1divert(-1)# -*- Autoconf -*- 2# This file is part of Autoconf. 3# Base M4 layer. 4# Requires GNU M4. 5# 6# Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software 7# Foundation, Inc. 8# 9# This program is free software; you can redistribute it and/or modify 10# it under the terms of the GNU General Public License as published by 11# the Free Software Foundation; either version 2, or (at your option) 12# any later version. 13# 14# This program is distributed in the hope that it will be useful, 15# but WITHOUT ANY WARRANTY; without even the implied warranty of 16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17# GNU General Public License for more details. 18# 19# You should have received a copy of the GNU General Public License 20# along with this program; if not, write to the Free Software 21# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 22# 02110-1301, USA. 23# 24# As a special exception, the Free Software Foundation gives unlimited 25# permission to copy, distribute and modify the configure scripts that 26# are the output of Autoconf. You need not follow the terms of the GNU 27# General Public License when using or distributing such scripts, even 28# though portions of the text of Autoconf appear in them. The GNU 29# General Public License (GPL) does govern all other use of the material 30# that constitutes the Autoconf program. 31# 32# Certain portions of the Autoconf source text are designed to be copied 33# (in certain cases, depending on the input) into the output of 34# Autoconf. We call these the "data" portions. The rest of the Autoconf 35# source text consists of comments plus executable code that decides which 36# of the data portions to output in any given case. We call these 37# comments and executable code the "non-data" portions. Autoconf never 38# copies any of the non-data portions into its output. 39# 40# This special exception to the GPL applies to versions of Autoconf 41# released by the Free Software Foundation. When you make and 42# distribute a modified version of Autoconf, you may extend this special 43# exception to the GPL to apply to your modified version as well, *unless* 44# your modified version has the potential to copy into its output some 45# of the text that was the non-data portion of the version that you started 46# with. (In other words, unless your change moves or copies text from 47# the non-data portions to the data portions.) If your modification has 48# such potential, you must delete any notice of this special exception 49# to the GPL from your modified version. 50# 51# Written by Akim Demaille. 52# 53 54# Set the quotes, whatever the current quoting system. 55changequote() 56changequote([, ]) 57 58# Some old m4's don't support m4exit. But they provide 59# equivalent functionality by core dumping because of the 60# long macros we define. 61ifdef([__gnu__], , 62[errprint(M4sugar requires GNU M4. Install it before installing M4sugar or 63set the M4 environment variable to its absolute file name.) 64m4exit(2)]) 65 66 67## ------------------------------- ## 68## 1. Simulate --prefix-builtins. ## 69## ------------------------------- ## 70 71# m4_define 72# m4_defn 73# m4_undefine 74define([m4_define], defn([define])) 75define([m4_defn], defn([defn])) 76define([m4_undefine], defn([undefine])) 77 78m4_undefine([define]) 79m4_undefine([defn]) 80m4_undefine([undefine]) 81 82 83# m4_copy(SRC, DST) 84# ----------------- 85# Define DST as the definition of SRC. 86# What's the difference between: 87# 1. m4_copy([from], [to]) 88# 2. m4_define([to], [from($@)]) 89# Well, obviously 1 is more expensive in space. Maybe 2 is more expensive 90# in time, but because of the space cost of 1, it's not that obvious. 91# Nevertheless, one huge difference is the handling of `$0'. If `from' 92# uses `$0', then with 1, `to''s `$0' is `to', while it is `from' in 2. 93# The user will certainly prefer to see `to'. 94m4_define([m4_copy], 95[m4_define([$2], m4_defn([$1]))]) 96 97 98# m4_rename(SRC, DST) 99# ------------------- 100# Rename the macro SRC as DST. 101m4_define([m4_rename], 102[m4_copy([$1], [$2])m4_undefine([$1])]) 103 104 105# m4_rename_m4(MACRO-NAME) 106# ------------------------ 107# Rename MACRO-NAME as m4_MACRO-NAME. 108m4_define([m4_rename_m4], 109[m4_rename([$1], [m4_$1])]) 110 111 112# m4_copy_unm4(m4_MACRO-NAME) 113# --------------------------- 114# Copy m4_MACRO-NAME as MACRO-NAME. 115m4_define([m4_copy_unm4], 116[m4_copy([$1], m4_bpatsubst([$1], [^m4_\(.*\)], [[\1]]))]) 117 118 119# Some m4 internals have names colliding with tokens we might use. 120# Rename them a` la `m4 --prefix-builtins'. 121m4_rename_m4([builtin]) 122m4_rename_m4([changecom]) 123m4_rename_m4([changequote]) 124m4_rename_m4([debugfile]) 125m4_rename_m4([debugmode]) 126m4_rename_m4([decr]) 127m4_undefine([divert]) 128m4_rename_m4([divnum]) 129m4_rename_m4([dumpdef]) 130m4_rename_m4([errprint]) 131m4_rename_m4([esyscmd]) 132m4_rename_m4([eval]) 133m4_rename_m4([format]) 134m4_rename_m4([ifdef]) 135m4_rename([ifelse], [m4_if]) 136m4_undefine([include]) 137m4_rename_m4([incr]) 138m4_rename_m4([index]) 139m4_rename_m4([indir]) 140m4_rename_m4([len]) 141m4_rename([m4exit], [m4_exit]) 142m4_rename([m4wrap], [m4_wrap]) 143m4_ifdef([mkstemp],dnl added in M4 1.4.8 144[m4_rename_m4([mkstemp]) 145m4_copy([m4_mkstemp], [m4_maketemp]) 146m4_undefine([maketemp])], 147[m4_rename_m4([maketemp]) 148m4_copy([m4_maketemp], [m4_mkstemp])]) 149m4_rename([patsubst], [m4_bpatsubst]) 150m4_undefine([popdef]) 151m4_rename_m4([pushdef]) 152m4_rename([regexp], [m4_bregexp]) 153m4_rename_m4([shift]) 154m4_undefine([sinclude]) 155m4_rename_m4([substr]) 156m4_rename_m4([symbols]) 157m4_rename_m4([syscmd]) 158m4_rename_m4([sysval]) 159m4_rename_m4([traceoff]) 160m4_rename_m4([traceon]) 161m4_rename_m4([translit]) 162m4_undefine([undivert]) 163 164 165## ------------------- ## 166## 2. Error messages. ## 167## ------------------- ## 168 169 170# m4_location 171# ----------- 172m4_define([m4_location], 173[__file__:__line__]) 174 175 176# m4_errprintn(MSG) 177# ----------------- 178# Same as `errprint', but with the missing end of line. 179m4_define([m4_errprintn], 180[m4_errprint([$1 181])]) 182 183 184# m4_warning(MSG) 185# --------------- 186# Warn the user. 187m4_define([m4_warning], 188[m4_errprintn(m4_location[: warning: $1])]) 189 190 191# m4_fatal(MSG, [EXIT-STATUS]) 192# ---------------------------- 193# Fatal the user. :) 194m4_define([m4_fatal], 195[m4_errprintn(m4_location[: error: $1])dnl 196m4_expansion_stack_dump()dnl 197m4_exit(m4_if([$2],, 1, [$2]))]) 198 199 200# m4_assert(EXPRESSION, [EXIT-STATUS = 1]) 201# ---------------------------------------- 202# This macro ensures that EXPRESSION evaluates to true, and exits if 203# EXPRESSION evaluates to false. 204m4_define([m4_assert], 205[m4_if(m4_eval([$1]), 0, 206 [m4_fatal([assert failed: $1], [$2])])]) 207 208 209 210## ------------- ## 211## 3. Warnings. ## 212## ------------- ## 213 214 215# _m4_warn(CATEGORY, MESSAGE, STACK-TRACE) 216# ---------------------------------------- 217# Report a MESSAGE to the user if the CATEGORY of warnings is enabled. 