This file is indexed.

/usr/bin/autom4te2.64 is in autoconf2.64 2.64+dfsg-0.1.

This file is owned by root:root, with mode 0o755.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
#! /usr/bin/perl -w
# -*- perl -*-
# Generated from autom4te.in; do not edit by hand.

eval 'case $# in 0) exec /usr/bin/perl -S "$0";; *) exec /usr/bin/perl -S "$0" "$@";; esac'
    if 0;

# autom4te - Wrapper around M4 libraries.
# Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009 Free
# Software Foundation, Inc.

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.


BEGIN
{
  my $pkgdatadir = $ENV{'autom4te_perllibdir'} || '/usr/share/autoconf2.64';
  unshift @INC, $pkgdatadir;

  # Override SHELL.  On DJGPP SHELL may not be set to a shell
  # that can handle redirection and quote arguments correctly,
  # e.g.: COMMAND.COM.  For DJGPP always use the shell that configure
  # has detected.
  $ENV{'SHELL'} = '/bin/bash' if ($^O eq 'dos');
}

use Autom4te::C4che;
use Autom4te::ChannelDefs;
use Autom4te::Channels;
use Autom4te::FileUtils;
use Autom4te::General;
use Autom4te::XFile;
use File::Basename;
use strict;

# Data directory.
my $pkgdatadir = $ENV{'AC_MACRODIR'} || '/usr/share/autoconf2.64';

# $LANGUAGE{LANGUAGE} -- Automatic options for LANGUAGE.
my %language;

my $output = '-';

# Mode of the output file except for traces.
my $mode = "0666";

# If melt, don't use frozen files.
my $melt = 0;

# Names of the cache directory, cache directory index, trace cache
# prefix, and output cache prefix.  And the IO object for the index.
my $cache;
my $icache;
my $tcache;
my $ocache;
my $icache_file;

# The macros to trace mapped to their format, as specified by the
# user.
my %trace;

# The macros the user will want to trace in the future.
# We need `include' to get the included file, `m4_pattern_forbid' and
# `m4_pattern_allow' to check the output.
#
# FIXME: What about `sinclude'?
my @preselect = ('include',
		 'm4_pattern_allow', 'm4_pattern_forbid',
		 '_m4_warn');

# M4 include path.
my @include;

# Do we freeze?
my $freeze = 0;

# $M4.
my $m4 = $ENV{"M4"} || '/usr/bin/m4';
# Some non-GNU m4's don't reject the --help option, so give them /dev/null.
fatal "need GNU m4 1.4 or later: $m4"
  if system "$m4 --help </dev/null 2>&1 | grep reload-state >/dev/null";

# Set some high recursion limit as the default limit, 250, has already
# been hit with AC_OUTPUT.  Don't override the user's choice.
$m4 .= ' --nesting-limit=1024'
  if " $m4 " !~ / (--nesting-limit(=[0-9]+)?|-L[0-9]*) /;


# @M4_BUILTIN -- M4 builtins and a useful comment.
my @m4_builtin = `echo dumpdef | $m4 2>&1 >/dev/null`;
map { s/:.*//;s/\W// } @m4_builtin;


# %M4_BUILTIN_ALTERNATE_NAME
# --------------------------
# The builtins are renamed, e.g., `define' is renamed `m4_define'.
# So map `define' to `m4_define' and conversely.
# Some macros don't follow this scheme: be sure to properly map to their
# alternate name too.
#
# FIXME: Trace status of renamed builtins was fixed in M4 1.4.5, which
# we now depend on; do we still need to do this mapping?
#
# So we will merge them, i.e., tracing `BUILTIN' or tracing
# `m4_BUILTIN' will be the same: tracing both, but honoring the
# *last* trace specification.
#
# FIXME: This is not enough: in the output `$0' will be `BUILTIN'
# sometimes and `m4_BUILTIN' at others.  We should return a unique name,
# the one specified by the user.
#
# FIXME: To be absolutely rigorous, I would say that given that we
# _redefine_ divert (instead of _copying_ it), divert and the like
# should not be part of this list.
my %m4_builtin_alternate_name;
@m4_builtin_alternate_name{"$_", "m4_$_"} = ("m4_$_", "$_")
  foreach (grep { !/m4wrap|m4exit|dnl|ifelse|__.*__/ } @m4_builtin);
@m4_builtin_alternate_name{"ifelse", "m4_if"}   = ("m4_if", "ifelse");
@m4_builtin_alternate_name{"m4exit", "m4_exit"} = ("m4_exit", "m4exit");
@m4_builtin_alternate_name{"m4wrap", "m4_wrap"} = ("m4_wrap", "m4wrap");


# $HELP
# -----
$help = "Usage: $0 [OPTION]... [FILES]

Run GNU M4 on the FILES, avoiding useless runs.  Output the traces if tracing,
the frozen file if freezing, otherwise the expansion of the FILES.

