1 #!/usr/bin/env perl
2 # SPDX-License-Identifier: GPL-2.0
3 #
4 # Treewide grep for references to files under Documentation, and report
5 # non-existing files in stderr.
6 
7 use warnings;
8 use strict;
9 use Getopt::Long qw(:config no_auto_abbrev);
10 
11 # NOTE: only add things here when the file was gone, but the text wants
12 # to mention a past documentation file, for example, to give credits for
13 # the original work.
14 my %false_positives = (
15 	"Documentation/scsi/scsi_mid_low_api.rst" => "Documentation/Configure.help",
16 	"drivers/vhost/vhost.c" => "Documentation/virtual/lguest/lguest.c",
17 );
18 
19 my $scriptname = $0;
20 $scriptname =~ s,.*/([^/]+/),$1,;
21 
22 # Parse arguments
23 my $help = 0;
24 my $fix = 0;
25 my $warn = 0;
26 
27 if (! -e ".git") {
28 	printf "Warning: can't check if file exists, as this is not a git tree\n";
29 	exit 0;
30 }
31 
32 GetOptions(
33 	'fix' => \$fix,
34 	'warn' => \$warn,
35 	'h|help|usage' => \$help,
36 );
37 
38 if ($help != 0) {
39     print "$scriptname [--help] [--fix]\n";
40     exit -1;
41 }
42 
43 # Step 1: find broken references
44 print "Finding broken references. This may take a while...  " if ($fix);
45 
46 my %broken_ref;
47 
48 my $doc_fix = 0;
49 
50 open IN, "git grep ':doc:\`' Documentation/|"
51      or die "Failed to run git grep";
52 while (<IN>) {
53 	next if (!m,^([^:]+):.*\:doc\:\`([^\`]+)\`,);
54 	next if (m,sphinx/,);
55 
56 	my $file = $1;
57 	my $d = $1;
58 	my $doc_ref = $2;
59 
60 	my $f = $doc_ref;
61 
62 	$d =~ s,(.*/).*,$1,;
63 	$f =~ s,.*\<([^\>]+)\>,$1,;
64 
65 	if ($f =~ m,^/,) {
66 		$f = "$f.rst";
67 		$f =~ s,^/,Documentation/,;
68 	} else {
69 		$f = "$d$f.rst";
70 	}
71 
72 	next if (grep -e, glob("$f"));
73 
74 	if ($fix && !$doc_fix) {
75 		print STDERR "\nWARNING: Currently, can't fix broken :doc:`` fields\n";
76 	}
77 	$doc_fix++;
78 
79 	print STDERR "$file: :doc:`$doc_ref`\n";
80 }
81 close IN;
82 
83 open IN, "git grep 'Documentation/'|"
84      or die "Failed to run git grep";
85 while (<IN>) {
86 	next if (!m/^([^:]+):(.*)/);
87 
88 	my $f = $1;
89 	my $ln = $2;
90 
91 	# On linux-next, discard the Next/ directory
92 	next if ($f =~ m,^Next/,);
93 
94 	# Makefiles and scripts contain nasty expressions to parse docs
95 	next if ($f =~ m/Makefile/ || $f =~ m/\.sh$/);
96 
97 	# It doesn't make sense to parse hidden files
98 	next if ($f =~ m#/\.#);
99 
100 	# Skip this script
101 	next if ($f eq $scriptname);
102 
103 	# Ignore the dir where documentation will be built
104 	next if ($ln =~ m,\b(\S*)Documentation/output,);
105 
106 	if ($ln =~ m,\b(\S*)(Documentation/[A-Za-z0-9\_\.\,\~/\*\[\]\?+-]*)(.*),) {
107 		my $prefix = $1;
108 		my $ref = $2;
109 		my $base = $2;
110 		my $extra = $3;
111 
112 		# some file references are like:
113 		# /usr/src/linux/Documentation/DMA-{API,mapping}.txt
114 		# For now, ignore them
115 		next if ($extra =~ m/^{/);
116 
117 		# Remove footnotes at the end like:
118 		# Documentation/devicetree/dt-object-internal.txt[1]
119 		$ref =~ s/(txt|rst)\[\d+]$/$1/;
120 
121 		# Remove ending ']' without any '['
122 		$ref =~ s/\].*// if (!($ref =~ m/\[/));
123 
124 		# Remove puntuation marks at the end
125 		$ref =~ s/[\,\.]+$//;
126 
127 		my $fulref = "$prefix$ref";
128 
129 		$fulref =~ s/^(\<file|ref)://;
130 		$fulref =~ s/^[\'\`]+//;
