etc/texi2pod.pl

   1 #! /usr/bin/perl -w
   2
   3 #   Copyright (C) 1999-2021 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 2, 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, $flag);
  62     } elsif (/^--no-split$/) {
  63         # ignore option for makeinfo compatibility
  64     } elsif (/^-/) {
  65         usage();
  66     } else {
  67         $in = $_, next unless defined $in;
  68         $out = $_, next unless defined $out;
  69         usage();
  70     }
  71 }
  72
  73 if (defined $in) {
  74     $inf = gensym();
  75     open($inf, "<$in") or die "opening \"$in\": $!\n";
  76     $ibase = $1 if $in =~ m|^(.+)/[^/]+$|;
  77 } else {
  78     $inf = \*STDIN;
  79 }
  80
  81 if (defined $out) {
  82     open(STDOUT, ">$out") or die "opening \"$out\": $!\n";
  83 }
  84
  85 while(defined $inf) {
  86 while(<$inf>) {
  87     # Certain commands are discarded without further processing.
  88     /^\@(?:
  89          [a-z]+index            # @*index: useful only in complete manual
  90          |need                  # @need: useful only in printed manual
  91          |(?:end\s+)?group      # @group .. @end group: ditto
  92          |page                  # @page: ditto
  93          |node                  # @node: useful only in .info file
  94          |(?:end\s+)?ifnottex   # @ifnottex .. @end ifnottex: use contents
  95         )\b/x and next;
  96
  97     chomp;
  98
  99     # Look for filename and title markers.
 100     /^\@setfilename\s+([^.]+)/ and $fn = $1, next;
 101     /^\@settitle\s+([^.]+)/ and $tl = postprocess($1), next;
 102
 103     # Identify a man title but keep only the one we are interested in.
 104     /^\@c\s+man\s+title\s+([A-Za-z0-9-]+)\s+(.+)/ and do {
 105         if (exists $defs{$1}) {
 106             $fn = $1;
 107             $tl = postprocess($2);
 108         }
 109         next;
 110     };
 111
 112     # Look for blocks surrounded by @c man begin SECTION ... @c man end.
 113     # This really oughta be @ifman ... @end ifman and the like, but such
 114     # would require rev'ing all other Texinfo translators.
 115     /^\@c\s+man\s+begin\s+([A-Z]+)\s+([A-Za-z0-9-]+)/ and do {
 116         $output = 1 if exists $defs{$2};
 117         $sect = $1;
 118         next;
 119     };
 120     /^\@c\s+man\s+begin\s+([A-Z]+)/ and $sect = $1, $output = 1, next;
 121     /^\@c\s+man\s+end/ and do {
 122         $sects{$sect} = "" unless exists $sects{$sect};
 123         $sects{$sect} .= postprocess($section);
 124         $section = "";
 125         $output = 0;
 126         next;
 127     };
 128
 129     # handle variables
 130     /^\@set\s+([a-zA-Z0-9_-]+)\s*(.*)$/ and do {
 131         $defs{$1} = $2;
 132         next;
 133     };
 134     /^\@clear\s+([a-zA-Z0-9_-]+)/ and do {
 135         delete $defs{$1};
 136         next;
 137     };
 138
 139     next unless $output;
 140
 141     # Discard comments.  (Can't do it above, because then we'd never see
 142     # @c man lines.)
 143     /^\@c\b/ and next;
 144
 145     # End-block handler goes up here because it needs to operate even
 146     # if we are skipping.
 147     /^\@end\s+([a-z]+)/ and do {
 148         # Ignore @end foo, where foo is not an operation which may
 149         # cause us to skip, if we are presently skipping.
 150         my $ended = $1;
 151         next if $skipping && $ended !~ /^(?:ifset|ifclear|ignore|menu|iftex|copying)$/;
 152
 153         die "\@end $ended without \@$ended at line $.\n" unless defined $endw;
 154         die "\@$endw ended by \@end $ended at line $.\n" unless $ended eq $endw;
 155
 156         $endw = pop @endwstack;
 157
 158         if ($ended =~ /^(?:ifset|ifclear|ignore|menu|iftex)$/) {
 159             $skipping = pop @skstack;
 160             next;
 161         } elsif ($ended =~ /^(?:example|smallexample|display)$/) {
 162             $shift = "";
 163             $_ = "";    # need a paragraph break
 164         } elsif ($ended =~ /^(?:itemize|enumerate|[fv]?table)$/) {
 165             $_ = "\n=back\n";
 166             $ic = pop @icstack;
 167         } elsif ($ended eq "multitable") {
 168             $_ = "\n=back\n";
 169         } else {
 170             die "unknown command \@end $ended at line $.\n";
 171         }
 172     };
 173
 174     # We must handle commands which can cause skipping even while we
 175     # are skipping, otherwise we will not process nested conditionals
 176     # correctly.
