1#! /usr/bin/perl -w
2
3#   Copyright (C) 1999, 2000, 2001, 200 Free Software Foundation, Inc.
4
5# This file is part of GNU CC.
6
7# GNU CC 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# GNU CC 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 GNU CC; see the file COPYING.  If not, write to
19# the Free Software Foundation, 59 Temple Place - Suite 330,
20# Boston MA 02111-1307, 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$ibase = "";
39
40while ($_ = shift) {
41    if (/^-D(.*)$/) {
42	if ($1 ne "") {
43	    $flag = $1;
44	} else {
45	    $flag = shift;
46	}
47	$value = "";
48	($flag, $value) = ($flag =~ /^([^=]+)(?:=(.+))?/);
49	die "no flag specified for -D\n"
50	    unless $flag ne "";
51	die "flags may only contain letters, digits, hyphens, dashes and underscores\n"
52	    unless $flag =~ /^[a-zA-Z0-9_-]+$/;
53	$defs{$flag} = $value;
54    } elsif (/^-/) {
55	usage();
56    } else {
57	$in = $_, next unless defined $in;
58	$out = $_, next unless defined $out;
59	usage();
60    }
61}
62
63if (defined $in) {
64    $inf = gensym();
65    open($inf, "<$in") or die "opening \"$in\": $!\n";
66    $ibase = $1 if $in =~ m|^(.+)/[^/]+$|;
67} else {
68    $inf = \*STDIN;
69}
70
71if (defined $out) {
72    open(STDOUT, ">$out") or die "opening \"$out\": $!\n";
73}
74
75while(defined $inf) {
76while(<$inf>) {
77    # Certain commands are discarded without further processing.
78    /^\@(?:
79	 [a-z]+index		# @*index: useful only in complete manual
80	 |need			# @need: useful only in printed manual
81	 |(?:end\s+)?group	# @group .. @end group: ditto
82	 |page			# @page: ditto
83	 |node			# @node: useful only in .info file
84	 |(?:end\s+)?ifnottex   # @ifnottex .. @end ifnottex: use contents
85	)\b/x and next;
86
87    chomp;
88
89    # Look for filename and title markers.
90    /^\@setfilename\s+([^.]+)/ and $fn = $1, next;
91    /^\@settitle\s+([^.]+)/ and $tl = postprocess($1), next;
92
93    # Identify a man title but keep only the one we are interested in.
94    /^\@c\s+man\s+title\s+([A-Za-z0-9-]+)\s+(.+)/ and do {
95	if (exists $defs{$1}) {
96	    $fn = $1;
97	    $tl = postprocess($2);
98	}
99	next;
100    };
101
102    # Look for blocks surrounded by @c man begin SECTION ... @c man end.
103    # This really oughta be @ifman ... @end ifman and the like, but such
104    # would require rev'ing all other Texinfo translators.
105    /^\@c\s+man\s+begin\s+([A-Z]+)\s+([A-Za-z0-9-]+)/ and do {
106	$output = 1 if exists $defs{$2};
107        $sect = $1;
108	next;
109    };
110    /^\@c\s+man\s+begin\s+([A-Z]+)/ and $sect = $1, $output = 1, next;
111    /^\@c\s+man\s+end/ and do {
112	$sects{$sect} = "" unless exists $sects{$sect};
113	$sects{$sect} .= postprocess($section);
114	$section = "";
115	$output = 0;
116	next;
117    };
118
119    # handle variables
120    /^\@set\s+([a-zA-Z0-9_-]+)\s*(.*)$/ and do {
121	$defs{$1} = $2;
122	next;
123    };
124    /^\@clear\s+([a-zA-Z0-9_-]+)/ and do {
125	delete $defs{$1};
126	next;
127    };
128
129    next unless $output;
130
131    # Discard comments.  (Can't do it above, because then we'd never see
132    # @c man lines.)
133    /^\@c\b/ and next;
134
135    # End-block handler goes up here because it needs to operate even
136    # if we are skipping.
137    /^\@end\s+([a-z]+)/ and do {
138	# Ignore @end foo, where foo is not an operation which may
139	# cause us to skip, if we are presently skipping.
140	my $ended = $1;
141	next if $skipping && $ended !~ /^(?:ifset|ifclear|ignore|menu|iftex)$/;
142
143	die "\@end $ended without \@$ended at line $.\n" unless defined $endw;
144	die "\@$endw ended by \@end $ended at line $.\n" unless $ended eq $endw;
145
146	$endw = pop @endwstack;
147
148	if ($ended =~ /^(?:ifset|ifclear|ignore|menu|iftex)$/) {
149	    $skipping = pop @skstack;
150	    next;
151	} elsif ($ended =~ /^(?:example|smallexample|display)$/) {
152	    $shift = "";
153	    $_ = "";	# need a paragraph break
154	} elsif ($ended =~ /^(?:itemize|enumerate|[fv]?table)$/) {
155	    $_ = "\n=back\n";
156	    $ic = pop @icstack;
157	} else {
158	    die "unknown command \@end $ended at line $.\n";
159	}
160    };
161
162    # We must handle commands which can cause skipping even while we
163    # are skipping, otherwise we will not process nested conditionals
164    # correctly.
