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6b98e4b563
* src/gram.h, src/gram.c (grammar_rhs_print, grammar_rules_print): New. Don't print the rules' location, it is confusing and useless. (rule_print): Use grammar_rhs_print. * src/print.c (print_grammar): Use grammar_rules_print.
535 lines
15 KiB
C
535 lines
15 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 "quotearg.h"
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#include "hash.h"
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#include "complain.h"
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#include "symtab.h"
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#include "gram.h"
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/*------------------------.
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| Distinguished symbols. |
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`------------------------*/
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symbol_t *errtoken = NULL;
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symbol_t *undeftoken = NULL;
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symbol_t *eoftoken = NULL;
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symbol_t *axiom = NULL;
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symbol_t *startsymbol = NULL;
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location_t startsymbol_location;
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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, location_t location)
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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->location = location;
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res->number = NUMBER_UNDEFINED;
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res->prec = 0;
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res->assoc = right_assoc;
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res->user_token_number = USER_NUMBER_UNDEFINED;
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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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| Return the tag of this SYMBOL in a printable form. Warning: use |
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| the first QUOTEARG slot: 0. |
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`-----------------------------------------------------------------*/
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const char *
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symbol_tag_get (symbol_t *symbol)
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{
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return quotearg_style (escape_quoting_style, symbol->tag);
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}
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/*------------------------------------------------------------.
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| Return the tag of this SYMBOL in a printable form. Use the |
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| QUOTEARG slot number N. |
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`------------------------------------------------------------*/
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const char *
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symbol_tag_get_n (symbol_t *symbol, int n)
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{
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return quotearg_n_style (n, escape_quoting_style, symbol->tag);
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}
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/*-------------------------------.
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| Print the tag of this SYMBOL. |
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`-------------------------------*/
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void
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symbol_tag_print (symbol_t *symbol, FILE *out)
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{
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fputs (symbol_tag_get (symbol), out);
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}
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/*------------------------------------------------------------------.
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| Set the TYPE_NAME associated to SYMBOL. Does nothing if passed 0 |
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| as TYPE_NAME. |
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`------------------------------------------------------------------*/
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void
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symbol_type_set (symbol_t *symbol, char *type_name)
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{
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if (type_name)
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{
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if (symbol->type_name)
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complain (_("type redeclaration for %s"), symbol->tag);
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symbol->type_name = type_name;
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}
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}
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/*------------------------------------------------------------------.
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| Set the PRECEDENCE associated to SYMBOL. Does nothing if invoked |
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| with UNDEF_ASSOC as ASSOC. |
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`------------------------------------------------------------------*/
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void
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symbol_precedence_set (symbol_t *symbol,
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int prec, associativity assoc)
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{
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if (assoc != undef_assoc)
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{
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if (symbol->prec != 0)
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complain (_("redefining precedence of %s"), symbol->tag);
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symbol->prec = prec;
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symbol->assoc = assoc;
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}
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/* Only terminals have a precedence. */
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symbol_class_set (symbol, token_sym);
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}
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/*-------------------------------------.
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| Set the CLASS associated to SYMBOL. |
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`-------------------------------------*/
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void
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symbol_class_set (symbol_t *symbol, symbol_class class)
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{
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if (symbol->class != unknown_sym && symbol->class != class)
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complain (_("symbol %s redefined"), symbol->tag);
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if (class == nterm_sym && symbol->class != nterm_sym)
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symbol->number = nvars++;
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else if (class == token_sym && symbol->number == NUMBER_UNDEFINED)
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symbol->number = ntokens++;
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symbol->class = class;
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}
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/*-------------------------------------------------.
