Re: [PATCH v2] checkpatch: add double empty line check

Andy Whitcroft
2012-11-20T11:52:47Z

On Sat, Nov 17, 2012 at 01:17:37PM +0200, Eilon Greenstein wrote:
> Changes from previous attempt:
> - Use CHK instead of WARN
> - Issue only one warning per empty lines block
>
> Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
> ---
> scripts/checkpatch.pl | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 21a9f5d..13d264f 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -3579,6 +3579,14 @@ sub process {
> WARN("EXPORTED_WORLD_WRITABLE",
> "Exporting world writable files is usually an error. Consider more restrictive permissions.\n" . $herecurr);
> }
> +
> +# check for double empty lines
> + if ($line =~ /^\+\s*$/ &&
> + ($rawlines[$linenr] =~ /^\s*$/ ||
> + $prevline =~ /^\+?\s*$/ && $rawlines[$linenr] !~ /^\+\s*$/)) {
> + CHK("DOUBLE_EMPTY_LINE",
> + "One empty line should be sufficient. Consider removing this one.\n" . $herecurr);
> + }
> }
>
> # If we have no input at all, then there is nothing to report on

In your previous version you indicated you would be emiting one per group
of lines, I do not see how this does that. Also this fails if the fragment
is at the top of the hunk emiting a perl warning. We should probabally
use the suppress approach.

How about something like the below.

-apw

>From 848ebffa8656a1ff96a91788ec0f1c04dab9c3e9 Mon Sep 17 00:00:00 2001
From: Andy Whitcroft <apw@canonical.com>
Date: Sat, 17 Nov 2012 13:17:37 +0200
Subject: [PATCH] checkpatch: strict warning for multiple blank lines

Signed-off-by: Andy Whitcroft <apw@canonical.com>
---
scripts/checkpatch.pl | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index f18750e..dbc68f3 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1411,6 +1411,7 @@ sub process {
my %suppress_whiletrailers;
my %suppress_export;
my $suppress_statement = 0;
+ my $suppress_multipleblank = -1;

# Pre-scan the patch sanitizing the lines.
# Pre-scan the patch looking for any __setup documentation.
@@ -1521,6 +1522,7 @@ sub process {
%suppress_whiletrailers = ();
%suppress_export = ();
$suppress_statement = 0;
+ $suppress_multipleblank = -1;
next;

# track the line number as we move through the hunk, note that
@@ -1930,6 +1932,15 @@ sub process {
"use the SSYNC() macro in asm/blackfin.h\n" . $herevet);
}

+# multiple blank lines.
+ if ($line =~ /^-/ || ($suppress_multipleblank == $linenr && $line =~ /^[ \+]\s*$/)) {
+ $suppress_multipleblank++;
+ } elsif ($prevline =~ /^\+\s*$/ and $line =~ /^\+\s*$/) {
+ $suppress_multipleblank = $linenr + 1;
+ CHK("MULTIPLE_EMPTY_LINE",
+ "One empty line should be sufficient. Consider removing this one.\n" . $herecurr);
+ }
+
# Check for potential 'bare' types
my ($stat, $cond, $line_nr_next, $remain_next, $off_next,
$realline_next);
--
1.7.10.4