BSD 4_3_Net_2 release

[unix-history] / usr / src / usr.bin / yacc / symtab.c

/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Robert Paul Corbett.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
static char sccsid[] = "@(#)symtab.c    5.3 (Berkeley) 6/1/90";
#endif /* not lint */

#include "defs.h"

/* TABLE_SIZE is the number of entries in the symbol table. */
/* TABLE_SIZE must be a power of two.                       */

#define TABLE_SIZE 1024


bucket **symbol_table;
bucket *first_symbol;
bucket *last_symbol;


int
hash(name)
char *name;
{
   register char *s;
   register int c, k;

   assert(name && *name);
   s = name;
   k = *s;
   while (c = *++s)
       k = (31*k + c) & (TABLE_SIZE - 1);

   return (k);
}


bucket *
make_bucket(name)
char *name;
{
   register bucket *bp;

   assert(name);
   bp = (bucket *) MALLOC(sizeof(bucket));
   if (bp == 0) no_space();
   bp->link = 0;
   bp->next = 0;
   bp->name = MALLOC(strlen(name) + 1);
   if (bp->name == 0) no_space();
   bp->tag = 0;
   bp->value = UNDEFINED;
   bp->index = 0;
   bp->prec = 0;
   bp-> class = UNKNOWN;
   bp->assoc = TOKEN;

   if (bp->name == 0) no_space();
   strcpy(bp->name, name);

   return (bp);
}


bucket *
lookup(name)
char *name;
{
   register bucket *bp, **bpp;

   bpp = symbol_table + hash(name);
   bp = *bpp;

   while (bp)
   {
       if (strcmp(name, bp->name) == 0) return (bp);
       bpp = &bp->link;
       bp = *bpp;
   }

   *bpp = bp = make_bucket(name);
   last_symbol->next = bp;
   last_symbol = bp;

   return (bp);
}


create_symbol_table()
{
   register int i;
   register bucket *bp;

   symbol_table = (bucket **) MALLOC(TABLE_SIZE*sizeof(bucket *));
   if (symbol_table == 0) no_space();
   for (i = 0; i < TABLE_SIZE; i++)
       symbol_table[i] = 0;

   bp = make_bucket("error");
   bp->index = 1;
   bp->class = TERM;

   first_symbol = bp;
   last_symbol = bp;
   symbol_table[hash("error")] = bp;
}


free_symbol_table()
{
   FREE(symbol_table);
   symbol_table = 0;
}


free_symbols()
{
   register bucket *p, *q;

   for (p = first_symbol; p; p = q)
   {
       q = p->next;
       FREE(p);
   }
}