1  /* PR middle-end/94195 - missing warning reading a smaller object via
       2     an lvalue of a larger type
       3     { dg-do compile }
       4     { dg-options "-O2 -Wall" }
       5     { dg-require-effective-target alloca } */
       6  
       7  typedef __INT16_TYPE__ int16_t;
       8  typedef __SIZE_TYPE__  size_t;
       9  
      10  void* alloca (size_t);
      11  
      12  void sink (void*);
      13  
      14  
      15  void byte_store_to_decl (void)
      16  {
      17    struct S6 { char a[6]; } s;   // { dg-message "at offset 6 into object 's' of size 6" "note" }
      18  
      19    char *p = (char*)&s;
      20  
      21    p[0] = 0; p[1] = 1; p[2] = 2; p[3] = 3; p[4] = 4; p[5] = 5;
      22    p[6] = 6;                     // { dg-warning "array subscript 6 is outside array bounds of 'struct S6\\\[1]" }
      23  
      24    sink (&s);
      25  }
      26  
      27  
      28  void word_store_to_decl (void)
      29  {
      30    struct S6 { char a[6]; } s;   // { dg-message "at offset 5 into object 's' of size 6" "note" }
      31  
      32    char *p = (char*)&s;
      33  
      34    int16_t *q = (int16_t*)(p + 1);
      35  
      36    q[0] = 0; q[1] = 1;
      37    q[2] = 2;                     // { dg-warning "array subscript 'int16_t {aka short int}\\\[2]' is partly outside array bounds of 'struct S6\\\[1]'" }
      38  
      39    sink (&s);
      40  }
      41  
      42  
      43  void word_store_to_alloc (void)
      44  {
      45    struct S6 { char a[6]; } *p;
      46    p = alloca (sizeof *p);       // { dg-message "at offset 5 into object of size 6 allocated by 'alloca'" "note" }
      47  
      48    int16_t *q = (int16_t*)((char*)p + 1);
      49  
      50    q[0] = 0; q[1] = 1;
      51    q[2] = 2;                     // { dg-warning "array subscript 'int16_t {aka short int}\\\[2]' is partly outside array bounds of 'unsigned char\\\[6]'" }
      52  
      53    sink (p);
      54  }