checkpatch: Detect '%#' or '%0#' in printf-style format strings
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>
Message-Id: <20200914172623.72955-1-dovmurik@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index ca4445f..6ed3497 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2880,14 +2880,20 @@
$herecurr);
}
-# check for %L{u,d,i} in strings
+# format strings checks
my $string;
while ($line =~ /(?:^|")([X\t]*)(?:"|$)/g) {
$string = substr($rawline, $-[1], $+[1] - $-[1]);
$string =~ s/%%/__/g;
+ # check for %L{u,d,i} in strings
if ($string =~ /(?<!%)%L[udi]/) {
ERROR("\%Ld/%Lu are not-standard C, use %lld/%llu\n" . $herecurr);
- last;
+ }
+ # check for %# or %0# in printf-style format strings
+ if ($string =~ /(?<!%)%0?#/) {
+ ERROR("Don't use '#' flag of printf format " .
+ "('%#') in format strings, use '0x' " .
+ "prefix instead\n" . $herecurr);
}
}
