[PATCH 34/34] checkpatch: Warn about usage of __DATE__, __TIME__ and __TIMESTAMP__

Michal Marek
2011-04-05T14:59:41Z

The __TIME__ and __DATE__ macros are evil. Every C textbook mentions
them, but forgets to add the tiny detail that they make sure that your
code will never result in the same binary. __TIMESTAMP__ is a bit more
sane, but again produces noise as soon as you switch branches back and
forth, or apply a patch and revert it.

Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
---
scripts/checkpatch.pl | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4c0383d..dbcdf04 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2804,6 +2804,11 @@ sub process {
WARN("__func__ should be used instead of gcc specific __FUNCTION__\n" . $herecurr);
}

+# check for pointless usage of __TIME__ and friends
+ if ($line =~ /\b__(TIME|DATE|TIMESTAMP)__\b/) {
+ WARN("Usage of __$1__ should be avoided to keep the build deterministic\n" . $herecurr);
+ }
+
# check for semaphores initialized locked
if ($line =~ /^.\s*sema_init.+,\W?0\W?\)/) {
WARN("consider using a completion\n" . $herecurr);
--
1.7.4.1