218# This is for traces only. 219# The STACK-TRACE is a \n-separated list of "LOCATION: MESSAGE". 220m4_define([_m4_warn], []) 221 222 223# m4_warn(CATEGORY, MESSAGE) 224# -------------------------- 225# Report a MESSAGE to the user if the CATEGORY of warnings is enabled. 226m4_define([m4_warn], 227[_m4_warn([$1], [$2], 228m4_ifdef([m4_expansion_stack], 229 [m4_defn([m4_expansion_stack]) 230m4_location[: the top level]]))dnl 231]) 232 233 234 235## ------------------- ## 236## 4. File inclusion. ## 237## ------------------- ## 238 239 240# We also want to neutralize include (and sinclude for symmetry), 241# but we want to extend them slightly: warn when a file is included 242# several times. This is in general a dangerous operation because 243# quite nobody quotes the first argument of m4_define. 244# 245# For instance in the following case: 246# m4_define(foo, [bar]) 247# then a second reading will turn into 248# m4_define(bar, [bar]) 249# which is certainly not what was meant. 250 251# m4_include_unique(FILE) 252# ----------------------- 253# Declare that the FILE was loading; and warn if it has already 254# been included. 255m4_define([m4_include_unique], 256[m4_ifdef([m4_include($1)], 257 [m4_warn([syntax], [file `$1' included several times])])dnl 258m4_define([m4_include($1)])]) 259 260 261# m4_include(FILE) 262# ---------------- 263# As the builtin include, but warns against multiple inclusions. 264m4_define([m4_include], 265[m4_include_unique([$1])dnl 266m4_builtin([include], [$1])]) 267 268 269# m4_sinclude(FILE) 270# ----------------- 271# As the builtin sinclude, but warns against multiple inclusions. 272m4_define([m4_sinclude], 273[m4_include_unique([$1])dnl 274m4_builtin([sinclude], [$1])]) 275 276 277 278## ------------------------------------ ## 279## 5. Additional branching constructs. ## 280## ------------------------------------ ## 281 282# Both `m4_ifval' and `m4_ifset' tests against the empty string. The 283# difference is that `m4_ifset' is specialized on macros. 284# 285# In case of arguments of macros, eg $[1], it makes little difference. 286# In the case of a macro `FOO', you don't want to check `m4_ifval(FOO, 287# TRUE)', because if `FOO' expands with commas, there is a shifting of 288# the arguments. So you want to run `m4_ifval([FOO])', but then you just 289# compare the *string* `FOO' against `', which, of course fails. 290# 291# So you want a variation of `m4_ifset' that expects a macro name as $[1]. 292# If this macro is both defined and defined to a non empty value, then 293# it runs TRUE etc. 294 295 296# m4_ifval(COND, [IF-TRUE], [IF-FALSE]) 297# ------------------------------------- 298# If COND is not the empty string, expand IF-TRUE, otherwise IF-FALSE. 299# Comparable to m4_ifdef. 300m4_define([m4_ifval], 301[m4_if([$1], [], [$3], [$2])]) 302 303 304# m4_n(TEXT) 305# ---------- 306# If TEXT is not empty, return TEXT and a new line, otherwise nothing. 307m4_define([m4_n], 308[m4_if([$1], 309 [], [], 310 [$1 311])]) 312 313 314# m4_ifvaln(COND, [IF-TRUE], [IF-FALSE]) 315# -------------------------------------- 316# Same as `m4_ifval', but add an extra newline to IF-TRUE or IF-FALSE 317# unless that argument is empty. 318m4_define([m4_ifvaln], 319[m4_if([$1], 320 [], [m4_n([$3])], 321 [m4_n([$2])])]) 322 323 324# m4_ifset(MACRO, [IF-TRUE], [IF-FALSE]) 325# -------------------------------------- 326# If MACRO has no definition, or of its definition is the empty string, 327# expand IF-FALSE, otherwise IF-TRUE. 328m4_define([m4_ifset], 329[m4_ifdef([$1], 330 [m4_ifval(m4_defn([$1]), [$2], [$3])], 331 [$3])]) 332 333 334# m4_ifndef(NAME, [IF-NOT-DEFINED], [IF-DEFINED]) 335# ----------------------------------------------- 336m4_define([m4_ifndef], 337[m4_ifdef([$1], [$3], [$2])]) 338 339 340# m4_case(SWITCH, VAL1, IF-VAL1, VAL2, IF-VAL2, ..., DEFAULT) 341# ----------------------------------------------------------- 342# m4 equivalent of 343# switch (SWITCH) 344# { 345# case VAL1: 346# IF-VAL1; 347# break; 348# case VAL2: 349# IF-VAL2; 350# break; 351# ... 352# default: 353# DEFAULT; 354# break; 355# }. 356# All the values are optional, and the macro is robust to active 357# symbols properly quoted. 358m4_define([m4_case], 359[m4_if([$#], 0, [], 360 [$#], 1, [], 361 [$#], 2, [$2], 362 [$1], [$2], [$3], 363 [$0([$1], m4_shiftn(3, $@))])]) 364 365 366# m4_bmatch(SWITCH, RE1, VAL1, RE2, VAL2, ..., DEFAULT) 367# ----------------------------------------------------- 368# m4 equivalent of 369# 370# if (SWITCH =~ RE1) 371# VAL1; 372# elif (SWITCH =~ RE2) 373# VAL2; 374# elif ... 375# ... 376# else 377# DEFAULT 378# 379# All the values are optional, and the macro is robust to active symbols 380# properly quoted. 381m4_define([m4_bmatch], 382[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])], 383 [$#], 1, [m4_fatal([$0: too few arguments: $#: $1])], 384 [$#], 2, [$2], 385 [m4_if(m4_bregexp([$1], [$2]), -1, [$0([$1], m4_shiftn(3, $@))], 386 [$3])])]) 387 388 389# m4_car(LIST) 390# m4_cdr(LIST) 391# ------------ 392# Manipulate m4 lists. 393m4_define([m4_car], [[$1]]) 394m4_define([m4_cdr], 395[m4_if([$#], 0, [m4_fatal([$0: cannot be called without arguments])], 396 [$#], 1, [], 397 [m4_dquote(m4_shift($@))])]) 398 399 400# m4_map(MACRO, LIST) 401# ------------------- 402# Invoke MACRO($1), MACRO($2) etc. where $1, $2... are the elements 403# of LIST (which can be lists themselves, for multiple arguments MACROs). 404m4_define([m4_fst], [$1]) 405m4_define([m4_map], 406[m4_if([$2], [[]], [], 407 [_m4_map([$1], [$2])])]) 408m4_define([_m4_map], 409[m4_ifval([$2], 410 [$1(m4_fst($2))[]_m4_map([$1], m4_cdr($2))])]) 411 412 413# m4_map_sep(MACRO, SEPARATOR, LIST) 414# ---------------------------------- 415# Invoke MACRO($1), SEPARATOR, MACRO($2), ..., MACRO($N) where $1, $2... $N 416# are the elements of LIST (which can be lists themselves, for multiple 417# arguments MACROs). 418m4_define([m4_map_sep], 419[m4_if([$3], [[]], [], 420 [$1(m4_fst($3))[]_m4_map([$2[]$1], m4_cdr($3))])]) 421 422 423## ---------------------------------------- ## 424## 6. Enhanced version of some primitives. ## 425## ---------------------------------------- ## 426 427# m4_bpatsubsts(STRING, RE1, SUBST1, RE2, SUBST2, ...) 428# ---------------------------------------------------- 429# m4 equivalent of 430# 431# $_ = STRING; 432# s/RE1/SUBST1/g; 433# s/RE2/SUBST2/g; 434# ... 435# 436# All the values are optional, and the macro is robust to active symbols 437# properly quoted. 438# 439# I would have liked to name this macro `m4_bpatsubst', unfortunately, 440# due to quotation problems, I need to double quote $1 below, therefore 441# the anchors are broken :( I can't let users be trapped by that. 442m4_define([m4_bpatsubsts], 443[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])], 444 [$#], 1, [m4_fatal([$0: too few arguments: $#: $1])], 445 [$#], 2, [m4_builtin([patsubst], $@)], 446 [$0(m4_builtin([patsubst], [[$1]], [$2], [$3]), 447 m4_shiftn(3, $@))])]) 448 449 450 451# m4_do(STRING, ...) 452# ------------------ 453# This macro invokes all its arguments (in sequence, of course). It is 454# useful for making your macros more structured and readable by dropping 455# unnecessary dnl's and have the macros indented properly. 