Re: [Mingw-users] Symbols

[Mark J. <mj...@gm...>]

"ernesto basc��������������������������������" schrieb:

>I wrote this post several days ago but I did not get any reply. I hope to 
>get some tips about my problem now. Thanks!
>
>I created this very small program:
>  
>
[..]

>I compiled it using:
>
>g++ -c main.cpp -DDLL
>ar -r main.a main.o
>g++ -shared -o main.dll main.a -Wl,-output-def,main.def
>
>and it does not export any symbols, but doing a:
>
>g++ -shared -o main.dll main.o -Wl,-output-def,main.def
>
>publishes everything perfectly.
>
>Any ideas?
>  
>
I guess it's a problem similar to another one I've found. My assumption 
is that every module stored in a library will only become part of the 
output when it's accessed directly from an object.

The problem I had seems to be similar:

Every static constructor at global scope stored in an archive will not 
be linked into the output. Example:

a.cpp:
#include <stdio.h>
class PrintMeBeforeMain {
public:
  PrintMeBeforeMain(void) {
    printf("This comes from 'PrintMeBeforeMain'\n");
  }
};
static PrintMeBeforeMain print_me_before_main;

main.cpp
#include <stdio.h>

int main(int argc, char **argv)
{
  printf("This output comes from the 'main' function\n");
  return 0;
}

g++ -o a.o a.cpp
ar ru libtest.a a.o
g++ -o test_app.exe main.cpp -L. -ltest
./test_app

Output:
This output comes from the 'main' function

This is really annoying. It doesn't help if you specify the libtest.a 
directly after main.cpp. Maybe s/o knows a work-around?

Regards,
Mark