Cygwin: sys/termios.h: define struct winsize before using it

Long-standing bug in the sys/termios.h file which, for some reason,
has never been encountered before.

STC:

  #include <sys/termios.h>

  int main()
  {
    struct winsize win;
    tcgetwinsize (0, &win);
  }

Result with gcc 12.4.0:

  termios-bug.c: In function ‘main’:
  termios-bug.c:7:20: warning: passing argument 2 of ‘tcgetwinsize’ from incompatible pointer type [-Wincompatible-pointer-types]
      7 |   tcgetwinsize (0, &win);
	|                    ^~~~
	|                    |
	|                    struct winsize *
  In file included from termios-bug.c:1:
  /usr/include/sys/termios.h:304:42: note: expected ‘struct winsize *’ but argument is of type ‘struct winsize *’
    304 | int tcgetwinsize(int fd, struct winsize *winsz);
	|                          ~~~~~~~~~~~~~~~~^~~~~

This warning apparently becomes an error with C23.

The reason is that struct winsize is defined in sys/termios.h after
using it as argument type in function declarations.  From the compil;er
perspective it's now a different type , regardless of having the same
name.

Move declaration of struct winsize up so it's defined before being used.

Reported-by: Zachary Santer <zsanter@gmail.com>
Suggested-by: Zachary Santer <zsanter@gmail.com>
Addresses: https://cygwin.com/pipermail/cygwin/2025-July/258474.html
Fixes: 1fd5e000ace55 ("import winsup-2000-02-17 snapshot")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

0 files changed, 0 insertions, 0 deletions