1#! /usr/bin/env perl
2
3#   Copyright (C) 1999, 2000, 2001, 2003, 2007, 2009 Free Software
4#   Foundation, Inc.
5
6# This file is part of GCC.
7
8# GCC is free software; you can redistribute it and/or modify
9# it under the terms of the GNU General Public License as published by
10# the Free Software Foundation; either version 3, or (at your option)
11# any later version.
12
13# GCC is distributed in the hope that it will be useful,
14# but WITHOUT ANY WARRANTY; without even the implied warranty of
15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16# GNU General Public License for more details.
17
18# You should have received a copy of the GNU General Public License
19# along with GCC.  If not, see <http://www.gnu.org/licenses/>.
20
21# This does trivial (and I mean _trivial_) conversion of Texinfo
22# markup to Perl POD format.  It's intended to be used to extract
23# something suitable for a manpage from a Texinfo document.
24
25use warnings;
26
27$output = 0;
28$skipping = 0;
29%sects = ();
30$section = "";
31@icstack = ();
32@endwstack = ();
33@skstack = ();
34@instack = ();
35$shift = "";
36%defs = ();
37$fnno = 1;
38$inf = "";
39$ibase = "";
40
41while ($_ = 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 (/^-/) {
56	usage();
57    } else {
58	$in = $_, next unless defined $in;
59	$out = $_, next unless defined $out;
60	usage();
61    }
62}
63
64if (defined $in) {
65    $inf = gensym();
66    open($inf, "<$in") or die "opening \"$in\": $!\n";
67    $ibase = $1 if $in =~ m|^(.+)/[^/]+$|;
68} else {
69    $inf = \*STDIN;
70}
71
72if (defined $out) {
73    open(STDOUT, ">$out") or die "opening \"$out\": $!\n";
74}
75
76while(defined $inf) {
77while(<$inf>) {
78    # Certain commands are discarded without further processing.
79    /^\@(?:
80	 [a-z]+index		# @*index: useful only in complete manual
81	 |need			# @need: useful only in printed manual
82	 |(?:end\s+)?group	# @group .. @end group: ditto
83	 |page			# @page: ditto
84	 |node			# @node: useful only in .info file
85	 |(?:end\s+)?ifnottex   # @ifnottex .. @end ifnottex: use contents
86	)\b/x and next;
87
88    chomp;
89
90    # Look for filename and title markers.
91    /^\@setfilename\s+([^.]+)/ and $fn = $1, next;
92    /^\@settitle\s+([^.]+)/ and $tl = postprocess($1), next;
93
94    # Identify a man title but keep only the one we are interested in.
95    /^\@c\s+man\s+title\s+([A-Za-z0-9-]+)\s+(.+)/ and do {
96	if (exists $defs{$1}) {
97	    $fn = $1;
98	    $tl = postprocess($2);
99	}
100	next;
101    };
102
103    # Look for blocks surrounded by @c man begin SECTION ... @c man end.
104    # This really oughta be @ifman ... @end ifman and the like, but such
105    # would require rev'ing all other Texinfo translators.
106    /^\@c\s+man\s+begin\s+([A-Z]+)\s+([A-Za-z0-9-]+)/ and do {
107	$output = 1 if exists $defs{$2};
108        $sect = $1;
109	next;
110    };
111    /^\@c\s+man\s+begin\s+([A-Z]+)/ and $sect = $1, $output = 1, next;
112    /^\@c\s+man\s+end/ and do {
113	$sects{$sect} = "" unless exists $sects{$sect};
114	$sects{$sect} .= postprocess($section);
115	$section = "";
116	$output = 0;
117	next;
118    };
119
120    # handle variables
121    /^\@set\s+([a-zA-Z0-9_-]+)\s*(.*)$/ and do {
122	$defs{$1} = $2;
123	next;
124    };
125    /^\@clear\s+([a-zA-Z0-9_-]+)/ and do {
126	delete $defs{$1};
127	next;
128    };
129
130    next unless $output;
131
132    # Discard comments.  (Can't do it above, because then we'd never see
133    # @c man lines.)
