1 #!/usr/bin/env perl
2 # SPDX-License-Identifier: GPL-2.0-or-later
3 use strict;
4 
5 # Copyright (c) 2017-2020 Mauro Carvalho Chehab <mchehab@kernel.org>
6 #
7 
8 my $prefix = "./";
9 $prefix = "$ENV{'srctree'}/" if ($ENV{'srctree'});
10 
11 my $conf = $prefix . "Documentation/conf.py";
12 my $requirement_file = $prefix . "Documentation/sphinx/requirements.txt";
13 my $virtenv_prefix = "sphinx_";
14 
15 #
16 # Static vars
17 #
18 
19 my %missing;
20 my $system_release;
21 my $need = 0;
22 my $optional = 0;
23 my $need_symlink = 0;
24 my $need_sphinx = 0;
25 my $need_pip = 0;
26 my $need_virtualenv = 0;
27 my $rec_sphinx_upgrade = 0;
28 my $verbose_warn_install = 1;
29 my $install = "";
30 my $virtenv_dir = "";
31 my $python_cmd = "";
32 my $activate_cmd;
33 my $min_version;
34 my $cur_version;
35 my $rec_version = "3.4.3";
36 my $latest_avail_ver;
37 
38 #
39 # Command line arguments
40 #
41 
42 my $pdf = 1;
43 my $virtualenv = 1;
44 my $version_check = 0;
45 
46 #
47 # List of required texlive packages on Fedora and OpenSuse
48 #
49 
50 my %texlive = (
51 	'amsfonts.sty'       => 'texlive-amsfonts',
52 	'amsmath.sty'        => 'texlive-amsmath',
53 	'amssymb.sty'        => 'texlive-amsfonts',
54 	'amsthm.sty'         => 'texlive-amscls',
55 	'anyfontsize.sty'    => 'texlive-anyfontsize',
56 	'atbegshi.sty'       => 'texlive-oberdiek',
57 	'bm.sty'             => 'texlive-tools',
58 	'capt-of.sty'        => 'texlive-capt-of',
59 	'cmap.sty'           => 'texlive-cmap',
60 	'ecrm1000.tfm'       => 'texlive-ec',
61 	'eqparbox.sty'       => 'texlive-eqparbox',
62 	'eu1enc.def'         => 'texlive-euenc',
63 	'fancybox.sty'       => 'texlive-fancybox',
64 	'fancyvrb.sty'       => 'texlive-fancyvrb',
65 	'float.sty'          => 'texlive-float',
66 	'fncychap.sty'       => 'texlive-fncychap',
67 	'footnote.sty'       => 'texlive-mdwtools',
68 	'framed.sty'         => 'texlive-framed',
69 	'luatex85.sty'       => 'texlive-luatex85',
70 	'multirow.sty'       => 'texlive-multirow',
71 	'needspace.sty'      => 'texlive-needspace',
72 	'palatino.sty'       => 'texlive-psnfss',
73 	'parskip.sty'        => 'texlive-parskip',
74 	'polyglossia.sty'    => 'texlive-polyglossia',
75 	'tabulary.sty'       => 'texlive-tabulary',
76 	'threeparttable.sty' => 'texlive-threeparttable',
77 	'titlesec.sty'       => 'texlive-titlesec',
78 	'ucs.sty'            => 'texlive-ucs',
79 	'upquote.sty'        => 'texlive-upquote',
80 	'wrapfig.sty'        => 'texlive-wrapfig',
81 	'ctexhook.sty'       => 'texlive-ctex',
82 );
83 
84 #
85 # Subroutines that checks if a feature exists
86 #
87 
88 sub check_missing(%)
89 {
90 	my %map = %{$_[0]};
91 
92 	foreach my $prog (sort keys %missing) {
93 		my $is_optional = $missing{$prog};
94 
95 		# At least on some LTS distros like CentOS 7, texlive doesn't
96 		# provide all packages we need. When such distros are
97 		# detected, we have to disable PDF output.
