On Thu, 2018-01-04 at 16:07 -0800, Matthew Wilcox wrote: > On Thu, Jan 04, 2018 at 03:47:32PM -0800, Paul E. McKenney wrote: > > I was under the impression that typeof did not actually evaluate its > > argument, but rather only returned its type. And there are a few macros > > with this pattern in mainline. > > > > Or am I confused about what typeof does? > > I think checkpatch is confused by the '*' in the typeof argument: > > $ git diff |./scripts/checkpatch.pl --strict > CHECK: Macro argument reuse 'ptr' - possible side-effects? > #29: FILE: include/linux/rcupdate.h:896: > +#define kfree_rcu(ptr, rcu_head) \ > + __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) > > If one removes the '*', the warning goes away. > > I'm no perlista, but Joe, would this regexp modification make sense? > > +++ b/scripts/checkpatch.pl > @@ -4957,7 +4957,7 @@ sub process { > next if ($arg =~ /\.\.\./); > next if ($arg =~ /^type$/i); > my $tmp_stmt = $define_stmt; > - $tmp_stmt =~ s/\b(typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)*\b//g; > + $tmp_stmt =~ s/\b(typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\**\(*\s*$arg\s*\)*\b//g; I supposed ideally it'd be more like $tmp_stmt =~ s/\b(?:typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*(?:\s*\*\s*)*\s*\(*\s*$arg\s*\)*\b//g; Adding ?: at the start to not capture and (?:\s*\*\s*)* for any number of * with any surrounding spacings. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>