456m4_define([m4_do], 457[m4_if($#, 0, [], 458 $#, 1, [$1], 459 [$1[]m4_do(m4_shift($@))])]) 460 461 462# m4_define_default(MACRO, VALUE) 463# ------------------------------- 464# If MACRO is undefined, set it to VALUE. 465m4_define([m4_define_default], 466[m4_ifndef([$1], [m4_define($@)])]) 467 468 469# m4_default(EXP1, EXP2) 470# ---------------------- 471# Returns EXP1 if non empty, otherwise EXP2. 472m4_define([m4_default], 473[m4_ifval([$1], [$1], [$2])]) 474 475 476# m4_defn(NAME) 477# ------------- 478# Unlike to the original, don't tolerate popping something which is 479# undefined. 480m4_define([m4_defn], 481[m4_ifndef([$1], 482 [m4_fatal([$0: undefined macro: $1])])dnl 483m4_builtin([defn], $@)]) 484 485 486# _m4_dumpdefs_up(NAME) 487# --------------------- 488m4_define([_m4_dumpdefs_up], 489[m4_ifdef([$1], 490 [m4_pushdef([_m4_dumpdefs], m4_defn([$1]))dnl 491m4_dumpdef([$1])dnl 492m4_popdef([$1])dnl 493_m4_dumpdefs_up([$1])])]) 494 495 496# _m4_dumpdefs_down(NAME) 497# ----------------------- 498m4_define([_m4_dumpdefs_down], 499[m4_ifdef([_m4_dumpdefs], 500 [m4_pushdef([$1], m4_defn([_m4_dumpdefs]))dnl 501m4_popdef([_m4_dumpdefs])dnl 502_m4_dumpdefs_down([$1])])]) 503 504 505# m4_dumpdefs(NAME) 506# ----------------- 507# Similar to `m4_dumpdef(NAME)', but if NAME was m4_pushdef'ed, display its 508# value stack (most recent displayed first). 509m4_define([m4_dumpdefs], 510[_m4_dumpdefs_up([$1])dnl 511_m4_dumpdefs_down([$1])]) 512 513 514# m4_popdef(NAME) 515# --------------- 516# Unlike to the original, don't tolerate popping something which is 517# undefined. 518m4_define([m4_popdef], 519[m4_ifndef([$1], 520 [m4_fatal([$0: undefined macro: $1])])dnl 521m4_builtin([popdef], $@)]) 522 523 524# m4_quote(ARGS) 525# -------------- 526# Return ARGS as a single arguments. 527# 528# It is important to realize the difference between `m4_quote(exp)' and 529# `[exp]': in the first case you obtain the quoted *result* of the 530# expansion of EXP, while in the latter you just obtain the string 531# `exp'. 532m4_define([m4_quote], [[$*]]) 533m4_define([m4_dquote], [[$@]]) 534 535 536# m4_noquote(STRING) 537# ------------------ 538# Return the result of ignoring all quotes in STRING and invoking the 539# macros it contains. Amongst other things useful for enabling macro 540# invocations inside strings with [] blocks (for instance regexps and 541# help-strings). 542m4_define([m4_noquote], 543[m4_changequote(-=<{,}>=-)$1-=<{}>=-m4_changequote([,])]) 544 545 546# m4_shiftn(N, ...) 547# ----------------- 548# Returns ... shifted N times. Useful for recursive "varargs" constructs. 549m4_define([m4_shiftn], 550[m4_assert(($1 >= 0) && ($# > $1))dnl 551_m4_shiftn($@)]) 552 553m4_define([_m4_shiftn], 554[m4_if([$1], 0, 555 [m4_shift($@)], 556 [_m4_shiftn(m4_eval([$1]-1), m4_shift(m4_shift($@)))])]) 557 558 559# m4_undefine(NAME) 560# ----------------- 561# Unlike to the original, don't tolerate undefining something which is 562# undefined. 563m4_define([m4_undefine], 564[m4_ifndef([$1], 565 [m4_fatal([$0: undefined macro: $1])])dnl 566m4_builtin([undefine], $@)]) 567 568 569## -------------------------- ## 570## 7. Implementing m4 loops. ## 571## -------------------------- ## 572 573 574# m4_for(VARIABLE, FIRST, LAST, [STEP = +/-1], EXPRESSION) 575# -------------------------------------------------------- 576# Expand EXPRESSION defining VARIABLE to FROM, FROM + 1, ..., TO. 577# Both limits are included, and bounds are checked for consistency. 578m4_define([m4_for], 579[m4_pushdef([$1], m4_eval([$2]))dnl 580m4_if(m4_eval(([$3]) > $1), 1, 581[m4_pushdef([_m4_step], m4_eval(m4_default([$4], 1)))dnl 582m4_assert(_m4_step > 0)dnl 583_m4_for([$1], m4_eval((([$3]) - $1) / _m4_step * _m4_step + $1), _m4_step, [$5])], 584 m4_eval(([$3]) < $1), 1, 585[m4_pushdef([_m4_step], m4_eval(m4_default([$4], -1)))dnl 586m4_assert(_m4_step < 0)dnl 587_m4_for([$1], m4_eval(($1 - ([$3])) / -(_m4_step) * _m4_step + $1), _m4_step, [$5])], 588 [m4_pushdef(_m4_step,[])dnl 589$5])[]dnl 590m4_popdef([_m4_step])dnl 591m4_popdef([$1])]) 592 593 594# _m4_for(VARIABLE, LAST, STEP, EXPRESSION) 595# ----------------------------------------- 596# Core of the loop, no consistency checks, all arguments are plain numbers. 597m4_define([_m4_for], 598[$4[]dnl 599m4_if($1, [$2], [], 600 [m4_define([$1], m4_eval($1+[$3]))_m4_for([$1], [$2], [$3], [$4])])]) 601 602 603# Implementing `foreach' loops in m4 is much more tricky than it may 604# seem. Actually, the example of a `foreach' loop in the m4 605# documentation is wrong: it does not quote the arguments properly, 606# which leads to undesirable expansions. 607# 608# The example in the documentation is: 609# 610# | # foreach(VAR, (LIST), STMT) 611# | m4_define([foreach], 612# | [m4_pushdef([$1])_foreach([$1], [$2], [$3])m4_popdef([$1])]) 613# | m4_define([_arg1], [$1]) 614# | m4_define([_foreach], 615# | [m4_if([$2], [()], , 616# | [m4_define([$1], _arg1$2)$3[]_foreach([$1], 617# | (shift$2), 618# | [$3])])]) 619# 620# But then if you run 621# 622# | m4_define(a, 1) 623# | m4_define(b, 2) 624# | m4_define(c, 3) 625# | foreach([f], [([a], [(b], [c)])], [echo f 626# | ]) 627# 628# it gives 629# 630# => echo 1 631# => echo (2,3) 632# 633# which is not what is expected. 634# 635# Of course the problem is that many quotes are missing. So you add 636# plenty of quotes at random places, until you reach the expected 637# result. Alternatively, if you are a quoting wizard, you directly 638# reach the following implementation (but if you really did, then 639# apply to the maintenance of m4sugar!). 640# 641# | # foreach(VAR, (LIST), STMT) 642# | m4_define([foreach], [m4_pushdef([$1])_foreach($@)m4_popdef([$1])]) 643# | m4_define([_arg1], [[$1]]) 644# | m4_define([_foreach], 645# | [m4_if($2, [()], , 646# | [m4_define([$1], [_arg1$2])$3[]_foreach([$1], 647# | [(shift$2)], 648# | [$3])])]) 649# 650# which this time answers 651# 652# => echo a 653# => echo (b 654# => echo c) 655# 656# Bingo! 657# 658# Well, not quite. 659# 660# With a better look, you realize that the parens are more a pain than 661# a help: since anyway you need to quote properly the list, you end up 662# with always using an outermost pair of parens and an outermost pair 663# of quotes. Rejecting the parens both eases the implementation, and 664# simplifies the use: 665# 666# | # foreach(VAR, (LIST), STMT) 667# | m4_define([foreach], [m4_pushdef([$1])_foreach($@)m4_popdef([$1])]) 668# | m4_define([_arg1], [$1]) 669# | m4_define([_foreach], 670# | [m4_if($2, [], , 671# | [m4_define([$1], [_arg1($2)])$3[]_foreach([$1], 672# | [shift($2)], 673# | [$3])])]) 674# 675# 676# Now, just replace the `$2' with `m4_quote($2)' in the outer `m4_if' 677# to improve robustness, and you come up with a quite satisfactory 678# implementation. 679 680 681# m4_foreach(VARIABLE, LIST, EXPRESSION) 682# -------------------------------------- 683# 684# Expand EXPRESSION assigning each value of the LIST to VARIABLE. 685# LIST should have the form `item_1, item_2, ..., item_n', i.e. the 686# whole list must *quoted*. Quote members too if you don't want them 687# to be expanded. 