external/bsd/byacc/dist/symtab.c

   1 /*      $NetBSD: symtab.c,v 1.8 2015/01/03 23:22:52 christos Exp $      */
   2
   3 /* Id: symtab.c,v 1.11 2014/03/26 00:17:09 Tom.Shields Exp  */
   4
   5 #include "defs.h"
   6
   7 #include <sys/cdefs.h>
   8 __RCSID("$NetBSD: symtab.c,v 1.8 2015/01/03 23:22:52 christos Exp $");
   9
  10 /* TABLE_SIZE is the number of entries in the symbol table. */
  11 /* TABLE_SIZE must be a power of two.                       */
  12
  13 #define TABLE_SIZE 1024
  14
  15 static bucket **symbol_table = 0;
  16 bucket *first_symbol;
  17 bucket *last_symbol;
  18
  19 static int
  20 hash(const char *name)
  21 {
  22     const char *s;
  23     int c, k;
  24
  25     assert(name && *name);
  26     s = name;
  27     k = *s;
  28     while ((c = *++s) != 0)
  29         k = (31 * k + c) & (TABLE_SIZE - 1);
  30
  31     return (k);
  32 }
  33
  34 bucket *
  35 make_bucket(const char *name)
  36 {
  37     bucket *bp;
  38
  39     assert(name != 0);
  40
  41     bp = TMALLOC(bucket, 1);
  42     NO_SPACE(bp);
  43
  44     bp->link = 0;
  45     bp->next = 0;
  46
  47     bp->name = TMALLOC(char, strlen(name) + 1);
  48     NO_SPACE(bp->name);
  49
  50     bp->tag = 0;
  51     bp->value = UNDEFINED;
  52     bp->index = 0;
  53     bp->prec = 0;
  54     bp->class = UNKNOWN;
  55     bp->assoc = TOKEN;
  56 #if defined(YYBTYACC)
  57     bp->args = -1;
  58     bp->argnames = 0;
  59     bp->argtags = 0;
  60     bp->destructor = 0;
  61 #endif
  62     strcpy(bp->name, name);
  63
  64     return (bp);
  65 }
  66
  67 bucket *
  68 lookup(const char *name)
  69 {
  70     bucket *bp, **bpp;
  71
  72     bpp = symbol_table + hash(name);
  73     bp = *bpp;
  74
  75     while (bp)
  76     {
  77         if (strcmp(name, bp->name) == 0)
  78             return (bp);
  79         bpp = &bp->link;
  80         bp = *bpp;
  81     }
  82
  83     *bpp = bp = make_bucket(name);
  84     last_symbol->next = bp;
  85     last_symbol = bp;
  86
  87     return (bp);
  88 }
  89
  90 void
  91 create_symbol_table(void)
  92 {
  93     int i;
  94     bucket *bp;
  95
  96     symbol_table = TMALLOC(bucket *, TABLE_SIZE);
  97     NO_SPACE(symbol_table);
  98
  99     for (i = 0; i < TABLE_SIZE; i++)
 100         symbol_table[i] = 0;
 101
 102     bp = make_bucket("error");
 103     bp->index = 1;
 104     bp->class = TERM;
 105
 106     first_symbol = bp;
 107     last_symbol = bp;
 108     symbol_table[hash("error")] = bp;
 109 }
 110
 111 void
 112 free_symbol_table(void)
 113 {
 114     FREE(symbol_table);
 115     symbol_table = 0;
 116 }
 117
 118 void
 119 free_symbols(void)
 120 {
 121     bucket *p, *q;
 122
 123     for (p = first_symbol; p; p = q)
 124     {
 125         q = p->next;
 126         FREE(p);
 127     }
 128 }