http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46596
--- Comment #5 from Jan Hubicka <hubicka at ucw dot cz> 2012-02-29 15:07:18 UTC --- > glibc runs into the "sorry, unimplemented" part of the issue, with > delta-reduced code like: > > $ cat test.i > typedef __builtin_va_list __gnuc_va_list; > extern __inline __attribute__ ((__always_inline__)) __attribute__ > ((__artificial__)) void syslog (int __pri, const char *__fmt, ...) { > }; > typedef __gnuc_va_list va_list; > void __syslog(int pri, const char *fmt, ...) { > } > extern __typeof (__syslog) syslog __attribute__ ((alias ("__syslog"))); The problem here seems to be that typeof copies always inline attribute. GCC before version 4.7 do not see through aliases and thus it has always inline function that is alias but it can not see the body. So the message is correct. GCC 4.7 newly understands alaises, but this was major change of the internal representation and can not be backported. For older GCC, i think only workaround is to call __syslog instead of syslog or drop the idea of using always iline here. Extern inlines will be inlined anyway. Honza