Re: [PATCH] checkpatch: check for missing \n at the end of logging message

[Christophe JAILLET]

Le 09/04/2020 Ã 05:10, Joe Perches a ÃcritÂ:
> On Wed, 2020-04-08 at 22:23 +0200, Marion & Christophe JAILLET wrote:
> > Le 08/04/2020 Ã 04:14, Joe Perches a Ãcrit :
> > > This works rather better:
> > >
> > > Perhaps you could test?
> > > ---
> > >
> > > v2:
> > >
> > > o Avoid pr_cont
> > > o Use only last format line if split across multiple lines
> > >
> > >    scripts/checkpatch.pl | 22 ++++++++++++++++++++++
> > >    1 file changed, 22 insertions(+)
> > >
> > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > > index d64c67..f00a6c8 100755
> > > --- a/scripts/checkpatch.pl
> > > +++ b/scripts/checkpatch.pl
> > > @@ -5673,6 +5673,28 @@ sub process {
> > >    			}
> > >    		}
> > >    
> > > +# check for possible missing newlines at the end of common logging functions
> > > +		if (defined($stat) &&
> > > +		    $stat =~ /^\+\s*($logFunctions)\s*\((?:\s*$FuncArg\s*,\s*){0,3}\s*$String/ &&
> > > +		    $1 !~ /_cont$/ && $1 =~ /^(?:pr|dev|netdev|netif|wiphy)_/) {
> > > +			my $cnt = statement_rawlines($stat);
> > > +			my $extracted_string = "";
> > > +			for (my $i = 0; $i < $cnt; $i++) {
> > > +				next if ($lines[$linenr + $i - 1] !~ /$String\s*[,\)]/);
> > > +				$extracted_string = get_quoted_string($lines[$linenr + $i - 1],
> > > +								      $rawlines[$linenr + $i - 1]);
> > > +				last if ($extracted_string ne "");
> > > +			}
> > > +			if ($extracted_string ne "" && $extracted_string !~ /\\n"$/) {
> > > +				my $herectx = $here . "\n";
> > > +				for (my $n = 0; $n < $cnt; $n++) {
> > > +					$herectx .=  raw_line($linenr, $n) . "\n";
> > > +				}
> > > +				WARN("MISSING_FORMAT_NEWLINE",
> > > +				     "Possible missing '\\n' at the end of a logging message format string\n" . $herectx);
> > > +			}
> > > +		}
> > > +
> > >    # check for logging functions with KERN_<LEVEL>
> > >    		if ($line !~ /printk(?:_ratelimited|_once)?\s*\(/ &&
> > >    		    $line =~ /\b$logFunctions\s*\(.*\b(KERN_[A-Z]+)\b/) {
> > For what I wanted to check and according to the few tests I've made, it
> > looks fine.
> >
> > Thank you very much for sharing this much more robust (and working)
> > alternative.
> >
> > For what it worth: (i.e. much more tests should be done)
> > Tested-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> Then I think you really haven't tested it very thoroughly.
>
> For instance:
>
> $ git ls-files -- 'drivers/*.[ch]' | \
>    xargs ./scripts/checkpatch.pl -f --quiet --no-summary --types=MISSING_FORMAT_NEWLINE
>
> emits many false positives.
>
> Some types of false positives:
>
> o Many of the formats seem to end in a ':' or a ' '
>    maybe those should be excluded
>     #86: FILE: drivers/android/binder_alloc_selftest.c:86:
>     +	pr_err("free seq: ");
>
>     o Split string formats should be excluded better
>       as only the first string fragment is checked:
>     #1001: FILE: drivers/ata/pata_octeon_cf.c:1001:
>     +	dev_info(&pdev->dev, "version " DRV_VERSION" %d bit%s.\n",
>     +		 is_16bit ? 16 : 8,
>     +		 cf_port->is_true_ide ? ", True IDE" : "");
>
>     probably a few others, including a desire to check
>     if a pr_cont is below the use within a few lines.
>
>     > Maybe, at least a Suggested-By: would be appreciated.
>
> No worries, when it's cooked, it'll have that.
>
> cheers, Joe
I think that, at least printk(), WARN() and co, and panic() should also 
be handled the same way.


A few files (5 according to my grep) also have something like:
ÂÂ #define pr_fmt(fmt) "bcache: %s()" fmt "\n", __func__
and then sometimes a mix of pr_xxx() with either trailing \n or not.

Maybe those should be handled manually to be consistent and avoid a "\n" 
in pr_fmt which is not widely used in other files

CJ