98 		#
99 		# So, we need to ignore the packages that distros would
100 		# need for LaTeX to work
101 		if ($is_optional == 2 && !$pdf) {
102 			$optional--;
103 			next;
104 		}
105 
106 		if ($verbose_warn_install) {
107 			if ($is_optional) {
108 				print "Warning: better to also install \"$prog\".\n";
109 			} else {
110 				print "ERROR: please install \"$prog\", otherwise, build won't work.\n";
111 			}
112 		}
113 		if (defined($map{$prog})) {
114 			$install .= " " . $map{$prog};
115 		} else {
116 			$install .= " " . $prog;
117 		}
118 	}
119 
120 	$install =~ s/^\s//;
121 }
122 
123 sub add_package($$)
124 {
125 	my $package = shift;
126 	my $is_optional = shift;
127 
128 	$missing{$package} = $is_optional;
129 	if ($is_optional) {
130 		$optional++;
131 	} else {
132 		$need++;
133 	}
134 }
135 
136 sub check_missing_file($$$)
137 {
138 	my $files = shift;
139 	my $package = shift;
140 	my $is_optional = shift;
141 
142 	for (@$files) {
143 		return if(-e $_);
144 	}
145 
146 	add_package($package, $is_optional);
147 }
148 
149 sub findprog($)
150 {
151 	foreach(split(/:/, $ENV{PATH})) {
152 		return "$_/$_[0]" if(-x "$_/$_[0]");
153 	}
154 }
155 
156 sub find_python_no_venv()
157 {
158 	my $prog = shift;
159 
160 	my $cur_dir = qx(pwd);
161 	$cur_dir =~ s/\s+$//;
162 
163 	foreach my $dir (split(/:/, $ENV{PATH})) {
164 		next if ($dir =~ m,($cur_dir)/sphinx,);
165 		return "$dir/python3" if(-x "$dir/python3");
166 	}
167 	foreach my $dir (split(/:/, $ENV{PATH})) {
168 		next if ($dir =~ m,($cur_dir)/sphinx,);
169 		return "$dir/python" if(-x "$dir/python");
170 	}
171 	return "python";
172 }
173 
174 sub check_program($$)
175 {
176 	my $prog = shift;
177 	my $is_optional = shift;
178 
179 	return $prog if findprog($prog);
180 
181 	add_package($prog, $is_optional);
182 }
183 
184 sub check_perl_module($$)
185 {
186 	my $prog = shift;
187 	my $is_optional = shift;
188 
189 	my $err = system("perl -M$prog -e 1 2>/dev/null /dev/null");
190 	return if ($err == 0);
191 
192 	add_package($prog, $is_optional);
193 }
194 
195 sub check_python_module($$)
196 {
197 	my $prog = shift;
198 	my $is_optional = shift;
199 
200 	return if (!$python_cmd);
201 
202 	my $err = system("$python_cmd -c 'import $prog' 2>/dev/null /dev/null");
203 	return if ($err == 0);
204 
205 	add_package($prog, $is_optional);
206 }
207 
208 sub check_rpm_missing($$)
209 {
210 	my @pkgs = @{$_[0]};
211 	my $is_optional = $_[1];
212 
213 	foreach my $prog(@pkgs) {
214 		my $err = system("rpm -q '$prog' 2>/dev/null >/dev/null");
215 		add_package($prog, $is_optional) if ($err);
216 	}
217 }
218 
219 sub check_pacman_missing($$)
220 {
221 	my @pkgs = @{$_[0]};
222 	my $is_optional = $_[1];
223 
224 	foreach my $prog(@pkgs) {
225 		my $err = system("pacman -Q '$prog' 2>/dev/null >/dev/null");
226 		add_package($prog, $is_optional) if ($err);
227 	}
228 }
229 
230 sub check_missing_tex($)
231 {
232 	my $is_optional = shift;
233 	my $kpsewhich = findprog("kpsewhich");
234 
235 	foreach my $prog(keys %texlive) {
236 		my $package = $texlive{$prog};
237 		if (!$kpsewhich) {
238 			add_package($package, $is_optional);
239 			next;
240 		}
241 		my $file = qx($kpsewhich $prog);
242 		add_package($package, $is_optional) if ($file =~ /^\s*$/);
243 	}
244 }
245 
246 sub get_sphinx_fname()
247 {
248 	my $fname = "sphinx-build";
249 	return $fname if findprog($fname);
250 
251 	$fname = "sphinx-build-3";
252 	if (findprog($fname)) {
253 		$need_symlink = 1;
254 		return $fname;
255 	}
256 
257 	return "";
258 }
259 
260 sub get_sphinx_version($)
261 {
262 	my $cmd = shift;
263 	my $ver;
264 
265 	open IN, "$cmd --version 2>&1 |";
