summaryrefslogtreecommitdiffstats
path: root/texi2pod.pl
blob: 5d28a056d9744d75900d0284261aedc3a26a7c0d (plain) (blame)
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
#! /usr/bin/perl -w

#   Copyright (C) 1999, 2000, 2001, 2003 Free Software Foundation, Inc.

# This file is part of GCC.

# GCC 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.

# GCC 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 GCC; see the file COPYING.  If not, write to
# the Free Software Foundation, 51 Franklin Street, Fifth Floor,
# Boston MA 02110-1301, USA.

# This does trivial (and I mean _trivial_) conversion of Texinfo
# markup to Perl POD format.  It's intended to be used to extract
# something suitable for a manpage from a Texinfo document.

$output = 0;
$skipping = 0;
%sects = ();
$section = "";
@icstack = ();
@endwstack = ();
@skstack = ();
@instack = ();
$shift = "";
%defs = ();
$fnno = 1;
$inf = "";
$ibase = "";
@ipath = ();

while ($_ = shift) {
    if (/^-D(.*)$/) {
	if ($1 ne "") {
	    $flag = $1;
	} else {
	    $flag = shift;
	}
	$value = "";
	($flag, $value) = ($flag =~ /^([^=]+)(?:=(.+))?/);
	die "no flag specified for -D\n"
	    unless $flag ne "";
	die "flags may only contain letters, digits, hyphens, dashes and underscores\n"
	    unless $flag =~ /^[a-zA-Z0-9_-]+$/;
	$defs{$flag} = $value;
    } elsif (/^-I(.*)$/) {
	if ($1 ne "") {
	    $flag = $1;
	} else {
	    $flag = shift;
	}
        push (@ipath, $flag);
    } elsif (/^-/) {
	usage();
    } else {
	$in = $_, next unless defined $in;
	$out = $_, next unless defined $out;
	usage();
    }
}

if (defined $in) {
    $inf = gensym();
    open($inf, "<$in") or die "opening \"$in\": $!\n";
    $ibase = $1 if $in =~ m|^(.+)/[^/]+$|;
} else {
    $inf = \*STDIN;
}

if (defined $out) {
    open(STDOUT, ">$out") or die "opening \"$out\": $!\n";
}

while(defined $inf) {
while(<$inf>) {
    # Certain commands are discarded without further processing.
    /^\@(?:
	 [a-z]+index		# @*index: useful only in complete manual
	 |need			# @need: useful only in printed manual
	 |(?:end\s+)?group	# @group .. @end group: ditto
	 |page			# @page: ditto
	 |node			# @node: useful only in .info file
	 |(?:end\s+)?ifnottex   # @ifnottex .. @end ifnottex: use contents
	)\b/x and next;

    chomp;

    # Look for filename and title markers.
    /^\@setfilename\s+([^.]+)/ and $fn = $1, next;
    /^\@settitle\s+([^.]+)/ and $tl = postprocess($1), next;

    # Identify a man title but keep only the one we are interested in.
    /^\@c\s+man\s+title\s+([A-Za-z0-9-]+)\s+(.+)/ and do {
	if (exists $defs{$1}) {
	    $fn = $1;
	    $tl = postprocess($2);
	}
	next;
    };

    # Look for blocks surrounded by @c man begin SECTION ... @c man end.
    # This really oughta be @ifman ... @end ifman and the like, but such
    # would require rev'ing all other Texinfo translators.
    /^\@c\s+man\s+begin\s+([A-Z]+)\s+([A-Za-z0-9-]+)/ and do {
	$output = 1 if exists $defs{$2};
        $sect = $1;
	next;
    };
    /^\@c\s+man\s+begin\s+([A-Z]+)/ and $sect = $1, $output = 1, next;
    /^\@c\s+man\s+end/ and do {
	$sects{$sect} = "" unless exists $sects{$sect};
	$sects{$sect} .= postprocess($section);
	$section = "";
	$output = 0;
	next;
    };

