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
|
# help-extract -- extract --help and --version output from a script.
# Copyright (C) 2020-2022 Free Software Foundation, Inc.
# This program 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 3 of the License, or
# (at your option) any later version.
# This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
# Written by Zack Weinberg.
use 5.010;
use strict;
use warnings;
use File::Spec::Functions qw(catfile);
# This script is not intended to be used directly. It's run by
# help2man via wrappers in man/, e.g. man/autoconf.w, as if it were
# one of autoconf's executable scripts. It extracts the --help and
# --version output of that script from its source form, without
# actually running it. The script to work from is set by the wrapper,
# and several other parameters are passed down from the Makefile as
# environment variables; see parse_args below.
# The point of this script is, the preprocessed forms of the
# executable scripts, and their wrappers for uninstalled use
# (e.g. <build-dir>/{bin,tests}/autoconf) do not need to exist to
# generate the corresponding manpages. This is desirable because we
# can't put those dependencies in the makefiles without breaking
# people's ability to build autoconf from a release tarball without
# help2man installed. It also ensures that we will generate manpages
# from the current source code and not from an older version of the
# script that has already been installed.
## ----------------------------- ##
## Extraction from Perl scripts. ##
## ----------------------------- ##
sub eval_qq_no_interpolation ($)
{
# The argument is expected to be a "double quoted string" including the
# leading and trailing delimiters. Returns the text of this string after
# processing backslash escapes but NOT interpolation.
my $s = $_[0];
# Escape $ and @ inside the string, if they are not already escaped.
# The regex matches the empty string, but only if it is preceded by an
# even number of backslashes (including zero) and followed by either a
# literal $ or a literal @. Then we insert a backslash at the position
# of the match.
$s =~ s/ (?:\A|[^\\]) (?:\\\\)* \K (?=[\$\@]) /\\/xg;
# It is now safe to feed the string to 'eval'.
return eval $s;
}
sub extract_channeldefs_usage ($)
{
my ($channeldefs_pm) = @_;
my $usage = "";
my $parse_state = 0;
local $_;
open (my $fh, "<", $channeldefs_pm) or die "$channeldefs_pm: $!\n";
while (<$fh>)
{
if ($parse_state == 0)
{
$parse_state = 1 if /^sub usage\b/;
}
elsif ($parse_state == 1)
{
if (s/^ return "//)
{
$parse_state = 2;
$usage .= $_;
}
}
elsif ($parse_state == 2)
{
if (s/(?<!\\) ((?>\\\\)*) "; $/$1/x)
{
$usage .= $_;
return $usage;
}
else
{
$usage .= $_;
}
}
}
die "$channeldefs_pm: unexpected EOF in state $parse_state\n";
}
sub extract_perl_assignment (*$$$)
{
my ($fh, $source, $channeldefs_pm, $what) = @_;
my $value = "";
my $parse_state = 0;
local $_;
while (<$fh>)
{
if ($parse_state == 0)
{
if (s/^\$\Q${what}\E = (?=")//o)
{
$value .= $_;
$parse_state = 1;
}
}
elsif ($parse_state == 1)
{
if (/^"\s*\.\s*Autom4te::ChannelDefs::usage\s*(?:\(\))?\s*\.\s*"$/)
{
$value .= extract_channeldefs_usage ($channeldefs_pm);
}
elsif (/^";$/)
{
$value .= '"';
return eval_qq_no_interpolation ($value);
}
else
{
$value .= $_;
}
}
}
die "$source: unexpected EOF in state $parse_state\n";
}
## -------------- ##
## Main program. ##
## -------------- ##
sub extract_assignment ($$$)
{
my ($source, $channeldefs_pm, $what) = @_;
open (my $fh, "<", $source) or die "$source: $!\n";
my $firstline = <$fh>;
if ($firstline =~ /\@PERL\@/ || $firstline =~ /-\*-\s*perl\s*-\*-/i)
{
return extract_perl_assignment ($fh, $source, $channeldefs_pm, $what);
}
else
{
die "$source: language not recognized\n";
}
}
sub main ()
{
# Most of our arguments come from environment variables, because
# help2man doesn't allow for passing additional command line
# arguments to the wrappers, and it's easier to write the wrappers
# to not mess with the command line.
my $usage = "Usage: $0 script-source (--help | --version)
Extract help and version information from a perl script.
Required environment variables:
top_srcdir relative path from cwd to the top of the source tree
channeldefs_pm relative path from top_srcdir to ChannelDefs.pm
PACKAGE_NAME the autoconf PACKAGE_NAME substitution variable
VERSION the autoconf VERSION substitution variable
RELEASE_YEAR the autoconf RELEASE_YEAR substitution variable
The script-source argument should also be relative to top_srcdir.
";
my $source = shift(@ARGV) || die $usage;
my $what = shift(@ARGV) || die $usage;
my $top_srcdir = $ENV{top_srcdir} || die $usage;
my $channeldefs_pm = $ENV{channeldefs_pm} || die $usage;
my $package_name = $ENV{PACKAGE_NAME} || die $usage;
my $version = $ENV{VERSION} || die $usage;
my $release_year = $ENV{RELEASE_YEAR} || die $usage;
if ($what eq "-h" || $what eq "--help")
{
$what = "help";
}
elsif ($what eq "-V" || $what eq "--version")
{
$what = "version";
}
else
{
die $usage;
}
my $cmd_name = $source;
$cmd_name =~ s{^.*/([^./]+)\.in$}{$1};
$source = catfile($top_srcdir, $source);
$channeldefs_pm = catfile($top_srcdir, $channeldefs_pm);
my $text = extract_assignment ($source, $channeldefs_pm, $what);
$text =~ s/\$0\b/$cmd_name/g;
$text =~ s/[@]PACKAGE_NAME@/$package_name/g;
$text =~ s/[@]VERSION@/$version/g;
$text =~ s/[@]RELEASE_YEAR@/$release_year/g;
print $text;
}
main;
### Setup "GNU" style for perl-mode and cperl-mode.
## Local Variables:
## perl-indent-level: 2
## perl-continued-statement-offset: 2
## perl-continued-brace-offset: 0
## perl-brace-offset: 0
## perl-brace-imaginary-offset: 0
## perl-label-offset: -2
## cperl-indent-level: 2
## cperl-brace-offset: 0
## cperl-continued-brace-offset: 0
## cperl-label-offset: -2
## cperl-extra-newline-before-brace: t
## cperl-merge-trailing-else: nil
## cperl-continued-statement-offset: 2
## End:
|
