libstdc++ localization aborts with an exception

[Marian Asokarajan]

Hello,

if I try to instantiate the standard C++ class std::locale for locales
other than "C", it aborts with an exception in FreeBSD 7-R.

I suppose it has something to do with, how libstdc++ is build under fBSD.
There is an option for libstdc++ called
--enable-clocale[=MODEL]  use MODEL for target locale package [default=auto]

these MODELs are located in the base system source directory
/usr/src/contrib/libstdc++/config/locale/

And probably the "darwin" (or "generic") model is used, instead of "gnu"
(s.a. line 5801 in file /usr/src/contrib/libstdc++/configure).
If it is so, why doesn't the "gnu" model apply to FreeBSD ?

gcc -v reports:
Using built-in specs.
Target: i386-undermydesk-freebsd
Configured with: FreeBSD/i386 system compiler
Thread model: posix
gcc version 4.2.1 20070719  [FreeBSD]

on my FreeBSD 7.0-RELEASE system.
My $LANG is set to de_DE.UTF-8 (via login.conf).
locale -a|grep de_DE reports:
de_DE.ISO8859-1
de_DE.ISO8859-15
de_DE.UTF-8


Here's a C++ code you may want to try (compile with CC <filename.cc>).
It works well with "setenv LANG C", but fails if LANG=de_DE.UTF-8 (or any other) !
//---------------------------------------------------
#include <locale>
#include <iostream>
#include <clocale>

int main()
{
  using std::cout;
  using std::endl;

  // C L10n
  const char* const lstr = std::setlocale(LC_ALL, "");
  cout << "C setlocale()\nresult=";
  cout << ( lstr ? lstr : "0" ) << "\n" << endl;

  // C++ L10n
  cout << "C++ std::locale" << endl;
  std::locale loc("");
  cout << "std::locale loc=" << loc.name() << endl;
}
//---------------------------------------------------


Output (set $LANG to de_DE.UTF-8 and run with ./a.out):
-------------------------------------------------------------------
C setlocale()
result=de_DE.UTF-8

C++ std::locale
terminate called after throwing an instance of 'std::runtime_error'
   what():  locale::facet::_S_create_c_locale name not valid
Abort (core dumped)
-------------------------------------------------------------------


Thanks in advance for any ideas.


Marian