Re: Undefined reference

[Ulrich Weigand <weigand at immd1 dot informatik dot uni-erlangen dot de>]

Paolo Carlini wrote:

> Notice that there are no differences in the basic_string code itself 
> present in the various branches (3.2, 3.3 and 3.4) and the problem 
> appear at link time and only for dynamic linking, therefore probably 
> your guess is correct. Unfortunately I haven't made much progress yet in 
> trying to understand what is going wrong.
> 
> Do you have any hints?

Well, the symbol is indeed stripped out by the version script.
The mangled name is 

_ZNSbIwSt11char_traitsIwESaIwEE12_S_constructEmwRKS1_

but the version script (config/linker-map.gnu) only exports those:

    # std::string, std::wstring minus static data members
    _ZNKS[sb]*;
    _ZNS[sb]D*;
    _ZNS[sb]C*;
    _ZStplI[cw]St11char_traitsI[cw]ESaI[cw]EESbIT_T0_T1_EPKS3_RKS6_;
    _ZStplI[cw]St11char_traitsI[cw]ESaI[cw]EESbIT_T0_T1_ES3_RKS6_;
    _ZNS[sb]I[cw]St11char_traitsI[cw]ESaI[cw]EE[A-Ra-z]*;
    _ZNS[sb]I[cw]St11char_traitsI[cw]ESaI[cw]EE[0-9][A-Ra-z]*;
    _ZNS[sb]I[cw]St11char_traitsI[cw]ESaI[cw]EE[0-9][0-9][A-Ra-z]*;
    _ZNS[sb]I[cw]St11char_traitsI[cw]ESaI[cw]EE[0-9]_[A-Ra-z]*;
    _ZNS[sb]I[cw]St11char_traitsI[cw]ESaI[cw]EE[0-9][0-9]_[A-Ra-z]*;
    _ZNS[sb]I[cw]St11char_traitsI[cw]ESaI[cw]EE20_S_empty_rep_storageE;

Note that only names starting with _A ... _R (or small letters) are
exported, those starting with _S appear to be deliberately stripped
(with the exception of _S_empty_rep_storage).

Unfortunately I don't understand the reasons behind this, so I
cannot say whether this symbol should be added to the script,
or else the symbol should not have been used in the first place ...

Bye,
Ulrich


-- 
  Dr. Ulrich Weigand
  weigand at informatik dot uni-erlangen dot de