The patch titled
Subject: checkpatch: warn on self-assignments
has been added to the -mm tree. Its filename is
checkpatch-warn-on-self-assignments.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/checkpatch-warn-on-self-assignments.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/checkpatch-warn-on-self-assignments.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Joe Perches <joe@xxxxxxxxxxx>
Subject: checkpatch: warn on self-assignments
The uninitialized_var() macro was removed recently via commit 63a0895d960a
("compiler: Remove uninitialized_var() macro") as it's not a particularly
useful warning and its use can "paper over real bugs".
Add a checkpatch test to warn on self-assignments as a means to avoid
compiler warnings and as a back-door mechanism to reproduce the old
uninitialized_var macro behavior.
Link: https://lkml.kernel.org/r/afc2cffdd315d3e4394af149278df9e8af7f49f4.camel@xxxxxxxxxxx
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Cc: Denis Efremov <efremov@xxxxxxxxx>
Cc: Julia Lawall <julia.lawall@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
scripts/checkpatch.pl | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/scripts/checkpatch.pl~checkpatch-warn-on-self-assignments
+++ a/scripts/checkpatch.pl
@@ -3901,6 +3901,17 @@ sub process {
#ignore lines not being added
next if ($line =~ /^[^\+]/);
+# check for self assigments used to avoid compiler warnings
+# e.g.: int foo = foo, *bar = NULL;
+# struct foo bar = *(&(bar));
+ if ($line =~ /^\+\s*(?:$Declare)?([A-Za-z_][A-Za-z\d_]*)\s*=/) {
+ my $var = $1;
+ if ($line =~ /^\+\s*(?:$Declare)?$var\s*=\s*(?:$var|\*\s*\(?\s*&\s*\(?\s*$var\s*\)?\s*\)?)\s*[;,]/) {
+ WARN("SELF_ASSIGNMENT",
+ "Do not use self-assignments to avoid compiler warnings\n" . $herecurr);
+ }
+ }
+
# check for dereferences that span multiple lines
if ($prevline =~ /^\+.*$Lval\s*(?:\.|->)\s*$/ &&
$line =~ /^\+\s*(?!\#\s*(?!define\s+|if))\s*$Lval/) {
_
Patches currently in -mm which might be from joe@xxxxxxxxxxx are
checkpatch-test-git_dir-changes.patch
get_maintainer-add-test-for-file-in-vcs.patch
get_maintainer-exclude-maintainers-files-from-git-fallback.patch
checkpatch-move-repeated-word-test.patch
checkpatch-add-test-for-comma-use-that-should-be-semicolon.patch
checkpatch-warn-on-self-assignments.patch