266 	while (<IN>) {
267 		if (m/^\s*sphinx-build\s+([\d\.]+)((\+\/[\da-f]+)|(b\d+))?$/) {
268 			$ver=$1;
269 			last;
270 		}
271 		# Sphinx 1.2.x uses a different format
272 		if (m/^\s*Sphinx.*\s+([\d\.]+)$/) {
273 			$ver=$1;
274 			last;
275 		}
276 	}
277 	close IN;
278 	return $ver;
279 }
280 
281 sub check_sphinx()
282 {
283 	open IN, $conf or die "Can't open $conf";
284 	while (<IN>) {
285 		if (m/^\s*needs_sphinx\s*=\s*[\'\"]([\d\.]+)[\'\"]/) {
286 			$min_version=$1;
287 			last;
288 		}
289 	}
290 	close IN;
291 
292 	die "Can't get needs_sphinx version from $conf" if (!$min_version);
293 
294 	$virtenv_dir = $virtenv_prefix . "latest";
295 
296 	my $sphinx = get_sphinx_fname();
297 	if ($sphinx eq "") {
298 		$need_sphinx = 1;
299 		return;
300 	}
301 
302 	$cur_version = get_sphinx_version($sphinx);
303 	die "$sphinx didn't return its version" if (!$cur_version);
304 
305 	if ($cur_version lt $min_version) {
306 		printf "ERROR: Sphinx version is %s. It should be >= %s\n",
307 		       $cur_version, $min_version;
308 		$need_sphinx = 1;
309 		return;
310 	}
311 
312 	return if ($cur_version lt $rec_version);
313 
314 	# On version check mode, just assume Sphinx has all mandatory deps
315 	exit (0) if ($version_check);
316 }
317 
318 #
319 # Ancillary subroutines
320 #
321 
322 sub catcheck($)
323 {
324   my $res = "";
325   $res = qx(cat $_[0]) if (-r $_[0]);
326   return $res;
327 }
328 
329 sub which($)
330 {
331 	my $file = shift;
332 	my @path = split ":", $ENV{PATH};
333 
334 	foreach my $dir(@path) {
335 		my $name = $dir.'/'.$file;
336 		return $name if (-x $name );
337 	}
338 	return undef;
339 }
340 
341 #
342 # Subroutines that check distro-specific hints
343 #
344 
345 sub give_debian_hints()
346 {
347 	my %map = (
348 		"python-sphinx"		=> "python3-sphinx",
349 		"yaml"			=> "python3-yaml",
350 		"ensurepip"		=> "python3-venv",
351 		"virtualenv"		=> "virtualenv",
352 		"dot"			=> "graphviz",
353 		"convert"		=> "imagemagick",
354 		"Pod::Usage"		=> "perl-modules",
355 		"xelatex"		=> "texlive-xetex",
356 		"rsvg-convert"		=> "librsvg2-bin",
357 	);
358 
359 	if ($pdf) {
360 		check_missing_file(["/usr/share/texlive/texmf-dist/tex/latex/ctex/ctexhook.sty"],
361 				   "texlive-lang-chinese", 2);
362 
363 		check_missing_file(["/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf"],
364 				   "fonts-dejavu", 2);
365 
366 		check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJK-Regular.ttc",
367 				    "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
368 				    "/usr/share/fonts/opentype/noto/NotoSerifCJK-Regular.ttc"],
369 				   "fonts-noto-cjk", 2);
370 	}
371 
372 	check_program("dvipng", 2) if ($pdf);
373 	check_missing(\%map);
374 
375 	return if (!$need && !$optional);
376 	printf("You should run:\n") if ($verbose_warn_install);
377 	printf("\n\tsudo apt-get install $install\n");
378 }
379 
380 sub give_redhat_hints()
381 {
382 	my %map = (
383 		"python-sphinx"		=> "python3-sphinx",
384 		"yaml"			=> "python3-pyyaml",
385 		"virtualenv"		=> "python3-virtualenv",
386 		"dot"			=> "graphviz",
387 		"convert"		=> "ImageMagick",
388 		"Pod::Usage"		=> "perl-Pod-Usage",
389 		"xelatex"		=> "texlive-xetex-bin",
390 		"rsvg-convert"		=> "librsvg2-tools",
391 	);
392 
393 	my @fedora26_opt_pkgs = (
394 		"graphviz-gd",		# Fedora 26: needed for PDF support
395 	);
396 
397 	my @fedora_tex_pkgs = (
398 		"texlive-collection-fontsrecommended",
399 		"texlive-collection-latex",
400 		"texlive-xecjk",
401 		"dejavu-sans-fonts",
402 		"dejavu-serif-fonts",
403 		"dejavu-sans-mono-fonts",
404 	);
405 
406 	#
407 	# Checks valid for RHEL/CentOS version 7.x.
