absyntax_utils/function_call_iterator.cc
author Mario de Sousa <msousa@fe.up.pt>
Mon, 22 Aug 2011 16:08:07 +0100
changeset 358 a2c4af8f0c18
parent 279 c0453b7f99df
child 596 4efb11e44065
permissions -rwxr-xr-x
Add support for '**' (power) operator in ST expressions
/*
 *  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"


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

#define ERROR error_exit(__FILE__,__LINE__)
/* function defined in main.cc */
extern void error_exit(const char *file_name, int line_no);





/* 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 */
identifier_c *function_call_iterator_c::fname(void) {
  identifier_c *identifier = dynamic_cast<identifier_c *>(current_fcall_name);
  if (identifier == NULL) ERROR;
  return identifier;
}


/***************************************/
/* 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;
  }