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Kamil Rytarowskicb77f0d2017-05-07 23:25:26 +02001#!/usr/bin/env perl
H. Peter Anvin6e019b02007-03-16 14:45:06 -07002#
3# Clean a patch file -- or directory of patch files -- of stealth whitespace.
4# WARNING: this can be a highly destructive operation. Use with caution.
5#
6
Kamil Rytarowskicb77f0d2017-05-07 23:25:26 +02007use warnings;
H. Peter Anvin6e019b02007-03-16 14:45:06 -07008use bytes;
9use File::Basename;
10
H. Peter Anvincb3ed5b2007-05-25 17:58:26 -070011# Default options
12$max_width = 79;
13
H. Peter Anvin6e019b02007-03-16 14:45:06 -070014# Clean up space-tab sequences, either by removing spaces or
15# replacing them with tabs.
16sub clean_space_tabs($)
17{
18 no bytes; # Tab alignment depends on characters
19
20 my($li) = @_;
21 my($lo) = '';
22 my $pos = 0;
23 my $nsp = 0;
24 my($i, $c);
25
26 for ($i = 0; $i < length($li); $i++) {
27 $c = substr($li, $i, 1);
28 if ($c eq "\t") {
29 my $npos = ($pos+$nsp+8) & ~7;
30 my $ntab = ($npos >> 3) - ($pos >> 3);
31 $lo .= "\t" x $ntab;
32 $pos = $npos;
33 $nsp = 0;
34 } elsif ($c eq "\n" || $c eq "\r") {
35 $lo .= " " x $nsp;
36 $pos += $nsp;
37 $nsp = 0;
38 $lo .= $c;
39 $pos = 0;
40 } elsif ($c eq " ") {
41 $nsp++;
42 } else {
43 $lo .= " " x $nsp;
44 $pos += $nsp;
45 $nsp = 0;
46 $lo .= $c;
47 $pos++;
48 }
49 }
50 $lo .= " " x $nsp;
51 return $lo;
52}
53
H. Peter Anvincb3ed5b2007-05-25 17:58:26 -070054# Compute the visual width of a string
55sub strwidth($) {
56 no bytes; # Tab alignment depends on characters
57
58 my($li) = @_;
59 my($c, $i);
60 my $pos = 0;
61 my $mlen = 0;
62
63 for ($i = 0; $i < length($li); $i++) {
64 $c = substr($li,$i,1);
65 if ($c eq "\t") {
66 $pos = ($pos+8) & ~7;
67 } elsif ($c eq "\n") {
68 $mlen = $pos if ($pos > $mlen);
69 $pos = 0;
70 } else {
71 $pos++;
72 }
73 }
74
75 $mlen = $pos if ($pos > $mlen);
76 return $mlen;
77}
78
H. Peter Anvin6e019b02007-03-16 14:45:06 -070079$name = basename($0);
80
H. Peter Anvincb3ed5b2007-05-25 17:58:26 -070081@files = ();
82
83while (defined($a = shift(@ARGV))) {
84 if ($a =~ /^-/) {
85 if ($a eq '-width' || $a eq '-w') {
86 $max_width = shift(@ARGV)+0;
87 } else {
88 print STDERR "Usage: $name [-width #] files...\n";
89 exit 1;
90 }
91 } else {
92 push(@files, $a);
93 }
94}
95
96foreach $f ( @files ) {
H. Peter Anvin6e019b02007-03-16 14:45:06 -070097 print STDERR "$name: $f\n";
98
99 if (! -f $f) {
100 print STDERR "$f: not a file\n";
101 next;
102 }
103
104 if (!open(FILE, '+<', $f)) {
105 print STDERR "$name: Cannot open file: $f: $!\n";
106 next;
107 }
108
109 binmode FILE;
110
111 # First, verify that it is not a binary file; consider any file
112 # with a zero byte to be a binary file. Is there any better, or
113 # additional, heuristic that should be applied?
