Re: GCC-3.0.4 (pre) on AIX requires pthreads

[Benjamin Kosnik <bkoz at redhat dot com>]

Loren I'm in favor of this patch. Do you have any feedback from HPUX or 
AIX people? 

-benjamin

> This patch fixes, in a general manner, the HPUX10 configuration bug
> recently uncovered by Jeff Law related to multilib'd libgcc
> construction when a multilib option affects the proper creation of
> (what had been known as) gthr-default.h .  The root issue was that
> gthr-default.h was built only once yet required a different contents
> for each multilib that impacted selection of the thread abstraction
> layer.  A related problem hasn't been reported yet but multilib'd
> libstdc++-v3 has a similar potential problem to that Jeff uncovered
> with libgcc and it is not solvable with the same technique used by
> Jeff since there is a race between which built copy of gthr-default.h
> would be installed.  Few ports are normally configured in this manner.
> As problems were found, they have been fixed in a manner useful for
> the port.  Now that we have about 7 months of experience with ``Thread
> model'' reporting, it is time to retune some things to bring port
> configurations closer together.
> 
> This patch has the pleasant side-effect of removing more dependencies
> between support library configuration and gcc itself (and I confess is
> something that I wanted to further cleanup for some time).
> 
> Bootstrapped and checked on i386-unknown-freebsd4.4,
> alphaev67-dec-osf5.1 (along with a simple patch to enable multilib
> keyed on -pthread for this platform), sparc-sun-solaris2.7.  Passed
> `make check' with no new regressions.  Manually inspected output from:
> ``./xgcc -B./ -E -dM - [-pthread] [-no-gcc] </dev/null'' to ensure
> that multilib'd platform with similar keying of thread abstraction now
> worked without an extra per-port hack.  After converting the
> alpha*-dec-osf5.1 port (--enable-thread=posix configuration) to use
> multilib and setting a proper THREAD_MODEL_SPEC along with this patch,
> I saw all non-fatal bootstrap warnings about missing pthread_* symbols
> and the requirement that all compiler runs provide -pthread to produce
> useful executables disappear.