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/*

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 *  matiec - a compiler for the programming languages defined in IEC 61131-3

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 *

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 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

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 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

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 *

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 *  This program 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 3 of the License, or

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 *  (at your option) any later version.

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 *

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 *  This program 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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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

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 *

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 * Based on the

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 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

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 *

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 */

    27

    28

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/*

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 * Conversion of st statements (i.e. ST code).

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 *

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 * This is part of the 4th stage that generates

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 * a C source program equivalent to the IL and ST, or SFC

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 * code.

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 */

    36

    37

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/***********************************************************************/

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/***********************************************************************/

    40

/***********************************************************************/

    41

/***********************************************************************/

    42

    43

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class generate_c_st_c: public generate_c_typedecl_c {

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  public:

    47

    typedef enum {

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      expression_vg,

    49

      assignment_vg,

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      complextype_base_vg,

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      complextype_suffix_vg,

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      fparam_output_vg

    53

    } variablegeneration_t;

    54

    61

  private:

    62

    /* When calling a function block, we must first find it's type,

    63

     * by searching through the declarations of the variables currently

    64

     * in scope.

    65

     * This class does just that...

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     * A new class is instantiated whenever we begin generating the code

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     * for a function block type declaration, or a program declaration.

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     * This object instance will then later be called while the

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     * function block's or the program's body is being handled.

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     *

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     * Note that functions cannot contain calls to function blocks,

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     * so we do not create an object instance when handling

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     * a function declaration.

    74

     */

    75

    search_fb_instance_decl_c *search_fb_instance_decl;

    76

    77

    /* When compiling st code, it becomes necessary to determine the

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     * data type of st expressions. To do this, we must first find the

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     * st operand's declaration, within the scope of the function block

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     * or function currently being processed.

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     * The following object does just that...

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     * This object instance will then later be called while the

    83

     * remaining st code is being handled.

    84

     */

    85

    search_expression_type_c *search_expression_type;

    86

    87

    search_varfb_instance_type_c *search_varfb_instance_type;

    88

    89

    search_base_type_c search_base_type;

    90

    91

    symbol_c* current_array_type;

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    symbol_c* current_param_type;

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    int fcall_number;

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    symbol_c *fbname;

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    variablegeneration_t wanted_variablegeneration;

   101

   102

  public:

   103

    generate_c_st_c(stage4out_c *s4o_ptr, symbol_c *name, symbol_c *scope, const char *variable_prefix = NULL)

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    : generate_c_typedecl_c(s4o_ptr) {

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      search_fb_instance_decl = new search_fb_instance_decl_c(scope);

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      search_expression_type = new search_expression_type_c(scope);

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      search_varfb_instance_type = new search_varfb_instance_type_c(scope);

   108

      this->set_variable_prefix(variable_prefix);

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      current_array_type = NULL;

   110

      current_param_type = NULL;

   111

      fcall_number = 0;

   112

      fbname = name;

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      wanted_variablegeneration = expression_vg;

   115

    }

   116

   117

    virtual ~generate_c_st_c(void) {

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      delete search_fb_instance_decl;

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      delete search_expression_type;

   120

      delete search_varfb_instance_type;

   121

    }

   122

   123

   124

  public:

   125

    void generate(statement_list_c *stl) {

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      stl->accept(*this);

   127

    }

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   129

  private:

   130

   131

void *print_getter(symbol_c *symbol) {

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  unsigned int vartype = search_varfb_instance_type->get_vartype(symbol);

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  if (wanted_variablegeneration == fparam_output_vg) {

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  	if (vartype == search_var_instance_decl_c::external_vt)

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      s4o.print(GET_EXTERNAL_BY_REF);

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    else if (vartype == search_var_instance_decl_c::located_vt)

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      s4o.print(GET_LOCATED_BY_REF);

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    else

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      s4o.print(GET_VAR_BY_REF);

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  }

   141

  else {

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	if (vartype == search_var_instance_decl_c::external_vt)

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	  s4o.print(GET_EXTERNAL);

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	else if (vartype == search_var_instance_decl_c::located_vt)

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	  s4o.print(GET_LOCATED);