114 $is_binary = 0;
115
116 while (read(FILE, $data, 65536) > 0) {
117 if ($data =~ /\0/) {
118 $is_binary = 1;
119 last;
120 }
121 }
122
123 if ($is_binary) {
124 print STDERR "$name: $f: binary file\n";
125 next;
126 }
127
128 seek(FILE, 0, 0);
129
130 $in_bytes = 0;
131 $out_bytes = 0;
H. Peter Anvincb3ed5b2007-05-25 17:58:26 -0700132 $lineno = 0;
H. Peter Anvin6e019b02007-03-16 14:45:06 -0700133
134 @lines = ();
135
136 $in_hunk = 0;
137 $err = 0;
138
139 while ( defined($line = <FILE>) ) {
H. Peter Anvincb3ed5b2007-05-25 17:58:26 -0700140 $lineno++;
H. Peter Anvin6e019b02007-03-16 14:45:06 -0700141 $in_bytes += length($line);
142
143 if (!$in_hunk) {
H. Peter Anvincb3ed5b2007-05-25 17:58:26 -0700144 if ($line =~
145 /^\@\@\s+\-([0-9]+),([0-9]+)\s+\+([0-9]+),([0-9]+)\s\@\@/) {
H. Peter Anvin6e019b02007-03-16 14:45:06 -0700146 $minus_lines = $2;
147 $plus_lines = $4;
148 if ($minus_lines || $plus_lines) {
149 $in_hunk = 1;
150 @hunk_lines = ($line);
151 }
152 } else {
153 push(@lines, $line);
154 $out_bytes += length($line);
155 }
156 } else {
157 # We're in a hunk
158
159 if ($line =~ /^\+/) {
160 $plus_lines--;
161
162 $text = substr($line, 1);
163 $text =~ s/[ \t\r]*$//; # Remove trailing spaces
164 $text = clean_space_tabs($text);
165
H. Peter Anvincb3ed5b2007-05-25 17:58:26 -0700166 $l_width = strwidth($text);
167 if ($max_width && $l_width > $max_width) {
168 print STDERR
169 "$f:$lineno: adds line exceeds $max_width ",
170 "characters ($l_width)\n";
171 }
172
H. Peter Anvin6e019b02007-03-16 14:45:06 -0700173 push(@hunk_lines, '+'.$text);
174 } elsif ($line =~ /^\-/) {
175 $minus_lines--;
176 push(@hunk_lines, $line);
177 } elsif ($line =~ /^ /) {
178 $plus_lines--;
179 $minus_lines--;
180 push(@hunk_lines, $line);
181 } else {
182 print STDERR "$name: $f: malformed patch\n";
183 $err = 1;
184 last;
185 }
186
187 if ($plus_lines < 0 || $minus_lines < 0) {
188 print STDERR "$name: $f: malformed patch\n";
189 $err = 1;
190 last;
191 } elsif ($plus_lines == 0 && $minus_lines == 0) {
192 # End of a hunk. Process this hunk.
193 my $i;
194 my $l;
195 my @h = ();
196 my $adj = 0;
197 my $done = 0;
198
199 for ($i = scalar(@hunk_lines)-1; $i > 0; $i--) {
200 $l = $hunk_lines[$i];
201 if (!$done && $l eq "+\n") {
202 $adj++; # Skip this line
203 } elsif ($l =~ /^[ +]/) {
204 $done = 1;
205 unshift(@h, $l);
206 } else {
207 unshift(@h, $l);
208 }
209 }
210
211 $l = $hunk_lines[0]; # Hunk header
212 undef @hunk_lines; # Free memory
213
214 if ($adj) {
215 die unless
216 ($l =~ /^\@\@\s+\-([0-9]+),([0-9]+)\s+\+([0-9]+),([0-9]+)\s\@\@(.*)$/);
217 my $mstart = $1;
218 my $mlin = $2;
219 my $pstart = $3;
220 my $plin = $4;
221 my $tail = $5; # doesn't include the final newline
222
223 $l = sprintf("@@ -%d,%d +%d,%d @@%s\n",
224 $mstart, $mlin, $pstart, $plin-$adj,
225 $tail);
226 }
227 unshift(@h, $l);
228
229 # Transfer to the output array
230 foreach $l (@h) {
231 $out_bytes += length($l);
232 push(@lines, $l);
233 }
234
235 $in_hunk = 0;
236 }
237 }
238 }
239
240 if ($in_hunk) {
241 print STDERR "$name: $f: malformed patch\n";
242 $err = 1;
243 }
244
245 if (!$err) {
246 if ($in_bytes != $out_bytes) {
247 # Only write to the file if changed
248 seek(FILE, 0, 0);
249 print FILE @lines;
250
251 if ( !defined($where = tell(FILE)) ||
252 !truncate(FILE, $where) ) {
253 die "$name: Failed to truncate modified file: $f: $!\n";
254 }
255 }
256 }
257
258 close(FILE);
259}