Re: [Mingw-users] entry point not found

[Greg C. <gch...@sb...>]

On 2010-10-28 13:24Z, Andrea Galeazzi wrote:
> Tor was right, I used g++ -e __Z12OmegaStartupv and it works. Now the 
> question is: do I to inspect the object file in order to know which 
> symbol must be specified to the -e linker option? It sounds me very 
> strange...

'__Z12OmegaStartupv' is a "mangled" name. C++ functions can be
overloaded, e.g.:
  void f();
  int f(char *);
The C++ compiler can figure out which one to call in any context,
but those two functions must have different names in the object
file--they can't both be called simply 'f'--so their signatures
are encoded into "mangled" names. All C++ compilers do this. And
they deliberately do it in mutually incompatible ways, for safety:
  http://www.mingw.org/wiki/MixingCompilers
Even different versions of the same compiler may treat mangling
differently.

In situations like yours, it would be easier and more robust to
have one simple name. That's why C++ provides 'extern "C"'. If
you write
  extern "C" void f();
then f()'s name will not be "mangled"--it will be the same name
that the compiler would use for this function:
  void f(void);
in a C program.

That name is '_f', prefixed with '_' because that's the normal
convention for C linkage, for all compilers on this platform.