absyntax_utils/search_il_label.cc
author mjsousa
Sat, 07 May 2016 21:17:49 +0100
changeset 1010 242907849850
parent 460 00f39a4b25fb
permissions -rw-r--r--
Correctly identify errors when parsing erroneous code (make sure flex goes back to INITIAL state when code contains errors that do not allow determining whether ST or IL is being parsed)
/*
 *  matiec - a compiler for the programming languages defined in IEC 61131-3
 *
 *  Copyright (C) 2012  Mario de Sousa (msousa@fe.up.pt)
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * This code is made available on the understanding that it will not be
 * used in safety-critical situations without a full and competent review.
 */

/*
 * An IEC 61131-3 compiler.
 *
 * Based on the
 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
 *
 */


/*
 *  Search for a specific label in an IL list. 
 *
 *  when instantiated, must be given a pointer to one of the following
 *     - function_declaration_c
 *     - function_block_declaration_c
 *     - program_declaration_c
 *     - instruction_list_c
 *
 * which is where all calls to search for a specific label will look for said label.
 */



#include "absyntax_utils.hh"



/* set to 1 to see debug info during execution */
static int debug = 0;

search_il_label_c::search_il_label_c(symbol_c *search_scope) {
  this->search_scope = search_scope;
  this->search_label = NULL;
}

search_il_label_c::~search_il_label_c(void) {
}


il_instruction_c *search_il_label_c::find_label(const char *label) {
  return find_label(new identifier_c(label));
}


il_instruction_c *search_il_label_c::find_label(symbol_c *label) {
  search_label = label;
  il_instruction_c *res = (il_instruction_c *)search_scope->accept(*this);
  search_label = NULL;
  return res;
}


/****************************************/
/* B.2 - Language IL (Instruction List) */
/****************************************/
/***********************************/
/* B 2.1 Instructions and Operands */
/***********************************/

/* | label ':' [il_incomplete_instruction] eol_list */
// SYM_REF2(il_instruction_c, label, il_instruction)
// void *visit(instruction_list_c *symbol);
void *search_il_label_c::visit(il_instruction_c *symbol) {
// printf("search_il_label_c::visit(il_instruction_c *symbol): searching for %s\n", ((identifier_c *)search_label)->value);
	if (NULL != symbol->label)
		if (compare_identifiers(search_label, symbol->label) == 0)
			return symbol;

	return NULL;
}