This is the mail archive of the cygwin mailing list for the Cygwin project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Building DLL's using g++, not gcc


I've been trying to build a DLL using g++, and given the problems I was 
having, I decided to try a 'toy' example, which is available at:
	http://cygwin.com/cygwin-ug-net/dll.html
I tweaked the two files around thusly:


hello.C:
-----
#include <stdio.h>
int hello() { printf("Hello World\n");}
-----

main.C:
-----
#include <stdio.h>
typedef void (*fn_type)();

extern "C" {
  int dlopen(char*);
  int dlsym( int, char*);
}

int main() {
  int handle = 0;
  fn_type fn = 0;
  if ((handle = dlopen( "hello.dll")) == 0) {
    printf( "Cannot open hello.dll\n");
  }
  if ((fn = (fn_type) dlsym( handle, "hello")) == 0) {
    printf( "Cannot open hello()\n");
  }
  fn();
}
-----

This way, hello.C is a valid C or C++ application, and main.C is a
valid C++ application. I build main.exe by:

	g++ -o main main.C

If I build hello.dll this way, it works:

	gcc -shared -o hello.dll hello.C
	./main
	Hello world!

But if I build hello.dll this way, it doesn't work:

	g++ -shared -o hello.dll hello.C
	./main
	bash: [2084: 2] testaddr: Inappropriate ioctl for device

Why? What am I doing wrong?

~David Svoboda


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]