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Annotation of src/usr.bin/yacc/symtab.c, Revision 1.15

1.15    ! chl         1: /*     $OpenBSD: symtab.c,v 1.14 2012/03/03 19:15:00 nicm Exp $        */
1.2       deraadt     2: /*     $NetBSD: symtab.c,v 1.4 1996/03/19 03:21:48 jtc Exp $   */
                      3:
                      4: /*
                      5:  * Copyright (c) 1989 The Regents of the University of California.
                      6:  * All rights reserved.
                      7:  *
                      8:  * This code is derived from software contributed to Berkeley by
                      9:  * Robert Paul Corbett.
                     10:  *
                     11:  * Redistribution and use in source and binary forms, with or without
                     12:  * modification, are permitted provided that the following conditions
                     13:  * are met:
                     14:  * 1. Redistributions of source code must retain the above copyright
                     15:  *    notice, this list of conditions and the following disclaimer.
                     16:  * 2. Redistributions in binary form must reproduce the above copyright
                     17:  *    notice, this list of conditions and the following disclaimer in the
                     18:  *    documentation and/or other materials provided with the distribution.
1.8       millert    19:  * 3. Neither the name of the University nor the names of its contributors
1.2       deraadt    20:  *    may be used to endorse or promote products derived from this software
                     21:  *    without specific prior written permission.
                     22:  *
                     23:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     24:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     25:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     26:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     27:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     28:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     29:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     30:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     31:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     32:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     33:  * SUCH DAMAGE.
                     34:  */
1.1       deraadt    35:
                     36: #include "defs.h"
                     37:
                     38: /* TABLE_SIZE is the number of entries in the symbol table. */
                     39: /* TABLE_SIZE must be a power of two.                      */
                     40:
                     41: #define        TABLE_SIZE 1024
                     42:
                     43:
                     44: bucket **symbol_table;
                     45: bucket *first_symbol;
                     46: bucket *last_symbol;
                     47:
1.6       millert    48: int hash(char *);
1.4       pvalchev   49:
1.1       deraadt    50:
                     51: int
1.9       pvalchev   52: hash(char *name)
1.1       deraadt    53: {
1.5       mpech      54:     char *s;
                     55:     int c, k;
1.1       deraadt    56:
                     57:     assert(name && *name);
                     58:     s = name;
                     59:     k = *s;
1.12      pvalchev   60:     while ((c = *++s))
1.1       deraadt    61:        k = (31*k + c) & (TABLE_SIZE - 1);
                     62:
                     63:     return (k);
                     64: }
                     65:
                     66:
                     67: bucket *
1.9       pvalchev   68: make_bucket(char *name)
1.1       deraadt    69: {
1.5       mpech      70:     bucket *bp;
1.1       deraadt    71:
                     72:     assert(name);
                     73:     bp = (bucket *) MALLOC(sizeof(bucket));
                     74:     if (bp == 0) no_space();
                     75:     bp->link = 0;
                     76:     bp->next = 0;
1.7       deraadt    77:     bp->name = strdup(name);
1.1       deraadt    78:     if (bp->name == 0) no_space();
                     79:     bp->tag = 0;
                     80:     bp->value = UNDEFINED;
                     81:     bp->index = 0;
                     82:     bp->prec = 0;
                     83:     bp-> class = UNKNOWN;
                     84:     bp->assoc = TOKEN;
                     85:
                     86:     return (bp);
                     87: }
                     88:
                     89:
                     90: bucket *
1.9       pvalchev   91: lookup(char *name)
1.1       deraadt    92: {
1.5       mpech      93:     bucket *bp, **bpp;
1.1       deraadt    94:
                     95:     bpp = symbol_table + hash(name);
                     96:     bp = *bpp;
                     97:
                     98:     while (bp)
                     99:     {
                    100:        if (strcmp(name, bp->name) == 0) return (bp);
                    101:        bpp = &bp->link;
                    102:        bp = *bpp;
                    103:     }
                    104:
                    105:     *bpp = bp = make_bucket(name);
                    106:     last_symbol->next = bp;
                    107:     last_symbol = bp;
                    108:
                    109:     return (bp);
                    110: }
                    111:
                    112:
1.4       pvalchev  113: void
1.9       pvalchev  114: create_symbol_table(void)
1.1       deraadt   115: {
1.5       mpech     116:     bucket *bp;
1.1       deraadt   117:
1.14      nicm      118:     symbol_table = CALLOC(TABLE_SIZE, sizeof(bucket *));
                    119:     if (symbol_table == NULL) no_space();
1.1       deraadt   120:
                    121:     bp = make_bucket("error");
                    122:     bp->index = 1;
                    123:     bp->class = TERM;
                    124:
                    125:     first_symbol = bp;
                    126:     last_symbol = bp;
                    127:     symbol_table[hash("error")] = bp;
                    128: }
                    129:
                    130:
1.4       pvalchev  131: void
1.9       pvalchev  132: free_symbol_table(void)
1.1       deraadt   133: {
                    134:     FREE(symbol_table);
                    135:     symbol_table = 0;
                    136: }
                    137:
                    138:
1.4       pvalchev  139: void
1.9       pvalchev  140: free_symbols(void)
1.1       deraadt   141: {
1.5       mpech     142:     bucket *p, *q;
1.1       deraadt   143:
                    144:     for (p = first_symbol; p; p = q)
                    145:     {
                    146:        q = p->next;
                    147:        FREE(p);
                    148:     }
                    149: }