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	else

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	  s4o.print(GET_VAR);

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  }

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  s4o.print("(");

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   151

  variablegeneration_t old_wanted_variablegeneration = wanted_variablegeneration;

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  wanted_variablegeneration = complextype_base_vg;

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  symbol->accept(*this);

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  if (search_varfb_instance_type->type_is_complex())

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    s4o.print(",");

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  wanted_variablegeneration = complextype_suffix_vg;

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  symbol->accept(*this);

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  s4o.print(")");

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  wanted_variablegeneration = old_wanted_variablegeneration;

   160

  return NULL;

   161

}

   162

   163

void *print_setter(symbol_c* symbol,

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		symbol_c* type,

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		symbol_c* value,

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		symbol_c* fb_symbol = NULL,

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		symbol_c* fb_value = NULL) {

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  unsigned int vartype = search_varfb_instance_type->get_vartype(symbol);

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  if (vartype == search_var_instance_decl_c::external_vt) {

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    symbolic_variable_c *variable = dynamic_cast<symbolic_variable_c *>(symbol);

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    /* TODO Find a solution for forcing global complex variables */

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    if (variable != NULL) {

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      s4o.print(SET_EXTERNAL);

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      s4o.print("(");

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      variable->var_name->accept(*this);

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      s4o.print(",");

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    }

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    else {

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      s4o.print(SET_COMPLEX_EXTERNAL);

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      s4o.print("(");

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    }

   183

  }

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  else {

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    if (vartype == search_var_instance_decl_c::located_vt)

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      s4o.print(SET_LOCATED);

   187

    else

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      s4o.print(SET_VAR);

   189

    s4o.print("(");

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  }

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   192

  if (fb_symbol != NULL) {

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    print_variable_prefix();

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    fb_symbol->accept(*this);

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    s4o.print(".");

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  }

   197

  else

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    wanted_variablegeneration = complextype_base_vg;

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  symbol->accept(*this);

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  s4o.print(",");

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  wanted_variablegeneration = expression_vg;

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  print_check_function(type, value, fb_value);

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  /* We need to call search_varfb_instance_type->get_vartype() again, as it may have been called

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   * again since we called it in the beginning of this print_setter() function.

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   * This make sure the call to search_varfb_instance_type->type_is_complex() will return

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   * the correct value regarding our 'symbol'.

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   */

   209

  search_varfb_instance_type->get_vartype(symbol);

   210

  if (search_varfb_instance_type->type_is_complex()) {

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    s4o.print(",");

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    wanted_variablegeneration = complextype_suffix_vg;

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    symbol->accept(*this);

   214

  }

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  s4o.print(")");

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  wanted_variablegeneration = expression_vg;

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  return NULL;

   218

}

   219

   238

/*********************/

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/* B 1.4 - Variables */

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/*********************/

   241

void *visit(symbolic_variable_c *symbol) {

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  unsigned int vartype;

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  if (wanted_variablegeneration == complextype_base_vg)

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         generate_c_base_c::visit(symbol);

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  else if (wanted_variablegeneration == complextype_suffix_vg)

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         return NULL;

   247

  else if (this->is_variable_prefix_null()) {

   248

         vartype = search_varfb_instance_type->get_vartype(symbol);

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         if (wanted_variablegeneration == fparam_output_vg) {

   250

           s4o.print("&(");

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           generate_c_base_c::visit(symbol);

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           s4o.print(")");

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         } 

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         else {

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           generate_c_base_c::visit(symbol);

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         }

   257

  }

   258

  else

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      print_getter(symbol);

   260

  return NULL;

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}

   262

   263

/********************************************/

   264

/* B.1.4.1   Directly Represented Variables */

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/********************************************/

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// direct_variable: direct_variable_token   {$$ = new direct_variable_c($1);};

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void *visit(direct_variable_c *symbol) {

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  TRACE("direct_variable_c");

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  /* Do not use print_token() as it will change everything into uppercase */

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  if (strlen(symbol->value) == 0) ERROR;

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  if (this->is_variable_prefix_null()) {

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    if (wanted_variablegeneration != fparam_output_vg)

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	  s4o.print("*(");

