麻烦大家看看这个cygwin的编译的c程序怎么有这些错误？

#include <X11/Xlib.h> // X11 library headers
#include <X11/Xutil.h>
#include <X11/Xos.h>
#define X_RESN 800 /* x resolution */
#define Y_RESN 800 /* y resolution */

#include <stdio.h>

int main (int argc, char **argv ) {

        /* --------------------------- X11 graphics setup ------------------------------ */
        Window win; /* initialization for a window */
    unsigned int width, height, /* window size */
        win_x,win_y, /* window position */
        border_width, /* border width in pixels */
        display_width, display_height, /* size of screen */
        screen; /* which screen */
    char *window_name = "My graphics program", *display_name = NULL;
    GC gc;
    unsigned long valuemask = 0;
    XGCValues values;
    Display *display;
    XSizeHints size_hints;
    Pixmap bitmap;
    XPoint points[800];
    FILE *fp, *fopen ();
    char str[100];

        XSetWindowAttributes attr[1];
    if ( (display = XOpenDisplay (display_name)) == NULL ) { /* connect to Xserver */
        fprintf (stderr, "drawon: cannot connect to X server %s\n",XDisplayName (display_name) );
        exit (-1);
    }
    screen = DefaultScreen (display); /* get screen size */
    display_width = DisplayWidth (display, screen);
    display_height = DisplayHeight (display, screen);
    width = X_RESN; /* set window size */
    height = Y_RESN;
    win_x = 0; win_y = 0; /* set window position */
    border_width = 4; /* create opaque window */
    win = XCreateSimpleWindow (display, RootWindow (display, screen),
        win_x, win_y, width, height, border_width,
        BlackPixel (display, screen), WhitePixel (display, screen));
    size_hints.flags = USPosition|USSize;
    size_hints.x = win_x;
    size_hints.y = win_y;
    size_hints.width = width;
    size_hints.height = height;
    size_hints.min_width = 300;
    size_hints.min_height = 300;
    XSetNormalHints (display, win, &size_hints);
    XStoreName(display, win, window_name);
    gc = XCreateGC (display, win, valuemask, &values); /* create graphics context */
    XSetBackground (display, gc, WhitePixel (display, screen));
    XSetForeground (display, gc, BlackPixel (display, screen));
    XSetLineAttributes (display, gc, 1, LineSolid, CapRound, JoinRound);
    attr[0].backing_store = Always;
    attr[0].backing_planes = 1;
    attr[0].backing_pixel = BlackPixel(display, screen);
    XChangeWindowAttributes(display, win, CWBackingStore | CWBackingPlanes | CWBackingPixel, attr);
    XMapWindow (display, win);
    XSync(display, 0);

}