1  /* Verify that structure return doesn't invoke memcpy on 
       2     overlapping objects.  */
       3  
       4  extern void abort (void);
       5  extern int inside_main;
       6  typedef __SIZE_TYPE__ size_t;
       7  
       8  struct S {
       9    char stuff[1024];
      10  };
      11  
      12  union U {
      13    struct {
      14      int space;
      15      struct S s;
      16    } a;
      17    struct {
      18      struct S s;
      19      int space;
      20    } b;
      21  };
      22    
      23  struct S f(struct S *p)
      24  {
      25    return *p;
      26  }
      27  
      28  void g(union U *p)
      29  {
      30  }
      31  
      32  void *memcpy(void *a, const void *b, size_t len)
      33  {
      34    if (inside_main)
      35      {
      36        if (a < b && a+len > b)
      37          abort ();
      38        if (b < a && b+len > a)
      39          abort ();
      40        return a;
      41      }
      42    else
      43      {
      44        char *dst = (char *) a;
      45        const char *src = (const char *) b;
      46        while (len--)
      47          *dst++ = *src++;
      48        return a;
      49      }
      50  }