+/* 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.
+ *
+ * Redistribution and use in source and binary forms are permitted provided
+ * that: (1) source distributions retain this entire copyright notice and
+ * comment, and (2) distributions including binaries display the following
+ * acknowledgement: ``This product includes software developed by the
+ * University of California, Berkeley and its contributors'' in the
+ * documentation or other materials provided with the distribution and in
+ * all advertising materials mentioning features or use of this software.
+ * 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.
+ */
+
+/* $Header: /home/daffy/u0/vern/flex/RCS/sym.c,v 2.19 95/03/04 16:11:04 vern Exp $ */
+
+#include "flexdef.h"
+
+
+/* declare functions that have forward references */
+
+int hashfunct PROTO((register char[], int));
+
+
+struct hash_entry *ndtbl[NAME_TABLE_HASH_SIZE];
+struct hash_entry *sctbl[START_COND_HASH_SIZE];
+struct hash_entry *ccltab[CCL_HASH_SIZE];
+
+struct hash_entry *findsym();
+
+
+/* addsym - add symbol and definitions to symbol table
+ *
+ * -1 is returned if the symbol already exists, and the change not made.
+ */
+
+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.
+ */
+ Char *copy_unsigned_string();
+
+ (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 */
+
+struct hash_entry *findsym( sym, table, table_size )
+register 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" */
+
+int hashfunct( str, hash_size )
+register 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 )
+char name[];
+Char definition[];
+ {
+ char *copy_string();
+ Char *copy_unsigned_string();
+
+ 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 )
+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 )
+char str[];
+int xcluflg;
+ {
+ char *copy_string();
+
+ /* Generate start condition definition, for use in BEGIN et al. */
+ action_define( str, lastsc );
+
+ 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 )
+char str[];
+ {
+ return findsym( str, sctbl, START_COND_HASH_SIZE )->int_val;
+ }
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