Re: [PATCH v2] scripts: checkpatch: Check multiple blank lines when deleting code

[Alex Ghiti]

On 3/5/19 6:17 PM, Joe Perches wrote:

On Tue, 2019-03-05 at 02:12 -0500, Alexandre Ghiti wrote:

By matching only current line starting with '+', we miss the case
when deleting code makes consecutive blank lines appear: this patch
then makes it possible to detect this case by also matching current
line starting with ' ', which is an already existing blank line.

[]

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl

[]

@@ -2081,10 +2081,15 @@ sub fix_inserted_deleted_lines {
                }

while (defined($inserted) && ${$inserted}{'LINENR'} == $old_linenr) {

+                       my $len = 1;
                        push(@lines, ${$inserted}{'LINE'});
+                       # Do not increment the length when inserting a deletion 
line.
+                       if (${$inserted}{'LINE'} =~ /^\-/) {
+                               $len = 0;
+                       }
                        $inserted = @{$insertedRef}[$next_insert++];
                        $new_linenr++;
-                       fixup_current_range(\$lines[$range_last_linenr], 
$delta_offset++, 1);
+                       fixup_current_range(\$lines[$range_last_linenr], 
$delta_offset++, $len);

I think this is confusing and unnecessary.
Using --fix can not delete context lines from a patch.

Ok, I was expecting your comment on that, I agree with you.
So I'll get rid of the possibility to fix the deletion case, this will
only be a warning.

                }

if ($save_line) {

@@ -3298,12 +3303,18 @@ sub process {

# check for multiple consecutive blank lines

                if ($prevline =~ /^[\+ ]\s*$/ &&
-                   $line =~ /^\+\s*$/ &&
+                   $line =~ /^[\+ ]\s*$/ &&
                    $last_blank_line != ($linenr - 1)) {
                        if (CHK("LINE_SPACING",
                                "Please don't use multiple blank lines\n" . $hereprev) 
&&
                            $fix) {

It's simpler to add a check that $line starts /^\+/ before $fix

Maybe it'd be better to have a separate test for this to make
the output message clearer too.

Something like
        "Avoid deleting lines that create consecutive blank lines"

Ok,

Thanks for your comments,

                                fix_delete_line($fixlinenr, $rawline);
+                               if ($line =~ /^ \s*$/) {
+                                       # If the line is not an inserted blank 
line, the multiple
+                                       # consecutive blank lines are caused by 
deletion: fix this
+                                       # by replacing the blank line with a 
deletion line.
+                                       fix_insert_line($fixlinenr, "\-");
+                               }
                        }

$last_blank_line = $linenr;