165    /^\@ifset\s+([a-zA-Z0-9_-]+)/ and do {
166	push @endwstack, $endw;
167	push @skstack, $skipping;
168	$endw = "ifset";
169	$skipping = 1 unless exists $defs{$1};
170	next;
171    };
172
173    /^\@ifclear\s+([a-zA-Z0-9_-]+)/ and do {
174	push @endwstack, $endw;
175	push @skstack, $skipping;
176	$endw = "ifclear";
177	$skipping = 1 if exists $defs{$1};
178	next;
179    };
180
181    /^\@(ignore|menu|iftex)\b/ and do {
182	push @endwstack, $endw;
183	push @skstack, $skipping;
184	$endw = $1;
185	$skipping = 1;
186	next;
187    };
188
189    next if $skipping;
190
191    # Character entities.  First the ones that can be replaced by raw text
192    # or discarded outright:
193    s/\@copyright\{\}/(c)/g;
194    s/\@dots\{\}/.../g;
195    s/\@enddots\{\}/..../g;
196    s/\@([.!? ])/$1/g;
197    s/\@[:-]//g;
198    s/\@bullet(?:\{\})?/*/g;
199    s/\@TeX\{\}/TeX/g;
200    s/\@pounds\{\}/\#/g;
201    s/\@minus(?:\{\})?/-/g;
202    s/\\,/,/g;
203
204    # Now the ones that have to be replaced by special escapes
205    # (which will be turned back into text by unmunge())
206    s/&/&amp;/g;
207    s/\@\{/&lbrace;/g;
208    s/\@\}/&rbrace;/g;
209    s/\@\@/&at;/g;
210
211    # Inside a verbatim block, handle @var specially.
212    if ($shift ne "") {
213	s/\@var\{([^\}]*)\}/<$1>/g;
214    }
215
216    # POD doesn't interpret E<> inside a verbatim block.
217    if ($shift eq "") {
218	s/</&lt;/g;
219	s/>/&gt;/g;
220    } else {
221	s/</&LT;/g;
222	s/>/&GT;/g;
223    }
224
225    # Single line command handlers.
226
227    /^\@include\s+(.+)$/ and do {
228	push @instack, $inf;
229	$inf = gensym();
230
231	# Try cwd and $ibase.
232	open($inf, "<" . $1)
233	    or open($inf, "<" . $ibase . "/" . $1)
234		or die "cannot open $1 or $ibase/$1: $!\n";
235	next;
236    };
237
238    /^\@(?:section|unnumbered|unnumberedsec|center)\s+(.+)$/
239	and $_ = "\n=head2 $1\n";
240    /^\@subsection\s+(.+)$/
241	and $_ = "\n=head3 $1\n";
242
243    # Block command handlers:
244    /^\@itemize\s+(\@[a-z]+|\*|-)/ and do {
245	push @endwstack, $endw;
246	push @icstack, $ic;
247	$ic = $1;
248	$_ = "\n=over 4\n";
249	$endw = "itemize";
250    };
251
252    /^\@enumerate(?:\s+([a-zA-Z0-9]+))?/ and do {
253	push @endwstack, $endw;
254	push @icstack, $ic;
255	if (defined $1) {
256	    $ic = $1 . ".";
257	} else {
258	    $ic = "1.";
259	}
260	$_ = "\n=over 4\n";
261	$endw = "enumerate";
262    };
263
264    /^\@([fv]?table)\s+(\@[a-z]+)/ and do {
265	push @endwstack, $endw;
266	push @icstack, $ic;
267	$endw = $1;
268	$ic = $2;
269	$ic =~ s/\@(?:samp|strong|key|gcctabopt|env)/B/;
270	$ic =~ s/\@(?:code|kbd)/C/;
271	$ic =~ s/\@(?:dfn|var|emph|cite|i)/I/;
272	$ic =~ s/\@(?:file)/F/;
273	$_ = "\n=over 4\n";
274    };
275
276    /^\@((?:small)?example|display)/ and do {
277	push @endwstack, $endw;
278	$endw = $1;
279	$shift = "\t";
280	$_ = "";	# need a paragraph break
281    };
282
283    /^\@itemx?\s*(.+)?$/ and do {
284	if (defined $1) {
285	    # Entity escapes prevent munging by the <> processing below.
286	    $_ = "\n=item $ic\&LT;$1\&GT;\n";
287	} else {
288	    $_ = "\n=item $ic\n";
289	    $ic =~ y/A-Ya-y/B-Zb-z/;
290	    $ic =~ s/(\d+)/$1 + 1/eg;
291	}
292    };
293
294    $section .= $shift.$_."\n";
295}
296# End of current file.
