contrib/texi2pod.pl

   1 #! /usr/bin/perl -w
   2
   3 #   Copyright (C) 1999-2023 Free Software Foundation, Inc.
   4
   5 # This file is part of GCC.
   6
   7 # GCC is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 3, or (at your option)
  10 # any later version.
  11
  12 # GCC is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16
  17 # You should have received a copy of the GNU General Public License
  18 # along with GCC; see the file COPYING.  If not, write to
  19 # the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  20 # Boston MA 02110-1301, USA.
  21
  22 # This does trivial (and I mean _trivial_) conversion of Texinfo
  23 # markup to Perl POD format.  It's intended to be used to extract
  24 # something suitable for a manpage from a Texinfo document.
  25
  26 $output = 0;
  27 $skipping = 0;
  28 %sects = ();
  29 $section = "";
  30 @icstack = ();
  31 @endwstack = ();
  32 @skstack = ();
  33 @instack = ();
  34 $shift = "";
  35 %defs = ();
  36 $fnno = 1;
  37 $inf = "";
  38 $ibase = "";
  39 @ipath = ();
  40
  41 while ($_ = shift) {
  42     if (/^-D(.*)$/) {
  43         if ($1 ne "") {
  44             $flag = $1;
  45         } else {
  46             $flag = shift;
  47         }
  48         $value = "";
  49         ($flag, $value) = ($flag =~ /^([^=]+)(?:=(.+))?/);
  50         die "no flag specified for -D\n"
  51             unless $flag ne "";
  52         die "flags may only contain letters, digits, hyphens, dashes and underscores\n"
  53             unless $flag =~ /^[a-zA-Z0-9_-]+$/;
  54         $defs{$flag} = $value;
  55     } elsif (/^-I(.*)$/) {
  56         if ($1 ne "") {
  57             $flag = $1;
  58         } else {
  59             $flag = shift;
  60         }
  61         push (@ipath, $flag);
  62     } elsif (/^-/) {
  63         usage();
  64     } else {
  65         $in = $_, next unless defined $in;
  66         $out = $_, next unless defined $out;
  67         usage();
  68     }
  69 }
  70
  71 if (defined $in) {
  72     $inf = gensym();
  73     open($inf, "<$in") or die "opening \"$in\": $!\n";
  74     $ibase = $1 if $in =~ m|^(.+)/[^/]+$|;
  75 } else {
  76     $inf = \*STDIN;
  77 }
  78
  79 if (defined $out) {
  80     open(STDOUT, ">$out") or die "opening \"$out\": $!\n";
  81 }
  82
  83 while(defined $inf) {
  84 while(<$inf>) {
  85     # Certain commands are discarded without further processing.
  86     /^\@(?:
  87          [a-z]+index            # @*index: useful only in complete manual
  88          |need                  # @need: useful only in printed manual
  89          |(?:end\s+)?group      # @group .. @end group: ditto
  90          |page                  # @page: ditto
  91          |node                  # @node: useful only in .info file
  92          |(?:end\s+)?ifnottex   # @ifnottex .. @end ifnottex: use contents
  93         )\b/x and next;
  94
  95     chomp;
  96
  97     # Look for filename and title markers.
  98     /^\@setfilename\s+([^.]+)/ and $fn = $1, next;
  99     /^\@settitle\s+([^.]+)/ and $tl = postprocess($1), next;
 100
 101     # Identify a man title but keep only the one we are interested in.
 102     /^\@c\s+man\s+title\s+([A-Za-z0-9-]+)\s+(.+)/ and do {
 103         if (exists $defs{$1}) {
 104             $fn = $1;
 105             $tl = postprocess($2);
 106         }
 107         next;
 108     };
 109
 110     # Look for blocks surrounded by @c man begin SECTION ... @c man end.
 111     # This really oughta be @ifman ... @end ifman and the like, but such
 112     # would require rev'ing all other Texinfo translators.
