static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
{
Dwarf_Die die_mem;
int ret;
pr_debug("Converting variable %s into trace event.\n",
dwarf_diename(vr_die));
ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
pf->tvar);
if (ret == -ENOENT)
pr_err("Failed to find the location of %s at this address.\n"
" Perhaps, it has been optimized out.\n", pf->pvar->var);
else if (ret == -ENOTSUP)
pr_err("Sorry, we don't support this variable location yet.\n");
else if (pf->pvar->field) {
ret = convert_variable_fields(vr_die, pf->pvar->var,
pf->pvar->field, &pf->tvar->ref,
&die_mem);
vr_die = &die_mem;
}
if (ret == 0)
ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
return ret;
}
/* Show a variables in kprobe event format */
static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
{
Dwarf_Attribute attr;
Dwarf_Die die_mem;
Dwarf_Op *expr;
size_t nexpr;
int ret;
if (dwarf_attr(vr_die, DW_AT_location, &attr) == NULL)
goto error;
/* TODO: handle more than 1 exprs */
ret = dwarf_getlocation_addr(&attr, pf->addr, &expr, &nexpr, 1);
if (ret <= 0 || nexpr == 0)
goto error;
ret = convert_location(expr, pf);
if (ret == 0 && pf->pvar->field) {
ret = convert_variable_fields(vr_die, pf->pvar->var,
pf->pvar->field, &pf->tvar->ref,
&die_mem);
vr_die = &die_mem;
}
if (ret == 0) {
if (pf->pvar->type) {
pf->tvar->type = strdup(pf->pvar->type);
if (pf->tvar->type == NULL)
ret = -ENOMEM;
} else
ret = convert_variable_type(vr_die, pf->tvar);
}
/* *expr will be cached in libdw. Don't free it. */
return ret;
error:
/* TODO: Support const_value */
pr_err("Failed to find the location of %s at this address.\n"
" Perhaps, it has been optimized out.\n", pf->pvar->var);
return -ENOENT;
}
