Re: [PATCH] checkpatch: use patch subject when reading from stdin

[Joe Perches]

On Tue, 2019-10-08 at 17:28 +0200, Geert Uytterhoeven wrote:
> Hi Joe,
> 
> On Tue, Oct 8, 2019 at 5:20 PM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > On Tue, 2019-10-08 at 11:40 +0200, Geert Uytterhoeven wrote:
> > > When reading a patch file from standard input, checkpatch calls it "Your
> > > patch", and reports its state as:
> > > 
> > >     Your patch has style problems, please review.
> > > 
> > > or:
> > > 
> > >     Your patch has no obvious style problems and is ready for submission.
> > > 
> > > Hence when checking multiple patches by piping them to checkpatch, e.g.
> > > when checking patchwork bundles using:
> > > 
> > >     formail -s scripts/checkpatch.pl < bundle-foo.mbox
> > > 
> > > it is difficult to identify which patches need to be reviewed and
> > > improved.
> > > 
> > > Fix this by replacing "Your patch" by the patch subject, if present.
> > []
> > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > []
> > > @@ -1047,6 +1047,10 @@ for my $filename (@ARGV) {
> > >       }
> > >       while (<$FILE>) {
> > >               chomp;
> > > +             if ($vname eq 'Your patch') {
> > > +                     my ($subject) = $_ =~ /^Subject:\s*(.*)/;
> > > +                     $vname = '"' . $subject . '"' if $subject;
> > 
> > Hi again Geert.
> > 
> > Just some stylistic nits:
> > 
> > $filename is not quoted so I think adding quotes
> > before and after $subject may not be useful.
> 
> Filename is indeed not quoted, but $git_commits{$filename} is.

If I understand your use case, this will only show the last
patch $subject of a bundle?

Also, it'll show things like "duplicate signature" when multiple
patches are tested in a single bundle.

For instance, if I have a git format-patch series in an output
directory and do

$ cat <output_dir>/*.patch | ./scripts/checkpatch.pl

Bad output happen.

Maybe this might be better:

---
 scripts/checkpatch.pl | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index cf7543a9d1b2..2f79c585e795 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2444,6 +2444,15 @@ sub process {
 
 		my $rawline = $rawlines[$linenr - 1];
 
+# if input from stdin, report the subject lines if they exist
+		if ($filename eq '-' && !$quiet &&
+		    $rawline =~ /^Subject:\s*(.*)/) {
+			report("stdin", "STDIN", '-' x length($1));
+			report("stdin", "STDIN", $1);
+			report("stdin", "STDIN", '-' x length($1));
+			%signatures = ();	# avoid duplicate signatures
+		}
+
 # check if it's a mode change, rename or start of a patch
 		if (!$in_commit_log &&
 		    ($line =~ /^ mode change [0-7]+ => [0-7]+ \S+\s*$/ ||