stage4/generate_cc/generate_cc_il.cc
changeset 70 e1f0ebd2d9ec
parent 69 41cb5b80416e
child 71 c2c867171c07
--- a/stage4/generate_cc/generate_cc_il.cc	Tue Oct 23 10:35:58 2007 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1465 +0,0 @@
-/*
- * (c) 2003 Mario de Sousa
- *
- * Offered to the public under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2 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.
- *
- * 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 IL and ST compiler.
- *
- * Based on the
- * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
- *
- */
-
-
-/*
- * Conversion of il statements (i.e. IL code).
- *
- * This is part of the 4th stage that generates
- * a c++ source program equivalent to the IL and ST
- * code.
- */
-
-
-
-
-/***********************************************************************/
-/***********************************************************************/
-/***********************************************************************/
-/***********************************************************************/
-
-/* Returns the data type of an il_operand.
- *
- * Note that the il_operand may be a variable, in which case
- * we return the type of the variable instance.
- * The il_operand may also be a constant, in which case
- * we return the data type of that constant.
- *
- * The variable instance may be a member of a structured variable,
- * or an element in an array, or any combination of the two.
- *
- * The class constructor must be given the search scope
- * (function, function block or program within which
- * the possible il_operand variable instance was declared).
- */
-
-class search_il_operand_type_c {
-
-  private:
-    search_varfb_instance_type_c search_varfb_instance_type;
-    search_constant_type_c search_constant_type;
-
-  public:
-    search_il_operand_type_c(symbol_c *search_scope): search_varfb_instance_type(search_scope) {}
-
-  public:
-    symbol_c *get_type(symbol_c *il_operand) {
-      symbol_c *res;
-
-      /* We first assume that it is a constant... */
-      res = search_constant_type.get_type(il_operand);
-      if (res != NULL) return res;
-
-      /* Nope, now we assume it is a variable, and determine its type... */
-      res = search_varfb_instance_type.get_type(il_operand);
-      if (NULL != res) return res;
-
-      /* not found */
-      return NULL;
-    }
-};
-
-
-
-/***********************************************************************/
-/***********************************************************************/
-/***********************************************************************/
-/***********************************************************************/
-
-
-/* A new class to ouput the il default variable to c++ code
- * We use this class, inheriting from symbol_c, so it may be used
- * as any other symbol_c object in the intermediate parse tree,
- * more specifically, so it can be used as any other il operand.
- * This makes the rest of the code much easier...
- *
- * Nevertheless, the basic visitor class visitor_c does not know
- * how to visit this new il_default_variable_c class, so we have
- * to extend that too.
- * In reality extending the basic symbols doesn't quite work out
- * as cleanly as desired (we need to use dynamic_cast in the
- * accept method of the il_default_variable_c), but it is cleaner
- * than the alternative...
- */
-class il_default_variable_c;
-
-/* This visitor class is not really required, we could place the
- * visit() method directly in genertae_cc_il_c, but doing it in
- * a seperate class makes the architecture more evident...
- */
-class il_default_variable_visitor_c {
-  public:
-    virtual void *visit(il_default_variable_c *symbol) = 0;
-
-    virtual ~il_default_variable_visitor_c(void) {return;}
-};
-
-
-/* A class to print out to the resulting C++ code
- * the IL default variable name.
- *
- * It includes a reference to its name,
- * and the data type of the data currently stored
- * in this C++ variable... This is required because the
- * C++ variable is a union, and we must know which member
- * of the union top reference!!
- *
- * Note that we also need to keep track of the data type of
- * the value currently being stored in the default variable.
- * This is required so we can process parenthesis,
- *
- * e.g. :
- *         LD var1
- *         AND (
- *         LD var2
- *         OR var3
- *         )
- *
- * Note that we only execute the 'AND (' operation when we come across
- * the ')', i.e. once we have evaluated the result of the
- * instructions inside the parenthesis.
- * When we do execute the 'AND (' operation, we need to know the data type
- * of the operand, which in this case is the result of the evaluation of the
- * instruction list inside the parenthesis. We can only know this if we
- * keep track of the data type currently stored in the default variable!
- *
- * We use the current_type inside the generate_cc_il::default_variable_name variable
- * to track this!
- */
-class il_default_variable_c: public symbol_c {
-  public:
-    symbol_c *var_name;  /* in principle, this should point to an indentifier_c */
-    symbol_c *current_type;
-
-  public:
-    il_default_variable_c(const char *var_name_str, symbol_c *current_type);
-    virtual void *accept(visitor_c &visitor);
-};
-
-
-/***********************************************************************/
-/***********************************************************************/
-/***********************************************************************/
-/***********************************************************************/
-
-
-
-class generate_cc_il_c: public generate_cc_typedecl_c, il_default_variable_visitor_c {
-
-  private:
-    /* When compiling il code, it becomes necessary to determine the
-     * data type of il operands. To do this, we must first find the
-     * il operand's declaration, within the scope of the function block
-     * or function currently being processed.
-     * The following object does just that...
-     * This object instance will then later be called while the
-     * remaining il code is being handled.
-     */
-    //search_il_operand_type_c *search_il_operand_type;
-    search_expression_type_c *search_expression_type;
-
-    /* The initial value that should be given to the IL default variable
-     * imediately after a parenthesis is opened.
-     * This variable is only used to pass data from the
-     * il_expression_c visitor to the simple_instr_list_c visitor.
-     *
-     * e.g.:
-     *         LD var1
-     *         AND ( var2
-     *         OR var3
-     *         )
-     *
-     * In the above code sample, the line 'AND ( var2' constitutes
-     * an il_expression_c, where var2 should be loaded into the
-     * il default variable before continuing with the expression
-     * inside the parenthesis.
-     * Unfortunately, only the simple_instr_list_c may do the
-     * initial laoding of the var2 bariable following the parenthesis,
-     * so the il_expression_c visitor will have to pass 'var2' as a
-     * parameter to the simple_instr_list_c visitor.
-     * Ergo, the existance of the following parameter...!