   274

  }

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  else {

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    switch (wanted_variablegeneration) {

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      case expression_vg:

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  	    s4o.print(GET_LOCATED);

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  	    s4o.print("(");

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  	    break;

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      case fparam_output_vg:

   282

        s4o.print(GET_LOCATED_BY_REF);

   283

        s4o.print("(");

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        break;

   285

      default:

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        break;

   287

    }

   288

  }

   289

  this->print_variable_prefix();

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  s4o.printlocation(symbol->value + 1);

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  if ((this->is_variable_prefix_null() && wanted_variablegeneration != fparam_output_vg) ||

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	  wanted_variablegeneration != assignment_vg)

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    s4o.print(")");

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  return NULL;

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}

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/*************************************/

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/* B.1.4.2   Multi-element Variables */

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/*************************************/

   300

   301

// SYM_REF2(structured_variable_c, record_variable, field_selector)

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void *visit(structured_variable_c *symbol) {

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  TRACE("structured_variable_c");

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  switch (wanted_variablegeneration) {

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    case complextype_base_vg:

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      symbol->record_variable->accept(*this);

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      break;

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    case complextype_suffix_vg:

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      symbol->record_variable->accept(*this);

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      s4o.print(".");

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      symbol->field_selector->accept(*this);

   312

      break;

   313

    default:

   314

      if (this->is_variable_prefix_null()) {

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    	symbol->record_variable->accept(*this);

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    	s4o.print(".");

   317

    	symbol->field_selector->accept(*this);

   318

      }

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      else

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    	print_getter(symbol);

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      break;

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  }

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  return NULL;

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}

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   326

/*  subscripted_variable '[' subscript_list ']' */

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//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

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void *visit(array_variable_c *symbol) {

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  switch (wanted_variablegeneration) {

   330

    case complextype_base_vg:

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      symbol->subscripted_variable->accept(*this);

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      break;

   333

    case complextype_suffix_vg:

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      symbol->subscripted_variable->accept(*this);

   335

   336

      current_array_type = search_varfb_instance_type->get_type_id(symbol->subscripted_variable);

   337

      if (current_array_type == NULL) ERROR;

   338

   339

      s4o.print(".table");

   340

      wanted_variablegeneration = expression_vg;

   341

      symbol->subscript_list->accept(*this);

   342

      wanted_variablegeneration = complextype_suffix_vg;

   343

   344

      current_array_type = NULL;

   345

      break;

   346

    default:

   347

      if (this->is_variable_prefix_null()) {

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    	symbol->subscripted_variable->accept(*this);

   349

   350

    	current_array_type = search_varfb_instance_type->get_type_id(symbol->subscripted_variable);

   351

    	if (current_array_type == NULL) ERROR;

   352

   353

    	s4o.print(".table");

   354

        symbol->subscript_list->accept(*this);

   355

   356

        current_array_type = NULL;

   357

      }

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      else

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    	print_getter(symbol);

   360

      break;

   361

  }

   362

  return NULL;

   363

}

   364

   365

/* subscript_list ',' subscript */

   366

void *visit(subscript_list_c *symbol) {

   367

  for (int i =  0; i < symbol->n; i++) {

   368

    s4o.print("[__");

   369

    current_array_type->accept(*this);

   370

    s4o.print("_TRANSIDX(");

   371

    print_integer(i);

   372

    s4o.print(",");

   373

    symbol->elements[i]->accept(*this);

   374

    s4o.print(")]");

   375

  }

   376

  return NULL;

   377

}

   378

   379

/******************************************/

   380

/* B 1.4.3 - Declaration & Initialisation */

   381

/******************************************/

   382

   383

/* helper symbol for structure_initialization */

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/* structure_element_initialization_list ',' structure_element_initialization */

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void *visit(structure_element_initialization_list_c *symbol) {

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  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   387

  structure_initialization->init_structure_default(this->current_param_type);

   388

  structure_initialization->init_structure_values(symbol);

   389

  delete structure_initialization;

   390

  return NULL;

   391

}

   392

   393

/* helper symbol for array_initialization */

   394

/* array_initial_elements_list ',' array_initial_elements */

   395

void *visit(array_initial_elements_list_c *symbol) {

   396

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   397

  array_initialization->init_array_size(this->current_param_type);