If some of the FILES are named \`FILE.m4f\' they are considered to be M4
frozen files of all the previous files (which are therefore not loaded).
If \`FILE.m4f\' is not found, then \`FILE.m4\' will be used, together with
all the previous files.

Some files may be optional, i.e., will only be processed if found in the
include path, but then must end in \`.m4?\';  the question mark is not part of
the actual file name.

Operation modes:
  -h, --help               print this help, then exit
  -V, --version            print version number, then exit
  -v, --verbose            verbosely report processing
  -d, --debug              don\'t remove temporary files
  -o, --output=FILE        save output in FILE (defaults to \`-\', stdout)
  -f, --force              don\'t rely on cached values
  -W, --warnings=CATEGORY  report the warnings falling in CATEGORY
  -l, --language=LANG      specify the set of M4 macros to use
  -C, --cache=DIRECTORY    preserve results for future runs in DIRECTORY
      --no-cache           disable the cache
  -m, --mode=OCTAL         change the non trace output file mode (0666)
  -M, --melt               don\'t use M4 frozen files

Languages include:
  \`Autoconf\'   create Autoconf configure scripts
  \`Autotest\'   create Autotest test suites
  \`M4sh\'       create M4sh shell scripts
  \`M4sugar\'    create M4sugar output

" . Autom4te::ChannelDefs::usage . "

The environment variables \`M4\' and \`WARNINGS\' are honored.

Library directories:
  -B, --prepend-include=DIR  prepend directory DIR to search path
  -I, --include=DIR          append directory DIR to search path

Tracing:
  -t, --trace=MACRO[:FORMAT]  report the MACRO invocations
  -p, --preselect=MACRO       prepare to trace MACRO in a future run

Freezing:
  -F, --freeze   produce an M4 frozen state file for FILES

FORMAT defaults to \`\$f:\$l:\$n:\$%\', and can use the following escapes:
  \$\$     literal \$
  \$f     file where macro was called
  \$l     line where macro was called
  \$d     nesting depth of macro call
  \$n     name of the macro
  \$NUM   argument NUM, unquoted and with newlines
  \$SEP\@  all arguments, with newlines, quoted, and separated by SEP
  \$SEP*  all arguments, with newlines, unquoted, and separated by SEP
  \$SEP%  all arguments, without newlines, unquoted, and separated by SEP
SEP can be empty for the default (comma for \@ and *, colon for %),
a single character for that character, or {STRING} to use a string.

Report bugs to <bug-autoconf\@gnu.org>.
GNU Autoconf home page: <http://www.gnu.org/software/autoconf/>.
General help using GNU software: <http://www.gnu.org/gethelp/>.
";

# $VERSION
# --------
$version =  <<"EOF";
autom4te (GNU Autoconf) 2.64
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv2+: GNU GPL version 2 or later
<http://gnu.org/licenses/old-licenses/gpl-2.0.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Akim Demaille.
EOF


## ---------- ##
## Routines.  ##
## ---------- ##


# $OPTION
# files_to_options (@FILE)
# ------------------------
# Transform Autom4te conventions (e.g., using foo.m4f to designate a frozen
# file) into a suitable command line for M4 (e.g., using --reload-state).
# parse_args guarantees that we will see at most one frozen file, and that
# if a frozen file is present, it is the first argument.
sub files_to_options (@)
{
  my (@file) = @_;
  my @res;
  foreach my $file (@file)
    {
      my $arg = shell_quote ($file);
      if ($file =~ /\.m4f$/)
	{
	  $arg = "--reload-state=$arg";
	  # If the user downgraded M4 from 1.6 to 1.4.x after freezing
	  # the file, then we ensure the frozen __m4_version__ will
	  # not cause m4_init to make the wrong decision about the
	  # current M4 version.
	  $arg .= " --undefine=__m4_version__"
	    unless grep {/__m4_version__/} @m4_builtin;
	}
      push @res, $arg;
    }
  return join ' ', @res;
}


