g++: a bug or a feature ???

[Yzhar Keysar <yzhark at milk dot silicon-value dot com>]

Hi,

I have some linkage problems, probably relates to "6.4 Vague Linkage" 
section in the "Using GCC" document.

I'm working on a linux/Unix based project, where writing functors and 
using them  with the STL is a way of life.
when writing two fuctors ( or for simplicity : inline functions ) with 
the same prototype ( i.e. signature) but in different objects ,
I get no warning in compile time nor in linkage time. and runtime uses 
only ONE copy of them.

the problem is that in a large project, I could choose by mistake an 
already existed function prototype but have a different implementation.
thus using only one copy at runtime will be wrong. further more, using -O 
(optimization directive) inlines the corresponded function,
such that it calls to the correct function result in an inconsistency 
with non optimized objects.

I'm aware of the advantages of such feature ( as described for the weak 
(W) symbol ), but I really wish to have a warning of "duplicate 
declaration",
which I can turn off in case I wish it not.

I tried to turn of -fno-weak, but newly bigger problems have arisen from 
the depth. so I decided to stay with a quite well defined problem.



Example code:
-----------------------

//main.cc
#include <iostream>
#include "test.hh"

inline void g() { cerr<<"Main.g()\n" ; }

void main() {
    g();    // wish to activate g() in main.cc

    f();     // wish to activate g() in test.cc through f().
}
//--------end of main.cc

//test.cc
#include <iostream>
#include "test.hh"

inline void g() { cerr<<"Test.g()\n" ; }

void f() {
    g();    // wish to activate g() in test.cc
}
//--------end of test.cc

// test.hh

void f();
//--------end of test.hh


output:

Main.g()
Main.g()   *** WRONG ***




Working Environment
-------------------------------
compiler: g++_3.0.2 and g++_2.95.3
linker: GNU ld version 2.11.90.0.8 (with BFD 2.11.90.0.8)


thanx in advance
 -- 
Yzhar Keysar
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