gcc/testsuite/gcc.dg/Wvla-larger-than-2.c

   1 /* { dg-do compile } */
   2 /* { dg-require-effective-target stdint_types } */
   3 /* { dg-require-effective-target alloca } */
   4 /* { dg-options "-O2 -Wvla-larger-than=40" } */
   5
   6 #include <stdint.h>
   7
   8 void f0 (void *);
   9 void
  10 f1 (__SIZE_TYPE__ a)
  11 {
  12   if (a <= 10)
  13     {
  14       // 10 * 4 bytes = 40: OK!
  15       uint32_t x[a];
  16       f0 (x);
  17     }
  18 }
  19
  20 void
  21 f2 (__SIZE_TYPE__ a)
  22 {
  23   if (a <= 11)
  24     {
  25       // 11 * 4 bytes = 44: Not OK.
  26       uint32_t x[a]; // { dg-warning "array may be too large" }
  27       f0 (x);
  28     }
  29 }
  30
  31 void
  32 f3 (__SIZE_TYPE__ a, __SIZE_TYPE__ b)
  33 {
  34   if (a <= 5 && b <= 3)
  35     {
  36       // 5 * 3 * 4 bytes = 60: Not OK.
  37       uint32_t x[a][b]; // { dg-warning "array may be too large" }
  38       f0 (x);
  39     }
  40 }
  41
  42 void
  43 f4 (__SIZE_TYPE__ a, __SIZE_TYPE__ b)
  44 {
  45   if (a <= 5 && b <= 2)
  46     {
  47       // 5 * 2 * 4 bytes = 40 bytes: OK!
  48       uint32_t x[a][b];
  49       f0 (x);
  50     }
  51 }
  52
  53 void
  54 f5 (__SIZE_TYPE__ len)
  55 {
  56   // Test that a direct call to __builtin_alloca_with_align is not
  57   // confused with a VLA.
  58   void *p = __builtin_alloca_with_align (len, 8);
  59   f0 (p);
  60 }
  61
  62 void
  63 f6 (unsigned stuff)
  64 {
  65   int n = 7000;
  66   do {
  67     char a[n]; // { dg-warning "variable-length array is too large" }
  68     f0 (a);
  69   } while (stuff--);
  70 }