gcc/testsuite/gcc.dg/Walloca-3.c

   1 /* { dg-do compile } */
   2 /* { dg-require-effective-target alloca } */
   3 /* { dg-options "-Walloca-larger-than=2000 -O2" } */
   4
   5 void f (void *);
   6
   7 __SIZE_TYPE__ LIMIT;
   8
   9 // Warn when there is an alloca bound, but it is an unknown bound.
  10
  11 void
  12 g1 (__SIZE_TYPE__ n)
  13 {
  14   void *p;
  15   if (n < LIMIT)
  16     p = __builtin_alloca (n); // { dg-warning "may be too large" }
  17   else
  18     p = __builtin_malloc (n);
  19   f (p);
  20 }
  21
  22 // Similar to the above, but do not get confused by the upcast.
  23
  24 unsigned short SHORT_LIMIT;
  25 void
  26 g2 (unsigned short n)
  27 {
  28   void *p;
  29   if (n < SHORT_LIMIT)
  30     p = __builtin_alloca (n); // { dg-warning "may be too large" }
  31   else
  32     p = __builtin_malloc (n);
  33   f (p);
  34 }