 113     /^\@c\s+man\s+begin\s+([A-Z]+)\s+([A-Za-z0-9-]+)/ and do {
 114         $output = 1 if exists $defs{$2};
 115         $sect = $1;
 116         next;
 117     };
 118     /^\@c\s+man\s+begin\s+([A-Z]+)/ and $sect = $1, $output = 1, next;
 119     /^\@c\s+man\s+end/ and do {
 120         $sects{$sect} = "" unless exists $sects{$sect};
 121         $sects{$sect} .= postprocess($section);
 122         $section = "";
 123         $output = 0;
 124         next;
 125     };
 126
 127     # handle variables
 128     /^\@set\s+([a-zA-Z0-9_-]+)\s*(.*)$/ and do {
 129         $defs{$1} = $2;
 130         next;
 131     };
 132     /^\@clear\s+([a-zA-Z0-9_-]+)/ and do {
 133         delete $defs{$1};
 134         next;
 135     };
 136
 137     next unless $output;
 138
 139     # Discard comments.  (Can't do it above, because then we'd never see
 140     # @c man lines.)
 141     /^\@c\b/ and next;
 142
 143     # End-block handler goes up here because it needs to operate even
 144     # if we are skipping.
 145     /^\@end\s+([a-z]+)/ and do {
 146         # Ignore @end foo, where foo is not an operation which may
 147         # cause us to skip, if we are presently skipping.
 148         my $ended = $1;
 149         next if $skipping && $ended !~ /^(?:ifset|ifclear|ignore|menu|iftex|copying)$/;
 150
 151         die "\@end $ended without \@$ended at line $.\n" unless defined $endw;
 152         die "\@$endw ended by \@end $ended at line $.\n" unless $ended eq $endw;
 153
 154         $endw = pop @endwstack;
 155
 156         if ($ended =~ /^(?:ifset|ifclear|ignore|menu|iftex)$/) {
 157             $skipping = pop @skstack;
 158             next;
 159         } elsif ($ended =~ /^(?:example|smallexample|display)$/) {
 160             $shift = "";
 161             $_ = "";    # need a paragraph break
 162         } elsif ($ended =~ /^(?:itemize|enumerate|[fv]?table)$/) {
 163             $_ = "\n=back\n";
 164             $ic = pop @icstack;
 165         } elsif ($ended eq "multitable") {
 166             $_ = "\n=back\n";
 167             $ic = pop @icstack;
 168         } else {
 169             die "unknown command \@end $ended at line $.\n";
 170         }
 171     };
 172
 173     # We must handle commands which can cause skipping even while we
 174     # are skipping, otherwise we will not process nested conditionals
 175     # correctly.
 176     /^\@ifset\s+([a-zA-Z0-9_-]+)/ and do {
 177         push @endwstack, $endw;
 178         push @skstack, $skipping;
 179         $endw = "ifset";
 180         $skipping = 1 unless exists $defs{$1};
 181         next;
 182     };
 183
 184     /^\@ifclear\s+([a-zA-Z0-9_-]+)/ and do {
 185         push @endwstack, $endw;
 186         push @skstack, $skipping;
 187         $endw = "ifclear";
 188         $skipping = 1 if exists $defs{$1};
 189         next;
 190     };
 191
 192     /^\@(ignore|menu|iftex|copying)\b/ and do {
 193         push @endwstack, $endw;
 194         push @skstack, $skipping;
 195         $endw = $1;
 196         $skipping = 1;
 197         next;
 198     };
 199
 200     next if $skipping;
 201
 202     # Character entities.  First the ones that can be replaced by raw text
 203     # or discarded outright:
 204     s/\@copyright\{\}/(c)/g;
 205     s/\@dots\{\}/.../g;
 206     s/\@enddots\{\}/..../g;
 207     s/\@([.!? ])/$1/g;
 208     s/\@[:-]//g;
 209     s/\@bullet(?:\{\})?/*/g;
 210     s/\@TeX\{\}/TeX/g;
 211     s/\@pounds\{\}/\#/g;
 212     s/\@minus(?:\{\})?/-/g;
 213     s/\@tie\{\}/ /g;
 214     s/\\,/,/g;
 215
 216     # Now the ones that have to be replaced by special escapes
 217     # (which will be turned back into text by unmunge())
 218     # Replace @@ before @{ and @} in order to parse @samp{@@} correctly.
