unexpected hidden symbol in gcc 4.0.0

[Paul Koning <pkoning at equallogic dot com>]

I ran into link errors complaining about references to hidden symbol
_Unwind_GetIP from a DSO.

It turns out unwind-dw2.c is compiled with -fvisibility=hidden for the
static library case (but not for the shared library case).

In my link, I was using the libgcc.a (for that particular platform I
don't use libgcc.so).  So the linker complained.

The documentation for -fvisibility=hidden suggets that this switch is
useful for shared libraries, to make things smaller and faster.  It
doesn't seem to be appropriate for object libraries. 

I suppose I can override the "hidden" attribute for that one symbol,
or change Makefiles so that switch isn't put there, but I'm wondering
why this change and why the mismatch between usage and documentation.

    paul