Windows: preventing assert() failures from opening the debug popup

Question

How can I prevent the debug popup window from appearing when an assertion fails on a Windows machine? The app I'm writing is console based and I'm using assert() to test certain things when it's executed in test mode. I'm using MinGW + GCC 4.

Edit: This is the test program.

#include <stdlib.h>
#include <assert.h>

int main(void) {
    _set_error_mode(_OUT_TO_STDERR);
    assert(0 == 1);
    return EXIT_SUCCESS;
}

Flags: gcc -mwindows -pedantic -Wall -Wextra -c -g -Werror -MMD -MP -MF ...

Tried without -mwindows as well. I still get the debug popup no matter what. This is on a Vista x86 machine.

Answer 1

There are many ways you can do that. The crudest is to redefine the assert macro (see the mingw assert.h header). You can also call (which is what I would advise):

_set_error_mode (_OUT_TO_STDERR);

Edit: Really, it works for me:

#include <stdlib.h>
#include <assert.h>

int main (void)
{
  _set_error_mode (_OUT_TO_STDERR);
  assert (0 == 1);
  return 0;
}

Compile with gcc -mwindows, it doesn't show the dialog box at runtime. Remove the line with _set_error_mode, and it shows the dialog box. If it doesn't work for you, please give a complete example.