 177     /^\@ifset\s+([a-zA-Z0-9_-]+)/ and do {
 178         push @endwstack, $endw;
 179         push @skstack, $skipping;
 180         $endw = "ifset";
 181         $skipping = 1 unless exists $defs{$1};
 182         next;
 183     };
 184
 185     /^\@ifclear\s+([a-zA-Z0-9_-]+)/ and do {
 186         push @endwstack, $endw;
 187         push @skstack, $skipping;
 188         $endw = "ifclear";
 189         $skipping = 1 if exists $defs{$1};
 190         next;
 191     };
 192
 193     /^\@(ignore|menu|iftex|copying)\b/ and do {
 194         push @endwstack, $endw;
 195         push @skstack, $skipping;
 196         $endw = $1;
 197         $skipping = 1;
 198         next;
 199     };
 200
 201     next if $skipping;
 202
 203     # Character entities.  First the ones that can be replaced by raw text
 204     # or discarded outright:
 205     s/\@copyright\{\}/(c)/g;
 206     s/\@dots\{\}/.../g;
 207     s/\@enddots\{\}/..../g;
 208     s/\@([.!? ])/$1/g;
 209     s/\@[:-]//g;
 210     s/\@bullet(?:\{\})?/*/g;
 211     s/\@TeX\{\}/TeX/g;
 212     s/\@pounds\{\}/\#/g;
 213     s/\@minus(?:\{\})?/-/g;
 214     s/\\,/,/g;
 215
 216     # Now the ones that have to be replaced by special escapes
 217     # (which will be turned back into text by unmunge())
 218     s/&/&amp;/g;
 219     s/\@\{/&lbrace;/g;
 220     s/\@\}/&rbrace;/g;
 221     s/\@\@/&at;/g;
 222
 223     # Inside a verbatim block, handle @var specially.
 224     if ($shift ne "") {
 225         s/\@var\{([^\}]*)\}/<$1>/g;
 226     }
 227
 228     # POD doesn't interpret E<> inside a verbatim block.
 229     if ($shift eq "") {
 230         s/</&lt;/g;
 231         s/>/&gt;/g;
 232     } else {
 233         s/</&LT;/g;
 234         s/>/&GT;/g;
 235     }
 236
 237     # Single line command handlers.
 238
 239     /^\@include\s+(.+)$/ and do {
 240         push @instack, $inf;
 241         $inf = gensym();
 242         $file = postprocess($1);
 243
 244         # Try cwd and $ibase, then explicit -I paths.
