usr.bin/lex/sym.c

   1 /* sym - symbol table routines */
   2
   3 /*-
   4  * Copyright (c) 1990 The Regents of the University of California.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Vern Paxson.
   9  *
  10  * The United States Government has rights in this work pursuant
  11  * to contract no. DE-AC03-76SF00098 between the United States
  12  * Department of Energy and the University of California.
  13  *
  14  * Redistribution and use in source and binary forms are permitted provided
  15  * that: (1) source distributions retain this entire copyright notice and
  16  * comment, and (2) distributions including binaries display the following
  17  * acknowledgement:  ``This product includes software developed by the
  18  * University of California, Berkeley and its contributors'' in the
  19  * documentation or other materials provided with the distribution and in
  20  * all advertising materials mentioning features or use of this software.
  21  * Neither the name of the University nor the names of its contributors may
  22  * be used to endorse or promote products derived from this software without
  23  * specific prior written permission.
  24  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  25  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  26  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  27  */
  28
  29 /* $Header: /home/daffy/u0/vern/flex/RCS/sym.c,v 2.19 95/03/04 16:11:04 vern Exp $ */
  30 /* $FreeBSD: src/usr.bin/lex/sym.c,v 1.5 1999/10/27 07:56:47 obrien Exp $ */
  31 /* $DragonFly: src/usr.bin/lex/sym.c,v 1.4 2005/08/04 17:31:22 drhodus Exp $ */
  32
  33 #include "flexdef.h"
  34
  35
  36 /* declare functions that have forward references */
  37
  38 int hashfunct PROTO((char[], int));
  39
  40
  41 struct hash_entry *ndtbl[NAME_TABLE_HASH_SIZE];
  42 struct hash_entry *sctbl[START_COND_HASH_SIZE];
  43 struct hash_entry *ccltab[CCL_HASH_SIZE];
  44
  45 struct hash_entry *findsym();
  46
  47
  48 /* addsym - add symbol and definitions to symbol table
  49  *
  50  * -1 is returned if the symbol already exists, and the change not made.
  51  */
  52
  53 int addsym(char *sym, char *str_def, int int_def, hash_table table,
  54            int table_size)
  55         {
  56         int hash_val = hashfunct( sym, table_size );
  57         struct hash_entry *sym_entry = table[hash_val];
  58         struct hash_entry *new_entry;
  59         struct hash_entry *successor;
  60
  61         while ( sym_entry )
  62                 {
  63                 if ( ! strcmp( sym, sym_entry->name ) )
  64                         { /* entry already exists */
  65                         return -1;
  66                         }
  67
  68                 sym_entry = sym_entry->next;
  69                 }
  70
  71         /* create new entry */
  72         new_entry = (struct hash_entry *)
  73                 flex_alloc( sizeof( struct hash_entry ) );
  74
  75         if ( new_entry == NULL )
  76                 flexfatal( _( "symbol table memory allocation failed" ) );
  77
  78         if ( (successor = table[hash_val]) != 0 )
  79                 {
  80                 new_entry->next = successor;
  81                 successor->prev = new_entry;
  82                 }
  83         else
  84                 new_entry->next = NULL;
  85
  86         new_entry->prev = NULL;
  87         new_entry->name = sym;
  88         new_entry->str_val = str_def;
  89         new_entry->int_val = int_def;
  90
  91         table[hash_val] = new_entry;
  92
  93         return 0;
  94         }
  95
  96
  97 /* cclinstal - save the text of a character class */
  98
  99 void cclinstal(Char *ccltxt, int cclnum)
 100         {
 101         /* We don't bother checking the return status because we are not
 102          * called unless the symbol is new.
 103          */
 104         Char *copy_unsigned_string();
 105
 106         (void) addsym( (char *) copy_unsigned_string( ccltxt ),
 107                         (char *) 0, cclnum,
 108                         ccltab, CCL_HASH_SIZE );
 109         }
 110
 111
 112 /* ccllookup - lookup the number associated with character class text
 113  *
 114  * Returns 0 if there's no CCL associated with the text.
