gcc/testsuite/gcc.dg/split-4.c

   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* *-*-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 }