-     */
-    symbol_c *il_default_variable_init_value;
-
-    /* Operand to the IL operation currently being processed... */
-    /* These variables are used to pass data from the
-     * il_simple_operation_c and il_expression_c visitors
-     * to the il operator visitors (i.e. LD_operator_c,
-     * LDN_operator_c, ST_operator_c, STN_operator_c, ...)
-     */
-    symbol_c *current_operand;
-    symbol_c *current_operand_type;
-
-    /* Label to which the current IL jump operation should jump to... */
-    /* This variable is used to pass data from the
-     * il_jump_operation_c visitor
-     * to the il jump operator visitors (i.e. JMP_operator_c,
-     * JMPC_operator_c, JMPCN_operator_c, ...)
-     */
-    symbol_c *jump_label;
-
-    /* The result of the comparison IL operations (GT, EQ, LT, ...)
-     * is a boolean variable.
-     * This class keeps track of the current data type stored in the
-     * il default variable. This is usually done by keeping a reference
-     * to the data type of the last operand. Nevertheless, in the case of
-     * the comparison IL operators, the data type of the result (a boolean)
-     * is not the data type of the operand. We therefore need an object
-     * of the boolean data type to keep as a reference of the current
-     * data type.
-     * The following object is it...
-     */
-    bool_type_name_c bool_type;
-
-    /* the data type of the IL default variable... */
-    #define IL_DEFVAR_T VAR_LEADER "IL_DEFVAR_T"
-    /* The name of the IL default variable... */
-    #define IL_DEFVAR   VAR_LEADER "IL_DEFVAR"
-    /* The name of the variable used to pass the result of a
-     * parenthesised instruction list to the immediately preceding
-     * scope ...
-     */
-    #define IL_DEFVAR_BACK   VAR_LEADER "IL_DEFVAR_BACK"
-    il_default_variable_c default_variable_name;
-    il_default_variable_c default_variable_back_name;
-
-    /* Some function calls in the body of functions or function blocks
-     * may leave some parameters to their default values, and
-     * ignore some output parameters of the function being called.
-     * Our conversion of ST functions to C++ does not contemplate that,
-     * i.e. each called function must get all it's input and output
-     * parameters set correctly.
-     * For input parameters we merely need to call the function with
-     * the apropriate default value, but for output parameters
-     * we must create temporary variables to hold the output value.
-     *
-     * We declare all the temporary output variables at the begining of
-     * the body of each function or function block, and use them as
-     * in function calls later on as they become necessary...
-     * Note that we cannot create these variables just before a function
-     * call, as the function call itself may be integrated within an
-     * expression, or another function call!
-     *
-     * The variables are declared in the exact same order in which they
-     * will be used later on during the function calls, which allows us
-     * to simply re-create the name that was used for the temporary variable
-     * instead of keeping it in some list.
-     * The names are recreated by the temp_var_name_factory, after reset()
-     * has been called!
-     *
-     * This function will genertae code similar to...
-     *
-     *     INT __TMP_0 = 23;
-     *     REAL __TMP_1 = 45.5;
-     *     ...
-     */
-    temp_var_name_c temp_var_name_factory;
-
-    /* When calling a function block, we must first find it's type,
-     * by searching through the declarations of the variables currently
-     * in scope.
-     * This class does just that...
-     * A new class is instantiated whenever we begin generating the code
-     * for a function block type declaration, or a program declaration.
-     * This object instance will then later be called while the
-     * function block's or the program's body is being handled.
-     *
-     * Note that functions cannot contain calls to function blocks,
-     * so we do not create an object instance when handling
-     * a function declaration.
-     */
-    search_fb_instance_decl_c *search_fb_instance_decl;
-
-
-  public:
-    generate_cc_il_c(stage4out_c *s4o_ptr, symbol_c *scope, const char *variable_prefix = NULL)
-    : generate_cc_typedecl_c(s4o_ptr),
-      default_variable_name(IL_DEFVAR, NULL),
-      default_variable_back_name(IL_DEFVAR_BACK, NULL)
-    {
-      //search_il_operand_type  = new search_il_operand_type_c(scope);
-      search_expression_type = new search_expression_type_c(scope);
-      search_fb_instance_decl = new search_fb_instance_decl_c(scope);
-      current_operand = NULL;
-      current_operand_type = NULL;
-      il_default_variable_init_value = NULL;
-      this->set_variable_prefix(variable_prefix);
-    }
-
-    virtual ~generate_cc_il_c(void) {
-      delete search_fb_instance_decl;
-      //delete search_il_operand_type;
-      delete search_expression_type;
-    }
-
-    void generate(instruction_list_c *il) {
-      generate_cc_tempvardecl_c generate_cc_tempvardecl(&s4o);
-      generate_cc_tempvardecl.generate(il, &temp_var_name_factory);
-      il->accept(*this);
-    }
-
-    /* Declare the backup to the default variable, that will store the result
-     * of the IL operations executed inside a parenthesis...
