Re: [PATCH] checkpatch: fix TYPO_SPELLING check for words with apostrophe

[Joe Perches <joe@perches.com>]

On Mon, 2020-11-30 at 22:33 +0530, Dwaipayan Ray wrote:
> On Mon, Nov 30, 2020 at 10:13 PM Joe Perches <joe@perches.com> wrote:
> > 
> > On Mon, 2020-11-30 at 20:15 +0530, Dwaipayan Ray wrote:
> > > checkpatch reports a false TYPO_SPELLING warning for some words
> > > containing an apostrophe.
> > > 
> > > A false positive is "doesn't". Occurrence of the word causes
> > > checkpatch to emit the following warning:
> > > 
> > > "WARNING: 'doesn'' may be misspelled - perhaps 'doesn't'?"
> > > 
> > > Check the word boundary for such cases so that words like
> > > "doesn't", "zig-zag", etc. aren't misinterpreted due to wrong
> > > splitting of the word by the \b regex metacharacter.
> > []
> > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > []
> > > @@ -3106,7 +3106,7 @@ sub process {
> > >  # Check for various typo / spelling mistakes
> > >               if (defined($misspellings) &&
> > >                   ($in_commit_log || $line =~ /^(?:\+|Subject:)/i)) {
> > > -                     while ($rawline =~ /(?:^|[^a-z@])($misspellings)(?:\b|$|[^a-z@])/gi) {
> > > +                     while ($rawline =~ /(?:^|[^a-z@])($misspellings)(?:\b(?![^\w]?[a-z@]+)|$|[^a-z@])/gi) {
> > 
> > Wouldn't it be simpler to change the existing [^a-z@] blocks to [^a-z@'-] ?
> > 
> Hi,
> I tried it and it doesn't seem to work. Probably because the first
> group already causes the
> word to be captured. In this case `doesn'` was already captured
> because of the \b group.
> 
> Is the first group modification perhaps okay? Or would you suggest
> something else?

Seems to work for me:

$ git diff --stat -p scripts/checkpatch.pl
 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 7dc094445d83..a6d4d524ae66 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3106,7 +3106,7 @@ sub process {
 # Check for various typo / spelling mistakes
 		if (defined($misspellings) &&
 		    ($in_commit_log || $line =~ /^(?:\+|Subject:)/i)) {
-			while ($rawline =~ /(?:^|[^a-z@])($misspellings)(?:\b|$|[^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]/);

$ cat t_spell.c
// SPDX-License-Identifier: GPL-2.0-only
void foo(void)
{
	//misspelled arne't word
}

$ ./scripts/checkpatch.pl -f --strict t_spell.c
CHECK: 'arne't' may be misspelled - perhaps 'aren't'?
#4: FILE: t_spell.c:4:
+	//misspelled arne't word

total: 0 errors, 0 warnings, 1 checks, 5 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

t_spell.c has style problems, please review.

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.