# load_configuration ($FILE)
# --------------------------
# Load the configuration $FILE.
sub load_configuration ($)
{
  my ($file) = @_;
  use Text::ParseWords;

  my $cfg = new Autom4te::XFile ("< " . open_quote ($file));
  my $lang;
  while ($_ = $cfg->getline)
    {
      chomp;
      # Comments.
      next
	if /^\s*(\#.*)?$/;

      my @words = shellwords ($_);
      my $type = shift @words;
      if ($type eq 'begin-language:')
	{
	  fatal "$file:$.: end-language missing for: $lang"
	    if defined $lang;
	  $lang = lc $words[0];
	}
      elsif ($type eq 'end-language:')
	{
	  error "$file:$.: end-language mismatch: $lang"
	    if $lang ne lc $words[0];
	  $lang = undef;
	}
      elsif ($type eq 'args:')
	{
	  fatal "$file:$.: no current language"
	    unless defined $lang;
	  push @{$language{$lang}}, @words;
	}
      else
	{
	  error "$file:$.: unknown directive: $type";
	}
    }
}


# parse_args ()
# -------------
# Process any command line arguments.
sub parse_args ()
{
  # We want to look for the early options, which should not be found
  # in the configuration file.  Prepend to the user arguments.
  # Perform this repeatedly so that we can use --language in language
  # definitions.  Beware that there can be several --language
  # invocations.
  my @language;
  do {
    @language = ();
    use Getopt::Long;
    Getopt::Long::Configure ("pass_through", "permute");
    GetOptions ("l|language=s" => \@language);

    foreach (@language)
      {
	error "unknown language: $_"
	  unless exists $language{lc $_};
	unshift @ARGV, @{$language{lc $_}};
      }
  } while @language;

  # --debug is useless: it is parsed below.
  if (exists $ENV{'AUTOM4TE_DEBUG'})
    {
      print STDERR "$me: concrete arguments:\n";
      foreach my $arg (@ARGV)
	{
	  print STDERR "| $arg\n";
	}
    }

  # Process the arguments for real this time.
  my @trace;
  my @prepend_include;
  parse_WARNINGS;
  getopt
    (
     # Operation modes:
     "o|output=s"   => \$output,
     "W|warnings=s" => \&parse_warnings,
     "m|mode=s"     => \$mode,
     "M|melt"       => \$melt,

     # Library directories:
     "B|prepend-include=s" => \@prepend_include,
     "I|include=s"         => \@include,

     # Tracing:
     # Using a hash for traces is seducing.  Unfortunately, upon `-t FOO',
     # instead of mapping `FOO' to undef, Getopt maps it to `1', preventing
     # us from distinguishing `-t FOO' from `-t FOO=1'.  So let's do it
     # by hand.
     "t|trace=s"     => \@trace,
     "p|preselect=s" => \@preselect,

     # Freezing.
     "F|freeze" => \$freeze,

     # Caching.
     "C|cache=s" => \$cache,
     "no-cache"  => sub { $cache = undef; },
    );

  fatal "too few arguments
Try `$me --help' for more information."
    unless @ARGV;

  # Freezing:
  # We cannot trace at the same time (well, we can, but it sounds insane).
  # And it implies melting: there is risk not to update properly using
  # old frozen files, and worse yet: we could load a frozen file and
  # refreeze it!  A sort of caching :)
  fatal "cannot freeze and trace"
    if $freeze && @trace;
  $melt = 1
    if $freeze;

  # Names of the cache directory, cache directory index, trace cache
  # prefix, and output cache prefix.  If the cache is not to be
  # preserved, default to a temporary directory (automatically removed
  # on exit).
  $cache = $tmp
    unless $cache;
  $icache = "$cache/requests";
  $tcache = "$cache/traces.";
  $ocache = "$cache/output.";

  # Normalize the includes: the first occurrence is enough, several is
  # a pain since it introduces a useless difference in the path which
  # invalidates the cache.  And strip `.' which is implicit and always
  # first.
  @include = grep { !/^\.$/ } uniq (reverse(@prepend_include), @include);

  # Convert @trace to %trace, and work around the M4 builtins tracing
  # problem.
  # The default format is `$f:$l:$n:$%'.
  foreach (@trace)
    {
      /^([^:]+)(?::(.*))?$/ms;
      $trace{$1} = defined $2 ? $2 : '$f:$l:$n:$%';
      $trace{$m4_builtin_alternate_name{$1}} = $trace{$1}
	if exists $m4_builtin_alternate_name{$1};
    }

  # Work around the M4 builtins tracing problem for @PRESELECT.
  # FIXME: Is this still needed, now that we rely on M4 1.4.5?
  push (@preselect,
	map { $m4_builtin_alternate_name{$_} }
	grep { exists $m4_builtin_alternate_name{$_} } @preselect);