688# 689# This macro is robust to active symbols: 690# | m4_define(active, [ACT, IVE]) 691# | m4_foreach(Var, [active, active], [-Var-]) 692# => -ACT--IVE--ACT--IVE- 693# 694# | m4_foreach(Var, [[active], [active]], [-Var-]) 695# => -ACT, IVE--ACT, IVE- 696# 697# | m4_foreach(Var, [[[active]], [[active]]], [-Var-]) 698# => -active--active- 699m4_define([m4_foreach], 700[m4_pushdef([$1])_m4_foreach($@)m4_popdef([$1])]) 701 702m4_define([_m4_foreach], 703[m4_ifval([$2], 704 [m4_define([$1], m4_car($2))$3[]dnl 705_m4_foreach([$1], m4_cdr($2), [$3])])]) 706 707 708# m4_foreach_w(VARIABLE, LIST, EXPRESSION) 709# ---------------------------------------- 710# 711# Like m4_foreach, but the list is whitespace separated. 712# 713# This macro is robust to active symbols: 714# m4_foreach_w([Var], [ active 715# b act\ 716# ive ], [-Var-])end 717# => -active--b--active-end 718# 719m4_define([m4_foreach_w], 720[m4_foreach([$1], m4_split(m4_normalize([$2])), [$3])]) 721 722 723 724## --------------------------- ## 725## 8. More diversion support. ## 726## --------------------------- ## 727 728 729# _m4_divert(DIVERSION-NAME or NUMBER) 730# ------------------------------------ 731# If DIVERSION-NAME is the name of a diversion, return its number, 732# otherwise if it is a NUMBER return it. 733m4_define([_m4_divert], 734[m4_ifdef([_m4_divert($1)], 735 [m4_indir([_m4_divert($1)])], 736 [$1])]) 737 738# KILL is only used to suppress output. 739m4_define([_m4_divert(KILL)], -1) 740 741 742# _m4_divert_n_stack 743# ------------------ 744# Print m4_divert_stack with newline prepended, if it's nonempty. 745m4_define([_m4_divert_n_stack], 746[m4_ifdef([m4_divert_stack], [ 747m4_defn([m4_divert_stack])])]) 748 749 750# m4_divert(DIVERSION-NAME) 751# ------------------------- 752# Change the diversion stream to DIVERSION-NAME. 753m4_define([m4_divert], 754[m4_define([m4_divert_stack], m4_location[: $0: $1]_m4_divert_n_stack)dnl 755m4_builtin([divert], _m4_divert([$1]))dnl 756]) 757 758 759# m4_divert_push(DIVERSION-NAME) 760# ------------------------------ 761# Change the diversion stream to DIVERSION-NAME, while stacking old values. 762m4_define([m4_divert_push], 763[m4_pushdef([m4_divert_stack], m4_location[: $0: $1]_m4_divert_n_stack)dnl 764m4_pushdef([_m4_divert_diversion], [$1])dnl 765m4_builtin([divert], _m4_divert([$1]))dnl 766]) 767 768 769# m4_divert_pop([DIVERSION-NAME]) 770# ------------------------------- 771# Change the diversion stream to its previous value, unstacking it. 772# If specified, verify we left DIVERSION-NAME. 773# When we pop the last value from the stack, we divert to -1. 774m4_define([m4_divert_pop], 775[m4_ifndef([_m4_divert_diversion], 776 [m4_fatal([too many m4_divert_pop])])dnl 777m4_if([$1], [], [], 778 [$1], m4_defn([_m4_divert_diversion]), [], 779 [m4_fatal([$0($1): diversion mismatch: ]_m4_divert_n_stack)])dnl 780m4_popdef([m4_divert_stack])dnl 781m4_popdef([_m4_divert_diversion])dnl 782m4_builtin([divert], 783 m4_ifdef([_m4_divert_diversion], 784 [_m4_divert(m4_defn([_m4_divert_diversion]))], 785 -1))dnl 786]) 787 788 789# m4_divert_text(DIVERSION-NAME, CONTENT) 790# --------------------------------------- 791# Output CONTENT into DIVERSION-NAME (which may be a number actually). 792# An end of line is appended for free to CONTENT. 793m4_define([m4_divert_text], 794[m4_divert_push([$1])dnl 795$2 796m4_divert_pop([$1])dnl 797]) 798 799 800# m4_divert_once(DIVERSION-NAME, CONTENT) 801# --------------------------------------- 802# Output once CONTENT into DIVERSION-NAME (which may be a number 803# actually). An end of line is appended for free to CONTENT. 804m4_define([m4_divert_once], 805[m4_expand_once([m4_divert_text([$1], [$2])])]) 806 807 808# m4_undivert(DIVERSION-NAME) 809# --------------------------- 810# Undivert DIVERSION-NAME. 811m4_define([m4_undivert], 812[m4_builtin([undivert], _m4_divert([$1]))]) 813 814 815## -------------------------------------------- ## 816## 8. Defining macros with bells and whistles. ## 817## -------------------------------------------- ## 818 819# `m4_defun' is basically `m4_define' but it equips the macro with the 820# needed machinery for `m4_require'. A macro must be m4_defun'd if 821# either it is m4_require'd, or it m4_require's. 822# 823# Two things deserve attention and are detailed below: 824# 1. Implementation of m4_require 825# 2. Keeping track of the expansion stack 826# 827# 1. Implementation of m4_require 828# =============================== 829# 830# Of course m4_defun AC_PROVIDE's the macro, so that a macro which has 831# been expanded is not expanded again when m4_require'd, but the 832# difficult part is the proper expansion of macros when they are 833# m4_require'd. 834# 835# The implementation is based on two ideas, (i) using diversions to 836# prepare the expansion of the macro and its dependencies (by Franc,ois 837# Pinard), and (ii) expand the most recently m4_require'd macros _after_ 838# the previous macros (by Axel Thimm). 839# 840# 841# The first idea: why using diversions? 842# ------------------------------------- 843# 844# When a macro requires another, the other macro is expanded in new 845# diversion, GROW. When the outer macro is fully expanded, we first 846# undivert the most nested diversions (GROW - 1...), and finally 847# undivert GROW. To understand why we need several diversions, 848# consider the following example: 849# 850# | m4_defun([TEST1], [Test...REQUIRE([TEST2])1]) 851# | m4_defun([TEST2], [Test...REQUIRE([TEST3])2]) 852# | m4_defun([TEST3], [Test...3]) 853# 854# Because m4_require is not required to be first in the outer macros, we 855# must keep the expansions of the various level of m4_require separated. 856# Right before executing the epilogue of TEST1, we have: 857# 858# GROW - 2: Test...3 859# GROW - 1: Test...2 860# GROW: Test...1 861# BODY: 862# 863# Finally the epilogue of TEST1 undiverts GROW - 2, GROW - 1, and 864# GROW into the regular flow, BODY. 865# 866# GROW - 2: 867# GROW - 1: 868# GROW: 869# BODY: Test...3; Test...2; Test...1 870# 871# (The semicolons are here for clarification, but of course are not 872# emitted.) This is what Autoconf 2.0 (I think) to 2.13 (I'm sure) 873# implement. 874# 875# 876# The second idea: first required first out 877# ----------------------------------------- 878# 879# The natural implementation of the idea above is buggy and produces 880# very surprising results in some situations. Let's consider the 881# following example to explain the bug: 882# 883# | m4_defun([TEST1], [REQUIRE([TEST2a])REQUIRE([TEST2b])]) 884# | m4_defun([TEST2a], []) 885# | m4_defun([TEST2b], [REQUIRE([TEST3])]) 886# | m4_defun([TEST3], [REQUIRE([TEST2a])]) 887# | 888# | AC_INIT 889# | TEST1 890# 891# The dependencies between the macros are: 892# 893# 3 --- 2b 894# / \ is m4_require'd by 895# / \ left -------------------- right 896# 2a ------------ 1 897# 898# If you strictly apply the rules given in the previous section you get: 899# 900# GROW - 2: TEST3 901# GROW - 1: TEST2a; TEST2b 902# GROW: TEST1 903# BODY: 904# 905# (TEST2a, although required by TEST3 is not expanded in GROW - 3 906# because is has already been expanded before in GROW - 1, so it has 907# been AC_PROVIDE'd, so it is not expanded again) so when you undivert 908# the stack of diversions, you get: 909# 910# GROW - 2: 911# GROW - 1: 912# GROW: 913# BODY: TEST3; TEST2a; TEST2b; TEST1 914# 915# i.e., TEST2a is expanded after TEST3 although the latter required the 916# former. 