297close($inf);
298$inf = pop @instack;
299}
300
301die "No filename or title\n" unless defined $fn && defined $tl;
302
303$sects{NAME} = "$fn \- $tl\n";
304$sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};
305
306for $sect (qw(NAME SYNOPSIS DESCRIPTION OPTIONS ENVIRONMENT FILES
307	      BUGS NOTES FOOTNOTES SEEALSO AUTHOR COPYRIGHT)) {
308    if(exists $sects{$sect}) {
309	$head = $sect;
310	$head =~ s/SEEALSO/SEE ALSO/;
311	print "=head1 $head\n\n";
312	print scalar unmunge ($sects{$sect});
313	print "\n";
314    }
315}
316
317sub usage
318{
319    die "usage: $0 [-D toggle...] [infile [outfile]]\n";
320}
321
322sub postprocess
323{
324    local $_ = $_[0];
325
326    # @value{foo} is replaced by whatever 'foo' is defined as.
327    while (m/(\@value\{([a-zA-Z0-9_-]+)\})/g) {
328	if (! exists $defs{$2}) {
329	    print STDERR "Option $2 not defined\n";
330	    s/\Q$1\E//;
331	} else {
332	    $value = $defs{$2};
333	    s/\Q$1\E/$value/;
334	}
335    }
336
337    # Formatting commands.
338    # Temporary escape for @r.
339    s/\@r\{([^\}]*)\}/R<$1>/g;
340    s/\@(?:dfn|var|emph|cite|i)\{([^\}]*)\}/I<$1>/g;
341    s/\@(?:code|kbd)\{([^\}]*)\}/C<$1>/g;
342    s/\@(?:gccoptlist|samp|strong|key|option|env|command|b)\{([^\}]*)\}/B<$1>/g;
343    s/\@sc\{([^\}]*)\}/\U$1/g;
344    s/\@file\{([^\}]*)\}/F<$1>/g;
345    s/\@w\{([^\}]*)\}/S<$1>/g;
346    s/\@(?:dmn|math)\{([^\}]*)\}/$1/g;
347
348    # Cross references are thrown away, as are @noindent and @refill.
349    # (@noindent is impossible in .pod, and @refill is unnecessary.)
350    # @* is also impossible in .pod; we discard it and any newline that
351    # follows it.  Similarly, our macro @gol must be discarded.
352
353    s/\(?\@xref\{(?:[^\}]*)\}(?:[^.<]|(?:<[^<>]*>))*\.\)?//g;
354    s/\s+\(\@pxref\{(?:[^\}]*)\}\)//g;
355    s/;\s+\@pxref\{(?:[^\}]*)\}//g;
356    s/\@noindent\s*//g;
357    s/\@refill//g;
358    s/\@gol//g;
359    s/\@\*\s*\n?//g;
360
361    # @uref can take one, two, or three arguments, with different
362    # semantics each time.  @url and @email are just like @uref with
363    # one argument, for our purposes.
364    s/\@(?:uref|url|email)\{([^\},]*)\}/&lt;B<$1>&gt;/g;
365    s/\@uref\{([^\},]*),([^\},]*)\}/$2 (C<$1>)/g;
366    s/\@uref\{([^\},]*),([^\},]*),([^\},]*)\}/$3/g;
367
368    # Turn B<blah I<blah> blah> into B<blah> I<blah> B<blah> to
369    # match Texinfo semantics of @emph inside @samp.  Also handle @r
370    # inside bold.
371    s/&LT;/</g;
372    s/&GT;/>/g;
373    1 while s/B<((?:[^<>]|I<[^<>]*>)*)R<([^>]*)>/B<$1>${2}B</g;
374    1 while (s/B<([^<>]*)I<([^>]+)>/B<$1>I<$2>B</g);
375    1 while (s/I<([^<>]*)B<([^>]+)>/I<$1>B<$2>I</g);
376    s/[BI]<>//g;
377    s/([BI])<(\s+)([^>]+)>/$2$1<$3>/g;
378    s/([BI])<([^>]+?)(\s+)>/$1<$2>$3/g;
379
380    # Extract footnotes.  This has to be done after all other
381    # processing because otherwise the regexp will choke on formatting
382    # inside @footnote.
383    while (/\@footnote/g) {
384	s/\@footnote\{([^\}]+)\}/[$fnno]/;
385	add_footnote($1, $fnno);
386	$fnno++;
387    }
388
389    return $_;
390}
391
392sub unmunge
393{
394    # Replace escaped symbols with their equivalents.
395    local $_ = $_[0];
396
397    s/&lt;/E<lt>/g;
398    s/&gt;/E<gt>/g;
399    s/&lbrace;/\{/g;
400    s/&rbrace;/\}/g;
401    s/&at;/\@/g;
402    s/&amp;/&/g;
403    return $_;
404}
405
406sub add_footnote
407{
408    unless (exists $sects{FOOTNOTES}) {
409	$sects{FOOTNOTES} = "\n=over 4\n\n";
410    }
411
412    $sects{FOOTNOTES} .= "=item $fnno.\n\n"; $fnno++;
413    $sects{FOOTNOTES} .= $_[0];
414    $sects{FOOTNOTES} .= "\n\n";
415}
416
417# stolen from Symbol.pm
418{
419    my $genseq = 0;
420    sub gensym
421    {
422	my $name = "GEN" . $genseq++;
423	my $ref = \*{$name};
424	delete $::{$name};
425	return $ref;
426    }
427}
428