Crash with SBValue (core dumped)

[tetenpapier]

In some cases, SBValue contains an other struct in value. Example: SBFrame when I want to get the list of registers :

for r in target.process().selected_thread().selected_frame().registers().iter() {
     println!("SBValue : {:?}", r); // ok
     println!("SBValue name : {:?}", r.name()); // ok
     println!("SBValue value : {:?}", r.value()); // crash
}

I think it's due to return type (&str).

[waywardmonkeys]

Yes, this should probably be Option<&str> or even Option<String> ... if the SBValue doesn't have an associated underlying value, then the result of SBValue::GetValue will be nullptr:

const char *SBValue::GetValue() {
  LLDB_RECORD_METHOD_NO_ARGS(const char *, SBValue, GetValue);

  const char *cstr = nullptr;
  ValueLocker locker;
  lldb::ValueObjectSP value_sp(GetSP(locker));
  if (value_sp) {
    cstr = value_sp->GetValueAsCString();
  }

  return cstr;
}

On the Rust side, this is what it is doing now:

    pub fn value(&self) -> &str {
        unsafe {
            match CStr::from_ptr(sys::SBValueGetValue(self.raw)).to_str() {
                Ok(s) => s,
                _ => panic!("Invalid string?"),
            }
        }
    }

So that clearly should be handling the nullptr case there and returning an Option.

[tetenpapier]

Ok, I see. The value isn't set in ValueObjectRegisterSet. However, when I print a register set, I get something in value and I don't understand why. Is it because of pointer in C++ ?

SBValue : SBValue { General Purpose Registers = {                                                                                                                                                                                           
  rax = 0x0000000000000000                                                                                                                                                                                                                  
  rbx = 0x0000000000000000                                                                                                                                                                                                                  
  rcx = 0x0000000000000000                                                                                                                                                                                                                  
  rdx = 0x0000000000000000
//...
}

[tetenpapier]

Ok, I've understood where was my error. I've patched the crate and I'll make a PR with new bindings soon.