131 		$fulref =~ s,^\$\(.*\)/,,;
132 		$base =~ s,.*/,,;
133 
134 		# Remove URL false-positives
135 		next if ($fulref =~ m/^http/);
136 
137 		# Remove sched-pelt false-positive
138 		next if ($fulref =~ m,^Documentation/scheduler/sched-pelt$,);
139 
140 		# Discard some build examples from Documentation/target/tcm_mod_builder.rst
141 		next if ($fulref =~ m,mnt/sdb/lio-core-2.6.git/Documentation/target,);
142 
143 		# Check if exists, evaluating wildcards
144 		next if (grep -e, glob("$ref $fulref"));
145 
146 		# Accept relative Documentation patches for tools/
147 		if ($f =~ m/tools/) {
148 			my $path = $f;
149 			$path =~ s,(.*)/.*,$1,;
150 			$path =~ s,testing/selftests/bpf,bpf/bpftool,;
151 			next if (grep -e, glob("$path/$ref $path/../$ref $path/$fulref"));
152 		}
153 
154 		# Discard known false-positives
155 		if (defined($false_positives{$f})) {
156 			next if ($false_positives{$f} eq $fulref);
157 		}
158 
159 		if ($fix) {
160 			if (!($ref =~ m/(scripts|Kconfig|Kbuild)/)) {
161 				$broken_ref{$ref}++;
162 			}
163 		} elsif ($warn) {
164 			print STDERR "Warning: $f references a file that doesn't exist: $fulref\n";
165 		} else {
166 			print STDERR "$f: $fulref\n";
167 		}
168 	}
169 }
170 close IN;
171 
172 exit 0 if (!$fix);
173 
174 # Step 2: Seek for file name alternatives
175 print "Auto-fixing broken references. Please double-check the results\n";
176 
177 foreach my $ref (keys %broken_ref) {
178 	my $new =$ref;
179 
180 	my $basedir = ".";
181 	# On translations, only seek inside the translations directory
182 	$basedir  = $1 if ($ref =~ m,(Documentation/translations/[^/]+),);
183 
184 	# get just the basename
185 	$new =~ s,.*/,,;
186 
187 	my $f="";
188 
189 	# usual reason for breakage: DT file moved around
190 	if ($ref =~ /devicetree/) {
191 		# usual reason for breakage: DT file renamed to .yaml
192 		if (!$f) {
193 			my $new_ref = $ref;
194 			$new_ref =~ s/\.txt$/.yaml/;
195 			$f=$new_ref if (-f $new_ref);
196 		}
197 
198 		if (!$f) {
199 			my $search = $new;
200 			$search =~ s,^.*/,,;
201 			$f = qx(find Documentation/devicetree/ -iname "*$search*") if ($search);
202 			if (!$f) {
203 				# Manufacturer name may have changed
204 				$search =~ s/^.*,//;
205 				$f = qx(find Documentation/devicetree/ -iname "*$search*") if ($search);
206 			}
207 		}
208 	}
209 
210 	# usual reason for breakage: file renamed to .rst
211 	if (!$f) {
212 		$new =~ s/\.txt$/.rst/;
213 		$f=qx(find $basedir -iname $new) if ($new);
214 	}
215 
216 	# usual reason for breakage: use dash or underline
217 	if (!$f) {
218 		$new =~ s/[-_]/[-_]/g;
219 		$f=qx(find $basedir -iname $new) if ($new);
220 	}
221 
222 	# Wild guess: seek for the same name on another place
223 	if (!$f) {
224 		$f = qx(find $basedir -iname $new) if ($new);
225 	}
226 
227 	my @find = split /\s+/, $f;
228 
229 	if (!$f) {
230 		print STDERR "ERROR: Didn't find a replacement for $ref\n";
231 	} elsif (scalar(@find) > 1) {
232 		print STDERR "WARNING: Won't auto-replace, as found multiple files close to $ref:\n";
233 		foreach my $j (@find) {
234 			$j =~ s,^./,,;
235 			print STDERR "    $j\n";
236 		}
237 	} else {
238 		$f = $find[0];
239 		$f =~ s,^./,,;
240 		print "INFO: Replacing $ref to $f\n";
241 		foreach my $j (qx(git grep -l $ref)) {
242 			qx(sed "s\@$ref\@$f\@g" -i $j);
243 		}
244 	}
245 }
246