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| Set the USER_TOKEN_NUMBER associated to SYMBOL. |
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`-------------------------------------------------*/
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void
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symbol_user_token_number_set (symbol_t *symbol, int user_token_number)
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{
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assert (symbol->class == token_sym);
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if (symbol->user_token_number != USER_NUMBER_UNDEFINED
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&& symbol->user_token_number != user_token_number)
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complain (_("redefining user token number of %s"), symbol->tag);
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symbol->user_token_number = user_token_number;
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/* User defined EOF token? */
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if (user_token_number == 0)
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{
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eoftoken = symbol;
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eoftoken->number = 0;
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/* It is always mapped to 0, so it was already counted in
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NTOKENS. */
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--ntokens;
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}
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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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| If THIS is not defined, report an error, and consider it a |
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| nonterminal. |
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`-----------------------------------------------------------*/
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static bool
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symbol_check_defined (symbol_t *this)
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{
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if (this->class == unknown_sym)
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{
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complain_at
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(this->location,
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_("symbol %s is used, but is not defined as a token and has no rules"),
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this->tag);
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this->class = nterm_sym;
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this->number = nvars++;
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}
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return TRUE;
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}
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/*-------------------------------------------------------------------.
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| Declare the new SYMBOL. Make it an alias of SYMVAL, and type them |
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| with TYPENAME. |
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`-------------------------------------------------------------------*/
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void
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symbol_make_alias (symbol_t *symbol, symbol_t *symval)
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{
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if (symval->alias)
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warn (_("symbol `%s' used more than once as a literal string"),
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symval->tag);
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else if (symbol->alias)
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warn (_("symbol `%s' given more than one literal string"),
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symbol->tag);
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else
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{
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symval->class = token_sym;
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symval->user_token_number = symbol->user_token_number;
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symbol->user_token_number = USER_NUMBER_ALIAS;
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symval->alias = symbol;
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symbol->alias = symval;
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/* symbol and symval combined are only one symbol */
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nsyms--;
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ntokens--;
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assert (ntokens == symbol->number || ntokens == symval->number);
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symbol->number = symval->number =
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(symval->number < symbol->number) ? symval->number : symbol->number;
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}
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}
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/*---------------------------------------------------------.
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| Check that THIS, and its alias, have same precedence and |
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| associativity. |
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`---------------------------------------------------------*/
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static bool
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symbol_check_alias_consistence (symbol_t *this)
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{
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/* Check only those who _are_ the aliases. */
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if (this->alias && this->user_token_number == USER_NUMBER_ALIAS)
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{
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if (this->prec != this->alias->prec)
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{
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if (this->prec != 0 && this->alias->prec != 0)
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complain (_("conflicting precedences for %s and %s"),
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this->tag, this->alias->tag);
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if (this->prec != 0)
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this->alias->prec = this->prec;
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else
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this->prec = this->alias->prec;
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}
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if (this->assoc != this->alias->assoc)
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{
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/* FIXME: For some reason (probably the S/R => keep the S),
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the right assoc is chosen has the ``not set''. This is
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not nice, fix this! */
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if (this->assoc != right_assoc
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&& this->alias->assoc != right_assoc)
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complain (_("conflicting associativities for %s and %s"),
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this->tag, this->alias->tag);
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if (this->assoc != 0)
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this->alias->assoc = this->assoc;
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else
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this->assoc = this->alias->assoc;
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}
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}
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return TRUE;
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}
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/*-------------------------------------------------------------------.
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| Assign a symbol number, and write the definition of the token name |
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| into FDEFINES. Put in SYMBOLS. |
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`-------------------------------------------------------------------*/
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static bool
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symbol_pack (symbol_t *this)
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{
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if (this->class == nterm_sym)
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{
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this->number += ntokens;
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}
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else if (this->alias)
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{
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/* This symbol and its alias are a single token defn.
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Allocate a tokno, and assign to both check agreement of
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prec and assoc fields and make both the same */
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if (this->number == NUMBER_UNDEFINED)
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{
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if (this == eoftoken || this->alias == eoftoken)
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this->number = this->alias->number = 0;
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else
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{
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assert (this->alias->number != NUMBER_UNDEFINED);
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this->number = this->alias->number;
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}
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}
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/* Do not do processing below for USER_NUMBER_ALIASs. */
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if (this->user_token_number == USER_NUMBER_ALIAS)
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return TRUE;
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}
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else /* this->class == token_sym */
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{
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assert (this->number != NUMBER_UNDEFINED);
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}
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symbols[this->number] = this;
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return TRUE;
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}
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/*--------------------------------------------------.