134    /^\@c\b/ and next;
135
136    # End-block handler goes up here because it needs to operate even
137    # if we are skipping.
138    /^\@end\s+([a-z]+)/ and do {
139	# Ignore @end foo, where foo is not an operation which may
140	# cause us to skip, if we are presently skipping.
141	my $ended = $1;
142	next if $skipping && $ended !~ /^(?:ifset|ifclear|ignore|menu|iftex|copying)$/;
143
144	die "\@end $ended without \@$ended at line $.\n" unless defined $endw;
145	die "\@$endw ended by \@end $ended at line $.\n" unless $ended eq $endw;
146
147	$endw = pop @endwstack;
148
149	if ($ended =~ /^(?:ifset|ifclear|ignore|menu|iftex)$/) {
150	    $skipping = pop @skstack;
151	    next;
152	} elsif ($ended =~ /^(?:example|smallexample|display)$/) {
153	    $shift = "";
154	    $_ = "";	# need a paragraph break
155	} elsif ($ended =~ /^(?:itemize|enumerate|[fv]?table)$/) {
156	    $_ = "\n=back\n";
157	    $ic = pop @icstack;
158	} else {
159	    die "unknown command \@end $ended at line $.\n";
160	}
161    };
162
163    # We must handle commands which can cause skipping even while we
164    # are skipping, otherwise we will not process nested conditionals
165    # correctly.
166    /^\@ifset\s+([a-zA-Z0-9_-]+)/ and do {
167	push @endwstack, $endw;
168	push @skstack, $skipping;
169	$endw = "ifset";
170	$skipping = 1 unless exists $defs{$1};
171	next;
172    };
173
174    /^\@ifclear\s+([a-zA-Z0-9_-]+)/ and do {
175	push @endwstack, $endw;
176	push @skstack, $skipping;
177	$endw = "ifclear";
178	$skipping = 1 if exists $defs{$1};
179	next;
180    };
181
182    /^\@(ignore|menu|iftex|copying)\b/ and do {
183	push @endwstack, $endw;
184	push @skstack, $skipping;
185	$endw = $1;
186	$skipping = 1;
187	next;
188    };
189
190    next if $skipping;
191
192    # Character entities.  First the ones that can be replaced by raw text
193    # or discarded outright:
194    s/\@copyright\{\}/(c)/g;
195    s/\@dots\{\}/.../g;
196    s/\@enddots\{\}/..../g;
197    s/\@([.!? ])/$1/g;
198    s/\@[:-]//g;
199    s/\@bullet(?:\{\})?/*/g;
200    s/\@TeX\{\}/TeX/g;
201    s/\@pounds\{\}/\#/g;
202    s/\@minus(?:\{\})?/-/g;
203    s/\\,/,/g;
204
205    # Now the ones that have to be replaced by special escapes
206    # (which will be turned back into text by unmunge())
207    s/&/&amp;/g;
208    s/\@\@/&at;/g;
209    s/\@\{/&lbrace;/g;
210    s/\@\}/&rbrace;/g;
211
212    # Inside a verbatim block, handle @var specially.
213    if ($shift ne "") {
214	s/\@var\{([^\}]*)\}/<$1>/g;
215    }
216
217    # POD doesn't interpret E<> inside a verbatim block.
218    if ($shift eq "") {
219	s/</&lt;/g;
220	s/>/&gt;/g;
221    } else {
222	s/</&LT;/g;
223	s/>/&GT;/g;
224    }
225
226    # Single line command handlers.
227
228    /^\@include\s+(.+)$/ and do {
229	push @instack, $inf;
230	$inf = gensym();
231	$file = postprocess($1);
232
233	# Try cwd and $ibase.
