Daniel Jacobowitz - Re: Top-level libgcc question (IA64/Linux bootstrap failure) (original) (raw)

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• From: Daniel Jacobowitz
• To: Roger Sayle
• Cc: gcc-patches at gcc dot gnu dot org
• Date: Sat, 3 Feb 2007 17:32:15 -0500
• Subject: Re: Top-level libgcc question (IA64/Linux bootstrap failure)
• References: <9382.68.35.10.103.1170540585.squirrel@mail.eyesopen.com>

On Sat, Feb 03, 2007 at 03:09:45PM -0700, Roger Sayle wrote:

I'm trying to track down the cause of a bootstrap failure that I'm seeing on ia64-unknown-linux-gnu, that I think may have been caused either by the move of libgcc to the top-level or some recent libunwind changes.

The issue is that I'm on an older Linux distribution that doesn't provide a system libunwind, so libgcc builds a suitable libunwind.{a,so} itself. Unfortunately, the failure I'm seeing is during the build of libgcc_s.so.1.tmp that the linker fails with "cannot find -lunwind".

In theory, the problem should be reproduceable with the configure option --without-system-libunwind, but the failure mode is such that the linker will just silently continue to pick up the system /lib/libunwind.*.

I suspect the fix is that I just need to figure out where to stick a -L./ or specify ./libunwind.so or something during the libgcc.so link step.

Yes, I noticed this while experimenting with the recent profiledbootstrap bug, but I didn't change it then - I solved that another way and it didn't occur to me that libunwind was similar. What you want is probably "-B./" in addition to $(CFLAGS) in the two subst expressions for $(SHLIB_LINK).

which when necessary would create a dependency for libgcc_s.so on libunwind.so. However, in the current libgcc/Makefile.in, there appears to be no-way to get libgcc_s$(SHLIB_EXT) dependent upon libunwind$(SHLIB_EXT). Indeed my current failure is when attempting to build libgcc.so, which is done before building libunwind.so.

Try this pseudo-patch?

ifneq ($(LIBUNWIND),) all: libunwind$(SHLIB_EXT) +libgcc_s$(SHLIB_EXT): libunwind$(SHLIB_EXT) endif

-- Daniel Jacobowitz CodeSourcery

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