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