234	open($inf, "<" . $file)
235	    or open($inf, "<" . $ibase . "/" . $file)
236		or die "cannot open $file or $ibase/$file: $!\n";
237	next;
238    };
239
240    /^\@(?:section|unnumbered|unnumberedsec|center)\s+(.+)$/
241	and $_ = "\n=head2 $1\n";
242    /^\@subsection\s+(.+)$/
243	and $_ = "\n=head3 $1\n";
244
245    # Block command handlers:
246    /^\@itemize(?:\s+(\@[a-z]+|\*|-))?/ and do {
247	push @endwstack, $endw;
248	push @icstack, $ic;
249	if (defined $1) {
250	    $ic = $1;
251	} else {
252	    $ic = '@bullet';
253	}
254	$_ = "\n=over 4\n";
255	$endw = "itemize";
256    };
257
258    /^\@enumerate(?:\s+([a-zA-Z0-9]+))?/ and do {
259	push @endwstack, $endw;
260	push @icstack, $ic;
261	if (defined $1) {
262	    $ic = $1 . ".";
263	} else {
264	    $ic = "1.";
265	}
266	$_ = "\n=over 4\n";
267	$endw = "enumerate";
268    };
269
270    /^\@([fv]?table)\s+(\@[a-z]+)/ and do {
271	push @endwstack, $endw;
272	push @icstack, $ic;
273	$endw = $1;
274	$ic = $2;
275	$ic =~ s/\@(?:samp|strong|key|gcctabopt|env)/B/;
276	$ic =~ s/\@(?:code|kbd)/C/;
277	$ic =~ s/\@(?:dfn|var|emph|cite|i)/I/;
278	$ic =~ s/\@(?:file)/F/;
279	$_ = "\n=over 4\n";
280    };
281
282    /^\@((?:small)?example|display)/ and do {
283	push @endwstack, $endw;
284	$endw = $1;
285	$shift = "\t";
286	$_ = "";	# need a paragraph break
287    };
288
289    /^\@itemx?\s*(.+)?$/ and do {
290	if (defined $1) {
291            my $thing = $1;
292            if ($ic =~ /\@asis/) {
293                $_ = "\n=item $thing\n";
294            } else {
295                # Entity escapes prevent munging by the <> processing below.
296                $_ = "\n=item $ic\&LT;$thing\&GT;\n";
297            }
298	} else {
299	    $_ = "\n=item $ic\n";
300	    $ic =~ y/A-Ya-y/B-Zb-z/;
301	    $ic =~ s/(\d+)/$1 + 1/eg;
302	}
303    };
304
305    $section .= $shift.$_."\n";
306}
307# End of current file.
308close($inf);
309$inf = pop @instack;
310}
311
312die "No filename or title\n" unless defined $fn && defined $tl;
313
314$sects{NAME} = "$fn \- $tl\n";
315$sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};
316
317for $sect (qw(NAME SYNOPSIS DESCRIPTION OPTIONS ENVIRONMENT EXITSTATUS
318           FILES BUGS NOTES FOOTNOTES SEEALSO AUTHOR COPYRIGHT)) {
319    if(exists $sects{$sect}) {
320	$head = $sect;
321	$head =~ s/SEEALSO/SEE ALSO/;
322	$head =~ s/EXITSTATUS/EXIT STATUS/;
323	print "=head1 $head\n\n";
324	print scalar unmunge ($sects{$sect});
325	print "\n";
326    }
327}
328
329sub usage
330{
331    die "usage: $0 [-D toggle...] [infile [outfile]]\n";
332}
333
334sub postprocess
335{
336    local $_ = $_[0];
337
338    # @value{foo} is replaced by whatever 'foo' is defined as.
339    while (m/(\@value\{([a-zA-Z0-9_-]+)\})/g) {
340	if (! exists $defs{$2}) {
341	    print STDERR "Option $2 not defined\n";
342	    s/\Q$1\E//;
343	} else {
344	    $value = $defs{$2};
345	    s/\Q$1\E/$value/;
346	}
347    }
348
349    # Formatting commands.
350    # Temporary escape for @r.
