gcc/cpphash.h

   1 /* different kinds of things that can appear in the value field
   2    of a hash node.  Actually, this may be useless now. */
   3 union hashval {
   4   int ival;
   5   char *cpval;
   6   DEFINITION *defn;
   7 #if 0
   8   KEYDEF *keydef;
   9 #endif
  10 };
  11
  12 struct hashnode {
  13   struct hashnode *next;        /* double links for easy deletion */
  14   struct hashnode *prev;
  15   struct hashnode **bucket_hdr; /* also, a back pointer to this node's hash
  16                                    chain is kept, in case the node is the head
  17                                    of the chain and gets deleted. */
  18   enum node_type type;          /* type of special token */
  19   int length;                   /* length of token, for quick comparison */
  20   U_CHAR *name;                 /* the actual name */
  21   union hashval value;          /* pointer to expansion, or whatever */
  22 };
  23
  24 typedef struct hashnode HASHNODE;
  25
  26 /* Some definitions for the hash table.  The hash function MUST be
  27    computed as shown in hashf () below.  That is because the rescan
  28    loop computes the hash value `on the fly' for most tokens,
  29    in order to avoid the overhead of a lot of procedure calls to
  30    the hashf () function.  Hashf () only exists for the sake of
  31    politeness, for use when speed isn't so important. */
  32
  33 #define HASHSIZE 1403
  34 static HASHNODE *hashtab[HASHSIZE];
  35 #define HASHSTEP(old, c) ((old << 2) + c)
  36 #define MAKE_POS(v) (v & 0x7fffffff) /* make number positive */
  37
  38 extern HASHNODE *install PARAMS ((U_CHAR *,int,enum node_type, int,char *,int));