 219     s/&/&amp;/g;
 220     s/\@\@/&at;/g;
 221     s/\@\{/&lbrace;/g;
 222     s/\@\}/&rbrace;/g;
 223     s/\@`\{(.)\}/&$1grave;/g;
 224
 225     # Inside a verbatim block, handle @var, @samp and @url specially.
 226     if ($shift ne "") {
 227         s/\@var\{([^\}]*)\}/<$1>/g;
 228         s/\@samp\{([^\}]*)\}/"$1"/g;
 229         s/\@url\{([^\}]*)\}/<$1>/g;
 230     }
 231
 232     # POD doesn't interpret E<> inside a verbatim block.
 233     if ($shift eq "") {
 234         s/</&lt;/g;
 235         s/>/&gt;/g;
 236     } else {
 237         s/</&LT;/g;
 238         s/>/&GT;/g;
 239     }
 240
 241     # Single line command handlers.
 242
 243     /^\@include\s+(.+)$/ and do {
 244         push @instack, $inf;
 245         $inf = gensym();
 246         $file = postprocess($1);
 247
 248         # Try cwd and $ibase, then explicit -I paths.
 249         $done = 0;
 250         foreach $path ("", $ibase, @ipath) {
 251             $mypath = $file;
 252             $mypath = $path . "/" . $mypath if ($path ne "");
 253             open($inf, "<" . $mypath) and ($done = 1, last);
 254         }
 255         die "cannot find $file" if !$done;
 256         next;
 257     };
 258
 259     /^\@(?:section|unnumbered|unnumberedsec|center|heading)\s+(.+)$/
 260         and $_ = "\n=head2 $1\n";
 261     /^\@subsection\s+(.+)$/
 262         and $_ = "\n=head3 $1\n";
 263     /^\@subsubsection\s+(.+)$/
 264         and $_ = "\n=head4 $1\n";
 265
 266     # Block command handlers:
 267     /^\@itemize(?:\s+(\@[a-z]+|\*|-))?/ and do {
 268         push @endwstack, $endw;
 269         push @icstack, $ic;
 270         if (defined $1) {
 271             $ic = $1;
 272         } else {
 273             $ic = '*';
 274         }
 275         $_ = "\n=over 4\n";
 276         $endw = "itemize";
 277     };
 278
 279     /^\@enumerate(?:\s+([a-zA-Z0-9]+))?/ and do {
 280         push @endwstack, $endw;
 281         push @icstack, $ic;
 282         if (defined $1) {
 283             $ic = $1 . ".";
 284         } else {
 285             $ic = "1.";
 286         }
 287         $_ = "\n=over 4\n";
 288         $endw = "enumerate";
 289     };
 290
 291     /^\@multitable\s.*/ and do {
 292         push @endwstack, $endw;
 293         push @icstack, $ic;
 294         $endw = "multitable";
 295         $ic = "";
 296         $_ = "\n=over 4\n";
 297     };
 298
 299     /^\@([fv]?table)\s+(\@[a-z]+)/ and do {
 300         push @endwstack, $endw;
 301         push @icstack, $ic;
 302         $endw = $1;
 303         $ic = $2;
 304         $ic =~ s/\@(?:samp|strong|key|gcctabopt|env)/B/;
 305         $ic =~ s/\@(?:code|kbd)/C/;
 306         $ic =~ s/\@(?:dfn|var|emph|cite|i)/I/;
 307         $ic =~ s/\@(?:file)/F/;
 308         $ic =~ s/\@(?:asis)//;
 309         $_ = "\n=over 4\n";
 310     };
 311
 312     /^\@((?:small)?example|display)/ and do {
 313         push @endwstack, $endw;
 314         $endw = $1;
 315         $shift = "\t";
 316         $_ = "";        # need a paragraph break
 317     };
 318
 319     /^\@(headitem|item)\s+(.*\S)\s*$/ and $endw eq "multitable" and do {
 320         @columns = ();
 321         $item = $1;
 322         for $column (split (/\s*\@tab\s*/, $2)) {
 323             # @strong{...} is used a @headitem work-alike
 324             $column =~ s/^\@strong\{(.*)\}$/$1/;
 325             $column = "I<$column>" if $item eq "headitem";
 326             push @columns, $column;
 327         }
 328         $_ = "\n=item ".join (" : ", @columns)."\n";
 329     };
 330
 331     /^\@itemx?\s*(.+)?$/ and do {
 332         if (defined $1) {
 333             if ($ic) {
 334                 if ($endw eq "enumerate") {
 335                     $_ = "\n=item $ic $1\n";
 336                     $ic =~ s/(\d+)/$1 + 1/eg;
 337                 } else {
 338                     # Entity escapes prevent munging by the <>
 339                     # processing below.
