libasn1parser/asn1p_list.h

   1 /*
   2  * Singly linked tail queue support.
   3  */
   4 #ifndef ASN1_PARSER_LIST_H
   5 #define ASN1_PARSER_LIST_H
   6
   7 #define TQ_HEAD(type)                                   \
   8         struct {                                        \
   9                 type *tq_head;                          \
  10                 type**tq_tail;                          \
  11         }
  12
  13 #define TQ_MOVE(to, from)       do {                    \
  14         if(&(TQ_FIRST(from)) == (from)->tq_tail) {      \
  15                 TQ_INIT(to);                            \
  16         } else {                                        \
  17                 (to)->tq_head = (from)->tq_head;        \
  18                 (to)->tq_tail = (from)->tq_tail;        \
  19         }                                               \
  20         TQ_INIT(from);                                  \
  21         } while(0)
  22
  23 #define TQ_ENTRY(type)                                  \
  24         struct {                                        \
  25                 type *tq_next;                          \
  26         }
  27
  28 #define TQ_FIRST(headp)         ((headp)->tq_head)
  29 #define TQ_NEXT(el, field)      ((el)->field.tq_next)
  30
  31 #define TQ_INIT(head) do {                              \
  32         TQ_FIRST((head)) = 0;                           \
  33         (head)->tq_tail = &TQ_FIRST((head));            \
  34         } while(0)
  35
  36 #define TQ_FOR(var, head, field)                        \
  37         for((var) = TQ_FIRST((head));                   \
  38                 (var); (var) = TQ_NEXT((var), field))
  39
  40 /* MSVC does not have typeof(), cannot prevent side effects! */
  41 #define TQ_ADD(head, xel, field) do {                   \
  42         typeof(xel) __el = (xel);                       \
  43         assert(TQ_NEXT((__el), field) == 0);            \
  44         *(head)->tq_tail = (__el);                      \
  45         (head)->tq_tail = &TQ_NEXT((__el), field);      \
  46         } while(0)
  47
  48 #define TQ_CONCAT(head1, head2, field) do {             \
  49         if(TQ_FIRST(head2)) {                           \
  50                 *(head1)->tq_tail = (head2)->tq_head;   \
  51                 (head1)->tq_tail = (head2)->tq_tail;    \
  52                 TQ_INIT(head2);                         \
  53         }                                               \
  54         } while(0)
  55
  56 /*
  57  * Remove the first element and return it.
  58  */
  59 #define TQ_REMOVE(head, field)  ({                      \
  60         typeof(TQ_FIRST((head))) __fel;                 \
  61         __fel = TQ_FIRST((head));                       \
  62         if(__fel == 0                                   \
  63         || (TQ_FIRST((head)) = TQ_NEXT(__fel, field))   \
  64                 == 0) {                                 \
  65                 (head)->tq_tail = &TQ_FIRST((head));    \
  66         } else {                                        \
  67                 TQ_NEXT(__fel, field) = 0;              \
  68         }                                               \
  69         __fel; })
  70
  71
  72 #endif  /* ASN1_PARSER_LIST_H */