relation.
|
|
m4_define([m4_set_union],
|
|
[m4_set_listc([$1])m4_if([$1], [$2], [],
|
|
[m4_set_map_sep([$2], [_$0([$1],], [)])])])
|
|
|
|
m4_define([_m4_set_union],
|
|
[m4_ifdef([_m4_set([$1],$2)], [], [,[$2]])])
|
|
|
|
|
|
## ------------------- ##
|
|
## 16. 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: $1])])])
|
|
|
|
|
|
|
|
## ------------------------ ##
|
|
## 17. Setting M4sugar up. ##
|
|
## ------------------------ ##
|
|
|
|
# _m4_divert_diversion should be defined.
|
|
m4_divert_push([KILL])
|
|
|
|
# m4_init
|
|
# -------
|
|
# Initialize the m4sugar language.
|
|
m4_define([m4_init],
|
|
[# All the M4sugar macros start with `m4_', except `dnl' kept as is
|
|
# for sake of simplicity.
|
|
m4_pattern_forbid([^_?m4_])
|
|
m4_pattern_forbid([^dnl$])
|
|
|
|
# If __m4_version__ is defined, we assume that we are being run by M4
|
|
# 1.6 or newer, thus $@ recursion is linear, and debugmode(+do)
|
|
# is available for faster checks of dereferencing undefined macros
|
|
# and forcing dumpdef to print to stderr regardless of debugfile.
|
|
# But if it is missing, we assume we are being run by M4 1.4.x, that
|
|
# $@ recursion is quadratic, and that we need foreach-based
|
|
# replacement macros. Also, m4 prior to 1.4.8 loses track of location
|
|
# during m4wrap text; __line__ should never be 0.
|
|
#
|
|
# Use the raw builtin to avoid tripping up include tracing.
|
|
# Meanwhile, avoid m4_copy, since it temporarily undefines m4_defn.
|
|
m4_ifdef([__m4_version__],
|
|
[m4_debugmode([+do])
|
|
m4_define([m4_defn], _m4_defn([_m4_defn]))
|
|
m4_define([m4_dumpdef], _m4_defn([_m4_dumpdef]))
|
|
m4_define([m4_popdef], _m4_defn([_m4_popdef]))
|
|
m4_define([m4_undefine], _m4_defn([_m4_undefine]))],
|
|
[m4_builtin([include], [m4sugar/foreach.m4])
|
|
m4_wrap_lifo([m4_if(__line__, [0], [m4_pushdef([m4_location],
|
|
]]m4_dquote(m4_dquote(m4_dquote(__file__:__line__)))[[)])])])
|
|
|
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# Rewrite the first entry of the diversion stack.
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m4_divert([KILL])
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# Check the divert push/pop perfect balance.
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# Some users are prone to also use m4_wrap to register last-minute
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# m4_divert_text; so after our diversion cleanups, we restore
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# KILL as the bottom of the diversion stack.
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m4_wrap([m4_popdef([_m4_divert_diversion])m4_ifdef(
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[_m4_divert_diversion], [m4_fatal([$0: unbalanced m4_divert_push:
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]m4_divert_stack)])_m4_popdef([_m4_divert_stack])m4_divert_push([KILL])])
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])
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