   398

  array_initialization->init_array_values(symbol);

   399

  delete array_initialization;

   400

  return NULL;

   401

}

   402

   403

/***************************************/

   404

/* B.3 - Language ST (Structured Text) */

   405

/***************************************/

   406

/***********************/

   407

/* B 3.1 - Expressions */

   408

/***********************/

   409

void *visit(or_expression_c *symbol) {

   410

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   411

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   412

  if (!search_expression_type->is_same_type(left_type, right_type))

   413

      ERROR;

   414

  if (search_expression_type->is_bool_type(left_type))

   415

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " || ");

   416

  if (search_expression_type->is_binary_type(left_type))

   417

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " | ");

   418

  ERROR;

   419

  return NULL;

   420

}

   421

   422

void *visit(xor_expression_c *symbol) {

   423

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   424

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   425

  if (!search_expression_type->is_same_type(left_type, right_type))

   426

      ERROR;

   427

  if (search_expression_type->is_bool_type(left_type)) {

   428

    s4o.print("(");

   429

    symbol->l_exp->accept(*this);

   430

    s4o.print(" && !");

   431

    symbol->r_exp->accept(*this);

   432

    s4o.print(") || (!");

   433

    symbol->l_exp->accept(*this);

   434

    s4o.print(" && ");

   435

    symbol->r_exp->accept(*this);

   436

    s4o.print(")");

   437

    return NULL;

   438

  }

   439

  if (search_expression_type->is_binary_type(left_type))

   440

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " ^ ");

   441

  ERROR;

   442

  return NULL;

   443

}

   444

   445

void *visit(and_expression_c *symbol) {

   446

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   447

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   448

  if (!search_expression_type->is_same_type(left_type, right_type))

   449

      ERROR;

   450

  if (search_expression_type->is_bool_type(left_type))

   451

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " && ");

   452

  if (search_expression_type->is_binary_type(left_type))

   453

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " & ");

   454

  ERROR;

   455

  return NULL;

   456

}

   457

   458

void *visit(equ_expression_c *symbol) {

   459

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   460

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   461

  if (!search_expression_type->is_same_type(left_type, right_type))

   462

      ERROR;

   463

  if (search_expression_type->is_time_type(left_type) ||

   464

      search_expression_type->is_string_type(left_type))

   465

    return print_compare_function("__eq_", left_type, symbol->l_exp, symbol->r_exp);

   466

  return print_binary_expression(symbol->l_exp, symbol->r_exp, " == ");

   467

}

   468

   469

void *visit(notequ_expression_c *symbol) {

   470

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   471

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   472

  if (!search_expression_type->is_same_type(left_type, right_type))

   473

      ERROR;

   474

  if (search_expression_type->is_time_type(left_type) ||

   475

      search_expression_type->is_string_type(left_type))

   476

    return print_compare_function("__ne_", left_type, symbol->l_exp, symbol->r_exp);

   477

  return print_binary_expression(symbol->l_exp, symbol->r_exp, " != ");

   478

}

   479

   480

void *visit(lt_expression_c *symbol) {

   481

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   482

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   483

  if (!search_expression_type->is_same_type(left_type, right_type))

   484

      ERROR;

   485

  if (search_expression_type->is_time_type(left_type) ||

   486

      search_expression_type->is_string_type(left_type))

   487

    return print_compare_function("__lt_", left_type, symbol->l_exp, symbol->r_exp);

   488

  if (!search_base_type.type_is_enumerated(left_type))

   489

    return print_binary_expression(symbol->l_exp, symbol->r_exp, " < ");

   490

  ERROR;

   491

  return NULL;

   492

}

   493

   494

void *visit(gt_expression_c *symbol) {

   495

  symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);

   496

  symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);

   497

  if (!search_expression_type->is_same_type(left_type, right_type))

   498

      ERROR;

   499

  if (search_expression_type->is_time_type(left_type) ||

   500

      search_expression_type->is_string_type(left_type))

   501

    return print_compare_function("__gt_", left_type, symbol->l_exp, symbol->r_exp);