 245         $done = 0;
 246         foreach $path ("", $ibase, @ipath) {
 247             $mypath = $file;
 248             $mypath = $path . "/" . $mypath if ($path ne "");
 249             open($inf, "<" . $mypath) and ($done = 1, last);
 250         }
 251         die "cannot find $file" if !$done;
 252         next;
 253     };
 254
 255     /^\@(?:section|unnumbered|unnumberedsec|center)\s+(.+)$/
 256         and $_ = "\n=head2 $1\n";
 257     /^\@subsection\s+(.+)$/
 258         and $_ = "\n=head3 $1\n";
 259     /^\@subsubsection\s+(.+)$/
 260         and $_ = "\n=head4 $1\n";
 261
 262     # Block command handlers:
 263     /^\@itemize(?:\s+(\@[a-z]+|\*|-))?/ and do {
 264         push @endwstack, $endw;
 265         push @icstack, $ic;
 266         if (defined $1) {
 267             $ic = $1;
 268         } else {
 269             $ic = '*';
 270         }
 271         $_ = "\n=over 4\n";
 272         $endw = "itemize";
 273     };
 274
 275     /^\@enumerate(?:\s+([a-zA-Z0-9]+))?/ and do {
 276         push @endwstack, $endw;
 277         push @icstack, $ic;
 278         if (defined $1) {
 279             $ic = $1 . ".";
 280         } else {
 281             $ic = "1.";
 282         }
 283         $_ = "\n=over 4\n";
 284         $endw = "enumerate";
 285     };
 286
 287     /^\@multitable\s.*/ and do {
 288         push @endwstack, $endw;
 289         $endw = "multitable";
 290         $_ = "\n=over 4\n";
 291     };
 292
 293     /^\@([fv]?table)\s+(\@[a-z]+)/ and do {
 294         push @endwstack, $endw;
 295         push @icstack, $ic;
 296         $endw = $1;
 297         $ic = $2;
 298         $ic =~ s/\@(?:samp|strong|key|gcctabopt|env)/B/;
 299         $ic =~ s/\@(?:code|kbd)/C/;
 300         $ic =~ s/\@(?:dfn|var|emph|cite|i)/I/;
 301         $ic =~ s/\@(?:file)/F/;
 302         $_ = "\n=over 4\n";
 303     };
 304
 305     /^\@((?:small)?example|display)/ and do {
 306         push @endwstack, $endw;
 307         $endw = $1;
 308         $shift = "\t";
 309         $_ = "";        # need a paragraph break
 310     };
 311
 312     /^\@item\s+(.*\S)\s*$/ and $endw eq "multitable" and do {
 313         @columns = ();
 314         for $column (split (/\s*\@tab\s*/, $1)) {
 315             # @strong{...} is used a @headitem work-alike
 316             $column =~ s/^\@strong\{(.*)\}$/$1/;
 317             push @columns, $column;
 318         }
 319         $_ = "\n=item ".join (" : ", @columns)."\n";
 320     };
 321
 322     /^\@itemx?\s*(.+)?$/ and do {
 323         if (defined $1) {
 324             # Entity escapes prevent munging by the <> processing below.
 325             $_ = "\n=item $ic\&LT;$1\&GT;\n";
 326         } else {
 327             $_ = "\n=item $ic\n";
 328             $ic =~ y/A-Ya-y/B-Zb-z/;
 329             $ic =~ s/(\d+)/$1 + 1/eg;
 330         }
 331     };
 332
 333     $section .= $shift.$_."\n";
 334 }
 335 # End of current file.
 336 close($inf);
 337 $inf = pop @instack;
 338 }
 339
 340 die "No filename or title\n" unless defined $fn && defined $tl;
 341
 342 $sects{NAME} = "$fn \- $tl\n";
 343 $sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};
 344
 345 for $sect (qw(NAME SYNOPSIS TARGET DESCRIPTION OPTIONS ENVIRONMENT FILES
 346               BUGS NOTES FOOTNOTES SEEALSO AUTHOR COPYRIGHT)) {
 347     if(exists $sects{$sect}) {
 348         $head = $sect;
 349         $head =~ s/SEEALSO/SEE ALSO/;
 350         print "=head1 $head\n\n";
 351         print scalar unmunge ($sects{$sect});
 352         print "\n";
 353     }
 354 }
 355
 356 sub usage
 357 {
 358     die "usage: $0 [-D toggle...] [infile [outfile]]\n";
 359 }
 360
 361 sub postprocess
 362 {
 363     local $_ = $_[0];
 364
 365     # @value{foo} is replaced by whatever 'foo' is defined as.
 366     while (m/(\@value\{([a-zA-Z0-9_-]+)\})/g) {
 367         if (! exists $defs{$2}) {
 368             print STDERR "Option $2 not defined\n";
 369             s/\Q$1\E//;
 370         } else {
 371             $value = $defs{$2};
 372             s/\Q$1\E/$value/;
 373         }
 374     }
 375
 376     # Formatting commands.
 377     # Temporary escape for @r.
 378     s/\@r\{([^\}]*)\}/R<$1>/g;
 379     s/\@(?:dfn|var|emph|cite|i)\{([^\}]*)\}/I<$1>/g;
 380     s/\@(?:code|kbd)\{([^\}]*)\}/C<$1>/g;
 381     s/\@(?:gccoptlist|samp|strong|key|option|env|command|b)\{([^\}]*)\}/B<$1>/g;
 382     s/\@sc\{([^\}]*)\}/\U$1/g;
 383     s/\@file\{([^\}]*)\}/F<$1>/g;
 384     s/\@w\{([^\}]*)\}/S<$1>/g;
 385     s/\@(?:dmn|math)\{([^\}]*)\}/$1/g;
 386     s/\@t\{([^\}]*)\}/$1/g;
 387
 388     # keep references of the form @ref{...}, print them bold
 389     s/\@(?:ref)\{([^\}]*)\}/B<$1>/g;
 390
 391     # Change double single quotes to double quotes.
