Re: [B.A.T.M.A.N.] checkpatch: CHECK: No space is necessary after a cast

Joe Perches
2015-02-19T19:55:41Z

On Thu, 2015-02-19 at 13:35 +0800, Marek Lindner wrote:
> Hi Joe,

Hi Marek

> we have come across a checkpatch false-positive:
[]
> BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
> CHECK: No space is necessary after a cast
> #440: FILE: main.c:440:
> + BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
[]
> Can you make a suggestion / patch for checkpatch to better handle this case ?

The "sizeof" test in the current script doesn't work.

I believe the patch below works with no false positives
but <shrug> it's perl regexes against odd coding styles
and weird macros, who knows for sure...

I did run it against drivers/, net/ and include/

Give this a try:
---
scripts/checkpatch.pl | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d124359..2f5bb27 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2552,9 +2552,15 @@ sub process {
}
}

- if ($line =~ /^\+.*(\w+\s*)?\(\s*$Type\s*\)[ \t]+(?!$Assignment|$Arithmetic|[,;:\?\(\{\}\[\<\>]|&&|\|\||\\$)/ &&
- (!defined($1) || $1 !~ /sizeof\s*/)) {
- if (CHK("SPACING",
+# check for space after cast like "(int) foo" or "(struct foo) bar"
+# avoid checking a few false positives:
+# "sizeof(<type>)" or "__alignof__(<type>)"
+# function pointer declarations like "(*foo)(int) = bar;"
+# structure definitions like "(struct foo) { 0 };"
+# multiline macros that define functions
+ if ($line =~ /^\+(.*)\(\s*$Type\s*\)([ \t]++)((?![={]|\\$))/ &&
+ (!defined($1) || $1 !~ /\b(?:sizeof|__alignof__)\s*$/)) {
+ if (CHK("SPACING",
"No space is necessary after a cast\n" . $herecurr) &&
$fix) {
$fixed[$fixlinenr] =~