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| Put THIS in TOKEN_TRANSLATIONS if it is a token. |
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`--------------------------------------------------*/
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static bool
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symbol_translation (symbol_t *this)
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{
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/* Non-terminal? */
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if (this->class == token_sym
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&& this->user_token_number != USER_NUMBER_ALIAS)
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{
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/* A token which translation has already been set? */
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if (token_translations[this->user_token_number] != undeftoken->number)
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complain (_("tokens %s and %s both assigned number %d"),
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symbols[token_translations[this->user_token_number]]->tag,
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this->tag, this->user_token_number);
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token_translations[this->user_token_number] = this->number;
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}
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return TRUE;
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}
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/*----------------------.
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| A symbol 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 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, location_t location)
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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, location);
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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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/*--------------------------------------------------------------.
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| Check that all the symbols are defined. Report any undefined |
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| symbols and consider them nonterminals. |
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`--------------------------------------------------------------*/
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void
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symbols_check_defined (void)
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{
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symbols_do (symbol_check_defined, NULL);
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}
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/*------------------------------------------------------------------.
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| Set TOKEN_TRANSLATIONS. Check that no two symbols share the same |
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| number. |
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`------------------------------------------------------------------*/
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static void
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symbols_token_translations_init (void)
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{
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int num_256_available_p = TRUE;
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int i;
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/* Find the highest user token number, and whether 256, the POSIX
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preferred user token number for the error token, is used. */
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max_user_token_number = 0;
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for (i = 0; i < ntokens; ++i)
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{
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symbol_t *this = symbols[i];
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if (this->user_token_number != USER_NUMBER_UNDEFINED)
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{
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if (this->user_token_number > max_user_token_number)
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max_user_token_number = this->user_token_number;
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if (this->user_token_number == 256)
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num_256_available_p = FALSE;
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}
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}
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/* If 256 is not used, assign it to error, to follow POSIX. */
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if (num_256_available_p
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&& errtoken->user_token_number == USER_NUMBER_UNDEFINED)
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errtoken->user_token_number = 256;
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/* Set the missing user numbers. */
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if (max_user_token_number < 256)
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max_user_token_number = 256;
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for (i = 0; i < ntokens; ++i)
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{
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symbol_t *this = symbols[i];
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if (this->user_token_number == USER_NUMBER_UNDEFINED)
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this->user_token_number = ++max_user_token_number;
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if (this->user_token_number > max_user_token_number)
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max_user_token_number = this->user_token_number;
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}
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token_translations = XCALLOC (symbol_number_t, max_user_token_number + 1);
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/* Initialize all entries for literal tokens to 2, the internal
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token number for $undefined., which represents all invalid
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inputs. */
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for (i = 0; i < max_user_token_number + 1; i++)
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token_translations[i] = undeftoken->number;
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symbols_do (symbol_translation, NULL);
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}
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/*----------------------------------------------------------------.
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| Assign symbol numbers, and write definition of token names into |
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| FDEFINES. Set up vectors SYMBOL_TABLE, TAGS of symbols. |
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`----------------------------------------------------------------*/
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void
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symbols_pack (void)
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{
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symbols = XCALLOC (symbol_t *, nsyms);
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symbols_do (symbol_check_alias_consistence, NULL);
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symbols_do (symbol_pack, NULL);
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symbols_token_translations_init ();
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if (startsymbol->class == unknown_sym)
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fatal_at (startsymbol_location,
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_("the start symbol %s is undefined"), startsymbol->tag);
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else if (startsymbol->class == token_sym)
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fatal_at (startsymbol_location,
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_("the start symbol %s is a token"), startsymbol->tag);
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}
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