Hello all,
While hacking on gengtype with Basile, we noticed a strange piece of code at
line 2539 in gcc/gengtype.c r162692
static void
output_type_enum (outf_p of, type_p s)
{
if (s->kind == TYPE_PARAM_STRUCT && s->u.s.line.file != NULL) /* Strange code
@@*/
{
oprintf (of, ", gt_e_");
output_mangled_typename (of, s);
}
else if (UNION_OR_STRUCT_P (s) && s->u.s.line.file != NULL)
{
oprintf (of, ", gt_ggc_e_");
output_mangled_typename (of, s);
}
else
oprintf (of, ", gt_types_enum_last");
}
We think that the enum type_kind discriminates fields union in struct type. So
for TYPE_PARAM_STRUCT we believe that
the param_struct field of union u inside struct type is used. If this is true,
the test s->u.s.line.file != NULL is meaningless when s->kind ==
TYPE_PARAM_STRUCT, it should be s->u.param_struct.line.file != NULL instead in
our opinion.
However, the existing code appears to work but we don't understand why.
Or can a type have a kind TYPE_PARAM_STRUCT and only have s->u.s valid? It
might be related to the code in new_structure near line 638 of gengtype.c
which sets ls->kind = TYPE_LANG_STRUCT.
Perhaps TYPE_PARAM_STRUCT has two different roles. If that is indeed the case,
we have to distinguish them when serializing gengtype's state.
Cheers.
--
Jeremie Salvucci & Basile Starynkevitch