-     */
-    void declare_backup_variable(void) {
-      s4o.print(s4o.indent_spaces);
-      s4o.print(IL_DEFVAR_T);
-      s4o.print(" ");
-      print_backup_variable();
-      s4o.print(";\n");
-    }
-    
-    void print_backup_variable(void) {
-      this->default_variable_back_name.accept(*this);
-    }
-
-  private:
-    /* A helper function... */
-    /*
-    bool is_bool_type(symbol_c *type_symbol) {
-      return (NULL != dynamic_cast<bool_type_name_c *>(type_symbol));
-    }
-    */
-
-    /* A helper function... */
-    void *XXX_operator(symbol_c *lo, const char *op, symbol_c *ro) {
-      if ((NULL == lo) || (NULL == ro)) ERROR;
-      if (NULL == op) ERROR;
-
-      lo->accept(*this);
-      s4o.print(op);
-      ro->accept(*this);
-      return NULL;
-    }
-
-    /* A helper function... */
-    void *XXX_function(const char *func, symbol_c *lo, symbol_c *ro) {
-      if ((NULL == lo) || (NULL == ro)) ERROR;
-      if (NULL == func) ERROR;
-
-      lo->accept(*this);
-      s4o.print(" = ");
-      s4o.print(func);
-      s4o.print("(");
-      lo->accept(*this);
-      s4o.print(", ");
-      ro->accept(*this);
-      s4o.print(")");
-      return NULL;
-    }
-
-    /* A helper function... */
-    void *XXX_CAL_operator(const char *param_name, symbol_c *fb_name) {
-      if (NULL == fb_name) ERROR;
-      symbolic_variable_c *sv = dynamic_cast<symbolic_variable_c *>(fb_name);
-      if (NULL == sv) ERROR;
-      identifier_c *id = dynamic_cast<identifier_c *>(sv->var_name);
-      if (NULL == id) ERROR;
-
-      identifier_c param(param_name);
-
-      //SYM_REF3(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list)
-      il_param_assignment_c il_param_assignment(&param, &this->default_variable_name, NULL);
-      // SYM_LIST(il_param_list_c)
-      il_param_list_c il_param_list;
-      il_param_list.add_element(&il_param_assignment);
-      CAL_operator_c CAL_operator;
-      // SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list)
-      il_fb_call_c il_fb_call(&CAL_operator, id, NULL, &il_param_list);
-
-      il_fb_call.accept(*this);
-      return NULL;
-    }
-
-    /* A helper function... */
-    void *CMP_operator(symbol_c *o, const char *operation) {
-      if (NULL == o) ERROR;
-      if (NULL == this->default_variable_name.current_type) ERROR;
-
-      symbol_c *backup = this->default_variable_name.current_type;
-      this->default_variable_name.current_type = &(this->bool_type);
-      this->default_variable_name.accept(*this);
-      this->default_variable_name.current_type = backup;
-
-      s4o.print(" = ");
-      s4o.print(operation);
-      this->default_variable_name.current_type->accept(*this);
-      s4o.print("(2, ");
-      this->default_variable_name.accept(*this);
-      s4o.print(", ");
-      o->accept(*this);
-      s4o.print(")");
-
-      /* the data type resulting from this operation... */
-      this->default_variable_name.current_type = &(this->bool_type);
-      return NULL;
-    }
-
-
-    /* A helper function... */
-    void C_modifier(void) {
-      if (search_expression_type->is_bool_type(default_variable_name.current_type)) {
-        s4o.print("if (");
-        this->default_variable_name.accept(*this);
-        s4o.print(") ");
-      }
-      else {ERROR;}
-    }
-
-    /* A helper function... */
-    void CN_modifier(void) {
-      if (search_expression_type->is_bool_type(default_variable_name.current_type)) {
-        s4o.print("if (!");
-        this->default_variable_name.accept(*this);
-        s4o.print(") ");
-      }
-      else {ERROR;}
-    }
-
-
-public:
-void *visit(il_default_variable_c *symbol) {
-  //s4o.print("il_default_variable_c VISITOR!!\n");
-  symbol->var_name->accept(*this);
-  if (NULL != symbol->current_type) {
-    s4o.print(".");
-    symbol->current_type->accept(*this);
-    s4o.print("var");
-  }
-  return NULL;
-}
-
-
-private:
-
-/********************************************/
-/* B.1.4.1   Directly Represented Variables */
-/********************************************/
-// direct_variable: direct_variable_token   {$$ = new direct_variable_c($1);};
-void *visit(direct_variable_c *symbol) {
-  TRACE("direct_variable_c");
-  /* Do not use print_token() as it will change everything into uppercase */
-  if (strlen(symbol->value) == 0) ERROR;
-  s4o.print("*(");
-  this->print_variable_prefix();
-  s4o.printlocation(symbol->value + 1);
-  s4o.print(")");
-  return NULL;
-}
-
-/****************************************/
-/* B.2 - Language IL (Instruction List) */
-/****************************************/
-
-/***********************************/
-/* B 2.1 Instructions and Operands */
-/***********************************/
-
-/* please see the comment before the RET_operator_c visitor for details... */
-#define END_LABEL VAR_LEADER "end"
-
-/*| instruction_list il_instruction */
-void *visit(instruction_list_c *symbol) {
-  
-  /* Declare the backup to the default variable, that will store the result
-   * of the IL operations executed inside a parenthesis...
-   */
-  declare_backup_variable();
-  
-  /* Declare the default variable, that will store the result of the IL operations... */
-  s4o.print(s4o.indent_spaces);
-  s4o.print(IL_DEFVAR_T);
-  s4o.print(" ");
-  this->default_variable_name.accept(*this);
-  s4o.print(";\n\n");
-
-  print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");
-
-  /* write the label marking the end of the code block */
-  /* please see the comment before the RET_operator_c visitor for details... */
-  s4o.print("\n");
-  s4o.print(s4o.indent_spaces);
-  s4o.print(END_LABEL);
-  s4o.print(":\n");
-  s4o.indent_right();
-  /* since every label must be followed by at least one statement, and
-   * only the functions will introduce the return statement after this label,
-   * function blocks written in IL would result in invalid C++ code.
-   * To work around this we introduce the equivalent of a 'nop' operation
-   * to humour the compiler...