  # If we find frozen files, then all the files before it are
  # discarded: the frozen file is supposed to include them all.
  #
  # We don't want to depend upon m4's --include to find the top level
  # files, so we use `find_file' here.  Try to get a canonical name,
  # as it's part of the key for caching.  And some files are optional
  # (also handled by `find_file').
  my @argv;
  foreach (@ARGV)
    {
      if ($_ eq '-')
	{
	  push @argv, $_;
	}
      elsif (/\.m4f$/)
	{
	  # Frozen files are optional => pass a `?' to `find_file'.
	  my $file = find_file ("$_?", @include);
	  if (!$melt && $file)
	    {
	      @argv = ($file);
	    }
	  else
	    {
	      s/\.m4f$/.m4/;
	      push @argv, find_file ($_, @include);
	    }
	}
      else
	{
	  my $file = find_file ($_, @include);
	  push @argv, $file
	    if $file;
	}
    }
  @ARGV = @argv;
}


# handle_m4 ($REQ, @MACRO)
# ------------------------
# Run m4 on the input files, and save the traces on the @MACRO.
sub handle_m4 ($@)
{
  my ($req, @macro) = @_;

  # GNU m4 appends when using --debugfile/--error-output.
  unlink ($tcache . $req->id . "t");

  # Run m4.
  #
  # We don't output directly to the cache files, to avoid problems
  # when we are interrupted (that leaves corrupted files).
  xsystem ("$m4 --gnu"
	   . join (' --include=', '', map { shell_quote ($_) } @include)
	   . ' --debug=aflq'
	   . (!exists $ENV{'AUTOM4TE_NO_FATAL'} ? ' --fatal-warning' : '')
	   . " --debugfile=" . shell_quote ("$tcache" . $req->id . "t")
	   . join (' --trace=', '', map { shell_quote ($_) } sort @macro)
	   . " " . files_to_options (@ARGV)
	   . " > " . shell_quote ("$ocache" . $req->id . "t"));

  # Everything went ok: preserve the outputs.
  foreach my $file (map { $_ . $req->id } ($tcache, $ocache))
    {
      use File::Copy;
      move ("${file}t", "$file")
	or fatal "cannot rename ${file}t as $file: $!";
    }
}


# warn_forbidden ($WHERE, $WORD, %FORBIDDEN)
# ------------------------------------------
# $WORD is forbidden.  Warn with a dedicated error message if in
# %FORBIDDEN, otherwise a simple `error: possibly undefined macro'
# will do.
my $first_warn_forbidden = 1;
sub warn_forbidden ($$%)
{
  my ($where, $word, %forbidden) = @_;
  my $message;

  for my $re (sort keys %forbidden)
    {
      if ($word =~ $re)
	{
	  $message = $forbidden{$re};
	  last;
	}
    }
  $message ||= "possibly undefined macro: $word";
  warn "$where: error: $message\n";
  if ($first_warn_forbidden)
    {
      warn <<EOF;
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
EOF
      $first_warn_forbidden = 0;
    }
}


# handle_output ($REQ, $OUTPUT)
# -----------------------------
# Run m4 on the input files, perform quadrigraphs substitution, check for
# forbidden tokens, and save into $OUTPUT.
sub handle_output ($$)
{
  my ($req, $output) = @_;

  verb "creating $output";

  # Load the forbidden/allowed patterns.
  handle_traces ($req, "$tmp/patterns",
		 ('m4_pattern_forbid' => 'forbid:$1:$2',
		  'm4_pattern_allow'  => 'allow:$1'));
  my @patterns = new Autom4te::XFile ("< " . open_quote ("$tmp/patterns"))->getlines;
  chomp @patterns;
  my %forbidden =
    map { /^forbid:([^:]+):.+$/ => /^forbid:[^:]+:(.+)$/ } @patterns;
  my $forbidden = join ('|', map { /^forbid:([^:]+)/ } @patterns) || "^\$";
  my $allowed   = join ('|', map { /^allow:([^:]+)/  } @patterns) || "^\$";

  verb "forbidden tokens: $forbidden";
  verb "forbidden token : $_ => $forbidden{$_}"
    foreach (sort keys %forbidden);
  verb "allowed   tokens: $allowed";

