[nacked] checkpatch-check-for-functions-with-passed-by-value-structs-or-unions.patch removed from -mm tree

[akpm@xxxxxxxxxxxxxxxxxxxx]

The patch titled
     Subject: checkpatch: check for functions with 'passed by value' structs or unions
has been removed from the -mm tree.  Its filename was
     checkpatch-check-for-functions-with-passed-by-value-structs-or-unions.patch

This patch was dropped because it was nacked

------------------------------------------------------
From: Joe Perches <joe@xxxxxxxxxxx>
Subject: checkpatch: check for functions with 'passed by value' structs or unions

I was cc'd on a patch where structs were passed by value instead of using
pointers to the structs.  This can cause defects when the called function
modifies the 'passed by value' struct instead of the calling function's
struct.

There are what seems to be some false positives for a few of the .h files
in include/linux/...  where the false positives are for very small structs
where the indirection via a pointer might be slower than than the passed
by value use.

Link: http://lkml.kernel.org/r/84972e19138f1f8eafe74c6b5f1ad874f8525706.camel@xxxxxxxxxxx
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 scripts/checkpatch.pl |   22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

--- a/scripts/checkpatch.pl~checkpatch-check-for-functions-with-passed-by-value-structs-or-unions
+++ a/scripts/checkpatch.pl
@@ -6092,8 +6092,10 @@ sub process {
 # check for function definitions
 		if ($perl_version_ok &&
 		    defined $stat &&
-		    $stat =~ /^.\s*(?:$Storage\s+)?$Type\s*($Ident)\s*$balanced_parens\s*{/s) {
+		    $stat =~ /^.\s*(?:$Storage\s+)?$Type\s*($Ident)\s*$balanced_parens\s*([\{;])/s) {
 			$context_function = $1;
+			my $args = $2;
+			my $term = $3;
 
 # check for multiline function definition with misplaced open brace
 			my $ok = 0;
@@ -6104,12 +6106,26 @@ sub process {
 				$herectx .=  $rl . "\n";
 				$ok = 1 if ($rl =~ /^[ \+]\{/);
 				$ok = 1 if ($rl =~ /\{/ && $n == 0);
-				last if $rl =~ /^[ \+].*\{/;
+				last if ($rl =~ /^[ \+].*[\{;]/);
 			}
-			if (!$ok) {
+			if (!$ok && $term eq '{') {
 				ERROR("OPEN_BRACE",
 				      "open brace '{' following function definitions go on the next line\n" . $herectx);
 			}
+
+# check for 'passed by value' uses of a struct or a union that might
+# be better 'passed by reference'
+
+			while ($args =~ /(?:$Storage\s+)?($Type)\s*($Ident(?:\s*\[\s*\])?)?\s*,?/g) {
+				my $type = trim($1);
+				my $ident = defined($2) ? trim($2) : "";
+				if ($type =~ /\b(?:union|struct)\b/ &&
+				    !($type =~ /(?:\*|\bconst|\])$/ ||
+				      $ident =~ /\]$/)) {
+					WARN("AGGREGATE_BY_VALUE",
+					     "Unusual 'passed by value' use of '$type'\n" . $herectx);
+				}
+			}
 		}
 
 # checks for new __setup's
_

Patches currently in -mm which might be from joe@xxxxxxxxxxx are