Re: [PATCH v2] checkpatch: add check for continue statement in UNNECESSARY_ELSE

From: Joe Perches
Date: Fri Oct 01 2021 - 17:09:31 EST


On Sat, 2021-10-02 at 02:17 +0530, Utkarsh Verma wrote:
> UNNECESSARY_ELSE only checks for the usage of else after a return or
> break. But the same logic is also true for continue statement.
>
> else used after a continue statement is unnecessary. So add a test
> for continue statement also.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -4011,15 +4011,15 @@ sub process {
>  
>
>  # check indentation of any line with a bare else
>  # (but not if it is a multiple line "if (foo) return bar; else return baz;")
> -# if the previous line is a break or return and is indented 1 tab more...
> +# if the previous line is a break or continue or return and is indented 1 tab more...
>   if ($sline =~ /^\+([\t]+)(?:}[ \t]*)?else(?:[ \t]*{)?\s*$/) {
>   my $tabs = length($1) + 1;
> - if ($prevline =~ /^\+\t{$tabs,$tabs}break\b/ ||
> + if ($prevline =~ /^\+\t{$tabs,$tabs}(?:break|continue)\b/ ||
>   ($prevline =~ /^\+\t{$tabs,$tabs}return\b/ &&
>   defined $lines[$linenr] &&
>   $lines[$linenr] !~ /^[ \+]\t{$tabs,$tabs}return/)) {
>   WARN("UNNECESSARY_ELSE",
> - "else is not generally useful after a break or return\n" . $hereprev);
> + "else is not generally useful after a break or continue or return\n" . $hereprev);
>   }
>   }
>  
>

Maybe make the output specific to the break/continue/return
(untested)

if ($prevline =~ /^\+\t{$tabs,$tabs}(break|continue|return)\b/ &&
!($1 == "return" &&
defined $lines[$linenr] &&
$lines[$linenr] !~ /^[ \+]\t{$tabs,$tabs}return/)) {
WARN("UNNECESSARY_ELSE",
"else is not generally useful after a $1\n" . $hereprev);