408 	#
409 	my $old = 0;
410 	my $rel;
411 	my $noto_sans_redhat = "google-noto-sans-cjk-ttc-fonts";
412 	$rel = $1 if ($system_release =~ /release\s+(\d+)/);
413 
414 	if (!($system_release =~ /Fedora/)) {
415 		$map{"virtualenv"} = "python-virtualenv";
416 
417 		if ($rel && $rel < 8) {
418 			$old = 1;
419 			$pdf = 0;
420 
421 			printf("Note: texlive packages on RHEL/CENTOS <= 7 are incomplete. Can't support PDF output\n");
422 			printf("If you want to build PDF, please read:\n");
423 			printf("\thttps://www.systutorials.com/241660/how-to-install-tex-live-on-centos-7-linux/\n");
424 		}
425 	} else {
426 		if ($rel && $rel < 26) {
427 			$old = 1;
428 		}
429 		if ($rel && $rel >= 38) {
430 			$noto_sans_redhat = "google-noto-sans-cjk-fonts";
431 		}
432 	}
433 	if (!$rel) {
434 		printf("Couldn't identify release number\n");
435 		$old = 1;
436 		$pdf = 0;
437 	}
438 
439 	if ($pdf) {
440 		check_missing_file(["/usr/share/fonts/google-noto-cjk/NotoSansCJK-Regular.ttc",
441 				    "/usr/share/fonts/google-noto-sans-cjk-fonts/NotoSansCJK-Regular.ttc"],
442 				   $noto_sans_redhat, 2);
443 	}
444 
445 	check_rpm_missing(\@fedora26_opt_pkgs, 2) if ($pdf && !$old);
446 	check_rpm_missing(\@fedora_tex_pkgs, 2) if ($pdf);
447 	check_missing_tex(2) if ($pdf);
448 	check_missing(\%map);
449 
450 	return if (!$need && !$optional);
451 
452 	if (!$old) {
453 		# dnf, for Fedora 18+
454 		printf("You should run:\n") if ($verbose_warn_install);
455 		printf("\n\tsudo dnf install -y $install\n");
456 	} else {
457 		# yum, for RHEL (and clones) or Fedora version < 18
458 		printf("You should run:\n") if ($verbose_warn_install);
459 		printf("\n\tsudo yum install -y $install\n");
460 	}
461 }
462 
463 sub give_opensuse_hints()
464 {
465 	my %map = (
466 		"python-sphinx"		=> "python3-sphinx",
467 		"yaml"			=> "python3-pyyaml",
468 		"virtualenv"		=> "python3-virtualenv",
469 		"dot"			=> "graphviz",
470 		"convert"		=> "ImageMagick",
471 		"Pod::Usage"		=> "perl-Pod-Usage",
472 		"xelatex"		=> "texlive-xetex-bin",
473 	);
474 
475 	# On Tumbleweed, this package is also named rsvg-convert
476 	$map{"rsvg-convert"} = "rsvg-view" if (!($system_release =~ /Tumbleweed/));
477 
478 	my @suse_tex_pkgs = (
479 		"texlive-babel-english",
480 		"texlive-caption",
481 		"texlive-colortbl",
482 		"texlive-courier",
483 		"texlive-dvips",
484 		"texlive-helvetic",
485 		"texlive-makeindex",
486 		"texlive-metafont",
487 		"texlive-metapost",
488 		"texlive-palatino",
489 		"texlive-preview",
490 		"texlive-times",
491 		"texlive-zapfchan",
492 		"texlive-zapfding",
493 	);
494 
495 	$map{"latexmk"} = "texlive-latexmk-bin";
496 
497 	# FIXME: add support for installing CJK fonts
498 	#
499 	# I tried hard, but was unable to find a way to install
500 	# "Noto Sans CJK SC" on openSUSE
501 
502 	check_rpm_missing(\@suse_tex_pkgs, 2) if ($pdf);
503 	check_missing_tex(2) if ($pdf);
504 	check_missing(\%map);
505 
506 	return if (!$need && !$optional);
507 	printf("You should run:\n") if ($verbose_warn_install);
508 	printf("\n\tsudo zypper install --no-recommends $install\n");
509 }
510 
511 sub give_mageia_hints()
512 {
513 	my %map = (
514 		"python-sphinx"		=> "python3-sphinx",
515 		"yaml"			=> "python3-yaml",
516 		"virtualenv"		=> "python3-virtualenv",
517 		"dot"			=> "graphviz",
518 		"convert"		=> "ImageMagick",
519 		"Pod::Usage"		=> "perl-Pod-Usage",
520 		"xelatex"		=> "texlive",
521 		"rsvg-convert"		=> "librsvg2",
522 	);
523 
524 	my @tex_pkgs = (
525 		"texlive-fontsextra",
526 	);
527 
528 	$map{"latexmk"} = "texlive-collection-basic";
529 
530 	my $packager_cmd;
531 	my $noto_sans;
532 	if ($system_release =~ /OpenMandriva/) {
533 		$packager_cmd = "dnf install";
534 		$noto_sans = "noto-sans-cjk-fonts";
535 		@tex_pkgs = ( "texlive-collection-fontsextra" );
536 	} else {
537 		$packager_cmd = "urpmi";
538 		$noto_sans = "google-noto-sans-cjk-ttc-fonts";
539 	}
540 
541 
542 	if ($pdf) {
