Template function is not found in object file after compiling with gcc 4.1.2‏

[Jian-ping Hui <jphui@xxxxxxxxxx>]

Hi Folks,
 
I ran into a problem while building an old project with gcc 4.1.2. In object
file, I could not find the expected symbol for template function. Here is an
example program:
========
test.hpp
========
class T
{
public:
        T()
        {};
        ~T()
        {};
};
template <class MyT>
class test
{
public:
        int ftest();
};
 
========
test.cpp
========
#include <test.hpp>

template class test<T>;
template <class MyT>
int
test<MyT>::ftest()
{
        return 0;
}
 
I ran the command
    gcc  -c -I.  -o test.o test.cpp
to compile test.cpp. In the object file "test.o", I could not find the
symbol name "ftest" if I compiled test.cpp with gcc 4.1.2.
> gcc -v
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
--disable-dssi --enable-plugin
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic
--host=x86_64-redhat-linux
Thread model: posix
gcc version 4.1.2 20080704 (Red Hat 4.1.2-44)
> gcc  -c -I.  -W -Wall -Wextra -o test.o test.cpp
> nm test.o
   <Nothing listed here>
 
If we compiled test.cpp with gcc 3.4.6, we could see the symbols as
expected:
> gcc -v
Reading specs from /usr/lib/gcc/x86_64-redhat-linux/3.4.6/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--disable-checking --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-java-awt=gtk
--host=x86_64-redhat-linux
Thread model: posix
gcc version 3.4.6 20060404 (Red Hat 3.4.6-3)
> gcc  -c -I.  -W -Wall -Wextra -o test.o test.cpp
> nm test.o
                 U __gxx_personality_v0
0000000000000000 W _ZN4testI1TE5ftestEv
We can see the function "ftest" is defined in this object file.
 
This problem has troubled me for a few days. Could you please give some
helps to help me understand why the symbols "ftest" cannot be found if we
compiled test.cpp with gcc 4.1.2? Are there any available options to work
around this? Thanks for all your kindly helps in advance.
 
Thanks again.
 
Best Regards
Jian-ping 

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