[Bug c/46596] misbehavior when mixing always_inline and alias attributes in the same compilation unit

["hubicka at ucw dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

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