-   */
-  s4o.print(s4o.indent_spaces);
-  s4o.print("/* to humour the compiler, we insert a nop */\n");
-  s4o.print(s4o.indent_spaces);
-  this->default_variable_name.accept(*this);
-  s4o.print(" = ");
-  this->default_variable_name.accept(*this);
-  s4o.print(";\n");
-  s4o.indent_left();
-
-  return NULL;
-}
-
-
-/* | label ':' [il_incomplete_instruction] eol_list */
-// SYM_REF2(il_instruction_c, label, il_instruction)
-void *visit(il_instruction_c *symbol) {
-  if (NULL != symbol->label) {
-    symbol->label->accept(*this);
-    s4o.print(":\n");
-    s4o.print(s4o.indent_spaces);
-  }
-  symbol->il_instruction->accept(*this);
-  return NULL;
-}
-
-/* | il_simple_operator [il_operand] */
-//SYM_REF2(il_simple_operation_c, il_simple_operator, il_operand)
-void *visit(il_simple_operation_c *symbol) {
-  this->current_operand = symbol->il_operand;
-  if (NULL == this->current_operand) {
-    this->current_operand_type = NULL;
-  } else {
-    this->current_operand_type = search_expression_type->get_type(this->current_operand);
-    if (NULL == this->current_operand_type) ERROR;
-  }
-
-  symbol->il_simple_operator->accept(*this);
-
-  this->current_operand = NULL;
-  this->current_operand_type = NULL;
-  return NULL;
-}
-
-
-/* | function_name [il_operand_list] */
-// SYM_REF2(il_function_call_c, function_name, il_operand_list)
-void *visit(il_function_call_c *symbol) {
-  function_declaration_c *f_decl = function_symtable.find_value(symbol->function_name);
-
-  if (f_decl == function_symtable.end_value()) {
-    /* should never occur. The function being called MUST be in the symtable... */
-    function_type_t current_function_type = get_function_type((identifier_c *)symbol->function_name);
-    if (current_function_type == function_none) ERROR;
-    
-    symbol_c *param_data_type = default_variable_name.current_type;
-    symbol_c *return_data_type = (symbol_c *)search_expression_type->compute_standard_function_il(symbol, param_data_type);
-    if (NULL == return_data_type) ERROR;
-    
-    default_variable_name.current_type = return_data_type;
-    this->default_variable_name.accept(*this);
-    default_variable_name.current_type = param_data_type;
-    s4o.print(" = ");
-    
-    function_call_param_iterator_c function_call_param_iterator(symbol);
-    
-    int nb_param = 1;
-    if (symbol->il_operand_list != NULL)
-      nb_param += ((list_c *)symbol->il_operand_list)->n;
-
-#include "il_code_gen.c"
-
-#if 0
-    for(int current_param = 0; current_param < nb_param; current_param++) {
-      symbol_c *param_value;
-      if (current_param == 0)
-        param_value = &this->default_variable_name;
-      else {
-        symbol_c *param_name = NULL;
-        switch (current_function_type) {
-          default: ERROR;
-        }
-        
-         
-        /* Get the value from a foo(<param_name> = <param_value>) style call */
-        param_value = function_call_param_iterator.search(param_name);
-        delete param_name;
-        
-        /* Get the value from a foo(<param_value>) style call */
-        if (param_value == NULL)
-          param_value = function_call_param_iterator.next();
-        
-        if (param_value == NULL) ERROR;
-      }
-      
-      switch (current_function_type) {
-        case (function_sqrt):
-          if (current_param == 0) {
-            s4o.print("sqrt(");
-            param_value->accept(*this);
-            s4o.print(")");
-          }
-          else ERROR;
-          break;
-        default: ERROR;
-      }
-    } /* for(...) */
-#endif
-
-    /* the data type returned by the function, and stored in the il default variable... */
-    default_variable_name.current_type = return_data_type;
-  }
-  else {
-    /* determine the base data type returned by the function being called... */
-    search_base_type_c search_base_type;
-    symbol_c *return_data_type = (symbol_c *)f_decl->type_name->accept(search_base_type);
-    symbol_c *param_data_type = default_variable_name.current_type;
-    if (NULL == return_data_type) ERROR;
-  
-    default_variable_name.current_type = return_data_type;
-    this->default_variable_name.accept(*this);
-    default_variable_name.current_type = param_data_type;
-    s4o.print(" = ");
-  
-    symbol->function_name->accept(*this);
-    s4o.print("(");
-  
-    /* loop through each function parameter, find the value we should pass
-     * to it, and then output the c equivalent...
-     */
-  
-    function_param_iterator_c fp_iterator(f_decl);
-    identifier_c *param_name;
-    function_call_param_iterator_c function_call_param_iterator(symbol);
-    for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {
-      if (i != 1)
-        s4o.print(", ");
-  
-      symbol_c *param_type = fp_iterator.param_type();
-      if (param_type == NULL) ERROR;
-  
-      function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();
-  
-  
-      symbol_c *param_value = NULL;
-  
-      /* if it is the first parameter, semantics specifies that we should
-       * get the value off the IL default variable!
-       */
-     if (1 == i)
-       param_value = &this->default_variable_name;
-  
-      /* Get the value from a foo(<param_name> = <param_value>) style call */
-      /* NOTE: the following line of code is not required in this case, but it doesn't
-       * harm to leave it in, as in the case of a non-formal syntax function call,
-       * it will always return NULL.
-       * We leave it in in case we later decide to merge this part of the code together
-       * with the function calling code in generate_cc_st_c, which does require
-       * the following line...
-       */
-      if (param_value == NULL)
-        param_value = function_call_param_iterator.search(param_name);
-  
-      /* Get the value from a foo(<param_value>) style call */
-      if (param_value == NULL)
-        param_value = function_call_param_iterator.next();
-  
-      switch (param_direction) {
-        case function_param_iterator_c::direction_in:
-          if (param_value == NULL) {
-            /* No value given for parameter, so we must use the default... */
-            /* First check whether default value specified in function declaration...*/
-            param_value = fp_iterator.default_value();
-          }
-          if (param_value == NULL) {
-            /* If not, get the default value of this variable's type */
-            param_value = (symbol_c *)param_type->accept(*type_initial_value_c::instance());
-          }
-          if (param_value == NULL) ERROR;
-          param_value->accept(*this);
-          break;
-        case function_param_iterator_c::direction_out:
-        case function_param_iterator_c::direction_inout:
-          if (param_value == NULL) {
-  	  /* no parameter value given, so we pass a previously declared temporary variable. */
-            std::string *temp_var_name = temp_var_name_factory.new_name();
-            s4o.print(*temp_var_name);
-            delete temp_var_name;
-          } else {
-            param_value->accept(*this);
-          }
-          break;
-        case function_param_iterator_c::direction_extref:
-          /* TODO! */
-          ERROR;
-          break;
-      } /* switch */
-    } /* for(...) */
-  
-    s4o.print(")");
-    /* the data type returned by the function, and stored in the il default variable... */
-    default_variable_name.current_type = return_data_type;
-  }
-  
-  return NULL;
-}
-
-
-/* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */
-//SYM_REF4(il_expression_c, il_expr_operator, il_operand, simple_instr_list, unused)
-void *visit(il_expression_c *symbol) {
-  /* We will be recursevely interpreting an instruction list,
-   * so we store a backup of the data type of the value currently stored
-   * in the default variable, and set the current data type to NULL
-   */
-  symbol_c *old_current_default_variable_data_type = this->default_variable_name.current_type;
-  this->default_variable_name.current_type = NULL;
-
- /* Pass the symbol->il_operand to the simple_instr_list visitor
-  * using the il_default_variable_init_value parameter...