 340                     $_ = "\n=item $ic\&LT;$1\&GT;\n";
 341                 }
 342             } else {
 343                 $_ = "\n=item $1\n";
 344             }
 345         } else {
 346             $_ = "\n=item Z\&LT;\&GT;$ic\n";
 347             $ic =~ y/A-Ya-y/B-Zb-z/;
 348             $ic =~ s/(\d+)/$1 + 1/eg;
 349         }
 350     };
 351
 352     $section .= $shift.$_."\n";
 353 }
 354 # End of current file.
 355 close($inf);
 356 $inf = pop @instack;
 357 }
 358
 359 die "No filename or title\n" unless defined $fn && defined $tl;
 360
 361 $sects{NAME} = "$fn \- $tl\n";
 362 $sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};
 363
 364 for $sect (qw(NAME SYNOPSIS DESCRIPTION OPTIONS ENVIRONMENT FILES
 365               BUGS NOTES FOOTNOTES SEEALSO AUTHOR COPYRIGHT)) {
 366     if(exists $sects{$sect}) {
 367         $head = $sect;
 368         $head =~ s/SEEALSO/SEE ALSO/;
 369         print "=head1 $head\n\n";
 370         print scalar unmunge ($sects{$sect});
 371         print "\n";
 372     }
 373 }
 374
 375 sub usage
 376 {
 377     die "usage: $0 [-D toggle...] [infile [outfile]]\n";
 378 }
 379
 380 sub postprocess
 381 {
 382     local $_ = $_[0];
 383
 384     # @value{foo} is replaced by whatever 'foo' is defined as.
 385     while (m/(\@value\{([a-zA-Z0-9_-]+)\})/g) {
 386         if (! exists $defs{$2}) {
 387             print STDERR "Option $2 not defined\n";
 388             s/\Q$1\E//;
 389         } else {
 390             $value = $defs{$2};
 391             s/\Q$1\E/$value/;
 392         }
 393     }
 394
 395     # Formatting commands.
 396     # Temporary escape for @r.
 397     s/\@r\{([^\}]*)\}/R<$1>/g;
 398     s/\@sc\{([^\}]*)\}/\U$1/g;
 399     s/\@(?:dfn|var|emph|cite|i)\{([^\}]*)\}/I<$1>/g;
 400     s/\@(?:code|kbd)\{([^\}]*)\}/C<$1>/g;
 401     s/\@(?:samp|strong|key|option|env|command|b)\{([^\}]*)\}/B<$1>/g;
 402     s/\@acronym\{([^\}]*)\}/\U$1/g;
 403     s/\@file\{([^\}]*)\}/F<$1>/g;
 404     s/\@w\{([^\}]*)\}/S<$1>/g;
 405     s/\@(?:dmn|math)\{([^\}]*)\}/$1/g;
 406     s/\@\///g;
 407     s/\@t\{([^\}]*)\}/$1/g;
 408
 409     # keep references of the form @ref{...}, print them bold
 410     s/\@(?:ref)\{([^\}]*)\}/B<$1>/g;
 411
 412     # Change double single quotes to double quotes.