    # handle variables
    /^\@set\s+([a-zA-Z0-9_-]+)\s*(.*)$/ and do {
	$defs{$1} = $2;
	next;
    };
    /^\@clear\s+([a-zA-Z0-9_-]+)/ and do {
	delete $defs{$1};
	next;
    };

    next unless $output;

    # Discard comments.  (Can't do it above, because then we'd never see
    # @c man lines.)
    /^\@c\b/ and next;

    # End-block handler goes up here because it needs to operate even
    # if we are skipping.
    /^\@end\s+([a-z]+)/ and do {
	# Ignore @end foo, where foo is not an operation which may
	# cause us to skip, if we are presently skipping.
	my $ended = $1;
	next if $skipping && $ended !~ /^(?:ifset|ifclear|ignore|menu|iftex|copying)$/;

	die "\@end $ended without \@$ended at line $.\n" unless defined $endw;
	die "\@$endw ended by \@end $ended at line $.\n" unless $ended eq $endw;

	$endw = pop @endwstack;

	if ($ended =~ /^(?:ifset|ifclear|ignore|menu|iftex)$/) {
	    $skipping = pop @skstack;
	    next;
	} elsif ($ended =~ /^(?:example|smallexample|display)$/) {
	    $shift = "";
	    $_ = "";	# need a paragraph break
	} elsif ($ended =~ /^(?:itemize|enumerate|[fv]?table)$/) {
	    $_ = "\n=back\n";
	    $ic = pop @icstack;
	} elsif ($ended eq "multitable") {
	    $_ = "\n=back\n";
	} else {
	    die "unknown command \@end $ended at line $.\n";
	}
    };

    # We must handle commands which can cause skipping even while we
    # are skipping, otherwise we will not process nested conditionals
    # correctly.
    /^\@ifset\s+([a-zA-Z0-9_-]+)/ and do {
	push @endwstack, $endw;
	push @skstack, $skipping;
	$endw = "ifset";
	$skipping = 1 unless exists $defs{$1};
	next;
    };

    /^\@ifclear\s+([a-zA-Z0-9_-]+)/ and do {
	push @endwstack, $endw;
	push @skstack, $skipping;
	$endw = "ifclear";
	$skipping = 1 if exists $defs{$1};
	next;
    };

    /^\@(ignore|menu|iftex|copying)\b/ and do {
	push @endwstack, $endw;
	push @skstack, $skipping;
	$endw = $1;
	$skipping = 1;
	next;
    };

    next if $skipping;

    # Character entities.  First the ones that can be replaced by raw text
    # or discarded outright:
    s/\@copyright\{\}/(c)/g;
    s/\@dots\{\}/.../g;
    s/\@enddots\{\}/..../g;
    s/\@([.!? ])/$1/g;
    s/\@[:-]//g;
    s/\@bullet(?:\{\})?/*/g;
    s/\@TeX\{\}/TeX/g;
    s/\@pounds\{\}/\#/g;
    s/\@minus(?:\{\})?/-/g;
    s/\\,/,/g;

    # Now the ones that have to be replaced by special escapes
    # (which will be turned back into text by unmunge())
    s/&/&amp;/g;
    s/\@\{/&lbrace;/g;
    s/\@\}/&rbrace;/g;
    s/\@\@/&at;/g;

    # Inside a verbatim block, handle @var specially.
    if ($shift ne "") {
	s/\@var\{([^\}]*)\}/<$1>/g;
    }

    # POD doesn't interpret E<> inside a verbatim block.
    if ($shift eq "") {
	s/</&lt;/g;
	s/>/&gt;/g;
    } else {
	s/</&LT;/g;
	s/>/&GT;/g;
    }

    # Single line command handlers.

    /^\@include\s+(.+)$/ and do {
	push @instack, $inf;
	$inf = gensym();
	$file = postprocess($1);

	# Try cwd and $ibase, then explicit -I paths.
	$done = 0;
	foreach $path ("", $ibase, @ipath) {
	    $mypath = $file;
	    $mypath = $path . "/" . $mypath if ($path ne "");
	    open($inf, "<" . $mypath) and ($done = 1, last);
	}
	die "cannot find $file" if !$done;
	next;
    };

