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/* $OpenBSD: sym.c,v 1.9 2015/11/19 23:34:56 mmcc Exp $ */
/* sym - symbol table routines */
/* Copyright (c) 1990 The Regents of the University of California. */
/* All rights reserved. */
/* This code is derived from software contributed to Berkeley by */
/* Vern Paxson. */
/* The United States Government has rights in this work pursuant */
/* to contract no. DE-AC03-76SF00098 between the United States */
/* Department of Energy and the University of California. */
/* This file is part of flex. */
/* 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. */
/* 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR */
/* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
/* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
/* PURPOSE. */
#include "flexdef.h"
/* Variables for symbol tables:
* sctbl - start-condition symbol table
* ndtbl - name-definition symbol table
* ccltab - character class text symbol table
*/
struct hash_entry {
struct hash_entry *prev, *next;
char *name;
char *str_val;
int int_val;
};
typedef struct hash_entry **hash_table;
#define NAME_TABLE_HASH_SIZE 101
#define START_COND_HASH_SIZE 101
#define CCL_HASH_SIZE 101
static struct hash_entry *ndtbl[NAME_TABLE_HASH_SIZE];
static struct hash_entry *sctbl[START_COND_HASH_SIZE];
static struct hash_entry *ccltab[CCL_HASH_SIZE];
/* declare functions that have forward references */
static int addsym PROTO ((char[], char *, int, hash_table, int));
static struct hash_entry *findsym PROTO ((const char *sym,
hash_table table,
int table_size));
static int hashfunct PROTO ((const char *, int));
/* addsym - add symbol and definitions to symbol table
*
* -1 is returned if the symbol already exists, and the change not made.
*/
static int addsym (sym, str_def, int_def, table, table_size)
char sym[];
char *str_def;
int int_def;
hash_table table;
int table_size;
{
int hash_val = hashfunct (sym, table_size);
struct hash_entry *sym_entry = table[hash_val];
struct hash_entry *new_entry;
struct hash_entry *successor;
while (sym_entry) {
if (!strcmp (sym, sym_entry->name)) { /* entry already exists */
return -1;
}
sym_entry = sym_entry->next;
}
/* create new entry */
new_entry = (struct hash_entry *)
malloc (sizeof (struct hash_entry));
if (new_entry == NULL)
flexfatal (_("symbol table memory allocation failed"));
if ((successor = table[hash_val]) != 0) {
new_entry->next = successor;
successor->prev = new_entry;
}
else
new_entry->next = NULL;
new_entry->prev = NULL;
new_entry->name = sym;
new_entry->str_val = str_def;
new_entry->int_val = int_def;
table[hash_val] = new_entry;
return 0;
}
/* cclinstal - save the text of a character class */
void cclinstal (ccltxt, cclnum)
u_char ccltxt[];
int cclnum;
{
/* We don't bother checking the return status because we are not
* called unless the symbol is new.
*/
(void) addsym ((char *) copy_unsigned_string (ccltxt),
(char *) 0, cclnum, ccltab, CCL_HASH_SIZE);
}
/* ccllookup - lookup the number associated with character class text
*
* Returns 0 if there's no CCL associated with the text.
*/
int ccllookup (ccltxt)
u_char ccltxt[];
{
return findsym ((char *) ccltxt, ccltab, CCL_HASH_SIZE)->int_val;
}
/* findsym - find symbol in symbol table */
static struct hash_entry *findsym (sym, table, table_size)
const char *sym;
hash_table table;
int table_size;
{
static struct hash_entry empty_entry = {
(struct hash_entry *) 0, (struct hash_entry *) 0,
(char *) 0, (char *) 0, 0,
};
struct hash_entry *sym_entry =
table[hashfunct (sym, table_size)];
while (sym_entry) {
if (!strcmp (sym, sym_entry->name))
return sym_entry;
sym_entry = sym_entry->next;
}
return &empty_entry;
}
/* hashfunct - compute the hash value for "str" and hash size "hash_size" */
static int hashfunct (str, hash_size)
const char *str;
int hash_size;
{
int hashval;
int locstr;
hashval = 0;
locstr = 0;
while (str[locstr]) {
hashval = (hashval << 1) + (unsigned char) str[locstr++];
hashval %= hash_size;
}
return hashval;
}
/* ndinstal - install a name definition */
void ndinstal (name, definition)
const char *name;
u_char definition[];
{
if (addsym (copy_string (name),
(char *) copy_unsigned_string (definition), 0,
ndtbl, NAME_TABLE_HASH_SIZE))
synerr (_("name defined twice"));
}
/* ndlookup - lookup a name definition
*
* Returns a nil pointer if the name definition does not exist.
*/
u_char *ndlookup (nd)
const char *nd;
{
return (u_char *) findsym (nd, ndtbl, NAME_TABLE_HASH_SIZE)->str_val;
}
/* scextend - increase the maximum number of start conditions */
void scextend ()
{
current_max_scs += MAX_SCS_INCREMENT;
++num_reallocs;
scset = reallocate_integer_array (scset, current_max_scs);
scbol = reallocate_integer_array (scbol, current_max_scs);
scxclu = reallocate_integer_array (scxclu, current_max_scs);
sceof = reallocate_integer_array (sceof, current_max_scs);
scname = reallocate_char_ptr_array (scname, current_max_scs);
}
/* scinstal - make a start condition
*
* NOTE
* The start condition is "exclusive" if xcluflg is true.
*/
void scinstal (str, xcluflg)
const char *str;
int xcluflg;
{
if (++lastsc >= current_max_scs)
scextend ();
scname[lastsc] = copy_string (str);
if (addsym (scname[lastsc], (char *) 0, lastsc,
sctbl, START_COND_HASH_SIZE))
format_pinpoint_message (_
("start condition %s declared twice"),
str);
scset[lastsc] = mkstate (SYM_EPSILON);
scbol[lastsc] = mkstate (SYM_EPSILON);
scxclu[lastsc] = xcluflg;
sceof[lastsc] = false;
}
/* sclookup - lookup the number associated with a start condition
*
* Returns 0 if no such start condition.
*/
int sclookup (str)
const char *str;
{
return findsym (str, sctbl, START_COND_HASH_SIZE)->int_val;
}
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