  # Read the (cached) raw M4 output, produce the actual result.  We
  # have to use the 2nd arg to have Autom4te::XFile honor the third, but then
  # stdout is to be handled by hand :(.  Don't use fdopen as it means
  # we will close STDOUT, which we already do in END.
  my $out = new Autom4te::XFile;
  if ($output eq '-')
    {
      $out->open (">$output");
    }
  else
    {
      $out->open($output, O_CREAT | O_WRONLY | O_TRUNC, oct ($mode));
    }
  fatal "cannot create $output: $!"
    unless $out;
  my $in = new Autom4te::XFile ("< " . open_quote ($ocache . $req->id));

  my %prohibited;
  my $res;
  while ($_ = $in->getline)
    {
      s/\s+$//;
      s/__oline__/$./g;
      s/\@<:\@/[/g;
      s/\@:>\@/]/g;
      s/\@\{:\@/(/g;
      s/\@:\}\@/)/g;
      s/\@S\|\@/\$/g;
      s/\@%:\@/#/g;

      $res = $_;

      # Don't complain in comments.  Well, until we have something
      # better, don't consider `#include' etc. are comments.
      s/\#.*//
	unless /^\#\s*(if|include|endif|ifdef|ifndef|define)\b/;
      foreach (split (/\W+/))
	{
	  $prohibited{$_} = $.
	    if !/^$/ && /$forbidden/o && !/$allowed/o && ! exists $prohibited{$_};
	}

      # Performed *last*: the empty quadrigraph.
      $res =~ s/\@&t\@//g;

      print $out "$res\n";
    }

  $out->close();

  # If no forbidden words, we're done.
  return
    if ! %prohibited;

  # Locate the forbidden words in the last input file.
  # This is unsatisfying but...
  $exit_code = 1;
  if ($ARGV[$#ARGV] ne '-')
    {
      my $prohibited = '\b(' . join ('|', keys %prohibited) . ')\b';
      my $file = new Autom4te::XFile ("< " . open_quote ($ARGV[$#ARGV]));

      while ($_ = $file->getline)
	{
	  # Don't complain in comments.  Well, until we have something
	  # better, don't consider `#include' etc. to be comments.
	  s/\#.*//
	    unless /^\#(if|include|endif|ifdef|ifndef|define)\b/;

	  # Complain once per word, but possibly several times per line.
	  while (/$prohibited/)
	    {
	      my $word = $1;
	      warn_forbidden ("$ARGV[$#ARGV]:$.", $word, %forbidden);
	      delete $prohibited{$word};
	      # If we're done, exit.
	      return
		if ! %prohibited;
	      $prohibited = '\b(' . join ('|', keys %prohibited) . ')\b';
	    }
	}
    }
  warn_forbidden ("$output:$prohibited{$_}", $_, %forbidden)
    foreach (sort { $prohibited{$a} <=> $prohibited{$b} } keys %prohibited);
}


## --------------------- ##
## Handling the traces.  ##
## --------------------- ##


# $M4_MACRO
# trace_format_to_m4 ($FORMAT)
# ----------------------------
# Convert a trace $FORMAT into a M4 trace processing macro's body.
sub trace_format_to_m4 ($)
{
  my ($format) = @_;
  my $underscore = $_;
  my %escape = (# File name.
		'f' => '$1',
		# Line number.
		'l' => '$2',
		# Depth.
		'd' => '$3',
		# Name (also available as $0).
		'n' => '$4',
		# Escaped dollar.
		'$' => '$');

  my $res = '';
  $_ = $format;
  while ($_)
    {
      # $n -> $(n + 4)
      if (s/^\$(\d+)//)
	{
	  $res .= "\$" . ($1 + 4);
	}
      # $x, no separator given.
      elsif (s/^\$([fldn\$])//)
	{
	  $res .= $escape{$1};
	}
      # $.x or ${sep}x.
      elsif (s/^\$\{([^}]*)\}([@*%])//
	    || s/^\$(.?)([@*%])//)
	{
	  # $@, list of quoted effective arguments.
	  if ($2 eq '@')
	    {
	      $res .= ']at_at([' . ($1 ? $1 : ',') . '], $@)[';
	    }
	  # $*, list of unquoted effective arguments.
	  elsif ($2 eq '*')
	    {
	      $res .= ']at_star([' . ($1 ? $1 : ',') . '], $@)[';
	    }
	  # $%, list of flattened unquoted effective arguments.
	  elsif ($2 eq '%')
	    {
	      $res .= ']at_percent([' . ($1 ? $1 : ':') . '], $@)[';
	    }
	}
      elsif (/^(\$.)/)
	{
	  error "invalid escape: $1";
	}
      else
	{
	  s/^([^\$]+)//;
	  $res .= $1;
	}
    }

