egcs-970929: Missing symbols

[Kurt Garloff]

 Hi egcs-hackers,

 egcs-970929 (2.90.11) seems to swallow some code on my machine
 (ix86-linux, glibc-2.0.5c, binutils-2.8.1.0.11) when using template
 friend functions.

 Here is some code:

garloff@kg1:~/numerix/egcs $ cat test.cc
/* test.cc */
/* demonstrates egcs++ bug */
/* K.Garloff@ping.de 97/10/02 */

#include <iostream.h>

template <class T>
class cplx
{
 private: 
   T re, im;
   
 public:
   cplx ()  { re = 0; im = 0; };
   cplx (const T r)  { re = r; im = 0; }
   cplx (const T r, const T i)  { re = r; im = i; };
   cplx (const cplx& c)  { re = c.re; im = c.im; };
   ~cplx () {};
   
   friend T real (const cplx<T>& c);
   friend ostream& operator << (ostream&, const cplx<T>&);
};

template <class T>
T real (const cplx<T>& c)
{
   return c.re;
};

template <class T>
ostream& operator << (ostream& ost, const cplx<T>& c)
{
   ost << '(' << c.re;
   if (c.im < 0) return ost << " - i" << -c.im << ')';
   else return ost << " + i" << c.im << ')';
};
   
 
int main ()
{
   cplx<double> cd (2, -1.5);
   cout << real (cd) << '\n';
   cout << cd << endl;
}

garloff@kg1:~/numerix/egcs $ g++ -c test.cc -fno-exceptions

 compiles fine (the -fno-exceptions is just to keep a short symbol table),
 but:

garloff@kg1:~/numerix/egcs $ nm test.o |c++filt
00000000 W cplx<double>::~cplx(void)
         U __builtin_delete
         U ostream::operator<<(ostream &(*)(ostream &))
         U ostream::operator<<(char)
         U ostream::operator<<(double)
         U operator<<(ostream &, cplx<double> const &)
00000000 W cplx<double>::cplx(double, double)
         U cout
         U endl(ostream &)
00000000 t gcc2_compiled.
00000000 T main
         U real(cplx<double> const &)

 This will never link, because the two friend functions (operator << and
 real) are entirely missing. I first thought that it is a name
 (de)mangling bug, but I found (looking into assembly code), that it's not
 only the symbols that are wrong or missing but there is no code at all 
 for ostream& operator << (ostream&, const cplx<double>&) nor for 
 double real (const cplx<double>&).

 egcs-970917 (2.90.08) works well (2.90.10 as well, but it's not on this 
 machine):

garloff@kg1:~/numerix/egcs $ g++ -V egcs-2.90.08 -c test.cc -fno-exceptions
garloff@kg1:~/numerix/egcs $ nm test.o |c++filt
00000000 W cplx<double>::~cplx(void)
         U __builtin_delete
         U ostream::operator<<(char const *)
         U ostream::operator<<(ostream &(*)(ostream &))
         U ostream::operator<<(char)
         U ostream::operator<<(double)
00000000 W operator<<(ostream &, cplx<double> const &)
00000000 W cplx<double>::cplx(double, double)
         U cout
         U endl(ostream &)
00000000 t gcc2_compiled.
00000000 T main
00000000 W real(cplx<double> const &)

----------------------------------------------------------------------


Kurt Garloff, Dortmund 
<K.Garloff@ping.de>