Re: Curent 3.0 branch of gcc fails to configure on AIX

[David Edelsohn <dje at watson dot ibm dot com>]

Alexandre,

	Your 2001-04-26 libstdc++ patch to determine what threads package
to use has broken libstdc++-v3 configuration on AIX.

	GCC for AIX uses a fake thread model of "aix" for Objective C
which dynamically chooses POSIX or Single as necessary (gcc/gthr-aix.h).
libstdc++-v3 could not follow this approach.  AIX needs to multilib
pthreads support, so the information is determined for each multilib
configuration directory.  The determination of the threads package is
included in libstdc++-v3/configure.target.

	libstdc++-v3 configuration cannot understand the "aix" thread
model response from GCC and the single, uniform, non-multilib information
provided does not allow libstdc++-v3 to be configured properly for AIX on
a multilib directory-by-directory basis.

	Let's discuss how you want to expand your configuration changes to
accomodate AIX.  My suggestion is to continue to allow configure.target to
define this type of information and libstdc++-v3/configure should accept
that override information instead of using target_thread_file set by
inquiring GCC.  In other words, configure.target should set
target_thread_file, instead of enable_threads, and configure only should
inquire that value from GCC if it is not already set.  Alternatively, the
thread model response from GCC must be more intelligent for AIX by knowing
the commandline argument which affects pthread multilib status.

Thanks, David