Re: Problems building shared libraries under Irix6

[Jeffrey A Law <law at cygnus dot com>]

  In message <199712161724.JAA25082@Canada.AI.SRI.COM>you write:
  > 
  > All of the discussion wrt. __register_frame under Linux (mostly on
  > gcc2 with spillover here) begs an important question: why is libgcc.a
  > linked in when building shared libraries?  Under Irix 6.x, this
  > inclusion on the link line seems to break shared libraries
  > completely.  They can no longer be linked against since
  > __register_frame was included.
The shared library needs to be self-contained as far as functions for
internal use are concerned.

Consider __muldi3 for 64bit multiplies.

If you build a dynamic library which uses 64bit multiply, but do not link
in libgcc to the library, then the library will have a reference, but no
definition of __muldi3.

If you later load that library into a program via shl_load/dl_open and the
program does not have __muldi3 defined (because the main program never used
64bit multiplies), then you lose.

The __register_frame stuff is needed to make sure that unwinding
information for the shared library is registered so that you can throw
through a shared library.

Jim has a patch to move __register_frame and friends elsewhere so that
they don't cause multiple symbol definitions.  Assuming he thinks the patch
is correct, he should apply it so this problem goes away.

jeff