Targets using implicit extern "C"

[Ian Lance Taylor]

"Joseph S. Myers" <joseph@codesourcery.com> writes:

> In particular, I'm surprised at the Darwin configurations apparently
> not defining NO_IMPLICIT_EXTERN_C, and at most OpenBSD configurations
> not doing so (but alpha-openbsd gets it from alpha/alpha.h); VxWorks
> configurations are also inconsistent in this regard
> (powerpc-wrs-vxworks gets it from rs6000/sysv4.h).  If
> NO_IMPLICIT_EXTERN_C were defined in elfos.h that would massively
> reduce the number of targets which do not define it (and therefore the
> number needing changing to replace NO_IMPLICIT_EXTERN_C by an
> IMPLICIT_EXTERN_C macro with the opposite sense).

How would people feel about adding a configure option
--with-implicit-extern-c?  Then we could justifiably flip the default
for the generic *-elf, etc., targets.  In fact in general we could
then take the macro out of the tm.h files and into config.gcc, which
is probably a more reliable place to put it anyhow.

Ian