917# 918# Starting from 2.50, uses an implementation provided by Axel Thimm. 919# The idea is simple: the order in which macros are emitted must be the 920# same as the one in which macro are expanded. (The bug above can 921# indeed be described as: a macro has been AC_PROVIDE'd, but it is 922# emitted after: the lack of correlation between emission and expansion 923# order is guilty). 924# 925# How to do that? You keeping the stack of diversions to elaborate the 926# macros, but each time a macro is fully expanded, emit it immediately. 927# 928# In the example above, when TEST2a is expanded, but it's epilogue is 929# not run yet, you have: 930# 931# GROW - 2: 932# GROW - 1: TEST2a 933# GROW: Elaboration of TEST1 934# BODY: 935# 936# The epilogue of TEST2a emits it immediately: 937# 938# GROW - 2: 939# GROW - 1: 940# GROW: Elaboration of TEST1 941# BODY: TEST2a 942# 943# TEST2b then requires TEST3, so right before the epilogue of TEST3, you 944# have: 945# 946# GROW - 2: TEST3 947# GROW - 1: Elaboration of TEST2b 948# GROW: Elaboration of TEST1 949# BODY: TEST2a 950# 951# The epilogue of TEST3 emits it: 952# 953# GROW - 2: 954# GROW - 1: Elaboration of TEST2b 955# GROW: Elaboration of TEST1 956# BODY: TEST2a; TEST3 957# 958# TEST2b is now completely expanded, and emitted: 959# 960# GROW - 2: 961# GROW - 1: 962# GROW: Elaboration of TEST1 963# BODY: TEST2a; TEST3; TEST2b 964# 965# and finally, TEST1 is finished and emitted: 966# 967# GROW - 2: 968# GROW - 1: 969# GROW: 970# BODY: TEST2a; TEST3; TEST2b: TEST1 971# 972# The idea is simple, but the implementation is a bit evolved. If you 973# are like me, you will want to see the actual functioning of this 974# implementation to be convinced. The next section gives the full 975# details. 976# 977# 978# The Axel Thimm implementation at work 979# ------------------------------------- 980# 981# We consider the macros above, and this configure.ac: 982# 983# AC_INIT 984# TEST1 985# 986# You should keep the definitions of _m4_defun_pro, _m4_defun_epi, and 987# m4_require at hand to follow the steps. 988# 989# This implements tries not to assume that the current diversion is 990# BODY, so as soon as a macro (m4_defun'd) is expanded, we first 991# record the current diversion under the name _m4_divert_dump (denoted 992# DUMP below for short). This introduces an important difference with 993# the previous versions of Autoconf: you cannot use m4_require if you 994# are not inside an m4_defun'd macro, and especially, you cannot 995# m4_require directly from the top level. 996# 997# We have not tried to simulate the old behavior (better yet, we 998# diagnose it), because it is too dangerous: a macro m4_require'd from 999# the top level is expanded before the body of `configure', i.e., before 1000# any other test was run. I let you imagine the result of requiring 1001# AC_STDC_HEADERS for instance, before AC_PROG_CC was actually run.... 1002# 1003# After AC_INIT was run, the current diversion is BODY. 1004# * AC_INIT was run 1005# DUMP: undefined 1006# diversion stack: BODY |- 1007# 1008# * TEST1 is expanded 1009# The prologue of TEST1 sets _m4_divert_dump, which is the diversion 1010# where the current elaboration will be dumped, to the current 1011# diversion. It also m4_divert_push to GROW, where the full 1012# expansion of TEST1 and its dependencies will be elaborated. 1013# DUMP: BODY 1014# BODY: empty 1015# diversions: GROW, BODY |- 1016# 1017# * TEST1 requires TEST2a 1018# _m4_require_call m4_divert_pushes another temporary diversion, 1019# GROW - 1, and expands TEST2a in there. 1020# DUMP: BODY 1021# BODY: empty 1022# GROW - 1: TEST2a 1023# diversions: GROW - 1, GROW, BODY |- 1024# Than the content of the temporary diversion is moved to DUMP and the 1025# temporary diversion is popped. 1026# DUMP: BODY 1027# BODY: TEST2a 1028# diversions: GROW, BODY |- 1029# 1030# * TEST1 requires TEST2b 1031# Again, _m4_require_call pushes GROW - 1 and heads to expand TEST2b. 1032# DUMP: BODY 1033# BODY: TEST2a 1034# diversions: GROW - 1, GROW, BODY |- 1035# 1036# * TEST2b requires TEST3 1037# _m4_require_call pushes GROW - 2 and expands TEST3 here. 1038# (TEST3 requires TEST2a, but TEST2a has already been m4_provide'd, so 1039# nothing happens.) 1040# DUMP: BODY 1041# BODY: TEST2a 1042# GROW - 2: TEST3 1043# diversions: GROW - 2, GROW - 1, GROW, BODY |- 1044# Than the diversion is appended to DUMP, and popped. 1045# DUMP: BODY 1046# BODY: TEST2a; TEST3 1047# diversions: GROW - 1, GROW, BODY |- 1048# 1049# * TEST1 requires TEST2b (contd.) 1050# The content of TEST2b is expanded... 1051# DUMP: BODY 1052# BODY: TEST2a; TEST3 1053# GROW - 1: TEST2b, 1054# diversions: GROW - 1, GROW, BODY |- 1055# ... and moved to DUMP. 1056# DUMP: BODY 1057# BODY: TEST2a; TEST3; TEST2b 1058# diversions: GROW, BODY |- 1059# 1060# * TEST1 is expanded: epilogue 1061# TEST1's own content is in GROW... 1062# DUMP: BODY 1063# BODY: TEST2a; TEST3; TEST2b 1064# GROW: TEST1 1065# diversions: BODY |- 1066# ... and it's epilogue moves it to DUMP and then undefines DUMP. 1067# DUMP: undefined 1068# BODY: TEST2a; TEST3; TEST2b; TEST1 1069# diversions: BODY |- 1070# 1071# 1072# 2. Keeping track of the expansion stack 1073# ======================================= 1074# 1075# When M4 expansion goes wrong it is often extremely hard to find the 1076# path amongst macros that drove to the failure. What is needed is 1077# the stack of macro `calls'. One could imagine that GNU M4 would 1078# maintain a stack of macro expansions, unfortunately it doesn't, so 1079# we do it by hand. This is of course extremely costly, but the help 1080# this stack provides is worth it. Nevertheless to limit the 1081# performance penalty this is implemented only for m4_defun'd macros, 1082# not for define'd macros. 1083# 1084# The scheme is simplistic: each time we enter an m4_defun'd macros, 1085# we prepend its name in m4_expansion_stack, and when we exit the 1086# macro, we remove it (thanks to pushdef/popdef). 1087# 1088# In addition, we want to detect circular m4_require dependencies. 1089# Each time we expand a macro FOO we define _m4_expanding(FOO); and 1090# m4_require(BAR) simply checks whether _m4_expanding(BAR) is defined. 1091 1092 1093# m4_expansion_stack_push(TEXT) 1094# ----------------------------- 1095m4_define([m4_expansion_stack_push], 1096[m4_pushdef([m4_expansion_stack], 1097 [$1]m4_ifdef([m4_expansion_stack], [ 1098m4_defn([m4_expansion_stack])]))]) 1099 1100 1101# m4_expansion_stack_pop 1102# ---------------------- 1103m4_define([m4_expansion_stack_pop], 1104[m4_popdef([m4_expansion_stack])]) 1105 1106 1107# m4_expansion_stack_dump 1108# ----------------------- 1109# Dump the expansion stack. 