    /^\@(?:section|unnumbered|unnumberedsec|center)\s+(.+)$/
	and $_ = "\n=head2 $1\n";
    /^\@subsection\s+(.+)$/
	and $_ = "\n=head3 $1\n";
    /^\@subsubsection\s+(.+)$/
	and $_ = "\n=head4 $1\n";

    # Block command handlers:
    /^\@itemize(?:\s+(\@[a-z]+|\*|-))?/ and do {
	push @endwstack, $endw;
	push @icstack, $ic;
	if (defined $1) {
	    $ic = $1;
	} else {
	    $ic = '*';
	}
	$_ = "\n=over 4\n";
	$endw = "itemize";
    };

    /^\@enumerate(?:\s+([a-zA-Z0-9]+))?/ and do {
	push @endwstack, $endw;
	push @icstack, $ic;
	if (defined $1) {
	    $ic = $1 . ".";
	} else {
	    $ic = "1.";
	}
	$_ = "\n=over 4\n";
	$endw = "enumerate";
    };

    /^\@multitable\s.*/ and do {
	push @endwstack, $endw;
	$endw = "multitable";
	$_ = "\n=over 4\n";
    };

    /^\@([fv]?table)\s+(\@[a-z]+)/ and do {
	push @endwstack, $endw;
	push @icstack, $ic;
	$endw = $1;
	$ic = $2;
	$ic =~ s/\@(?:samp|strong|key|gcctabopt|option|env)/B/;
	$ic =~ s/\@(?:code|kbd)/C/;
	$ic =~ s/\@(?:dfn|var|emph|cite|i)/I/;
	$ic =~ s/\@(?:file)/F/;
	$_ = "\n=over 4\n";
    };

    /^\@((?:small)?example|display)/ and do {
	push @endwstack, $endw;
	$endw = $1;
	$shift = "\t";
	$_ = "";	# need a paragraph break
    };

    /^\@item\s+(.*\S)\s*$/ and $endw eq "multitable" and do {
	@columns = ();
	for $column (split (/\s*\@tab\s*/, $1)) {
	    # @strong{...} is used a @headitem work-alike
	    $column =~ s/^\@strong{(.*)}$/$1/;
	    push @columns, $column;
	}
	$_ = "\n=item ".join (" : ", @columns)."\n";
    };

    /^\@itemx?\s*(.+)?$/ and do {
	if (defined $1) {
	    # Entity escapes prevent munging by the <> processing below.
	    $_ = "\n=item $ic\&LT;$1\&GT;\n";
	} else {
	    $_ = "\n=item $ic\n";
	    $ic =~ y/A-Ya-y/B-Zb-z/;
	    $ic =~ s/(\d+)/$1 + 1/eg;
	}
    };

    $section .= $shift.$_."\n";
}
# End of current file.
close($inf);
$inf = pop @instack;
}

die "No filename or title\n" unless defined $fn && defined $tl;

$sects{NAME} = "$fn \- $tl\n";
$sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};

for $sect (qw(NAME SYNOPSIS DESCRIPTION OPTIONS ENVIRONMENT FILES
	      BUGS NOTES FOOTNOTES SEEALSO AUTHOR COPYRIGHT)) {
    if(exists $sects{$sect}) {
	$head = $sect;
	$head =~ s/SEEALSO/SEE ALSO/;
	print "=head1 $head\n\n";
	print scalar unmunge ($sects{$sect});
	print "\n";
    }
}

sub usage
{
    die "usage: $0 [-D toggle...] [infile [outfile]]\n";
}

sub postprocess
{
    local $_ = $_[0];

    # @value{foo} is replaced by whatever 'foo' is defined as.
    while (m/(\@value\{([a-zA-Z0-9_-]+)\})/g) {
	if (! exists $defs{$2}) {
	    print STDERR "Option $2 not defined\n";
	    s/\Q$1\E//;
	} else {
	    $value = $defs{$2};
	    s/\Q$1\E/$value/;
	}
    }