543 		check_missing_file(["/usr/share/fonts/google-noto-cjk/NotoSansCJK-Regular.ttc",
544 				    "/usr/share/fonts/TTF/NotoSans-Regular.ttf"],
545 				   $noto_sans, 2);
546 	}
547 
548 	check_rpm_missing(\@tex_pkgs, 2) if ($pdf);
549 	check_missing(\%map);
550 
551 	return if (!$need && !$optional);
552 	printf("You should run:\n") if ($verbose_warn_install);
553 	printf("\n\tsudo $packager_cmd $install\n");
554 }
555 
556 sub give_arch_linux_hints()
557 {
558 	my %map = (
559 		"yaml"			=> "python-yaml",
560 		"virtualenv"		=> "python-virtualenv",
561 		"dot"			=> "graphviz",
562 		"convert"		=> "imagemagick",
563 		"xelatex"		=> "texlive-xetex",
564 		"latexmk"		=> "texlive-core",
565 		"rsvg-convert"		=> "extra/librsvg",
566 	);
567 
568 	my @archlinux_tex_pkgs = (
569 		"texlive-core",
570 		"texlive-latexextra",
571 		"ttf-dejavu",
572 	);
573 	check_pacman_missing(\@archlinux_tex_pkgs, 2) if ($pdf);
574 
575 	if ($pdf) {
576 		check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJK-Regular.ttc"],
577 				   "noto-fonts-cjk", 2);
578 	}
579 
580 	check_missing(\%map);
581 
582 	return if (!$need && !$optional);
583 	printf("You should run:\n") if ($verbose_warn_install);
584 	printf("\n\tsudo pacman -S $install\n");
585 }
586 
587 sub give_gentoo_hints()
588 {
589 	my %map = (
590 		"yaml"			=> "dev-python/pyyaml",
591 		"virtualenv"		=> "dev-python/virtualenv",
592 		"dot"			=> "media-gfx/graphviz",
593 		"convert"		=> "media-gfx/imagemagick",
594 		"xelatex"		=> "dev-texlive/texlive-xetex media-fonts/dejavu",
595 		"rsvg-convert"		=> "gnome-base/librsvg",
596 	);
597 
598 	check_missing_file(["/usr/share/fonts/dejavu/DejaVuSans.ttf"],
599 			   "media-fonts/dejavu", 2) if ($pdf);
600 
601 	if ($pdf) {
602 		check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJKsc-Regular.otf",
603 				    "/usr/share/fonts/noto-cjk/NotoSerifCJK-Regular.ttc"],
604 				   "media-fonts/noto-cjk", 2);
605 	}
606 
607 	check_missing(\%map);
608 
609 	return if (!$need && !$optional);
610 
611 	printf("You should run:\n") if ($verbose_warn_install);
612 	printf("\n");
613 
614 	my $imagemagick = "media-gfx/imagemagick svg png";
615 	my $cairo = "media-gfx/graphviz cairo pdf";
616 	my $portage_imagemagick = "/etc/portage/package.use/imagemagick";
617 	my $portage_cairo = "/etc/portage/package.use/graphviz";
618 
619 	if (qx(grep imagemagick $portage_imagemagick 2>/dev/null) eq "") {
620 		printf("\tsudo su -c 'echo \"$imagemagick\" > $portage_imagemagick'\n")
621 	}
622 	if (qx(grep graphviz $portage_cairo 2>/dev/null) eq  "") {
623 		printf("\tsudo su -c 'echo \"$cairo\" > $portage_cairo'\n");
624 	}
625 
626 	printf("\tsudo emerge --ask $install\n");
627 
628 }
629 
630 sub check_distros()
631 {
632 	# Distro-specific hints
633 	if ($system_release =~ /Red Hat Enterprise Linux/) {
634 		give_redhat_hints;
635 		return;
636 	}
637 	if ($system_release =~ /CentOS/) {
638 		give_redhat_hints;
639 		return;
640 	}
641 	if ($system_release =~ /Scientific Linux/) {
642 		give_redhat_hints;
643 		return;
644 	}
645 	if ($system_release =~ /Oracle Linux Server/) {
646 		give_redhat_hints;
647 		return;
648 	}
649 	if ($system_release =~ /Fedora/) {
650 		give_redhat_hints;
651 		return;
652 	}
653 	if ($system_release =~ /Ubuntu/) {
654 		give_debian_hints;
655 		return;
656 	}
657 	if ($system_release =~ /Debian/) {
658 		give_debian_hints;
659 		return;
660 	}
661 	if ($system_release =~ /openSUSE/) {
662 		give_opensuse_hints;
663 		return;
664 	}
665 	if ($system_release =~ /Mageia/) {
666 		give_mageia_hints;
667 		return;
668 	}
669 	if ($system_release =~ /OpenMandriva/) {
670 		give_mageia_hints;
671 		return;
672 	}
673 	if ($system_release =~ /Arch Linux/) {
674 		give_arch_linux_hints;
675 		return;
676 	}
677 	if ($system_release =~ /Gentoo/) {
678 		give_gentoo_hints;
679 		return;
680 	}
681 
682 	#
683 	# Fall-back to generic hint code for other distros
684 	# That's far from ideal, specially for LaTeX dependencies.
