summaryrefslogtreecommitdiffstats
path: root/scripts/cleanpatch
blob: ab5ebddded201747ad9b2bc416e523c46610f894 (plain)
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
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
#!/usr/bin/env perl 
#
# Clean a patch file -- or directory of patch files -- of stealth whitespace.
# WARNING: this can be a highly destructive operation.  Use with caution.
#

use bytes;
use File::Basename;
use warnings;

# Default options
$max_width = 79;

# Clean up space-tab sequences, either by removing spaces or
# replacing them with tabs.
sub clean_space_tabs($)
{
    no bytes;			# Tab alignment depends on characters

    my($li) = @_;
    my($lo) = '';
    my $pos = 0;
    my $nsp = 0;
    my($i, $c);

    for ($i = 0; $i < length($li); $i++) {
	$c = substr($li, $i, 1);
	if ($c eq "\t") {
	    my $npos = ($pos+$nsp+8) & ~7;
	    my $ntab = ($npos >> 3) - ($pos >> 3);
	    $lo .= "\t" x $ntab;
	    $pos = $npos;
	    $nsp = 0;
	} elsif ($c eq "\n" || $c eq "\r") {
	    $lo .= " " x $nsp;
	    $pos += $nsp;
	    $nsp = 0;
	    $lo .= $c;
	    $pos = 0;
	} elsif ($c eq " ") {
	    $nsp++;
	} else {
	    $lo .= " " x $nsp;
	    $pos += $nsp;
	    $nsp = 0;
	    $lo .= $c;
	    $pos++;
	}
    }
    $lo .= " " x $nsp;
    return $lo;
}

# Compute the visual width of a string
sub strwidth($) {
    no bytes;			# Tab alignment depends on characters

    my($li) = @_;
    my($c, $i);
    my $pos = 0;
    my $mlen = 0;

    for ($i = 0; $i < length($li); $i++) {
	$c = substr($li,$i,1);
	if ($c eq "\t") {
	    $pos = ($pos+8) & ~7;
	} elsif ($c eq "\n") {
	    $mlen = $pos if ($pos > $mlen);
	    $pos = 0;
	} else {
	    $pos++;
	}
    }

    $mlen = $pos if ($pos > $mlen);
    return $mlen;
}

$name = basename($0);

@files = ();

while (defined($a = shift(@ARGV))) {
    if ($a =~ /^-/) {
	if ($a eq '-width' || $a eq '-w') {
	    $max_width = shift(@ARGV)+0;
	} else {
	    print STDERR "Usage: $name [-width #] files...\n";
	    exit 1;
	}
    } else {
	push(@files, $a);
    }
}

foreach $f ( @files ) {
    print STDERR "$name: $f\n";

    if (! -f $f) {
	print STDERR "$f: not a file\n";
	next;
    }

    if (!open(FILE, '+<', $f)) {
	print STDERR "$name: Cannot open file: $f: $!\n";
	next;
    }

    binmode FILE;

    # First, verify that it is not a binary file; consider any file
    # with a zero byte to be a binary file.  Is there any better, or
    # additional, heuristic that should be applied?
    $is_binary = 0;

    while (read(FILE, $data, 65536) > 0) {
	if ($data =~ /\0/) {
	    $is_binary = 1;
	    last;
	}
    }

    if ($is_binary) {
	print STDERR "$name: $f: binary file\n";
	next;
    }

    seek(FILE, 0, 0);

    $in_bytes = 0;
    $out_bytes = 0;
    $lineno = 0;

    @lines  = ();

    $in_hunk = 0;
    $err = 0;

    while ( defined($line = <FILE>) ) {
	$lineno++;
	$in_bytes += length($line);

	if (!$in_hunk) {
	    if ($line =~
		/^\@\@\s+\-([0-9]+),([0-9]+)\s+\+([0-9]+),([0-9]+)\s\@\@/) {
		$minus_lines = $2;
		$plus_lines = $4;
		if ($minus_lines || $plus_lines) {
		    $in_hunk = 1;
		    @hunk_lines = ($line);
		}
	    } else {
		push(@lines, $line);
		$out_bytes += length($line);
	    }
	} else {
	    # We're in a hunk

	    if ($line =~ /^\+/) {
		$plus_lines--;

		$text = substr($line, 1);
		$text =~ s/[ \t\r]*$//;		# Remove trailing spaces
		$text = clean_space_tabs($text);

		$l_width = strwidth($text);
		if ($max_width && $l_width > $max_width) {
		    print STDERR
			"$f:$lineno: adds line exceeds $max_width ",
			"characters ($l_width)\n";
		}

		push(@hunk_lines, '+'.$text);
	    } elsif ($line =~ /^\-/) {
		$minus_lines--;
		push(@hunk_lines, $line);
	    } elsif ($line =~ /^ /) {
		$plus_lines--;
		$minus_lines--;
		push(@hunk_lines, $line);
	    } else {
		print STDERR "$name: $f: malformed patch\n";
		$err = 1;
		last;
	    }

	    if ($plus_lines < 0 || $minus_lines < 0) {
		print STDERR "$name: $f: malformed patch\n";
		$err = 1;
		last;
	    } elsif ($plus_lines == 0 && $minus_lines == 0) {
		# End of a hunk.  Process this hunk.
		my $i;
		my $l;
		my @h = ();
		my $adj = 0;
		my $done = 0;

		for ($i = scalar(@hunk_lines)-1; $i > 0; $i--) {
		    $l = $hunk_lines[$i];
		    if (!$done && $l eq "+\n") {
			$adj++; # Skip this line
		    } elsif ($l =~ /^[ +]/) {
			$done = 1;
			unshift(@h, $l);
		    } else {
			unshift(@h, $l);
		    }
		}

		$l = $hunk_lines[0];  # Hunk header
		undef @hunk_lines;    # Free memory

		if ($adj) {
		    die unless
			($l =~ /^\@\@\s+\-([0-9]+),([0-9]+)\s+\+([0-9]+),([0-9]+)\s\@\@(.*)$/);
		    my $mstart = $1;
		    my $mlin = $2;
		    my $pstart = $3;
		    my $plin = $4;
		    my $tail = $5; # doesn't include the final newline

		    $l = sprintf("@@ -%d,%d +%d,%d @@%s\n",
				 $mstart, $mlin, $pstart, $plin-$adj,
				 $tail);
		}
		unshift(@h, $l);

		# Transfer to the output array
		foreach $l (@h) {
		    $out_bytes += length($l);
		    push(@lines, $l);
		}

		$in_hunk = 0;
	    }
	}
    }

    if ($in_hunk) {
	print STDERR "$name: $f: malformed patch\n";
	$err = 1;
    }

    if (!$err) {
	if ($in_bytes != $out_bytes) {
	    # Only write to the file if changed
	    seek(FILE, 0, 0);
	    print FILE @lines;

	    if ( !defined($where = tell(FILE)) ||
		 !truncate(FILE, $where) ) {
		die "$name: Failed to truncate modified file: $f: $!\n";
	    }
	}
    }

    close(FILE);
}