    # Formatting commands.
    # Temporary escape for @r.
    s/\@r\{([^\}]*)\}/R<$1>/g;
    s/\@(?:dfn|var|emph|cite|i)\{([^\}]*)\}/I<$1>/g;
    s/\@(?:code|kbd)\{([^\}]*)\}/C<$1>/g;
    s/\@(?:gccoptlist|samp|strong|key|option|env|command|b)\{([^\}]*)\}/B<$1>/g;
    s/\@sc\{([^\}]*)\}/\U$1/g;
    s/\@file\{([^\}]*)\}/F<$1>/g;
    s/\@w\{([^\}]*)\}/S<$1>/g;
    s/\@(?:dmn|math)\{([^\}]*)\}/$1/g;

    # keep references of the form @ref{...}, print them bold
    s/\@(?:ref)\{([^\}]*)\}/B<$1>/g;

    # Change double single quotes to double quotes.
    s/''/"/g;
    s/``/"/g;

    # Cross references are thrown away, as are @noindent and @refill.
    # (@noindent is impossible in .pod, and @refill is unnecessary.)
    # @* is also impossible in .pod; we discard it and any newline that
    # follows it.  Similarly, our macro @gol must be discarded.

    s/\(?\@xref\{(?:[^\}]*)\}(?:[^.<]|(?:<[^<>]*>))*\.\)?//g;
    s/\s+\(\@pxref\{(?:[^\}]*)\}\)//g;
    s/;\s+\@pxref\{(?:[^\}]*)\}//g;
    s/\@noindent\s*//g;
    s/\@refill//g;
    s/\@gol//g;
    s/\@\*\s*\n?//g;

    # Anchors are thrown away
    s/\@anchor\{(?:[^\}]*)\}//g;

    # @uref can take one, two, or three arguments, with different
    # semantics each time.  @url and @email are just like @uref with
    # one argument, for our purposes.
    s/\@(?:uref|url|email)\{([^\},]*)\}/&lt;B<$1>&gt;/g;
    s/\@uref\{([^\},]*),([^\},]*)\}/$2 (C<$1>)/g;
    s/\@uref\{([^\},]*),([^\},]*),([^\},]*)\}/$3/g;

    # Un-escape <> at this point.
    s/&LT;/</g;
    s/&GT;/>/g;

    # Now un-nest all B<>, I<>, R<>.  Theoretically we could have
    # indefinitely deep nesting; in practice, one level suffices.
    1 while s/([BIR])<([^<>]*)([BIR])<([^<>]*)>/$1<$2>$3<$4>$1</g;

    # Replace R<...> with bare ...; eliminate empty markup, B<>;
    # shift white space at the ends of [BI]<...> expressions outside
    # the expression.
    s/R<([^<>]*)>/$1/g;
    s/[BI]<>//g;
    s/([BI])<(\s+)([^>]+)>/$2$1<$3>/g;
    s/([BI])<([^>]+?)(\s+)>/$1<$2>$3/g;

    # Extract footnotes.  This has to be done after all other
    # processing because otherwise the regexp will choke on formatting
    # inside @footnote.
    while (/\@footnote/g) {
	s/\@footnote\{([^\}]+)\}/[$fnno]/;
	add_footnote($1, $fnno);
	$fnno++;
    }

    return $_;
}

sub unmunge
{
    # Replace escaped symbols with their equivalents.
    local $_ = $_[0];

    s/&lt;/E<lt>/g;
    s/&gt;/E<gt>/g;
    s/&lbrace;/\{/g;
    s/&rbrace;/\}/g;
    s/&at;/\@/g;
    s/&amp;/&/g;
    return $_;
}

sub add_footnote
{
    unless (exists $sects{FOOTNOTES}) {
	$sects{FOOTNOTES} = "\n=over 4\n\n";
    }

    $sects{FOOTNOTES} .= "=item $fnno.\n\n"; $fnno++;
    $sects{FOOTNOTES} .= $_[0];
    $sects{FOOTNOTES} .= "\n\n";
}

# stolen from Symbol.pm
{
    my $genseq = 0;
    sub gensym
    {
	my $name = "GEN" . $genseq++;
	my $ref = \*{$name};
	delete $::{$name};
	return $ref;
    }
}