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- /* $Header$ */
- /* IDENTIFIER DESCRIPTOR */
- #include "nopp.h"
- /* Since the % operation in the calculation of the hash function
- turns out to be expensive, it is replaced by the cheaper XOR (^).
- Each character of the identifier is xored with an 8-bit mask which
- depends on the position of the character; the sum of these results
- is the hash value. The random masks are obtained from a
- congruence generator in idf.c.
- */
- #define HASHSIZE 256 /* must be a power of 2 */
- #define HASH_X 0253 /* Knuth's X */
- #define HASH_A 77 /* Knuth's a */
- #define HASH_C 153 /* Knuth's c */
- extern char hmask[]; /* the random masks */
- #define HASHMASK (HASHSIZE-1) /* since it is a power of 2 */
- #define STARTHASH() (0)
- #define ENHASH(hs,ch,ps) (hs + (ch ^ hmask[ps]))
- #define STOPHASH(hs) (hs & HASHMASK)
- struct idstack_item { /* stack of identifiers */
- struct idstack_item *next;
- struct idf *is_idf;
- };
- /* allocation definitions of struct idstack_item */
- /* ALLOCDEF "idstack_item" */
- extern char *st_alloc();
- extern struct idstack_item *h_idstack_item;
- #define new_idstack_item() ((struct idstack_item *) \
- st_alloc((char **)&h_idstack_item, sizeof(struct idstack_item)))
- #define free_idstack_item(p) st_free(p, h_idstack_item, sizeof(struct idstack_item))
- struct idf {
- struct idf *next;
- char *id_text;
- #ifndef NOPP
- struct macro *id_macro;
- int id_resmac; /* if nonzero: keyword of macroproc. */
- #endif NOPP
- int id_reserved; /* non-zero for reserved words */
- struct def *id_def; /* variables, typedefs, enum-constants */
- struct sdef *id_sdef; /* selector tags */
- struct tag *id_struct; /* struct and union tags */
- struct tag *id_enum; /* enum tags */
- int id_special; /* special action needed at occurrence */
- };
- /* allocation definitions of struct idf */
- /* ALLOCDEF "idf" */
- extern char *st_alloc();
- extern struct idf *h_idf;
- #define new_idf() ((struct idf *) \
- st_alloc((char **)&h_idf, sizeof(struct idf)))
- #define free_idf(p) st_free(p, h_idf, sizeof(struct idf))
- extern struct idf *str2idf(), *idf_hashed();
- extern int level;
- extern struct idf *gen_idf();
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