685 	#
686 	my %map = (
687 		"sphinx-build" => "sphinx"
688 	);
689 	check_missing_tex(2) if ($pdf);
690 	check_missing(\%map);
691 	print "I don't know distro $system_release.\n";
692 	print "So, I can't provide you a hint with the install procedure.\n";
693 	print "There are likely missing dependencies.\n";
694 }
695 
696 #
697 # Common dependencies
698 #
699 
700 sub deactivate_help()
701 {
702 	printf "\n    If you want to exit the virtualenv, you can use:\n";
703 	printf "\tdeactivate\n";
704 }
705 
706 sub get_virtenv()
707 {
708 	my $ver;
709 	my $min_activate = "$ENV{'PWD'}/${virtenv_prefix}${min_version}/bin/activate";
710 	my @activates = glob "$ENV{'PWD'}/${virtenv_prefix}*/bin/activate";
711 
712 	@activates = sort {$b cmp $a} @activates;
713 
714 	foreach my $f (@activates) {
715 		next if ($f lt $min_activate);
716 
717 		my $sphinx_cmd = $f;
718 		$sphinx_cmd =~ s/activate/sphinx-build/;
719 		next if (! -f $sphinx_cmd);
720 
721 		my $ver = get_sphinx_version($sphinx_cmd);
722 
723 		if (!$ver) {
724 			$f =~ s#/bin/activate##;
725 			print("Warning: virtual environment $f is not working.\nPython version upgrade? Remove it with:\n\n\trm -rf $f\n\n");
726 		}
727 
728 		if ($need_sphinx && ($ver ge $min_version)) {
729 			return ($f, $ver);
730 		} elsif ($ver gt $cur_version) {
731 			return ($f, $ver);
732 		}
733 	}
734 	return ("", "");
735 }
736 
737 sub recommend_sphinx_upgrade()
738 {
739 	my $venv_ver;
740 
741 	# Avoid running sphinx-builds from venv if $cur_version is good
742 	if ($cur_version && ($cur_version ge $rec_version)) {
743 		$latest_avail_ver = $cur_version;
744 		return;
745 	}
746 
747 	# Get the highest version from sphinx_*/bin/sphinx-build and the
748 	# corresponding command to activate the venv/virtenv
749 	($activate_cmd, $venv_ver) = get_virtenv();
750 
751 	# Store the highest version from Sphinx existing virtualenvs
752 	if (($activate_cmd ne "") && ($venv_ver gt $cur_version)) {
753 		$latest_avail_ver = $venv_ver;
754 	} else {
755 		$latest_avail_ver = $cur_version if ($cur_version);
756 	}
757 
758 	# As we don't know package version of Sphinx, and there's no
759 	# virtual environments, don't check if upgrades are needed
760 	if (!$virtualenv) {
761 		return if (!$latest_avail_ver);
762 	}
763 
764 	# Either there are already a virtual env or a new one should be created
765 	$need_pip = 1;
766 
767 	return if (!$latest_avail_ver);
768 
769 	# Return if the reason is due to an upgrade or not
770 	if ($latest_avail_ver lt $rec_version) {
771 		$rec_sphinx_upgrade = 1;
772 	}
773 
774 	return $latest_avail_ver;
775 }
776 
777 #
778 # The logic here is complex, as it have to deal with different versions:
779 #	- minimal supported version;
780 #	- minimal PDF version;
781 #	- recommended version.
782 # It also needs to work fine with both distro's package and venv/virtualenv
783 sub recommend_sphinx_version($)
784 {
785 	my $virtualenv_cmd = shift;
786 
787 	# Version is OK. Nothing to do.
788 	if ($cur_version && ($cur_version ge $rec_version)) {
789 		return;
790 	};
791 
792 	if (!$need_sphinx) {
793 		# sphinx-build is present and its version is >= $min_version
794 
795 		#only recommend enabling a newer virtenv version if makes sense.
796 		if ($latest_avail_ver gt $cur_version) {
797 			printf "\nYou may also use the newer Sphinx version $latest_avail_ver with:\n";
798 			printf "\tdeactivate\n"  if ($ENV{'PWD'} =~ /${virtenv_prefix}/);
799 			printf "\t. $activate_cmd\n";
800 			deactivate_help();
801 
802 			return;
803 		}
804 		return if ($latest_avail_ver ge $rec_version);
805 	}
806 
807 	if (!$virtualenv) {
808 		# No sphinx either via package or via virtenv. As we can't
809 		# Compare the versions here, just return, recommending the
810 		# user to install it from the package distro.
