freebsd-dev/contrib/byacc/symtab.c
2012-09-14 21:17:53 +00:00

118 lines
1.8 KiB
C

/* $Id: symtab.c,v 1.10 2012/05/26 15:16:12 tom Exp $ */
#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
static bucket **symbol_table = 0;
bucket *first_symbol;
bucket *last_symbol;
static int
hash(const char *name)
{
const char *s;
int c, k;
assert(name && *name);
s = name;
k = *s;
while ((c = *++s) != 0)
k = (31 * k + c) & (TABLE_SIZE - 1);
return (k);
}
bucket *
make_bucket(const char *name)
{
bucket *bp;
assert(name != 0);
bp = TMALLOC(bucket, 1);
NO_SPACE(bp);
bp->link = 0;
bp->next = 0;
bp->name = TMALLOC(char, strlen(name) + 1);
NO_SPACE(bp->name);
bp->tag = 0;
bp->value = UNDEFINED;
bp->index = 0;
bp->prec = 0;
bp->class = UNKNOWN;
bp->assoc = TOKEN;
strcpy(bp->name, name);
return (bp);
}
bucket *
lookup(const char *name)
{
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);
}
void
create_symbol_table(void)
{
int i;
bucket *bp;
symbol_table = TMALLOC(bucket *, TABLE_SIZE);
NO_SPACE(symbol_table);
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;
}
void
free_symbol_table(void)
{
FREE(symbol_table);
symbol_table = 0;
}
void
free_symbols(void)
{
bucket *p, *q;
for (p = first_symbol; p; p = q)
{
q = p->next;
FREE(p);
}
}