351    s/\@r\{([^\}]*)\}/R<$1>/g;
352    s/\@(?:dfn|var|emph|cite|i)\{([^\}]*)\}/I<$1>/g;
353    s/\@(?:code|kbd)\{([^\}]*)\}/C<$1>/g;
354    s/\@(?:gccoptlist|samp|strong|key|option|env|command|b)\{([^\}]*)\}/B<$1>/g;
355    s/\@sc\{([^\}]*)\}/\U$1/g;
356    s/\@file\{([^\}]*)\}/F<$1>/g;
357    s/\@w\{([^\}]*)\}/S<$1>/g;
358    s/\@(?:dmn|math)\{([^\}]*)\}/$1/g;
359
360    # keep references of the form @ref{...}, print them bold
361    s/\@(?:ref)\{([^\}]*)\}/B<$1>/g;
362
363    # Change double single quotes to double quotes.
364    s/''/"/g;
365    s/``/"/g;
366
367    # Cross references are thrown away, as are @noindent and @refill.
368    # (@noindent is impossible in .pod, and @refill is unnecessary.)
369    # @* is also impossible in .pod; we discard it and any newline that
370    # follows it.  Similarly, our macro @gol must be discarded.
371
372    s/\(?\@xref\{(?:[^\}]*)\}(?:[^.<]|(?:<[^<>]*>))*\.\)?//g;
373    s/\s+\(\@pxref\{(?:[^\}]*)\}\)//g;
374    s/;\s+\@pxref\{(?:[^\}]*)\}//g;
375    s/\@noindent\s*//g;
376    s/\@refill//g;
377    s/\@gol//g;
378    s/\@\*\s*\n?//g;
379
380    # @uref can take one, two, or three arguments, with different
381    # semantics each time.  @url and @email are just like @uref with
382    # one argument, for our purposes.
383    s/\@(?:uref|url|email)\{([^\},]*)\}/&lt;B<$1>&gt;/g;
384    s/\@uref\{([^\},]*),([^\},]*)\}/$2 (C<$1>)/g;
385    s/\@uref\{([^\},]*),([^\},]*),([^\},]*)\}/$3/g;
386
387    # Un-escape <> at this point.
388    s/&LT;/</g;
389    s/&GT;/>/g;
390
391    # Now un-nest all B<>, I<>, R<>.  Theoretically we could have
392    # indefinitely deep nesting; in practice, one level suffices.
393    1 while s/([BIR])<([^<>]*)([BIR])<([^<>]*)>/$1<$2>$3<$4>$1</g;
394
395    # Replace R<...> with bare ...; eliminate empty markup, B<>;
396    # shift white space at the ends of [BI]<...> expressions outside
397    # the expression.
398    s/R<([^<>]*)>/$1/g;
399    s/[BI]<>//g;
400    s/([BI])<(\s+)([^>]+)>/$2$1<$3>/g;
401    s/([BI])<([^>]+?)(\s+)>/$1<$2>$3/g;
402
403    # Extract footnotes.  This has to be done after all other
404    # processing because otherwise the regexp will choke on formatting
405    # inside @footnote.
406    while (/\@footnote/g) {
407	s/\@footnote\{([^\}]+)\}/[$fnno]/;
408	add_footnote($1, $fnno);
409	$fnno++;
410    }
411
412    return $_;
413}
414
415sub unmunge
416{
417    # Replace escaped symbols with their equivalents.
418    local $_ = $_[0];
419
420    s/&lt;/E<lt>/g;
421    s/&gt;/E<gt>/g;
422    s/&lbrace;/\{/g;
423    s/&rbrace;/\}/g;
424    s/&at;/\@/g;
425    s/&amp;/&/g;
426    return $_;
427}
428
429sub add_footnote
430{
431    unless (exists $sects{FOOTNOTES}) {
432	$sects{FOOTNOTES} = "\n=over 4\n\n";
433    }
434
435    $sects{FOOTNOTES} .= "=item $fnno.\n\n"; $fnno++;
436    $sects{FOOTNOTES} .= $_[0];
437    $sects{FOOTNOTES} .= "\n\n";
438}
439
440# stolen from Symbol.pm
441{
442    my $genseq = 0;
443    sub gensym
444    {
445	my $name = "GEN" . $genseq++;
446	my $ref = \*{$name};
447	delete $::{$name};
448	return $ref;
449    }
450}
451