unexpected hidden symbol in gcc 4.0.0

[Paul Koning]

>>>>> "Daniel" == Daniel Jacobowitz <drow@false.org> writes:

 Daniel> On Fri, May 13, 2005 at 05:33:21PM -0400, Paul Koning wrote:
 >> 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.

 Daniel> It sounds like you are building with --enable-shared and then
 Daniel> picking/choosing the libraries, but you haven't described how
 Daniel> you build, so I'm just guessing.

 Daniel> Normally in an --enable-shared build the copy in libgcc_eh.a
 Daniel> has hidden visibility, and can be included in built
 Daniel> libraries.  The copy in libgcc_s.so.1 is globally visible.

 Daniel> You are also misinterpreting the problem.  The hidden symbol
 Daniel> is not the problem; libstdc++ with an undefined reference to
 Daniel> _Unwind_GetIP, and no dependency on libgcc_s.so.1, is the
 Daniel> problem.

Ok, I can work on that.

The puzzle is that the build procedure is unchanged from gcc 3.3.3,
and with that version the application builds just fine.  It just drags
in unwind_dw2.o from libgcc.a and all is well.

   paul