linux/scripts/cleanpatch

260 lines
5.0 KiB
Perl
Executable File

#!/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 warnings;
use bytes;
use File::Basename;
# 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);
}