http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56243
--- Comment #7 from fabien at gcc dot gnu.org 2013-02-25 20:56:42 UTC ---
(In reply to comment #6)
> (In reply to comment #4)
[...]
> If so, this corrected test case still triggers ICE:
Good point. Further reduced:
struct A
{
virtual int String ();
};
class F: public A { };
struct G
{
F value;
};
class D
{
template <int>
void Verify()
{
G x;
F& name = x.value;
name.String();
}
};
I restarted the analysis from the beginning. My fix for c++/11750 was basically
to restrict the cases where the unsafe front-end de-virtualization was done. It
wouldn't help to refine that change because anyway, it would still be possible
to find a testcase that shows the same ICE.
My attempts to fix the problem on the constexpr side failed probably because it
is correct.
The problem is more related to the COMPONENT_REF 'G'. Probably because
D::Verify is not instantiated yet, the field 'value' of G is still an
IDENTIFIER_NODE instead of being a FIELD_DECL, which leads to a crash while
calling DECL_FIELD_IS_BASE.
Hence, I can only see two solutions:
1) make 'value' a FIELD_DECL before or during the
fold_non_dependent_expr_sfinae call. Not sure it is simple.
2) check that the first operand of a COMPONENT_REF is actually a FIELD_DECL
before calling DECL_FIELD_IS_BASE on it.
Upcoming patch for the solution 2 on gcc-patch...
