ffmpeg/doc/texi2pod.pl

449 lines
12 KiB
Prolog
Executable File

#!/usr/bin/env perl
# Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
# This file is part of GNU CC.
# GNU CC 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.
# GNU CC 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 GNU CC; 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.
use warnings;
$output = 0;
$skipping = 0;
%sects = ();
@sects_sequence = ();
$section = "";
@icstack = ();
@endwstack = ();
@skstack = ();
@instack = ();
$shift = "";
%defs = ();
$fnno = 1;
$inf = "";
@ibase = ();
while ($_ = 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} = $value;
} elsif (/^-I(.*)$/) {
push @ibase, $1 ne "" ? $1 : shift;
} elsif (/^-/) {
usage();
} else {
$in = $_, next unless defined $in;
$out = $_, next unless defined $out;
usage();
}
}
push @ibase, ".";
if (defined $in) {
$inf = gensym();
open($inf, "<$in") or die "opening \"$in\": $!\n";
push @ibase, $1 if $in =~ m|^(.+)/[^/]+$|;
} else {
$inf = \*STDIN;
}
if (defined $out) {
open(STDOUT, ">$out") or die "opening \"$out\": $!\n";
}
while(defined $inf) {
INF: while(<$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($2);
}
next;
};
/^\@include\s+(.+)$/ and do {
push @instack, $inf;
$inf = gensym();
for (@ibase) {
open($inf, "<" . $_ . "/" . $1) and next INF;
}
die "cannot open $1: $!\n";
};
# 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-Za-z ]+)/ and $sect = $1, push (@sects_sequence, $sect), $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 && $ended !~ /^(?:ifset|ifclear|ignore|menu|iftex)$/;
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|(?:multi|[fv])?table)$/) {
$_ = "\n=back\n";
$ic = pop @icstack;
} 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)\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.
/^\@(?:section|unnumbered|unnumberedsec|center|heading)\s+(.+)$/
and $_ = "\n=head2 $1\n";
/^\@(?:subsection|subheading)\s+(.+)$/
and $_ = "\n=head3 $1\n";
/^\@(?:subsubsection|subsubheading)\s+(.+)$/
and $_ = "\n=head4 $1\n";
# Block command handlers:
/^\@itemize\s*(\@[a-z]+|\*|-)?/ and do {
push @endwstack, $endw;
push @icstack, $ic;
$ic = $1 ? $1 : "*";
$_ = "\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";
};
/^\@((?:multi|[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/;
$ic =~ s/\@(?:columnfractions)//;
$_ = "\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 {
my $columns = $1;
$columns =~ s/\@tab/ : /;
$_ = "\n=item B&LT;". $columns ."&GT;\n";
};
/^\@tab\s+(.*\S)\s*$/ and $endw eq "multitable" and do {
my $columns = $1;
$columns =~ s/\@tab/ : /;
$_ = " : ". $columns;
$section =~ s/\n+\s+$//;
};
/^\@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};
unshift @sects_sequence, "NAME";
for $sect (@sects_sequence) {
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;
# 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/\@anchor{(?:[^\}]*)\}//g;
s/\(?\@xref\{(?:[^\}]*)\}(?:[^.<]|(?:<[^<>]*>))*\.\)?//g;
s/\s+\(\@pxref\{(?:[^\}]*)\}\)//g;
s/;\s+\@pxref\{(?:[^\}]*)\}//g;
s/\@ref\{([^\}]*)\}/$1/g;
s/\@noindent\s*//g;
s/\@refill//g;
s/\@gol//g;
s/\@\*\s*\n?//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;
# Turn B<blah I<blah> blah> into B<blah> I<blah> B<blah> to
# match Texinfo semantics of @emph inside @samp. Also handle @r
# inside bold.
s/&LT;/</g;
s/&GT;/>/g;
1 while s/B<((?:[^<>]|I<[^<>]*>)*)R<([^>]*)>/B<$1>${2}B</g;
1 while (s/B<([^<>]*)I<([^>]+)>/B<$1>I<$2>B</g);
1 while (s/I<([^<>]*)B<([^>]+)>/I<$1>B<$2>I</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;
}
}