1  int open(const char *, int mode);
       2  void close(int fd);
       3  int write (int fd, void *buf, int nbytes);
       4  int read (int fd, void *buf, int nbytes);
       5  
       6  #define O_RDONLY 0
       7  #define O_WRONLY 1
       8  #define O_RDWR 2
       9  #define O_ACCMODE 0x3
      10  
      11  void f (int fd) __attribute__((fd_arg(1))); /* { dg-message "argument 1 of 'f' must be an open file descriptor, due to '__attribute__\\(\\(fd_arg\\(1\\)\\)\\)'" } */
      12  
      13  void
      14  test_1 (const char *path)
      15  {
      16      int fd = open (path, O_RDWR);
      17      close(fd);
      18      f(fd); /* { dg-warning "'f' on closed file descriptor 'fd'" } */
      19        /* { dg-message "\\(3\\) 'f' on closed file descriptor 'fd'; 'close' was at \\(2\\)" "" { target *-*-* } .-1 } */
      20  }
      21  
      22  void g (int fd) __attribute__((fd_arg_read(1))); /* { dg-message "argument 1 of 'g' must be a readable file descriptor, due to '__attribute__\\(\\(fd_arg_read\\(1\\)\\)\\)'" } */
      23  
      24  void
      25  test_2 (const char *path)
      26  {
      27    int fd = open (path, O_WRONLY);
      28    if (fd != -1)
      29    {
      30      g (fd); /* { dg-warning "'g' on write-only file descriptor 'fd'" } */
      31    }
      32    close (fd);
      33  }
      34  
      35  void h (int fd) __attribute__((fd_arg_write(1))); /* { dg-message "argument 1 of 'h' must be a writable file descriptor, due to '__attribute__\\(\\(fd_arg_write\\(1\\)\\)\\)'" } */
      36  void
      37  test_3 (const char *path)
      38  {
      39    int fd = open (path, O_RDONLY);
      40    if (fd != -1)
      41    {
      42      h (fd); /* { dg-warning "'h' on read-only file descriptor 'fd'" } */
      43    }
      44    close(fd);
      45  }
      46  
      47  void ff (int fd) __attribute__((fd_arg(1))); /* { dg-message "argument 1 of 'ff' must be an open file descriptor, due to '__attribute__\\(\\(fd_arg\\(1\\)\\)\\)'" } */
      48  
      49  void test_4 (const char *path)
      50  {
      51    int fd = open (path, O_RDWR);
      52    ff (fd); /* { dg-warning "'ff' on possibly invalid file descriptor 'fd'" } */
      53    close(fd);
      54  }