 392     s/''/"/g;
 393     s/``/"/g;
 394
 395     # Cross references are thrown away, as are @noindent and @refill.
 396     # (@noindent is impossible in .pod, and @refill is unnecessary.)
 397     # @* is also impossible in .pod; we discard it and any newline that
 398     # follows it.  Similarly, our macro @gol must be discarded.
 399
 400     s/\(?\@xref\{(?:[^\}]*)\}(?:[^.<]|(?:<[^<>]*>))*\.\)?//g;
 401     s/\s+\(\@pxref\{(?:[^\}]*)\}\)//g;
 402     s/;\s+\@pxref\{(?:[^\}]*)\}//g;
 403     s/\@noindent\s*//g;
 404     s/\@refill//g;
 405     s/\@gol//g;
 406     s/\@\*\s*\n?//g;
 407
 408     # Anchors are thrown away
 409     s/\@anchor\{(?:[^\}]*)\}//g;
 410
 411     # @uref can take one, two, or three arguments, with different
 412     # semantics each time.  @url and @email are just like @uref with
 413     # one argument, for our purposes.
 414     s/\@(?:uref|url|email)\{([^\},]*)\}/&lt;B<$1>&gt;/g;
 415     s/\@uref\{([^\},]*),([^\},]*)\}/$2 (C<$1>)/g;
 416     s/\@uref\{([^\},]*),([^\},]*),([^\},]*)\}/$3/g;
 417
 418     # Un-escape <> at this point.
 419     s/&LT;/</g;
 420     s/&GT;/>/g;
 421
 422     # Now un-nest all B<>, I<>, R<>.  Theoretically we could have
 423     # indefinitely deep nesting; in practice, one level suffices.
 424     1 while s/([BIR])<([^<>]*)([BIR])<([^<>]*)>/$1<$2>$3<$4>$1</g;
 425
 426     # Replace R<...> with bare ...; eliminate empty markup, B<>;
 427     # shift white space at the ends of [BI]<...> expressions outside
 428     # the expression.
 429     s/R<([^<>]*)>/$1/g;
 430     s/[BI]<>//g;
 431     s/([BI])<(\s+)([^>]+)>/$2$1<$3>/g;
 432     s/([BI])<([^>]+?)(\s+)>/$1<$2>$3/g;
 433
 434     # Extract footnotes.  This has to be done after all other
 435     # processing because otherwise the regexp will choke on formatting
 436     # inside @footnote.
 437     while (/\@footnote/g) {
 438         s/\@footnote\{([^\}]+)\}/[$fnno]/;
 439         add_footnote($1, $fnno);
 440         $fnno++;
 441     }
 442
 443     return $_;
 444 }
 445
 446 sub unmunge
 447 {
 448     # Replace escaped symbols with their equivalents.
 449     local $_ = $_[0];
 450
 451     s/&lt;/E<lt>/g;
 452     s/&gt;/E<gt>/g;
 453     s/&lbrace;/\{/g;
 454     s/&rbrace;/\}/g;
 455     s/&at;/\@/g;
 456     s/&amp;/&/g;
 457     return $_;
 458 }
 459
 460 sub add_footnote
 461 {
 462     unless (exists $sects{FOOTNOTES}) {
 463         $sects{FOOTNOTES} = "\n=over 4\n\n";
 464     }
 465
 466     $sects{FOOTNOTES} .= "=item $fnno.\n\n"; $fnno++;
 467     $sects{FOOTNOTES} .= $_[0];
 468     $sects{FOOTNOTES} .= "\n\n";
 469 }
 470
 471 # stolen from Symbol.pm
 472 {
 473     my $genseq = 0;
 474     sub gensym
 475     {
 476         my $name = "GEN" . $genseq++;
 477         my $ref = \*{$name};
 478         delete $::{$name};
 479         return $ref;
 480     }
 481 }