scripts/checkpatch: Support codespell checking

Add two spelling check options (--codespell and --codespellfile) to
enhance spelling check through dictionary, which copied the Linux
kernel's implementation in checkpatch.pl.

This check uses the dictionary at "/usr/share/codespell/dictionary.txt"
by default, if there is no dictionary specified under this path, it
will look for the dictionary of python3's codespell (This requires user
to add python3's path in environment variable $PATH, and to install
codespell by "pip install codespell").

Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Tested-by: Samuel Tardieu <sam@rfc1149.net>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Message-ID: <20240105083848.267192-1-zhao1.liu@linux.intel.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

scripts/checkpatch.pl

@@ -35,6 +35,9 @@
 my $root;
 my %debug;
 my $help = 0;
+my $codespell = 0;
+my $codespellfile = "/usr/share/codespell/dictionary.txt";
+my $user_codespellfile = "";
 
 sub help {
 	my ($exitcode) = @_;
@@ -66,6 +69,9 @@ sub help {
                              is all off)
   --test-only=WORD           report only warnings/errors containing WORD
                              literally
+  --codespell                Use the codespell dictionary for spelling/typos
+                             (default: $codespellfile)
+  --codespellfile            Use this codespell dictionary
   --color[=WHEN]             Use colors 'always', 'never', or only when output
                              is a terminal ('auto'). Default is 'auto'.
   -h, --help, --version      display this help and exit
@@ -85,28 +91,50 @@ sub help {
 }
 
 GetOptions(
-	'q|quiet+'	=> \$quiet,
-	'tree!'		=> \$tree,
-	'signoff!'	=> \$chk_signoff,
-	'patch!'	=> \$chk_patch,
-	'branch!'	=> \$chk_branch,
-	'emacs!'	=> \$emacs,
-	'terse!'	=> \$terse,
-	'f|file!'	=> \$file,
-	'strict!'	=> \$no_warnings,
-	'root=s'	=> \$root,
-	'summary!'	=> \$summary,
-	'mailback!'	=> \$mailback,
-	'summary-file!'	=> \$summary_file,
-
-	'debug=s'	=> \%debug,
-	'test-only=s'	=> \$tst_only,
-	'color=s'       => \$color,
-	'no-color'      => sub { $color = 'never'; },
-	'h|help'	=> \$help,
-	'version'	=> \$help
+	'q|quiet+'		=> \$quiet,
+	'tree!'			=> \$tree,
+	'signoff!'		=> \$chk_signoff,
+	'patch!'		=> \$chk_patch,
+	'branch!'		=> \$chk_branch,
+	'emacs!'		=> \$emacs,
+	'terse!'		=> \$terse,
+	'f|file!'		=> \$file,
+	'strict!'		=> \$no_warnings,
+	'root=s'		=> \$root,
+	'summary!'		=> \$summary,
+	'mailback!'		=> \$mailback,
+	'summary-file!'		=> \$summary_file,
+	'debug=s'		=> \%debug,
+	'test-only=s'		=> \$tst_only,
+	'codespell!'		=> \$codespell,
+	'codespellfile=s'	=> \$user_codespellfile,
+	'color=s'		=> \$color,
+	'no-color'		=> sub { $color = 'never'; },
+	'h|help'		=> \$help,
+	'version'		=> \$help
 ) or help(1);
 
+if ($user_codespellfile) {
+	# Use the user provided codespell file unconditionally
+	$codespellfile = $user_codespellfile;
+} elsif (!(-f $codespellfile)) {
+	# If /usr/share/codespell/dictionary.txt is not present, try to find it
+	# under codespell's install directory: <codespell_root>/data/dictionary.txt
+	if (($codespell || $help) && which("python3") ne "") {
+		my $python_codespell_dict = << "EOF";
+
+import os.path as op
+import codespell_lib
+codespell_dir = op.dirname(codespell_lib.__file__)
+codespell_file = op.join(codespell_dir, 'data', 'dictionary.txt')
+print(codespell_file, end='')
+EOF
+
+		my $codespell_dict = `python3 -c "$python_codespell_dict" 2> /dev/null`;
+		$codespellfile = $codespell_dict if (-f $codespell_dict);
+	}
+}
+
 help(0) if ($help);
 
 my $exit = 0;
@@ -337,6 +365,36 @@ sub help {
 	qr{guintptr},
 );
 
+# Load common spelling mistakes and build regular expression list.
+my $misspellings;
+my %spelling_fix;
+
+if ($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;
+
 # This can be modified by sub possible.  Since it can be empty, be careful
 # about regexes that always match, because they can cause infinite loops.
 our @modifierList = (
@@ -477,6 +535,18 @@ sub top_of_kernel_tree {
 	return 1;
 }
 
+sub which {
+	my ($bin) = @_;
+
+	foreach my $path (split(/:/, $ENV{PATH})) {
+		if (-e "$path/$bin") {
+			return "$path/$bin";
+		}
+	}
+
+	return "";
+}
+
 sub expand_tabs {
 	my ($str) = @_;
 
@@ -1585,6 +1655,21 @@ sub process {
 			WARN("8-bit UTF-8 used in possible commit log\n" . $herecurr);
 		}
 
+# Check for various typo / spelling mistakes
+		if (defined($misspellings) &&
+		    ($in_commit_log || $line =~ /^(?:\+|Subject:)/i)) {
+			while ($rawline =~ /(?:^|[^\w\-'`])($misspellings)(?:[^\w\-'`]|$)/gi) {
+				my $typo = $1;
+				my $blank = copy_spacing($rawline);
+				my $ptr = substr($blank, 0, $-[1]) . "^" x length($typo);
+				my $hereptr = "$hereline$ptr\n";
+				my $typo_fix = $spelling_fix{lc($typo)};
+				$typo_fix = ucfirst($typo_fix) if ($typo =~ /^[A-Z]/);
+				$typo_fix = uc($typo_fix) if ($typo =~ /^[A-Z]+$/);
+				WARN("'$typo' may be misspelled - perhaps '$typo_fix'?\n" . $hereptr);
+			}
+		}
+
 # ignore non-hunk lines and lines being removed
 		next if (!$hunk_line || $line =~ /^-/);