checkpatch: add check for sscanf without return use

Naked use sscanf can be troublesome because the pointed to variables may
not have been set.

Add a warning when the sscanf return value is not used.

For now, do not add __must_check to the sscanf prototype because that will
cause a couple of hundred new warnings when compiling a kernel.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joe Perches 2013-11-12 15:10:15 -08:00 committed by Linus Torvalds
parent 2b7ab45395
commit 823b794ce1

View File

@ -4019,6 +4019,23 @@ sub process {
}
}
# check for naked sscanf
if ($^V && $^V ge 5.10.0 &&
defined $stat &&
$stat =~ /\bsscanf\b/ &&
($stat !~ /$Ident\s*=\s*sscanf\s*$balanced_parens/ &&
$stat !~ /\bsscanf\s*$balanced_parens\s*(?:$Compare)/ &&
$stat !~ /(?:$Compare)\s*\bsscanf\s*$balanced_parens/)) {
my $lc = $stat =~ tr@\n@@;
$lc = $lc + $linenr;
my $stat_real = raw_line($linenr, 0);
for (my $count = $linenr + 1; $count <= $lc; $count++) {
$stat_real = $stat_real . "\n" . raw_line($count, 0);
}
WARN("NAKED_SSCANF",
"unchecked sscanf return value\n" . "$here\n$stat_real\n");
}
# check for new externs in .h files.
if ($realfile =~ /\.h$/ &&
$line =~ /^\+\s*(extern\s+)$Type\s*$Ident\s*\(/s) {