 115  */
 116
 117 int ccllookup(Char *ccltxt)
 118         {
 119         return findsym( (char *) ccltxt, ccltab, CCL_HASH_SIZE )->int_val;
 120         }
 121
 122
 123 /* findsym - find symbol in symbol table */
 124
 125 struct hash_entry *findsym(char *sym, hash_table table, int table_size)
 126         {
 127         static struct hash_entry empty_entry =
 128                 {
 129                 (struct hash_entry *) 0, (struct hash_entry *) 0,
 130                 (char *) 0, (char *) 0, 0,
 131                 } ;
 132         struct hash_entry *sym_entry =
 133                 table[hashfunct( sym, table_size )];
 134
 135         while ( sym_entry )
 136                 {
 137                 if ( ! strcmp( sym, sym_entry->name ) )
 138                         return sym_entry;
 139                 sym_entry = sym_entry->next;
 140                 }
 141
 142         return &empty_entry;
 143         }
 144
 145
 146 /* hashfunct - compute the hash value for "str" and hash size "hash_size" */
 147
 148 int hashfunct(char *str, int hash_size)
 149         {
 150         int hashval;
 151         int locstr;
 152
 153         hashval = 0;
 154         locstr = 0;
 155
 156         while ( str[locstr] )
 157                 {
 158                 hashval = (hashval << 1) + (unsigned char) str[locstr++];
 159                 hashval %= hash_size;
 160                 }
 161
 162         return hashval;
 163         }
 164
 165
 166 /* ndinstal - install a name definition */
 167
 168 void ndinstal(char *name, Char *definition)
 169         {
 170         char *copy_string();
 171         Char *copy_unsigned_string();
 172
 173         if ( addsym( copy_string( name ),
 174                         (char *) copy_unsigned_string( definition ), 0,
 175                         ndtbl, NAME_TABLE_HASH_SIZE ) )
 176                 synerr( _( "name defined twice" ) );
 177         }
 178
 179
 180 /* ndlookup - lookup a name definition
 181  *
 182  * Returns a nil pointer if the name definition does not exist.
 183  */
 184
 185 Char *ndlookup(char *nd)
 186         {
 187         return (Char *) findsym( nd, ndtbl, NAME_TABLE_HASH_SIZE )->str_val;
 188         }
 189
 190
 191 /* scextend - increase the maximum number of start conditions */
 192
 193 void scextend(void)
 194         {
 195         current_max_scs += MAX_SCS_INCREMENT;
 196
 197         ++num_reallocs;
 198
 199         scset = reallocate_integer_array( scset, current_max_scs );
 200         scbol = reallocate_integer_array( scbol, current_max_scs );
 201         scxclu = reallocate_integer_array( scxclu, current_max_scs );
 202         sceof = reallocate_integer_array( sceof, current_max_scs );
 203         scname = reallocate_char_ptr_array( scname, current_max_scs );
 204         }
 205
 206
 207 /* scinstal - make a start condition
 208  *
 209  * NOTE
 210  *    The start condition is "exclusive" if xcluflg is true.
 211  */
 212
 213 void scinstal(char *str, int xcluflg)
 214         {
 215         char *copy_string();
 216
 217         /* Generate start condition definition, for use in BEGIN et al. */
 218         action_define( str, lastsc );
 219
 220         if ( ++lastsc >= current_max_scs )
 221                 scextend();
 222
 223         scname[lastsc] = copy_string( str );
 224
 225         if ( addsym( scname[lastsc], (char *) 0, lastsc,
 226                         sctbl, START_COND_HASH_SIZE ) )
 227                 format_pinpoint_message(
 228                                 _( "start condition %s declared twice" ),
 229                                         str );
 230
 231         scset[lastsc] = mkstate( SYM_EPSILON );
 232         scbol[lastsc] = mkstate( SYM_EPSILON );
 233         scxclu[lastsc] = xcluflg;
 234         sceof[lastsc] = false;
 235         }
 236
 237
 238 /* sclookup - lookup the number associated with a start condition
 239  *
 240  * Returns 0 if no such start condition.
 241  */
 242
 243 int sclookup(char *str)
 244         {
 245         return findsym( str, sctbl, START_COND_HASH_SIZE )->int_val;
 246         }