gcc/testsuite/gcc.dg/Wzero-length-array-bounds-2-novec.c

   1 /* Test to verify that -Wzero-length-bounds and not -Warray-bounds is
   2    issued for accesses to interior zero-length array members that are
   3    within the bounds of the enclosing struct.
   4    { dg-do compile }
   5    { dg-options "-O2 -Wall -fno-tree-vectorize" } */
   6
   7 void sink (void*);
   8
   9 struct A { int i; };
  10 struct B { int j; struct A a[0]; };
  11
  12 struct C
  13 {
  14   struct B b1;
  15   struct B b2;
  16 };
  17
  18 char cbuf1[1 * sizeof (struct C)];
  19 char cbuf2[2 * sizeof (struct C)] = { };
  20
  21 void test_C_global_buf (void)
  22 {
  23   struct C *p = (struct C*)&cbuf1;
  24
  25   p->b1.a[-1].i = 0;     // { dg-warning "\\\[-Warray-bounds" }
  26   p->b1.a[ 0].i = 0;     // { dg-warning "\\\[-Wzero-length-bounds" }
  27   p->b1.a[ 1].i = 0;     // { dg-warning "\\\[-Warray-bounds" }
  28   sink (p);
  29
  30   p->b2.a[ 0].i = 0;     // { dg-warning "\\\[-Warray-bounds" }
  31   p->b2.a[ 1].i = 0;     // { dg-warning "\\\[-Warray-bounds" }
  32   sink (p);
  33
  34   p = (struct C*)&cbuf2;
  35   p->b1.a[-1].i = 0;     // { dg-warning "\\\[-Warray-bounds" }
  36   p->b1.a[ 0].i = 0;     // { dg-warning "\\\[-Wzero-length-bounds" }
  37   p->b1.a[ 1].i = 0;     // { dg-warning "\\\[-Wzero-length-bounds" }
  38   sink (p);
  39
  40   p->b2.a[ 0].i = 0;
  41   p->b2.a[ 1].i = 0;
  42   p->b2.a[ 2].i = 0;     // { dg-warning "\\\[-Warray-bounds" }
  43   p->b2.a[ 3].i = 0;     // { dg-warning "\\\[-Warray-bounds" }
  44   sink (p);
  45 }