  $_ = $underscore;
  return '[[' . $res . ']]';
}


# handle_traces($REQ, $OUTPUT, %TRACE)
# ------------------------------------
# We use M4 itself to process the traces.  But to avoid name clashes when
# processing the traces, the builtins are disabled, and moved into `at_'.
# Actually, all the low level processing macros are in `at_' (and `_at_').
# To avoid clashes between user macros and `at_' macros, the macros which
# implement tracing are in `AT_'.
#
# Having $REQ is needed to neutralize the macros which have been traced,
# but are not wanted now.
sub handle_traces ($$%)
{
  my ($req, $output, %trace) = @_;

  verb "formatting traces for `$output': " . join (', ', sort keys %trace);

  # Processing the traces.
  my $trace_m4 = new Autom4te::XFile ("> " . open_quote ("$tmp/traces.m4"));

  $_ = <<'EOF';
  divert(-1)
  changequote([, ])
  # _at_MODE(SEPARATOR, ELT1, ELT2...)
  # ----------------------------------
  # List the elements, separating then with SEPARATOR.
  # MODE can be:
  #  `at'       -- the elements are enclosed in brackets.
  #  `star'     -- the elements are listed as are.
  #  `percent'  -- the elements are `flattened': spaces are singled out,
  #                and no new line remains.
  define([_at_at],
  [at_ifelse([$#], [1], [],
	     [$#], [2], [[[$2]]],
	     [[[$2]][$1]$0([$1], at_shift(at_shift($@)))])])

  define([_at_percent],
  [at_ifelse([$#], [1], [],
	     [$#], [2], [at_flatten([$2])],
	     [at_flatten([$2])[$1]$0([$1], at_shift(at_shift($@)))])])

  define([_at_star],
  [at_ifelse([$#], [1], [],
	     [$#], [2], [[$2]],
	     [[$2][$1]$0([$1], at_shift(at_shift($@)))])])

  # FLATTEN quotes its result.
  # Note that the second pattern is `newline, tab or space'.  Don't lose
  # the tab!
  define([at_flatten],
  [at_patsubst(at_patsubst([[[$1]]], [\\\n]), [[\n\t ]+], [ ])])

  define([at_args],    [at_shift(at_shift(at_shift(at_shift(at_shift($@)))))])
  define([at_at],      [_$0([$1], at_args($@))])
  define([at_percent], [_$0([$1], at_args($@))])
  define([at_star],    [_$0([$1], at_args($@))])

EOF
  s/^  //mg;s/\\t/\t/mg;s/\\n/\n/mg;
  print $trace_m4 $_;

  # If you trace `define', then on `define([m4_exit], defn([m4exit])' you
  # will produce
  #
  #    AT_define([m4sugar.m4], [115], [1], [define], [m4_exit], <m4exit>)
  #
  # Since `<m4exit>' is not quoted, the outer m4, when processing
  # `trace.m4' will exit prematurely.  Hence, move all the builtins to
  # the `at_' name space.

  print $trace_m4 "# Copy the builtins.\n";
  map { print $trace_m4 "define([at_$_], defn([$_]))\n" } @m4_builtin;
  print $trace_m4 "\n";

  print $trace_m4 "# Disable them.\n";
  map { print $trace_m4 "at_undefine([$_])\n" } @m4_builtin;
  print $trace_m4 "\n";


  # Neutralize traces: we don't want traces of cached requests (%REQUEST).
  print $trace_m4
   "## -------------------------------------- ##\n",
   "## By default neutralize all the traces.  ##\n",
   "## -------------------------------------- ##\n",
   "\n";
  print $trace_m4 "at_define([AT_$_], [at_dnl])\n"
    foreach (sort keys %{$req->macro});
  print $trace_m4 "\n";

  # Implement traces for current requests (%TRACE).
  print $trace_m4
    "## ------------------------- ##\n",
    "## Trace processing macros.  ##\n",
    "## ------------------------- ##\n",
    "\n";
  foreach (sort keys %trace)
    {
      # Trace request can be embed \n.
      (my $comment = "Trace $_:$trace{$_}") =~ s/^/\# /;
      print $trace_m4 "$comment\n";
      print $trace_m4 "at_define([AT_$_],\n";
      print $trace_m4 trace_format_to_m4 ($trace{$_}) . ")\n\n";
    }
  print $trace_m4 "\n";