 413     s/''/"/g;
 414     s/``/"/g;
 415
 416     # Cross references are thrown away, as are @noindent and @refill.
 417     # (@noindent is impossible in .pod, and @refill is unnecessary.)
 418     # @* is also impossible in .pod; we discard it and any newline that
 419     # follows it.  Similarly, our macro @gol must be discarded.
 420
 421     s/\(?\@xref\{(?:[^\}]*)\}(?:[^.<]|(?:<[^<>]*>))*\.\)?//g;
 422     s/\s+\(\@pxref\{(?:[^\}]*)\}\)//g;
 423     s/;\s+\@pxref\{(?:[^\}]*)\}//g;
 424     s/\@noindent\s*//g;
 425     s/\@refill//g;
 426     s/\@gol//g;
 427     s/\@\*\s*\n?//g;
 428
 429     # Anchors are thrown away
 430     s/\@anchor\{(?:[^\}]*)\}//g;
 431
 432     # @uref can take one, two, or three arguments, with different
 433     # semantics each time.  @url and @email are just like @uref with
 434     # one argument, for our purposes.
 435     s/\@(?:uref|url|email)\{([^\},]*)\}/&lt;B<$1>&gt;/g;
 436     s/\@uref\{([^\},]*),([^\},]*)\}/$2 (C<$1>)/g;
 437     s/\@uref\{([^\},]*),([^\},]*),([^\},]*)\}/$3/g;
 438
 439     # Handle gccoptlist here, so it can contain the above formatting
 440     # commands.
 441     s/\@gccoptlist\{([^\}]*)\}/B<$1>/g;
 442
 443     # Un-escape <> at this point.
 444     s/&LT;/</g;
 445     s/&GT;/>/g;
 446
 447     # Now un-nest all B<>, I<>, R<>.  Theoretically we could have
 448     # indefinitely deep nesting; in practice, one level suffices.
 449     1 while s/([BIR])<([^<>]*)([BIR])<([^<>]*)>/$1<$2>$3<$4>$1</g;
 450
 451     # Replace R<...> with bare ...; eliminate empty markup, B<>;
 452     # shift white space at the ends of [BI]<...> expressions outside
 453     # the expression.
 454     s/R<([^<>]*)>/$1/g;
 455     s/[BI]<>//g;
 456     s/([BI])<(\s+)([^>]+)>/$2$1<$3>/g;
 457     s/([BI])<([^>]+?)(\s+)>/$1<$2>$3/g;
 458
 459     # Extract footnotes.  This has to be done after all other
 460     # processing because otherwise the regexp will choke on formatting
 461     # inside @footnote.
 462     while (/\@footnote/g) {
 463         s/\@footnote\{([^\}]+)\}/[$fnno]/;
 464         add_footnote($1, $fnno);
 465         $fnno++;
 466     }
 467
 468     return $_;
 469 }
 470
 471 sub unmunge
 472 {
 473     # Replace escaped symbols with their equivalents.
 474     local $_ = $_[0];
 475
 476     s/&(.)grave;/E<$1grave>/g;
 477     s/&lt;/E<lt>/g;
 478     s/&gt;/E<gt>/g;
 479     s/&lbrace;/\{/g;
 480     s/&rbrace;/\}/g;
 481     s/&at;/\@/g;
 482     s/&amp;/&/g;
 483     return $_;
 484 }
 485
 486 sub add_footnote
 487 {
 488     unless (exists $sects{FOOTNOTES}) {
 489         $sects{FOOTNOTES} = "\n=over 4\n\n";
 490     }
 491
 492     $sects{FOOTNOTES} .= "=item $fnno.\n\n"; $fnno++;
 493     $sects{FOOTNOTES} .= $_[0];
 494     $sects{FOOTNOTES} .= "\n\n";
 495 }
 496
 497 # stolen from Symbol.pm
 498 {
 499     my $genseq = 0;
 500     sub gensym
 501     {
 502         my $name = "GEN" . $genseq++;
 503         my $ref = \*{$name};
 504         delete $::{$name};
 505         return $ref;
 506     }
 507 }