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

[Joe Perches]

On Fri, 2020-04-10 at 12:46 -0700, Joe Perches wrote:
> On Fri, 2020-04-10 at 19:35 +0200, Christophe JAILLET wrote:
> > Le 08/04/2020 à 04:14, Joe Perches a écrit :
> > > This works rather better:
> > > Perhaps you could test?
> []
> > I'm looking at some modification done in the last month that could have 
> > been spotted by the above script.
> > 
> >      ./scripts/checkpatch.pl -f drivers/usb/phy/phy-jz4770.c
> > 
> > correctly spots the 3 first cases, but the 3 last (line 202, 210 and 
> > 217) are missed.
> > I don't understand why.
> 
> It has to do with checkpatch's single statement parsing.
> 
> This case:
> 
> 	if (foo)
> 		dev_warn(...);
> 
> is parsed as a single statement but
> 
> 	if (foo) {
> 		dev_warn(...);
> 	};
> 
> is parsed as multiple statements so for the
> second case
> 
> 		dev_warn(...);
> 
> is analyzed as a separate statement.
> 
> The regex match for this missing newline test expects
> that each printk is a separate statement so the first
> case doesn't match.
> 
> Clearly the regex can be improved here.

So on top of the original patch:
---
 scripts/checkpatch.pl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index f00a6c8..54eaa7 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5675,8 +5675,8 @@ 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)_/) {
+		    $stat =~ /^\+\s*(?:if\s*$balanced_parens\s*)?($logFunctions)\s*\((?:\s*$FuncArg\s*,\s*){0,3}\s*$String/ &&
+		    $2 !~ /_cont$/ && $2 =~ /^(?:pr|dev|netdev|netif|wiphy)_/) {
 			my $cnt = statement_rawlines($stat);
 			my $extracted_string = "";
 			for (my $i = 0; $i < $cnt; $i++) {