  # Reenable output.
  print $trace_m4 "at_divert(0)at_dnl\n";

  # Transform the traces from m4 into an m4 input file.
  # Typically, transform:
  #
  # | m4trace:configure.ac:3: -1- AC_SUBST([exec_prefix], [NONE])
  #
  # into
  #
  # | AT_AC_SUBST([configure.ac], [3], [1], [AC_SUBST], [exec_prefix], [NONE])
  #
  # Pay attention that the file name might include colons, if under DOS
  # for instance, so we don't use `[^:]+'.
  my $traces = new Autom4te::XFile ("< " . open_quote ($tcache . $req->id));
  while ($_ = $traces->getline)
    {
      # Trace with arguments, as the example above.  We don't try
      # to match the trailing parenthesis as it might be on a
      # separate line.
      s{^m4trace:(.+):(\d+): -(\d+)- ([^(]+)\((.*)$}
       {AT_$4([$1], [$2], [$3], [$4], $5};
      # Traces without arguments, always on a single line.
      s{^m4trace:(.+):(\d+): -(\d+)- ([^)]*)\n$}
       {AT_$4([$1], [$2], [$3], [$4])\n};
      print $trace_m4 "$_";
    }
  $trace_m4->close;

  my $in = new Autom4te::XFile ("$m4 " . shell_quote ("$tmp/traces.m4") . " |");
  my $out = new Autom4te::XFile ("> " . open_quote ($output));

  # This is dubious: should we really transform the quadrigraphs in
  # traces?  It might break balanced [ ] etc. in the output.  The
  # consensus seeems to be that traces are more useful this way.
  while ($_ = $in->getline)
    {
      # It makes no sense to try to transform __oline__.
      s/\@<:\@/[/g;
      s/\@:>\@/]/g;
      s/\@\{:\@/(/g;
      s/\@:\}\@/)/g;
      s/\@S\|\@/\$/g;
      s/\@%:\@/#/g;
      s/\@&t\@//g;
      print $out $_;
    }
}


# $BOOL
# up_to_date ($REQ)
# -----------------
# Are the cache files of $REQ up to date?
# $REQ is `valid' if it corresponds to the request and exists, which
# does not mean it is up to date.  It is up to date if, in addition,
# its files are younger than its dependencies.
sub up_to_date ($)
{
  my ($req) = @_;

  return 0
    if ! $req->valid;

  my $tfile = $tcache . $req->id;
  my $ofile = $ocache . $req->id;

  # We can't answer properly if the traces are not computed since we
  # need to know what other files were included.  Actually, if any of
  # the cache files is missing, we are not up to date.
  return 0
    if ! -f $tfile || ! -f $ofile;

  # The youngest of the cache files must be older than the oldest of
  # the dependencies.
  my $tmtime = mtime ($tfile);
  my $omtime = mtime ($ofile);
  my ($file, $mtime) = ($tmtime < $omtime
			? ($ofile, $omtime) : ($tfile, $tmtime));

  # We depend at least upon the arguments.
  my @dep = @ARGV;

  # stdin is always out of date.
  if (grep { $_ eq '-' } @dep)
    { return 0 }

  # Files may include others.  We can use traces since we just checked
  # if they are available.
  handle_traces ($req, "$tmp/dependencies",
		 ('include'    => '$1',
		  'm4_include' => '$1'));
  my $deps = new Autom4te::XFile ("< " . open_quote ("$tmp/dependencies"));
  while ($_ = $deps->getline)
    {
      chomp;
      my $file = find_file ("$_?", @include);
      # If a file which used to be included is no longer there, then
      # don't say it's missing (it might no longer be included).  But
      # of course, that causes the output to be outdated (as if the
      # time stamp of that missing file was newer).
      return 0
	if ! $file;
      push @dep, $file;
    }

  # If $FILE is younger than one of its dependencies, it is outdated.
  return up_to_date_p ($file, @dep);
}


## ---------- ##
## Freezing.  ##
## ---------- ##

# freeze ($OUTPUT)
# ----------------
sub freeze ($)
{
  my ($output) = @_;

  # When processing the file with diversion disabled, there must be no
  # output but comments and empty lines.
  my $result = xqx ("$m4"
		    . ' --fatal-warning'
		    . join (' --include=', '', map { shell_quote ($_) } @include)
		    . ' --define=divert'
		    . " " . files_to_options (@ARGV)
		    . ' </dev/null');
  $result =~ s/#.*\n//g;
  $result =~ s/^\n//mg;

  fatal "freezing produced output:\n$result"
    if $result;

