// run time version of pointerref intrinsic
DLLEXPORT jl_value_t *jl_pointerref(jl_value_t *p, jl_value_t *i)
{
JL_TYPECHK(pointerref, pointer, p);
JL_TYPECHK(pointerref, long, i);
jl_value_t *ety = jl_tparam0(jl_typeof(p));
if (ety == (jl_value_t*)jl_any_type) {
jl_value_t **pp = (jl_value_t**)(jl_unbox_long(p) + (jl_unbox_long(i)-1)*sizeof(void*));
return *pp;
}
else {
if (!jl_is_datatype(ety))
jl_error("pointerref: invalid pointer");
size_t nb = LLT_ALIGN(jl_datatype_size(ety), ((jl_datatype_t*)ety)->alignment);
char *pp = (char*)jl_unbox_long(p) + (jl_unbox_long(i)-1)*nb;
return jl_new_bits(ety, pp);
}
}
JL_DLLEXPORT jl_value_t *jl_get_nth_field_checked(jl_value_t *v, size_t i)
{
jl_datatype_t *st = (jl_datatype_t*)jl_typeof(v);
if (i >= jl_datatype_nfields(st))
jl_bounds_error_int(v, i + 1);
size_t offs = jl_field_offset(st, i);
if (jl_field_isptr(st, i)) {
jl_value_t *fval = *(jl_value_t**)((char*)v + offs);
if (fval == NULL)
jl_throw(jl_undefref_exception);
return fval;
}
jl_value_t *ty = jl_field_type(st, i);
if (jl_is_uniontype(ty)) {
size_t fsz = jl_field_size(st, i);
uint8_t sel = ((uint8_t*)v)[offs + fsz - 1];
ty = jl_nth_union_component(ty, sel);
if (jl_is_datatype_singleton((jl_datatype_t*)ty))
return ((jl_datatype_t*)ty)->instance;
}
return jl_new_bits(ty, (char*)v + offs);
}
