2019-03-05 07:14:19

by Alexandre Ghiti

[permalink] [raw]
Subject: [PATCH v2] scripts: checkpatch: Check multiple blank lines when deleting code

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.

Signed-off-by: Alexandre Ghiti <[email protected]>
---

Changes in v2:
- Fix the --fix option

scripts/checkpatch.pl | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index b737ca9d7204..7dc12c137009 100755
--- 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);
}

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) &&
$fix) {
fix_delete_line($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;
--
2.20.1



2019-03-05 23:18:10

by Joe Perches

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

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.

> }
>
> 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"

> 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;


2019-03-06 07:15:01

by Alexandre Ghiti

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

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;