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153 lines
3.5 KiB
C
153 lines
3.5 KiB
C
/* Symbol table manager for Bison,
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Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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Bison is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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Bison is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Bison; see the file COPYING. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "system.h"
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#include "hash.h"
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#include "symtab.h"
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#include "gram.h"
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/*---------------------------------.
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| Create a new symbol, named TAG. |
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`---------------------------------*/
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static symbol_t *
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symbol_new (const char *tag)
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{
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symbol_t *res = XMALLOC (symbol_t, 1);
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res->tag = xstrdup (tag);
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res->type_name = NULL;
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res->number = -1;
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res->prec = 0;
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res->assoc = right_assoc;
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res->user_token_number = SUNDEF;
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res->alias = NULL;
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res->class = unknown_sym;
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nsyms++;
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return res;
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}
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/*------------.
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| Free THIS. |
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`------------*/
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static void
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symbol_free (symbol_t *this)
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{
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#if 0
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/* This causes crashes because one string can appear more
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than once. */
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XFREE (this->type_name);
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#endif
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XFREE (this->tag);
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XFREE (this);
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}
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/*----------------------.
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| A symbol_t hash table. |
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`----------------------*/
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/* Initial capacity of symbols hash table. */
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#define HT_INITIAL_CAPACITY 257
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static struct hash_table *symbol_table = NULL;
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static bool
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hash_compare_symbol_t (const symbol_t *m1, const symbol_t *m2)
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{
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return strcmp (m1->tag, m2->tag) ? FALSE : TRUE;
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}
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static unsigned int
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hash_symbol_t (const symbol_t *m, unsigned int tablesize)
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{
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return hash_string (m->tag, tablesize);
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}
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/*-------------------------------.
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| Create the symbol_t hash table. |
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`-------------------------------*/
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void
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symbols_new (void)
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{
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symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
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NULL,
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(Hash_hasher) hash_symbol_t,
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(Hash_comparator) hash_compare_symbol_t,
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(Hash_data_freer) symbol_free);
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}
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/*----------------------------------------------------------------.
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| Find the symbol named KEY, and return it. If it does not exist |
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| yet, create it. |
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`----------------------------------------------------------------*/
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symbol_t *
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getsym (const char *key)
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{
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symbol_t probe;
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symbol_t *entry;
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(const char *) probe.tag = key;
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entry = hash_lookup (symbol_table, &probe);
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if (!entry)
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{
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/* First insertion in the hash. */
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entry = symbol_new (key);
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hash_insert (symbol_table, entry);
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}
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return entry;
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}
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/*-------------------.
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| Free the symbols. |
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`-------------------*/
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void
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symbols_free (void)
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{
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hash_free (symbol_table);
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}
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/*---------------------------------------------------------------.
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| Look for undefined symbols, report an error, and consider them |
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| terminals. |
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`---------------------------------------------------------------*/
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void
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symbols_do (symbol_processor processor, void *processor_data)
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{
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hash_do_for_each (symbol_table,
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(Hash_processor) processor,
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processor_data);
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}
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