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+/* 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 ((register char[], char *, int, hash_table, int));
+static struct hash_entry *findsym PROTO ((register const char *sym,
+ hash_table table,
+
+ int table_size));
+static int hashfunct PROTO ((register 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)
+ register char sym[];
+ char *str_def;
+ int int_def;
+ hash_table table;
+ int table_size;
+{
+ int hash_val = hashfunct (sym, table_size);
+ register struct hash_entry *sym_entry = table[hash_val];
+ register struct hash_entry *new_entry;
+ register 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 *)
+ flex_alloc (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)
+ 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)
+ 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)
+ register 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,
+ };
+ register 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)
+ register const char *str;
+ int hash_size;
+{
+ register int hashval;
+ register 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;
+ 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.
+ */
+
+Char *ndlookup (nd)
+ const char *nd;
+{
+ return (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;
+}