According to the coding style document, we should use literal '0x' prefix
instead of printf's '#' flag (which appears as '%#' or '%0#' in the format
string). Add a checkpatch rule to enforce that.
Note that checkpatch already had a similar rule for trace-events files.
Example usage:
$ scripts/checkpatch.pl --file chardev/baum.c
...
ERROR: Don't use '#' flag of printf format ('%#') in format strings, use
'0x' prefix instead
#366: FILE: chardev/baum.c:366:
+ DPRINTF("Broken packet %#2x, tossing\n", req); \
...
ERROR: Don't use '#' flag of printf format ('%#') in format strings, use
'0x' prefix instead
#472: FILE: chardev/baum.c:472:
+ DPRINTF("unrecognized request %0#2x\n", req);
...
Signed-off-by: Dov Murik <dovmurik@linux.vnet.ibm.com>
---
scripts/checkpatch.pl | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index bd3faa154c..6ec2a9f6a1 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2891,6 +2891,18 @@ sub process {
}
}
+# check for %# or %0# in printf-style format strings
+ while ($line =~ /(?:^|")([X\t]*)(?:"|$)/g) {
+ my $string = substr($rawline, $-[1], $+[1] - $-[1]);
+ $string =~ s/%%/__/g;
+ if ($string =~ /(?<!%)%0?#/) {
+ ERROR("Don't use '#' flag of printf format " .
+ "('%#') in format strings, use '0x' " .
+ "prefix instead\n" . $herecurr);
+ last;
+ }
+ }
+
# QEMU specific tests
if ($rawline =~ /\b(?:Qemu|QEmu)\b/) {
ERROR("use QEMU instead of Qemu or QEmu\n" . $herecurr);