Re: Thread support for HPUX 11 (pa, ia64)

[law at redhat dot com]

In message <87fzjvwyq2.fsf@codesourcery.com>, "Zack Weinberg" writes:
 >--=-=-=
 >
 >
 >These patches make --enable-threads work with HPUX 11.
 >
 >HP-UX 11, in contrast to 10 and previous versions, has a full
 >implementation of POSIX threads.  It still supports DCE threads but it
 >seems silly to use them except for backward compatibility purposes.
 >Accordingly, I've disabled --enable-threads=dce for these targets;
 >it's posix or nothing.  (This allows much simplification of LIB_SPEC.)
 >
 >All versions of HPUX, whether for the PA or the IA64, have an
 >ingrained bug in the linker and dynamic loader, which makes weak
 >external references useless.  This makes it necessary to set
 >GTHREAD_USE_WEAK to 0 in both the gcc and libstdc++ configuration, or
 >you get link errors for all programs using libstdc++.  This was
 >already being done for pa32 hpux (SOM-based); the patch enables it for
 >pa64 and ia64 (allegedly ELF-based).
 >
 >These have been bootstrapped on hppa2.0w-hp-hpux11.11 and
 >ia64-hp-hpux11.23, with --enable-threads=posix.  I get no
 >regressions relative to --disable-threads.
 >
 >I am including patches for mainline and 3.3 (they are slightly
 >different).  This is a feature addition, not a regression fix, but it
 >should affect only HPUX systems and only when --enable-threads is
 >given, and for those targets it is not a risky change in my opinion.
 >John, I'd appreciate your opinion on whether this is a safe change for
 >the branch.
My only comment would be that you may want to go ahead and use 
weak external references when we're using gnu-ld -- at least if it's
reasonable to do so from an implementation standpoint.  We have gnu-ld
on the PA64 platform.

jeff