gcc/testsuite/gcc.dg/pr85388-4.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 { i?86-*-linux* i?86-*-gnu* x86_64-*-linux* } } } */
   4 /* { dg-require-effective-target cet } */
   5 /* { dg-require-effective-target split_stack } */
   6 /* { dg-options "-fsplit-stack -fcf-protection" } */
   7
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/types.h>
  11 #include <sys/resource.h>
  12
  13 /* Use a noinline function to ensure that the buffer is not removed
  14    from the stack.  */
  15 static void use_buffer (char *buf, size_t) __attribute__ ((noinline));
  16 static void
  17 use_buffer (char *buf, size_t c)
  18 {
  19   size_t i;
  20
  21   for (i = 0; i < c; ++i)
  22     buf[i] = (char) i;
  23 }
  24
  25 /* Each recursive call uses 10 * i bytes.  We call it 1000 times,
  26    using a total of 5,000,000 bytes.  If -fsplit-stack is not working,
  27    that will overflow our stack limit.  */
  28
  29 static void
  30 down1 (int i)
  31 {
  32   char buf[10 * i];
  33
  34   if (i > 0)
  35     {
  36       use_buffer (buf, 10 * i);
  37       down1 (i - 1);
  38     }
  39 }
  40
  41 /* Same thing, using alloca.  */
  42
  43 static void
  44 down2 (int i)
  45 {
  46   char *buf = alloca (10 * i);
  47
  48   if (i > 0)
  49     {
  50       use_buffer (buf, 10 * i);
  51       down2 (i - 1);
  52     }
  53 }
  54
  55 int
  56 main (void)
  57 {
  58   struct rlimit r;
  59
  60   /* We set a stack limit because we are usually invoked via make, and
  61      make sets the stack limit to be as large as possible.  */
  62   r.rlim_cur = 8192 * 1024;
  63   r.rlim_max = 8192 * 1024;
  64   if (setrlimit (RLIMIT_STACK, &r) != 0)
  65     abort ();
  66   down1 (1000);
  67   down2 (1000);
  68   return 0;
  69 }