1  /* This test needs to use setrlimit to set the stack size, so it can
       2     only run on Unix.  */
       3  /* { dg-do run { target *-*-linux* *-*-gnu* *-*-solaris* *-*-darwin* } } */
       4  /* { dg-require-effective-target split_stack } */
       5  /* { dg-options "-fsplit-stack" } */
       6  
       7  #include <stdlib.h>
       8  #include <string.h>
       9  #include <sys/types.h>
      10  #include <sys/resource.h>
      11  
      12  /* Use a noinline function to ensure that the buffer is not removed
      13     from the stack.  */
      14  static void use_buffer (char *buf, size_t) __attribute__ ((noinline));
      15  static void
      16  use_buffer (char *buf, size_t c)
      17  {
      18    size_t i;
      19  
      20    for (i = 0; i < c; ++i)
      21      buf[i] = (char) i;
      22  }
      23  
      24  /* Each recursive call uses 10 * i bytes.  We call it 1000 times,
      25     using a total of 5,000,000 bytes.  If -fsplit-stack is not working,
      26     that will overflow our stack limit.  */
      27  
      28  static void
      29  down1 (int i)
      30  {
      31    char buf[10 * i];
      32  
      33    if (i > 0)
      34      {
      35        use_buffer (buf, 10 * i);
      36        down1 (i - 1);
      37      }
      38  }
      39  
      40  /* Same thing, using alloca.  */
      41  
      42  static void
      43  down2 (int i)
      44  {
      45    char *buf = alloca (10 * i);
      46  
      47    if (i > 0)
      48      {
      49        use_buffer (buf, 10 * i);
      50        down2 (i - 1);
      51      }
      52  }
      53  
      54  int
      55  main (void)
      56  {
      57    struct rlimit r;
      58  
      59    /* We set a stack limit because we are usually invoked via make, and
      60       make sets the stack limit to be as large as possible.  */
      61    r.rlim_cur = 8192 * 1024;
      62    r.rlim_max = 8192 * 1024;
      63    if (setrlimit (RLIMIT_STACK, &r) != 0)
      64      abort ();
      65    down1 (1000);
      66    down2 (1000);
      67    return 0;
      68  }