dwarf2out suspicious code

[Nathan Sidwell]

Honza, Ricard,

I fell over this assert in dwarf2out.c, but the later comment says it 
can happen??  does a checking build fail on LTO?

static inline void
add_AT_die_ref (dw_die_ref die, enum dwarf_attribute attr_kind, 
dw_die_ref targ_die)
{
  dw_attr_node attr;
  gcc_checking_assert (targ_die != NULL);

  /* With LTO we can end up trying to reference something we didn't create
     a DIE for.  Avoid crashing later on a NULL referenced DIE.  */
  if (targ_die == NULL)
    return;

nathan
--
Nathan Sidwell