modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/20010910-1.c (about)

     1  /* Test case contributed by Ingo Rohloff <rohloff@in.tum.de>.
     2     Code distilled from Linux kernel.  */
     3  
     4  /* Compile this program with a gcc-2.95.2 using
     5     "gcc -O2" and run it. The result will be that
     6     rx_ring[1].next == 0   (it should be == 14)
     7     and
     8     ep.skbuff[4] == 5      (it should be 0)
     9  */
    10  
    11  extern void abort(void);
    12  
    13  struct epic_rx_desc 
    14  {
    15    unsigned int next;
    16  };
    17  
    18  struct epic_private 
    19  {
    20    struct epic_rx_desc *rx_ring;
    21    unsigned int rx_skbuff[5];
    22  };
    23  
    24  static void epic_init_ring(struct epic_private *ep)
    25  {
    26    int i;
    27  
    28    for (i = 0; i < 5; i++) 
    29    {
    30      ep->rx_ring[i].next = 10 + (i+1)*2;
    31      ep->rx_skbuff[i] = 0;
    32    }
    33    ep->rx_ring[i-1].next = 10;
    34  }
    35  
    36  static int check_rx_ring[5] = { 12,14,16,18,10 };
    37  
    38  int main(void)
    39  {
    40    struct epic_private ep;
    41    struct epic_rx_desc rx_ring[5];
    42    int i;
    43  
    44    for (i=0;i<5;i++)
    45    {
    46      rx_ring[i].next=0;
    47      ep.rx_skbuff[i]=5;
    48    }
    49    
    50    ep.rx_ring=rx_ring;
    51    epic_init_ring(&ep);
    52    
    53    for (i=0;i<5;i++)
    54    {
    55      if ( rx_ring[i].next != check_rx_ring[i] ) abort();
    56      if ( ep.rx_skbuff[i] != 0 ) abort();
    57    }
    58    return 0;
    59  }