On 12/01/2017 01:31 AM, Markus Armbruster wrote:
Eric Blake <ebl...@redhat.com> writes:
On 11/30/2017 08:01 AM, Eric Blake wrote:
while (0) is only idiomatic in a macro definition, where the caller
will be supplying the trailing ';'. Warn if the macro has a duplicate.
+# 'while (0);' is odd; only macros should use while (0), without trailing ;
+ if ($line =~ /while\s*\(0\);/) {
Should this also check for uses of 'while (false);' ?
Do we think it's likely to occur?
Not as frequent, but it does appear in the code base.
Interestingly enough, we have an instance of 'do/while (false);' in
tests/vhost-user-bridge.c that is NOT in a macro, but is used for the
convenience of being able to 'break;' out early rather than using a
goto. Similarly for chardev/char-serial.c using 'while (0);' outside
of a macro.
That "cure" merely adds gratuitous cleverness to the "disease".
Those may be worth rewriting to use goto as separate
patches if we want to restrict ALL use of 'while \((0|false)\);'
I'd support that.
Okay, I'll post a v2 along those lines.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
