tools: Add cleanpatch

There are some errors reported by checkpatch.pl that can be easily cleaned up by
using the cleanpatch tool.

Import the cleanpatch script from linux kernel 3.5.4 stable version as from the
following commit:

commit cb3ed5b7e09c6c0462e396d55e3fecc0980a333a
Author: H. Peter Anvin <hpa@zytor.com>
Date:   Fri May 25 17:58:26 2007 -0700

    scripts: Make cleanfile/cleanpatch warn about long lines

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

diff --git a/tools/cleanpatch b/tools/cleanpatch
new file mode 100755 (executable)
index 0000000..9680d03
--- /dev/null
+++ b/tools/cleanpatch
@@ -0,0 +1,258 @@
+#!/usr/bin/perl -w
+#
+# 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;
+
+# 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);
+}