-  * Note that the simple_instr_list_c visitor will set this parameter
-  * to NULL as soon as it does not require it any longer,
-  * so we don't do it here again after the
-  *   symbol->simple_instr_list->accept(*this);
-  * returns...
-  */
-  this->il_default_variable_init_value = symbol->il_operand;
-
-  /* Now do the parenthesised instructions... */
-  /* NOTE: the following code line will get the variable
-   * this->default_variable_name.current_type updated!
-   */
-  symbol->simple_instr_list->accept(*this);
-
-  /* Now do the operation, using the previous result! */
-  /* NOTE: The result of the previous instruction list will be stored
-   * in a variable named IL_DEFVAR_BACK. This is done in the visitor
-   * to instruction_list_c objects...
-   */
-  this->current_operand = &(this->default_variable_back_name);
-  this->current_operand_type = this->default_variable_back_name.current_type;
-
-  this->default_variable_name.current_type = old_current_default_variable_data_type;
-  if (NULL == this->current_operand_type) ERROR;
-
-  symbol->il_expr_operator->accept(*this);
-
-  this->current_operand = NULL;
-  this->current_operand_type = NULL;
-  this->default_variable_back_name.current_type = NULL;
-  return NULL;
-}
-
-/*  il_jump_operator label */
-// SYM_REF2(il_jump_operation_c, il_jump_operator, label)
-void *visit(il_jump_operation_c *symbol) {
- /* Pass the symbol->label to the il_jump_operation visitor
-  * using the jump_label parameter...
-  */
-  this->jump_label = symbol->label;
-  symbol->il_jump_operator->accept(*this);
-  this->jump_label = NULL;
-
-  return NULL;
-}
-
-/*   il_call_operator prev_declared_fb_name
- * | il_call_operator prev_declared_fb_name '(' ')'
- * | il_call_operator prev_declared_fb_name '(' eol_list ')'
- * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'
- * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'
- */
-// SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list)
-void *visit(il_fb_call_c *symbol) {
-  symbol->il_call_operator->accept(*this);
-  s4o.print("{\n");
-  s4o.indent_right();
-  s4o.print(s4o.indent_spaces);
-
-  /* first figure out what is the name of the function block type of the function block being called... */
-  symbol_c *function_block_type_name = this->search_fb_instance_decl->get_type_name(symbol->fb_name);
-    /* should never occur. The function block instance MUST have been declared... */
-  if (function_block_type_name == NULL) ERROR;
-
-  /* Now find the declaration of the function block type being called... */
-  function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(function_block_type_name);
-    /* should never occur. The function block type being called MUST be in the symtable... */
-  if (fb_decl == function_block_type_symtable.end_value()) ERROR;
-
-  /* loop through each function block parameter, find the value we should pass
-   * to it, and then output the c equivalent...
-   */
-  function_param_iterator_c fp_iterator(fb_decl);
-  identifier_c *param_name;
-  function_call_param_iterator_c function_call_param_iterator(symbol);
-  for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {
-    function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();
-
-    /* Get the value from a foo(<param_name> = <param_value>) style call */
-    symbol_c *param_value = function_call_param_iterator.search(param_name);
-
-    /* Get the value from a foo(<param_value>) style call */
-    if (param_value == NULL)
-      param_value = function_call_param_iterator.next();
-
-    /* now output the value assignment */
-    if (param_value != NULL)
-      if ((param_direction == function_param_iterator_c::direction_in) ||
-          (param_direction == function_param_iterator_c::direction_inout)) {
-        symbol->fb_name->accept(*this);
-        s4o.print(".");
-        param_name->accept(*this);
-        s4o.print(" = ");
-        param_value->accept(*this);
-        s4o.print(";\n" + s4o.indent_spaces);
-      }
-  } /* for(...) */
-
-  /* now call the function... */
-  function_block_type_name->accept(*this);
-  s4o.print(FB_FUNCTION_SUFFIX);
-  s4o.print("(&");
-  symbol->fb_name->accept(*this);
-  s4o.print(")");
-
-  /* loop through each function parameter, find the variable to which
-   * we should atribute the value of all output or inoutput parameters.
-   */
-  fp_iterator.reset();
-  function_call_param_iterator.reset();
-  for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {
-    function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();
-
-    /* Get the value from a foo(<param_name> = <param_value>) style call */
-    symbol_c *param_value = function_call_param_iterator.search(param_name);
-
-    /* Get the value from a foo(<param_value>) style call */
-    if (param_value == NULL)
-      param_value = function_call_param_iterator.next();
-
-    /* now output the value assignment */
-    if (param_value != NULL)
-      if ((param_direction == function_param_iterator_c::direction_out) ||
-          (param_direction == function_param_iterator_c::direction_inout)) {
-        s4o.print(";\n"+ s4o.indent_spaces);
-        param_value->accept(*this);
-        s4o.print(" = ");
-        symbol->fb_name->accept(*this);
-        s4o.print(".");
-        param_name->accept(*this);
-      }
-  } /* for(...) */
-
-  s4o.print(";\n");
-  s4o.indent_left();
-  s4o.print(s4o.indent_spaces);
-  s4o.print("}");
-
-  return NULL;
-}
-
-
-
-/* | function_name '(' eol_list [il_param_list] ')' */
-// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list)
-void *visit(il_formal_funct_call_c *symbol) {
-  function_declaration_c *f_decl = function_symtable.find_value(symbol->function_name);
-
-  if (f_decl == function_symtable.end_value())
-    /* should never occur. The function being called MUST be in the symtable... */
-    ERROR;
-
-  symbol->function_name->accept(*this);
-  s4o.print("(");
-
-  /* loop through each function parameter, find the value we should pass
-   * to it, and then output the c equivalent...
-   */
-
-  function_param_iterator_c fp_iterator(f_decl);
-  identifier_c *param_name;
-  function_call_param_iterator_c function_call_param_iterator(symbol);
-  for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {
-    if (i != 1)
-      s4o.print(", ");
-
-    symbol_c *param_type = fp_iterator.param_type();
-    if (param_type == NULL) ERROR;
-
-    function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();
-
-
-    symbol_c *param_value = NULL;
-
-    /* Get the value from a foo(<param_name> = <param_value>) style call */
-    if (param_value == NULL)
-      param_value = function_call_param_iterator.search(param_name);
-
-    /* Get the value from a foo(<param_value>) style call */
-    /* NOTE: the following line of code is not required in this case, but it doesn't
-     * harm to leave it in, as in the case of a formal syntax function call,
-     * it will always return NULL.
-     * We leave it in in case we later decide to merge this part of the code together
-     * with the function calling code in generate_cc_st_c, which does require
-     * the following line...
-     */
-    if (param_value == NULL)
-      param_value = function_call_param_iterator.next();
-
-    switch (param_direction) {
-      case function_param_iterator_c::direction_in:
-        if (param_value == NULL) {
-          /* No value given for parameter, so we must use the default... */
-          /* First check whether default value specified in function declaration...*/
-          param_value = fp_iterator.default_value();
-        }
-        if (param_value == NULL) {
-          /* If not, get the default value of this variable's type */
-          param_value = (symbol_c *)param_type->accept(*type_initial_value_c::instance());
-        }
-        if (param_value == NULL) ERROR;
-        param_value->accept(*this);
-	break;
-      case function_param_iterator_c::direction_out:
-      case function_param_iterator_c::direction_inout:
-        if (param_value == NULL) {
-	  /* no parameter value given, so we pass a previously declared temporary variable. */
-          std::string *temp_var_name = temp_var_name_factory.new_name();
-          s4o.print(*temp_var_name);
-          delete temp_var_name;
-	} else {
-          param_value->accept(*this);
-	}
-	break;
-      case function_param_iterator_c::direction_extref:
-        /* TODO! */
-        ERROR;
-	break;
-    } /* switch */
-  } /* for(...) */
-
-  // symbol->parameter_assignment->accept(*this);
-  s4o.print(")");
-  return NULL;
-}
-
-
-/* | il_operand_list ',' il_operand */
-// SYM_LIST(il_operand_list_c)
-void *visit(il_operand_list_c *symbol) {ERROR; return NULL;} // should never get called!
-
-
-/* | simple_instr_list il_simple_instruction */
-// SYM_LIST(simple_instr_list_c)
-void *visit(simple_instr_list_c *symbol) {
-  /* A simple_instr_list_c is used to store a list of il operations
-   * being done within parenthesis...
-   *
-   * e.g.:
-   *         LD var1
-   *         AND ( var2
-   *         OR var3
-   *         OR var4
-   *         )
-   *
-   * This will be converted to C++ by defining a new scope
-   * with a new il default variable, and executing the il operands
-   * within this new scope.
-   * At the end of the scope the result, i.e. the value currently stored
-   * in the il default variable is copied to the variable used to take this
-   * value to the outside scope...
-   *
-   * The above example will result in the following C++ code:
-   * {__IL_DEFVAR_T __IL_DEFVAR_BACK;
-   *  __IL_DEFVAR_T __IL_DEFVAR;
-   *
-   *  __IL_DEFVAR.INTvar = var1;
-   *  {
-   *    __IL_DEFVAR_T __IL_DEFVAR;
-   *
-   *    __IL_DEFVAR.INTvar = var2;
-   *    __IL_DEFVAR.INTvar |= var3;
-   *    __IL_DEFVAR.INTvar |= var4;
-   *
-   *    __IL_DEFVAR_BACK = __IL_DEFVAR;
-   *  }
-   *  __IL_DEFVAR.INTvar &= __IL_DEFVAR_BACK.INTvar;
-   *
-   * }
-   *
-   *  The intial value of the il default variable (in the above
-   * example 'var2') is passed to this simple_instr_list_c visitor
-   * using the il_default_variable_init_value parameter.
-   * Since it is possible to have parenthesis inside other parenthesis
-   * recursively, we reset the il_default_variable_init_value to NULL
-   * as soon as we no longer require it, as it may be used once again
-   * in the line
-   *  print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");
-   *
-   */
-
-  /* Declare the default variable, that will store the result of the IL operations... */
-  s4o.print("{\n");
-  s4o.indent_right();
-
-  s4o.print(s4o.indent_spaces);
-  s4o.print(IL_DEFVAR_T);
-  s4o.print(" ");
-  this->default_variable_name.accept(*this);
-  s4o.print(";\n\n");
-
-  /* Check whether we should initiliase the il default variable... */
-  if (NULL != this->il_default_variable_init_value) {
-    /* Yes, we must... */
-    /* We will do it by instatiating a LD operator, and having this
-     * same generate_cc_il_c class visiting it!
-     */
-    LD_operator_c ld_oper;
-    il_simple_operation_c il_simple_oper(&ld_oper, this->il_default_variable_init_value);
-
-    s4o.print(s4o.indent_spaces);
-    il_simple_oper.accept(*this);
-    s4o.print(";\n");
-  }
-
-  /* this parameter no longer required... */
-  this->il_default_variable_init_value = NULL;
-
-  print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");
-
-  /* copy the result in the default variable to the variable
-   * used to pass the data out to the scope enclosing
-   * the current scope!
-   *
-   * We also need to update the data type currently stored within
-   * the variable used to pass the data to the outside scope...
-   */
-  this->default_variable_back_name.current_type = this->default_variable_name.current_type;
-  s4o.print("\n");
-  s4o.print(s4o.indent_spaces);
-  this->default_variable_back_name.accept(*this);
-  s4o.print(" = ");
-  this->default_variable_name.accept(*this);
-  s4o.print(";\n");
-
-  s4o.indent_left();
-  s4o.print(s4o.indent_spaces);
-  s4o.print("}\n");
-  s4o.print(s4o.indent_spaces);
-  return NULL;
-}
-
-/* | il_initial_param_list il_param_instruction */
-// SYM_LIST(il_param_list_c)
-void *visit(il_param_list_c *symbol) {ERROR; return NULL;} // should never get called!
-
-/*  il_assign_operator il_operand
- * | il_assign_operator '(' eol_list simple_instr_list ')'
- */
-// SYM_REF4(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list, unused)
-void *visit(il_param_assignment_c *symbol) {ERROR; return NULL;} // should never get called!
-
-/*  il_assign_out_operator variable */
-// SYM_REF2(il_param_out_assignment_c, il_assign_out_operator, variable);
-void *visit(il_param_out_assignment_c *symbol) {ERROR; return NULL;} // should never get called!
-
-/*******************/
-/* B 2.2 Operators */
-/*******************/
-
-void *visit(LD_operator_c *symbol)	{
-  /* the data type resulting from this operation... */
-  this->default_variable_name.current_type = this->current_operand_type;
-  XXX_operator(&(this->default_variable_name), " = ", this->current_operand);
-  return NULL;
-}
-
-void *visit(LDN_operator_c *symbol)	{
-  /* the data type resulting from this operation... */
-  this->default_variable_name.current_type = this->current_operand_type;
-  XXX_operator(&(this->default_variable_name),
-               search_expression_type->is_bool_type(this->current_operand_type)?" = !":" = ~",
-               this->current_operand);
-  return NULL;
-}
-
-void *visit(ST_operator_c *symbol)	{
-  XXX_operator(this->current_operand, " = ",&(this->default_variable_name));
-  /* the data type resulting from this operation is unchamged. */
-  return NULL;
-}
-
-void *visit(STN_operator_c *symbol)	{
-  XXX_operator(this->current_operand,
-               search_expression_type->is_bool_type(this->current_operand_type)?" = !":" = ~",
-               &(this->default_variable_name));
-  /* the data type resulting from this operation is unchamged. */
-  return NULL;
-}
-
-void *visit(NOT_operator_c *symbol)	{
-  if ((NULL != this->current_operand) || (NULL != this->current_operand_type)) ERROR;
-  XXX_operator(&(this->default_variable_name),
-               search_expression_type->is_bool_type(this->default_variable_name.current_type)?" = !":" = ~",
-               &(this->default_variable_name));
-  /* the data type resulting from this operation is unchanged. */
-  return NULL;
-}
-
-void *visit(S_operator_c *symbol)	{
-  if ((NULL == this->current_operand) || (NULL == this->current_operand_type)) ERROR;
-
-  C_modifier();
-  this->current_operand->accept(*this);
-  s4o.print(search_expression_type->is_bool_type(this->current_operand_type)?" = true":" = 1");
-  /* the data type resulting from this operation is unchanged! */
-  return NULL;
-}
-
-void *visit(R_operator_c *symbol)	{
-  if ((NULL == this->current_operand) || (NULL == this->current_operand_type)) ERROR;
-
-  C_modifier();
-  this->current_operand->accept(*this);
-  s4o.print(search_expression_type->is_bool_type(this->current_operand_type)?" = false":" = 0");
-  /* the data type resulting from this operation is unchanged! */
-  return NULL;
-}
-
-void *visit(S1_operator_c *symbol)	{return XXX_CAL_operator("S1", this->current_operand);}
-void *visit(R1_operator_c *symbol)	{return XXX_CAL_operator("R1", this->current_operand);}
-void *visit(CLK_operator_c *symbol)	{return XXX_CAL_operator("CLK", this->current_operand);}
-void *visit(CU_operator_c *symbol)	{return XXX_CAL_operator("CU", this->current_operand);}
-void *visit(CD_operator_c *symbol)	{return XXX_CAL_operator("CD", this->current_operand);}
-void *visit(PV_operator_c *symbol)	{return XXX_CAL_operator("PV", this->current_operand);}
-void *visit(IN_operator_c *symbol)	{return XXX_CAL_operator("IN", this->current_operand);}
-void *visit(PT_operator_c *symbol)	{return XXX_CAL_operator("PT", this->current_operand);}
-
-void *visit(AND_operator_c *symbol)	{
-  if (search_expression_type->is_binary_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name), " &= ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(OR_operator_c *symbol)	{
-  if (search_expression_type->is_binary_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name), " |= ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(XOR_operator_c *symbol)	{
-  if (search_expression_type->is_binary_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    // '^' is a bit by bit exclusive OR !! Also seems to work with boolean types!
-    XXX_operator(&(this->default_variable_name), " ^= ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(ANDN_operator_c *symbol)	{
-  if (search_expression_type->is_binary_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name),
-                 search_expression_type->is_bool_type(this->current_operand_type)?" &= !":" &= ~",
-                 this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(ORN_operator_c *symbol)	{
-  if (search_expression_type->is_binary_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name),
-                 search_expression_type->is_bool_type(this->current_operand_type)?" |= !":" |= ~",
-                 this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(XORN_operator_c *symbol)	{
-  if (search_expression_type->is_binary_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name),
-                 // bit by bit exclusive OR !! Also seems to work with boolean types!
-                 search_expression_type->is_bool_type(this->current_operand_type)?" ^= !":" ^= ~",
-                 this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(ADD_operator_c *symbol)	{
-  if (search_expression_type->is_time_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_time_type(this->current_operand_type)) {
-    XXX_function("__time_add", &(this->default_variable_name), this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-    return NULL;
-  }
-  if (search_expression_type->is_num_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name), " += ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-    return NULL;
-  }
-  ERROR;
-  return NULL;
-}
-
-void *visit(SUB_operator_c *symbol)	{
-  if (search_expression_type->is_time_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_time_type(this->current_operand_type)) {
-    XXX_function("__time_sub", &(this->default_variable_name), this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-    return NULL;
-  }
-  if (search_expression_type->is_num_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name), " -= ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-    return NULL;
-  }
-  ERROR;
-  return NULL;
-}
-
-void *visit(MUL_operator_c *symbol)	{
-  if (search_expression_type->is_time_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_integer_type(this->current_operand_type)) {
-    XXX_function("__time_mul", &(this->default_variable_name), this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-    return NULL;
-  }
-  if (search_expression_type->is_num_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name), " *= ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-    return NULL;
-  }
-  ERROR;
-  return NULL;
-}
-
-void *visit(DIV_operator_c *symbol)	{
-  if (search_expression_type->is_num_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name), " /= ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(MOD_operator_c *symbol)	{
-  if (search_expression_type->is_num_type(this->default_variable_name.current_type) &&
-      search_expression_type->is_same_type(this->default_variable_name.current_type, this->current_operand_type)) {
-    XXX_operator(&(this->default_variable_name), " %= ", this->current_operand);
-    /* the data type resulting from this operation... */
-    this->default_variable_name.current_type = this->current_operand_type;
-  }
-  else {ERROR;}
-  return NULL;
-}
-
-void *visit(GT_operator_c *symbol)	{
-  return CMP_operator(this->current_operand, "__gt_");
-}
-
-void *visit(GE_operator_c *symbol)	{
-  return CMP_operator(this->current_operand, "__ge_");
-}
-
-void *visit(EQ_operator_c *symbol)	{
-  return CMP_operator(this->current_operand, "__eq_");
-}
-
-void *visit(LT_operator_c *symbol)	{
-  return CMP_operator(this->current_operand, "__lt_");
-}
-
-void *visit(LE_operator_c *symbol)	{
-  return CMP_operator(this->current_operand, "__le_");
-}
-
-void *visit(NE_operator_c *symbol)	{
-  return CMP_operator(this->current_operand, "__ne_");
-}
-
-
-//SYM_REF0(CAL_operator_c)
-// This method will be called from within the il_fb_call_c visitor method
-void *visit(CAL_operator_c *symbol) {return NULL;}
-
-//SYM_REF0(CALC_operator_c)
-// This method will be called from within the il_fb_call_c visitor method
-void *visit(CALC_operator_c *symbol) {C_modifier(); return NULL;}
-
-//SYM_REF0(CALCN_operator_c)
-// This method will be called from within the il_fb_call_c visitor method
-void *visit(CALCN_operator_c *symbol) {CN_modifier(); return NULL;}
-
-/* NOTE: The semantics of the RET operator requires us to return a value
- *       if the IL code is inside a function, but simply return no value if
- *       the IL code is inside a function block or program!
- *       Nevertheless, it is the generate_cc_c class itself that
- *       introduces the 'reaturn <value>' into the c++ code at the end
- *       of every function. This class does not know whether the IL code
- *       is inside a function or a function block.
- *       We work around this by jumping to the end of the code,
- *       that will be marked by the END_LABEL label in the
- *       instruction_list_c visitor...
- */
-// SYM_REF0(RET_operator_c)
-void *visit(RET_operator_c *symbol) {
-  s4o.print("goto ");s4o.print(END_LABEL);
-  return NULL;
-}
-
-// SYM_REF0(RETC_operator_c)
-void *visit(RETC_operator_c *symbol) {
-  C_modifier();
-  s4o.print("goto ");s4o.print(END_LABEL);
-  return NULL;
-}
-
-// SYM_REF0(RETCN_operator_c)
-void *visit(RETCN_operator_c *symbol) {
-  CN_modifier();
-  s4o.print("goto ");s4o.print(END_LABEL);
-  return NULL;
-}
-
-//SYM_REF0(JMP_operator_c)
-void *visit(JMP_operator_c *symbol)	{
-  if (NULL == this->jump_label) ERROR;
-
-  s4o.print("goto ");
-  this->jump_label->accept(*this);
-  /* the data type resulting from this operation is unchanged! */
-  return NULL;
-}
-
-// SYM_REF0(JMPC_operator_c)
-void *visit(JMPC_operator_c *symbol)	{
-  if (NULL == this->jump_label) ERROR;
-
-  C_modifier();
-  s4o.print("goto ");
-  this->jump_label->accept(*this);
-  /* the data type resulting from this operation is unchanged! */
-  return NULL;
-}
-
-// SYM_REF0(JMPCN_operator_c)
-void *visit(JMPCN_operator_c *symbol)	{
-  if (NULL == this->jump_label) ERROR;
-
-  CN_modifier();
-  s4o.print("goto ");
-  this->jump_label->accept(*this);
-  /* the data type resulting from this operation is unchanged! */
-  return NULL;
-}
-
-#if 0
-/*| [NOT] any_identifier SENDTO */
-SYM_REF2(il_assign_out_operator_c, option, variable_name)
-#endif
-
-}; /* generate_cc_il_c */
-
-
-
-
-
-
-
-
-
-/* The implementation of the single visit() member function
- * of il_default_variable_c.
- * It can only come after the full declaration of
- * generate_cc_il_c. Since we define and declare
- * generate_cc_il_c simultaneously, it can only come
- * after the definition...
- */
-void *il_default_variable_c::accept(visitor_c &visitor) {
-  /* An ugly hack!! */
-  /* This is required because we need to over-ride the base
-   * accept(visitor_c &) method of the class symbol_c,
-   * so this method may be called through a symbol_c *
-   * reference!
-   *
-   * But, the visitor_c does not include a visitor to
-   * an il_default_variable_c, which means that we couldn't
-   * simply call visitor.visit(this);
-   *
-   * We therefore need to use the dynamic_cast hack!!
-   *
-   * Note too that we can't cast a visitor_c to a
-   * il_default_variable_visitor_c, since they are not related.
-   * Nor may the il_default_variable_visitor_c inherit from
-   * visitor_c, because then generate_cc_il_c would contain
-   * two visitor_c base classes, one each through
-   * il_default_variable_visitor_c and generate_cc_type_c
-   *
-   * We could use virtual inheritance of the visitor_c, but it
-   * would probably create more problems than it is worth!
-   */
-  generate_cc_il_c *v;
-  v = dynamic_cast<generate_cc_il_c *>(&visitor);
-  if (v == NULL) ERROR;
-
-  return v->visit(this);
-}
-
-
-
-
-il_default_variable_c::il_default_variable_c(const char *var_name_str, symbol_c *current_type) {
-  if (NULL == var_name_str) ERROR;
-  /* Note: current_type may start off with NULL */
-
-  this->var_name = new identifier_c(var_name_str);
-  if (NULL == this->var_name) ERROR;
-
-  this->current_type = current_type;
-}