On Thursday 2010-02-11 10:56, Patrick McHardy wrote: >Alexey Dobriyan wrote: >> On Thu, Feb 11, 2010 at 11:27 AM, Patrick McHardy <kaber@xxxxxxxxx> wrote: >>> Alexey Dobriyan wrote: >>>>> -static inline int ebt_basic_match(struct ebt_entry *e, struct ethhdr *h, >>>>> - const struct net_device *in, const struct net_device *out) >>>>> +static inline int >>>>> +ebt_basic_match(const struct ebt_entry *e, const struct ethhdr *h, >>>>> + const struct net_device *in, const struct net_device *out) >>>> These const modifiers are pointless because compilers are smart enough >>>> to notice non-modifiability and generate the very same code in both cases. > >Yes, occasionally it has caught typos or other variable mixups for me. >It also documents that a variable is only supposed to be read. In this case it allows parameter and local variable reduction because I have proven, by means of const, that they would remain the same over the entire function. (Scheduled commit 3c58069510: http://dev.medozas.de/gitweb.cgi?p=linux;a=commit;h=3c58069510a498110240ceaff8c2a10c0d9b4460 - this will be in the next pull group.) >>>>> - struct ebt_entry *e = (struct ebt_entry *)chain->data; >>>>> + const struct ebt_entry *e = (struct ebt_entry *)chain->data; >>>> And such things are wrong (not second const). >>> What's wrong about this? >> >> Should it be (const struct ebt_entry *)? > >That's not necessary. Its just declaring the the memory should >not be modified through e. The const qualification happens >automatically. Conversion from T* to const T* is permitted and implicit across =. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
