On Wed, Jul 22, 2009 at 02:30:55PM -0400, Laine Stump wrote:
On 07/22/2009 11:36 AM, Daniel P. Berrange wrote:
On Wed, Jul 22, 2009 at 11:25:38AM -0400, Laine Stump wrote:
On 07/22/2009 10:20 AM, Daniel Veillard wrote:
Agreed, patch applied, I only had to add _() to get the message localized,
I've idly wondered about that macro, as it causes scores of compile warnings, like this:
datatypes.c:291: warning: format not a string literal and no format arguments
What's it for? And what's the best way to change things to eliminate the warnings?
It is a potential security hole, if the user finds a way to send a string with an embeded format specifier. Thus if you're not doing any subsitutions, and the string isn't constant, then you should always at least do
char *therealstring = ...from somewhere untrusted... printf("%s", therealstring)
Yeah, I understand the perils of using a non-literal string as the format to *printf(). I'm wondering what the purpose of _() is, and why it causes the compiler to believe the string isn't a literal. (I received this warning when others don't because I use "-Wformat -Wformat-security" in my CFLAGS, at Jim's suggestion).
Hmm, everyone gets -Wformat -Wformat-security added by default if they run autogen.sh without the 'compile-warnings' flag. I'd say its more likely that you are building without gettext support, hence _() turns into a no-op, and thus lets the compiler identify these format problems more reliably.
NB, anyone sending patches should always set
--enable-compile-warnings=error
when running 'autogen.sh' and make sure all warnings & errors are fixed before submitting a patch.
It's actually because I like doing this that I'd like to know the preferred method of eliminating the warnings I mentioned. There are a bunch of them pre-existing in the code that I want to get rid of so I can turn on warnings=error (without turning off these warnings in CFLAGS), and I want to do it the "accepted" way. For example, from domain_conf.c:2137:
virDomainReportError(conn, VIR_ERR_XML_ERROR, _("invalid security type"));
spits out the warning. We all know that it really *is* literal, but the macro is changing the class so the compile thinks it isn't. It would be simple to just change it to:
virDomainReportError(conn, VIR_ERR_XML_ERROR, "%s", _("invalid security type"));
(and there are plenty of those too), but that's inefficient, and doesn't do the _() around the "%s" (is that correct or not?).
This is actually good, because it protects against a translator introduceing a '%' sequence in the non-english text either delibrately or accidentally. Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|