Messages in this thread | | | Date | Wed, 12 May 2004 10:59:24 -0700 | From | Stephen Hemminger <> | Subject | GCC nested functions? |
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I used GCC nested functions in the (not released) bridge sysfs interface for 2.6.6. It seemed like a nice way to express the sysfs related interface without doing lots of code copying (or worse lots of macros).
The code in question looks like: static ssize_t store_bridge_parm(struct class_device *cd, const char *buf, size_t len, void (*store)(struct net_bridge *, unsigned long)) { struct net_bridge *br = to_bridge(cd); char *endp; unsigned long val; if (!capable(CAP_NET_ADMIN)) return -EPERM; val = simple_strtoul(buf, &endp, 0); if (endp == buf) return -EINVAL; spin_lock_bh(&br->lock); store(br, val); spin_unlock_bh(&br->lock); return len; } ...
static ssize_t store_forward_delay(struct class_device *cd, const char *buf, size_t len) { void store(struct net_bridge *br, unsigned long val) { unsigned long delay = clock_t_to_jiffies(val); br->forward_delay = delay; if (br_is_root_bridge(br)) br->bridge_forward_delay = delay; } return store_bridge_parm(cd, buf, len, store); }
This works fine for GCC 2.95 and 3.X for i386 and x86_64 architectures, but the ia64 (cross compiler) pukes with:
In function `store_forward_delay': : undefined reference to `__ia64_trampoline'
Redoing it as separate functions is easy enough, but the questions are: - Are gcc nested functions allowed in the kernel? If not where should this restriction be put in Documentation? CodingStyles? - Or is gcc on ia64 just too stupid? or do some more support routines need to exist in arch/ia64? - Do other architectures (sparc, ppc) have similar problems?
Thanks.
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