checkpatch: add optional --codespell dictionary to find more typos

If a codespell dictionary exists, use it if desired.  default is off,
maybe it could be turned on later.

codespell's dictionary format allows multiple possible corrections, ignore
that for now and only use the first suggestion.

Also add \b to spelling test so that consecutive misspelled words
are found properly.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masanari Iida <standby24x7@gmail.com>
Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -47,6 +47,8 @@
 my $minimum_perl_version = 5.10.0;
 my $min_conf_desc_length = 4;
 my $spelling_file = "$D/spelling.txt";
+my $codespell = 0;
+my $codespellfile = "/usr/local/share/codespell/dictionary.txt";
 
 sub help {
 	my ($exitcode) = @_;
@@ -88,6 +90,9 @@ sub help {
                              file.  It's your fault if there's no backup or git
   --ignore-perl-version      override checking of perl version.  expect
                              runtime errors.
+  --codespell                Use the codespell dictionary for spelling/typos
+                             (default:/usr/local/share/codespell/dictionary.txt)
+  --codespellfile            Use this codespell dictionary
   -h, --help, --version      display this help and exit
 
 When FILE is - read standard input.
@@ -146,6 +151,8 @@ sub help {
 	'ignore-perl-version!' => \$ignore_perl_version,
 	'debug=s'	=> \%debug,
 	'test-only=s'	=> \$tst_only,
+	'codespell!'	=> \$codespell,
+	'codespellfile=s'	=> \$codespellfile,
 	'h|help'	=> \$help,
 	'version'	=> \$help
 ) or help(1);
@@ -449,7 +456,6 @@ sub hash_show_words {
 my %spelling_fix;
 
 if (open(my $spelling, '<', $spelling_file)) {
-	my @spelling_list;
 	while (<$spelling>) {
 		my $line = $_;
 
@@ -461,15 +467,39 @@ sub hash_show_words {
 
 		my ($suspect, $fix) = split(/\|\|/, $line);
 
-		push(@spelling_list, $suspect);
 		$spelling_fix{$suspect} = $fix;
 	}
 	close($spelling);
-	$misspellings = join("|", @spelling_list);
 } else {
 	warn "No typos will be found - file '$spelling_file': $!\n";
 }
 
+if ($codespell) {
+	if (open(my $spelling, '<', $codespellfile)) {
+		while (<$spelling>) {
+			my $line = $_;
+
+			$line =~ s/\s*\n?$//g;
+			$line =~ s/^\s*//g;
+
+			next if ($line =~ m/^\s*#/);
+			next if ($line =~ m/^\s*$/);
+			next if ($line =~ m/, disabled/i);
+
+			$line =~ s/,.*$//;
+
+			my ($suspect, $fix) = split(/->/, $line);
+
+			$spelling_fix{$suspect} = $fix;
+		}
+		close($spelling);
+	} else {
+		warn "No codespell typos will be found - file '$codespellfile': $!\n";
+	}
+}
+
+$misspellings = join("|", sort keys %spelling_fix) if keys %spelling_fix;
+
 sub build_types {
 	my $mods = "(?x:  \n" . join("|\n  ", @modifierList) . "\n)";
 	my $all = "(?x:  \n" . join("|\n  ", @typeList) . "\n)";
@@ -2305,7 +2335,7 @@ sub process {
 # Check for various typo / spelling mistakes
 		if (defined($misspellings) &&
 		    ($in_commit_log || $line =~ /^(?:\+|Subject:)/i)) {
-			while ($rawline =~ /(?:^|[^a-z@])($misspellings)(?:$|[^a-z@])/gi) {
+			while ($rawline =~ /(?:^|[^a-z@])($misspellings)(?:\b|$|[^a-z@])/gi) {
 				my $typo = $1;
 				my $typo_fix = $spelling_fix{lc($typo)};
 				$typo_fix = ucfirst($typo_fix) if ($typo =~ /^[A-Z]/);