gcc/testsuite/gcc.dg/Wstringop-overflow-21.c

   1 /* PR middle-end/92312 - bogus -Wstringop-overflow storing into a trailing
   2    array backed by larger buffer
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall -Wno-array-bounds" } */
   5
   6 struct S0 { char a, b[0]; };
   7
   8 void sink (void*);
   9
  10 void test_memset_zero_length (void)
  11 {
  12   char a[3];
  13   struct S0 *p = (struct S0*)a;
  14   p->a = 0;
  15   __builtin_memset (p->b, 0, 2);
  16   sink (p);
  17
  18   __builtin_memset (p->b, 0, 3);    // { dg-warning "\\\[-Wstringop-overflow" }
  19   sink (p);
  20 }
  21
  22 void test_store_zero_length (int i)
  23 {
  24   char a[3];
  25   struct S0 *p = (struct S0*)a;
  26   p->a = 0;                         // { dg-warning "\\\[-Wstringop-overflow" "pr102706" { target { vect_slp_v4qi_store_align } } }
  27   p->b[0] = 0;
  28   p->b[1] = 1;                      // { dg-bogus "\\\[-Wstringop-overflow" }
  29   p->b[2] = 2;                      // { dg-warning "\\\[-Wstringop-overflow" "pr102706" { xfail { vect_slp_v4qi_store_align } } }
  30   p->b[i] = 2;
  31   sink (p);
  32 }
  33
  34
  35 struct Sx { char a, b[]; };
  36
  37 void test_memset_flexarray (int i)
  38 {
  39   char a[3];
  40   struct Sx *p = (struct Sx*)a;
  41   p->a = 0;
  42   __builtin_memset (p->b, 0, 2);
  43   sink (p);
  44
  45   __builtin_memset (p->b, 0, 3);    // { dg-warning "\\\[-Wstringop-overflow" }
  46   sink (p);
  47 }
  48
  49 void test_store_flexarray (int i)
  50 {
  51   char a[3];
  52   struct Sx *p = (struct Sx*)a;
  53   p->a = 0;                         // { dg-warning "\\\[-Wstringop-overflow" "pr102706" { target { vect_slp_v4qi_store_align } } }
  54   p->b[0] = 0;
  55   p->b[1] = 1;                      // { dg-bogus "\\\[-Wstringop-overflow" }
  56   p->b[2] = 1;                      // { dg-warning "\\\[-Wstringop-overflow" "pr102706" { xfail { vect_slp_v4qi_store_align } } }
  57   p->b[i] = 2;
  58   sink (p);
  59 }