1110m4_define([m4_expansion_stack_dump], 1111[m4_ifdef([m4_expansion_stack], 1112 [m4_errprintn(m4_defn([m4_expansion_stack]))])dnl 1113m4_errprintn(m4_location[: the top level])]) 1114 1115 1116# _m4_divert(GROW) 1117# ---------------- 1118# This diversion is used by the m4_defun/m4_require machinery. It is 1119# important to keep room before GROW because for each nested 1120# AC_REQUIRE we use an additional diversion (i.e., two m4_require's 1121# will use GROW - 2. More than 3 levels has never seemed to be 1122# needed.) 1123# 1124# ... 1125# - GROW - 2 1126# m4_require'd code, 2 level deep 1127# - GROW - 1 1128# m4_require'd code, 1 level deep 1129# - GROW 1130# m4_defun'd macros are elaborated here. 1131 1132m4_define([_m4_divert(GROW)], 10000) 1133 1134 1135# _m4_defun_pro(MACRO-NAME) 1136# ------------------------- 1137# The prologue for Autoconf macros. 1138m4_define([_m4_defun_pro], 1139[m4_ifndef([m4_expansion_stack], [_m4_defun_pro_outer[]])dnl 1140m4_expansion_stack_push(m4_defn([m4_location($1)])[: $1 is expanded from...])dnl 1141m4_pushdef([_m4_expanding($1)])dnl 1142]) 1143 1144m4_define([_m4_defun_pro_outer], 1145[m4_copy([_m4_divert_diversion], [_m4_divert_dump])dnl 1146m4_divert_push([GROW])dnl 1147]) 1148 1149# _m4_defun_epi(MACRO-NAME) 1150# ------------------------- 1151# The Epilogue for Autoconf macros. MACRO-NAME only helps tracing 1152# the PRO/EPI pairs. 1153m4_define([_m4_defun_epi], 1154[m4_popdef([_m4_expanding($1)])dnl 1155m4_expansion_stack_pop()dnl 1156m4_ifndef([m4_expansion_stack], [_m4_defun_epi_outer[]])dnl 1157m4_provide([$1])dnl 1158]) 1159 1160m4_define([_m4_defun_epi_outer], 1161[m4_undefine([_m4_divert_dump])dnl 1162m4_divert_pop([GROW])dnl 1163m4_undivert([GROW])dnl 1164]) 1165 1166 1167# m4_defun(NAME, EXPANSION) 1168# ------------------------- 1169# Define a macro which automatically provides itself. Add machinery 1170# so the macro automatically switches expansion to the diversion 1171# stack if it is not already using it. In this case, once finished, 1172# it will bring back all the code accumulated in the diversion stack. 1173# This, combined with m4_require, achieves the topological ordering of 1174# macros. We don't use this macro to define some frequently called 1175# macros that are not involved in ordering constraints, to save m4 1176# processing. 1177m4_define([m4_defun], 1178[m4_define([m4_location($1)], m4_location)dnl 1179m4_define([$1], 1180 [_m4_defun_pro([$1])$2[]_m4_defun_epi([$1])])]) 1181 1182 1183# m4_defun_once(NAME, EXPANSION) 1184# ------------------------------ 1185# As m4_defun, but issues the EXPANSION only once, and warns if used 1186# several times. 1187m4_define([m4_defun_once], 1188[m4_define([m4_location($1)], m4_location)dnl 1189m4_define([$1], 1190 [m4_provide_if([$1], 1191 [m4_warn([syntax], [$1 invoked multiple times])], 1192 [_m4_defun_pro([$1])$2[]_m4_defun_epi([$1])])])]) 1193 1194 1195# m4_pattern_forbid(ERE, [WHY]) 1196# ----------------------------- 1197# Declare that no token matching the extended regular expression ERE 1198# should be seen in the output but if... 1199m4_define([m4_pattern_forbid], []) 1200 1201 1202# m4_pattern_allow(ERE) 1203# --------------------- 1204# ... but if that token matches the extended regular expression ERE. 1205# Both used via traces. 1206m4_define([m4_pattern_allow], []) 1207 1208 1209## ----------------------------- ## 1210## Dependencies between macros. ## 1211## ----------------------------- ## 1212 1213 1214# m4_before(THIS-MACRO-NAME, CALLED-MACRO-NAME) 1215# --------------------------------------------- 1216m4_define([m4_before], 1217[m4_provide_if([$2], 1218 [m4_warn([syntax], [$2 was called before $1])])]) 1219 1220 1221# m4_require(NAME-TO-CHECK, [BODY-TO-EXPAND = NAME-TO-CHECK]) 1222# ----------------------------------------------------------- 1223# If NAME-TO-CHECK has never been expanded (actually, if it is not 1224# m4_provide'd), expand BODY-TO-EXPAND *before* the current macro 1225# expansion. Once expanded, emit it in _m4_divert_dump. Keep track 1226# of the m4_require chain in m4_expansion_stack. 1227# 1228# The normal cases are: 1229# 1230# - NAME-TO-CHECK == BODY-TO-EXPAND 1231# Which you can use for regular macros with or without arguments, e.g., 1232# m4_require([AC_PROG_CC], [AC_PROG_CC]) 1233# m4_require([AC_CHECK_HEADERS(limits.h)], [AC_CHECK_HEADERS(limits.h)]) 1234# which is just the same as 1235# m4_require([AC_PROG_CC]) 1236# m4_require([AC_CHECK_HEADERS(limits.h)]) 1237# 1238# - BODY-TO-EXPAND == m4_indir([NAME-TO-CHECK]) 1239# In the case of macros with irregular names. For instance: 1240# m4_require([AC_LANG_COMPILER(C)], [indir([AC_LANG_COMPILER(C)])]) 1241# which means `if the macro named `AC_LANG_COMPILER(C)' (the parens are 1242# part of the name, it is not an argument) has not been run, then 1243# call it.' 1244# Had you used 1245# m4_require([AC_LANG_COMPILER(C)], [AC_LANG_COMPILER(C)]) 1246# then m4_require would have tried to expand `AC_LANG_COMPILER(C)', i.e., 1247# call the macro `AC_LANG_COMPILER' with `C' as argument. 1248# 1249# You could argue that `AC_LANG_COMPILER', when it receives an argument 1250# such as `C' should dispatch the call to `AC_LANG_COMPILER(C)'. But this 1251# `extension' prevents `AC_LANG_COMPILER' from having actual arguments that 1252# it passes to `AC_LANG_COMPILER(C)'. 1253m4_define([m4_require], 1254[m4_ifdef([_m4_expanding($1)], 1255 [m4_fatal([$0: circular dependency of $1])])dnl 1256m4_ifndef([_m4_divert_dump], 1257 [m4_fatal([$0($1): cannot be used outside of an ]dnl 1258m4_bmatch([$0], [^AC_], [[AC_DEFUN]], [[m4_defun]])['d macro])])dnl 1259m4_provide_if([$1], 1260 [], 1261 [_m4_require_call([$1], [$2])])dnl 1262]) 1263 1264 1265# _m4_require_call(BODY-TO-EXPAND) 1266# -------------------------------- 1267# If m4_require decides to expand the body, it calls this macro. 1268m4_define([_m4_require_call], 1269[m4_define([_m4_divert_grow], m4_decr(_m4_divert_grow))dnl 1270m4_divert_push(_m4_divert_grow)dnl 1271m4_default([$2], [$1]) 1272m4_provide_if([$1], 1273 [], 1274 [m4_warn([syntax], 1275 [$1 is m4_require'd but not m4_defun'd])])dnl 1276m4_divert(m4_defn([_m4_divert_dump]))dnl 1277m4_undivert(_m4_divert_grow)dnl 1278m4_divert_pop(_m4_divert_grow)dnl 1279m4_define([_m4_divert_grow], m4_incr(_m4_divert_grow))dnl 1280]) 1281 1282 1283# _m4_divert_grow 1284# --------------- 1285# The counter for _m4_require_call. 1286m4_define([_m4_divert_grow], _m4_divert([GROW])) 1287 1288 1289# m4_expand_once(TEXT, [WITNESS = TEXT]) 1290# -------------------------------------- 1291# If TEXT has never been expanded, expand it *here*. Use WITNESS as 1292# as a memory that TEXT has already been expanded. 1293m4_define([m4_expand_once], 1294[m4_provide_if(m4_ifval([$2], [[$2]], [[$1]]), 1295 [], 1296 [m4_provide(m4_ifval([$2], [[$2]], [[$1]]))[]$1])]) 1297 1298 1299# m4_provide(MACRO-NAME) 1300# ---------------------- 1301m4_define([m4_provide], 1302[m4_define([m4_provide($1)])]) 1303 1304 1305# m4_provide_if(MACRO-NAME, IF-PROVIDED, IF-NOT-PROVIDED) 1306# ------------------------------------------------------- 1307# If MACRO-NAME is provided do IF-PROVIDED, else IF-NOT-PROVIDED. 1308# The purpose of this macro is to provide the user with a means to 1309# check macros which are provided without letting her know how the 1310# information is coded. 