absyntax_utils/function_call_iterator.cc
author mjsousa
Sat, 07 May 2016 21:17:49 +0100
changeset 1010 242907849850
parent 958 7474d2cd1d6e
permissions -rwxr-xr-x
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) 2003-2011  Mario de Sousa (msousa@fe.up.pt)
 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant
 *
 *  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)
 *
 */


/*
 * Function call parameter iterator.
 *
 * This is part of the 4th stage that generates
 * a c++ source program equivalent to the IL and ST
 * code.
 */

/* given a function_body_c, iterate through each
 * function/FB call in that code.
 */


#include "function_call_iterator.hh"
#include "../main.hh" // required for ERROR() and ERROR_MSG() macros.


//#define DEBUG
#ifdef DEBUG
#define TRACE(classname) printf("\n____%s____\n",classname);
#else
#define TRACE(classname)
#endif





/* initialise the iterator object.
 * We must be given a reference to the function declaration
 * that will be analysed...
 */
function_call_iterator_c::function_call_iterator_c(symbol_c *symbol) {
  this->start_symbol = symbol;
  next_fcall = fcall_count = 0;
  current_finvocation = NULL;
  current_fcall_name = NULL;
}

/* Skip to the next function call. After object creation,
 * the object references _before_ the first, so
 * this function must be called once to get the object to
 * reference the first function call...
 *
 * Returns the function_invocation_c!
 */
//function_invocation_c *next(void) {TRACE("function_call_iterator_c::next(): called ");
symbol_c *function_call_iterator_c::next(void) {TRACE("function_call_iterator_c::next(): called ");
  fcall_count = 0;
  next_fcall++;
  current_finvocation = NULL;
  current_fcall_name = NULL;

  start_symbol->accept(*this);
  return current_finvocation;
}

/* Returns the name of the currently referenced function invocation */
token_c *function_call_iterator_c::fname(void) {
  token_c *fname_sym = dynamic_cast<token_c *>(current_fcall_name);
  if (fname_sym == NULL) ERROR;
  return fname_sym;
}


/***************************************/
/* B.3 - Language ST (Structured Text) */
/***************************************/
/***********************/
/* B 3.1 - Expressions */
/***********************/
  void *function_call_iterator_c::visit(function_invocation_c *symbol) {
    fcall_count++;
    if (next_fcall == fcall_count) {
      current_finvocation = symbol;
      current_fcall_name = symbol->function_name;
    }
    return NULL;
  }



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

/* | function_name [il_operand_list] */
// SYM_REF2(il_function_call_c, function_name, il_operand_list)
  void *function_call_iterator_c::visit(il_function_call_c *symbol) {
    fcall_count++;
    if (next_fcall == fcall_count) {
      current_finvocation = symbol;
      current_fcall_name = symbol->function_name;
    }
    return NULL;
  }



/* | function_name '(' eol_list [il_param_list] ')' */
// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list)
  void *function_call_iterator_c::visit(il_formal_funct_call_c *symbol) {
    fcall_count++;
    if (next_fcall == fcall_count) {
      current_finvocation = symbol;
      current_fcall_name = symbol->function_name;
    }
    return NULL;
  }