freebsd-nq/contrib/gcc/cpphash.h
1999-08-26 09:30:50 +00:00

41 lines
1.4 KiB
C

/* different kinds of things that can appear in the value field
of a hash node. Actually, this may be useless now. */
union hashval {
int ival;
char *cpval;
DEFINITION *defn;
#if 0
KEYDEF *keydef;
#endif
};
struct hashnode {
struct hashnode *next; /* double links for easy deletion */
struct hashnode *prev;
struct hashnode **bucket_hdr; /* also, a back pointer to this node's hash
chain is kept, in case the node is the head
of the chain and gets deleted. */
enum node_type type; /* type of special token */
int length; /* length of token, for quick comparison */
U_CHAR *name; /* the actual name */
union hashval value; /* pointer to expansion, or whatever */
};
typedef struct hashnode HASHNODE;
/* Some definitions for the hash table. The hash function MUST be
computed as shown in hashf () below. That is because the rescan
loop computes the hash value `on the fly' for most tokens,
in order to avoid the overhead of a lot of procedure calls to
the hashf () function. Hashf () only exists for the sake of
politeness, for use when speed isn't so important. */
#define HASHSIZE 1403
static HASHNODE *hashtab[HASHSIZE];
#define HASHSTEP(old, c) ((old << 2) + c)
#define MAKE_POS(v) (v & 0x7fffffff) /* make number positive */
extern HASHNODE *install PARAMS ((U_CHAR *,int,enum node_type, int,char *,int));
extern int hashf PARAMS ((const U_CHAR *, int, int));
extern void delete_macro PARAMS ((HASHNODE *));