1311m4_define([m4_provide_if], 1312[m4_ifdef([m4_provide($1)], 1313 [$2], [$3])]) 1314 1315 1316## -------------------- ## 1317## 9. Text processing. ## 1318## -------------------- ## 1319 1320 1321# m4_cr_letters 1322# m4_cr_LETTERS 1323# m4_cr_Letters 1324# ------------- 1325m4_define([m4_cr_letters], [abcdefghijklmnopqrstuvwxyz]) 1326m4_define([m4_cr_LETTERS], [ABCDEFGHIJKLMNOPQRSTUVWXYZ]) 1327m4_define([m4_cr_Letters], 1328m4_defn([m4_cr_letters])dnl 1329m4_defn([m4_cr_LETTERS])dnl 1330) 1331 1332 1333# m4_cr_digits 1334# ------------ 1335m4_define([m4_cr_digits], [0123456789]) 1336 1337 1338# m4_cr_symbols1 & m4_cr_symbols2 1339# ------------------------------- 1340m4_define([m4_cr_symbols1], 1341m4_defn([m4_cr_Letters])dnl 1342_) 1343 1344m4_define([m4_cr_symbols2], 1345m4_defn([m4_cr_symbols1])dnl 1346m4_defn([m4_cr_digits])dnl 1347) 1348 1349 1350# m4_re_escape(STRING) 1351# -------------------- 1352# Escape RE active characters in STRING. 1353m4_define([m4_re_escape], 1354[m4_bpatsubst([$1], 1355 [[][*+.?\^$]], [\\\&])]) 1356 1357 1358# m4_re_string 1359# ------------ 1360# Regexp for `[a-zA-Z_0-9]*' 1361# m4_dquote provides literal [] for the character class. 1362m4_define([m4_re_string], 1363m4_dquote(m4_defn([m4_cr_symbols2]))dnl 1364[*]dnl 1365) 1366 1367 1368# m4_re_word 1369# ---------- 1370# Regexp for `[a-zA-Z_][a-zA-Z_0-9]*' 1371m4_define([m4_re_word], 1372m4_dquote(m4_defn([m4_cr_symbols1]))dnl 1373m4_defn([m4_re_string])dnl 1374) 1375 1376 1377# m4_tolower(STRING) 1378# m4_toupper(STRING) 1379# ------------------ 1380# These macros lowercase and uppercase strings. 1381m4_define([m4_tolower], 1382[m4_translit([$1], m4_defn([m4_cr_LETTERS]), m4_defn([m4_cr_letters]))]) 1383m4_define([m4_toupper], 1384[m4_translit([$1], m4_defn([m4_cr_letters]), m4_defn([m4_cr_LETTERS]))]) 1385 1386 1387# m4_split(STRING, [REGEXP]) 1388# -------------------------- 1389# 1390# Split STRING into an m4 list of quoted elements. The elements are 1391# quoted with [ and ]. Beginning spaces and end spaces *are kept*. 1392# Use m4_strip to remove them. 1393# 1394# REGEXP specifies where to split. Default is [\t ]+. 1395# 1396# If STRING is empty, the result is an empty list. 1397# 1398# Pay attention to the m4_changequotes. When m4 reads the definition of 1399# m4_split, it still has quotes set to [ and ]. Luckily, these are matched 1400# in the macro body, so the definition is stored correctly. 1401# 1402# Also, notice that $1 is quoted twice, since we want the result to 1403# be quoted. Then you should understand that the argument of 1404# patsubst is ``STRING'' (i.e., with additional `` and ''). 1405# 1406# This macro is safe on active symbols, i.e.: 1407# m4_define(active, ACTIVE) 1408# m4_split([active active ])end 1409# => [active], [active], []end 1410 1411m4_define([m4_split], 1412[m4_ifval([$1], [_m4_split($@)])]) 1413 1414m4_define([_m4_split], 1415[m4_changequote(``, '')dnl 1416[dnl Can't use m4_default here instead of m4_if, because m4_default uses 1417dnl [ and ] as quotes. 1418m4_bpatsubst(````$1'''', 1419 m4_if(``$2'',, ``[ ]+'', ``$2''), 1420 ``], ['')]dnl 1421m4_changequote([, ])]) 1422 1423 1424 1425# m4_flatten(STRING) 1426# ------------------ 1427# If STRING contains end of lines, replace them with spaces. If there 1428# are backslashed end of lines, remove them. This macro is safe with 1429# active symbols. 1430# m4_define(active, ACTIVE) 1431# m4_flatten([active 1432# act\ 1433# ive])end 1434# => active activeend 1435m4_define([m4_flatten], 1436[m4_translit(m4_bpatsubst([[[$1]]], [\\ 1437]), [ 1438], [ ])]) 1439 1440 1441# m4_strip(STRING) 1442# ---------------- 1443# Expands into STRING with tabs and spaces singled out into a single 1444# space, and removing leading and trailing spaces. 1445# 1446# This macro is robust to active symbols. 1447# m4_define(active, ACTIVE) 1448# m4_strip([ active <tab> <tab>active ])end 1449# => active activeend 1450# 1451# Because we want to preserve active symbols, STRING must be double-quoted. 1452# 1453# Then notice the 2 last patterns: they are in charge of removing the 1454# leading/trailing spaces. Why not just `[^ ]'? Because they are 1455# applied to doubly quoted strings, i.e. more or less [[STRING]]. So 1456# if there is a leading space in STRING, then it is the *third* 1457# character, since there are two leading `['; equally for the last pattern. 1458m4_define([m4_strip], 1459[m4_bpatsubsts([[$1]], 1460 [[ ]+], [ ], 1461 [^\(..\) ], [\1], 1462 [ \(..\)$], [\1])]) 1463 1464 1465# m4_normalize(STRING) 1466# -------------------- 1467# Apply m4_flatten and m4_strip to STRING. 1468# 1469# The argument is quoted, so that the macro is robust to active symbols: 1470# 1471# m4_define(active, ACTIVE) 1472# m4_normalize([ act\ 1473# ive 1474# active ])end 1475# => active activeend 1476 1477m4_define([m4_normalize], 1478[m4_strip(m4_flatten([$1]))]) 1479 1480 1481 1482# m4_join(SEP, ARG1, ARG2...) 1483# --------------------------- 1484# Produce ARG1SEPARG2...SEPARGn. 1485m4_defun([m4_join], 1486[m4_case([$#], 1487 [1], [], 1488 [2], [[$2]], 1489 [[$2][$1]$0([$1], m4_shiftn(2, $@))])]) 1490 1491 1492 1493# m4_append(MACRO-NAME, STRING, [SEPARATOR]) 1494# ------------------------------------------ 1495# Redefine MACRO-NAME to hold its former content plus `SEPARATOR`'STRING' 1496# at the end. It is valid to use this macro with MACRO-NAME undefined, 1497# in which case no SEPARATOR is added. Be aware that the criterion is 1498# `not being defined', and not `not being empty'. 1499# 1500# This macro is robust to active symbols. It can be used to grow 1501# strings. 1502# 1503# | m4_define(active, ACTIVE) 1504# | m4_append([sentence], [This is an]) 1505# | m4_append([sentence], [ active ]) 1506# | m4_append([sentence], [symbol.]) 1507# | sentence 1508# | m4_undefine([active])dnl 1509# | sentence 1510# => This is an ACTIVE symbol. 1511# => This is an active symbol. 1512# 1513# It can be used to define hooks. 1514# 1515# | m4_define(active, ACTIVE) 1516# | m4_append([hooks], [m4_define([act1], [act2])]) 1517# | m4_append([hooks], [m4_define([act2], [active])]) 1518# | m4_undefine([active]) 1519# | act1 1520# | hooks 1521# | act1 1522# => act1 1523# => 1524# => active 1525m4_define([m4_append], 1526[m4_define([$1], 1527 m4_ifdef([$1], [m4_defn([$1])$3])[$2])]) 1528 1529 1530# m4_append_uniq(MACRO-NAME, STRING, [SEPARATOR]) 1531# ----------------------------------------------- 1532# As `m4_append', but append only if not yet present. 1533m4_define([m4_append_uniq], 1534[m4_ifdef([$1], 1535 [m4_bmatch([$3]m4_defn([$1])[$3], m4_re_escape([$3$2$3]), [], 1536 [m4_append($@)])], 1537 [m4_append($@)])]) 1538 1539 1540# m4_text_wrap(STRING, [PREFIX], [FIRST-PREFIX], [WIDTH]) 1541# ------------------------------------------------------- 1542# Expands into STRING wrapped to hold in WIDTH columns (default = 79). 