  # If freezing produces output, something went wrong: a bad `divert',
  # or an improper paren etc.
  xsystem ("$m4"
	   . ' --fatal-warning'
	   . join (' --include=', '', map { shell_quote ($_) } @include)
	   . " --freeze-state=" . shell_quote ($output)
	   . " " . files_to_options (@ARGV)
	   . ' </dev/null');
}

## -------------- ##
## Main program.  ##
## -------------- ##

mktmpdir ('am4t');
load_configuration ($ENV{'AUTOM4TE_CFG'} || "$pkgdatadir/autom4te.cfg");
load_configuration ("$ENV{'HOME'}/.autom4te.cfg")
  if exists $ENV{'HOME'} && -f "$ENV{'HOME'}/.autom4te.cfg";
load_configuration (".autom4te.cfg")
  if -f ".autom4te.cfg";
parse_args;

# Freezing does not involve the cache.
if ($freeze)
  {
    freeze ($output);
    exit $exit_code;
  }

# We need our cache directory.  Don't fail with parallel creation.
if (! -d "$cache")
  {
    mkdir "$cache", 0755
      or -d "$cache"
      or fatal "cannot create $cache: $!";
  }

# Open the index for update, and lock it.  autom4te handles several
# files, but the index is the first and last file to be updated, so
# locking it is sufficient.
$icache_file = new Autom4te::XFile $icache, O_RDWR|O_CREAT;
$icache_file->lock (LOCK_EX);

# Read the cache index if available and older than autom4te itself.
# If autom4te is younger, then some structures such as C4che might
# have changed, which would corrupt its processing.
Autom4te::C4che->load ($icache_file)
  if -f $icache && mtime ($icache) > mtime ($0);

# Add the new trace requests.
my $req = Autom4te::C4che->request ('input' => \@ARGV,
				    'path'  => \@include,
				    'macro' => [keys %trace, @preselect]);

# If $REQ's cache files are not up to date, or simply if the user
# discarded them (-f), declare it invalid.
$req->valid (0)
  if $force || ! up_to_date ($req);

# We now know whether we can trust the Request object.  Say it.
verb "the trace request object is:\n" . $req->marshall;

# We need to run M4 if (i) the user wants it (--force), (ii) $REQ is
# invalid.
handle_m4 ($req, keys %{$req->macro})
  if $force || ! $req->valid;

# Issue the warnings each time autom4te was run.
my $separator = "\n" . ('-' x 25) . " END OF WARNING " . ('-' x 25) . "\n\n";
handle_traces ($req, "$tmp/warnings",
	       ('_m4_warn' => "\$1::\$f:\$l::\$2::\$3$separator"));
# Swallow excessive newlines.
for (split (/\n*$separator\n*/o, contents ("$tmp/warnings")))
{
  # The message looks like:
  # | syntax::input.as:5::ouch
  # | ::input.as:4: baz is expanded from...
  # | input.as:2: bar is expanded from...
  # | input.as:3: foo is expanded from...
  # | input.as:5: the top level
  my ($cat, $loc, $msg, $stacktrace) = split ('::', $_, 4);
  msg $cat, $loc, "warning: $msg";
  for (split /\n/, $stacktrace)
    {
      my ($loc, $trace) = split (': ', $_, 2);
      msg $cat, $loc, $trace;
    }
}

# Now output...
if (%trace)
  {
    # Always produce traces, since even if the output is young enough,
    # there is no guarantee that the traces use the same *format*
    # (e.g., `-t FOO:foo' and `-t FOO:bar' are both using the same M4
    # traces, hence the M4 traces cache is usable, but its formatting
    # will yield different results).
    handle_traces ($req, $output, %trace);
  }
else
  {
    # Actual M4 expansion, if the user wants it, or if $output is old
    # (STDOUT is pretty old).
    handle_output ($req, $output)
      if $force || mtime ($output) < mtime ($ocache . $req->id);
  }

# If we ran up to here, the cache is valid.
$req->valid (1);
Autom4te::C4che->save ($icache_file);

exit $exit_code;

### Setup "GNU" style for perl-mode and cperl-mode.
## Local Variables:
## perl-indent-level: 2
## perl-continued-statement-offset: 2
## perl-continued-brace-offset: 0
## perl-brace-offset: 0
## perl-brace-imaginary-offset: 0
## perl-label-offset: -2
## cperl-indent-level: 2
## cperl-brace-offset: 0
## cperl-continued-brace-offset: 0
## cperl-label-offset: -2
## cperl-extra-newline-before-brace: t
## cperl-merge-trailing-else: nil
## cperl-continued-statement-offset: 2
## End: