1  /* PR middle-end/92815 - spurious -Wstringop-overflow writing into
       2     a flexible array of an extern struct
       3     { dg-do compile }
       4     { dg-options "-Wall -fdump-tree-optimized" }
       5     { dg-require-effective-target large_initializer } */
       6  
       7  #define PTRDIFF_MAX __PTRDIFF_MAX__
       8  
       9  typedef __SIZE_TYPE__ size_t;
      10  
      11  #define bos0(expr) __builtin_object_size (expr, 0)
      12  #define bos1(expr) __builtin_object_size (expr, 1)
      13  #define bos2(expr) __builtin_object_size (expr, 2)
      14  #define bos3(expr) __builtin_object_size (expr, 3)
      15  
      16  void fail (const char*, ...);
      17  
      18  #define A(x, n01, n23)							\
      19    ((bos0 (&x) == n01 ? (void)0 : fail (#x, __LINE__, bos0 (&x), n01)),	\
      20     (bos1 (&x) == n01 ? (void)0 : fail (#x, __LINE__, bos1 (&x), n01)),	\
      21     (bos2 (&x) == n23 ? (void)0 : fail (#x, __LINE__, bos2 (&x), n23)),	\
      22     (bos3 (&x) == n23 ? (void)0 : fail (#x, __LINE__, bos3 (&x), n23)))
      23  
      24  struct Ax_m3 { char a[PTRDIFF_MAX - 3], ax[]; };
      25  
      26  struct Ax_m3 xm3_0 = { { 0 } };
      27  struct Ax_m3 xm3_1 = { { 0 }, { 1 } };
      28  struct Ax_m3 xm3_2 = { { 0 }, { 1, 2 } };
      29  struct Ax_m3 xm3_3 = { { 0 }, { 1, 2, 3 } };
      30  struct Ax_m3 xm3_4 = { { 0 }, { 1, 2, 3, 3 } };   // { dg-error "too large" }
      31  
      32  void test_axm3 (void)
      33  {
      34    A (xm3_0, sizeof xm3_0, sizeof xm3_0);
      35    A (xm3_1, sizeof xm3_1 + 1, sizeof xm3_1 + 1);
      36    A (xm3_2, sizeof xm3_2 + 2, sizeof xm3_2 + 2);
      37    A (xm3_3, (size_t)-1, 0);   // expect failure
      38    A (xm3_4, (size_t)-1, 0);   // expect failure
      39  }
      40  
      41  
      42  struct Ax_mx { char a[PTRDIFF_MAX], ax[]; };
      43  struct Ax_mx xmx_0 = { { 0 } };
      44  struct Ax_mx xmx_1 = { { 0 }, { 1 } };            // { dg-error "too large" }
      45  extern struct Ax_mx xmx_x;
      46  
      47  void test_axmx (void)
      48  {
      49    A (xmx_0, (size_t)-1, 0);   // expect failure
      50    A (xmx_1, (size_t)-1, 0);   // expect failure
      51    A (xmx_x, (size_t)-1, 0);   // expect failure
      52  }