1543# If PREFIX is given, each line is prefixed with it. If FIRST-PREFIX is 1544# specified, then the first line is prefixed with it. As a special case, 1545# if the length of FIRST-PREFIX is greater than that of PREFIX, then 1546# FIRST-PREFIX will be left alone on the first line. 1547# 1548# Typical outputs are: 1549# 1550# m4_text_wrap([Short string */], [ ], [/* ], 20) 1551# => /* Short string */ 1552# 1553# m4_text_wrap([Much longer string */], [ ], [/* ], 20) 1554# => /* Much longer 1555# => string */ 1556# 1557# m4_text_wrap([Short doc.], [ ], [ --short ], 30) 1558# => --short Short doc. 1559# 1560# m4_text_wrap([Short doc.], [ ], [ --too-wide ], 30) 1561# => --too-wide 1562# => Short doc. 1563# 1564# m4_text_wrap([Super long documentation.], [ ], [ --too-wide ], 30) 1565# => --too-wide 1566# => Super long 1567# => documentation. 1568# 1569# FIXME: there is no checking of a longer PREFIX than WIDTH, but do 1570# we really want to bother with people trying each single corner 1571# of a software? 1572# 1573# This macro does not leave a trailing space behind the last word, 1574# what complicates it a bit. The algorithm is stupid simple: all the 1575# words are preceded by m4_Separator which is defined to empty for the 1576# first word, and then ` ' (single space) for all the others. 1577m4_define([m4_text_wrap], 1578[m4_pushdef([m4_Prefix], [$2])dnl 1579m4_pushdef([m4_Prefix1], m4_default([$3], [m4_Prefix]))dnl 1580m4_pushdef([m4_Width], m4_default([$4], 79))dnl 1581m4_pushdef([m4_Cursor], m4_qlen(m4_Prefix1))dnl 1582m4_pushdef([m4_Separator], [])dnl 1583m4_Prefix1[]dnl 1584m4_if(m4_eval(m4_qlen(m4_Prefix1) > m4_len(m4_Prefix)), 1585 1, [m4_define([m4_Cursor], m4_len(m4_Prefix)) 1586m4_Prefix], 1587 m4_if(m4_eval(m4_qlen(m4_Prefix1) < m4_len(m4_Prefix)), 1588 [0], [], 1589 [m4_define([m4_Cursor], m4_len(m4_Prefix))[]dnl 1590m4_for(m4_Space, m4_qlen(m4_Prefix1), m4_eval(m4_len(m4_Prefix) - 1), 1591 [], [ ])])[]dnl 1592)[]dnl 1593m4_foreach_w([m4_Word], [$1], 1594[m4_define([m4_Cursor], m4_eval(m4_Cursor + m4_qlen(m4_defn([m4_Word])) + 1))dnl 1595dnl New line if too long, else insert a space unless it is the first 1596dnl of the words. 1597m4_if(m4_eval(m4_Cursor > m4_Width), 1598 1, [m4_define([m4_Cursor], 1599 m4_eval(m4_len(m4_Prefix) + m4_qlen(m4_defn([m4_Word])) + 1))] 1600m4_Prefix, 1601 [m4_Separator])[]dnl 1602m4_defn([m4_Word])[]dnl 1603m4_define([m4_Separator], [ ])])dnl 1604m4_popdef([m4_Separator])dnl 1605m4_popdef([m4_Cursor])dnl 1606m4_popdef([m4_Width])dnl 1607m4_popdef([m4_Prefix1])dnl 1608m4_popdef([m4_Prefix])dnl 1609]) 1610 1611 1612# m4_text_box(MESSAGE, [FRAME-CHARACTER = `-']) 1613# --------------------------------------------- 1614m4_define([m4_text_box], 1615[@%:@@%:@ m4_bpatsubst([$1], [.], m4_if([$2], [], [[-]], [[$2]])) @%:@@%:@ 1616@%:@@%:@ $1 @%:@@%:@ 1617@%:@@%:@ m4_bpatsubst([$1], [.], m4_if([$2], [], [[-]], [[$2]])) @%:@@%:@[]dnl 1618]) 1619 1620 1621# m4_qlen(STRING) 1622# --------------- 1623# Expands to the length of STRING after autom4te converts all quadrigraphs. 1624m4_define([m4_qlen], 1625[m4_len(m4_bpatsubsts([[$1]], [@\(<:\|:>\|S|\|%:\)@], [P], [@&t@]))]) 1626 1627 1628# m4_qdelta(STRING) 1629# ----------------- 1630# Expands to the net change in the length of STRING from autom4te converting the 1631# quadrigraphs in STRING. This number is always negative or zero. 1632m4_define([m4_qdelta], 1633[m4_eval(m4_qlen([$1]) - m4_len([$1]))]) 1634 1635 1636 1637## ----------------------- ## 1638## 10. Number processing. ## 1639## ----------------------- ## 1640 1641# m4_sign(A) 1642# ---------- 1643# 1644# The sign of the integer A. 1645m4_define([m4_sign], 1646[m4_bmatch([$1], 1647 [^-], -1, 1648 [^0+], 0, 1649 1)]) 1650 1651# m4_cmp(A, B) 1652# ------------ 1653# 1654# Compare two integers. 1655# A < B -> -1 1656# A = B -> 0 1657# A > B -> 1 1658m4_define([m4_cmp], 1659[m4_sign(m4_eval([$1 - $2]))]) 1660 1661 1662# m4_list_cmp(A, B) 1663# ----------------- 1664# 1665# Compare the two lists of integers A and B. For instance: 1666# m4_list_cmp((1, 0), (1)) -> 0 1667# m4_list_cmp((1, 0), (1, 0)) -> 0 1668# m4_list_cmp((1, 2), (1, 0)) -> 1 1669# m4_list_cmp((1, 2, 3), (1, 2)) -> 1 1670# m4_list_cmp((1, 2, -3), (1, 2)) -> -1 1671# m4_list_cmp((1, 0), (1, 2)) -> -1 1672# m4_list_cmp((1), (1, 2)) -> -1 1673m4_define([m4_list_cmp], 1674[m4_if([$1$2], [()()], 0, 1675 [$1], [()], [$0((0), [$2])], 1676 [$2], [()], [$0([$1], (0))], 1677 [m4_case(m4_cmp(m4_car$1, m4_car$2), 1678 -1, -1, 1679 1, 1, 1680 0, [$0((m4_shift$1), (m4_shift$2))])])]) 1681 1682 1683 1684## ------------------------ ## 1685## 11. Version processing. ## 1686## ------------------------ ## 1687 1688 1689# m4_version_unletter(VERSION) 1690# ---------------------------- 1691# Normalize beta version numbers with letters to numbers only for comparison. 1692# 1693# Nl -> (N+1).-1.(l#) 1694# 1695#i.e., 2.14a -> 2.15.-1.1, 2.14b -> 2.15.-1.2, etc. 1696# This macro is absolutely not robust to active macro, it expects 1697# reasonable version numbers and is valid up to `z', no double letters. 1698m4_define([m4_version_unletter], 1699[m4_translit(m4_bpatsubsts([$1], 1700 [\([0-9]+\)\([abcdefghi]\)], 1701 [m4_eval(\1 + 1).-1.\2], 1702 [\([0-9]+\)\([jklmnopqrs]\)], 1703 [m4_eval(\1 + 1).-1.1\2], 1704 [\([0-9]+\)\([tuvwxyz]\)], 1705 [m4_eval(\1 + 1).-1.2\2]), 1706 [abcdefghijklmnopqrstuvwxyz], 1707 [12345678901234567890123456])]) 1708 1709 1710# m4_version_compare(VERSION-1, VERSION-2) 1711# ---------------------------------------- 1712# Compare the two version numbers and expand into 1713# -1 if VERSION-1 < VERSION-2 1714# 0 if = 1715# 1 if > 1716m4_define([m4_version_compare], 1717[m4_list_cmp((m4_split(m4_version_unletter([$1]), [\.])), 1718 (m4_split(m4_version_unletter([$2]), [\.])))]) 1719 1720 1721# m4_PACKAGE_NAME 1722# m4_PACKAGE_TARNAME 1723# m4_PACKAGE_VERSION 1724# m4_PACKAGE_STRING 1725# m4_PACKAGE_BUGREPORT 1726# -------------------- 1727m4_include([m4sugar/version.m4]) 1728 1729 1730# m4_version_prereq(VERSION, [IF-OK], [IF-NOT = FAIL]) 1731# ---------------------------------------------------- 1732# Check this Autoconf version against VERSION. 1733m4_define([m4_version_prereq], 1734[m4_if(m4_version_compare(m4_defn([m4_PACKAGE_VERSION]), [$1]), -1, 1735 [m4_default([$3], 1736 [m4_fatal([Autoconf version $1 or higher is required], 1737 63)])], 1738 [$2])[]dnl 1739]) 1740 1741 1742 1743## ------------------- ## 1744## 12. File handling. ## 1745## ------------------- ## 1746 1747 1748# It is a real pity that M4 comes with no macros to bind a diversion 1749# to a file. So we have to deal without, which makes us a lot more 1750# fragile that we should. 1751 1752 1753# m4_file_append(FILE-NAME, CONTENT) 1754# ---------------------------------- 1755m4_define([m4_file_append], 1756[m4_syscmd([cat >>$1 <<_m4eof 1757$2 1758_m4eof 1759]) 1760m4_if(m4_sysval, [0], [], 1761 [m4_fatal([$0: cannot write: $1])])]) 1762 1763 1764 1765## ------------------------ ## 1766## 13. Setting M4sugar up. ## 1767## ------------------------ ## 1768 1769 1770# m4_init 1771# ------- 1772m4_define([m4_init], 1773[# All the M4sugar macros start with `m4_', except `dnl' kept as is 1774# for sake of simplicity. 1775m4_pattern_forbid([^_?m4_]) 1776m4_pattern_forbid([^dnl$]) 1777 1778# _m4_divert_diversion should be defined: 1779m4_divert_push([KILL]) 1780 1781# Check the divert push/pop perfect balance. 1782m4_wrap([m4_divert_pop([]) 1783 m4_ifdef([_m4_divert_diversion], 1784 [m4_fatal([$0: unbalanced m4_divert_push:]_m4_divert_n_stack)])[]]) 1785]) 1786