811 		return if (!$latest_avail_ver);
812 
813 		# User doesn't want a virtenv recommendation, but he already
814 		# installed one via virtenv with a newer version.
815 		# So, print commands to enable it
816 		if ($latest_avail_ver gt $cur_version) {
817 			printf "\nYou may also use the Sphinx virtualenv version $latest_avail_ver with:\n";
818 			printf "\tdeactivate\n"  if ($ENV{'PWD'} =~ /${virtenv_prefix}/);
819 			printf "\t. $activate_cmd\n";
820 			deactivate_help();
821 
822 			return;
823 		}
824 		print "\n";
825 	} else {
826 		$need++ if ($need_sphinx);
827 	}
828 
829 	# Suggest newer versions if current ones are too old
830 	if ($latest_avail_ver && $latest_avail_ver ge $min_version) {
831 		# If there's a good enough version, ask the user to enable it
832 		if ($latest_avail_ver ge $rec_version) {
833 			printf "\nNeed to activate Sphinx (version $latest_avail_ver) on virtualenv with:\n";
834 			printf "\t. $activate_cmd\n";
835 			deactivate_help();
836 
837 			return;
838 		}
839 
840 		# Version is above the minimal required one, but may be
841 		# below the recommended one. So, print warnings/notes
842 
843 		if ($latest_avail_ver lt $rec_version) {
844 			print "Warning: It is recommended at least Sphinx version $rec_version.\n";
845 		}
846 	}
847 
848 	# At this point, either it needs Sphinx or upgrade is recommended,
849 	# both via pip
850 
851 	if ($rec_sphinx_upgrade) {
852 		if (!$virtualenv) {
853 			print "Instead of install/upgrade Python Sphinx pkg, you could use pip/pypi with:\n\n";
854 		} else {
855 			print "To upgrade Sphinx, use:\n\n";
856 		}
857 	} else {
858 		print "\nSphinx needs to be installed either:\n1) via pip/pypi with:\n\n";
859 	}
860 
861 	$python_cmd = find_python_no_venv();
862 
863 	printf "\t$virtualenv_cmd $virtenv_dir\n";
864 
865 	printf "\t. $virtenv_dir/bin/activate\n";
866 	printf "\tpip install -r $requirement_file\n";
867 	deactivate_help();
868 
869 	printf "\n2) As a package with:\n";
870 
871 	my $old_need = $need;
872 	my $old_optional = $optional;
873 	%missing = ();
874 	$pdf = 0;
875 	$optional = 0;
876 	$install = "";
877 	$verbose_warn_install = 0;
878 
879 	add_package("python-sphinx", 0);
880 
881 	check_distros();
882 
883 	$need = $old_need;
884 	$optional = $old_optional;
885 
886 	printf "\n    Please note that Sphinx >= 3.0 will currently produce false-positive\n";
887 	printf "   warning when the same name is used for more than one type (functions,\n";
888 	printf "   structs, enums,...). This is known Sphinx bug. For more details, see:\n";
889 	printf "\thttps://github.com/sphinx-doc/sphinx/pull/8313\n";
890 }
891 
892 sub check_needs()
893 {
894 	# Check if Sphinx is already accessible from current environment
895 	check_sphinx();
896 
897 	if ($system_release) {
898 		print "Detected OS: $system_release.\n";
899 	} else {
900 		print "Unknown OS\n";
901 	}
902 	printf "Sphinx version: %s\n\n", $cur_version if ($cur_version);
903 
904 	# Check python command line, trying first python3
905 	$python_cmd = findprog("python3");
906 	$python_cmd = check_program("python", 0) if (!$python_cmd);
907 
908 	# Check the type of virtual env, depending on Python version
909 	if ($python_cmd) {
910 		if ($virtualenv) {
911 			my $tmp = qx($python_cmd --version 2>&1);
912 			if ($tmp =~ m/(\d+\.)(\d+\.)/) {
913 				if ($1 < 3) {
914 					# Fail if it finds python2 (or worse)
915 					die "Python 3 is required to build the kernel docs\n";
916 				}
917 				if ($1 == 3 && $2 < 3) {
918 					# Need Python 3.3 or upper for venv
919 					$need_virtualenv = 1;
920 				}
921 			} else {
922 				die "Warning: couldn't identify $python_cmd version!";
923 			}
924 		} else {
925 			add_package("python-sphinx", 0);
926 		}
927 	}
928 
929 	my $venv_ver = recommend_sphinx_upgrade();
930 
931 	my $virtualenv_cmd;
932 
933 	if ($need_pip) {
934 		# Set virtualenv command line, if python < 3.3
