Re: [PATCH V2] checkpatch: Warn on unnecessary void function return statements

Anish Bhatt
2014-06-18T19:59:16Z

On Wed 18 Jun 2014 10:44:44 AM PDT, Joe Perches wrote:
> With some exceptions, warn on void functions that end with a
> "return;", because it's unnecessary.
>
> Check the closing brace at the start of a line.
> If the line before that has a single tab, then return;
> look at the line before that. If it's not a label,
> emit a warning.
>
> So, emit a warning on:
>
> void function(...)
> {
> [...]
> return;
> }
>
> but do not emit a warning on the below because
> gcc requires any statement (including a bare
> semicolon) before the closing function brace:
>
> void function(...)
> {
> [...]
> goto label;
> [...]
>
> label:
> return;
> }
>
> Signed-off-by: Joe Perches <joe@perches.com>
> ---
>
> V2: The previous patch had a few too many false positives
> on styles that should be acceptable.
>
> scripts/checkpatch.pl | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 862cc7a..b191c88 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -3470,6 +3470,18 @@ sub process {
> }
> }
>
> +# unnecessary return in a void function
> +# at end-of-function, with the previous line a single leading tab, then return;
> +# and the line before that not a goto label target like "out:"
> + if ($sline =~ /^[ \+]}\s*$/ &&
> + $prevline =~ /^\+\treturn\s*;\s*$/ &&
> + $linenr >= 3 &&
> + $lines[$linenr - 3] =~ /^[ +]/ &&
> + $lines[$linenr - 3] !~ /^[ +]\s*$Ident\s*:/) {
> + WARN("RETURN_VOID",
> + "void function return statements are not generally useful\n" . $hereprev);
> + }
> +
> # if statements using unnecessary parentheses - ie: if ((foo == bar))
> if ($^V && $^V ge 5.10.0 &&
> $line =~ /\bif\s*((?:\(\s*){2,})/) {
>
>

Confirming, no longer hitting previous false positives for me.
-Anish

--
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