g++ unref symbols

[Petr Ovchenkov <ptr at ParaGraph dot Ru>]

Compiler specs (indeed problem exist on all gcc compilers since
2.95.2, don't now about earlier versions): 

c360> c++ -v
Reading specs from /usr/local/lib/gcc-lib/hppa2.0n-hp-hpux11.00/2.96/specs
gcc version 2.96 20000731 (experimental)
c360> uname -a
HP-UX c360 B.11.00 A 9000/785 2002760784 two-user license

(Sun's Solaris x86 has the same problem).

Breaf description:

g++ produce UNDEF reference for inlined class member functions,
if don't see all virtual (only virtual significant) member functions.

File x1.h:

// -- x1.h

class A
{
  public:
    A()
      { }

    virtual void qq();
};

// -- EOF x1.h

File main.cc:

// -- main.cc

#include "x1.h"

/*
void A::qq()
{
}
*/

A a;

// -- EOF main.cc

> c++ -c main.cc
> nm -C main.o
00000000 t $CODE$
         U $global$
00000000 T global constructors keyed to a
         U A::A(void)
00000000 t __static_initialization_and_destruction_0
40000000 D a
00000000 t gcc2_compiled.


We see, that A::A(void) 'UNDEFINED'. If we uncomment void A::qq()
in main.cc or remove word 'virtual' in x1.h, we will see 

00000000 t A::A(void)

LOCAL as expected.



Significance:

Lets suppose that x1.h is header from library, and void A::qq() body
exist in library. But when we compile some other (program's) module
(say, main.cc) we find unreferenced symbols on linkage step.


Sincerely yours,

          - Petr Ovchenkov