935 		if ($need_virtualenv) {
936 			$virtualenv_cmd = findprog("virtualenv-3");
937 			$virtualenv_cmd = findprog("virtualenv-3.5") if (!$virtualenv_cmd);
938 			if (!$virtualenv_cmd) {
939 				check_program("virtualenv", 0);
940 				$virtualenv_cmd = "virtualenv";
941 			}
942 		} else {
943 			$virtualenv_cmd = "$python_cmd -m venv";
944 			check_python_module("ensurepip", 0);
945 		}
946 	}
947 
948 	# Check for needed programs/tools
949 	check_perl_module("Pod::Usage", 0);
950 	check_python_module("yaml", 0);
951 	check_program("make", 0);
952 	check_program("gcc", 0);
953 	check_program("dot", 1);
954 	check_program("convert", 1);
955 
956 	# Extra PDF files - should use 2 for is_optional
957 	check_program("xelatex", 2) if ($pdf);
958 	check_program("rsvg-convert", 2) if ($pdf);
959 	check_program("latexmk", 2) if ($pdf);
960 
961 	# Do distro-specific checks and output distro-install commands
962 	check_distros();
963 
964 	if (!$python_cmd) {
965 		if ($need == 1) {
966 			die "Can't build as $need mandatory dependency is missing";
967 		} elsif ($need) {
968 			die "Can't build as $need mandatory dependencies are missing";
969 		}
970 	}
971 
972 	# Check if sphinx-build is called sphinx-build-3
973 	if ($need_symlink) {
974 		printf "\tsudo ln -sf %s /usr/bin/sphinx-build\n\n",
975 		       which("sphinx-build-3");
976 	}
977 
978 	recommend_sphinx_version($virtualenv_cmd);
979 	printf "\n";
980 
981 	print "All optional dependencies are met.\n" if (!$optional);
982 
983 	if ($need == 1) {
984 		die "Can't build as $need mandatory dependency is missing";
985 	} elsif ($need) {
986 		die "Can't build as $need mandatory dependencies are missing";
987 	}
988 
989 	print "Needed package dependencies are met.\n";
990 }
991 
992 #
993 # Main
994 #
995 
996 while (@ARGV) {
997 	my $arg = shift(@ARGV);
998 
999 	if ($arg eq "--no-virtualenv") {
1000 		$virtualenv = 0;
1001 	} elsif ($arg eq "--no-pdf"){
1002 		$pdf = 0;
1003 	} elsif ($arg eq "--version-check"){
1004 		$version_check = 1;
1005 	} else {
1006 		print "Usage:\n\t$0 <--no-virtualenv> <--no-pdf> <--version-check>\n\n";
1007 		print "Where:\n";
1008 		print "\t--no-virtualenv\t- Recommend installing Sphinx instead of using a virtualenv\n";
1009 		print "\t--version-check\t- if version is compatible, don't check for missing dependencies\n";
1010 		print "\t--no-pdf\t- don't check for dependencies required to build PDF docs\n\n";
1011 		exit -1;
1012 	}
1013 }
1014 
1015 #
1016 # Determine the system type. There's no standard unique way that would
1017 # work with all distros with a minimal package install. So, several
1018 # methods are used here.
1019 #
1020 # By default, it will use lsb_release function. If not available, it will
1021 # fail back to reading the known different places where the distro name
1022 # is stored
1023 #
1024 
1025 $system_release = qx(lsb_release -d) if which("lsb_release");
1026 $system_release =~ s/Description:\s*// if ($system_release);
1027 $system_release = catcheck("/etc/system-release") if !$system_release;
1028 $system_release = catcheck("/etc/redhat-release") if !$system_release;
1029 $system_release = catcheck("/etc/lsb-release") if !$system_release;
1030 $system_release = catcheck("/etc/gentoo-release") if !$system_release;
1031 
1032 # This seems more common than LSB these days
1033 if (!$system_release) {
1034 	my %os_var;
1035 	if (open IN, "cat /etc/os-release|") {
1036 		while (<IN>) {
1037 			if (m/^([\w\d\_]+)=\"?([^\"]*)\"?\n/) {
1038 				$os_var{$1}=$2;
1039 			}
1040 		}
1041 		$system_release = $os_var{"NAME"};
1042 		if (defined($os_var{"VERSION_ID"})) {
1043 			$system_release .= " " . $os_var{"VERSION_ID"} if (defined($os_var{"VERSION_ID"}));
1044 		} else {
1045 			$system_release .= " " . $os_var{"VERSION"};
1046 		}
1047 	}
1048 }
1049 $system_release = catcheck("/etc/issue") if !$system_release;
1050 $system_release =~ s/\s+$//;
1051 
1052 check_needs;
1053