Re: PR c/43288 (ICE with __attribute__ ((common)))

[Steve Ellcey <sje at cup dot hp dot com>]

On Thu, 2010-03-11 at 16:54 -0500, John David Anglin wrote:
> > I think I have a var decl that is weak and common because that is
> > how HPPA is doing comdats in SOM.   Dave can correct me if I have
> > that wrong.
> 
> See define for MAKE_DECL_ONE_ONLY in som.h.  We don't set both
> DECL_COMMON and DECL_WEAK.  Some other code must be setting
> DECL_COMMON or DECL_WEAK to cause the error (or maybe MAKE_DECL_ONE_ONLY
> is used twice, once before DECL_INITIAL is set).
> 
> Dave

Yes, MAKE_DECL_ONE_ONLY is called twice because make_decl_one_only is
called twice.  The first call seems to happen before we have an
initializer and the second one after.  We could workaround this by
setting DECL_COMMON to 0 when setting DECL_WEAK to 1 (and visa versa) in
MAKE_DECL_ONE_ONLY but I think that is just a workaround for the real
problem.  The problem seems to only happen when using the
"__fundamental_type_info" class.  If I change the name of this class to
something generic like "foo" then I don't get the bug.

Steve Ellcey
sje@cup.hp.com


$ cat a.C                       
class t { virtual ~t(); };
namespace  __cxxabiv1 {
class __fundamental_type_info : public t {};
}

$ obj_gcc/gcc/cc1plus -quiet a.C
a.C:4:1: internal compiler error: in make_decl_rtl, at varasm.c:1447
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

$ cat b.C                       
class t { virtual ~t(); };
namespace  __cxxabiv1 {
class foo : public t {};
}

$ obj_gcc/gcc/cc1plus -quiet b.C